Efficient electrochemical water splitting to hydrogen and oxygen is considered a promising technology to overcome our dependency on fossil fuels. Searching for novel catalytic materials for ...electrochemical oxygen generation is essential for improving the total efficiency of water splitting processes. We report the synthesis, structural characterization, and electrochemical performance in the oxygen evolution reaction of Fe-doped NiO nanocrystals. The facile solvothermal synthesis in tert-butanol leads to the formation of ultrasmall crystalline and highly dispersible Fe x Ni1–x O nanoparticles with dopant concentrations of up to 20%. The increase in Fe content is accompanied by a decrease in particle size, resulting in nonagglomerated nanocrystals of 1.5–3.8 nm in size. The Fe content and composition of the nanoparticles are determined by X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy measurements, while Mössbauer and extended X-ray absorption fine structure analyses reveal a substitutional incorporation of Fe(III) into the NiO rock salt structure. The excellent dispersibility of the nanoparticles in ethanol allows for the preparation of homogeneous ca. 8 nm thin films with a smooth surface on various substrates. The turnover frequencies (TOF) of these films could be precisely calculated using a quartz crystal microbalance. Fe0.1Ni0.9O was found to have the highest electrocatalytic water oxidation activity in basic media with a TOF of 1.9 s–1 at the overpotential of 300 mV. The current density of 10 mA cm–2 is reached at an overpotential of 297 mV with a Tafel slope of 37 mV dec–1. The extremely high catalytic activity, facile preparation, and low cost of the single crystalline Fe x Ni1–x O nanoparticles make them very promising catalysts for the oxygen evolution reaction.
We prove that the quantum relative entropy decreases monotonically under the application of any positive trace-preserving linear map, for underlying separable Hilbert spaces. This answers in the ...affirmative a natural question that has been open for a long time, as monotonicity had previously only been shown to hold under additional assumptions, such as complete positivity or Schwarz-positivity of the adjoint map. The first step in our proof is to show monotonicity of the sandwiched Renyi divergences under positive trace-preserving maps, extending a proof of the data processing inequality by Beigi (J Math Phys 54:122202,
2013
) that is based on complex interpolation techniques. Our result calls into question several measures of non-Markovianity that have been proposed, as these would assess all positive trace-preserving time evolutions as Markovian.
Biomarkers of alcohol consumption are important not only in forensic contexts, e.g., in child custody proceedings or as documentation of alcohol abstinence after temporary confiscation of a driver's ...license. They are increasingly being used in clinical medicine as well for verification of abstinence or to rule out the harmful use of alcohol.
This review is based on pertinent publications that were retrieved by a selective literature search in PubMed concerning the direct and indirect alcohol markers discussed here, as well as on the authors' experience in laboratory analysis and clinical medicine.
Alongside the direct demonstration of ethanol, the available markers of alcohol consumption include the classic indirect markers carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), and mean corpuscular volume (MCV) as well as direct alcohol markers such as ethyl glucuronide (EtG) and ethyl sulfate (EtS) in serum and urine and EtG and fatty acid ethyl esters (FAEE) in hair. Phosphatidylethanol (PEth) is a promising parameter that com - plements the existing spectrum of tests with high specificity (48-89%) and sensi - tivity (88-100%). In routine clinical practice, the demonstration of positive alcohol markers often leads patients to admit previously denied alcohol use. This makes it possible to motivate the patient to undergo treatment for alcoholism.
The available alcohol biomarkers vary in sensitivity and specificity with respect to the time period over which they indicate alcohol use and the minimum extent of alcohol use that they can detect. The appropriate marker or combination of markers should be chosen in each case according to the particular question that is to be answered by laboratory analysis.
The chain of chirality transfer in tellurium nanocrystals Ben-Moshe, Assaf; da Silva, Alessandra; Müller, Alexander ...
Science (American Association for the Advancement of Science),
05/2021, Letnik:
372, Številka:
6543
Journal Article
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Despite persistent and extensive observations of crystals with chiral shapes, the mechanisms underlying their formation are not well understood. Although past studies suggest that chiral shapes can ...form because of crystallization in the presence of chiral additives, or because of an intrinsic tendency that stems from the crystal structure, there are many cases in which these explanations are not suitable or have not been tested. Here, an investigation of model tellurium nanocrystals provides insights into the chain of chirality transfer between crystal structure and shape. We show that this transfer is mediated by screw dislocations, and shape chirality is not an outcome of the chiral crystal structure or ligands.
