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    题名 作者 年代 出处 被引量
1The system of physico-geographical regions of the Qinghai-Xizang (Tibet) Plateau显示文摘The Qinghai-Xizang Plateau is a unique physico-geographical region on the earth. As a whole, the spatial differentiation of physico-geographical regions of the plateau is mainly determined by topographic configuration and atmospheric circulation, warm and humid in the southeast, cold and arid in the northwest. The natural landscapes apppear in the following succession: forest → meadow → steppe → desert. The system of physico-geographical regions of the plateau is demarcated on the principle of bio-climate or the principle of three dimension zonality. Based on the thermal conditions, moisture regimes and variation in landform the Qinghai-Xizang Plateau is sequentially demarcated. The duration of mean daily temperature above 10℃ is the principal index, the subsidiary criterion is mean temperature of the warmest month, two temperature belts may be divided: plateau subpolar and plateau temperate. Annual aridity is taken as the principal index, subordinated by annual precipitation. Four moisture郑度 1996Science China Earth Sciences1996,39,4:35
2Salient object detection: A survey显示文摘Detecting and segmenting salient objects from natural scenes, often referred to as salient object detection, has attracted great interest in computer vision. While many models have been proposed and several applications have emerged, a deep understanding of achievements and issues remains lacking. We aim to provide a comprehensive review of recent progress in salient object detection and situate this field among other closely related areas such as generic scene segmentation, object proposal generation, and saliency for fixation prediction. Covering 228 publications, we survey i) roots, key concepts, and tasks, ii) core techniques and main modeling trends, and iii) datasets and evaluation metrics for salient object detection. We also discuss open problems such as evaluation metrics and dataset bias in model performance, and suggest future research directions.Ali Borji Ming-Ming Cheng Qibin Hou Huaizu Jiang Jia Li 2019Computational Visual Media2019,5,2:40
3Map and analysis of microsatellites in the genome of Populus: The first sequenced perennial plant显示文摘Environmental Sciences Division, Oak Ridge National Laboratory, TN, USA We mapped and analyzed the microsatellites throughout 284295605 base pairs of the unambiguously assembled sequence scaffolds along 19 chromosomes of the haploid poplar genome. Totally, we found 150985 SSRs with repeat unit lengths between 2 and 5 bp. The established microsatellite physical map demonstrated tr at SSRs were distributed relatively evenly across the genome of Populus. On average, These SSRs occurred every 1883 bp within the poplar genome and the SSR densities in intergenic regions, introns, exons and UTRs were 85.4%, 10.7%, 2.7% and 1.2%, respectively. We took di-, tri-, tetra-and pentamers as the four classes of repeat units and found that the density of each class of SSRs decreased with the repeat unit lengths except for the tetranucleotide repeats. It was noteworthy that the length diversification of microsatellite sequences was negatively correlated with their repeat unit length and the SSRs with shorter repeat units gained repeats faster than the SSRs with longer repeat units. We also found that the GC content of poplar sequence significantly correlated with densities of SSRs with uneven repeat unit lengths (tri-and penta-), but had no significant correlation with densities of SSRs with even repeat unit lengths (di-and tetra-). In poplar genome, there were evidences that the occurrence of different microsatellites was under selection and the GC content in SSR sequences was found to significantly relate to the functional importance of microsatellites.LI ShuXian & YIN TongMing College of Environment and Forest Resources, Nanjing Forestry University, Nanjing 210037, China Environmental Sciences Division, Oak Ridge National Laboratory, TN, USA 2007Science China(Life Sciences)2007,50,5:25
4“Global Region”结构与重构研究——以长三角地区为例显示文摘考虑到全球城市体系由“树枝纵向结构”向“网络状横向结构”的转变,同济大学吴志强教授在我国首先提出了“Global Regions(GRs)”的概念,认为GRs从区域协调的角度较好的解决了大都市带来的一些城市社会经济问题, 这是一种城市要素集聚的新形态。GRs 也是在城市之间竞争向以区域为主的竞争演变的背景下提出的一种新的城市区域发展模式和形态。选取长江三角洲地区作为中国比较典型的GRs作为实证研究的对象,进行长三角地区静态区域结构格局和动态区域结构重构的分析,同时就重构的动力机制从地方化、全球化角度进行探讨。于涛方 吴志强 2006城市规划学刊2006,,2:26
