There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B fac...There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESⅢ, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESⅢ during the remaining operation period of BEPCⅡ. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCⅡ to higher luminosity.展开更多
The primary pattern of the late Cenozoic to the present tectonic deformation of China is characterized by relative movements and interactions of tectonic blocks. Active tectonic blocks are geological units that have b...The primary pattern of the late Cenozoic to the present tectonic deformation of China is characterized by relative movements and interactions of tectonic blocks. Active tectonic blocks are geological units that have been separated from each other by active tectonic zones. Boundaries between blocks are the highest gradient of differential movement. Most of tectonic activity occurs on boundaries of the blocks. Earthquakes are results of abrupt releases of accumulated strain energy that reaches the threshold of strength of the earth's crust. Boundaries of tectonic blocks are the locations of most discontinuous deformation and highest gradient of stress accumulation, thus are the most likely places for strain energy accumulation and releases, and in turn, devastating earthquakes. Almost all earthquakes of magnitude greater than 8 and 80%-90% of earthquakes of magnitude over 7 occur along boundaries of active tectonic blocks. This fact indicates that differential movements and interactions of active tectonic blocks are the primary mechanism for the occurrences of devastating earthquakes.展开更多
Metamaterials are artificial structures that are usually described by effective medium parameters on the macroscopic scale,and these metamaterials are referred to as‘analog metamaterials’.Here,we propose‘digital me...Metamaterials are artificial structures that are usually described by effective medium parameters on the macroscopic scale,and these metamaterials are referred to as‘analog metamaterials’.Here,we propose‘digital metamaterials’through two steps.First,we present‘coding metamaterials’that are composed of only two types of unit cells,with 0 and p phase responses,which we name‘0’and‘1’elements,respectively.By coding‘0’and‘1’elements with controlled sequences(i.e.,1-bit coding),we can manipulate electromagnetic(EM)waves and realize different functionalities.The concept of coding metamaterials can be extended from 1-bit coding to 2-bit coding or higher.In 2-bit coding,four types of unit cells,with phase responses of 0,p/2,p,and 3p/2,are required to mimic the‘00’,‘01’,‘10’and‘11’elements,respectively.The 2-bit coding has greater freedom than 1-bit coding for controlling EM waves.Second,we propose a unique metamaterial particle that has either a‘0’or‘1’response controlled by a biased diode.Based on this particle,we present‘digital metamaterials’with unit cells that possess either a‘0’or‘1’state.Using a field-programmable gate array,we realize digital control over the digital metamaterial.By programming different coding sequences,a single digital metamaterial has the ability to manipulate EM waves in different manners,thereby realizing‘programmable metamaterials’.The above concepts and physical phenomena are confirmed through numerical simulations and experiments using metasurfaces.展开更多
China is one of the countries with the highest incidence of gastric cancer.There are differences in epidemiological characteristics,clinicopathological features,tumor biological characteristics,treatment patterns,and ...China is one of the countries with the highest incidence of gastric cancer.There are differences in epidemiological characteristics,clinicopathological features,tumor biological characteristics,treatment patterns,and drug selection between gastric cancer patients from the Eastern and Western countries.Non-Chinese guidelines cannot specifically reflect the diagnosis and treatment characteristics for the Chinese gastric cancer patients.The Chinese Society of Clinical Oncology(CSCO)arranged for a panel of senior experts specializing in all sub-specialties of gastric cancer to compile,discuss,and revise the guidelines on the diagnosis and treatment of gastric cancer based on the findings of evidence-based medicine in China and abroad.By referring to the opinions of industry experts,taking into account of regional differences,giving full consideration to the accessibility of diagnosis and treatment resources,these experts have conducted experts’consensus judgement on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes.This guideline uses tables and is complemented by explanatory and descriptive notes covering the diagnosis,comprehensive treatment,and follow-up visits for gastric cancer.展开更多
This paper presents a new method for the detection and parameter estimation of multicomponent LFM signals based on the fractional Fourier transform. For the optimization in the fractional Fourier domain, an algorithm ...This paper presents a new method for the detection and parameter estimation of multicomponent LFM signals based on the fractional Fourier transform. For the optimization in the fractional Fourier domain, an algorithm based on Quasi-Newton method is proposed which consists of two steps of searching, leading to a reduction in computation without loss of accuracy. And for multicomponent signals, we further propose a signal separation technique in the fractional Fourier domain which can effectively suppress the interferences on the detection of the weak components brought by the stronger components. The statistical analysis of the estimate errors is also performed which perfects the method theoretically, and finally, simulation results are provided to show the validity of our method.展开更多
