This paper describes the access to, and the content, characteristics, and potential applications of the tropical cyclone(TC) database that is maintained and actively developed by the China Meteorological Administratio...This paper describes the access to, and the content, characteristics, and potential applications of the tropical cyclone(TC) database that is maintained and actively developed by the China Meteorological Administration, with the aim of facilitating its use in scientific research and operational services. This database records data relating to all TCs that have passed through the western North Pacific(WNP) and South China Sea(SCS) since 1949. TC data collection has expanded over recent decades via continuous TC monitoring using remote sensing and specialized field detection techniques,allowing collation of a multi-source TC database for the WNP and SCS that covers a long period, with wide coverage and many observational elements. This database now comprises a wide variety of information related to TCs, such as historical or real-time locations(i.e., best track and landfall), intensity, dynamic and thermal structures, wind strengths, precipitation amounts, and frequency. This database will support ongoing research into the processes and patterns associated with TC climatic activity and TC forecasting.展开更多
Ulcerative colitis(UC) is an inflammatory disease that mainly affects the colon and rectum. It is believed that genetic factors, host immune system disorders, intestinal microbiota dysbiosis, and environmental factors...Ulcerative colitis(UC) is an inflammatory disease that mainly affects the colon and rectum. It is believed that genetic factors, host immune system disorders, intestinal microbiota dysbiosis, and environmental factors contribute to the pathogenesis of UC. however, studies on the role of intestinal microbiota in the pathogenesis of UC have been inconclusive. Studies have shown that probiotics improve intestinal mucosa barrier function and immune system function and promote secretion of anti-inflammatory factors, thereby inhibiting the growth of harmful bacteria in the intestine. Fecal microbiota transplantation(FMT) can reduce bowel permeability and thus the severity of disease by increasing the production of short-chain fatty acids, especially butyrate, which help maintain the integrity of the epithelial barrier. FMT can also restore immune dysbiosis by inhibiting Th1 differentiation, activity of T cells, leukocyte adhesion, and production of inflammatory factors. Probiotics and FMT are being increasingly used to treat UC, but their use is controversial because of uncertain efficacy. Here, we briefly review the role of intestinal microbiota in thepathogenesis and treatment of UC.展开更多
Background Fluid therapy for severe acute pancreatitis （SAP） should not only resolve deficiency of blood volume, but also prevent fluid sequestration in acute response stage. Up to date, there has not a strategy for...Background Fluid therapy for severe acute pancreatitis （SAP） should not only resolve deficiency of blood volume, but also prevent fluid sequestration in acute response stage. Up to date, there has not a strategy for fluid therapy dedicated to SAP. So, this study was aimed to investigate the effects of fluid therapy treatment on prognosis of SAP. Methods Seventy-six patients were admitted prospectively according to the criteria within 72 hours of SAP onset. They were randomly assigned to a rapid fluid expansion group （Group I, n=36） and a controlled fluid expansion group （Group II n=-40）. Hemodynamic disorders were either quickly （fluid infusion rate was 10-15 ml.kg-1-h-1, Group I） or gradually improved （fluid infusion rate was 5-10 ml-kg1.h-1, Group II） through controlling the rate of fluid infusion. Parameters of fluid expansion, blood lactate concentration were obtained when meeting the criteria for fluid expansion. And APACHE II scores were obtained serially for 72 hours. Rate of mechanical ventilation, incidence of abdominal compartment syndrome （ACS）, sepsis, and survival rate were obtained. Results The two groups had statistically different （P 〈0.05） time intervals to meet fluid expansion criteria （Group I, 13.5±6.6 hours; Group II, （24.0±5.4） hours）. Blood lactate concentrations were both remarkably lower as compared to the level upon admission （P 〈0.05） and reached the normal level in both groups upon treatment. It was only at day 1 that hematocrit was significantly lower in Group I （35.6%±6.8%） than in Group II （38.5%±5.4%） （P〈0.01）. Amount of crystalloid and colloid in group I （（4028±1980）ml and （1336±816）ml） on admission day was more than those of group II （（2472±1871）ml and （970±633）ml）. No significant difference was found in the total amount of fluids within four days of admission between the two groups （P〉0.05）. Total amount of fluid sequestration within 4 days was higher in Group I （（5378±2751）ml�展开更多
Dendrobium officinale Kimura et Migo is a traditional Chinese orchid herb that has both ornamental value and a broad range of therapeutic effects. Here, we report the first de novo assembled 1.35 Gb genome se- quences...Dendrobium officinale Kimura et Migo is a traditional Chinese orchid herb that has both ornamental value and a broad range of therapeutic effects. Here, we report the first de novo assembled 1.35 Gb genome se- quences for D. officinale by combining the second-generation Illumina Hiseq 2000 and third-generation PacBio sequencing technologies. We found that orchids have a complete inflorescence gene set and have some specific inflorescence genes. We observed gene expansion in gene families related to fungus symbiosis and drought resistance. We analyzed biosynthesis pathways of medicinal components of D. officinale and found extensive duplication of SPS and SuSy genes, which are related to polysaccharide generation, and that the pathway of D. officinale alkaloid synthesis could be extended to generate 16- epivellosimine. The D. officinale genome assembly demonstrates a new approach to deciphering large complex genomes and, as an important orchid species and a traditional Chinese medicine, the D. officinale genome will facilitate future research on the evolution of orchid plants, as well as the study of medicinal components and potential genetic breeding of the dendrobe.展开更多
Recent efforts and advances in additive manufacturing(AM) on different types of new materials are presented and reviewed. Special attention is paid to the material design of cladding layers, the choice of feedstock ma...Recent efforts and advances in additive manufacturing(AM) on different types of new materials are presented and reviewed. Special attention is paid to the material design of cladding layers, the choice of feedstock materials, the metallurgical behavior and synthesis principle during the AM process, and the resulted microstructures and properties, as well as the relationship between these factors. Thereafter,the trend of development in the future is forecasted, including: Effects of the particles size and size distribution of powders; Approaches for producing fine microstructures; Opportunities for creating new materials by AM; Wide applications in reconditioning of damaged components; Challenges for deep understanding and applications of the AMed new materials. The idea of "Develop Materials" or "Create Materials" by AM is highlighted, but a series of scientific, technological and engineering problems remain to be solved in future.展开更多
