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21.
符文琛 《工业卫生与职业病》1987,(1)
通过对冶金、锻造、铸造、陶瓷、纺织、印染、铁路、航运等行业的16个作业环境热环境参数和工人生理反应关系的调查,对现行的高温作业分级标准不足之处提出了一些看法,并认为IS0提出的热环境下机体反应的阈限值对我国亦是适宜的。经统计学分析发现,作业环境的计算温度和工人平均体温之间有明显相关(r=0.86)。不同气温下464名工人的主观感觉调查表明,35℃时100%的工人都有热或很热的感觉。 相似文献
22.
The distribution kinetics of a novel potent immunosuppressant, FK-506 (FK) has been studied in comparison with cyclosporin A (CyA) both in vivo and in vitro using blood specimens. The infusion studies on FK, 5.0 mg kg-1 through the portal and femoral veins showed that the mean hepatic extraction ratio of FK was 27.9 per cent. The effect of clamping both the hepatic artery and the portal vein on the plasma disappearance profiles of FK, 5.0 mg kg-1, and CyA, 3.5 mg kg-1 was studied. The plasma disposition kinetics of CyA was almost the same as in the normal rats. However, the plasma FK levels were about 10 times higher than those obtained in the control group rats. This difference is attributed to the restricted initial distribution of FK to the liver, because the volume of the initial distribution space, V1, of FK was about 10 times smaller than that obtained in normal rats. In in vitro experiments, drug distribution was studied in blood samples (2.0 ml) spiked with FK or CyA, 1.0 micrograms ml-1. The plasma drug levels measured at 2 min after drug administration were 0.842 +/- 0.012 micrograms ml-1 and 0.769 +/- 0.047 micrograms ml-1 for FK and CyA, respectively. The distribution volume in the blood compartment, VB, was determined by dividing the spiked amount of drugs with these plasma concentrations. The VB was 2.38 +/- 0.04 ml for FK and 2.62 +/- 0.16 ml for CyA. There was no significant difference in VB between FK and CyA. The plasma free fraction, fp of the drugs was measured by the equilibrium dialysis method. For FK, the mean fp values (+/- SE) were 1.31 +/- 0.18 per cent (2.0 micrograms ml-1) and 1.93 +/- 0.18 per cent (5.0 micrograms ml-1). For CyA, the fp values were 4.85 +/- 0.36 per cent (1.0 micrograms ml-1) and 5.75 +/- 0.82 per cent (5.0 micrograms ml-1). The hydrophobicity parameter, logP' determined through the HPLC method was 0.386 for FK and 0.545 for CyA. Although FK was less hydrophobic than CyA, its protein binding was higher than CyA. 相似文献
23.
目的:建立精浆尿酸(UA)的检测方法并探讨精浆UA水平与精液参数的相关性。方法:根据检测血清UA的方法加以改良建立检测精浆UA的方法,并观察批内变异和不同技术人员检测结果之间的差异以评价方法的可接受性。同时分析138例男性精浆UA水平与患者年龄、禁欲时间、精液量、pH、精子密度、活动率、a+b级精子百分率和正常形态精子百分率之间的相关性。结果:精浆UA检测方法的批内变异为9.16%,2位技术人员的检测结果没有显著性差异(P=0.541)。精浆UA水平与正常形态精子百分率呈正相关(r=0.350,P=0.025),与精子活动率和a+b级精子百分率有呈正相关的趋势(r=0.147和0.156,P=0.085和0.068),而与精液分析其他参数如精液量、pH、精子密度、禁欲时间以及患者年龄等无相关性。结论:通过对血清UA检测方法加以改良可以建立可接受的精浆UA检测方法。精子形态学、活动率及a+b级精子百分率可能与精浆UA水平高低有关。 相似文献
24.
计算机辅助精液分析男性不育患者精子运动参数与精子活力的相关性 总被引:2,自引:1,他引:1
目的探讨计算机辅助精液分析精子运动参数在评价男性不育患者精子活力中的价值。方法按《WHO人类精液及精子-宫颈黏液相互作用实验检验手册》标准,采用国产WLJY-9000伟力彩色精子质量检测系统对276例男性不育患者的精液进行平均直线运动速度、平均曲线运动速度、运动的前向性、运动的直线性、运动的摆动性、平均路径速度、精子活力及分级等进行检测并分析其相关性。结果276名男性不育患者的平均精子活力为(48.93±19.10)%,分级为A级(32.11±17.25)%、B级(17.03±8.91)%、C级(10.14±5.99)%。平均直线运动速度、平均曲线运动速度、运动的前向性、运动的直线性、运动的摆动性、平均路径速度与精子活力的相关系数分别为0.60(P〈0.01)、0.59(P〈0.01)、0.51(P〈0.01)、0.55(P〈0.01)、0.52(P〈0.01)、0.67(P〈0.01)。结论计算机辅助精液分析精子运动参数平均直线运动速度、平均曲线运动速度、平均路径速度是反映精子活力的有效指标,精子运动参数对男性不育的诊断和生育能力的评估具有实用意义。 相似文献
25.
