Cross-cultural invariance of the Academic Expectations Stress Inventory: Adolescent samples from Canada and Singapore

We provide further evidence for the two-factor structure of the 9-item Academic Expectations Stress Inventory (AESI) using confirmatory factor analysis on a sample of 289 Canadian adolescents and 310 Singaporean adolescents. Examination of measurement invariance tests the assumption that the model underlying a set of scores is directly comparable across groups. This study also examined the cross-cultural validity of the AESI using multigroup confirmatory factor analysis across both the Canadian and Singaporean adolescent samples. The results suggested cross-cultural invariance of form, factor loadings, and factor variances and covariances of the AESI across both samples. Evidence of AESI's convergent and discriminant validity was also reported. Findings from t-tests revealed that Singaporean adolescents reported a significantly higher level of academic stress arising from self expectations, other expectations, and overall academic stress, compared to Canadian adolescents. Also, a larger cross-cultural effect was associated with academic stress arising from other expectations compared with academic stress arising from self expectations.     

白内障超声乳化术后角膜地形图和屈光状态的观察

目的　观察白内障超声乳化人工晶状体植入术后 ,患者角膜地形图和屈光状态的变化。方法　对2 0 0 0年～ 2 0 0 1年行白内障超声乳化的 136例 (15 1只眼 )患者术前、术后随访一年的资料进行回顾性分析。结果　术后 1、3、6、12月术眼的球镜、散光、角膜地形图曲率和散光 sim k值统计结果无明显差异 ;术后 1～ 12月视力和屈光状态稳定 (方差分析 P >0 .0 5 )。术后 6月平均视力为 0 .5 9± 0 .2 3,矫正视力为 0 .82± 0 .19,术后 6月 ,球镜为 (-0 .2 4± 0 .88) D,散光为 (- 0 .5 6± 1.0 1) D,在± 1.0 D之内球镜和散光眼分别为 84.0 %和 6 4.0 % ,≥ 0 .5和≥ 0 .8的视力分别为 70 .0 %和 2 8.0 % ,≥ 0 .5和≥ 0 .8的矫正视力分别为 94.0 %和 72 .0 %。≥ 0 .5和≥ 0 .8裸眼视力和矫正视力的平均百分率分别由 6 1.96 %和 2 3.49%提高到配镜矫正后的 92 .35 %和 6 3.0 9%。结论　超声乳化术后角膜形态和屈光状态保持良好的稳定性 ,患者可以达到良好的视力。由于植入的人工晶状体无调节功能和测量误差 ,目前部分患者需要配戴较低度数的眼镜矫正远或近视力 ,达到更好的视觉效果。     

ITERATIVE DYNAMIC PROGRAMMING FOR MINIMUM ENERGY CONTROL PROBLEMS WITH TIME DELAY

This paper presents the use of iterative dynamic programming employing exact penalty functions for minimum energy control problems. We show that exact continuously non-differentiable penalty functions are superior to continuously differentiable penalty functions in terms of satisfying final state constraints. We also demonstrate that the choice of an appropriate penalty function factor depends on the relative size of the time delay with respect to the final time and on the expected value of the energy consumption. A quadratic approximation (QA) of the delayed variables is much better than a linear approximation (LA) of the same for relatively large time delays. The QA improves the rate of convergence and avoids the formation of ‘kinks‘. A more general way of selecting appropriate penalty function factors is given and the results obtained using four illustrative examples of varying complexity corroborate the efficacy of the method.     

3种氟喹诺酮类药物抗生素后效应的研究

应用AVANTAGF分析仪的光密度法测定了环丙沙星（CPLX）、氧氟沙星（OFLX）和氟罗沙星（FLRX）的抗生素后效应（PAE）．结果表明氟喹诺酮类抗菌药物对革兰氏阳性球菌和革兰氏阴性杆菌均产生明显的PAE．并随抗菌药物浓度的增大、对受试菌的PAE逐渐延长．呈现了明显的浓度依赖性；3种抗菌药物对铜绿假单胞菌的PAE都较长．MIC均较小．显示了良好的杀菌效果：氯罗沙星对除金葡球菌之外的受试菌的PAE均比其它2药较长．PAE的存在提示在临床设计给药方案时．可适当延长给药间期．减少给药次数与剂量．仍能维持抗菌效果。     

痛觉测试笔的临床研究

目的通过应用痛觉测试笔测试痛觉平面,探讨其临床应用的实用性。方法选择100名志愿者观察痛觉测试笔产生刺痛感的定性描述,另500例行硬膜外阻滞的患者用针刺法和测试笔同时间同检查部位测试。结果100名志愿者认为痛觉测试笔对皮肤只引起如针刺样疼痛,每次测试产生刺痛程度一致,不产生肌肉抽搐、不放散。500例行硬膜外阻滞患者针刺法和测试笔测得的麻醉平面一致,测试笔无划痕反应。结论测试笔可替代锐器针刺法检测麻醉平面,可减少针刺法引起的皮肤损伤。     

Do forceps biopsies truthfully reflect the nature of endoscopically uncovered polypoid lesions of the colon?

