46 results on '"Alexander Berg"'
Search Results
2. Fertility-preserving myeloablative conditioning using single-dose CD117 antibody-drug conjugate in a rhesus gene therapy model
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Naoya Uchida, Ulana Stasula, Selami Demirci, Paula Germino-Watnick, Malikiya Hinds, Anh Le, Rebecca Chu, Alexander Berg, Xiong Liu, Ling Su, Xiaolin Wu, Allen E. Krouse, N. Seth Linde, Aylin Bonifacino, So Gun Hong, Cynthia E. Dunbar, Leanne Lanieri, Anjali Bhat, Rahul Palchaudhuri, Bindu Bennet, Megan Hoban, Kirk Bertelsen, Lisa M. Olson, Robert E. Donahue, and John F. Tisdale
- Subjects
Science - Abstract
Abstract Hematopoietic stem cell (HSC) gene therapy has curative potential; however, its use is limited by the morbidity and mortality associated with current chemotherapy-based conditioning. Targeted conditioning using antibody-drug conjugates (ADC) holds promise for reduced toxicity in HSC gene therapy. Here we test the ability of an antibody-drug conjugate targeting CD117 (CD117-ADC) to enable engraftment in a non-human primate lentiviral gene therapy model of hemoglobinopathies. Following single-dose CD117-ADC, a >99% depletion of bone marrow CD34 + CD90 + CD45RA- cells without lymphocyte reduction is observed, which results are not inferior to multi-day myeloablative busulfan conditioning. CD117-ADC, similarly to busulfan, allows efficient engraftment, gene marking, and vector-derived fetal hemoglobin induction. Importantly, ADC treatment is associated with minimal toxicity, and CD117-ADC-conditioned animals maintain fertility. In contrast, busulfan treatment commonly causes severe toxicities and infertility in humans. Thus, the myeloablative capacity of single-dose CD117-ADC is sufficient for efficient engraftment of gene-modified HSCs while preserving fertility and reducing adverse effects related to toxicity in non-human primates. This targeted conditioning approach thus provides the proof-of-principle to improve risk-benefit ratio in a variety of HSC-based gene therapy products in humans.
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- 2023
- Full Text
- View/download PDF
3. Kommission für forschungsnahe Dienste
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Alexander Berg-Weiß, Elke Bongartz, Sibylle Hermann, Miriam Kötter, Caroline Leiß, and Christoph Müller
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Forschungsnahe Dienste ,VDB-Kommissionen ,Jahresbericht ,Bibliography. Library science. Information resources - Published
- 2023
- Full Text
- View/download PDF
4. Sputum lipoarabinomannan (LAM) as a biomarker to determine sputum mycobacterial load: exploratory and model-based analyses of integrated data from four cohorts
- Author
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Aksana Jones, Jay Saini, Belinda Kriel, Laura E. Via, Yin Cai, Devon Allies, Debra Hanna, David Hermann, Andre G. Loxton, Gerhard Walzl, Andreas H. Diacon, Klaus Romero, Ryo Higashiyama, Yongge Liu, and Alexander Berg
- Subjects
Tuberculosis ,Lipoarabinomannan ,LAM ,Biomarker ,Mycobacterium ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Despite the high global disease burden of tuberculosis (TB), the disease caused by Mycobacterium tuberculosis (Mtb) infection, novel treatments remain an urgent medical need. Development efforts continue to be hampered by the reliance on culture-based methods, which often take weeks to obtain due to the slow growth rate of Mtb. The availability of a “real-time” measure of treatment efficacy could accelerate TB drug development. Sputum lipoarabinomannan (LAM; an Mtb cell wall glycolipid) has promise as a pharmacodynamic biomarker of mycobacterial sputum load. Methods The present analysis evaluates LAM as a surrogate for Mtb burden in the sputum samples from 4 cohorts of a total of 776 participants. These include those from 2 cohorts of 558 non-TB and TB participants prior to the initiation of treatment (558 sputum samples), 1 cohort of 178 TB patients under a 14-day bactericidal activity trial with various mono- or multi-TB drug therapies, and 1 cohort of 40 TB patients with data from the first 56-day treatment of a standard 4-drug regimen. Results Regression analysis demonstrated that LAM was a predictor of colony-forming unit (CFU)/mL values obtained from the 14-day treatment cohort, with well-estimated model parameters (relative standard error ≤ 22.2%). Moreover, no changes in the relationship between LAM and CFU/mL were observed across the different treatments, suggesting that sputum LAM can be used to reasonably estimate the CFU/mL in the presence of treatment. The integrated analysis showed that sputum LAM also appears to be as good a predictor of time to Mycobacteria Growth Incubator Tube (MGIT) positivity as CFU/mL. As a binary readout, sputum LAM positivity is a strong predictor of solid media or MGIT culture positivity with an area-under-the-curve value of 0.979 and 0.976, respectively, from receiver-operator curve analysis. Conclusions Our results indicate that sputum LAM performs as a pharmacodynamic biomarker for rapid measurement of Mtb burden in sputum, and thereby may enable more efficient early phase clinical trial designs (e.g., adaptive designs) to compare candidate anti-TB regimens and streamline dose selection for use in pivotal trials. Trial registration NexGen EBA study (NCT02371681)
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- 2022
- Full Text
- View/download PDF
5. Development of physiologically‐based pharmacokinetic models for standard of care and newer tuberculosis drugs
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Helen Humphries, Lisa Almond, Alexander Berg, Iain Gardner, Oliver Hatley, Xian Pan, Ben Small, Mian Zhang, Masoud Jamei, and Klaus Romero
- Subjects
Therapeutics. Pharmacology ,RM1-950 - Abstract
Abstract Tuberculosis (TB) remains a global health problem and there is an ongoing effort to develop more effective therapies and new combination regimes that can reduce duration of treatment. The purpose of this study was to demonstrate utility of a physiologically‐based pharmacokinetic modeling approach to predict plasma and lung concentrations of 11 compounds used or under development as TB therapies (bedaquiline [and N‐desmethyl bedaquiline], clofazimine, cycloserine, ethambutol, ethionamide, isoniazid, kanamycin, linezolid, pyrazinamide, rifampicin, and rifapentine). Model accuracy was assessed by comparison of simulated plasma pharmacokinetic parameters with healthy volunteer data for compounds administered alone or in combination. Eighty‐four percent (area under the curve [AUC]) and 91% (maximum concentration [Cmax]) of simulated mean values were within 1.5‐fold of the observed data and the simulated drug‐drug interaction ratios were within 1.5‐fold (AUC) and twofold (Cmax) of the observed data for nine (AUC) and eight (Cmax) of the 10 cases. Following satisfactory recovery of plasma concentrations in healthy volunteers, model accuracy was assessed further (where patients’ with TB data were available) by comparing clinical data with simulated lung concentrations (9 compounds) and simulated lung: plasma concentration ratios (7 compounds). The 5th–95th percentiles for the simulated lung concentration data recovered between 13% (isoniazid and pyrazinamide) and 88% (pyrazinamide) of the observed data points (Am J Respir Crit Care Med, 198, 2018, 1208; Nat Med, 21, 2015, 1223; PLoS Med, 16, 2019, e1002773). The impact of uncertain model parameters, such as the fraction of drug unbound in lung tissue mass (fumass), is discussed. Additionally, the variability associated with the patient lung concentration data, which was sparse and included extensive within‐subject, interlaboratory, and experimental variability (as well interindividual variability) is reviewed. All presented models are transparently documented and are available as open‐source to aid further research.
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- 2021
- Full Text
- View/download PDF
6. Potentiale nutzen und Verbindungen herstellen
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Benjamin Auberer, Alexander Berg-Weiß, Vanessa Gabriel, and Martin Spenger
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Fachreferat ,Forschungsdaten ,Forschungsdatenmanagement ,Datenkompetenz ,Data Literacy ,Bibliography. Library science. Information resources - Abstract
In diesem Artikel werden Handlungsoptionen und -spielräume wissenschaftlicher Bibliotheken im Kontext eines sich durch die Digitalisierung verändernden Aufgaben- und Anforderungsspektrums thematisiert. Dieses Themenfeld wird durch die Linse der Berufsgruppe der wissenschaftlichen Bibliothekar*innen bzw. Fachreferent*innen betrachtet. Bestehenden Strukturen, insbesondere den Fachreferaten, kommt in diesem Prozess eine besondere Rolle zu, bieten sie doch Chancen, neue Themen effizient und gezielt an der eigenen Einrichtung einzubinden. Durch die Übernahme neuer Aufgaben durch die Fachreferent*innen besteht jedoch der Bedarf einer Selbstvergewisserung, um adäquat auf neue Situationen reagieren zu können. Anhand des Beispiels Forschungsdatenmanagement (FDM) an der Universitätsbibliothek der LMU (UB der LMU) werden Möglichkeiten aufgezeigt, wie eine Kooperation zwischen FDM-Beratung, Fachreferaten und Forschenden aussehen kann. Welche Rolle spielen dabei Konzepte wie „Embedded Librarian“ oder „Data Literacy“? Und wie können Fachreferent*innen einbezogen werden, um die FDM-Strukturen der eigenen Einrichtung erfolgreich weiterzuentwickeln?
