Odor pollution in landfill area has attracted more social attention in China. It is very important to control the generation of odor pollutants in situ. Analyzing odorous materials production form buried waste, simula...Odor pollution in landfill area has attracted more social attention in China. It is very important to control the generation of odor pollutants in situ. Analyzing odorous materials production form buried waste, simulated columns of different volatile solid (VS) content and different buried period waste were designed. Gas compounds produced from the columns were collected and analyzed by comprehensive two-dimensional gas chromatography (GC × GC) method. It has remarkable relationship between VS content and concentrations of odorous material. When VS content more than 40%, the total amount of odorous compounds increases remarkably. It can be inferred that reduced VS content of original waste may effective decreasing odorous materials production in landfill area. The old rubbish produced more odorous compounds than that of fresh one in simulated columns.展开更多
The interfacial contacts between the electron transporting layers(ETLs)and the photoactive layers are crucial to device performance and stability for OSCs with inverted architecture.Herein,atomic layer deposition(ALD)...The interfacial contacts between the electron transporting layers(ETLs)and the photoactive layers are crucial to device performance and stability for OSCs with inverted architecture.Herein,atomic layer deposition(ALD)fabricated ultrathin Al_(2)O_(3)layers are applied to modify the ETLs/active blends(PM6:BTP-BO-4F)interfaces of OSCs,thus improving device performance.The ALD-Al_(2)O_(3)thin layers on ZnO significantly improved its surface morphology,which led to the decreased work function of ZnO and reduced recombination losses in devices.The simultaneous increase in open-circuit voltage(V_(OC)),short-circuit current density(J_(SC))and fill factor(FF)were achieved for the OSCs incorporated with ALD-Al_(2)O_(3)interlayers of a certain thickness,which produced a maximum PCE of 16.61%.Moreover,the ALD-Al_(2)O_(3)interlayers had significantly enhanced device stability by suppressing degradation of the photoactive layers induced by the photocatalytic activity of ZnO and passivating surface defects of ZnO that may play the role of active sites for the adsorption of oxygen and moisture.展开更多
Given the rapid changes in social structure(urbanization),economic structure(industrialization),and demographic structure(population aging)in China,cancer has become a major public health problem1.Extensive evidence h...Given the rapid changes in social structure(urbanization),economic structure(industrialization),and demographic structure(population aging)in China,cancer has become a major public health problem1.Extensive evidence has indicated that screening can decrease cancer mortality,particularly among high-risk groups,and several representative national and regional cancer screening programs have been launched in China to cope with the increasing burden of cancer.展开更多
Through a series of exploration based on PSR framework model,for the purpose of building a suitable Chongqing agricultural nonpoint source pollution evaluation index system model framework,combined with the presence o...Through a series of exploration based on PSR framework model,for the purpose of building a suitable Chongqing agricultural nonpoint source pollution evaluation index system model framework,combined with the presence of Chongqing specific agro-environmental issues,we build a agricultural non-point source pollution assessment index system,and then study the agricultural system pressure,agro-environmental status and human response in total 3 major categories,develope an agricultural non-point source pollution evaluation index consisting of 3 criteria indicators and 19 indicators. As can be seen from the analysis,pressures and responses tend to increase and decrease linearly,state and complex have large fluctuations,and their fluctuations are similar mainly due to the elimination of pressures and impact,increasing the impact for agricultural non-point source pollution.展开更多
目的调查临床监查员(clinical research associate,CRA)对上海市医院临床试验服务的满意度,以提升临床试验服务质量。方法2023年10—11月采用典型调查方法和修订的SERVQUAL(service quality)量表对CRA进行问卷调查,内容包括保证性、可...目的调查临床监查员(clinical research associate,CRA)对上海市医院临床试验服务的满意度,以提升临床试验服务质量。方法2023年10—11月采用典型调查方法和修订的SERVQUAL(service quality)量表对CRA进行问卷调查,内容包括保证性、可靠性、有形性、响应性及移情性等5个维度29个条目。根据修正的服务重要性绩效满意度分析(importance-performance analysis,IPA)明确落入改进区的条目。结果对于来自10家申办者及其委托机构的163名CRA进行问卷调查,回收有效问卷160份。根据修正的IPA象限图,保证性、可靠性、有形性、响应性及移情性维度落入改进区的条目分别为6、2、1、2和2条。结论CRA对上海市医院的临床试验服务可能未达到满意水平,临床试验机构可从规范化意识、审查模式、流程获取、答复响应、管理体系灵活性等方面进行优化,从而提高临床试验服务质量。展开更多
