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1.
Background: Cardiac-specific troponin T (cTnT) and troponin I (cTnI) are considered diagnostically equal in patients with acute coronary syndrome (ACS). The aim of this systematic review was to compare the prevalence and prognostic strength of elevations of cTnT and cTnI in patients with other conditions than ACS.

Methods: A systemic review was conducted in concordance with the PRISMA guidelines. The studies were identified by searching PubMed, EMBASE and Cochrane Central Register, from May to August 2016. Studies measuring both cTnT and cTnI in populations without ACS were eligible.

Results: Twenty-nine studies were included (n?=?25,859). Seventeen studies reported on prognostic information with follow-up time ranging for 30?d–5?years. Elevation above the 99th percentile (reference value for a healthy population) in non-ACS population was reported to be 0–39% for cTnI and 40–100% for cTnT. Elevation of cTnT tends to be a superior predictor for all-cause mortality and elevation of cTnI tends to be a superior predictor for cardiovascular related mortality.

Discussion: In the absence of ACS, elevation of cTnT is more frequent than elevation of cTnI.

Conclusion: Both cTnT and cTnI elevations have important prognostic information regarding morbidity, cardiac mortality and all-cause mortality.  相似文献   


2.
The metabolic performance of ectotherms is expected to be driven by the environment in which they live. Ecologically similar species with contrasting elevation distributions occurring in sympatry at mid‐elevations, provide good models for studying how physiological responses to temperature vary as a function of adaptation to different elevations. Under sympatry, at middle elevations, where divergent species ranges overlap, sympatric populations are expected to have similar thermal responses, suggesting similar local acclimation or adaptation, while observed differences would suggest adaptation to each species’ core range. We analysed the metabolic traits of sympatric species pairs from three ectotherm groups: reptiles (Reptilia: Lacertidae), amphibians (Amphibia: Salamandridae) and beetles (Coleoptera: Carabidae), living at different elevations, in order to test how adaptation to different elevations affects metabolic responses to temperature. We experimentally tested the thermal response of respiration rate (RR) and estimated potential metabolic activity (PMA) at three temperature regimes surrounding the groups’ optimal activity body temperatures. RR was relatively similar among groups and showed a positive response to increasing temperature, which was more pronounced in the high‐elevation species of reptiles and beetles. Relative to RR, PMA displayed a stronger and more consistent positive response to increased temperature in all three groups. For all three groups, the average biochemical capacity for metabolism (PMA) was higher in the range‐restricted, high‐elevation species, and this difference increased at higher temperatures in a consistent manner. These results, indicating consistent pattern in three independently evolved animal groups, suggest a ubiquitous adaptive syndrome and represent a novel understanding of the mechanisms shaping spatial biodiversity patterns. Our results also highlight the importance of geographic patterns for the mechanistic understanding of adaptations in physiological traits, including species’ potential to respond/adapt to global climate changes.  相似文献   

3.
刺梨低海拔引种栽培研究初报   总被引:2,自引:0,他引:2  
1993年2月从保靖县梅花乡海拔300m高的山地引进了一批大果形的刺梨枝条,在低海拔(45.5m)扦插繁殖,经过4个的栽培试验初步弄清了其物候期、结果习性及果实生长动态,为选育适应低海拔栽培的刺梨优良品种提供了科学依据。  相似文献   

4.
云丘山不同海拔梯度橿子栎叶性特征研究   总被引:1,自引:1,他引:0  
在吕梁山南段云丘山,以橿子栎为主要研究对象,采用野外调查和室内实验相结合的方法,对比叶面积(SLA)、叶面积(LA)、叶干物质含量(LDMC)、叶长宽比(L/W)、叶绿素含量(Chl)以及叶氮含量等有代表性的指标进行分析.结果表明:(1)随着海拔梯度的增加,橿子栎 L/W、Chl、SLA、LA、单位面积的叶氮含量(N area )、单位重量的叶氮含量(N mass )、叶饱和鲜重和叶干重均呈先上升后下降的趋势,在海拔1180 m 处有最大值;LDMC 与海拔呈显著负相关(P <0.05);(2)橿子栎 LA 与 SLA 和 N mass 呈极显著正相关关系(P <0.01),与 LDMC 呈显著负相关关系(P <0.05),与 N area呈极显著负相关关系(P <0.01);(3)橿子栎叶片 SLA与 L/W 呈显著正相关(P <0.05),与 N mass 呈极显著正相关关系(P <0.01),橿子栎叶片 SLA 与 LDMC 和N area呈显著负相关关系(P <0.05);(4)橿子栎 LDMC 与 N area 呈显著正相关(P <0.05).通过对云丘山景区橿子栎叶片性状随海拔变化规律的研究,可以探索橿子栎叶片性状与海拔梯度变化的关系以及最适生长环境,从而为景区橿子栎林的保护和抚育提供理论依据,为合理开发橿子栎林资源提供基础资料.  相似文献   

