离析数字学术、数字人文、人文计算三大主题,分别以CNKI和Web of Science数据简析了三大主题的高引论文特征,研究揭示:国内发文较国际发文具有一定的滞后性,国内研究在开创性和探索性方面存在不足。共被引网络体现的关联性中文高引论文...离析数字学术、数字人文、人文计算三大主题,分别以CNKI和Web of Science数据简析了三大主题的高引论文特征,研究揭示:国内发文较国际发文具有一定的滞后性,国内研究在开创性和探索性方面存在不足。共被引网络体现的关联性中文高引论文高于外文高引论文,其中数字学术与数字人文两个主题的关联性较强,而数字学术与人文计算的关联性较弱;引文网络则体现三主题间的耦合都较弱。数字人文作为三大主题中最活跃的主题值得持续关注。展开更多
目的:本文以呼吸医学为切入点,分析呼吸医学高引文作者群体及其选刊的10年对比,分析相对高影响力研究等作者选刊所看重的期刊特征。方法:检索科睿唯安Web of Science数据库中,呼吸系统高被引论文(Highly cited papers)。使用Citespace工...目的:本文以呼吸医学为切入点,分析呼吸医学高引文作者群体及其选刊的10年对比,分析相对高影响力研究等作者选刊所看重的期刊特征。方法:检索科睿唯安Web of Science数据库中,呼吸系统高被引论文(Highly cited papers)。使用Citespace工具,对过去10年高被引文的趋势进行分析。结果:亚洲及南美国家的高引文数量均有明显增加。《柳叶刀·呼吸医学》的影响力逐渐增强。创刊10年,能快速崛起的原因,可能在于《柳叶刀》的品牌化效应,及其高质量的审稿等因素。结论:注重期刊的品牌建设,提高审稿效率和质量,能增加医学期刊对高质量研究的吸引力。展开更多
目的:了解和分析近3年中国骨科国际论文的发展现状,分布情况和主要特点。方法:使用Web of Science网站检索近3年SCI收录的中国骨科论文,根据论文数,按照科研机构和来源期刊进行排序;通过引用频次排序,获取引用数高的论文,并进行分析。结...目的:了解和分析近3年中国骨科国际论文的发展现状,分布情况和主要特点。方法:使用Web of Science网站检索近3年SCI收录的中国骨科论文,根据论文数,按照科研机构和来源期刊进行排序;通过引用频次排序,获取引用数高的论文,并进行分析。结果:近3年分别有1238篇,1264篇和1225篇来自中国的骨科论文被SCI数据库收录,上海交通大学(n=75)和Eur Spine J(n=114)为发表中国论文数量最多的机构和杂志。纳入的143篇高引论文中,发表最多的研究类型为临床论著(n=70)和系统综述/meta分析(n=50)。高引临床论著涉及最多的主题为"膝",高引系统综述/meta分析最多主题为"脊柱"。结论:2015—2017年,上海交通大学和Eur Spine J发表最多中国骨科SCI论文;高引论文中,涉及最多的主题为"脊柱"和"膝",论文类型分布不均衡,主要集中在临床论著和系统综述。展开更多
[Objective] The aim was to explore the special methods for amplification of large-family genes by using primers with high degeneracy.[Method] By using the primers with high degeneracy,conventional PCR,conventional tou...[Objective] The aim was to explore the special methods for amplification of large-family genes by using primers with high degeneracy.[Method] By using the primers with high degeneracy,conventional PCR,conventional touchdown PCR and the optimized abnormal touchdown PCR were respectively carried out to amplify the genomic DNA of Cyprinus carpio.[Result] Only one evident electrophoretic band and a few Sox genes were obtained by using normal PCR;no obvious electrophoretic band but dispersive product was obtained by normal touchdown PCR;ideal result was obtained by the abnormal touchdown PCR that three evident electrophoretic bands and much more Sox genes were amplified.[Conclusion] The research provided theoretical basis for the optimization and selection of PCR amplification conditions of the large-family genes.展开更多
[Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B o...[Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B on maize and providing scientific reference to make proper countermeasures. [ Method] The location test in field and lift lamp of UV-B were used to observe the changes of maize height, leaf area and number of green leaves under influences of different UV-B radiation. [ Result] In arid regions of middle-high elevation, enhanced ultraviolet radiation-B could dwarf maize plant, decrease leaf area, decline number of green leaves and yield. The reason of decreasing leaf area was that enhanced ultraviolet radiation-B shortened leaf length and leaf width while the reason of declining yield was that yield components were all negatively influ- enced and with the increase of ultraviolet radiation-B, the yield declined dramatically. [ Concluslonl The result of this experiment would be good for maize production in arid regions of middle-high elevation.展开更多
The Fenglin and Fengcong landform units are considered to be an important representation for defining the degree of development of Karst landforms. However, these terrain features have been proven difficult to delinea...The Fenglin and Fengcong landform units are considered to be an important representation for defining the degree of development of Karst landforms. However, these terrain features have been proven difficult to delineate and extract automatically because of their complex morphology. In this paper, a new method for identifying the Fenglin and Fengcong landform units is proposed. This method consists of two steps:(1) terrain openness calculation and(2) toe line extraction. The proposed method is applied and validated in the Karst case area of Guilin by using ASTER GDEM with one arc-second resolution. The openness of both the positive and negative terrain and a threshold were used to extract toe lines for segmenting depressions and pinnacles in Fenglin and Fengcong landforms. A comparison between the extracted Fenglin and Fengcong landform units and their real units from high resolution images wascarried out to evaluate the capability of the proposed method. Results show the proposed method can effectively extract the Fenglin and Fengcong landform units, and has an overall accuracy of 93.28%. The proposed method is simple and easy to implement and is expected to play an important role in the automatic extraction of similar landform units in the Karst area.展开更多
