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  • Decoding the evolution and transmissions of the novel pneumonia coronavirus (SARS-CoV-2) using whole genomic data

    Subjects: Biology >> Virology Subjects: Biology >> Biological Evolution Subjects: Biology >> Genetics submitted time 2020-02-21

    Abstract: Background. The outbreak of COVID-19 started in mid-December 2019 in Wuhan, Central China. Up to February 18, 2020, SARS-CoV-2 has infected more than 70,000 people in China, and another 25 countries across five continents. In this study, we used 93 complete genomes of SARS-CoV-2 from the GISAID EpiFluTM database to decode the evolution and human-to-human transmissions of SARS-CoV-2 in the recent two months. Methods. Alignment of coding-regions was conducted haplotype analyses using DnaSP. Substitution sites were analyzed in codon. Evolutionary analysis of haplotypes used NETWORK. Population size changes were estimated using both DnaSP and Arlequin. Expansion date of population size was calculated based on the expansion parameter tau (τ) using the formula t=τ/2u. Findings. Eight coding-regions have 120 substitution sites, including 79 non-synonymous and 40 synonymous substitutions. Forty-two non-synonymous substitutions changed the biochemical property of amino acids. No evident combination was found. Fifty-eight haplotypes were classified as five groups, and 31 haplotypes were found in samples from both China and other countries, respectively. The rooted network suggested H13 and H35 to be ancestral haplotypes, and H1 (and its descendent haplotypes including all samples from the Hua Nan market) was derived H3 haplotype. Population size of SARS-CoV-2 were estimated to have a recent expansion on 6 January 2020, and an early expansion on 8 December 2019. Interpretation. Genomic variations of SARS-CoV-2 are still low in comparisons with published genomes of SARS-CoV and MERS-CoV. Phyloepidemiologic analyses indicated the SARS-CoV-2 source at the Hua Nan market should be imported from other places. The crowded market boosted SARS-CoV-2 rapid circulations in the market and spread it to the whole city in early December 2019. Furthermore, phyloepidemiologic approaches have recovered specific direction of human-to-human transmissions, and the import sources of international infectious cases.

  • Heterogeneity in cancer stem cells

    Subjects: Biology >> Biophysics >> Oncology submitted time 2016-05-11

    Abstract: Accumulating evidence suggests that cancer stem cells (CSCs) are heterogeneous populations and their phenotypes are unstable. A number of intrinsic and extrinsic mechanisms contribute to CSC phenotypic variation. The existence of various CSC subpopulations which would lead to a rapid relapse after primary treatments might pose a problem for CSC targeted therapeutics. In order to develop more effective approaches to cancer therapeutics, more CSC-related surface markers or targeting molecules, as well as some novel targeting strategies should be explored. This review summarized the origin and performance of heterogeneity in CSCs and discussed their therapeutic implications. (c) 2014 Elsevier Ireland Ltd. All rights reserved.

  • Effective Treatment of Severe COVID-19 Patients with Tocilizumab

    Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2020-03-05

    Abstract: Background: In December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in Wuhan, China, which spread rapidly and has become a world-wide public health challenge. We aimed to assess the efficacy of tocilizumab in severe patients with Corona Virus Disease-19 (COVID-19) and seek a new therapeutic strategy. Methods: The patients diagnosed as severe or critical COVID-19 in The First Affiliated Hospital of University of Science and Technology of China (Anhui Provincial Hospital) and Anhui Fuyang Second People’s Hospital were given tocilizumab in addition to routine therapy between February 5 and February 14, 2020. The changes of clinical manifestations, CT scan image, and laboratory examinations were retrospectively analyzed. Findings: Within a few days, the fever returned to normal and all other symptoms improved remarkably. Fifteen of the 20 patients (75.0%) had lowered their oxygen intake and one patient need no oxygen therapy. CT scans manifested that the lung lesion opacity absorbed in 19 patients (90.5%). The percentage of lymphocytes in peripheral blood, which decreased in 85.0% patients (17/20) before treatment (mean, 15.52 ± 8.89%), returned to normal in 52.6% patients (10/19) on the fifth day after treatment. Abnormally elevated C-reactive protein decreased significantly in 84.2% patients (16/19). No obvious adverse reactions were observed. Nineteen patients (90.5%) have been discharged on average 13.5 days after the treatment with tocilizumab and the rest are recovering well. Interpretation: Tocilizumab is an effective treatment in severe patients of COVID-19, which provided a new therapeutic strategy for this fatal infectious disease" "

