70 research outputs found

    m6A reader proteins: the executive factors in modulating viral replication and host immune response

    Get PDF
    N6-Methyladenosine (m6A) modification is the most abundant covalent modification of RNA. It is a reversible and dynamic process induced by various cellular stresses including viral infection. Many m6A methylations have been discovered, including on the genome of RNA viruses and on RNA transcripts of DNA viruses, and these methylations play a positive or negative role on the viral life cycle depending on the viral species. The m6A machinery, including the writer, eraser, and reader proteins, achieves its gene regulatory role by functioning in an orchestrated manner. Notably, data suggest that the biological effects of m6A on target mRNAs predominantly depend on the recognition and binding of different m6A readers. These readers include, but are not limited to, the YT521-B homology (YTH) domain family, heterogeneous nuclear ribonucleoproteins (HNRNPs), insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs), and many others discovered recently. Indeed, m6A readers have been recognized not only as regulators of RNA metabolism but also as participants in a variety of biological processes, although some of these reported roles are still controversial. Here, we will summarize the recent advances in the discovery, classification, and functional characterization of m6A reader proteins, particularly focusing on their roles and mechanisms of action in RNA metabolism, gene expression, and viral replication. In addition, we also briefly discuss the m6A-associated host immune responses in viral infection

    Denoising Analysis of Partial Discharge Acoustic Signal Based on SVMD-PCA

    Get PDF
    Partial discharge (PD) acoustic signal detection is one of the effective means to assess the insulation status of power transformers. In actual monitoring, white noise is likely to cause strong interference to the partial discharge acoustic signal of the transformer, which seriously affects the discharge fault identification and monitoring results. In order to suppress the interference of white noise in partial discharge detection, this paper proposes an adaptive partial discharge based on the combination of variational mode decomposition (VMD) and principal component analysis (PCA) based on improved Spearman correlation coefficient. The white noise suppression method is analyzed for the separation and denoising of partial discharge acoustic signals in the environment of −10 ∌ 10 dB. Firstly, the Spearman correlation coefficient is used to determine the optimal number of decomposing modes of VMD. Then the decomposed modal components are adaptively reduced and reconstructed by principal component analysis to remove redundant clutter interference and reduce the influence of human error. Finally, through the simulation signal and actual discharge pulse acoustic signal are tested for denoising. The results show that SVMD-PCA can suppress the interference of white noise in partial discharge acoustic signals and extract clean discharge pulse signal characteristics, the method has enhanced anti-noise performance and can effectively suppress white noise interference

    Media use degree and depression: A latent profile analysis from Chinese residents

    Get PDF
    BackgroundPrevious studies have emphasized the media as an essential channel for understanding information about depression. However, they have not divided groups according to the degree of media use to study their differences in depression. Therefore, this study aims to explore the influence of media use on depression and the influencing factors of depression in people with different media use degrees.MethodsBased on seven items related to media use, a total of 11, 031 respondents were categorized by the frequency of media use using latent profile analysis (LPA). Secondly, multiple linear regression analyzes were conducted to analyze the effects of depression in people with different degrees of media use. Finally, factors influencing depression among people with different degrees of media use were explored separately.ResultsAll respondents were classified into three groups: media use low-frequency (9.7%), media use general (67.1%), and media use high-frequency (23.2%). Compared with media use general group, media use low-frequency (ÎČ = 0.019, p = 0.044) and media use high-frequency (ÎČ = 0.238, p < 0.001) groups are significantly associated with depression. The factors influencing depression in the population differed between media use low-frequency, media use general, and media use high-frequency groups.ConclusionThe government and the appropriate departments should develop targeted strategies for improving the overall health status of people with different media use degrees

    Media use degree and depression: A latent profile analysis from Chinese residents

