Uniformity and standardization of single and opposing cobalt 60 sources for total body irradiation

The use of total body irradiation (TBI), chemotherapy, and allogeneic bone marrow transplantation in the management of relapsing leukemia has been established with dual source cobalt irradiation. In many facilities in order to reproduce the clinical results with single source irradiation, dosimetry must be compared under situations of varying configurations in order to standardize TBI techniques. Once intercomparison is achieved by on site dosimetric evaluation, recommendations are made for patient position, length of exposure in different positions and average thickness and beam data used to calculate absorbed dose. Homogeneity of single and opposing cobalt sources is also compared.     

Quality control materials development for proximate composition determination in baby foods to enhance the Portuguese food composition database: Packaging conditions

Food matrix reference materials play an important role in the quality of data used in food composition databanks concerning the precision, trueness and accuracy of analytical values. In this work the feasibility studies according to ISO 34 (ISO, 2000) of two commercial baby foods (ready-to-eat baby soup and milk-based powdered infant formula) were evaluated to check for their suitability as quality control materials for the analysis of moisture, protein, fat, ash and acidity. The suitability of plastic packaging materials to guarantee the reference materials’ characteristics is discussed. Official methods of analysis were used to evaluate the homogeneity and to monitor short-term and long-term stability studies. ANOVA was carried out to confirm homogeneity within and between samples. ISO 34 method was applied to monitor stability at different temperatures. The coefficients of variation obtained between sachets for milk-based powdered infant formula were less than 4.4% for moisture and 0.5% for fat. The stability data over 8.5 months storage period at 20 °C, 5 °C and ?20 °C and ?70 °C indicate that both materials are stable depending on the parameter studied and temperature. According to results, quality control materials (QCMs) prepared in agreement with ISO 34 requirements are a valuable tool in food composition analysis.     

Probability of interface imperfections within SEM cross-sections of adhesively luted GFP

ObjectivesTo calculate the probability of interface imperfections within SEM cross-sections of adhesively luted GFP depending on the level of analysis and the cement application method by means of LOM (light-optical microscopic evaluation method).Material and methodsFour groups of artificial root canals received GFPs (n = 5) under following experimental conditions: I = RelyX? Unicem, applied with application aid, II = RelyX? Unicem, III = Panavia F 2.0 and IV = Variolink II. In groups II–IV only posts were loaded with cement (i.e. conventional post cementation). After GFP cementation, standardized photographs were taken perpendicularly to post surface under light-optical microscope from two opposite sides. The length of homogenous cement interface areas were measured using surface-analyzing software. The homogenous areas were related to length of apical, middle, cervical post section and to complete post length to generate the probabilities (%) of hitting imperfections when using SEM cross-section analysis.ResultsThe probabilities (%) of hitting imperfections within SEM cross-sections for cervical, middle, and apical level of analysis were: I = 78, 64, 82; II = 89, 98, 99; III = 72, 91, 99; and IV = 85, 91, 97, respectively. For complete post length median values of probabilities (%) were: I = 75; II = 95; III = 87; and IV = 91.SignificanceThe probabilities show, that SEM cross-section evaluation concerning detection of cement interface imperfections of adhesively luted GFPs depends on the cement application method and the level of analysis and seeming therefore not always unrestricted representative for the whole specimen.     

网状Meta分析一致性的鉴别与处理方法

与传统Meta分析相比,网状Meta分析的混杂因素较多且处理更为困难。由于证据相互传递,异质性可能会被带入间接比较中。因此,异质性的有效鉴别与正确处理备受关注。为保证网状Meta分析结果的可靠性,方法学家提出一致性概念并给出一系列鉴别与处理方法。基于Bucher法的延伸,目前一致性鉴别与处理的方法已扩展至节点分析法、假设检验及两步法等十余种量化措施。然而,由于方法学基本理论与侧重点的差异以及统计效能的局限性,使得目前相关检测与处理方法的力度仍不够高效。因此,高效、简洁、解释度高的检测与处理方法依旧需要进一步探索。     

抑郁反应,抑郁发作,双相障碍(抑郁相)同异源性的临床研究

目的：探讨抑郁反应、抑郁发作、双相障碍（抑郁相）的同异源性。方法：抽取我院20年来住院诊断为抑郁反应、抑郁发作、双相障碍（抑郁相）病例各60例比较分析。结果：抑郁反应与抑郁发作两组病例，从发病年龄、起病因素、遗传背景、临床表现、预后情况均无明显差异。结论：抑郁反应与抑郁发作是同源性疾病，抑郁发作与双相障碍（抑郁相）是异源性疾病。     

