Wissenschaftliche Artikel der BAM
Filtern
Dokumenttyp
- Zeitschriftenartikel (356)
- Beitrag zu einem Tagungsband (1)
- Sonstiges (1)
Sprache
- Englisch (348)
- Deutsch (9)
- Mehrsprachig (1)
Schlagworte
- Fluorescence (53)
- Quantum yield (35)
- Sensor (25)
- Lifetime (21)
- Quality assurance (20)
- Dye (18)
- Photophysics (18)
- Nano (16)
- Synthesis (13)
- Cancer (12)
- Magnetic resonance imaging (12)
- NIR (12)
- Photoluminescence (12)
- Imaging (11)
- Immunoassay (11)
- Lanthanide (10)
- Method (10)
- Nanomaterial (10)
- Nanoparticle (10)
- Particle (9)
- Electrochemistry (8)
- ICP-MS (8)
- Mass spectrometry (8)
- Mechanism (8)
- Molecularly imprinted polymers (8)
- Nanoparticles (8)
- Quantum dots (8)
- Reference material (8)
- ELISA (7)
- Energy transfer (7)
- Raman spectroscopy (7)
- Soil (7)
- Affinity chromatography (6)
- Contrast agent (6)
- Gadolinium (6)
- Luminescence (6)
- MRI (6)
- Mass Spectrometry (6)
- Multiplexing (6)
- Mycotoxins (6)
- Optical probe (6)
- PH (6)
- Surface chemistry (6)
- Traceability (6)
- Upconversion nanoparticle (6)
- Core-shell particles (5)
- Cr(III) (5)
- Flow cytometry (5)
- Laser ablation (5)
- Ligand (5)
- Microscopy (5)
- Raman microspectroscopy (5)
- Single particle (5)
- Aggregation (4)
- Analytical Chemistry (4)
- Antikörper (4)
- Brightness (4)
- Calibration (4)
- Cement (4)
- IgG (4)
- Industry 4.0 (4)
- Interlaboratory comparison (4)
- LA-ICP-MS (4)
- LC-MS/MS (4)
- LIBS (4)
- Lab-on-a-chip (4)
- Metabolomics (4)
- Nitrotyrosine (4)
- Polymer (4)
- Quantitative spectroscopy (4)
- Reproducibility (4)
- SWIR (4)
- Signal enhancement (4)
- XPS (4)
- XRF (4)
- Air pollution (3)
- Allergy (3)
- Antibiotics (3)
- BODIPY (3)
- Bead (3)
- Biosensing (3)
- Biosensor (3)
- Bisphenol A (3)
- Brain (3)
- Coating (3)
- Complex (3)
- Copper (3)
- Corrosion (3)
- Crystal (3)
- DNA origami (3)
- Ergot alkaloids (3)
- Excitation power density (3)
- Extracellular matrix (3)
- Food (3)
- Food analysis (3)
- Gadofosveset (3)
- Gas chromatography (3)
- General Medicine (3)
- HPLC (3)
- HRMS (3)
- High-resolution mass spectrometry (3)
- Human serum (3)
- Hydrolysis (3)
- Iron oxide (3)
- Isotope dilution (3)
- Isotope ratio (3)
- MOF (3)
- Mass Spectroscopy (3)
- Mechanochemistry (3)
- Metrology (3)
- Microfluidics (3)
- Molecular imaging (3)
- Molecular imprinting (3)
- Monoclonal antibody (3)
- Mycotoxin (3)
- NMR (3)
- Nitration (3)
- Optical spectroscopy (3)
- PFAS (3)
- Pollution (3)
- Probe (3)
- Process Industry (3)
- Protein A (3)
- Quantification (3)
- Raman (3)
- Reference materials (3)
- Screening (3)
- Sensitization (3)
- Spectroscopy (3)
- Switch (3)
- Teststreifen (3)
- Transformation products (3)
- Tyrosine (3)
- Uncertainty (3)
- Upconversion (3)
- AAS (2)
- Absolute isotope ratio (2)
- Adsorption (2)
- Affinitätschromatographie (2)
- Aggregation induced emission (2)
- Amorphous carbon (2)
- Amoxicillin (2)
- Amperometry (2)
- Antibody (2)
- Aromatic amino acid analysis (2)
- Atherosclerosis (2)
- Bacteria (2)
- Barcoding (2)
- Bead-based assay (2)
- Benz[a]anthracene (BaA) (2)
- Benzo[a]pyrene (BaP) (2)
- Biochemistry (2)
- Biocides (2)
- Bioconjugation (2)
- CONSENS (2)
- Certified reference material (2)
- Charge transfer (2)
- Chromatography (2)
- Comparability (2)
- Core−shell particles (2)
- Cuprorivaite (2)
- Cytotoxicity (2)
- Degradation (2)
- Delta scale (2)
- Derivatization (2)
- Diagnosis (2)
- Diagnostics (2)
- Digitalisation (2)
- Dimerization (2)
- Dityrosine (2)
- Documentation (2)
- Egyptian blue (2)
- Electron microscopy (2)
- Emission spectroscopy (2)
- Endocrine disruptor (2)
- Endokrine Disruptoren (2)
- Enhancement (2)
- Environmental Chemistry (2)
- FPLC (2)
- Fatty acid metabolism (2)
- Fertilizer (2)
- Ferumoxytol (2)
- Fluoride (2)
- Gas chromatography (GC) (2)
- General Earth and Planetary Sciences (2)
- Glyphosate (2)
- HPLC-MS/MS (2)
- HTS (2)
- Health, Toxicology and Mutagenesis (2)
- Heart failure (2)
- Hybridoma (2)
- Hydrazinolysis (2)
- ICP-OES (2)
- Immunoaffinity extraction (2)
- Immunocapture (2)
- Immunoglobulins (2)
- Immunosensor (2)
- Indium phosphide (2)
- Indoor air (2)
- Inflammation (2)
- Iron (2)
- Isotope (2)
- Isotope dilution (ID) (2)
- Isotope ratios (2)
- LIF (2)
- Label (2)
- Lanthanides (2)
- Lateral flow assay (2)
- Life sciences (2)
- Limit of detection (2)
- Lipidomic profile (2)
- Liquid chromatography (LC) (2)
- Lithium (2)
- MALDI (2)
- MALDI-TOF MS (2)
- MC-ICP-MS (2)
- Magnetic beads (2)
- Mass spectrometry (MS) (2)
- Measurement uncertainty (2)
- Mercury (2)
- Mesoporous materials (2)
- Metabolic stress (2)
- Method development (2)
- Microbeads (2)
- Mikrofluidik (2)
- Mikroplastik (2)
- Modelling (2)
- Modular Production (2)
- Molecularly Imprinted Polymers (2)
- Monolithic column (2)
- Multiplex (2)
- Nanomaterials (2)
- Nickel (2)
- Nitrogen oxides (2)
- Nontarget analysis (2)
- Open Science (2)
- Optical detection (2)
- Origami (2)
- Oxygen (2)
- Ozone (2)
- Passivation (2)
- Peptide (2)
- Peptide library (2)
- Ph (2)
- Phenylalanine (2)
- Phosphorylated peptides (2)
- Photodegradation (2)
- Polycyclic aromatic hydrocarbon (PAH) (2)
- Process Analytical Technology (2)
- Process analytical technology (2)
- Production (2)
- Prostate cancer (2)
- Protein (2)
- Protein G (2)
- Protein nitration (2)
- Quality Control (2)
- Quality control (2)
- Quantum dot (2)
- Real-time process monitoring (2)
- Regeneration (2)
- SPR (2)
- Sapphire (2)
- Self-assembly (2)
- Sensorpartikel (2)
- Sensors (2)
- Sequence coverage (2)
- Serum (2)
- Sewage sludge (2)
- Shell (2)
- Sialic acid (2)
- Single molecule (2)
- Smart sensors (2)
- Software (2)
- Solid state NMR (2)
- Sr isotopes (2)
- Standardization (2)
- Standards (2)
- Surface (2)
- Synthetic peptides (2)
- Sythesis (2)
- Test strips (2)
- Theory (2)
- Thermal anhydrite (2)
- Thermal desorption (2)
- Toxicity (2)
- Transformation product (2)
- Triple isotope fractionation (2)
- Triplet-triplet annihilation (2)
- Tumor (2)
- Tumor metabolism (2)
- Ultrafine particles (2)
- Upconversion nanoparticles (2)
- Validation (2)
- Wasser (2)
- Water analysis (2)
- Yb(III) complex (2)
- ZIF (2)
- ZIF-8 (2)
- 1-indanol (1)
- 150th anniversary (1)
- 150th anniversary of BAM (1)
- 2,5-dihydroxyacetophenone (1)
- 280 nm (1)
- 2D chromatography (1)
- 3D-Mikrofluidik (1)
- 6xHis (1)
- AAA (1)
- AAAA (1)
- ABC (1)
- ABID (1)
- AF4 (1)
- AIE (1)
- AIS (1)
- ATCUN (1)
- Aautomatisation (1)
- Absorption (1)
- Abwasser (1)
- Acoustic (1)
- Acoustic resonance (1)
- Acrylamide (1)
- Acute myocardial infarction (1)
- Additive Fertigung (1)
- Additive Manufacturing (1)
- Additive manufacturing (1)
- Adsorbable organically bound fluorine (AOF) (1)
- Adulteration (1)
- Advanced Materials (1)
- Advanced material (1)
- Advanced materials (1)
- Advanced nanomaterials (1)
- Affinity (1)
- Affinity Chromatography (1)
- Affinity Extraction (1)
- Affinity Separation (1)
- Affinity extraction (1)
- Affinitätsextraktion (1)
- AgInS (1)
- Agarose (1)
- Aggregates (1)
- Aggregation-induced emission (1)
- Aging (1)
- Agriculture (1)
- Air filter samples (1)
- Air particulate matter (1)
- Air sampling (1)
- Airport (1)
- AlCl (1)
- Alanine scan (1)
- Algorithms (1)
- Altenuene (1)
- Alternaria mycotoxins (1)
- Aluminum (1)
- Aluminum oxide (1)
- Alzheimer’s disease (1)
- Amino acid analysis (1)
- Amplification (1)
- Amyloid-beta (1)
- Analysis (1)
- Analytical methods (1)
- Analytical sciences (1)
- Aneurysm (1)
- Angiography (1)
- Angiotensin II (1)
- Anhydrite (1)
- Aniline (1)
- Animal slurry (1)
- Anion recognition (1)
- Antagonists (1)
- Anthropocene (1)
- Antibodies (1)
- Antibody Purification (1)
- Antibody antigen complex (1)
- Antibody coating (1)
- Antibody identification (1)
- Antibody quality (1)
- Antibody-gated indicator delivery (1)
- Antifouling surface (1)
- Antigens (1)
- Antimicrobial resistance (1)
- App (1)
- Application (1)
- Aptamere (1)
- Aqueous quantum dot (1)
- Aqueous synthesis (1)
- Arabidopsis (1)
- Argon (1)
- Array (1)
- Arsenite (1)
- Artificial Neural Networks (1)
- Artificial intelligence (1)
- Artificial neural networks (1)
- Artificial weathering (1)
- Ash content (1)
- Aspergillus (1)
- Assay (1)
- Atherosclerotic plaques (1)
- Atmospheric aerosol (1)
- Atomic Absorption Spectrometry (1)
- Atomic absorption spectrometry (1)
- Atomic and molecular physics, and optics (1)
- Atomic force microscopy (1)
- Atomic weight (1)
- Augenbohne (1)
- Autoantibodies (1)
- Automated Purification (1)
- Automated image analysis (1)
- Automation (1)
- Autophagy (1)
- Aviation (1)
- Aza-BODIPY (1)
- BAM (1)
- BCA test (1)
- BODIPY dyes (1)
- BODIPY probe (1)
- BODIPYs (1)
- BPA removal (1)
- Back-side integration (1)
- Bacterial lipopolysaccharides (1)
- Bacterial lysates (1)
- Ball milling (1)
- Bassanite (1)
- Bead injections (1)
- Benchmarking study (1)
- Benchtop NMR (1)
- Benzene-1,3,5-tricarboxylic acid (1)
- Benzin (1)
- Benzothiadiazole (1)
- Benzoxadiazole dyes (1)
- Beschichtung (1)
- Bet v 1 (1)
- Betula pendula (1)
- Binary gas mixture (1)
- Binder (1)
- Binding molecule (1)
- Binding strength (1)
- Bio-interaction (1)
- Bioanalysis (1)
- Biochip (1)
- Biodiesel (1)
- Biodiesel fuel (1)
- Biofilm (1)
- Bioimaging (1)
- Bioinformatics (1)
- Biokorrosion (1)
- Biology (1)
- Biomarker (1)
- Biomarkers (1)
- Biomimicry (1)
- Biosensoren (1)
- Biosensors (1)
- Bioseparation (1)
- Biosilicification (1)
- Biosynthesis (1)
- Biotechnology (1)
- Biotests (1)
- Birch pollen allergen (1)
- Bismuth (1)
- Boden (1)
- Boltzmann plot (1)
- Bombs (1)
- Boron compound (1)
- Borosilicate Glass (1)
- Borosilicatglas (1)
- Borosilikatglas (1)
- Bovine serum albumin (BSA) (1)
- Bradford (1)
- Building material (1)
- Bundesanstalt für Materialforschung und -prüfung (1)
- Byproducts (1)
- C-C coupling (1)
- CCQM (1)
- CE/MC-ICP-MS (1)
- CEA (1)
- CO2 + n-alkanes (1)
- COVID-19 (1)
- CRM (1)
- CRP (1)
- CUINS2 nanocrystals (1)
- CaCl emission bands (1)
- Cadmium (1)
- Calcite (1)
- Calcium (1)
- Calcium carbonate (1)
- Calcium carbonates (1)
- Calibrated fluorescence measurements (1)
- Calibration-free analysis (1)
- Cancer awareness measure (1)
- Cancer cells (1)
- Cancer risk (1)
- Canine olfactometry (1)
- Carbamazepine (1)
- Cardiac troponin (1)
- Cardiolipins (1)
- Cardiovascular (1)
- Carrier (1)
- Carrier protein (1)
- Carrier-Material (1)
- Carriers (1)
- Cconventional method (1)
- Cell (1)
- Cell proliferation (1)
- Cell studies (1)
- Cellular substructure (1)
- Cellulose (1)
- Cement clinker remnants (1)
- Cerium oxide (1)
- Charged dyes (1)
- Chelate (1)
- Chemical Process Control (1)
- Chemical Safety (1)
- Chemical evolution (1)
- Chemical protein modification (1)
- Chemiluminescence (1)
- Chemodosimeter (1)
- Chemometrics (1)
- Chicken antibodies (1)
- Chirality (1)
- Chlorides (1)
- Chlorine (1)
- Chlorine determination (1)
