An experimentally supported, mathematical explanation of the gas chromatographic elution behaviour of the long-chain carbon members of the homologous series

By substituting the saturated vapour phase tension of the pure normal hydrocarbons described by the Clausius-Clapeyron law into the accepted expression of the specific retention volume (V_g,T), a theoretically coherent and relatively simple mathematical evidence of the elution behaviour of the homologous members has been deduced. It gives exponential retention time dependence on carbon number for isothermal, and nearly equidistant (i.e., approximately linear retention-time dependence on carbon number) elution for linear temperature programmed gas chromatographic runs. The final equations are in close correlation with the experimental results. Special emphasis is placed on the fact that a good approximation—not strict physical laws—have been found.     

CS_2作业工人血清脂质过氧化水平与LDH同功酶谱研究

ＣＳ_２作业工人血清脂质过氧化水平与ＬＤＨ同功酶谱研究张文昌，连祥霖，张连娜，杨乃富（福建医学院劳动卫生学教研室，福州３５０００４）结果表明，高接触水平组（浓度为１０．４２～４６．５４ｍｇ／ｍ３或Σｍｇ·年≥５０）血清ＬＰＯ含量与对照比较，显著性增高?..     

Efficacy of cyclosporin in difficult-to-treat idiopathic membranous nephropathy

SUMMARY: Poor tolerance and the potential long-term toxicity have limited the widespread use of corticosteroids and cytotoxic drugs in the treatment of idiopathic membranous nephropathy (IMN). Cyclosporin A (CyA) has been proven to be a less toxic alternative, but its efficacy needs further confirmation. Cyclosporin A (2–3mg/kg per day) in combination with low-dose methylprednisolone (4mg/day) was given to 28 nephrotic patients with IMN who had failed to respond, or tolerate, or to complete treatments with steroids and/or cytotoxic drugs. the mean duration of treatment was 11 ± 7 months. Seven patients (25%) showed a complete remission of proteinuria, 17 (60%) a partial one, and four (15%) did not respond at all. the average time to achieve optimal remission was 4.2 ± 1.4 weeks following the initiation of therapy. In those who responded completely or partially, plasma creatinine (Per) did not change significantly from pre CyA levels during follow up (1.0 ± 0.3 vs 1.2 ± 0.3mg/dL, P =NS). the remaining four patients who had renal insufficiency already before CyA (mean Per: 2.1 ± 0.8mg/dL), showed a rapid deterioration of renal function after the initiation of CyA (mean Per: 3.1 ± 1.5 mg/dL, P <0.01), and as a consequence, the drug was discontinued. A mul-tivariate analysis on the clinical and histological features demonstrated that the degree of renal function impairment ( P <0.02), the percentage of obsolete glomeruli ( P <0.01), and the severity of interstitial fibrosis ( P <0.005) independently predicted the response to therapy. Low dose CyA is an effective and safe alternative treatment for patients with IMN and normal renal function. However, the drug should be given with caution to patients with established renal insufficiency.     

模糊数学方法用于职业危害因素的综合评价

模糊数学方法用于职业危害因素的综合评价徐新云（湖南省劳动卫生职业病研究所，长沙４１０００７）用模糊数学方法进行综合评价时，首先要确定评判等级，各评判因素在不同等级中的取值，以及各评判因素的权重系数三方面内容。本文将评判等级定为优、良、一般、差、很差５...     

Aptitude for physical exercise in a population of female hospital workers

Summary The aim of this study was to evaluate the level of physical capacity in a female hospital population of Paris and its suburbs. A total of 1505 women working in the selected departments filled in a questionnaire concerning their working conditions, life habits and health and also attended a medical examination. The effort test performed consisted in flexing the legs 20 times with the chest held straigt, in 40 s. The heart rates were measured for the first, the second and the third minutes of recovery (first 15 s multiplied by 4). The blood pressure was measured just after the heart rate, for the first and the third minute. Recovery indices have been constituted from the results. The respective weights of anthropometric and sociodemographic risk factors for recovery indices were studied in multiple logistic regression models. The classification enables us to consider about 25%–30% of our population as having a satisfactory physical capacity, about 26%–27% as having an acceptable capacit, and about 24%–27% as having a weak capacity. About 21% of the population presented an excessive pressure reaction and 44% a questionable pressure reaction. Our results concerning the level of physical capacity of the female nursing staff should be taken into account especially in the future planning of work loads and architectural choices, which must avoid excessive physical burdens in relation to this level. An improvement in the level of physical capacity could be envisaged as well.     

