TY - JOUR A1 - Afonso, Luis Claudio Sugi A1 - Pereira, Clayton R. A1 - Weber, Silke A. T. A1 - Hook, Christian A1 - Falcão, Alexandre X. A1 - Papa, Joao Paulo T1 - Hierarchical learning using deep optimum-path forest JF - Journal of Visual Communication and Image Representation N2 - Bag-of-Visual Words (BoVW) and deep learning techniques have been widely used in several domains, which include computer-assisted medical diagnoses. In this work, we are interested in developing tools for the automatic identification of Parkinson’s disease using machine learning and the concept of BoVW. The proposed approach concerns a hierarchical-based learning technique to design visual dictionaries through the Deep Optimum-Path Forest classifier. The proposed method was evaluated in six datasets derived from data collected from individuals when performing handwriting exams. Experimental results showed the potential of the technique, with robust achievements. KW - Handwriting dynamics KW - Hierarchical representation KW - Optimum-path forest KW - Parkinson’s disease Y1 - 2020 U6 - https://doi.org/10.1016/j.jvcir.2020.102823 VL - 71 IS - August PB - Elsevier ER - TY - JOUR A1 - Afonso, Luis Claudio Sugi A1 - Rosa, Gustavo H. A1 - Pereira, Clayton R. A1 - Weber, Silke A. T. A1 - Hook, Christian A1 - Albuquerque, Victor Hugo C. A1 - Papa, Joao Paulo T1 - A recurrence plot-based approach for Parkinson's disease identification JF - Future generation computer systems - The international journal of escience N2 - Parkinson's disease (PD) is a neurodegenerative disease that affects millions of people worldwide, causing mental and mainly motor dysfunctions. The negative impact on the patient's daily routine has moved the science in search of new techniques that can reduce its negative effects and also identify the disease in individuals. One of the main motor characteristics of PD is the hand tremor faced by patients, which turns out to be a crucial information to be used towards a computer-aided diagnosis. In this context, we make use of handwriting dynamics data acquired from individuals when submitted to some tasks that measure abilities related to writing skills. This work proposes the application of recurrence plots to map the signals onto the image domain, which are further used to feed a Convolutional Neural Network for learning proper information that can help the automatic identification of PD. The proposed approach was assessed in a public dataset under several scenarios that comprise different combinations of deep-based architectures, image resolutions, and training set sizes. Experimental results showed significant accuracy improvement compared to our previous work with an average accuracy of over 87%. Moreover, it was observed an improvement in accuracy concerning the classification of patients (i.e., mean recognition rates above to 90%). The promising results showed the potential of the proposed approach towards the automatic identification of Parkinson's disease. KW - Classification KW - Convolutional neural networks KW - diagnosis KW - Optimum-path forest KW - Parkinson's disease KW - Recurrence plot Y1 - 2019 U6 - https://doi.org/10.1016/j.future.2018.11.054 VL - 94 IS - May SP - 282 EP - 292 PB - Elsevier ER - TY - CHAP A1 - Altenbuchner, Amelie A1 - Weber, Karsten ED - Haltaufderheide, Joschka ED - Hovemann, Johanna ED - Vollmann, Jochen T1 - Geriatric trauma patients as research subjects in a technology-driven research project BT - A preliminary field report T2 - Aging between Participation and Simulation N2 - This article highlights methodological and ethical challenges in research with adults of older and oldest age, by presenting field experiences of the current research project “Motion Monitoring of Geriatric Trauma Patients - Explorative Study on the Rehabilitation Process after Hip Fracture Using Sensor-based Data”. Depiction of the survey situation, with regard to the subjects in particular, can serve as practical examples for designing future research projects. The group of older adults is a rather large and growing group for which research is required, especially concerning their heterogeneity, their individual autonomy and quality of life. It is assumed, that research designs of studies on the target group must be specifically adjusted, in particular when considering the attribution of vulnerability of the group members. At the same time, it is not clear yet what exact specifics of the subjects and target group must be considered in research designs, as surprisingly little is known about the target group as subjects and corresponding theories have been insufficiently tested. The exploratory long-term design of the research project presented in the second section of this chapter has a positive evaluation of an ethics committee. Still ethical challenges occurred in the field situation, that are illustrated in the third section of this chapter, by providing information on the patients, their role as research subjects, how they were recruited, how an informed consensus was reached, and in some cases how participation was rejected or abandoned. After