Influence of different intensities of vibration on proliferation and differentiation of human periodontal ligament stem cells

Introduction

To understand the effects of low-magnitude, high-frequency (LMHF) mechanical vibration at different intensities on human periodontal ligament stem cell (hPDLSC) proliferation and osteogenic differentiation.

Material and methods

The effect of vibration on hPDLSC proliferation, osteogenic differentiation, tenogenic differentiation and cytoskeleton was assessed at the cellular, genetic and protein level.

Results

The PDLSC proliferation was decreased after different magnitudes of mechanical vibration; however, there were no obvious senescent cells in the experimental and the static control group. Expression of osteogenesis markers was increased. The expression of alkaline phosphatase (ALP) and osteocalcin (OCN) mRNA was up-regulated at 0.1 g, 0.3 g, 0.6 g and 0.9 g magnitude, with the peak at 0.3 g. The type I collagen (Col-I) level was increased after vibration exposure at 0.1 g, 0.3 g, and 0.6 g, peaking at 0.3 g. The expression levels of both mRNA and protein of Runx2 and osterix (OSX) significantly increased at a magnitude of 0.1 g to 0.9 g, reached a peak at 0.3 g and then decreased slowly. The scleraxis, tenogenic markers, and mRNA expression decreased at 0.05 g, 0.1 g, and 0.3 g, and significantly increased at 0.6 g and 0.9 g. Compared with the static group, the F-actin stress fibers of hPDLSCs became thicker and clearer following vibration.

Conclusions

The LMHF mechanical vibration promotes PDLSC osteogenic differentiation and implies the existence of a magnitude-dependent effect of vibration on determining PDLSC commitment to the osteoblast lineage. Changes in the cytoskeleton of hPDLSCs after vibration may be one of the mechanisms of the biological effects.     

An ultrasensitive chemiluminescent ELISA for determination of chloramphenicol in milk,milk powder,honey, eggs and chicken muscle

A competitive, direct, chemiluminescent enzyme-linked immunosorbent assay (CL-ELISA) for chloramphenicol (CAP) residues in milk, milk powder, honey, eggs and chicken muscle has been developed. The method gave a detection limit of 0.7 ng L^?1 and a linear range of 2.1–92.4 ng L^?1, with the IC₅₀ of 13.6 ng L^?1 under optimal conditions, dramatically better than any previously reported ELISA method for CAP detection. Spiked at levels of 5–60 ng L^?1 in different food samples, recoveries were in the range of 72.1–116.0%, with coefficient of variations of 4.2–20.2%. In a study of incurred residues, the chicken muscle samples diluted 5-, 10- and 20-fold, results obtained by CL-ELISA correlated well with those obtained by gas chromatography with microcell electron capture detector and traditional ELISA. The developed CL-ELISA method is, therefore, suitable for rapid screening trace CAP residues in food samples.     

Temporal features of elevated hair cortisol among earthquake survivors

This study aimed to determine the effect on hair cortisol level of a chronic stress response from the Wenchuan earthquake, and to explore the temporal features of elevated hair cortisol. We recruited two cohorts of earthquake survivors: cohort A consisted of 12 male adults and 8 females and cohort B of 20 male adolescents, with 23 and 29 participants as controls, respectively. Their hair samples closest to the scalp were assayed with mass spectrometry to determine cortisol content. Results revealed that hair cortisol content in survivors of cohort A was significantly higher than in the control. For survivors of cohort B, hair cortisol levels increased 6 and 22 weeks after the earthquake and decreased 43 weeks after the outburst. In conclusion, the chronic stress response elicited by the earthquake resulted in elevated hair cortisol. Timing since the earthquake outburst played an important role in the long‐term response of the HPA axis to a major acute stressor.     