AIM: To compare effects of different resuscitation fluid on microcirculation, inflammation, intestinal barrier and clinical results in severe acute pancreatitis (SAP). METHODS: One hundred and twenty patients with SAP...AIM: To compare effects of different resuscitation fluid on microcirculation, inflammation, intestinal barrier and clinical results in severe acute pancreatitis (SAP). METHODS: One hundred and twenty patients with SAP were enrolled at the Pancreatic Disease Institute between January 2007 and March 2010. The patients were randomly treated with normal saline (NS group), combination of normal saline and hydroxyethyl starch (HES) (SH group), combination of normal saline, hydroxyethyl starch and glutamine (SHG group) in resuscitation. The ratio of normal saline to HES in the SH and SHG groups was 3:1. The glutamine (20% glutamine dipeptide, 100 mL/d) was supplemented into the resuscitation liquid in the SHG group. Complications and outcomes including respiratory and abdominal infection, sepsis, abdominal hemorrhage, intra-abdominal hypertension, abdominal compartment syndrome (ACS), renal failure, acute respiratory distress syndrome (ARDS), multiple organ dysfunction syndrome (MODS), operation intervention, length of intensive care unit stay, length of hospital stay, and mortality at 60 d were compared. Moreover, blood oxygen saturation (SpO 2 ), gastric intramucosal pH value (pHi), intra-abdominal pressure (IAP), inflammation cytokines, urine lactulose/mannitol (L/M) ratio, and serum endotoxin were investigated to evaluate the inflammatory reaction and gut barrier. RESULTS: Compared to the NS group, patients in the SH and SHG groups accessed the endpoint more quickly (3.9 ± 0.23 d and 4.1 ± 0.21 d vs 5.8 ± 0.25 d, P < 0.05) with less fluid volume (67.26 ± 28.53 mL/kg/d, 61.79 ± 27.61 mL/kg per day vs 85.23 ± 21.27 mL/kg per day, P < 0.05). Compared to the NS group, incidence of renal dysfunction, ARDS, MODS and ACS in the SH and SHG groups was obviously lower. Furthermore, incidence of respiratory and abdominal infection was significantly decreased in the SH and SHG groups, while no significant difference in sepsis was seen. Moreover, less operation time was needed in the SH and SHG group than the NS group, but展开更多
The NE-to NNE-striking Tan-Lu Fault Zone(TLFZ) is the largest fault zone in East China, and a typical representative for the circum-Pacific tectonics. Its late Mesozoic evolution resulted from subduction of the Paleo-...The NE-to NNE-striking Tan-Lu Fault Zone(TLFZ) is the largest fault zone in East China, and a typical representative for the circum-Pacific tectonics. Its late Mesozoic evolution resulted from subduction of the Paleo-Pacific Plate,and can be used for indication to the subduction history. The TLFZ reactivated at the end of Middle Jurassic since its origination in Middle Triassic. This phase of sinistral motion can only be recognized along the eastern edge of the Dabie-Sulu orogenis,and indicates initiation of the Paleo-Pacific(Izanagi) Plate subduction beneath the East China continent. After the Late Jurassic standstill, the fault zone experienced intense sinistral faulting again at the beginning of Early Cretaceous under N-S compression that resulted from the NNW-ward, low-angle, high-speed subduction of the Izanagi Plate. It turned into normal faulting in the rest of Early Cretaceous, which was simultaneous with the peak destruction of the North China Craton caused by backarc extension that resulted from rollback of the subducting Izanagi Plate. The TLFZ was subjected to sinistral, transpressive displacement again at the end of Early Cretaceous. This shortening event led to termination of the North China Craton destruction. The fault zone suffered local normal faulting in Late Cretaceous due to the far-field, weak backarc extension. The late Mesozoic evolution of the TLFZ show repeated alternation between the transpressive strike-slip motion and normal faulting. Each of the sinistral faulting event took place in a relatively short period whereas every normal faulting event lasted in a longer period, which are related to the subduction way and history of the Paleo-Pacific Plates.展开更多
Very recently,a novel coronavirus,2019-nCoV,emerged in Wuhan,China and then quickly spread worldwide,resulting in>17,388 confirmed cases and 361 deaths as of 3 February 2020,thus calling for the development of safe...Very recently,a novel coronavirus,2019-nCoV,emerged in Wuhan,China and then quickly spread worldwide,resulting in>17,388 confirmed cases and 361 deaths as of 3 February 2020,thus calling for the development of safe and effective therapeutics and prophylatics.1,2 Similar to severe acute respiratory syndrome(SARS)-CoV,2019-nCoV belongs to lineage B betacoronavirus,and it has the ability to utilize human angiotensin-converting enzyme 2(ACE2)as a receptor to infect human cells.展开更多
MQTT是一个基于TCP/IP协议的简单、轻量型的发布/订阅消息协议,是新兴IoT(Internet of Things)领域的理想之选。IBM Bluemix Internet of Things(IoT)服务提供了简单且强大的功能将全球不同种类的设备和应用程序互联起来。在该IoT服务...MQTT是一个基于TCP/IP协议的简单、轻量型的发布/订阅消息协议,是新兴IoT(Internet of Things)领域的理想之选。IBM Bluemix Internet of Things(IoT)服务提供了简单且强大的功能将全球不同种类的设备和应用程序互联起来。在该IoT服务的基础上,研究了MQTT协议的结构和消息格式,设计了一款基于MQTT协议的移动通信客户端,实现了设备和移动端的数据传输,完成了在客户端的数据可视化。展开更多
Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,na...Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,namely Bhabha scattering,dimuon production and generic hadronic events with charged particles.The combined efficiency of all active triggers approaches 100%in most cases,with uncertainties small enough not to affect most physics analyses.展开更多
From 2000 to 2019,11,895 new names or new additions to the Chinese vascular flora were proposed by 4226 individuals(4086 articles and 140 books),as documented in the Chinese Plant Names Index(CPNI).During those 20 yea...From 2000 to 2019,11,895 new names or new additions to the Chinese vascular flora were proposed by 4226 individuals(4086 articles and 140 books),as documented in the Chinese Plant Names Index(CPNI).During those 20 years,4407 new taxa of vascular plants were described from China,including 7 new families,132 new genera,3543 new species,68 new subspecies,497 new varieties and 160 new forms.Additionally,3562 new combinations and names at new rank and 306 new replacement names were also proposed.Among these various new names were 150 invalid names and 108 illegitimate names,including some that have not been resolved.Six hundred and forty three vascular plants were reported as new to China,while 2349 names were reduced to synonyms of 1406 taxa.The data show that the Chinese flora increased in size at the rate of about 200 taxa annually during those years.Despite the increased attention given to biodiversity in recent years,the evidence indicates that a large number of species in China have yet to be discovered.Further basic investigation of the Chinese flora is needed.Additionally,in the past two decades only 8.5%of the newly published species have been based on molecular evidence,but in the past five years such data have increased significantly,reaching about 20%.Molecular data will undoubtedly become increasingly significant in the discovery of new species in the coming years.Yunnan,Guangxi,Sichuan,Xizang and Taiwan were important sources of new discoveries,with more than 3300 new taxa and records from these five provinces.By area,Taiwan and Hainan,two islands in southern China,have the highest density of newly discovered species.Regional plant surveys are still needed,especially in areas in the southwest and on the southern islands.展开更多