a summary, the end of the paper is marked by recommendations on how to design future research projects. Cumulatively it must always be expected that interaction between researchers and research subjects of this target group can become very intensive, what requires to follow clearly defined procedures and at the same time to be prepared to act flexibly. Y1 - 2020 SN - 9783110677485 U6 - https://doi.org/10.1515/9783110677485-006 SP - 87 EP - 104 PB - De Gruyter CY - Berlin u.a. ER - TY - JOUR A1 - Alvarez Moret, Judit A1 - Obermeier, Tina A1 - Pohl, Fabian A1 - Löschel, Rainer A1 - Kölbl, Oliver A1 - Dobler, Barbara T1 - Second cancer risk after radiation therapy of ependymoma using the flattening filter free irradiation mode of a linear accelerator JF - Journal of Applied Clinical Medical Physics N2 - Pediatric patients suffering from ependymoma are usually treated with cranial or craniospinal three-dimensional (3D) conformal radiotherapy (3DCRT). Intensity-modulated techniques spare dose to the surrounding tissue, but the risk for second malignancies may be increased due to the increase in low-dose volume. The aim of this study is to investigate if the flattening filter free (FFF) mode allows reducing the risk for second malignancies compared to the mode with flattening filter (FF) for intensity-modulated techniques and to 3DCRT. A reduction of the risk would be advantageous for treating pediatric ependymoma. 3DCRT was compared to intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) with and without flattening filter. Dose-volume histograms (DVHs) were compared to evaluate the plan quality and used to calculate the excess absolute risk (EAR) to develop second cancer in the brain. Dose verification was performed with a two-dimensional (2D) ionization chamber array and the out-of-field dose was measured with an ionization chamber to determine the EAR in peripheral organs. Delivery times were measured. Both VMAT and IMRT achieved similar plan quality in terms of dose sparing in the OAR and higher PTV coverage as compared to 3DCRT. Peripheral dose in low-dose region, which is proportional to the EAR in organs located in this region, for example, gonads, bladder, or bowel, could be significantly reduced using FFF. The lowest peripheral EAR and lowest delivery times were hereby achieved with VMATFFF . The EAR calculated based on DVH in the brain could not be reduced using FFF mode. VMATFFF improved the target coverage and homogeneity and kept the dose in the OAR similar compared to 3DCRT. In addition, delivery times were significantly reduced using VMATFFF . Therefore, for radiotherapy of ependymoma patients, VMATFFF may be considered advantageous for the combination of Elekta Synergy linac and Oncentra External Beam planning system used in this study. KW - Adolescent KW - Child KW - Child, Preschool KW - Ependymoma/radiotherapy KW - Humans KW - Infant KW - Neoplasms, Radiation-Induced KW - Neoplasms, Second Primary KW - Particle Accelerators KW - Radiotherapy Dosage KW - Radiotherapy Planning, Computer-Assisted KW - Radiotherapy, Intensity-Modulated KW - Retrospective Studies Y1 - 2018 U6 - https://doi.org/10.1002/acm2.12438 VL - 19 IS - 5 SP - 632 EP - 639 PB - Wiley ER - TY - CHAP A1 - Anderson, Philip ED - Haker, Hille ED - Greening, Molly T1 - Unaccompanied Refugee Children and Adolescents and Access to Vocational Training in Germany – with a Focus on Bavaria (Loyola University) T2 - Unaccompanied migrant children KW - Unaccompanied immigrant children Y1 - 2019 SN - 978-1-4985-7454-9 SP - 63 EP - 74 PB - Lexington Books CY - Lanham; Boulder; New York ER - TY - JOUR A1 - Anderson, Philip T1 - Vocational Training and Therapeutic Care of Young Asylum Seekers and Refugees in Germany JF - Rajagiri Journal of Social Development N2 - Against the background of the huge rise in the number of asylum seekers and refugees absorbed into German society over the last couple of years this article examines the innovative Bavarian programme of preparatory classes for asylum seekers between 16 and 21 years of age. The challenges faced by educational and social work professionals working with this target group are documented alongside the particular resources which these highly-motivated young people as a rule bring with them. Specific requirements for psychotherapy professionals are addressed as well as a range of recommendations formulated by the author to enable the longer-term success of this vocational training programme in integrating these young people into the German educational and employment system. It has become apparent that a holistic approach to the lives of the target group by professionals in education, social work and therapy is necessary to enable young asylums seekers to complete vocational training successfully. Transitional management is a key part of the process of setting asylum seekers on the path to an apprenticeship. Coordination with the Labour Office, local authority administration and local decision-makers are further parts of the equation. This must intermesh with civil society engagement to provide the maximum use of resources