547 research outputs found

    Effect of Aging Treatment on Surface Roughness, Mechanical Properties, and Fracture Behavior of 6xxx and 7xxx Aluminum Alloys

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    The effect of aging treatment on the surface roughness and mechanical properties of AA6061 and AA7075 alloys was studied. Microhardness and tensile tests were used to investigae the mechanical properties. X-ray diffraction analysis was used to investigate the surface of the specimens. Furthermore, after tensile tests fractured surfaces were examined with scanning electron microscopy. An atomic force microscope was employed for analysis of the effect of aging treatment on surface roughness. Higher surface roughness with an increase in the volume fraction of the precipitate was revealed.Исследовано влияние процесса старения на шероховатость поверхности и механические свойства алюминиевых сплавов AA6061 и AA7075. Механические свойства исследовали при испытаниях на микротвердость и растяжение. Поверхность образцов исследовали с помощью рентгеноструктурного анализа. После испытания на растяжение поверхность разрушения исследовали методом растровой электронной микроскопии. Влияние процесса старения на шероховатость поверхности изучали с помощью атомно-силового микроскопа. Показано, что с ростом шероховатости поверхности увеличивается количество выделившихся фаз.Досліджено вплив процесу старіння на шорсткість поверхні і механічні властивості алюмінієвих сплавів АА6061 та АА7075. Механічні властивості досліджували при випробуваннях на мікротвердість і розтяг. Поверхню зразків досліджували за допомогою рентгеноструктурного аналізу. Після випробувань на розтяг поверхню руйнування досліджували методом растрової електронної мікроскопії. Вплив процесу старіння на шорсткість поверхні вивчали за допомогою атомно-силового мікроскопа. Показано, що з ростом шорсткості поверхні збільшується кількість виділених фа

    A sub-group of patients with hospital-acquired pneumonia do not require broad-spectrum gram-negative antimicrobial coverage

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    C.D.R. is supported by an Edinburgh Clinical Academic Track (ECAT)/Wellcome Trust PhD Training Fellowship for Clinicians award (214178/Z/18/Z).Among 200 patients developing hospital-acquired pneumonia (HAP) outside the intensive care unit, 61% were treated empirically without broad-spectrum Gram-negative coverage, with clinical cure in 69.7%. Lower disease severity markers (systemic inflammatory response syndrome, hypoxia, tachypnoea, neutrophilia) and the absence of diabetes mellitus and prior doxycycline treatment (but not the time to HAP onset) identified patients not requiring broad-spectrum Gram-negative coverage.Publisher PDFPeer reviewe

    A Digital Revival of Oriental Studies

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    The Digital Orientalist est une revue numérique à la fois multidisciplinaire et internationale qui publie des courts articles sur l’utilisation des méthodes numériques et des technologies d’information dans les études orientales. Elle contient des articles sur les divers sujets écrits par les chercheurs, étudiants et bibliothécaires de différents pays. Les études islamiques, les études japonaises et asiatiques, l’archéologie, l’informatique, la cartographie numérique, les études africaines et les études indiennes sont parmi ces sujets. Cet article vise à expliquer la raison d’être de la revue ainsi que la façon dont la revue utilise le terme « orientaliste ». Il fait valoir l’importance de l’utilisation des nouvelles technologies d’information dans la recherche et l’enseignement des études orientales.The Digital Orientalist is a multidisciplinary and international online magazine that publishes short articles on using information technologies and digital humanities methods in Oriental Studies disciplines. It consists of the articles on a variety of topics written by scholars, students and librarians from different countries. These topics include but not limited to Islamic Studies, Japanese and East Asian Studies, Archaeology, Information Science, Digital Cartography, African Studies and Indian Studies. This article aims to explain the Digital Orientalist’s raison d’être as well as the way it uses the term “Orientalist”. It highlights the importance of the new technologies and digital humanities in research and teaching of Oriental Studies

    From von Neumann architecture and Atanasoff’s ABC to Neuromorphic Computation and Kasabov’s NeuCube. Part II: Applications

