Dysregulated expression of microRNAs （miRNAs） in various tissues has been associated with a variety of diseases, including cancers. Here we demonstrate that miRNAs are present in the serum and plasma of humans and o...Dysregulated expression of microRNAs （miRNAs） in various tissues has been associated with a variety of diseases, including cancers. Here we demonstrate that miRNAs are present in the serum and plasma of humans and other animals such as mice, rats, bovine fetuses, calves, and horses. The levels of miRNAs in serum are stable, reproducible, and consistent among individuals of the same species. Employing Solexa, we sequenced all serum miRNAs of healthy Chinese subjects and found over 100 and 91 serum miRNAs in male and female subjects, respectively. We also identified specific expression patterns of serum miRNAs for lung cancer, colorectal cancer, and diabetes, providing evidence that serum miRNAs contain fingerprints for various diseases. Two non-small cell lung cancer-specific serum miRNAs obtained by Solexa were further validated in an independent trial of 75 healthy donors and 152 cancer patients, using quantitative reverse transcription polymerase chain reaction assays. Through these analyses, we conclude that serum miRNAs can serve as potential biomarkers for the detection of various cancers and other diseases.展开更多
Using the in situ zircon U-Pb dating method of LA-ICPMS, we analyzed the 31 Ma old SHRIMP U-Pb age of the Yongsheng nepheline syenite from southern Jilin Province under different spot sizes. The obtained ages are comp...Using the in situ zircon U-Pb dating method of LA-ICPMS, we analyzed the 31 Ma old SHRIMP U-Pb age of the Yongsheng nepheline syenite from southern Jilin Province under different spot sizes. The obtained ages are comparable with that of SHRIMP in both accuracy and precision. The age is also identical to that of the Yinmawanshan gabbro from the Liaodong Peninsula within error. Both the Yongsheng nepheline syenite and the Yinmawanshan gabbro represent the youngest known exposed intrusions in northeastern and even eastern China. The results indicate the Eocene mantle-derived magmatic underplating, and the rapid crustal uplifting of this region since 30 Ma. The analyses also document extremely high LREE concentrations and relatively flat REE patterns for the zircons from the Yongsheng nepheline syenite, which represent a new type of zircon REE pattern.展开更多
As the world strives to reduce the impact of population growth, urbanization, agricultural expansion, and climate change on food security, energy and water shortage, resource over-exploration, biodiversity loss, envir...As the world strives to reduce the impact of population growth, urbanization, agricultural expansion, and climate change on food security, energy and water shortage, resource over-exploration, biodiversity loss, environmental pollution, and ultimately human health, timely and higher resolution land cover information is urgently needed to achieve the sustainable development goals of the United Nations.展开更多
The outbreak of the 2019-nCoV infection began in December 2019 in Wuhan,Hubei province,and rapidly spread to many provinces in China as well as other countries.Here we report the epidemiological,clinical,laboratory,an...The outbreak of the 2019-nCoV infection began in December 2019 in Wuhan,Hubei province,and rapidly spread to many provinces in China as well as other countries.Here we report the epidemiological,clinical,laboratory,and radiological characteristics,as well as potential biomarkers for predicting disease severity in 2019-nCoV-infected patients in Shenzhen,China.All 12 cases of the 2019-nCoV-infected patients developed pneumonia and half of them developed acute respiratory distress syndrome (ARDS).The most common laboratory abnormalities were hypoalbuminemia,lymphopenia,decreased percentage of lymphocytes (LYM) and neutrophils (NEU),elevated C-reactive protein (CRP) and lactate dehydrogenase (LDH),and decreased CD8 count.The viral load of 2019-nCoV detected from patient respiratory tracts was positively linked to lung disease severity.ALB,LYM,LYM (%),LDH,NEU (%),and CRP were highly correlated to the acute lung injury.Age,viral load,lung injury score,and blood biochemistry indexes,albumin (ALB),CRP,LDH,LYM (%),LYM,and NEU (%),may be predictors of disease severity.Moreover,the Angiotensin Ⅱlevel in the plasma sample from 2019-nCoV infected patients was markedly elevated and linearly associated to viral load and lung injury.Our results suggest a number of potential diagnosis biomarkers and angiotensin receptor blocker (ARB) drugs for potential repurposing treatment of 2019-nCoV infection.展开更多
In December 2019, a new type viral pneumonia cases occurred in Wuhan, Hubei Province;and then named "2019 novel coronavirus(2019-nCoV)" by the World Health Organization(WHO) on 12 January 2020. For it is a n...In December 2019, a new type viral pneumonia cases occurred in Wuhan, Hubei Province;and then named "2019 novel coronavirus(2019-nCoV)" by the World Health Organization(WHO) on 12 January 2020. For it is a never been experienced respiratory disease before and with infection ability widely and quickly, it attracted the world’s attention but without treatment and control manual. For the request from frontline clinicians and public health professionals of 2019-nCoV infected pneumonia management, an evidence-based guideline urgently needs to be developed. Therefore, we drafted this guideline according to the rapid advice guidelines methodology and general rules of WHO guideline development;we also added the first-hand management data of Zhongnan Hospital of Wuhan University. This guideline includes the guideline methodology, epidemiological characteristics, disease screening and population prevention, diagnosis, treatment and control(including traditional Chinese Medicine), nosocomial infection prevention and control, and disease nursing of the 2019-nCoV. Moreover, we also provide a whole process of a successful treatment case of the severe 2019-nCoV infected pneumonia and experience and lessons of hospital rescue for 2019-nCoV infections. This rapid advice guideline is suitable for the first frontline doctors and nurses, managers of hospitals and healthcare sections, community residents, public health persons, relevant researchers, and all person who are interested in the 2019-nCoV.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
Postoperative pain is the most common complaint after laparoscopic cholecystectomy. This study was carried out to evaluate whether preoperative administration of intramuscular dezocine can provide postoperative analge...Postoperative pain is the most common complaint after laparoscopic cholecystectomy. This study was carried out to evaluate whether preoperative administration of intramuscular dezocine can provide postoperative analgesia and reduce postoperative opioid consumption in patients undergoing laparoscopic cholecystectomy. Patients （ASA Ⅰ or Ⅱ ） scheduled for laparoscopic cholecystectomy were randomly assigned into intramuscular dezocine group （group 1） or intramuscular normal saline group （group 2）. Dezocine and equal volume normal saline were administered intramuscularly 10 rain before the induction of anesthesia. After operation, the severity of postoperative pain, postoperative fentanyl requirement, incidence and severity of side-effects were assessed. Postoperative pain and postoperative patient-controlled fentanyl consumption were reduced significantly in group l compared with group 2. The incidence and severity of side effects were similar between the two groups. Preoperative single-dose administration of intramuscular dezocine 0.1 mg/kg was effective in reducing postoperative pain and postoperative patient-controlled fentanyl requirement in patients undergoing laparoscopic cholecystectomy.展开更多