giving young refugees access to training, the labour market  and long term integration into German life. KW - social work KW - education KW - refugees KW - trauma therapy KW - vocational training Y1 - 2017 UR - http://journals.rajagiri.edu/index.php/rssJ/article/download/81/71/ VL - 8 IS - 2 SP - 111 EP - 128 PB - OJS/PKP ER - TY - JOUR A1 - Arribas, Julia A1 - Antonelli, Giulio A1 - Frazzoni, Leonardo A1 - Fuccio, Lorenzo A1 - Ebigbo, Alanna A1 - van der Sommen, Fons A1 - Ghatwary, Noha A1 - Palm, Christoph A1 - Coimbra, Miguel A1 - Renna, Francesco A1 - Bergman, Jacques J.G.H.M. A1 - Sharma, Prateek A1 - Messmann, Helmut A1 - Hassan, Cesare A1 - Dinis-Ribeiro, Mario J. T1 - Standalone performance of artificial intelligence for upper GI neoplasia: a meta-analysis JF - Gut N2 - Objective: Artificial intelligence (AI) may reduce underdiagnosed or overlooked upper GI (UGI) neoplastic and preneoplastic conditions, due to subtle appearance and low disease prevalence. Only disease-specific AI performances have been reported, generating uncertainty on its clinical value. Design: We searched PubMed, Embase and Scopus until July 2020, for studies on the diagnostic performance of AI in detection and characterisation of UGI lesions. Primary outcomes were pooled diagnostic accuracy, sensitivity and specificity of AI. Secondary outcomes were pooled positive (PPV) and negative (NPV) predictive values. We calculated pooled proportion rates (%), designed summary receiving operating characteristic curves with respective area under the curves (AUCs) and performed metaregression and sensitivity analysis. Results: Overall, 19 studies on detection of oesophageal squamous cell neoplasia (ESCN) or Barrett's esophagus-related neoplasia (BERN) or gastric adenocarcinoma (GCA) were included with 218, 445, 453 patients and 7976, 2340, 13 562 images, respectively. AI-sensitivity/specificity/PPV/NPV/positive likelihood ratio/negative likelihood ratio for UGI neoplasia detection were 90% (CI 85% to 94%)/89% (CI 85% to 92%)/87% (CI 83% to 91%)/91% (CI 87% to 94%)/8.2 (CI 5.7 to 11.7)/0.111 (CI 0.071 to 0.175), respectively, with an overall AUC of 0.95 (CI 0.93 to 0.97). No difference in AI performance across ESCN, BERN and GCA was found, AUC being 0.94 (CI 0.52 to 0.99), 0.96 (CI 0.95 to 0.98), 0.93 (CI 0.83 to 0.99), respectively. Overall, study quality was low, with high risk of selection bias. No significant publication bias was found. Conclusion: We found a high overall AI accuracy for the diagnosis of any neoplastic lesion of the UGI tract that was independent of the underlying condition. This may be expected to substantially reduce the miss rate of precancerous lesions and early cancer when implemented in clinical practice. KW - Artificial Intelligence Y1 - 2021 U6 - https://doi.org/10.1136/gutjnl-2020-321922 VL - 70 IS - 8 SP - 1458 EP - 1468 PB - BMJ CY - London ER - TY - CHAP A1 - Auer, Simon A1 - Kubowitsch, Simone A1 - Krutsch, Werner A1 - Renkawitz, Tobias A1 - Süß, Franz A1 - Dendorfer, Sebastian T1 - Effect of mental demand on knee forces in professional youth soccer players T2 - ISBS Proceedings Archive N2 - Soccer is one of the most popular sports all around the world. It is an injurious type of sport with a focus on lower extremities and high psychological pressure during matches. The stressor is linked with injuries and an increased musculoskeletal loading. This study investigates the influence of cognitive stress on the load profile of the knee joint. Twelve professional youth soccer players performed highly dynamic runs with and without additional cognitive stress. The runs were analysed with a musculoskeletal simulation software. The data analysis shows no difference in knee joint reaction loading under additional mental stress compared to the baseline. Yet running times are significantly lower in the baseline. While there is no increase in the joint loads, the running times indicate an altered movement behaviour when the subjects are exposed to additional mental demand. KW - Kniegelenk KW - Körperliche Belastung KW - Stress KW - Computersimulation Y1 - 2020 UR - https://commons.nmu.edu/isbs/vol38/iss1/28 VL - 38 IS - 1, Art. 28 ER - TY - JOUR A1 - Auer, Simon A1 - Kurbowitsch, Simone A1 - Süß, Franz A1 - Renkawitz, Tobias A1 - Krutsch, Werner A1 - Dendorfer, Sebastian T1 - Mental stress reduces performance and changes musculoskeletal loading in football-related movements JF - Science and Medicine in Football N2 - Purpose: Football players have a high risk of leg muscle injuries, especially when exposed to mental stress. Hence, this study investigated the musculoskeletal response of elite youth football players during highly dynamic movements under stress. The hypothesis is that mental stress reduces performance and changes the muscular forces exerted. Materials & methods: Twelve elite youth football players were subjected to mental stress while performing sports-specific change-of-direction movements. A modified version of the d2 attention test was used as stressor. The kinetics are computed using inverse dynamics. Running times and exerted forces of injury-prone