564 research outputs found

    Intertwined chiral charge orders and topological stabilization of the light-induced state of a prototypical transition metal dichalcogenide

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    The fundamental idea that the constituents of interacting many body systems in complex quantum materials may self-organise into long range order under highly non-equilibrium conditions leads to the notion that entirely new and unexpected functionalities might be artificially created. However, demonstrating new emergent order in highly non-equilibrium transitions has proven surprisingly difficult. In spite of huge recent advances in experimental ultrafast time-resolved techniques, methods that average over successive transition outcomes have so far proved incapable of elucidating the emerging spatial structure. Here, using scanning tunneling microscopy, we report for the first time the charge order emerging after a single transition outcome in a prototypical two-dimensional dichalcogenide 1T-TaS2_2 initiated by a single optical pulse. By mapping the vector field of charge displacements of the emergent state, we find surprisingly intricate, long-range, topologically non-trivial charge order in which chiral domain tiling is intertwined with unique unpaired dislocations which play a crucial role in enhancing the emergent states remarkable stability. The discovery of the principles that lead to metastability in charge-ordered systems open the way to designing novel emergent functionalities, particularly ultrafast all-electronic non-volatile cryo-memories.Comment: preprint version of the paper published in npj Quantum Material

    Differential Diagnosis of Monotonous Fetal Heart Rate

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    The aim was to explore the possibility to forecast a risk of hypoxic lesions in a monotonous fetal heart rate via ECG measurements by the methods of time and frequency analysis. The study involved 50 healthy pregnant women with singleton pregnancy at 37-41 weeks of gestation along with 17 pregnant women in the same period of gestation who had a monotonous fetal heart rate registered of various origin. The registration of fetal heart rates was performed using fetal monitor “Monica AN24” (“Monica Healthcare Ltd”, United Kingdom), transabdominal, using ECG electrodes. The software package “Monica DK” has been used to retrieve the “beat-to-beat” data. Analysis of experimental data was carried out on the basis of LABVIEW® software (National Instruments®, USA). The analysis of time parameters for fetal hypoxia showed a sharp decline in the spread function and a sharp increase in the concentration function. Spectral analysis showed a significant decrease in the ratio of high- to low-frequency components of the spectrum. In the analysis of fetal ECG, the ST segment depression was noted, which is also indicative of fetal hypoxia

    Regional differences in AIDS and non-AIDS related mortality in HIV-positive individuals across Europe and Argentina: the EuroSIDA study

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    BACKGROUND Differences in access to care and treatment have been reported in Eastern Europe, a region with one of the fastest growing HIV epidemics, compared to the rest of Europe. This analysis aimed to establish whether there are regional differences in the mortality rate of HIV-positive individuals across Europe, and Argentina. METHODS 13,310 individuals under follow-up were included in the analysis. Poisson regression investigated factors associated with the risk of death. FINDINGS During 82,212 person years of follow-up (PYFU) 1,147 individuals died (mortality rate 14.0 per 1,000 PYFU (95% confidence interval [CI] 13.1-14.8). Significant differences between regions were seen in the rate of all-cause, AIDS and non-AIDS related mortality (global p<0.0001 for all three endpoints). Compared to South Europe, after adjusting for baseline demographics, laboratory measurements and treatment, a higher rate of AIDS related mortality was observed in East Europe (IRR 2.90, 95%CI 1.97-4.28, p<.0001), and a higher rate of non-AIDS related mortality in North Europe (IRR 1.51, 95%CI 1.24-1.82, p<.0001). The differences observed in North Europe decreased over calendar-time, in 2009-2011, the higher rate of non-AIDS related mortality was no longer significantly different to South Europe (IRR 1.07, 95%CI 0.66-1.75, p = 0.77). However, in 2009-2011, there remained a higher rate of AIDS-related mortality (IRR 2.41, 95%CI 1.11-5.25, p = 0.02) in East Europe compared to South Europe in adjusted analysis. INTERPRETATIONS There are significant differences in the rate of all-cause mortality among HIV-positive individuals across different regions of Europe and Argentina. Individuals in Eastern Europe had an increased risk of mortality from AIDS related causes and individuals in North Europe had the highest rate of non-AIDS related mortality. These findings are important for understanding and reviewing HIV treatment strategies and policies across the European region

    A survey of multi-task learning methods in chemoinformatics

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    Despite the increasing volume of available data, the proportion of experimentally measured data remains small compared to the virtual chemical space of possible chemical structures. Therefore, there is a strong interest in simultaneously predicting different ADMET and biological properties of molecules, which are frequently strongly correlated with one another. Such joint data analyses can increase the accuracy of models by exploiting their common representation and identifying common features between individual properties. In this work we review the recent developments in multi-learning approaches as well as cover the freely available tools and packages that can be used to perform such studies

    Prokineticin Receptor-1 Signaling Inhibits Dose- and Time-Dependent Anthracycline-Induced Cardiovascular Toxicity Via Myocardial and Vascular Protection

