Strategies in assessing the need for updating evidence-based guidelines for six clinical topics: an exploration of two search methodologies

BACKGROUND: Because of the expense of updating practice guidelines, recent attention has focused on approaches that can reliably assess any updating required. Shekelle et al. (Journal of the American Medical Association 2001, 286, 1461-7) proposed using limited literature searches with expert involvement to reduce resources used in assessing whether a guideline needs updating. OBJECTIVES: This study compared Shekelle's method and the traditional systematic review method regarding comprehensiveness and effort. METHODS: Two research teams translated critical key questions on screening test treatments and outcomes to Medical Subjects Headings (MeSH) and search strategies. They refined Shekelle's method over three iterations, seeking greater efficiency. Using both methods independently, teams assessed the need to update six topics from the 1996 Guide to Clinical Preventive Services (US Preventive Services Task Force). Outcomes included completeness of study identification, importance of missed studies and effort involved. RESULTS: The revised review approach produced fewer citations than the traditional approach and saved time, identifying fewer eligible studies than the traditional approach. None of the studies missed was rated important by the experts consulted. CONCLUSIONS: The revised review approach provides an acceptable method for judging whether a guideline requires updating. Librarians were an integral part of the research process that streamlined the searches.     

利用双标图分析基因型和环境交互作用

在作物的品种区域化试验中，品种的基因型和环境（Ｇ×Ｅ）交互作用越来越受到重视．一种新的非常有效的分析Ｇ×Ｅ交互作用模型是加性主效应和乘积交互作用模型（简称ＡＭＭＩ模型），而双标图（ｂｉｐｌｏｔ）是解释ＡＭＭＩ分析结果的一种直观有效的图形工具．本文对ＡＭＭＩ模型及双标图作一扼要介绍，并选用１９９５年南方水稻区试单季晚粳组数据作为实例，给出了两种新的双标图，以帮助我们更深入地了解Ｇ×Ｅ交互作用．     

Role of CD97stalk and CD55 as molecular markers for prognosis and therapy of gastric carcinoma patients

Objectives: To explore the mechanism of development and aggressiveness in gastric carcinomas by investigating the expression and role of CD97 and its cellular ligand CD55 in gastric carcinomas. Methods: Tumor and corresponding normal mucosal tissue, collected from 39 gastric carcinoma patients, were examined by immunohistochemistry and RT-PCR for the expression of CD97 and CD55. Results: CD97stalk was strongly stained on scattered tumor cells or small tumor cell clusters at the invasion front of gastric carcinomas. The expression of CD97stalk was frequently observed in tumors of stage Ⅰ and T1 gastric carcinoma patients. The expression of CD97stalk between Stage Ⅰ and Stage Ⅱ, Ⅲ, Ⅳ specimens showed significant difference (P＜0.05), between T1 and T2, T3, T4 specimens also showed significant difference (P＜0.05). Specimens with tumor invasion depth limited in mucosa of T 1 specimens showed higher positive CD55 expression than specimens with the same tumor invasion depth in T2, T3, T4 specimens, the expression of CD55 between T1 and T2, T3, T4 specimens was significantly different (P＜0.05).There was strong correlation between the distribution patterns of CD97stalk and CD55 on tumor tissues (r=0.73, P＜0.05). Signet ring cell carcinomas frequently contained strong CD97stalk and CD55-staining. Conclusions: Our results suggest that CD97stalk is probably involved in the growth, invasion and aggressiveness of gastric carcinomas by binding its cellular ligand CD55. CD97stalk and CD55 could be useful as molecular markers for prognosis and therapy of gastric carcinoma patients.     

The development of spoken language in deaf children: explaining the unexplained variance

Using a large existing data base on children with severe and profound deafness, 10 children were identified whose level of spoken laguage was most above and 10 whose level was most below that expected on the basis of their hearing loss, age, and intelligence. A study of their personal characteristics, family background, and educational history identified factors associated with unusually high performance; these includes earlier use of binaural ear-level aids, more highly educated mothers, auditory/verbal or auditory/oral instruction, reliance on spoken language as a method of communication, individualized instruction, integration, and structured teaching by parents. Parents of high performers also reported being highly commited to and focusing family resouces on developing their child's spoken language.     