5Trends in particulate matter and its chemical compositions in China from 2013–2017显示文摘Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationality of environmental air quality control strategies.Based on the sampling and chemical composition data of PM2.5 in different key regions of China in the CARE-China observation network,this research analyzes the environmental air quality data released by the China National Environmental Monitoring Centre during the studied period to determine the changes in the particulate matter mass concentration in key regions and the evolution of the corresponding chemical compositions during the implementation of the Action Plan for Prevention and Control of Air Pollution from 2013-2017.The results show the following.(1)The particulate matter mass concentration in China showed a significant downward trend;however,the PM2.5 annual mass concentration in 64%of cities exceeds the New Chinese Ambient Air Quality Standard(CAAQS)GradeⅡ(GB3095-2012).The region to the east of the Taihang Mountains,the Fenhe and Weihe River Plain and the Urumqi-Changji regions in Xinjiang,all have PM2.5 concentration loading that is still high,and heavy haze pollution occurred frequently in the autumn and winter.(2)During the heavy pollution in the autumn and winter,the concentrations of sulfate and organic components decreased significantly.The mean SO42-concentration in PM2.5 decreased by 76%,12%,81%and 38%in Beijing-Tianjin-Hebei(BTH),the Pearl River Delta(PRD),the Sichuan-Chongqing region(SC)and the Fenhe and Weihe River Plain,respectively.The mean organic matter(OM)concentration decreased by 70%,44%,48%and 31%,respectively,and the mean concentration of NH4+decreased by 68%,1.6%,38%and 25%,respectively.The mean elemental carbon(EC)concentration decreased by 84%and 20%in BTH and SC,respectively,and it increased by 61%and 11%in the PRD and Fenhe and Weihe River Plain,respectively.The mean concentration of mineral and unresolved chemical components(MI)dropped by 70%,24%and 13%in BTH,the PRD and the Fenhe and Weihe River Plain,respectively.The change in the PM2.5 chemical composition is consistent with the decrease of the PM2.5mass concentration.(3)In 2015,the mean OM concentration contributions to fine particles and coarse particles were 13-46%and 46-57%,respectively,and the mean MI concentration contributions to fine particles and coarse and particles were 31-60%and 39-73%,respectively;these values are lower than the 2013 values from the key regions,which is the most important factor behind the decrease of the particulate matter mass concentration.From 2013 to 2015,among the chemical components of different particle size fractions,the peak value of the coarse particle size fraction decreased significantly,and the fine particle size fractions of SO42-,NO3-,and NH4+decreased with the decrease of the particulate matter mass concentration in different particle size fractions.The fine-particle size peaks of SO42-,NO3-and NH4+shifted from 0.65-1.1μm to the finer size range of0.43-0.65μm during the same time frame.Yuesi WANG Wenjie LI Wenkang GAO Zirui LIU Shili TIAN Rongrong SHEN Dongsheng JI Shuai WANG Lili WANG Guiqian TANG Tao SONG Mengtian CHENG Gehui WANG Zhengyu GONG Jiming HAO Yuanhang ZHANG 2019Science China Earth Sciences2019,62,12:23
6Prevention and treatment technologies of railway tunnel water inrush and mud gushing in China显示文摘Water inrush and mud gushing are one of the biggest hazards in tunnel construction. Unfavorable geological sections can be observed in almost all railway tunnels under construction or to be constructed, and vary in extent. Furthermore, due to the different heights of mountains and the lengths of tunnels, the locations of the unfavorable geological sections cannot be fully determined before construction, which increases the risk of water inrush and mud gushing. Based on numerous cases of water inrush and mud gushing in railway tunnels, the paper tries to classify water inrush and mud gushing in railway tunnels in view of the conditions of the surrounding rocks and meteorological factors associated with tunnel excavation. In addition, the causes of water inrush and mud gushing in combination of macroand micromechanisms are summarized, and site-specifc treatment method is put forward. The treatment methods include choosing a method of advance geological forecast according to risk degrees of different sections in the tunnel, determining the items of predictions, and choosing the appropriate methods, i.e. draining-oriented method, blocking-oriented method or draining-and-blocking method. The treatment technologies of railway water inrush and mud gushing are also summarized, including energy relief and pressure relief technology, advance grouting technology, and advance jet grouting technology associated with their key technical features and applicable conditions. The results in terms of treatment methods can provide reference to the prevention and treatment of tunnel water inrush and mud gushing.Yong Zhao Pengfei Li Siming Tian 2013Journal of Rock Mechanics and Geotechnical Engineering2013,5,6:16
