Subjects: Biology >> Ecology submitted time 2017-04-26 Cooperative journals: 《生态学报》
Abstract：全球气候变化不仅包括平均气温上升，而且诸如热浪的极端天气事件出现的频率和程度也增大。寄生蜂虽在寄主体内完成生长发育，也会受到极端气温的影响。为探究短时高温对寄生性天敌斑痣悬茧蜂（Meteorus pulchricornis）幼虫发育表现的影响，以斜纹夜蛾（Spodoptera litura）幼虫为寄主，分别对1-6日龄子代蜂进行39℃、持续4h的高温胁迫处理，以发育全程进行适温（昼29℃、夜26℃）处理为对照，观察子代存活、发育历期、羽化和成虫寿命等发育指标。高温胁迫处理1日和5日龄子代蜂幼虫使幼虫存活率下降，与对照相比分别降低36.1%和28.6%；高温胁迫可延长子代蜂幼虫发育历期，与对照相比，高温处理2、3、5日和6日龄子代蜂幼虫使幼虫发育历期分别延长了5.0%，5.2%，7.0%和12.1%；高温胁迫处理5、6日龄子代蜂幼虫使羽化出的成虫体型（用后足胫节长度表示）比对照分别减小1.8%和2.6%。高温胁迫处理对子代蜂蛹发育历期、羽化率以及成虫寿命等均没有显著影响。研究结果说明，短时高温胁迫对斑痣悬茧蜂高龄幼虫的负面影响比对低龄幼虫大。
Subjects: Biology >> Ecology submitted time 2017-04-11 Cooperative journals: 《生态学报》
Abstract：种内和种间捕食卵现象常见于对食蚜瓢虫的研究报道中。源自亚洲、入侵北美和欧洲的异色瓢虫（Harmonia axyridis）由于卵含有生物碱而被认为可能是威胁本土瓢虫生存的原因，但该推测只有在明确异色瓢虫在原产地是否对本土瓢虫具有类似负面影响后，才能确证。通过饲喂实验，旨在明确异色瓢虫在原产地是否对本土七星瓢虫（Coccinella septempunctata）和龟纹瓢虫（Propylea japonica）具有食卵负面作用，为揭示异色瓢虫入侵机理提供依据。实验中用蚜虫（对照）和3种瓢虫卵对瓢虫初孵1龄幼虫进行饲喂处理，观察幼虫生长发育指标。对瓢虫初龄幼虫存活表现的分析结果表明：（1）龟纹瓢虫初孵幼虫取食同种卵和七星瓢虫卵后存活至2龄的比率均高于取食异色瓢虫卵的近7倍；（2）七星瓢虫幼虫取食异色瓢虫卵未存活到2龄，但取食其他瓢虫卵和蚜虫后85%以上个体存活至2龄；（3）异色瓢虫初孵幼虫取食同种和其他2种瓢虫卵后有90%以上存活至2龄。龟纹瓢虫和七星瓢虫1龄幼虫取食异种卵比同种卵后的发育历期显著延长，但异色瓢虫并未表现出差异。龟纹瓢虫和异色瓢虫1龄幼虫取食同种和异种卵后的体增重相同，但七星瓢虫取食龟纹瓢虫卵后体增重比取食同种卵减小。研究结果说明，异色瓢虫卵对七星瓢虫和龟纹瓢虫初孵幼虫的生存具有负面影响，反之不然。所以，取食异色瓢虫卵本身并非是导致北美和欧洲本土瓢虫数量减少的原因。
Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2022-10-28 Cooperative journals: 《中国全科医学》
Abstract： Background Esophageal and gastric variceal bleeding (EGVB) is one of the most common and dangerous complications of liver cirrhosis. However, whether EGVB affect the mortality of patients with cirrhosis during 1 year remains unclear. Objective To illustrate the influence factors of EGVB on the death of patients with liver cirrhosis within 1 year and further provide guidance for follow-up. Methods The clinical data of cirrhotic patients admitted to the Affiliated Changsha Central Hospital were collected from January 2015 to May 2021. Patients with liver cirrhosis were divided into two parts: EGVB group and control group without bleeding. Logistic Regression Analysis was conducted for screening factors affecting the death of patients during 1 year. Furthermore, the covariates of equilibrium between the two group were balanced by 1:2 Propensity Score Matching (PSM). Then, Univariate and Multivariate Logistic Regression were applied to identify the risk factors of death. Results Among 812 patients with cirrhosis included, 158 (19.5%) cases