隐藏的地震

大地震不仅可以发生在切割地表的断层上，而且也发生在褶皱地体之下的“盲”断层上。     

Dielectrophoretic differentiation of mouse ovarian surface epithelial cells, macrophages, and fibroblasts using contactless dielectrophoresis

Ovarian cancer is the leading cause of death from gynecological malignancies in women. The primary challenge is the detection of the cancer at an early stage, since this drastically increases the survival rate. In this study we investigated the dielectrophoretic responses of progressive stages of mouse ovarian surface epithelial (MOSE) cells, as well as mouse fibroblast and macrophage cell lines, utilizing contactless dielectrophoresis (cDEP). cDEP is a relatively new cell manipulation technique that has addressed some of the challenges of conventional dielectrophoretic methods. To evaluate our microfluidic device performance, we computationally studied the effects of altering various geometrical parameters, such as the size and arrangement of insulating structures, on dielectrophoretic and drag forces. We found that the trapping voltage of MOSE cells increases as the cells progress from a non-tumorigenic, benign cell to a tumorigenic, malignant phenotype. Additionally, all MOSE cells display unique behavior compared to fibroblasts and macrophages, representing normal and inflammatory cells found in the peritoneal fluid. Based on these findings, we predict that cDEP can be utilized for isolation of ovarian cancer cells from peritoneal fluid as an early cancer detection tool.     

Construction and operation of a microrobot based on magnetotactic bacteria in a microfluidic chip

Magnetotactic bacteria (MTB) are capable of swimming along magnetic field lines. This unique feature renders them suitable in the development of magnetic-guided, auto-propelled microrobots to serve in target molecule separation and detection, drug delivery, or target cell screening in a microfluidic chip. The biotechnology to couple these bacteria with functional loads to form microrobots is the critical point in its application. Although an immunoreaction approach to attach functional loads to intact MTB was suggested, details on its realization were hardly mentioned. In the current paper, MTB-microrobots were constructed by attaching 2 μm diameter microbeads to marine magnetotactic ovoid MO-1 cells through immunoreactions. These microrobots were controlled using a special control and tracking system. Experimental results prove that the attachment efficiency can be improved to ∼30% via an immunoreaction. The motility of the bacteria attached with different number of loads was also assessed. The results show that MTB can transport one load at a velocity of ∼21 μm/s and still move and survive for over 30 min. The control and tracking system is fully capable of directing and monitoring the movement of the MTB-microrobots. The rotating magnetic fields can stop the microrobots by trapping them as they swim within a circular field with a controllable size. The system has potential use in chemical analyses and medical diagnoses using biochips as well as in nano/microscale transport.     

Gravity-oriented microfluidic device for uniform and massive cell spheroid formation

We propose a simple method for forming massive and uniform three-dimensional (3-D) cell spheroids in a multi-level structured microfluidic device by gravitational force. The concept of orienting the device vertically has allowed spheroid formation, long-term perfusion, and retrieval of the cultured spheroids by user-friendly standard pipetting. We have successfully formed, perfused, and retrieved uniform, size-controllable, well-conditioned spheroids of human embryonic kidney 293 cells (HEK 293) in the gravity-oriented microfluidic device. We expect the proposed method will be a useful tool to study in-vitro 3-D cell models for the proliferation, differentiation, and metabolism of embryoid bodies or tumours.     

高校教师隐性知识转移与共享因素分析

利用对高校教师隐性知识转移的调查,分析了高校教师隐性知识转移的现状、影响因素及对绩效的影响.分析表明,个人接触是最好的隐性知识转移方式,而对人际关系忠诚、情感距离及团队的目标、氛围、领导风格是影响团队成员隐性知识共享的重要因素;在隐性知识共享对绩效的影响方面,普遍认为,隐性知识共享能够增加团队成员科研成果的数量、质量,节约科研时间、成本,同时也有利于团队成员获得更多的发展机会.     

Predicting First Grade Reading Performance from Kindergarten Response to Tier 1 Instruction

Many schools are beginning to implement multi-tier response to intervention (RTI) models for the prevention of reading difficulties and to assist in the identification of students with learning disabilities (LD). The present study was part of our larger ongoing longitudinal RTI investigation within the Florida Learning Disabilities Center grant. This study used a longitudinal correlational design, conducted in 7 ethnically and socio-economically diverse schools. We observed reading instruction in 20 classrooms, examined response rates to kindergarten Tier 1 instruction, and predicted students' first grade reading performance based upon kindergarten growth and end of year reading performance (n = 203). Teachers followed an explicit core reading program and overall, classroom instruction was rated as effective. Results indicate that controlling for students' end of kindergarten reading, their growth across kindergarten on a variety of language and literacy measures suppressed predictions of first grade performance. Specifically, the steeper the students' trajectory to a satisfactory outcome, the less likely they were to demonstrate good performance in first grade. Implications for future research and RTI implementation are discussed.