AIM:To sum up the clinical and pathological characte- ristics of solid pseudopapillary tumor (SPT) and the experience with it.METHODS: A total of 553 SPT patients reported in Chinese literature between January 1996 an...AIM:To sum up the clinical and pathological characte- ristics of solid pseudopapillary tumor (SPT) and the experience with it.METHODS: A total of 553 SPT patients reported in Chinese literature between January 1996 and January 2009 were retrospectively reviewed and analyzed. RESULTS: The mean age of the 553 SPT patients included in this review was 27.2 years, and the male to female ratio was 1:8.37. Their symptoms were non-specific, and nearly one third of the patients were asymptomatic. Computed tomography and ultraso-nography were performed to show the nature and location of SPT. Most of the tumors were distributed in the pancreatic head (39.8%), tail (24.1%), body andtail (19.5%). Forty-five patients (9.2%) were diagnosed as malignant SPT with metastasis or invasion. None of the clinical factors was closely related to the malignant potential of SPT. Surgery was the main therapeutic modality for SPT. Local resection, distal pancreatectomy and pancreatoduodenectomy were the most common surgical procedures. Local recurrence and hepatic metastasis were found in 11 and 2 patients, respectively, after radical resection. Four patients died of tumor progression within 4 years after palliative resection of SPT. The prognosis of SPT patients was good with a 5-year survival rate of 96.9%.CONCLUSION: SPT of the pancreas is a rare indolent neoplasm that typically occurs in young females. It is a low-grade malignancy and can be cured with extended resection. The prognosis of such patients is good although the tumor may recur and metastasize.展开更多
Seed plants have evolved to maintain the dormancy of freshly matured seeds until the appropriate time for germination. Seed dormancy and germination are distinct physiological processes, and the transition from dorman...Seed plants have evolved to maintain the dormancy of freshly matured seeds until the appropriate time for germination. Seed dormancy and germination are distinct physiological processes, and the transition from dormancy to germination is not only a critical developmental step in the life cycle of plants but is also impor- tant for agricultural production. These processes are precisely regulated by diverse endogenous hormones and environmental cues. Although ABA （abscisic acid） and GAs （gibberellins） are known to be the primary phytohormones that antagonistically regulate seed dormancy, recent findings demonstrate that another phytohormone, auxin, is also critical for inducing and maintaining seed dormancy, and therefore might act as a key protector of seed dormancy. In this review, we summarize our current understanding of the sophisticated molecular networks involving the critical roles of phytohormones in regulating seed dormancy and germination, in which AP2-domain-containing transcription factors play key roles. We also discuss the interactions （crosstalk） of diverse hormonal signals in seed dormancy and germination, focusing on the ABA/GA balance that constitutes the central node.展开更多
Background: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,...Background: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 batorigin CoV causing severe and fatal pneumonia in humans.Methods: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.Results: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 unknownβ-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.Conclusion:A novel bat-borne CoV was identified that is associated with severe and fatal respiratory disease in humans.展开更多
State-of-the-art technologies such as the Internet of Things(IoT),cloud computing(CC),big data analytics(BDA),and artificial intelligence(AI)have greatly stimulated the development of smart manufacturing.An important ...State-of-the-art technologies such as the Internet of Things(IoT),cloud computing(CC),big data analytics(BDA),and artificial intelligence(AI)have greatly stimulated the development of smart manufacturing.An important prerequisite for smart manufacturing is cyber-physical integration,which is increasingly being embraced by manufacturers.As the preferred means of such integration,cyber-physical systems(CPS)and digital twins(DTs)have gained extensive attention from researchers and practitioners in industry.With feedback loops in which physical processes affect cyber parts and vice versa,CPS and DTs can endow manufacturing systems with greater efficiency,resilience,and intelligence.CPS and DTs share the same essential concepts of an intensive cyber-physical connection,real-time interaction,organization integration,and in-depth collaboration.However,CPS and DTs are not identical from many perspectives,including their origin,development,engineering practices,cyber-physical mapping,and core elements.In order to highlight the differences and correlation between them,this paper reviews and analyzes CPS and DTs from multiple perspectives.展开更多
High-precision major element and Hf isotope data are reported for the Neoproterozoic Suxiong volcanic rocks along the western margin of the Yangtze Block. These volcanic rocks have variable εHf(T) values and Fe/Mn ra...High-precision major element and Hf isotope data are reported for the Neoproterozoic Suxiong volcanic rocks along the western margin of the Yangtze Block. These volcanic rocks have variable εHf(T) values and Fe/Mn ratios. The relatively primitive basalts have high Fe/Mn ratios and high Hf-Nd isotopic compositions, indicating that they were generated by partial melting of garnet clinopyroxene in mantle plume at high pressure. Thus, the Suxiong basalts are genetically related to the proposed Neoproterozoic super-plume. On the contrary, a few differentiated basalts have low Fe/Mn ratios and low Hf-Nd isotopic compositions. They are likely to experience assimilation-fractional crystallization process. The Suxiong rhyolites have consistent Hf and Nd model ages of 1.3―1.4 Ga. They are likely generated by shallow dehydration melting of pre-existing young arc igne-ous rocks associated with the basaltic underplating/intrusion in a continental rift.展开更多