Liver fibrosis is a reversible wound-healing process aimed at maintaining organ integrity, and presents as the critical pre-stage of liver cirrhosis, which will eventually progress to hepatocellular carcinoma in the a...Liver fibrosis is a reversible wound-healing process aimed at maintaining organ integrity, and presents as the critical pre-stage of liver cirrhosis, which will eventually progress to hepatocellular carcinoma in the absence of liver transplantation. Fibrosis generally results from chronic hepatic injury caused by various factors, mainly viral infection, schistosomiasis, and alcoholism; however, the exact pathological mechanisms are still unknown. Although numerous drugs have been shown to have antifibrotic activity in vitro and in animal models, none of these drugs have been shown to be efficacious in the clinic. Importantly, hepatic stellate cells(HSCs) play a key role in the initiation, progression, and regression of liver fibrosis by secreting fibrogenic factors that encourage portal fibrocytes, fibroblasts, and bone marrow-derived myofibroblasts to produce collagen and thereby propagate fibrosis. These cells are subject to intricate cross-talk with adjacent cells, resulting in scarring and subsequent liver damage. Thus, an understanding of the molecular mechanisms of liver fibrosis and their relationships with HSCs is essential for the discovery of new therapeutic targets. This comprehensive review outlines the role of HSCs in liver fibrosis and details novel strategies to suppress HSC activity, thereby providing new insights into potential treatments for liver fibrosis.展开更多
Objective： In this study,we aimed to estimate the updated incidence and mortality rate of stomach cancer based on the cancer registration data in 2014,collected by the National Central Cancer Registry of China（NCCRC...Objective： In this study,we aimed to estimate the updated incidence and mortality rate of stomach cancer based on the cancer registration data in 2014,collected by the National Central Cancer Registry of China（NCCRC）.Methods： In 2017,339 registries＇ data were qualified based on the criteria of data quality control of the NCCRC.Cases of stomach cancer were retrieved from the national database.We estimated numbers of stomach cancer cases and deaths in China using age-specific rates and corresponding national population stratified by area,sex,agegroup（0,1–4,5–9,10–14,…,85＋）.Chinese standard population in 2000 and Segi＇s world population were applied for age-standardized incidence and mortality rates.Results： In 2014,410,400 new stomach cancer cases and 293,800 cancer-associated deaths were estimated to have occurred in China.The crude incidence rate of stomach cancer was 30.00/100,000,age-standardized incidence rates by Chinese standard population（ASIRC） and by world standard population（ASIRW） were 19.62/100,000 and19.51/100,000,respectively.The crude mortality rate of stomach cancer was 21.48/100,000,age-standardized mortality rates by Chinese（ASMRC） and by world standard population（ASMRW） were 13.44/100,000 and13.30/100,000,respectively.Incidence and mortality rates in rural areas were both higher than that in urban areas.Stomach cancer has a strong relationship with gender and age.The disease has occurred more frequently among men than women with a male to female ratio of 2.4 for ASIRC.After age group of 40-44 years,incidence rates are substantially higher in men than in women,same pattern was seen for age-specific mortality rates.Conclusions： There is still a heavy burden of stomach cancer in China.The incidence and mortality patterns of stomach cancer show substantial gender and regional disparities.Great effort is needed to provide more accessible health services,sufficient financial resources,and adequate cancer-care infrastructure for the Chinese population,espec展开更多
Tea is the world＇s oldest and most popular caffeine-containing beverage with immense economic, medicinal, and cultural importance. Here, we present the first high-quality nucleotide sequence of the repeat-rich （80.9...Tea is the world＇s oldest and most popular caffeine-containing beverage with immense economic, medicinal, and cultural importance. Here, we present the first high-quality nucleotide sequence of the repeat-rich （80.9%）, 3.02-Gb genome of the cultivated tea tree Camellia sinensis. We show that an extraordinarily large genome size of tea tree is resulted from the slow, steady, and long-term amplification of a few LTR retrotransposon families. In addition to a recent whole-genome duplication event, lineage-specific expansions of genes associated with flavonoid metabolic biosynthesis were discovered, which enhance catechin production, terpene enzyme activation, and stress tolerance, important features for tea flavor and adaptation. We demonstrate an independent and rapid evolution of the tea caffeine synthesis pathway relative to cacao and coffee. A comparative study among 25 Camellia species revealed that higher expression levels of most flavonoid- and caffeinebut not theanine-related genes contribute to the increased production of catechins and caffeine and thus enhance tea-processing suitability and tea quality. These novel findings pave the way for further metabolomic and functional genomic refinement of characteristic biosynthesis pathways and will help develop a more diversified set of tea flavors that would eventually satisfy and attract more tea drinkers worldwide.展开更多
Thirty years ago,Coullet et al.proposed that a special optical field exists in laser cavities bearing some analogy with the superfluid vortex.Since then,optical vortices have been widely studied,inspired by the hydrod...Thirty years ago,Coullet et al.proposed that a special optical field exists in laser cavities bearing some analogy with the superfluid vortex.Since then,optical vortices have been widely studied,inspired by the hydrodynamics sharing similar mathematics.Akin to a fluid vortex with a central flow singularity,an optical vortex beam has a phase singularity with a certain topological charge,giving rise to a hollow intensity distribution.Such a beam with helical phase fronts and orbital angular momentum reveals a subtle connection between macroscopic physical optics and microscopic quantum optics.These amazing properties provide a new understanding of a wide range of optical and physical phenomena,including twisting photons,spin–orbital interactions,Bose-Einstein condensates,etc.,while the associated technologies for manipulating optical vortices have become increasingly tunable and flexible.Hitherto,owing to these salient properties and optical manipulation technologies,tunable vortex beams have engendered tremendous advanced applications such as optical tweezers,high-order quantum entanglement,and nonlinear optics.This article reviews the recent progress in tunable vortex technologies along with their advanced applications.展开更多