  • Furin, a potential therapeutic target for COVID-19

    Subjects: Medicine, Pharmacy >> Pharmacology submitted time 2020-02-23

    Abstract: A novel coronavirus (SARS-CoV-2) infectious disease has broken out in Wuhan, Hubei Province since December 2019, and spread rapidly from Wuhan to other areas, which has been listed as an international concerning public health emergency. We compared the Spike proteins from four sources, SARS-CoV-2, SARS-CoV, MERS-CoV and Bat-CoVRaTG13, and found that the SARS-CoV-2 virus sequence had redundant PRRA sequences. Through a series of analyses, we propose the reason why SARS-CoV-2is more infectious than other coronaviruses. And through structure based virtual ligand screening, we foundpotentialfurin inhibitors, which might be used in the treatment of new coronary pneumonia. " "

  • A furin cleavage site was discovered in the S protein of the Wuhan 2019 novel coronavirus

    Subjects: Biology >> Virology submitted time 2020-02-14

    Abstract: Abstract: In 2019, the 2019 novel Coronavirus (2019-nCoV) has caused the pneumonia outbreak in Wuhan (a city of China). In our previous study, the analytical results showed that both 2019-nCoV and SARS coronavirus belongs to Betacoronavirus subgroup B (BB coronavirus), but have large differences. The most important finding was that the alternative translation of Nankai CDS could produce more than 17 putative proteins, which may be responsible for the host adaption. The genotyping of 13 viruses using the 17 putative proteins revealed the high mutation rate and diversity of betacoronavirus. The present study for the first time reported a very important mutation in the Spike (S) proteins of BB coronavirus. By this mutation, 2019-nCoV acquired a cleavage site for furin enzyme, which is not present in the S proteins of all other BB coronavirus (e.g. SARS coronavirus) except the Mouse Hepatitis coronavirus (MHV). This mutation may increase the efficiency of virus infection into cells, making 2019-nCoV has significantly stronger transmissibility than SARS coronavirus. Because of this mutation, the packing mechanism of the 2019-nCoV may be changed to being more similar to those of MHV, HIV, Ebola virus (EBoV) and some avian influenza viruses, other than those of all other BB coronavirus (e.g. SARS coronavirus) except the Mouse Hepatitis coronavirus (MHV). In addition, we unexpectedly found that some avian influenza viruses acquired a cleavage site for furin enzyme by mutation as 2019-nCoV. Further studies of this mutation will help to reveal the stronger transmissibility of 2019-nCoV and lay foundations for vaccine development and drug design of, but not limited to 2019-nCoV.

  • Bayes Factor and Its Implementation in JASP: A Practical Primer

    Subjects: Psychology >> Statistics in Psychology submitted time 2018-05-08

    Abstract: Statistical inference plays a critical role in modern scientific research, however, the dominant method for statistical inference in science, null hypothesis significance testing (NHST), is often misunderstood and misused, which leads to unreproducible findings. To address this issue, researchers propose to adopt the Bayes factor as an alternative to NHST. The Bayes factor is a principled Bayesian tool for model selection and hypothesis testing, and can be interpreted as the strength for both the null hypothesis H0 and the alternative hypothesis H1 based on the current data. Compared to NHST, the Bayes factor has the following advantages: it quantifies the evidence that the data provide for both the H0 and the H1, it is not “violently biased” against H0, it allows one to monitor the evidence as the data accumulate, and it does not depend on sampling plans. Importantly, the recently developed open software JASP makes the calculation of Bayes factor accessible for most researchers in psychology, as we demonstrated for the t-test. Given these advantages, adopting the Bayes factor will improve psychological researchers’ statistical inferences. Nevertheless, to make the analysis more reproducible, researchers should keep their data analysis transparent and open.

  • 迁移学习研究进展

    Subjects: Computer Science >> Computer Application Technology submitted time 2016-05-03

    Abstract:近年来,迁移学习已经引起了广泛的关注。迁移学习是运用已存有的知识对不同但相关领域问题进行求解的新的一种机器学习方法。传统机器学习基于两个基本假设:(1) 用于学习的训练样本与新的测试样本满足独立同分布的条件;(2) 必须有足够可利用的训练样本才能学习得到一个好的分类模型。迁移学习降低了要求,目的是迁移已有的知识来解决目标领域中仅有少量或没有有标签样本数据时的学习问题。本文对迁移学习算法以及相关理论研究进展进行了综述,并介绍了我们在该领域所做的研究工作,特别是利用生成模型在概念层面建立迁移学习模型。最后指出了迁移学习下一步可能的研究方向。