The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays a...The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays and address the errors in the calibration of the E-C relationship,comprehensive tests and comparative studies of the three aforementioned crystals were conducted using Compton electrons,radioactive sources,and mono-energetic X-rays.The nonlinearity test results of the Compton electrons and X-rays demonstrated substantial differences,with all three crystals presenting a higher nonlinearity for X/-rays than for Compton electrons.Despite the LaBr_(3)(Ce)and LaBr_(3)(Ce,Sr)crystals having higher absolute light yields,they exhibited a noticeable nonlinear decrease in the light yield,especially at energies below 400 keV.The NaI(Tl)crystal demonstrated an"excess"light output in the 6-200 keV range,reaching a maximum"excess"of 9.2%at 30 keV in the X-ray testing and up to 15.5%at 14 keV during Compton electron testing,indicating a significant advantage in the detection of low-energy gamma rays.Furthermore,we explored the underlying causes of the observed nonlinearity in these crystals.This study not only elucidates the detector responses of GECAM,but also initiates a comprehensive investigation of the nonlinearity of domestically produced lanthanum bromide and sodium iodide crystals.展开更多
This study conducted a comparative analysis of extractable hopanoid hydrocarbons and those released via stepwise pyrolysis of typical Eocene immature oil shales in China,namely the Huadian,Maoming,and Fushun shales.Bo...This study conducted a comparative analysis of extractable hopanoid hydrocarbons and those released via stepwise pyrolysis of typical Eocene immature oil shales in China,namely the Huadian,Maoming,and Fushun shales.Both the Huadian and Maoming shales exhibit immature indicators in extractable and kerogen-bound hopanoids(notably,high abundance of C_(29)to C_(32)17β,21β-hopanes and unsaturated hopenes).In contrast,the Fushun oil shale's hopanoids from extracts and pyrolyzates suggest a higher maturity level.The absence of neohopenes in the pyrolyzates of the shales underpins that the kerogenbound hopanoid skeletons resist rearrangement.However,the Huadian oil shale's asymmetric distribution of C_(29)and C_(30)hopenes and neohopenes hints at the presence of an additional source.Novel unsaturated hopenes,such as hop-20(21)-enes,identified in pyrolyzates of the three kerogens at various pyrolysis temperatures,reveal the occurrence of double bonds in kerogen-bound hopanoid skeletons without methyl rearrangements.The absence of hop-20-(21)-ene in extracts suggests that it might act as an intermediate of these novel hopenes during the epimerization of hopanoid skeletons within kerogen.The extractable and pyrolytic hopanoids'stereochemical alignment indicates that epimerization may occur in both ring systems and alkyl side chains of kerogen-bound hopanoid skeletons.Sequential stepwise pyrolysis proves to be a quick screening method for geological hopanoids without causing any significant alteration to the original skeletons even when cracking multiple covalent bonds is necessary.展开更多
Realtime trigger and localization of bursts are the key functions of GECAM,an all-sky gamma-ray monitor launched on 2020 December 10.We developed a multifunctional trigger and localization software operating in the CP...Realtime trigger and localization of bursts are the key functions of GECAM,an all-sky gamma-ray monitor launched on 2020 December 10.We developed a multifunctional trigger and localization software operating in the CPU of the GECAM Electronic Box.This onboard software has the following features:high trigger efficiency for real celestial bursts with a suppression of false triggers caused by charged particle bursts and background fluctuation,dedicated localization algorithm optimized for both short and long bursts,and low time latency of the trigger information which is downlinked through the Global Short Message Communication service of the global BeiDou navigation system.This paper provides a detailed description of the design and development of the trigger and localization software system for GECAM.It covers the general design,workflow,the main functions,and the algorithms used in the system.The paper also includes on-ground trigger tests using simulated gamma-ray bursts generated by a dedicated X-ray tube,as well as an overview of the performance for real celestial bursts during its in-orbit operation.展开更多
AIM： To evaluate the predictive value of neutrophil in- filtration as a marker of Helicobacter pylori （H. pyloni） infection. METHODS： A total of 315 patients with dyspepsia symptoms who underwent upper gastrointes...AIM： To evaluate the predictive value of neutrophil in- filtration as a marker of Helicobacter pylori （H. pyloni） infection. METHODS： A total of 315 patients with dyspepsia symptoms who underwent upper gastrointestinal en- doscopy were enrolled in this study. Biopsies were evaluated using the updated Sydney system. The medication history of all patients in the preceding 4 wk was recorded. The diagnosis of H. pylori infection was based on 13C-urea breath test at least 4 wk after with- drawal of antisecretory drugs, antibiotics and related drugs. For the patients with subtotal gastrectomy, the diagnosis of H. pylori infection was based on anti-H. pylori immunoglobulin G （IgG） antibody. Serum anti-H. pylori IgG antibody was measured by enzyme-linked immunosorbent assays （Biohit, Finland）. RESULTS： The sensitivity, specificity, positive predic- tive value and negative predictive value of neutrophil infiltration in the diagnosis ofH, pylorlinfection were 92.3%, 83.5%, 77.4% and 94.7%, respectively. Neu- trophil infiltration of gastric mucosa in the histological analysis was strongly associated withH, pylorlinfection （77.4% vs 5.3% in the neutrophil infiltration negative group, P = 0.000）. Moderate neutrophil infiltration was more frequent in H. pylorl infection when compared to mild infiltration （81.8% and 75%, respectively）, but did not reach statistical significance. For those patients with negative rapid urease test, H. pylori was detected in 73.2% of patients with positive neutrophil infiltration on histology. In patients with subtotal gastrectomy, the diagnostic accuracy of neutrophil infiltration in H. pylori infection was 50%. CONCLUSION： Neutrophil infiltration is closely associ- ated withH, pylori and may be recognized as a sign of this infection.展开更多
