急性缺氧下听觉运动反应的研究

受试者为9名男性青年。在低压舱模拟海拔3000、4000、5000和6000m,分别进行1h实验,共36人次。各高度上停留时作听觉检测,并记录了脑电和主诉。结果表明,在3000m,人的听觉运动反应基本正常;而在5000m、6000m,听觉运动反应的正确率、延时率、遗漏率和反应时等多项指标发生显著变化,工效降低。本研究为急性缺氧防护生理标准和缺氧耐力提供了工效的依据。     

急性缺氧性缺氧时心脏功能的改变

F_(IO_2)(吸入气氧浓度)为12.35、9.87及7.7l％,分别吸入10、8及5min时,心功能呈代偿性增强改变。F_(IO_2)为9.37％、吸入20min时心功能的变化趋势与9.87％8min时仍基本相同。继发性缺二氧化碳对缺氧引起的心功能代偿性增强,在一定程度上起抵消作用。F_(IO_2)为9.87％时的缺氧程度约相当于18km高空加压供氧总压值为15.3kPa(115mmHg)时的缺氧。单纯从缺氧因素考虑,将总压值由常用的17.3kPa(130mmHg)降低为15.3kPa是可允许的。     

急性低氧对大鼠血液中儿茶酚胺及血小板聚集性的影响

健康ＳＤ雄性大鼠,体重２５０－３００ｇ,麻醉、气管插管,用人工呼吸机经气袋供气,自发吸入氧浓度为９％的氧氮混合气,用高效液相色谱－电化学联合检测法及电阻法检测循环血液中儿茶酚胺及全血血小权聚集性的动态变化。结果：急性低氧１５ｍｉｎ时血液中肾肾上腺素（Ａ）浓度及全血血小板聚集性显著增加（Ｐ〈０．０１）,而去甲肾上腺素（ＮＡ）浓度虽有所增加,但无统计学意义（Ｐ〉０．０５）;复氧１５ｍｉｎ时血液中儿茶酚     

On some formulas in a partnership model from the perspective of a semi-Markov process

Many deterministic models of sexually transmitted diseases, as well as population models in general, contain elements of stochastic or statistical reasoning. An example of such a model is that of Dietz and Hadeler (1988) concerning sexually transmitted diseases in which there is partnership formation and dissolution. Among the interesting formulas in this paper, which enter into the analysis of the model, are those for the expected number of partners a male or female has during a lifetime. To a probabilist such formulas suggest the possibility that some stochastic process may be constructed so as to yield these formulas as well as others that may be of interest. The principal purpose of this paper is to demonstrate that such a stochastic process does indeed exist in the form of a three state semi-Markov process in continuous time with stationary laws of evolution and with a one-step density matrix determined by four parameters which were interpreted as constant latent risk functions in the classical theory of competing risks. This construction of a semi-Markov process not only provides a framework for the systematic derivation of the formulas of Dietz and Hadeler but also suggests pathways,for extensions to the age-dependent case.This research was partially supported by NATO Grant D.890350     

The ‘World Prodigy’ oil spill in Narragansett Bay,Rhode Island: acute effects on macrobenthic crustacean populations

On June 26,1989, the tanker World Prodigy ran aground just outside the mouth of the West Passage of Narragansett Bay, Rhode Island, USA. About 922 metric tons of No. 2 fuel oil were released into the water and drifted over a total area of about 120 sq miles. Three days after the spill only a small fraction of the oil remained.The effects on macrobenthic crustaceans within the first five weeks after the spill were studied at five stations with a varying degree of oil exposure, including one control site never reached by oil from the spill. Significant differencies between these stations were noted for total amphipod abundance, the amphipod genus Ampelisca and ostracods (retained on a 0.3 mm mesh), but not for amphipods of the genus Corophium. At the most heavily impacted station (23 µg oil g^–1 sediment dry weight), the total amphipod abundance, dominated by Ampelisca verrilli, decreased by 86% within the first two weeks after the spill. Decreases in total amphipod abundance significantly larger than at the control site were noted also at two other stations, one of which with only trace amounts of oil detected in the sediment. The amphipod populations at these sites were dominated by juvenile specimens.These findings confirm the extreme sensitivity to oil pollution of amphipods and ostracods, noted in earlier field and experimental studies.     

聚焦色谱法测定肌型肌酸激酶亚型

报道了测定CK-MM亚型的聚焦色谱法,此法简单,快速,结果可靠,线性范围宽,最低检测限（8U／L）较正常参考值低,比国外报道的类似方法高6倍以上,分离度亦有改进.测定了20例健康人血清亚型分布,与文献报道结果相近.该法自动化程度高,已在急性心梗的诊断中实际应用.     