- Chloroanilines (1)
- Ciaaw.org (1)
- Citation (1)
- Citizen Science (1)
- Citrullinated (1)
- Classical primary measurement method (CPM) (1)
- Classification (1)
- Cleaning (1)
- Cleavage (1)
- Climate (1)
- Clinical Biochemistry (1)
- Clone M2 (1)
- Cmos (1)
- Cobaloxime complex (1)
- Cocoa (1)
- Collaborative trial (1)
- Collagen (1)
- Collection (1)
- Colloidal semiconductor nanocrystals (1)
- Color (1)
- Column holder (1)
- Combinatorial chemistry (1)
- Combinatorial peptide library (1)
- Combustion (1)
- Combustion ion chromatography (1)
- Combustion ion chromatography (CIC) (1)
- Commercial metal-organic frameworks (1)
- Commercialization (1)
- Compartmentalization (1)
- Competitive immunoassay (1)
- Complexation (1)
- Compound-independent calibration (1)
- Concentration step (1)
- Concrete (1)
- Conductometry (1)
- Conformation (1)
- Conjugate (1)
- Construction (1)
- Construction products (1)
- Consumer Products (1)
- Continuous Processes (1)
- Continuous Sensor (1)
- Continuous processes (1)
- Conventional isotope ratio (1)
- Converter material (1)
- Coordination polymer (1)
- Core-shell (1)
- Core–shell particles (1)
- Corona virus (1)
- Corophium volutator (1)
- Corundum (1)
- Cr(III) complex (1)
- Cross section (1)
- Cross-sectioning (1)
- Cryoadsorption (1)
- Cucurbituril (1)
- Cyanide in soil (1)
- Cyber-Physical Systems (1)
- Cyber-physical system (1)
- Cyclic voltammetry (1)
- Cyclometalated iridium (III) complexes (1)
- Cytoplasm (1)
- DFA (1)
- DFT (1)
- DHAP (1)
- DNA (1)
- DNA radiation damage (1)
- DNA strand breaks (1)
- DPA (1)
- Damage-associated molecular patterns (DAMPs) (1)
- Data (1)
- Data Fusion (1)
- Data infrastructures (1)
- Data processing (1)
- De novo peptide sequencing (1)
- Deep learning-based tools (1)
- Degradation of refrigerants (1)
- Delta isotope standard (1)
- Delta value (1)
- Dendrimer (1)
- Density data (1)
- Design of experiment (1)
- Deterioration (1)
- Development (1)
- Diagnostic Antibodies (1)
- Diastolic dysfunction (1)
- Diatomic molecule (1)
- Diclofenac (1)
- Diesel exhaust (1)
- Diffusion (1)
- Digestion (1)
- Digital Transformation (1)
- Digital Twins (1)
- Digital holographic cytometry (1)
- Digital immunoassay (1)
- Digital representations (1)
- Digital transformation (1)
- Digital twins (1)
- Digital workflows (1)
- Digitalisierung der Prozessindustrie (1)
- Digitization of process industry (1)
- Dip-stick assay (1)
- Disinfection (1)
- Dissociation constant (1)
- Dissolution (1)
- Dityrosine crosslinking (1)
- Docking (1)
- Down Stream Processing (1)
- Downstream Processing (1)
- Downstream processing (1)
- Druckstabilität (1)
- Drug Discovery (1)
- Dual sensing (1)
- Dual-color labeling glycan (1)
- Duplex stainless steels (1)
- Dyad (1)
- Dye loading optimisation (1)
- Dye monomers (1)
- Dye release (1)
- Dyes (1)
- Dyes/pigments (1)
- Dynamic calibration gas mixtures (1)
- EC/MS (1)
- ECR (1)
- EDTAD (1)
- EP-3533 (1)
- ESMA (1)
- EU-WFD (1)
- EXAFS (1)
- Early Earth (1)
- Ecotoxicity (1)
- Editorial (1)
- Elastin (1)
- Elastin-specific contrast agent ESMA (1)
- Elastin-specific molecular agent (1)
- Electrochemical (1)
- Electrochemical titration (1)
- Electron transfer (1)
- Elektrochemie (1)
- Elektrochemilumineszenz (1)
- Element Specific Bioimaging Using Laser Ablation (1)
- Emergency (1)
- Emission testing (1)
- Enantiomeric excess ee (1)
- Encapsulation (1)
- Encoding (1)
- Endokriner Disruptor (1)
- Enhancement strategy (1)
- Environment (1)
- Environmental Engineering (1)
- Environmental pollutants (1)
- Environmental simulations (1)
- Environmental speciation (1)
- Enzyme (1)
- Enzyme-Linked Immunosorbent Assay (1)
- Equation of state (1)
- Equations of state (1)
- Equilibrium constant (1)
- Error correction (1)
- Escherichia coli (1)
- Esterification (1)
- Estrogens (1)
- Ethylenediaminetetraacetic acid (1)
- Etofenprox (1)
- European Reference Material (1)
- Evanescent wave (1)
- Ex vivo (1)
- Excimers (1)
- Excitation (1)
- Exhaust (1)
- Exocytosis (1)
- Experiment (1)
- Explosiven (1)
- Explosives detection (1)
- Exposure (1)
- Extractable organically bound fluorine (EOF) (1)
- Extraction (1)
- FFF-3D printer (1)
- FFF-3D printing (1)
- FLAG peptide (1)
- FRET (1)
- Feature selection (1)
- Fenton (1)
- Fenton’s reagent (1)
- Finow Canal (1)
- Flexible crystals (1)
- Flourescence (1)
- Flourescin (1)
- Flow injection immunoassay (1)
- Fluorescein (1)
- Fluorescence Polarization (1)
- Fluorescence label (1)
- Fluorescence life time (1)
- Fluorescence spectroscopy (1)
- Fluorescence standard (1)
- Fluorescent dyes (1)
- Fluorescent probes (1)
- Fluorescent sensors (1)
- Fluoreszenz (1)
- Fluorides (1)
- Fluorination (1)
- Fluoroacetic acid (1)
- Fluorophilic interactions (1)
- Folding chirality (1)
- Food fermentation (1)
- Food safety (1)
- Forsterite (1)
- Fourier transform spectroscopy (1)
- Fow injection analysis (1)
- Fragmentation pathway (1)
- Freisetzung (1)
- Fully aromatic frameworks (1)
- Functional group quantification (1)
- Functional monomers (1)
- Fungicide (1)
- Funtional Groups (1)
- Fusarium (1)
- Fusarium mycotoxin (1)
- GC/MS (1)
- GC/MS-MS (1)
- GF-MAS (1)
- GMAW (1)
- Gadolinium-based contrast agent (1)
- Gadovist (1)
- Galvanic anodes (1)
- Gamma-hydroxybutyric acid (1)
- Gas analysis (1)
- Gas sensing (1)
- Gasoline (1)
- Gated materials (1)
- Gd-DOTA (1)
- General Chemistry (1)
- Genotoxicity testing (1)
- Geological material (1)
- Germanium chlorides (1)
- Gesteuerte Freisetzung (1)
- Gesteuerten Nanopartikeln (1)
- Ggadolinium (1)
- Github (1)
- Glasmonolith (1)
- Glass Support (1)
- Gold (1)
- Gold nanocluster (1)
- Gold nanoparticles (1)
- Grafting (1)
- Graphene (1)
- Graphite furnace (1)
- Grass pollen (1)
- Green light excitation (1)
- Grignard reaction (1)
- Grignard-Reaktion (1)
- Ground water (1)
- Groundwater (1)
- Group profile (1)
- Guanidinium receptors (1)
- Gypsum (1)
- Gypsum dehydration (1)
- HAXPES (1)
- HF free Digestion (1)
- HPLC-DAD/FLD (1)
- HPSEC (1)
- HR-CS-MAS (1)
- Hafnium (1)
- Hay fever (1)
- Heart attack (1)
- Heat accumulation (1)
- Heat flow (1)
- Heat-transfer Measurements (1)
- Heavy chains (1)
- Hemihydrate (1)
- Hepatocellular carcinoma (1)
- HexaHis-Tag (1)
- High entropy alloy (1)
- High pH (1)
- High pressure experiments (1)
- High resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) (1)
- High-Speed (1)
- High-Speed Separations (1)
- High-fired gypsum (1)
- High-fired gypsum mortar (1)
- High-fired medieval gypsum mortars (1)
- High-frequency arc discharge (1)
- High-pressure density (1)
- High-resolution continuum source graphite furnace atomic absorption spectrometry (1)
- High-resolution continuum source molecular absorption spectrometry (1)
- High-throughput (1)
- Highspeed (1)
- His6 (1)
- His8 (1)
- Histidine (1)
- Hot-electrons (1)
- Human Plasma (1)
- Human leukocyte antigen (HLA) (1)
- Human papillomavirus (1)
- Human serum albumin (1)
- Humic matter (1)
- Hydrated silicate melts (1)
- Hydration (1)
- Hydrochloric acid (1)
- Hydrodynamic chromatography (HDC) (1)
- Hydrodynamic model (1)
- Hydrogen Storage (1)
- Hydrogen adsorption (1)
- Hydrogen adsorption storage (1)
- Hydrogen reduction (1)
- Hydrogen uptake reproducibility (1)
- Hydrogen-containing gas mixture (1)
- Hydrogen-enriched natural gas (1)
- Hydrogenasen (1)
- Hydrothermal fluid (1)
- Hydroxy warfarin (1)
- IC50 (1)
- ICP-MS/MS (1)
- ICP-TOFMS (1)
- ICP-ToF-MS (1)
- ID-MS (1)
- ILC (1)
- IMAC purification (1)
- IR spectroscopy (1)
- ISO REMCO (1)
- Identity (1)
- IgE (1)
- IgG determination (1)
- IgY (1)
- Image analysis (1)
- Image segmentation (1)
- Imaging Technique (1)
- Imidazole (1)
- Immobilisierung (1)
- Immunassay (1)
- Immunglobulin (1)
- Immunglobuline (1)
- Immunoassays (1)
- Immunoglobulin E (1)
- Immunohistochemistry (1)
- Immunology (1)
- Immunometric assay (1)
- Immunometric biosensor (1)
- Immunoprecipitation (1)
- Impact (1)
- Imprinting (1)
- Impurites (1)
- In situ (1)
- In situ EXAFS (1)
- In situ SAXS/WAXS (1)
- In situ measurement (1)
- In vivo (1)
- In-house calibration solution (1)
- In-situ analysis (1)
- In-situ process monitoring (1)
- In-vivo (1)
- Indicator displacement assay (1)
- Indoor air quality (1)
- Inductively Coupled Mass Spectroscopy (1)
- Inductively coupled plasma mass spectroscopy (1)
- Inductively‑coupled mass spectrometry (1)
- Industrial gypsum (1)
- Inert gases (1)
- Infrared thermography (1)
- Infrastruktur (1)
- Inhibition (1)
- Inline Analytics (1)
- Inorganic chemical analysis (1)
- Inorganic impurities (1)
- Instrumental isotope fractionation (1)
- Inter layer time (1)
- Interferometric spectroscopy (1)
- Intermixing (1)
- Internal standard (1)
- Ion mobility spectrometry (1)
- Ionophore (1)
- Ionophore antibiotics (1)
- Iposomes (1)
- Iridium (1)
- Isotope Dilution (1)
- Isotope Labelling (1)
- Isotope amount ratio (1)
- Isotope delta value (1)
- Isotope dilution mass spectrometry (1)
- Isotope reference material (1)
- Isotope-labeled (1)
- Isotopic analysis (1)
- Isotopic fractionation (1)
- Isotopologue Distribution (1)
- Iterative real-time optimization (1)
- Jahrestag (1)
- Job plot (1)
- Kjeldahl (1)
- Knowledge graphs (1)
- Kompost (1)
- LA/ICP-MS Imaging (1)
- LC-MS (1)
- LC-UV absorbance (1)
- LC/HRMS (1)
- LC/MS-MS (1)
- LFIA (1)
- LSVEC (1)
- Lab on a chip (1)
- Lab-on-a-Chip (1)
- Laboratory 4.0 (1)
- Lacunary Keggin ion (1)
- Ladder sequencing (1)
- Lasalocid (1)
- Laser Ablation (1)
- Laser ablation-inductively coupled plasma-mass spectrometry (1)
- Laser ablation-inductively coupled plasma-mass spectroscopy (1)
- Laser induced breakdown Spectrocopy (LIBS) (1)
- Laser induced breakdown spectroscopy (1)
- Laser induced plasma (1)
- Laser induced plasma deposition (1)
- Laser powder bed fusion (1)
- Laser-induced breakdown spectroscopy (1)
- Laser-induced dielectric breakdown (LIDB) (1)
- Laser-induced fluorescence (1)
- Lastwechsel (1)
- Layer-by-Layer (1)
- Layers (1)
- Leaching (1)
- Lead (1)
- Legacy pollution (1)
- LiYF4 (1)
- Library (1)
- Life science (1)
- Lifetime encoding (1)
- Lifetime-encoded beads (1)
- Light chain (1)
- Light chains (1)
- Light harvesting (1)
- Lipidomics (1)
- Lipids (1)
- Liquid chromatography (1)
- Liver X receptor (1)
- Lluminescence (1)
- Longst luminescence lifetime (1)
- Low-cost (1)
- Low-energy electrons (1)
- Luminescent lifetime (1)
- Luminol (1)
- Lymnaea stagnalis (1)
- Lysergic acid hydrazide (1)
- Lysosome (1)
- MALDI-TOF-MS (1)
- MC-TIMS (1)
- MCR (1)
- MIC (1)
- MICAP-MS (1)
- MIP (1)
- MLCT (1)
- MOF´s (1)
- MOSH/MOAH (1)
- MR Angiography (1)
- MR imaging (1)
- MST (1)
- MW-AES (1)
- MYCN (1)
- Machine learning (1)
- Macrophages (1)
- Magnesium (1)
- Magnesium carbonates (1)
- Magnetic (1)
- Magnetic nanocatalyst (1)
- Magnetpartikel (1)
- Mass-Spectrometry (1)
- Massenspektrometrie (1)