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    Spatio/Spector-Temporal Data (SSTD) analyzing is a challenging task, as temporal features may manifest complex interactions that may also change over time. Making use of suitable models that can capture the “hidden” interactions and interrelationship among multivariate data, is vital in SSTD investigation. This chapter describes a number of prominent applications built using the Kasabov’s NeuCube-based Spiking Neural Network (SNN) architecture for mapping, learning, visualization, classification/regression and better understanding and interpretation of SSTD

    Competing health risks associated with the COVID-19 pandemic and early response : a scoping review

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    Funding: Amrita Rao is supported in part by the National Institute of Mental Health [F31MH124458]. Carrie Lyons is supported by the National Institute of Mental Health [F31MH128079] and by the National Institute of Allergy and Infectious Diseases Johns Hopkins HIV Epidemiology and Prevention Sciences Training Program [T32AI102623-08]. Julia Marcus is supported in part by the National Institute of Allergy and Infectious Diseases [K01AI122853]. Sharmistha Mishra is supported by a Tier 2 Canada Research Chair in Mathematical Modeling. Refilwe Nancy Phaswana-Mafuya is supported by the South African Medical Research Council.Background : COVID-19 has rapidly emerged as a global public health threat with infections recorded in nearly every country. Responses to COVID-19 have varied in intensity and breadth, but generally have included domestic and international travel limitations, closure of non-essential businesses, and repurposing of health services. While these interventions have focused on testing, treatment, and mitigation of COVID-19, there have been reports of interruptions to diagnostic, prevention, and treatment services for other public health threats. Objectives : We conducted a scoping review to characterize the early impact of COVID-19 on HIV, tuberculosis, malaria, sexual and reproductive health, and malnutrition. Methods : A scoping literature review was completed using searches of PubMed and preprint servers (medRxiv/bioRxiv) from November 1st, 2019 to October 31st, 2020, using Medical Subject Headings (MeSH) terms related to SARS-CoV-2 or COVID-19 and HIV, tuberculosis, malaria, sexual and reproductive health, and malnutrition. Empiric studies reporting original data collection or mathematical models were included, and available data synthesized by region. Studies were excluded if they were not written in English. Results : A total of 1604 published papers and 205 preprints were retrieved in the search. Overall, 8.0% (129/1604) of published studies and 10.2% (21/205) of preprints met the inclusion criteria and were included in this review: 7.3% (68/931) on HIV, 7.1% (24/339) on tuberculosis, 11.6% (26/224) on malaria, 7.8% (19/183) on sexual and reproductive health, and 9.8% (13/132) on malnutrition. Thematic results were similar across competing health risks, with substantial indirect effects of the COVID-19 pandemic and response on diagnostic, prevention, and treatment services for HIV, tuberculosis, malaria, sexual and reproductive health, and malnutrition. Discussion : COVID-19 emerged in the context of existing public health threats that result in millions of deaths every year. Thus, effectively responding to COVID-19 while minimizing the negative impacts of COVID-19 necessitates innovation and integration of existing programs that are often siloed across health systems. Inequities have been a consistent driver of existing health threats; COVID-19 has worsened disparities, reinforcing the need for programs that address structural risks. The data reviewed here suggest that effective strengthening of health systems should include investment and planning focused on ensuring the continuity of care for both rapidly emergent and existing public health threats.Publisher PDFPeer reviewe

    Genetics and epigenetics of liver cancer

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    Hepatocellular carcinoma (HCC) represents a major form of primary liver cancer in adults. Chronic infections with hepatitis B (HBV) and C (HCV) viruses and alcohol abuse are the major factors leading to HCC. This deadly cancer affects more than 500,000 people worldwide and it is quite resistant to conventional chemo- and radiotherapy. Genetic and epigenetic studies on HCC may help to understand better its mechanisms and provide new tools for early diagnosis and therapy. Recent literature on whole genome analysis of HCC indicated a high number of mutated genes in addition to well-known genes such as TP53, CTNNB1, AXIN1 and CDKN2A, but their frequencies are much lower. Apart from CTNNB1 mutations, most of the other mutations appear to result in loss-of-function. Thus, HCC-associated mutations cannot be easily targeted for therapy. Epigenetic aberrations that appear to occur quite frequently may serve as new targets. Global DNA hypomethylation, promoter methylation, aberrant expression of non-coding RNAs and dysregulated expression of other epigenetic regulatory genes such as EZH2 are the best-known epigenetic abnormalities. Future research in this direction may help to identify novel biomarkers and therapeutic targets for HCC. © 2013 Elsevier B.V