China’s population has rapidly aged over the recent decades of social and economic development as neurodegenerative disorders have proliferated,especially Alzheimer’s disease(AD)and related dementias(ADRD).AD’s inc...China’s population has rapidly aged over the recent decades of social and economic development as neurodegenerative disorders have proliferated,especially Alzheimer’s disease(AD)and related dementias(ADRD).AD’s incidence rate,morbidity,and mortality have steadily increased to make it presently the fifth leading cause of death among urban and rural residents in China and magnify the resulting financial burdens on individuals,families and society.The‘Healthy China Action’plan of 2019-2030 promotes the transition from disease treatment to health maintenance for this expanding population with ADRD.This report describes related epidemiological trends,evaluates the economic burden of the disease,outlines current clinical diagnosis and treatment status and delineates existing available public health resources.More specifically,it examines the public health impact of ADRD,including prevalence,mortality,costs,usage of care,and the overall effect on caregivers and society.In addition,this special report presents technical guidance and supports for the prevention and treatment of AD,provides expertise to guide relevant governmental healthcare policy development and suggests an information platform for international exchange and cooperation.展开更多
High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal elements.Although in the infant stage,the emerging ...High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal elements.Although in the infant stage,the emerging of this new family of materials has brought new opportunities for material design and property tailoring.Distinct from metals,the diversity in crystal structure and electronic structure of ceramics provides huge space for properties tuning through band structure engineering and phonon engineering.Aside from strengthening,hardening,and low thermal conductivity that have already been found in high-entropy alloys,new properties like colossal dielectric constant,super ionic conductivity,severe anisotropic thermal expansion coefficient,strong electromagnetic wave absorption,etc.,have been discovered in HECs.As a response to the rapid development in this nascent field,this article gives a comprehensive review on the structure features,theoretical methods for stability and property prediction,processing routes,novel properties,and prospective applications of HECs.The challenges on processing,characterization,and property predictions are also emphasized.Finally,future directions for new material exploration,novel processing,fundamental understanding,in-depth characterization,and database assessments are given.展开更多
Dear Editor Salvia miltiorrhiza Bunge （Danshen） is a medicinal plant of the Lamiaceae family, and its dried roots have long been used in traditional Chinese medicine with hydrophilic phenolic acids and tanshinones a...Dear Editor Salvia miltiorrhiza Bunge （Danshen） is a medicinal plant of the Lamiaceae family, and its dried roots have long been used in traditional Chinese medicine with hydrophilic phenolic acids and tanshinones as pharmaceutically active components （Zhang et al., 2014; Xu et al., 2016）. The first step of tanshinone biosynthesis is bicyclization of the general diterpene precursor （E,E,E）-geranylgeranyl diphosphate （GGPP） to copalyl diphosphate （CPP） by CPP synthases （CPSs）, which is followed by a cyclization or rearrangement reaction catalyzed by kaurene synthase-like enzymes （KSL）. The resulting intermediate is usually an olefin, which requires the insertion of oxygen by cytochrome P450 mono-oxygenases （CYPs） for the final production of diterpenoids （Zi et al., 2014）. While the CPS, KSL, and several early acting CYPs （CYP76AH1, CYP76AH3, and CYP76AK1） for tanshinone biosynthesis have been identified in S. miltiorrhiza （Gao et al., 2009; Guo et al., 2013, 2016; Zi and Peters, 2013）, the majority of the overall biosynthetic pathway, as well as the relevant regulatory factors associated with tanshinone production, remains elusive （Figure 1B）.展开更多
Objective Since HFMD was designated as a class C communicable disease in May 2008,18 months surveillance data have been accumulated to December 2009.This article was to describe the distribution of HFMD for age,sex,ar...Objective Since HFMD was designated as a class C communicable disease in May 2008,18 months surveillance data have been accumulated to December 2009.This article was to describe the distribution of HFMD for age,sex,area,and time between 2008 and 2009,to reveal the characteristics of the epidemic.Methods We analyzed weekly reported cases of HFMD from May 2008 to December 2009,and presented data on the distribution of age,sex,area and time.A discrete Poisson model was used to detect spatial-temporal clusters of HFMD.Results More than 1 065 000 cases of HFMD were reported in China's Mainland from May 2008 to December 2009 （total incidence：12.47 per 10 000）.Male incidence was higher than female for all ages and 91.9% of patients were 5 years old.The incidence was highest in Beijing,Shanghai,Zhejiang and Hainan.The highest peak of HFMD cases was in April and the number of cases remained high from April to August.The spatial-temporal distribution detected four clusters.Conclusion Children 5 years old were susceptible to HFMD and we should be aware of their vulnerability.The incidence was higher in urban than rural areas,and an annual pandemic usually starts in April.展开更多
Objective： To analyze the trends of incidence rate and age at diagnosis for cervical cancer incidence in China using population-based cancer registration data from 2000 to 2014. Methods： Data were from National Cent...Objective： To analyze the trends of incidence rate and age at diagnosis for cervical cancer incidence in China using population-based cancer registration data from 2000 to 2014. Methods： Data were from National Central Cancer Registry of China. Crude incidence rates （CIRs）, age-specific incidence rate, age-standardized incidence rates （ASIRs）, age percentage distribution, standardized age percentage distribution, mean age at diagnosis and standardized mean age at diagnosis for cervical cancer in all areas of China, urban China and rural China were calculated separately. The world Segi＇s population was applied to remove the age structure influence. Joinpoint regression was performed to obtain average annual percent change （AAPC） and age- period-cohort analysis was used to examine the incidence trends. Results： CIRs and ASIRs for cervical cancer increased in China from 2000 to 