Simultaneous in-situ determination of U-Pb ages and 20 trace elements of three international zircon standards(91500,GJ1 and TEMORA 1) and one laboratory zircon standard(SK10-2) separated from Cenozoic fine-grained gab...Simultaneous in-situ determination of U-Pb ages and 20 trace elements of three international zircon standards(91500,GJ1 and TEMORA 1) and one laboratory zircon standard(SK10-2) separated from Cenozoic fine-grained gabbro was carried out on quadrupole ICP-MS equipped with 193 nm excimer laser in 20 μm spot size. The weighted mean 206Pb/238U ages of 91500,GJ1 and TEMORA 1 are 1064.4±4.8 Ma(2σ ),603.2±2.4 Ma(2σ ) and 418.2±2.4 Ma(2σ ),respectively. The relative standard de-viations(RSDs) of 206Pb/238U ages(2σ ) are less than 2.2% for single measurements and 0.6% for weighted means. The obtained weighted mean 206Pb/238U ages of three standard zircons agree with the recommended values within 2σ error. The weighted mean 206Pb/238U age of SK10-2 is 31.42±0.25 Ma(2σ ) and the RSDs of 206Pb/238U ages(2σ ) are between 2.4% and 5.7% for single measurements and less than 0.8% for weighted mean. The obtained weighted mean 206Pb/238U age is in good agreement with the age obtained by Yuan(2004). Trace element concentrations of NIST612 and NIST614 obtained under the same LA-ICP-MS operating conditions agree with the recommended values within analytical error. The results indicate that it is possible to measure U-Pb age and trace elements simultaneously by LA-ICP-MS in a small spot size of 20 μm.展开更多
On May 12, 2008, a strong earthquake with a magnitude of 8.0 (Ms) struck Wenchuan town, in the eastern Sichuan area of west China. Following the earthquake on May 18, the Southwest Jiaotong University organized a dama...On May 12, 2008, a strong earthquake with a magnitude of 8.0 (Ms) struck Wenchuan town, in the eastern Sichuan area of west China. Following the earthquake on May 18, the Southwest Jiaotong University organized a damage survey team and dispatched it to the affected area for the investigation into the damage and collection of information and data. This paper outlines the findings of this investigation on the earthquake disaster to mountain tunnels and geotechnical engineering. The systematic investigation, involving geological conditions, design documents, construction and maintenance records of the tunnels, has been conducted and the degree of damage to investigated tunnels has been assessed according to the width and length of cracks, the stability of the slope above the tunnel, and the condition of the groundwater inrush. The results show that the major damage of the mountain tunnels was mainly concentrated in the tunnel portals due to widespread landslides and rockfalls, and the inner part of investigated tunnels suffered moderate damages mainly due to fault displacements. It is hoped that the information shared herein could enhance the outstanding of seismic behavior of mountain tunnels and improve seismic design and construction procedures.展开更多
Previous studies have showed clinical characteristics of patients with the 2019 novel coronavirus disease(COVID-19)and the evidence of person-to-person transmission.Limited data are available for asymptomatic infectio...Previous studies have showed clinical characteristics of patients with the 2019 novel coronavirus disease(COVID-19)and the evidence of person-to-person transmission.Limited data are available for asymptomatic infections.This study aims to present the clinical characteristics of 24 cases with asymptomatic infection screened from close contacts and to show the transmission potential of asymptomatic COVID-19 virus carriers.Epidemiological investigations were conducted among all close contacts of COVID-19 patients(or suspected patients)in Nanjing,Jiangsu Province,China,from Jan 28 to Feb 9,2020,both in clinic and in community.Asymptomatic carriers were laboratory-confirmed positive for the COVID-19 virus by testing the nucleic acid of the pharyngeal swab samples.Their clinical records,laboratory assessments,and chest CT scans were reviewed.As a result,none of the 24 asymptomatic cases presented any obvious symptoms while nucleic acid screening.Five cases(20.8%)developed symptoms(fever,cough,fatigue,etc.)during hospitalization.Twelve(50.0%)cases showed typical CT images of ground-glass chest and 5(20.8%)presented stripe shadowing in the lungs.The remaining 7(29.2%)cases showed normal CT image and had no symptoms during hospitalization.These 7 cases were younger(median age:14.0 years;P=0.012)than the rest.None of the 24 cases developed severe COVID-19 pneumonia or died.The median communicable period,defined as the interval from the first day of positive nucleic acid tests to the first day of continuous negative tests,was 9.5 days(up to 21 days among the 24 asymptomatic cases).Through epidemiological investigation,we observed a typical asymptomatic transmission to the cohabiting family members,which even caused severe COVID-19 pneumonia.Overall,the asymptomatic carriers identified from close contacts were prone to be mildly ill during hospitalization.However,the communicable period could be up to three weeks and the communicated patients could develop severe illness.These results highlighted the importance of close cont展开更多
The Xianghualing Sn-polymetallic orefield in Hunan Province, southern China, is a largesize tin orefield. Although numerous studies have been undertaken on this orefield, its genesis, mineralization age, and tectonic ...The Xianghualing Sn-polymetallic orefield in Hunan Province, southern China, is a largesize tin orefield. Although numerous studies have been undertaken on this orefield, its genesis, mineralization age, and tectonic setting are still controversial, mainly because of the lack of reliable geochronological data on tin mineralization. The ^40Ar^39Ar stepwise heating dating method was first employed on muscovite from different deposits in this orefield. The muscovite sample from the Xianghualing Sn-polymetallic deposit defines a plateau age of 154.4±1.1 Ma and an isochron age of 151.9±3.0 Ma; muscovite from the Xianghuapu W-polymetallic deposit yields a plateau age of 161.3±1.1 Ma and an isochron age of 160.0±3.2 Ma; muscovite from the Jianfengling greisen-type Sn-polymetallic deposit gives a plateau age of 158.7±1.2 Ma and an isochron age of 160.3±3.2 Ma. The tungsten-tin mineralization ages in the Xianghualing area are therefore restricted within 150-160 Ma. The tungstentin mineralization in Xianghualing occurred at the same time as the regional tin-tungsten mineralization including the Furong tin orefield, Shizhuyuan tungsten-tin polymetallic deposit and Yaogangxian tungsten-polymetallic deposit. Thus, the large-scale tungsten-tin metallogenesis in South China occurring at 160-150 Ma, probably is closely related to asthenospheric upwelling and crustmantle interaction under a geodynamic setting of crustal extension and lithosphere thinning during the transformation of tectonic regimes during the Mid-Late Jurassic.展开更多
