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71.
生物资源在减轻植物病害中的作用、潜力及其利用对策   总被引:2,自引:0,他引:2  
论述了生物资源在减轻植物病害灾害和促进农业可持续发展中所具有的良好生态效益和经济效益 ,以及巨大开发潜力 ,讨论并提出了减轻植物病害中生物资源利用所面临的问题和应采取的对策  相似文献   
72.
The impact of a methanolic extract of Ocimum sanctum leaves on isoproterenol-induced myocardial damage and its mechanism of action on mitochondrial function in male rats has been investigated. Administration of isoproterenol caused increased oxidative stress and mitochondrial damage leading to decreased production of adenosine triphosphate. Pre-treatment with the extract reduced the generation of the reactive oxygen species and increased the antioxidant status compared to an isoproterenol-treated group. There was enhancement in the activities of tricarboxylic acid cycle enzymes, electron transport chain components, and adenosine triphosphate production in the mitochondria of the extract pre-treated rats. Mitochondrial membrane damage induced by isoproterenol was also reduced, as evidenced by the increased mitochondrial membrane potential, decreased mitochondrial Ca2+ overload, and reduced release of cytochrome c. Hence, O. sanctum can protect the heart from isoproterenol-induced cardiac damage.  相似文献   
73.
北京地区奥运会期间PM2.5对心脑血管疾病的影响   总被引:1,自引:0,他引:1  
为了探讨2008年奥运会前后减排和限行措施对北京居民心脑血管健康的影响,调查了2006~2010年7~9月的空气质量状况及北京急救中心心脑血管疾病日入院人数,采用时间序列方法中的非参数广义相加模型(GAM),在控制了长期趋势、"星期几效应"及气象因素的影响后,分析了北京PM2.5浓度与心脑血管疾病日入院人数的暴露-反应关系,并按性别、年份建立了模型.结果表明,PM2.5对心脑血管疾病的影响具有一定的滞后效应,全人群、男性和女性滞后均为0~2d,在2006~2010年7~9月中,2008年3个人群的RR均最小,2009年RR最大.PM2.5日均浓度每增加10μg/m3,2008年男性、女性及全人群日入院人数风险分别增加0.18%、0.07%和0.00%,2009年男性、女性及全人群日入院人数风险分别增加3.43%、2.10%和2.97%.2008年7~9月采取的相关政策措施对降低了北京地区居民心脑血管疾病的发病风险具有重要作用.  相似文献   
74.
卢兰  陈锐 《灾害学》1997,12(1):11-15,58
简述了耗散结构理论及其在植物病虫害防治工作中的适用性及运用方法。  相似文献   
75.
立足于目前农业生产上化学农药使用的现状,从“人—化学农药—作物病虫害”系统阐述了化学农药滥用所造成的危害和灾难,并剖析了发生灾难的主要原因.用事实说明了化学农药的利弊;指出使用者的素质是能否科学用药的关键.最后,提出了克服灾害的主要途径。  相似文献   
76.
/ A predictive model for assessing stand condition as a function of suitability for achieving specified management objectives was originally developed using a data set for only 28 stands. In this study, we evaluate the model using an operational-sized data set composed of currently collected stand inventory data for 238 stands in the Snowy Range of the Medicine Bow National Forest in southern Wyoming. We compared its predictions of old growth suitability to results of a separate special old growth survey. Stands were characterized as profiles of variables derived from stand inventory data, and plotted as points in two-dimensional space where similarity between stands was reflected by the distance between their points. Results suggest the model is useful for classifying stand condition using relatively large sets of data currently collected during routine stand inventories.  相似文献   
77.
78.
Polybrominated diphenyl ethers (PBDEs), widely used as flame retardants in commercial products, have become ubiquitous environmental contaminants. Although adult human exposure to PBDEs is well documented, developmental exposure is less well characterized. The objectives of this study were to measure maternal and fetal exposure to nine PBDE congeners and to investigate potential associations with birth weight. PBDE congeners were quantified in maternal serum at 24-28 weeks of pregnancy, delivery, and umbilical cord serum (UCS) by gas chromatography-mass spectrometry (GC/MS/MS). Complete blood sample sets were obtained from 97 pregnant women (mean age 33.1 ± 0.5 years). PBDE-28, -47 and -99 were quantified in all samples tested and PBDE-47 was the most abundant congener measured in both maternal (mid-pregnancy and delivery samples geometric mean = 26.9 and 26.9, respectively) and UCS (GM = 56.0 ng g−1 lipid). The UCS concentration for all congeners with the exception of PBDE-153 was higher vs. maternal delivery samples (< 0.001). Only the UCS concentration of PBDE-17 and -99 were significantly associated (β = −49.860, = 0.032, and β = −3.645, = 0.05) with birth weight. However, after adjustment for potential confounders only the association between PBDE-99 and birth weight remained significant (β = −3.951 and = 0.016). We conclude that: the fetus is exposed to PBDEs from at least the second trimester of pregnancy onward; PBDE congeners are higher in UCS compared to maternal serum samples collected at delivery; and that developmental PBDE exposure is potentially associated with lower birth weight.  相似文献   
79.
基于职业病报告数据的监测预警系统设计   总被引:3,自引:0,他引:3  
为了对单病种职业病的预防控制水平、某类职业病的预防控制水平进行动态评估和决策,运用信息监测预警的基本原理和理论,整理分析职业病报告数据,提出基于职业病报告的监测预警指标体系,构建出基于职业病报告数据的监测预警体系和运行模式。通过该监测预警系统的运行,可以科学的判断出应重点控制的职业病种(发病率高、发病工龄短、潜伏期短、病死率高、后果严重的职业病),应重点控制的高危地区、高危行业、高危工种、高危人群,针对具体职业病病种应重点控制的影响因素等。  相似文献   
80.
Abstract

The effects of low levels of diazinon treatment on four marker enzymes in rat heart and skeletal muscle have been investigated. Adult male Wistar rats were treated twice a week with a dose of 0.5 ml‐kg‐1day‐1 diazinon for 28 weeks. Diazinon treated rats gained significantly less weight than Sham‐treated controls. Typical differences in Succinate dehydrogenase (SDH), Lactate dehydrogenase (LDH), Phosphofructo kinase (PFK) and Hexokinase (HK) activities were observed between heart and skeletal muscles. Diazinon feeding had no effect on heart, soleus, gastrocnemius and plantaris SDH, LDH and PFK enzyme activities after 28 weeks. HK activity was significantly increased in sham‐control soieus and plantaris muscles after 28 weeks. Diazinon feeding inhibited HK activity in plantaris muscle after 28 weeks treatment These results demonstrate that chronic low levels of diazinon have little effect on the glycolytic and oxidative activity in heart and skeletal muscle.  相似文献   
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