2014. The AAPC of ASIRs in China was at 9.2% [95% confidence interval （95% CI）： 7.0%-I 1.5%, P〈0.05], and the AAPC in rural areas was relatively high. The age-specific incidence rate in groups aged 0-69 years have significantly increased over time. Groups aged 40-69 years showed the highest incidence risk, and the annual percent changes （APCs） of incidence rate in groups aged 40-59 years in urban China and groups aged 0-49 years in rural China were more than 10%. For each age group, the urban-to-rural incidence rate ratios （IRRs） got close to 1 over time. There were clear birth cohort effects in successive generations born from 1940 to 1970 in China. In rural China, the standardized mean age at diagnosis had significantly declined by 5.18 years. In China, the main peak and secondary peak of standardized age percentages appeared in the groups aged 45-49 and 40-44 years, respectively. In rural China, the main peak of standardized age percentage moved from the group aged 55-59 years to the group aged 45-49 years, and the standardized age percentages of groups aged 25-34 years also increased. In China, the stan展开更多
The theory of the concept lattice is an efficient tool for knowledge representation and knowledge discovery, and is applied to many fields successfully. One focus of knowledge discovery is knowledge reduction. This pa...The theory of the concept lattice is an efficient tool for knowledge representation and knowledge discovery, and is applied to many fields successfully. One focus of knowledge discovery is knowledge reduction. This paper proposes the theory of attribute reduction in the concept lattice, which extends the theory of the concept lattice. In this paper, the judgment theorems of consistent sets are examined, and the discernibility matrix of a formal context is introduced, by which we present an approach to attribute reduction in the concept lattice. The characteristics of three types of attributes are analyzed.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
Tartary buckwheat （Fagopyrum tataricum） is an important pseudocereal crop that is strongly adapted to growth in adverse environments. Its gluten-free grain contains complete proteins with a well-balanced composition...Tartary buckwheat （Fagopyrum tataricum） is an important pseudocereal crop that is strongly adapted to growth in adverse environments. Its gluten-free grain contains complete proteins with a well-balanced composition of essential amino acids and is a rich source of beneficial phytochemicals that provide significant health benefits. Here, we report a high-quality, chromosome-scale Tartary buckwheat genome sequence of- 489.3 Mb that is assembled by combining whole-genome shotgun sequencing of both Illumina short reads and single-molecule real-time long reads, sequence tags of a large DNA insert fosmid library, Hi-C sequencing data, and BioNano genome maps. We annotated 33 366 high-confidence protein-coding genes based on expression evidence. Comparisons of the intra-genome with the sugar beet genome revealed an independent whole-genome duplication that occurred in the buckwheat lineage after they diverged from the common ancestor, which was not shared with rosids or asterids. The reference genome facilitated the identification of many new genes predicted to be involved in rutin biosynthesis and regulation, aluminum stress resistance, and in drought and cold stress responses. Our data suggest that Tartary buckwheat＇s ability to tolerate high levels of abiotic stress is attributed to the expansion of several gene families involved in signal transduction, gene regulation, and membrane transport. The availability of these genomic resources will facilitate the discovery of agronomically and nutritionally important genes and genetic improvement of Tartary buckwheat.展开更多
Considerable research is now focusing on abrupt Holocene changes at millennial- and centennial-scales all over the world. This study shows that the changes in theHolocene summer monsoon can be divided into two main pe...Considerable research is now focusing on abrupt Holocene changes at millennial- and centennial-scales all over the world. This study shows that the changes in theHolocene summer monsoon can be divided into two main periods, based on climatic proxy records of lake sediments from the Sanjiaocheng section located at the NW boundary of the summer monsoon, Gansu Province. The early and middle Holocene was humid with stronger summer monsoon, while the late Holocene is dry with weak summer monsoon. Detailed results also show a series of millennial- and centennial-scale changes in the intensity of the summer monsoon, with a periodicity of 1600 years during the whole Holocene, and with a periodicity of 800 years during the early Holocene. Ten dry events during the Holocene are associated with the weakening of the summer monsoon. These rapid climatic changes may be representative of a global climatic change pattern during the Holocene.展开更多
基金Supported in part by National Key Basic Research Program of China (2015CB856700)National Natural Science Foundation of China (NSFC) (11335008,11425524, 11625523, 11635010, 11735014, 11822506, 11935018)+18 种基金the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Programthe CAS Center for Excellence in Particle Physics (CCEPP)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (U1532257, U1532258, U1732263)CAS Key Research Program of Frontier Science (QYZDJ-SSW-SLH003, QYZDJ-SSW-SLH040)100 Talents Program of CASCAS PIFIthe Thousand Talents Program of ChinaIN-PAC and Shanghai Key Laboratory for Particle Physics and CosmologyGerman Research Foundation DFG under Contracts NosCollaborative Research Center CRC 1044, FOR 2359Istituto Nazionale di Fisica Nucleare, ItalyKoninklijke Nederlandse Akademie van Wetenschappen (KNAW) (530-4CDP03)Ministry of Development of Turkey (DPT2006K-120470)National Science and Technology fundThe Knut and Alice Wallenberg Foundation (Sweden) (2016.0157)The Swedish Research CouncilU. S. Department of Energy (DE-FG02-05ER41374, DESC-0010118, DE-SC-0012069)University of Groningen (Ru G) and the Helmholtzzentrum fuer Schwerionenforschung Gmb H (GSI), Darmstadtthe Russian Ministry of Science and Higher Education (14.W03.31.0026).