7Progress in Semi-arid Climate Change Studies in China显示文摘This article reviews recent progress in semi-arid climate change research in China.Results indicate that the areas of semiarid regions have increased rapidly during recent years in China,with an increase of 33%during 1994-2008 compared to 1948-62.Studies have found that the expansion rate of semi-arid areas over China is nearly 10 times higher than that of arid and sub-humid areas,and is mainly transformed from sub-humid/humid regions.Meanwhile,the greatest warming during the past 100 years has been observed over semi-arid regions in China,and mainly induced by radiatively forced processes.The intensity of the regional temperature response over semi-arid regions has been amplified by land-atmosphere interactions and human activities.The decadal climate variation in semi-arid regions is modulated by oceanic oscillations,which induce land-sea and north-south thermal contrasts and affect the intensities of westerlies,planetary waves and blocking frequencies.In addition,the drier climates in semi-arid regions across China are also associated with the weakened East Asian summer monsoon in recent years.Moreover,dust aerosols in semi-arid regions may have altered precipitation by affecting the local energy and hydrological cycles.Finally,semi-arid regions in China are projected to continuously expand in the 21st century,which will increase the risk of desertification in the near future.Jianping HUANG Jieru MA Xiaodan GUAN Yue LI Yongli HE 2019Advances in Atmospheric Sciences2019,36,9:15
8Conservation needs of amphibians in China: A review显示文摘The conservation status of all the amphibians in China is analyzed,and the country is shown to be a global priority for conservation in comparison to many other countries of the world.Three Chinese regions are particularly rich in amphibian diversity:Hengduan,Nanling,and Wuyi mountains.Sala-manders are more threatened than frogs and toads.Several smaller families show a high propensity to become seriously threatened:Bombinatoridae,Cryptobranchidae,Hynobiidae and Salamandridae.Like other parts of the world,stream-breeding,high-elevation forest amphibians have a much higher likeli-hood of being seriously threatened.Habitat loss,pollution,and over-harvesting are the most serious threats to Chinese amphibians.Over-harvesting is a less pervasive threat than habitat loss,but it is more likely to drive a species into rapid decline.Five conservation challenges are mentioned with recommendations for the highest priority research and conservation actions.Michael Wai Neng LAU Simon N STUART Janice S CHANSON Neil A COX Debra L FISCHMAN 2007Science China(Life Sciences)2007,50,2:12
9Distribution of lipids in modern soils from various regions with continuous climate (moisture-heat) change in China and their climate significance显示文摘Total 26 modern soil samples were collected from various regions under different climate conditions from tropical to arid temperate in China and systematically analyzed for their organic matters by GC/MS in order to evaluate climatic impacts on soil organic components. Abundant lipids molecules were recognized, including n-alkanes, n-alkenones, and long-chain branched alkanes. We find the pre- dominance of main peaks of long-chain n-alkanes (nC29, nC31, nC33) and short-chain ones (nC16, nC17, nC18) records information of soil generation in warm-humid and cold-dry regions. The proportion of n-alkanes (nC16+nC17+nC18) to (nC29+nC31+nC33) varies in good agreement with moisture-heat conditions and thus probably can serve as a new index for climate change. The ratios of C21-/nC22+, nC17/nC31 and (nC15+nC17+nC19) / ( nC27+nC29 +nC31) of n-alkanes, indicating respectively input ratios of lower bacterial alga, aquatic organisms, and higher plants and terraneous organisms, co-vary well in different climate regions from forest to grassland and desert, suggesting that they have also reflected the difference of climates between monsoon region and inland one. The C21-/C22+ ratio of n-alkan-2-one records largely the discrepancy of temperature from north to south of China bordered by the Qinling Mountains, but less humidity. The C21-/C22+ ratio of n-alkan-3-ones changes well with climatic factors, such as tem- perature and humidity. The biogenic source of series A-D long-chain branched alkanes may be derived from some kinds of special epiphyte that most likely live in weak oxic-anoxic and moisture-heat envi- ronments, suggesting their distribution record as well some information on climatic change. All these researches demonstrate that the distributions of lipids molecules in modern soils in China record well signals of climates from quite different climatic regions, and can serve as important climatic proxies to reveal climatic change over China.WANG YongLi FANG XiaoMin BAI Yan XI XiaoXia ZHANG XiZheng WANG YouXiao 2007Science China Earth Sciences2007,50,4:11
