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971.
广东汉族人β2-肾上腺素能受体基因Gln27Glu多态性 总被引:2,自引:0,他引:2
目的 探讨β2-AR 16位点基因多态性在广东汉族人群中的分布.方法 应用聚合酶链反应技术对122例正常人β2-肾上腺素能受体基因Gln27Glu进行扩增并进行图谱分析.并结合文献进行了不同种族间的分析比较.结果 广东汉族人群β2-AR基因27位点多态性分布频率:Gln/Gln基因型占36.88%,Gln/Glu基因型占52.46%,Glu/Glu基因型占10.66%.结论 广东汉族人群存在出β2-AR Gln27Glu基因多态性,其分布频率与英美高加索人群有一定差异. 相似文献
972.
细胞核形态和DNA指数分析在星形细胞瘤分级诊断中的应用 总被引:1,自引:0,他引:1
目的 探索自动图像分析系统在胶质瘤分级诊断中的应用。方法 采用自行设计组装的MIPS-I型自动图像分析系统对3个级别星形细胞瘤的细胞核形态和DNA指数(倍体)同时进行原位定量测定。结果 在星形细胞瘤分级诊断中,5项反映核形态的参数诊断正确率为56.3%;代表核DNA改变的7项参数诊断正确率为70.8%;综合应用12项参数诊断正确率为75%。结论 细胞核形态和DNA指数分析可作为星形细胞瘤分级诊断的参考指标之一。 相似文献
973.
974.
Qin W Gao J Xing Q Yang J Qian X Li X Guo Z Chen H Wang L Huang X Gu N Feng G He L 《Neuroscience letters》2005,375(3):207-210
Recently, proteolipid protein 1 (PLP1) has been identified as downregulated in schizophrenia by quantitative PCR and other technologies. In this work we attempted to investigate the role of PLP1 in the etiology of schizophrenia using a family based association study in 487 Chinese Han family trios. The TDT for allelic association demonstrated that, in male, a weak association was detected in SNP rs475827 with p=0.0294, suggesting that the genetic polymorphisms within PLP1 in male are likely to confer an increased susceptibility to schizophrenia in the Chinese population. 相似文献
975.
湖南省两地区成瘾物质使用状况调查报告:使用率及相关因素 总被引:12,自引:1,他引:12
本文采用整群抽样的方法,对湖南两地区城乡共2377人(15岁以上)的成瘾物质使用状况进行调查,其中男1179(49.6%)人,女1199(50.4%人),平均年龄男女分别为41.2(SD=17.5)和43.4(SD=18.6)。结果表明,饮酒率男性为57.5%,女性为17.3%,吸烟率男女分别为68.2%和11.7%;饮酒者多集中在每月饮1次左右的人群中(男57.9%,女77.9%),但吸烟者多集中在每日吸20支及以上(男52.4%,女42.9%)的人群中。除解热镇痛剂外,男性各种精神活性物质的使用频率及剂量皆男高于女性,开始使用的年龄及成瘾的年龄男性低于女性;性别、使用频度、最早使用的年龄、婚姻与饮酒、吸烟量关系最为密切。有14人使用过鸦片类物质,4人使用过兴奋剂。作者讨论了我国成瘾物质使用的特点,指出经济水平、社会文化背景等因素与我国社会性成瘾物质的使用有密切关系。 相似文献
976.
