|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Patterns of above-and belowground biomass allocation in China's grasslands:Evidence from individual-level observations显示文摘Above-and belowground biomass allocation not only influences growth of individual plants,but also influences vegetation structures and functions,and consequently impacts soil carbon input as well as terrestrial ecosystem carbon cycling.However,due to sampling difficulties,a considerable amount of uncertainty remains about the root:shoot ratio(R/S),a key parameter for models of terrestrial ecosystem carbon cycling.We investigated biomass allocation patterns across a broad spatial scale.We collected data on individual plant biomass and systematically sampled along a transect across the temperate grasslands in Inner Mongolia as well as in the alpine grasslands on the Tibetan Plateau.Our results indicated that the median of R/S for herbaceous species was 0.78 in China's grasslands as a whole.R/S was significantly higher in temperate grasslands than in alpine grasslands(0.84 vs.0.65).The slope of the allometric relationship between above-and belowground biomass was steeper for temperate grasslands than for alpine.Our results did not support the hypothesis that aboveground biomass scales isometrically with belowground biomass.The R/S in China's grasslands was not significantly correlated with mean annual temperature(MAT) or mean annual precipitation(MAP).Moreover,comparisons of our results with previous findings indicated a large difference between R/S data from individual plants and communities.This might be mainly caused by the underestimation of R/S at the individual level as a result of an inevitable loss of fine roots and the overestimation of R/S in community-level surveys due to grazing and difficulties in identifying dead roots.Our findings suggest that root biomass in grasslands tended to have been overestimated in previous reports of R/S. | WANG Liang*,NIU KeChang,YANG YuanHe & ZHOU Peng Department of Ecology,Key Laboratory for Earth Surface Processes of the Ministry of Education,Peking University,Beijing 100871,China. | 2010 | Science China(Life Sciences)2010，53，7： | 54 |
| 2 | Carbon density and distribution of six Chinese temperate forests显示文摘Quantifying forest carbon(C) storage and distribution is important for forest C cycling studies and terrestrial ecosystem modeling.Forest inventory and allometric approaches were used to measure C density and allocation in six representative temperate forests of similar stand age(42-59 years old) and growing under the same climate in northeastern China.The forests were an aspen-birch forest,a hardwood forest,a Korean pine plantation,a Dahurian larch plantation,a mixed deciduous forest,and a Mongolian oak forest.There were no significant differences in the C densities of ecosystem components(except for detritus) although the six forests had varying vegetation compositions and site conditions.However,the differences were significant when the C pools were normalized against stand basal area.The total ecosystem C density varied from 186.9 tC hm-2 to 349.2 tC hm-2 across the forests.The C densities of vegetation,detritus,and soil ranged from 86.3-122.7 tC hm-2,6.5-10.5 tC hm-2,and 93.7-220.1 tC hm-2,respectively,which accounted for 39.7% ± 7.1%(mean ± SD),3.3% ± 1.1%,and 57.0% ± 7.9% of the total C densities,respectively.The overstory C pool accounted for > 99% of the total vegetation C pool.The foliage biomass,small root(diameter < 5mm) biomass,root-shoot ratio,and small root to foliage biomass ratio varied from 2.08-4.72 tC hm-2,0.95-3.24 tC hm-2,22.0%-28.3%,and 34.5%-122.2%,respectively.The Korean pine plantation had the lowest foliage production efficiency(total biomass/foliage biomass:22.6 g g-1) among the six forests,while the Dahurian larch plantation had the highest small root production efficiency(total biomass/small root biomass:124.7 g g-1).The small root C density decreased with soil depth for all forests except for the Mongolian oak forest,in which the small roots tended to be vertically distributed downwards.The C density of coarse woody debris was significantly less in the two plantations than in the four naturally regenerated forests.The variability of C allocation patterns in a specific forest is jointly influenced by vegetation type,management history,and local water and nutrient availability.The study provides important data for developing and validating C cycling models for temperate forests. | ZHANG QuanZhi & WANG ChuanKuan* College of Forestry,Northeast Forestry University,Harbin 150040,China | 2010 | Science China(Life Sciences)2010，53，7： | 36 |