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- 2022
- Full Text
- View/download PDF
7. Openness in Libraries
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Alexander Berg-Weiß, Sibylle Hermann, Miriam Kötter, Caroline Leiß, Christoph Müller, and Annette Strauch-Davey
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Openness ,Change Management ,Open Science ,Research Support Services ,Commission for Research-Related Services ,Bibliography. Library science. Information resources - Published
- 2022
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8. Openness in Bibliotheken
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Alexander Berg-Weiß, Sibylle Hermann, Miriam Kötter, Caroline Leiß, Christoph Müller, and Annette Strauch-Davey
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Openness ,Change Management ,Open Science ,Forschungsnahe Dienste ,Kommission für forschungsnahe Dienste ,Bibliography. Library science. Information resources - Published
- 2022
- Full Text
- View/download PDF
9. Bericht der Kommission für forschungsnahe Dienste 2021
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Alexander Berg-Weiß, Sibylle Hermann, Miriam Kötter, Caroline Leiß, Christoph Müller, and Annette Strauch-Davey
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Forschungsnahe Dienste ,VDB-Kommissionen ,Jahresbericht ,Bibliography. Library science. Information resources - Published
- 2022
- Full Text
- View/download PDF
10. Hollow-fibre system model of tuberculosis reproducibility and performance specifications for best practice in drug and combination therapy development
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Tawanda Gumbo, Shashikant Srivastava, Devyani Deshpande, Jotam G Pasipanodya, Alexander Berg, Klaus Romero, David Hermann, and Debra Hanna
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Pharmacology ,Microbiology (medical) ,Infectious Diseases ,Pharmacology (medical) - Abstract
Background The hollow-fibre system model of tuberculosis (HFS-TB) has been endorsed by regulators; however, application of HFS-TB requires a thorough understanding of intra- and inter-team variability, statistical power and quality controls. Methods Three teams evaluated regimens matching those in the Rapid Evaluation of Moxifloxacin in Tuberculosis (REMoxTB) study, plus two high-dose rifampicin/pyrazinamide/moxifloxacin regimens, administered daily for up to 28 or 56 days against Mycobacterium tuberculosis (Mtb) under log-phase growth, intracellular growth or semidormant growth under acidic conditions. Target inoculum and pharmacokinetic parameters were pre-specified, and the accuracy and bias at achieving these calculated using percent coefficient of variation (%CV) at each sampling point and two-way analysis of variance (ANOVA). Results A total of 10 530 individual drug concentrations, and 1026 individual cfu counts were measured. The accuracy in achieving intended inoculum was >98%, and >88% for pharmacokinetic exposures. The 95% CI for the bias crossed zero in all cases. ANOVA revealed that the team effect accounted for 20% difference in slope, with a power of >99%. Conclusions HFS-TB is a highly tractable tool for choosing combination regimens with little variability between teams, and between replicates.
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- 2023
11. A prognostic classification system for uveal melanoma based on a combination of patient age and sex, the American Joint Committee on Cancer and the Cancer Genome Atlas models
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Viktor T. Gill, Shiva Sabazade, Christina Herrspiegel, Kathryn G. Ewens, Adrianna Opalko, Nicole Dan, Tinna Christersdottir, Alexander Berg Rendahl, Carol L. Shields, Stefan Seregard, Arupa Ganguly, and Gustav Stålhammar
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Ophthalmology ,General Medicine - Abstract
To revisit the independent importance of ciliary body involvement (CBI), monosomy 3 (M3), tumour size, histological and clinical factors in uveal melanoma (UM) and to devise a new prognostic classification based on a combination of the American Joint Committee on Cancer (AJCC) and the Cancer Genome Atlas (TCGA) models.Two cohorts with a total of 1796 patients were included. Clinicopathological factors were compared between patients with and without CBI and M3. Development of the prognostic classification was performed in a training cohort and was then tested in two independent validation cohorts.Tumours with CBI were more common in women, had greater apical thickness, greater basal tumour diameter, greater rates of vasculogenic mimicry and greater rates of M3, were more often asymptomatic at diagnosis and had poorer 5- and 10-year globe conservation rates (p 0.023). In multivariate logistic regression, patient age at diagnosis, tumour diameter and CBI were independent predictors of M3 (p 0.001). In multivariate Cox regression, male sex, age at diagnosis, tumour diameter, M3 and CBI were independent predictors of metastasis. The proposed prognostic classification combined patient age, sex, CBI, extraocular extension, M3, 8q (optional) and tumour size, and demonstrated greater prognostic acumen than both AJCC 4 T categories and TCGA groups A to D in validation cohorts.Tumour size does not confound the prognostic implication of CBI, M3, male sex and age at diagnosis in UM. These factors were included in a new prognostic classification that outperforms AJCC T category and TCGA groups.
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- 2022
12. Development of physiologically‐based pharmacokinetic models for standard of care and newer tuberculosis drugs
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Iain Gardner, Oliver Hatley, Lisa Almond, Ben G Small, Klaus Romero, Mian Zhang, Helen Humphries, Xian Pan, Masoud Jamei, and Alexander Berg
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medicine.medical_specialty ,Antitubercular Agents ,Cmax ,RM1-950 ,Gastroenterology ,Article ,chemistry.chemical_compound ,Pharmacokinetics ,Internal medicine ,Isoniazid ,medicine ,Humans ,Tuberculosis ,Pharmacology (medical) ,Ethambutol ,business.industry ,Research ,Area under the curve ,Standard of Care ,Articles ,Pyrazinamide ,Rifapentine ,chemistry ,Modeling and Simulation ,Ethionamide ,Therapeutics. Pharmacology ,Bedaquiline ,business ,medicine.drug - Abstract
Tuberculosis (TB) remains a global health problem and there is an ongoing effort to develop more effective therapies and new combination regimes that can reduce duration of treatment. The purpose of this study was to demonstrate utility of a physiologically‐based pharmacokinetic modeling approach to predict plasma and lung concentrations of 11 compounds used or under development as TB therapies (bedaquiline [and N‐desmethyl bedaquiline], clofazimine, cycloserine, ethambutol, ethionamide, isoniazid, kanamycin, linezolid, pyrazinamide, rifampicin, and rifapentine). Model accuracy was assessed by comparison of simulated plasma pharmacokinetic parameters with healthy volunteer data for compounds administered alone or in combination. Eighty‐four percent (area under the curve [AUC]) and 91% (maximum concentration [C max]) of simulated mean values were within 1.5‐fold of the observed data and the simulated drug‐drug interaction ratios were within 1.5‐fold (AUC) and twofold (C max) of the observed data for nine (AUC) and eight (C max) of the 10 cases. Following satisfactory recovery of plasma concentrations in healthy volunteers, model accuracy was assessed further (where patients’ with TB data were available) by comparing clinical data with simulated lung concentrations (9 compounds) and simulated lung: plasma concentration ratios (7 compounds). The 5th–95th percentiles for the simulated lung concentration data recovered between 13% (isoniazid and pyrazinamide) and 88% (pyrazinamide) of the observed data points (Am J Respir Crit Care Med, 198, 2018, 1208; Nat Med, 21, 2015, 1223; PLoS Med, 16, 2019, e1002773). The impact of uncertain model parameters, such as the fraction of drug unbound in lung tissue mass (fumass), is discussed. Additionally, the variability associated with the patient lung concentration data, which was sparse and included extensive within‐subject, interlaboratory, and experimental variability (as well interindividual variability) is reviewed. All presented models are transparently documented and are available as open‐source to aid further research.
- Published
- 2021
13. Comparison of the dietary omega-3 fatty acids impact on murine psoriasis-like skin inflammation and associated lipid dysfunction
- Author
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Alexander V. Sorokin, Hildur Arnardottir, Maryia Svirydava, Qimin Ng, Yvonne Baumer, Alexander Berg, Carla J. Pantoja, Elizabeth M. Florida, Heather L. Teague, Zhi-Hong Yang, Pradeep K. Dagur, Tiffany M. Powell-Wiley, Zu-Xi Yu, Martin P. Playford, Alan T. Remaley, and Nehal N. Mehta
- Subjects
Nutrition and Dietetics ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,Molecular Biology ,Biochemistry - Published
- 2023
14. Sputum lipoarabinomannan (LAM) as a biomarker to determine sputum mycobacterial load: exploratory and model-based analyses of integrated data from four cohorts
- Author
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Aksana, Jones, Jay, Saini, Belinda, Kriel, Laura E, Via, Yin, Cai, Devon, Allies, Debra, Hanna, David, Hermann, Andre G, Loxton, Gerhard, Walzl, Andreas H, Diacon, Klaus, Romero, Ryo, Higashiyama, Yongge, Liu, Alexander, Berg, Institute of Infectious Disease and Molecular Medicine, and Faculty of Health Sciences
- Subjects
Lipopolysaccharides ,Infectious Diseases ,Lipoarabinomannan ,Sputum ,Humans ,Tuberculosis ,Mycobacterium tuberculosis ,Biomarker ,LAM ,bacterial infections and mycoses ,Biomarkers ,Mycobacterium - Abstract
Background Despite the high global disease burden of tuberculosis (TB), the disease caused by Mycobacterium tuberculosis (Mtb) infection, novel treatments remain an urgent medical need. Development efforts continue to be hampered by the reliance on culture-based methods, which often take weeks to obtain due to the slow growth rate of Mtb. The availability of a “real-time” measure of treatment efficacy could accelerate TB drug development. Sputum lipoarabinomannan (LAM; an Mtb cell wall glycolipid) has promise as a pharmacodynamic biomarker of mycobacterial sputum load. Methods The present analysis evaluates LAM as a surrogate for Mtb burden in the sputum samples from 4 cohorts of a total of 776 participants. These include those from 2 cohorts of 558 non-TB and TB participants prior to the initiation of treatment (558 sputum samples), 1 cohort of 178 TB patients under a 14-day bactericidal activity trial with various mono- or multi-TB drug therapies, and 1 cohort of 40 TB patients with data from the first 56-day treatment of a standard 4-drug regimen. Results Regression analysis demonstrated that LAM was a predictor of colony-forming unit (CFU)/mL values obtained from the 14-day treatment cohort, with well-estimated model parameters (relative standard error ≤ 22.2%). Moreover, no changes in the relationship between LAM and CFU/mL were observed across the different treatments, suggesting that sputum LAM can be used to reasonably estimate the CFU/mL in the presence of treatment. The integrated analysis showed that sputum LAM also appears to be as good a predictor of time to Mycobacteria Growth Incubator Tube (MGIT) positivity as CFU/mL. As a binary readout, sputum LAM positivity is a strong predictor of solid media or MGIT culture positivity with an area-under-the-curve value of 0.979 and 0.976, respectively, from receiver-operator curve analysis. Conclusions Our results indicate that sputum LAM performs as a pharmacodynamic biomarker for rapid measurement of Mtb burden in sputum, and thereby may enable more efficient early phase clinical trial designs (e.g., adaptive designs) to compare candidate anti-TB regimens and streamline dose selection for use in pivotal trials. Trial registration NexGen EBA study (NCT02371681)
- Published
- 2022
15. Model-Based Meta-Analysis of Relapsing Mouse Model Studies from the Critical Path to Tuberculosis Drug Regimens Initiative Database
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Alexander Berg, James Clary, Debra Hanna, Eric Nuermberger, Anne Lenaerts, Nicole Ammerman, Michelle Ramey, Dan Hartley, David Hermann, and Medical Microbiology & Infectious Diseases
- Subjects
Pharmacology ,Mice ,Infectious Diseases ,SDG 3 - Good Health and Well-being ,Recurrence ,Antitubercular Agents ,Critical Pathways ,Animals ,Tuberculosis ,Pharmacology (medical) ,Mycobacterium tuberculosis - Abstract
Tuberculosis (TB), the disease caused by Mycobacterium tuberculosis (Mtb), remains a leading infectious disease-related cause of death worldwide, necessitating the development of new and improved treatment regimens. Nonclinical evaluation of candidate drug combinations via the relapsing mouse model (RMM) is an important step in regimen development, through which candidate regimens that provide the greatest decrease in the probability of relapse following treatment in mice may be identified for further development. Although RMM studies are a critical tool to evaluate regimen efficacy, making comprehensive "apples to apples" comparisons of regimen performance in the RMM has been a challenge in large part due to the need to evaluate and adjust for variability across studies arising from differences in design and execution. To address this knowledge gap, we performed a model-based meta-analysis on data for 17 unique regimens obtained from a total of 1592 mice across 28 RMM studies. Specifically, a mixed-effects logistic regression model was developed that described the treatment duration- dependent probability of relapse for each regimen and identified relevant covariates contributing to interstudy variability. Using the model, covariate-normalized metrics of interest, namely, treatment duration required to reach 50% and 10% relapse probability, were derived and used to compare relative regimen performance. Overall, the model-based meta-analysis approach presented herein enabled cross-study comparison of efficacy in the RMM and provided a framework whereby data from emerging studies may be analyzed in the context of historical data to aid in selecting candidate drug combinations for clinical evaluation as TB drug regimens.
