股骨远端骨折两种固定方法对比研究

目的 对比应用逆行交锁髓内钉(GSH)和动力髁螺钉(DCS)内固定治疗股骨远端骨折的效果.方法 采用回顾性研究方法对我院自2000年8月～2004年10月治疗的54例股骨远端骨折病例进行对照研究,按A0分类:A1型17例,A2型14例,A3型11例,B1型2例,C1型6例,C2型3例,C3型1例.其中,DCS内固定30例,GSH固定24例.分组统计手术时间,出血量,骨折愈合时间,并发症,膝关节功能.结果 所有病例经5月～2年随访,平均9个月;骨折愈合时间为4.6月(4～9月).DCS固定组平均手术时间1.5小时(1～2.5小时).出血量105 ml(50～200 ml),骨折愈合时间平均4.7月(4～8月),并发症发生5例(发生率16.7%),根据Kolmert膝关节功能评分,优20例,良6例,可4例,优良率为86.6%.GSH固定组手术时间1.8小时(1.5～3.5小时).术中出血量平均120 ml(100～250 ml),平均骨折愈合时间5.1个月(4.5～9个月),并发症发生5例(发生率28%),根据Kolmert膝关节功能评分标准,优15例,良7例,可2例,优良率为91.7%.两组比较,结果无显著差异(P＞0.05) 结论 逆行带锁髓内钉(GSH)及动力髁螺钉(DCS)均是治疗股骨远端骨折的较好方法,但各有其最佳适应症.选择好适应症以及术者技术熟练有利于骨折愈合及关节功能恢复.     

Assessment of personal airborne exposures and surface contamination from x-ray vaporization of beryllium targets at the National Ignition Facility

This article presents air and surface sampling data collected over the first two years since beryllium was introduced as a target material at the National Ignition Facility. Over this time, 101 experiments with beryllium-containing targets were executed. The data provides an assessment of current conditions in the facility and a baseline for future impacts as new, reduced regulatory limits for beryllium are being proposed by both the Occupational Safety and Health Administration and Department of Energy. This study also investigates how beryllium deposits onto exposed surfaces as a result of x-ray vaporization and the effectiveness of simple decontamination measures in reducing the amount of removable beryllium from a surface. Based on 1,961 surface wipe samples collected from entrant components (equipment directly exposed to target debris) and their surrounding work areas during routine reconfiguration activities, only one result was above the beryllium release limit of 0.2 µg/100 cm² and 27 results were above the analytical reporting limit of 0.01 µg/100 cm², for a beryllium detection rate of 1.4%. Surface wipe samples collected from the internal walls of the NIF target chamber, however, showed higher levels of beryllium, with beryllium detected on 73% and 87% of the samples during the first and second target chamber entries (performed annually), respectively, with 23% of the samples above the beryllium release limit during the second target chamber entry. The analysis of a target chamber wall panel exposed during the first 30 beryllium-containing experiments (cumulatively) indicated that 87% of the beryllium contamination remains fixed onto the surface after wet wiping the surface and 92% of the non-fixed contamination was removed by decontaminating the surface using a dry wipe followed by a wet wipe. Personal airborne exposures assessed during access to entrant components and during target chamber entry indicated that airborne beryllium was not present in workers' breathing zones. All the data thus far have shown that beryllium has been effectively managed to prevent exposures to workers during routine and non-routine work.     

Comparative 13-week cigarette smoke inhalation study in Sprague-Dawley rats: evaluation of cigarettes with two banded cigarette paper technologies.

This study compared the toxicological responses of Sprague-Dawley rats exposed nose-only to mainstream smoke (MS) from Test cigarettes (1, 2, and 3) to those of Control cigarettes without banded cigarette paper technologies (BCPT). Test cigarettes 1 and 2 had bands based on one technology (different band weight application) while Test cigarette 3 had bands based on another technology. The banded papers are representative of current marketed technologies. Rats were exposed to humidified HEPA filtered air (Sham) or to MS at concentrations of 0.06, 0.20, or 0.80 mg wet total particulate matter per liter air. Each exposure group contained 30 animals/sex (sentinel had 20 animals/sex). The study had two phases (13 weeks each): MS exposure (1 h/day, 5 days/week) and recovery without smoke exposure. Endpoints included clinical observations, respiratory physiology, hematology, serum chemistry, blood carboxyhemoglobin (COHb), serum nicotine, body/organ weights, gross pathology, and histopathology. Comparisons conducted were: Sham exposed vs. all cigarettes, Control cigarette vs. all Test cigarettes, and Test 1 vs. Test 2. Control and Test MS had comparable effects on respiratory physiology, COHb, serum nicotine, serum chemistry, and hematology. While some minor differences were observed, Control and Test MS had comparable effects on clinical signs, body/organ weights, and gross pathology/histopathology. Consequently, exposure of rats to equivalent MS concentrations from the four cigarettes induced similar toxicological responses in this study.     