Background Diabetes management could be improved by diabetes education, through influencing attitudes towards diabetes, knowledge and behaviors of patients. The purpose of this study was to characterize the impact of ...Background Diabetes management could be improved by diabetes education, through influencing attitudes towards diabetes, knowledge and behaviors of patients. The purpose of this study was to characterize the impact of diabetes education on glycemic control, and to assess the attitude, knowledge and self-care behavior in patients with type 2 diabetes in China. Methods This questionnaire-based survey was conducted in 50 medical centers across China from April to July of 2010. The patients with type 2 diabetes were eligible for the study. The information of glycemic control and diabetes education was collected. The diabetes attitude scale-3 formulae, a questionnaire of diabetes knowledge and Summary of Diabetes Self-care Activities scale were used to assess attitude, knowledge and the self-care of patients, respectively. Results Among the 5961 eligible respondents （3233 males; mean age （59.50＋12.48） years; mean hemoglobin Alc （HbAlc） （8.27＋2.23）%）, most patients （79.8%） considered themselves educated on diabetes. Compared with patients without diabetes education, their educated counterparts showed significant lower value of HbAlc, after controlling for age, gender, body mass index and duration of diabetes （P 〈0.01）. The patients who received diabetes education also performed significant higher scores on attitude, knowledge and self-care than their uneducated counterparts. Patients with lower income or education level tended to have higher glucose levels, and showed lower percentage of patients received diabetic education. Conclusions Chinese patients with diabetes education achieved better glycemic control than un-educated patients. Our study indicates effort is required to provide professional education to patients, with emphasis on lower income and lower education level populations.展开更多
The concentrations of eight heavy metals （Cu, Zn, Pb, Cd, Cr, Ni, Hg, and As） in the intertidal surface sediments from Quanzhou Bay were determined to evaluate their levels and spatial distribution due to urbanizati...The concentrations of eight heavy metals （Cu, Zn, Pb, Cd, Cr, Ni, Hg, and As） in the intertidal surface sediments from Quanzhou Bay were determined to evaluate their levels and spatial distribution due to urbanization and economic development of Quanzhou region, southeast China. The ranges of the measured concentrations in the sediments are as follows： 24.8-119.7 mg/kg for Cu, 105.5-241.9 mg/kg for Zn, 34.3-100. 9 mg/kg for Pb, 0.28-0. 89 mg/kg for Cd, 51.1-121.7 mg/kg for Cr, 16.1-45.7 mg/kg for Ni, 0.17-0.74 mg/kg for Hg, and 17.7-30.2 mg/kg for As. The overall average concentrations of above metals exceed the primary standard criteria but meet the secondary standard criteria of the Chinese National Standard of Marine Sediment Quality. Several contents of Cu and Hg exceed the secondary standard criteria at some stations. The results of geoaccumulation index （Igeo） show that Cd causes strong pollution in most of the study area. There are no significant correlations among most of these heavy metals, indicating they have different anthropogenic and natural sources. Some locations present severe pollution by heavy metals depending on the sources, of which sewage outlets, aquatic breeding, and commercial ports are the main sources of contaminants to the area.展开更多
The chemical characteristics（water-soluble ions and carbonaceous species） of PM2.5 in Guangzhou were measured during a typical haze episode.Most of the chemical species in PM2.5 showed significant difference between...The chemical characteristics（water-soluble ions and carbonaceous species） of PM2.5 in Guangzhou were measured during a typical haze episode.Most of the chemical species in PM2.5 showed significant difference between normal and haze days.The highest contributors to PM2.5 were organic carbon（OC）,nitrate,and sulfate in haze days and were OC,sulfate,and elemental carbon（EC） in normal days.The concentrations of secondary species such as,NO3^-,SO4^2-,and NH4^＋ in haze days were 6.5,3.9,and 5.3 times higher than those in normal days,respectively,while primary species（EC,Ca^2＋,K^＋） show similar increase from normal to haze days by a factor about 2.2-2.4.OC/EC ratio ranged from 2.8 to 6.2 with an average of 4.7 and the estimation on a minimum OC/EC ratio showed that SOC（secondary organic carbon） accounted more than 36.6% for the total organic carbon in haze days.The significantly increase in the secondary species（SOC,NO3^-,SO4^2-,and NH4^＋）,especially in NO3^-,caused the worst air quality in this region.Simultaneously,the result illustrated that the serious air pollution in haze episodes was strongly correlated with the meteorological conditions.During the sampling periods,air pollution and visibility had a good relationship with the air mass transport distance;the shorter air masses transport distance,the worse air quality and visibility in Guangzhou,indicating the strong domination of local sources contributing to haze formation.High concentration of the secondary aerosol in haze episodes was likely due to the higher oxidation rates of sulfur and nitrogen species.展开更多
Licorice is a common herb which has been used in traditional Chinese medicine for centuries.More than 20 triterpenoids and nearly 300 flavonoids have been isolated from licorice. Recent studies have shown that these m...Licorice is a common herb which has been used in traditional Chinese medicine for centuries.More than 20 triterpenoids and nearly 300 flavonoids have been isolated from licorice. Recent studies have shown that these metabolites possess many pharmacological activities, such as antiviral,antimicrobial, anti-inflammatory, antitumor and other activities. This paper provides a summary of the antiviral and antimicrobial activities of licorice. The active components and the possible mechanisms for these activities are summarized in detail. This review will be helpful for the further studies of licorice for its potential therapeutic effects as an antiviral or an antimicrobial agent.展开更多
The integrated extraction of coal and gas combines coal mining with gas capture. Taking into account the gas deposition and flow conditions in the Chinese coal basins, this paper describes the status of the theory and...The integrated extraction of coal and gas combines coal mining with gas capture. Taking into account the gas deposition and flow conditions in the Chinese coal basins, this paper describes the status of the theory and key technologies of this integrated extraction system, and presents its application and practice in the Shaqu, Zhongxing, Fenghuangshan and Pingmei mines. Areas for further improvements in future studies are discussed, focusing in particular on the fundamentals of the extraction system to make it greener, more scientific, and more advanced in both the exploitation and utilization of coal and the gas in coal.展开更多
基金Acknowledgments We thank Drs Fengyong Liu and Sheng Luan at UC Berkeley, USA, for their discussion and help with the writing of the manuscript. This work was supported by grants from the National Natural Science Foundation of China （no. 30225037, 30471991, 30570731）, National Basic Research Program of China （973 Program） （no. 2006CB503909, 2004CB518603）, the ＂111＂ Project, and the Natural Science Foundation of Jiangsu Province （no. BK2004082, BK2006714）.
