Gender differences in 24-hour urinary diaries of asymptomatic North American adults

PURPOSE: Two previously published studies from our center have described the urinary habits of asymptomatic men (284) and women (300) as revealed by 24-hour urinary diaries. Those gender specific studies found that urinary diary variables are affected by age and race. By comparing the data from those studies we determined the effect of gender on voiding habits. MATERIALS AND METHODS: In this secondary analysis we matched each female urinary diary to that of a male of similar age and race. Diary variables were compared using paired sign tests with results considered significant at the 5% level. RESULTS: A total of 141 matched pairs were studied. The population age ranged from 18 to 68 years and was racially diverse (56% black, 31% white, 7% Hispanic and 6% Asian). Men had higher total fluid intake and mean voided volume than women (p <0.001 and 0.04, respectively). Women voided more frequently than men (p = 0.006) and had more voids per liter of fluid intake (p <0.001). No gender differences were found for body mass index, nighttime or daytime diuresis rates, total urine volume, maximum voided volume or rates of nocturia. CONCLUSIONS: This analysis suggests that there are significant gender effects on 24-hour diary variables, with females tending to void more often and at lower mean volumes. The results of our study may be useful in the design of research studies or for patient counseling.     

A review of blinding in randomized controlled trials found results inconsistent and questionable

BACKGROUND AND OBJECTIVE: To determine methods to assess the success of blinding in randomized controlled trials (RCTs). METHODS: We searched MEDLINE, the Cochrane Controlled Trials Register, and the Cochrane Method Register and performed a manual search to target studies that attempt to assess blinding and describe the methods used in those studies. RESULTS: A total of 90 reports were selected. Reports assessed the success of blinding participants (n = 58), care providers (n = 36), and outcome assessors (n = 15). Of the 58 reports assessing the success of blinding participants, 54 (93%) reported asking participants to guess their treatment assignment. There was no consistency in timing of assessment (e.g., once at the end of the trial, 57%, or several times during the trial, 26%) or modalities of answering (e.g., "do not know" answers, 43%, or participants forced to guess, 31%). A statistical analysis was performed in 57% of reports. The statistical analysis mainly compared the proportion of correct guesses to those produced by chance (32%) or checked for a relation between participants' guesses and treatment assignment (23%). CONCLUSIONS: Methods of assessing the success of blinding, analysis and reporting the results were inconsistent and questionable.     

How to Measure Self-management Abilities in Older People by Self-report. The Development of the SMAS-30

This paper presents the results of two studies carried out in order to design and test a self-report instrument to measure Self-Management Ability (the SMAS-30) in aging individuals. SMA refers to the core behavioral and cognitive abilities which presumably contribute to sustainable well-being in later life. Robust findings of the studies (n=275 and n=1338) showed that SMA could be measured reliably as a composite concept of abilities systematically linked to dimensions of well-being in adults aged 65 and over, with the different sub-scales revealing a profile of inter-related abilities. A sub-sample of participants in Study 2 (n=86) showed that the SMAS-30 had high reproducibility over a period of 16 weeks. The validity of the SMAS-30 was supported by meaningful associations with other constructs in both studies. As expected, the older and frailer the people, and the poorer their perceived health, the lower their SMA. Moreover, SMA was positively related to several dimensions of subjective well-being and the related concepts of general self-efficacy and mastery.     

关于重构我国公共卫生体系的政策建议

SARS的爆发流行使我国公共卫生体系存在的问题暴露无疑．但也使越来越多的人开始注意到公共卫生的重要性。从党的十六大提出的“全面建设小康社会”的宏伟目标和十六届三中全会提出的“以人为本、协调发展”的科学发展观出发．运用公共物品理论、卫生保健公平性理论及人力资本理论．就重新构建我国高效、一体化公共卫生体系提出一些政策建议。     

Application of optimum linear filter theory to the detection of cortical signals preceding facial movement in cat

Summary Linear filter analysis was used to detect the occurrence of neuroelectric signals in associated noisy background electrical activity by matching a signal template against incoming neuroelectric data. Bach signal to be detected in the neuroelectric data consisted of a gross potential change recorded at the coronal — precruciate cortex of a cat, evoked by an auditory conditional stimulus, and related to the production of a conditioned facial movement. Detection of the occurrence of the signal corresponded closely to detection of the ensuing movement.The operation of the matched filter on the signals in noise was studied for different threshold levels of detection. Threshold settings were selected to maximize successful detections and to minimize false alarms. The results of our experimental detections agreed closely with predicted, theoretical detection levels derived from Wiener's models of optimum detection of signals in additive noise. Levels of detection were found to depend upon the signal to noise ratios and frequency spectra of the analyzed data and could be predicted a priori from a knowledge of the latter on the basis of Wiener's theory. The ability to predict optimum detection levels, by the linear filter method, of cortical electrical signals related to the production of movements may provide a basis for evaluating the merit of such signals in the design of prosthetic devices for motor control.Visiting scientist from Department of Electrical Engineering, Aria Mehr University, Tehran, Iran.     