background and purpose A multicentre prospective registry study of individually tailored stenting for a patient with symptomatic intracranial atherosclerotic stenosis(ICAS)combined with poor collaterals in China showe...background and purpose A multicentre prospective registry study of individually tailored stenting for a patient with symptomatic intracranial atherosclerotic stenosis(ICAS)combined with poor collaterals in China showed that the short-term safety and efficacy of stenting was acceptable.However,it remained uncertain whether the low event rate could be of a long term.We reported the 1-year outcome of this registry study to evaluate the long-term efficacy of individually tailored stenting for patients with severe symptomatic ICAS combined with poor collaterals.Methods Patients with symptomatic ICAS caused by 70%-99% stenosis located at the intracranial internal carotid,middle cerebral,intracranial vertebral or basilar arteries combined with poor collaterals were enrolled.Balloon-mounted stent or balloon plus self-expanding stent were selected based on the ease of vascular access and lesion morphology determined by the operators.The primary outcome was the rate of 30-day stroke,transient ischaemic attack and death,and 12-month ischaemic stroke within the same vascular territory,haemorrhagic stroke and vascular death after stenting.results From September 2013 to January 2015,300 patients(ages 58.3±9.78 years)were recruited.Among them,159 patients were treated with balloon-mounted stent and 141 with balloon plus self-expanding stent.During the 1-year follow-up,25 patients had a primary end point event.The probability of primary outcome at 1 year was 8.1%(95% CI 5.3% to 11.7%).In 76 patients with digital subtraction angiography follow-up,27.6%(21/76)had re-stenosis≥50% and 18.4%(14/76)had re-stenosis≥70%.No baseline characteristic was associated with the primary outcome.Conclusion The event rate remains low over 1 year of individually tailored stenting for patients with severe symptomatic ICAS combined with poor collaterals.Further randomised trial of comparing individually tailored stenting with best medical therapy is needed.展开更多
In recent years,the large-scale integration of re-newable energy sources represented by wind power and the widespread application of power electronic devices in power systems have led to the emergence of multi-frequen...In recent years,the large-scale integration of re-newable energy sources represented by wind power and the widespread application of power electronic devices in power systems have led to the emergence of multi-frequency oscillation problems covering multiple frequency segments,which seriously threaten system stability and restrict the accommodation of renewable energy.The oscillation problems related to renewable energy integration have become one of the most popular topics in the field of wind power integration and power system stability research.It has received extensive attention from both academia and industries with many promising research results achieved to date.This paper first analyzes several typical multi-frequency oscillation events caused by large-scale wind power integration in domestic and foreign projects,then studies the multi-frequency oscillation problems,including wind turbine’s shafting torsional oscillation,sub/super-synchronous oscillation and high frequency resonance.The state of the art is systematically summarized from the aspects of oscillation mechanism,analysis methods and mitigation measures,and the future research directions are explored.展开更多
China has been the forerunner of large-scale membrane bioreactor （MBR） application. Since the first large-scale MBR （≥ 10 000 m^3·d^-1） was put into operation in 2006, the engineering implementation of MBR i...China has been the forerunner of large-scale membrane bioreactor （MBR） application. Since the first large-scale MBR （≥ 10 000 m^3·d^-1） was put into operation in 2006, the engineering implementation of MBR in China has attained tremendous development. This paper outlines the commercial application of MBR since 2006 and provides a variety of engineering statistical data, covering the fields of municipal wastewater, industrial wastewater, and polluted surface water treatment. The total treatment capacity of MBRs reached 1× 10^6 m^3·d^-1 in 2010, and has currently exceeded 4.5 × 10^6 m^3·d^-1 with -75% of which pertaining to municipal wastewater treatment. The anaerobic/anoxic/aerobie-MBR and its derivative processes have been the most popular in the large-scale municipal application, with the process features and typical ranges of parameters also presented in this paper. For the treatment of various types of industrial wastewater, the configurations of the MBR-based processes are delineated with representative engineering cases. In view of the significance of the cost issue, statistics of capital and operating costs are also provided, including cost structure and energy composition. With continuous stimulation from the environmental stress, political propulsion, and market demand in China, the total treatment capacity is expected to reach 7.5 × 10^6 m^3·d^-1 by 2015 and a further expansion of the market is foreseeable in the next five years. However, MBR application is facing several challenges, such as the relatively high energy consumption. Judging MBR features and seeking suitable application areas should be of importance for the long-term development of this technology.展开更多
Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationali...Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationality of environmental air quality control strategies.Based on the sampling and chemical composition data of PM2.5 in different key regions of China in the CARE-China observation network,this research analyzes the environmental air quality data released by the China National Environmental Monitoring Centre during the studied period to determine the changes in the particulate matter mass concentration in key regions and the evolution of the corresponding chemical compositions during the implementation of the Action Plan for Prevention and Control of Air Pollution from 2013-2017.The results show the following.(1)The particulate matter mass concentration in China showed a significant downward trend;however,the PM2.5 annual mass concentration in 64%of cities exceeds the New Chinese Ambient Air Quality Standard(CAAQS)GradeⅡ(GB3095-2012).The region to the east of the Taihang Mountains,the Fenhe and Weihe River Plain and the Urumqi-Changji regions in Xinjiang,all have PM2.5 concentration loading that is still high,and heavy haze pollution occurred frequently in the autumn and winter.(2)During the heavy pollution in the autumn and winter,the concentrations of sulfate and organic components decreased significantly.The mean SO42-concentration in PM2.5 decreased by 76%,12%,81%and 38%in Beijing-Tianjin-Hebei(BTH),the Pearl River Delta(PRD),the Sichuan-Chongqing region(SC)and the Fenhe and Weihe River Plain,respectively.The mean organic matter(OM)concentration decreased by 70%,44%,48%and 31%,respectively,and the mean concentration of NH4+decreased by 68%,1.6%,38%and 25%,respectively.The mean elemental carbon(EC)concentration decreased by 84%and 20%in BTH and SC,respectively,and it increased by 61%and 11%in the PRD and Fenhe and Weihe River Plain,respectively.The mean concentration of mineral and unresolved chemica展开更多
