Maternal androgens in egg yolks: relation with sex,incubation time and embryonic growth

Hormones of maternal origin are known to be transferred to the egg yolks of oviparous species. Several studies have shown that within and between clutch variation of maternal androgens may be adaptively tuned. Moreover, it has recently been hypothesized that sex steroids of maternal origin may play a role in adaptive sex ratio manipulation. For sex determination the eggs have to be incubated to allow the germinal disc to grow and thus extract sufficient DNA. This means that yolk hormone levels are determined after a number of days of incubation and this may hamper interpretation of the data. If yolk utilization or embryonic hormone production are influenced by the sex of the embryo, differences in hormone content at a certain stage of incubation do not reflect the mother's initial allocation. In this experiment we show that testosterone levels in chicken eggs do not change with incubation period. A4 levels decrease between 3 and 5 days of incubation, which we cannot explain. Male eggs did not contain higher levels of testosterone or androstenedione than female eggs, in contrast to the data reported for another galliform species, the peacock. We conclude that it is unlikely that maternal androgens are a key factor in the avian sex determination mechanism.     

晚发生维生素K缺乏症12例报告

作者通过对12例晚发性维生素K缺乏症的临床疗效观察,分析了它的发病原因、发病年龄和临床表现,概括了本病的诊断、治疗和预防方法,并讨论了早期诊断、早期治疗和预防对晚发性维生素K缺乏症的发生、发展和预后的重要性。     

HEART RATE, SKIN CONDUCTANCE, AND INTENSITY RATINGS DURING EXPERIMENTALLY INDUCED ANXIETY: HABITUATION WITHIN AND AMONG DAYS

Twenty Ss were divided into two groups according to whether they received as a noxious stimulus in a count-up a mild shock or a punishing sound. Trials were varied over as well as within days. Among the findings: (1) There was considerable evidence of response fractionation among and within measures of heart rate, skin conductance, and rated stimulus intensity. (2) Trials over days exhibited an incubation effect for shock in the skin conductance data, a displacement of maximum heart rate reactivity toward the beginning of the time dimension, and a greater degree of habituation of the rated intensity of the shock stimulus than of the sound stimulus. It was concluded that habituation and incubation reflect cognitive processes, that the forward displacement of heart rate is the result of a centrally mediated inhibitory process, and that the gradient of such inhibition is steeper than the gradient of anxiety.     

孵化理论在基层医疗机构急诊急救护理能力建设中的应用效果分析

目的探讨医联体背景下孵化理论在基层医疗机构急诊急救护理能力建设中的应用效果。方法对南通市两家基层医疗机构的护理人员进行急诊急救理论和技能培训,对护理管理者进行管理工具等培训。结果经过孵化培训后,两家基层机构护理管理者管理能力得到提高;急诊护理人员理论及技能水平均得到提升,差异具有统计学意义（P＜0.05）。两家基层医疗机构急诊护理人员对培训效果满意。结论医联体背景下孵化理论在基层医疗机构急诊急救护理能力建设中应用能够提高基层医疗机构急诊急救水平。     

人脂肪间充质干细胞体外分离、培养的方法研究

目的：探讨人脂肪间充质干细胞体外分离及培养方法。方法用消化离心的方法获得人脂肪间充质干细胞,以1×104/cm2接种于体积分数为0．1％胎牛血清的LG-DMEM培养基中,并进行细胞形态学观察,绘制细胞生长曲线,流式细胞仪检测细胞表面抗原,行成脂及成骨诱导检测其多向分化潜能。结果获取的脂肪间充质干细胞大小较为均匀,呈梭形的成纤维细胞样,细胞增殖良好;细胞生长曲线测定表明接种后第4天细胞进入指数增长期,第8天后生长进入平台期,体外能长期培养存活,并保持不分化状态;流式细胞仪检测表明细胞高表达 CD13、CD73,低表达 CD34、CD45及 HLA-DR;能诱导成脂及成骨细胞。结论利用消化离心法在体外能分离得到脂肪间充质干细胞,细胞生长良好,可作为组织工程的种子细胞。     

北京市新型冠状病毒Omicron BA.2和BF.7变异株感染者潜伏期特征分析

目的 对北京市由新型冠状病毒（新冠病毒）Omicron BA.2和BF.7变异株引起的疫情中的感染者进行流行病学调查，估算2种变异株分支的潜伏期及其影响因素，为新冠病毒传播动力学模型的建立提供基本参数。方法 选取北京市2022年4月（Omicron BA.2变异株）及10月（Omicron BF.7变异株）疫情中具有明确暴露时间和发病时间的感染者进行研究，采用秩和检验对不同变异株的潜伏期差异进行分析。使用Weibull、Gamma和lognormal分布对Omicron变异株的潜伏期分布进行拟合。采用多因素方差分析比较不同年龄、性别、变异株类型及疫苗接种状态下的潜伏期。结果 共纳入64例BA.2变异株感染者及58例BF.7变异株感染者。BA.2和BF.7变异株感染者潜伏期M（Q₁，Q₃）分别为3.00（3.00，4.00）d和3.00（2.00，3.25）d。lognormal分布的拟合效果最佳。多因素方差分析结果显示，不同类型的Omicron变异株潜伏期存在一定差异，与BA.2变异株感染者相比，BF.7变异株感染者的潜伏期更短。结论 Omicron BF.7变异株感染者潜伏期较BA.2变异株的潜伏期短。