muscles were analysed. Results: The stressor runs were rated more mentally demanding by the players (p = 0.006, rs = 0.37) with unchanged physical demand (p = 0.777, rs = 0.45). This resulted in 10% longer running times under stress (p < 0.001, d = −1.62). The musculoskeletal analysis revealed higher peak muscle forces under mental stress for some players but not for others. Discussion: The study shows that motion capture combined with musculoskeletal computation is suitable to analyse the effects of stress on athletes in highly dynamic movements. For the first time in football medicine, our data quantifies an association between mental stress with reduced football players’ performance and changes in muscle force. KW - Biomechanics KW - muscle injury KW - attention KW - musculoskeletal simulation Y1 - 2020 U6 - https://doi.org/10.1080/24733938.2020.1860253 VL - 5 IS - 4 SP - 323 EP - 329 PB - Taylor & Francis ER - TY - JOUR A1 - Auer, Simon A1 - Schiebl, Jonas A1 - Iversen, Kristoffer A1 - Subhash Chander, Divyaksh A1 - Damsgaard, Michael A1 - Dendorfer, Sebastian T1 - Biomechanical assessment of the design and efficiency of occupational exoskeletons with the AnyBody Modeling System JF - Zeitschrift für Arbeitswissenschaften N2 - Exoskeletons were invented over 100 years ago but have only become popular in the last two decades, especially in the working industry as they can decrease work-related loads significantly. The most often used exoskeletons are for the lower back and shoulder since these are commonly affected body regions. All devices have in common that their purpose is to reduce internal loads of vulnerable body regions. Nevertheless, there is still little understanding on how biomechanical loading in the human body changes when exoskeletons are used. Therefore, further analyses are needed. A promising candidate for these are musculoskeletal models, which are based on an inverse dynamics approach and can calculate external parameters such as ground reaction forces or other interaction forces as well as internal parameters such as joint reaction forces or muscle activities. The various examples in the literature show that these models are increasingly used for assessing the biomechanical effects of exoskeletons on the human body. Furthermore, musculoskeletal models can calculate biomechanical loadings of humans with and without exoskeletons for all kinds of applications and allow an evaluation of their purpose. Practical Relevance: This article highlights the possibilities of musculoskeletal models for assessing the design and efficiency of occupational exoskeletons. Several practical use cases are described along with distinct descriptions of common implications of musculoskeletal and exoskeleton modeling. KW - Biomechanics KW - Ergonomics KW - Motion capture KW - Inverse dynamics Y1 - 2022 U6 - https://doi.org/10.1007/s41449-022-00336-4 N1 - Corresponding author: Sebastian Dendorfer VL - 76 IS - 4 SP - 440 EP - 449 PB - Springer Nature ER - TY - JOUR A1 - Aurbach, Maximilian A1 - Spicka, Jan A1 - Süß, Franz A1 - Dendorfer, Sebastian T1 - Evaluation of musculoskeletal modelling parameters of the shoulder complex during humeral abduction above 90° JF - Journal of Biomechanics N2 - Based on electromyographic data and force measurements within the shoulder joint, there is an indication that muscle and resulting joint reaction forces keep increasing over an abduction angle of 90°. In inverse dynamics models, no single parameter could be attributed to simulate this force behaviour accordingly. The aim of this work is to implement kinematic, kinetic and muscle model modifications to an existing model of the shoulder (AnyBody™) and assess their single and combined effects during abduction up to 140° humeral elevation. The kinematics and the EMG activity of 10 test subjects were measured during humeral abduction. Six modifications were implemented in the model: alternative wrapping of the virtual deltoid muscle elements, utilization of a three element Hill model, strength scaling, motion capture driven clavicle elevation/protraction, translation of the GH joint in dependency of the acting forces and an alteration of the scapula/clavicle rhythm. From the six modifications, 16 different combinations were considered. Parameter combinations with the Hill model changed the resultant GH joint reaction force and led to an increase in force during abduction of the humerus above 90°. Under the premise of muscle activities and forces within the GH joint rising after 90° of humeral abduction, we propose that the Hill type muscle model is a crucial parameter for accurately modelling the shoulder. Furthermore, the outcome of this study indicates that the Hill model induces the co-contraction of the muscles of the shoulder without the need of an additional stability criterion for an inverse dynamics approach. KW - Shoulder joint KW - Musculoskeletal modelling KW - EMG KW - Glenohumeral joint reaction force KW - Muscle model KW - Schultergelenk KW - Bewegungsapparat KW - Biomechanik KW - Simulation Y1 - 2020 U6 - https://doi.org/10.1016/j.jbiomech.2020.109817 