The prolonged mei-yu/baiu system with anomalous precipitation in the year 2020 has swollen many rivers and lakes,caused flash flooding,urban flooding and landslides,and consistently wreaked havoc across large swathes ...The prolonged mei-yu/baiu system with anomalous precipitation in the year 2020 has swollen many rivers and lakes,caused flash flooding,urban flooding and landslides,and consistently wreaked havoc across large swathes of China,particularly in the Yangtze River basin.Significant precipitation and flooding anomalies have already been seen in magnitude and extension so far this year,which have been exerting much higher pressure on emergency responses in flood control and mitigation than in other years,even though a rainy season with multiple ongoing serious flood events in different provinces is not that uncommon in China.Instead of delving into the causes of the uniqueness of this year’s extreme precipitation-flooding situation,which certainly warrants in-depth exploration,in this article we provide a short view toward a more general hydrometeorological solution to this annual nationwide problem.A“glocal”(global to local)hydrometeorological solution for floods(GHS-F)is considered to be critical for better preparedness,mitigation,and management of different types of significant precipitation-caused flooding,which happen extensively almost every year in many countries such as China,India and the United States.Such a GHS-F model is necessary from both scientific and operational perspectives,with the strength in providing spatially consistent flood definitions and spatially distributed flood risk classification considering the heterogeneity in vulnerability and resilience across the entire domain.Priorities in the development of such a GHS-F are suggested,emphasizing the user’s requirements and needs according to practical experiences with various flood response agencies.展开更多
Glucocorticoids(GCs)have been the mainstay of immunosuppressive therapy in solid organ transplantation(SOT)for decades,due to their potent effects on innate immunity and tissue protective effects.However,some SOT cent...Glucocorticoids(GCs)have been the mainstay of immunosuppressive therapy in solid organ transplantation(SOT)for decades,due to their potent effects on innate immunity and tissue protective effects.However,some SOT centers are reluctant to administer GCs long-term because of the various related side effects.This review summarizes the advantages and disadvantages of GCs in SOT.PubMed and Scopus databases were searched from 2011 to April 2021 using search syntaxes covering“transplantation”and“glucocorticoids”.GCs are used in transplant recipients,transplant donors,and organ perfusate solution to improve transplant outcomes.In SOT recipients,GCs are administered as induction and maintenance immunosuppressive therapy.GCs are also the cornerstone to treat acute antibody-and T-cell-mediated rejections.Addition of GCs to organ perfusate solution and pretreatment of transplant donors with GCs are recommended by some guidelines and protocols,to reduce ischemia-reperfusion injury peri-transplant.GCs with low bioavailability and high potency for GC receptors,such as budesonide,nanoparticle-mediated targeted delivery of GCs to specific organs,and combination use of dexamethasone with inducers of immuneregulatory cells,are new methods of GC application in SOT patients to reduce side effects or induce immune-tolerance instead of immunosuppression.Various side effects involving different non-targeted organs/tissues,such as bone,cardiovascular,neuromuscular,skin and gastrointestinal tract,have been noted for GCs.There are also potential drug-drug interactions for GCs in SOT patients.展开更多
Allelopathy was defined in 1996 by IAS （international allelopathy society） as any process involving secondary metabolites produced by plant, algae, bacteria and fungi that influences the growth and development of ag...Allelopathy was defined in 1996 by IAS （international allelopathy society） as any process involving secondary metabolites produced by plant, algae, bacteria and fungi that influences the growth and development of agricultural and biological systems. Rice allelopathy against weeds was reported since 1989, which offers an integrated weed management with substantially reduced herbicide usage. Application of allelopathic rice cultivars is thought a resources conservation and environmental friendly way of weed bio-control, and could promote the sustainable development of agriculture. Screening or evaluating the allelopathic potential rice variety is the first step. In this paper, a new bioassay method was set up by the allelopathic potential of 9 rice lines on the target weed barnyardgrass （Echinochloa crusgalli）, and comparing with bioassay methods such as relay seeding in filter paper （RSF） and relay seeding in agar （RSA）. The results indicated that three methods had a same tendency in evaluating the allelopathic potential of rice; there existed a significant difference among different bioassay methods, and an interaction between bioassay methods and rice lines. The method of root exudates （RE） with the highest value and a correlation efficiency of 0.98 was considered as ideal bioassay method for evaluation of allelopathic potential.展开更多
