R-相热处理镍钛锉预备S形树脂根管成形能力的体外研究

目的 比较TF、K3和EndoWave 3种机用镍钛锉预备S形树脂模拟根管的成形能力.方法 120个S形树脂模拟根管,随机分为3组,每组40例,使用TF、K3和EndoWave 3种器械分别进行根管预备,记录预备时间;数码显微镜获取预备前、后根管图像,使用Photoshop和ImageJ软件进行图像重叠,测量预备后根管冠方弯曲角度和根方弯曲角度的变化值;从根尖止点开始,每隔1 mm测量根管内、外侧壁树脂去除量,共10个测量点.以外弯量减去内弯量,表示中心定位能力.单因素方差分析进行统计学检验,显著性水平0.05.结果 TF预备时间为(14.00 ±4.56)s,显著短于K3和EndoWave[(59.53±35.92)s和(44.00±14.38)s] (P ＜0.05).3种器械预备后根管冠方和根方弯曲角度变化差异无统计学意义(P＞0.05).3种器械预备后,根尖弯曲处,TF在内侧壁树脂去除量显著小于EndoWave和K3(P＜0.05);冠部弯曲处,TF在外侧壁去除量显著小于K3(P＜0.05);根管直线段,TF在内侧壁的去除量显著小于EndoWave和K3(P＜0.05).中心定位能力方面,TF在距根尖孔L 5～ 9mm位点均显著优于EndoWave(P＜0.05);除距根尖止点6mm位点以外,其他位点TF均与K3差异无统计学意义.结论 TF预备S形树脂模拟根管效率高,不良预备形较少且根管偏移较小.     

Is it possible to make an accurate diagnosis based only on a medical history? A pilot study on women's knee joints

The purpose of this pilot study was to determine if an accurate diagnosis could be made concerning the knee joint using only the patients' medical history information. Only women were chosen for this study because of existing unpublished data on a cohort of 100 women with normal knees to act as a control (group I). From the 2,266 knee surgical procedures in the database of one surgeon, two other groups were selected. Group II was those women with only a torn medial meniscus. Group III were those women with only a torn anterior cruciate ligament (ACL). The medical history data of one half of the database were statistically analyzed to determine the questions that were the best predictors of each group. The medical history questions discovered to be best predictors were different from what might be expected from an individual surgeon's experience, expert opinion, or a medical consensus opinion panel, but the predictors did have a foundation in fact and are substantiated by statistical analyses. Using these predictors, a validation was performed on the other half of the database. When the top 142 predicting questions were used, the diagnostic accuracy was 98%; 98 of 100 of the “normal” group, 57 of 59 cases classified as having a torn meniscus, whereas 128 of 129 cases classified as having a torn ACL were correctly identified. When the only the 30 strongest predictors were used, the diagnostic accuracy was 85%: 100 of 100 cases were correctly classified as normal, 45 of 59 cases were correctly classified as having a torn meniscus, and 101 of 129 cases were correctly classified as having a torn ACL. This study demonstrated that statistical methods applied to medical historical data can make a differential clinical diagnosis of an unknown knee joint problem with high degree of accuracy and with statistical significance. In the future, computerized medical diagnostic instruments can be constructed using these statistical methods.     

透光法静脉旋切术治疗下肢静脉曲张46例围术期护理

目的:探讨Trivex系统治疗下肢静脉曲张的疗效及围术期护理方法.方法:对46例(57条肢体)下肢静脉曲张患者采用Trivex系统进行透光法静脉旋切术治疗,并给予术前充分准备和心理护理、术中配合、术后康复指导及并发症观察处理.结果:本组患者无严重并发症发生,无静脉曲张复发.结论:Trivex手术创伤较小、切口小、手术时间短、并发症少,是治疗下肢静脉曲张的较好选择,做好围术期护理有利于提高临床效果.     

机械预备对根管弯曲度改变的体外研究

目的 比较手工不锈钢K锉、步退法和机用旋转ProTaper镍钛锉、改良冠向下法对弯曲根管弯曲度的改变和根管成形的效果.方法 60个离体后牙的弯曲根管分成A、B两组,分别使用手工不锈钢K锉、步退法和机用旋转ProTaper镍钛锉、改良冠向下法进行机械预备,对根管预备前后的样本拍摄X线片,测量机械预备前后根管的弯曲度,分析预备前后根管弯曲度的改变.结果 两种预备法机械预备前后根管弯曲角度的差值有显著性差异（P=0.012）.结论 机用旋转ProTaper镍钛锉预备具有良好的根管成形效果.     