- Published
- 2022
16. Cohort Profile:COVIDMENT: COVID-19 cohorts on mental health across six nations
- Author
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Unnarsdóttir, Anna Bára, Lovik, Anikó, Fawns-Ritchie, Chloe, Ask, Helga, Kõiv, Kadri, Hagen, Kristen, Didriksen, Maria, Christoffersen, Lea Arregui Nordahl, Garðarsson, Alexander Berg, McIntosh, Andrew, Kähler, Anna K, Campbell, Archie, Hauksdóttir, Arna, Erikstrup, Christian, Mikkelsen, Dorte Helenius, Altschul, Drew, Thordardottir, Edda Bjork, Frans, Emma Maria, Kvale, Gerd, Tómasson, Gunnar, Kariis, Hanna Maria, Jónsdóttir, Harpa Lind, Rúnarsdóttir, Harpa, Magnúsdóttir, Ingibjörg, Eid, Jarle, Jakobsdóttir, Jóhanna, Nielsen, Kaspar René, Kaspersen, Kathrine Agergård, Milani, Lili, Trogstad, Lill-Iren Schou, Yi, Lu, Bruun, Mie Topholm, Sullivan, Patrick F, Magnus, Per Minor, Shen, Qing, Nesvåg, Ragnar, Brandlistuen, Ragnhild E, Mägi, Reedik, Ostrowski, Sisse Rye, Løkhammer, Solveig, Solem, Stian, Reichborn-Kjennerud, Ted, Hansen, Thomas Folkmann, Werge, Thomas, Aspelund, Thor, Porteous, David J, Fang, Fang, Lehto, Kelli, Andreassen, Ole A, Pedersen, Ole Birger Vesterager, Hellard, Stephanie Le, Valdimarsdóttir, Unnur A, Unnarsdóttir, Anna Bára, Lovik, Anikó, Fawns-Ritchie, Chloe, Ask, Helga, Kõiv, Kadri, Hagen, Kristen, Didriksen, Maria, Christoffersen, Lea Arregui Nordahl, Garðarsson, Alexander Berg, McIntosh, Andrew, Kähler, Anna K, Campbell, Archie, Hauksdóttir, Arna, Erikstrup, Christian, Mikkelsen, Dorte Helenius, Altschul, Drew, Thordardottir, Edda Bjork, Frans, Emma Maria, Kvale, Gerd, Tómasson, Gunnar, Kariis, Hanna Maria, Jónsdóttir, Harpa Lind, Rúnarsdóttir, Harpa, Magnúsdóttir, Ingibjörg, Eid, Jarle, Jakobsdóttir, Jóhanna, Nielsen, Kaspar René, Kaspersen, Kathrine Agergård, Milani, Lili, Trogstad, Lill-Iren Schou, Yi, Lu, Bruun, Mie Topholm, Sullivan, Patrick F, Magnus, Per Minor, Shen, Qing, Nesvåg, Ragnar, Brandlistuen, Ragnhild E, Mägi, Reedik, Ostrowski, Sisse Rye, Løkhammer, Solveig, Solem, Stian, Reichborn-Kjennerud, Ted, Hansen, Thomas Folkmann, Werge, Thomas, Aspelund, Thor, Porteous, David J, Fang, Fang, Lehto, Kelli, Andreassen, Ole A, Pedersen, Ole Birger Vesterager, Hellard, Stephanie Le, and Valdimarsdóttir, Unnur A
- Published
- 2022
17. FlexSensor: Automated measurement software for rapid photonic circuits capturing
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Christoph Schmidt, Jakob Wilhelm Hinum-Wagner, Reinhard Klambauer, and Alexander Bergmann
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Silicon photonics ,Wafer-level measurements ,Measurement automation ,Graphical user interface ,Computer software ,QA76.75-76.765 - Abstract
This paper introduces the automation measurement software FlexSensor for capturing resonant spectra, an innovative and extensible software program developed explicitly for measuring and evaluating wafer-level Silicon Photonic (SiPh) circuits. Wafer-level Silicon Photonics allows the integration of numerous optical components and structures on a single wafer. However, researchers and engineers need precise and repeatable measurements to characterize them and face significant challenges when dealing with large numbers of complex systems on a single wafer. A toolchain gap hampers the measuring of such highly integrated photonic structures: While the setup necessitates the integration of an optimized hardware and software toolchain, there is neither software nor a standardized way to implement a reproducible measurement routine for a massive set of measurements.FlexSensor allows integration and control of external hardware (tunable lasers, analog–digital converters) and supports measurement data storage and evaluation. The software enables researchers and engineers to efficiently analyze the spectral response of photonic structures and facilitate rapid measuring.
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- 2024
- Full Text
- View/download PDF
18. A qualitative study on music teachers' perceptions of digital composition for pupils in primary school
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Hansson, Alexander Berg and Eidsvaag, Fritz Flåmo
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iPad ,Musikk ,Musikkinstrumenter ,Musikk på iPad ,Improvisasjon ,Digital komponering ,GarageBand ,Barneskolen ,Musikklærere - Abstract
Denne masteroppgaven er basert på fire musikklæreres utsagn om hvordan de oppfatter at bruk av iPad bidrar til å heve kvaliteten på sine elevers arbeidsprosess og produkter når de skal lage musikk. Det fokuseres både på positive og negative aspekter ved dette. Informantene er norske lærere på ulike barneskoler i Bærum. Hovedproblemstillingen i denne masteroppgaven er: Hvordan oppfatter musikklærere at bruk av digitale verktøy kan virke hemmende eller fremmende for elevers arbeid med komponering på barneskolen, sammenlignet med tradisjonelle musikkinstrumenter? I læreplanen (LK20) for musikkfaget er digitale ferdigheter og det å lage musikk to viktige elementer. Data fra studien viser at lærerne mener det er mange gode grunner til at vi må bruke de digitale ressursene skolen har tilgjengelig når elever skal komponere og improvisere. Disse funnene støttes av tidligere forskning på digital komponering i skolen. Lærerne mener også at det er viktig å ta vare på tradisjonen med akustiske instrumenter og lydkilder, og kan med fordel kombineres med de mange lydene som finnes på iPaden, i GarageBand spesielt. This master's thesis is based on statements from four music teachers of how they perceive the use of iPad helps to raise the quality of their students' work process and musical products when they make music in school. It focuses on both positive and negative aspects of this. The informants are Norwegian teachers at various primary schools in Bærum. The main research question in this master's thesis is: How do music teachers perceive that the use of digital tools can have an inhibiting or promoting effect on students' engagement in composition in primary school, in relation to traditional musical instruments? In the Norwegian curriculum (LK20) for music, digital skills and making music are two important elements. Data in the study shows that the teachers believe there are many good reasons why we must use the digital resources at the school when students compose and improvise music. These findings are supported by previous research on digital composition in schools. The teachers also believe that it is important to hold on to the tradition of acoustic instruments and sound sources, and can be combined with the many sounds found on the iPad, in GarageBand in particular.