Structural variants(SVs)are a type of genetic variation that contribute substantially to phenotypic diversity and evolution.Further study of SVs will help us understand the influence of SVs associated with tea quality...Structural variants(SVs)are a type of genetic variation that contribute substantially to phenotypic diversity and evolution.Further study of SVs will help us understand the influence of SVs associated with tea quality and stress resistance and provide new insight into tea plant breeding improvement and genetic research.However,SVs have not been thoroughly discovered in the tea plant genomes.Herein,we constructed a large-scale SV map across a population of 107 resequenced genomes,including both ancient and cultivated tea plants.A total of 44,240 highconfident SVs were identified,including 34,124 DEL(deletions),4,448 DUP(duplications),2,503 INV(inversions),544 INS(insertions)and 2,621 TRA(translocations).In total,12,400 protein-coding genes were overlapped with SVs,of which 49.5%were expressed in all five tea tissues.SVbased analysis of phylogenetic relationships and population structure in tea plants showed a consistent evolutionary history with the SNP-based results.We also identified SVs subject to artificial selection and found that genes under domestication were enriched in metabolic pathways involving theanine and purine alkaloids,biosynthesis of monoterpenoid,phenylpropanoid,fatty acid,and isoflavonoid,contributing to traits of agronomic interest in tea plants.In addition,a total of 27 terpene synthase(TPS)family genes were selected during domestication.These results indicate that these SVs could provide extensive genomic information for tea quality improvement.展开更多
Objective To evaluate the role of ^1H spetral selected point-resolved spectroscopy （SS-PRESS） sequence in distingnishing benign from malignant breast lesions by the malignancy marker of choline peak and to investiga...Objective To evaluate the role of ^1H spetral selected point-resolved spectroscopy （SS-PRESS） sequence in distingnishing benign from malignant breast lesions by the malignancy marker of choline peak and to investigate the factors influencing the diagnosis. Methods A total of 131 patients （ aged 24-83 years, average 44. 8 years） were enrolled in this study. The examinations were performed on a 1.5T scanner with four-channel phased array breast coiL Singie-voxel proton magnetic resonance spectroscopy （1H MRS） was acquired by SS-PRESS sequence in these patients referred to surgical or biopsy consultation. Results Among these patients, 74 were proved to have breast carcinomas and 57 have benign lesions by histopathological examinations, Thirty-one elevated choline peaks were observed in these 74 confirmed malignant lesions, and 5 detectable choline peaks were demonstrated in the 57 benign lesions. The sensitivity and specificity of ^1H SSPRESS MRS were 41.9% and 91.2%, respectively. The main factors influencing the diagnosis were signal-to-noise ratio and pathological type. Conclusions ^1H SS-PRESS MRS can provide a noninvasive, biochemical measurement of metabolism and improve the specificity of breast magnetic resonance imaging. Choline peak in vivo is a specific but not sensitive marker of malignancy. Technique factors and histopathological characterization of lesions influence the detection rate.展开更多
Agriculture is the foundation of national economy,and agricultural development is related to the rapid development of long-term stability of the society and economy. Agriculture includes farming,forestry,animal husban...Agriculture is the foundation of national economy,and agricultural development is related to the rapid development of long-term stability of the society and economy. Agriculture includes farming,forestry,animal husbandry,and fisheries. Agricultural listed company as an agricultural enterprise " leader",which directly affects the development of the entire growth of the agricultural industry development and policy,so the study of agricultural listed company's growth is particularly important. This paper uses AHP weighting method to evaluate 2012 financial data on the growth of agricultural listed companies.展开更多
文摘Odor pollution in landfill area has attracted more social attention in China. It is very important to control the generation of odor pollutants in situ. Analyzing odorous materials production form buried waste, simulated columns of different volatile solid (VS) content and different buried period waste were designed. Gas compounds produced from the columns were collected and analyzed by comprehensive two-dimensional gas chromatography (GC × GC) method. It has remarkable relationship between VS content and concentrations of odorous material. When VS content more than 40%, the total amount of odorous compounds increases remarkably. It can be inferred that reduced VS content of original waste may effective decreasing odorous materials production in landfill area. The old rubbish produced more odorous compounds than that of fresh one in simulated columns.