were diagnosed with EGVB, and other 654 (80.5%) cases had no EGVB. The 1-year mortality of EGVB and control group was 13.3% and 13.9%. There was no difference in 1-year mortality between the two groups. Before matching, Logistic regression analysis showed that serum sodium level [OR=0.95, 95%CI(0.90-0.99)] and Albumin level [OR=0.95, 95%CI(0.91-0.99)] were associated with decreased risk of 1-year death (P<0.05), while age [OR=1.04, 95%CI(1.02-1.06)] and hepatic encephalopathy (grade III-IV) [OR=3.72，95%CI(1.21-11.37)]were associated with increased risk (P<0.05). After matching, there was 145 cases in EGVB group and 290 cases in control group, and that 1-year mortality of both groups was 12.4%. Logistic regression analysis revealed that blood urea nitrogen (BUN) [OR=1.15, 95%CI(1.02-1.29)] was an independent risk factor for death during 1 year in EGVB group, while age [OR=1.09, 95%CI(1.04-1.14)] and neutrophil count/lymphocyte count (NLR) [OR=1.09，95%CI(1.00-1.18)] acted as the independent risk factor in control group without bleeding. Conclusion Whether EGVB happens or not has no obvious effect on the 1-year mortality of cirrhosis patients. However, there were considerable discrepancies of risk factors affecting the 1-year death between the two groups, which provides a new reference for clinical follow-up and treatment of patients with liver cirrhosis.
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究饲粮中添加稀土壳糖胺螯合盐（rare earth-chitosan chelate，RECC）对断奶仔猪生长性能、血清生化指标、营养物质消化率及粪中微生物菌群的影响。试验选取240头28日龄健康纯种大白仔猪，随机分成4组，每组4个重复，每个重复15头仔猪。对照组饲喂基础饲粮，试验组分别饲喂在基础饲粮中添加0.02%、0.03%和0.04% RECC的饲粮。试验期28 d。结果显示：1）与对照组相比，饲粮添加0.02%和0.03% RECC显著提高断奶仔猪平均日增重和平均日采食量（P0.05），但有降低大肠杆菌数的趋势。综上所述，饲粮中添加RECC可以通过提高断奶仔猪体内的激素含量、调节微生物平衡，进而改善仔猪的生长、免疫等功能，且RECC在断奶仔猪中较为适宜的添加量为0.02%。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究牛磺酸（Tau）对种公猪性欲、精液品质、血清激素含量及精浆抗氧化能力的影响。选用24头年龄、体重相近的健康成年大约克夏种公猪，随机分为4个组，每组6个重复，每个重复1头猪。各组分别饲喂牛磺酸添加水平为0（对照组）、2、4、6 g/kg的饲粮，试验期90 d，分为1~45 d和46~90 d 2个阶段。结果表明：1）试验46～90 d时，添加6 g/kg牛磺酸显著提高了种公猪的性欲（P<0.05）、采精量（P<0.01）、精子活力（P<0.05），4 g/kg牛磺酸改善了精子密度和精子畸形率（P<0.05）；2）与对照组相比，6 g/kg牛磺酸水平组极显著提高了种公猪血清促黄体素（LH）含量（P<0.01），显著提高了睾酮（T）含量（P<0.05）；3）试验46～90 d时，6 g/kg牛磺酸显著降低了种公猪精浆丙二醛（MDA）含量（P<0.05），显著提高了超氧化物歧化酶（SOD）活力（P<0.05），4 g/kg牛磺酸显著提高了谷胱甘肽过氧化物酶（GSH-Px）活力（P<0.05）。由此可见，饲粮中长期添加牛磺酸可以调控种公猪血清激素含量，增加精浆抗氧化能力，进而增强种公猪性欲，提高种公猪精液品质，本试验条件下牛磺酸适宜添加水平为6 g/kg。
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