Classification and cyclic fatigue evaluation of new kinematics for endodontic instruments

This study evaluated the effect of new motions of the motor TriAuto ZX2 on the cyclic fatigue of endodontic instruments. Vortex Blue 35.06 instruments were divided into four groups (n = 10) and tested for fatigue in a curved artificial canal (90° and 2 mm radius) using the following motions: continuous rotation (CR), Optimum Torque Reverse (OTR) set at 180° and the Optimum Glide Path (OGP), which was tested at 90° and 240°. The time to fracture (TTF) and the lengths of the fractured fragments were recorded. The mean TTF was significantly different among the groups (anova , P < 0.05): OGP 90° (213.39 ± 27.45), OTR 180° (121.24 ± 17.03), OGP 240° (45.24 ± 5.61) and CR (8.43 ± 1.27). Weibull analysis confirmed the shortest life expectancy for CR and the longest survival for OGP at 90°. The resistance to fatigue was affected by motions and pre‐set angles. The proprietary movements that are currently available for endodontic instruments were classified according to their kinematics.     

生物伯德图用于血压稳定性的分析和计算

本文用生物伯德图分析了血压稳定性。按照经典的控制理论,讨论了生物系统的稳定性,提出了血压控制的数学模型。根据生物特点,建立了生物伯德图的表达式。作为系统稳定性的指标,增益裕量和相位裕量可以用作图法求得,也可以用计算机求解。实验结果与理论分析能很好地符合。     

停—升—停多项式凸轮曲线族

提出三个多项式凸轮曲线族。使用者可根据不同的用途，用优化方法求得待定系数值，从满足边界条件的曲线族中挑选出一条综合性能最优的凸轮曲线。还提供了待定系数与所选凸轮曲线的诸特性值之间关系的图表。     

Spontaneous tension oscillation in skinned bovine cardiac muscle

 Skinned fibres from bovine ventricles exhibited spontaneous tension oscillations when MgADP and inorganic phosphate (Pi) were added to the solution bathing fibres in the relaxed state (ADP-SPOC). A similar type of oscillation was observed at intermediate concentrations of free Ca²⁺ in the absence of MgADP and Pi (Ca-SPOC). To investigate the correlation between ADP-SPOC and Ca-SPOC, we constructed two-dimensional state diagrams of cardiac muscle using different concentrations of Pi (0–20 mM) and free Ca²⁺ [pCa=around 5 (+Ca²⁺), pCa=5.15–6.9 and +EGTA (–Ca²⁺)], with varying concentrations of MgADP (0–10 mM), with 2 mM MgATP and 2 mM free Mg²⁺ maintaining ionic strength at 0.15±0.01 M, pH 7.0, 25 °C. The three-dimensional (pCa-Pi-MgADP) state diagram thus obtained was divided into three regions, i.e. the contraction region in which tension oscillation was undetectable, the spontaneous tension oscillation (SPOC) region and the relaxation region. We found that the regions of ADP-SPOC and Ca-SPOC were continuously connected by a single oscillation region sandwiched between the contraction and relaxation regions. The state diagram, which encompasses physiological conditions, shows that the probability of SPOC is higher in cardiac muscle than in skeletal muscle. From these results, we suggest that, despite distinct ionic conditions, the molecular state of cross-bridges during SPOC is common to both ADP-SPOC and Ca-SPOC. Received 19 February 1996 / Received after revision: 16 July 1996 / Accepted: 14 August 1996     

Series dead space volume assessed as the mean value of a distribution function

Series dead space (VdS) is assumed to be represented by that volume exhaled until alveolar gas is observed. Phase II of the single breath CO₂-diagram contains the (flow, concentration and sequence weighted) distribution off all stationary interfaces (SI) expired before phase III. We describe a new method to estimate the mean value of VdS based on the differentiation of phase II. This approximation of VdS is called the Pre Interface Expirate (PIE) and is compared in this study with the integrative approach of Langley. Tidal volume (Vt) and PEEP were varied from 71 to 123% and from 0 to 6 cmH₂O respectively.The estimation of VdS by differentiation of phase II (PIE) shows excellent reproducibility and depends only on phase II — not on phase III and IV as does VdS-Langley. PIE does not depend on Vt and PEEP per se but reflects the distension of convective airways due to elevated end-inspiratory airway pressure.Our results confirm the predictions of Paiva's model calculations in that the size of VdS is determined by the distension of airways rather than by the altered position of the SI.     

