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991.
本文以蚕豆田间斑潜蝇及天敌复合生态系统为例,首先确定了复合生态系统中的昆虫种群,然后运用主成份分析方法对复合生态系统起主要作用的昆虫种群进行了分析,并进一步建立评价函数对复合生态系统各时期进行评分并排序,比较复合生态系统各时期复合体的大小,其结果可直接用于指导实践.  相似文献   
992.
记述采自四川1新种,李氏诺Rhopalopsole lii sp.nov.,并讨论了其与近似种的区别.模式标本保存在中国农业大学标本馆.  相似文献   
993.
Overwintering larvae of the Shonai ecotype of the rice stem borer, Chilo suppressalis, enter diapause in early September and terminate diapause at the end of October. Cold acclimation at 0°C did not influence glycerol, trehalose or glycogen content in larvae collected on 22 September. Acclimation at 0°C increased the glycerol content and reduced the glycogen content significantly in larvae collected on 2 October and 22 November compared with acclimation at 15°C. These results indicate that overwintering larvae at different phases of diapause development respond differently to the low temperature stimulus for glycerol synthesis. Thus, we evaluated the metabolic rearrangements associated with glycerol synthesis during diapause development and after temperature acclimation. Larvae collected on 2 October were acclimated at 15°C for 15 and 60 days. Some of those acclimated at 15°C were then moved to 0°C for 15 days. The larvae acclimated at 15°C for 15 days were in deep diapause and accumulated little glycerol, while larvae acclimated at 15°C for 60 days were nearly ready to emerge from diapause and accumulated glycerol at 155.5 μmol/g. When larvae acclimated to 15°C for 15 days were transferred to 0°C, glycerol accumulation was stimulated to the same extent (ca 140 μmol/g) as it was in larvae that were acclimated to 15°C for 60 days and then transferred to 0°C. These results indicate that low temperature has a cumulative effect on glycerol production in larvae at different phases of diapause development. Glycerol accumulation was accomplished by activation of glycogen phosphorylase and inhibition of fructose-1,6-bisphosphatase, and activation of enzymes associated with glycerol synthesis, mainly glyceraldehyde-3-phosphatase and polyol dehydrogenase with glyceraldehyde activity.  相似文献   
994.
长江江豚锌、铜、铅、镉和砷的摄入与累积   总被引:5,自引:2,他引:5  
根据室内饲养的3头长江江豚(Neophocaena phocaenoides asiaeorientalis)食物鲫(Carassius auratus)中锌(Zn)、铜 (Cu)、铅(Pb)、镉(Cd)、砷(As)的浓度值和饲养记录,推算出了饲养条件下江豚这些微量元素每日及每周估计摄入 量的范围。必需元素的需求方面与世界卫生组织/联合国粮农组织(WHO/FAO)提出的人暂定每周耐受摄人量 (PTWI)相类似,可是毒性较强的元素Cd、As、Pb的摄入量大大高于人体的PTWI。对湖北天鹅洲故道收集到的一头 江豚的10种组织、器官的研究发现,摄入后的Zn、Cu、Pb、Cd、As显示出有组织、器官选择性累积的倾向。这可能主 要与鲸类组织、器官对相应的元素有特殊的要求相关。本研究的结果还显示出有必要建立饲养鲸类动物食物安全 管理规范以控制食源污染。更深入地研究各组织、器官中微量元素与生命机能的关系,应该是鲸类动物微量元素 的营养化学和生态毒理学发展的重要方向之一。  相似文献   
995.
Summary A new cell line, designated IOZCAS-Ha-I, was initiated from the fat body of larvae of Helicoverpa armigera (Lepidoptera: Noctuidae) in TNM-FH medium containing 10% fetal bovine serum. Spherical cells were predominant among the various cell types. The cell line showed a typical lepidopteran chromosome pattern ranging from 58 to 239 chromosomes in the majority of the cells, it was confirmed to have originated from the H. armigera by the DNA amplification-fingerprinting polymerase chain reaction (DAF-PCR) technique. The new cell line was only slightly susceptible to the multiple nucleocapsid nuclear polyhedrosis viruses (NPV) from H. armigera.  相似文献   
996.
胚胎植入中白细胞介素-1的信号转导及其生理作用   总被引:1,自引:0,他引:1  
本文论述了白细胞介素-1(IL-1)的信号转导通路及其在胚胎植入中的调节作用。指出:植入过程中,IL-1起着十分重要的作用,但并非唯一的重要因子,成功的胚胎植入需要多种细胞因子的协同作用。  相似文献   
997.
Ding X  Li J  Hu J  Li Q 《Analytical biochemistry》2005,339(1):46-53
The direct electron transfer of surface-confined horse heart cytochrome c (Cyt c) was achieved using COOH-terminated alkanethiolate-modified gold electrode. Later DNA was immobilized on the two-layer modified electrode. The quantitative determination of DNA was explored and the interaction between cytochrome c and DNA was studied. The binding site sizes were determined to be 15 bp per Cyt c molecule with double-stranded (ds) DNA and 30 nucleotides binding one Cyt c molecule with single-stranded (ss) DNA. At the dsDNA/Cyt c/MUA/Au electrode, the rate constant of oxidation electron transfer k(s,ox)=1.59x10(-3)cms-1 was obtained, at the ssDNA/Cyt c/MUA/Au electrode, the value was 2.43x10(-3)ms-1 when the scan rate was 1.0V/s. The different electrodes were characterized with electrochemical quartz crystal microbalance and atomic force microscope.  相似文献   
998.