VL - 106 IS - June PB - Elsevier ER - TY - JOUR A1 - Aurbach, Maximilian A1 - Špička, Jan A1 - Süß, Franz A1 - Vychytil, J. A1 - Havelková, Leonard A1 - Ryba, T. A1 - Dendorfer, Sebastian T1 - Torus obstacle method as a wrapping approach of the deltoid muscle group for humeral abduction in musculoskeletal simulation JF - Journal of Biomechanics N2 - Musculoskeletal models of the shoulder complex are valuable research aids to investigate tears of the supraspinatus and the resulting mechanical impact during abduction of the humerus. One of the major contributors to this motion is the deltoid muscle group and for this, an accurate modeling of the lines of action is indispensable. The aim of this work was to utilize a torus obstacle wrapping approach for the deltoids of an existing shoulder model and assess the feasibility of the approach during humeral abduction. The shoulder model from the AnyBody™ modeling system was used as a platform. The size of the tori is based on a magnetic resonance imaging (MRI) approach and several kinematic couplings are implemented to determine the trajectories of the tori during abduction. To assess the model behavior, the moment arms of the virtual muscle elements and the resultant glenohumeral joint reaction force (GHJF) were compared with reference data from the literature during abduction of the humerus in the range 20°–120°. The root mean square error for the anterior, lateral and posterior part between the simulated muscle elements and reference data from the literature was 3.9, 1.7 and 5.8 mm, respectively. The largest deviation occurred on the outer elements of the muscle groups, with 12.6, 10.4 and 20.5 mm, respectively. During abduction, there is no overlapping of the muscle elements and these are in continuous contact with the torus obstacles, thus enabling a continuous force transmission. This results in a rising trend of the resultant GHJF. The torus obstacle approach as a wrapping method for the deltoid muscles provides a guided muscle pathing by simultaneously approximating the curvature of the deltoid muscle. The results from the comparison of the simulated moment arms and the resultant GHJF are in accordance with those in the literature in the range 20°–120° of abduction. Although this study shows the strength of the torus obstacle as a wrapping approach, the method of fitting the tori according to MRI data was not suitable. A cadaver study is recommended to better validate and mathematically describe the torus approach. KW - Muscoloskeletal model KW - AnyBody Modeling System KW - MRI KW - Shoulder joint complex KW - Muscle trajectory KW - Torus KW - Wrapping Y1 - 2020 U6 - https://doi.org/10.1016/j.jbiomech.2020.109864 VL - 109 IS - August PB - Elsevier ER - TY - JOUR A1 - Axer, Markus A1 - Amunts, Katrin A1 - Gräßel, David A1 - Palm, Christoph A1 - Dammers, Jürgen A1 - Axer, Hubertus A1 - Pietrzyk, Uwe A1 - Zilles, Karl T1 - Novel Approach to the Human Connectome BT - Ultra-High Resolution Mapping of Fiber Tracts in the Brain JF - NeuroImage N2 - Signal transmission between different brain regions requires connecting fiber tracts, the structural basis of the human connectome. In contrast to animal brains, where a multitude of tract tracing methods can be used, magnetic resonance (MR)-based diffusion imaging is presently the only promising approach to study fiber tracts between specific human brain regions. However, this procedure has various inherent restrictions caused by its relatively low spatial resolution. Here, we introduce 3D-polarized light imaging (3D-PLI) to map the three-dimensional course of fiber tracts in the human brain with a resolution at a submillimeter scale based on a voxel size of 100 μm isotropic or less. 3D-PLI demonstrates nerve fibers by utilizing their intrinsic birefringence of myelin sheaths surrounding axons. This optical method enables the demonstration of 3D fiber orientations in serial microtome sections of entire human brains. Examples for the feasibility of this novel approach are given here. 3D-PLI enables the study of brain regions of intense fiber crossing in unprecedented detail, and provides an independent evaluation of fiber tracts derived from diffusion imaging data. KW - Connectome KW - Human brain KW - Method KW - Polarized light imaging KW - Tractography KW - Systems biology KW - Bildgebendes Verfahren KW - Dreidimensionale Bildverarbeitung KW - Polarisiertes Licht KW - Gehirnkarte Y1 - 2011 U6 - https://doi.org/10.1016/j.neuroimage.2010.08.075 VL - 54 IS - 2 SP - 1091 EP - 1101 ER - TY - JOUR A1 - Baldwin, Andrew A1 - Hartl, Maximilian A1 - Tschaikowsky, Mathaeus A1 - Balzer, Bizan N. A1 - Booth, Brian W. T1 - Degradation and release of tannic acid from an injectable tissue regeneration bead matrix in vivo JF - Journal of biomedical materials research, part B - Applied Biomaterials N2 - The development of multifunctional biomaterials as both tissue regeneration and drug delivery devices is currently a major focus in biomedical research. Tannic Acid (TA), a naturally occurring plant polyphenol, displays unique medicinal abilities as an antioxidant, an