The development of pressure sensors with highly sensitivity, fast response and facile fabrication technique is desirable for wearable electronics. Here, we successfully fabricated a flexible transparent capacitive pre...The development of pressure sensors with highly sensitivity, fast response and facile fabrication technique is desirable for wearable electronics. Here, we successfully fabricated a flexible transparent capacitive pressure sensor based on patterned microstructured silver nanowires(AgNWs)/polydimethylsiloxane(PDMS) composite dielectrics. Compared with the pure PDMS dielectric layer with planar structures, the patterned microstructured sensor exhibits a higher sensitivity(0.831 kPa^-1, <0.5 kPa), a lower detection limit,good stability and durability. The enhanced sensing mechanism about the conductive filler content and the patterned microstructures has also been discussed. A 5×5 sensor array was then fabricated to be used as flexible and transparent wearable touch keyboards systems. The fabricated pressure sensor has great potential in the future electronic skin area.展开更多
Selective laser melting （SLM）, as one of the additive manufacturing technologies, is widely investigated to fabricate metal parts. In SLM, parts are manufactured directly from powders in a layer-by-layer fashion; SL...Selective laser melting （SLM）, as one of the additive manufacturing technologies, is widely investigated to fabricate metal parts. In SLM, parts are manufactured directly from powders in a layer-by-layer fashion; SLM also provides several advantages, such as production of complex parts with high three-dimensional accuracy, compared with other additive manufacturing technologies. Therefore, SLM can be applied in aeronautics, astronautics, medicine, and die and mould industry. However, this technique differs from traditional methods, such as casting and forging; for instance, the former greatly differs in terms of microstructure and properties of products. This paper summarizes relevant studies on metal material fabrication through SLM. Based on a work completed in Huazhong Univ. Sci Tech., Rapid Manuf. Center （HUST-RMC） and compared with characteristics described in other reported studies, microstructure, properties, dimensional accuracy, and application of SLM are presented.展开更多
In 6G era,service forms in which computing power acts as the core will be ubiquitous in the network.At the same time,the collaboration among edge computing,cloud computing and network is needed to support edge computi...In 6G era,service forms in which computing power acts as the core will be ubiquitous in the network.At the same time,the collaboration among edge computing,cloud computing and network is needed to support edge computing service with strong demand for computing power,so as to realize the optimization of resource utilization.Based on this,the article discusses the research background,key techniques and main application scenarios of computing power network.Through the demonstration,it can be concluded that the technical solution of computing power network can effectively meet the multi-level deployment and flexible scheduling needs of the future 6G business for computing,storage and network,and adapt to the integration needs of computing power and network in various scenarios,such as user oriented,government enterprise oriented,computing power open and so on.展开更多
Selective laser melting （SLM）, an additive manufacturing process, is capable of manufacturing metallic parts with complex shapes directly from computer-aided design （CAD） models. SLM parts are created on a layer-b...Selective laser melting （SLM）, an additive manufacturing process, is capable of manufacturing metallic parts with complex shapes directly from computer-aided design （CAD） models. SLM parts are created on a layer-by-layer manner, making it more flexible than traditional material processing techniques, in this paper, Inconel 625 alloy, a widely used material in the aerospace industry, were chosen as the build material. Scanning electron microscopy （SEM）, electron back scattering diffraction （EBSD） and X-ray diffraction （XRD） analysis techniques were employed to analyze its microstructure. It was observed that the molten pool was composed of elongated columnar crystal, Due to the rapid cooling speed, the primary dendrite arm space was approximately 0.5 μm and the hardness of SLM state was very high （343 HV）. The inverse pole figure （IPF） indicated that the growing orientation of the most grains was 〈001〉 due to the epitaxial growth and heat conduction. The XRD results revealed that the austenite structure with large lattice distortion was fully formed. No carbides or precipitated phases were found. After heat treatment the grains grew into two microstructures with distinct morphological characters, namely, rectangular grains and limited in the molten pool, and equiaxed grains along the molten boundaries. Upon experiencing the heat treatment, MC carbides with triangular shapes gradually precipitated. The results also identified that a large number of zigzag grain boundaries were formed. In this study, the grain formation and microstructure, and the laws of the molten pool evolution were also analyzed and discussed,展开更多
基金supported by the Key Projects of the National Key R&D Program (Grant No. 2018YFC1506300)the Key Program for International S&T Cooperation Projects of China (Grant No. 2017YFE0107700)。
文摘This paper describes the access to, and the content, characteristics, and potential applications of the tropical cyclone(TC) database that is maintained and actively developed by the China Meteorological Administration, with the aim of facilitating its use in scientific research and operational services. This database records data relating to all TCs that have passed through the western North Pacific(WNP) and South China Sea(SCS) since 1949. TC data collection has expanded over recent decades via continuous TC monitoring using remote sensing and specialized field detection techniques,allowing collation of a multi-source TC database for the WNP and SCS that covers a long period, with wide coverage and many observational elements. This database now comprises a wide variety of information related to TCs, such as historical or real-time locations(i.e., best track and landfall), intensity, dynamic and thermal structures, wind strengths, precipitation amounts, and frequency. This database will support ongoing research into the processes and patterns associated with TC climatic activity and TC forecasting.
