Germanium-lead perovskite light-emitting diodes.

Reducing environmental impact is a key challenge for perovskite optoelectronics, as most high-performance devices are based on potentially toxic lead-halide perovskites. For photovoltaic solar cells, tin-lead (Sn-Pb) perovskite materials provide a promising solution for reducing toxicity. However, Sn-Pb perovskites typically exhibit low luminescence efficiencies, and are not ideal for light-emitting applications. Here we demonstrate highly luminescent germanium-lead (Ge-Pb) perovskite films with photoluminescence quantum efficiencies (PLQEs) of up to ~71%, showing a considerable relative improvement of ~34% over similarly prepared Ge-free, Pb-based perovskite films. In our initial demonstration of Ge-Pb perovskite LEDs, we achieve external quantum efficiencies (EQEs) of up to ~13.1% at high brightness (~1900 cd m-2), a step forward for reduced-toxicity perovskite LEDs. Our findings offer a new solution for developing eco-friendly light-emitting technologies based on perovskite semiconductors

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Investigation on Platform for Evaluation Management and Consultation Services of Polypharmacy among Older Patients Needs of Healthcare Professionals

Background Polypharmacy is common among older patients with common diseases. There is a strong need for evaluation management and consultation services of polypharmacy among older patients from medical workers, patients and their families. However, the functional design of how to scientifically and accurately manage services and consultations based on Internet technology for different categories of users has not been adequately studied. Objective To conduct investigation on the design of the service functions and methods of platform for evaluation management and consultation services of polypharmacy among older patients for healthcare professionals, taking the Internet services oriented to improve irrational drug use and reduce drug-related adverse events in older patients as a new idea. Methods Healthcare professionals from medical institutions participating in the National Key Research and Development Program (Multiple Drug Use Risk Management for Common Diseases of the Elderly) from 2021-02-20 to 2021-03-06 were selected as research subjects, the self-designed Questionnaire on Platform for Evaluation Management and Consultation Services of Polypharmacy among Older Patients Needs of Healthcare Professionals focusing on the necessity, operation mode and function of the platform were distributed. Principal component analysis was used to extract common factors for each platform function, and further factor rotation was performed using Kaiser's normalized maximum variance method, and the mean values of each factor score were ranked to explain the relative importance of each factor. Results A total of 548 valid research questionnaires were collected in this study with recovery rate of 100.00%. The cumulative total variance explained by the third factor in the sum of squared factor extracted for the 8 platform functions (patient compliance evaluation, prescription appropriateness evaluation, prescription economy evaluation, medication administration notification and reminder, medication administration precautions, medication administration record management, potential medication problem reminder, adverse drug reactions record and analysis) was 77.036%. The 8 platform functions were finally extracted into 3 factors, named as reminder factor (F1) , evaluation factor (F2) , and adverse analysis factor (F3) , and the ranking of the mean values of the 3 factors in descending order was F1 (mean factor score of 2.977) , F2 (mean factor score of 0.118) , and F3 (mean factor score of 0.112) . Conclusion From the perspective of healthcare professionals, reminder, evaluation and adverse analysis are the main operation modes and core functions of the platform for evaluation management and consultation services of polypharmacy among older patients, with reminder-related functions as the most important functions, which will provide substantial help to ensure the effective contribution of the platform to the construction of polypharmacy risk monitoring and control system for common diseases of the elderly in China

Investigation on Platform for Evaluation Management and Consultation Services of Polypharmacy among Older Patients Needs of General Population

Background Our research team has previously conducted investigation on platform for evaluation management and consultation services of polypharmacy among older patients needs of healthcare professionals to ensure a close association between the design and development of the platform and actual needs. However, the awareness of the risks associated with polypharmacy in the elderly and needs of manage services and consultations based on Internet among general population have been rarely reported in China. Objective To understand the awareness of platform for evaluation management and consultation services of polypharmacy among older patients of general population, so as to further explore the operation mode of the platform and provide guidance for its improvement and refinement. Methods The self-designed Questionnaire on Platform for Evaluation Management and Consultation Services of Polypharmacy among Older Patients Needs of General Population focusing on the operation mode and importance of each function were distributed to the users of HeFen Club platform of China Mobile from 2021-09-29 to 2021-10-09, using HeFen Club WeChat public platform of China Mobile as the investigation platform and web-based questionnaire survey for general population as the investigation method. Principal component analysis was used to extract common factors for each platform function, and Kaiser's normalized maximum variance method was further used to rotate the factors and rank the mean scores of each factor to explain the relative importance of each factor. Results A total of 29 502 valid questionnaires were collected in this study with a recovery rate of 94.89%. The cumulative total variance explained by the fourth factor in the sum of squared factor extracted for the 12 platform functions (patient compliance evaluation, prescription appropriateness evaluation, prescription economy evaluation, medication administration notification and reminder, medication administration precautions, medication administration record management, potential medication problem reminder, manual real-time consultation, manual non-real-time consultation, self-service query, medication administration reminder, and record analysis) was 76.791%; The 12 platform functions were finally extracted into 4 factors, named as reminder factor (F1) , evaluation factor (F2) , query and record factor (F3) and consultation factor (F4) , and the ranking of the mean values of the 4 factors in descending order was F2 (mean factor score of 0.507) , F1 (mean factor score of 0.457) , F3 (mean factor score of 0.430) , and F4 (mean factor score of 0.253) . Conclusion Nearly 90.00% of the respondents believe that older adults with multiple common diseases are at risk of polypharmacy and need a platform for management and consultation services of polypharmacy. From a public perspective, reminder, evaluation, querying and record, consultation are the main operation modes and core functions of the platform for evaluation management and consultation services of polypharmacy among older patients