文摘There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESⅢ, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESⅢ during the remaining operation period of BEPCⅡ. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCⅡ to higher luminosity.
文摘The primary pattern of the late Cenozoic to the present tectonic deformation of China is characterized by relative movements and interactions of tectonic blocks. Active tectonic blocks are geological units that have been separated from each other by active tectonic zones. Boundaries between blocks are the highest gradient of differential movement. Most of tectonic activity occurs on boundaries of the blocks. Earthquakes are results of abrupt releases of accumulated strain energy that reaches the threshold of strength of the earth's crust. Boundaries of tectonic blocks are the locations of most discontinuous deformation and highest gradient of stress accumulation, thus are the most likely places for strain energy accumulation and releases, and in turn, devastating earthquakes. Almost all earthquakes of magnitude greater than 8 and 80%-90% of earthquakes of magnitude over 7 occur along boundaries of active tectonic blocks. This fact indicates that differential movements and interactions of active tectonic blocks are the primary mechanism for the occurrences of devastating earthquakes.
基金This work was supported in part by the National High Tech(863)Projects(2012AA030402 and 2011AA010202)in part by the National Science Foundation of China(61138001,60990320 and 60990324)in part by the 111 Project(111-2-05)and in part by the Joint Research Center on Terahertz Science.
文摘Metamaterials are artificial structures that are usually described by effective medium parameters on the macroscopic scale,and these metamaterials are referred to as‘analog metamaterials’.Here,we propose‘digital metamaterials’through two steps.First,we present‘coding metamaterials’that are composed of only two types of unit cells,with 0 and p phase responses,which we name‘0’and‘1’elements,respectively.By coding‘0’and‘1’elements with controlled sequences(i.e.,1-bit coding),we can manipulate electromagnetic(EM)waves and realize different functionalities.The concept of coding metamaterials can be extended from 1-bit coding to 2-bit coding or higher.In 2-bit coding,four types of unit cells,with phase responses of 0,p/2,p,and 3p/2,are required to mimic the‘00’,‘01’,‘10’and‘11’elements,respectively.The 2-bit coding has greater freedom than 1-bit coding for controlling EM waves.Second,we propose a unique metamaterial particle that has either a‘0’or‘1’response controlled by a biased diode.Based on this particle,we present‘digital metamaterials’with unit cells that possess either a‘0’or‘1’state.Using a field-programmable gate array,we realize digital control over the digital metamaterial.By programming different coding sequences,a single digital metamaterial has the ability to manipulate EM waves in different manners,thereby realizing‘programmable metamaterials’.The above concepts and physical phenomena are confirmed through numerical simulations and experiments using metasurfaces.
文摘China is one of the countries with the highest incidence of gastric cancer.There are differences in epidemiological characteristics,clinicopathological features,tumor biological characteristics,treatment patterns,and drug selection between gastric cancer patients from the Eastern and Western countries.Non-Chinese guidelines cannot specifically reflect the diagnosis and treatment characteristics for the Chinese gastric cancer patients.The Chinese Society of Clinical Oncology(CSCO)arranged for a panel of senior experts specializing in all sub-specialties of gastric cancer to compile,discuss,and revise the guidelines on the diagnosis and treatment of gastric cancer based on the findings of evidence-based medicine in China and abroad.By referring to the opinions of industry experts,taking into account of regional differences,giving full consideration to the accessibility of diagnosis and treatment resources,these experts have conducted experts’consensus judgement on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes.This guideline uses tables and is complemented by explanatory and descriptive notes covering the diagnosis,comprehensive treatment,and follow-up visits for gastric cancer.