A study of the x-ray sensitivity of amorphous selenium (a-Se) for digital mammography has been performed. A uniform layer of a-Se was deposited on a glass substrate with electrodes on both surfaces. The deposition procedure was identical to that used for a-Se flat-panel detectors. A high voltage was applied to the top surface of the a-Se layer in order to establish an electric field E(Se). Then the sample was exposed to x rays with 27 kVp spectra generated from an x-ray tube with a molybdenum (Mo) target. The mean x-ray energy of the spectrum used was approximately 16.6 keV. The x-ray current generated by the a-Se layer was measured as a function of E(Se). From the current measurement and the estimation of total x-ray energy absorbed in the a-Se, the energy required to create one electron-hole pair (EHP), W, was determined as a function of E(Se). It was found that at the most commonly used E(Se) of 10 V/microm, W was measured as 64 eV. This is considerably higher than the widely accepted typical value of W = 50 eV measured at higher x-ray photon energies (e.g., 50 keV). The dependence of W as a function of E(Se) can be best fitted using the empirical expression of E(Se)-gamma. This relationship is consistent with the results obtained at higher x-ray energies. This article provides an accurate measurement of x-ray sensitivity of a-Se at mammographic energies independent of detector operation, such as the most recently developed flat-panel detectors. The results will be a useful tool for investigation and optimization of a-Se-based x-ray imaging detectors, such as determination of pixel fill-factor and optimal E(Se) during operation. 相似文献
977.
978.
A panel of six monoclonal antibodies (mAbs) against a grouper iridovirus (SGIV) were produced by immunization of Balb/c mice with purified virus preparations. Isotyping test revealed all the mAbs were IgG1. None of the mAbs possessed the ability to neutralize SGIV in cell cultures. Western blot showed that 4 mAbs reacted with 2 SGIV proteins at molecular mass of approximately 100 and 117 kDa in gradient-purified virus. Immunofluorescent studies showed that the two specific viral proteins VP100 and VP117 were localized within virus assembly sites in the cytoplasm of SGIV-infected grouper cells (GP). Fractionations of the iridovirus in a 20-60% sucrose gradient were detected successfully by all the six mAbs using immunodot blot. An antigen-capture enzyme-linked immunosorbent assay (ELISA) system, based on the use of mAb 7E11 for capture and a rabbit polyclonal antibody to SGIV for detection was developed. SGIV antigen was detected in gradient-purified virus and virus-infected grouper blood. These novel mAbs will facilitate the development of more specific and standardized diagnostic techniques for marine fish iridovirus. 相似文献
979.
Wei S Ong WY Thwin MM Fong CW Farooqui AA Gopalakrishnakone P Hong W 《Neuroscience》2003,121(4):891-898
Recent evidence shows that secretory phospholipase A2 (sPLA2) may play a role in membrane fusion and fission, and may thus affect neurotransmission. The present study therefore aimed to elucidate the effects of sPLA2 on vesicle exocytosis. External application of group IIA sPLA2 (purified crotoxin subunit B or purified human synovial sPLA2) caused an immediate increase in exocytosis and neurotransmitter release in pheochromocytoma-12 (PC12) cells, detected by carbon fiber electrodes placed near the cells, or by changes in membrane capacitance of the cells. EGTA and a specific inhibitor of sPLA2 activity, 12-epi-scalaradial, abolished the increase in neurotransmitter release, indicating that the effect of sPLA2 was dependent on calcium and sPLA2 enzymatic activity. A similar increase in neurotransmitter release was also observed in hippocampal neurons after external application of sPLA2, as detected by changes in membrane capacitance of the neurons. In contrast to external application, internal application of sPLA2 to PC12 cells and neurons produced blockade of neurotransmitter release. Our recent studies showed high levels of sPLA2 activity in the normal rat hippocampus, medulla oblongata and cerebral neocortex. The sPLA2 activity in the hippocampus was significantly increased, after kainate-induced neuronal injury. The observed effects of sPLA2 on neurotransmitter release in this study may therefore have a physiological, as well as a pathological role. 相似文献
980.
独立成分分析是一种新的信号处理统计方法。被广泛用于各个领域。在信号分析中面临的难题是:源信号的不同特性(既包括超高斯信号又包括亚高斯信号);未知的独立源数目;传感器信号受到较大的加性噪声污染。针对以上难题,本文提出了一种独立成分分析的鲁棒算法。该方法先对观测数据作预处理,将包含噪声的高维传感器观测信号降维分解到信号子空间和噪声子空间。利用交叉验证法估计出独立源的数目(解决了独立成分分析本身不能确定源数目的缺陷);然后利用快速稳定的FastICA算法分离独立成分。通过人工合成的数据和实际的脑磁图数据分析。验证了这种方法的功效。 相似文献