  • 大数据的核心问题与研究体系

    Subjects: Computer Science >> Computer Application Technology submitted time 2017-03-09

    Abstract:

  • 深度学习概述

    Subjects: Computer Science >> Computer Application Technology submitted time 2016-05-03

    Abstract:深度学习是机器学习领域的一个新的研究方向,其核心思想在于模拟人脑的层级抽象结构,通过无监 督的方式从大规模数据(例如图像、声音和文本)中学习特征。近年来,深度学习在计算机视觉、语音识 别等研究领域取得的巨大成功使得研究者们对其寄予更多的关注。本文从深度学习的概念、发展历程、模 型、训练方法以及应用等几个方面对其进行概述,并对深度学习的未来发展做出展望。

  • PROSODIC BOUNDARIES EFFECT ON SEGMENT ARTICULATION IN STANDARD CHINESE:AN ARTICULATORY AND ACOUSTIC STUDY

    Subjects: Linguistics and Applied Linguistics >> Linguistics and Applied Linguistics submitted time 2019-06-20

    Abstract: " This paper presents an electropalatographic (EPG) and acoustic study of prosodic boundaries effect on the domain-initial segments in Standard Chinese.1 Two speech sounds, namely, the voiceless unaspirated alveolar stop /t/ and the high front vowel /i/, were studied to examine the domain-initial strengthening in both spatial and temporal dimensions. The articulatory and acoustic parameters of the speech sounds were compared in initial positions of five prosodic constituents in Standard Chinese, namely, a Syllable, a Foot, an Immediate Phrase, an Intonational Phrase, and an Utterance. The results show that: (1) the production of the domain-initial consonantal gesture was prosodically encoded. The linguopalatal contact and the seal duration varied as a function of the prosodic boundary strength. The linguopalatal contact was dependent on the seal duration in a nonlinear fashion. Of the acoustic properties of the domain-initial stop, the total voiceless interval and voicing during closure were found to be reliable acoustic correlates that mark the hierarchical structure of the prosody. (2) At the release moment of the domain-initial stop, no consistent pattern was found to support the domain-initial strengthening. The linguopalatal contact of the vowel immediately following the domain-initial consonant did not show a clear trend of domain-initial strengthening; however, the phonatory features of vowels were indicative of pitch reset at major prosodic boundaries. These indicate that the domain-initial strengthening is restricted on the segment immediately following the boundary. In conclusion Standard Chinese strengthens the phonetic features of the domain-initial segments as a function of boundary strength, which serves as an important way to mark prosodic structure in Standard Chinese.

  • Investigation and analysis on the status quo of Chinese researchers' cognition and use of arXiv

    Subjects: Library Science,Information Science >> Library Science submitted time 2016-03-14

    Abstract: [Objective] To understand Chinese users' cognition and usage of the arXiv preprint platform, as well as their opinions and suggestions on the development of arXiv. [Methods] Based on a questionnaire survey of teachers, researchers and postgraduate groups in 9 domestic universities and scientific research institutions, the author obtained 510 survey data, and used SPSS and other analytical tools to analyze the survey data. [Results] The results show that the awareness of arXiv by Chinese researchers is not very high, but domestic researchers who are familiar with arXiv have realized that publishing papers on arXiv is an important means to occupy the first publishing rights of results and solicit peer opinions. [Limitations] The survey sampling is limited to member units of the China arXiv Service Working Group, and arXiv users of non-member units are not included. 【Conclusion】In order to allow arXiv to benefit more scientific research in my country, the China arXiv Service Working Group needs to take more active actions to accelerate the wider and in-depth application of arXiv in China.

  • 基于语言结构功能的音位负担计算方法

    Subjects: Linguistics and Applied Linguistics >> Linguistics and Applied Linguistics submitted time 2019-06-20

    Abstract: "

  • Transplantation of ACE2- mesenchymal stem cells improves the outcome of patients with COVID-19 pneumonia

    Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2020-02-28

    Abstract: A coronavirus (HCoV-19) has caused the novel coronavirus disease (COVID-19) outbreak in Wuhan, China, Preventing and reversing the cytokine storm may be the key to save the patients with severe COVID-19 pneumonia. Mesenchymal stem cells (MSCs) have been shown to possess a comprehensive powerful immunomodulatory function. This study aims to investigate whether MSC transplantation improve the outcome of 7 enrolled patients with COVID-19 pneumonia in Beijing YouAn Hospital, China from Jan 23, 2020. to Feb 16, 2020. The clinical outcomes, as well as changes of inflammatory and immune function levels and adverse effects of 7 enrolled patients were assessed for 14 days after MSC injection. MSCs could cure or significantly improve the functional outcomes of seven patients with COVID-19 pneumonia in 14 days without observed adverse effect. The pulmonary function and symptoms of all patients with COVID-19 pneumonia were significantly improved in 2 days after MSC transplantation. Among them, two common and one severe patient were recovered and discharged in 10 days after treatment. After treatment, the peripheral lymphocytes were increased and the overactivated cytokine-secreting immune cells CXCR3 CD4 T cells, CXCR3 CD8 T cells, and CXCR3 NK cells were disappeared in 3-6 days. And a group of CD14 CD11c CD11bmid regulatory DC cell population dramatically increased. Meanwhile, the level TNF-α is significantly decreased while IL-10 increased in MSC treatment group compared to the placebo control group. Furthermore, the gene expression profile showed MSCs were ACE2- and TMPRSS2- which indicated MSCs are free from COVID-19 infection. Thus, the intravenous transplantation of MSCs was safe and effective for treatment in patients with COVID-19 pneumonia, especially for the patients in critically severe condition.

  • Clinical remission of a critically ill COVID-19 patient treated by human umbilical cord mesenchymal stem cells

    Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2020-02-27

    Abstract: 该论文正式发表的链接如下:https://journals.lww.com/md-journal/Fulltext/2020/07310/Clinical_remission_of_a_critically_ill_COVID_19.79.aspx

  • COVID-19 outbreak increased risk of schizophrenia in aged adults

    Subjects: Psychology >> Clinical and Counseling Psychology Subjects: Medicine, Pharmacy >> Preventive Medicine and Hygienics submitted time 2020-02-29

    Abstract: We noticed an unusual increase of first-time patients with schizophrenia (F20) in January 2020 since the outbreak of COVID-19. The aim of this retrospective study is to validate this observation and find potential risk factors, if applicable. A total number of 13,783 records from outpatients in January 2020 were investigated thoroughly. Comparisons between incidence of schizophrenia in outpatients in January 2020 and similar periods of 2017-2019 were made to minimize seasonal influence. Relationship of incidence of schizophrenia and COVID-19 infections in China was calculated. Limited personal information (age, gender, approximate residence) was analyzed to find risk factors.After excluding seasonal factors such as Spring festival, a positive relationship between incidence of schizophrenia in first-time patients and countrywide epidemic situation was found. Statistical results further showed a significant increase of median age from 39 to 50 for first-time patients diagnosed with schizophrenia which is unusual. Meanwhile, a slight but not significant change was found in distribution of gender and approximate residence (urban/suburb). Our data supported that COVID-19 outbreak increased risk of schizophrenia in aged adults which is consistent with the fact that COVID-19 is more lethal to elders. We strongly appeal that public healthcare in countries either with or without infected patients should prepare in advance for potential risks in public mental health. "

  • Lasso regression: From explanation to prediction

    Subjects: Psychology >> Statistics in Psychology submitted time 2020-05-14

    Abstract: Psychological researches focus on describing, explaining and predicting behavior, and having a good understanding of the association between variables is an essential part of this process. Regression analysis, a method to evaluate the relationship between variables, is widely used in psychological studies. However, due to its highly focus on the interpretation of sample data, the traditional ordinary least squares regression has several drawbacks, such as over-fitting problem and limitation on dealing with multicollinearity, which may undermine the generalizability of the model. These drawbacks have an inevitable influence on the promotion and prediction of the model conclusion. With the rapid development of methodology, Least absolute shrinkage and selection operator (Lasso) regression has been emerged to better compensate for the limitations of traditional methods. By introducing a penalty term in the model and shrinking the regression coefficients to zero, Lasso regression can achieve a higher accuracy of model prediction and model generalizability with the cost of a certain estimation bias. Besides, Lasso regression can also effectively deal with the multicollinearity problem. Therefore, it has been widely used in medicine, economics, neuroscience and other fields. In psychology, due to the limitations of computer computing power, researchers used to mainly rely on hypothesis testing to understand the association among variables to verify theories. Now, with the rapid development of machine learning, a shift from focusing on interpretation of the regression coefficients to improving the prediction of the model has emerged and become more and more important. Therefore, based on fundamental theories and real data analysis, the aim of this paper is to introduce the principles, implementation steps and advantages of the Lasso regression. With the help of statistic science, it is promising that more and more applied researchers will be called upon to focus on the emerging statistical tools to promote the development of psychology.

