视屏显示终端作业对人体肌肉骨骼系统影响研究

本文就视屏显示终端作业对工作者骨骼系统影响因素以及表现、预防措施进行综述。     

办公室里“脱疲”法

螺旋扭转站立,把双腿伸直,右腿跨过左腿同时,保持右腿伸直;上半身扭转至右手撑地,左手肘部贴近右膝盖,这时你会感到腰部的肌肉正在进行扭转式抻拉。这个动作会帮你摆脱腰酸背痛的困扰。建议每侧坚持10秒钟,重复3次。     

室外温度与室内恒温下EC随死后经历时间的变化

目的在室外环境和室内恒温条件下测定昼夜不同时间猪后腿肌肉电导率(electrical conductivity,EC)值,分析并比较两种环境条件下,EC值随死后经历时间(time since death, TSD)变化的规律。方法取5块即刻屠宰的猪后腿肌肉,均分为两份,随机分成两组,分别置于秋季室外环境和室内18℃恒温环境中。在死后10d内分别于早晚8时(每隔12h)取样,测定其浸渍液EC值。结果两种环境条件下,EC随TSD变化的趋势在整体上是一致的,二者相关性均较好(R2室外=0.971,P室外=0.004,R2室内=0.98,P室内=0.002)。室外环境温度下,肌肉的EC值在白天增长明显,夜间增长不明显,尤其环境温度低于13℃时,出现明显的平台现象,与室内恒温条件下肌肉EC值持续上升的变化趋势有显著的差异。结论无论室外环境温度还是室内恒温下,肌肉EC与TSD的相关性均较好,但在具体分析时,应考虑到夜间低温平台期造成的时间延搁。     

大鼠肌肉挫伤后COX6C mRNA的表达与损伤时间关系

目的探讨肌肉挫伤后组织中细胞色素c氧化酶亚基Ⅵc(cytochrome c oxidase subunitⅥc,COX6C)mRNA的表达变化及其与损伤时间的关系。方法 54只健康成年SD大鼠随机被分为正常对照组和损伤后0.5、1、6、12、18、24、30和36 h组,采用重力锤自由落体方式制作大鼠肌肉挫伤模型。于相应时间提取挫伤处肌肉组织样本进行常规组织学观察,并提取组织中总RNA采用real-time PCR检测COX6C mRNA相对表达量。结果损伤后6 h内仅见肌纤维间出血、肌细胞肿胀等改变,未见炎症细胞浸润。损伤6 h以后逐渐出现肌细胞变性、坏死、炎症细胞浸润、纤维结缔组织增生等改变。COX6C mRNA在损伤后6 h以前其表达量均高于正常对照组,而在损伤6~36 h,其表达量均低于正常对照组。结论 COX6C mRNA在大鼠肌肉挫伤后呈现规律性表达,结合组织学检查有助于损伤时间的推断和研究。     

Reliability Study on Quantitative Detection of Extensor Digitorum Brevis Strength with Needle Electromyography and Nerve Conduction

Objective To study the objectivity and reliability of needle electromyography and nerve con- duction for detection of musculus extensor digitorum brevis strength, which may provide a basis for es- tablishing a quantitative detection of muscle strength in forensic clinical study. Methods Forty-four healthy people were enrolled as the subjects, and during toe dorsiflexion, the following items including needle electromyography indexes, motor unit potential （MUP） amplitude, MUP count, recruitment reaction type, and nerve conduction detection indexes, compound muscle action potential （CMAP） amplitude, CMAP latent period and motor nerve conduction velocity （MNCV）, were simultaneously detected under the co- operation and disguise condition. Results Under the cooperation condition, regardless of the same opera- tor or different operators, there were good test-retest reliabilities in MUP amplitude, CMAP amplitude, CMAP latent period and MNCV, while there were normal test-retest reliabilities in MUP count and re- cruitment reaction type and the repeatability of the same operator was slightly better than the repeatabili- ty between different operators. Under the disguise condition, test-retest reliabilities of MUP amplitude, CMAP amplitude, CMAP latent period and M-NCV were relatively high, while test-retest reliabilities of MUP count and recruitment reaction type were relatively low. Conclusion There are good test-retest reli- abilities in MUP amplitude, CMAP amplitude, CMAP latent period and M-NCV, which can be conducive to comparison between different operators and results at various times; MUP count and recruitment reac- tion type, which can be easily affected by subjectivity of operators and examinees, can be used to dif- ferentiate whether an examinee disguises or not. The indexes used to objectively judge muscle strength remain to be further investigated.     

鱼肌肉中氟苯尼考和氟苯尼考胺残留的高效液相色谱检测

建立了同时检测鱼肌肉组织中氟苯尼考和氟苯尼考胺残留的高效液相色谱检测法。以水和丙酮为提取溶液,Oasis MCX固相萃取柱为净化柱,采用Inertsil ODS—3(5μm,250 mm×4.6 mm i.d.)反相色谱柱,以A液(0.02 mol/L庚烷磺酸-钠0.025 mol/L磷酸钠溶液,二者体积比68∶32,pH3.85)与B液(含1 mL/L三乙胺的甲醇溶液)为流动相,梯度洗脱,紫外检测器225 nm处检测。结果显示,在10~1 000μg/kg浓度范围内,线性关系良好;加标回收率为75.9%~82.8%,日内变异系数为2.1%~5.8%,日间变异系数为4.7%~7.7%;氟苯尼考胺和氟苯尼考的检测限分别为5μg/kg和10μg/kg,定量限分别为10μg/kg和20μg/kg。结果表明,所建立的检测方法具有灵敏、准确、简便、快速的特点,适于同时检测鱼肌肉中氟苯尼考和氟苯尼考胺的残留。     

肌皮神经损伤后屈肘肌力与针极肌电图指标的相关性

目的 研究肌皮神经损伤者的屈肘肌力变化及其与针极肌电图指标的相关性。方法 收集单侧臂丛神经损伤（累及肌皮神经）致屈肘肌力降低案例30例，根据Lovett肌力分级标准进行徒手肌力评定，并将30例受试者分为A组（伤侧徒手肌力1级和2级，16例）和B组（伤侧徒手肌力3级和4级，14例）。对所有受试者的伤侧和健侧肱二头肌行针极肌电图检测。记录肱二头肌复合肌肉动作电位（compoundmuscle actionpotential,CMAP）的潜伏期和波幅。受试者进行最大随意收缩时，记录募集反应类型以及募集电位的平均转折数和平均波幅，并采用microFET2便携式肌力测试仪检测屈肘定量肌力。计算残存屈肘肌力百分比（伤侧与健侧定量肌力的比值）。比较各针极肌电图指标、定量肌力、残存屈肘肌力百分比在两组之间和组内伤侧与健侧之间的差异。分别分析屈肘徒手肌力分级、定量肌力与针极肌电图指标的相关性。结果 肌皮神经损伤后B组的伤侧残存屈肘肌力百分比为23.43%,A组的伤侧残存屈肘肌力百分比为4.13%。伤侧徒手肌力分级与募集反应类型相关，相关系数为0.886(P<0.05)。伤侧定量肌力与CMAP潜伏期...