| 3 | Restoring the Treg cell to Th17 cell ratio may alleviate HBV-related acute-on-chronic liver failure显示文摘AIM: To investigate the role of T helper 17 cells (Th17) and regulatory T cells (Treg) in hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF).METHODS: We enrolled 79 patients with HBV infection into the study, 50 patients with HBV-related ACLF and 29 patients with chronic hepatitis B (CHB), from the First Affiliated Hospital of Medical College from January 2009 to June 2012. The ACLF patients were diagnosed according to the criteria recommended by The 19th Conference of the Asian Pacific Association for the Study of the Liver in 2009. Twenty healthy individuals with a similar gender and age structures to the two patient groups were also included as the normal controls (NC). Of the 50 ACLF patients, 28 were subsequently classified as non-survivors: 19 patients died from multiorgan failure, 3 underwent liver transplantation, and 6 discontinued therapy during follow-up because of financial reasons. The remaining 22 ACLF patients whose liver and anticoagulation function recovered to nearly normal levels within the next 6 mo were classified as survivors. The number of circulating Treg and Th17 cells was determined upon diagnosis and during the 8th week of follow-up through flow cytometry. RESULTS: The percentage of circulating Treg cells in the ACLF group was significantly higher than that in the CHB group (5.50% ± 1.15% vs 3.30% ± 1.13%, P < 0.01). The percentages of circulating Th17 cells in the ACLF and the CHB groups were significantly higher than that in the NC group (6.32% ± 2.22% vs 1.56% ± 0.44%, P < 0.01; 3.53% ± 1.65% vs 1.56% ± 0.44%, P < 0.01). No significant difference in Treg cell to Th17 cell ratio was observed between the ACLF group and the CHB group (0.98 ± 0.44 vs 1.12 ± 0.64, P = 0.991), whereas those in the two HBV infection groups were significantly lower than that in the NC group (1.85 ± 1.22; both P < 0.01). The percentage of Treg cells in the survivors during the 8th week of follow-up was significantly lower than that during peak ACLF severity [total bilirubin (TBIL) peak] (3.45% ± 0.97% vs 5.18% ± 1.02%, P < 0.01). The percentage of Th17 cells in survivors during the 8th week of follow-up was significantly lower than that during the peak TBIL (2.89% ±0.60% vs 5.24% ± 1.46%; P < 0.01). The Treg cell to Th17 cell ratio during the 8 th week of follow-up was significantly higher than that during the TBIL peak (1.22 ± 0.36 vs 1.10 ± 0.54; P < 0.05). CONCLUSION: Restoring the Treg cell to Th17 cell ratio during the follow-up phase of ACLF could maintain the immune system at a steady state, which favours good prognosis. | Ying-Hua Niu Dong-Lin Yin Hong-Li Liu Rui-Tian Yi Yu-Cong Yang Hong-An Xue Tian-Yan Chen Shu-Lin Zhang Shu-Mei Lin Ying-Ren Zhao | 2013 | World Journal of Gastroenterology2013，19，26： | 36 |
| 4 | 超急性期脑梗死的多层螺旋CT灌注成像与脑卒中评分及预后相关性的研究显示文摘目的探讨超急性期脑梗死的多层螺旋CT(MSCT)灌注成像与临床神经功能缺损评分及预后的相关性。方法对25例临床拟诊大脑半球缺血的患者,在发病6h内进行MSCT灌注成像,同时由临床医师进行脑卒中评分(NIHSS);于30~40d后对其中23例患者进行随访。分析影像检查结果与临床的相关性。结果(1)NIHSS初的线性回归方程为:Y=-3.12+6.70X1+0.001X2+4.21X3,其中X1为并发症(无并发症X1=1,有并发症X1=2)(t=4.77,P=0.000),X2为脑血流量图所示缺血面积(面积CBF)(t=2.69,P=0.015),X3为缺血部位(大脑前动脉或大脑后动脉X3=1,大脑中动脉X3=2)(t=2.44,P=0.026);(2)NIHSS终的线性回归方程为:Y=2.62+6.26X1-0.23X2,其中X1为并发症(无并发症X1=1,有并发症X1=2)(t=4.15,P=0.001),X2为缺血程度(t=-2.64,P=0.016);(3)缺血脑组织可恢复比率(potentialrecuperationratio,PRR)=面积半暗带/(面积半暗带+面积梗死),与神经功能恢复比率(NIHSS差/NIHSS初)有相关关系(r=0.502,P=0.020)。结论NIHSS评分与面积CBF无相关关系,而与多种因素有关,非单一因素所决定;PRR可以预测半暗带并提示临床预后,为临床治疗提供有价值的信息。 | 陈涓 刘银红 赵斌 周诚 杨正汉 | 2005 | 中华放射学杂志2005，39，4： | 36 |