基金Supported by the National Natural Science Foundation of China,No.81670504 and No.81472287the New Xiangya Talent Project of the Third Xiangya Hospital of Central South University,No.20150308
文摘Ulcerative colitis(UC) is an inflammatory disease that mainly affects the colon and rectum. It is believed that genetic factors, host immune system disorders, intestinal microbiota dysbiosis, and environmental factors contribute to the pathogenesis of UC. however, studies on the role of intestinal microbiota in the pathogenesis of UC have been inconclusive. Studies have shown that probiotics improve intestinal mucosa barrier function and immune system function and promote secretion of anti-inflammatory factors, thereby inhibiting the growth of harmful bacteria in the intestine. Fecal microbiota transplantation(FMT) can reduce bowel permeability and thus the severity of disease by increasing the production of short-chain fatty acids, especially butyrate, which help maintain the integrity of the epithelial barrier. FMT can also restore immune dysbiosis by inhibiting Th1 differentiation, activity of T cells, leukocyte adhesion, and production of inflammatory factors. Probiotics and FMT are being increasingly used to treat UC, but their use is controversial because of uncertain efficacy. Here, we briefly review the role of intestinal microbiota in thepathogenesis and treatment of UC.
文摘Background Fluid therapy for severe acute pancreatitis （SAP） should not only resolve deficiency of blood volume, but also prevent fluid sequestration in acute response stage. Up to date, there has not a strategy for fluid therapy dedicated to SAP. So, this study was aimed to investigate the effects of fluid therapy treatment on prognosis of SAP. Methods Seventy-six patients were admitted prospectively according to the criteria within 72 hours of SAP onset. They were randomly assigned to a rapid fluid expansion group （Group I, n=36） and a controlled fluid expansion group （Group II n=-40）. Hemodynamic disorders were either quickly （fluid infusion rate was 10-15 ml.kg-1-h-1, Group I） or gradually improved （fluid infusion rate was 5-10 ml-kg1.h-1, Group II） through controlling the rate of fluid infusion. Parameters of fluid expansion, blood lactate concentration were obtained when meeting the criteria for fluid expansion. And APACHE II scores were obtained serially for 72 hours. Rate of mechanical ventilation, incidence of abdominal compartment syndrome （ACS）, sepsis, and survival rate were obtained. Results The two groups had statistically different （P 〈0.05） time intervals to meet fluid expansion criteria （Group I, 13.5±6.6 hours; Group II, （24.0±5.4） hours）. Blood lactate concentrations were both remarkably lower as compared to the level upon admission （P 〈0.05） and reached the normal level in both groups upon treatment. It was only at day 1 that hematocrit was significantly lower in Group I （35.6%±6.8%） than in Group II （38.5%±5.4%） （P〈0.01）. Amount of crystalloid and colloid in group I （（4028±1980）ml and （1336±816）ml） on admission day was more than those of group II （（2472±1871）ml and （970±633）ml）. No significant difference was found in the total amount of fluids within four days of admission between the two groups （P〉0.05）. Total amount of fluid sequestration within 4 days was higher in Group I （（5378±2751）ml�
文摘Dendrobium officinale Kimura et Migo is a traditional Chinese orchid herb that has both ornamental value and a broad range of therapeutic effects. Here, we report the first de novo assembled 1.35 Gb genome se- quences for D. officinale by combining the second-generation Illumina Hiseq 2000 and third-generation PacBio sequencing technologies. We found that orchids have a complete inflorescence gene set and have some specific inflorescence genes. We observed gene expansion in gene families related to fungus symbiosis and drought resistance. We analyzed biosynthesis pathways of medicinal components of D. officinale and found extensive duplication of SPS and SuSy genes, which are related to polysaccharide generation, and that the pathway of D. officinale alkaloid synthesis could be extended to generate 16- epivellosimine. The D. officinale genome assembly demonstrates a new approach to deciphering large complex genomes and, as an important orchid species and a traditional Chinese medicine, the D. officinale genome will facilitate future research on the evolution of orchid plants, as well as the study of medicinal components and potential genetic breeding of the dendrobe.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51775525, 51605456 and 51701198)
文摘Recent efforts and advances in additive manufacturing(AM) on different types of new materials are presented and reviewed. Special attention is paid to the material design of cladding layers, the choice of feedstock materials, the metallurgical behavior and synthesis principle during the AM process, and the resulted microstructures and properties, as well as the relationship between these factors. Thereafter,the trend of development in the future is forecasted, including: Effects of the particles size and size distribution of powders; Approaches for producing fine microstructures; Opportunities for creating new materials by AM; Wide applications in reconditioning of damaged components; Challenges for deep understanding and applications of the AMed new materials. The idea of "Develop Materials" or "Create Materials" by AM is highlighted, but a series of scientific, technological and engineering problems remain to be solved in future.