antibiotic, and as an anticancer agent. TA has applications in biomaterials acting as a crosslinker in polymer hydrogels improving thermal stability and mechanical properties. We have developed injectable cell seeded collagen beads crosslinked with TA for breast reconstruction and anticancer activity following lumpectomy. This study determined the longevity of the bead implants by establishing a degradation time line and TA release profile in vivo. Beads crosslinked with 0.1% TA and 1% TA were compared to observe the differences in TA concentration on degradation and release. We found collagen/TA beads degrade at similar rates in vivo, yet are resistant to complete degradation after 16 weeks. TA is released over time in vivo through diffusion and cellular activity. Changes in mechanical properties in collagen/TA beads before implantation to after 8 weeks in vivo also indicate loss of TA over a longer period of time. Elastic moduli decreased uniformly in both 0.1% and 1% TA beads. This study establishes that collagen/TA materials can act as a drug delivery system, rapidly releasing TA within the first week following implantation. However, the beads retain TA long term allowing them to resist degradation and remain in situ acting as a cell scaffold and tissue filler. This confirms its potential use as an anticancer and minimally invasive breast reconstructive device following lumpectomy. KW - Antioxidant KW - APOPTOSIS KW - biomaterial KW - cancer KW - Cancer-cells KW - collagen KW - EARLY OSTEOARTHRITIS KW - HYDROGELS KW - IMMEDIATE BREAST RECONSTRUCTION KW - MECHANICAL PROPERTIES KW - MEDICINAL PLANTS KW - POLYPHENOLS KW - tannic acid KW - tissue regeneration Y1 - 2021 U6 - https://doi.org/10.1002/jbm.b.34990 SN - 1552-4981 VL - 110 IS - 5 SP - 1165 EP - 1177 PB - Wiley ER - TY - JOUR A1 - Bartsch, Alexander A1 - Beham, Daniela A1 - Gebhardt, Jakob A1 - Ehrlich, Ingo A1 - Schratzenstaller, Thomas A1 - Monkman, Gareth J. T1 - Mechanical Properties of NdPrFeB Based Magnetoactive Bisphenol-Free Boron-Silicate Polymers JF - Journal of Nanomedicine and Nanotechnology N2 - Following a ban on many materials containing bisphenol-A, new bisphenol-free Boron silicates have been found as substitutes. The purpose of this study is to describe the mechanical properties of these bisphenol-free magnetoactive borosilicate polymers containing hard magnetic particles. Samples of 0%, 33% and 66% by wt. were loaded for compression using a universal testing machine. The maximum forces occurring for different travel speeds were compared before and after post-magnetization treatments. The post-magnetization included 2 stages. In addition, the change in mechanical properties within 24 hours after the post-magnetization process was investigated. Furthermore, the influence of speed and particle content were investigated. In general, there is a correlation between the required compressive force and, the level of post-magnetization stress, the increase in travel speed and particle content in the boron silicate. Comparison of the non-post-magnetized and post-magnetized samples using two-tailed t-tests shows that the p-values for all weight fraction changes in NdPrFeB particles and travel speeds are less than 0.001. Also, a comparison between tests in which the traverse speed was varied also showed significant changes in the resulting compression forces. The same is valid for changes in the weight ratio of the NdPrFeB particles in the samples. For post-magnetized samples, no significant difference can be observed in the first 24 hours following magnetization. In summary, the material presents viscoelastic, plastic force-displacement behavior, which can be well recognized by its bi-linear curve shape. The investigation shows that borosilicate polymers based on NdPrFeB can have their mechanical behavior modified and controlled by post-magnetization processes. This opens new possibilities for many future applications. Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-67425 UR - https://www.walshmedicalmedia.com/open-access/mechanical-properties-of-ndprfeb-based-magnetoactive-bisphenolfree-boronsilicate-polymers-124385.html SN - 2157-7439 N1 - Corresponding author: Alexander Bartsch VL - 14 IS - 6 PB - Walsh Medical Media ER - TY - JOUR A1 - Becker, Johanna Sabine A1 - Matusch, Andreas A1 - Becker, Julia Susanne A1 - Wu, Bei A1 - Palm, Christoph A1 - Becker, Albert Johann A1 - Salber, Dagmar T1 - Mass spectrometric imaging (MSI) of metals using advanced BrainMet techniques for biomedical research JF - International Journal of Mass Spectrometry N2 - Mass spectrometric imaging (MSI) is a young innovative analytical technique and combines different fields of advanced mass spectrometry and biomedical research with the aim to provide maps of elements and molecules, complexes or fragments. Especially essential metals such as zinc, copper, iron and manganese play a functional role in signaling, metabolism and homeostasis of the cell. Due to the high degree of spatial organization of metals in biological systems their distribution analysis is of key interest in life sciences. We have