70 research outputs found
Subordination of Shareholder Loans from a Legal and Economic Perspective
Gesellschafterdarlehen, Volkswirtschaft, Recht, Bewertung, Shareholder loan, Economy, Law, Evaluation
An electron acceptor molecule in a nanomesh: F4TCNQ on h-BN/Rh(111)
The adsorption of molecules on surfaces affects the surface dipole and thus
changes in the work function may be expected. The effect in change of work
function is particularly strong if charge between substrate and adsorbate is
involved. Here we report the deposition of a strong electron acceptor molecule,
tetrafluorotetracyanoquinodimethane CFN (FTCNQ) on a
monolayer of hexagonal boron nitride nanomesh (-BN on Rh(111)). The work
function of the FTCNQ/-BN/Rh system increases upon increasing
molecular coverage. The magnitude of the effect indicates electron transfer
from the substrate to the FTCNQ molecules. Density functional theory
calculations confirm the work function shift and predict doubly charged
FTCNQ in the nanomesh pores, where the -BN is closest to the Rh
substrate, and to have the largest binding energy there. The preferred
adsorption in the pores is conjectured from a series of ultraviolet
photoelectron spectroscopy data, where the bands in the pores are
first attenuated. Scanning tunneling microscopy measurements indicate that
FTCNQ molecules on the nanomesh are mobile at room temperature, as
"hopping" between neighboring pores is observed
Time-Resolved Photoelectron Spectroscopy to Probe Ultrafast Charge Transfer and Electron Dynamics in Solid Surface Systems and at Metal- Molecule Interfaces
Photoelectron spectroscopy (PES) is a versatile tool, which provides insight into electronic structure and dynamics in condensed matter, surfaces, interfaces and molecules. The history of PES is briefly outlined and illustrated by current developments in the field of time-resolved PES.
Our group's research is mostly aimed at studying ultrafast processes and associated lifetimes related to electronic excitation at solid surfaces
Advanced Materials and Measuring Techniques for Chemical Sensors
This overview focuses on modifications of chemical compounds used in the development of chemical sensors, and on materials and chemical sensors which may be sufficiently mature to be used in the industry. Special attention is paid to gas-selective optode membranes which incorporate compounds such as cobyrinate derivatives and Ru(II)complexes that are chemically modified in view of a specific application. New materials are described, e.g. the magnesium-selective ionophores currently used for diagnostic applications, and a class of substituted polymethine dyes characterized by an amine donor and a bisdicyanovinyl-ideneindandione acceptor group, where the target pKa can be modulated by decisive substituents.Three projects are discussed in more detail: 1) the development of ion-selective nanoprobes on the basis of coated AFM-tips; 2) reactands and chromoreactands which are covalently bound to acrylate-based copolymers and allow to monitor alcohols and amines continuously, and 3) a continuous-flow module integrating a fiber-optical probe that allows to monitor variations in the absorption spectrum of chromoreactands in the transflection mode
Natural language processing analysis of the theories of people with multiple sclerosis about causes of their disease.
BACKGROUND
While potential risk factors for multiple sclerosis (MS) have been extensively researched, it remains unclear how persons with MS theorize about their MS. Such theories may affect mental health and treatment adherence. Using natural language processing techniques, we investigated large-scale text data about theories that persons with MS have about the causes of their disease. We examined the topics into which their theories could be grouped and the prevalence of each theory topic.
METHODS
A total of 486 participants of the Swiss MS Registry longitudinal citizen science project provided text data on their theories about the etiology of MS. We used the transformer-based BERTopic Python library for topic modeling to identify underlying topics. We then conducted an in-depth characterization of the topics and assessed their prevalence.
RESULTS
The topic modeling analysis identifies 19 distinct topics that participants theorize as causal for their MS. The topics most frequently cited are Mental Distress (31.5%), Stress (Exhaustion, Work) (29.8%), Heredity/Familial Aggregation (27.4%), and Diet, Obesity (16.0%). The 19 theory topics can be grouped into four high-level categories: physical health (mentioned by 56.2% of all participants), mental health (mentioned by 53.7%), risk factors established in the scientific literature (genetics, Epstein-Barr virus, smoking, vitamin D deficiency/low sunlight exposure; mentioned by 47.7%), and fate/coincidence (mentioned by 3.1%). Our study highlights the importance of mental health issues for theories participants have about the causes of their MS.
CONCLUSIONS
Our findings emphasize the importance of communication between healthcare professionals and persons with MS about the pathogenesis of MS, the scientific evidence base and mental health
Simple Questionnaires to Improve Pooling Strategies for SARS-CoV-2 Laboratory Testing
Background: Liberal PCR testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is key to contain the coronavirus disease 2019 (COVID-19) pandemic. Combined multi-sample testing in pools instead of single tests might enhance laboratory capacity and reduce costs, especially in low- and middle-income countries.
Objective: The purpose of our study was to assess the value of a simple questionnaire to guide and further improve pooling strategies for SARS-CoV-2 laboratory testing.
