类金刚石薄膜的碳相成分对其血小板黏附特性的影响

对不同工艺和条件制备的 7个类金刚石薄膜 (Diamondlikecarbon ,DLC)试样 ,经X光电子能谱 (XPS)碳相成分分析后 ,分别进行了血小板黏附实验、黏附血小板的形貌观察、分类计数和形态指数计算 ,并通过灰色关联分析 ,研究了碳相成分对血小板黏附量、黏附血小板的形态指数的影响。结果显示 :来自全方位离子注入离子束增强沉积工艺的DLC ,其血小板黏附量和形态指数明显小于等离子体化学气相沉积工艺制备的样品 ;在DLC的 5种碳相成分中 ,DLC碳相与血小板黏附量和形态指数的 (负 )关联度远大于其它碳相成分 ,除此之外只有C H和C O碳相与血小板形态指数的 (正 )关联度较大。表明 :(1)DLC碳相对血小板黏附的影响远较其它碳相成分为大 ,增加DLC碳相的含量是优化DLC血液相容性的关键所在 ;(2 )C H和C O碳相对黏附血小板的变形有促进作用 ,须从工艺上抑制其产生或尽可能降低其含量 ;(3)采用全方位离子注入离子束增强沉积工艺有助于改善DLC的血液相容性。这些结论对设计与改进DLC的制备工艺具有重要的指导意义。     

Evaluation of quantitative aerosol techniques for use in bronchoprovocation studies

To investigate airway physiology by use of inhaled aerosols, it is frequently necessary to measure the actual amount of material deposited on the airway wall as well as the site of particle deposition. To satisfy these needs, radiolabeled aerosols and gamma camera techniques have been used to measure regional deposition of inhaled particles. To make quantitative measurements of the amount deposited, previous investigators have used a "phantom" technique to indirectly calibrate the gamma camera for the attenuation of gamma rays through the lungs and chest wall. For this calibration, the phantom is a simulated lung containing a known amount of radioactivity. Radioactive counts emitted from the phantom are assumed to be attenuated in the same manner as the intact human lung. The present article describes a technique to determine directly the amount of inhaled aerosol deposited in the lung and simultaneously to calibrate the gamma camera for each individual subject. We used right angle light scattering and a gamma camera to measure individual values of the deposition fraction (DF) of inhaled aerosol deposited in the lung and the coefficient of attenuation (AC) of gamma rays in normal and obstructed lungs of human subjects. Radiolabeled monodisperse aerosols 1 and 2 microns in diameter were used. Knowledge of the activity of the inhaled aerosol (microcurie per liter), the volume inhaled, and the measured DF determined each subject's AC (counts per minute per microcurie). DF varied by an order of magnitude in normal (0.04 to 0.48) and obstructed (0.16 to 0.75) of subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transport of molecules across tumor vasculature

The vascular-extravascular exchange of fluid and solute molecules in a tissue is determined by three transport parameters (vascular permeability, P, hydraulic conductivity, L_p, and reflection coefficient, ); the surface area for exchange, A; and the transluminal concentration and pressure gradients. The transport parameters and the exchange area for a given molecule are governed by the structure of the vessel wall. In general, tumor vessels have wide interendothelial junctions; large number of fenestrae and transendothelial channels formed by vesicles; and discontinuous or absent basement membrane. While these factors favor movement of molecules across tumor vessels, high interstitial pressure and low microvascular pressure may retard extravasation of molecules and cells, especially in large tumors. These characteristics of the transvascular transport have significant implications in tumor growth, metastasis, detection and treatment.     

Genetic Analysis Workshop II: pedigree analysis of a binary trait without assuming an underlying liability

A model for concordance in a binary measure that does not rely on the assumption of an underlying latent liability dichotomized about a threshold has been demonstrated for twin pairs [Hannah et al, 1983]. It is extended here to pedigrees of arbitrary structure by making an assumption that is, for small incidence rates, almost equivalent to postulating that relative risks are multiplicative. The model is applied to the workshop data to determine the extent to which the known structure of the simulated models can be recovered.     

Chemical and statistical considerations in the determination of partition coefficients of weakly ionizable drugs and poisons

Equations have been developed that relate the concentration (or a parameter directly proportional to concentration, such as optical absorbance) of a weakly ionizable solute in a water-immiscible phase, in equilibrium with an aqueous phase, to the pH of the aqueous phase, the partition coefficient of the unionized solute and the phase volume ratio. These relationships have been used in the design of experimental methods for determining partition coefficients, which require measurement of solute concentration in only one phase. Data obtained in this way permit ready recognition of deviations from assumptions made in the development of the model; these assumptions include insolubility of the ionized solute in the water-immiscible phase and lack of interaction between buffer components and solute. Conditions for optimal liquid—liquid extraction of weakly ionizable solutes are more easily recognized. With these techniques, the negative logarithm of the acid dissociation constant (pK′_a) and the logarithm of the octanol—water partition coefficient (log P) have been measured for warfarin (pK′_a = 5.15 ± 0.04; log P = 2.82 ± 0.06), strychnine (pK′_a = 8.29 ± 0.02; log P = 2.23 ± 0.04), phenol (pK′_a = 9.88 ± 0.02; log P = 1.75 ± 0.05), procaine (pK′_a = 8.11 ± 0.04; log P = 1.10 ± 0.08), and ephedrine (pK′_a = 9.92 ± 0.01; log P = 1.65 ± 0.04) at 21°C.     

