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51.
Michael L. Freeman Paul Goldhagen Elaine Sierra Eric J. Hall 《International journal of radiation oncology, biology, physics》1982,8(8):1355-1361
Chinese hamster ovary (CHO) cells, in either exponential growth or unfed plateau phase were exposed to graded doses of radiation from Iodine-125 or from Cesium-137 at various dose-rates and the cells were assayed for reproductive integrity. From the patterns of cell survival obtained, the relative biological effectiveness (RBE) of the emission from 125I was determined relative to 137Cs. The RBE determined using cells in exponential growth was found to have a value of about 1.2, which was independent of the level of cell survival and did not vary over the dose-rate range from 7.5 to 53 cGy/hr. Using plateau phase cells the RBE has a constant value of about 1.3 between 13 to 46 cGy/hr, but is closer to 2.0 at lower dose-rates of 5 to 7 cGy/hr. 相似文献
52.
Criteria for maximum oxygen uptake in progressive bicycle tests 总被引:1,自引:0,他引:1
K. NiemelÄ I. Palatsi M. Linnaluoto J. Takkunen 《European journal of applied physiology》1980,44(1):51-59
Summary Different criteria for
O2 max in a progressive bicycle exercise were studied in 115 healthy subjects. In the repeated progressive tests performed on 16 men, aged 25–35 years, three types of
O2 response against work load were noticed: a linear increase, an unexpectedly high increase, and a plateau; the last two only appearing when
O2 max was achieved. The last three
O2 values at least were required to define the plateau. Most commonly, subjective exhaustion was achieved, respiratory quotient (R) was over 1.15 and maximal heart rate (HR) at the estimated level for age, though
O2 max was not achieved. No significant differences were found between peak
O2 in the first progressive test (mean=2.95 l/min), the second progressive test (mean=3.14 l/min), or the constant-load test (mean=3.05 l/min). In the progressive test performed once on 55 men and 44 women, aged 35–62 years, subjective exhaustion was achieved by most of the subjects, but the plateau in
O2 was shown only in 17 subjects, and the peak
O2 values were somewhat lower than expected. Moreover, R max did not correlate with peak
O2, and was over 1.15 only in 9 subjects, and HR max was often below the estimated level. Thus, the progressive test appeared to be convenient in testing the physical work capacity of the subjects, but the establishment of the physiological maximum was more difficult: the relatively uncommon plateau in
O2 was the only useful criterion for
O2 max, the value of other criteria being unacceptable. 相似文献
53.
为探讨多发性骨髓瘤(Multiplemyeloma,MM)平台期脱逸机制,以克隆性IgH基因重排作为骨髓瘤细胞克隆的基因标志,应用聚合酶链反应(PCR)基因扩增结合扩增产物直接测序技术分析不同临床期MM骨髓瘤细胞克隆IgH基因重排方式。结果23例MM中18例检测到克隆性IgH基因重排,不同患者的重排呈多样性,同一患者不同临床期骨髓瘤细胞具有相同的IgH基因重排,3例患者PCR扩增产物直接测序证实MM在病情演变过程中骨髓瘤细胞克隆IgH基因未发生突变或碱基置换。结论:MM平台期脱逸过程中,骨髓瘤细胞克隆本身并没有发生演变 相似文献
54.
目的探讨高原部队独生子女官兵的心理健康状况及其相关因素,为指导部队独生子女官兵心理工作提供依据。方法采用团体现场问卷调查方式对驻高原某部220名独生子女官兵进行焦虑自评量表(SAS)和抑郁自评量表(SDS)测评。结果独生子女官兵焦虑/抑郁的检出率分别为29.5%和39.1%;SAS总均分(粗分)为(34.66±8.52),SDS总均分(粗分)为(38.58±10.24)均与中国常模有明显差异(P<0.01);且年龄、军龄、职别、城乡差别及入伍动机均与焦虑/抑郁水平密切相关。结论①高原部队独生子女官兵存在较为严重的焦虑/抑郁情绪,且焦虑/抑郁水平较高;②高原环境因素及其产生的心理应激是焦虑、抑郁情绪产生的重要因素;③年龄、军龄、职别、城乡差别及入伍动机等因素均与焦虑/抑郁情绪的发生密切相关。 相似文献
55.
