Examination of the Diagnostic Value and Estimation of the Chaos Phenomenon in Temporomandibular Joint Sounds Using Fractal Dimension

.The aim of this study is to estimate the chaos phenomenon in temporomandibular joints (TMJ) sound using fractal dimension (FD), and to examine the diagnostic value of the FD in comparing TMJ sounds produced by 6 asymptomatic and 25 symptomatic TMJ. Multiple mandibular opening and closing cycles recorded were used to calculate the waveform dimension and correlation dimension in the FD. Chaos in the TMJ sounds was estimated by the FD that was saturated with some constant value to an increase of embedding dimension. Results reveal that fractal analysis produces a high degree of reproducibility within, and similarity across subjects, and indicate that both FD values of the asymptomatic TMJ sounds are significantly higher than those of the symptomatic. These findings suggest that chaos is present in TMJ sounds and the difference in the FD is of diagnostic value in evaluation of pathological change in TMJ sound signals.     

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.     

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。     

水—DMF—NaCl系统活度系数和粘度测定

利用电池电动势法测定了298.15K下NaCl在不同DMF含量的水－DMF混合溶剂中的活度系数。结果表明,随着混合溶剂中DMF含量的增加NaCl的活度系数减小,测定了水－DMF－NaCl混合物在不同温度下的粘度。