四成分教学设计模型--面向复杂学习环境的多媒体原理

四成分教学设计模型认为要实现复杂学习需要借助学习任务、支持性信息、程序性信息和子任务练习等因素。本文探讨运用这一模型设计多媒体学习环境及相关的14条多媒体原理。学习者可以在一个模拟的环境下完成学习任务,利用相关的多媒体原理有利于促进归纳学习过程;学习者还可以在超媒体系统中掌握支持性信息,相关的多媒体原理有利于促进信息的提取和精细加工过程;学习者也可以通过电子绩效支持系统来获取程序性信息,相关的多媒体原理有利于知识处理;最后,学习者能通过基于计算机练习程序来进行子任务的练习与训练,相关的多媒体原理有利于促进知识技能的巩固。本文还讨论了四成分模型框架的启示和不足。

战术指挥官谈阿富汗“持久自由行动”的经验

本文是美军一名战术指挥官从自己的亲身经历出发来评述阿富汗“持久自由行动”的特点和经验教训，视角极为独特，对我们认识美军在阿富汗战争中遭遇的处境极有帮助。作者从部署前的训练谈起，涉及部队部署后的环境、战术层面的战场信息作战、金钱与反恐、交战原则，以及美军如何与当地民众接触等内容，在这些第一手感性认识的基础上，提出了战术指挥官应借鉴和遵循的经验原则，最后提出了其个人对战争和战场变化的看法。

小肠活检标本的低乳糖酶活性:是否应限制小肠黏膜损伤患儿饮食中乳糖的摄入

Objective. Small intestinal mucosal damage can result in decreased lactase activity (LA).When LA is low in a small-bowel biopsy (SBB) specimen, a reduction of dietary lactose intake is usually advised. This is often done by reducing dietary dairy products, which also reduces the intake of calcium, protein and vitamins. Since intestinal damage can have a patchy character and LA varies along the horizontal axis of the small intestine, the relevance of SBB measurement for intestinal LA could be questioned. We compared LA in the SBB with the in vivo capacity to digest lactose using the Lactose Digestion Index (LDI). Material and methods. LA was measured in 18 children aged 0.8-10.9 years (mean 3.9, SD 2.4) undergoing SBB for various indications. In all children the LDI was determined using the 13C-lactose/2H-glucose test. Results. In 9/18 biopsy specimens LA was low (< 10 U/g protein). LDI was normal in 14/18 patients. In 8 out of 9 patients with normal lactase activity, LDI was also normal, while in 6 out of 9 patients LDI was normal despite low LA in the biopsy. In patients with normal LDI, histology was normal in 6/14, in 4/14 mild histological changes (Marsh II) were seen and in 4 patients histological damage was severe (grade III). Conclusions. In children with small-bowel mucosal damage, lactose digestive capacity can remain high despite low LA and histological changes in an SBB. Extrapolation of LA in SBB specimens to overall lactose digestive capacity may not be reliable. The advice concerning the restriction of intake of dairy products cannot be based on the data of the SBB only.

普通人群消化不良的危险因素调查:非甾体抗炎药、吸烟、失业比幽门螺杆菌感染更严重

Objective. Dyspepsia, a common condition in the community, affects quality of life and imposes costs on both the individual and the community. Several factors including Helicobacter pylori, acetylic salicylic acid (ASA)/non-steroidal anti-inflammatory drugs (NSAIDs) use, low-dose ASA use, alcohol consumption, cigarette smoking and social status might be responsible. Material and methods. A cross-sectional study from the inclusion (intervention group) of a general population study evaluating rates of dyspepsia after H. pylori screening and eradication was carried out. A total of 10,007 individuals aged 40-64 years received questionnaires and an invitation to take part in H. pylori screening. Information on dyspepsia (the gastrointestinal symptom rating scale (GSRS) and “most bothersome symptom”), use of ASA/NSAIDs, use of low-dose ASA, lifestyle factors and level of education and employment status was obtained from the questionnaire. Dyspepsia was defined as a score of ≥2 in the GSRS dimension abdominal pain syndrome (aps), allowing for a maximum of one light problem score in any of the 3 items in the dimension to be overlooked. Results. In all, 5749/10,007 individuals participated in the study; 24.9%reported dyspepsia. In a multiple logistic regression analysis H. pylori infection was found to be a risk factor for dyspepsia, odds ratio (OR) 1.21 (CI; 1.03-1.42). However, the highest ORs for dyspepsia were: for daily use of ASA/NSAIDs 2.33 (CI; 1.72-3.15), unemployment 2.18 (CI; 2.86-2.56) and cigarette smoking ≥20 g/day 1.55 (CI; 1.29-1.86). Conclusions. H. pylori infection is a significant risk factor for dyspepsia although of less importance than ASA/NSAIDs use, unemployment and heavy smoking.

