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棉田动物群落动态及天敌与害虫种群之间的关系   总被引:1,自引:0,他引:1  
通过对棉田动物群落动态及天敌与害虫种群之间关系的系统研究,得出:l)棉田生物多样性指数越大,群落稳定性越高;2)龟纹瓢虫与棉蚜种群数量之间极相关,草间小黑株与棉蚜种群之间有相关关系,棉蚜及龟纹瓢虫种群增长为指数增长;3)棉蚜及其多种天敌在水平分布上均为聚集格局;4)棉蚜、龟纹瓢虫及草间小黑蛛在垂直分布上均为聚集格局,龟纹瓢虫对棉蚜聚集场所具有追随跟踪攻击作用.  相似文献   
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The chemical composition of the essential oil obtained by hydrodistillation from the aerial parts of Mentha haplocalyx was investigated by GC‐FID and GC/MS analyses. In sum, 23 components, representing 92.88% of the total oil composition, were identified, and the main compounds were found to be menthol (59.71%), menthyl acetate (7.83%), limonene (6.98%), and menthone (4.44%). By bioassay‐guided fractionation (contact toxicity), three compounds were obtained from the essential oil and identified as menthol, menthyl acetate, and limonene. The essential oil and the three isolated compounds exhibited potent contact toxicity against Lasioderma serricorne adults, with LD50 values of 16.5, 7.91, 5.96, and 13.7 μg/adult, respectively. Moreover, the oil and its isolated compounds also exhibited strong repellency against L. serricorne adults. At the lower concentrations tested and at 2 h after exposure, menthol showed even significantly stronger repellency than the positive control DEET. The study revealed that the bioactivity properties of the essential oil can be attributed to the synergistic effects of its diverse major and minor components, which indicates that the M. haplocalyx oil and its isolated compounds have potential for the development as natural insecticides and/or repellents to control insects in stored grains and traditional Chinese medicinal materials.  相似文献   
224.
Triple negative breast cancer (TNBC) is a more common type of breast cancer with high distant metastasis and poor prognosis. The potential role of lamins in cancer progression has been widely revealed. However, the function of lamin B2 (LMNB2) in TNBC progression is still unclear. The present study aimed to investigate the role of LMNB2 in TNBC. The cancer genome atlas (TCGA) database analysis and immunohistochemistry (IHC) were performed to examine LMNB2 expression levels. LMNB2 short hairpin RNA plasmid or lentivirus was used to deplete the expression of LMNB2 in human TNBC cell lines including MDA-MB-468 and MDA-MB-231. Alterations in cell proliferation and apoptosis in vitro and the nude mouse tumorigenicity assay in vivo were subsequently analyzed. The human TNBC tissues shown high expression of LMNB2 according to the bioinformation analysis and IHC assays. LMNB2 expression was correlated with the clinical pathological features of TNBC patients, including pTNM stage and lymph node metastasis. Through in vitro and in vivo assays, we confirmed LMNB2 depletion suppressed the proliferation and induced the apoptosis of TNBC cells, and inhibited tumor growth of TNBC cells in mice, with the decrease in Ki67 expression or the increase in caspase-3 expression. In conclusion, LMNB2 may promote TNBC progression and could serve as a potential therapeutic target for TNBC treatment.  相似文献   
225.
International Journal of Peptide Research and Therapeutics - The peptides YYGGEGSSSEQG and SESEM derived from rice α-globulin have been reported to possess anti-atherosclerotic activity, but...  相似文献   
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Fanconi anemia is a rare genetic disease characterized by bone marrow failure, multiple congenital malformations, and an increased susceptibility to malignancy. At least 15 genes have been identified that are involved in the pathogenesis of Fanconi anemia. However, it is still a challenge to assign the complementation group and to characterize the molecular defects in patients with Fanconi anemia. In the current study, whole exome sequencing was used to identify the affected gene(s) in a boy with Fanconi anemia. A recurring, non-synonymous mutation was found (c.3971C>T, p.P1324L) as well as a novel frameshift mutation (c.989_995del, p.H330LfsX2) in FANCA gene. Our results indicate that whole exome sequencing may be useful in clinical settings for rapid identification of disease-causing mutations in rare genetic disorders such as Fanconi anemia.  相似文献   
228.
Molecular dynamics simulation is used to study the decomposition and stability of SII hydrogen and hydrogen/tetrahydrofuran (THF) hydrates at 150 K, 220 K and 100 bar. The modelling of the microscopic decomposition process of hydrogen hydrate indicates that the decomposition of hydrogen hydrate is led by the diffusive behaviour of H2 molecules. The hydrogen/THF hydrate presents higher stability, by comparing the distributions of the tetrahedral angle of H2O molecules, radial distribution functions of H2O molecules and mean square displacements or diffusion coefficients of H2O and H2 molecules in hydrogen hydrate with those in hydrogen/THF hydrate. It is also found that the resistance of the diffusion behaviour of H2O and H2 molecules can be enhanced by encaging THF molecules in the (51264) cavities. Additionally, the motion of THF molecules is restricted due to its high interaction energy barrier. Accordingly, THF, as a stabiliser, is helpful in increasing the stability of hydrogen hydrate.  相似文献   
229.
Cinnamomum camphora is an excellent tree species for construction of forest construction of Henan Province, China. The diverse bioactive components of nano-catalyzed pyrolyzates form cold-acclimated C. camphora branch (CCB) in North China were explored. The raw powder of CCB treated with nano-catalyst (Ag, NiO, 1/2Ag + 1/2NiO) were pyrolyzed at two temperatures (550 °C and 700 °C), respectively. The main pyrolyzates are bioactive components of bioenergy, biomedicines, food additive, spices, cosmetics and chemical, whose total relative contents at 550 °C pyrolyzates are higher than those at 700 °C pyrolyzates. There are abundant components of spices and biomedicine at 550 °C pyrolyzates, while more spices and food additive at 700 °C pyrolyzates. At 550 °C, the content of biomedicine components reaches the highest by 1/2Ag + 1/2NiO nanocatalysis, while the contents of spices and food additive components reach the highest by NiO nanocatalysis. At 700 °C, the content of bioenergy components reaches the highest by 1/2Ag + 1/2NiO nanocatalysis, and the content of cosmetics components reaches the highest by Ag nanocatalysis. The findings suggested that the branch of the cold-acclimated C. camphora have the potential to develop into valued-added products of bioenergy, biomedicine, cosmetics, spices and food additive by nanocatalysis.  相似文献   
230.
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