- Material sciences (1)
- Materials informatics (1)
- Mechanical properties (1)
- Medical diagnostics (1)
- Medicinal application (1)
- Medicine (1)
- Medium entropy alloy (1)
- MefHySto (1)
- Mercury speciation (1)
- Meso Portland cement (1)
- Mesofluidics (1)
- Mesoporous particles (1)
- Metabolic Flux (1)
- Metabolization (1)
- Metal cluster (1)
- Metal toxicity (1)
- Metal uptake (1)
- Metalloprotein (1)
- Metals (1)
- Metal−organic frameworks (1)
- Methanol oxidation (1)
- Methylanilines (1)
- Methylmercury (1)
- Metrologie (1)
- Metrology in chemistry (1)
- Microarray (1)
- Microbe interactions (1)
- Microbially Induced Corrosion (1)
- Microfluidic (1)
- Microfluidic mixing (1)
- Microfluidic system (1)
- Microfluids (1)
- Micrometeorites (1)
- Microorganism (1)
- Microplastic-induced effects (1)
- Microplatic (1)
- Microscope slides (1)
- Microwave inductively coupled atmospheric pressure mass spectrometry (MICAP-MS) (1)
- Microwave-assisted synthesis (1)
- Miller and Urey (1)
- Mineral identification (1)
- Mineral oil hydrocarobons (1)
- Mineral paragenesis (1)
- Miniaturization (1)
- Missing fragmentation sites (1)
- Mixed surface (1)
- Mixture toxicity (1)
- Mobile analytics (1)
- Mobile phase (1)
- Model (1)
- Model Predictive Control (1)
- Modeling (1)
- Modified mycotoxins (1)
- Modifier adaptation (1)
- Molecular Biology (1)
- Molecular MRI (1)
- Molecular Organic Frameworks (1)
- Molecular imprinted polymers (1)
- Molecular marker (1)
- Molecular spectra (1)
- Molecular-MRI (1)
- Molecule (1)
- Monensin (1)
- Monoclonal Antibodies (1)
- Monoclonal Antibody (1)
- Monoclonal antibodies (1)
- Monolith (1)
- Monomer (1)
- Monte Carlo algorithm (1)
- Mounting media (1)
- Multi-collector inductively coupled plasma-mass spectrometry (ICP-MS) (1)
- Multi-element analysis (1)
- Multi-prinicpal element alloys (MPEAs) (1)
- Multiple sclerosis (1)
- Multiple-injection sample-standard bracketing (1)
- Multiplexed assay (1)
- Multivariat (1)
- Multivariate (1)
- Multivariate data analysis (1)
- Multivariate methods (1)
- Murchison meteorite (1)
- NIR Spectroscopy (1)
- NIR dyes (1)
- NIR-I (1)
- NIR-II fluorescence (1)
- NIST (1)
- NIST-mAb 8671 (1)
- NMR Spectroscopy (1)
- NMR spectroscopy (1)
- NMR-Spektroskopie (1)
- NSE (1)
- Nanaoparticle (1)
- Nanaoparticles (1)
- Nano-carrier (1)
- Nanocarrier (1)
- Nanolenses (1)
- Nanomaterial design (1)
- Nanoparticle characterization (1)
- Nanoparticle dimers (1)
- Nanopartikel (1)
- Nanopowder (1)
- Nanosafety (Safe-by-design) (1)
- Nanoscience (1)
- Nanosciences (1)
- Nanostructures (1)
- Naphthalene (Nap) (1)
- Neoallergen (1)
- Neoepitopes (1)
- Neural networks (1)
- Neutral dyes (1)
- Nickel chelate (1)
- Nile Red (1)
- Nitrogen dioxide (1)
- Nitrogen microwave inductively coupled atmospheric pressure mass spectrometry (1)
- Nitrogen monoxide (1)
- Nitrogen plasma (1)
- Non-targeted analysis (1)
- Nonspecific binding (NSB) (1)
- Nuclear Magnetic Resonance Spectroscopy (1)
- Nuclear receptor (1)
- Nucleocapsid (1)
- OBOC library (1)
- Ochratoxin A (1)
- Oil spills (1)
- Oligomerization (1)
- Oligonucleotides (1)
- On-chip screening (1)
- On-line CE/MC-ICP-MS (1)
- On-site detection (1)
- One-bead-one-compound library (1)
- Online NMR Spectroscopy (1)
- Online NMR spectroscopy (1)
- Online biosensor (1)
- Online detection (1)
- Ontologies (1)
- Open science (1)
- Optical assay (1)
- Optical imaging (1)
- Optically active surfaces (1)
- Orbitrap (1)
- Organic Synthesis (1)
- Organic calibration solution (1)
- Organic contaminants (1)
- Organic-inorganic hybrid composites (1)
- Organic–inorganic nanostructures (1)
- Oriented immobilization (1)
- Osmotic minipumps (1)
- Oxidative metabolism (1)
- Oxygen evolution reaction (1)
- Oxygen isotope ratios (1)
- Oxygen sensitive (1)
- PAHs (1)
- PCA (1)
- PDT (1)
- PEM-Wasserelektrolyse (1)
- PIC technology (1)
- PLSR (1)
- PSA (1)
- Packing density (1)
- Pants (1)
- Partial least square discriminant analysis (PLS-DA) (1)
- Particle architecture (1)
- Particle synthesis (1)
- Pattern recognition receptor (1)
- Pd(II) (1)
- Peer review (1)
- Peptide aptamers (1)
- Peptide binder (1)
- Peptide folding (1)
- Peptide mass fingerprinting (1)
- Peptide probe (1)
- Peptides (1)
- Peptides and Proteins (1)
- Per- and polyfluorinated alkyl substances (PFASs) (1)
- Per- and polyfluoroalkyl substances (PFAS) (1)
- Perfluorooctanoic Acid (PFOA) (1)
- Permethrin (1)
- Peroxidase (1)
- Perturbed-Chain Statistical Association Fluid Theory (1)
- Pesticide (1)
- Pestizid (1)
- Petroleum (1)
- Pflanzenvirus (1)
- Pflanzenwachstum (1)
- Pharmaceutical (1)
- Pharmaceutical Science (1)
- Phase Imaging (1)
- Phenanthrene (1)
- Phenothrin (1)
- Phenylketonuria (1)
- Phl p 5 (1)
- Phleum pratense (1)
- Phosphinine (1)
- Phospholipids (1)
- Phosphor (1)
- Phosphorescence (1)
- Phosphorus elimination (1)
- Phosphorus recovery (1)
- Photocatalysis (1)
- Photocatalytic reduction (1)
- Photochemistry (1)
- Photoinduced Electron Transfer (1)
- Photoinduced electron transfer (1)
- Photonic biosensor (1)
- Photosensitization (1)
- Photostability (1)
- Physical and theoretical chemistry (1)
- Physical twin (1)
- Physico-chemical characterisation of minerals (1)
- Phytoliths (1)
- Planck function (1)
- Plant virus (1)
- Plant-model mismatch (1)
- Plasma (1)
- Plasma chemistry (1)
- Plasmonic heating (1)
- Plastic deformation (1)
- Point of inflection (1)
- Polarised light microscopy (1)
- Polarity (1)
- Polishing (1)
- Pollen (1)
- Pollen extract (1)
- Pollutant (1)
- Polyclonal Antibodies (1)
- Polycyclic aromatic hydrocarbons (1)
- Polyelektrolyt (1)
- Polyglycerol (1)
- Polymer particles (1)
- Polymer-based products (1)
- Polymere (1)
- Polymerization (1)
- Polymers (1)
- Polyoxometalates (1)
- Polystyrene microparticles (1)
- Pore fluids (1)
- Porous rock (1)
- Porphyrin (1)
- Portable (1)
- Portland clinker (1)
- Potash (1)
- Powder X-ray diffraction (1)
- Power density (1)
- Pphotophysics (1)
- Prebiotic chemistry (1)
- Precision agriculture (1)
- Precision farming (1)
- Preprocessing (1)
- Primary difference measurement method (PDM) (1)
- Primary transfer standards (PTSs) (1)
- Primordial soup (1)
- Principal component analysis (PCA) (1)
- Priority effect (1)
- Process Analytical Tecnology (1)
- Process Control (1)
- Process control (1)
- Process industry (1)
- Process intelligence (1)
- Process monitoring (1)
- Process sensors 4.0 (1)
- Programmed cell death (1)
- Proinflammatory cytokines (1)
- Protein Purification (1)
- Protein content (1)
- Protein degradation (1)
- Protein folding (1)
- Protein hydrolysis (1)
- Protein oligomerization (1)
- Protein oligomers (1)
- Protein quantification (1)
- Protein test (1)
- Protein-modification (1)
- Proteinoid (1)
- Prouess-Sensoren 4.0 (1)
- Provenance (1)
- Provenancing (1)
- Proximal soil sensing (1)
- Proximity-enhanced reaction (1)
- Prozessanalytik (1)
- Prozesskontrolle (1)
- Pseudomonas aeruginosa (1)
- Pt(111) (1)
- Pt(II) (1)
- PtNP (1)
- Public Health, Environmental and Occupational Health (1)
- Purification (1)
- Purity (1)
- Quality assurancemechanism (1)
- Quantitative Analysis (1)
- Quantitative determination (1)
- Quantitative protein analysis (1)
- Quantum chemistry (1)
- Quartz (1)
- R package (1)
- RBD (1)
- REMPI (1)
- Racemate (1)
- Rainwater (1)
- Raman band width (1)
- Raman microscopy (1)
- Raman-spectroscopy (1)
- Rapid test (1)
- Rapid tests (1)
- Rat/human liver microsomes (1)
- Ratiometric (1)
- Reactor control (1)
- Real-time imaging (1)
- Real-time quality control (1)
- Recombinant Antibody (1)
- Recombinant antibody (1)
- Recombinant protein (1)
- Redox (1)
- Redox switch (1)
- Reference (1)
- Reference Material (1)
- Reference Materials (1)
- Reference data (1)
- References (1)
- Reinigung (1)
- Reliability (1)
- Remediation (1)
- Renal disease (1)
- Renewable copolymers (1)
- Replication (1)
- Replication crisis (1)
- Reporter (1)
- Reproducibility crisis (1)
- Resistance (1)
- Resonance wavelength shift (1)
- Reverse microemulsion (1)
- Reversible covalent hydrazine chemistry (RCHC) (1)
- Rheumatoid arthritis (1)
- Rhizopus (1)
- Rhizopus and Aspergillus oryzae (1)
- Rhodamine (1)
- Ring resonator (1)
- River water sulfate (1)
- Robustness (1)
- Rosamine (1)
- Roughness (1)
- Ruthenium(II) complexes (1)
- Rückverstromung (1)
- SA conjugates (1)
- SAXS (1)
- SBA-15 (1)
- SBA-16 (1)
- SEC (1)
- SEM (1)
- SERDS (1)
- SERS (1)
- SI Traceability (1)
- SIDA-LC-MS/MS (1)
- SKPFM (1)
- SOM-SM (1)
- SVOC (1)
- Safe by design (1)
- Salicylic acid (1)
- Salinomycin (1)
- Salts (1)
- Sample preparation (1)
- Scale anchor (1)
- Scale conversion (1)
- Scattering (1)
- Schlangenbohne (1)
- Schlieren Imaging (1)
- Schnelltest (1)
- Schnelltests (1)
- Scientific publication (1)
- Seawater (1)
- Security (1)
- Sediment (1)
- Segregation (1)
- Selenium (1)
- Self-absorption (1)
- Self-assembled monolayers (SAM) (1)
- Semiconductor (1)
- Semiconductor nanocrystals (1)
- Semiconductor quantum dot (1)
- Sensor Materials (1)
- Sensory particles (1)
- Sequence dependence (1)
- Sequencing (1)
- Sequencing algorithm (1)
- Shadowgraphy (1)
- Silanization (1)
- Silica and polystyrene nanoparticles (1)
- Silica coating (1)
- Silica diagenesis (1)
- Silicon (1)
- Silicon chlorides (1)
- Silicon isotopes (1)
- Simulation (1)
- Single Cell (1)
- Single enhancement (1)
- Single particle ICP-MS (1)
- Single-cell analysis (1)
- Single-sinker densimeter (1)
- Singlet oxygen (1)
- Sintered Material (1)
- Small-angle scattering (1)
- Smart actuators (1)
- Smart test laboratories (1)
- Smarte Aktoren (1)
- Smarte Sensoren (1)
- Smarter Sensor (1)
- Smartphone readout (1)
- Soil contact (1)
- Soil heterogeneity (1)
- Sol-gel process (1)
- Solar cells (1)
- Solar concentrator (1)
- Solar energy (1)
- Solid (1)
- Solid state (1)
- Solid state emission (1)
- Solid-phase extraction (SPE) (1)
- Sorghum (1)
- Spark plasma sintering (1)
- Spatial heterodyne spectrometer (1)
- Special issue (1)
- Specific probe (1)
- Spectoscopic imaging (1)
- Spectrometer (1)
- Spectrometry (1)
- Spectroscopic imaging (1)
- Spectroscopy / Instrumentation (1)
- Spectroscopy / Theory (1)
- Speed of sound (1)
- Spike protein (1)
- Sr isotope analysis (1)
- SsNMR (1)
- Stability (1)
- Stable isotopes (1)
- Standard atomic weight (1)
- Stationäre Phase (1)
- Statistics (1)
- Steel (1)
- Stepwise growth (1)
- Stranski–Krastanow growth (1)
- Strontium isotope (1)
- Structural Biology (1)
- Structure-property relationship (1)
- Sub-4nm particles (1)
- Substance release (1)
- Sulfide sensing (1)
- Sulfur (1)
- Sulfur isotopes (1)
- Sulphur isotope (1)
- Sum Parameter (1)
- Sum Parameter Method (1)
- Sum parameter method (1)
- Supported catalyst (1)
- Supramolecular Chemistry (1)
- Surface Chemistry (1)
- Surface coating (1)
- Surface derivatization (1)
- Surface ligand (1)