基金Supported by National Science Foundation Committee of China,No. 30600594 and 30972900the Fundamental Research Funds for the Central Universities of China, No. 2011JC046
文摘AIM: To compare effects of different resuscitation fluid on microcirculation, inflammation, intestinal barrier and clinical results in severe acute pancreatitis (SAP). METHODS: One hundred and twenty patients with SAP were enrolled at the Pancreatic Disease Institute between January 2007 and March 2010. The patients were randomly treated with normal saline (NS group), combination of normal saline and hydroxyethyl starch (HES) (SH group), combination of normal saline, hydroxyethyl starch and glutamine (SHG group) in resuscitation. The ratio of normal saline to HES in the SH and SHG groups was 3:1. The glutamine (20% glutamine dipeptide, 100 mL/d) was supplemented into the resuscitation liquid in the SHG group. Complications and outcomes including respiratory and abdominal infection, sepsis, abdominal hemorrhage, intra-abdominal hypertension, abdominal compartment syndrome (ACS), renal failure, acute respiratory distress syndrome (ARDS), multiple organ dysfunction syndrome (MODS), operation intervention, length of intensive care unit stay, length of hospital stay, and mortality at 60 d were compared. Moreover, blood oxygen saturation (SpO 2 ), gastric intramucosal pH value (pHi), intra-abdominal pressure (IAP), inflammation cytokines, urine lactulose/mannitol (L/M) ratio, and serum endotoxin were investigated to evaluate the inflammatory reaction and gut barrier. RESULTS: Compared to the NS group, patients in the SH and SHG groups accessed the endpoint more quickly (3.9 ± 0.23 d and 4.1 ± 0.21 d vs 5.8 ± 0.25 d, P < 0.05) with less fluid volume (67.26 ± 28.53 mL/kg/d, 61.79 ± 27.61 mL/kg per day vs 85.23 ± 21.27 mL/kg per day, P < 0.05). Compared to the NS group, incidence of renal dysfunction, ARDS, MODS and ACS in the SH and SHG groups was obviously lower. Furthermore, incidence of respiratory and abdominal infection was significantly decreased in the SH and SHG groups, while no significant difference in sepsis was seen. Moreover, less operation time was needed in the SH and SHG group than the NS group, but
基金supported by the National Natural Science Foundation of China(Grant Nos.41472186&91414301)the National Key Basic Research Program of China(Grant No.2016YFC0600102)
文摘The NE-to NNE-striking Tan-Lu Fault Zone(TLFZ) is the largest fault zone in East China, and a typical representative for the circum-Pacific tectonics. Its late Mesozoic evolution resulted from subduction of the Paleo-Pacific Plate,and can be used for indication to the subduction history. The TLFZ reactivated at the end of Middle Jurassic since its origination in Middle Triassic. This phase of sinistral motion can only be recognized along the eastern edge of the Dabie-Sulu orogenis,and indicates initiation of the Paleo-Pacific(Izanagi) Plate subduction beneath the East China continent. After the Late Jurassic standstill, the fault zone experienced intense sinistral faulting again at the beginning of Early Cretaceous under N-S compression that resulted from the NNW-ward, low-angle, high-speed subduction of the Izanagi Plate. It turned into normal faulting in the rest of Early Cretaceous, which was simultaneous with the peak destruction of the North China Craton caused by backarc extension that resulted from rollback of the subducting Izanagi Plate. The TLFZ was subjected to sinistral, transpressive displacement again at the end of Early Cretaceous. This shortening event led to termination of the North China Craton destruction. The fault zone suffered local normal faulting in Late Cretaceous due to the far-field, weak backarc extension. The late Mesozoic evolution of the TLFZ show repeated alternation between the transpressive strike-slip motion and normal faulting. Each of the sinistral faulting event took place in a relatively short period whereas every normal faulting event lasted in a longer period, which are related to the subduction way and history of the Paleo-Pacific Plates.
基金This work was supported by the National Megaprojects of China for Major Infectious Diseases(2018ZX10301403).
文摘Very recently,a novel coronavirus,2019-nCoV,emerged in Wuhan,China and then quickly spread worldwide,resulting in>17,388 confirmed cases and 361 deaths as of 3 February 2020,thus calling for the development of safe and effective therapeutics and prophylatics.1,2 Similar to severe acute respiratory syndrome(SARS)-CoV,2019-nCoV belongs to lineage B betacoronavirus,and it has the ability to utilize human angiotensin-converting enzyme 2(ACE2)as a receptor to infect human cells.
文摘MQTT是一个基于TCP/IP协议的简单、轻量型的发布/订阅消息协议,是新兴IoT(Internet of Things)领域的理想之选。IBM Bluemix Internet of Things(IoT)服务提供了简单且强大的功能将全球不同种类的设备和应用程序互联起来。在该IoT服务的基础上,研究了MQTT协议的结构和消息格式,设计了一款基于MQTT协议的移动通信客户端,实现了设备和移动端的数据传输,完成了在客户端的数据可视化。
基金Supported in part by National Key Basic Research Program of China(2015CB856700)National Natural Science Foundation of China(NSFC)(11625523,11635010,11735014,11822506,11835012,11935015,11935016,11935018,11961141012)+15 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility ProgramJoint Large-Scale Scientific Facility Funds of the NSFC and CAS(U 1732263,U 1832207)CAS Key Research Program of Frontier Sciences(QYZDJ-SSWSLH003,QYZDJ-SSW-SLH040)100 Talents Program of CASINPAC and Shanghai Key Laboratory for Particle Physics and CosmologyERC(758462)German Research Foundation DFG under Contracts Nos.Collaborative Research Center CRC 1044,FOR 2359Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development o f Turkey(DPT2006K-120470)National Science and Technology fundOlle Engkvist Foundation(200-0605)STFC(United Kingdom)The Knut and Alice Wallenberg Foundation(Sweden)(2016.0157)The Royal Society,UK(DH140054,DH160214)The Swedish Research CouncilU.S.Department of Energy(DEFG02-05ER41374,DE-SC-0012069)。
文摘Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,namely Bhabha scattering,dimuon production and generic hadronic events with charged particles.The combined efficiency of all active triggers approaches 100%in most cases,with uncertainties small enough not to affect most physics analyses.