This article examines early antiterrorism negotiations within international organisations (IOs) and their outcomes. It assesses how international cooperation emerged in specialised, regional, and ...global IOs and provides a long-term overview from the 1960s until the late 1980s. Drawing on primary sources and scholarly literature, this article identifies the patterns, trends, and key characteristics of the successfully adopted measures. It demonstrates that early multilateral antiterrorism efforts faced several obstacles (sovereignty, national interests, mistrust, and geopolitics), and, therefore, international negotiations fared better when following a piecemeal approach within specialised or regional organisations, where the focus could be on specific aspects of terrorism (e.g., hostage-takings). A key characteristic of the successfully adopted antiterrorism instruments was the aut dedere aut iudicare principle, which allowed states to maintain perceptions of sovereignty by either extraditing or trying a suspect. The antiterrorism efforts examined here were mostly preventative in design and worked to discourage future terrorists by ensuring that safe havens were closed and that perpetrators faced justice. The shift to suicide terrorism in the 1990s would instead require new international antiterrorism efforts to focus on pre-emptive strategies, depriving terrorists of the means to carry out attacks. The roots of these measures were laid in the 1980s.
Point-of-care (PoC) tests are practical and effective diagnostic solutions for major clinical problems, ranging from the monitoring of a pandemic to recurrent or simple measurements. Although, in ...recent years, a great improvement in the analytical performance of such sensors has been observed, there is still a major issue that has not been properly solved: the ability to perform adequate sample treatments. The main reason is that normally sample treatments require complicated or long procedures not adequate for deployment at the PoC. In response, a sensing platform, called paper-based electrophoretic bioassay (PEB), that combines the key characteristics of a lateral flow assay (LFA) with the sample treatment capabilities of electrophoresis is developed. In particular, the ability of PEB to separate different types of particles and to detect human antibodies in untreated spiked whole blood is demonstrated. Finally, to make the platform suitable for PoC, PEB is coupled with a smartphone that controls the electrophoresis and reads the optical signal generated. It is believed that the PEB platform represents a much-needed solution for the detection of low target concentrations in complex media, solving one of the major limitations of LFA and opening opportunities for point-of-care sensors.
•Nanoscale strain maps rely on precise measurement of Bragg scattered electrons.•Precision of strain maps depends on template matching procedure.•Bullseye patterned probes improve the robustness to ...complex scattering effects.•We observe up to 30 times higher precision using bullseye probes.
Nanoscale strain mapping by four-dimensional scanning transmission electron microscopy (4D-STEM) relies on determining the precise locations of Bragg-scattered electrons in a sequence of diffraction patterns, a task which is complicated by dynamical scattering, inelastic scattering, and shot noise. These features hinder accurate automated computational detection and position measurement of the diffracted disks, limiting the precision of measurements of local deformation. Here, we investigate the use of patterned probes to improve the precision of strain mapping. We imprint a “bullseye” pattern onto the probe, by using a binary mask in the probe-forming aperture, to improve the robustness of the peak finding algorithm to intensity modulations inside the diffracted disks. We show that this imprinting leads to substantially improved strain-mapping precision at the expense of a slight decrease in spatial resolution. In experiments on an unstrained silicon reference sample, we observe an improvement in strain measurement precision from 2.7% of the reciprocal lattice vectors with standard probes to 0.3% using bullseye probes for a thin sample, and an improvement from 4.7% to 0.8% for a thick sample. We also use multislice simulations to explore how sample thickness and electron dose limit the attainable accuracy and precision for 4D-STEM strain measurements.
Background If a COVID-19 patient develops a so-called severe course, he or she must be taken to hospital as soon as possible. This proves difficult in domestic isolation, as patients are not ...continuously monitored. The aim of our study was to establish a telemonitoring system in this setting. Methods Oxygen saturation, respiratory rate, heart rate and temperature were measured every 15 minutes using an in-ear device. The data was transmitted to the Telecovid Centre via mobile network or internet and monitored 24/7 by a trained team. The data were supplemented by daily telephone calls. The patients' individual risk was assessed using a modified National Early Warning Score. In case of a deterioration, a physician initiated the appropriate measures. Covid-19 Patients were included if they were older than 60 years or fulfilled at least one of the following conditions: pre-existing disease (cardiovascular, pulmonary, immunologic), obesity (BMI >35), diabetes mellitus, hypertension, active malignancy, or pregnancy. Findings 153 patients (median age 59 years, 77 female) were included. Patients were monitored for 9 days (median, IQR 6-13 days) with a daily monitoring time of 13.3 hours (median, IQR 9.4-17.0 hours). 20 patients were referred to the clinic by the Telecovid team. 3 of these required intensive care without invasive ventilation, 4 with invasive ventilation, 1 of the latter died. All patients agreed that the device was easy to use. About 90% of hospitalised patients indicated that they would have delayed hospitalisation further if they had not been part of the study. Interpretation Our study demonstrates the successful implementation of a remote monitoring system in a pandemic situation. All clinically necessary information was obtained and adequate measures were derived from it without delay.
Fix food metrics Sukhdev, Pavan; May, Peter; Müller, Alexander
Nature (London),
12/2016, Letnik:
540, Številka:
7631
Journal Article
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Current patterns of crop and livestock production and of processing, transport and consumption, are not delivering healthy, nutritious food to society. They are generating large and unacceptable ...impacts on the environment and on vulnerable populations.
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