文摘Dysregulated expression of microRNAs （miRNAs） in various tissues has been associated with a variety of diseases, including cancers. Here we demonstrate that miRNAs are present in the serum and plasma of humans and other animals such as mice, rats, bovine fetuses, calves, and horses. The levels of miRNAs in serum are stable, reproducible, and consistent among individuals of the same species. Employing Solexa, we sequenced all serum miRNAs of healthy Chinese subjects and found over 100 and 91 serum miRNAs in male and female subjects, respectively. We also identified specific expression patterns of serum miRNAs for lung cancer, colorectal cancer, and diabetes, providing evidence that serum miRNAs contain fingerprints for various diseases. Two non-small cell lung cancer-specific serum miRNAs obtained by Solexa were further validated in an independent trial of 75 healthy donors and 152 cancer patients, using quantitative reverse transcription polymerase chain reaction assays. Through these analyses, we conclude that serum miRNAs can serve as potential biomarkers for the detection of various cancers and other diseases.
基金co-supported by the National Natural Science Foundation of China(Grant Nos.40133020 and 40272045)the Chinese Ministry of Science and Technology of China(Grant No.G1999043202)the Chinese Academy of Sciences and the Key Laboratory of Continental Dynamics,Northwest University,the Ministry of Education of China.
文摘Using the in situ zircon U-Pb dating method of LA-ICPMS, we analyzed the 31 Ma old SHRIMP U-Pb age of the Yongsheng nepheline syenite from southern Jilin Province under different spot sizes. The obtained ages are comparable with that of SHRIMP in both accuracy and precision. The age is also identical to that of the Yinmawanshan gabbro from the Liaodong Peninsula within error. Both the Yongsheng nepheline syenite and the Yinmawanshan gabbro represent the youngest known exposed intrusions in northeastern and even eastern China. The results indicate the Eocene mantle-derived magmatic underplating, and the rapid crustal uplifting of this region since 30 Ma. The analyses also document extremely high LREE concentrations and relatively flat REE patterns for the zircons from the Yongsheng nepheline syenite, which represent a new type of zircon REE pattern.
基金partially supported by the National Key Research and Development Program of China(2016YFA0600103)Delos Living LLCthe Cyrus Tang Foundation
文摘As the world strives to reduce the impact of population growth, urbanization, agricultural expansion, and climate change on food security, energy and water shortage, resource over-exploration, biodiversity loss, environmental pollution, and ultimately human health, timely and higher resolution land cover information is urgently needed to achieve the sustainable development goals of the United Nations.
基金This work was supported by the National Science and Technology Major Project(2017ZX10103011 and 2017ZX10204401)Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2017-I2M-1-009)+1 种基金Shenzhen Science and Technology Research and Development Project(JCYJ20180504165549581 and JCYJ20170413141236903)China Postdoctoral Science Foundation(2019T120147).
文摘The outbreak of the 2019-nCoV infection began in December 2019 in Wuhan,Hubei province,and rapidly spread to many provinces in China as well as other countries.Here we report the epidemiological,clinical,laboratory,and radiological characteristics,as well as potential biomarkers for predicting disease severity in 2019-nCoV-infected patients in Shenzhen,China.All 12 cases of the 2019-nCoV-infected patients developed pneumonia and half of them developed acute respiratory distress syndrome (ARDS).The most common laboratory abnormalities were hypoalbuminemia,lymphopenia,decreased percentage of lymphocytes (LYM) and neutrophils (NEU),elevated C-reactive protein (CRP) and lactate dehydrogenase (LDH),and decreased CD8 count.The viral load of 2019-nCoV detected from patient respiratory tracts was positively linked to lung disease severity.ALB,LYM,LYM (%),LDH,NEU (%),and CRP were highly correlated to the acute lung injury.Age,viral load,lung injury score,and blood biochemistry indexes,albumin (ALB),CRP,LDH,LYM (%),LYM,and NEU (%),may be predictors of disease severity.Moreover,the Angiotensin Ⅱlevel in the plasma sample from 2019-nCoV infected patients was markedly elevated and linearly associated to viral load and lung injury.Our results suggest a number of potential diagnosis biomarkers and angiotensin receptor blocker (ARB) drugs for potential repurposing treatment of 2019-nCoV infection.
基金supported(in part)by the Entrusted Project of National Center for Medical Service Administration,National Health and Family Planning Commission China(No.[2019]099)the First Level Funding of the Second Medical Leading Talent Project in Hubei Provincethe Special Project for Emergency of the Ministry of Science and Technology(2020YFC0841300)。
文摘In December 2019, a new type viral pneumonia cases occurred in Wuhan, Hubei Province;and then named "2019 novel coronavirus(2019-nCoV)" by the World Health Organization(WHO) on 12 January 2020. For it is a never been experienced respiratory disease before and with infection ability widely and quickly, it attracted the world’s attention but without treatment and control manual. For the request from frontline clinicians and public health professionals of 2019-nCoV infected pneumonia management, an evidence-based guideline urgently needs to be developed. Therefore, we drafted this guideline according to the rapid advice guidelines methodology and general rules of WHO guideline development;we also added the first-hand management data of Zhongnan Hospital of Wuhan University. This guideline includes the guideline methodology, epidemiological characteristics, disease screening and population prevention, diagnosis, treatment and control(including traditional Chinese Medicine), nosocomial infection prevention and control, and disease nursing of the 2019-nCoV. Moreover, we also provide a whole process of a successful treatment case of the severe 2019-nCoV infected pneumonia and experience and lessons of hospital rescue for 2019-nCoV infections. This rapid advice guideline is suitable for the first frontline doctors and nurses, managers of hospitals and healthcare sections, community residents, public health persons, relevant researchers, and all person who are interested in the 2019-nCoV.