基金This study was supported by the Special Fund for Scientific Research of Shanghai Landscaping&City Appearance Administrative Bureau,China(G182415)the National Specimen Information Infrastructure(2018 Special Funds),China and Shanghai Sailing Program,China(14YF1413800).
文摘From 2000 to 2019,11,895 new names or new additions to the Chinese vascular flora were proposed by 4226 individuals(4086 articles and 140 books),as documented in the Chinese Plant Names Index(CPNI).During those 20 years,4407 new taxa of vascular plants were described from China,including 7 new families,132 new genera,3543 new species,68 new subspecies,497 new varieties and 160 new forms.Additionally,3562 new combinations and names at new rank and 306 new replacement names were also proposed.Among these various new names were 150 invalid names and 108 illegitimate names,including some that have not been resolved.Six hundred and forty three vascular plants were reported as new to China,while 2349 names were reduced to synonyms of 1406 taxa.The data show that the Chinese flora increased in size at the rate of about 200 taxa annually during those years.Despite the increased attention given to biodiversity in recent years,the evidence indicates that a large number of species in China have yet to be discovered.Further basic investigation of the Chinese flora is needed.Additionally,in the past two decades only 8.5%of the newly published species have been based on molecular evidence,but in the past five years such data have increased significantly,reaching about 20%.Molecular data will undoubtedly become increasingly significant in the discovery of new species in the coming years.Yunnan,Guangxi,Sichuan,Xizang and Taiwan were important sources of new discoveries,with more than 3300 new taxa and records from these five provinces.By area,Taiwan and Hainan,two islands in southern China,have the highest density of newly discovered species.Regional plant surveys are still needed,especially in areas in the southwest and on the southern islands.
基金This work is supported by National Natural Science Foundation of China(81371290),Beijing High-level Personnel Funds(2013-2-019)This study is also funded by the National Science and Technology Support Program of‘The 12th Five-Year Plan’of the Ministry of Science and Technology(2011BAI08B02).
文摘background and purpose A multicentre prospective registry study of individually tailored stenting for a patient with symptomatic intracranial atherosclerotic stenosis(ICAS)combined with poor collaterals in China showed that the short-term safety and efficacy of stenting was acceptable.However,it remained uncertain whether the low event rate could be of a long term.We reported the 1-year outcome of this registry study to evaluate the long-term efficacy of individually tailored stenting for patients with severe symptomatic ICAS combined with poor collaterals.Methods Patients with symptomatic ICAS caused by 70%-99% stenosis located at the intracranial internal carotid,middle cerebral,intracranial vertebral or basilar arteries combined with poor collaterals were enrolled.Balloon-mounted stent or balloon plus self-expanding stent were selected based on the ease of vascular access and lesion morphology determined by the operators.The primary outcome was the rate of 30-day stroke,transient ischaemic attack and death,and 12-month ischaemic stroke within the same vascular territory,haemorrhagic stroke and vascular death after stenting.results From September 2013 to January 2015,300 patients(ages 58.3±9.78 years)were recruited.Among them,159 patients were treated with balloon-mounted stent and 141 with balloon plus self-expanding stent.During the 1-year follow-up,25 patients had a primary end point event.The probability of primary outcome at 1 year was 8.1%(95% CI 5.3% to 11.7%).In 76 patients with digital subtraction angiography follow-up,27.6%(21/76)had re-stenosis≥50% and 18.4%(14/76)had re-stenosis≥70%.No baseline characteristic was associated with the primary outcome.Conclusion The event rate remains low over 1 year of individually tailored stenting for patients with severe symptomatic ICAS combined with poor collaterals.Further randomised trial of comparing individually tailored stenting with best medical therapy is needed.
基金This work was supported by the National Natural Science Foundation of China(No.51577174).
文摘In recent years,the large-scale integration of re-newable energy sources represented by wind power and the widespread application of power electronic devices in power systems have led to the emergence of multi-frequency oscillation problems covering multiple frequency segments,which seriously threaten system stability and restrict the accommodation of renewable energy.The oscillation problems related to renewable energy integration have become one of the most popular topics in the field of wind power integration and power system stability research.It has received extensive attention from both academia and industries with many promising research results achieved to date.This paper first analyzes several typical multi-frequency oscillation events caused by large-scale wind power integration in domestic and foreign projects,then studies the multi-frequency oscillation problems,including wind turbine’s shafting torsional oscillation,sub/super-synchronous oscillation and high frequency resonance.The state of the art is systematically summarized from the aspects of oscillation mechanism,analysis methods and mitigation measures,and the future research directions are explored.
文摘China has been the forerunner of large-scale membrane bioreactor （MBR） application. Since the first large-scale MBR （≥ 10 000 m^3·d^-1） was put into operation in 2006, the engineering implementation of MBR in China has attained tremendous development. This paper outlines the commercial application of MBR since 2006 and provides a variety of engineering statistical data, covering the fields of municipal wastewater, industrial wastewater, and polluted surface water treatment. The total treatment capacity of MBRs reached 1× 10^6 m^3·d^-1 in 2010, and has currently exceeded 4.5 × 10^6 m^3·d^-1 with -75% of which pertaining to municipal wastewater treatment. The anaerobic/anoxic/aerobie-MBR and its derivative processes have been the most popular in the large-scale municipal application, with the process features and typical ranges of parameters also presented in this paper. For the treatment of various types of industrial wastewater, the configurations of the MBR-based processes are delineated with representative engineering cases. In view of the significance of the cost issue, statistics of capital and operating costs are also provided, including cost structure and energy composition. With continuous stimulation from the environmental stress, political propulsion, and market demand in China, the total treatment capacity is expected to reach 7.5 × 10^6 m^3·d^-1 by 2015 and a further expansion of the market is foreseeable in the next five years. However, MBR application is facing several challenges, such as the relatively high energy consumption. Judging MBR features and seeking suitable application areas should be of importance for the long-term development of this technology.