10Changes in the epidemiology of hepatitis A in three socio-economic regions of China,1990-2017显示文摘Background:Hepatitis A(HepA)vaccination and economic transitions can change the epidemiology of HepA.China's Gross Domestic Product(GDP)per capita was known to be inversely associated with the incidence of HepA,but a deeper understanding of the epidemiology of HepA in different socio-economic regions is lacking.We compare the changing epidemiology of HepA in three socioeconomic-geographic regions of China.Methods:We obtained data on all HepA cases reported through the National Notifiable Disease Reporting System and assessed trends and changes in age-specific incidence rates by age quartile and season.We categorized the country into three regions,the sequential years into five era,compared the incidence,quartile age;seasonal intensity and coverage of HepA of the three regions.Linear regression was peiformed to analyse trends in incidence of HepA and to analyse the association between coverage and incidence.Results:The annual mean incidences of HepA in the eastern,central,and western regions decreased from 63.52/100000,50.57/100000 and 46.39/100000 in 1990-1992 to 1.18/100000,1.05/100000 and 3.14/100000 in 2012-2017,respectively.Decreases in incidence were seen in all age groups in the three regions;the incidence was highest(9.3/100000)in the youngest age group(0-4 years)of the western region,while in the central region,the age group with the highest incidence changed from 0 to 9 years to adults>60 years old.In 2017,the median age of HepA cases was 43 years(Q-Q3:33-55),47 years(Q1-Q3:32-60)and 33 years(Q1-Q3:9-52)in the eastern,central,and western provinces,respectively.Seasonal peaks became smaller or were nearly elimination nationwide,but seasonality persisted in some provinces.After the Expanded Program on Immunization(EPI)included HepA vaccine into the routine schedule in 2007,HepA coverage increased to>80%in the three regions and was negatively association with the HepA incidence.Conclusion:The incidence of HepA decreased markedly between 1990 and 2017.A socioeconomic inequity in coverage of HepA vaccine was almost eliminated after HepA vaccine was introduced into China's EPI system,but inequity in incidence still existed in lower socio-economic developed region.Xiao-Jin Sun Guo-Min Zhang Rong-Jun Zhou Hui Zheng Ning Miao Zun-Dong Yin Fu-Zhen Wang 2019Infectious Diseases of Poverty2019,8,5:9
11Nuclear magnetic resonance based metabolomic differentiation of different Astragali Radix显示文摘Astragali Radix(AR) is one of the most popular herbal medicines in traditional Chinese medicine(TCM). Wild AR is believed to be of high quality, and substitution with cultivated AR is frequently encountered in the market. In the present study, two types of ARs(wild and cultivated) from Astragalus membranaceus(Fisch.) Bge. and A. membranaceus var. mongholicus(Bge.) Hsiao, growing in different regions of China, were analyzed by NMR profiling coupled with multivariate analysis. Results showed that both could be differentiated successfully and cultivation patterns or growing years might have greater impact on the metabolite compositions than the variety; the metabolites responsible for the separation were identified. In addition, three extraction methods were compared and the method(M1) was used for further analysis. In M1, the extraction solvent composed of water, methanol, and chloroform in the ratio of 1 : 1 : 2 was used to obtain the aqueous methanol(upper layer) and chloroform(lower layer) fractions, respectively, showing the best separation. The differential metabolites among different methods were also revealed. Moreover, the sucrose/glucose ratio could be used as a simple index to differentiate wild and cultivated AR. Meanwhile, the changes of correlation pattern among the differential metabolites of the two varieties were found. The work demonstrated that NMR-based non-targeted profiling approach, combined with multivariate statistical analysis, can be used as a powerful tool for differentiating AR of different cultivation types or growing years.LI Ai-Ping LI Zhen-Yu QU Ting-Li QIN Xue-Mei DU Guan-Hua 2017Chinese Journal of Natural Medicines2017,15,5:9