注氮改性纯钛表面的微观摩擦性能研究

目的改变纯钛表面的成分,提高其硬度和耐磨损性能。方法对纯钛试样表面行3×1017 ions.cm-2和9×1017 ions.cm-2两种剂量的氮离子注入。以能量散射光谱测定分析其表面元素的改变,显微硬度仪测量其显微硬度,纳米划痕仪测量其表面的耐磨损性能,扫描电子显微镜观察其注入前后的划痕形貌。综合分析其微观摩擦学性能的改变。结果氮离子注入后,纯钛试样表面成金黄色。在注入3×1017 ions.cm-2和9×1017 ions.cm-2剂量的氮离子试样表面,氮元素的原子百分率分别为24.08%和35.83%。试样表面的显微硬度值提高。纯钛的摩擦系数较氮离子注入前明显降低,其中注入剂量为9×1017 ions.cm-2的纯钛较剂量为3×1017 ions.cm-2的纯钛摩擦系数小。结论氮离子注入可提高纯钛的硬度,改善其耐磨损性能。     

不同种类的固定修复体市场需求分析

目的探讨不同种类固定修复体的市场需求和需求变化。方法收集四川华西义齿修复制作中心2009—2011年生产的95 789件固定修复体为研究对象,统计产量构成比、绘制产量趋势图,分析固定修复体的市场需求及变化,采用季节指数分析固定修复体的产量规律。结果金属烤瓷修复体的构成比达到90%以上,钯银合金烤瓷修复体是主要的修复体选择类别,镍铬合金烤瓷修复体产量逐年降低,钴铬合金烤瓷修复体、种植体固定修复体、全瓷修复体产量保持稳定增长,金铂合金烤瓷修复体稳定在一定水平呈上下波动;季节指数的高峰为7月,指数达到1.155 56,低谷为2月,指数达到0.840 79,季节指数最高和最低月份相差0.314 77。结论金属烤瓷修复体占市场需求的主导地位,镍铬合金烤瓷修复体的产量逐年降低并逐渐被钴铬合金烤瓷修复体代替,固定修复体的产量存在季节波动,应优化资源配置并积极推广新技术。     

伴靠近下颌神经管埋伏牙的种植修复1例

后牙种植术区伴有靠近下颌神经管的阻生牙临床病例报道少见。本文报道了1例右下颌区第二前磨牙缺失伴第一磨牙阻生的患者,并结合临床资料和文献资料,对其种植方案及铸造金属基台和聚合瓷的应用效果进行讨论。     

地佐辛与芬太尼用于非体外循环下冠状动脉旁路移植术后患者镇痛效果的比较

目的:评价地佐辛注射液用于非体外循环下冠状动脉旁路移植患者术后镇痛的临床效果。方法:选择非体外循环下行冠状动脉旁路移植术的成年患者100例,性别不限,体质量指数18～29kg/m2,ASA分级为Ⅱ-Ⅲ级,随机分为芬太尼和地佐辛组,试验组术后镇痛泵配方为:地佐辛0.8 mg/kg+托烷司琼20 mg+0.9%氯化钠注射液稀释至200 mL;术后均采用皮下给药,给药速度为2 mL/h,4 d结束镇痛。对照组为芬太尼30 ug/kg+托烷司琼20 mg+0.9﹪氯化钠注射液稀释至200 mL。对两组镇痛效果进行评分和恶心呕吐等并发症进行记录。结果:每组患者最终完成49例,两组镇痛效果差异无统计学意义(P>0.05),试验组术后恶心、呕吐评分显著低于对照组(P<0.05)。结论:地佐辛术后镇痛效果优于芬太尼,可以安全的用于非体外循环冠状动脉旁路移植患者术后疼痛治疗。     

