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991.
The results of a two-year longitudinal study of the effect that development program incentives have upon family planning in Northeastern Thailand are presented. These incentives, implemented by the Population and Community Development Association, Thailand, included animal raising and agricultural, home industry, and environmental activities. An experimental design including baseline and follow-up surveys supplemented by a continuous monitoring system was utilized to test hypotheses on the family planning impacts of the incentives. Findings indicate that the incentives contributed significantly to the maintenance of high levels of family planning practice through the program period 1982-1984. 相似文献
992.
J P Hendershott 《American Industrial Hygiene Association journal》1986,47(12):742-746
A method was developed for the simultaneous determination of a number of reactive chloroformates and phosgene in air at low concentration levels. The procedure utilized the collection of air containing these contaminants on a di-n-butylamine-coated solid adsorbent. After samples were taken, the carbamate and urea derivatives were desorbed with hexane, washed with 1N HCl and analyzed by gas chromatography with flame ionization detection. The procedure provided an accurate exposure level for each of the desired compounds on a time-weighted average basis. Average recovery efficiencies ranged from 98% to 106%, with an average detection limit of 0.7 micrograms or 0.08 ppm v/v in 1.5 L of air. More recent tests have extended the use of the technique to include carboxylic acid chlorides--specifically, pivalic acid chloride and 3-chloropivalic acid chloride. The average recovery efficiency for these compounds was 69%. 相似文献
993.
994.
995.
Relationship between transmitter release and presynaptic calcium influx when calcium enters through discrete channels. 总被引:12,自引:2,他引:10 下载免费PDF全文
R S Zucker A L Fogelson 《Proceedings of the National Academy of Sciences of the United States of America》1986,83(9):3032-3036
We have used a three-dimensional diffusion model of calcium entering the presynaptic nerve terminal through discrete channels to simulate experiments relating transmitter release to presynaptic calcium current. The relationship will be less than linear, or will curve downward, if calcium channels are well separated. It will resemble a power-law function with exponent less than the cooperativity of calcium action if channels are clustered closer together. Large presynaptic depolarizations elicit more release than small depolarizations admitting the same calcium influx. This occurs because large pulses open more channels near each other, with the result that the calcium concentration near release sites is greater, due to overlap of calcium diffusing from adjacent channels. 相似文献
996.
Prognostic factors in neuroblastoma 总被引:1,自引:0,他引:1
Between 1951 and 1978 88 patients under 15 years of age were admitted with the diagnosis of neuroblastoma or ganglioneuroblastoma to the Helsinki University Central Hospital for treatment. The relative importance of various prognostic factors for survival was investigated by the use of the Cox regression analysis and by comparison of adjusted survival curves. In regression analysis prior to classification of the patient sample, stage emerged as the overwhelmingly most significant prognostic variable, while histology and age showed a weaker effect and chemotherapy did not display any effect in this setting. Adjusted comparison of survival curves showed significantly improved survival for patients under one year of age in combined stages III and IV, and for stage III patients treated with combination chemotherapy following non-radical surgery. Thus, while stage is the strongest overall prognostic factor, the effect of age is seen especially in the more advanced cases and the beneficial effect of chemotherapy in the cases where radical operation has not been possible. 相似文献
997.
S Pampfer L Vankrieken E Loumaye R De Hertogh K Thomas 《Human reproduction (Oxford, England)》1989,4(4):396-402
Follicular fluids from eight patients with one ovary and from ten patients with two ovaries were investigated for bioactive inhibin, total renin, oestradiol (E2) and progesterone (P4) concentrations. Four follicular fluids were pooled per patient before assessment. All women had been stimulated similarly using a protocol including a GnRH agonist, HMG and HCG. Renin levels were significantly lower and P4 significantly higher in pools of follicular fluid from patients with one ovary, whereas inhibin and E2 concentrations were similar in both patient groups. A significant negative correlation was found in the pools of follicular fluid between inhibin and E2 in both groups. These results suggest a role for inhibin and renin in the paracrine and autocrine control of stimulated follicular development. 相似文献
998.
J. LEAKE S. J. KELLIE† J. PRITCHARD† J. M. CHESSELLS† R. A. RISDON 《Histopathology》1989,14(3):255-268
A review of the pathological material from 42 children with non-Hodgkin's lymphoma seen over a 44 month period revealed 10 large cell tumours. Of these, six were classified as peripheral T-cell lymphoma, an entity rarely reported in childhood. Three patients were boys and three girls (median age 9.5 years), and extranodal presentation was a feature of two patients. Five had high-grade tumours; of these, three were classified as large cell anaplastic, Ki-1 positive and two as pleomorphic large cell. The remaining patient had a low-grade tumour of angioimmunoblastic type. T-cell subsets were examined in three cases and showed the following phenotypes: CD4-, CD8-; CD4+, CD8-; CD4-, CD8+. Three of the patients with high-grade tumours died, with a mean survival of 22 weeks. The remaining patients are alive and clinically disease-free for between 10 and 24 months after treatment. 相似文献
999.
1000.
Potential roles of protease inhibitors in Alzheimer's disease 总被引:1,自引:0,他引:1
C R Abraham 《Neurobiology of aging》1989,10(5):463-5; discussion 477-8
Recently, protease inhibitors have been recognized as potential contributors to the pathogenesis of Alzheimer's disease. In this role, they could mediate an exaggerated regenerative response in the brain, participate as acute phase reactants, or be involved in the aberrant proteolytic processing of the amyloid proteins. Protease inhibitors are, therefore, attractive targets for drug intervention in Alzheimer's disease. 相似文献