Scanning X-ray nanodiffraction: from the experimental approach towards spatially resolved scattering simulations

An enhancement on the method of X-ray diffraction simulations for applications using nanofocused hard X-ray beams is presented. We combine finite element method, kinematical scattering calculations, and a spot profile of the X-ray beam to simulate the diffraction of definite parts of semiconductor nanostructures. The spot profile could be acquired experimentally by X-ray ptychography. Simulation results are discussed and compared with corresponding X-ray nanodiffraction experiments on single SiGe dots and dot molecules

Clinical and virological characteristics of hospitalised COVID-19 patients in a German tertiary care centre during the first wave of the SARS-CoV-2 pandemic: a prospective observational study.

Funder: Humboldt-Universität zu Berlin (1034)PURPOSE: Adequate patient allocation is pivotal for optimal resource management in strained healthcare systems, and requires detailed knowledge of clinical and virological disease trajectories. The purpose of this work was to identify risk factors associated with need for invasive mechanical ventilation (IMV), to analyse viral kinetics in patients with and without IMV and to provide a comprehensive description of clinical course. METHODS: A cohort of 168 hospitalised adult COVID-19 patients enrolled in a prospective observational study at a large European tertiary care centre was analysed. RESULTS: Forty-four per cent (71/161) of patients required invasive mechanical ventilation (IMV). Shorter duration of symptoms before admission (aOR 1.22 per day less, 95% CI 1.10-1.37, p < 0.01) and history of hypertension (aOR 5.55, 95% CI 2.00-16.82, p < 0.01) were associated with need for IMV. Patients on IMV had higher maximal concentrations, slower decline rates, and longer shedding of SARS-CoV-2 than non-IMV patients (33 days, IQR 26-46.75, vs 18 days, IQR 16-46.75, respectively, p < 0.01). Median duration of hospitalisation was 9 days (IQR 6-15.5) for non-IMV and 49.5 days (IQR 36.8-82.5) for IMV patients. CONCLUSIONS: Our results indicate a short duration of symptoms before admission as a risk factor for severe disease that merits further investigation and different viral load kinetics in severely affected patients. Median duration of hospitalisation of IMV patients was longer than described for acute respiratory distress syndrome unrelated to COVID-19

Clinical and virological characteristics of hospitalised COVID-19 patients in a German tertiary care centre during the first wave of the SARS-CoV-2 pandemic: a prospective observational study

Purpose: Adequate patient allocation is pivotal for optimal resource management in strained healthcare systems, and requires detailed knowledge of clinical and virological disease trajectories. The purpose of this work was to identify risk factors associated with need for invasive mechanical ventilation (IMV), to analyse viral kinetics in patients with and without IMV and to provide a comprehensive description of clinical course. Methods: A cohort of 168 hospitalised adult COVID-19 patients enrolled in a prospective observational study at a large European tertiary care centre was analysed. Results: Forty-four per cent (71/161) of patients required invasive mechanical ventilation (IMV). Shorter duration of symptoms before admission (aOR 1.22 per day less, 95% CI 1.10-1.37, p < 0.01) and history of hypertension (aOR 5.55, 95% CI 2.00-16.82, p < 0.01) were associated with need for IMV. Patients on IMV had higher maximal concentrations, slower decline rates, and longer shedding of SARS-CoV-2 than non-IMV patients (33 days, IQR 26-46.75, vs 18 days, IQR 16-46.75, respectively, p < 0.01). Median duration of hospitalisation was 9 days (IQR 6-15.5) for non-IMV and 49.5 days (IQR 36.8-82.5) for IMV patients. Conclusions: Our results indicate a short duration of symptoms before admission as a risk factor for severe disease that merits further investigation and different viral load kinetics in severely affected patients. Median duration of hospitalisation of IMV patients was longer than described for acute respiratory distress syndrome unrelated to COVID-19

In-plane strain distribution in free-standing GaAs/InGaAs/GaAs single quantum well surface nanostructures on GaAs[001]

The vertical variation of in-plane strain induced by an In0.1Ga0.9AsIn0.1Ga0.9As single quantum well (SQW) embedded in a free-standing wire structure on GaAs[001] has been investigated by depth resolved x-ray grazing incidence diffraction. If the wires are oriented along the [110] direction both the shape and strain influence on the x-ray intensity distribution can be separated by running transverse or longitudinal scans across the grating truncation rods (GTRs) close to the (2̄20)(2̄20) and (2̄2̄0)(2̄2̄0) in-plane Bragg reflection, respectively. The GTRs themselves are modulated due to the vertical layering of the wires. The vertical strain variation in the vicinity of SQW is particularly inspected at the weak (200) Bragg reflection which is most sensitive to the scattering density difference between the SQW and GaAs. The theoretical analysis is based on the distorted wave Born approximation for grazing incidence geometry. The structural parameters of the surface nanostructure were determined with high accuracy by fitting of the complete set of experimental GTRs simultaneously. In agreement with finite-element calculations we find a maximum in-plane lattice displacement within the SQW of (Δa‖/a≈3.5×10−4)(Δa‖/a≈3.5×10−4) with respect to the substrate. It induces dilative in-plane strain in the GaAs confinement layers decreasing towards the upper free surface and the bulk, respectively. The evaluated in-plane strain within the SQW is used for estimating the strain induced redshift of the photoluminescence wavelength of the respective optical device

Multimedial-partizipative Arbeitsplanung Abschlussbericht

SIGLEAvailable from TIB Hannover: F00B801 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman

Entwicklung einer Richtlinie zur ergonomischen Gestaltung multimedialer Arbeitsmittel fuer die Fertigung - Richtlinie zur ergonomischen Gestaltung multimedialer Arbeitsmittel Schlussbericht

SIGLEAvailable from TIB Hannover: F03B341 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany); Arbeitsgemeinschaft Industrieller Forschungsvereinigungen 'Otto von Guericke' e.V. (AIF), Koeln (Germany)DEGerman

Cognitive reserve and the risk of postoperative neurocognitive disorders in older age

BACKGROUND: Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are postoperative neurocognitive disorders (PNDs) that frequently occur in the aftermath of a surgical intervention. Cognitive reserve (CR) is a concept posited to explain why cognitive health varies between individuals. On this qualitative understanding of cognitive health, factors like IQ, education level, and occupational complexity can affect the impact of neuropathological processes on cognitive outcomes. METHODS: We investigated the association between CR and POD and CR and POCD on data from 713 patients aged≥65 years with elective surgery. Peak pre-morbid IQ was estimated from vocabulary. Occupational complexity was coded according to the Dictionary of Occupational Titles (DOT). Education level was classed according to the International Standard Classification of Education (ISCED). These three factors were used as proxies of CR. In a series of regression models, age, sex, depression, site of surgery, and several lifestyle and vascular factors were controlled for. RESULTS: Patients with a higher IQ had lower odds of developing POD. We found no significant association between the other two CR markers with POD. None of the CR markers was associated with POCD. CONCLUSION: The significant association of a higher IQ with lower POD risk allows for the stratification of elderly surgical patients by risk. This knowledge can aid the prevention and/or early detection of POD. Further research should attempt to determine the lack of associations of CR markers with POCD in our study