- Surface plasmon resonance (1)
- Surface waters (1)
- Surface-enhanced Raman scattering (1)
- Surface-plasmon resonance (1)
- Surrogate citations (1)
- Sustainable Production (1)
- Suzuki coupling (1)
- Suzuki-Miyaura coupling (1)
- Swell-capture (1)
- Synchrotron FTIR (1)
- TEM (1)
- TFA (1)
- TLR4 activation (1)
- Tantalum oxyfluorides (1)
- Target (1)
- Tau (1)
- Temperature (1)
- Temperature Control (1)
- Terephthalic acid (1)
- Terrorism (1)
- Test midpoint (1)
- Test strip (1)
- Tetracyclin (1)
- Tetramethylammonium hydroxide (1)
- Theranostic (1)
- Therapeutic Antibodies (1)
- Thermal Process Engineering (1)
- Thermocouple (1)
- Thermodynamic analysis (1)
- Thermography (1)
- Thick shells (1)
- Thickness (1)
- Thin films (1)
- Tholins (1)
- Tissue (1)
- Titan-Halterung (1)
- Titanium dioxide (1)
- ToF-SIMS (1)
- Toll-like receptor 4 (1)
- Tomography (1)
- Topical collection: Analytical Methods and Applications in the Materials and Life Sciences (1)
- Total cyanide (1)
- Total element determination (1)
- Toxicity testing (1)
- Toys (1)
- Trace Analysis (1)
- Transferrin (1)
- Transformation (1)
- Transient signal (1)
- Transpassive dissolution (1)
- Trennung (1)
- Truffle (1)
- Truffle Aroma (1)
- Trust (1)
- Tryptic digest (1)
- Tryptophan (1)
- Tuber melanosporum (1)
- Tutzing Symposion (1)
- Type-I pyrethroids (1)
- UV Vis (1)
- UV radiation (1)
- UV–Vis spectroscopy (1)
- Ultrasensitive (1)
- Umweltschadstoffe (1)
- Upconverion (1)
- Upconverstion (1)
- Upscaling (1)
- Uptake studies (1)
- VO (1)
- VVOC (1)
- Validate method (1)
- Validation trial (1)
- Vanadium (1)
- Vanadium oxide catalysts (1)
- Vegetable edible oil (1)
- Veterinary drugs (1)
- Vigna unguiculata (1)
- Virial coefficients (1)
- Visualization (1)
- Vocabulary providers (1)
- Volatile organic compounds (1)
- Volatile organic compounds; (1)
- Volumetric uptake (1)
- Vor-Ort-Analytik (1)
- WD-XRF (1)
- WWTP (1)
- Warfarin (1)
- Wasserstoff (1)
- Wasserstoff-Qualität (1)
- Wasserstoffspeicher (1)
- Wastewater (1)
- Water (1)
- Water contact (1)
- Whole water samples (1)
- Wipe test (1)
- Wood chips (1)
- Work function (1)
- Workflow (1)
- X-Ray analysis (1)
- X-Ray fluorescence (1)
- X-ray (1)
- X-ray diffraction (1)
- X-ray spectroscopy (1)
- XANES (1)
- YES assay (1)
- Yerba mate tea (1)
- Ytterbium (1)
- Zearalenone (1)
- Zearalenone sulfate (1)
- Zellulose (1)
- Zenodo (1)
- Zeolithe (1)
- Zinc (1)
- Zinc oxide (1)
- a-zearalenol (1)
- biokompatibel (1)
- calibration (1)
- compost (1)
- dye (1)
- gesintert (1)
- lank characterization (1)
- magnetic nanocatalysts (1)
- pH probe (1)
- photoluminescence (1)
- research landscape (1)
- self-replication (1)
- spICP-MS (1)
- species-specific isotope information (1)
- tandard addition (1)
- temperature (1)
- thermophysical properties (1)
- transmission mode (1)
- β-Lactam (1)
- γ-H2AX assay (1)
Organisationseinheit der BAM
- 1 Analytische Chemie; Referenzmaterialien (358) (entfernen)
Paper des Monats
- ja (12)
Binder remnants in historical mortars represent a record of the connection between the raw materials that enter the kiln, the process parameters, and the end product of the calcination. Raman microspectroscopy combines high structural sensitivity with micrometre to sub-micrometre spatial resolution and compatibility with conventional thin-sectional samples in an almost unique fashion, making it an interesting complementary extension of the existing methodological arsenal for mortar analysis. Raman spectra are vibrational fingerprints of crystalline and amorphous compounds, and contain marker bands that are specific for minerals and their polymorphic forms. Relative intensities of bands that are related to the same crystalline species change according to crystal orientations, and band shifts can be caused by the incorporation of foreign ions into crystal lattices, as well as stoichiometric changes within solid solution series. Finally, variations in crystallinity affect band widths. These effects are demonstrated based on the analysis of three historical mortar samples: micrometric distribution maps of phases and polymorphs, crystal orientations, and compositional variations of solid solution series of unreacted clinker grains in the Portland cement mortars of two 19th century castings, and the crystallinities of thermal anhydrite clusters in a high-fired medieval gypsum mortar as a measure for the applied burning temperature were successfully acquired.
Superficial white matter (SWM) contains the most cortico-cortical white matter connections in the human brain encompassing the short U-shaped association fibers. Despite its importance for brain connectivity, very little is known about SWM in humans, mainly due to the lack of noninvasive imaging methods. Here, we lay the groundwork for systematic in vivo SWM mapping using ultrahigh resolution 7 T magnetic resonance imaging. Using biophysical modeling informed by quantitative ion beam microscopy on postmortem brain tissue, we demonstrate that MR contrast in SWM is driven by iron and can be linked to the microscopic iron distribution. Higher SWM iron concentrations were observed in U-fiber–rich frontal, temporal, and parietal areas, potentially reflecting high fiber density or late myelination in these areas. Our SWM mapping approach provides the foundation for systematic studies of interindividual differences, plasticity, and pathologies of this crucial structure for cortico-cortical connectivity in humans.
The interaction of microplastics with freshwater biota and their interaction with other stressors is still not very well understood. Therefore, we investigated the ingestion, excretion and toxicity of microplastics in the freshwater gastropod Lymnaea stagnalis.
MP ingestion was analyzed as tissues levels in L. stagnalis after 6–96 h of exposure to 5–90 μm spherical polystyrene (PS) microplastics. To understand the excretion, tissue levels were determined after 24 h of exposure followed by a 12 h–7 d depuration period. To assess the toxicity, snails were exposed for 28 d to irregular PS microplastics (<63 μm, 6.4–100,000 particles mL−1), both alone and in combination with copper as additional stressor. To compare the toxicity of natural and synthetic particles, we also included diatomite particles. Microplastics ingestion and excretion significantly depended on the particle size and the exposure/depuration duration. An exposure to irregular PS had no effect on survival, reproduction, energy reserves and oxidative stress. However, we observed slight effects on immune cell phagocytosis. Exposure to microplastics did not exacerbate the reproductive toxicity of copper. In addition, there was no pronounced difference between the effects of microplastics and diatomite. The tolerance towards microplastics may originate from an adaptation of L. stagnalis to particle-rich environments or a general stress resilience. In conclusion, despite high uptake rates, PS fragments do not appear to be a relevant stressor for stress tolerant freshwater gastropods considering current environmental levels of microplastics.
Multiple works have studied possible associations between human leukocyte antigen (HLA) alleles and end stage renal disease (ESRD) showing, however, contradictory and inconsistent results. Here, we revisit the association between ESRD and HLA antigens, comparing HLA polymorphism (at HLA-A, -B, -C, -DRB1, -DQB1 and DQA1 loci) in ESRD patients (n = 497) and controls (n = 672). Our data identified several HLA alleles that displayed a significant positive or negative association with ESRD. We also determined whether heterozygosity or homozygosity of the ESRD-associated HLA alleles at different loci could modify the prevalence of the disease. Few HLA allele combinations displayed significant associations with ESRD, among which A*3_26 combination showed the highest strength of association (OR = 4.488, P≤ 0.05) with ESRD. Interestingly, the age of ESRD onset was not affected by HLA allele combinations at different loci. We also performed an extensive literature analysis to determine whether the association of HLA to ESRD can be similar across different ethnic groups. Our analysis showed that at least certain HLA alleles, HLA-A*11, HLA-DRB1*11, and HLA-DRB1*4, display a significant association with ESRD in different ethnic groups. The findings of our study will help in determining possible protective or susceptible roles of various HLA alleles in ESRD.
Upconversion photoluminescence in hetero-oligonuclear metal complex architectures featuring organic ligands is an interesting but still rarely observed phenomenon, despite its great potential from a basic research and application perspective. In this context, a new photonic material consisting of molecular chromium(III) and ytterbium(III) complex Ions was developed that exhibits excitation-power density-dependent cooperative sensitization of the chromium-centered 2E/2T1 phosphorescence at approximately 775 nm after excitation of the ytterbium band 2F7/2!2F5/2 at approximately 980 nm in the solid state at ambient temperature. The upconversion process is insensitive to atmospheric oxygen and can be observed in the presence of water molecules in the crystal lattice.
Time-gated Förster resonance energy transfer (TG-FRET) between Tb complexes and luminescent semiconductor quantum dots (QDs) provides highly advantageous photophysical properties for multiplexed biosensing. Multiplexed Tb-to-QD FRET immunoassays possess a large potential for in vitro diagnostics, but their performance is often insufficient for their application under clinical conditions. Here, we developed a homogeneous TG-FRET immunoassay for the quantification of carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and prostatespecific antigen (PSA) from a single serum sample by multiplexed Tb-to-QD FRET. Tb–IgG antibody donor conjugates were combined with compact QD-F(ab’)2 antibody acceptor conjugates with three different QDs emitting at 605, 650, and 705 nm. Upon antibody–antigen–antibody Sandwich complex formation, the QD acceptors were sensitized via FRET from Tb, and the FRET ratios of QD and Tb TG luminescence intensities increased specifically with increasing antigen concentrations.
Although limits of detection (LoDs: 3.6 ng/mL CEA, 3.5 ng/mL NSE, and 0.3 ng/mL PSA) for the triplexed assay were slightly higher compared to the single-antigen assays, they were still in a clinically relevant concentration range and could be quantified in 50 μL serum samples on a B·R·A·H·M·S KRYPTOR Compact PLUS clinical immunoassay plate reader. The simultaneous quantification of CEA, NSE, and PSA at different concentrations from the same serum sample demonstrated actual multiplexing Tb-to-QD FRET immunoassays and the potential of this technology for translation into clinical diagnostics.