- Published
- 2022
19. Cohort Profile:COVIDMENT: COVID-19 cohorts on mental health across six nations
- Author
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Anna Bára Unnarsdóttir, Anikó Lovik, Chloe Fawns-Ritchie, Helga Ask, Kadri Kõiv, Kristen Hagen, Maria Didriksen, Lea Arregui Nordahl Christoffersen, Alexander Berg Garðarsson, Andrew McIntosh, Anna K Kähler, Archie Campbell, Arna Hauksdóttir, Christian Erikstrup, Dorte Helenius Mikkelsen, Drew Altschul, Edda Bjork Thordardottir, Emma Maria Frans, Gerd Kvale, Gunnar Tómasson, Hanna Maria Kariis, Harpa Lind Jónsdóttir, Harpa Rúnarsdóttir, Ingibjörg Magnúsdóttir, Jarle Eid, Jóhanna Jakobsdóttir, Kaspar René Nielsen, Kathrine Agergård Kaspersen, Lili Milani, Lill-Iren Schou Trogstad, Lu Yi, Mie Topholm Bruun, Patrick F Sullivan, Per Minor Magnus, Qing Shen, Ragnar Nesvåg, Ragnhild E Brandlistuen, Reedik Mägi, Sisse Rye Ostrowski, Solveig Løkhammer, Stian Solem, Ted Reichborn-Kjennerud, Thomas Folkmann Hansen, Thomas Werge, Thor Aspelund, David J Porteous, Fang Fang, Kelli Lehto, Ole A Andreassen, Ole Birger Vesterager Pedersen, Stephanie Le Hellard, and Unnur A Valdimarsdóttir
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Cohort Profile ,Epidemiology ,Mental Disorders ,QUESTIONNAIRE ,COVID-19 ,General Medicine ,DEPRESSION ,Cohort Studies ,Mental Health ,ANXIETY ,Humans ,AcademicSubjects/MED00860 ,SCALE ,Mental Disorders/epidemiology - Abstract
Key features • COVIDMENT [www.covidment.is] is a NordForsk-funded research collaboration across six nations, with the overarching aim to significantly advance current knowledge on mental morbidity trajectories associated with the coronavirus disease 2019 (COVID-19) in the general population and in specific risk groups. • From March 2020 through August 2021, 392 817 individuals have been recruited to the seven COVIDMENT cohorts: the Danish Blood Donor Study (N ¼ 71 562), the Estonian Biobank COVID-19 and Mental Health Data Collection cohorts (N ¼ 13 329 and N ¼ 86 116, respectively), the Icelandic COVID-19 National Resilience Cohort (N ¼ 22 849), the Norwegian BRY.DEG2020 (N ¼ 19 343), the Norwegian Mother, Father and Child Cohort Study (N ¼ 132 486), the Scottish Generation Scotland/CovidLife (N ¼ 18 518) and the Swedish Omtanke2020 (N ¼ 28 614). Semi-harmonized questionnaire data have been collected across all COVIDMENT cohorts with longitudinal data available, e.g. through linkage to the national registers. • The average age of participants ranged from 31.8 to 58.5 years across cohorts. The prevalence of depressive symptoms above cut-off point varied considerably across cohorts (4.2–20.8%). The prevalence of depressive symptoms was highest at COVID-19 incidence of 30 cases per week per 100 000 persons, i.e. 14.3% [95% confidence interval (CI): 9.4–21.8%], which was 61.0% (95% CI: 34.0–94.1%) higher than the prevalence at COVID-19 incidence of 0 cases per week per 100 000 persons (P ¼ 1.1 x 10 ^( 6)). •
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- 2021
20. Cohort Profile: COVIDMENT: COVID-19 cohorts on mental health across six nations
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Unnarsdóttir, Anna Bára, primary, Lovik, Anikó , additional, Fawns-Ritchie, Chloe, additional, Ask, Helga, additional, Kõiv, Kadri, additional, Hagen, Kristen, additional, Didriksen, Maria, additional, Christoffersen, Lea Arregui Nordahl, additional, Garðarsson, Alexander Berg, additional, McIntosh, Andrew, additional, Kähler, Anna K, additional, Campbell, Archie, additional, Hauksdóttir, Arna, additional, Erikstrup, Christian, additional, Mikkelsen, Dorte Helenius, additional, Altschul, Drew, additional, Thordardottir, Edda Bjork, additional, Frans, Emma Maria, additional, Kvale, Gerd, additional, Tómasson, Gunnar, additional, Kariis, Hanna Maria, additional, Jónsdóttir, Harpa Lind, additional, Rúnarsdóttir, Harpa, additional, Magnúsdóttir, Ingibjörg, additional, Eid, Jarle, additional, Jakobsdóttir, Jóhanna, additional, Nielsen, Kaspar René, additional, Kaspersen, Kathrine Agergård, additional, Milani, Lili, additional, Trogstad, Lill-Iren Schou, additional, Yi, Lu, additional, Bruun, Mie Topholm, additional, Sullivan, Patrick F, additional, Magnus, Per Minor, additional, Shen, Qing, additional, Nesvåg, Ragnar, additional, Brandlistuen, Ragnhild E, additional, Mägi, Reedik, additional, Ostrowski, Sisse Rye, additional, Løkhammer, Solveig, additional, Solem, Stian, additional, Reichborn-Kjennerud, Ted, additional, Hansen, Thomas Folkmann, additional, Werge, Thomas, additional, Aspelund, Thor, additional, Porteous, David J, additional, Fang, Fang, additional, Lehto, Kelli, additional, Andreassen, Ole A, additional, Pedersen, Ole Birger Vesterager, additional, Hellard, Stephanie Le, additional, and Valdimarsdóttir, Unnur A, additional
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- 2021
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21. Dynamics of task preparation processes revealed by effect course analysis on response times and error rates
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Alexander Berger, Wilfried Kunde, and Markus Kiefer
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Medicine ,Science - Abstract
Abstract Cuing or executing a task impacts processing pathways for task-relevant information. While there is ample evidence that processing associated with task execution changes with practice, such evidence regarding cue-induced task preparation is scarce. Here we explored practice-related changes of processing pathways by task cuing in order to assess the plasticity of task preparation. We first developed and validated a new method for the study of practice-related changes, the effect course analysis. The effect course analysis is a model-free, non-parametric method designed to reveal effect changes within an experimental session on a continuous time scale. Then we applied this method to a new study in which cued task sets were supposed to remain activated during assessment of task-relevant pathways, as potential task execution was postponed at the end of the trial. The results showed that, with little practice, task cuing amplified task-relevant pathways, whereas this effect vanished with practice, suggesting that practice prompts fundamental changes of how task cues are used for task preparation. Hence, if one cannot be certain that cognitive processing is stationary, investigating the time course of experimental effects appears to be crucial to determine how cognitive processing is influenced by practice.
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- 2024
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22. MODL-25. Radiation and focused ultrasound–mediated blood–brain barrier opening for DMG: safety and feasibility of combinatorial therapy
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Nicholas McQuillan, Masih Tazhibi, Hong-Jian Wei, Antonios Pouliopoulos, Ethan Bendau, Andrea Webster Carrion, Alexander Berg, Danae Kokossis, Xu Zhang, Zhiguo Zhang, Zachary Englander, Nina Yoh, Chia-Ing Jan, Robyn D Gartrell, James Garvin, Luca Szalontay, Elisa Konofagou, Stergios Zacharoulis, and Cheng-Chia Wu
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Cancer Research ,Oncology ,Neurology (clinical) - Abstract
Diffuse midline glioma (DMG) is a pediatric tumor with dismal prognosis. Systemic therapeutic strategies have been unsuccessful to date and radiotherapy (RT) remains the standard of care. A central impediment to systemic therapy is the blood-brain barrier (BBB), which precludes drug delivery to the tumor site. Focused ultrasound (FUS) with intravenous microbubbles can transiently and non-invasively circumvent the BBB to enhance drug delivery. Nevertheless, it remains unclear whether FUS is safe at the brainstem in combination with clinical doses of RT. In this study, we hypothesized that FUS-mediated BBB-opening (BBBO) is safe and feasible with 39 Gy RT. To establish a safety timeline, we administered FUS to the brainstem of nontumor bearing mice concurrent with or adjuvant to radiation; then, we validated our findings in a syngeneic orthotopic xenograft DMG model which received repeated sonication concurrent with RT. Male B6 (Cg)-Tyrc-2J/J albino mice received intracranial injection of 4423 mouse DMG cells (PDGFB+, H3.3K27M, p53−/−) at a location posterior and lateral to the lambda. A clinical RT dose of 39 Gy in 13 fractions was delivered to the brainstem with the Small Animal Radiation Research Platform (SARRP) or the XRAD-320 irradiator. FUS was administered with a 0.5 MHz transducer, and both BBBO and tumor volume were monitored with MRI. FUS-mediated BBBO in nontumor bearing mice receiving RT did not affect cardiorespiratory rate, motor function, and tissue integrity. Moreover, tumor bearing mice tolerated repeated brainstem BBBO concurrent with RT. 39 Gy over 13 fractions offered local control, although disease progression occurred in all animals approximately 3-4 weeks post-RT. Ultimately, repeated FUS-mediated BBB opening concurrent with RT is safe and feasible. In our brainstem DMG model, relapse occurs, making it ideal for future tests of combinatorial RT and FUS-mediated drug delivery.
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- 2022
23. Nahrungsbeziehungen als Wechselwirkungen verstehen - Eine explorative Studie zur Wirkung von Conceptual Change-Stories
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Cornelia Averdunk, Jörg Zabel, and Alexander Bergmann-Gering
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Conceptual Change Story ,Conceptual Change ,Nahrungsbeziehungen ,Wechselwirkung ,Sekundarstufe I ,Special aspects of education ,LC8-6691 - Abstract
Wechselwirkung ist ein zentrales, übergreifendes Konzept im Bereich Ökologie. Nahrungsbeziehungen in Ökosystemen eignen sich besonders, um das Konzept Wechselwirkung in der Sekundarstufe I beispielhaft einzuführen. Studien zeigen, dass Lernenden die elaborierte Beschreibung von Nahrungsbeziehungen schwerfällt und sie oftmals nur direkte Wechselwirkungen beschreiben. In der Forschungsliteratur wird ein Bedarf an unterrichtlichen Strategien benannt, mit deren Hilfe Schüler:innen aufbauend auf ihre bisherigen Konzepte fachlich angemessenere entwickeln können und dabei Nahrungsbeziehungen auch als indirekte und zyklische Wechselwirkungen erklären. Das Projekt entwickelt auf Basis von Conceptual Change-Texts ein innovatives Lernmedium: Conceptual Change-Stories. Diese greifen Konstruktionsprinzipien von Conceptual Change-Texts auf, bieten aber durch die narrative Textgestaltung vereinfachte Zugänge zum Verstehen von Nahrungsbeziehungen als Wechsel-wirkungen. In der vorliegenden Studie wird die Wirkung der Conceptual Change-Stories auf die Beschreibungen von Nah-rungsbeziehungen bei Schüler:innen der Klassenstufe 6 untersucht. Die Ergebnisse liefern Anhaltspunkte zur (Weiter-) Entwicklung von Conceptual Change-Stories. Erste Ergebnisse deuten an, dass Conceptual Change-Stories ein geeignetes Lern-medium darstellen können, um Wechselwirkungen im Nahrungsnetz verstehbar zu machen.