文摘This paper presents a new method for the detection and parameter estimation of multicomponent LFM signals based on the fractional Fourier transform. For the optimization in the fractional Fourier domain, an algorithm based on Quasi-Newton method is proposed which consists of two steps of searching, leading to a reduction in computation without loss of accuracy. And for multicomponent signals, we further propose a signal separation technique in the fractional Fourier domain which can effectively suppress the interferences on the detection of the weak components brought by the stronger components. The statistical analysis of the estimate errors is also performed which perfects the method theoretically, and finally, simulation results are provided to show the validity of our method.
文摘AIM:To sum up the clinical and pathological characte- ristics of solid pseudopapillary tumor (SPT) and the experience with it.METHODS: A total of 553 SPT patients reported in Chinese literature between January 1996 and January 2009 were retrospectively reviewed and analyzed. RESULTS: The mean age of the 553 SPT patients included in this review was 27.2 years, and the male to female ratio was 1:8.37. Their symptoms were non-specific, and nearly one third of the patients were asymptomatic. Computed tomography and ultraso-nography were performed to show the nature and location of SPT. Most of the tumors were distributed in the pancreatic head (39.8%), tail (24.1%), body andtail (19.5%). Forty-five patients (9.2%) were diagnosed as malignant SPT with metastasis or invasion. None of the clinical factors was closely related to the malignant potential of SPT. Surgery was the main therapeutic modality for SPT. Local resection, distal pancreatectomy and pancreatoduodenectomy were the most common surgical procedures. Local recurrence and hepatic metastasis were found in 11 and 2 patients, respectively, after radical resection. Four patients died of tumor progression within 4 years after palliative resection of SPT. The prognosis of SPT patients was good with a 5-year survival rate of 96.9%.CONCLUSION: SPT of the pancreas is a rare indolent neoplasm that typically occurs in young females. It is a low-grade malignancy and can be cured with extended resection. The prognosis of such patients is good although the tumor may recur and metastasize.
文摘Seed plants have evolved to maintain the dormancy of freshly matured seeds until the appropriate time for germination. Seed dormancy and germination are distinct physiological processes, and the transition from dormancy to germination is not only a critical developmental step in the life cycle of plants but is also impor- tant for agricultural production. These processes are precisely regulated by diverse endogenous hormones and environmental cues. Although ABA （abscisic acid） and GAs （gibberellins） are known to be the primary phytohormones that antagonistically regulate seed dormancy, recent findings demonstrate that another phytohormone, auxin, is also critical for inducing and maintaining seed dormancy, and therefore might act as a key protector of seed dormancy. In this review, we summarize our current understanding of the sophisticated molecular networks involving the critical roles of phytohormones in regulating seed dormancy and germination, in which AP2-domain-containing transcription factors play key roles. We also discuss the interactions （crosstalk） of diverse hormonal signals in seed dormancy and germination, focusing on the ABA/GA balance that constitutes the central node.
基金This study was supported by grants from the Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(No.2016-I2M-1-014)the National Major Science&Technology Project for Control and Prevention of Major Infectious Diseases in China(Nos.2017ZX10103004,2018ZX10305409,2017ZX10204401)the National Natural Science Foundation(No.81930063)
文摘Background: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 batorigin CoV causing severe and fatal pneumonia in humans.Methods: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.Results: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 unknownβ-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.Conclusion:A novel bat-borne CoV was identified that is associated with severe and fatal respiratory disease in humans.
基金This work is financially supported by the National Key Research and Development Program of China(2016YFB1101700)the National Natural Science Foundation of China(51875030)the Academic Excellence Foundation of BUAA for PhD Students.
文摘State-of-the-art technologies such as the Internet of Things(IoT),cloud computing(CC),big data analytics(BDA),and artificial intelligence(AI)have greatly stimulated the development of smart manufacturing.An important prerequisite for smart manufacturing is cyber-physical integration,which is increasingly being embraced by manufacturers.As the preferred means of such integration,cyber-physical systems(CPS)and digital twins(DTs)have gained extensive attention from researchers and practitioners in industry.With feedback loops in which physical processes affect cyber parts and vice versa,CPS and DTs can endow manufacturing systems with greater efficiency,resilience,and intelligence.CPS and DTs share the same essential concepts of an intensive cyber-physical connection,real-time interaction,organization integration,and in-depth collaboration.However,CPS and DTs are not identical from many perspectives,including their origin,development,engineering practices,cyber-physical mapping,and core elements.In order to highlight the differences and correlation between them,this paper reviews and analyzes CPS and DTs from multiple perspectives.
基金supported by NSFC(Grant No.40421303)Chinese Academy of Sciences(Grant Nos.KZCX3-SW-141 and GIGCX-04-06).