The imbalance between supply and demand of Artemia cysts in China and around the world is increasing now.Salt lakes in Tibet may contribute to the solution of the problem.In Northern Tibet there are 26 saline lakes wh...The imbalance between supply and demand of Artemia cysts in China and around the world is increasing now.Salt lakes in Tibet may contribute to the solution of the problem.In Northern Tibet there are 26 saline lakes whose salinity and temperature may support Artemia survival at an altitude of 4 000–5 100 m.We found Artemia in 15 of these lakes.The saline lakes with Artemia populations mainly belong to the shallow basin lakes,and the majority of these lakes are small in area.The total area of lakes without Artemia is more than 1 000 km 2.Lake Dangxiong Co(Co means lake in Tibet) was chosen for the intentional introduction of Artemia sinica.In 2004,850 g of A.sinica cysts,originating from Qinghai,were introduced in the lake.Surveys in 2006–2014 showed that the average abundance of Artemia adults in the lake gradually increased from 20 ind./m 3 in 2006 to 1950 ind./m 3 in 2013.We assume that two subpopulations of A.sinica,separated by depth,may exist in the lake.The new Artemia population caused an increase in the number of species of phytoplankton and heterotrophic protozoa with a decrease of their total abundance.Water transparency also increased.Dominance in phytoplankton passed from cyanobacteria to diatoms.Changes occurred not only in the lake ecosystem;the number of water birds using the lakes also dramatically increased.Preliminary calculations showed that is it possible to harvest at least about 150 t cysts per year from the lake as well as 3.2 thousand tons of frozen or 350 t of dried biomass of adult Artemia.展开更多
Purpose: The purpose of this study was to examine, using meta-analytic measures, the evidence regarding the optimal exercise intensity at which improvements in speed of cognitive function are triggered. Specifically,...Purpose: The purpose of this study was to examine, using meta-analytic measures, the evidence regarding the optimal exercise intensity at which improvements in speed of cognitive function are triggered. Specifically, it was hypothesized that the catecholamine, lactate, and ventilatory thresholds is the point at which significant improvements in speed of cognitive function are observed. Methods: We compared mean effect sizes for threshold studies and for those studies where exercise intensity was classed as moderate (40%-- 79% VO2 or equivalent) but in which the thresholds were not measured. Results: Random effects meta-analysis showed significant, moderate, mean effect sizes for studies at the threshold (g = 0.58, Z = 2.98, p 〈 0.003) and for those during moderate intensity exercise but in which the threshold was not measured ( g = 0.54, Z = 5.0l, p 〈 0.001). There was no significant difference between mean effect sizes, which suggests that the thresholds are unlikely to represent a trigger point. Conclusion: Moderate intensity exercise, even below the thresholds, can induce improved speed of cognition, possibly due to a combination of increased peripheral catecholamine concentrations inducing vagal/nucleus tractus solitarii pathway activation and central increases due to perceptions of stress.展开更多
Objective To examine the relationship between Tpeak- Tend interval (Tpe) and Tpe/QT ratio with occurrence of ventricular premature beats (VPBs) and left ventricular remodeling in hypertension. Methods A total of 5...Objective To examine the relationship between Tpeak- Tend interval (Tpe) and Tpe/QT ratio with occurrence of ventricular premature beats (VPBs) and left ventricular remodeling in hypertension. Methods A total of 52 patients with mild to moderate essential hypertension were included, undergoing echocardiography and 24-hours Holter monitoring. Ventricular remodeling was assessed by left ventricular mass index (LVMI) using the Devereux formula and diastolic fimction by transmitral E and A wave velocities and E/A ratio. Tpe was measured in the precordial leads. The end of the T wave was set by the method of the tangent to the