Boron neutron capture therapy (BNCT) is a radiotherapeutic modality based on the nuclear capture of slow neutrons by stable 10B atoms followed by charged particle Emission that inducing extensive damage on a very localized level (<10 um). To be effcient, a suffcient amount of 10B should accumulate in the tumor area while being almost cleared from the normal surroundings. A water-soluble aza-boron-dipyrromethene dyes (BODIPY) fluorophore was reported to strongly accumulate in the tumor area with high and BNCT compatible Tumor/Healthy Tissue ratios.
The clinically used 10B-BSH (sodium borocaptate) was coupled to the water-soluble aza-BODIPY platform for enhanced 10B-BSH tumor vectorization. We demonstrated a strong uptake of the compound in tumor cells and determined its biodistribution in mice-bearing tumors. A model of chorioallantoic membrane-bearing glioblastoma xenograft was developed to evidence the BNCT potential of such compound, by subjecting it to slow neutrons. We demonstrated the Tumor accumulation of the compound in real-time using optical imaging and ex vivo using elemental imaging based on laser-induced breakdown spectroscopy. The tumor growth was significantly reduced as compared to BNCT with 10B-BSH. Altogether, the fluorescent aza-BODIPY/10B-BSH compound is able to vectorize and image the 10B-BSH in the tumor area, increasing its theranostic potential for effcient approach of BNCT.
The Tutzing Symposium "100 % digital: survival strategies for the process industry" (see 4.1) in April 2018 was characterized by a great momentum which has been taken up and continued until today. The aim was to implement the ideas from the Tutzing Symposium in a coordinated and targeted manner. For this purpose, development needs as well as the numerous currently planned or already started research and development activities in the context of digitalisation were first compiled and analysed. This resulted in the current research landscape for digitalization in the process industry. It now enables to identify open topics and to translate them into research funding programs as well as to define new projects in the dialogue between users, suppliers and research, which are to be meaningfully interlinked and consolidated with existing projects.
Due to the strong interest in digitalisation, activities are constantly being added, so that this paper can only provide a snapshot of the situation in the period 2019-2020.
The continuous improvement of analytical procedures using multi-collector technologies in ICP-mass spectrometry has led to an increased demand for isotope standards with improved homogeneity and reduced measurement uncertainty. For magnesium, this has led to a variety of available standards with different quality levels ranging from artefact standards to isotope reference materials certified for absolute isotope ratios. This required an intercalibration of all standards and reference materials, which we present in this interlaboratory comparison study. The materials Cambridge1, DSM3, ERMAE143, ERM-AE144, ERM-AE145, IRMM-009 and NIST SRM 980 were cross-calibrated with expanded measurement uncertainties (95% confidence level) of less than 0.030‰ for the δ25/24Mg values and less than 0.037‰ for the δ26/24Mg values. Thus, comparability of all magnesium isotope delta (δ) measurements based on these standards and reference materials is established. Further, ERM-AE143 anchors all magnesium δ-scales to absolute isotope ratios and therefore establishes SI traceability, here traceability to the SI base unit mole. This applies especially to the DSM3 scale, which is proposed to be maintained. With ERM-AE144 and ERM-AE145, which are product and educt of a sublimation-condensation process, for the first time a set of isotope reference materials is available with a published value for the apparent triple isotope fractionation exponent θapp, the fractionation relationship ln α(25/24Mg)/ln α(26/24Mg).
The illegal use of explosives by terrorists and other criminals is an increasing issue in public spaces, such as airports, railway stations, highways, sports venues, theaters, and other large buildings. Security in these environments can be achieved by different means, including the installation of scanners and other analytical devices to detect ultra-small traces of explosives in a very short time-frame to be able to take action as early as possible to prevent the detonation of such devices. Unfortunately, an ideal explosive detection system still does not exist, which means that a compromise is needed in practice. Most detection devices lack the extreme analytical sensitivity, which is nevertheless necessary due to the low vapor pressure of nearly all explosives. In addition, the rate of false positives needs to be virtually zero, which is also very difficult to achieve. Here we present an immunosensor system based on kinetic competition, which is known to be very fast and may even overcome affinity limitation, which impairs the performance of many traditional competitive assays. This immunosensor consists of a monolithic glass column with a vast excess of immobilized hapten, which traps the fluorescently labeled antibody as long as no explosive is present. In the case of the explosive 2,4,6-trinitrotoluene (TNT), some binding sites of the antibody will be blocked, which leads to an immediate breakthrough of the labeled protein, detectable by highly sensitive laser-induced fluorescence with the help of a Peltier-cooled complementary metal-oxide-semiconductor (CMOS) camera. Liquid handling is performed with high-precision syringe pumps and chip-based mixing-devices and flow-cells. The system achieved limits of detection of 1 pM (1 ppt) of the fluorescent label and around 100 pM (20 ppt) of TNT. The total assay time is less than 8 min. A cross-reactivity test with 5000 pM solutions showed no signal by pentaerythritol tetranitrate (PETN), 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). This immunosensor belongs to the most sensitive and fastest detectors for TNT with no significant cross-reactivity by non-related compounds. The consumption of the labeled antibody is surprisingly low: 1 mg of the reagent would be sufficient for more than one year of continuous biosensor operation.
The presence of microplastic (MP) particles in aquatic environments raised concern About possible enrichment of organic and inorganic pollutants due to their specific surface and chemical properties. In particular the role of metals within this context is still poorly understood. Therefore, the aim of this work was to develop a fully validated acid digestion protocol for metal analysis in different polymers, which is a prerequisite to study such interactions.
The proposed digestion protocol was validated using six different certified reference materials in the microplastic size range consisting of polyethylene, polypropylene, acrylonitrile butadiene styrene and polyvinyl chloride. As ICP-MS/MS enabled time-efficient, sensitive and robust analysis of 56 metals in one measurement, the method was suitable to provide mass fractions for a multitude of other elements beside the certified ones (As, Cd, Cr, Hg, Pb, Sb, Sn and Zn). Three different microwaves, different acid mixtures as well as different temperatures in combination with different hold times were tested for optimization purposes.
With the exception of Cr in acrylonitrile butadiene styrene, recovery rates obtained using the optimized protocol for all six certified reference materials fell within a range from 95.9% ± 2.7% to 112% ± 7%. Subsequent optimization further enhanced both precision and recoveries ranging from 103% ± 5% to 107 ± 4% (U; k = 2 (n = 3)) for all certified metals (incl. Cr) in acrylonitrile butadiene styrene. The results clearly show the analytical challenges that come along with metal analysis in chemically resistant plastics. Addressing specific analysis Tools for different sorption scenarios and processes as well as the underlying kinetics was beyond this study’s scope. However, the future application of the two recommended thoroughly validated total acid digestion protocols as a first step in the direction of harmonization of metal analysis in/on MP will enhance the significance and comparability of the generated data. It will contribute to a better understanding of the role of MP as vector for trace metals in the environment.
Determination of elemental mass fractions in sediments plays a major role in evaluating the environmental status of aquatic ecosystems. Herewith, the optimization of a new total digestion protocol and the subsequent analysis of 48 elements in different sediment reference materials (NIST SRM 2702, GBW 07313, GBW 07311 and JMC-2) based on ICP-MS/MS detection is presented. The developed method applies microwave acid digestion and utilizes HBF4 as fluoride source for silicate decomposition. Similar to established protocols based on HF, HBF4 ensures the dissolution of the silicate matrix, as well as other refractory oxides. As HBF4 is not acutely toxic; no special precautions have to be made and digests can be directly measured via ICP-MS without specific sample inlet systems, evaporation steps or the addition of e.g. H3BO3, in order to mask excess HF. Different acid mixtures with and without HBF4 were evaluated in terms of digestion efficiency based on the trace metal recovery. The optimized protocol (5 mL HNO3, 2 mL HCL, 1 mL HBF4) allows a complete dissolution of the analyzed reference materials, as well as quantitative recoveries for a wide variety of certified analytes. Low recoveries for e.g. Sr, Ba and rare earth elements due to fluoride precipitation of HF-based digestions protocols, can be avoided by the usage of HBF4 instead. Based on the usage of high purity HBF4 all relevant trace, as well as matrix elements can be analyzed with sufficiently low LOQs (0.002 μg L−1 for U up to 6.7 μg L−1 for Al). In total, 34 elements were within a recovery range of 80%–120% for all three analyzed reference materials GBW 07313, GBW 07311 and JMC-2. 14 elements were outside a recovery range of 80%–120% for at least one of the analyzed reference materials.
In the blossoming field of Cd-free semiconductor quantum dots (QDs), ternary I–III–VI QDs have received increasing attention due to the ease of the environmentally friendly synthesis of high-quality materials in water, their high photoluminescence (PL) Quantum yields (QYs) in the red and near infrared (NIR) region, and their inherently low toxicity. Moreover, their oxygen-insensitive long PL lifetimes of up to several hundreds of nanoseconds close a gap for applications exploiting the compound-specific parameter PL lifetime. To overcome the lack of reproducible synthetic methodologies and to enable a design-based control of their PL properties, we assessed and modelled the synthesis of high-quality MPA-capped AgInS2/ZnS (AIS/ZnS) QDs. Systematically refined Parameters included reaction time, temperature, Ag:In ratio, S:In ratio, Zn:In ratio, MPA:In ratio, and pH using a design-of-experiment approach.
Guidance for the optimization was provided by mathematical models developed for the application-relevant PL parameters, maximum PL wavelength, QY, and PL lifetime as well as the elemental composition in terms of Ag:In:Zn ratio. With these experimental data-based models, MPA:In and Ag:In ratios and pH values were identified as the most important synthesis parameters for PL Control and an insight into the connection of these parameters could be gained. Subsequently, the experimental conditions to synthetize QDs with tunable emission and high QY were predicted. The excellent agreement between the predicted and experimentally found PL features confirmed the reliability of our methodology for the rational design of high quality AIS/ZnS QDs with defined PL features.
This approach can be straightforwardly extended to other ternary and quaternary QDs and to doped QDs.
In this work, a method for species-specific isotopic analysis of sulfur via capillary electrophoresis hyphenated on-line with multicollector ICP-MS (CE/MC-ICP-MS) was developed. Correction for the mass bias caused by instrumental mass discrimination was realized via external correction with multiple-injection sample-standard bracketing. By comparing the isotope ratio measurement results obtained using the newly developed on-line CE/MC-ICP-MS method with those obtained via traditional MC-ICP-MS measurement after analyte/matrix separation by anion exchange chromatography for isotopic reference materials and an in-house bracketing standard, the most suitable data evaluation method could be identified. The repeatability for the sulfate-δ34S value (calculated from 18 measurements of a standard conducted over seven measurement sessions) was 0.57‰ (2SD) and thereby only twice that obtained with off-line measurements (0.30‰, n = 68). As a proof of concept for analysis of samples with a real matrix, the determination of the sulfur isotopic composition of naturally present sulfate was performed for different river systems. The CE/MC-ICP-MS results thus obtained agreed with the corresponding off-line MC-ICP-MS results within the 2SD ranges, and the repeatability of consecutive δ34S measurements (n = 3) was between 0.3‰ and 1.3‰ (2SD). Finally, the isotopic analysis of two different S-species in a river water sample spiked with 2-pyridinesulfonic acid (PSA) was also accomplished.
Sphingosine-1-phosphate (S1P) is a bioactive sphingo-lipid with a broad range of activities coupled to its role in G-protein coupled receptor signalling. Monitoring of both intra and extra cellular levels of this lipid is challenging due to its low abundance and lack of robust affinity assays or sensors. We here report on fluorescent sensory core-shell molecularly imprinted polymer (MIP) particles responsive to near physiologically relevant levels of S1P and the S1P receptor modulator fingolimod phosphate (FP) in spiked human serum samples. Imprinting was achieved using the tetrabutylammonium (TBA) salt of FP or phosphatidic acid (DPPA·Na) as templates in combination with a polymerizable nitrobenzoxadiazole (NBD)-urea monomer with the dual role of capturing the phospho-anion and signalling its presence. The monomers were grafted from ca 300 nm RAFT-modified silica core particles using ethyleneglycol dimethacrylate (EGDMA) as crosslinker resulting in 10–20 nm thick shells displaying selective fluorescence response to the targeted lipids S1P and DPPA in aqueous buffered media. Potential use of the sensory particles for monitoring S1P in serum was demonstrated on spiked serum samples, proving a linear range of 18–60 μM and a detection limit of 5.6 μM, a value in the same range as the plasma concentration of the biomarker.
The potential release of hazardous substances from polymer-based products is currently in the focus of environmental policy. Environmental simulations are applied to expose such products to selected aging conditions and to investigate release processes. Commonly applied aging exposure types such as solar and UV radiation in combination with water contact, corrosive gases, and soil contact as well as expected general effects on polymers and additional ingredients of polymer-based products are described. The release of substances is based on mass-transfer processes to the material surfaces. Experimental approaches to investigate transport processes that are caused by water contact are presented. For tailoring the tests, relevant aging exposure types and release quantification methods must be combined appropriately. Several studies on the release of hazardous substances such as metals, polyaromatic hydrocarbons, flame retardants, antioxidants, and carbon nanotubes from polymers are summarized exemplarily. Differences between natural and artificial exposure tests are discussed and demonstrated for the release of flame retardants from several polymers and for biocides from paints. Requirements and limitations to apply results from short-term artificial environmental exposure tests to predict long-term environmental behavior of polymers are presented.
N-Benzyl aroyl-S,N-ketene acetals can be readily synthesized by condensation of aroyl chlorides and N-Benzyl 2-methyl benzothiazolium salts in good to excellent yields, yielding a library of 35 chromophores with bright solid-state emission and aggregation-induced emission characteristics.
