黑龙江省逊克县火山熔岩地区啮齿动物携带病原体调查

目的 调查黑龙江省逊克县火山熔岩地区啮齿动物携带病原体状况.方法 2014年4-9月,采集啮齿动物样本107只,解剖取脏器肺、肾、肝、肾和膀胱样本,采用PCR方法分别扩增10种鼠传病原体的特异性核酸片段,通过基因测序进一步鉴定.结果 在107份鼠肺中共检出汉城型汉坦病毒RNA核酸阳性样本5份,感染率为4.67％;107份鼠肾中共检出钩端螺旋体DNA核酸阳性样本6份,感染率为5.61％;107份鼠脾中共检出巴尔通体DNA核酸阳性样本7份,感染率为6.54％,嗜吞噬细胞无形体4份,感染率为3.74％;107份鼠肝、鼠脾中鼠疫菌、巴贝西原虫、斑点热群立克次体、恙虫病立克次体、莫氏立克次体的DNA核酸检测结果均为阴性;107份鼠膀胱中伯氏疏螺旋体的DNA核酸检测结果为阴性;在鼠体内还存在复合感染情况,感染率为2.80％.结论 黑龙江省逊克县火山熔岩地区啮齿动物中存在汉坦病毒、钩端螺旋体、巴尔通体和嗜吞噬细胞无形体的感染.     

浓硫酸酸蚀聚醚酮酮的时间对其与牙本质剪切粘接强度的影响

目的研究浓硫酸酸蚀聚醚酮酮(polyether?ketone?ketone,PEKK)不同时间对其与牙本质剪切粘接强度的影响,为临床使用PEKK修复体的粘接操作提供科学依据。方法制备PEKK试件44个,随机平均分为A、B、C、D 4组:A组为对照组,仅用水磨砂纸打磨;B组、C组、D组为实验组,分别用98%浓硫酸酸蚀经打磨试件表面5 s、30 s、60 s。另外,每组随机抽取1个试件用慢速切割机制备出剖面,在扫描电镜下观察其剖面的表面形貌。4组试件与牙本质通过树脂粘接后在37℃蒸馏水浸泡24 h,测量剪切粘接强度后统计分析,通过扫描电子显微镜与体视显微镜检查试件断裂界面,统计粘接失败类型。结果B组PEKK试件酸蚀处理后剖面呈海绵状且孔隙大小均匀,C组、D组可见试件剖面有破坏状孔蚀样结构;剪切粘接强度B组(16.84±1.84)MPa、C组(12.33±1.22)MPa和D组(6.44±1.18)MPa均大于A组(3.99±1.06)MPa(P<0.05),其中B组与牙本质的剪切粘接强度最高(16.84±1.84)MPa。结论采用98%浓硫酸酸蚀PEKK表面5 s处理方法可以使PEKK与牙本质获得较好的剪切粘接强度。     

大学生公正世界信念与利他行为的相关性

目的分析探讨大学生公正世界信念与利他行为的相关关系。方法采用利他行为调查问卷和公正世界信念量表对来自河北省唐山市2所高校的528名大学生进行问卷调查。结果在10个调查项目中,前8项除了F2(42.0%)和F7(38.4%)之外做肯定选择的百分率在62.3%~80.1%之间。F6,F8,F9的公正世界水平差异有显著的统计学意义,χ2分别为7.171,8.413,8.058,高等水平的公正世界信念水平更愿意提供帮助(P0.05)。列联系数分别为0.116,0.125,0.123,且均有统计学意义,大学生公正世界信念与利他行为存在一定相关。F1,F3,F4,F5,F6,F8终极公正得分愿意提供帮助组高于不愿意提供帮助组,t分别为2.22,3.14,3.08,2.54,3.36,2.24,差异极其显著(P0.05或P0.01)。F9,F10终极公正、固有公正、总分得分积极回答组组高于消极回答组,t分别为2.63,2.16,2.46;-2.57,-2.77,-2.99,差异显著(P0.05)。F6,F7固有公正得分愿意提供帮助组高于不愿意提供帮助组,t分别为2.05,2.76,差异显著(P0.05),F3,F4,F5,F6,F8公正世界信念总得分愿意提供帮助组高于不愿意提供帮助组,t分别为3.19,2.86,2.73,3.15,2.33,2.46,差异显著。结论大学生公正世界信念有助于利他行为的发生,高水平的公正世界信念更容易提供帮助。     