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Postoperative pain is the most common complaint after laparoscopic cholecystectomy. This study was carried out to evaluate whether preoperative administration of intramuscular dezocine can provide postoperative analgesia and reduce postoperative opioid consumption in patients undergoing laparoscopic cholecystectomy. Patients （ASA Ⅰ or Ⅱ ） scheduled for laparoscopic cholecystectomy were randomly assigned into intramuscular dezocine group （group 1） or intramuscular normal saline group （group 2）. Dezocine and equal volume normal saline were administered intramuscularly 10 rain before the induction of anesthesia. After operation, the severity of postoperative pain, postoperative fentanyl requirement, incidence and severity of side-effects were assessed. Postoperative pain and postoperative patient-controlled fentanyl consumption were reduced significantly in group l compared with group 2. The incidence and severity of side effects were similar between the two groups. Preoperative single-dose administration of intramuscular dezocine 0.1 mg/kg was effective in reducing postoperative pain and postoperative patient-controlled fentanyl requirement in patients undergoing laparoscopic cholecystectomy.
基金Supported by the National Natural Science Foundation of China,No.81300251
文摘Liver fibrosis is a reversible wound-healing process aimed at maintaining organ integrity, and presents as the critical pre-stage of liver cirrhosis, which will eventually progress to hepatocellular carcinoma in the absence of liver transplantation. Fibrosis generally results from chronic hepatic injury caused by various factors, mainly viral infection, schistosomiasis, and alcoholism; however, the exact pathological mechanisms are still unknown. Although numerous drugs have been shown to have antifibrotic activity in vitro and in animal models, none of these drugs have been shown to be efficacious in the clinic. Importantly, hepatic stellate cells(HSCs) play a key role in the initiation, progression, and regression of liver fibrosis by secreting fibrogenic factors that encourage portal fibrocytes, fibroblasts, and bone marrow-derived myofibroblasts to produce collagen and thereby propagate fibrosis. These cells are subject to intricate cross-talk with adjacent cells, resulting in scarring and subsequent liver damage. Thus, an understanding of the molecular mechanisms of liver fibrosis and their relationships with HSCs is essential for the discovery of new therapeutic targets. This comprehensive review outlines the role of HSCs in liver fibrosis and details novel strategies to suppress HSC activity, thereby providing new insights into potential treatments for liver fibrosis.
基金supported by grants from the Beijing Young Talent Program (No.2016000021469 G189)Special Fund for Health Research in the Public Interest (No.201502001)CAMS Innovation Fund for Medical Sciences (CIFMS) (No.2016-12M-2-004)
文摘Objective： In this study,we aimed to estimate the updated incidence and mortality rate of stomach cancer based on the cancer registration data in 2014,collected by the National Central Cancer Registry of China（NCCRC）.Methods： In 2017,339 registries＇ data were qualified based on the criteria of data quality control of the NCCRC.Cases of stomach cancer were retrieved from the national database.We estimated numbers of stomach cancer cases and deaths in China using age-specific rates and corresponding national population stratified by area,sex,agegroup（0,1–4,5–9,10–14,…,85＋）.Chinese standard population in 2000 and Segi＇s world population were applied for age-standardized incidence and mortality rates.Results： In 2014,410,400 new stomach cancer cases and 293,800 cancer-associated deaths were estimated to have occurred in China.The crude incidence rate of stomach cancer was 30.00/100,000,age-standardized incidence rates by Chinese standard population（ASIRC） and by world standard population（ASIRW） were 19.62/100,000 and19.51/100,000,respectively.The crude mortality rate of stomach cancer was 21.48/100,000,age-standardized mortality rates by Chinese（ASMRC） and by world standard population（ASMRW） were 13.44/100,000 and13.30/100,000,respectively.Incidence and mortality rates in rural areas were both higher than that in urban areas.Stomach cancer has a strong relationship with gender and age.The disease has occurred more frequently among men than women with a male to female ratio of 2.4 for ASIRC.After age group of 40-44 years,incidence rates are substantially higher in men than in women,same pattern was seen for age-specific mortality rates.Conclusions： There is still a heavy burden of stomach cancer in China.The incidence and mortality patterns of stomach cancer show substantial gender and regional disparities.Great effort is needed to provide more accessible health services,sufficient financial resources,and adequate cancer-care infrastructure for the Chinese population,espec
基金This work was supported by the project of Yunnan Innovation Team Project, the Hundreds Oversea Talents Program of Yunnan Province, the Top Talents Program of Yunnan Province （Grant 20080A009）, the Key Project of the Natural Science Foundation of Yunnan Province （201401 PC00397）, National Science Foundation of China （U0936603）, Key Project of Natural Science Foundation of Yunnan Province （2008CC016）, Frontier Grant of Kunming Institute of Botany, CAS （672705232515）, Top Talents Program of Yunnan Province （20080A009）, and Hundreds Talents Program of Chinese Academy of Sciences （CAS） （to L.G.）.
文摘Tea is the world＇s oldest and most popular caffeine-containing beverage with immense economic, medicinal, and cultural importance. Here, we present the first high-quality nucleotide sequence of the repeat-rich （80.9%）, 3.02-Gb genome of the cultivated tea tree Camellia sinensis. We show that an extraordinarily large genome size of tea tree is resulted from the slow, steady, and long-term amplification of a few LTR retrotransposon families. In addition to a recent whole-genome duplication event, lineage-specific expansions of genes associated with flavonoid metabolic biosynthesis were discovered, which enhance catechin production, terpene enzyme activation, and stress tolerance, important features for tea flavor and adaptation. We demonstrate an independent and rapid evolution of the tea caffeine synthesis pathway relative to cacao and coffee. A comparative study among 25 Camellia species revealed that higher expression levels of most flavonoid- and caffeinebut not theanine-related genes contribute to the increased production of catechins and caffeine and thus enhance tea-processing suitability and tea quality. These novel findings pave the way for further metabolomic and functional genomic refinement of characteristic biosynthesis pathways and will help develop a more diversified set of tea flavors that would eventually satisfy and attract more tea drinkers worldwide.
基金funded by The National Key Research and Development Program of China(Grant No.2017YFB1104500)Natural Science Foundation of Beijing Municipality(4172030)+3 种基金Beijing Young Talents Support Project(2017000020124G044)Leading talents of Guangdong province program(00201505)National Natural Science Foundation of China(U1701661,91750205,61975133,11604218,61975087)Natural Science Foundation of Guangdong Province(2016A030312010,2017A030313351).
