@article{MaierClausiusRichteretal.2021, author = {Maier, Petra and Clausius, Benjamin and Richter, Asta and Bittner, Benjamin and Hort, Norbert and Menze, Roman}, title = {Crack Propagation in As-Extruded and Heat-Treated Mg-Dy-Nd-Zn-Zr Alloy Explained by the Effect of LPSO Structures and Their Micro- and Nanohardness}, series = {Materials}, volume = {14}, journal = {Materials}, number = {13}, publisher = {MDPI}, issn = {1996-1944}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-14194}, year = {2021}, abstract = {The investigation of the crack propagation in as-extruded and heat-treated Mg-Dy-Nd-Zn-Zr alloy with a focus on the interaction of long-period stacking-ordered (LPSO) structures is the aim of this study. Solution heat treatment on a hot extruded Mg-Dy-Nd-Zn-Zr (RESOLOY®) was done to change the initial fine-grained microstructure, consisting of grain boundary blocky LPSO and lamellar LPSO structures within the matrix, into coarser grains of less lamellar and blocky LPSO phases. C-ring compression tests in Ringer solution were used to cause a fracture. Crack initiation and propagation is influenced by twin boundaries and LPSO lamellae. The blocky LPSO phases also clearly hinder crack growth, by increasing the energy to pass either through the phase or along its interface. The microstructural features were characterized by micro- and nanohardness as well as the amount and location of LPSO phases in dependence on the heat treatment condition. By applying nanoindentation, blocky LPSO phases show a higher hardness than the grains with or without lamellar LPSO phases and their hardness decreases with heat treatment time. On the other hand, the matrix increases in hardness by solid solution strengthening. The microstructure consisting of a good balance of grain size, matrix and blocky LPSO phases and twins shows the highest fracture energy.}, language = {en} } @article{GrebinykPrylutskaGrebinyketal.2021, author = {Grebinyk, Anna and Prylutska, Svitlana and Grebinyk, Sergii and Evstigneev, Maxim and Krysiuk, Iryna and Skaterna, Tetiana and Horak, Iryna and Sun, Yanfang and Drobot, Liudmyla and Matyshevska, Olga and Prylutskyy, Yuriy and Ritter, Uwe and Frohme, Marcus}, title = {Antitumor efficiency of the natural alkaloid berberine complexed with C60 fullerene in Lewis lung carcinoma in vitro and in vivo}, series = {Cancer Nanotechnology}, volume = {12}, journal = {Cancer Nanotechnology}, publisher = {BioMed Central}, issn = {1868-6966}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-14749}, pages = {24}, year = {2021}, abstract = {Background Berberine (Ber) is a herbal alkaloid with pharmacological activity in general and a high anticancer potency in particular. However, due to its low bioavailability, the difficulty in reaching a target and choosing the right dose, there is a need to improve approaches of Ber use in anticancer therapy. In this study, Ber, noncovalently bound to a carbon nanostructure C60 fullerene (C60) at various molar ratios of the components, was explored against Lewis lung carcinoma (LLC). Methods C60-Ber noncovalent nanocomplexes were synthesized in 1:2, 1:1 and 2:1 molar ratios. Ber release from the nanocomplexes was studied after prolonged incubation at different pH with the liquid chromatography-mass spectrometry analysis of free Ber content. Biological effects of the free and C60-complaxated Ber were studied in vitro towards LLC cells with phase-contrast and fluorescence microscopy, flow cytometry, MTT reduction, caspase activity and wound closure assays. The treatment with C60-Ber nanocomplex was evaluated in vivo with the LLC-tumored C57Bl mice. The mice body weight, tumor size, tumor weight and tumor weight index were assessed for four groups, treated with saline, 15 mg C60/kg, 7.5 mg Ber/kg or 2:1 C60-Ber nanocomplex (15 mg C60/kg, 7.5 mg Ber/kg). Results Ber release from C60-Ber nanocomplexes was promoted with medium acidification. LLC cells treatment with C60-Ber nanocomplexes was followed by enhanced Ber intracellular uptake as compared to free Ber. The cytotoxicity of the studied agents followed the order: free Ber < 1:2 < 1:1 < 2:1 C60-Ber nanocomplex. The potency of cytotoxic effect of 2:1 C60-Ber nanocomplex was confirmed by 21.3-fold decrease of IC50 value (0.8 ± 0.3 µM) compared to IC50 for free Ber (17 ± 2 µM). C60-Ber nanocomplexes induced caspase 3/7 activation and suppressed the migration activity of LLC cells. The therapeutic potency of 2:1 C60-Ber nanocomplex was confirmed in a mouse model of LLC. The tumor growth in the group treated with 2:1 C60-Ber nanocomplex is suppressed by approximately 50\% at the end of experiment, while in the tumor-bearing group treated with free Ber no therapeutic effect was detected. Conclusions This study indicates that complexation of natural alkaloid Ber with C60 may be a novel therapeutic strategy against lung carcinoma.