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We construct the ( β -deformed) higher order total derivative operators and analyze their remarkable properties. In terms of these operators, we derive the higher order constraints for the ( β -deformed) Hermitian matrix models. We prove that these ( β -deformed) higher order constraints are reducible to the Virasoro constraints. Meanwhile, the Itoyama–Matsuo conjecture for the constraints of the Hermitian matrix model is proved. We also find that through rescaling variable transformations, two sets of the constraint operators become the W -operators of W -representations for the ( β -deformed) partition function hierarchies in the literature.

Human infections with zoonotic coronaviruses (CoVs), including severe acute respiratory syndrome (SARS)-CoV and Middle East respiratory syndrome (MERS)-CoV, have raised great public health concern globally. Here, we report a novel bat-origin CoV causing severe and fatal pneumonia in humans. We collected clinical data and bronchoalveolar lavage (BAL) specimens from five patients with severe pneumonia from Wuhan Jinyintan Hospital, Hubei province, China. Nucleic acids of the BAL were extracted and subjected to next-generation sequencing. Virus isolation was carried out, and maximum-likelihood phylogenetic trees were constructed. Five patients hospitalized from December 18 to December 29, 2019 presented with fever, cough, and dyspnea accompanied by complications of acute respiratory distress syndrome. Chest radiography revealed diffuse opacities and consolidation. One of these patients died. Sequence results revealed the presence of a previously unknown β-CoV strain in all five patients, with 99.8% to 99.9% nucleotide identities among the isolates. These isolates showed 79.0% nucleotide identity with the sequence of SARS-CoV (GenBank NC_004718) and 51.8% identity with the sequence of MERS-CoV (GenBank NC_019843). The virus is phylogenetically closest to a bat SARS-like CoV (SL-ZC45, GenBank MG772933) with 87.6% to 87.7% nucleotide identity, but is in a separate clade. Moreover, these viruses have a single intact open reading frame gene 8, as a further indicator of bat-origin CoVs. However, the amino acid sequence of the tentative receptor-binding domain resembles that of SARS-CoV, indicating that these viruses might use the same receptor. A novel bat-borne CoV was identified that is associated with severe and fatal respiratory disease in humans.

Danmu commenting is a new feature of the streaming industry, popular in East Asia. Danmu comments are displayed as streams of comments superimposed on video screens and synchronised to the specific playback time at which the users sent them, moving horizontally from right to left. Interestingly, users do not have options such as “replies” to structure their comments; their interactions commonly include poor addressivity, hidden authorship, and unmarked sending time. The ways in which users actually interact with each other and, more importantly, the implications of such danmu-enabled social interactions on building virtual communities are so far understudied. Through a case study centred on Bilibili, a leading Chinese danmu platform, this article argues that in spite of their visually chaotic manner, the social interactive patterns of danmu commenters contribute to community building. Under the theoretical framework of “sense of virtual community,” the study adopts a data-driven methodology to qualitatively analyse such fragmented data. Results show that Bilibili users have discovered various ways to initiate social contact with each other through the creative use of linguistic and semiotic resources. Their ritualised performance in the Bilibili community is centred around the social aims of danmu comments, danmu clusters, and danmu language, all of which strengthen their sense of virtual community on the dimensions of membership, influence, and immersion. This article contributes to the research on this emerging media phenomenon by illustrating a new mode of watching and engaging in a participatory online community of practice that this platform encourages.

The first endothelium-derived relaxing factor (EDRF) ever identified is a gasotransmitter, nitric oxide (NO). Recent studies have provided several lines of evidence to support the premise that hydrogen sulfide (H2S), another gasotransmitter, is a new EDRF. H2S production is catalyzed in mammalian cells by cystathionine β-synthase (CBS) and/or cystathionine γ-lyase (CSE). The expression of CSE proteins and the activity of CBS have been observed in vascular endothelial cells. A measurable amount of H2S is produced from endothelium upon muscarinic cholinergic stimulation. The endothelium-dependent vasorelaxation induced by H2S shares many common mechanistic traits with those of endothelium-derived hyperpolarizing factor (EDHF). Deficiency in CSE expression increases blood pressure in CSE knockout mice and significantly diminishes endothelium-dependent relaxation of resistance arteries. More extensive and mechanistic studies in the future will help to determine whether H2S is a new EDRF or the very EDHF.