目的 探讨青海高原地区子痫前期患者胎盘及血清中人类白细胞抗原G(HLA-G)表达水平及临床意义.方法 收集2010年9月至2011年3月在青海大学附属医院产科分娩的30名子痫前期患者和30名正常妊娠妇女的胎盘组织和血清样品,应用实时定量RT-PCR技术研究HLA-G mRNA在正常妊娠者和子痫前期患者胎盘中的表达差异,并应用双抗体夹心酶联免疫吸附法(ELISA)检测血清中可溶性HLA-G的表达.结果 (1)青海高原地区子痫前期患者胎盘组织中HLA-GmRNA表达水平为1.42±4.92,明显低于正常妊娠组(9.00±9.94),差异有统计学意义(P<0.01);(2)子痫前期血清可溶性人类白细胞抗原G( soluble HLA-G,sHLA-G)浓度为688.34±181.988 ng/L,明显低于正常妊娠组织(1030.2±238.568ng/L),差异有统计学意义(P<0.01).结论 青海高原地区子痫前期胎盘组织HLA-GmRNA表达水平及血清sHLA-G浓度均明显降低,可能与子痫前期的发生有关. 相似文献
56.
57.
Pilon骨折一直是骨科难处理的一类骨折,近年来研究表明[1] Pilon骨折占胫骨骨折的7%~10%.胫骨远端Pilon骨折最常发生于高处坠落、车祸骤停、滑雪或绊脚前摔.胫骨轴向暴力或下肢的扭转暴力是胫骨远端关节面骨折的主要原因.目前国际上对其治疗方法争议较多[2].近年来随着城市建筑和交通道路的高速发展,胫骨远端Pilon骨折的发生逐渐增多.回顾分析我院16例小切口有限内固定治疗Pilon,骨折患者的临床资料,总结护理经验,现报告如下. 相似文献
58.
研究圣脑康丸抗缺氧、抗疲劳、耐寒的作用。方法:给小鼠以高、中、低(2.70、1.35、0.68g/kg)3个剂量圣脑康丸溶液灌胃,对照组灌等量蒸馏水;7d后小鼠分别进行常压密闭缺氧实验、抗疲劳实验、耐寒实验。结果:在小鼠常压缺氧实验中,圣脑康丸中剂量组(P〈0.01)高剂量组(P〈O.05),与对照组比较均能明显延长小鼠常压缺氧条件下存活时间;在小鼠抗疲劳实验中,圣脑康丸高剂量组(P〈0.05),与对照组比较均能明显延长小鼠在水中的存活时间;在小鼠耐寒实验中圣脑康丸3个剂量组都能明显降低小鼠的死亡率。结论:圣脑康丸具有明显的抗缺氧、抗疲劳、耐寒作用。 相似文献
59.
60.
Chabert M Viovy JL 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(9):3191-3196
We present a purely hydrodynamic method for the high-throughput encapsulation of single cells into picoliter droplets, and spontaneous self-sorting of these droplets. Encapsulation uses a cell-triggered Rayleigh-Plateau instability in a flow-focusing geometry, and self-sorting puts to work two extra hydrodynamic mechanisms: lateral drift of deformable objects in a shear flow, and sterically driven dispersion in a compressional flow. Encapsulation and sorting are achieved on-flight in continuous flow at a rate up to 160 cells per second. The whole process is robust and cost-effective, involving no optical or electrical discrimination, active sorting, flow switching, or moving parts. Successful encapsulation and sorting of 70-80% of the injected cell population into drops containing one and only one cell, with <1% contamination by empty droplets, is demonstrated. The system is also applied to the direct encapsulation and sorting of cancerous lymphocytes from a whole blood mixture, yielding individually encapsulated cancer cells with a >10,000-fold enrichment as compared with the initial mix. The method can be implemented in simple "soft lithography" chips, allowing for easy downstream coupling with microfluidic cell biology or molecular biology protocols. 相似文献