尼卡地平与硝普钠用于主动脉腔内修复术控制性降压效果的比较

目的:观察尼卡地平用于覆膜支架主动脉腔内修复术中控制性降压的效果,并与传统降压药物硝普钠进行比较。方法:选用40例Standford B型主动脉夹层拟经股动脉行覆膜支架主动脉腔内修复手术患者,随机分为尼卡地平(N)组和硝普钠(S)组。观察2组降压前、降压4 min和停止降压后10 min、20 min的心率(HR)、收缩压(SBP)、舒张压(DBP)、中心静脉压(CVP)和收缩压与心率乘积(RPP)的变化。结果:应用两种方法均呈现较明显的降压效果。与降压前比较,SBP、DBP明显下降(P<0.01),N组HR无显著变化,S组HR明显增快(P<0.05)。停止用药后,N组血压变化平稳,缓慢回升;S组有血压反跳现象(P<0.05)。降压4 min时,N组RPP明显下降(P<0.05),S组RPP无显著变化。CVP无显著变化。结论:尼卡地平用于夹层动脉瘤覆膜支架主动脉腔内修复术中的控制性降压作用迅速,用药后对心率无显著影响,其效果优于硝普钠,特别适用于伴有冠心病行主动脉夹层腔内修复术的患者。     

Current status, crisis and trends in Chinese dental technicians

Background: Chinese dental technicians play a significant role in the globalised market of dental prosthesis fabrication, but this subject has not been investigated in detail. The demand for dental prostheses increases as individuals pay increasing attention to their oral health. Therefore, it is important to investigate the status of Chinese dental technicians. Objective: To evaluate the current status of Chinese dental technicians. Methods: Dental technicians’ resumés, which reveal information regarding dental technician manpower, degrees, working age and salary, etc., were analysed and compared with those abroad. We also estimated the future demands of dental technician manpower, and discussed some potential solutions. Results: There are fewer dental technicians in China than in other developed countries; they are also of a lower standard. Male technicians outnumber females. The education level of technicians is insufficient, and the education programme is still in its exploratory stage. Conclusions: The development of dental technician teams in China represents both an opportunity and a challenge. It is important to move forward from the current situation to yield long‐term development. This article provides information on the Chinese dental technology industry, identifies the problems and offers solutions for its development.     

螺旋断层固定野和旋转调强放疗技术在全身照射中的应用对比研究

目的 探究使用螺旋断层固定野调强（TD）和螺旋断层旋转调强（HT）放射治疗技术在全身照射（TBI）中的应用对比,并评估TD治疗技术下计划的质量和执行效率,指导临床选择最佳的计划设计方案。方法 对郑州大学第一附属医院收治的8例身高在120 cm左右的已行TBI的急性白血病患者进行回顾性研究,分别选择TD和HT治疗技术进行计划设计,其中TD分别设计2~12内奇数个均分射野的计划,且起始角度分别从180°和0°开始,其余计划参数都保持一致。最后对设计好的计划剂量分布进行统计,比较TD与HT治疗技术下的计划在靶区的平均剂量（PTV_Dmean）、均匀性指数（HI）和危及器官（OARs）受量,以评估计划质量,并比较治疗出束时间以评估治疗效率。结果 9野的TD计划相对于HT计划在PTV_Dmean和靶区HI能达到一致效果,差异无统计学意义。但TD<9野的计划相对于HT计划在PTV_Dmean（t=-3.12、-5.41、-20.33、-4.56、-7.22、-11.27,P<0.05）和靶区HI（t=-2.94、-5.18、-15.66、-4.31、-5.51、-9.13,P<0.05）无剂量学优势,差异有统计学意义。同时TD计划中起始角度对PTV_Dmean和靶区HI没有影响。在危及器官方面,≥ 7野TD计划与HT计划在左肺平均剂量与右肺平均剂量差异无统计学意义;左眼晶状体计划危及体积（PRV）的最大剂量（2.14±0.60）Gy与右眼晶状体PRV最大剂量（3.05±0.10）Gy在3野TD计划与HT计划差异有统计学意义（t=0.77、0.63,P<0.05）,眼晶状体PRV在最大剂量方面具有一定优势。治疗出束时间差异无统计学意义。TD计划中起始角度对左右眼晶状体PRV最大剂量、左肺平均剂量及治疗出束时间没有影响。结论 对于≥ 9野的TD调强计划相对于HT计划在靶区、危及器官及治疗出束时间方面能达到一致的结果,但在眼晶状体PRV最大剂量方面具有一定优势。