steepest descending slope of the T wave. Results Tpe and Tpe/QT in leads V2 (r = 0.33, P = 0.01; r = 0.27, P = 0.04 respectively) and V3 (r = 0.40, P = 0.002; r = 0.40, P = 0.003, respectively) correlated significantly with LVMI. A significant inverse relationship was observed between E/A ratio and QT (r = -0.33, P = 0.01), Tpe in V3 (r = -0.39, P = 0.003) and Tpe/QT in V3 (r = -0.31, P = 0.02). Tpe in V3, V5, mean Tpe and maximum Tpe with cut-offvalues of 60 ms, 59 ms, 62 ms and 71 ms, respectively, associated with the occurrence of ventricular premature beats. Conclusions The repolarization parameters Tpe interval and Tpe/QT ratio correlate with LVMI and indices of left ventricular diastolic function and show better predictive values than traditional parameters such as QT interval and QT dispersion. Lead V3 is the best lead for measuring Tpe and Tpe/QT. These ECG indices can therefore be used in clinical practice to monitor LV remodeling and predict occurrence of VPBs.展开更多
Desertification, soil salinization and grassland degradation are the major environmental hazards faced by the Gannan Plateau, northeastern Tibetan Plateau. Ecological risk assessment plays an important role in formula...Desertification, soil salinization and grassland degradation are the major environmental hazards faced by the Gannan Plateau, northeastern Tibetan Plateau. Ecological risk assessment plays an important role in formulating environmental management strategies yet little attention to this region. In this study, we established an ecological risk assessment index system based on 30 evaluation indices in the categories of hydrometeorology, ecological environment, ground surface disturbance, and society and economy for the Gannan Plateau. An entropy method was used to calculate an index weight,and subsequently the matter-element method was used together with extension theory to establish a matter-element extension model of ecological risk. We assessed the ecological risk in this region by calculating the degree of association between index layer, system layer and target layer, and the cumulative ecological risk index. The degrees of ecological risk for the counties of the region were determined by using Arc GIS which would represent a spatial heterogeneity of the risk grade in production. Our results showed that the areas of high ecological risk were in Zhouqu County and Zhuoni County, and others were of low risk(Hezuo City, Diebu County, Xiahe County and Lintan County) or intermediate risk(Maqu County). The results of the assessment were in accord with the actual observed situation. Thus, our ecological risk assessment index system is appropriate for this region and suggests that high risk counties need a priori ecological protection. Such research could provide a technological support which would potentially prevent or reduce disasters by establishing an ecological barrier to promote the sustainable development of Gannan Plateau.展开更多
AIM:To determine the efficacy and success of percutaneous aspiration irrigation and reaspiration(PAIR) in the management of hepatic hydatidosis.METHODS:Twenty-six patients with 32 hepatic hydatid cysts had PAIR.Twenty...AIM:To determine the efficacy and success of percutaneous aspiration irrigation and reaspiration(PAIR) in the management of hepatic hydatidosis.METHODS:Twenty-six patients with 32 hepatic hydatid cysts had PAIR.Twenty-two patients received at least 2 wk of drug therapy before the procedure was carried out to reduce the risk of recurrence from spillage during the procedure.The procedure was performed under local anesthesia with a 19-gauge 20 cm long needle,the cyst was punctured,cystic content(approximately 30 mL) was aspirated by a 12-14 F pigtail catheter and aspirated fluids were sent for analysis.Once the cyst was almost empty,two-thirds of the net amount of material aspirated was replaced by hypertonic saline and left in the cavity for about 30 min,with the catheter left in place for reaspiration of most of the fluid.When the amount of fluid drained was less than 10 mL per 24 h,the drainage catheter was removed.RESULTS:All 32 cysts showed evidence of immediate collapse after completion of the procedure,and before discharge from hospital,ultrasound examination showed fluid reaccumulation in all cysts.Serial follow-up showed a progressive decrease in the size and change in the appearance of cysts.To confirm the sterility of these cystic cavities,seven cysts were reaspirated on average 3 mo after the procedure.Investigations revealed no viable scolices.CONCLUSION:PAIR using hypertonic saline is very effective and safe with proper precautions.展开更多