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- 2024
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24. Rigorous Design Optimization of a Fiber-Enabled Polarimetric Waveguide Interferometer for Biosensing
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Samuel M. Hormann, Gandolf Feigl, Jakob W. Hinum-Wagner, and Alexander Bergmann
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Integrated photonics ,silicon nitride ,interferometer ,polarimeter ,biosensing ,point-of-care ,Applied optics. Photonics ,TA1501-1820 ,Optics. Light ,QC350-467 - Abstract
Integrated photonic sensors have gained significant attention for biosensing applications. An especially potent design is the polarimetric waveguide interferometer, which utilizes polarization diversity for effective self-referencing. However, its implementations are held back by the need for bulky free-space optics or unreliable waveguide junctions for polarization handling. To overcome these limitations, we propose a novel concept for a compact photonic system that employs edge couplers to excite both polarizations from an optical fiber and an in-line polarizer to obtain the phase information in the fiber-based readout. Additionally, we improve the waveguide design methodology to minimize the limit of detection through balancing sensitivity with optical loss. To this end, we create a unified perturbative approach based on atomic force microscopy and ellipsometry data to model sensitivity, surface-roughness-induced scattering, absorption, and radiation. We then incorporate the coupling efficiency into a figure of merit for the combined system. Thus, we optimize the geometry of a strip waveguide on a CMOS-foundry-sourced silicon nitride platform for biosensing. Through exhaustive screening of the design space, we discover that polarization diversity simultaneously leverages high sensitivity and low overlap with sidewall roughness. Further, we present designs that eliminate the phase signal from two major noise sources: thermal and bulk refractive index fluctuations. Finally, we provide design recommendations and achieve a 5.2-fold improvement over a comparable bimodal waveguide interferometer. Thus, our aim is to design a robust, compact, sensitive, and cost-effective polarimetric waveguide interferometer through an efficient concept and an optimized design.
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- 2024
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25. Cohort Profile: COVIDMENT: COVID-19 cohorts on mental health across six nations.
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Unnarsdóttir, Anna Bára, Lovik, Anikó, Fawns-Ritchie, Chloe, Ask, Helga, Kõiv, Kadri, Hagen, Kristen, Didriksen, Maria, Christoffersen, Lea Arregui Nordahl, Garðarsson, Alexander Berg, McIntosh, Andrew, Kähler, Anna K, Campbell, Archie, Hauksdóttir, Arna, Erikstrup, Christian, Mikkelsen, Dorte Helenius, Altschul, Drew, Thordardottir, Edda Bjork, Frans, Emma Maria, Kvale, Gerd, and Tómasson, Gunnar
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- 2022
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26. Qualitative and Quantitative Analyses of Automotive Exhaust Plumes for Remote Emission Sensing Application Using Gas Schlieren Imaging Sensor System
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Hafiz Hashim Imtiaz, Paul Schaffer, Yingjie Liu, Paul Hesse, Alexander Bergmann, and Martin Kupper
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remote emission sensing ,synthetic schlieren imaging ,background-oriented schlieren imaging ,optical gas imaging ,exhaust detection ,exhaust plume size measurement ,Meteorology. Climatology ,QC851-999 - Abstract
Remote emission sensing (RES) is a state-of-the-art technique for monitoring thousands of vehicles on the road every day to detect high emitters. Modern commercial RES systems use absorption spectroscopy to measure the ratio of pollutants to CO2 from vehicle exhaust gases. In this work, we present an approach to enable direct concentration measurements by spectroscopic techniques in RES through measurement of the absorption path length. Our gas schlieren imaging sensor (GSIS) system operates on the principle of background-oriented schlieren (BOS) imaging in combination with advanced image processing and deep learning techniques to calculate detected exhaust plume sizes. We performed a qualitative as well as a quantitative analysis of vehicle exhaust and plume dimensions with the GSIS system. We present the system details and results from the GSIS system in the lab in comparison to a BOS model based on flow simulations, the results from characterization measurements in the lab with defined gas mixtures and temperatures, and the results from measurements on the road from different vehicles.
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- 2024
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27. Integration digitalisierungsbezogener Kompetenzen in die Hochschullehre
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Maja Funke, Alexander Bergmann-Gering, and Jörg Zabel
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Digitalisierung ,Kompetenzorientierung ,Hochschullehre ,Lehramtsstudium ,Education (General) ,L7-991 - Abstract
Damit (angehende) Lehrkräfte digitale Medien zukünftig im Fachunterricht einsetzen, müssen sie im Rahmen des Lehramtsstudiums digitalisie-rungsbezogene Kompetenzen erwerben. Zwar beschreiben diverse Modelle solche Kompetenzen für die Lehrer*innenbildung, jedoch erweist es sich als Herausforderung, diese Kompetenzen in die Curricula universitärer Lehrveranstaltungen zu integrieren. Um Studium und Lehre in entsprechender Weise zu verändern, bedarf es eines Vorgehens, das nicht lediglich „top-down“-Steuerungsansätze des Change-Managements auf Hochschulen überträgt, sondern stattdessen deren organisationale Eigenheiten ernst nimmt und relevante Akteur*innen im Sinne eines „bottom-up“-Veränderungsprozesses einbezieht. Ein solches Vorgehen zur Veränderung universitärer Studienprogramme (im Sinne der Integration digitalisierungsbezogener Kompetenzen in Ausbildungsziele) wurde im Rahmen des Projekts „BiodigitaliS“ entwickelt. Dies erfolgte unter Bezug auf das Modell der Pädagogischen Hochschulentwicklung und unter Verwendung des Kompetenzrahmens „DiKoLAN“. Die Konzeption des Vorgehens sowie die Ergebnisse seiner Durchführung am Standort Leipzig werden im vorliegenden Beitrag beschrieben. Unter Berücksichtigung der Kontextbedingungen am Standort (Struktur und Organisation des Lehrangebots, Voraussetzungen und Bedarfe Studierender) und unter starkem Einbezug der Lehrenden konnten digitalisierungsbezogene Kompetenzen umfassender, gezielt und systematisch in die Ausbildungsziele bestehender biologiedidaktischer Lehrveranstaltungen integriert werden. Mit den formulierten Ausbildungszielen liefert das Vorgehen eine Grundlage für die Gestaltung und Evaluation von Hochschullehre zur Förderung digitalisierungsbezogener Kompetenzen. Vor dem Hintergrund der Ergebnisse wird im Beitrag ein Verfahren zur Integration digitalisierungsbezogener Kompetenzen in die Ausbildungsziele universitärer Lehre (IKAL-Verfahren) vorgestellt und anhand von Leitlinien für nachhaltige Veränderungen von Hochschullehre diskutiert. Abschließend erfolgt ein Ausblick auf die Übertragbarkeit des Verfahrens auf hochschulische Lehrveranstaltungen in anderen Bereichen.
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- 2024
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28. Aon: a service to augment Alliance Genome Resource data with additional species
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Sophie K. Kearney, Alexander Berger, and Erich Baker
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Ortholog ,Homology ,AGR ,Medicine ,Biology (General) ,QH301-705.5 ,Science (General) ,Q1-390 - Abstract
Abstract Objective Cross-species comparative genomics requires access to accurate homology data across the entire range of annotated genes. The Alliance of Genome Resources (AGR) provides an open-source and comprehensive database of homology data calculated using a wide array of algorithms at differing stringencies to elucidate orthologous relationships. However, the current AGR application program interface (API) is limited to five homology endpoints for nine species. While AGR provides a robust resource for several canonical species, its utility can be greatly enhanced by increased filtering and data processing options and incorporating additional species. Results Here, we describe a novel API tool, AON, that expands access to the AGR orthology resource by creating a data structure that supports 50 additional endpoints. More importantly, it provides users with a framework for adding bespoke endpoints, custom species, and additional orthology data. We demonstrate AON’s functionality by incorporating the service into the GeneWeaver ecosystem for supporting cross-species data analysis.
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- 2023
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29. Measurement and Analysis of Brake and Tyre Particle Emissions from Automotive Series Components for High-Load Driving Tests on a Wheel and Suspension Test Bed
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Martin Kupper, Ludwig Schubert, Manfred Nachtnebel, Hartmuth Schröttner, Michael Peter Huber, Peter Fischer, and Alexander Bergmann
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non-exhaust emissions ,brake wear aerosol ,particle measurement ,ultrafine particles ,electron microscopy ,Meteorology. Climatology ,QC851-999 - Abstract
A current challenge in realising clean road transport is non-exhaust emissions. Important advances regarding measurement systems, including well-defined characterisation techniques, as well as regulation, will be made in the next few years. In this work, we present the detailed results of particle emission analyses, consisting of aerosol (size distribution, particle number (PN), and mass (PM)) and electron microscopy (EM) measurements, under different load conditions on a test bed for a wheel suspension and brakes. Standard tyres and brakes from serial production were tested with a high-load driving cycle, while particle measurements were conducted by gravimetric measurements and with a TSI SMPS, a TSI APS, and a GRIMM OPS. Furthermore, samples were analysed by electron microscopy. A bimodal particle size distribution (PSD) was obtained with an SMPS, with peaks at 20 nm and around 400 nm. The results of an EM analysis of >1400 single particles from the electrostatic sampler match the PSD results. The EM analysis also showed ultrafine particles, mainly containing O, Fe, Si, Ba, Mg, and S, and also fractal particles with high-C fractions. Our results suggest, in agreement with the previously published literature, that particulate emissions are related to the brake disc temperature and occur in significant amounts above a threshold temperature.
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- 2024
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30. Ultrafast Humidity Sensing Layers Made by Two‐Photon Polymerization and Initiated Chemical Vapor Deposition
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Stefan Cesnik, Gabriel Hernández Rodríguez, Alexander Bergmann, and Anna Maria Coclite
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Two‐photon‐polymerization 3D printing ,humidity sensors ,hydrogel thin films ,Technology (General) ,T1-995 ,Science - Abstract
Abstract Humidity sensors are used in many applications. The design of fast sensors that can operate in explosive environments is a difficult task. Therefore, current research efforts aim at combining reliability, sensitivity and high sensing speed. The use of structured ultrathin hydrogels perfectly meets these requirements. Nanostructures are directly fabricated with a two‐photon‐polymerisation (2PP) 3D printer to use them as templates for hydrogels. After the 3D printing multiple templates are coated with ultrathin films of poly(2‐hydroxyethyl‐methacrylate) (pHEMA) using initiated chemical vapor deposition (iCVD). p(HEMA) is a humidity responsive hydrogel which changes its thickness by orders of magnitude depending on the ambient conditions. The 3D printed structures are optimized to give both a fast response time, and an optical read‐out method for visible wavelengths. Upon hydrogel swelling, the height of the nanostructure pillars increases, keeping their periodicity constant. This induces a change in intensity of the first ‐order refraction peak, which can be easily measured also at low humidity levels. The humidity response of the nanostructures is measured and an influence for different hydrogel thicknesses and humidity flow rates is observed. The ultrathin film with the lowest thickness of 50 nm shows the fastest response to relative humidity, which is much faster than commercial sensors with 8 s response time.
