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排序方式: 共有428条查询结果,搜索用时 15 毫秒
1.
外科医生和手术室人员经常接触手术设备产生的烟气,病人也会暴露于烟气中,特别是腹腔镜手术中产生的烟气滞留于腹腔内这一密闭空间并被吸收.这些烟气是一种与香烟烟气相似的毒性物质,然而对这种毒性物质的影响还未引起足够重视.应该采取必要措施尽可能减少手术中烟气的不良影响. 相似文献
2.
取代四氢异喹啉衍生物的合成及其生物活性 总被引:7,自引:0,他引:7
粉防己碱有钙拮抗作用,临床试用于治疗高血压,其裂解产物钙拮抗作用降低,但有α-肾上腺素能受体拮抗作用,本文以裂解物为先导化合物设计合成了两类取代的四氢异喹啉衍生物Ⅲ及Ⅳ。初步药理试验表明:大部分化合物有α-肾上腺素能受体拮抗作用,少数化合物钙拮抗活性有所增强,其中Ⅲ15,19对正常麻醉大鼠有一定的降压作用、Ⅳ17,19对实验性动物心律失常有明显的保护作用。部分化合物量化计算表明:化合物与α1-受体作用方式可能是形成电荷转移复合物。 相似文献
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Two fast magnetic resonance (MR) imaging techniques, advanced Fourier and partial-flip imaging, were used at 0.35 T to examine 21 patients with suspected intracranial lesions; the results were quantitatively compared with a conventional spin-echo study. Both of the fast MR techniques yielded a fourfold reduction in imaging time per section. The advanced Fourier sequence showed contrast that was identical to the conventional spin-echo study with signal-to-noise ratios of 58% and 57% for the first and second echoes, respectively. The partial-flip sequence showed a contrast of 109% and 57% for lesions versus substantia alba, and 107% and 78% for substantia grisea versus substantia alba relative to the first and second echoes of the conventional spin-echo study. The partial-flip sequence was particularly sensitive to magnetic susceptibility; this produced artifacts that may undermine the usefulness of partial flip for routine screening in certain parts of the brain. However, this susceptibility significantly improved the detection of intracranial hemorrhage when compared with the spin-echo sequence, particularly when combined with phase mapping of the partial-flip study. 相似文献
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Abstract The Checkerboard Cardiovascular Curriculum (CCC) project was designed to develop a culturally-oriented educational program for reducing coronary heart disease (CHD) risk factors in rural American Indians and Hispanics in the state of New Mexico. Because so little information is available on children from these ethnic groups, the purposes of this paper are: 1) to describe and compare some physical characteristics of Hispanics and Navajo, Laguna and Acoma Indians which are associated with CHD risk factors; and 2) to assess the short-term effectiveness of the CCC in altering these CHD risk factors. Body weight, height, blood pressure, one mile walk/run data, and triceps, subscapula, and calf skinfold thicknesses were collected for 97 boys and 79 girls from the four ethnic groups. Results of analyses of covariance (ANCOVA), controlling for age, indicated ethnic differences for all dependent variables. The average body mass index of all Indian children exceeded the median values reported in the second National Health and Nutrition Examination Survey (NHANES-II). The average sum of the triceps and subscapula skinfolds of the children from all ethnic groups failed to meet acceptable standards established by The National Children and Youth Fitness Study (NCYFS). The results of the CCC project suggest that these children are in need of health promotion and physical fitness programs that emphasize obesity and cardiovascular fitness and provide for ethnic and cultural differences. 相似文献
8.
Regulation of main olfactory bulb mitral cell excitability by metabotropic glutamate receptor mGluR1
In the rodent main olfactory bulb (MOB), mitral cells (MCs) express high levels of the group I metabotropic glutamate receptor (mGluR) subtype, mGluR1. The significance of this receptor in modulating MC excitability is unknown. We investigated the physiological role of mGluR1 in regulating MC activity in rat and mouse MOB slices. The selective group I agonist (RS)-3,5-dihydroxyphenylglycine (DHPG), but not group II or III agonists, induced potent, dose-dependent, and reversible depolarization and increased firing of MCs. These effects persisted in the presence of blockers of fast synaptic transmission, indicating that they are due to direct activation of mGluRs on MCs. Voltage-clamp recordings showed that DHPG elicited a voltage-dependent inward current consisting of multiple components sensitive to potassium and calcium channel blockade and intracellular calcium chelation. MC excitatory responses to DHPG were absent in mGluR1 knockout mice but persisted in mGluR5 knockout mice. Broad-spectrum LY341495, MCPG, as well as preferential mGluR1 LY367385 antagonists blocked the excitatory effects of DHPG and also potently modulated MC spontaneous and olfactory nerve-evoked excitability. mGluR antagonists altered spontaneous membrane potential bistability, increasing the duration of the up and down states. mGluR antagonists also substantially attenuated MC responses to sensory input, decreasing the probability and increasing the latency of olfactory nerve-evoked spikes. These findings suggest that endogenous glutamate tonically modulates MC excitability and responsiveness to olfactory nerve input, and hence the operation of the MOB circuitry, via activation of mGluR1. 相似文献
9.
应用免疫组织化学荧光三标方法结合激光共聚焦显微镜技术研究了大鼠舌咽和神经迷走神经感觉神经节内ATP受体P2X2、P2X3与calretinin、植物凝集素(IB4)结合位点的共存。结果显示:舌咽和迷走神经感觉神经节内可见大量P2X2、P2X3阳性的神经元胞体和纤维,P2X2受体阳性细胞多为大、中、小型神经元,P2X3阳性细胞多为中、小型神经元;可见较多的P2X2/IB4及P2X3/IB4双标神经元。有(91.1±4.7)%(结状神经节)、(78.8±2.4)%(岩神经节)、(76.8±2.7)%(颈静脉神经节)为P2X2阳性细胞;(77.0±3.2)%(结状神经节)、(91.2±3.9)%(岩神经节)、(78.4±3.6)%(颈静脉神经节)的P2X3阳性细胞结合IB4;有8.9±1.6%(结状神经节)、7.7±1.4%(岩神经节)、9.1±1.1%(颈静脉神经节)的P2X2阳性细胞呈calretinin阳性;三神经节内均观察到少量P2X2/calretinin/IB4三标细胞。P2X3/calretinin双标或P2X3/calretinin/IB4三标神经元数量较少。这些结果提示,舌咽和迷走神经感觉神经节内ATP受体P2X2、P2X3与IB4结合位点存在广泛的共存,部分P2X2受体与calretinin存在着共存。 相似文献
10.
We describe a new method for the percutaneous drainage of pancreatic pseudocysts using a transgastric approach. We used this technique in three dogs and six patients for whom no other "safe" access route was available. The procedures were performed under US guidance alone or with US combined with fluoroscopy. No complications were observed. 相似文献