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    Abstract Background High prevalence of heart failure during and following cancer treatments remains a subject of intense research and therapeutic interest. Objectives This study investigated how different concentrations of doxorubicin (DOX) can affect the function of the cardiac cells. This study also examined whether activation of prokineticin receptor-1 (PKR1) by a nonpeptide agonist, IS20, prevents DOX-induced cardiovascular toxicity in mouse models. Methods We used cultured cardiomyocytes, endothelial cells (ECs), and epicardium-derived progenitor cells (EPDCs) for in vitro, assays and tumor-bearing and acute and chronic toxicity mouse models for in vivo assays. Results Brief exposure to cardiomyocytes with high-dose DOX increases the accumulation of reactive oxygen species (ROS) by inhibiting a detoxification mechanism via stabilization of cytoplasmic NRF2. Prolonged exposure to medium-dose DOX induces apoptosis in cardiomyocytes, ECs, and EPDCs. However, low-dose DOX promotes functional defects without inducing apoptosis in EPDCs and ECs. IS20 alleviates detrimental effects of DOX in cardiac cells via activating AKT or mitogen-activated protein kinase pathways. Genetic or pharmacological inactivation of PKR1 subdues these effects of IS20. In a chronic mouse model of DOX cardiotoxicity, IS20 normalizes an elevated serum marker of cardiotoxicity and vascular and EPDC deficits, attenuates apoptosis and fibrosis, and improves the survival rate and cardiac function. IS20 does not interfere with the cytotoxicity or antitumor effects of DOX in breast cancer lines or in a mouse model of breast cancer but attenuates the decreases in LV diastolic volume induced by acute DOX treatment. Conclusions This study identifies the molecular and cellular signature of dose-dependent DOX-mediated cardiotoxicity and provides evidence that PKR1 is a promising target to combat cardiotoxicity of cancer treatments

    Active Learning for Image Recognition Using a Visualization-Based User Interface

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    Limberg C, Krieger K, Wersing H, Ritter H. Active Learning for Image Recognition Using a Visualization-Based User Interface. In: Tetko IV, Kůrková V, Karpov P, Theis F, eds. Artificial Neural Networks and Machine Learning – ICANN 2019: Deep Learning. Lecture Notes in Computer Science. Vol 11728. Cham: Springer; 2019: 495-506

    Persistent disparities in antiretroviral treatment (ART) coverage and virological suppression across Europe, 2004 to 2015

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    Background: Direct comparisons between countries in core HIV care parameters are often hampered by differences in data collection. Aim: Within the EuroSIDA study, we compared levels of antiretroviral treatment (ART) coverage and virological suppression (HIV RNA < 500 copies/mL) across Europe and explored temporal trends. Methods: In three cross-sectional analyses in 2004—05, 2009—10 and 2014—15, we assessed country-specific percentages of ART coverage and virological suppression among those on ART. Temporal changes were analysed using logistic regression. Results: Overall, the percentage of people on ART increased from 2004—05 (67.8%) to 2014—15 (78.2%), as did the percentage among those on ART who were virologically suppressed (75.2% in 2004—05, 87.7% in 2014—15). However, the rate of improvement over time varied significantly between regions (p < 0.01). In 2014—15, six of 34 countries had both ART coverage and virological suppression of above 90% among those on ART. The pattern varied substantially across clinics within countries, with ART coverage ranging from 61.9% to 97.0% and virological suppression from 32.2% to 100%. Compared with Western Europe (as defined in this study), patients in other regions were less likely to be virologically suppressed in 2014—15, with the lowest odds of suppression (adjusted odds ratio = 0.16; 95% confidence interval (CI): 0.13—0.21) in Eastern Europe. Conclusions: Despite overall improvements over a decade, we found persistent disparities in country-specific estimates of ART coverage and virological suppression. Underlying reasons for this variation warrant further analysis to identify a best practice and benchmark HIV care across EuroSIDA

    Electrophysical Characteristics of a Polymer Composite Based on Ultrahigh Molecular Weight Polyethylene with CuO Nanoparticles

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    Методом импедансной спектроскопии исследованы электрофизические свойства композитного материала на основе сверхвысокомолекулярного полиэтилена с ограниченной массовой концентрацией 0,5 мас.% оксида меди CuO в диапазоне частот от 102 до 108 Гц. Предполагается, что введение в состав полимера малых концентраций наночастиц способствует более равномерному их осаждению на поверхностях полимерных гранул. Это позволяет в процессе тестирования таких образцов выявить наиболее вероятные механизмы их поляризации и протекания электрического тока в относительно однородном ансамбле наночастиц в полимерной матрице. Установлено, что внедряемые в полимерную матрицу наночастицы незначительно влияют на процессы электрической поляризации, но приводят к появлению частотно-зависимой проводимости в широком диапазоне частот. Этот процесс сопровождается существенным возрастанием диэлектрических потерь. Электрофизические характеристики полученных композитов обсуждаются с учётом переноса электрических зарядов (ионов или электронов) как по внутренней, так и по поверхностной структуре наночастиц CuOThe electrophysical properties of a composite material based on ultrahigh molecular weight polyethylene with a limited mass concentration of 0.5 wt% copper oxide CuO in the frequency range from 102 to 108 Hz were studied by impedance spectroscopy. It is assumed that the introduction of low concentrations of nanoparticles into the polymer composition contributes to their more uniform deposition on the surfaces of polymer granules. This makes it possible to reveal the most probable mechanisms of their polarization and the flow of electric current in a relatively homogeneous ensemble of nanoparticles in a polymer matrix during testing of such samples. It has been established that nanoparticles introduced into the polymer matrix have little effect on the processes of electric polarization, but lead to the appearance of frequency-dependent conductivity in a wide frequency range. This process is accompanied by a significant increase in dielectric losses. The electrophysical characteristics of the resulting composites are discussed taking into account the transfer of electric charges (ions or electrons) both along the internal and surface structures of CuO nanoparticle
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