    Get PDF
    Background: Previous studies have emphasized the media as an essential channel for understanding information about depression. However, they have not divided groups according to the degree of media use to study their differences in depression. Therefore, this study aims to explore the influence of media use on depression and the influencing factors of depression in people with different media use degrees. Methods: Based on seven items related to media use, a total of 11, 031 respondents were categorized by the frequency of media use using latent profile analysis (LPA). Secondly, multiple linear regression analyzes were conducted to analyze the effects of depression in people with different degrees of media use. Finally, factors influencing depression among people with different degrees of media use were explored separately. Results: All respondents were classified into three groups: media use low-frequency (9.7%), media use general (67.1%), and media use high-frequency (23.2%). Compared with media use general group, media use low-frequency (ÎČ = 0.019, p = 0.044) and media use high-frequency (ÎČ = 0.238, p < 0.001) groups are significantly associated with depression. The factors influencing depression in the population differed between media use low-frequency, media use general, and media use high-frequency groups. Conclusion: The government and the appropriate departments should develop targeted strategies for improving the overall health status of people with different media use degrees

    Core-Shell nanomaterials for drug delivery and controlled release

    No full text

    Etudes sur le phĂ©nomĂšne de colmatage dans les gĂ©nĂ©rateurs de vapeur des rĂ©acteurs Ă  eau pressurisĂ©e (REP) – comprĂ©hension et hiĂ©rarchisation de ces mĂ©canismes de formation

    No full text
    The steam generator is an essential component in PWR. After 15-20 years of functioning, an obstruction by deposits of flow holes between Tube Support Plate (TSP) and primary tubes is observed, called TSP clogging. This phenomenon may lead to dramatic consequences for nuclear power plant operation. The aim of this thesis is to deepen the understanding of the mechanisms responsible for TSP clogging by identifying and prioritizing the preponderant processes. COLENTEC is an experimental facility designed to reproduce TSP clogging deposits under representative conditions. Microscopic characterizations allowed revealing the deposit formation by precipitation and the initiation role of material passivation in deposit formation. Lipping and ripple forms, specifying TSP clogging, were not observed in COLENTEC tests. This is suggested to be caused by insufficient concentration of suitable particles at the test section. Particle deposition is supposed to be essential for the formation of lipping deposits. Electrokinetic and flashing phenomena are supposed to contribute to TSP clogging formation. An experimental collaboration with the University of Manchester was established to better understand the clogging formation by investigating the role of electrokinetic phenomenon. This study allowed reforming deposits with lipping and ripple forms as observed in EDF steam generators. Electrokinetic involvement, strongly affected by flow velocity, was considerably suggested in TSP clogging formation. Numerical quantification of deposit formation by each phenomenon was performed and compared to EDF feedbacks. Electrokinetic phenomenon was found to play a predominant role.Le gĂ©nĂ©rateur de vapeur est un composant essentiel du rĂ©acteur Ă  eau pressurisĂ©e. AprĂšs 15 Ă  20 ans de fonctionnement du GV, un phĂ©nomĂšne de colmatage est observĂ©, qui induit le bouchage du passage foliĂ© entre les tubes GV et la plaque entretoise. Ce phĂ©nomĂšne peut avoir de graves consĂ©quences pour le fonctionnement de la centrale nuclĂ©aire. L’objectif majeur de cette thĂšse est d’approfondir les connaissances des mĂ©canismes responsables de la formation du colmatage en identifiant et hiĂ©rarchisant les processus prĂ©pondĂ©rants. L’installation COLENTEC est un outil expĂ©rimental conçu pour reproduire des dĂ©pĂŽts dans des conditions reprĂ©sentatives d’un GV. La post-caractĂ©risation microscopique a permis d’identifier la contribution du phĂ©nomĂšne de prĂ©cipitation et le rĂŽle d’initiation de la passivation du matĂ©riau. Les formes spĂ©cifiques du colmatage, lipping Ă  l’entrĂ©e et rides le long de la plaque entretoise, n’ont pas Ă©tĂ© observĂ©es dans les essais COLENTEC. Cela peut ĂȘtre provoquĂ© par l’absence de particules dans la section d’essai ou une vitesse insuffisante du fluide. Le flashing et le phĂ©nomĂšne Ă©lectrocinĂ©tique ont Ă©tĂ© supposĂ©s contribuer Ă  la formation du colmatage. Une collaboration avec l’UniversitĂ© de Manchester a Ă©tĂ© Ă©tablie au cours de ce travail afin d’étudier expĂ©rimentalement le phĂ©nomĂšne Ă©lectrocinĂ©tique. Les travaux effectuĂ©s ont permis de mieux comprendre ce phĂ©nomĂšne et de suggĂ©rer son influence considĂ©rable dans la formation du colmatage. Des quantifications numĂ©riques de chaque phĂ©nomĂšne ont Ă©tĂ© rĂ©alisĂ©es, prĂ©disant un rĂŽle prĂ©dominant du phĂ©nomĂšne Ă©lectrocinĂ©tique