低氧低二氧化碳对大鼠脑血流的调节作用

低氧下脑血流与急性高原病有关,许多研究已证明,低氧不适应者的ＣＢＦ明显高于低氧适应者,而高原世居者则低于海平正常值。低氧下低动脉血二氧化碳分压有对抗低氧扩血管及降低ＣＢＦ的作用。因此研究低氧下低ＰａＣＯ２对ＣＢＦ的调节作用对于研究急性高原病的防治及其机理分析具有重要意义。本项研究目的：（１）揭示低氧下低ＰａＣＯ２与ＣＢＦ之间的关系;（２）通过增加通气量使ＰａＣＯ２下降至合适水平,以保护脑血流维持在     

MPEG－SOD对急性低氧下鼠左心功能的保护作用

单甲氧基聚乙二醇（ＭＰＥＧ）活化后与超氧化物歧化酶（ＳＯＤ）偶联,经纯化后得到ＭＰＥＧ－ＳＯＤ,鉴定其分子量约为７．０×１０５Ｄａｔｉｏｎ。其在血液循环中酶活性半衰期超过３０ｈ,远大于天然ＳＯＤ（６－１０ｍｉｎ）。ＳＤ雄性大鼠分三组．对照组（ｎ＝８．由股静脉注入０．２ｍｌ生理盐水）、ＮａｔｉｖｅＳＯＤ组（ｎ＝８,注以０．２ｍｌ生理盐水配的８００ＵＳＯＤ）和ＭＰＥＧ－ＳＯＤ组（ｎ＝９,注以８００ＵＭＰＥＧ－ＳＯＤ）。低氧前三组鼠的心率（ＨＲ）、左室内峰压（ＬＶＰ）、左室压微分（ＬＶ±ｄｐ／ｄｔｍａｘ）和股动脉压（ＡＰ）均无统计学差别。在模拟６０００—６５００ｍ高度急性低氧１．８．１４ｍｉｎ记录上述各项指标,结果如下：除ＨＲ外,ＮａｔｉｖｅＳＯＤ组与对照组各指标均无统计学差别,ＭＰＥＧ－ＳＯＤ组的各项指标均明显高于对照组。表明ＭＰＥＧ－ＳＯＤ对急性低氧导致的左心室力学指标的减弱有明显保护作用,提示超氧自由基（Ｏ２－）在急性低氧导致左心室功能损伤中起重要作用,即可能是由Ｏ２－及其衍生的其它自由基损害心肌细胞生物膜系统所致。     

内毒素致大鼠肺损伤时肺组织β受体的变化与膜磷脂代谢的关系

采用放射性配基结合分析法,现察内毒大致大鼠急性肺损伤时肺β－肾上腺素能受体（β－ＡＲ）的变化。分别用荧光偏振法和高效液相色谱测定肺组织细胞膜脂流动性和磷脂含量。结果显示：（１）静脉注射内毒素后４ｈ,大鼠肺β－ＡＲ的最大结合容量明显降低,较对照组减少４７％;（２）内毒素组肺膜脂流动性和磷脂含量均明显降低,同时伴有肺组织磷脂酶Ａ２（ＰＬＡ２）活性升高。提示：（１）β－ＡＲ下调导致其介导的功能减弱,在内毒素诱导的大鼠急性肺损伤发病机理中起一定作用;（２）ＰＬＡ２激活是膜磷脂减少的重要原因,后者可导致膜脂流动性降低,结果引起β－ＡＲ的侧向扩散和旋转运劝减弱,从而减少β－ＡＲ与配基结合的机率,出现β－ＡＫ下调。     

高原鼠兔氧比传导特征的实验研究

本实验采用国外新近提出的一项能综合评价机体气体交换系统中各氧降阶差时运氧能力的适应水平高低的重要指标──氧比传导（ＭＯ２－ＳＣ）,研究了高原鼠兔气体交换系统运氧能力的低氧适应特征及规律。结果表明,对照条件下,在吸入气（Ｉ）至肺泡气（Ａ）（Ｉ→Ａ）、Ａ至动脉血（ａ）（Ａ→ａ）、ａ至混合静脉血（ｖ）（ａ→ｖ）及Ｉ→ｖ各阶差中,以Ａ→ａ的ＭＯ２－ＳＣ运氧能力最大。低氧１５ｍｍ后,Ｉ→Ａ及ａ→ｖ的ＭＯ２－ＳＣ均显著升高,并以Ｉ→Ａ增加最为显著,该水平运氧能力是对照的２倍,增长１２０．９％;而Ａ→ａ及Ｉ→ｖＭＯ２－ＳＣ变化无显著性差异。低氧３０ｍｉｎ时,Ｉ→Ａ的ＭＯ２－ＳＣ继续显著增长,运氧能力是对照的２．７倍,增长１７０．７％,其余３个氧降阶差的ＭＯ２－ＳＣ无显著性改变。以上结果表明,高原鼠兔低氧代偿贮备较大,尤以肺泡气至动脉血阶差最为重要,而通气氧传导能力的增强也是高原鼠兔低氧适应的主要原因。