文摘High-precision major element and Hf isotope data are reported for the Neoproterozoic Suxiong volcanic rocks along the western margin of the Yangtze Block. These volcanic rocks have variable εHf(T) values and Fe/Mn ratios. The relatively primitive basalts have high Fe/Mn ratios and high Hf-Nd isotopic compositions, indicating that they were generated by partial melting of garnet clinopyroxene in mantle plume at high pressure. Thus, the Suxiong basalts are genetically related to the proposed Neoproterozoic super-plume. On the contrary, a few differentiated basalts have low Fe/Mn ratios and low Hf-Nd isotopic compositions. They are likely to experience assimilation-fractional crystallization process. The Suxiong rhyolites have consistent Hf and Nd model ages of 1.3―1.4 Ga. They are likely generated by shallow dehydration melting of pre-existing young arc igne-ous rocks associated with the basaltic underplating/intrusion in a continental rift.
基金This report was supported by a grant from Brain Science and Brain-Like Intelligence Technology of the Ministry of Science and Technology of China(2021ZD0201804).
文摘China’s population has rapidly aged over the recent decades of social and economic development as neurodegenerative disorders have proliferated,especially Alzheimer’s disease(AD)and related dementias(ADRD).AD’s incidence rate,morbidity,and mortality have steadily increased to make it presently the fifth leading cause of death among urban and rural residents in China and magnify the resulting financial burdens on individuals,families and society.The‘Healthy China Action’plan of 2019-2030 promotes the transition from disease treatment to health maintenance for this expanding population with ADRD.This report describes related epidemiological trends,evaluates the economic burden of the disease,outlines current clinical diagnosis and treatment status and delineates existing available public health resources.More specifically,it examines the public health impact of ADRD,including prevalence,mortality,costs,usage of care,and the overall effect on caregivers and society.In addition,this special report presents technical guidance and supports for the prevention and treatment of AD,provides expertise to guide relevant governmental healthcare policy development and suggests an information platform for international exchange and cooperation.
基金Financial supports from the National Natural Science Foundation of China under Grant Nos.51972089,51672064,and U1435206 are also acknowledged.
文摘High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal elements.Although in the infant stage,the emerging of this new family of materials has brought new opportunities for material design and property tailoring.Distinct from metals,the diversity in crystal structure and electronic structure of ceramics provides huge space for properties tuning through band structure engineering and phonon engineering.Aside from strengthening,hardening,and low thermal conductivity that have already been found in high-entropy alloys,new properties like colossal dielectric constant,super ionic conductivity,severe anisotropic thermal expansion coefficient,strong electromagnetic wave absorption,etc.,have been discovered in HECs.As a response to the rapid development in this nascent field,this article gives a comprehensive review on the structure features,theoretical methods for stability and property prediction,processing routes,novel properties,and prospective applications of HECs.The challenges on processing,characterization,and property predictions are also emphasized.Finally,future directions for new material exploration,novel processing,fundamental understanding,in-depth characterization,and database assessments are given.
文摘Dear Editor Salvia miltiorrhiza Bunge （Danshen） is a medicinal plant of the Lamiaceae family, and its dried roots have long been used in traditional Chinese medicine with hydrophilic phenolic acids and tanshinones as pharmaceutically active components （Zhang et al., 2014; Xu et al., 2016）. The first step of tanshinone biosynthesis is bicyclization of the general diterpene precursor （E,E,E）-geranylgeranyl diphosphate （GGPP） to copalyl diphosphate （CPP） by CPP synthases （CPSs）, which is followed by a cyclization or rearrangement reaction catalyzed by kaurene synthase-like enzymes （KSL）. The resulting intermediate is usually an olefin, which requires the insertion of oxygen by cytochrome P450 mono-oxygenases （CYPs） for the final production of diterpenoids （Zi et al., 2014）. While the CPS, KSL, and several early acting CYPs （CYP76AH1, CYP76AH3, and CYP76AK1） for tanshinone biosynthesis have been identified in S. miltiorrhiza （Gao et al., 2009; Guo et al., 2013, 2016; Zi and Peters, 2013）, the majority of the overall biosynthetic pathway, as well as the relevant regulatory factors associated with tanshinone production, remains elusive （Figure 1B）.
文摘Objective Since HFMD was designated as a class C communicable disease in May 2008,18 months surveillance data have been accumulated to December 2009.This article was to describe the distribution of HFMD for age,sex,area,and time between 2008 and 2009,to reveal the characteristics of the epidemic.Methods We analyzed weekly reported cases of HFMD from May 2008 to December 2009,and presented data on the distribution of age,sex,area and time.A discrete Poisson model was used to detect spatial-temporal clusters of HFMD.Results More than 1 065 000 cases of HFMD were reported in China's Mainland from May 2008 to December 2009 （total incidence：12.47 per 10 000）.Male incidence was higher than female for all ages and 91.9% of patients were 5 years old.The incidence was highest in Beijing,Shanghai,Zhejiang and Hainan.The highest peak of HFMD cases was in April and the number of cases remained high from April to August.The spatial-temporal distribution detected four clusters.Conclusion Children 5 years old were susceptible to HFMD and we should be aware of their vulnerability.The incidence was higher in urban than rural areas,and an annual pandemic usually starts in April.
