Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and pathogenic coronavirus that emerged in late 2019 and has caused a pandemic of acute respiratory disease, ...named 'coronavirus disease 2019' (COVID-19), which threatens human health and public safety. In this Review, we describe the basic virology of SARS-CoV-2, including genomic characteristics and receptor use, highlighting its key difference from previously known coronaviruses. We summarize current knowledge of clinical, epidemiological and pathological features of COVID-19, as well as recent progress in animal models and antiviral treatment approaches for SARS-CoV-2 infection. We also discuss the potential wildlife hosts and zoonotic origin of this emerging virus in detail.
Severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) are two highly transmissible and pathogenic viruses that emerged in humans at the ...beginning of the 21st century. Both viruses likely originated in bats, and genetically diverse coronaviruses that are related to SARS-CoV and MERS-CoV were discovered in bats worldwide. In this Review, we summarize the current knowledge on the origin and evolution of these two pathogenic coronaviruses and discuss their receptor usage; we also highlight the diversity and potential of spillover of bat-borne coronaviruses, as evidenced by the recent spillover of swine acute diarrhoea syndrome coronavirus (SADS-CoV) to pigs.
We present a 1.488-approximation algorithm for the metric uncapacitated facility location (UFL) problem. Previously, the best algorithm was due to Byrka (2007). Byrka proposed an algorithm ...parametrized by γ and used it with γ≈1.6774. By either running his algorithm or the algorithm proposed by Jain, Mahdian and Saberi (STOCʼ02), Byrka obtained an algorithm that gives expected approximation ratio 1.5. We show that if γ is randomly selected, the approximation ratio can be improved to 1.488. Our algorithm cuts the gap with the 1.463 approximability lower bound by almost 1/3.
Smart materials are highly desirable over the recent decade due to the growing demand of complicated nature. Stable stimuli-responsive smart materials exhibit widespread potential for applications in ...smart windows, sensors, separators, chemical valves, and release platforms but are rare. Despite being good candidates, viologen-based multifunctional smart materials are still a challenging task for chemists. To obtain such materials, the judicious strategy is to introduce polynuclear metal–carboxylate clusters as electron donors into a stable framework to increase chromic sensitivity. Toward this endeavor, we have synthesized a novel viologen-based polymer with a unique Anderson-like metal–carboxylate cluster, Zn7(bpybc)3(o-BDC)6·2NO3·6H2O (bpybc = 1,1′-bis(4-carboxyphenyl)-4,4′-bipyridinium, o-BDC = o-benzenedicarboylic acid) (1), which is a particular 7-fold interpenetrated framework with a 3D pcu network in which bpybc ligand as the linker and Zn7O30C12 as the second building unit (Zn7 SBU) were used as 6-connected nodes. More importantly, it shows excellent chromic behavior in response to multiple external stimuli especially soft X-ray and UV dual light, temperature, electricity, and organic amines, which stand out in the viologen-based polymers. Interestingly, the coloration process of 1 from “core” to “edge” is observed upon heating at the appropriate temperature, which has not yet been found in other reported thermochromic materials. Of particular interest for 1 is the couple of quaternary stimuli-sensitive abilities because it simultaneously meets the following conditions: (i) the capability of withstanding high light, higher temperature, extreme pH, and other harsh conditions; and (ii) the high sensitivity to external stimuli keeping away from photodegradation, thermal relaxation, side reactions, and so on. To be noted, 1 has high thermal stability and chemical stability, which are excellent advantages as smart materials. To further develop possible practical utilization, 1 has been doped into the polymer matrixes to construct a hybrid film, which not only keeps the response to external stimuli but also significantly improves the repeatability of the photochromic process, indicating that a new smart device with multi-stimuli-responsive functions will emerge successively in the future.
