四种超硬石膏模型精度及抗弯强度的比较

背景:在临床上,超硬石膏广泛应用于制作固定义齿、大支架可摘义齿等需精细复制口腔情况的工作模型,其抗弯强度足够抵抗脱模时的力量不会发生模型牙体的折断.但当印模为硬质材料如聚醚橡胶印模等,存在牙体折断现象.目的:比较4种超硬石膏YCG,丹特纳,贺利氏,穗诚模型的尺寸精度及抗弯强度.方法:制作三单位固定桥和长方体(50 mm× 10 mm×5 mm)的金属模具,灌注4种超硬石膏模型,分别采用万能工具显微镜和万能试验机测量其尺寸精度及抗弯强度.结果与结论:YCG、丹特纳、贺利氏、穗诚4种超硬石膏近远中方向尺寸精度均值分别为:15.043,15.034,15.037,15.040 mm,颊舌方向为:7.020,7.015,7.019,7.019 mm,牙体长轴方向为:8.022,8.018,8.019,8.02 mm.4种超硬石膏模型抗弯强度均值分别为:15.687,13.000,22.521,18.675 MPa.4种石膏模型尺寸精度差异无显著性意义 (P > 0.05),但抗弯强度差异有高度显著性意义(P < 0.01).贺利氏石膏抗弯强度显著高于其他3种石膏 (P < 0.01),穗诚石膏抗弯强度显著高于丹特纳(P < 0.01).说明贺利氏石膏的抗弯强度是4种超硬石膏中最高者,穗诚的抗弯强度高于丹特纳,提示临床上应根据实际情况尽量选择抗弯强度大的石膏材料.     

腹腔镜手术治疗103例非腹腔型隐睾

目的探讨腹腔镜手术对于非腹腔型隐睾的治疗优势。方法回顾性研究2004年1月至2009年1月所收治的103例非腹腔型隐睾患儿(腹腔镜手术45例,传统开放手术58例)的住院及随访资料,比较两种手术方式手术时间、术中出血量、术后住院时间及术后并发症等各项临床指标的差异。结果两组在手术时间、术中出血量及并发症等方面差异均有统计学意义(P<0.05),腹腔镜组比开放式手术组手术时间短、术中出血少、术后恢复快、住院时间短,双侧隐睾不需增加切口。结论治疗非腹腔型隐睾腹腔镜手术与传统开放式手术相比具有较明显优势,可替代传统开放手术作为首选手术方式。     

Modelling and simulation of placebo effect: application to drug development in schizophrenia

High and variable placebo effect (PE) within and among clinical trials can substantially affect conclusions about the efficacy of new drugs in the treatment of schizophrenia and other neuropsychiatric disorders. In recent years, it has become increasingly difficult to prove drug efficacy against placebo, and one of the reasons is that the placebo response has increased over recent years. The increased placebo response over the years is partly explained by unidentified parallel interventions, patient factors, issues with trial designs, and regional variability or demographic differences. In addition, a nocebo effect, which is undesirable effects a subject manifests after receiving placebo, e.g. extrapyramidal side effects, in placebo arms of antipsychotic trials could also influence the PE and clinical trial outcomes. Placebo effects (PEs) are a natural phenomenon and cannot be avoided completely in clinical trials. However, accounting for the PE via mixed effects modelling approaches could reduce bias in quantifying the overall effect size of the drug treatment. This review article focuses on the PE and its impact on schizophrenia clinical trial outcomes. The authors briefly describe the factors that lead to high and variable PE. Next, pharmacometric approaches to account for the PE and dropouts in schizophrenia clinical trials are described. Finally, some points are provided that could be considered while designing and optimizing antipsychotic trials via simulation approaches.     

Role of theories in school-based diabetes care interventions: A critical review

BACKGROUNDDiabetes is one of the most common chronic diseases of childhood. School plays an essential role in the management of student diabetes, which reduces the risk of short- and long-term diabetes complications and ensures that students are well-positioned for optimal academic performance and growth.AIMThe aim of this review was to systematically identify and synthesize the literature concerning theory-based diabetes care interventions in K-12 schools in the United States. It critically assessed the specific role of theories and associated essential constructs in intervention design, implementation, outcome measurement, and evaluation.METHODSRelevant literature was identified by keyword searches of the Cochrane Library, PubMed, and Web of Science.RESULTSFour interventions met the eligibility criteria and were included in the review. Of those, two evaluated online diabetes education programs for school personnel and the other two assessed in-person interventions. Three studies adopted a one-group pre-post study design, and the remaining one adopted a one-shot case-study design. Three of the interventions adopted social cognitive theory, and the remaining one was guided by the diffusion of innovations theory. Three studies identified core constructs of a theory as predictors of behavioral change. Two used theory to select or develop intervention techniques. Two studies used theory to customize participant intervention techniques. Two studies discussed their findings in the context of theory. No study used theory to select potential intervention participants.CONCLUSIONIn conclusion, despite the value of theory in intervention design and evaluation, theory-based diabetes interventions at school remain scarce. Future research may seek ways to better integrate theory and empirical research.