Chemical ablation of the gallbladder is effective in patients at high risk of complications after surgery. Percutaneous gallbladder drainage is an effective treatment for cholecystitis; however, when the drain tube ca...Chemical ablation of the gallbladder is effective in patients at high risk of complications after surgery. Percutaneous gallbladder drainage is an effective treatment for cholecystitis; however, when the drain tube cannot be removed because of recurrent symptoms, retaining it can cause problems. An 82-year-old woman presented with cholecystitis and cholangitis caused by biliary stent occlusion and suspected tumor invasion of the cystic duct. We present successful chemical ablation of the gallbladder using pure alcohol, through a percutaneous gallbladder drainage tube, in a patient who developed intractable cholecystitis with obstruction of the cystic duct after receiving a biliary stent. Our results suggest that chemical ablation therapy is an effective alternative to surgical therapy for intractable cholecystitis.展开更多
In this paper, based on the analysis of satellite measurements, the authors conclude that the continuous seasonal droughts intensify the browning of woody vegetation and that evergreen needleleaf forest(ENF) shows a l...In this paper, based on the analysis of satellite measurements, the authors conclude that the continuous seasonal droughts intensify the browning of woody vegetation and that evergreen needleleaf forest(ENF) shows a larger browning percentage than other woody vegetation types over Yunnan Province. Based on the Tropical Rainfall Measuring Mission(TRMM) precipitation standardized anomaly, in the dry season, which is from October to March, the 2010 drought affected an area of Yunnan Province 1.77 times larger than the 2012 drought, but in the post-drought months(April to June), the browning area of all woody vegetation in 2012 was 1.11 times larger than that in 2010 on the basis of the enhanced vegetation index(EVI) standardized anomaly. The reduction of vegetation greenness over large areas of Yunnan Province represents a photosynthetic capacity loss which will have an impact on carbon fluxes to the atmosphere.展开更多
Recent advances in broadband technology have caused forwarding engines to handle pack- ets with over 10 gigabit per second. In this paper, we present a high-speed forwarding pipeline which can finish all of the routin...Recent advances in broadband technology have caused forwarding engines to handle pack- ets with over 10 gigabit per second. In this paper, we present a high-speed forwarding pipeline which can finish all of the routing and forwarding tasks in the way of pipelining. We also establish the analysis model of the pipeline with which one can evaluate some key performance parameters of the forwarding engine such as forwarding rate and forwarding delay. We find that the pipeline is of good scalability and can forward unicast packets up to the speed of 40Gbit/s.展开更多
文摘离析数字学术、数字人文、人文计算三大主题,分别以CNKI和Web of Science数据简析了三大主题的高引论文特征,研究揭示:国内发文较国际发文具有一定的滞后性,国内研究在开创性和探索性方面存在不足。共被引网络体现的关联性中文高引论文高于外文高引论文,其中数字学术与数字人文两个主题的关联性较强,而数字学术与人文计算的关联性较弱;引文网络则体现三主题间的耦合都较弱。数字人文作为三大主题中最活跃的主题值得持续关注。
文摘目的:本文以呼吸医学为切入点,分析呼吸医学高引文作者群体及其选刊的10年对比,分析相对高影响力研究等作者选刊所看重的期刊特征。方法:检索科睿唯安Web of Science数据库中,呼吸系统高被引论文(Highly cited papers)。使用Citespace工具,对过去10年高被引文的趋势进行分析。结果:亚洲及南美国家的高引文数量均有明显增加。《柳叶刀·呼吸医学》的影响力逐渐增强。创刊10年,能快速崛起的原因,可能在于《柳叶刀》的品牌化效应,及其高质量的审稿等因素。结论:注重期刊的品牌建设,提高审稿效率和质量,能增加医学期刊对高质量研究的吸引力。
文摘[Objective] The aim was to explore the special methods for amplification of large-family genes by using primers with high degeneracy.[Method] By using the primers with high degeneracy,conventional PCR,conventional touchdown PCR and the optimized abnormal touchdown PCR were respectively carried out to amplify the genomic DNA of Cyprinus carpio.[Result] Only one evident electrophoretic band and a few Sox genes were obtained by using normal PCR;no obvious electrophoretic band but dispersive product was obtained by normal touchdown PCR;ideal result was obtained by the abnormal touchdown PCR that three evident electrophoretic bands and much more Sox genes were amplified.[Conclusion] The research provided theoretical basis for the optimization and selection of PCR amplification conditions of the large-family genes.