基金financial support from National Natural Science Foundation of China(No.21875106,21850410456,21875052,51972172)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB36000000)Jiangsu Excellent Postdoctoral Program
文摘The interfacial contacts between the electron transporting layers(ETLs)and the photoactive layers are crucial to device performance and stability for OSCs with inverted architecture.Herein,atomic layer deposition(ALD)fabricated ultrathin Al_(2)O_(3)layers are applied to modify the ETLs/active blends(PM6:BTP-BO-4F)interfaces of OSCs,thus improving device performance.The ALD-Al_(2)O_(3)thin layers on ZnO significantly improved its surface morphology,which led to the decreased work function of ZnO and reduced recombination losses in devices.The simultaneous increase in open-circuit voltage(V_(OC)),short-circuit current density(J_(SC))and fill factor(FF)were achieved for the OSCs incorporated with ALD-Al_(2)O_(3)interlayers of a certain thickness,which produced a maximum PCE of 16.61%.Moreover,the ALD-Al_(2)O_(3)interlayers had significantly enhanced device stability by suppressing degradation of the photoactive layers induced by the photocatalytic activity of ZnO and passivating surface defects of ZnO that may play the role of active sites for the adsorption of oxygen and moisture.
基金supported by grants from the National Key Research and Development Program of China(Grant No.2021YFC2500400)the National Natural Science Foundation of China(Grant Nos.81974439&82204121)+2 种基金the Beijing-Tianjin-Hebei Basic Research Cooperation Special Project(20JCZXJC00090)the Tianjin Health Committee Foundation(Grant No.TJWJ2021MS008)the Tianjin Key Medical Discipline(Specialty)Construction Project(Grant No.TJYXZDXK-009A).
文摘Given the rapid changes in social structure(urbanization),economic structure(industrialization),and demographic structure(population aging)in China,cancer has become a major public health problem1.Extensive evidence has indicated that screening can decrease cancer mortality,particularly among high-risk groups,and several representative national and regional cancer screening programs have been launched in China to cope with the increasing burden of cancer.
基金Supported by Chongqing Municipal Key Laboratory of Institutions of Higher Education(WEPKL2013MS-10)Chongqing Municipal Innovation Planning Project for University Students in 2013(201310643003)
文摘Through a series of exploration based on PSR framework model,for the purpose of building a suitable Chongqing agricultural nonpoint source pollution evaluation index system model framework,combined with the presence of Chongqing specific agro-environmental issues,we build a agricultural non-point source pollution assessment index system,and then study the agricultural system pressure,agro-environmental status and human response in total 3 major categories,develope an agricultural non-point source pollution evaluation index consisting of 3 criteria indicators and 19 indicators. As can be seen from the analysis,pressures and responses tend to increase and decrease linearly,state and complex have large fluctuations,and their fluctuations are similar mainly due to the elimination of pressures and impact,increasing the impact for agricultural non-point source pollution.
文摘目的调查临床监查员(clinical research associate,CRA)对上海市医院临床试验服务的满意度,以提升临床试验服务质量。方法2023年10—11月采用典型调查方法和修订的SERVQUAL(service quality)量表对CRA进行问卷调查,内容包括保证性、可靠性、有形性、响应性及移情性等5个维度29个条目。根据修正的服务重要性绩效满意度分析(importance-performance analysis,IPA)明确落入改进区的条目。结果对于来自10家申办者及其委托机构的163名CRA进行问卷调查,回收有效问卷160份。根据修正的IPA象限图,保证性、可靠性、有形性、响应性及移情性维度落入改进区的条目分别为6、2、1、2和2条。结论CRA对上海市医院的临床试验服务可能未达到满意水平,临床试验机构可从规范化意识、审查模式、流程获取、答复响应、管理体系灵活性等方面进行优化,从而提高临床试验服务质量。
基金This work was supported by the National Key Research and Development Program(Nos.2022YFB3503600 and 2021YFA0718500)Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDA15360102)National Natural Science Foundation of China(Nos.12273042 and 12075258).