浙江省肠道病毒71型的分离与VP1区域序列分析

目的研究浙江省手足口病患者中肠道病毒（EV）71型分离株的病毒基因特征。方法采集手足口病患者粪便、疱疹液和咽拭子标本，进行病毒分离和逆转录一聚合酶链反应（RT—PCR）特异性扩增进行鉴定，同时选取其中6株EV71分离毒株，对其抗原决定簇部位VP1区进行核苷酸序列测定并参考EV71A、B、C各基因型的参考毒株和以往中国EV71的分离毒株进行同源性分析和构建系统发生树。结果从14份标本中分离出EV9株，经中和试验和RT—PCR特异性扩增，均证实为EV71。其中6株EV71分离毒株与A、B基因型参考毒株的核苷酸和氨基酸同源性分别为82．9％～85．5％和94．9％～98．0％；与C基因型比较，同源性分别为89．2％～94．1％和97．0％～99．0％。而与C基因型的C1、C2、C3、C4亚型代表株的核苷酸同源性分别为91．0％～92．2％、90．2％～90．3％、89．2％～89.5％、96．7％～96．9％，其中与国内以往分离到的C4亚型毒株的核苷酸同源性可达93.8％～97．1％。在系统发生树上，这6株毒株均在C基因型中，与属C4亚型的11株毒株属同一分支。结论浙江省手足口病患者中分离的EV71毒株属C基因型的C4亚型。     

Structural and analytical comparison of gallbladder stones collected from a single patient: studies of five cases

We observed the gross and fine structure of gallbladder stones collected from five adult patients (cases I–V) by optical photography, radiography, scanning electron microscopy, and backscattered electron microscopy, and then measured the components by energy-dispersive X-ray microanalysis and infrared spectroscopy. From the stones, calcium (Ca) phosphate, Ca bilirubinate, and Ca palmitate or fatty acid Ca were identified. The 3 cholesterol stones (case I) and the 2 brown pigment stones (case II) showed macroscopic homogeneity, respectively. In addition, their fine structure and components were also similar to each other. The black pigment stones (case III) showed macroscopic homogeneity, but they were divided into radiopaque (30 stones) and radiolucent types (60 stones). The former had Ca phosphate in the center surrounded with Ca bilirubinate, and the latter was dotted with minute deposits of Ca bilirubinate. The 6 cholesterol stones (case IV) were divided into two types in size. The 5 large stones, of macroscopic homogeneity, had a core region of Ca palmitate and clear concentric rings of Ca phosphate, whereas the smaller stone was almost filled with Ca phosphate deposits in the center. From the different distributions of Ca phosphate, the smaller stone may have been formed later than the 5 large stones. Case V contained 4 stones. The 3 large cholesterol stones, of more or less macroscopic homogeneity, had a core region and concentric rings of Ca phosphate, but 1 smaller stone was dotted with minute deposits mainly containing iron (Fe) and/or silicon elements (rare type). Therefore, the stones of cases III, IV, and V showed considerable heterogeneity, respectively. In many stones, the initial precipitation of Ca salts will have become the nidus, and the concentric rings and dotted deposits of Ca salts may have accelerated cholesterol stone growth. In addition, the dotted deposits of Ca bilirubinate in the black pigment stones and the dotted deposits containing Fe in the rare stone may have become also the nidi.     

福州120院前急救系统2341例患者呼救原因、时间、季节与年龄的同质分析

[目的 ]研究福州 12 0院前急救系统的呼救原因、时间、季节与患者年龄等 4个指标间的关系 ,探索其规律 ,以制订应急措施 ,改善服务。[方法 ]收集 1997— 2 0 0 1年的登记资料 ,在累计约 1 5万例呼救病例中 ,以单纯随机抽样选取2 3 41例 ,对有关指标以SPSS 11 5建立数据库 ,进行同质分析 (homogeneityanalysis ,HOMALS) ,并绘制 2维或 3维图来表述。[结果 ]①上午、60岁以上老人多见心脑血管疾病呼救 ,且春季多发 ;②青年人的交通肇事及挫裂挤压伤多见于上半夜 ,且冬季多发 ;③下半夜多见壮年人的急性胃肠炎发作。其它指标未见显著的同质关系。[结论 ]同质分析法可分析这 4个指标间的同质关系 ,发现有关规律 ,它比多维列联表的 2 检验法等 ,可更加清晰、直观地描述有关指标间的同质关系 ,这对制订应急措施有重要意义。