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- 2023
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31. Multifaceted contributions of Dicer2 to arbovirus transmission by Aedes aegypti
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Sarah Hélène Merkling, Anna Beth Crist, Annabelle Henrion-Lacritick, Lionel Frangeul, Elodie Couderc, Valérie Gausson, Hervé Blanc, Alexander Bergman, Artem Baidaliuk, Ottavia Romoli, Maria-Carla Saleh, and Louis Lambrechts
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CP: Immunology ,CP: Microbiology ,Biology (General) ,QH301-705.5 - Abstract
Summary: Arthropod-borne viruses (arboviruses) transmitted by Aedes aegypti mosquitoes are an increasing threat to global health. The small interfering RNA (siRNA) pathway is considered the main antiviral immune pathway of insects, but its effective impact on arbovirus transmission is surprisingly poorly understood. Here, we use CRISPR-Cas9-mediated gene editing in vivo to mutate Dicer2, a gene encoding the RNA sensor and key component of the siRNA pathway. The loss of Dicer2 enhances early viral replication and systemic viral dissemination of four medically significant arboviruses (chikungunya, Mayaro, dengue, and Zika viruses) representing two viral families. However, Dicer2 mutants and wild-type mosquitoes display overall similar levels of vector competence. In addition, Dicer2 mutants undergo significant virus-induced mortality during infection with chikungunya virus. Together, our results define a multifaceted role for Dicer2 in the transmission of arboviruses by Ae. aegypti mosquitoes and pave the way for further mechanistic investigations.
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- 2023
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32. Long‐term prognostic value of vasodilator stress cardiac magnetic resonance in patients with atrial fibrillation
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Karl J. Weiss, Sarah B. Nasser, Tamar Bigvava, Adelina Doltra, Bernhard Schnackenburg, Alexander Berger, Markus S. Anker, Christian Stehning, Patrick Doeblin, Mohamed Abdelmeguid, Mohamed Talat, Rolf Gebker, Wael E‐Naggar, Burkert Pieske, and Sebastian Kelle
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Atrial fibrillation ,Perfusion ,Ischaemia ,Prognosis ,Cardiac magnetic resonance ,Late gadolinium enhancement ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Abstract Aims Although the prevalence of coronary artery disease (CAD) is high among patients with atrial fibrillation (AF), studies on stress perfusion cardiac magnetic resonance (CMR) imaging frequently exclude patients with AF, and its prognostic and diagnostic value in high‐risk patients with suspected or known CAD remains unclear. Methods and results In this longitudinal cohort study, we included 164 consecutive patients with AF during vasodilator perfusion CMR. Diagnostic value was evaluated regarding invasive coronary angiography in a subset of patients. We targeted a follow‐up of >5 years and used CMR results as stratification, and the primary outcome was major adverse cardiac events [MACE, cardiovascular (CV) death and myocardial infarction (MI)]. Secondary outcomes included late coronary revascularization or stroke and the components of the primary outcome. Of the whole cohort (73.8% male, mean age 72.2 years ± 7.8 SD), 99.4% were successfully scanned (163/164 patients). Median CHA2DS2‐VASc score was 4 [interquartile range (IQR) 3–5], and median 10‐year risk for CV events based on SMART risk score was high (24%, IQR 16–32%). Thirty‐two patients (19.6%) presented with ischaemia and 52 patients (31.9%) with late gadolinium enhancement (LGE). A combination of LGE and inducible ischaemia was present in 20 patients (12.3%). Diagnostic accuracy was 86.2% [confidence interval (CI) 68.3–96.1%]. The median follow‐up was 6.6 years (IQR 3.6–7.8). Ischaemia in vasodilator perfusion CMR was significantly associated with the occurrence of MACE [P
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- 2022
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33. European first-year university students accept evolution but lack substantial knowledge about it: a standardized European cross-country assessment
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Paul Kuschmierz, Anna Beniermann, Alexander Bergmann, Rianne Pinxten, Tuomas Aivelo, Justyna Berniak-Woźny, Gustav Bohlin, Anxela Bugallo-Rodriguez, Pedro Cardia, Bento Filipe Barreiras Pinto Cavadas, Umran Betul Cebesoy, Dragana D. Cvetković, Emilie Demarsy, Mirko S. Đorđević, Szymon M. Drobniak, Liudmyla Dubchak, Radka M. Dvořáková, Jana Fančovičová, Corinne Fortin, Momir Futo, Nicoleta Adriana Geamănă, Niklas Gericke, Donato A. Grasso, Ádám Z. Lendvai, Evangelia Mavrikaki, Andra Meneganzin, Athanasios Mogias, Andrea Möller, Paulo G. Mota, Yamama Naciri, Zoltán Németh, Katarzyna Ożańska-Ponikwia, Silvia Paolucci, Péter László Pap, Maria Petersson, Barbara Pietrzak, Telmo Pievani, Alma Pobric, Juris Porozovs, Giulia Realdon, Xana Sá-Pinto, Uroš B. Savković, Mathieu Sicard, Mircea T. Sofonea, Andrej Sorgo, Alexandru N. Stermin, Ioan Tăușan, Gregor Torkar, Lütfullah Türkmen, Slavica Tutnjević, Anna E. Uitto, Máté Varga, Mirna Varga, Lucia Vazquez-Ben, Constantinos Venetis, Enrique Viguera, Lisa Christine Virtbauer, Albena Vutsova, Inmaculada Yruela, Jelle Zandveld, and Dittmar Graf
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Evolution ,Acceptance ,Knowledge ,Multilevel modeling ,Socioscientific issues ,Religious faith ,Special aspects of education ,LC8-6691 ,QH359-425 - Abstract
Abstract Background Investigations of evolution knowledge and acceptance and their relation are central to evolution education research. Ambiguous results in this field of study demonstrate a variety of measuring issues, for instance differently theorized constructs, or a lack of standardized methods, especially for cross-country comparisons. In particular, meaningful comparisons across European countries, with their varying cultural backgrounds and education systems, are rare, often include only few countries, and lack standardization. To address these deficits, we conducted a standardized European survey, on 9200 first-year university students in 26 European countries utilizing a validated, comprehensive questionnaire, the “Evolution Education Questionnaire”, to assess evolution acceptance and knowledge, as well as influencing factors on evolution acceptance. Results We found that, despite European countries’ different cultural backgrounds and education systems, European first-year university students generally accept evolution. At the same time, they lack substantial knowledge about it, even if they are enrolled in a biology-related study program. Additionally, we developed a multilevel-model that determines religious faith as the main influencing factor in accepting evolution. According to our model, knowledge about evolution and interest in biological topics also increase acceptance of evolution, but to a much lesser extent than religious faith. The effect of age and sex, as well as the country’s affiliation, students’ denomination, and whether or not a student is enrolled in a biology-related university program, is negligible. Conclusions Our findings indicate that, despite all their differences, most of the European education systems for upper secondary education lead to acceptance of evolution at least in university students. It appears that, at least in this sample, the differences in knowledge between countries reflect neither the extent to which school curricula cover evolutionary biology nor the percentage of biology-related students in the country samples. Future studies should investigate the role of different European school curricula, identify particularly problematic or underrepresented evolutionary concepts in biology education, and analyze the role of religious faith when teaching evolution.
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- 2021
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34. Implementation of a Spatially-Variant and Tissue-Dependent Positron Range Correction for PET/CT Imaging
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Hunor Kertész, Thomas Beyer, Vladimir Panin, Walter Jentzen, Jacobo Cal-Gonzalez, Alexander Berger, Laszlo Papp, Peter L. Kench, Deepak Bharkhada, Jorge Cabello, Maurizio Conti, and Ivo Rausch
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positron emission tomography ,image reconstruction ,positron range correction ,PET quantification ,PRC ,Physiology ,QP1-981 - Abstract
AimTo develop and evaluate a new approach for spatially variant and tissue-dependent positron range (PR) correction (PRC) during the iterative PET image reconstruction.Materials and MethodsThe PR distributions of three radionuclides (18F, 68Ga, and 124I) were simulated using the GATE (GEANT4) framework in different material compositions (lung, water, and bone). For every radionuclide, the uniform PR kernel was created by mapping the simulated 3D PR point cloud to a 3D matrix with its size defined by the maximum PR in lung (18F) or water (68Ga and 124I) and the PET voxel size. The spatially variant kernels were composed from the uniform PR kernels by analyzing the material composition of the surrounding medium for each voxel before implementation as tissue-dependent, point-spread functions into the iterative image reconstruction. The proposed PRC method was evaluated using the NEMA image quality phantom (18F, 68Ga, and 124I); two unique PR phantoms were scanned and evaluated following OSEM reconstruction with and without PRC using different metrics, such as contrast recovery, contrast-to-noise ratio, image noise and the resolution evaluated in terms of full width at half maximum (FWHM).ResultsThe effect of PRC on 18F-imaging was negligible. In contrast, PRC improved image contrast for the 10-mm sphere of the NEMA image quality phantom filled with 68Ga and 124I by 33 and 24%, respectively. While the effect of PRC was less noticeable for the larger spheres, contrast recovery still improved by 5%. The spatial resolution was improved by 26% for 124I (FWHM of 4.9 vs. 3.7 mm).ConclusionFor high energy positron-emitting radionuclides, the proposed PRC method helped recover image contrast with reduced noise levels and with improved spatial resolution. As such, the PRC approach proposed here can help improve the quality of PET data in clinical practice and research.