Varying the substituent from electron-donating to electronwithdrawing enables the tuning of the solid-state emission Color from deep blue to red.
Simultaneous characterization of poly(acrylic acid) andpolysaccharide polymers and copolymers
(2020)
Copolymer products that result from grafting acrylic acid and other hydrophilicmonomers onto polysaccharides have recently gained significant interest in researchand industry. Originating from renewable sources, these biodegradable, low toxicity,and polar copolymer products exhibit potential to replace polymers from fossil sourcesin several applications and industries. The methods usually employed to character-ize these copolymers are, however, quite limited, especially for the measurement ofbulk properties. With more sophisticated applications, for example, in pharmaceu-tics requiring a more detailed analysis of the chemical structure, we describe a newapproach for this kind of complex polymers. Our approach utilizes chromatographyin combination with several detection methods to separate and characterize reactionproducts of the copolymerization of acrylic acid and chemically hydrolyzed starch.These samples consisted of a mixture of homopolymer poly (acrylic acid), homopoly-mer hydrolyzed starch, and – in a lower amount – the formed copolymers. Several chro-matographic methods exist that are capable of characterizing either poly (acrylic acid)or hydrolyzed starch. In contrast, our approach offers simultaneous characterization ofboth polymers. The combination of LC and UV/RI offered insight into the compositionand copolymer content of the samples. Size exclusion chromatography experimentsrevealed the molar mass distribution of homopolymers and copolymers. FTIR inves-tigations confirmed the formation of copolymers while ESI-MS gave more details onthe end groups of hydrolyzed starches and poly (acrylic acids). Evidence of copolymerstructures was obtained through NMR measurements. Finally, two-dimensional chro-matography led to the separation of the copolymers from both homopolymers as wellas the additional separation of sodium clusters. The methods described in this work area powerful toolset to characterize copolymerization products of hydrolyzed starch andpoly(acrylic acid). Together, our approach successfully correlates the physicochemicalproperties of such complex mixtures with their actual composition.
Transparent dispersions of hydrophobic SrF2 :Eu3+ nanoparticles in cyclohexane with up to 20% europium were obtained by fluorolytic sol-gel synthesis followed by Phase transfer into cyclohexane through capping with sodium dodecylbenzenesulfonate (SDBS). The particles were characterized by TEM, XRD and DLS as spherical objects with a diameter between 6 and 11 nm in dry state. 1H-13CP MAS NMR experiments revealed the binding of the anionic sulfonate head group to the particle surface. The particles show bright red luminescence upon excitation of the aromatic capping agents, acting as antennas for an Energy transfer from the benzenesulfonate unit to the Eu3+ centers in the particles. This synthesis method overcomes the current obstacle of the fluorolytic sol-gel synthesis that transparent dispersions can be obtained directly only in hydrophilic solvents. To demonstrate the potential of such hydrophobized alkaline-earth fluoride particles, transparent luminescent organic-inorganic composites with 10% SrF2 :Eu3+ embedded into polyTEGDMA, polyBMA, poly-BDDMA and polyD3MA, respectively, were prepared, endowing the polymers with the luminescence features of the nanoparticles.
Since 1 January 2019 a maximum content of 0.6 mg kg−1 cadmium (Cd) in cocoa powder sold to the final consumer or as an ingredient in sweetened cocoa powder sold to the final consumer (drinking chocolate) is set by the Commission Regulation (EU) No. 488/2014. Monitoring compliance with the specified limit value requires analytical measuring methods and reference materials for quality control. However, suitable certified reference materials intended for quality assurance and quality control purposes are still lacking. Therefore, three cocoa reference materials (ERM®-BD513, ERM®-514 and ERM®-515) were developed according to the requirements of ISO 17034 and the recommendations of ISO Guide 35. The whole process of reference material development, including material preparation, assessment of homogeneity and stability, characterisation and value assignment is presented. The assignment of the certified mass fractions was based upon an interlaboratory comparison study involving 19 expert laboratories for Cd and 12 laboratories for acrylamide. The certified mass fractions and expanded uncertainties (k = 2) of the reference materials were (0.181 ± 0.009) mg kg−1 Cd (ERM®-BD513), (0.541 ± 0.024) mg kg−1 Cd (ERM®-BD514) and (0.690 ± 0.029) mg kg−1 Cd (ERM®-BD515). Acrylamide contents are given for information.
We present here the design and characterization of a set of spectral calibration beads. These calibration beads are intended for the determination and regular control of the spectral characteristics of fluorescence microscopes and other fluorescence measuring devices for the readout of bead-based assays. This set consists of micrometer-sized polymer beads loaded with dyes from the liquid Calibration Kit Spectral Fluorescence Standards developed and certified by BAM for the wavelength-dependent Determination of the spectral responsivity of fluorescencemeasuring devices like spectrofluorometers. To cover the wavelength Region from 400 to 800 nm, two new near-infrared emissive dyes were included, which were spectroscopically characterized in solution and encapsulated in the beads. The resulting set of beads presents the first step towards a new platform of spectral calibration beads for the determination of the spectral characteristics of fluorescence instruments like fluorescence microscopes, FCM setups, and microtiter plate readers, thereby meeting the increasing demand for reliable and comparable fluorescence data especially in strongly regulated areas, e.g., medical diagnostics. This will eventually provide the basis for standardized calibration procedures for imaging systems as an alternative to microchannel slides containing dye solutions previously reported by us.
Industry 4.0 is all about interconnectivity, sensor-enhanced process control, and data-driven systems. Process analytical technology (PAT) such as online nuclear magnetic resonance (NMR) spectroscopy is gaining in importance, as it increasingly contributes to automation and digitalization in production. In many cases up to now, however, a classical evaluation of process data and their transformation into knowledge is not possible or not economical due to the insufficiently large datasets available. When developing an automated method applicable in process control, sometimes only the basic data of a limited number of batch tests from typical product and process development campaigns are available. However, these datasets are not large enough for training machine-supported procedures. In this work, to overcome this limitation, a new procedure was developed, which allows physically motivated multiplication of the available reference data in order to obtain a sufficiently large dataset for training machine learning algorithms. The underlying example chemical synthesis was measured and analyzed with both application-relevant low-field NMR and high-field NMR spectroscopy as reference method. Artificial neural networks (ANNs) have the potential to infer valuable process information already from relatively limited input data. However, in order to predict the concentration at complex conditions (many reactants and wide concentration ranges), larger ANNs and, therefore, a larger Training dataset are required. We demonstrate that a moderately complex problem with four reactants can be addressed using ANNs in combination with the presented PAT method (low-field NMR) and with the proposed approach to generate meaningful training data.
N-Myc is a transcription factor that is aberrantly expressed in many tumor types and is often correlated with poor patient prognosis. Recently, several lines of evidence pointed to the fact that oncogenic activation of Myc family proteins is concomitant with reprogramming of tumor cells to cope with an enhanced need for metabolites during cell growth. These adaptions are driven by the ability of Myc proteins to act as transcriptional amplifiers in a tissue-of-origin specific manner. Here, we describe the effects of N-Myc overexpression on metabolic reprogramming in neuroblastoma cells. Ectopic expression of N-Myc induced a glycolytic switch that was concomitant with enhanced sensitivity towards 2-deoxyglucose, an inhibitor of glycolysis. Moreover, global metabolic profiling revealed extensive alterations in the cellular metabolome resulting from overexpression of N-Myc. Limited supply with either of the two main carbon sources, glucose or glutamine, resulted in distinct shifts in steady-state metabolite levels and significant changes in glutathione metabolism. Interestingly, interference with glutamine-glutamate conversion preferentially blocked proliferation of N-Myc overexpressing cells, when glutamine levels were reduced. Thus, our study uncovered N-Myc induction and nutrient levels as important metabolic master switches in neuroblastoma cells and identified critical nodes that restrict tumor cell proliferation.
Synthesis, characterization, electrochemistry, and photophysics of novel homo- and heteroleptic ruthenium(II) complexes [Ru(cpmp)2] 2+ (22+) and [Ru(cpmp)(ddpd)]2+ (32+) bearing the tridentate ligands 6,2’’-carboxypyridyl-2,2’-methylamine-pyridylpyridine (cpmp) and N,N’-dimethyl-N,N’-dipyridin-2-ylpyridine-2,6-diamine (ddpd) are reported. The complexes possess one (32+) or two (22+) electron-deficient dipyridyl ketone fragments as electron accepting sites enabling intraligand charge transfer (ILCT), ligand-toligand charge transfer (LL’CT) and low-energy metal-to-ligand charge transfer (MLCT) absorptions. The latter peak around 544 nm (green light). 22+ shows 3MLCT phosphorescence in the red to near-infrared spectral region at room temperature in deaerated acetonitrile solution with an emission quantum yield of 1.3 % and a 3MLCT lifetime of 477 ns, while 3
2+ is much less luminescent. This different behaviour is ascribed to the energy gap law and the shape of the parasitic excited 3MC state potential energy surface. This study highlights the importance of the excited state energies and geometries for the actual excited state dynamics. Aromatic and aliphatic amines reductively quench the excited state of 22+ paving the way to photocatalytic applications using low-energy green light as exemplified with the green-light sensitized thiol-ene click reaction.
Even though being the subject of natural scientific research for many decades, the system CaSO4–H2O, consisting of the five crystalline phases gypsum, bassanite, and the anhydrites III, II, and I, has left many open questions for research. Raman spectroscopy was used because of its structural sensitivity and in situ measurement capability to obtain further insight by studying phase transitions in both ex situ and in situ experiments. The findings include significant contributions to the completeness and understanding of Raman spectroscopic data of the system. The dehydration path gypsum–bassanite–anhydrite III was shown to have strong parallels to a physical drying process, which depends on many parameters beyond the burning temperature. Raman band width determination was demonstrated to enable the quantitative discrimination of α-bassanite and β-bassanite as well as the postulated three sub-forms of anhydrite II (AII), which are all based on differences in crystallinity. In the latter case, the observed continuous structural variations over increasing burning temperatures were elucidated as a combination of decreasing surface areas and healing of crystal lattice defects. We propose an only two-fold sub-division of AII into reactive “disordered AII” and much less reactive “crystalline AII” with a transition temperature of 650°C ± 50 K.
Thousands of antibodies for diagnostic and other analytical purposes are on the market. However, it is often difficult to identify duplicates, reagent changes, and to assign the correct original publications to an antibody. This slows down scientific progress and might even be a cause of irreproducible research and a waste of resources. Recently, activities were started to suggest the sole use of recombinant antibodies in combination with the open communication of their sequence. In this case, such uncertainties should be eliminated. Unfortunately, this approach seems to be rather a long-term vision since the development and manufacturing of recombinant antibodies remain quite expensive in the foreseeable future. Nearly all commercial antibody suppliers also may be reluctant to publish the sequence of their antibodies, since they fear counterfeiting. De novo sequencing of antibodies is also not feasible today for a reagent user without access to the hybridoma clone. Nevertheless, it seems to be crucial for any scientist to have the opportunity to identify an antibody undoubtedly to guarantee the traceability of any research activity using antibodies from a third party as a tool. For this purpose, we developed a method for the identification of antibodies based on a MALDI-TOF MS fingerprint. To circumvent lengthy denaturation, reduction, alkylation, and enzymatic digestion steps, the fragmentation was performed with a simple formic acid hydrolysis step. Eighty-nine unknown monoclonal antibodies were used for this study to examine the feasibility of this approach. Although the molecular assignment of peaks was rarely possible, antibodies could be easily recognized in a blinded test, simply from their mass-spectral fingerprint. A general protocol is given, which could be used without any optimization to generate fingerprints for a database. We want to propose that, in most scientific projects relying critically on antibody reagents, such a fingerprint should be established to prove and document the identity of the used antibodies, as well as to assign a specific reagent to a datasheet of a commercial supplier, public database record, or antibody ID.
Nano-carrier systems such as liposomes have promising biomedical applications. Nevertheless, characterization of these complex samples is a challenging analytical task. In this study a coupled hydrodynamic chromatography-single particle-inductively coupled plasma mass spectrometry (HDC-spICP-MS) approach was validated based on the technical specification (TS) 19590:2017 of the international organization for standardization (ISO). The TS has been adapted to the hyphenated setup. The quality criteria (QC), e.g., linearity of the calibration, transport efficiency, were investigated. Furthermore, a cross calibration of the particle size was performed with values from dynamic light scattering (DLS) and transmission electron microscopy (TEM). Due to an additional Y-piece, an online-calibration routine was implemented. This approach allows the calibration of the ICP-MS during the dead time of the chromatography run, to reduce the required time and enhance the robustness of the results. The optimized method was tested with different gold nanoparticle (Au-NP) mixtures to investigate the characterization properties of HDC separations for samples with increasing complexity. Additionally, the technique was successfully applied to simultaneously determine both the hydrodynamic radius and the Au-NP content in liposomes. With the established hyphenated setup, it was possible to distinguish between different subpopulations with various NP loads and different hydrodynamic diameters inside the liposome carriers.