developed analytical techniques termed BrainMet using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) imaging to measure the distribution of trace metals in biological tissues for biomedical research and feasibility studies—including bioaccumulation and bioavailability studies, ecological risk assessment and toxicity studies in humans and other organisms. The analytical BrainMet techniques provide quantitative images of metal distributions in brain tissue slices which can be combined with other imaging modalities such as photomicrography of native or processed tissue (histochemistry, immunostaining) and autoradiography or with in vivo techniques such as positron emission tomography or magnetic resonance tomography. Prospective and instrumental developments will be discussed concerning the development of the metalloprotein microscopy using a laser microdissection (LMD) apparatus for specific sample introduction into an inductively coupled plasma mass spectrometer (LMD-ICP-MS) or an application of the near field effect in LA-ICP-MS (NF-LA-ICP-MS). These nano-scale mass spectrometric techniques provide improved spatial resolution down to the single cell level. KW - Bioimaging KW - Brain tissue KW - Laser ablation inductively coupled plasma mass spectrometry KW - Laser microdissection inductively coupled plasma mass spectrometry KW - Metals KW - Metallomics KW - Nano-LA-ICP-MS KW - Tumour KW - Massenspektrometrie KW - Bildgebendes Verfahren KW - Metalle KW - Metallproteide KW - Gehirn Y1 - 2011 U6 - https://doi.org/10.1016/j.ijms.2011.01.015 VL - 307 IS - 1-3 SP - 3 EP - 15 PB - eLSEVIER CY - Elsevier ER - TY - JOUR A1 - Becker, Johanna Sabine A1 - Matusch, Andreas A1 - Palm, Christoph A1 - Salber, Dagmar A1 - Morton, Kathryn A. A1 - Becker, Julia Susanne T1 - Bioimaging of metals in brain tissue by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and metallomics JF - Metallomics N2 - Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been developed and established as an emerging technique in the generation of quantitative images of metal distributions in thin tissue sections of brain samples (such as human, rat and mouse brain), with applications in research related to neurodegenerative disorders. A new analytical protocol is described which includes sample preparation by cryo-cutting of thin tissue sections and matrix-matched laboratory standards, mass spectrometric measurements, data acquisition, and quantitative analysis. Specific examples of the bioimaging of metal distributions in normal rodent brains are provided. Differences to the normal were assessed in a Parkinson’s disease and a stroke brain model. Furthermore, changes during normal aging were studied. Powerful analytical techniques are also required for the determination and characterization of metal-containing proteins within a large pool of proteins, e.g., after denaturing or non-denaturing electrophoretic separation of proteins in one-dimensional and two-dimensional gels. LA-ICP-MS can be employed to detect metalloproteins in protein bands or spots separated after gel electrophoresis. MALDI-MS can then be used to identify specific metal-containing proteins in these bands or spots. The combination of these techniques is described in the second section. KW - ICP-Massenspektrometrie KW - Metalle KW - Metallproteide KW - Elektrophorese KW - Gehirn Y1 - 2010 U6 - https://doi.org/10.1039/b916722f IS - 2 SP - 104 EP - 111 PB - Oxford Academic Press ER - TY - JOUR A1 - Belli, Renan A1 - Kreppel, Stefan A1 - Petschelt, Anselm A1 - Hornberger, Helga A1 - Boccaccini, Aldo R. A1 - Lohbauer, Ulrich T1 - Strengthening of dental adhesives via particle reinforcement JF - Journal of the Mechanical Behavior of Biomedical Materials N2 - The bond between methacrylic polymer adhesives and dental restoratives is not perfect and may fail either in the short or in the long term. This study aims to evaluate the effects of particle incorporation in a self-etch model adhesive on mechanical and physical properties that are relevant during application and service. Filled adhesives containing 5, 10, 15 or 25 wt% glass fillers were compared to their unfilled counterpart in terms of water sorption and solubility; viscosity and dynamic viscosity during polymerization were recorded using rheological measurements and compared to FTIR analysis of the real-time degree of cure. Elastic modulus and ultimate tensile strength measurements were performed in uniaxial tension; the energy to fracture was used to calculate the fracture toughness of the adhesives. Finally, the experimental adhesives were applied on dentin substrate to test the bond strength using the microtensile test. Results showed that the incorporation of 5–10 wt% nanofiller to self-etching dental adhesives is efficient in accelerating the polymerization reaction and increasing the degree of cure without compromising the film viscosity for good wettability or water sorption and solubility. Fillers increased the elastic modulus, tensile strength and fracture toughness to a plateau between 5 and 15 wt% filler concentration, and despite the tendency to