Analysis of the degree of precision of a computer-assisted dietary survey method

A computer-assisted method for the registration of food intakes in real time according to a concise and simple procedure was subjected to a series of controls in order to assess precision. The method employs the 'portion' of a composite dish as unit of measure. The constancy of the portion was tested. The results show that the recipes of the diet of a subject may be stored and utilized in deferred time without loss of precision: data to be recorded in real time are then very limited. The length of period of analysis was also studied. The time of investigation should not be shorter than two weeks to obtain precise information on the feeding habits of an individual subject, whereas for a group of subjects the diary of a single day provides information of sufficient precision.     

Occupational allergic contact dermatitis and composition of acrylates in dentin bonding systems

Background Dentin-bonding systems contain sensitizing acrylates. They are increasingly used in dentistry, but only few cases of allergy have been encountered. Objective This study reports observations on eleven patients sensitized by acrylates in dentin-bonding compounds. Furthermore, the composition of dentin-bonding products was analysed and compared with the information given in the material safety data sheets. Methods Patch testing was performed to reveal allergic contact dermatitis, and chamber provocation tests to reveal possible respiratory sensitivity. Gas chromatography/mass spectrometry was used to analyse the chemical composition of the bonding products. Results The most common sensitizer in our material of eleven patients was 2-hydroxyethyl methacrylate (2-HEMA). Another putative sensitizer, BIS-GMA, used in dentin adhesives, did not cause sensitization. The typical allergic dermatitis localized to the fingertips (pulpitis). Seven of the eleven patients also developed paresthesia of the fingertips. One patient with positive patch test reactions to (meth)acrylates had pharyngitis hut no skin symptoms. One patient was sensitized because she had been patch tested with too high a concentration (undiluted) of dentin-bonding components. Material safety sheets gave inaccurate or wrong information about the contents. Conclusion Dentin-bonding acrylates are strong sensitizers, and even a single exposure may sensitize.     

用石英晶体微天平法研究聚乳酸的酶降解过程

利用石英晶体微天平(QCM)探讨影响聚乳酸降解速率的不同因素。聚乳酸的酶降解分两步进行：酶吸附到聚乳酸的表面和聚乳酸在酶作用下的降解。聚乳酸的降解初速率随酶加入量的增加而增大,但达到一定的加入量之后,降解初速率接近一个常数;当pH为7~9时,聚乳酸的降解初速率随pH的增大而增大;当温度为25~40 ℃时,降解初速率随温度的升高而增大。     

齿科桩钉用纤维/树脂复合材料细胞毒性实验研究

目的：研究齿科桩钉用纳米SiO2／S－Gf/EAM复合材料的细胞毒性。方法：用四唑盐比色法研究纳米SiO2／S－Gf/EAM复合材料的细胞毒性。结果：随着培养时间的增加，所测材料各浓度组的吸光值也相应增加，阳性对照组增加较慢，空白对照组和测试材料组增加较快，低浓度组的吸光值高于高浓度组，实验材料的细胞毒性为0级。结论：纳米SiO2／S－Gf/EAM复合材料无明显细胞毒性。     

GC GRADIA DIRECT光固化复合树脂修复切缘缺损疗效观察

目的：应用GC GRADIA DIRECT光固化复合树脂修复切缘缺损观察病例的疗效。方法：将189颗切缘缺损牙齿应用GC GRADIA DIRECT光固化复合树脂进行修复,并经过2年的随访观察。结果：应用GC GRADIA DIRECT光固化复合树脂进行修复切缘缺损成功率为97.88%。结论：GC GRADIA DIRECT光固化纳米混合型复合树脂模仿自然牙体散射和漫反射的光学原理,实现＂隐形＂修复（变色龙效果）。同时具有良好的粘结性能,高抗压强度,良好光泽度和抛光性,长期稳定性强等特点。因此GC GRADIA DIRECT光固化复合树脂是修复前牙各类牙体缺损的理想材料。     

