Checklist for optimization and validation of real‐time PCR assays

Real‐time polymerase chain reaction (PCR) is a frequently used technique in molecular diagnostics. To date, practical guidelines for the complete process of optimization and validation of commercial and in‐house developed molecular diagnostic methods are scare. Therefore, we propose a practical guiding principle for the optimization and validation of real‐time PCR assays. Based on literature, existing guidelines, and personal experience, we created a checklist that can be used in different steps of the development and validation process of commercial and in‐house developed real‐time PCR assays. Furthermore, determination of target values and reproducibility of internal quality controls are included, which allows a statistical follow‐up of the performance of the assay. Recently, we used this checklist for the development of various qualitative and quantitative assays for microbiological and hematological applications, for which accreditation according to ISO 15189:2007 was obtained. In our experience, the use of the proposed guidelines leads to a more efficient and standardized optimization and validation. Ultimately, this results in reliable and robust molecular diagnostics. The proposed checklist is independent of environment, equipment, and specific applications and can be used in other laboratories. A worldwide consensus on this kind of checklist should be aimed at. J. Clin. Lab. Anal. 23:145–151, 2009. © 2009 Wiley‐Liss, Inc.     

Optimal design of simply supported columns subject to distributed axial load and stress constraint

The optimum designs are given for columns, which are simply supported and under distributed and concentrated axial loads. The objective is to maximize the buckling load subject to volume and maximum stress constraints. The area of the minimum cross‐section under a stress constraint is not known a priori as it depends on the maximum buckling load which in turn depends on the optimum shape. This minimum cross‐sectional area is computed as part of an iterative procedure. An iterative solution method is developed based on finite elements and the results are obtained for n=1, 2, 3, defined as I =α_nAⁿ with I being the moment of inertia, and A the cross‐sectional area. Numerical results show that the optimal areas become larger in the direction of the distributed load. Results are given for uniformly and triangular distributed loads, which are shown to have distinct effects on the optimal column shape. Copyright © 2009 John Wiley & Sons, Ltd.     

Optimizing saturation–recovery measurements of the longitudinal relaxation rate under time constraints

The saturation–recovery method using two and three recovery times is studied for conditions in which the sum of recovery times is 1.5T₁ to 3T₁, where T₁ is the longitudinal relaxation time. These conditions can reduce scan time considerably for long T₁ species and make longitudinal relaxation rate R₁ (R₁ = 1/T₁) mapping for body fluids clinically feasible. Monte Carlo computer simulation is carried out to determine the ideal set of recovery times under various constraints of the sum of recovery times. The ideal set is found to be approximately invariant to the signal‐to‐noise ratio. For the three‐point method, two of the recovery times should be set the same or approximately the same and should be shorter than the third one. Only marginal improvements in accuracy and precision can be achieved by the three‐point method over the two‐point method under a common constraint of the sum of recovery times. Three‐dimensional, high resolution, whole‐brain saturation–recovery scans on volunteers with a fast‐spin‐echo technique (XETA) and completed in a scan time of 10 min generated R₁ measurements of cerebrospinal fluid (T₁ ～ 4 s) in agreement with the computer simulation and literature results, which demonstrates the clinical feasibility of applying the two‐point saturation–recovery method for R₁ mapping for long relaxation components. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.     

药品单剂量调剂操作系统的优化

目的：优化药品单剂量调剂,加强信息化管理,优化操作流程。方法：采用东华软件：住院药房管理系统（DT-CIS-IP）和住院药品调剂系统（DT-CIS-ID）实施。结果：东华软件成功实现了我院4300病床的药品单剂量调剂及各部门管理联网,优化了操作系统及流程,且系统运行稳定。结论：东华软件进行药品单剂量调剂,加强了药品的出入管理,优化了药品单剂量调剂的操作流程。     

基于改良遗传算法的调强射野角度优化

免了手工多次调整射野方向,提高了效率和效果.     

屈光性白内障手术新进展

随着白内障手术技巧的不断发展和人工晶体的不断开发,白内障手术进入屈光性白内障手术时代。屈光性白内障手术不仅涵盖精细的手术过程,还包括不断更新的手术设备、准确完善的术前检查、精确的人工晶状体测算以及术前、术后视功能分析、个性化的屈光性人工晶状体的选择。现就近年来屈光性白内障手术术前及术后评估、手术操作与设计和人工晶体优选情况做一综述。     

枯草芽胞杆菌肌苷发酵过程参数相关分析

基于参数相关的研究方法已成功地应用于多个发酵产品的过程优化,本文通过对枯草芽胞杆菌肌苷生产过程的尾气变化规律、碳氮源消耗和产物浓度的分析和计算,并根据摄氧率(OUR)、二氧化碳释放率(CER)、呼吸熵(RQ)和产物得率(YP/G)的相关性,在工程尺度将发酵过程分为4个阶段,为其他尺度的研究和过程优化提供了线索。     

The clinical application of intensity-modulated radiation therapy

Intensity-modulated radiation therapy is a delivery system that, when coupled with a treatment-planning optimization system, presents the opportunity to conform the dose to the target better than 3-dimensional conformal therapy, particularly in the case of concave targets. Appropriate clinical applications of this technology to challenging patient treatment scenarios requires careful consideration of issues related to target volume-dose heterogeneity and the influence of patient setup uncertainties. These issues are reviewed and illustrated. To date, clinical reports of these treatments for prostate and head and neck cancers have the most mature data. Those results are summarized here. Future applications of this technology can be expected to take careful, considered advantage of this technology to further rearrange dose distributions across target volumes to produce an integrated overall gain in treatment objectives. However, these innovative applications need to be approached with caution, preferably in prospective clinical trials that would help determine if the hypothetical clinical benefits are in fact realizable.     

Development of a Decision Support Model for Scheduling Clinical Studies and Assigning Medical Personnel

Clinical studies for the development of new drugs in the pharmaceutical industry consist of a number of individual tasks which have to be carried out in a pre-defined chronological order. Each task requires certain types of medical personnel. This paper investigates the scheduling of clinical studies to be performed during a short-term planning horizon, the allocation of workforce between the studies, and the assignment of individual employees to tasks. Instead of developing a complex monolithic decision model, a hierarchical modelling approach is suggested. In the first stage, a compact integer optimization model is solved in order to determine the start-off times of the studies and the required staffing while taking the limited availability of personnel into account. The objective is to minimize total staffing costs. The assignment of individual employees to tasks is then made in the second stage of the procedure using a binary optimization model.