12Optimal performance regions of an irreversible energy selective electron heat engine with double resonances显示文摘A theoretical model for irreversible double resonance ESE(energy selective electron) device with phonon induced bypass heat leakage which is operating as heat engine system is proposed. The thermodynamic performance is optimized and the impacts of heat leakage and structure parameters of the electron system on its performance are discussed in detail by using FTT(finite time thermodynamics). Moreover, performances of the ESE system with multiple optimization objective functions, including power output, thermal efficiency, ecological function and efficient power, are explored by numerical examples. New optimal performance regions and the selection plans of optimization objective functions of the ESE system are obtained. It reveals that the characteristic of power versus efficiency behave as loop-shaped curves in spite of the heat leakage which will always decrease the efficiency of the electron engine. By properly choosing the design parameters, the ESE engine can be designed to operate at optimal conditions according to different design purpose. The preferred design area should be located between the optimal effective power condition and the optimal ecological function condition.DING ZeMin CHEN LinGen GE YanLin XIE ZhiHui 2019Science China(Technological Sciences)2019,62,3:8
13Changes in newly notified cases and control of tuberculosis in China:time-series analysis of surveillance data显示文摘Background:China has made progress in tuberculosis control,but this disease remains a burden in many regions of China.We performed time-series analysis to examine changes in the rates of newly notified and newly smear-positive cases of tuberculosis in different regi ons of China from 1997 to 2018 a nd assessed the effect of the current control program.Methods:National and provincial notification data on tuberculosis from 1997 to 2018,which covers 31 provinces in the mainland of China,were extracted from the Chinese public health science data center.The annual percentage changes in newly notified and smear-positive cases were analyzed using a joinpoint regression method.Ye-Sheng Wang Wen-Long Zhu Tao Li Wei Chen Wei-Bing Wang 2021Infectious Diseases of Poverty2021,10,1:8
14基于地貌分区的1990-2015年中国耕地时空特征变化分析(英文)显示文摘Landforms are an important factor determining the spatial pattern of cropland through allocation of surface water and heat. Therefore, it is of great importance to study the change in cropland distribution from the perspective of geomorphologic divisions. Based on China's multi-year land cover data(1990, 1995, 2000, 2005, 2010 and 2015) and geomorphologic regionalization data, we analyzed the change in cropland area and its distribution pattern in six geomorphologic regions of China over the period of 1990-2015 with the aid of GIS techniques. Our results showed that the total cropland area increased from 177.1 to 178.5 million ha with an average increase rate of 0.03%. Cropland area decreased in southern China and increased in northern China. Region I(Eastern hilly plains) had the highest cropland increase rate, while the cropland dynamic degree of Region IV(Northwestern middle and high mountains, basins and plateaus) was significantly higher than that of other regions. The barycenter of China's cropland shifted from northern China to the northwest over the 25-year period. Regions IV and I were the two regions with the greatest increase of cropland. Region II(Southeastern low and middle mountains) and Region V(Southwestern middle and low mountains, plateaus and basins) were the main decreasing cropland regions. The area of cropland remained almost unchanged in Region III(Northern China and Inner Mongolia eastern-central mountains and plateaus) and Region VI(Tibetan Plateau). The loss of cropland occurred mostly in Regions I and II as a result of growing industrialization and urbanization, while the increase of cropland occurred mainly in Region IV because of reclamation of grassland and other wasteland. These analyzing results would provide fundamental information for further studies of urban planning, ecosystem management, and natural resourcesconservation in China.高晓雨 程维明 王楠 刘樯漪 马廷 陈印军 周成虎 2019Journal of Geographical Sciences2019,29,2:7
15Detection of hyper-conserved regions in hepatitis B virus X gene potentially useful for gene therapy显示文摘AIM To detect hyper-conserved regions in the hepatitis B virus(HBV) X gene(HBX) 5' region that could be candidates for gene therapy.METHODS The study included 27 chronic hepatitis B treatmentnaive patients in various clinical stages(from chronic infection to cirrhosis and hepatocellular carcinoma, both HBeA g-negative and HBeA g-positive), and infected with HBV genotypes A-F and H. In a serum sample from each patient with viremia > 3.5 log IU/m L, the HBX 5' end region [nucleotide(nt) 1255-1611] was PCRamplified and submitted to next-generation sequencing(NGS). We assessed genotype variants by phylogenetic