The catalytic behavior of iron phthalocyanine (FePc)-sensitized magnetic nanocatalysts was evaluated for their application in the oxidative treatment of Bisphenol A (BPA) under mild environmental conditions. Two types of FePc (Fe(II)Pc and Fe(III)Pc), which are highly photosensitive compounds, were immobilized on the surface of functionalized magnetite. The nanomaterials were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray difraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analyses (TGA). The generation of singlet Oxygen by nanomaterials was also investigated. In the presence of UVA light exposure (365nm) and 15mM H2O2, the M@Fe(III)Pc photocatalyst gave the best results; for a catalyst concentration of 2.0gL −1, around 60% BPA was removed after 120min of reaction. These experimental conditions were further tested under natural solar light exposure, for which also M@Fe(III)Pc exhibited enhanced oxidative catalytic activity, being able to remove 83% of BPA in solution. The water samples were less cytotoxic after treatment, this being confrmed by the MCF-7 cell viability assay.
Separation technology as a sub-discipline of thermal process engineering is one of the most critical steps in the production of chemicals, essential for the quality of intermediate and end products.
The discipline comprises the construction of facilities that convert raw materials into value-added products along the value chain. Conversions typically take place in repeated reaction and separation steps—either in batch or continuous processes. The end products are the result of several production and separation steps that are not only sequentially linked, but also include the treatment of unused raw materials, by-products and wastes. Production processes in the process industry are particularly susceptible to fluctuations in raw materials and other influences affecting product quality. This is a challenge, despite increasing fluctuations, to deliver targeted quality and simultaneously meet the increasing dynamics of the market, at least for high value fine chemicals. In order to survive successfully in a changed environment, chemical companies must tread new paths. This includes the potential of digital technologies. The full integration and intelligent networking of systems and processes is progressing hesitantly. This contribution aims to encourage a more holistic approach to the digitalization in thermal process engineering by introduction of integrated and networked systems and processes.
Mechanical flexibility in single crystals of covalently bound materials is a fascinating and poorly understood phenomenon. We present here the first example of a plastically flexible one-dimensional (1D) coordination polymer. The compound [Zn(m-Cl)2(3,5-dichloropyridine)2]n is flexible over two crystallographic faces. Remarkably, the single crystal remains intact when bent to 1808. A combination of microscopy, diffraction, and spectroscopic studies have been used to probe the structural response of the crystal lattice to mechanical bending. Deformation of the covalent polymer chains does not appear to be responsible for the observed macroscopic bending. Instead, our results suggest that mechanical bending occurs by displacement of the coordination polymer chains. Based on experimental and theoretical evidence, we propose a new model for mechanical flexibility in 1D coordination polymers. Moreover, our calculations propose a cause of the different mechanical properties of this compound and a structurally similar elastic material
Spatial heterodyne spectroscopy (SHS) is a novel spectral analysis technique that is being applied for Raman spectroscopy of minerals. This paper presents the theoretical basis of SHS and its application for Raman measurements of calcite, quartz and forsterite in marble, copper ore and nickel ore, respectively. The SHS measurements are done using a broadband (518–686 nm) and resolving power R ≈ 3000 instrument. The spectra obtained using SHS are compared to those obtained by benchtop and modular dispersive spectrometers. It is found that SHRS performance in terms of resolution is comparable to that of the benchtop spectrometer and better than the modular dispersive spectrometer, while the sensitivity of SHRS is worse than that of a benchtop spectrometer, but better than that of a modular dispersive spectrometer. When considered that SHS components are small and can be packaged into a handheld device, there is interest in developing an SHS-based Instrument for mobile Raman spectroscopy. This paper evaluates the possibility of such an application.
Current and future requirements to industrial analytical infrastructure—part 2: smart sensors
(2020)
Complex processes meet and need Industry 4.0 capabilities. Shorter product cycles, flexible production needs, and direct assessment of product quality attributes and raw material attributes call for an increased need of new process analytical technologies (PAT) concepts. While individual PAT tools may be available since decades, we need holistic concepts to fulfill above industrial needs. In this series of two contributions, we want to present a combined view on the future of PAT (process analytical technology), which is projected in smart labs (Part 1) and smart sensors (Part 2). Part 2 of this feature article series describes the future functionality as well as the ingredients of a smart sensor aiming to eventually fuel full PAT functionality. The smart sensor consists of (i) chemical and process information in the physical twin by smart field devices, by measuring multiple components, and is fully connected in the IIoT 4.0 environment. In addition, (ii) it includes process intelligence in the digital twin, as to being able to generate knowledge from multi-sensor and multi-dimensional data. The cyber-physical system (CPS) combines both elements mentioned above and allows the smart sensor to be self-calibrating and self-optimizing. It maintains its operation autonomously. Furthermore, it allows—as central PAT enabler—a flexible but also target-oriented predictive control strategy and efficient process development and can compensate variations of the process and raw material attributes. Future cyber-physical production systems—like smart sensors—consist of the fusion of two main pillars, the physical and the digital twins. We discuss the individual elements of both pillars, such as connectivity, and chemical analytics on the one hand as well as hybrid models and knowledge workflows on the other. Finally, we discuss its integration needs in a CPS in order to allow is versatile deployment in efficient process development and advanced optimum predictive process control.
The competitiveness of the chemical and pharmaceutical industry is based on ensuring the required product quality while making optimum use of plants, raw materials, and energy. In this context, effective process control using reliable chemical process analytics secures global competitiveness. The setup of those control strategies often originate in process development but need to be transferable along the whole product life cycle. In this series of two contributions, we want to present a combined view on the future of PAT (process analytical technology), which is projected in smart labs (part 1) and smart sensors (part 2). In laboratories and pilot plants, offline chemical analytical methods are frequently used, where inline methods are also used in production. Here, a transferability from process development to the process in operation would be desirable. This can be obtained by establishing PAT methods for production already during process development or scale-up. However, the current PAT (Bakeev 2005, Org Process Res 19:3–62; Simon et al. 2015, Org Process Res Dev 19:3–62) must become more flexible and smarter. This can be achieved by introducing digitalization-based knowledge management, so that knowledge from product development enables and accelerates the integration of PAT. Conversely, knowledge from the production process will also contribute to product and process development. This contribution describes the future role of the laboratory and develops requirements therefrom. In part 2, we examine the future functionality as well as the ingredients of a smart sensor aiming to eventually fuel full PAT functionality—also within process development or scale-up facilities (Eifert et al. 2020, Anal Bioanal Chem).
The DNA in living cells can be effectively damaged by high-energy radiation, which can lead to cell death. Through the ionization of water molecules, highly reactive secondary species such as low-energy electrons (LEEs) with the most probable energy around 10 eV are generated, which are able to induce DNA strand breaks via dissociative electron attachment. Absolute DNA strand break cross sections of specific DNA sequences can be efficiently determined using DNA origami nanostructures as platforms exposing the target sequences towards LEEs. In this paper, we systematically study the effect of the oligonucleotide length on the strand break cross section at various irradiation energies. The present work focuses on poly-adenine sequences (d(A4), d(A8), d(A12), d(A16), and d(A20)) irradiated with 5.0, 7.0, 8.4, and 10 eV electrons. Independent of the DNA length, the strand break cross section shows a maximum around 7.0 eV electron energy for all investigated oligonucleotides confirming that strand breakage occurs through the initial formation of negative ion resonances. When going from d(A4) to d(A16), the strand break cross section increases with oligonucleotide length, but only at 7.0 and 8.4 eV, i.e., close to the maximum of the negative ion resonance, the increase in the strand break cross section with the length is similar to the increase of an estimated geometrical cross section. For d(A20), a markedly lower DNA strand break cross section is observed for all electron energies, which is tentatively ascribed to a conformational change of the dA20 sequence. The results indicate that, although there is a general length dependence of strand break cross sections, individual nucleotides do not contribute independently of the absolute strand break cross section of the whole DNA strand. The absolute quantification of sequence specific strand breaks will help develop a more accurate molecular level understanding of radiation induced DNA damage, which can then be used for optimized risk estimates in cancer radiation therapy.
During R/V Meteor cruise 141/1, pore fluids of near surface sediments were investigated to find indications for hydrothermal activity in the Terceira Rift (TR), a hyperslow spreading center in the Central North Atlantic Ocean. To date, submarine hydrothermal fluid venting in the TR has only been reported for the D. João de Castro seamount, which presently seems to be inactive. Pore fluids sampled close to a volcanic cone at 2,800‐m water depth show an anomalous composition with Mg, SO4, and total alkalinity concentrations significantly higher than seawater and a nearby reference core. The most straightforward way of interpreting these deviations is the dissolution of the hydrothermally formed mineral caminite (MgSO4 0.25 Mg (OH)2 0.2H2O). This interpretation is corroborated by a thorough investigation of fluid isotope systems (δ26Mg, δ30Si, δ34S, δ44/42Ca, and 87Sr/86Sr). Caminite is known from mineral assemblages with anhydrite and forms in hydrothermal recharge zones only under specific conditions such as high fluid temperatures and in altered oceanic crust, which are conditions generally met at the TR. We hypothesize that caminite was formed during hydrothermal activity and is now dissolving during the waning state of the hydrothermal system, so that caminite mineralization is shifted out of its stability zone. Ongoing fluid circulation through the basement is transporting the geochemical signal via slow advection toward the seafloor.
The primary screening of hybridoma cells is a time-critical and laborious step during the development of monoclonal antibodies. Often, critical errors occur in this phase, which supports the notion that the generation of monoclonal antibodies with hybridoma technology is difficult to control and hence, a risky venture. We think that it is crucial to improve the screening process to eliminate most of the critical deficits of the conventional approach. With this new microarray-based procedure, several advances could be achieved: Selectivity for excellent binders, high-throughput, reproducible signals, avoidance of misleading avidity (multivalency) effects, and performance of simultaneous competition experiments. The latter can also be used to select clones of desired cross-reactivity properties. In this paper, a model system with two excellent clones against carbamazepine, two weak clones, and blank supernatant containing fetal bovine serum was designed to examine the effectiveness of the new system. The excellent clones could be detected largely independent of the immunoglobulin G (IgG) concentration, which is usually unknown during the clone screening since the determination and subsequent adjustment of the antibody concentration are not feasible in most cases. Furthermore, in this approach, the enrichment, isolation, and purification of IgG for characterization is not necessary. Raw cell culture supernatant can be used directly, even when fetal calf serum (FCS) or other complex media is used. In addition, an improved method for the oriented antibody-immobilization on epoxy-silanized slides is presented. Based on the results of this model system with simulated hybridoma supernatants, we conclude that this approach should be preferable to most other protocols leading to many false positives, causing expensive and lengthy elimination steps to weed out the poor clones.
Tempo-spectral multiplexing in flow cytometry with lifetime detection using QD-encoded polymer beads
(2020)
Semiconductor quantum dots (QDs) embedded into polymer microbeads are known to be very attractive emitters for spectral multiplexing and colour encoding. Their luminescence lifetimes or decay kinetics have been, however, rarely exploited as encoding parameter, although they cover time ranges which are not easily accessible with other luminophores. We demonstrate here the potential of QDs made from II/VI semiconductors with luminescence lifetimes of several 10 ns to expand the lifetime range of organic encoding luminophores in multiplexing applications using time-resolved flow cytometry (LT-FCM). For this purpose, two different types of QD-loaded beads were prepared and characterized by photoluminescence measurements on the ensemble level and by single-particle confocal laser scanning microscopy. Subsequently, these lifetime-encoded microbeads were combined with dye-encoded microparticles in systematic studies to demonstrate the potential of these QDs to increase the number of lifetime codes for lifetime multiplexing and combined multiplexing in the time and colour domain (tempo-spectral multiplexing). These studies were done with a recently developed novel luminescence lifetime flow cytometer (LT-FCM setup) operating in the time-domain, that presents an alternative to reports on phase-sensitive lifetime detection in flow cytometry.
The preparation of new active pharmaceutical ingredient (API) multicomponent Crystal forms, especially co-crystals and salts, is being considered as a reliable strategy to improve API solubility and bioavailability. In this study, three novel imidazole-based salts of the poorly water-soluble salicylic acid (SA) are reported exhibiting a remarkable improvement in solubility and dissolution rate properties. All structures were solved by powder X-ray diffraction. Multiple complementary techniques were used to solve co-crystal/salt ambiguities: density functional Theory calculations, Raman and 1H/13C solid-state NMR spectroscopies. In all molecular salts, the Crystal packing interactions are based on a common charged assisted +N-H SA)...O-(co-former) hydrogen bond interaction. The presence of an extra methyl group in different positions of the co-former, induced different supramolecular arrangements, yielding salts with different physicochemical properties.
All salts present much higher solubility and dissolution rate than pure SA. The most promising results were obtained for the salts with imidazole and 1-methylimidazole co-formers.
A concept for the growth of silica shells with a thickness of 5–250 nm onto oleate-coated NaYF4:Yb3+/Er3+ upconversion nanoparticles (UCNP) is presented. The concept enables the precise adjustment of shell thicknesses for the preparation of thick-shelled nanoparticles for applications in plasmonics and sensing. First, an initial 5–11 nm thick shell is grown onto the UCNPs in a reverse microemulsion. This is followed by a stepwise growth of these particles without a purification step, where in each step equal volumes of tetraethyl orthosilicate and ammonia water are added, while the volumes of cyclohexane and the surfactant Igepal® CO-520 are increased so that the ammonia water and surfactant concentrations remain constant. Hence, the number of micelles stays constant, and their size is increased to accommodate the growing core–shell particles. Consequently, the formation of core-free silica particles is suppressed. When the negative zeta potential of the particles, which continuously decreased during the stepwise growth, falls below −40 mV, the particles can be dispersed in an ammoniacal ethanol solution and grown further by the continuous addition of tetraethyl orthosilicate to a diameter larger than 500 nm. Due to the high colloidal stability, a coalescence of the particles can be suppressed, and single-core particles are obtained. This strategy can be easily transferred to other nanomaterials for the design of plasmonic nanoconstructs and sensor systems.
