Biomechanical behavior of brain injury caused by sticks using finite element model and Hybrid-III testing

Objective: To study the biomechanical mechanism of head injuries beaten with sticks, which is common in the battery or assaultive cases. Methods: In this study, the Hybrid-III anthropomorphic test device and finite element model (FEM) of the total human model for safety (THUMS) head were used to determine the biomechanical response of head while being beaten with different sticks. Total eight Hybrid-III tests and four finite element simulations were conducted. The contact force, resultant acceleration of head center of gravity, intracranial pressure and von Mises stress were calculated to determine the different biomechanical behavior of head with beaten by different sticks. Results: In Hybrid-III tests, the stick in each group demonstrated the similar kinematic behavior under the same loading condition. The peak values of the resultant acceleration for thick iron stick group, thin iron stick group, thick wooden stick group and thin wooden stick group were 203.4 g, 221.1 g, 170.5 g and 122.2 g respectively. In finite element simulations, positive intracranial pressure was initially observed in the frontal comparing with negative intracranial pressure in the contra-coup site. Subsequently the intracranial pressure in the coup site was decreasing toward negative value while the contra-coup intracranial pressure increasing toward positive values. Conclusions: The results illustrated that the stiffer and larger the stick was, the higher the von Mises stress, contact force and intracranial pressure were. We believed that the results in the Hybrid-III tests and THUMS head simulations for brain injury beaten with sticks could be reliable and useful for better understanding the injury mechanism.     

LC-MS/MS法测定人血浆中布康唑浓度的不确定度评定

目的：评定LC-MS/MS法测定人血浆中布康唑浓度的不确定度。方法：分析测定过程中不确定度的来源，包括对照品的称量、仪器误差、标准溶液的配制、含药血浆样品的配制、血浆样品的处理、标准曲线的拟合、基质效应、重复性等，评定各来源分量的不确定度，计算合成不确定度和扩展不确定度。结果：人血浆中低（60.0 pg·mL^-1）、中（600.0 pg·mL^-1）、高（6 400.0 pg·mL^-1）浓度布康唑的扩展不确定度分别为5.62，63.90，626.26 pg·mL^-1（k=2，P=95%）。结论：LC-MS/MS法测定人血浆中布康唑浓度的不确定度主要由基质效应、血浆样品的处理（提取回收率），仪器误差、重复性（精密度）引入。     

Craving-induced effects of different drug cues on persons abstaining from heroin

Background: The key factors of inducing drug cravings in persons abstaining from drug use remain a focus of addictions research. Given the accumulating evidences, the scope of cues investigated in the cue-reactivity paradigm has increased considerably. Yet, few studies have examined the effects of the intensity and endurance of different types of cues on their ability to induce craving. This study investigated differences among drug-cue words, negative physiological-cue words, and negative social-cue words in the induction of drug cravings among persons abstaining from heroin.

Methods: The sample consisted of 149 male abstinent heroin abusers from four addiction rehabilitation centers in China. Based on their abstinence lengths, they were labeled as short-term, medium-term, and long-term abstainer participants respectively. All participants completed a stress-imagery task and rated craving by visual analog scale.

Results: There was a significant interaction of cue type and abstinence length. There was no difference on the craving induced by three types of cue words in the short-term group. In the medium-term group, craving induced by negative social-cue words was significantly stronger than that by negative physiological-cue words, but not that by drug-cue words. In the long-term group, the craving induced by negative social-cue words remained the strongest, significantly stronger than that by both drug-cue words and negative physiological-cue words.

Conclusion: Negative social-cue words presented in the current study retain the ability to induce craving in heroin abstainers; this finding suggests that negative social cues encountered under more general circumstances could be a risk factor for relapse.     

外泌体在肿瘤转移前微环境形成中的作用

肿瘤的转移前微环境（pre-metastatic niche，PMN）特指原发肿瘤灶为肿瘤细胞远处播散和定植准备的微环境，此微环境的六个特征包括炎症、免疫抑制、血管生成/血管通透性、亲器官性、重编程和淋巴管生成。PMN形成的关键成分包括肿瘤源性分泌因子、细胞外囊泡（含外泌体）、骨髓源性细胞、免疫抑制细胞和宿主基质细胞等，其中，外泌体作为细胞间重要的信使，在肿瘤PMN的形成中具有重要作用。本综述就外泌体在肿瘤PMN形成中的作用进行探讨。     