| 5 | Supersonic flow imaging via nanoparticles显示文摘Due to influence of compressibility,shock wave,instabilities,and turbulence on supersonic flows, current flow visualization and imaging techniques encounter some problems in high spatiotemporal resolution and high signal-to-noise ratio(SNR)measurements.Therefore,nanoparticle based planar laser scattering method(NPLS)is developed here.The nanoparticles are used as tracer,and pulse planar laser is used as light source in NPLS;by recording images of particles in flow field with CCD, high spatiotemporal resolution supersonic flow imaging is realized.The flow-following ability of nanoparticles in supersonic flows is studied according to multiphase flow theory and calibrating experiment of oblique shock wave.The laser scattering characteristics of nanoparticles are analyzed with light scattering theory.The results of theoretical and experimental studies show that the dynamic behavior and light scattering characteristics of nanoparticles highly enhance the spatiotemporal resolution and SNR of NPLS,with which the flow field involving shock wave,expansion,Mach disk,boundary layer,sliding-line,and mixing layer can be imaged clearly at high spatiotemporal resolution. | ZHAO YuXin YI ShiHe TIAN LiFeng CHENG ZhongYu | 2009 | Science China(Technological Sciences)2009，52，12： | 31 |
| 6 | 鼎湖山针阔混交林旱季能量平衡研究显示文摘运用涡度相关(Eddy covariance,EC)法开路系统、常规微气象观测系统及土壤热通量板等设施对鼎湖山季风常绿阔叶林旱季(2003/1/9-2003/1/23)的能量分量进行测定。结果表明,平均净辐射通量(Netradiation,Rn)为53.14Wm-2,与下行短波辐射具有相同的变化趋势。林冠上层EC法潜热通量(Latentheat,LE)、显热通量(Sensibleheat,Hs)实测平均值分别为57.18Wm-2、43.40Wm-2,林冠下层分别为12.61Wm-2、7.61Wm-2。白昼EC法所测得的LE和Hs数据与利用波文比-能量平衡法(Bowenratioandenergybalance,BREB)计算出的数据相比,略偏低,而夜间及凌晨数据差异较大。土壤热通量日变化曲线呈“S”形,平均土壤热通量为-1.50Wm-2,表面土壤总热通量(Gt)仅为5cm处土壤热通量的84.0%,可见表层土壤尽管很薄,但其热储量不能忽略。将LE、Hs之和与可供能量(Rn-Gt)进行闭合,回归直线斜率为0.9128,相关系数达0.8517,与许多研究结果的60%-90%的区间相符,这说明鼎湖山涡度相关法通量观测数据是非常可靠的。 | 王旭 尹光彩 周国逸 闫俊华 SUN Ge 王春林 | 2005 | 热带亚热带植物学报2005，13，3： | 26 |
| 7 | Association of type 2 diabetes mellitus and the risk ofcolorectal cancer: A meta-analysis and systematic review显示文摘AIM To provide a quantitative assessment of theassociation between type 2 diabetes mellitus (T2DM)and the risk of colorectal cancer (CRC).METHODS: Systematic review was conductedthorough MEDLINE, EMBASE, Cochrane Library, and ISI Web of knowledge databases till 31st January 2014.This meta-analysis included the cohort studies thatillustrated relative risk (RR) or odds ratio estimateswith 95%CI for the predictive risk of CRC by T2DM.Summary relative risks with 95%CI were analyzed byusing an effects summary ratio model. Heterogeneityamong studies was assessed by the Cochran's Q and I 2statistics.RESULTS: The meta analysis of 8 finally selectedstudies showed a positive correlation of T2DM withthe risk of CRC as depicted by effects summary RRof 1.21 (95%CI: 1.02-1.42). Diabetic women showedgreater risk of developing CRC as their effect summaryRR of 1.22 (95%CI: 1.01-49) with significant overallZ test at 5% level of significance was higher than theeffect summary RR of 1.17 (95%CI: 1.00-1.37) of menshowing insignificant Z test. The effect summary RRof 1.19 with 95%CI of 1.07-1.33 indicate a positiverelationship between DM and increased risk of CRCwith significant heterogeneity (I 2 = 92% and P -value 〈0.05).CONCLUSION: Results from this systematic reviewand meta-analysis report that diabetic people have anincreased risk of CRC as compared to non-diabetics. | | 2015 | World Journal of Gastroenterology2015，21，19： | 26 |
| 8 | Effect of seawater on incident plane P and SV waves at ocean bottom and engineering characteristics of offshore ground motion records off the coast of southern California, USA显示文摘The effect of seawater on vertical ground motions is studied via a theoretical method and then actual offshore ground motion records are analyzed using a statistical method. A theoretical analysis of the effect of seawater on incident plane P and SV waves at ocean bottom indicate that on one hand, the affected frequency range of vertical ground motions is prominent due to P wave resonance in the water layer if the impedance ratio between the seawater and the underlying medium is large, but it is greatly suppressed if the impedance ratio is small; on the other hand, for the ocean bottom interface model selected herein, vertical ground motions consisting of mostly P waves are more easily affected by seawater than those dominated by SV waves. The statistical analysis of engineering parameters of offshore ground motion records indicate that:(1) Under the infl uence of softer surface soil at the seafl oor, both horizontal and vertical spectral accelerations of offshore motions are exaggerated at long period components, which leads to the peak spectral values moving to a longer period.