文摘The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays and address the errors in the calibration of the E-C relationship,comprehensive tests and comparative studies of the three aforementioned crystals were conducted using Compton electrons,radioactive sources,and mono-energetic X-rays.The nonlinearity test results of the Compton electrons and X-rays demonstrated substantial differences,with all three crystals presenting a higher nonlinearity for X/-rays than for Compton electrons.Despite the LaBr_(3)(Ce)and LaBr_(3)(Ce,Sr)crystals having higher absolute light yields,they exhibited a noticeable nonlinear decrease in the light yield,especially at energies below 400 keV.The NaI(Tl)crystal demonstrated an"excess"light output in the 6-200 keV range,reaching a maximum"excess"of 9.2%at 30 keV in the X-ray testing and up to 15.5%at 14 keV during Compton electron testing,indicating a significant advantage in the detection of low-energy gamma rays.Furthermore,we explored the underlying causes of the observed nonlinearity in these crystals.This study not only elucidates the detector responses of GECAM,but also initiates a comprehensive investigation of the nonlinearity of domestically produced lanthanum bromide and sodium iodide crystals.
基金funded by the Natural Science Foundation of China(No.42373028,No.42072154).
文摘This study conducted a comparative analysis of extractable hopanoid hydrocarbons and those released via stepwise pyrolysis of typical Eocene immature oil shales in China,namely the Huadian,Maoming,and Fushun shales.Both the Huadian and Maoming shales exhibit immature indicators in extractable and kerogen-bound hopanoids(notably,high abundance of C_(29)to C_(32)17β,21β-hopanes and unsaturated hopenes).In contrast,the Fushun oil shale's hopanoids from extracts and pyrolyzates suggest a higher maturity level.The absence of neohopenes in the pyrolyzates of the shales underpins that the kerogenbound hopanoid skeletons resist rearrangement.However,the Huadian oil shale's asymmetric distribution of C_(29)and C_(30)hopenes and neohopenes hints at the presence of an additional source.Novel unsaturated hopenes,such as hop-20(21)-enes,identified in pyrolyzates of the three kerogens at various pyrolysis temperatures,reveal the occurrence of double bonds in kerogen-bound hopanoid skeletons without methyl rearrangements.The absence of hop-20-(21)-ene in extracts suggests that it might act as an intermediate of these novel hopenes during the epimerization of hopanoid skeletons within kerogen.The extractable and pyrolytic hopanoids'stereochemical alignment indicates that epimerization may occur in both ring systems and alkyl side chains of kerogen-bound hopanoid skeletons.Sequential stepwise pyrolysis proves to be a quick screening method for geological hopanoids without causing any significant alteration to the original skeletons even when cracking multiple covalent bonds is necessary.
基金supported by the Strategic Priority Research Program on Space Science of the Chinese Academy of Sciences,the support from the Strategic Priority Research Program on Space Science(grant Nos.XDA15360300,XDA15360000,XDA15360102,XDA15052700 and E02212A02S)of the Chinese Academy of Sciencesthe National Natural Science Foundation of China(NSFC,Grant No.12173038)and BeiDou navigation system。
文摘Realtime trigger and localization of bursts are the key functions of GECAM,an all-sky gamma-ray monitor launched on 2020 December 10.We developed a multifunctional trigger and localization software operating in the CPU of the GECAM Electronic Box.This onboard software has the following features:high trigger efficiency for real celestial bursts with a suppression of false triggers caused by charged particle bursts and background fluctuation,dedicated localization algorithm optimized for both short and long bursts,and low time latency of the trigger information which is downlinked through the Global Short Message Communication service of the global BeiDou navigation system.This paper provides a detailed description of the design and development of the trigger and localization software system for GECAM.It covers the general design,workflow,the main functions,and the algorithms used in the system.The paper also includes on-ground trigger tests using simulated gamma-ray bursts generated by a dedicated X-ray tube,as well as an overview of the performance for real celestial bursts during its in-orbit operation.