Cross-species transmission of viruses from wildlife animal reservoirs poses a marked threat to human and animal health
. Bats have been recognized as one of the most important reservoirs for emerging ...viruses and the transmission of a coronavirus that originated in bats to humans via intermediate hosts was responsible for the high-impact emerging zoonosis, severe acute respiratory syndrome (SARS)
. Here we provide virological, epidemiological, evolutionary and experimental evidence that a novel HKU2-related bat coronavirus, swine acute diarrhoea syndrome coronavirus (SADS-CoV), is the aetiological agent that was responsible for a large-scale outbreak of fatal disease in pigs in China that has caused the death of 24,693 piglets across four farms. Notably, the outbreak began in Guangdong province in the vicinity of the origin of the SARS pandemic. Furthermore, we identified SADS-related CoVs with 96-98% sequence identity in 9.8% (58 out of 591) of anal swabs collected from bats in Guangdong province during 2013-2016, predominantly in horseshoe bats (Rhinolophus spp.) that are known reservoirs of SARS-related CoVs. We found that there were striking similarities between the SADS and SARS outbreaks in geographical, temporal, ecological and aetiological settings. This study highlights the importance of identifying coronavirus diversity and distribution in bats to mitigate future outbreaks that could threaten livestock, public health and economic growth.
This volume examines trends in inequality in the People's Republic of China. It contains findings on inequality nationwide, as well as within the rural and urban sectors, with an emphasis on public ...policy considerations. Several chapters focus on inequality of income; others analyse poverty, inequality in wealth, and the distribution of wages. Attention is given to groups such as migrants, women, and the elderly, as well as the relationship between income and health care funding and the impact of the rural tax reform. All contributors to this volume make use of a large, nationwide survey of Chinese households, the product of long-term co-operation between Chinese and international researchers that is unique in its scope and duration. Using these data, the contributors examine changes in inequality from 1988 to 2002.
This book, a sequel to Inequality and Public Policy in China (2008), examines the evolution of inequality in China from 2002 to 2007, a period when the new 'harmonious society' development strategy ...was adopted under Hu Jintao and Wen Jiabao. It fills a gap in knowledge about the outcomes of this development strategy for equity and inequality. Drawing on original information collected from the recent two waves of nationwide household surveys conducted by the China Household Income Project, this book provides a detailed overview of recent trends in income inequality and cutting-edge analysis of key factors underlying such trends. Topics covered include inequality in education, changes in homeownership and the distribution of housing wealth, the evolution of the migrant labor market, disparities between public and non-public sectors, patterns of work and non-work, gender, ethnicity, and the impacts of public policies such as reforms in taxation and social welfare programs.
“Second sound” has been observed in graphite
Dissipating high-density heat is a major technological challenge, both on the small scale of computer chips and the large scale of industrial processes ...such as nuclear reactors. One way to meet this challenge is the use of microscopic mechanisms to model and design solid-state materials for efficient transport of high heat loads. Recent experiments confirmed theoretical predictions of unusual high thermal conductivity in semiconducting boron arsenide (BAs) (
1
–
3
). On page 375 of this issue, Huberman
et al.
(
4
) demonstrate extraordinary collective phonon transport that underlies the record-high thermal conductivity in graphite. These insights may help to design future methods for efficient heat dissipation.
Bat Coronaviruses in China Fan, Yi; Zhao, Kai; Shi, Zheng-Li ...
Viruses,
03/2019, Volume:
11, Issue:
3
Journal Article
Peer reviewed
Open access
During the past two decades, three zoonotic coronaviruses have been identified as the cause of large-scale disease outbreaks⁻Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome ...(MERS), and Swine Acute Diarrhea Syndrome (SADS). SARS and MERS emerged in 2003 and 2012, respectively, and caused a worldwide pandemic that claimed thousands of human lives, while SADS struck the swine industry in 2017. They have common characteristics, such as they are all highly pathogenic to humans or livestock, their agents originated from bats, and two of them originated in China. Thus, it is highly likely that future SARS- or MERS-like coronavirus outbreaks will originate from bats, and there is an increased probability that this will occur in China. Therefore, the investigation of bat coronaviruses becomes an urgent issue for the detection of early warning signs, which in turn minimizes the impact of such future outbreaks in China. The purpose of the review is to summarize the current knowledge on viral diversity, reservoir hosts, and the geographical distributions of bat coronaviruses in China, and eventually we aim to predict virus hotspots and their cross-species transmission potential.
This paper considers the problem of sampled-data adaptive output feedback fuzzy stabilization for switched uncertain nonlinear systems associated with asynchronous switching. A state observer is ...designed to estimate the unmeasured states and fuzzy logic systems are employed to deal with the unknown nonlinear terms. Sampled-data controller and novel switched adaptive laws are constructed based on the recursive design method and an average dwell time constraint is given to ensure that the closed-loop system is stable. The proposed scheme is employed in a mass-spring-damper system to demonstrate its effectiveness.
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