34家医院医保精细化管理案例的定性比较

目的探究实现我国医院医保精细化管理的不同路径。方法采用模糊集定性比较分析方法（fsQCA）对34家医院医保精细化管理案例进行组态分析。结果路径一:组织建设+制度建设+创新模式建设（边缘条件）;路径二:制度建设+创新模式建设;路径三:组织建设+信息化建设;路径四:信息化建设+创新模式建设。结论我国医院医保精细化管理实现路径可分为传统驱动型、创新技术驱动型和综合驱动型3种模式。医院可多元性选择,进一步探索医保精细化管理的现实路径。     

慢阻肺患者住院费用影响因素的通径分析

目的 为了解慢阻肺患者住院费用的主要影响因素,减缓住院费用过快增长,减轻患者、家庭及社会的经济负担,优化医疗服务价格体系提供科学依据。方法 收集贵州省某三甲医院2015—2019年的9 223例慢阻肺患者病案首页信息,对慢阻肺患者的住院费用和住院天数进行描述性分析,并采用多元回归分析拟合通径分析模型的方法,研究慢阻肺患者住院费用的影响因素。结果 慢阻肺患者的人均住院天数为12.4 d,人均住院费用为18 598.81元,60岁以上患者占比达87.3%,医保患者占73.5%,且住院天数是影响住院费用的主要因素,总效应系数为0.719,危重型患者总效应系数为0.181排第二位。通径分析研究结果显示,年龄、医保、公费、危重、手术、药物过敏、医嘱离院不仅对住院费用存在着直接影响的效应,同时还通过住院天数间接影响着住院费用。结论 在不影响医疗质量的情况之下,按照临床路径的程序,合理缩短住院天数,并加强对于可控因素的限制,采取有效的措施,最大可能的减轻患者住院费用的负担。     

大黄-黄芪组分自微乳的制备及在体肠吸收特性研究

目的 研究大黄-黄芪多组分自微乳的处方与制备工艺,评价制剂质量,并考察其大鼠肠吸收特性。方法 通过溶解度实验、油相与乳化剂和助乳化剂配伍实验及伪三元相图的绘制,筛选出最优处方组成;并从自微乳的外观、形态、粒径、稳定性等方面对自微乳进行评价。通过大鼠在体单向肠灌流实验考察自微乳的肠吸收特性。结果 自微乳处方中油相为辛酸癸酸单双甘油酯、乳化剂为聚氧乙烯蓖麻油35、助乳化剂为乙二醇。在微乳形成区选择各辅料用量,采用适宜方法加入大黄总蒽醌及黄芪总皂苷制得的组分自微乳,外观均一透明,加水分散后形成黄色乳光的微乳液,透射电镜显微镜（transmission electron microscopy,TEM）下观察到微乳分散均匀,无黏连,呈大小均一圆球形乳滴;平均粒径为（33.01±0.12）nm、多分散指数（polydispersion index,PDI）为0.10±0.02、电位为（-10.10±1.00）m V;自微乳中大黄总蒽醌和黄芪总皂苷质量分数分别为6.29、8.80 mg/g。自微乳中大黄总蒽醌在十二指肠、空肠段的吸收速率常数（Ka）及表观吸收系数（Papp）较回肠段均有显著提高;黄芪...     

人格特征、自尊水平与航空兵部队人员心理健康的关系

目的:探讨航空兵部队人员人格特征、自尊水平与心理健康的关系。方法:运用EPQ、SES、SCL-90对443名航空兵部队人员进行调查。结果:神经质与SCL-90总均分成正相关(r=0.641,P<0.01);内外向与SCL-90总均分成负相关(r=-0.232,P<0.01);精神质与SCL-90总均分成正相关(r=0.398,P<0.01);自尊水平与SCL-90总均分成负相关(r=-0.381,P<0.01);神经质、精神质、自尊水平进入回归方程(P<0.001);神经质、精神质对心理健康有直接影响(效应系数分别为0.513和0.209);内外向、神经质通过影响自尊水平对心理健康具有间接效应(效应系数分别为0.216和-0.261)。结论:神经质、精神质和内外向是影响心理健康的因素,具有直接作用和间接作用两个方面;自尊是人格影响心理健康的中间环节。     

用Excel电子表格制作血常规室内质控图

目的 探讨用Excel电子表格制作血常规室内质控图的方法，提高质控图的质量。方法利用Microsoft Excel电子表格的函数计算功能，在活动单元格中输入各种质控参数及计算公式，自动计算平均值（x^-）、标准差（s）和变异系数（CV％），利用制作图表功能，设计制作质控图。结果每天在数据表中输入质控制，结果，计算机自动计算作图。可以对非随机因素引起的失控现象予以纠正。作好的质控图和数据表可以打印保存。结论用Excel电子表格制作室内质控图省时省力、美观准确。