}, language = {en} } @article{GoldenbergKoehlerDreyer2021, author = {Goldenberg, Leonid and K{\"o}hler, Mathias and Dreyer, Christian}, title = {SiO2 Nanoparticles-Acrylate Formulations for Core and Cladding in Planar Optical Waveguides}, series = {Nanomaterials}, volume = {11}, journal = {Nanomaterials}, number = {5}, publisher = {MDPI}, issn = {2079-4991}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-14057}, year = {2021}, abstract = {A combination of acrylate formulations and SiO2 nanoparticles is investigated with the aim to improve the optical properties of low-refractive index polymers that are used for the fabrication of planar optical waveguides. A decrease in refractive index and also in the thermo-optic coefficient of nanocomposite materials is clearly demonstrated, while some formulations exhibit an increase in the glass transition temperature. The possibility of using these nanocomposite materials to fabricate waveguiding layers with low optical propagation losses at telecommunication wavelengths around 1550 nm is also shown. The nanomaterials can be applied in optical microchips on polymer platforms.}, language = {en} } @phdthesis{Grebinyk2021, author = {Grebinyk, Anna}, title = {Synergistic Chemo- and Photodynamic Treatment of Cancer Cells with C60 Fullerene Nanocomplexes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-14137}, school = {Technische Hochschule Wildau}, year = {2021}, abstract = {Recent progress in nanotechnology has attracted interest to a biomedical application of the carbon nanoparticle C60 fullerene (C60) due to its unique structure and versatile biological activity. In the current study the dual functionality of C60 as a photosensitizer and a drug nanocarrier was exploited to improve the efficiency of chemotherapeutic drugs towards human leukemic cells. Pristine C60 demonstrated time-dependent accumulation with predominant mitochondrial localization in leukemic cells. C60's effects on leukemic cells irradiated with high power single chip LEDs of different wavelengths were assessed to find out the most effective photoexcitation conditions. A C60-based noncovalent nanosized system as a carrier for an optimized drug delivery to the cells was evaluated in accordance to its physicochemical properties and toxic effects. Finally, nanomolar amounts of C60-drug nanocomplexes in 1:1 and 2:1 molar ratios were explored to improve the efficiency of cell treatment, complementing it with photodynamic approach. A proposed treatment strategy was developed for C60 nanocomplexes with the common chemotherapeutic drug Doxorubicin, whose intracellular accumulation and localization, cytotoxicity and mechanism of action were investigated. The developed strategy was revealed to be transferable to an alternative potent anticancer drug - the herbal alkaloid Berberine. Hereafter, a strong synergy of treatments arising from the combination of C60-mediated drug delivery and C60 photoexcitation was revealed. Presented data indicate that a combination of chemo- and photodynamic treatments with C60-drug nanoformulations could provide a promising synergetic approach for cancer treatment.}, subject = {cancer}, language = {en} } @article{GrytsenkoKsianzouKolomzarovetal.2021, author = {Grytsenko, Kostyantyn and Ksianzou, Viachaslau and Kolomzarov, Yurii and Lytvyn, Peter and Dietzel, Birgit and Schrader, Sigurd}, title = {Fluoropolymer Film Formation by Electron Activated Vacuum Deposition}, series = {Surfaces}, volume = {4}, journal = {Surfaces}, number = {1}, publisher = {MDPI}, issn = {2571-9637}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-13786}, pages = {66 -- 80}, year = {2021}, abstract = {Polytetrafluoroethylene (PTFE), polyhexafluoropropylene (PHFP) and polychlorotrifluoroethylene (PCTFE) were heated to their decomposition temperature in a high vacuum. The emitted fragments passed an electron cloud, condensed on a substrate and formed fluoropolymer