Light absorption and emission in photovoltaic devices

Historically, light absorption and emission has long been of broad interest in photovoltaic research, where these processes have been not only optimized for a high conversion efficiency but investigated to develop reliable optical characterization techniques. Although various aspects are being perfected, some issues remain unsolved due to their complexity; new technical issues also arise as solar cell technology evolves, where rapid adjustment is required to keep pace with the development.This thesis covers multiple topics relevant to the field, contributing to both the physics and characterization of solar cells. First, as a complement to Shockley’s p-n junction diode theory, an investigation of optoelectronic transport in arbitrary three-dimensional solar cell geometries shows that the ideal solar cell equation retains its traditional form in the presence of photon recycling, which however improves the dark saturation and light-generated currents. Then, taking note of developments over recent years, the applicability of spectral response analysis is reassessed as a means of determining cell optical and electrical properties, giving rise not only to extended applicability to front surface field cells, but new blue response and simplified infrared response analyses. After that, increased insights into band luminescence imaging of operational devices are provided through analytic study. With the dependence clearly illustrated, the present analytical approach not only simplifies results when local spatial uniformity is assumed, but allows more insights into the impact of lateral carrier injection as an operational feature increasingly evident in high efficiency solar cells. Finally, radiative coupling between the cells in tandem stacks is investigated as an increasingly important factor for tandem devices where energy conversion efficiency now exceeds 46%. The investigation not only extends earlier coupling models to account for both electroluminescent and photoluminescent coupling components, but provides more general insight into the impact on device performance and demonstrates an equivalent circuit approach as an efficient means of clarifying the complex interactions involved

Ultralow-voltage operation of light-emitting diodes.

For a light-emitting diode (LED) to generate light, the minimum voltage required is widely considered to be the emitter's bandgap divided by the elementary charge. Here we show for many classes of LEDs, including those based on perovskite, organic, quantum-dot and III-V semiconductors, light emission can be observed at record-low voltages of 36-60% of their bandgaps, exhibiting a large apparent energy gain of 0.6-1.4 eV per photon. For 17 types of LEDs with different modes of charge injection and recombination (dark saturation currents of ~10-39-10-15 mA cm-2), their emission intensity-voltage curves under low voltages show similar behaviours. These observations and their consistency with the diode simulations suggest the ultralow-voltage electroluminescence arises from a universal origin-the radiative recombination of non-thermal-equilibrium band-edge carriers whose populations are determined by the Fermi-Dirac function perturbed by a small external bias. These results indicate the potential of low-voltage LEDs for communications, computational and energy applications

The fundamental issues in the controversy of the policy paradigms: policies, theories, and underpinnings

SIGLEBibliothek Weltwirtschaft Kiel C 152640 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

A Bayesian reanalysis of the Standard versus Accelerated Initiation of Renal-Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial

Background Timing of initiation of kidney-replacement therapy (KRT) in critically ill patients remains controversial. The Standard versus Accelerated Initiation of Renal-Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial compared two strategies of KRT initiation (accelerated versus standard) in critically ill patients with acute kidney injury and found neutral results for 90-day all-cause mortality. Probabilistic exploration of the trial endpoints may enable greater understanding of the trial findings. We aimed to perform a reanalysis using a Bayesian framework. Methods We performed a secondary analysis of all 2927 patients randomized in multi-national STARRT-AKI trial, performed at 168 centers in 15 countries. The primary endpoint, 90-day all-cause mortality, was evaluated using hierarchical Bayesian logistic regression. A spectrum of priors includes optimistic, neutral, and pessimistic priors, along with priors informed from earlier clinical trials. Secondary endpoints (KRT-free days and hospital-free days) were assessed using zero–one inflated beta regression. Results The posterior probability of benefit comparing an accelerated versus a standard KRT initiation strategy for the primary endpoint suggested no important difference, regardless of the prior used (absolute difference of 0.13% [95% credible interval [CrI] − 3.30%; 3.40%], − 0.39% [95% CrI − 3.46%; 3.00%], and 0.64% [95% CrI − 2.53%; 3.88%] for neutral, optimistic, and pessimistic priors, respectively). There was a very low probability that the effect size was equal or larger than a consensus-defined minimal clinically important difference. Patients allocated to the accelerated strategy had a lower number of KRT-free days (median absolute difference of − 3.55 days [95% CrI − 6.38; − 0.48]), with a probability that the accelerated strategy was associated with more KRT-free days of 0.008. Hospital-free days were similar between strategies, with the accelerated strategy having a median absolute difference of 0.48 more hospital-free days (95% CrI − 1.87; 2.72) compared with the standard strategy and the probability that the accelerated strategy had more hospital-free days was 0.66. Conclusions In a Bayesian reanalysis of the STARRT-AKI trial, we found very low probability that an accelerated strategy has clinically important benefits compared with the standard strategy. Patients receiving the accelerated strategy probably have fewer days alive and KRT-free. These findings do not support the adoption of an accelerated strategy of KRT initiation