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1.
目的:探讨姜黄素预处理对沙漠干热环境腹部枪弹伤动物模型生存时间的影响。方法:将24头长白仔猪随机分为2组(n=12):姜黄素预处理组和对照组。姜黄素预处理组给予长白仔猪姜黄素100 mg/kg拌料饲养,每天1次,连续7天,对照组给予常规饲料喂养。第8天,将两组猪放入西北特殊环境人工实验舱内,设置环境温度(40.5±0.5)℃,相对湿度(10±2)%,禁食水,放置3小时后建立腹部枪弹伤模型,模型成功后继续放在沙漠干热环境中,每10分钟检测体温变化,并计算长白仔猪的存活时间。结果:姜黄素预处理组平均存活时间为(85.27±2.39)min,对照组的动物模型平均生存时间为(60.10±3.25)min,姜黄素预处理组的生存时间平均比对照组延长约25 min,两组的Kaplan-Meier生存曲线经Log Rank检验具有显著性差异(P0.01)。建立腹部枪弹伤模型后,在相应时间点,姜黄素预处理组的体温明显低于未处理组(P0.01),姜黄素预处理组70 min时的体温与对照组50 min体温比较差异无统计学意义(P0.05)。结论:姜黄素预处理可明显提高干热环境下猪腹部枪弹伤模型的生存时间,体温升高可能是反映干热环境腹部枪弹伤后病程进展的重要指标。  相似文献   
2.
目的:研究除颤时间与心脏性猝死患者除颤复苏成功率的相关性。方法:选取2015年2月至2017年6月于我院接受除颤复苏治疗的心脏性猝死患者120例为研究对象。分析除颤时间与除颤复苏成功以及心功能舒张早期充盈峰速度(E峰)、左室射血分数(LVEF)、左心室舒张末期内径(LVEDD)以及E/舒张晚期充盈峰速度(A)水平的相关性。结果:电除颤时间2 min患者的复苏成功率为60.00%(21/35),显著高于电除颤时间2~5 min、5~10 min以及10 min患者的34.21%(13/38)、11.11%(3/27)、0.00%(0/20),而电除颤时间2~5 min患者的复苏成功率又显著高于电除颤时间5~10 min患者,差异均有统计学意义(均P0.05)。电除颤时间2 min、2~5 min、5~10 min以及10 min患者的E峰、LVEF、LVEDD以及E/A水平呈逐渐下降趋势,差异均有统计学意义(均P0.05)。Pearson相关性分析结果显示心脏性猝死患者除颤时间与除颤复苏成功率、E峰、LVEF、LVEDD以及E/A均呈负相关关系(r=-0.593,P=0.000;r=-0.476,P=0.001;r=-0.523,P=0.000;r=-0.502,P=0.000;r=-0.469,P=0.001)。结论:除颤时间与心脏性猝死患者除颤复苏成功率呈负相关关系,即除颤时间越早,患者复苏成功率越高。  相似文献   
3.
Data integration and visualization are crucial to obtain meaningful hypotheses from the diversity of ‘omics’ fields and the large volume of heterogeneous and distributed data sets. In this review we focus on network analysis as a key technique to integrate, visualize and extrapolate relevant information from diverse data. We first describe challenges in integrating different types of data and then focus on systematically exploring network properties to gain insight into network function. We also describe the relationship between network structures and function of elements that form it. Next, we highlight the role of the interactome in connecting data derived from different experiments, and we stress the importance of network analysis to recognize interaction context-specific features. Finally, we present an example integration to demonstrate the value of the network approach in cancer research, and highlight the importance of dynamic data in the specific context of signaling pathways.  相似文献   
4.
Giardia lamblia is a unicellular, early branching eukaryote causing giardiasis, one of the most common human enteric diseases. Giardia, a microaerophilic protozoan parasite has to build up mechanisms to protect themselves against oxidative stress within the human gut (oxygen concentration 60 μM) to establish its pathogenesis. G. lamblia is devoid of the conventional mechanisms of the oxidative stress management system, including superoxide dismutase, catalase, peroxidase, and glutathione cycling, which are present in most eukaryotes. NADH oxidase is a major component of the electron transport chain of G. lamblia, which in concurrence with disulfide reductase, protects oxygen-labile proteins such as pyruvate: ferredoxin oxidoreductase against oxidative stress by sustaining a reduced intracellular environment. It also contains the arginine dihydrolase pathway, which occurs in a number of anaerobic prokaryotes, includes substrate level phosphorylation and adequately active to make a major contribution to ATP production.  相似文献   
5.