Deferoxamine promotes recovery of traumatic spinal cord injury by inhibiting ferroptosis

Ferroptosis is an iron-dependent novel cell death pathway. Deferoxamine, a ferroptosis inhibitor, has been reported to promote spinal cord injury repair. It has yet to be clarified whether ferroptosis inhibition represents the mechanism of action of Deferoxamine on spinal cord injury recovery. A rat model of Deferoxamine at thoracic 10 segment was established using a modified Allen's method. Ninety 8-week-old female Wistar rats were used. Rats in the Deferoxamine group were intraperitoneally injected with 100 mg/kg Deferoxamine 30 minutes before injury. Simultaneously, the Sham and Deferoxamine groups served as controls. Drug administration was conducted for 7 consecutive days. The results were as follows:(1) Electron microscopy revealed shrunken mitochondria in the spinal cord injury group.(2) The Basso, Beattie and Bresnahan locomotor rating score showed that recovery of the hindlimb was remarkably better in the Deferoxamine group than in the spinal cord injury group.(3) The iron concentration was lower in the Deferoxamine group than in the spinal cord injury group after injury.(4) Western blot assay revealed that, compared with the spinal cord injury group, GPX4, xCT, and glutathione expression was markedly increased in the Deferoxamine group.(5) Real-time polymerase chain reaction revealed that, compared with the Deferoxamine group, mRNA levels of ferroptosis-related genes Acyl-CoA synthetase family member 2(ACSF2) and iron-responsive element-binding protein 2(IREB2) were up-regulated in the Deferoxamine group.(6) Deferoxamine increased survival of neurons and inhibited gliosis. These findings confirm that Deferoxamine can repair spinal cord injury by inhibiting ferroptosis. Targeting ferroptosis is therefore a promising therapeutic approach for spinal cord injury.     

西部地区基层医院继续医学教育的调查及思考

通过在西部基层医院实施继续医学教育并开展问卷调查,对调查结果如:基层参加继续医学教育人员的教育及职称状况;既往参加继续医学教育的经历;对基层进行继续医学教育的形式和内容等进行探讨,明确在基层进行继续医学教育优势,为进一步在基层开展继续医学教育提供参考依据。     

责任指数对口腔医学专业学生职业精神考核的设想

医学生的责任心体现在其一定行为表现上，是医学生职业精神培养的重要内涵，因此对影响医学生责任心的负向行为进行一定的干预具有重要意义。分析国内外医学院校应用责任指数考核在医学生行为督导养成的评价研究，遵循我国口腔医学专业人才培养的规律，结合口腔医学生成长的特点，借鉴职业精神考核的相关指标——责任指数考核法，试设计口腔医学生行为责任指数测评方案，并预设可行性，为拓宽口腔医学生职业精神的培养提供思路。     

白细胞介素35和白细胞介素37与结直肠癌临床病理学特征及预后的相关性研究

背景与目的：结直肠癌（colorectal cancer，CRC）为世界第三常见恶性肿瘤，近年来研究者认为白细胞介素（interleukin，IL）-35和（或）IL-37与CRC的发展有关，但其作用机制尚未阐明。探究IL-35和IL-37在CRC发展中的作用及其可能的机制，分析IL-35和IL-37与CRC患者预后的相关性。方法：收集2013年—2017年在上海交通大学医学院附属同仁医院接受治疗的191例CRC患者手术病理蜡块的肿瘤组织，与其匹配的非癌组织是来源于同一患者的肠癌手术切缘蜡块组织。应用免疫组织化学（immunohistochemistry，IHC）染色法将CRC患者的癌组织与非癌组织染色，并运用Image-Pro Plus将IHC染色阳性部分定量分析，结合随访结果，探讨癌组织与非癌组织中IL-35和IL-37的表达水平与CRC临床病理学特征及预后的相关性。结果：与非癌组织相比，CRC组织中IL-35的表达量减少了50%（P<0.000 1）。CRC组织中IL-37的表达量与非癌组织相比增加了40%（P=0.012）。多因素生存分析显示，癌组织中IL-35（HR=0.39；95% CI：0.16~0.97；P=0.04）的表达水平是CRC患者术后生存的独立预测指标。结论：IL-35和IL-37蛋白的表达水平可能与CRC的发展有关，IL-35的表达水平可能是CRC患者术后生存的独立预测指标。