5.
通过采样调查法和烘干称量法检测了青藏高原东缘不同海拔种群波缘风毛菊(Saussurea undulata)花期与果期的形态特征, 研究了其花期与果期的资源分配, 并对花期花部特征对果期种子特征的影响作出分析。结果表明: 1)波缘风毛菊在花期将更多的资源投入繁殖器官, 而在果期增加了对种子的资源投资; 2)波缘风毛菊花期部分花部特征的变异导致其果期产生的种子随海拔升高数量减少、百粒重增加, 因为波缘风毛菊需要在高寒草甸的极端环境下保证每粒种子的存活能力, 因此采取了产生更少但更大种子的生存策略。  相似文献   

6.
秦岭太白山木本植物物种多样性的梯度格局及环境解释   总被引:37,自引:3,他引:34  
物种多样性沿环境梯度的分布格局是生物多样性研究的重要议题,而海拔梯度包含了各种环境因子的综合影响,因此对于探讨物种多样性沿环境梯度的分布格局具有重要意义。秦岭山脉地处我国暖温带向亚热带的过渡带,其植被垂直带和物种多样性分布格局对于研究我国南北部植被分异特征具有重要意义。基于对秦岭山脉太白山南北坡海拔1200—3750m之间的垂直样带调查的83个样方,本文利用植被数量分析方法(DCA和TWINSPAN)和Shannon-Wiener多样性指数、Pielou指数以及Jaccard相异性系数对太白山木本植物物种多样性在南北坡沿海拔梯度分布格局进行了初步研究。结果表明:太白山的木本植物群落具有明显的环境梯度格局,海拔是决定太白山植物群落分布的主要因素,而坡向起到次要作用一植物群落类型与坡向的关系不大,当考虑群落的环境梯度格局时,DCA第一轴主要与年均温密切相关,而第二轴则取决于年平均相对湿度:乔木层和灌木层的物种具有相似的海拔梯度格局,植物群落中木本植物物种丰富度和多样性随着海拔的升高单调下降;群落均匀度随着海拔变化的规律不明显;灌木层的物种多样性比乔木层更为丰富,而南坡具有比北坡更多的物种数和更高的多样性。相邻海拔之问群落的相异性在南北坡具有不同的分布格局,在北坡2800m以下,群落相异性沿海拔梯度变化不大,而在2800m以上的高海拔地区,群落相异性随海拔的升高而降低;在南坡,随着海拔的升高,群落相异性不断减少。太白山南坡群落比北坡分布更连续。  相似文献   

7.
Ilia from a known sex, race, and age sample of fetal and infant skeletons from the collections of the Smithsonian Institution were evaluated for six metric and one nonmetric characters. Three indices calculated from the measurements were analyzed. The nonmetric trait was examined for fit with known sex. The three indices failed to show significant sex differences. The nonmetric trait, Auricular Surface Elevation, proved dependable (91% accurate) for the male Fetal and Six Month age groups.  相似文献   

8.
Three bag experiments were performed in Cheat Lake, West Virginia, an acid lake, to determine whether a blue-green alga,Anabaena, could be introduced coupled with a pH change to neutrality and nutrient addition.  相似文献   