文摘Thirty years ago,Coullet et al.proposed that a special optical field exists in laser cavities bearing some analogy with the superfluid vortex.Since then,optical vortices have been widely studied,inspired by the hydrodynamics sharing similar mathematics.Akin to a fluid vortex with a central flow singularity,an optical vortex beam has a phase singularity with a certain topological charge,giving rise to a hollow intensity distribution.Such a beam with helical phase fronts and orbital angular momentum reveals a subtle connection between macroscopic physical optics and microscopic quantum optics.These amazing properties provide a new understanding of a wide range of optical and physical phenomena,including twisting photons,spin–orbital interactions,Bose-Einstein condensates,etc.,while the associated technologies for manipulating optical vortices have become increasingly tunable and flexible.Hitherto,owing to these salient properties and optical manipulation technologies,tunable vortex beams have engendered tremendous advanced applications such as optical tweezers,high-order quantum entanglement,and nonlinear optics.This article reviews the recent progress in tunable vortex technologies along with their advanced applications.
基金Supported by the National Natural Science Foundation of China (Grant Nos.40472099, 40521001 and 40673019)Chinese Ministry of Education (Grant Nos.IRT0441 and 306021)
文摘Simultaneous in-situ determination of U-Pb ages and 20 trace elements of three international zircon standards(91500,GJ1 and TEMORA 1) and one laboratory zircon standard(SK10-2) separated from Cenozoic fine-grained gabbro was carried out on quadrupole ICP-MS equipped with 193 nm excimer laser in 20 μm spot size. The weighted mean 206Pb/238U ages of 91500,GJ1 and TEMORA 1 are 1064.4±4.8 Ma(2σ ),603.2±2.4 Ma(2σ ) and 418.2±2.4 Ma(2σ ),respectively. The relative standard de-viations(RSDs) of 206Pb/238U ages(2σ ) are less than 2.2% for single measurements and 0.6% for weighted means. The obtained weighted mean 206Pb/238U ages of three standard zircons agree with the recommended values within 2σ error. The weighted mean 206Pb/238U age of SK10-2 is 31.42±0.25 Ma(2σ ) and the RSDs of 206Pb/238U ages(2σ ) are between 2.4% and 5.7% for single measurements and less than 0.8% for weighted mean. The obtained weighted mean 206Pb/238U age is in good agreement with the age obtained by Yuan(2004). Trace element concentrations of NIST612 and NIST614 obtained under the same LA-ICP-MS operating conditions agree with the recommended values within analytical error. The results indicate that it is possible to measure U-Pb age and trace elements simultaneously by LA-ICP-MS in a small spot size of 20 μm.
基金Supported by the National Science Council of China (Grant No.50878187)
文摘On May 12, 2008, a strong earthquake with a magnitude of 8.0 (Ms) struck Wenchuan town, in the eastern Sichuan area of west China. Following the earthquake on May 18, the Southwest Jiaotong University organized a damage survey team and dispatched it to the affected area for the investigation into the damage and collection of information and data. This paper outlines the findings of this investigation on the earthquake disaster to mountain tunnels and geotechnical engineering. The systematic investigation, involving geological conditions, design documents, construction and maintenance records of the tunnels, has been conducted and the degree of damage to investigated tunnels has been assessed according to the width and length of cracks, the stability of the slope above the tunnel, and the condition of the groundwater inrush. The results show that the major damage of the mountain tunnels was mainly concentrated in the tunnel portals due to widespread landslides and rockfalls, and the inner part of investigated tunnels suffered moderate damages mainly due to fault displacements. It is hoped that the information shared herein could enhance the outstanding of seismic behavior of mountain tunnels and improve seismic design and construction procedures.
基金supported by the project of Jiangsu province medical youth talent(QNRC2016059)Nanjing medical science and technique development foundation(ZKX17040 and YKK18153)+1 种基金the National Natural Science Foundation of China(81903382)Cheung Kong Scholars Program of China。
文摘Previous studies have showed clinical characteristics of patients with the 2019 novel coronavirus disease(COVID-19)and the evidence of person-to-person transmission.Limited data are available for asymptomatic infections.This study aims to present the clinical characteristics of 24 cases with asymptomatic infection screened from close contacts and to show the transmission potential of asymptomatic COVID-19 virus carriers.Epidemiological investigations were conducted among all close contacts of COVID-19 patients(or suspected patients)in Nanjing,Jiangsu Province,China,from Jan 28 to Feb 9,2020,both in clinic and in community.Asymptomatic carriers were laboratory-confirmed positive for the COVID-19 virus by testing the nucleic acid of the pharyngeal swab samples.Their clinical records,laboratory assessments,and chest CT scans were reviewed.As a result,none of the 24 asymptomatic cases presented any obvious symptoms while nucleic acid screening.Five cases(20.8%)developed symptoms(fever,cough,fatigue,etc.)during hospitalization.Twelve(50.0%)cases showed typical CT images of ground-glass chest and 5(20.8%)presented stripe shadowing in the lungs.The remaining 7(29.2%)cases showed normal CT image and had no symptoms during hospitalization.These 7 cases were younger(median age:14.0 years;P=0.012)than the rest.None of the 24 cases developed severe COVID-19 pneumonia or died.The median communicable period,defined as the interval from the first day of positive nucleic acid tests to the first day of continuous negative tests,was 9.5 days(up to 21 days among the 24 asymptomatic cases).Through epidemiological investigation,we observed a typical asymptomatic transmission to the cohabiting family members,which even caused severe COVID-19 pneumonia.Overall,the asymptomatic carriers identified from close contacts were prone to be mildly ill during hospitalization.However,the communicable period could be up to three weeks and the communicated patients could develop severe illness.These results highlighted the importance of close cont
基金the Innovative Project of the Chinese Academy of Sciences （Grant No. KZCX3-SW-125） National Natural Science Foundation of China （Grant No. 40472053 , No. 40673021）.
文摘The Xianghualing Sn-polymetallic orefield in Hunan Province, southern China, is a largesize tin orefield. Although numerous studies have been undertaken on this orefield, its genesis, mineralization age, and tectonic setting are still controversial, mainly because of the lack of reliable geochronological data on tin mineralization. The ^40Ar^39Ar stepwise heating dating method was first employed on muscovite from different deposits in this orefield. The muscovite sample from the Xianghualing Sn-polymetallic deposit defines a plateau age of 154.4±1.1 Ma and an isochron age of 151.9±3.0 Ma; muscovite from the Xianghuapu W-polymetallic deposit yields a plateau age of 161.3±1.1 Ma and an isochron age of 160.0±3.2 Ma; muscovite from the Jianfengling greisen-type Sn-polymetallic deposit gives a plateau age of 158.7±1.2 Ma and an isochron age of 160.3±3.2 Ma. The tungsten-tin mineralization ages in the Xianghualing area are therefore restricted within 150-160 Ma. The tungstentin mineralization in Xianghualing occurred at the same time as the regional tin-tungsten mineralization including the Furong tin orefield, Shizhuyuan tungsten-tin polymetallic deposit and Yaogangxian tungsten-polymetallic deposit. Thus, the large-scale tungsten-tin metallogenesis in South China occurring at 160-150 Ma, probably is closely related to asthenospheric upwelling and crustmantle interaction under a geodynamic setting of crustal extension and lithosphere thinning during the transformation of tectonic regimes during the Mid-Late Jurassic.