基于COSMIN指南对癌症患者支持性照护需求量表的系统评价

背景国内外用于评估癌症患者支持性照护需求的量表较多，但有关此类量表质量的标准化评价研究及不同量表间的横向比较研究较为缺乏，也少有研究者对此类量表的测量特性进行系统的整合与评价。目的评价中文版癌症患者支持性照护需求量表的测量学性能及研究的方法学质量。方法2021年4月检索中国知网、万方数据知识服务平台、维普中文科技期刊全文数据库、中国生物医学文献数据库、PubMed、EmBase、Web of Science、CINAHL Complete数据库，获取有关中文版癌症患者支持性照护需求量表测量学性能评价的研究，检索时限均为建库至2021年3月30日。由两位研究者独立筛选文献、提取资料后，采用健康测量工具遴选标准（COSMIN）系统综述指南，在对量表的测量特性及研究的方法学质量进行评价的基础上，综合评定中文版癌症患者支持性照护需求评估量表各测量特性的证据等级，并形成对于量表的最终推荐意见。采用描述分析法对评价结果进行汇总、分析。结果共纳入15项研究，涉及8个中文版癌症患者支持性照护需求评估量表〔癌症患者支持性照护需求简明问卷中文版（SCNS-SF34）、中文版支持性照护需求筛查工具（SCNS-ST9-C）、癌症患者综合需求评估量表（CNAT）、癌症需求简明问卷（CNQ-SF）、中文版癌症患者未满足需求量表（CaSUN-C）、癌症患者未满足需求简明量表（SF-SUNS）、晚期癌症患者需求评估问卷（ACNQ-41）、晚期癌症患者需求评估表简表（ACNQ-29）〕。就量表的测量特性质量而言，除ACNQ-29的内容效度为"未提及"外，其余7个量表的内容效度均为"不确定"；除CaSUN-C、SF-SUNS的结构效度为"充分"外，其余6个量表的结构效度均为"不确定"；SCNS-SF34、CNQ-SF、CaSUN-C、SF-SUNS的内部一致性为"充分"，ACNQ-41的内部一致性为"不充分"，其余3个量表的内部一致性为"不确定"；CNAT、CNQ-SF、ACNQ-29的假设检验为"未提及"，CaSUN-C、SF-SUNS、ACNQ-41的假设检验为"不确定"，SCNS-SF34、SCNS-ST9-C的假设检验为"充分"；除ACNQ-41的稳定性为"不充分"，SCNS-ST9-C、ACNQ-29的稳定性为"未提及"外，其余5个量表的稳定性均为"充分"；仅SCNS-SF34的跨文化效度为"充分"，其余7个量表的跨文化效度均为"未提及"。8个量表的推荐等级均为B级。结论SCNS-SF34的测量特性得到了最为全面的评价，其具有较好的信效度，且临床应用可行性高，可暂时被推荐使用，但上述结论仍有待更多高质量证据加以支撑。     

机用镍钛器械ProTaper预备细小根管的临床分析

目的评价机用ProTaper预备细小根管的临床效果。方法用机用ProTaper和Glyde乳膏（含乙二胺四乙酸,EDTA）对92例患者的92颗患牙进行根管预备,并采用冷侧压充填,其中细小根管66颗、遗漏根管17颗、有近中颊根第二根管（MB2）的上颌第一磨牙6颗、有MB2的第二磨牙3颗。结果66颗患牙141个细小根管扩通率为95．74％,X线片显示根充物锥度、流畅度好：2个上颌第一磨牙腭根欠充．4个根管根尖1/3发生台阶。17个遗漏根管全部扩通。9个MB2根管5个扩通,4个根管未扩通。全部病例术中无器械折断。结论机用ProTaper和EDTA预备细小根管是有效的、安全的,但仍存在一定的局限性。     

A Passive Magnetically and Hydrodynamically Suspended Rotary Blood Pump

A combined hydrodynamic–magnetic bearing allows the design of rotary blood pumps that are not encumbered with mechanical bearings and magnets requiring sensors or electrical power. However, such pumps have so far needed very small and accurately manufactured gaps between rotor and housing to assure effective hydromagnetic bearing behavior. In order to use this concept in disposable pump heads, a design that allows larger rotor‐housing gaps, and thus larger manufacturing tolerances, is needed. A pump with passive magnetic bearings and a gap between rotor and housing in the range of 0.5 mm was designed. Numerical simulations were performed to optimize the rotor geometry at low levels of shear stress. An experimental test stand was used to find a range of speeds and gap settings that resulted in low levels of vibration and useful pressure–flow relationships. Three different rotor geometries were tested using a viscosity‐adjusted test fluid. Blood damage tests were conducted within the desirable range of speeds and gap settings. In this study stable pump performance was demonstrated at total gap widths between 0.3 and 0.7 mm at flows of 0–10 L/min, with afterloads up to 230 mm Hg. Best performance was achieved with rotors sliding on a fluid pillow between the rotor and the outer housing at a gap distance of 50 to 250 µm. The inner gap distance, between the rotor and the inner housing, could be as great as 500 µm. Hemolysis tests on the prototype within the chosen operating range showed lower values (NIH = 0.0029 ± 0.0012 g/100 L) than the Biomedicus BP‐80 pump (NIH = 0.0033 ± 0.0011 g/100 L). In conclusion, it is possible to build rotary blood pumps with passive hydromagnetic bearings that have large gaps between their rotors and housings. Rotor behavior is sensitive to the position of the permanent magnetic drive unit. To minimize vibration and blood damage, the fluid gaps and the rotational speed have to be adjusted according to the desired operating point of the pump. Further study is needed to optimize the magnetic drive unit and to ascertain its ability to withstand inertial loads imposed by sudden movements and external shock.     