    Existence of Ground State Solutions for a Class of Non-Autonomous Fractional Kirchhoff Equations

    No full text
    We take a look at the fractional Kirchhoff problem in this paper. Using a variational approach, we show that there exists a ground state solution for this problem. Furthermore, using the approach developed by Szulkin and Weth, we also find that positive ground state solutions exist for the fractional Kirchhoff equation with p=4

    Effects of nitrogen addition on species composition and diversity of early spring herbs in a Korean pine plantation

    No full text
    Abstract Under the background of global nitrogen deposition, temperate forest ecosystems are suffering increasing threats, and species diversity is gradually decreasing. In this study, nitrogen addition experiments were conducted on Korean pine (Pinus koraiensis) plantations in Northeast China to explore the effect of long‐term nitrogen addition on herb species diversity to test the following hypothesis: long‐term nitrogen addition further reduced plant species diversity by affecting plant growth, which may be due to soil acidification caused by excessive nitrogen addition. Experimental nitrogen addition was conducted from 2014 to 2021, and the nitrogen treatment levels were as follows: N0 (control treatment, 0/(kg N ha−1 year−1)), N20 (low nitrogen treatment, 20/(kg N ha−1 year−1)), N40 (medium nitrogen treatment, 40/(kg N ha−1 year−1)) and N80 (high nitrogen treatment, 80/(kg N ha−1 year−1)). A herb community survey was conducted in the region from 2015 to 2021. The results showed that long‐term nitrogen addition decreased soil pH, changed the species and composition of herbaceous plants, and decreased the species diversity of understory herbaceous plants. With the increase in nitrogen application years, middle‐ and high‐nitrogen treatments significantly reduced the diversity of early‐spring flowering herbs and early‐spring foliating herbs, and their diversity decreased with the decrease in soil pH, indicating that soil acidification caused by long‐term nitrogen addition may lead to the decrease of plant diversity. However, for early‐spring growing herbs, adequate nitrogen addition may promote their growth. Our results show that plants have evolved different life‐history strategies based on their adaptation mechanisms to the environment, and different life‐history strategies have different responses to long‐term nitrogen addition. However, for most plants, long‐term nitrogen application will have a negative impact on the growth and diversity of herbs in temperate forests

    Divergent Responses of Foliar N:P Stoichiometry During Different Seasons to Nitrogen Deposition in an Old-Growth Temperate Forest, Northeast China

    No full text
    Atmospheric nitrogen (N) deposition has rapidly increased during the last few decades; however, the seasonal responses of leaf N:P stoichiometry to N deposition remain unclear. In 2008, a simulated N deposition experiment (0, 30, 60, and 120 kg&middot;N&middot;ha&minus;1&middot;yr&minus;1) was conducted in an old-growth temperate forest in Northeast China. In 2014, the leaves of 17 woody species and soil were sampled in spring, summer, and autumn in each treatment, and N:P stoichiometry was assessed. Community N and P in summer were significantly lower than that in spring and autumn. Unlike broadleaved species, conifers showed no significant variation among the three seasons. N addition significantly enhanced community N and soil available P but decreased soil total P in summer and autumn, and decreased community P, as well as the P concentration of three life forms (conifer, tree, and shrub), in autumn. Our results emphasize the importance of multiple sampling across seasons in temperate forests. Arguing against the traditional consensus, the productivity of the old-growth temperate forests is limited by both N and P
    • 

    corecore