基金Supported by Natural Science Foundation of Ningxia Autonomous Re-gion(A1012)~~
文摘[Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B on maize and providing scientific reference to make proper countermeasures. [ Method] The location test in field and lift lamp of UV-B were used to observe the changes of maize height, leaf area and number of green leaves under influences of different UV-B radiation. [ Result] In arid regions of middle-high elevation, enhanced ultraviolet radiation-B could dwarf maize plant, decrease leaf area, decline number of green leaves and yield. The reason of decreasing leaf area was that enhanced ultraviolet radiation-B shortened leaf length and leaf width while the reason of declining yield was that yield components were all negatively influ- enced and with the increase of ultraviolet radiation-B, the yield declined dramatically. [ Concluslonl The result of this experiment would be good for maize production in arid regions of middle-high elevation.
基金supported by the National Natural Science Foundation of China (NO. 41601411, 41671389, 41571398, 41701449) Open Fund of State Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University (Grant No. 17S02) A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions-PAPD (Grant No. 164320H101)
文摘The Fenglin and Fengcong landform units are considered to be an important representation for defining the degree of development of Karst landforms. However, these terrain features have been proven difficult to delineate and extract automatically because of their complex morphology. In this paper, a new method for identifying the Fenglin and Fengcong landform units is proposed. This method consists of two steps:(1) terrain openness calculation and(2) toe line extraction. The proposed method is applied and validated in the Karst case area of Guilin by using ASTER GDEM with one arc-second resolution. The openness of both the positive and negative terrain and a threshold were used to extract toe lines for segmenting depressions and pinnacles in Fenglin and Fengcong landforms. A comparison between the extracted Fenglin and Fengcong landform units and their real units from high resolution images wascarried out to evaluate the capability of the proposed method. Results show the proposed method can effectively extract the Fenglin and Fengcong landform units, and has an overall accuracy of 93.28%. The proposed method is simple and easy to implement and is expected to play an important role in the automatic extraction of similar landform units in the Karst area.
基金Supported by the Special Fund for Public Welfare Land and Resources(No.201011001-4)the Project of China Geological Survey(No.1212011120982)
文摘The imbalance between supply and demand of Artemia cysts in China and around the world is increasing now.Salt lakes in Tibet may contribute to the solution of the problem.In Northern Tibet there are 26 saline lakes whose salinity and temperature may support Artemia survival at an altitude of 4 000–5 100 m.We found Artemia in 15 of these lakes.The saline lakes with Artemia populations mainly belong to the shallow basin lakes,and the majority of these lakes are small in area.The total area of lakes without Artemia is more than 1 000 km 2.Lake Dangxiong Co(Co means lake in Tibet) was chosen for the intentional introduction of Artemia sinica.In 2004,850 g of A.sinica cysts,originating from Qinghai,were introduced in the lake.Surveys in 2006–2014 showed that the average abundance of Artemia adults in the lake gradually increased from 20 ind./m 3 in 2006 to 1950 ind./m 3 in 2013.We assume that two subpopulations of A.sinica,separated by depth,may exist in the lake.The new Artemia population caused an increase in the number of species of phytoplankton and heterotrophic protozoa with a decrease of their total abundance.Water transparency also increased.Dominance in phytoplankton passed from cyanobacteria to diatoms.Changes occurred not only in the lake ecosystem;the number of water birds using the lakes also dramatically increased.Preliminary calculations showed that is it possible to harvest at least about 150 t cysts per year from the lake as well as 3.2 thousand tons of frozen or 350 t of dried biomass of adult Artemia.