In a series of laboratory experiments, acclimated pupae of Tuta absoluta were exposed to various constant low temperatures in order to estimate their maximum survival times (Kaplan–Meier, Lt99.99). A Weibull function was fitted to the data points, describing maximum survival time as a function of temperature. In another experiment at ?6°C, the progress of mortality increasing with exposure time was identified. These values were fitted by a sigmoidal function converging asymptotically to 100% mortality for very long exposure times. Analysing mortality data from the maximum survival experiment by a generalized linear model showed a significant common slope parameter (p < .001) that reveals parallelism of the survival curves at each temperature if a log time axis is used. These curves appear stretched (time scaled) if plotted with a nonlogarithmic time axis. By combining these mathematical relations, it was possible to calculate a species‐specific ‘mortality surface’ which exhibits mortalities, depending on temperature and duration of exposure. In order to accumulate hourly mortalities for courses of varying temperatures, an algorithm was developed which yields mortality values from that surface taking into account the attained mortality level. In validation experiments, recorded mortalities were compared against modelled mortalities. Prediction of mortality was partially supported by the model, but pupae experiencing intensely fluctuating temperatures showed decreased mortality, probably caused by rapid cold hardening during exposure. Despite this observation, mortality data converged to distinct levels very close to 100% depending on the intensity of temperature fluctuations that were characteristic for different types of experiments. The highest mortality limit occurred at intensely fluctuating temperatures in laboratory experiments. This constituted a benchmark that was not reached under various field conditions. Thus, it was possible to identify temperature limits for the extinction of field populations of Tuta absoluta pupae.  相似文献   
6.
Climate change is expected to alter precipitation patterns worldwide, which will affect streamflow in riverine ecosystems. It is vital to understand the impacts of projected flow variations, especially in tropical regions where the effects of climate change are expected to be one of the earliest to emerge. Space‐for‐time substitutions have been successful at predicting effects of climate change in terrestrial systems by using a spatial gradient to mimic the projected temporal change. However, concerns have been raised that the spatial variability in these models might not reflect the temporal variability. We utilized a well‐constrained rainfall gradient on Hawaii Island to determine (a) how predicted decreases in flow and increases in flow variability affect stream food resources and consumers and (b) if using a high temporal (monthly, four streams) or a high spatial (annual, eight streams) resolution sampling scheme would alter the results of a space‐for‐time substitution. Declines in benthic and suspended resource quantity (10‐ to 40‐fold) and quality (shift from macrophyte to leaf litter dominated) contributed to 35‐fold decreases in macroinvertebrate biomass with predicted changes in the magnitude and variability in the flow. Invertebrate composition switched from caddisflies and damselflies to taxa with faster turnover rates (mosquitoes, copepods). Changes in resource and consumer composition patterns were stronger with high temporal resolution sampling. However, trends and ranges of results did not differ between the two sampling regimes, indicating that a suitable, well‐constrained spatial gradient is an appropriate tool for examining temporal change. Our study is the first to investigate resource to community wide effects of climate change on tropical streams on a spatial and temporal scale. We determined that predicted flow alterations would decrease stream resource and consumer quantity and quality, which can alter stream function, as well as biomass and habitat for freshwater, marine, and terrestrial consumers dependent on these resources.  相似文献   
7.
李文卿  江源  赵守栋  张凌楠  刘锬 《生态学报》2017,37(10):3365-3374
研究利用在六盘山地区采集的油松树轮样芯建立树轮宽度标准年表(STD),分别与不同长度时间单元(月、半月、旬)和多时间尺度的标准化降水指数(SPIn)序列进行相关性分析。油松标准年表与不同长度时间单元SPI的相关结果显示,较小的时间单元会使相关性表达更加精确,而时间单元过小则会因为数据波动性增大而导致相关关系弱化。因此,相较于月和旬,半月是相关性分析更为合适的时间单元长度。油松标准年表与多时间尺度SPI的相关结果显示,SPI多时间尺度的特性有助于揭示油松径向生长对不同时间尺度水分状况的响应特征,且油松在不同生长时期对于不同时间尺度水分状况具有相异的响应机制。在温度较低(0℃)的冬季,短时间内的降水并不利于树木生长,而长时间良好的水分储备会为树木生长季需水提供保障;在生长季前期,长时间良好的水分状况比短期内的降水更有利于树木的生长;在生长季,补给性水分和土壤水分都对树木生长起着至关重要的作用。  相似文献   
8.
The decoupling of the retention time of easily degradable and persistent substances relieves the degradation process from inhibitors and increases the biogas yield. Anaerobic digestion of maize silage was investigated in a pilot‐scale plant with a coupled ultrafiltration membrane. The aim of the study was the evaluation of the influence of the membrane‐based relief of the degradation process and the increase of the retention time of persistent substances. For that purpose, the fermenter content was separated into solid and liquid fractions. The solid fraction was recirculated to the fermenter for longer retention time and higher substrate degradation rates. The fermentation process was improved by the removal of the liquid fraction and adding volatile fatty acids. The results showed an increase of the biogas yield by 7.2% in comparison to the anaerobic digestion without membrane filtration.  相似文献   
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