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91.
The growth-promoting activities of three different bovine sera have been compared in primary and secondary amniotic fluid cell cultures. In secondary amniotic fluid cell micro- cultures, aseptically collected calf serum (CS) was slightly, though not significantly more effective than fetal calf serum (FCS) in promoting DNA synthesis, while newborn calf serum (NCS) was significantly less effective than either CS or FCS. All three sera were optimally effective at concentrations of 10 per cent (v/v). Significant variation in quality occurred within four batches of each of CS and FCS, but not within four batches of NCS. A selected batch of CS was significantly more effective in promoting the growth of primary amniotic fluid cell cultures than were a number of batches of FCS then in routine laboratory use. It is suggested that CS may serve as an effective and economical alternative to FCS in the culture of amniotic fluid cells, thereby expanding the scope of serum batch testing. A possible explanation for the varying growth-promoting activities of different sera is discussed. 相似文献
92.
Among 5315 prenatal diagnoses performed for various indications (maternal age, neural tube defect, metabolic diseases, X-linked diseases, pathologic pregnancies) 29 unexpected structural chromosome rearrangements were found in fetal cells. Fourteen were de novo chromosome rearrangements, six unbalanced, and eight balanced. Fifteen were inherited and balanced rearrangements. This high frequency of structural anomalies is discussed. 相似文献
93.
废钻井液、泥浆的处理与控制对策 总被引:2,自引:0,他引:2
赵荣峰 《安全.健康和环境》2006,6(5):32-33
介绍中原油田分公司实施源头控制,减少废钻井液产生和利用无害化技术处理钻井废弃泥浆的实践,分析存在的主要问题,提出减少废钻井液产生的控制对策. 相似文献
94.
95.
Liquefied natural gas (LNG) has been largely indicated as a promising alternative solution for the transportation and storage of natural gas. In the case of accidental release on the ground, a pool fire scenario may occur. Despite the relevance of this accident, due to its likelihood and potential to trigger domino effects, accurate analyses addressing the characterization of pool fires of LNG are still missing.In this work, the fire dynamic simulator (FDS) has been adopted for the evaluation of the effects of the released amount of fuel and its composition (methane, ethane, and propane), on the thermal and chemical properties of small-scale LNG pool fire. More specifically, the heat release rate, the burning rate, the flame height, and thermal radiation, at different initial conditions, have been evaluated for pool having diameter smaller than 10 m. Safety distances have been calculated for all the investigated conditions, as well.Results have also been compared with data and correlations retrieved from the current literature. The equation of Thomas seems to work properly for the definition of the height over diameter ratio of the LNG pool fire for all the mixture and the investigated diameters.The addition of ethane and propane significantly affects the obtained results, especially in terms of radiative thermal radiation peaks, thus indicating the inadequacy of the commonly adopted assumption of pure methane as single, surrogate species for the LNG mixture. 相似文献
96.
为研究超临界CO2注入采空区防灭火的规律,自主研制了产生超临界CO2和模拟采空区遗煤自燃升温试验系统,得到了不同温压条件下超临界CO2注入采空区前后不同监测点的温度、O2和CO浓度变化数据信息。试验结果表明:注入采空区的超临界CO2发生相变,有序结构急速失序,大量吸收热量,采空区内的煤体、空气温度随时间呈线性快速下降规律,其降温能力是气态N2的10倍;超临界CO2在自燃发火煤体中的强渗透扩散特性,使自燃煤体快速惰化,防灭火效率高;停止注入后,小范围回温符合反二次函数特征;高压力超临界CO2相对于低压条件,防灭火性能更佳;超临界CO2是1种降温降氧能力显著,且输送性能优良的采空区新型防灭火材料,超临界CO2防灭火效果优于气态N2。 相似文献
97.
4种中草药的超临界CO2萃取物对霉菌的抑制效果 总被引:1,自引:1,他引:1
利用气相扩散法、固相扩散法、平板法研究了荷叶、艾叶、佩兰、细辛4种中草药的超临界CO2萃取物对霉菌的抑制作用和最低抑制浓度(MIC).结果表明,4种中草药的超临界CO2萃取物对单一或混合霉菌均有较强的抑制作用,荷叶和细辛的MIC<1.56g/L,佩兰的MIC<0.63g/L,艾叶的MIC<0.2g/L.表3参11 相似文献
98.
99.
超临界流体萃取在研究土壤和沉积物结合态残留中的应用 总被引:2,自引:1,他引:2
许多有机污染物在土壤和沉积物中形成持久稳定的结合态残留;结合态残留对土壤和沉积物的解毒过程、污染物长期分配行为、生物可用性和生物毒性都具有重要影响。为了揭示结合态残留的形成机制及其对污染物环境行为和毒理学参数的影响,从土壤或沉积物中提取出不同结合状态的有机污染物就显得非常重要。超临界流体萃取(SFE)可以实现选择性萃取,从而得到有关污染物一基体间相互作用的信息。文章介绍了SFE应用类型、超临界流体种类以及影响SFE萃取率的因素,对SFE模拟有机污染物长期吸附/解吸行为和生物可用性研究进行了论述,并认为SFE势必发展成为土壤或沉积物中结合态残留形成机理研究、土壤修复和生态风险评价的一种强有力的技术。 相似文献
100.
Complexity of seminal fluid: a review 总被引:2,自引:0,他引:2
Aldo Poiani 《Behavioral ecology and sociobiology》2006,60(3):289-310
The seminal fluid is a complex medium containing a great variety of molecules, mainly produced by sex accessory glands, and also cells other than spermatozoa (e.g. leucocytes). In this paper, I review current knowledge on composition of seminal fluid in both vertebrates (mainly mammals) and invertebrates (mainly insects) with internal fertilisation, in the light of possible benefits of seminal fluid components to males (e.g. sperm capacitation, sperm competition and fertilisation), possible costs to males (e.g. autoimmunity, antigenic effects), potential benefits to females being inseminated (e.g. food, immunostimulation and antibiotic effects) and potential costs to females (e.g. transmission of venereal diseases). The diversity of microorganismal, cellular and molecular components of seminal fluids can be interpreted in the light of emergence of co-adapted complexes, host–parasite coevolution, male–female arms races, sperm competition, pleiotropy and redundancy of function. 相似文献