工业X射线探伤防护剂量水平的研究

本文介绍了用实验方法研究不同管电压, 钢板厚度与散射线之间的关系.结果表明, 透射比随管电压升高而增加, 并随钢板厚度增加而下降；散射比随散射角的增大而逐渐下降, 至180°时为最低值。此研究为X射线探伤作业的辐射防护提供了依据。     

两种剂量奥曲肽治疗食管及胃曲张静脉出血效果比较

①目的　比较两种剂量奥曲肽治疗食管、胃曲张静脉出血的临床效果。②方法　将 88例食管、胃曲张静脉出血病人随机分为奥曲肽 5 0 μg/h和 2 5 μg/h剂量组 ,观察平均止血时间、止血率、再出血率和不良反应。 ③结果　 5 0 μg/h组平均止血时间明显短于 2 5 μg/h组 (t=2 .2 4 ,P <0 .0 5 ) ,总止血率明显高于 2 5 μg/h组 (χ2 =5 .36 0 ,P <0 .0 5 ) ,再出血率较 2 5 μg/h组低 (χ2 =7.990 ,P <0 .0 5 )。两组均有 1例病人出现恶心。④结论　奥曲肽 5 0 μg/h剂量治疗食管、胃曲张静脉出血的效果优于 2 5 μg/h剂量     

桡骨与尺骨的测量及回归分析

本文测量了桡骨与尺骨各100例,其中桡骨15项指标,尺骨14项指标。并用IBM·PC—XT计算机DBASEⅢ数据库管理系统进行了统计分析以及用桡、尺骨最大长分别与桡、尺骨其它各项指标间进行直线相关分析,建立了25个回归方程。     

我国食品放射性含量及其所致居民内照射剂量估算

为获得我食品和膳食中放放射性核素含量并为制定?食品中放射性物质限制浓度标准?提供依据,在1982～1086年问由30个辐射防护单位协作,测定了我过14类(27种)特定食品种22种放射性核素浓度.按我国三种主要膳食食类型．从14个正常本底辐射的省或自治区及三个非正常地区采集样品进行分析测定.估算了这些地区居氏15种放射往核素的年摄人最及所致待积剂量毒量.我国正常本底辐射地区成年男子对这15种核索年总摄入量约为4．2×10⁴Bq,所致总待积剂量当量约为0．43×10⁴Sv.在两个天然放射性较高地区天然放射性核素的年摄入量和所致待积剂量当量比正常本底辐射地区高得多,而在该核工厂周围地区采集的食未明显放射性污染.文章还讨论了各类食品或放射性核素对总待积剂量当量的相对贡献.     

The relationship between receptor-effector unit heterogeneity and the shape of the concentration-effect profile: Pharmacodynamic implications

The apparent concentration-effect relationship is the ensemble of many effector units (such as individual cells or channels) that do not always exhibit a uniform stimulus-effect relationship. This concept is substantiated by many observations of heterogeneity in receptor-effector populations including hormone secreting cells, response to hormonal stimuli, activity pattern of second messengers, stimulus-evoked synaptic currents, and single ion channels. The relationship between drug concentration and magnitude of pharmacologic response is commonly described by the sigmoidalE _max model which was derived from the Hill equation. The sigmoidicity factor (N) in this model is assumed to be a pure mathematical parameter without physiological connotations. This work demonstrates that the numerical value ofN (measured empirically) is the product of two factors: (i) the degree of heterogeneity of the effector subunits, i.e., the elemental component that upon drug stimulus contributes its pharmacological effect independently and does not interact with other subunits (it could range from a single receptor up to a whole tissue), and (ii) value ofN ^*—the shape factor of the subunits' concentration-effect relationship. A special case of this approach occurs whenN ^*>5, which is an on-off case. HereN is determined by the distribution (density equation) of the subunit values. In case of heterogeneity of the microparameters of the effector subunits the apparentN will always have a lower value thanN ^*. According to this theory it can be concluded that without knowledge of the distribution of the microparameters no mechanistic interpretation can be deduced from the apparentN value. If in the futureN ^* can be determined by theoretical or experimental methods, the distribution function relatingN ^* toN can be calculated. The relevance of this theory is increased in view of the progress being made in advanced research techniques which may enable us to determine the concentration-effect relationship at the level of the individual effector unit.     

A 500‐ml plastic bottle: An effective spacer for children with asthma

Inhaled therapy using a metered‐dose inhaler (MDI) with attached spacer has been increasingly recognized as the optimal method for delivering asthma medication for acute attacks and chronic prophylaxis. However, in developing countries the cost and availability of commercially produced spacers limit the use of MDI‐spacer delivery systems. A 500‐ml plastic bottle has been recently adapted to function as a spacer. This article reviews the current data on the efficacy of this bottle‐spacer and discusses its advantages and limitations. It is concluded that a modified 500‐ml plastic bottle is an effective spacer; modification and use of this device should be incorporated into international guidelines for the management of children with asthma.     

Infection dynamics and virus-induced apoptosis in cell culture-based influenza vaccine production—Flow cytometry and mathematical modeling

Cell culture-based influenza vaccine manufacturing is of growing importance. Depending on virus strains, differences in infection dynamics, virus-induced apoptosis, cell lysis and virus yields are observed. Comparatively little is known concerning details of virus–host cell interaction on a cellular level and virus spreading in a population of cells in bioreactors. In this study, the infection of MDCK cells with different influenza A virus strains in lab-scale microcarrier culture was investigated by flow cytometry. Together with the infection status of cells, virus-induced apoptosis was monitored. A mathematical model has been formulated to describe changes in the concentration of uninfected and infected adherent cells, dynamics of virus particle release (infectious virions, hemagglutinin content), and the time course of the percentage composition of the cell population.     

卵巢低反应患者大剂量超排卵的助孕结局

在辅助生殖助孕中通常采用控制性卵巢刺激(controlled ovarian hyperstimulation, COS),以获得适当数量的卵子用于体外受精,既希望获得理想的辅助生殖助孕成功率,又能降低卵巢过度刺激并发症.COS中约有9%~24%[1,2]的卵巢低反应发生率.卵巢低反应者获得有效卵子数少、可移植胚胎数少或无胚胎移植、取消治疗周期率高,累计成功率更低等,导致较差的治疗结局,是辅助生殖助孕中面临的棘手问题.针对卵巢低反应者,大多数辅助生殖中心仍会采用增加促性腺激素(Gn)的起始和(或)总用量以期获得提高助孕结局的目的.而大剂量Gn是否为改善低反应患者助孕结局的有效策略却仍存在争议.