高原小型制氧机应用质量专用检测装置的设计与研究

目的：解决现有高原小型制氧机应用质量控制检测手段中使用设备多、不便携带、方法繁杂等困难和问题,研究并制作一种适应高原边防环境需求的检测装置。方法：利用微处理器多任务处理的能力,采用模块化设计方案,设计制作出将氧气体积分数、输出压力、输出流量、环境等多个物理参数统一由主控微控制单元（micro control unit,MCU）集中处理并输出显示的检测仪器。结果：经过设计制作人员和高原部队的实地使用测试,验证了该测试仪达到了体积小、质量轻、操作简便、数据准确的预期目标。结论：该检测装置简化了高原小型制氧机应用质量控制检测的方法和过程,方便了高原部队和检修人员展开工作。     

便携式太阳能制氧机结构设计

目的：设计一种基于太阳能充电的便携式制氧机。方法：根据太阳能电池板的发电原理,通过柔性太阳能电池板将太阳能转化为电能并储存在储能电源中,采用变压吸附制氧工艺设计便携式制氧机。结果：便携式太阳能制氧机主要由制氧主机、太阳能电池板、储能电源及箱体组成．制氧流量为l～3L／min,氧气体积分数为50％一90％．储能电源充电时间约为7h,储能电源容量为40Ah,太阳能电池板输出电压为DCl2V。结论：太阳能充电为便携式制氧机提供了可靠的电源保障,延长了制氧机的使用时间,保证能及时制备应急呼吸用氧气,实现了无外接电源供应时制氧机的正常使用。     

髌骨爪包裹技术治疗髌骨下极骨折

<正>2012年1月~2013年1月,我院采用髌骨爪包裹技术治疗的67例髌骨下极骨折患者,疗效良好,报道如下。1材料与方法1.1病例资料本组67例,男40例,女27例,年龄21~70岁。全部为闭合新鲜髌骨下极骨折。受伤至手术时间为2~12 d。1.2手术方法硬膜外麻醉。取髌前纵行直切口,将骨折端复位,用克氏针或5号爱惜邦线临时缝合固定,对撕裂的     

Low prevalence of patellar tendon abnormality and low incidence of patellar tendinopathy in female collegiate volleyball players

ABSTRACT

The prevalence of patellar tendinopathy has been reported to be as high as 50% in elite male volleyball (VB) players; however, the rate of injury in female collegiate VB athletes is unknown. The purpose of this study was to 1) identify the prevalence of ultrasonographic evidence of patellar tendon abnormality at the start of the preseason in female collegiate VB players; 2) report the incidence of tendinopathy during the season; and 3) determine if the preseason presence of tendon abnormality is associated with onset of disease. One hundred and six female collegiate VB players had both patellar tendons imaged. Incidence of patellar tendinopathy was tracked during the course of the 4-month season. Twenty-two athletes presented with ultrasonographic evidence of patellar tendon abnormality in at least one knee at the start of the preseason. The incidence of time-loss patellar tendinopathy was 0.26 (95% CI: 0.04, 0.85) per 1000 athletic exposures. This study was unable to determine if preseason presence of tendon abnormality was associated with a greater risk of tendinopathy due to power. The prevalence of tendon abnormality in the preseason and the incidence of patellar tendinopathy in female collegiate VB players are lower than that observed in other populations.     

Shaping Ability of Different Nickel-Titanium Systems in Simulated S-shaped Canals with and without Glide Path

Introduction

The objective of this study was to compare the shaping ability of different rotary and reciprocating nickel-titanium file systems with and without previous glide path preparation in simulated S-shaped canals.

Methods

One hundred twenty S-shaped canals in resin blocks were prepared to an apical size 25 by using Reciproc, WaveOne, HyflexCM, F360, and OneShape systems either with or without previous glide path preparation (Pathfile) (12 canals/group). Material removal was measured at 20 measuring points, beginning 1 mm from the end point of preparation. Incidence of canal aberrations (zip/elbow, ledge formation), preparation time, and instrument failures were also recorded. Statistical analyses were performed by using analysis of variance and Tukey and χ² tests.

Results

For all systems, glide path preparation exerted no significant effect on preparation times (P > .05). Glide path preparation had no influence on the incidence of canal aberrations and instrument fractures (P > .05), with no significant differences between the 5 systems (P > .05). Glide path preparation had no influence on the centering ability of all systems (P > .05). On average, canals prepared with F360, OneShape, and HyflexCM remained better centered compared with those enlarged with WaveOne and Reciproc.

Conclusions

Under the conditions of this study, glide path preparation had no significant impact on canal straightening. Less tapered instruments maintained the original canal curvature better than instruments having greater tapers.     

Cyclic Fatigue Resistance of Nickel-Titanium Instruments after Immersion in Irrigant Solutions with or without Surfactants

Introduction

The aim of the study was to assess cyclic fatigue resistance of reciprocating (Reciproc and WaveOne) and continuous rotating (ProTaper) nickel-titanium files after immersion in different irrigation solutions with or without surfactants during several short time periods.

Methods

A total of 270 new Reciproc R25, WaveOne Primary, and ProTaper F2 files were tested. Instruments of each brand were divided into 1 control group (n = 10) formed by new files and 4 test groups (n = 20) formed by instruments dynamically immersed at 37°C for 16 mm in 5.25% sodium hypochlorite (NaOCl), Hypoclean (5.25% NaOCl with surfactant), 17% EDTA, or EDTA Plus (17% EDTA with surfactant). Each test group was subdivided into 2 subgroups (n = 10) on the basis of the time of dynamic immersion in the endodontic irrigant solution (45 seconds or 3 minutes). Resistance to cyclic fatigue was determined by recording time to fracture in a stainless steel artificial canal with a 60° angle of curvature and 5-mm radius of curvature. The fracture surface was examined by using scanning electron microscopy.