form agglomerations, active crack pinning/deflection toughening mechanisms have been observed. The bond strength between resin composite and dentin was also improved when adhesives with up to 10 wt% fillers were used, with no additional improvements with further packing. The use of fillers to reinforce dental adhesives may therefore be of great practical benefit by improving curing and mechanical properties. KW - Nanoparticles KW - Bond strength KW - Elasticity KW - Adhesives KW - Dentin Y1 - 2014 U6 - https://doi.org/10.1016/j.jmbbm.2014.05.007 VL - 37 IS - 9 SP - 100 EP - 108 ER - TY - JOUR A1 - Bender, Guzide A1 - Fahrioglu Yamaci, Rezan A1 - Taneri, Bahar T1 - CRISPR and KRAS: a match yet to be made JF - Journal of biomedical science N2 - CRISPR (clustered regularly interspaced short palindromic repeats) systems are one of the most fascinating tools of the current era in molecular biotechnology. With the ease that they provide in genome editing, CRISPR systems generate broad opportunities for targeting mutations. Specifically in recent years, disease-causing mutations targeted by the CRISPR systems have been of main research interest; particularly for those diseases where there is no current cure, including cancer. KRAS mutations remain untargetable in cancer. Mutations in this oncogene are main drivers in common cancers, including lung, colorectal and pancreatic cancers, which are severe causes of public health burden and mortality worldwide, with no cure at hand. CRISPR systems provide an opportunity for targeting cancer causing mutations. In this review, we highlight the work published on CRISPR applications targeting KRAS mutations directly, as well as CRISPR applications targeting mutations in KRAS-related molecules. In specific, we focus on lung, colorectal and pancreatic cancers. To date, the limited literature on CRISPR applications targeting KRAS, reflect promising results. Namely, direct targeting of mutant KRAS variants using various CRISPR systems resulted in significant decrease in cell viability and proliferation in vitro, as well as tumor growth inhibition in vivo. In addition, the effect of mutant KRAS knockdown, via CRISPR, has been observed to exert regulatory effects on the downstream molecules including PI3K, ERK, Akt, Stat3, and c-myc. Molecules in the KRAS pathway have been subjected to CRISPR applications more often than KRAS itself. The aim of using CRISPR systems in these studies was mainly to analyze the therapeutic potential of possible downstream and upstream effectors of KRAS, as well as to discover further potential molecules. Although there have been molecules identified to have such potential in treatment of KRAS-driven cancers, a substantial amount of effort is still needed to establish treatment strategies based on these discoveries. We conclude that, at this point in time, despite being such a powerful directed genome editing tool, CRISPR remains to be underutilized for targeting KRAS mutations in cancer. Efforts channelled in this direction, might pave the way in solving the long-standing challenge of targeting the KRAS mutations in cancers. KW - Animals KW - Clustered Regularly Interspaced Short Palindromic Repeats KW - Humans KW - Mice KW - Mutation KW - Proto-Oncogene Proteins p21(ras)/therapeutic use Y1 - 2021 U6 - https://doi.org/10.1186/s12929-021-00772-0 VL - 28 SP - 1 EP - 25 PB - Springer Nature ER - TY - JOUR A1 - Birkenmaier, Clemens A1 - Dornia, Christian A1 - Lehle, Karla A1 - Müller, Thomas A1 - Gruber, Michael Andreas A1 - Philipp, Alois A1 - Krenkel, Lars T1 - Analysis of Thrombotic Deposits in Extracorporeal Membrane Oxygenators by High-resolution Microcomputed Tomography: A Feasibility Study JF - ASAIO Journal / American Society for Artificial Internal Organs N2 - Coagulative disorders, especially clotting during extracorporeal membrane oxygenation, are frequent complications. Direct visualization and analysis of deposits in membrane oxygenators using computed tomography (CT) may provide an insight into the underlying mechanisms causing thrombotic events. However, the already established multidetector CT1 (MDCT) method shows major limitations. Here, we demonstrate the feasibility of applying industrial micro-CT (μCT) to circumvent these restrictions. Three clinically used membrane oxygenators were investigated applying both MDCT and μCT. The scans were analyzed in terms of clot volume and local clot distribution. As validation, the clot volume was also determined from the fluid volume, which could be filled into the respective used oxygenator compared to a new device. In addition, cross-sectional CT images were compared with crosscut oxygenators. Based on the μCT findings, a morphological measure (sphericity) for assessing clot structures in membrane oxygenators is introduced. Furthermore, by comparing MDCT and μCT results, an augmentation of the MDCT method is proposed, which allows for improved clot volume determination in a clinical setting. Y1 - 2020 U6 - https://doi.org/10.1097/MAT.0000000000001089 SN - 1538-943X VL - 66 IS - 8 SP - 922 EP - 928 PB - Lippincott Williams & Wilkins ER -