文摘Purpose: The purpose of this study was to examine, using meta-analytic measures, the evidence regarding the optimal exercise intensity at which improvements in speed of cognitive function are triggered. Specifically, it was hypothesized that the catecholamine, lactate, and ventilatory thresholds is the point at which significant improvements in speed of cognitive function are observed. Methods: We compared mean effect sizes for threshold studies and for those studies where exercise intensity was classed as moderate (40%-- 79% VO2 or equivalent) but in which the thresholds were not measured. Results: Random effects meta-analysis showed significant, moderate, mean effect sizes for studies at the threshold (g = 0.58, Z = 2.98, p 〈 0.003) and for those during moderate intensity exercise but in which the threshold was not measured ( g = 0.54, Z = 5.0l, p 〈 0.001). There was no significant difference between mean effect sizes, which suggests that the thresholds are unlikely to represent a trigger point. Conclusion: Moderate intensity exercise, even below the thresholds, can induce improved speed of cognition, possibly due to a combination of increased peripheral catecholamine concentrations inducing vagal/nucleus tractus solitarii pathway activation and central increases due to perceptions of stress.
文摘Objective To examine the relationship between Tpeak- Tend interval (Tpe) and Tpe/QT ratio with occurrence of ventricular premature beats (VPBs) and left ventricular remodeling in hypertension. Methods A total of 52 patients with mild to moderate essential hypertension were included, undergoing echocardiography and 24-hours Holter monitoring. Ventricular remodeling was assessed by left ventricular mass index (LVMI) using the Devereux formula and diastolic fimction by transmitral E and A wave velocities and E/A ratio. Tpe was measured in the precordial leads. The end of the T wave was set by the method of the tangent to the steepest descending slope of the T wave. Results Tpe and Tpe/QT in leads V2 (r = 0.33, P = 0.01; r = 0.27, P = 0.04 respectively) and V3 (r = 0.40, P = 0.002; r = 0.40, P = 0.003, respectively) correlated significantly with LVMI. A significant inverse relationship was observed between E/A ratio and QT (r = -0.33, P = 0.01), Tpe in V3 (r = -0.39, P = 0.003) and Tpe/QT in V3 (r = -0.31, P = 0.02). Tpe in V3, V5, mean Tpe and maximum Tpe with cut-offvalues of 60 ms, 59 ms, 62 ms and 71 ms, respectively, associated with the occurrence of ventricular premature beats. Conclusions The repolarization parameters Tpe interval and Tpe/QT ratio correlate with LVMI and indices of left ventricular diastolic function and show better predictive values than traditional parameters such as QT interval and QT dispersion. Lead V3 is the best lead for measuring Tpe and Tpe/QT. These ECG indices can therefore be used in clinical practice to monitor LV remodeling and predict occurrence of VPBs.
基金supported by the Soft Science Project of Gansu province(1504ZKCA090-1)the National Natural Science Foundation of china(grant nos.41671516,41701623,51369003)+2 种基金the Foundation for Excellent Youth Scholars of NIEER,CAS,National Natural Science Foundation of China(Grant No.41661144046)supported by the Special Foundation for Gansu Province International Scientific Cooperation(1604WKCA002)the Fundamental Research Funds for the Central Universities(lzujbky-2015-K10,lzujbky-2016-862516,lzujbky-2017-it90)
文摘Desertification, soil salinization and grassland degradation are the major environmental hazards faced by the Gannan Plateau, northeastern Tibetan Plateau. Ecological risk assessment plays an important role in formulating environmental management strategies yet little attention to this region. In this study, we established an ecological risk assessment index system based on 30 evaluation indices in the categories of hydrometeorology, ecological environment, ground surface disturbance, and society and economy for the Gannan Plateau. An entropy method was used to calculate an index weight,and subsequently the matter-element method was used together with extension theory to establish a matter-element extension model of ecological risk. We assessed the ecological risk in this region by calculating the degree of association between index layer, system layer and target layer, and the cumulative ecological risk index. The degrees of ecological risk for the counties of the region were determined by using Arc GIS which would represent a spatial heterogeneity of the risk grade in production. Our results showed that the areas of high ecological risk were in Zhouqu County and Zhuoni County, and others were of low risk(Hezuo City, Diebu County, Xiahe County and Lintan County) or intermediate risk(Maqu County). The results of the assessment were in accord with the actual observed situation. Thus, our ecological risk assessment index system is appropriate for this region and suggests that high risk counties need a priori ecological protection. Such research could provide a technological support which would potentially prevent or reduce disasters by establishing an ecological barrier to promote the sustainable development of Gannan Plateau.