文摘Background Diabetes management could be improved by diabetes education, through influencing attitudes towards diabetes, knowledge and behaviors of patients. The purpose of this study was to characterize the impact of diabetes education on glycemic control, and to assess the attitude, knowledge and self-care behavior in patients with type 2 diabetes in China. Methods This questionnaire-based survey was conducted in 50 medical centers across China from April to July of 2010. The patients with type 2 diabetes were eligible for the study. The information of glycemic control and diabetes education was collected. The diabetes attitude scale-3 formulae, a questionnaire of diabetes knowledge and Summary of Diabetes Self-care Activities scale were used to assess attitude, knowledge and the self-care of patients, respectively. Results Among the 5961 eligible respondents （3233 males; mean age （59.50＋12.48） years; mean hemoglobin Alc （HbAlc） （8.27＋2.23）%）, most patients （79.8%） considered themselves educated on diabetes. Compared with patients without diabetes education, their educated counterparts showed significant lower value of HbAlc, after controlling for age, gender, body mass index and duration of diabetes （P 〈0.01）. The patients who received diabetes education also performed significant higher scores on attitude, knowledge and self-care than their uneducated counterparts. Patients with lower income or education level tended to have higher glucose levels, and showed lower percentage of patients received diabetic education. Conclusions Chinese patients with diabetes education achieved better glycemic control than un-educated patients. Our study indicates effort is required to provide professional education to patients, with emphasis on lower income and lower education level populations.
基金supported by the National Natural Science Foundation of China(No.40673061)the Research Program of Science and Technology of Quanzhou City Government(No.2007Z43)the Foundation of Key Laboratory of Nuclear Resources and Environment(East China Institute of Technology),Ministry of Education(No.070714).
文摘The concentrations of eight heavy metals （Cu, Zn, Pb, Cd, Cr, Ni, Hg, and As） in the intertidal surface sediments from Quanzhou Bay were determined to evaluate their levels and spatial distribution due to urbanization and economic development of Quanzhou region, southeast China. The ranges of the measured concentrations in the sediments are as follows： 24.8-119.7 mg/kg for Cu, 105.5-241.9 mg/kg for Zn, 34.3-100. 9 mg/kg for Pb, 0.28-0. 89 mg/kg for Cd, 51.1-121.7 mg/kg for Cr, 16.1-45.7 mg/kg for Ni, 0.17-0.74 mg/kg for Hg, and 17.7-30.2 mg/kg for As. The overall average concentrations of above metals exceed the primary standard criteria but meet the secondary standard criteria of the Chinese National Standard of Marine Sediment Quality. Several contents of Cu and Hg exceed the secondary standard criteria at some stations. The results of geoaccumulation index （Igeo） show that Cd causes strong pollution in most of the study area. There are no significant correlations among most of these heavy metals, indicating they have different anthropogenic and natural sources. Some locations present severe pollution by heavy metals depending on the sources, of which sewage outlets, aquatic breeding, and commercial ports are the main sources of contaminants to the area.
基金supported by the National Excellent Youth Foundation of China (No. 20625722)the China Postdoctoral Science Foundation (No. 20080430396)
文摘The chemical characteristics（water-soluble ions and carbonaceous species） of PM2.5 in Guangzhou were measured during a typical haze episode.Most of the chemical species in PM2.5 showed significant difference between normal and haze days.The highest contributors to PM2.5 were organic carbon（OC）,nitrate,and sulfate in haze days and were OC,sulfate,and elemental carbon（EC） in normal days.The concentrations of secondary species such as,NO3^-,SO4^2-,and NH4^＋ in haze days were 6.5,3.9,and 5.3 times higher than those in normal days,respectively,while primary species（EC,Ca^2＋,K^＋） show similar increase from normal to haze days by a factor about 2.2-2.4.OC/EC ratio ranged from 2.8 to 6.2 with an average of 4.7 and the estimation on a minimum OC/EC ratio showed that SOC（secondary organic carbon） accounted more than 36.6% for the total organic carbon in haze days.The significantly increase in the secondary species（SOC,NO3^-,SO4^2-,and NH4^＋）,especially in NO3^-,caused the worst air quality in this region.Simultaneously,the result illustrated that the serious air pollution in haze episodes was strongly correlated with the meteorological conditions.During the sampling periods,air pollution and visibility had a good relationship with the air mass transport distance;the shorter air masses transport distance,the worse air quality and visibility in Guangzhou,indicating the strong domination of local sources contributing to haze formation.High concentration of the secondary aerosol in haze episodes was likely due to the higher oxidation rates of sulfur and nitrogen species.
基金supported by Beijing Project for Young Talents (YETP0819)
文摘Licorice is a common herb which has been used in traditional Chinese medicine for centuries.More than 20 triterpenoids and nearly 300 flavonoids have been isolated from licorice. Recent studies have shown that these metabolites possess many pharmacological activities, such as antiviral,antimicrobial, anti-inflammatory, antitumor and other activities. This paper provides a summary of the antiviral and antimicrobial activities of licorice. The active components and the possible mechanisms for these activities are summarized in detail. This review will be helpful for the further studies of licorice for its potential therapeutic effects as an antiviral or an antimicrobial agent.
文摘The integrated extraction of coal and gas combines coal mining with gas capture. Taking into account the gas deposition and flow conditions in the Chinese coal basins, this paper describes the status of the theory and key technologies of this integrated extraction system, and presents its application and practice in the Shaqu, Zhongxing, Fenghuangshan and Pingmei mines. Areas for further improvements in future studies are discussed, focusing in particular on the fundamentals of the extraction system to make it greener, more scientific, and more advanced in both the exploitation and utilization of coal and the gas in coal.