    Outcomes of COVID-19 related hospitalization among people with HIV in the ISARIC WHO Clinical Characterization Protocol (UK):a prospective observational study

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    BACKGROUND:Evidence is conflicting about how HIV modulates COVID-19. We compared the presentation characteristics and outcomes of adults with and without HIV who were hospitalized with COVID-19 at 207 centers across the United Kingdom and whose data were prospectively captured by the ISARIC WHO CCP study. METHODS:We used Kaplan-Meier methods and Cox regression to describe the association between HIV status and day-28 mortality, after separate adjustment for sex, ethnicity, age, hospital acquisition of COVID-19 (definite hospital acquisition excluded), presentation date, ten individual comorbidities, and disease severity at presentation (as defined by hypoxia or oxygen therapy). RESULTS:Among 47,592 patients, 122 (0.26%) had confirmed HIV infection and 112/122 (91.8%) had a record of antiretroviral therapy. At presentation, HIV-positive people were younger (median 56 versus 74 years; p<0.001) and had fewer comorbidities, more systemic symptoms and higher lymphocyte counts and C-reactive protein levels. The cumulative day-28 mortality was similar in the HIV-positive vs. HIV-negative groups (26.7% vs. 32.1%; p=0.16), but in those under 60 years of age HIV-positive status was associated with increased mortality (21.3% vs. 9.6%; p<0.001 [log-rank test]). Mortality was higher among people with HIV after adjusting for age (adjusted hazard ratio [aHR] 1.47, 95% confidence interval [CI] 1.01-2.14; p=0.05), and the association persisted after adjusting for the other variables (aHR 1.69; 95% CI 1.15-2.48; p=0.008) and when restricting the analysis to people aged <60 years (aHR 2.87; 95% CI 1.70-4.84; p<0.001). CONCLUSIONS:HIV-positive status was associated with an increased risk of day-28 mortality among patients hospitalized for COVID-19

    ATR2Cala2 from Arabidopsis-infecting downy mildew requires 4 TIR-NLR immune receptors for full recognition

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    Arabidopsis Col-0 RPP2A and RPP2B confer recognition of Arabidopsis downy mildew (Hyaloperonospora arabidopsidis [Hpa]) isolate Cala2, but the identity of the recognized ATR2Cala2 effector was unknown. To reveal ATR2Cala2, an F2 population was generated from a cross between Hpa-Cala2 and Hpa-Noks1. We identified ATR2Cala2 as a non-canonical RxLR-type effector that carries a signal peptide, a dEER motif, and WY domains but no RxLR motif. Recognition of ATR2Cala2 and its effector function were verified by biolistic bombardment, ectopic expression and Hpa infection. ATR2Cala2 is recognized in accession Col-0 but not in Ler-0 in which RPP2A and RPP2B are absent. In ATR2Emoy2 and ATR2Noks1 alleles, a frameshift results in an early stop codon. RPP2A and RPP2B are essential for the recognition of ATR2Cala2. Stable and transient expression of ATR2Cala2 under 35S promoter in Arabidopsis and Nicotiana benthamiana enhances disease susceptibility. Two additional Col-0 TIR-NLR (TNL) genes (RPP2C and RPP2D) adjacent to RPP2A and RPP2B are quantitatively required for full resistance to Hpa-Cala2. We compared RPP2 haplotypes in multiple Arabidopsis accessions and showed that all four genes are present in all ATR2Cala2-recognizing accessions

    Crimean-Congo hemorrhagic fever: epidemiological trends and controversies in treatment

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    Crimean-Congo hemorrhagic fever (CCHF) virus has the widest geographic range of all tick-borne viruses and is endemic in more than 30 countries in Eurasia and Africa. Over the past decade, new foci have emerged or re-emerged in the Balkans and neighboring areas. Here we discuss the factors influencing CCHF incidence and focus on the main issue of the use of ribavirin for treating this infection. Given the dynamics of CCHF emergence in the past decade, development of new anti-viral drugs and a vaccine is urgently needed to treat and prevent this acute, life-threatening disease
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