(2) The spectral ratios(V/H) of offshore ground motions are much smaller than onshore ground motions near the P wave resonant frequencies in the water layer; and as the period becomes larger, the effect of seawater becomes smaller, which leads to a similar V/H at intermediate periods(near 2 s). These results are consistent with the conclusions of Boore and Smith(1999), but the V/H of offshore motion may be smaller than the onshore ground motions at longer periods(more than 5 s). | Diao Hongqi Hu Jinjun Xie Lili | 2014 | Earthquake Engineering and Engineering Vibration2014，13，2： | 24 |
| 9 | Hypoalbuminemia in colorectal cancer prognosis:Nutritional marker or inflammatory surrogate?显示文摘Albumin is the single most abundant protein in the human serum. Its roles in physiology and pathology are diverse. Serum albumin levels have been classically thought to reflect the nutritional status of patients. This concept has been challenged in the last two decades as multiple factors, such as inflammation, appeared to affect albumin levels independent of nutrition. In general, cancer patients have a high prevalence of hypoalbuminemia. As such, the role of hypoalbuminemia in patients with colorectal cancer has received significant interest. We reviewed the English literature on the prognostic value of pretreatment albumin levels in colorectal cancer. We also consolidated the evidence that led to the current understanding of hypoalbuminemia as an inflammatory marker rather than as a nutritional one among patients with colorectal cancer. | Bassel Nazha Elias Moussaly Mazen Zaarour Chanudi Weerasinghe Basem Azab | 2015 | World Journal of Gastrointestinal Surgery2015，7，12： | 22 |
| 10 | Prognostic significance of the fibrinogen-to-albumin ratio in gallbladder cancer patients显示文摘AIM To investigate the prognostic role of fibrinogen-toalbumin ratio(FAR) on patients with gallbladder cancer(Gbc) in this study.METHODS One hundred and fifty-four Gbc patients were retro-spectively analyzed, who received potentially curative cholecystectomy in our institute from March 2005 to December 2017. Receiver operating characteristic curve(ROc curve) was used to determine the optimal cut-offs for these biomarkers. In addition, Kaplan-Meier survival analysis as well as multivariate analysis were applied for prognostic analyses.RESULTS ROc curve revealed that the optimal cut-off value for FAR was 0.08. FAR was significantly correlated with age(P = 0.045), jaundice(P < 0.001), differentiation(P = 0.002), resection margin status(P < 0.001), T stage(P < 0.001), TNM stage(P < 0.001), and c A199(P < 0.001) as well as albumin levels(P < 0.001). Multivariate analysis indicated that the resection margin status [hazard ratio(HR): 2.343, 95% confidence interval(c I): 1.532-3.581, P < 0.001], TNM stage(P = 0.035), albumin level(HR = 0.595, 95%c I: 0.385-0.921, P = 0.020) and FAR(HR: 2.813, 95%c I: 1.765-4.484, P < 0.001) were independent prognostic factors in Gbc patients.CONCLUSION An elevated preoperative FAR was significantly correlated with unfavorable overall survival in Gbc patients, while an elevated preoperative albumin level was a protective prognostic factor for patients with Gbc. The preoperative FAR could be used to predict the prognosis of Gbc patients, which was easily accessible, costeffective and noninvasive. | Wei-Yu Xu Hao-Hai Zhang Jian-Ping Xiong Xiao-bo Yang Yi bai Jian-Zhen Lin Jun-Yu Long Yong-chang Zheng Hai-Tao Zhao Xin-Ting Sang | 2018 | World Journal of Gastroenterology2018，24，29： | 23 |