BACKGROUND: Total excision of colonic polyps is not always attainable and in some patients it is clinically contraindicated. Also, a resected polyp may be lost at any step between its endoscopic removal and its embedding in paraffin. The aim of this study was to compare the histological features of colonic polyps as analysed by the study of biopsy-forceps obtained samples with those assessed on scrutinizing the totally resected growths. PATIENTS AND METHODS: This prospective study included a cohort of 59 patients in whom, in the course of an elective colonoscopy, a total excision of a 6 mm-sized or larger polyp was called for. Sizeable biopsies were obtained by means of an Olympus Multibyte forceps prior to the total polypectomy. Subsequent to the study of the polypectomy specimens, the forceps biopsy samples were submitted for histological examination. The pathologists were blinded as to the source of the tissue they were studying. The diagnoses rendered by evaluating the biopsy samples and polypectomy specimens of each patient were contrasted with each other. RESULTS: Major discrepancies between the histological features of the fragments captured by the biopsy-forceps and the factual nature of the totally removed polyps were uncovered in 11 (18.6%) of 59 cases. Intriguingly, the grade of the tumours was underrated in all the 11 cases, as judged by contrasting the tentative diagnoses of the forceps-biopsies with the decisive diagnoses of the polypectomies. Importantly, 2 adenocarcinomas would have been missed by just looking at the forceps-retrieved sample. CONCLUSIONS: In our experience, a discordance of 18.6% is to be expected between the diagnoses rendered after examining forceps-biopsies of and totally excised colonic polyps. Nevertheless, it is advisable to procure biopsies prior to the excision of the growths, because on those occasions in which patients' growths cannot be removed or have not been retrieved for one reason or another, a small forceps-captured tissue sample correctly reflects the characteristics of the polyp in 81.4% of the cases. Finally, the biopsies may be discarded in the event that total removal was successful.     

一种简单实用的测量气管截面积的方法

目的介绍一种简单实用而较精确的测量狭窄气管截面积的方法.方法利用纤维支气管镜、测长器、模拟气管等制作并校正测量标尺,并利用该标尺测量了3例气管状况异常患者的气管某一截面面积.结果用校正过的4种测量标尺测量了10个模拟气管的直径,和实测真值比较经t检验分析无显著性差异,利用上述标尺测量的3个患者的目的截面面积分别为约96 mm2、 105 mm2和192 mm2.结论本方法提供了一种简单、快速而又较精确的测量大气道某一截面面积的方法,为定量评价患者的通气功能、选择气管支架或采用其他干预手段处理气管病变提供了数据参考.     

Quality of life assessment and HIV infection: A review

In the last few years, survival of patients infected with human immunodeficiency virus (HIV) has been improved because of a decreased incidence of some opportunistic complications attributable to prophylactic treatments and antiretroviral drugs. The impact of these agents should also be reflected in the quality of life (QoL) of patients. We have reviewed this topic with an emphasis on different types of measurements such as Q-TWIST, MOS and the Spitzer score which seem to be most appropriate for this patient population. We do not think that a special type of assessment should be designed for HIV-infected persons. It would be less time-consuming to improve already existing validated scores focusing on HIV infection. QoL in intravenous drug users with HIV should be evaluated more often.     

Comparison of Tympanic, Esophageal and Blood Temperatures during Mild Hypothermic Cardiopulmonary Bypass: A Study using an Infrared Emission Detection Tympanic Thermometer

Objective. Tympanic temperature can be obtained instantaneously using an infrared emission detection (IRED) thermometer. Its accuracy has been documented in a variety of clinical settings, but its performance at low body temperatures is still unknown. In this study we evaluated its performance during coronary artery revascularization surgery in which mild hypothermic cardiopulmonary bypass (CPB) was used. Methods. Thirty adult patients undergoing coronary artery bypass graft surgery were enrolled in the study. Tympanic temperature obtained using IRED thermometry (Tt1) was compared with core temperatures from the esophagus (Te), and venous blood of CPB (Tv) before, during, and after CPB. We also measured tympanic temperature using a thermocouple probe (Tt2) in 16 of the 30 patients in order to study the agreement between the two methods. Values for correlation coefficients and limits of agreement were computed to assess the degree of agreement among the temperatures obtained. Results. The highest agreement with Tv during CPB was obtained from Tt1 (r = 0.94, 0.41 ± 1.73, limits of agreement) and from Te (0.91, 0.36 ± 2.46). Tt1 also showed good agreement with Tt2 during surgery. Conclusions. Infrared tympanic thermometry is a reliable, alternative method to measure tympanic temperature and may be useful to assess core temperature in both normothermic and mild hypothermic conditions.