基金supported by Program Grant in Fundamental Research from the Ministry of Science and Technology(No.2014FY121100)Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(No.201612M2004)
文摘Objective： To analyze the trends of incidence rate and age at diagnosis for cervical cancer incidence in China using population-based cancer registration data from 2000 to 2014. Methods： Data were from National Central Cancer Registry of China. Crude incidence rates （CIRs）, age-specific incidence rate, age-standardized incidence rates （ASIRs）, age percentage distribution, standardized age percentage distribution, mean age at diagnosis and standardized mean age at diagnosis for cervical cancer in all areas of China, urban China and rural China were calculated separately. The world Segi＇s population was applied to remove the age structure influence. Joinpoint regression was performed to obtain average annual percent change （AAPC） and age- period-cohort analysis was used to examine the incidence trends. Results： CIRs and ASIRs for cervical cancer increased in China from 2000 to 2014. The AAPC of ASIRs in China was at 9.2% [95% confidence interval （95% CI）： 7.0%-I 1.5%, P〈0.05], and the AAPC in rural areas was relatively high. The age-specific incidence rate in groups aged 0-69 years have significantly increased over time. Groups aged 40-69 years showed the highest incidence risk, and the annual percent changes （APCs） of incidence rate in groups aged 40-59 years in urban China and groups aged 0-49 years in rural China were more than 10%. For each age group, the urban-to-rural incidence rate ratios （IRRs） got close to 1 over time. There were clear birth cohort effects in successive generations born from 1940 to 1970 in China. In rural China, the standardized mean age at diagnosis had significantly declined by 5.18 years. In China, the main peak and secondary peak of standardized age percentages appeared in the groups aged 45-49 and 40-44 years, respectively. In rural China, the main peak of standardized age percentage moved from the group aged 55-59 years to the group aged 45-49 years, and the standardized age percentages of groups aged 25-34 years also increased. In China, the stan
基金This work was supported by the National 973 Program of China(Grant No．2002CB3 1 2200)the National Natural Science Foundation of China(Grant No．60373038) the Natural Scientific Research Project ofthe Education Department ofShaanxi Province in China(Grant No．04JK131)．
文摘The theory of the concept lattice is an efficient tool for knowledge representation and knowledge discovery, and is applied to many fields successfully. One focus of knowledge discovery is knowledge reduction. This paper proposes the theory of attribute reduction in the concept lattice, which extends the theory of the concept lattice. In this paper, the judgment theorems of consistent sets are examined, and the discernibility matrix of a formal context is introduced, by which we present an approach to attribute reduction in the concept lattice. The characteristics of three types of attributes are analyzed.
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.
文摘Tartary buckwheat （Fagopyrum tataricum） is an important pseudocereal crop that is strongly adapted to growth in adverse environments. Its gluten-free grain contains complete proteins with a well-balanced composition of essential amino acids and is a rich source of beneficial phytochemicals that provide significant health benefits. Here, we report a high-quality, chromosome-scale Tartary buckwheat genome sequence of- 489.3 Mb that is assembled by combining whole-genome shotgun sequencing of both Illumina short reads and single-molecule real-time long reads, sequence tags of a large DNA insert fosmid library, Hi-C sequencing data, and BioNano genome maps. We annotated 33 366 high-confidence protein-coding genes based on expression evidence. Comparisons of the intra-genome with the sugar beet genome revealed an independent whole-genome duplication that occurred in the buckwheat lineage after they diverged from the common ancestor, which was not shared with rosids or asterids. The reference genome facilitated the identification of many new genes predicted to be involved in rutin biosynthesis and regulation, aluminum stress resistance, and in drought and cold stress responses. Our data suggest that Tartary buckwheat＇s ability to tolerate high levels of abiotic stress is attributed to the expansion of several gene families involved in signal transduction, gene regulation, and membrane transport. The availability of these genomic resources will facilitate the discovery of agronomically and nutritionally important genes and genetic improvement of Tartary buckwheat.
基金This study was supported by the National Natural Science Foundation of China (Grant No. 49731010)the National Key Basic Research Project on Western Chinese Arid Areas (Grant No. G1999043501).
文摘Considerable research is now focusing on abrupt Holocene changes at millennial- and centennial-scales all over the world. This study shows that the changes in theHolocene summer monsoon can be divided into two main periods, based on climatic proxy records of lake sediments from the Sanjiaocheng section located at the NW boundary of the summer monsoon, Gansu Province. The early and middle Holocene was humid with stronger summer monsoon, while the late Holocene is dry with weak summer monsoon. Detailed results also show a series of millennial- and centennial-scale changes in the intensity of the summer monsoon, with a periodicity of 1600 years during the whole Holocene, and with a periodicity of 800 years during the early Holocene. Ten dry events during the Holocene are associated with the weakening of the summer monsoon. These rapid climatic changes may be representative of a global climatic change pattern during the Holocene.