Macromolecular Transport in the Arterial Wall: Alternative Models for Estimating Barriers

Early atherosclerosis, or atherogenesis, is characterized by the abnormal accumulation of plasma-borne macromolecules (e.g., LDL) in the arterial intima. The change of barrier characteristics of tissue in the arterial wall requires evaluation of macromolecular transport across the endothelial cell layer (ECL) and internal elastic lamina (IEL), the luminal and abluminal boundaries of the arterial intima, respectively. In this study, alternative mathematical models are derived from dynamic mass balances to describe macromolecular transport across the arterial wall. One model considers each medial layer as a spatially lumped compartment, whereas another model consists of a spatially lumped intima and spatially distributed media. Model simulations of a tracer concentration distribution in the arterial wall are compared with concentration distributions of horseradish peroxidase (HRP) after i.v. injection in mice. For each model, optimal parameter values are obtained that yield model outputs matching the data well for two different HRP circulation times. The model parameter estimates show that the ECL is the major barrier for macromolecular transport across the normal arterial wall. Sensitivity analysis indicates that the parameter estimates of the transport coefficients of the ECL and IEL are well determined. Optimal circulation times are determined and expected to yield improved precision of parameter estimates in future experiments to reflect disease progression.     

Research reports on treatments for bipolar disorder: preliminary assessment of methodological quality

OBJECTIVE: To assess frequencies of types of publications about bipolar disorder (BD) and evaluate methodological quality of treatment studies. METHOD: We classified 100 randomly selected articles (1998-2002) from five psychiatric journals with highest impact ratings, by topic areas, and assessed methods employed in treatment studies. RESULTS: Topics ranked: treatment (41%; 37% on pharmacotherapy) > biology (31%) > psychopathology (14%) = miscellaneous (14%). Of treatment studies, only 19% of original articles were randomized, 15% were relatively large (n > or = 50) but non-randomized, 65% were small non-randomized, case-series or -reports, and 53% relied on baseline-to-endpoint contrasts without a control group. Patient dropout rates were > or =40% in 43% of prospective studies. Only two reports provided confidence intervals; one included a power analysis, and 53% included no references on study design or statistical methods. CONCLUSION: Even in highly respected journals, the typical methodological quality of recent reports on therapeutics for BD was unexpectedly limited, and psychopathology and psychotherapies were little studied.     

Implant design and interface force transfer. A photoelastic and strain-gauge analysis

Objectives: To compare stress and strain magnitudes of butt‐joint and internal‐cone oral implants in a bone simulant. Material and methods: Photoelastic and strain‐gauged models of solitary Brånemark^®, ITI^® and Astra Tech^® implants were obtained. Vertical and 20° oblique forces of 100 and 150 N were applied on the abutments in separate load cases. Isochromatic fringe patterns around implants were observed and photographed in the field of a polariscope. Strain‐gauge measurements were performed and principal strains induced around implants were calculated. Results: Isochromatic fringe orders of all designs were similar under both loading conditions (P>0.05). Strains around Brånemark^® implants were lower than around Astra Tech^® and ITI^® implants, particularly under vertical loads. The latter implants had similar strain magnitudes (P>0.05), although strains around the conical Astra Tech^® implant were lower under vertical load. Conclusions: Butt‐joint and internal‐cone oral implants have similar force distribution characteristics. The implant–abutment mating design is not a decisive factor affecting stress and strain magnitudes in a bone simulant.     

Comparison of hydraulic and hemolytic properties of different impeller designs of an implantable rotary blood pump by computational fluid dynamics

A mixed-flow blood pump for long-term applications has been developed at the Helmholtz-Institute in Aachen, Germany. Central features of this implantable pump are a centrally integrated motor, a blood-immersed mechanical bearing, magnetic coupling of the impeller, and a shrouded impeller, which allows a relatively wide clearance. The aim of the study was a numerical analysis of hydraulic and hemolytic properties of different impeller design configurations. In vitro testing and numerical simulation techniques (computational fluid dynamics [CFD]) were applied to achieve a comprehensive overview. Pressure-flow charts were experimentally measured in a mock loop in order to validate the CFD data. In vitro hemolysis tests were performed at the main operating point of each impeller design. General flow patterns, pressure-flow charts, secondary flow rates, torque, and axial forces on the impeller were calculated by means of CFD. Furthermore, based on streak line techniques, shear stress (stress loading), exposure times, and volume percentage with critical stress loading have been determined. Comparison of CFD data with pressure head measurements showed excel-lent agreement. Also, impressive trend conformity was observed between in-vitro hemolysis results and numerical data. Comparison of design variations yielded clear trends and results. Design C revealed the best hydraulic and hemolytic properties and was chosen as the final design for the mixed-flow rotary blood pump.     

基于快速成型技术的个体化人工股骨髁关节面的设计与应用

目的设计、制造一种基于快速成型技术、复合异体半关节移植的个体化人工股骨髁关节面,探讨解决异体半关节移植中异体关节软骨坏死和异体-自体关节形状不匹配的方法。方法对异体半关节和骨肿瘤患肢股骨髁外表面行螺旋CT扫描,将CT断层图像进行矢量转换后在Surfacer 9．0软件进行矢量化三维重建,提取出合适的异体骨软骨下骨和患者关节软骨表面轮廓的三维图像,在计算机辅助下设计人工关节面,应用LPS600快速成型机制出快速成型树脂模型,以钛合金为材料铸造关节面假体主件,通过融合笼将关节面固定于关节上,抛光后获得人工关节软骨面成品。2002年2月对1例男性14岁右股骨下段骨肉瘤患者,行右股骨下段瘤段切除、人工股骨髁关节面复合大段同种异体骨移植重建股骨下端骨缺损术。结果新型复合异体半关节移植的个体化人工股骨髁关节假体与异体骨、对侧关节匹配良好;应用后随访16个月,膝关节功能良好。结论个体化股骨髁关节面明显改善了异体半关节移植患者的膝关节功能,为异体半关节移植中存在的异体关节软骨坏死和异体一自体关节形状不匹配提供一种解决方案。