Zhen-yu Wu Laurent P. Rivory Michael S. Roberts 《Journal of pharmacokinetics and pharmacodynamics》1993,21(6):653-688
Distribution of Evans Blue (EB), sucrose, and water into the isolated perfused rat hindlimb was studied under various conditions using the multiple indicator dilution (MID) technique. Statistical moment analyses of the outflow profiles for the EB, sucrose, and water were used to define the vascular, extravascular, and total water spaces, respectively. The varied perfusion conditions included albumin content (2, 4.7, and 7%), temperature (25, 37, and 42 C), perfusate flow rate (2, 4, 8, and 12 ml/min) and the presence/absence of red blood cells. The range of studies undertaken were chosen to represent the variety of conditions used in the preparation of both isolated animal and human limbs, the latter being particularly important in cytotoxic therapy for recurrent malignant melanoma. The distribution volumes of EB, sucrose, and water were dependent on the flow rate and the albumin content of perfusate. The normalized variances (CV
2
) of the markers were of the following order: sucrose (2.18) > water (1.58) > EB (0.68), indicating that some disequilibrium occurs during the capillary exchange of water and sucrose. It is suggested that a Krebs-Henseleit buffer containing 2% BSA is a suitable perfusate for most studies of the isolated rat hindlimb perfusion. The effect of albumin concentration manifests itself only at higher flows.We acknowledge the support of the National Heart Foundation (Queensland) and the Mayne Bequest Foundation. This study was conducted while the investigator (Z.Y. Wu) was in receipt of a WHO Research Training Grant. Professor M. S. Roberts also acknowledges the support of the Queensland and Northern New South Wales Lions Kidney & Medical Research Foundation. 相似文献
26.
研究了不同温度、浓度条件下,顺丁烯二酸(顺酸)非催化反应网络,即顺酸可生成反丁烯二酸(反酸)和苹果酸,反酸与苹果酸存在可逆反应。建立了该反应网络的动力学模型。测定了不同反应条件下顺酸、反酸和苹果酸浓度随时间变化的规律,据此,动力学参数进行了估值。 相似文献
27.
Daniel P. Venter 《European journal of pharmacology》1997,320(2-3):223-231
A new method for estimating relative efficacies and relative intrinsic efficacies of agonists is described. Relative efficacy is estimated by employing a newly defined efficacy related parameter (eES) and it may be estimated without prior knowledge of efficacy values or the value of the equilibrium dissociation constants, KA, of agonist-receptor complexes. The parameter eES is directly related to efficacy (e) and is defined as the ratio of maximal stimulus to maximal effect of an agonist. The value of eES indicates whether or not spare receptors are present for a particular agonist–effector system. The eES values of agonists are estimated by utilizing submaximal concentration–effect curves determined with fixed agonist-competitive antagonist concentration combinations and choosing a suitable reference (height of an agonistic concentration–effect curve) to which the height of the stimulus concentration–effect curves of the agonist may be compared. In addition to eES, other new agonist–effector parameters, namely SEm/Sm and φmin, were also defined. 相似文献
28.
The contribution of the central nervous system to tremor pathogenesis is unclear. Poor side-to-side coherence in physiological, essential, and parkinsonian tremors suggests distinct bilateral generators. By contrast, significant bilateral coherence demonstrated in orthostatic tremor and in enhanced physiological tremor (EPT) in patients with persistent mirror movements favours single or closely linked bilateral oscillators. We describe three patients (aged 21-37 years) who developed unusual bilateral postural and kinetic tremors at 6-13 Hz resembling EPT. The tremor involved all limbs, and in two cases the face or jaw, in the absence of other significant neurological features. Significant side-to-side coherence was demonstrated in each case using cross-correlation of electromyographic recordings from homologous muscle pairs. We postulate that these unusual tremors originate from a single brainstem source or from bilateral oscillators closely linked at or below this level. 相似文献
29.
本文探讨了环烷烃、环烯烃、双环[n.1.0]烷烃和双环[n.m.1]烷烃的张力与几何参数间的定量关系,得到十个满意的线性相关方程。 相似文献
30.
Hou Zhiful Cui Yananl Liu Xiachn Yang ShaojUan Wu Xiaodong Wang Weizhong Liu Ping 《吉林大学学报(医学版)》1998,(6)
目的:探讨大肠疾病形态计量学和凋亡规律。方法:应用图像自动分析系统,检测了大肠疾病形态计量学参数和凋亡指数(AI)。结果:大肠腺癌AI明显高于大肠腺瘤和炎性增生组(P分别<O.05和<O.001);细胞核面积、周长、凸状周长、等效直径、周长面积因子和核平均灰度六项参数,在腺癌组明显高于腺瘤和炎性增生,而灰度标准差明显低于其他两组,大肠腺癌AI与PM2/A相关系数为O.51(P<0.05)。结论:形态计量学参数和凋亡指数在鉴别大肠疾病中具有一定参考价值。 相似文献