基金Supported by The grant for Key Laboratory of Gastroenterology and Hepatology,Ministry of Health,Renji Hospital,Shanghai Jiao Tong University School of MedicineNational Natural Science Foundation of China,No.81170355
文摘AIM： To evaluate the predictive value of neutrophil in- filtration as a marker of Helicobacter pylori （H. pyloni） infection. METHODS： A total of 315 patients with dyspepsia symptoms who underwent upper gastrointestinal en- doscopy were enrolled in this study. Biopsies were evaluated using the updated Sydney system. The medication history of all patients in the preceding 4 wk was recorded. The diagnosis of H. pylori infection was based on 13C-urea breath test at least 4 wk after with- drawal of antisecretory drugs, antibiotics and related drugs. For the patients with subtotal gastrectomy, the diagnosis of H. pylori infection was based on anti-H. pylori immunoglobulin G （IgG） antibody. Serum anti-H. pylori IgG antibody was measured by enzyme-linked immunosorbent assays （Biohit, Finland）. RESULTS： The sensitivity, specificity, positive predic- tive value and negative predictive value of neutrophil infiltration in the diagnosis ofH, pylorlinfection were 92.3%, 83.5%, 77.4% and 94.7%, respectively. Neu- trophil infiltration of gastric mucosa in the histological analysis was strongly associated withH, pylorlinfection （77.4% vs 5.3% in the neutrophil infiltration negative group, P = 0.000）. Moderate neutrophil infiltration was more frequent in H. pylorl infection when compared to mild infiltration （81.8% and 75%, respectively）, but did not reach statistical significance. For those patients with negative rapid urease test, H. pylori was detected in 73.2% of patients with positive neutrophil infiltration on histology. In patients with subtotal gastrectomy, the diagnostic accuracy of neutrophil infiltration in H. pylori infection was 50%. CONCLUSION： Neutrophil infiltration is closely associ- ated withH, pylori and may be recognized as a sign of this infection.
基金This study was supported by the National Key R&D Program of China(Grant No.2017YFA0604300)the National Natural Science Foundation of China(Grant Nos.41861144014,41775106 and U1811464)+1 种基金the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(Grant No.2017ZT07X355)the project of the Chinese Ministry of Emergency Management on“Catastrophe Evaluation Modeling Study”.
文摘The prolonged mei-yu/baiu system with anomalous precipitation in the year 2020 has swollen many rivers and lakes,caused flash flooding,urban flooding and landslides,and consistently wreaked havoc across large swathes of China,particularly in the Yangtze River basin.Significant precipitation and flooding anomalies have already been seen in magnitude and extension so far this year,which have been exerting much higher pressure on emergency responses in flood control and mitigation than in other years,even though a rainy season with multiple ongoing serious flood events in different provinces is not that uncommon in China.Instead of delving into the causes of the uniqueness of this year’s extreme precipitation-flooding situation,which certainly warrants in-depth exploration,in this article we provide a short view toward a more general hydrometeorological solution to this annual nationwide problem.A“glocal”(global to local)hydrometeorological solution for floods(GHS-F)is considered to be critical for better preparedness,mitigation,and management of different types of significant precipitation-caused flooding,which happen extensively almost every year in many countries such as China,India and the United States.Such a GHS-F model is necessary from both scientific and operational perspectives,with the strength in providing spatially consistent flood definitions and spatially distributed flood risk classification considering the heterogeneity in vulnerability and resilience across the entire domain.Priorities in the development of such a GHS-F are suggested,emphasizing the user’s requirements and needs according to practical experiences with various flood response agencies.
文摘Glucocorticoids(GCs)have been the mainstay of immunosuppressive therapy in solid organ transplantation(SOT)for decades,due to their potent effects on innate immunity and tissue protective effects.However,some SOT centers are reluctant to administer GCs long-term because of the various related side effects.This review summarizes the advantages and disadvantages of GCs in SOT.PubMed and Scopus databases were searched from 2011 to April 2021 using search syntaxes covering“transplantation”and“glucocorticoids”.GCs are used in transplant recipients,transplant donors,and organ perfusate solution to improve transplant outcomes.In SOT recipients,GCs are administered as induction and maintenance immunosuppressive therapy.GCs are also the cornerstone to treat acute antibody-and T-cell-mediated rejections.Addition of GCs to organ perfusate solution and pretreatment of transplant donors with GCs are recommended by some guidelines and protocols,to reduce ischemia-reperfusion injury peri-transplant.GCs with low bioavailability and high potency for GC receptors,such as budesonide,nanoparticle-mediated targeted delivery of GCs to specific organs,and combination use of dexamethasone with inducers of immuneregulatory cells,are new methods of GC application in SOT patients to reduce side effects or induce immune-tolerance instead of immunosuppression.Various side effects involving different non-targeted organs/tissues,such as bone,cardiovascular,neuromuscular,skin and gastrointestinal tract,have been noted for GCs.There are also potential drug-drug interactions for GCs in SOT patients.