ObjectivesWe aimed to provide the most updated estimates on the global burden of inflammatory bowel disease (IBD) to improve management strategies.DesignWe extracted data from the Global Burden of Disease (GBD) 2019 database to evaluate IBD burden with different measures in 204 countries and territories from 1990 to 2019.SettingStudies from the GBD 2019 database generated by population-representative data sources identified through a literature review and research collaborations were included.ParticipantsPatients with an IBD diagnosis.OutcomesTotal numbers, age-standardised rates of prevalence, mortality and disability-adjusted life-years (DALYs), and their estimated annual percentage changes (EAPCs) were the main outcomes.ResultsIn 2019, there were approximately 4.9 million cases of IBD worldwide, with China and the USA having the highest number of cases (911 405 and 762 890 (66.9 and 245.3 cases per 100 000 people, respectively)). Between 1990 and 2019, the global age-standardised rates of prevalence, deaths and DALYs decreased (EAPCs=−0.66,–0.69 and −1.04, respectively). However, the age-standardised prevalence rate increased in 13 out of 21 GBD regions. A total of 147 out of 204 countries or territories experienced an increase in the age-standardised prevalence rate. From 1990 to 2019, IBD prevalent cases, deaths and DALYs were higher among females than among males. A higher Socio-demographic Index was associated with higher age-standardised prevalence rates.ConclusionsIBD will continue to be a major public health burden due to increasing numbers of prevalent cases, deaths and DALYs. The epidemiological trends and disease burden of IBD have changed dramatically at the regional and national levels, so understanding these changes would be beneficial for policy makers to tackle IBD.

Correlation and frustration play essential roles in physics, giving rise to novel quantum phases 1 – 6 . A typical frustrated system is correlated bosons on moat bands, which could host topological orders with long-range quantum entanglement 4 . However, the realization of moat-band physics is still challenging. Here, we explore moat-band phenomena in shallowly inverted InAs/GaSb quantum wells, where we observe an unconventional time-reversal-symmetry breaking excitonic ground state under imbalanced electron and hole densities. We find that a large bulk gap exists, encompassing a broad range of density imbalances at zero magnetic field ( B ), accompanied by edge channels that resemble helical transport. Under an increasing perpendicular B , the bulk gap persists, and an anomalous plateau of Hall signals appears, which demonstrates an evolution from helical-like to chiral-like edge transport with a Hall conductance approximately equal to e 2 / h at 35 tesla, where e is the elementary charge and h is Planck’s constant. Theoretically, we show that strong frustration from density imbalance leads to a moat band for excitons, resulting in a time-reversal-symmetry breaking excitonic topological order, which explains all our experimental observations. Our work opens up a new direction for research on topological and correlated bosonic systems in solid states beyond the framework of symmetry-protected topological phases, including but not limited to the bosonic fractional quantum Hall effect. This study reports an excitonic topological order emerging in imbalanced electron–hole bilayers.

Sodium‐ion batteries (SIBs) are considered as a low‐cost complementary or alternative system to prestigious lithium‐ion batteries (LIBs) because of their similar working principle to LIBs, cost‐effectiveness, and sustainable availability of sodium resources, especially in large‐scale energy storage systems (EESs). Among various cathode candidates for SIBs, Na‐based layered transition metal oxides have received extensive attention for their relatively large specific capacity, high operating potential, facile synthesis, and environmental benignity. However, there are a series of fatal issues in terms of poor air stability, unstable cathode/electrolyte interphase, and irreversible phase transition that lead to unsatisfactory battery performance from the perspective of preparation to application, outside to inside of layered oxide cathodes, which severely limit their practical application. This work is meant to review these critical problems associated with layered oxide cathodes to understand their fundamental roots and degradation mechanisms, and to provide a comprehensive summary of mainstream modification strategies including chemical substitution, surface modification, structure modulation, and so forth, concentrating on how to improve air stability, reduce interfacial side reaction, and suppress phase transition for realizing high structural reversibility, fast Na+ kinetics, and superior comprehensive electrochemical performance. The advantages and disadvantages of different strategies are discussed, and insights into future challenges and opportunities for layered oxide cathodes are also presented. Recent progress in layered oxide cathodes for sodium‐ion batteries (SIBs) from air stability, interface chemistry, and phase transition are comprehensively summarized. The intrinsic degradation mechanisms behind electrochemical performance and mainstream modification strategies are systematically sorted out and analyzed. The remaining challenges, promising optimization strategies as well as endeavor directions to break current limitations are also presented for the future design of high‐performance layered oxide cathodes for SIBs.