自制T形三维支架抗分离加压螺钉撬拨治疗胫骨平台骨折

目的 :观察T形三维支架抗分离加压螺钉经皮撬拨治疗胫骨平台骨折的疗效。方法 :首先手法矫正移位 ,残余移位则从胫骨一侧平台下做小切口 ,用撬拨器撬拨推挤骨块 ,塌陷≥ 5mm时用环钻植骨器取髂骨柱填塞。复位满意 ,在距关节面 1～ 1 5cm处平行拧入 1枚加压螺钉 ,再拧入螺母压紧 ,若骨块粉碎状 ,则加上带齿弧垫环抱。同法处理对侧骨块 ,将 2枚螺钉锁定到半环架上 ,再在胫骨中、上段前内侧拧入 2枚普通外固定螺钉并锁定在单臂架上 ,组合半环单臂支架。结果 :2 2例按Schatzker分类 :Ⅱ型 5例 ,Ⅲ型 6例 ,Ⅳ型 3例 ,Ⅴ型 4例 ,Ⅵ型 4例。平均随访 2 7年。均在 3个月内愈合 ,膝关节活动度平均 12 0°以上 ,无螺钉断裂、折弯、滑脱 ,无膝内外翻、感染。 16例达到解剖复位 ,6例接近解剖复位 ,按Hohl评分标准 ,优 15例 ,良 6例 ,可 1例。结论 :该法适应范围广 ,操作简便、固定可靠、创伤小、可早期功能锻炼 ,疗效好 ,便于临床推广。     

高压氧微重力培养提高冻存胰岛质量和移植效果的实验研究

目的 探讨胰岛冻存前后经高压氧细胞旋转培养系统(HORCCS)培养后移植入糖尿病大鼠能否提高胰岛移植的效果.方法 将分离纯化的大鼠胰岛分为:A.体外实验组:将各组大鼠胰岛经HORCCS培养或普通培养30 d,检测细胞内DNA和胰岛素含量,胰岛存活率,胰岛素分泌水平.B.胰岛移植实验组:将各组大鼠胰岛经HORCCS培养或普通培养7d,然后移植,观察移植受体血糖和胰岛素水平.电镜观察各胰岛移植实验组中培养7 d时的胰岛的超微结构改变.结果 经高压氧 RCCS培养14 d的胰岛存活率及胰岛素分泌水平高于普通培养组(P<0.05).移植了经HORCCS培养的胰岛后,受体血糖在移植后2周即恢复为正常值,并维持到移植后10周.全部受体维持正常血糖耐受曲线.电镜下可见经HORCCS培养后,冻存复苏胰岛表面形成微小的孔道.结论 胰岛冻存前后经高压氧RCCS培养后可以建立营养输送管道,不但有利于氧和营养物质的运输,更有利于胰岛内细胞的均匀一致的冻存,从而减少冻存对胰岛的损害,提高胰岛的分泌活性和成活率.     

Analysis of the arterial blood pressure waveform using Fast Fourier Transform technique during left ventricular nonpulsatile assistance: in vitro study

The arterial blood pressure waveform is variable during left ventricular assistance. The aim of this study is to examine the correlation between the left ventricular assist device (LVAD) condition and the arterial blood pressure waveform in a fixed cardiac output condition using a mock circuit. This mock circulation loop was composed of an aortic compliance chamber, a left atrial compliance chamber, a pneumatic pulsatile pump as a native heart, and a rotary blood pump representing the LVAD with left atrial drainage. The Fast Fourier Transform technique was utilized to analyze the arterial blood pressure waveform and calculate the pulsatility index (PI) and the pulse power index (PPI). The PI and PPI decreased with the increase of the LVAD rotational speed, exponentially. There was a significant negative correlation between the PI, PPI, and the LVAD rotational speed, flow rate, and assist ratio. The best correlation was observed between the PPI and the assist ratio (r = 0.986). From this viewpoint, an ideal LVAD condition may be estimated from the pulsatility change of the arterial blood pressure waveform.