  • 2019-nCoV Spatiotemporal datasets and typical applications

    Subjects: Survey & Drawing Science and Technology >> Photogrammetry and Remote Sensing Subjects: Medicine, Pharmacy >> Preventive Medicine and Hygienics Subjects: Statistics >> Biomedical Statistics submitted time 2020-02-19

    Abstract: " "

  • Research progress of biomagnetic receptor protein MagR/IscA

    Subjects: Biology >> Molecular Biology submitted time 2016-06-16

    Abstract: Iron-sulfur cluster proteins are a class of important mitochondrial functional proteins that play key roles in cellular energy metabolism, electron transport, substrate binding and activation, iron/sulfur storage, enzymatic reactions, and regulation of gene expression. Obstruction in the assembly and transport of iron-sulfur clusters will seriously affect the homeostasis of intracellular iron and the function of iron-sulfur proteins. Among them, IscA with a molecular weight of about 11-kDa is a highly conserved member of the iron-sulfur protein subfamily hesB. It can bind iron ions and [2Fe-2S] clusters, thereby participating in the synthesis of iron-sulfur cluster proteins, so it plays an important role in the iron-sulfur cluster assembly protein system. More noteworthy is that in 2015, Xie Can and Zhang Shengjia respectively The research group found that IscA1 has unique magnetic sensor (MagS) and magnetic receptor (MagR) functions. More importantly, it can regulate neural activity and behavioral localization by stimulating the expression of related magnetic genes through an external magnetic field. In view of the unique functions of magnetic receptors combined with related technologies, they are collectively referred to as magnetogenetics (magnetic genetics). This article briefly introduces the initial discovery and identification process of IscA protein, evolutionary conservation and its unique physiological and biological functions. , and condensed the mechanism regulation model of the magnetic genetic hypothesis.

  • 金庸小说人物的大五人格—基于文心系统的15部金庸小说分析

    Subjects: Psychology >> Personality Psychology submitted time 2018-02-12

    Abstract:[目的]从心理学的角度全面分析金庸小说人物人格与创作阶段、性别之间的关系。[方法]本文通过创作阶段对金庸15部小说进行划分,采用基于数据挖掘的文学智能分析方法,通过中文心理分析系统对人物对话进行处理,得到人物的大五人格预测分数。[结果] 女性人物的神经质倾向高于男性人物;创作阶段影响小说人物的尽责性、外向性倾向。[局限]仅仅对小说中的人物进行了分析,没有和金庸本人生平经历和创作时代特点相结合。[结论]本文从心理学人格理论出发探讨金庸小说的人物描写特点,丰富了“金学”的研究成果,为研究金庸的人物刻画风格与偏好提供了新的视角。

  • Copula Entropy: Theory and Applications

    Subjects: Mathematics >> Statistics and Probability Subjects: Statistics >> Mathematical Statistics Subjects: Information Science and Systems Science >> Basic Disciplines of Information Science and Systems Science submitted time 2024-04-11

    Abstract: Statistical independence is a core concept in statistics and machine learning. Representing and measuring independence are of fundamental importance in related fields. Copula theory provides the tool for representing statistical independence, while Copula Entropy (CE) presents the tool for measuring statistical independence. This paper first introduces the theory of CE, including its definition, theorem, properties, and estimation method. The theoretical applications of CE to structure learning, association discovery, variable selection, causal discovery, system identification, time lag estimation, domain adaptation, multivariate normality test, two-sample test, and change point detection are reviewed. The relationships between the former four applications and their connection to correlation and causality are discussed. The frameworks based on CE, the kernel method, and distance correlation for measuring statistical independence and conditional independence are compared. The advantage of CE over other independence and conditional independence measures is evaluated. The applications of CE in theoretical physics, astrophysics, geophysics, theoretical chemistry, cheminformatics, materials science, hydrology, climatology, meteorology, environmental science, ecology, animal morphology, agronomy, cognitive neuroscience, motor neuroscience, computational neuroscience, psychology, system biology, bioinformatics, clinical diagnostics, geriatrics, psychiatry, public health, economics, management, sociology, pedagogy, computational linguistics, mass media, law, political science, military science, informatics, energy, food engineering, architecture, civil engineering, transportation, manufacturing, reliability, metallurgy, chemical engineering, aeronautics and astronautics, weapon, automobile, electronics, communication, high performance computing, cybersecurity, remote sensing, and finance are briefly introduced.