9.
利用九寨沟自然保护区内8条动物监测样线在2003—2010年的生态监测数据,分析了植被、海拔、人为干扰对大中型野生动物分布的影响,结果显示:1)本监测共记录到保护区内大中型野生动物26种,其中兽类18种,鸟类8种,属于我国Ⅰ级、Ⅱ级保护动物的分别有5种和11种。2)针阔混交林和针叶林是大中型野生动物种类最丰富的两种植被类型(分别有26种和17种),阔叶林和灌丛次之(分别为10种和12种),草地最少(2种)。3)海拔2400 m以下的地方,大中型野生动物种类稀少,为10种,2400—2599 m海拔段物种数增加至20种,之后随海拔上升物种丰富度下降。4)人为干扰显著影响大中型野生动物的空间分布:历史上的人类活动将原生森林植被转化为次生的落叶阔叶林、灌丛和草地,使树正、亚纳和尖盘等地下坡位(相对海拔0—199 m)的大中型野生动物的物种丰富度降低(分别为4、2、2种)。包括旅游活动和交通在内的人为干扰,可能导致附近50m海拔范围内保护动物的缺失,并使下坡位的某些物种向高海拔处移动。生境破碎化则使野生动物的种类组成发生改变,使原有森林内部优势种,如羚牛(Budorcas taxicolor),逐渐被适应能力强的物种,如豹猫(Prionailurus bengalensis)、雉鸡(Phasianuscolchicus)和野猪(Sus scrofa)等所取代,并将长期影响野生动物种群的存活。当前九寨沟自然保护区大中型野生动物的分布是植被、海拔与人为干扰综合作用的结果。  相似文献   

10.
祁连山中部地区树轮宽度年表特征随海拔高度的变化   总被引:33,自引:4,他引:29  
利用采自祁连山中部地区不同海拔高度的四个采样点的青海云杉树轮样芯 ,分别建立了树木年轮宽度年表。发现随海拔高度的上升 ,树轮宽度指数的振幅减小 ,年表的平均敏感性降低 ,样本间的一致性也逐步减小 ,上限年表与气候因子的相关性最低 ,这与目前大家普遍认同的上限树木的生长受温度控制的概念并不一致。进一步的分析表明 ,年表的敏感性随海拔高度降低主要是由于该区域树木生长的限制因子是春季降水 ,而降水随海拔高度的升高而增加 ,从而使得春季降水对树木生长的限制作用随海拔升高而逐步减弱 ;生物学指标的测定结果表明 ,生长在高海拔的树木对环境的生态适应策略发生变化 ,其生理代谢维持在较低水平 ,以避免环境变化带来的影响 ,因此生长在高海拔的青海云杉对环境变化的敏感性较差。  相似文献   

11.
淡黄香青叶面气孔对不同海拔高度的适应表现   总被引:1,自引:1,他引:0  
对比分析了分布于马衔山不同海拔高度的淡黄香青气孔复体的适应表现。结果表明:随海拔升高,植株叶片上气孔分布区域增大,叶两面气孔数量增加,气孔向外突起程度增加,孔下室及气孔张度增大。同时气孔每天的开放时间缩短。研究认为气孔复体的变化是淡黄香青适应高山低氧低二氧化碳分压的表现,同时也是植株因海拔升高造成的光合物质分配改变的结果。  相似文献   

12.
Elevation has long been considered a major influence on the evolution of life-history traits. Most elevation-induced variation in life history traits has been attributed to changes in climate, duration of breeding season, predation, and food limitation. I use a phylogenetic approach to show that life histories are closely associated with breeding elevation in extant cardueline finches. Finches at high elevations had smaller clutches, fewer broods, and longer incubation periods. Neither food limitation nor nest predation appear to readily account for this strong elevational variation in cardueline life histories. However, juvenile survival may be greater at higher elevations as a result of prolonged parental care and shorter natal dispersal and can potentially compensate for reduced fecundity in high-elevation finches. Received: 28 September 1996 / Accepted: 24 March 1997  相似文献   

13.
Acute coronary syndromes are usually classified on the basis of the presence or absence of ST elevation on the ECG: ST-elevation myocardial infarction or non-ST-elevation myocardial infarction (NSTEMI)patients with acute myocardial infarction (AMI) need immediate therapy, without unnecessary delay and primary percutaneous coronary intervention (PPCI) should preferably be performed within 90 min after first medical contact. However, in AMI patients without ST-segment elevation (pre) hospital triage for immediate transfer to the catheterisation laboratory may be difficult. Moreover, initial diagnosis and risk stratification take place at busy emergency departments and chest pain units with additional risk of ‘PPCI delay’. Optimal timing of angiography and revascularisation remains a challenge. We describe a patient with NSTEMI who was scheduled for early coronary angiography within 24 h but retrospectively should have been sent to the cath lab immediately because he had a significant amount of myocardium at risk, undetected by non-invasive parameters.  相似文献   

