GRO.publications
Not a member yet
137257 research outputs found
Sort by
. . .in which I recount some experiences from my scientific life, point out the value of experiment and theory working together, indulge myself to a rant about science funding, and attempt to inspire young people about a life in science.
No full textDesign of Hydrogel Electrolytes Using Strong Bacterial Cellulose with Weak Ionic Interactions
No full textAlpha-synuclein misfolding as fluid biomarker for Parkinson’s disease measured with the iRS platform
No full textAbstract Misfolding and aggregation of alpha-synuclein (αSyn) play a key role in the pathophysiology of Parkinson’s disease (PD). Despite considerable advances in diagnostics, an early and differential diagnosis of PD still represents a major challenge. We innovated the immuno-infrared sensor (iRS) platform for measuring αSyn misfolding. We analyzed cerebrospinal fluid (CSF) from two cohorts comprising PD cases, atypical Parkinsonian disorders, and disease controls. We obtained an AUC of 0.90 ( n = 134, 95% CI 0.85–0.96) for separating PD/MSA from controls by determination of the αSyn misfolding by iRS. Using two thresholds divided individuals as unaffected/affected by misfolding with an intermediate area in between. Comparing the affected/unaffected cases, controls versus PD/MSA cases were classified with 97% sensitivity and 92% specificity. The spectral data revealed misfolding from an α-helical/random-coil αSyn in controls to β-sheet enriched αSyn in PD and MSA cases. Moreover, a first subgroup analysis implied the potential for patient stratification in clinically overlapping cases. The iRS, directly measuring all αSyn conformers, is complementary to the αSyn seed-amplification assays (SAAs), which however only amplify seeding competent conformers
When carbon monoxide goes “upside down”: vibrational signatures of CO at NaCl(100) from ab initio molecular dynamics
No full textThis article reports a systematic analysis of vibrational responses (VDOS, IR, VSF spectra) in CO/NaCl(100) across several “C-bound” and “O-bound” orientations, phases and temperatures, giving insight into picosecond vibrational dynamics.CO adsorbed on NaCl(100) is a model system for surface science showing a rich variety of interesting phenomena. It features several adsorption phases like tilted/antiparallel or perpendicular/upright, very long vibrational lifetimes of the CO internal stretch (IS) mode, anharmonicity-driven vibrational energy pooling, “C-bound” vs. “O-bound” adsorption, and heavy-atom gateway tunneling during CO inversion at low temperatures. Typically, these features and phenomena are experimentally probed by stationary and time-resolved vibrational spectra, exhibiting characteristic differences between the various adsorption modes and phases. To gain atom- and time-resolved insight into vibrational response of CO molecules on NaCl(100), vibrational density of states (VDOS), infrared (IR) and vibrational sum frequency (VSF) spectra are computed from velocity velocity correlation functions (VVCFs) by ab initio molecular dynamics (AIMD) for various coverages, temperatures and phases. In agreement with experiments, we find that increasing CO (“C-bound”) coverages as well as CO inversion lead to redshifts of the CO IS mode. We predict more diffuse spectra at T = 300 K compared to 30 K, reflecting the disorder of adsorbates and monolayer instability at room temperature. Analyzing molecularly decomposed and internal VDOS curves as well as computed non-linear correlation matrices give further insight into the complex molecular dynamics underlying the vibrational spectra, notably for the low-frequency regime where frustrated rotations, translations and intermolecular motions come into play. On a methodological side, we also test and discuss some intricate details of how to compute IR and VSF response using a modified formulation of the VVCF methods [Ohto et al. , J. Chem. Phys. , 2015, 143 , 124702], by including time and angle-dependent dipole and polarizability derivatives as well as intermolecular couplings by cross correlations. Their effect on computed vibrational spectra is studied. These findings provide a detailed, microscopic insight into the picosecond vibrational spectra and dynamics of CO on NaCl(100), highlighting the effects of temperature, coverage, and changes in adsorbate orientation.This article reports a systematic analysis of vibrational responses (VDOS, IR, VSF spectra) in CO/NaCl(100) across several “C-bound” and “O-bound” orientations, phases and temperatures, giving insight into picosecond vibrational dynamics.CO adsorbed on NaCl(100) is a model system for surface science showing a rich variety of interesting phenomena. It features several adsorption phases like tilted/antiparallel or perpendicular/upright, very long vibrational lifetimes of