Inflammatory mechanisms play important roles in intracerebral hemorrhage (ICH) and have been linked to the development of stroke-associated pneumonia (SAP). The neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), platelet-to-lymphocyte ratio (PLR) and systemic inflammation response index (SIRI) are inflammatory indexes that influence systemic inflammatory responses after stroke. In this study, we aimed to compare the predictive value of the NLR, SII, SIRI and PLR for SAP in patients with ICH to determine their application potential in the early identification of the severity of pneumonia. Patients with ICH in four hospitals were prospectively enrolled. SAP was defined according to the modified Centers for Disease Control and Prevention criteria. Data on the NLR, SII, SIRI and PLR were collected at admission, and the correlation between these factors and the clinical pulmonary infection score (CPIS) was assessed through Spearman's analysis. A total of 320 patients were enrolled in this study, among whom 126 (39.4%) developed SAP. The results of the receiver operating characteristic (ROC) analysis revealed that the NLR had the best predictive value for SAP (AUC: 0.748, 95% CI: 0.695-0.801), and this outcome remained significant after adjusting for other confounders in multivariable analysis (RR=1.090, 95% CI: 1.029-1.155). Among the four indexes, Spearman's analysis showed that the NLR was the most highly correlated with the CPIS (r=0.537, 95% CI: 0.395-0.654). The NLR could effectively predict ICU admission (AUC: 0.732, 95% CI: 0.671-0.786), and this finding remained significant in the multivariable analysis (RR=1.049, 95% CI: 1.009-1.089, P=0.036). Nomograms were created to predict the probability of SAP occurrence and ICU admission. Furthermore, the NLR could predict a good outcome at discharge (AUC: 0.761, 95% CI: 0.707-0.8147). Among the four indexes, the NLR was the best predictor for SAP occurrence and a poor outcome at discharge in ICH patients. It can therefore be used for the early identification of severe SAP and to predict ICU admission.

Key Points Hydrogen sulfide (H 2 S) is an important signalling molecule; it influences physiological and pathophysiological processes throughout the body. Accurate measurement of hydrogen sulfide remains a challenge, largely because it is highly reactive. H 2 S synthesis from the microbiome contributes substantially to 'tissue levels' of H 2 S. In circumstances of anoxia or hypoxia, H 2 S can 'rescue' mitochondria. H 2 S also exerts important anti-inflammatory and cytoprotective effects while driving the resolution of tissue injury. Animal studies of several H 2 S-releasing drugs show considerable promise for the safe treatment of a wide range of disorders, and several such drugs are now in clinical trials. Coupling of an H 2 S-releasing moiety to other drugs, such as anti-inflammatory drugs, can improve efficacy and/or substantially reduce toxicity. Based on studies in animal models, H 2 S-based drugs may be effective in chemoprevention of cancer, and have also shown promise in the treatment of several neurological disorders, such as Alzheimer disease. Hydrogen sulfide (H 2 S) is a ubiquitous gaseous signalling molecule with a plethora of important roles. In this Review, Wallace and Wang describe the pathways for the synthesis and metabolism of H 2 S and its major mechanisms of action in health and in disease processes, before discussing examples of attempts to exploit the actions of H 2 S in the design of novel drugs. Hydrogen sulfide (H 2 S) has become recognized as an important signalling molecule throughout the body, contributing to many physiological and pathological processes. In recent years, improved methods for measuring H 2 S levels and the availability of a wider range of H 2 S donors and more selective inhibitors of H 2 S synthesis have helped to more accurately identify the many biological effects of this highly reactive gaseous mediator. Animal studies of several H 2 S-releasing drugs have demonstrated considerable promise for the safe treatment of a wide range of disorders. Several such drugs are now in clinical trials.