| 11 | Prognostic and survival analysis of 837 Chinese colorectal cancer patients显示文摘AIM:To develop a prognostic model to predict survival of patients with colorectal cancer (CRC). METHODS:Survival data of 837 CRC patients undergoing surgery between 1996 and 2006 were collected and analyzed by univariate analysis and Cox proportional hazard regression model to reveal the prognostic factors for CRC. All data were recorded using a standard data form and analyzed using SPSS version 18.0 (SPSS, Chicago, IL, United States). Survival curves were calculated by the Kaplan-Meier method. The log rank test was used to assess differences in survival. Univariate hazard ratios and significant and independent predictors of disease-specific survival and were identified by Cox proportional hazard analysis. The stepwise procedure was set to a threshold of 0.05. Statistical significance was defined asP < 0.05. RESULTS:The survival rate was 74% at 3 years and 68% at 5 years. The results of univariate analysis suggested age, preoperative obstruction, serum carcinoembryonic antigen level at diagnosis, status of resection, tumor size, histological grade, pathological type, lymphovascular invasion, invasion of adjacent organs, and tumor node metastasis (TNM) staging were positive prognostic factors (P < 0.05). Lymph node ratio (LNR) was also a strong prognostic factor in stage Ⅲ CRC (P < 0.0001). We divided 341 stage Ⅲ patients into three groups according to LNR values (LNR1, LNR ≤ 0.33, n = 211; LNR2, LNR 0.34-0.66, n = 76; and LNR3, LNR ≥ 0.67, n = 54). Univariate analysis showed a significant statistical difference in 3-year survival among these groups:LNR1, 73%; LNR2, 55%; and LNR3, 42% (P < 0.0001). The multivariate analysis results showed that histological grade, depth of bowel wall invasion, and number of metastatic lymph nodes were the most important prognostic factors for CRC if we did not consider the interaction of the TNM staging system (P < 0.05). When the TNM staging was taken into account, histological grade lost its statistical significance, while the specific TNM staging system showed a statistically significant difference (P < 0.0001). CONCLUSION:The overall survival of CRC patients has improved between 1996 and 2006. LNR is a powerful factor for estimating the survival of stage Ⅲ CRC patients. | Ying Yuan Mo-Dan Li Han-Guang Hu Cai-Xia Dong Jia-Qi Chen Xiao-Fen Li Jing-Jing Li Hong Shen | 2013 | World Journal of Gastroenterology2013，19，17： | 20 |
| 12 | Grinding temperature and energy ratio coefficient in MQL grinding of high-temperature nickel-base alloy by using different vegetable oils as base oil显示文摘Vegetable oil can be used as a base oil in minimal quantity of lubrication(MQL). This study compared the performances of MQL grinding by using castor oil, soybean oil, rapeseed oil, corn oil, sunflower oil, peanut oil, and palm oil as base oils. A K-P36 numerical-control precision surface grinder was used to perform plain grinding on a workpiece material with a high-temperature nickel base alloy. A YDM–III 99 three-dimensional dynamometer was used to measure grinding force,and a clip-type thermocouple was used to determine grinding temperature. The grinding force, grinding temperature, and energy ratio coefficient of MQL grinding were compared among the seven vegetable oil types. Results revealed that(1) castor oil-based MQL grinding yields the lowest grinding force but exhibits the highest grinding temperature and energy ratio coefficient;(2) palm oil-based MQL grinding generates the second lowest grinding force but shows the lowest grinding temperature and energy ratio coefficient;(3) MQL grinding based on the five other vegetable oils produces similar grinding forces, grinding temperatures, and energy ratio coefficients, with values ranging between those of castor oil and palm oil;(4) viscosity significantly influences grinding force and grinding temperature to a greater extent than fatty acid varieties and contents in vegetable oils;(5) although more viscous vegetable oil exhibits greater lubrication and significantly lower grinding force than less viscous vegetable oil, high viscosity reduces the heat exchange capability of vegetable oil and thus yields a high grinding temperature;(6) saturated fatty acid is a more efficient lubricant than unsaturated fatty acid; and(7) a short carbon chain transfers heat more effectively than a long carbon chain. Palm oil is the optimum base oil of MQL grinding, and this base oil yields 26.98 N tangential grinding force,87.10 N normal grinding force, 119.6 °C grinding temperature, and 42.7% energy ratio coefficient. | Li Benkai Li Changhe Zhang Yanbin Wang Yaogang Jia Dongzhou Yang Min | 2016 | Chinese Journal of Aeronautics2016，29，4： | 20 |