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- 2022
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35. Strain Compensation Methods for Fiber Bragg Grating Temperature Sensors Suitable for Integration into Lithium-Ion Battery Electrolyte
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Johanna Unterkofler, Gregor Glanz, Markus Koller, Reinhard Klambauer, and Alexander Bergmann
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lithium-ion battery ,electrolyte ,fiber optic sensor ,internal temperature ,fiber Bragg grating ,sensor encapsulation ,Production of electric energy or power. Powerplants. Central stations ,TK1001-1841 ,Industrial electrochemistry ,TP250-261 - Abstract
Temperature is a crucial factor for the safe operation of lithium-ion batteries. During operation, the internal temperature rises above the external temperature due to poor inner thermal conductivity. Various sensors have been proposed to detect the internal temperature, including fiber Bragg grating sensors. However, to the authors’ knowledge, there is no detailed description of the encapsulation of the fiber Bragg grating sensor in the literature to shield it from strain. In this study, different encapsulation methods for strain compensation were compared to find the encapsulation material most compatible with the electrolyte. For this, we stored the proposed sensors with different encapsulation methods in ethylene carbonate:ethyl methyl carbonate (EC:EMC) 3:7 with LiPF6 (lithium hexafluorophosphate) electrolyte and applied temperature changes. After evaluating the sensor encapsulation methods in terms of handling, diameter, uncertainty, usability, and hysteresis behavior, the most suitable sensor encapsulation was found to be a fused silica capillary with polyimide coating.
- Published
- 2023
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36. Cross-species transcriptomic signatures predict response to MK2 inhibition in mouse models of chronic inflammation
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Lucia Suarez-Lopez, Bing Shui, Douglas K. Brubaker, Marza Hill, Alexander Bergendorf, Paul S. Changelian, Aisha Laguna, Alina Starchenko, Douglas A. Lauffenburger, and Kevin M. Haigis
- Subjects
Immunology ,Computational bioinformatics ,Systems biology ,Transcriptomics ,Science - Abstract
Summary: Inflammatory bowel diseases (IBDs) are genetically complex and exhibit significant inter-patient heterogeneity in disease presentation and therapeutic response. Here, we show that mouse models of IBD exhibit variable responses to inhibition of MK2, a pro-inflammatory serine/threonine kinase, and that MK2 inhibition suppresses inflammation by targeting inflammatory monocytes and neutrophils in murine models. Using a computational approach (TransComp-R) that allows for cross-species comparison of transcriptomic features, we identified an IBD patient subgroup that is predicted to respond to MK2 inhibition, and an independent preclinical model of chronic intestinal inflammation predicted to be non-responsive, which we validated experimentally. Thus, cross-species mouse-human translation approaches can help to identify patient subpopulations in which to deploy new therapies.
- Published
- 2021
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37. COVID-19 vs. Classical Myocarditis Associated Myocardial Injury Evaluated by Cardiac Magnetic Resonance and Endomyocardial Biopsy
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Radu Tanacli, Patrick Doeblin, Collin Götze, Victoria Zieschang, Alessandro Faragli, Christian Stehning, Grigorios Korosoglou, Jennifer Erley, Jakob Weiss, Alexander Berger, Felix Pröpper, Fridolin Steinbeis, Titus Kühne, Franziska Seidel, Dominik Geisel, Thula Cannon Walter-Rittel, Philipp Stawowy, Martin Witzenrath, Karin Klingel, Sophie Van Linthout, Burkert Pieske, Carsten Tschöpe, and Sebastian Kelle
- Subjects
COVID-19 ,myocarditis ,Lake Louise Criteria ,CMR ,biopsy ,inflammation ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Background: Despite the ongoing global pandemic, the impact of COVID-19 on cardiac structure and function is still not completely understood. Myocarditis is a rare but potentially serious complication of other viral infections with variable recovery, and is, in some cases, associated with long-term cardiac remodeling and functional impairment.Aim: To assess myocardial injury in patients who recently recovered from an acute SARS-CoV-2 infection with advanced cardiac magnetic resonance imaging (CMR) and endomyocardial biopsy (EMB).Methods: In total, 32 patients with persistent cardiac symptoms after a COVID-19 infection, 22 patients with acute classic myocarditis not related to COVID-19, and 16 healthy volunteers were included in this study and underwent a comprehensive baseline CMR scan. Of these, 10 patients post COVID-19 and 13 with non-COVID-19 myocarditis underwent a follow-up scan. In 10 of the post-COVID-19 and 15 of the non-COVID-19 patients with myocarditis endomyocardial biopsy (EMB) with histological, immunohistological, and molecular analysis was performed.Results: In total, 10 (31%) patients with COVID-19 showed evidence of myocardial injury, eight (25%) presented with myocardial oedema, eight (25%) exhibited global or regional systolic left ventricular (LV) dysfunction, and nine (28%) exhibited impaired right ventricular (RV) function. However, only three (9%) of COVID-19 patients fulfilled updated CMR–Lake Louise criteria (LLC) for acute myocarditis. Regarding EMB, none of the COVID-19 patients but 87% of the non-COVID-19 patients with myocarditis presented histological findings in keeping with acute or chronic inflammation. COVID-19 patients with severe disease on the WHO scale presented with reduced biventricular longitudinal function, increased RV mass, and longer native T1 times compared with those with only mild or moderate disease.Conclusions: In our cohort, CMR and EMB findings revealed that SARS-CoV-2 infection was associated with relatively mild but variable cardiac involvement. More symptomatic COVID-19 patients and those with higher clinical care demands were more likely to exhibit chronic inflammation and impaired cardiac function compared to patients with milder forms of the disease.
- Published
- 2021
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38. The Association Between Test Anxiety, Self-Efficacy, and Mental Images Among University Students: Results From an Online Survey
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Anna Maier, Caroline Schaitz, Julia Kröner, Alexander Berger, Ferdinand Keller, Petra Beschoner, Bernhard Connemann, and Zrinka Sosic-Vasic
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test anxiety ,anxiety ,self-efficacy ,mental images ,imagery ,Psychiatry ,RC435-571 - Abstract
Background and Objectives: A substantial portion of students report test anxiety, and those reporting low levels of self-efficacy seem to be especially affected. Previous research has indicated the relevance of mental images in the maintenance of anxiety disorders, however, no data are available with respect to test anxiety. In order to close this gap, the present study investigates the association between test anxiety, self-efficacy and mental images.Method: One hundred sixty-three university students completed an online survey. Test anxiety (PAF), general self-efficacy (WIRKALL-r), study-related self-efficacy (WIRK_STUD), intrusiveness of mental images (IFES), spontaneous use of imagery (SUIS) and vividness of imagery (VVIQ) were examined.Results: Test-related mental images were frequently reported among the surveyed students. Test anxiety showed a positive correlation with IFES and a negative correlation with self-efficacy. Mediation analyses showed that about one fifth of the influence of self-efficacy on test anxiety is mediated by IFES.Discussion: The present study gives first indication about an association between test anxiety, self-efficacy and mental images, even though the results are limited with respect to generalizability. Further investigations with respect to the impact of test-related mental images on the self-efficacy/test-anxiety linkage are needed.
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- 2021
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39. Correction to: European first-year university students accept evolution but lack substantial knowledge about it: a standardized European cross-country assessment
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Paul Kuschmierz, Anna Beniermann, Alexander Bergmann, Rianne Pinxten, Tuomas Aivelo, Justyna Berniak-Woźny, Gustav Bohlin, Anxela Bugallo-Rodriguez, Pedro Cardia, Bento Filipe Barreiras Pinto Cavadas, Umran Betul Cebesoy, Dragana D. Cvetković, Emilie Demarsy, Mirko S. Đorđević, Szymon M. Drobniak, Liudmyla Dubchak, Radka M. Dvořáková, Jana Fančovičová, Corinne Fortin, Momir Futo, Nicoleta Adriana Geamănă, Niklas Gericke, Donato A. Grasso, Konstantinos Korfiatis, Ádám Z. Lendvai, Evangelia Mavrikaki, Andra Meneganzin, Athanasios Mogias, Andrea Möller, Paulo G. Mota, Yamama Naciri, Zoltán Németh, Katarzyna Ożańska-Ponikwia, Silvia Paolucci, Péter László Pap, Maria Petersson, Barbara Pietrzak, Telmo Pievani, Alma Pobric, Juris Porozovs, Giulia Realdon, Xana Sá-Pinto, Uroš B. Savković, Mathieu Sicard, Mircea T. Sofonea, Andrej Sorgo, Alexandru N. Stermin, Ioan Tăușan, Gregor Torkar, Lütfullah Türkmen, Slavica Tutnjević, Anna E. Uitto, Máté Varga, Mirna Varga, Lucia Vazquez-Ben, Enrique Viguera, Lisa Christine Virtbauer, Albena Vutsova, Inmaculada Yruela, Jelle Zandveld, and Dittmar Graf
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Special aspects of education ,LC8-6691 ,Evolution ,QH359-425 - Published
- 2022
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40. Flow-Enhanced Photothermal Spectroscopy
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Ulrich Radeschnig, Alexander Bergmann, and Benjamin Lang
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gas sensing ,photothermal spectroscopy ,Fabry–Pérot interferometer ,PTS sensors ,Chemical technology ,TP1-1185 - Abstract
Photothermal spectroscopy (PTS) is a promising sensing technique for the measurement of gases and aerosols. PTS systems using a Fabry–Pérot interferometer (FPI) are considered particularly promising owing to their robustness and potential for miniaturization. However, limited information is available on viable procedures for signal improvement through parameter tuning. In our work, we use an FPI-based PTS configuration, in which the excitation laser irradiates the target collinearly to the flowing gas. We demonstrate that the generated thermal wave, and thus the signal intensity, is significantly affected by the ratio between excitation modulation frequency and gas flow velocity towards another. We provide an analytical model that predicts the signal intensity with particular considerations of these two parameter settings and validate the findings experimentally. The results reveal the existence of an optimal working regime, depending on the modulation frequency and flow velocity.