14.
目的:比较ST段抬高性和非ST段抬高性急性心肌梗死患者的冠状动脉病变特点。方法:选取100例在我院接受24h动态心电图和冠状动脉造影检查的急性心肌梗死患者,根据心电图结果分为观察组和对照组各50例。对照组为ST段抬高性心肌梗死(STEMI)患者,观察组为非ST段抬高性心肌梗死(NSTEMI)患者,比较两组患者冠状动脉病变的差异。结果:对照组LAD(左前降支)闭塞血管比例(52.00%)显著高于观察组(18.00%),差异具有统计学意义(P0.05)。对照组LCX(回旋支)闭塞血管比例(8.00%)显著低于观察组(50.00%),差异具有统计学意义(P0.05)。对照组RCA(右冠脉主干)闭塞血管比例(40.00%)和观察组(30.00%)比较,差异无统计学意义(P0.05)。对照组单支病变比例(46.00%)明显高于观察组(12.00%),对照组三支病变比例(20.00%)明显低于观察组(48.00%)比较,差异均具有统计学意义(P0.05)。对照组二支及正常血管比例与观察组比较,差异均无统计学意义(P0.05)。对照组罪犯血管狭窄程度在76%-90%、91%-99%及完全闭塞的比例与观察组比较差异均具有统计学意义(P0.05)。罪犯血管狭窄程度在50%及50%-75%时,两组差异无统计学意义(P0.05)。两组并发症发生情况比较,差异无统计学意义(P0.05)。结论:1NSTEMI罪犯血管闭塞以LCX多见,STEMI罪犯血管闭塞以LAD多见;2NSTEMI以三支血管病变较多见,STEMI以单支病变较多见。  相似文献   

15.
目的:探讨碘克沙醇注射液对介入治疗ST段抬高性心肌梗死患者治疗的有效性及安全性。方法:选取我院收治的介入ST段抬高性心肌梗死患者68例,根据选用的造影剂的不同,分为两组,每组各34例,其中对照组予碘普罗胺注射液,实验组予碘克沙醇注射液。治疗后,观察并比较两组患者的影像学质量,围手术期的不良反应,术前术后的肾功能情况。结果:治疗后,与对照组相比较,实验组的影像学质量明显改善(P0.05),围手术期不良反应显著减少(P0.05),肾功能改变不明显(P0.05),差异均有统计学意义。结论:碘克沙醇注射液对介入ST段抬高性心肌梗死患者治疗造影效果好,对患者的肾功能影响较低,更为安全有效,值得临床推广使用。  相似文献   

16.
刘天天  邓文洪 《生态学报》2015,35(8):2622-2627
2007年4月至7月,2007年12月至2008年1月,分别在北京市门头沟区小龙门森林公园、百花山自然保护区以及延庆县松山自然保护区,对同域分布的普通(Sitta europaea)和黑头(Sitta villosa)两种同域分布的类种群密度进行了调查。普通在小龙门森林公园、百花山自然保护区和松山自然保护区的种群密度分别是40.92、96.67只/km2和16.67只/km2。而黑头在上述3个调查区域的种群密度分别是2.03、16.67只/km2和23.33只/km2。普通的总体平均密度(51.4只/km2)高于黑头(20.68只/km2)。两种类分布的海拔和林型存在着差异。普通在海拔高度1070—1350 m的分布比较多。在海拔段1070—1250 m区间,普通的数量随海拔高度的增加呈递增的趋势。而黑头在海拔600—800 m分布较多,随着海拔高度的增加,种群数量呈递减趋势。普通主要分布在阔叶林和针阔混交林中,而黑头主要分布在针叶林中。  相似文献   