Tissue fixation security in transosseous rotator cuff repairs: A mechanical comparison of simple versus mattress sutures

The primary purpose of this investigation was to compare tissue fixation security by simple sutures versus mattress sutures in transosseous rotator cuff repair. These two repair techniques were each performed in 17 human cadaver shoulders, with two bone tunnels being used for the repair by two simple sutures and two other bone tunnels being used for the repair by one mattress suture. The repairs were loaded to failure in a servohydraulic materials test system. Rotator cuff repair by simple sutures was found to be significantly stronger than repair by mattress sutures (P = .0007). The average ultimate load to failure for the simple suture construct (189.62 N) was 39.72% greater than that for the mattress suture construct (135.71 N). Most of the failures occurred by suture breakage at the knot. Load-sharing by multiple suture tails and multiple knots in the simple suture configuration likely contributed to its superior strength characteristics compared with the mattress suture configuration.     

Should adhesive debonding be simulated for intra-radicular post stress analyses?

Objective

Elucidate the influence of debonding on stress distribution and maximum stresses for intra-radicular restorations.

胸腰椎运动段极限载荷值与对应的应力值测定及其临床意义

目的探讨脊柱的力学特性及损伤机制。方法采用１０具新鲜成年尸体胸腰椎（Ｔ１２，Ｌ１）建立运动段，测定胸腰椎脊柱在压缩及拉伸载荷下的极限载荷值与对应的应力值。结果测定压缩极限载荷值为４６０±５０ｋｇ，拉伸极限载荷值为３５０±３５ｋｇ及各组织相对应的应力值。结论对航空领域中各种致伤因素下飞行员脊柱损伤的研究具有一定的参考价值     

Tensile testing of bone over a wide range of strain rates: effects of strain rate,microstructure and density

Uniaxial tensile tests were performed on standardised longitudinal specimens of bovine compact bone at strain rates from 5·3×10^?4 to 237 s^?1. After testing, the microstructure and dry density of each specimen was determined. The test results demonstrated highly significant (P<0·01) positive correlations between ultimate strength and strain rate, and between ultimate strength and density. A highly significant negative correlation between ultimate strength and the extent of secondary Haversian remodelling was also found. The modulus of elasticity showed similar correlations with the test parameters. A multiple linear-regression analysis was used to derive equations for the ultimate strength and modulus as functions of strain rate and microstructure. The regression analyses accounted for 86% of the variance in strength and 50% of the variance in modulus. The extent of secondary Haversian remodelling showed a significant (P<0·01) negative correlation with the energy-absorption capacity. Strain rate also had a significant effect on the energy-absorption capacity. Specimens tested at higher strain rates generally absorbed more energy during failure. There was no evidence of a critical velocity at which the energy absorption capacity attained a maximum. The test results correlate well with previous studies of the mechanical properties of compact bone.     

医学人文关怀的基本内涵

医学人文关怀是医务工作者必备的基本素养。它不仅要求医务工作者运用知识、技能诊疗疾病,而且要求医务工作者给予患者广泛而精细的人文关怀。这就要求医者践行关爱、博爱、至善、至美、慎行的医学人文关怀。其中,关爱是医学人文关怀最基本的要求;博爱是医学人文关怀的追求;至善是医学人文关怀具体的体现;至美是医学人文关怀高层次的要求;慎行是医学人文关怀必备的行为。关爱、博爱、至善、至美、慎行应该体现在临床工作中的每一个步骤、每一个环节以至每一个细节。