Methods: Pharyngeal swabs for SARS-CoV-2 testing were obtained from healthcare and police staff, hospital inpatients, and nursing home residents in the southwestern part of Germany. We designed a simple questionnaire, which included questions pertaining to a suggestive clinical symptomatology, recent travel history, and contact with confirmed cases to stratify an individual’s pre-test probability of having contracted COVID-19. The questionnaire was adapted repeatedly in face of the unfolding pandemic in response to the evolving epidemiology and observed clinical symptomatology. Based on the response patterns, samples were either tested individually or in multi-sample pools. We compared the pool positivity rate and the number of total PCR tests required to obtain individual results between this questionnaire-based pooling strategy and randomly assembled pools.
Findings: Between March 11 and July 5, 2020, we processed 25,978 samples using random pooling (n = 6,012; 23.1%) or questionnaire-based pooling (n = 19,966; 76.9%). The overall prevalence of SARS-CoV-2 was 0.9% (n = 238). Pool positivity (14.6% vs. 1.2%) and individual SARS-CoV-2 prevalence (3.4% vs. 0.1%) were higher in the random pooling group than in the questionnaire group. The average number of PCR tests needed to obtain the individual result for one participant was 0.27 tests in the random pooling group, as compared to 0.09 in the questionnaire-based pooling group, leading to a laboratory capacity increase of 73% and 91%, respectively, as compared to single PCR testing.
Conclusions: Strategies that combine pool testing with a questionnaire-based risk stratification can increase laboratory testing capacities for COVID-19 and might be important tools, particularly in resource-constrained settings
Laurent inversion
There are well-understood methods, going back to Givental and Hori--Vafa, that to a Fano toric complete intersection X associate a Laurent polynomial f that corresponds to X under mirror symmetry. We describe a technique for inverting this process, constructing the toric complete intersection X directly from its Laurent polynomial mirror f. We use this technique to construct a new four-dimensional Fano manifold
Long-term risk of adverse outcomes according to atrial fibrillation type
Sustained forms of atrial fibrillation (AF) may be associated with a higher risk of adverse outcomes, but few if any long-term studies took into account changes of AF type and co-morbidities over time. We prospectively followed 3843 AF patients and collected information on AF type and co-morbidities during yearly follow-ups. The primary outcome was a composite of stroke or systemic embolism (SE). Secondary outcomes included myocardial infarction, hospitalization for congestive heart failure (CHF), bleeding and all-cause mortality. Multivariable adjusted Cox proportional hazards models with time-varying covariates were used to compare hazard ratios (HR) according to AF type. At baseline 1895 (49%), 1046 (27%) and 902 (24%) patients had paroxysmal, persistent and permanent AF and 3234 (84%) were anticoagulated. After a median (IQR) follow-up of 3.0 (1.9; 4.2) years, the incidence of stroke/SE was 1.0 per 100 patient-years. The incidence of myocardial infarction, CHF, bleeding and all-cause mortality was 0.7, 3.0, 2.9 and 2.7 per 100 patient-years, respectively. The multivariable adjusted (a) HRs (95% confidence interval) for stroke/SE were 1.13 (0.69; 1.85) and 1.27 (0.83; 1.95) for time-updated persistent and permanent AF, respectively. The corresponding aHRs were 1.23 (0.89, 1.69) and 1.45 (1.12; 1.87) for all-cause mortality, 1.34 (1.00; 1.80) and 1.30 (1.01; 1.67) for CHF, 0.91 (0.48; 1.72) and 0.95 (0.56; 1.59) for myocardial infarction, and 0.89 (0.70; 1.14) and 1.00 (0.81; 1.24) for bleeding. In this large prospective cohort of AF patients, time-updated AF type was not associated with incident stroke/SE
The Cumulative Impact of Harm Reduction on the Swiss HIV Epidemic: Cohort Study, Mathematical Model, and Phylogenetic Analysis.
Human immunodeficiency virus (HIV) transmission among injecting drug users (IDUs) is increasing in the United States due to the recent opioid epidemic and is the leading mode of transmission in Eastern Europe.
To evaluate the overall impact of HIV harm reduction, we combined (1) data from the Swiss HIV Cohort Study and public sources with (2) a mathematical model expressed as a system of ordinary differential equations. The model reconstructs the national epidemic from the first case in 1980 until 2015. Phylogenetic cluster analysis of HIV-1 pol sequences was used to quantify the epidemic spillover from IDUs to the general population.
Overall, harm reduction prevented 15903 (range, 15359-16448) HIV infections among IDUs until the end of 2015, 5446 acquired immune deficiency syndrome (AIDS) deaths (range, 5142-5752), and a peak HIV prevalence of 50.7%. Introduction of harm reduction 2 years earlier could have halved the epidemic, preventing 3161 (range, 822-5499) HIV infections and 1468 (range, 609-2326) AIDS deaths. Suddenly discontinuing all harm reduction in 2005 would have resulted in outbreak re-emergence with 1351 (range, 779-1925) additional HIV cases. Without harm reduction, the estimated additional number of heterosexuals infected by HIV-positive IDUs is estimated to have been 2540 (range, 2453-2627), which is equivalent to the total national reported incidence among heterosexuals in the period of 2007 to 2015.
Our results suggest that a paramount, population-level impact occurred because of the harm reduction package, beyond factors that can be explained by a reduction in risk behavior and a decrease in the number of drug users over time
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