Improvement of the Photocatalytic Activity of ZnO/Burkeite Heterostructure Prepared by Combustion Method

In this work, a novel route is discussed to produce in one step ZnO/Burkeite powders by the modified solution combustion method. The ZnO particles enhance the photocatalytic activity in the degradation of Rhodamine B, in which Burkeite mineral acts as a support due to the pH-dependent morphology of the particle aggregates of the as-synthesized powders. The X-ray diffraction (XRD) characterization shows the presence of a heterostructure: ZnO/Burkeite. The Scanning Electron Microscopy (SEM) image shows a morphological dependence with the pH of the solution used for the synthesis. The results show that the system with the highest degradation (92.4%) corresponds to the case in which ZnO/Burkeite heterostructure was synthesized with a pH 11

Liberando a los cuestionarios de Moodle de los ordenadores

El uso de cuestionarios Moodle ha demostrado su eficacia como sistema de evaluación y autoaprendizaje en la docencia; sin embargo, su aplicación se restringe por la necesidad de emplear un ordenador por usuario limitándose su potencial uso dentro de las aulas y marcadamente en grupos numerosos.El uso de Sistema de Respuesta Personal (PRS) aplicados en Moodle libera estas limitaciones con requerimientos de hardware mínimos, favoreciendo el feedback y aportando información instantánea. En este trabajo se expone la forma de aplicar los PRS dentro de campus virtuales para los casos de uso en evaluación y aprendizaje significativo en clases.Peer Reviewe

Global Impact of COVID-19 on Stroke Care and IV Thrombolysis

OBJECTIVE: To measure the global impact of COVID-19 pandemic on volumes of IV thrombolysis (IVT), IVT transfers, and stroke hospitalizations over 4 months at the height of the pandemic (March 1 to June 30, 2020) compared with 2 control 4-month periods. METHODS: We conducted a cross-sectional, observational, retrospective study across 6 continents, 70 countries, and 457 stroke centers. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases. RESULTS: There were 91,373 stroke admissions in the 4 months immediately before compared to 80,894 admissions during the pandemic months, representing an 11.5% (95% confidence interval [CI] -11.7 to -11.3, p < 0.0001) decline. There were 13,334 IVT therapies in the 4 months preceding compared to 11,570 procedures during the pandemic, representing a 13.2% (95% CI -13.8 to -12.7, p < 0.0001) drop. Interfacility IVT transfers decreased from 1,337 to 1,178, or an 11.9% decrease (95% CI -13.7 to -10.3, p = 0.001). Recovery of stroke hospitalization volume (9.5%, 95% CI 9.2-9.8, p < 0.0001) was noted over the 2 later (May, June) vs the 2 earlier (March, April) pandemic months. There was a 1.48% stroke rate across 119,967 COVID-19 hospitalizations. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was noted in 3.3% (1,722/52,026) of all stroke admissions. CONCLUSIONS: The COVID-19 pandemic was associated with a global decline in the volume of stroke hospitalizations, IVT, and interfacility IVT transfers. Primary stroke centers and centers with higher COVID-19 inpatient volumes experienced steeper declines. Recovery of stroke hospitalization was noted in the later pandemic months. © 2021 American Academy of Neurology

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 science. © The Author(s) 2019. Published by Oxford University Press