胃食管反流性疾病的咽喉部病变诊断:喉镜优于内镜

Objective. The laryngopharyngeal form of gastroesophageal reflux disease (LF GERD) is a frequent manifestation of supraesophageal GERD. Diagnosis of LF GERD is difficult: most of the common diagnostic methods of GERD have insufficient accuracy in establishing LF GERD. The purpose of this study was to evaluate the role of endoscopic and laryngologic examination in the diagnosis of LF GERD and to create a laryngoscopic reflux index (LRI). Material and methods. A total of 108 LF GERD patients and 90 controls were investigated. The criteria for LF GERD were: complaints, reflux-laryngitis, and esophagitis (endoscopic-ally or histologically proven). Lesions in four laryngeal regions were evaluated: arytenoids (A), intraarytenoid notch (IAN), vestibular folds (VF), and vocal cords (VC). Three types of mucosal lesions were evaluated on a points basis: alterations of the epithelium, erythema, and edema. Total LRI was calculated by summing-up the indices in the separate laryngeal areas. Results. The LRI mean value (11.48±3.78 points) of LF GERD patients was statistically significantly greater than that (1.64±1.93 points) of the controls. The most significant laryngoscopic changes of LF GERD were: mucosal lesions of IAN, mucosal lesions of VC, and edema of VC. A combination of these three findings reliably distinguishes the LF GERD patients from controls in 95.9%of cases. The mucosal lesions of IAN have the greatest importance in diagnosing LF GERD: the odds ratio to LF GERD -21.32, p < 0.001. Endoscopic esophagitis was established in 36 (33.3%) cases. The severity of esophagitis did not correlate with the severity of the laryngeal findings. Conclusions. Laryngoscopy is superior to endoscopy in diagnosing LF GERD. Endoscopy has limited value in the diagnosis of LF GERD. Establishing the LRI could be helpful in the differential diagnosis of the disease in the everyday clinical practice.

日本患者中IBD5和克罗恩病之间缺乏相关性揭示了炎症性肠病的人种特异性差异

Objective. Population-specific differences in the genetic susceptibility to inflammatory bowel disease (IBD) are indicated by the fact that Crohn’s disease (CD) in Japanese patients does not have any of the common CARD15 variants that are associated with CD in Caucasians. Recently, the disease-causing mutation in the IBD5 haplotype was identified. The TC haplotype, composed of L503F in SLC22A4 and -207G/C in SLC22A5 promoters, was reported to alter the function of the organic cation transporter and to be associated with CD in Caucasians. To determine whether the TC haplotype is also associated with IBD in a Japanese population, we genotyped L503F and -207G/C variants in Japanese subjects. Furthermore, we also performed a case-control association study with all representative single nucleotide polymorphisms (SNPs) in IBD5 using previous information of linkage disequilibrium extension reported in Japanese patients to determine whether there were variants in IBD5 specifically associated with IBD in Japanese patients. Material and methods. A total of 758 Japanese individuals, 241 patients with CD, 247 patients with ulcerative colitis (UC) and 270 healthy controls, were analyzed in this study. Genotyping for SNPs was determined by polymerase chain reaction-restriction fragment length polymorphism analysis. Results. We found L503F and -207G/C to be very rare (< 1%frequency) in CD, UC and HC in the Japanese population. Furthermore,we also found that none of the representative SNPs in IBDS was associated with CD or UC in the Japanese subjects. Conclusions. In contrast to Caucasians, IBD5 is not a major component of the susceptibility to IBD in the Japanese population.

性别对内镜治疗胃食管反流性疾病临床效果的影响

Objective. Gender differences in gastroesophageal reflux disease have been reported. Higher frequency and severity of symptoms, lower esophageal acid exposure and lower incidence of reflux-related complications have been observed in women. The aim of this study was to determine whether there are any gender differences in clinical presentation, diagnostic evaluations and response to endoscopic therapy in patients with gastroesophageal reflux disease. Material methods. Patients with gastroesophageal reflux disease referred for endoscopic therapy were scored for typical (heartburn and regurgitation) and atypical (chest pain, cough, wheezing, and hoarseness) symptoms at baseline. Upper endoscopy, manometry and pH studies were performed for all patients. Endoscopic treatment consisted of placement of two to three sutures within 2 cm of the squamocolumnar junction. Reflux symptoms were re-scored after endoscopic treatment. Results. Ninety-five patients (37 M, 58 F, mean age 51 years) were included in the analysis. Male and female patients at baseline reported similar severity of typical reflux symptoms as well as comparable prevalence of atypical symptoms. Manometric findings were also comparable between the genders. Endoscopic and ambulatory pH studies revealed a higher incidence of erosive esophagitis and a trend towards higher acid exposures in male patients. The response to endoscopic therapy was similar for men and women. Conclusions. Apart from a higher incidence of erosive esophagitis in male patients, no major differences were found in endoscopic, manometric, esophageal acid exposure studies and clinical response to endoscopic therapy between the genders.