评“McCall观察方法”——对一种色谱系统分配效果观察方法的商榷

本文通过理论分析和文献数据的分析,对McCall提出的色谱系统分配效果的观察方法提出了不同的看法,认为McCall方法中的所谓logK并不是常数。McCall的方法无论在理论上和实践上都是不妥的。     

Dissolution test for felodipine tablets using chemical oxidation in situ to maintain 'sink conditions'

A test model is described for the determination of the dissolution rate of the vasodilator, felodipine, a derivative of dihydropyridine that is practically insoluble in water. ‘Sink conditions’ are maintained by means of an oxidizing agent, ceric sulphate, which reacts rapidly with dissolved drug molecules in the dissolution fluid. A pyridine derivative is formed quantitatively in the oxidation reaction. The amount of dissolved felodipine is calculated from the concentration of the pyridine derivative, as determined by reversed-phase liquid chromatography. Dissolution rates depend on the concentration of the oxidizing agent so that high concentrations accelerate dissolution. The dissolution test suggested for 25-mg felodipine tablets is performed in 500 ml fluid that contains 5 mM ceric sulphate in 0.12 M sulphuric acid. The test is performed on single tablets with USP paddle equipment. Dissolution rates for nine different tablet compositions are correlated to such bioavailability parameters as maximum plasma concentration and total area under the plasma concentration—time curve. Interferences and limitations of the method are discussed.     

社区呼吸康复治疗在慢性呼吸系统 疾病患者干预管理中的应用*

摘 要： 目的：探究中老年人颈动脉斑块与血清25羟维生素D （25-OH-D） 的相关性。 方法：选取2019年1月—2020 年 12 月自愿参与该研究的上海市浦东新区北蔡社区常住居民 412 人为研究对象,测定及记录其一般临床资料及血清 25-OH-D 等实验室检测结果。依据血管 B 超结果将研究对象分为有斑块组 268 人和无斑块组 144 人,比较两组人群血清 25-OH-D水平差异,用Pearson相关性分析各变量的关系,采用logistic回归分析颈动脉斑块形成的危险因素。结果：有斑块 组血清 25-OH-D 为 （45.18±18.71） nmol/L,无斑块组为 （56.12±19.54） nmol/L,两组差异有统计学意义 （χ2=5.573,P＜ 0.05）。相关性分析显示颈动脉斑块与收缩压、HbA1c、年龄呈正相关 （r值分别为0.388、0.119和0.128,P值均＜0.05）;与 血清 25-OH-D 呈负相关 （r=-0.365,P＜0.01）。血清 25-OH-D 是颈动脉斑块形成的独立相关因素 （OR=0.973,95%CI： 0.960,0.985,P＜0.05）。结论：低水平血清25-OH-D是颈动脉斑块形成的独立危险因素。     

妊娠期糖尿病孕妇和糖耐量正常孕妇妊娠压力与社会支持的相关性研究

目的 分析妊娠期糖尿病（GDM）孕妇和糖耐量正常孕妇妊娠压力与社会支持的相关性,对比该相关性在两组间是否存在差异。方法 选取495名GDM孕妇和352名糖耐量正常孕妇,采用一般情况调查表、妊娠压力量表（PPS）和社会支持评定量表（SSRS）进行问卷调查,并运用典型相关分析来研究妊娠压力和社会支持的相关性。结果 GDM组与正常组孕妇都处于轻度压力状态（0.38±0.32分vs.0.38±0.31分, t =0.061, P> 0.05）,且社会支持度均相对较高（40.68±6.88分vs.40.66±6.71分, t=0.042 , P> 0.05）,组间比较显示差异无统计学意义。GDM组和正常组孕妇妊娠压力与社会支持均存在典型相关关系（ λGDM =0.291, F=4.282 ,P<0.01; λ正常 =0.271, F=2.900 ,P<0.01）。GDM组孕妇妊娠压力主要由“确保母子健康和安全”引起,且主观支持的影响较大;而正常组孕妇妊娠压力主要来自于“认同父母角色”,且客观支持的影响较大。结论 应重视孕妇的妊娠压力状态,根据妊娠压力来源的不同可提供有针对性的社会支持,减缓孕期压力,促进母婴健康。     

基于变异系数评价重症医学科DRG分组效能研究

目的评价重症医学科DRG分组的效能,发现存在的问题,为DRG付费或绩效考核提供建议。方法采用DRG分组器获得样本医院2016―2019年出院患者的分组结果。在2555名重症医学科出院患者中选取病例数排名前5位的DRG组作为DRG研究组。在351148名全院出院患者中筛选出DRG研究组的所有病例。对入组同一个DRG组的患者,根据其所属的出院科室分为全院组(包括重症医学科和非重症医学科出院患者)和重症医学科组(仅包括重症医学科出院患者)。通过计算住院费用的变异系数评价全院组和重症医学科组的组内同质性。结果在同一个DRG组中,重症医学科出院患者组住院费用的变异系数低于全院出院患者组,即对于同一个DRG分组病种,重症医学科出院患者单独评价时组内住院费用的同质性更高。结论应用DRG付费或绩效考核时,针对重症医学科出院的患者应考虑细化DRG分组或调整分组权重,以便形成更加科学合理的疾病分组。