17.
Ultrasound is used extensively to monitor the growth of ovarian follicles in in vitro fertilization and embryo transfer (IVF-ET) programs, as well as to follow the progress of early pregnancy. There have been scattered reports in the literature that exposure to ultrasound may have an adverse effect on reproduction in the rat (Bologne et al: CR Soc Biol 177:381-387, 1983; Demoulin et al: Ann NY Acad Sci 442:146-152, 1985), and also in humans (Demoulin et al: Ann NY Acad Sci 442: 146-152, 1985). We report here that diagnostic levels of pulsed ultrasound did not affect either the number of embryos produced, or the ability to incorporate labelled precursors into DNA and RNA, respectively. Measurements of temperature elevation of ovaries exposed to ultrasound showed that neither controls nor experimental tissue exhibited temperature elevation greater than 1 degree C.  相似文献   

18.
Elevational gradients are powerful natural experiments for the investigation of ecological responses to changing climates. Automated modified Pennsylvania light traps were used to sample macro‐moth assemblages for three consecutive nights at each of 24 sites ranging from 200 m asl to 1200 m asl within continuous tropical rainforest at Eungella, Queensland, Australia (21°S, 148°E). A total of 13 861 individual moths representing approximately 713 morphospecies and 10 045 individuals belonging to approximately 607 morphospecies where sampled during November 2013 and March 2014 respectively. Moth assemblages exhibited a strong elevational signal during both sampling seasons; we grouped these into lowland and upland assemblages. The dispersal pattern of moth assemblages across the landscape reflected the stratification of vegetation communities across elevation and correlated with shifts in eco‐physical variables, most notably temperature and substrate organic matter. Regional historical biogeographical events likely contributed to the observed patterns. The analysis presented here identifies a set of statistically defined elevationally restricted moths which may be of use as part of a multi‐taxon predictor set for monitoring future ecosystem level changes associated with elevation and, by implication, with climate.  相似文献   

19.
Lizard distribution patterns were examined in relation to elevation in two undulating landscapes. We asked three specific questions: (1) Were different lizard species associated with particular elevations? (2) Did biological attributes of lizards (e.g. body size, colour, reproduction strategy, etc.) vary with elevation? (3) Did species richness of lizards vary with elevation? Field data were collected in two undulating production landscapes in south‐eastern Australia, approximately 100 km to the west of the Australian Capital Territory. Lizards were surveyed using 648 pitfall traps and 3840 m of drift fence. Both study landscapes were divided into 50 m elevation classes. For each elevation class, survey effort, the capture rate of individual species, and species richness were recorded. Correspondence analysis was used to sort lizards according to their altitudinal distribution profiles. Analysis of variance was used to examine if biological attributes of lizards were related to their altitudinal distribution profiles. Generalized linear modelling was used to relate elevation to the capture rate of individual species, and to species richness. Lizard species differed in their altitudinal preferences. Skinks, taxa with a Bassian distribution or distribution restricted to the Great Dividing Range, dark‐bodied species and viviparous species were more likely to inhabit high elevations. Elevation was significantly related to the capture rate of seven species, and ecologically similar species replaced one another as elevation increased. Species richness peaked significantly at intermediate elevations in both landscapes. We conclude that lizards were highly sensitive to elevation. Elevation changes of as little as 50 m may be related to a change in species richness or species composition. Future research should assess if reptiles in other undulating landscapes with a temperate climate are similarly sensitive to elevation. If so, conservation activities in these landscapes need to consider the full spectrum of topographic positions and elevations.  相似文献   

20.
How global warming will affect insect parasitoids and their role as natural enemies of insect pests is difficult to assess within a short period of time. Considering that elevation gradients can be used as analogues for global warming, we carried out meta-analyses of 27 correlations between parasitoid richness and elevation and 140 correlations between parasitism rate and elevation in natural and semi-natural environments. We also explored various covariates that may explain the observed responses. Both parasitism rates and parasitoid species richness significantly decreased with increasing elevation. The decrease was greater for ectoparasitoids and parasitoids of ectophagous insects than for endoparasitoids and parasitoids of endophagous hosts, possibly because these latter are better protected from adverse and extreme climatic conditions occurring at higher elevations. Although our results suggest an increase of parasitism with increasing temperature, other factors regulating herbivorous insects have to be considered before concluding that climate warming will lead to a decrease in pest density.  相似文献   

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