analysis, and evaluated conservation of this region by calculating the information content of each nucleotide position in a multiple alignment of all unique sequences(haplotypes) obtained by NGS. Conservation at the HBx protein amino acid(aa) level was also analyzed.RESULTS NGS yielded 1333069 sequences from the 27 samples, with a median of 4578 sequences/sample(2487-9279, IQR 2817). In 14/27 patients(51.8%), phylogenetic analysis of viral nucleotide haplotypes showed a complex mixture of genotypic variants. Analysis of the information content in the haplotype multiple alignments detected 2 hyper-conserved nucleotide regions, one in the HBX upstream non-coding region(nt 1255-1286) and the other in the 5' end coding region(nt 1519-1603). This last region coded for a conserved amino acid region(aa 63-76) that partially overlaps a Kunitz-like domain.CONCLUSION Two hyper-conserved regions detected in the HBX 5' end may be of value for targeted gene therapy, regardless of the patients' clinical stage or HBV genotype.Carolina González David Tabernero Maria Francesca Cortese Josep Gregori Rosario Casillas Mar Riveiro-Barciela Cristina Godoy Sara Sopena Ariadna Rando Marcal Yll Rosa Lopez-Martinez Josep Quer Rafael Esteban Maria Buti Francisco Rodríguez-Frías 2018World Journal of Gastroenterology2018,24,19:6
16Validation and application of water levels derived from Sentinel-3A for the Brahmaputra River显示文摘For the first time ever, this study aims at applying Sentinel-3 A to the Great Brahmaputra River(GBR) and validating water levels derived from this newly-launched altimetry satellite mission. The GBR is divided into three primary parts:(1) a large section of the Yarlung Zangbo River in China, also termed the Upper Brahmaputra River(UBR) in this study, featured by high elevation,complex terrain, narrow river widths(from less than 100 to 400 m), and limited in situ measurements;(2) the Middle Brahmaputra River(MBR) with widths varying from ~400 m to ~1 km;(3) the Lower Brahmaputra River(LBR), dominated by braided channels with wide river channels(up to several kilometers). For the altimetry data, both waveform retracking and hooking effect correction were applied to mitigate the influence caused by land contamination and to improve the accuracy of water level retrievals. Water levels were derived from 41 virtual stations(VSs) across the GBR and different retracking algorithms were compared with in situ data from two gauging stations in the UBR. Time series of altimetry-based water levels were categorized into three types based on the quality: no data(type 1), degraded(type 2), and good(type 3). Results showed that the VSs(type 1) only existed in the mountainous regions, accounting for ~ a half of the total in the UBR. Validation with the gauged water levels showed that the TIC algorithm performed best among all of the retrackers applied, followed by the Ice-1 algorithm. The standard deviation of the difference between the gauged and TIC-derived water levels ranged from 0.41 to 0.76 m among four different VSs(type 3). In addition, the quality of VSs in the LBR was best, followed by the MBR. Our study has demonstrated the capability of Sentinel-3 A in monitoring water levels in the GBR, thereby paving the way for future applications such as discharge estimation and hydrologic/hydrodynamic applications.HUANG Qi LI XingDong HAN PengFei LONG Di ZHAO FanYu HOU AiZhong 2019Science China(Technological Sciences)2019,62,10:6
17An overview of the spatial patterns of land surface processes over arid and semiarid regions显示文摘With data from the project Collaborative Observation of Semi-arid/Arid Regions in North China, collected during July and September 2008, the spatial patterns of land surface processes over arid and semiarid regions have been investigated based on the ordinary Kriging interpolation approach. Generally, for the radiation processes, downward and upward short-wave radiation have a uniformly increasing trend with latitude, but the spatial patterns of long-wave radiation present notable regional differences: both upward and downward long-wave radiation increase with latitude in the west of North China, while in the east they vary inversely with latitude, suggesting surface temperature and clouds respectively have feedbacks to the long-wave radiation in the west and east of North China. The surface net radiation basically has a negative latitudinal trend. Long-wave radiation budget plays an important role in the spatial pattern of surface net radiation, particularly in the east of North China, although short-wave radiation budget largely determines the magnitude of surface net radiation. For the energy processes, latent and sensible heat flux varies conversely with latitude: more available land surface energy is consumed by evaporating soil water at lower latitudes while more is used for heating the atmosphere at higher latitudes. A soil heat flux maximum and minimum are found in Loess Plateau and Qinghai Plateau respectively, and a maximum is seen in the northeast China.Jian Zeng Jie Shen Qiang Zhang 2010Research in Cold and Arid Regions2010,2,4:6