幽门螺杆菌对胆囊结石形成的影响

目的 探讨幽门螺杆菌(Hp)与胆囊结石形成之间的关系.方法 从胆囊结石患者胆囊黏膜中检测Hp,并测量阳性和阴性组中的IL-2、IL-4、自由基以及PLA2含量.结果 54例中检出Hp 15例(27.8%).阳性组IL-2表达为(3.34±1.39)μg/ml,明显低于对照组的(4.98±2.08)μg/ml;IL-4表达为(14.34±8.29)pg/ml,明显高于阴性组的(6.73±2.14)pg/ml;自由基表达为(20.980±3.711)nU/ml,明显高于阴性组的(15.15±3.73)nU/ml,PLA2活性表达为(872.37±70.02)μmol/(L·s),明显高于阴性组的(586.42±57.35)μmol/(L·s),差异均有统计学意义(P＜0.01).自由基与PLA2活性的增高同IL-2活性降低以及IL-4活性的增高呈明显正相关.结论 胆囊结石患者存在有Hp感染因素,并有可能通过IL及自由基、PLA2促进胆囊结石的形成.     

纳米晶胶原基骨材料在股骨头缺血性坏死FicatⅢ期的初步临床应用

目的：探讨纳米晶胶原基骨材料治疗FicatⅢ期股骨头缺血性坏死（avascular necrosis of the femoral head，ANFH）的临床疗效。方法：3例患者，4个Ⅲ期股骨头坏死，通过股骨大转子下方穿刺钻孔，行坏死区病灶清除和纳米人工骨植入术，术后每3月复查X线平片，随访6～11月，2例术后11月CT复查。结果：2例3髋疗效好，11月后骨质修复良好，关节面无进一步塌陷；1例疗效差，因患肢术后早期负重，加重关节面塌陷。结论：纳米晶胶原基骨材料是一种优良的骨修复材料，治疗股骨头坏死效果好，植骨术后要避免过早负重。     

论解放军卫生工作的创始问题

解放军卫生工作从1927年建军时起逐步建立发展,1931年成立全军卫生工作的领导机关－军委总卫生部。此后,建立健全了各类卫生机构,形成了统一的领导体系,培养和配备了基本卫生人员,制订了各种规章制度,至1993年已完成了创始阶段。解放军卫生工作的主要创始人为贺诚。     

点刺"委中"放血对兔腰椎间盘突出症的影响

目的观察点刺"委中"放血对兔腰椎间盘突出症(lumbar intervertebral disc protrusion,LIDP)触觉与步态功能﹑血浆中前列腺素E2(Prostaglandin E2,PGE2)和髓核组织中磷脂酶A2(phospholipase A2,PLA2)含量的影响。方法将40只健康新西兰兔随机分为4组,即空白组、LIDP模型组、点刺委中组和点刺非经穴对照组。自制的LIDP动物病理模型造模器造LIDP病理模型,采用Siegal法记录触觉和步态功能,放射免疫方法测定血浆中PGE2和髓核组织中的PLA2的含量。结果点刺"委中"放血可改善家兔的触觉与步态功能,降低LIDP家兔血浆中PGE2和髓核组织中PLA2的含量,与模型组、对照组比较有显著性差异(P<0.01)。结论通过减少PGE2、PLA2等炎症因子含量减轻炎症反应可能是点刺委中放血治疗LIDP的作用机制。     

纳米羟磷灰石-脂肪族聚酯酰胺复合材料对成骨细胞的生物学作用

目的研究纳米羟磷灰石-脂肪族聚酯酰胺（nHA—PEA）对成骨细胞的生物学作用。方法以含有nHA—PEA的达尔贝科极限必需培养（DMEM）浸提液作用于试验组细胞,DMEM作用于对照组细胞,以甲噻唑四唑氮检测nHA—PEA对成骨细胞生长的影响,流式细胞计数细胞周期的变化,酶联免疫吸附测定细胞碱性磷酸酶（AKP）活性的变化。将细胞和材料联合培养,观察细胞在复合材料上的黏附和生长情况。结果试验组细胞的相对增殖率为92％．107％且无量效关系,试验组与对照组间差异无统计学意义（P〉0．05）;试验组和对照组细胞的细胞周期及AKP活性表达相似,组间差异无统计学意义（P〉0．05）。成骨细胞直接培养于复合材料上,显现出良好的黏附、铺展和生长行为。结论nHA—PEA对成骨细胞的生长和功能无不良影响,具有骨细胞相容性。