文摘AIM:To determine the efficacy and success of percutaneous aspiration irrigation and reaspiration(PAIR) in the management of hepatic hydatidosis.METHODS:Twenty-six patients with 32 hepatic hydatid cysts had PAIR.Twenty-two patients received at least 2 wk of drug therapy before the procedure was carried out to reduce the risk of recurrence from spillage during the procedure.The procedure was performed under local anesthesia with a 19-gauge 20 cm long needle,the cyst was punctured,cystic content(approximately 30 mL) was aspirated by a 12-14 F pigtail catheter and aspirated fluids were sent for analysis.Once the cyst was almost empty,two-thirds of the net amount of material aspirated was replaced by hypertonic saline and left in the cavity for about 30 min,with the catheter left in place for reaspiration of most of the fluid.When the amount of fluid drained was less than 10 mL per 24 h,the drainage catheter was removed.RESULTS:All 32 cysts showed evidence of immediate collapse after completion of the procedure,and before discharge from hospital,ultrasound examination showed fluid reaccumulation in all cysts.Serial follow-up showed a progressive decrease in the size and change in the appearance of cysts.To confirm the sterility of these cystic cavities,seven cysts were reaspirated on average 3 mo after the procedure.Investigations revealed no viable scolices.CONCLUSION:PAIR using hypertonic saline is very effective and safe with proper precautions.
文摘Chemical ablation of the gallbladder is effective in patients at high risk of complications after surgery. Percutaneous gallbladder drainage is an effective treatment for cholecystitis; however, when the drain tube cannot be removed because of recurrent symptoms, retaining it can cause problems. An 82-year-old woman presented with cholecystitis and cholangitis caused by biliary stent occlusion and suspected tumor invasion of the cystic duct. We present successful chemical ablation of the gallbladder using pure alcohol, through a percutaneous gallbladder drainage tube, in a patient who developed intractable cholecystitis with obstruction of the cystic duct after receiving a biliary stent. Our results suggest that chemical ablation therapy is an effective alternative to surgical therapy for intractable cholecystitis.
基金funded by the National Basic Research Program of China (Grant No. 2012CB956202)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05090200)
文摘In this paper, based on the analysis of satellite measurements, the authors conclude that the continuous seasonal droughts intensify the browning of woody vegetation and that evergreen needleleaf forest(ENF) shows a larger browning percentage than other woody vegetation types over Yunnan Province. Based on the Tropical Rainfall Measuring Mission(TRMM) precipitation standardized anomaly, in the dry season, which is from October to March, the 2010 drought affected an area of Yunnan Province 1.77 times larger than the 2012 drought, but in the post-drought months(April to June), the browning area of all woody vegetation in 2012 was 1.11 times larger than that in 2010 on the basis of the enhanced vegetation index(EVI) standardized anomaly. The reduction of vegetation greenness over large areas of Yunnan Province represents a photosynthetic capacity loss which will have an impact on carbon fluxes to the atmosphere.
基金Supported by the National High Technology Research and Development Program of China (No.2003AA103510).
文摘Recent advances in broadband technology have caused forwarding engines to handle pack- ets with over 10 gigabit per second. In this paper, we present a high-speed forwarding pipeline which can finish all of the routing and forwarding tasks in the way of pipelining. We also establish the analysis model of the pipeline with which one can evaluate some key performance parameters of the forwarding engine such as forwarding rate and forwarding delay. We find that the pipeline is of good scalability and can forward unicast packets up to the speed of 40Gbit/s.