Results

Immersion in NaOCl did not reduce the cyclic fatigue of reciprocating or continuous nickel-titanium files. The 17% EDTA reduced the fatigue resistance of all instruments after 3 minutes. The immersion in irrigants with surfactants did not influence the cyclic fatigue of instruments except for Reciproc immersed in Hypoclean solution.

Conclusions

EDTA immersion reduced the cyclic fatigue resistance of all instruments after 3 minutes. Addition of surfactants did not influence the cyclic fatigue of files except when added to NaOCl when it contacts Reciproc instruments.     

Evaluation of the Resistance to Cyclic Fatigue among ProTaper Next,ProTaper Universal,and Vortex Blue Rotary Instruments

Introduction

The purpose of this study was to compare the fracture resistance to cyclic fatigue of ProTaper Next (PTN; Dentsply Tulsa Dental Specialties, Tulsa, OK), ProTaper Universal (PTU, Dentsply Tulsa Dental Specialties), and Vortex Blue (VB, Dentsply Tulsa Dental Specialties) rotary instruments.

Methods

Twenty instruments each of PTN X1–X5, PTU S1–F5, and VB 20/04–50/04 were rotated until fracture in a simulated canal of 90° and a 5-mm radius using a custom-made testing platform. The number of cycles to fracture (NCF) was calculated. Weibull analysis was used to predict the maximum number of cycles when 99% of the instrument samples survive.

Results

VB 20/04–30/04 had significantly higher NCF than PTU S1–F5 and PTN X1–X5. VB 35/04–45/04 had significantly higher NCF than PTU S2–F5 and PTN X2–X5. PTN X1 had higher NCF than PTU S1–F5. PTN X2 had higher NCF than PTU F2–F5. The Weibull distribution predicted the highest number of cycles at which 99% of instruments survive to be 766 cycles for VB 25/04 and the lowest to be 50 cycles for PTU F2.

Conclusions

Under the limitations of this study, VB 20/04–45/04 were more resistant to cyclic fatigue than PTN X2–X5 and PTU S2–F5. PTN X1 and X2 were more resistant to cyclic fatigue than PTU F2–F5. The Weibull distribution appears to be a feasible and potentially clinically relevant model to predict resistance to cyclic fatigue.     

Reciprocating Versus Rotary Systems for Root Filling Removal: Assessment of the Apically Extruded Material

Introduction

This study was designed to quantitatively evaluate the amount of apically extruded debris by comparing the ProTaper Universal Retreatment system (Dentsply Maillefer, Ballaigues, Switzerland) with 2 reciprocating single-file systems (Reciproc [VDW, Munich, Germany] and WaveOne [Dentsply Maillefer]) during endodontic retreatment.

Methods

Forty-five mandibular premolars with a single canal were prepared with the ProTaper Universal system and then obturated. The specimens were divided into 3 groups (n = 15) according to the system used for filling removal: ProTaper Universal Retreatment system associated with the ProTaper Universal system (until file F4 40/0.06]), Reciproc system (Reciproc R40 [40/0.06]), and WaveOne system (WaveOne Large [40/0.08]). Sodium hypochlorite was used as an irrigant, and the apically extruded debris was collected in glass vials and then dried. The mean weight of debris was assessed with a microbalance and statistically analyzed using 1-way analysis of variance and post hoc Tukey multiple comparison tests (P < .05).

Results

The ProTaper Universal Retreatment system produced significantly more debris compared with the Reciproc and WaveOne systems (P < .01). The reciprocating systems showed no significant difference between them (P > .05).

Conclusions

Under the conditions of the present study, all systems caused apical debris extrusion. Reciprocating systems were associated with less debris extrusion when compared with a conventional rotary retreatment system.     

结合锥形束CT评价两种镍钛器械预备老年人磨牙弯曲根管的效果

目的：比较镍钛器械Twisted Files（TF）和ProTaper在老年人磨牙弯曲根管预备中的临床应用效果。方法：选择2011年8月至2013年8月在我科门诊就诊的有弯曲根管的牙髓炎或根尖周炎的老年患者磨牙90颗,随机分成三组,每组30颗,T组和P组分别采用机用镍钛器械Twisted Files（TF）和ProTaper以冠向下技术预备根管,K组采用手用不锈钢K锉以逐步后退法预备根管,全部患牙均采用冷牙胶侧方加压技术充填。记录三组病例根管预备时间和器械折断数,根据治疗前、中、后的X线片评价根管预备和充填情况,通过锥形束C T记录预备前后距离根尖3mm处根管偏移值。结果：T组、P组均能保持原根管的弯曲和走向,根管预备的锥度和流畅度好,根管充填质量高,T组的偏移量比P组和K组的偏移量小,三组间差异有统计学意义（P〈0.05）。T组的操作时间比P组和K组短,三组间差异有统计学意义（P〈0.05）。预备过程中T组未发生器械折断,P组3例发生器械折断。结论：TF相对与Protaper用于预备老年人磨牙弯曲根管,效率较高,成形效果佳,较安全,更适合于狭窄弯曲的老年根管。     

VERTICAL SUBLUXATION OF THE PATELLA: AN UNUSUAL FEATURE OF MULTIPLE EPIPHYSEAL DYSPLASIA

Book reviews in this article: Abnormally shaped, usually double-layered, patellae are recognized as occurring in multiple epiphyseal dysplasia. The case described is unusual in that an associated defect appeared in the femur and resulted in mechanical symptoms.