18TYMS/KRAS/BRAF molecular profiling predicts survival following adjuvant chemotherapy in colorectal cancer显示文摘BACKGROUND Patients with stage II-III colorectal cancer (CRC) treated with adjuvant chemotherapy, gain a 25% survival benefit. In the context of personalized medicine, there is a need to identify patients with CRC who may benefit from adjuvant chemotherapy. Molecular profiling could guide treatment decisions in these patients. Thymidylate synthase (TYMS) gene polymorphisms, KRAS and BRAF could be included in the molecular profile under consideration. AIM To investigate the association of TYMS gene polymorphisms, KRAS and BRAF mutations with survival of CRC patients treated with chemotherapy.METHODS A retrospective study studied formalin-fixed paraffin-embedded tissues (FFPEs) of consecutive patients treated with adjuvant chemotherapy during January/2005-January/2007. FFPEs were analysed with PCR for the detection of TYMS polymorphisms, mutated KRAS (mKRAS) and BRAF (mBRAF). Patients were classified into three groups (high, medium and low risk) according to 5’UTR TYMS polymorphisms Similarly, based on 3’UTR polymorphism ins/loss of heterozygosity (LOH) patients were allocated into two groups (high and low risk of relapse, respectively). Cox regression models examined the associated 5- year survival outcomes. RESULTS One hundred and thirty patients with early stage CRC (stage I-II: 55 patients;stage III 75 patients;colon: 70 patients;rectal: 60 patients) were treated with surgery and chemotherapy. The 5-year disease free survival and overall survival rate was 61.6% and 73.9% respectively. 5’UTR polymorphisms of intermediate TYMS polymorphisms (2RG/3RG, 2RG/LOH, 3RC/LOH) were associated with lower risk for relapse [hazard ratio (HR) 0.320, P = 0.02 and HR 0.343, P = 0.013 respectively] and death (HR 0.368, P = 0.031 and HR 0.394, P = 0.029 respectively). The 3’UTR polymorphism ins/LOH was independently associated with increased risk for disease recurrence (P = 0.001) and death (P = 0.005). mBRAF (3.8% of patients) was associated with increased risk of death (HR 4.500, P = 0.022) whereas mKRAS (39% of patients) not. CONCLUSION Prospective validating studies are required to confirm whether 2RG/3RG, 2RG/LOH, 3RC/LOH, absence of ins/LOH and wild type BRAF may indicate patients at lower risk of relapse following adjuvant chemotherapy.Anastasios Ntavatzikos Aris Spathis Paul Patapis Nikolaos Machairas Georgia Vourli George Peros Iordanis Papadopoulos Ioannis Panayiotides Anna Koumarianou 2019World Journal of Gastrointestinal Oncology2019,11,7:5
19Characterization and evolutionary dynamics of complex regions in eukaryotic genomes显示文摘Complex regions in eukaryotic genomes are typically characterized by duplications of chromosomal stretches that often include one or more genes repeated in a tandem array or in relatively close proximity. Nevertheless, the repetitive nature of these regions,together with the often high sequence identity among repeats, have made complex regions particularly recalcitrant to proper molecular characterization, often being misassembled or completely absent in genome assemblies. This limitation has prevented accurate functional and evolutionary analyses of these regions. This is becoming increasingly relevant as evidence continues to support a central role for complex genomic regions in explaining human disease, developmental innovations, and ecological adaptations across phyla. With the advent of long-read sequencing technologies and suitable assemblers, the development of algorithms that can accommodate sample heterozygosity, and the adoption of a pangenomic-like view of these regions, accurate reconstructions of complex regions are now within reach. These reconstructions will finally allow for accurate functional and evolutionary studies of complex genomic regions, underlying the generation of genotype-phenotype maps of unprecedented resolution.José Ranz Bryan Clifton 2019Science China(Life Sciences)2019,62,4:5
20民族旅游地居民对旅游发展的认知、态度及参与行为研究——以海南黎苗族为例显示文摘旅游地居民对旅游的认知、态度及参与行为对当地旅游业的可持续发展具有非常重要的作用。通过对海南黎苗旅游地居民对旅游发展的认知、态度和参与行为三项指标进行了问卷调查,并应用SPSS15.0和AMOS7.0软件构建了结构方程模型。研究结果表明,人口因素中年龄因素对居民的旅游认知差异没有显著影响;教育程度对居民旅游发展态度差异具有显著影响;所有的人口因素对居民旅游参与行为差异具有显著影响;居民对旅游的正面和负面认知对其旅游发展态度和参与行为均具有显著影响。朱海冰 张侨 2010天水师范学院学报2010,30,6:5
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