Grasses accumulate silicon in the form of silicic acid, which is precipitated as amorphous silica in microscopic particles termed phytoliths. These particles comprise a variety of morphologies according to the cell type in which the silica was deposited. Despite the evident morphological differences, phytolith chemistry has mostly been analysed in bulk samples, neglecting differences between the varied types formed in the same species. In this work, we extracted leaf phytoliths from mature plants of Sorghum bicolor (L.) Moench. Using solid state NMR and thermogravimetric analysis, we show that the extraction methods alter greatly the silica molecular structure, its condensation degree and the trapped organic matter. Measurements of individual phytoliths by Raman and synchrotron FTIR microspectroscopies in combination with multivariate analysis separated bilobate silica cells from prickles and long cells, based on the silica molecular structures and the fraction and composition of occluded organic matter. The variations in structure and composition of sorghum phytoliths suggest that the biological pathways leading to silica deposition vary between these cell types.
Metabolites from Alternaria fungi exhibit a variety of biological properties such as phytotoxic, cytotoxic, or antimicrobial activity. Optimization of a literature procedure culminated in an efficient total synthesis of (−)-altenuene as well as a stable isotope-labeled derivative suitable for implementation in a LC-MS/MS method for mycotoxin analysis.
In summary, we report a highly modular solid TTA-UC system comprising of a crystalline, thermally stable PCN222(Pd) MOF with CA-coated MOF channels and with a DPA annihilator embedded in a solution-like environment in the MOF channels. This solid material displays blue upconverted delayed emission with a luminescence lifetime of 373 us, a threshold value of 329 mW*cm-2 and a triplet–triplet energy transfer efficiency of 82%. This optical application adds another facet to the versatile chemistry of PCN-222 MOFs. The design concept is also applicable to other TTA-UC pairs and enables tuning of the UCL color, for example, by replacing DPA with other dyes as exemplarily shown for 2,5,8,11-tetra-tert-butyl-perylene, that yields UCL at 450 nm. Current work aims to reduce the oxygen sensitivity and to increase the retention of the trapped annihilators in organic environments, for example, by tuning the chain length of the carboxylic acid and by coating the MOF surface. In addition, the TTA-UC efficiency will be further enhanced by reducing the reabsorption of the UC emission caused by Pd(TCPP) and by optimizing the sensitizer/annihilator interface.
Organic and inorganic nanoparticles (NPs) are increasingly used as drug carriers, fluorescent sensors, and multimodal labels in the life and material sciences. These applications require knowledge of the chemical nature, total number of surface groups, and the number of groups accessible for subsequent coupling of e.g., antifouling ligands, targeting bioligands, or sensor molecules. To establish the concept of catch-and-release assays, cleavable probes were rationally designed from a quantitatively cleavable disulfide moiety and the optically detectable reporter 2-thiopyridone (2-TP). For quantifying surface groups on nanomaterials, first, a set of monodisperse carboxy-and amino-functionalized, 100 nm-sized polymer and silica NPs with different surface group densities was synthesized. Subsequently, the accessible functional groups (FGs) were quantified via optical spectroscopy of the cleaved off reporter after its release in solution. Method validation was done with inductively coupled plasma optical emission spectroscopy (ICP-OES) utilizing the sulfur atom of the cleavable probe. This comparison underlined the reliability and versatility of our probes, which can be used for surface group quantification on all types of transparent, scattering, absorbing and/or fluorescent particles. The correlation between the total and accessible number of FGs quantified by conductometric titration, qNMR, and with our cleavable probes, together with the comparison to results of conjugation studies with differently sized biomolecules reveal the potential of catch-and-release reporters for surface analysis. Our findings also underline the importance of quantifying particularly the accessible amount of FGs for many applications of NPs in the life sciences.
Within the framework of precision agriculture, the determination of various soil properties is moving into focus, especially the demand for sensors suitable for in-situ measurements. Energy-dispersive X-ray fluorescence (EDXRF) can be a powerful tool for this purpose. In this study a huge diverse soil set (n = 598) from 12 different study sites in Germany was analysed with EDXRF. First, a principal component analysis (PCA) was performed to identify possible similarities among the sample set.
Clustering was observed within the four texture classes clay, loam, silt and sand, as clay samples contain high and sandy soils low iron mass fractions. Furthermore, the potential of uni- and multivariate data evaluation with partial least squares regression (PLSR) was assessed for accurate Determination of nutrients in German agricultural samples using two calibration sample sets. Potassium and iron were chosen for testing the performance of both models. Prediction of these nutrients in 598 German soil samples with EDXRF was more accurate using PLSR which is confirmed by a better overall averaged deviation and PLSR should therefore be preferred.
Real-time monitoring of newly acidified organelles during autophagy in living cells is highly desirable for a better understanding of intracellular degradative processes. Herein, we describe a reaction-based boron dipyrromethene (BODIPY) dye containing strongly electron-withdrawing diethyl 2-cyanoacrylate groups at the α-positions. The probe exhibits intense red fluorescence in acidic organelles or the acidified cytosol while negligible fluorescence in other regions of the cell. The underlying mechanism is a nucleophilic reaction at the central meso-carbon of the indacene core, resulting in the loss of π-conjugation entailed by dramatic spectroscopic changes of more than 200 nm between its colorless, non-fluorescent leuco-BODIPY form and its red and brightly emitting form. The reversible transformation between red fluorescent BODIPY and leuco-BODIPY along with negligible cytotoxicity qualifies such dyes for rapid and direct intracellular lysosome imaging and cytosolic acidosis detection simultaneously without any washing step, enabling the real-time monitoring of newly acidified organelles during autophagy.
The tendency of boron-dipyrromethene (BODIPY) dyes to associate in water is well known, and usually a cause for inferior fluorescence properties. Synthetic efforts to chemically improve BODIPYs’ water solubility and minimize this problem have been numerous in the past. However, a deeper understanding of the phenomena responsible for fluorescence quenching is still required. Commonly, the spectroscopic behaviour in aqueous media has been attributed to aggregate or excimer formation, with such works often centring on a single BODIPY family. Herein, we provide an integrating discussion including very diverse types of BODIPY dyes. Our studies revealed that even subtle structural changes can distinctly affect the association behaviour of the fluorophores in water, involving different photophysical processes. The palette of behaviour found ranges from unperturbed emission, to the formation of H or J aggregates and excimers, to the involvement of tightly bound, preformed excimers. These results are a first step to a more generalized understanding of spectroscopic properties vs. structure, facilitating future molecular design of BODIPYs, especially as probes for biological applications.
Molecular MRI is a promising in-vivo modality to detect and quantify morphological and molecular vessel-wall changes in atherosclerosis. The combination of different molecular biomarkers may improve the risk stratification of patients. This study aimed to investigate the feasibility of simultaneous visualization and quantification of plaque-burden and inflammatory activity by dual-probe molecular
MRI in a mouse-model of progressive atherosclerosis and in response-to-therapy. Homozygous apolipoprotein E knockout mice (ApoE−/−) were fed a high-fat-diet (HFD) for up to four-months prior to MRI of the brachiocephalic-artery. To assess response-to-therapy, a statin was administered for the same duration. MR imaging was performed before and after administration of an elastin-specific gadolinium-based and a macrophage-specific iron-oxide-based probe. Following in-vivo MRI, samples were analyzed using histology, immunohistochemistry, inductively-coupled-mass-spectrometry and laser-inductively-coupled-mass-spectrometry. In atherosclerotic-plaques, intraplaque expression
of elastic-fibers and inflammatory activity were not directly linked. While the elastin-specific probe demonstrated the highest accumulation in advanced atherosclerotic-plaques after four-months of HFD, the iron-oxide-based probe showed highest accumulation in early atherosclerotic-plaques after two months of HFD. In-vivo measurements for the elastin and iron-oxide-probe were in good agreement
with ex-vivo histopathology (Elastica-van-Giesson stain: y = 298.2 + 5.8, R2 = 0.83, p < 0.05; Perls‘ Prussian-blue-stain: y = 834.1 + 0.67, R2 = 0.88, p < 0.05). Contrast-to-noise-ratio (CNR) measurements of the elastin probe were in good agreement with ICP-MS (y = 0.11x-11.3, R² = 0.73, p < 0.05). Late stage atherosclerotic-plaques displayed the strongest increase in both CNR and gadolinium concentration (p < 0.05). The gadolinium probe did not affect the visualization of the iron-oxide-probe and vice versa. This study demonstrates the feasibility of simultaneous assessment of plaque-burden.
Raman band widths of anhydrite II reveal the burning history of high-fired medieval gypsum mortars
(2019)
The use of high-fired gypsum as binder for masonry and joint mortars or stuccowork in Central Europe in the Early and High Middle Ages was a regional specific as it depended on local gypsum deposits. The calcination technology possible at the time resulted in an assemblage of calcium sulphate phases dehydrated to different degrees and partly thermally damaged accessory minerals of the raw gypsum. Because of the absence of medieval textbooks, the observation of high-temperature, low-pressure mineral transformations and the correlation of phases coexisting in not hydrated binder relicts in the gypsum matrix to the mineralogy of the raw material and the burning conditions constitute the only source to the historical technological know-how.
The CaSO4–H2O system consists of five crystalline phases, which can be discriminated by structural analysis methods, such as Raman spectroscopy, due to obvious differences in their spectroscopic data: gypsum (CaSO4 ⋅ 2 H2O), bassanite (hemihydrate, CaSO4 ⋅ ½ H2O), anhydrite III (CaSO4), anhydrite II (CaSO4), and anhydrite I (CaSO4). Only recently, it was possible to demonstrate that small spectroscopic variations exist also within the relatively large stability range of anhydrite II from approx. 180°C to 1180°C: all Raman bands narrow with increasing burning temperature applied in the synthesis from gypsum powder. The determination of band widths of down to 3 cm-1 and differences between them of a few tenths of a wavenumber is not a trivial task. Thus, this contribution discusses peak fitting and strategies for correction of instrument-dependent band broadening.
Raman maps of polished thin sections of gypsum mortars provide access to the burning histories of individual remnant thermal anhydrite grains and enable the discrimination of natural anhydrite originating from the gypsum deposit. This novel analytical method was applied to samples from medieval South Tyrolean stucco decorations and sculptures. Beyond that, Raman microspectroscopy was employed for following pyrometamorphic reactions in natural impurities of the raw material. In the presented examples mineral thermometry indicates process temperatures above 800°C: the breakdown of magnesium-rich chlorite led to the formation of forsterite Mg2SiO4, while the thermal decomposition of dolomite CaMg(CO3)2 yielded – after hydration and carbonation – magnesite MgCO3, CaCO3 polymorphs and magnesian calcite. Lower burning temperatures, which leave the accessory minerals in their pristine form, can be traced by measuring the spectra of anhydrite crystalites in grains of firing products and evaluating Raman band widths. Throughout the applications of this analytical method so far, calcination temperatures ranging from approx. 600°C to 900°C were determined.
Within the Working Group on Inorganic Analysis (IAWG) of the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology (CCQM) international key comparisons and pilot studies related to inorganic analysis are carried to ensure consistency in this field at the highest level. Some of these comparisons deal directly with the preparation and characterization of monoelemental solutions or with topics, closely related. The importance of monoelemental solutions lies in the fact that almost every measurement in inorganic analysis relies on the comparison with either a reference material, or references in form of solutions, usually (mono)elemental solutions. All quantitative measurement approaches, e.g. isotope dilution or standard addition, need an accurate reference solution made from a well characterized reference material, prepared under full gravimetric control. These primary (monoelemental) solutions do not only serve as arbitrary references/calibration solutions, but they also link up measurement results to the International System of units (SI), this way establishing the so-called metrological traceability to a measurement unit of the SI. Without such solutions on the highest possible level of accuracy and with the smallest possible associated uncertainties (for e.g. element content and/or impurities), an analysis itself can never be as good as it could be with appropriate reference solutions. This article highlights select key comparisons and pilot studies dealing with monoelemental solution related topics within the IAWG from the foundation of CCQM – 25 years ago – up to latest achievements in the field of inorganic analysis.
Photoactive metal complexes employing Earth‐abundant metal ions are a key to sustainable photophysical and photochemical applications. We exploit the effects of an inversion center and ligand non‐innocence to tune the luminescence and photochemistry of the excited state of the [CrN6] chromophore [Cr(tpe)2]3+ with close to octahedral symmetry (tpe=1,1,1‐tris(pyrid‐2‐yl)ethane). [Cr(tpe)2]3+ exhibits the longest luminescence lifetime (τ=4500 μs) reported up to date for a molecular polypyridyl chromium(III) complex together with a very high luminescence quantum yield of Φ=8.2 % at room temperature in fluid solution. Furthermore, the tpe ligands in [Cr(tpe)2]3+ are redox non‐innocent, leading to reversible reductive chemistry. The excited state redox potential and lifetime of [Cr(tpe)2]3+ surpass those of the classical photosensitizer [Ru(bpy)3]2+ (bpy=2,2′‐bipyridine) enabling energy transfer (to oxygen) and photoredox processes (with azulene and tri(n‐butyl)amine).