基金supported by the Ministry of Science and Technology National Key Research and Development Program (Grant No. 2017YFC0210000)the Fundamental Heavy Pollution Cause and Governance Research Project (Grant No. DQGG0101)the Beijing Municipal Science and Technology Commission Capital Blue Sky Action and Cultivation Project (Grant No. Z181100005418014)
文摘Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationality of environmental air quality control strategies.Based on the sampling and chemical composition data of PM2.5 in different key regions of China in the CARE-China observation network,this research analyzes the environmental air quality data released by the China National Environmental Monitoring Centre during the studied period to determine the changes in the particulate matter mass concentration in key regions and the evolution of the corresponding chemical compositions during the implementation of the Action Plan for Prevention and Control of Air Pollution from 2013-2017.The results show the following.(1)The particulate matter mass concentration in China showed a significant downward trend;however,the PM2.5 annual mass concentration in 64%of cities exceeds the New Chinese Ambient Air Quality Standard(CAAQS)GradeⅡ(GB3095-2012).The region to the east of the Taihang Mountains,the Fenhe and Weihe River Plain and the Urumqi-Changji regions in Xinjiang,all have PM2.5 concentration loading that is still high,and heavy haze pollution occurred frequently in the autumn and winter.(2)During the heavy pollution in the autumn and winter,the concentrations of sulfate and organic components decreased significantly.The mean SO42-concentration in PM2.5 decreased by 76%,12%,81%and 38%in Beijing-Tianjin-Hebei(BTH),the Pearl River Delta(PRD),the Sichuan-Chongqing region(SC)and the Fenhe and Weihe River Plain,respectively.The mean organic matter(OM)concentration decreased by 70%,44%,48%and 31%,respectively,and the mean concentration of NH4+decreased by 68%,1.6%,38%and 25%,respectively.The mean elemental carbon(EC)concentration decreased by 84%and 20%in BTH and SC,respectively,and it increased by 61%and 11%in the PRD and Fenhe and Weihe River Plain,respectively.The mean concentration of mineral and unresolved chemica
基金supported by the National Natural Science Foundation for Distinguished Young Scholars of China(NSFC,61625404)the Key Research Program of Frontier Sciences,CAS(QYZDY-SSW-JWC004)the NSFC(61504136)
文摘The development of pressure sensors with highly sensitivity, fast response and facile fabrication technique is desirable for wearable electronics. Here, we successfully fabricated a flexible transparent capacitive pressure sensor based on patterned microstructured silver nanowires(AgNWs)/polydimethylsiloxane(PDMS) composite dielectrics. Compared with the pure PDMS dielectric layer with planar structures, the patterned microstructured sensor exhibits a higher sensitivity(0.831 kPa^-1, <0.5 kPa), a lower detection limit,good stability and durability. The enhanced sensing mechanism about the conductive filler content and the patterned microstructures has also been discussed. A 5×5 sensor array was then fabricated to be used as flexible and transparent wearable touch keyboards systems. The fabricated pressure sensor has great potential in the future electronic skin area.
文摘Selective laser melting （SLM）, as one of the additive manufacturing technologies, is widely investigated to fabricate metal parts. In SLM, parts are manufactured directly from powders in a layer-by-layer fashion; SLM also provides several advantages, such as production of complex parts with high three-dimensional accuracy, compared with other additive manufacturing technologies. Therefore, SLM can be applied in aeronautics, astronautics, medicine, and die and mould industry. However, this technique differs from traditional methods, such as casting and forging; for instance, the former greatly differs in terms of microstructure and properties of products. This paper summarizes relevant studies on metal material fabrication through SLM. Based on a work completed in Huazhong Univ. Sci Tech., Rapid Manuf. Center （HUST-RMC） and compared with characteristics described in other reported studies, microstructure, properties, dimensional accuracy, and application of SLM are presented.
基金This work was supported by the National Key R&D Program of China No.2019YFB1802800.
文摘In 6G era,service forms in which computing power acts as the core will be ubiquitous in the network.At the same time,the collaboration among edge computing,cloud computing and network is needed to support edge computing service with strong demand for computing power,so as to realize the optimization of resource utilization.Based on this,the article discusses the research background,key techniques and main application scenarios of computing power network.Through the demonstration,it can be concluded that the technical solution of computing power network can effectively meet the multi-level deployment and flexible scheduling needs of the future 6G business for computing,storage and network,and adapt to the integration needs of computing power and network in various scenarios,such as user oriented,government enterprise oriented,computing power open and so on.
基金funded by the National Science & Technology Pillar Program of China (Granted No. 2012BAF08B00)the National Natural Science Foundation of China (Granted Nos. 51375189 and 51375188)+2 种基金the independent R&D subjects of Huazhong University of Science and Technologythe State Key Laboratory of Materials Processing and Die & Mold Technologyco-funded by China Scholarship Council (CSC)
文摘Selective laser melting （SLM）, an additive manufacturing process, is capable of manufacturing metallic parts with complex shapes directly from computer-aided design （CAD） models. SLM parts are created on a layer-by-layer manner, making it more flexible than traditional material processing techniques, in this paper, Inconel 625 alloy, a widely used material in the aerospace industry, were chosen as the build material. Scanning electron microscopy （SEM）, electron back scattering diffraction （EBSD） and X-ray diffraction （XRD） analysis techniques were employed to analyze its microstructure. It was observed that the molten pool was composed of elongated columnar crystal, Due to the rapid cooling speed, the primary dendrite arm space was approximately 0.5 μm and the hardness of SLM state was very high （343 HV）. The inverse pole figure （IPF） indicated that the growing orientation of the most grains was 〈001〉 due to the epitaxial growth and heat conduction. The XRD results revealed that the austenite structure with large lattice distortion was fully formed. No carbides or precipitated phases were found. After heat treatment the grains grew into two microstructures with distinct morphological characters, namely, rectangular grains and limited in the molten pool, and equiaxed grains along the molten boundaries. Upon experiencing the heat treatment, MC carbides with triangular shapes gradually precipitated. The results also identified that a large number of zigzag grain boundaries were formed. In this study, the grain formation and microstructure, and the laws of the molten pool evolution were also analyzed and discussed,