| 13 | Changes in individual plant traits and biomass allocation in alpine meadow with elevation variation on the Qinghai-Tibetan Plateau显示文摘Plant traits and individual plant biomass allocation of 57 perennial herbaceous species,belonging to three common functional groups (forbs,grasses and sedges) at subalpine (3700 m ASL),alpine (4300 m ASL) and subnival (≥5000 m ASL) sites were examined to test the hypothesis that at high altitudes,plants reduce the proportion of aboveground parts and allocate more biomass to belowground parts,especially storage organs,as altitude increases,so as to geminate and resist environmental stress.However,results indicate that some divergence in biomass allocation exists among organs.With increasing altitude,the mean fractions of total biomass allocated to aboveground parts decreased.The mean fractions of total biomass allocation to storage organs at the subalpine site (7%±2% S.E.) were distinct from those at the alpine (23%±6%) and subnival (21%±6%) sites,while the proportions of green leaves at all altitudes remained almost constant.At 4300 m and 5000 m,the mean fractions of flower stems decreased by 45% and 41%,respectively,while fine roots increased by 86% and 102%,respectively.Specific leaf areas and leaf areas of forbs and grasses deceased with rising elevation,while sedges showed opposite trends.For all three functional groups,leaf area ratio and leaf area root mass ratio decreased,while fine root biomass increased at higher altitudes.Biomass allocation patterns of alpine plants were characterized by a reduction in aboveground reproductive organs and enlargement of fine roots,while the proportion of leaves remained stable.It was beneficial for high altitude plants to compensate carbon gain and nutrient uptake under low temperature and limited nutrients by stabilizing biomass investment to photosynthetic structures and increasing the absorption surface area of fine roots.In contrast to forbs and grasses that had high mycorrhizal infection,sedges had higher single leaf area and more root fraction,especially fine roots. | MA WeiLing1,2,SHI PeiLi1*,LI WenHua1,HE YongTao1,ZHANG XianZhou1,SHEN ZhenXi1 & CHAI SiYue1,2 1Lhasa National Ecological Research Station,Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China 2Graduate University of Chinese Academy of Sciences,Beijing 100049,China | 2010 | Science China(Life Sciences)2010，53，9： | 19 |
| 14 | THE PRECURSOR OF INSTABILITY FOR NONLINEAR SYSTEMS AND ITS APPLICATION TO EARTHQUAKE PREDICTION显示文摘By analysing the instability process of various nonlinear systems, we conclude that their instability precursors are the continual heightening of the response rate or response ratio.Applying this theory to earthquake prediction, we adopt the periodical change of the stress in crust caused by the tide-generating force as the loading and unloading. If we can measure the ratio of the response (such as crust deformation, gravity and seismicity) during the loading period to that during the unloading period, this parameter must contain some characteristic information about the seismogenic process.With nine earthquakes (M≥7) data that occurred in Chinese mainland during 1970-1988, we take the sum of square root o?energy of small earthquakes, which is called the released strain by Benioff, as the response to the tidal loading and unloading. We find that the response ratios of seven earthquakes increase obviously before the main earthquakes. | 尹祥础 尹灿 | 1991 | Science China Chemistry1991，34，8： | 19 |
| 15 | 基于Moldflow的薄壁注塑件的工艺参数的优化显示文摘运用Moldflow软件分析薄壁塑件的成形工艺,并结合正交试验法,对不同工艺条件下的薄壁注塑过程进行模拟.首先以模具温度、熔体温度、注射压力及注射速率为工艺参数水平,建立正交试验表L27,获得注塑时间,再以注射时间、保压压力、保压时间及冷却时间为工艺参数,建立正交试验表L9,获得塑件成型后的体积收缩率、翘曲量两个数值,对所得到的数值运用信噪比和方差分析方法来进行处理,确定最佳成形工艺参数组合.预测最优参数组合成型所得的体积收缩率和最大翘曲值,最后通过软件模拟验证其正确性. | 俞华英 金杰 吕圣 | 2008 | 浙江工业大学学报2008，36，4： | 19 |
