新型3D打印组织补偿物的放疗应用研究

目的 研制一种能适用于不规则体表的3D打印组织补偿物。方法 对无组织补偿物、市售等效组织补偿膜及3D打印组织补偿物通过假人模体进行临床前评估。采集上述3套假人模体会阴部的CT图像,相同靶区给予同样处方剂量(D_95%=100 cGy)。采用同一TPS设计IMRT计划,比较三者PTV剂量学参数。评估该3D打印组织补偿物应用于10例患者后的剂量学参数指标。结果 选定材料的电子密度为1.00~1.01。无组织补偿物、市售等效组织补偿膜、3D打印组织补偿物的靶区D_max分别为182.9、118.9、114.8 cGy,D_mean分别为146.2、107.7、104.1 cGy,HI分别为0.565、0.15、0.11。10例患者的3D打印组织补偿物个体化程度高、剂量均匀性好(HI为0.03~0.15,中位数0.06)。共5例阴茎阴囊佩吉特氏病患者受益于3D打印组织补偿物的支撑固定作用。结论 该3D打印组织补偿物个体化程度高,可起到摆位支撑作用,能有效提高皮肤剂量。     

Explorative data analysis techniques and unsupervised clustering methods to support clinical assessment of Chronic Obstructive Pulmonary Disease (COPD) phenotypes

Chronic Obstructive Pulmonary Disease (COPD) is the fourth leading cause of death worldwide and represents one of the major causes of chronic morbidity. Cigarette smoking is the most important risk factor for COPD. In these patients, the airflow limitation is caused by a mixture of small airways disease and parenchyma destruction, the relative contribution of which varies from person to person. The twofold nature of the pathology has been studied in the past and according to some authors each patient should be classified as presenting a predominantly bronchial or emphysematous phenotype. In this study we applied various explorative analysis techniques (PCA, MCA, MDS) and recent unsupervised clustering methods (KHM) to study a large dataset, acquired from 415 COPD patients, to assess the presence of hidden structures in data corresponding to the different COPD phenotypes observed in clinical practice. In order to validate our methods, we compared the results obtained from a training set of 415 patients with lung density data acquired in a test set of 93 patients who underwent HRCT (High Resolution Computerized Tomography).     

Site planning for nuclear magnetic resonance imaging

The unique factors to be considered in selection of a site for a magnetic resonance imaging installation are addressed, with emphasis on the interaction of the magnet with its environment. The effect of ferrous objects on the magnet and the influence of the magnet on its surroundings are discussed. Design issues for magnetic shields are given.     

同种异体肢体移植的研究

目前先天性畸形,创伤性截肢及肿瘤切除术后所致的肢体缺损,仍只能用假肢替代,而假肢不具有生物功能。肢体移植的方法如能较成熟地应用于临床,无疑是肢体重建的最佳选择。由于各种强有力的免疫抑制剂的发现及应用、显微外科技术的发展,使同种异体肢体移植成为现实,现已展示了广阔的前景。本文从组织配型、冷冻保存、免疫抑制、基因治疗、组织工程等方面对肢体移植的研究进展简要综述。     

冰冻人血清α-淀粉酶催化活性浓度候选二级标准物质的研制

目的 研制冰冻人血清α-淀粉酶催化活性浓度候选二级标准物质,作为量值传递的标准.方法 参照JJF 1343—2012《标准物质定值的通用原则及统计学原理》和JJF 1644—2017《临床酶学标准物质的研制》要求进行均匀性、稳定性、互换性评价;联合6家通过中国合格评定国家认可委员会(CNAS)认可的校准实验室对标准物质...     

临床流程式考试量表在麻醉科住院医师规范化培训中的应用

目的:运用临床流程式考试（clinical flow examination,CFE）量表评估四川大学华西医院麻醉科住院医师规范化培训的效果。方法:采用CFE方法,98名学员进行连续3次考试,并分别对考核导师和学员进行满意度调查;然后对CFE量表进行信效度检验,并对成绩和满意度进行统计分析。应用SPSS 23.0软件进...     