the CO internal stretch (IS) mode, anharmonicity-driven vibrational energy pooling, “C-bound” vs. “O-bound” adsorption, and heavy-atom gateway tunneling during CO inversion at low temperatures. Typically, these features and phenomena are experimentally probed by stationary and time-resolved vibrational spectra, exhibiting characteristic differences between the various adsorption modes and phases. To gain atom- and time-resolved insight into vibrational response of CO molecules on NaCl(100), vibrational density of states (VDOS), infrared (IR) and vibrational sum frequency (VSF) spectra are computed from velocity velocity correlation functions (VVCFs) by ab initio molecular dynamics (AIMD) for various coverages, temperatures and phases. In agreement with experiments, we find that increasing CO (“C-bound”) coverages as well as CO inversion lead to redshifts of the CO IS mode. We predict more diffuse spectra at T = 300 K compared to 30 K, reflecting the disorder of adsorbates and monolayer instability at room temperature. Analyzing molecularly decomposed and internal VDOS curves as well as computed non-linear correlation matrices give further insight into the complex molecular dynamics underlying the vibrational spectra, notably for the low-frequency regime where frustrated rotations, translations and intermolecular motions come into play. On a methodological side, we also test and discuss some intricate details of how to compute IR and VSF response using a modified formulation of the VVCF methods [Ohto et al. , J. Chem. Phys. , 2015, 143 , 124702], by including time and angle-dependent dipole and polarizability derivatives as well as intermolecular couplings by cross correlations. Their effect on computed vibrational spectra is studied. These findings provide a detailed, microscopic insight into the picosecond vibrational spectra and dynamics of CO on NaCl(100), highlighting the effects of temperature, coverage, and changes in adsorbate orientation.Deutsche Forschungsgemeinschaft https://doi.org/10.13039/50110000165
A new mesophilic isolate of Pleurastrosarcina , a genus previously only reported from arid habitats
No full textEuropean Union’s Horizon 2020Austrian Science Fun
How Michaelis–Menten kinetics can represent ecosystem-scale respiration: scale and applicability
No full textContouring in transition: perceptions of AI-based autocontouring by radiation oncologists and medical physicists in German-speaking countries
No full textAbstract Background Artificial intelligence (AI)-based autocontouring software has the potential to revolutionize radiotherapy planning. In recent years, several AI-based autocontouring solutions with many advantages have emerged; however, their clinical use raises several challenges related to implementation, quality assurance, validation, and training. The aim of this study was to investigate the current use of AI-based autocontouring software and the associated expectations and hopes of radiation oncologists and medical physicists in German-speaking countries. Methods A digital survey consisting of 24 questions including single-choice, multiple-choice, free-response, and five-point Likert scale rankings was conducted using the online tool umfrageonline.com (enuvo GmbH, Pfäffikon SZ, Switzerland). Results A total of 163 participants completed the survey, with approximately two thirds reporting use of AI-based autocontouring software in routine clinical practice. Of the users, 92% found the software helpful in clinical practice. More than 90% reported using AI solutions to contour organs at risk (OARs) in the brain, head and neck, thorax, abdomen, and pelvis. The majority (88.8%) reported time savings in OAR delineation, with approximately 41% estimating savings of 11–20 min per case. However, nearly half of the respondents expressed concern about the potential degradation of resident training in sectional anatomy understanding. Of respondents, 60% would welcome guidelines for implementation and use of AI-based contouring aids from their respective radiation oncology societies. Respondents’ free-text comments emphasized the need for careful monitoring and postprocessing of AI-delivered autocontours as well as concerns about overreliance on AI and its impact on the development of young physicians’ contouring and planning skills. Conclusion Artificial intelligence-based autocontouring software shows promise for integration into radiation oncology workflows, with respondents recognizing its potential for time saving and standardization. However, successful implementation will require ongoing education and curriculum adaptation to ensure AI enhances, rather than replaces, clinical expertise
Synaptophysin accelerates synaptic vesicle fusion by expanding the membrane upon neurotransmitter loading