| 16 | Platelet-to-lymphocyte ratio in the setting of liver transplantation for hepatocellular cancer: A systematic review and meta-analysis显示文摘AIM To perform a systematic review and meta-analysis on platelet-to-lymphocyte ratio(PLR) as a risk factor for post-transplant hepatocellular cancer(HCC) recurrence. METHODS A systematic literature search was performed using PubM ed. Participants of any age and sex, who underwent liver transplantation for HCC were considered following these criteria:(1) studies comparing pre-transplant low vs high PLR values;(2) studies reporting post-transplant recurrence rates; and(3) if more than one study was reported by the same institute, only the most recent was included. The primary outcome measure was set for HCC recurrence after transplantation. RESULTS A total of 5 articles, published between 2014 and 2017, fulfilled the selection criteria. As for the quality of the reported studies, all the investigated articles presented an overall high quality. A total of 899 cases were investigated: 718 cases(80.0%) were males. Three studies coming from European countries and one from Japan presented HCV as the main cause of cirrhosis. On the opposite, one Chinese study presented a greater incidence of HBV-related cirrhotic cases. In all the studies apart one, the PLR cut-off value of 150 was reported. At meta-analysis, high PLR value was associated with a significant increase in recurrence after transplantation(OR = 3.33; 95%CI: 1.78-6.25; P < 0.001). A moderate heterogeneity was observed among the identified studies according to the Higgins I^2 statistic value.CONCLUSION Pre-transplant high PLR values are connected with an increased risk of post-operative recurrence of hepatocellular cancer. More studies are needed for better clarify the biological mechanisms of this results. | Quirino Lai Fabio Melandro Zoe Larghi Laureiro Francesco Giovanardi Stefano Ginanni Corradini Flaminia Ferri Redan Hassan Massimo Rossi Gianluca Mennini | 2018 | World Journal of Gastroenterology2018，24，15： | 19 |
| 17 | Association of platelet to lymphocyte ratio with in-hospital major adverse cardiovascular events and the severity of coronary artery disease assessed by the Gensini score in patients with acute myocardial infarction显示文摘Background:The platelet to lymphocyte ratio(PLR)has recently emerged as a potential inflammatory biomarker and has been shown to be significantly associated with atherosclerotic coronary artery disease(CAD).Therefore,we aimed to explore the association of PLR with in-hospital major adverse cardiovascular events(MACEs)and the severity of CAD assessed by the Gensini score(GS)in patients with acute myocardial infarction(AMI)undergoing coronary angiography.Methods:A total of 502 patients with AMI consecutively treated at the Affiliated Hospital of Qingdao University(Qingdao,China)and underwent coronary angiography from August 2017 to December 2018 were recruited in this study.The demographic,clinical,angiographic characteristics,and laboratory parameters were collected.According to the presence of in-hospital MACEs,the included patients were divided into the MACE group(n=81)and the non-MACE group(n=421).Further,according to tertiles of the GS,the patients were classified into three groups:the low GS group(GS≤32 points,n=173),medium GS group(32 points | Xue-Ting Li Hao Fang Dong Li Feng-Qiang Xu Bin Yang Rui Zhang Yi An | 2020 | Chinese Medical Journal2020，，4： | 19 |
| 18 | Distribution of Rb and Sr in the Luochuan loess-paleosol sequence of China during the last 800 ka——Implications for paleomonsoon variations显示文摘The concentrations of Rb and Sr, and magnetic susceptibility in loess and paleosol samples from the Luochuan profile have been measured. The loess units deposited in different geological periods display a very similar pattern of Rb and Sr distribution while paleosol units exhibit a dramatic increase in the Rb/Sr ratio, ranging from 20% to 120% in increase amplitude. Owing to different geochemical behavior of the two elements, Rb appears to be immobile while Sr appears to be mobile in the processes of weathering and pedogenesis. So variations of the Rb/Sr ratio in the loess-paleosol sequences could reflect intensities of weathering and pedogenesis, thus recording the relative wind strength of the East Asian summer monsoon circulation. This could be supported by the high degree of correlation between the Rb/Sr ratio and the magnetic susceptibility. A continuous record of the Rb/Sr ratio in the Luochuan profile over the last 800 ka bears a striking resemblance to the δ18O curve of the deep sea | 陈骏 安芷生 汪永进 季峻峰 陈旸 鹿化煜 | 1999 | Science China Earth Sciences1999，42，3： | 19 |