film. Growth rate of PTFE and PHFP films increased up to a factor five in the presence of the electron cloud. Mass spectrometry revealed changes in the mass spectra of fragments generated by thermal decomposition only and formed under electron activation. The observed changes were different for each fluoropolymer. Infrared spectroscopy (IRS) showed that the structure of the films was close to the structure of the bulk polymers. Atomic force microscopy (AFM) has revealed different morphologies of PTFE, PHFP and PCTFE films, suggesting a Volmer-Weber growth mechanism for PTFE and PHFP but a Frank-van der Merwe one for PCTFE. All films were smooth at nanoscale and transparent from ultraviolet to near-infrared region. Additional radio frequency (RF) plasma ignited in the emitted fragments at a low pressure increased mechanical characteristics of the films without losing their optical transparency and smoothness.}, language = {en} } @unpublished{Liebchen2021, author = {Liebchen, Christian}, title = {Maximizing Bidirectional Green Waves for Major Road Axes}, doi = {10.15771/2827}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15449}, pages = {1 -- 20}, year = {2021}, abstract = {Both, from an environmental perspective and with respect to road traffic flow quality, planning so-called green waves along major road axes is a well-established target for traffic engineers. For one-way road axes (e.g. the Avenues in Manhattan), this is a trivial downstream task. For bidirectional arterials, the well-known necessary condition for establishing a green wave in both direction is that the driving times between two subsequent crossings must be an integer multiple of half of the cycle time of the signal programs at the nodes. In this paper, we propose an integer linear optimization model to establish fixed-time green waves in both directions that are as long and as wide as possible, even in the situation where the driving time condition is not fulfilled. In particular, we are considering an arterial along whose nodes separate left-turn signal groups are realized. In our computational results, we provide examples which illustrate that allowing for selecting among different strategies for the left-turn phases is beneficial. Moreover, we show that there is always a solution with green waves in both directions that are as long and as wide as possible, where absolute priority is put on just one direction. Only when considering prioritized parts of a green band (e.g. some first few seconds), then an ideal green wave into one direction can provide suboptimal quality compared to optimizing both directions together.}, language = {en} } @article{VillringerSteglichPulweretal.2021, author = {Villringer, Claus and Steglich, Patrick and Pulwer, Silvio and Schrader, Sigurd and Laufer, Jan}, title = {Electro-optical properties of doped polymers with high transparency in the visible wavelength range}, series = {Optical Materials Express}, volume = {11}, journal = {Optical Materials Express}, number = {11}, publisher = {Optica Publishing Group}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15480}, pages = {3801 -- 3811}, year = {2021}, abstract = {The electro-optical (EO) properties of poly(methyl methacrylate) and the photopolymer poly(vinyl cinnamate) doped with varying concentrations of the EO chromophore 2-Methyl-4-nitroaniline were measured. The EO polymers were embedded in Fabry-P{\´e}rot etalons for the simultaneous determination of the Pockels and Kerr coefficients from measurements of the fringe shift induced by an external electric field. It was found that the host polymer has a significant impact on the EO performance and that the undoped host polymers exhibit a significant Pockels effect. Moreover, the Kerr effect provides a substantial contribution of 27\% to the total change of the refractive index at relatively high electric field strengths of E = 91.2 MV m-1.}, language = {en} } @article{KebdaniLehnertMichael2021, author = {Kebdani, Zaki and Lehnert, Martin and Michael, Sabrina}, title = {Hygienisch sicher reisen? - Der {\"o}ffentliche Verkehr in der Pandemie -}, series = {Eisenbahntechnische Rundschau (ETR)}, volume = {2021}, journal = {Eisenbahntechnische Rundschau (ETR)}, number = {9}, publisher = {DVV Media Group}, issn = {0013-2845}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-16716}, pages = {16 -- 21}, year = {2021}, abstract = {Entsprechend aktueller wissenschaftlicher Studien ist das Risiko, sich mit SARS-CoV-2 im {\"o}ffentlichen Verkehr zu infizieren, nicht h{\"o}her als im h{\"a}uslichen Umfeld. Besonders in Verkehrsmittelinnenr{\"a}umen kann durch eine ausreichende Frischluftzufuhr, Umluftfilterung, Einhaltung von Abst{\"a}nden und dem richtigen Tragen von geeigneten Schutzmasken das Ansteckungsrisiko effektiv reduziert werden.