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- 2022
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41. Total Synthesis of the Antimycobacterial Natural Product Chlorflavonin and Analogs via a Late-Stage Ruthenium(II)-Catalyzed ortho-C(sp2)-H-Hydroxylation
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Alexander Berger, Talea Knak, Anna-Lene Kiffe-Delf, Korana Mudrovcic, Vinayak Singh, Mathew Njoroge, Bjoern B. Burckhardt, Mohanraj Gopalswamy, Beate Lungerich, Lutz Ackermann, Holger Gohlke, Kelly Chibale, Rainer Kalscheuer, and Thomas Kurz
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Mycobacterium tuberculosis ,natural product ,flavonoid ,acetohydroxyacid synthase inhibitor ,ortho-C(sp2)-H-hydroxylation ,4H-chromen-4-one ,Medicine ,Pharmacy and materia medica ,RS1-441 - Abstract
The continuous, worldwide spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) endanger the World Health Organization’s (WHO) goal to end the global TB pandemic by the year 2035. During the past 50 years, very few new drugs have been approved by medical agencies to treat drug-resistant TB. Therefore, the development of novel antimycobacterial drug candidates to combat the threat of drug-resistant TB is urgent. In this work, we developed and optimized a total synthesis of the antimycobacterial natural flavonoid chlorflavonin by selective ruthenium(II)-catalyzed ortho-C(sp2)-H-hydroxylation of a substituted 3′-methoxyflavonoid skeleton. We extended our methodology to synthesize a small compound library of 14 structural analogs. The new analogs were tested for their antimycobacterial in vitro activity against Mycobacterium tuberculosis (Mtb) and their cytotoxicity against various human cell lines. The most promising new analog bromflavonin exhibited improved antimycobacterial in vitro activity against the virulent H37Rv strain of Mtb (Minimal Inhibitory Concentrations (MIC90) = 0.78 μm). In addition, we determined the chemical and metabolic stability as well as the pKa values of chlorflavonin and bromflavonin. Furthermore, we established a quantitative structure–activity relationship model using a thermodynamic integration approach. Our computations may be used for suggesting further structural changes to develop improved derivatives.
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- 2022
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42. Determination of Lamb Wave Modes on Lithium-Ion Batteries Using Piezoelectric Transducers
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Markus Koller, Gregor Glanz, Alexander Bergmann, and Hartmut Popp
- Subjects
lithium-ion batteries ,Lamb waves ,piezoelectric transducer ,battery management system ,structural health monitoring ,Chemical technology ,TP1-1185 - Abstract
This work presents a method to determine the type of Lamb mode (antisymmetric or symmetric) that propagates through a lithium-ion pouch cell. To determine the type of mode and the group velocity at a specific frequency, two- and three-transducer setups were created. For these setups, it is important that all transducers have the same polarization direction. Two transducers are affixed to the center of the cell at a distance of several centimeters from each other so that the group velocity can be determined. Using cross-correlation, the group velocity of the emerging mode can be calculated. The measurement setup and the processing method was first validated with experiments on acrylic glass and aluminum plates. The measurements were supported with FEM simulations and a numerically calculated model. The output voltages of the receiving piezo-elements obtained in the FEM simulation are in agreement with the underlying theories. The phase shift, which results from the output voltage of the piezo-elements mounted one above the other on different sides of the plate, shows the type of mode. The results of the experimental determination of the Lamb mode that propagates through a lithium-ion pouch cell were validated with a numerically calculated multi-layer model and therefore validate this novel experimental approach.
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- 2022
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43. Preclinical Efficacy and Toxicity Analysis of the Pan-Histone Deacetylase Inhibitor Gossypol for the Therapy of Colorectal Cancer or Hepatocellular Carcinoma
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Mascha Mayer, Alexander Berger, Christian Leischner, Olga Renner, Markus Burkard, Alexander Böcker, Seema Noor, Timo Weiland, Thomas S. Weiss, Christian Busch, Ulrich M. Lauer, Stephan C. Bischoff, and Sascha Venturelli
- Subjects
gossypol ,histone deacetylase ,epigenetics ,AT-101 ,colon cancer ,liver cancer ,Medicine ,Pharmacy and materia medica ,RS1-441 - Abstract
Gossypol, a sesquiterpenoid found in cotton seeds, exerts anticancer effects on several tumor entities due to inhibition of DNA synthesis and other mechanisms. In clinical oncology, histone deacetylase inhibitors (HDACi) are applied as anticancer compounds. In this study, we examined whether gossypol harbors HDAC inhibiting activity. In vitro analyses showed that gossypol inhibited class I, II, and IV HDAC, displaying the capability to laterally interact with the respective catalytic center and is, therefore, classified as a pan-HDAC inhibitor. Next, we studied the effects of gossypol on human-derived hepatoma (HepG2) and colon carcinoma (HCT-116) cell lines and found that gossypol induced hyperacetylation of histone protein H3 and/or tubulin within 6 h. Furthermore, incubation with different concentrations of gossypol (5–50 µM) over a time period of 96 h led to a prominent reduction in cellular viability and proliferation of hepatoma (HepG2, Hep3B) and colon carcinoma (HCT-116, HT-29) cells. In-depth analysis of underlying mechanisms showed that gossypol induced apoptosis via caspase activation. For pre-clinical evaluation, toxicity analyses showed toxic effects of gossypol in vitro toward non-malignant primary hepatocytes (PHH), the colon-derived fibroblast cell line CCD-18Co, and the intestinal epithelial cell line CCD 841 CoN at concentrations of ≥5 µM, and embryotoxicity in chicken embryos at ≥2.5 µM. In conclusion, the pronounced inhibitory capacity of gossypol on cancer cells was characterized, and pan-HDACi activity was detected in silico, in vitro, by inhibiting individual HDAC isoenzymes, and on protein level by determining histone acetylation. However, for clinical application, further chemical optimization is required to decrease cellular toxicity.
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- 2022
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44. Ground Contact Time Estimating Wearable Sensor to Measure Spatio-Temporal Aspects of Gait
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Severin Bernhart, Stefan Kranzinger, Alexander Berger, and Gerfried Peternell
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algorithm design and analysis ,gait recognition ,medical diagnosis ,motion estimation ,wearable sensors ,Chemical technology ,TP1-1185 - Abstract
Inpatient gait analysis is an essential part of rehabilitation for foot amputees and includes the ground contact time (GCT) difference of both legs as an essential component. Doctors communicate improvement advice to patients regarding their gait pattern based on a few steps taken at the doctor’s visit. A wearable sensor system, called Suralis, consisting of an inertial measurement unit (IMU) and a pressure measuring sock, including algorithms calculating GCT, is presented. Two data acquisitions were conducted to implement and validate initial contact (IC) and toe-off (TO) event detection algorithms as the basis for the GCT difference determination for able-bodied and prosthesis wearers. The results of the algorithms show a median GCT error of −51.7 ms (IMU) and 14.7 ms (sensor sock) compared to the ground truth and thus represent a suitable possibility for wearable gait analysis. The wearable system presented, therefore, enables a continuous feedback system for patients and, above all, a remote diagnosis of spatio-temporal aspects of gait behaviour based on reliable data collected in everyday life.
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- 2022
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45. Radial Thermal Conductivity Measurements of Cylindrical Lithium-Ion Batteries—An Uncertainty Study of the Pipe Method
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Markus Koller, Johanna Unterkofler, Gregor Glanz, Daniel Lager, Alexander Bergmann, and Hartmut Popp
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Lithium-ion battery ,18650 ,cylindrical cell ,radial thermal conductivity ,Fiber Bragg grating sensor ,thermal characterization ,Production of electric energy or power. Powerplants. Central stations ,TK1001-1841 ,Industrial electrochemistry ,TP250-261 - Abstract
A typical method for measuring the radial thermal conductivity of cylindrical objects is the pipe method. This method introduces a heating wire in combination with standard thermocouples and optical Fiber Bragg grating temperature sensors into the core of a cell. This experimental method can lead to high uncertainties due to the slightly varying setup for each measurement and the non-homogenous structure of the cell. Due to the lack of equipment on the market, researchers have to resort to such experimental methods. To verify the measurement uncertainties and to show the possible range of results, an additional method is introduced. In this second method the cell is disassembled, and the thermal conductivity of each cell component is calculated based on measurements with the laser flash method and differential scanning calorimetry. Those results are used to numerically calculate thermal conductivity and to parameterize a finite element model. With this model, the uncertainties and problems inherent in the pipe method for cylindrical cells were shown. The surprising result was that uncertainties of up to 25% arise, just from incorrect assumption about the sensor position. Furthermore, the change in radial thermal conductivity at different states of charge (SOC) was measured with fully functional cells using the pipe method.
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- 2022
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46. Systematic Review of Gossypol/AT-101 in Cancer Clinical Trials
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Olga Renner, Mascha Mayer, Christian Leischner, Markus Burkard, Alexander Berger, Ulrich M. Lauer, Sascha Venturelli, and Stephan C. Bischoff
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oral gossypol ,AT-101 ,clinical trial ,cancer ,oncologic patients ,Medicine ,Pharmacy and materia medica ,RS1-441 - Abstract
The potential of gossypol and of its R-(−)-enantiomer (R-(−)-gossypol acetic acid, AT-101), has been evaluated for treatment of cancer as an independent agent and in combination with standard chemo-radiation-therapies, respectively. This review assesses the evidence for safety and clinical effectiveness of oral gossypol/AT-101 in treating various types of cancer. The databases PubMed, MEDLINE, Cochrane, and ClinicalTrials.gov were examined. Phase I and II trials as well as single arm and randomized trials were included in this review. Results were screened to determine if they met inclusion criteria and then summarized using a narrative approach. A total of 17 trials involving 759 patients met the inclusion criteria. Overall, orally applied gossypol/AT-101 at low doses (30 mg daily or lower) was determined as well tolerable either as monotherapy or in combination with chemo-radiation. Adverse events should be strictly monitored and were successfully managed by dose-reduction or treating symptoms. There are four randomized trials, two performed in patients with advanced non-small cell lung cancer, one in subjects with head and neck cancer, and one in patients with metastatic castration-resistant prostate cancer. Thereby, standard chemotherapy (either docetaxel (two trials) or docetaxel plus cisplatin or docetaxel plus prednisone) was tested with and without AT-101. Within these trials, a potential benefit was observed in high-risk patients or in some patients with prolongation in progression-free survival or in overall survival. Strikingly, the most recent clinical trial combined low dose AT-101 with docetaxel, fluorouracil, and radiation, achieving complete responses in 11 of 13 patients with gastroesophageal carcinoma (median duration of 12 months) and a median progression-free survival of 52 months. The promising results shown in subsets of patients supports the need of further specification of AT-101 sensitive cancers as well as for the establishment of effective AT-101-based therapy. In addition, the lowest recommended dose of gossypol and its precise toxicity profile need to be confirmed in further studies. Randomized placebo-controlled trials should be performed to validate these data in large cohorts.
- Published
- 2022
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