No full textSynaptic transmission is mediated by the exocytotic release of neurotransmitters stored in synaptic vesicles (SVs). SVs filled with neurotransmitters preferentially undergo exocytosis, but it is unclear how this is achieved. Here, we show that during transmitter loading, SVs substantially increase in size, which is reversible and requires synaptophysin, an abundant membrane protein with an unclear function. SVs are larger when synaptophysin is knocked out, and conversely, liposomes are smaller when reconstituted with synaptophysin. Moreover, transmitter loading of SVs accelerates fusion in vitro, which is abolished when synaptophysin is lacking despite near normal transmitter uptake. We conclude that synaptophysin functions as a curvature-promoting entity in the SV membrane, allowing for major lateral expansion of the SV membrane during neurotransmitter filling, thus increasing their propensity for exocytosis.Synaptophysin allows synaptic vesicles to expand during loading with neurotransmitters, resulting in faster fusion.Synaptic transmission is mediated by the exocytotic release of neurotransmitters stored in synaptic vesicles (SVs). SVs filled with neurotransmitters preferentially undergo exocytosis, but it is unclear how this is achieved. Here, we show that during transmitter loading, SVs substantially increase in size, which is reversible and requires synaptophysin, an abundant membrane protein with an unclear function. SVs are larger when synaptophysin is knocked out, and conversely, liposomes are smaller when reconstituted with synaptophysin. Moreover, transmitter loading of SVs accelerates fusion in vitro, which is abolished when synaptophysin is lacking despite near normal transmitter uptake. We conclude that synaptophysin functions as a curvature-promoting entity in the SV membrane, allowing for major lateral expansion of the SV membrane during neurotransmitter filling, thus increasing their propensity for exocytosis.Synaptophysin allows synaptic vesicles to expand during loading with neurotransmitters, resulting in faster fusion
Soil bacterial community composition of different tropical land use systems in Jambi province, Indonesia
No full textABSTRACT We sequenced the V3-V4 region of 16S rRNA genes and transcripts to assess entire (DNA) and active (RNA) soil bacterial communities in four different Indonesian land use systems (jungle rubber, rubber, oil palm, and rainforest). Acidobacteriota and Planctomycetes were dominant, with higher relative abundances at active community level.Open-Access-Publikationsfonds 202
Normative values for the hypoparathyroidism patient questionnaire (HPQ28) in the German general population
No full textAbstract Background Patients with hypoparathyroidism (HypoPT) suffer from several complaints and reduced quality of life (QoL), even if disease-specific biochemical parameters are within the target range. To be able to quantify symptoms in HypoPT patients, we recently developed a disease-specific questionnaire, the Hypoparathyroidism Patient Questionnaire with 28 items (HPQ28). The aim of this study was to find normative values for the HPQ28 in the German general population. Methods We tasked an independent market and social research institute to obtain sociodemographic data and HPQ28 results from a representative sample of the German general population. The HPQ28 comprises five scales and three single items. The five scales indicate different areas of complaints: Pain and cramps (PaC) including five items, neurovegetative symptoms (NVS) including five items, loss of vitality (LoV) including six items, depression and anxiety (DaA) including five items, gastro-intestinal symptoms (GiS) including two items and two control items for depression. Three items were not attributable to any of the five scales: numbness and tingling in certain parts of the body (NT), troubled memory (TM), and racing heart (RH). Results Mean age (± standard deviation) in the representative general population sample ( n = 2506) was 49.5 ± 17.8 years, 51% were female. All scales and single items were affected by gender with women presenting significantly more complaints on every scale and single item in comparison to men ( p < 0.01, Mann-Whitney U test). In addition, all scales and single items, except for GiS, were affected by age in males and females ( p < 0.001, Spearman’s correlation). Regression analyses proved a linear trend in the different scores regarding age and gender ( p < 0.05 except for age on the GiS scale). Conclusions We present data from the first application of the HPQ28 in a representative sample of the German general population. Almost all scales and single item of the HPQ28 were dependent on age and gender, with older individuals and females presenting a higher burden of complaints. Trial registration DRKS, DRKS00027581. Registered 17th of January 2022, https//drks.de/search/de/trial/DRKS00027581