}, language = {de} } @article{HerkenhoffBovolentaBroedeletal.2021, author = {Herkenhoff, Marcos Edgar and Bovolenta, Luiz A. and Br{\"o}del, Oliver and dos Santos, Lucilene Delazari and de Oliveira, Arthur C. and Chuffa, Luiz G.A. and Ribeiro, Amanda O. and Lupi, Luiz A. and Dias, Marco A.D. and Hilsdorf, Alexandre W.S. and Frohme, Marcus and Pinhal, Danillo}, title = {Variant expression signatures of microRNAs and protein related to growth in a crossbreed between two strains of Nile tilapia (Oreochromis niloticus)}, series = {Genomics}, volume = {113}, journal = {Genomics}, number = {6}, publisher = {Elsevier}, issn = {0888-7543}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15571}, pages = {4303 -- 4312}, year = {2021}, abstract = {Nile tilapia (Oreochromis niloticus) is a species of worldwide importance for aquaculture. A crossbred lineage was developed through introgressive backcross breeding techniques and combines the high growth performance of the Chitralada (CHIT) lwith attractive reddish color of the Red Stirling (REDS) strains. Since the crossbreed has an unknown genetically improved background, the objective of this work was to characterize expression signatures that portray the advantageous phenotype of the crossbreeds. We characterized the microRNA transcriptome by high throughput sequencing (RNA-seq) and the proteome through mass spectrometry (ESI-Q-TOF-MS) and applied bioinformatics for the comparative analysis of such molecular data on the three strains. Crossbreed expressed a distinct set of miRNAs and proteins compared to the parents. They comprised several microRNAs regulate traits of economic interest. Proteomic profiles revealed differences between parental and crossbreed in expression of proteins associated with glycolisis. Distinctive miRNA and protein signatures contribute to the phenotype of crossbreed.}, language = {en} } @article{WielandKuhlsLentzetal.2021, author = {Wieland, Ralf and Kuhls, Katrin and Lentz, Hartmut H.K. and Conraths, Franz and Kampen, Helge and Werner, Doreen}, title = {Combined climate and regional mosquito habitat model based on machine learning}, series = {Ecological Modelling}, volume = {452}, journal = {Ecological Modelling}, address = {Elsevier}, issn = {0304-3800}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15649}, year = {2021}, abstract = {Besides invasive mosquito species also several native species are proven or suspected vectors of arboviruses as West Nile or Usutu virus in Western Europe. Habitat models of these native vectors can be a helpful tool for assessing the risk of autochthonous occurrence, outbreaks and spread of diseases caused by such arboviruses. Modelling native mosquitoes is complicated because of the perfect adaptation to the climatic and landscape conditions and their high abundance in contrast to invasive species. Here we present a new approach for such a habitat model for native mosquito species in Germany, which are considered as vectors of West Nile virus (WNV). Epizootic emergence of WNV was registered in Germany since 2018. The models are based on surveillance data of mosquitoes from the German citizen science project "M{\"u}ckenatlas" complemented by data from systematic trap monitoring in Germany, and on data freely available from the Deutscher Wetterdienst (DWD) and OpenStreetMap (OSM). While climatic factors still play an important role, we could show that habitat suitability is predictable only by the combination of the climate model with a regional model. Both models were based on a machine-learning approach using XGBoost. Evaluation of the accuracy of the models was done by statistical analysis, determining among others feature importances using the SHAP-Library. Final output of the combined climatic and regional models are maps showing the superposed habitat suitability which are generated through a number of steps described in detail. These maps also include the registered cases of WNV infections in the selected region of Germany.}, language = {en} }