| 19 | Theoretical analysis and experimental investigation on flexural performance of steel reinforced ultrahigh toughness cementitious composite (RUHTCC) beams显示文摘UHTCC (ultrahigh toughness cementitious composite), which is a kind of ultrahigh toughness cemen- titious composites material, exhibits pseudo strain hardening feature when subjected to tension load, and has enormous ductility and prominent crack dispersal ability. Accordingly, UHTCC can improve mechanical behavior of ordinary concrete structure especially its durability, and has been regarded as historical breakthrough to traditional cementitious materials. In this paper, the study focuses on flexure behavior of steel reinforced beam made of UHTCC. Based on the plane section assumption, along with two equilibrium equations of force and moment, the formulae to calculate the flexural load capability for the reinforced ultrahigh toughness cementitious composite (RUHTCC) beam were developed under the assumption that the compression stress- strain relationship in the UHTCC material is a bilinear model. Following this, the simplified formulae were further evolved by effective rectangle stress distribution approach in order to facilitate design of practical engineering. Two effective parameters introduced in effective rectangle approach were determined. The mathematical expressions to evaluate limited rein- forcement ratio, flexural stiffness as well as ductility index were proposed, too. Last, two series of dif- ferent reinforcement ratios of the RUHTCC beams were tested in four-point flexure loading. For com- parison purposes, ordinary RC (reinforced concrete) beams also were prepared. Both moment curva- ture curves and load mid-span displacement curves were recorded and compared with the theoretical calculations. A good agreement between them was found, which validates the proposed theoretical formulae. For ductility index, a slightly big difference between the experimental values and the calcu- lated ones exists. The experimental results show that, compared to control RC beams, the RUHTCC beam can improve both flexural capacity and ductility index, and the degree of improvement will de- crease with the increase in the reinforcement ratio. Particularly, the results also reveal that lager crack width in control beams can be greatly reduced by formation of tightly-spaced fine cracks in UHTCC, which offers more durable structures. | XU ShiLang ZHANG XiuFang | 2009 | Science China(Technological Sciences)2009，52，4： | 18 |
| 20 | 贺兰山保护区冬季岩羊集群特征的初步分析显示文摘Group size and composition of blue sheep(Pseudois nayaur)were studied in the Helan Mountains, Ningxia Autonomous Region from November to December 2003.We scanned mountain slopes with binoculars and observed with 20-60× spotting-scope. A total of 310 herds of blue sheep and 1 336 individuals were observed during the study period. Blue sheep were frequently seen in small herds of 2 to 8 individuals, which represent 94.8% of total herds observed. Herds consisting of 9 individuals or more represented 5.2%. The largest herd we observed numbered 51 individuals. Mean group size was 4.2 individuals. Blue sheep herds can be divided into three types: male herds (composed solely of males), female herds (consisting of females with or without juveniles of both sexes), and mixed herds (including adult males, females, and subadults).Among the 310 herds, female herds were counted 150 times(48.4%), mixed herds 154 times(49.7%), and male herds 6 times(1.9%). Of 1 336 blue sheep classified by sex and age, adults, subadults and juveniles composed 64.1%,20.8%, and 15.1% respectively. The female:male ratio of adults was 1∶0.73. The ratio of adult females to juveniles was 1∶0.56, which is higher than the ratio recorded in spring (1∶0.43) or summer (1∶0.44).The results showed that the Helan Mountains State Nature Reserve has succeed in protecting blue sheep. | 曹丽荣 刘振生 王小明 胡天华 翟昊 侯建海 | 2005 | 兽类学报2005，25，2： | 18 |
您所在的机构暂未开通此部分的功能，请联系管理员