冶金炼铁炉前工人职业性皮损调查研究

冶金炼铁炉前工人职业性皮损调查研究关虹，王溪鸿，杨玉萍（辽宁省本溪钢铁公司劳动卫生研究所，１１７０２１）作者对炼铁炉前工人＂熊猫眼＂样皮损病因及特异部位皮损进行研究，为改善劳动条件，防治职业性皮肤病提供一些依据。以某炼铁厂５号炉前工人为观察组，以炼钢...     

锰电焊工人某些内分泌功能研究

锰电焊工人某些内分泌功能研究崔金山，王薛君，张玉敏，马明月，李宏革，孙玉强，孔庆芝，窦林松，曹昆，裴秋铭，赵艳萍（沈阳医学院毒理教研室，１１００３１）研究对象选自某建筑机械厂结构车间锰电焊作业工人５１人（男４２人，女９人），年龄范围２１～５１岁，平均...     

Prediction of the average skin temperature in warm and hot environments

The prediction of the mean skin temperature used for the Required Sweat Rate index was criticised for not being valid in conditions with high radiation and high humidity. Based on a large database provided by 9 institutes, 1999 data points obtained using steady-state conditions, from 1399 experiments and involving 377 male subjects, were used for the development of a new prediction model. The observed mean skin temperatures ranged from 30.7 °C to 38.6 °C. Experimental conditions included air temperatures (T _a) between 20 and 55 °C, mean radiant temperatures (T _r) up to 145 °C, partial vapour pressures (P _a) from 0.2 to 5.3 kPa, air velocities (v _a) between 0.1 and 2 m/s, and metabolic rates (M) from 102 to 620 W. Rectal temperature (T _re) was included in the models to increase the accuracy of prediction. Separate models were derived for nude (clothing insulation, I_cl, ≤0.2 clo, where 1 clo=0.155 m² · °C · W⁻¹, which is equivalent to the thermal insulation of clothing necessary to maintain a resting subject in comfort in a normally ventilated room, air movement=10 cm/s, at a temperature of 21 °C and a humidity of less than 50%) and clothed (0.6 ≤ I_cl ≤ 1.0 clo) subjects using a multiple linear regression technique with re-sampling (non-parametric bootstrap). The following expressions were obtained for nude and clothed subjects, respectively: T _sk=7.19 + 0.064T _a + 0.061T _r + 0.198P _a− 0.348v _a + 0.616T _re and T _sk=12.17 + 0.020T _a + 0.044T _r + 0.194P _a − 0.253v _a + 0.0029M + 0.513T _re. For the nude and clothed subjects, 83.3% and 81.8%, respectively, of the predicted skin temperatures were within the range of ±1 °C of the observed skin temperatures. It is concluded that the proposed models for the prediction of the mean skin temperature are valid for a wide range of warm and hot ambient conditions in steady-state conditions, including those of high radiation and high humidity. Accepted: 7 February 2000     

免疫增强剂对反复呼吸道感染患儿免疫指标的影响

目的　观察免疫增强剂对反复呼吸道感染 (RRTI)患儿免疫指标的影响。方法 :用琼脂单向扩散法和荧光法 ,检测了 10 0例RRTI患儿分别用乌体林斯注射液和转移因子口服液治疗前后免疫球蛋白含量和T细胞亚群百分数 ,并与正常对照组比较。结果 :RRTI组患儿免疫指标均非常显著低于正常对照组 (P <0 .0 0 1) ,乌体林斯注射液含服治疗后IgG .IgM含量和CD3、CD4 、CD8百分数均有显著升高 (P <0 .0 5 ) ;转移因子口服液口服治疗后IgA .IgM含量和CD3、CD4 百分数均有显著升高 (P <0 .0 5 )。结论　免疫功能降低是RRTI发病的重要因素 ,免疫增强剂对RRTI疗效佳。