Estimating driver risk using alcohol biomarkers,interlock blood alcohol concentration tests and psychometric assessments: initial descriptives

Aim To identify alcohol biomarker and psychometric measures that relate to drivers' blood alcohol concentration (BAC) patterns from ignition interlock devices (IIDs). Design, setting, participants, measurements In Alberta, Canada, 534 drivers, convicted of driving under the influence of alcohol (DUI), installed IIDs and agreed to participate in a research study. IID BAC tests are an established proxy for predicting future DUI convictions. Three risk groups were defined by rates of failed BAC tests. Program entry and follow‐up blood samples (n = 302, 171) were used to measure phosphatidyl ethanol (PETH), carbohydrate deficient transferrin (%CDT), gamma glutamyltransferase (GGT) and other biomarkers. Program entry urine (n = 130) was analyzed for ethyl glucuronide (ETG) and ethyl sulphate (ETS). Entry hair samples were tested for fatty acid ethyl esters (FAEE) (n = 92) and ETG (n = 146). Psychometric measures included the DSM‐4 Diagnostic Interview Schedule Alcohol Module, Alcohol Use Disorders Identification Test (AUDIT), the time‐line follow‐back (TLFB), the Drinker Inventory of Consequences (DRINC) and the Temptation and Restraint Inventory (TRI). Findings Except for FAEE, all alcohol biomarkers were related significantly to the interlock BAC test profiles; higher marker levels predicted higher rates of interlock BAC test failures. PETH, the strongest with an overall analysis of variance F ratio of 35.5, had significant correlations with all nine of the other alcohol biomarkers and with 16 of 19 psychometric variables. Urine ETG and ETS were correlated strongly with the IID BAC tests. Conclusions The findings suggest that several alcohol biomarkers and assessments could play an important role in the prediction and control of driver alcohol risk when re‐licensing.     

Varian 23EX直线加速器真空电源故障处理

真空系统是直线加速器的重要组成部分,故障率较高。通过介绍Varian23EX直线加速器真空系统的基本构成和工作原理、对真空系统常见的联锁信号进行简要分析,以及就一例特殊的直线加速器真空电源故障现象、原因排查过程及故障解决的描述,总结了临床工程师在直线加速器的日常维护中应具备的技能和素质。     

股骨重建钉治疗同侧股骨颈、干骨折

目的 探讨使用股骨重建钉内固定治疗同侧股骨颈、干骨折的临床疗效、手术要点和围手术期注意事项。方法 对12例使用股骨重建钉治疗的疗效进行回顾性分析。手术采用闭合穿钉、闭合或小切口切开复位，用三维瞄准器锁定远骨折端，股骨颈保持15。前倾角置人2枚拉力螺纹钉。结果 11例获得随访，随访平均时间12．3个月(6～58个月)。远期疗效按马元璋评定标准：优5例，良4例，可2例，优良率81．8％，平均股骨颈骨折临床愈合时间5．2个月、股骨干骨折临床愈合时间6．7个月，一期骨折愈合率达到72．7％，其中3例术后10，12，15个月远骨折段骨延迟愈合，改为动力固定，4～6个月后骨折愈合。无股骨头坏死征象。结论 股骨颈骨折强调不切开复位，并争取解剖复位；股骨干骨折则常规闭合穿钉、小切口复位、有限扩髓、静力固定。股骨重建钉是目前治疗股骨干粉碎性骨折伴同侧股骨颈骨折的有效方法。     

西门子直线加速器剂量联锁的研究与实践

目的：在放射治疗中加速器出现剂量联锁后导致停机,并中断治疗。而直线加速器剂量联锁又是加速器各类故障中较为多发的联锁故障,研究探讨相应的通用解决路径,有助于快捷分析排查,及时恢复加速器正常运转,从而保证患者及时按既定计划进行放疗。方法：简要分析剂量联锁及引起剂量联锁的因素,以西门子ONCOR直线加速器的实例,对剂量联锁故障排除技巧进行了剖析,并总结得出解决剂量联锁问题的通用路径。结果：按此通用路径结合实际情况可解决多数加速器的剂量联锁故障,保证了临床放射治疗的进行。结论：实践证明利用这些方法处理加速器剂量联锁切实有效,可帮助提高医学工程技术人员对加速器联锁故障的维修速度与技能。