Introduction

Although AIDS-related deaths have had significant economic and social impact following an increased disease burden internationally, few studies have evaluated the cause of AIDS-related deaths among patients with AIDS on combination anti-retroviral therapy (cART) in China. This study examines the causes of death among AIDS-patients in China and uses a methodology to increase data accuracy compared to the previous studies on AIDS-related mortality in China, that have taken the reported cause of death in the National HIV Registry at face-value.

Methods

Death certificates/medical records were examined and a cross-sectional survey was conducted in three provinces to verify the causes of death among AIDS patients who died between January 1, 2010 and June 30, 2011. Chi-square analysis was conducted to examine the categorical variables by causes of death and by ART status. Univariate and multivariate logistic regression were used to evaluate factors associated with AIDS-related death versus non-AIDS related death.

Results

This study used a sample of 1,109 subjects. The average age at death was 44.5 years. AIDS-related deaths were significantly higher than non-AIDS and injury-related deaths. In the sample, 41.9% (465/1109) were deceased within a year of HIV diagnosis and 52.7% (584/1109) of the deceased AIDS patients were not on cART. For AIDS-related deaths (n = 798), statistically significant factors included CD4 count <200 cells/mm3 at the time of cART initiation (AOR 1.94, 95%CI 1.24–3.05), ART naïve (AOR 1.69, 95%CI 1.09–2.61; p = 0.019) and age <39 years (AOR 2.96, 95%CI 1.77–4.96).

Conclusion

For the AIDS patients that were deceased, only those who initiated cART while at a CD4 count ≥200 cells/mm3 were less likely to die from AIDS-related causes compared to those who didn’t initiate ART at all.  相似文献   
999.
Myostatin (MSTN), or growth and differentiation factor 8 (GDF8), is a member of the transforming growth factor (TGF)-β superfamily. This family functions as a negative regulator of skeletal muscle development and growth in mammals. Single-nucleotide polymorphisms in exon 1 of the Bian chicken myostatin gene were detected by polymerase chain reaction-restriction fragment length polymorphism. A mutation (c.234G>A) in exon 1 was found. Female Bian chickens of genotypes AA and GA had significantly higher body weights than those of genotype GG (P < 0.05 or P < 0.01) from 6 to 18 weeks of age. These results suggested that the mutation c.234G>A in exon 1 could be used as a genetic marker for Bian chicken growth traits.  相似文献   
1000.
O-GlcNAcylation is a post-translational modification that regulates a broad range of nuclear and cytoplasmic proteins and is emerging as a key regulator of various biological processes. Previous studies have shown that increased levels of global O-GlcNAcylation and O-GlcNAc transferase (OGT) are linked to the incidence of metastasis in breast cancer patients, but the molecular basis behind this is not fully known. In this study, we have determined that the actin-binding protein cofilin is O-GlcNAcylated by OGT and mainly, if not completely, mediates OGT modulation of cell mobility. O-GlcNAcylation at Ser-108 of cofilin is required for its proper localization in invadopodia at the leading edge of breast cancer cells during three-dimensional cell invasion. Loss of O-GlcNAcylation of cofilin leads to destabilization of invadopodia and impairs cell invasion, although the actin-severing activity or lamellipodial localization is not affected. Our study provides insights into the mechanism of post-translational modification in fine-tuning the regulation of cofilin activity and suggests its important implications in cancer metastasis.  相似文献   
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