The effects of oxytocin on the pattern of electrical propagation in the isolated pregnant uterus of the rat

 In the isolated pregnant myometrium of the rat, the pattern of propagation was investigated by recording simultaneously from 240 different extracellular sites while the contraction of the tissue was recorded isometrically. Analysis of all recorded electrograms allowed the two-dimensional spread of activity in the myometrium to be reconstructed. From these activation maps, the conduction velocities were measured in the longitudinal, oblique and transversal directions. At low concentrations (10^–9 and 5×10^–9 M), oxytocin significantly increased the frequency and duration of electrical bursts and the average spike intervals, without affecting the homogeneity of action potential propagation, concomitant with a significant increase in the amplitude of contractions. At high concentrations (10^–8 and 5×10^–8 M), oxytocin induced conduction blocks and the size of inexcitable areas was increased, concomitantly with an increase in muscle contractures. In contrast, the conduction velocities in the longitudinal, oblique and circular directions were not influenced by oxytocin at any concentrations. Received: 9 June 1998 / Received after revision: 14 September 1998 / Accepted: 23 September 1998     

Transactions

Abstract

Objective: The aim of this study was to develop and psychometrically evaluate speech audiometry materials that can be used to measure word recognition (WR) and speech recognition testing (SRT) in quiet for native speakers of Cantonese. Study Sample: Commonly used bisyllabic and trisyllabic Cantonese words were digitally recorded by native male and female talkers and then evaluated by twenty normal-hearing Cantonese listeners. Design: The recorded bisyllabic words were psychometrically evaluated and arranged into four WR lists and eight half-lists that are relatively homogeneous in audibility. Using logistic regression, SRT materials were developed by selecting 28 trisyllabic words with relatively steep psychometric functions and digitally adjusting their intensity to match the listeners’ mean pure-tone average. Result: The mean psychometric slopes for the WR materials were 7.5%/dB for the male talker and 7.6%/dB for the female talker, with no statistically significant differences between the lists or half-lists. At intensity levels required for 50% intelligibility, the mean psychometric slopes of the male and female talker SRT materials were 14.5%/dB and 14.9 %/dB, respectively. Conclusion: High-quality digital recordings of Cantonese speech audiometric WR and SRT materials were developed and validated in this study. These materials are available on compact disc, indexed by talker gender.

Sumario

Objetivo: El propósito de este estudio fue desarrollar y evaluar psicométricamente materiales de lenguaje que puedan utilizarse en reconocimiento de palabras (WR) y en pruebas de reconocimiento del lenguaje (SRT) en silencio para hablantes nativos del cantonés. Muestra del estudio: Se grabaron digitalmente palabras bisilábicas y trisilábicas comúnmente usadas en cantonés, usando hablantes nativos, masculinos y femeninos, que luego fueron evaluadas por veinte sujetos de origen cantonés con audición normal. Diseño: Las palabras bisilábicas grabadas fueron evaluadas psicométricamente y dispuestas en cuatro listas para WR y en 8 medias listas que eran relativamente homogéneas en cuanto a audibilidad. Usando regresión logística, se desarrollaron materiales para SRT por medio de la selección de 28 palabras trisilábicas con funciones audiométricas relativamente empinadas y ajustando la intensidad digitalmente para equipararse con el promedio tonal puro de los evaluadores. Resultados: La pendiente psicométrica media de los materiales para WR fue de 7.5%/dB para hablantes masculinos y de 7.6%/dB para hablantes femeninas, sin ninguna diferencia estadísticamente significativa entre las listas y las medias listas. A la intensidad requerida para el 50% de inteligibilidad, las pendientes psicométricas medias de los materiales para SRT, con hablantes masculinos y femeninos, fueron de 14.5%/dB y 14.9 %/dB, respectivamente. Conclusión: Se desarrollaron grabaciones digitales de alta calidad para materiales audiométricos en cantonés para WR y SRT, y se validaron en este estudio. Estos materiales están disponibles en disco compacto, y clasificados por el género del hablante.     

如何正确运用χ2检验——人-时间资料率比分析与SAS实现

本文目的是介绍"分层人-时间资料"率比分析方法与SAS实现方法,具体内容包括以下四个方面:①分层人-时间资料中第i层率比的点估计和置信区间估计;②不同层间率比的齐性检验;③合并率比的点估计与置信区间估计;④分层人-时间资料中发病密度的线性趋势检验.通过两个实例,展示基于SAS软件实现前述四个分析内容的统计计算过程,包括...