文摘Allelopathy was defined in 1996 by IAS （international allelopathy society） as any process involving secondary metabolites produced by plant, algae, bacteria and fungi that influences the growth and development of agricultural and biological systems. Rice allelopathy against weeds was reported since 1989, which offers an integrated weed management with substantially reduced herbicide usage. Application of allelopathic rice cultivars is thought a resources conservation and environmental friendly way of weed bio-control, and could promote the sustainable development of agriculture. Screening or evaluating the allelopathic potential rice variety is the first step. In this paper, a new bioassay method was set up by the allelopathic potential of 9 rice lines on the target weed barnyardgrass （Echinochloa crusgalli）, and comparing with bioassay methods such as relay seeding in filter paper （RSF） and relay seeding in agar （RSA）. The results indicated that three methods had a same tendency in evaluating the allelopathic potential of rice; there existed a significant difference among different bioassay methods, and an interaction between bioassay methods and rice lines. The method of root exudates （RE） with the highest value and a correlation efficiency of 0.98 was considered as ideal bioassay method for evaluation of allelopathic potential.
基金supported by Shenzhen Science and Technology Program(Grant No.RCYX20210706092103024)two projects funded by the State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops(No.SKL2018001 to X.Z.and No.SKL20190012 to H.Z.)。
文摘Structural variants(SVs)are a type of genetic variation that contribute substantially to phenotypic diversity and evolution.Further study of SVs will help us understand the influence of SVs associated with tea quality and stress resistance and provide new insight into tea plant breeding improvement and genetic research.However,SVs have not been thoroughly discovered in the tea plant genomes.Herein,we constructed a large-scale SV map across a population of 107 resequenced genomes,including both ancient and cultivated tea plants.A total of 44,240 highconfident SVs were identified,including 34,124 DEL(deletions),4,448 DUP(duplications),2,503 INV(inversions),544 INS(insertions)and 2,621 TRA(translocations).In total,12,400 protein-coding genes were overlapped with SVs,of which 49.5%were expressed in all five tea tissues.SVbased analysis of phylogenetic relationships and population structure in tea plants showed a consistent evolutionary history with the SNP-based results.We also identified SVs subject to artificial selection and found that genes under domestication were enriched in metabolic pathways involving theanine and purine alkaloids,biosynthesis of monoterpenoid,phenylpropanoid,fatty acid,and isoflavonoid,contributing to traits of agronomic interest in tea plants.In addition,a total of 27 terpene synthase(TPS)family genes were selected during domestication.These results indicate that these SVs could provide extensive genomic information for tea quality improvement.
文摘Objective To evaluate the role of ^1H spetral selected point-resolved spectroscopy （SS-PRESS） sequence in distingnishing benign from malignant breast lesions by the malignancy marker of choline peak and to investigate the factors influencing the diagnosis. Methods A total of 131 patients （ aged 24-83 years, average 44. 8 years） were enrolled in this study. The examinations were performed on a 1.5T scanner with four-channel phased array breast coiL Singie-voxel proton magnetic resonance spectroscopy （1H MRS） was acquired by SS-PRESS sequence in these patients referred to surgical or biopsy consultation. Results Among these patients, 74 were proved to have breast carcinomas and 57 have benign lesions by histopathological examinations, Thirty-one elevated choline peaks were observed in these 74 confirmed malignant lesions, and 5 detectable choline peaks were demonstrated in the 57 benign lesions. The sensitivity and specificity of ^1H SSPRESS MRS were 41.9% and 91.2%, respectively. The main factors influencing the diagnosis were signal-to-noise ratio and pathological type. Conclusions ^1H SS-PRESS MRS can provide a noninvasive, biochemical measurement of metabolism and improve the specificity of breast magnetic resonance imaging. Choline peak in vivo is a specific but not sensitive marker of malignancy. Technique factors and histopathological characterization of lesions influence the detection rate.
基金Supported by Research Center for Sustainable Development in Three Gorges Reservoir Area Open Fund Project(2014-sxxyjd-05)Youth Research Project of Chongqing Three Gorges University(11QN-07)Innovation Planning Project for University Students in Chongqing Three Gorges University(2014-56)
文摘Agriculture is the foundation of national economy,and agricultural development is related to the rapid development of long-term stability of the society and economy. Agriculture includes farming,forestry,animal husbandry,and fisheries. Agricultural listed company as an agricultural enterprise " leader",which directly affects the development of the entire growth of the agricultural industry development and policy,so the study of agricultural listed company's growth is particularly important. This paper uses AHP weighting method to evaluate 2012 financial data on the growth of agricultural listed companies.
