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Zirconia femoral heads provide increased fracture strength, but 343 zirconia head failures have been documented since 2000. Retrieval analysis of 6 fractured heads, 4 suspect heads, 4 control zirconia heads, and 2 failed alumina heads was performed. Zirconia failures have been isolated to heads sintered in a "tunnel" furnace introduced in 1998. The monoclinic composition at the taper surface of fractured and nonfractured heads was significantly elevated (21% to 68%) compared to that of control zirconia heads (less than 5%). Electron microscopy identified circular fracture footprints unique to the zirconia heads produced in the tunnel furnace. Cobalt chrome heads were used in the urgent revision setting due to Morse taper damage. Partial capsulectomy was performed in an effort to reduce future third body wear. Monoclinic phase transformation following implantation remains a potential mechanism of ceramic head failure. We recommend that patients with recalled zirconia heads be advised of a potential fracture risk.  相似文献   
84.
Effect Sizes (ES) are an increasingly important index used to quantify the degree of practical significance of study results. This paper gives an introduction to the computation and interpretation of effect sizes from the perspective of the consumer of the research literature. The key points made are: 1. ES is a useful indicator of the practical (clinical) importance of research results that can be operationally defined from being "negligible" to "moderate", to "important". 2. The ES has two advantages over statistical significance testing: (a) it is independent of the size of the sample; (b) it is a scale-free index. Therefore, ES can be uniformly interpreted in different studies regardless of the sample size and the original scales of the variables. 3. Calculations of the ES are illustrated by using examples of comparisons between two means, correlation coefficients, chi-square tests and two proportions, along with appropriate formulas. 4. Operational definitions for the ES s are given, along with numerical examples for the purpose of illustration.  相似文献   
85.
In order to teach suitable feeding and hygiene practices to a group of randomly selected Qashqa'i tribe families with 406 children aged 0-59 months, a culturally appropriate community-based education intervention approach was used. To assess the impact of the intervention on the study group, another group of families with 405 children were randomly selected to serve as the controls. At the beginning of the intervention programme both groups of children had access to a similar diet, consisting of cereals, beans, oil, sugar, milk and yoghurt. Baseline data, age, gender, weight, height and mean arm circumference (MAC), were obtained before the intervention. Using Hubley's behavioural change model, the components of which deal with beliefs, attitudes, subjective norms and enabling factors, the research team studied the behaviour of the family members and tried to change their nutritional behaviour. This was achieved by designing a suitable education programme to be carried out for 12 months. During the programme, families were instructed to follow different methods of food preparation and cooking practices. The final data were collected 3 months after the end of the intervention programme. The results indicated that the children in the study group gained: 1.16 (sd 1.2) kg body weight, 0.033 (sd 0.05) m in height, 0.0067 (sd 0.015) m in MAC, 0.8 (sd 1) in weight-for-age Z-score, 0.97 (sd 1.7) in height-for-age Z-score and 0.28 (sd 1.8) in weight-for-height Z-score by the end of the study. The corresponding values for the control group were 0.42 (sd 1.0), 0.0167 (sd 0.047), 0.0017 (sd 0.012), 0.35 (sd 1.1), 0.56 (sd 1.5) and 0.014 (sd 1.6) respectively and the differences were statistically significant (P<0.05). These findings suggest that educational interventions involving parents and/or other family members who might play a role in the care behaviour and care resources are important in feeding the children energy- and protein-enriched, hygienic, simple and cheap foods. Such practices could improve child growth even under conditions of poverty.  相似文献   
86.
OBJECTIVE: This study was designed to compare psychiatrists with other physicians on measures of academic performance before, during, and after medical school. METHOD: More than three decades of data for graduates of Jefferson Medical College (N=5,701) were analyzed. Those who pursued psychiatry were compared to physicians in seven other specialties on 18 performance measures. Analysis of covariance was used to control for gender effect. RESULTS: Compared to other physicians, psychiatrists scored higher on measures of verbal ability and general information before medical school and on evaluations of knowledge and skills in behavioral sciences during medical school, but they scored lower on United States Medical Licensing Examinations step 3. CONCLUSIONS: The results generally confirmed the authors' expectations about psychiatrists' academic performance. More attention should be paid to the general medical education of psychiatrists.  相似文献   
87.
In view of many changes taking place in today's health care marketplace, the theme of empathy in health provider-patient relations needs to be revisited. It has been proposed that patients benefit when all members of the health care team provide empathic care. Despite the role of empathy in patient outcomes, empirical research on empathy among health professionals is scarce partly because of a lack of a psychometrically sound tool to measure it. In this study, we briefly describe the development and validation of the Jefferson Scale of Physician Empathy (JSPE), an instrument that was specifically developed to measure empathy among health professionals (20 Likert-type items). The purpose of this study was to compare nurses and physicians on their responses to the JSPE. Study participants were 56 female registered nurses and 42 female physicians in the Internal Medicine postgraduate medical education program at Thomas Jefferson University Hospital. The reliability coefficients (Chronbach's coefficient alpha) were 0.87 for the nurses and 0.89 for physicians. Results of t test showed no significant difference between nurses and physicians on total scores of the JSPE; however, multivariate analyses of variance indicated statistically significant differences between the two groups on 5 of 20 items of the JSPE. Findings suggest that the JSPE is a reliable research tool that can be used to assess empathy among health professionals including nurses.  相似文献   
88.
BACKGROUND: Control of hyperlipidemia is vital in patients with cardiovascular disease (CVD). Omega-3 fatty acids (n-3FAs) have desirable effects on serum triglyceride (TG) levels, thrombosis, and arrhythmia, but lead to increases in serum low-density lipoprotein (LDL) and apo-B as well. OBJECTIVE: To determine and compare the effects of administration of n-3FAs, vitamin C (VitC) and n-3FAs + VitC on the serum levels of LDL, apoB, other serum lipids, and malondialdehyde (MDA). The present study was performed in Tehran University of Medical Sciences from 2000 to 2001. DESIGN: In a double-blind, placebo trial of parallel design, 68 hyperlipidemic patients [total cholesterol (TC) and TG greater than 200 mg/dL] were randomly assigned to receive daily 500 mg VitC, 1 g n-3FAs, 500 mg VitC + 1 g n-3FAs, or placebo (control) for 10 weeks. Fasting blood samples were collected at the beginning and at the end of the period. TG, TC, LDL-cholesterol-C (LDL-C), and high-density lipoprotein-cholesterol (HDL-C) were measured enzymatically, VitC and MDA colorimetrically, and apo-B and apo-A-I immunoturbidometrically. The pattern of food consumption, socio-economic, and anthropometric indices were determined; there was no significant change in these indices during the study. RESULTS: There was a significant difference in the blood VitC level at the end of the study in comparison to the initial value in the VitC (p = 0.001) and VitC + n-3FAs (p = 0.027) groups. Similarly, the serum TG level at the end of study was significantly different from the initial value in the n-3FAs group (p = 0.002) and also from the final value in the control group (p = 0.013). In the VitC group, there was a significant decrease in TC (p = 0.004), apo-B (p = 0.005), and MDA (p = 0.015) at the end of study as compared to the respective initial values. There was also a significant increase in blood VitC compared to the control value (p = 0.018) and a significant decrease in MDA compared to the n-3FAs group (p = 0.034). At the end of study, in the n-3FAs group, there was a significant (p = 0.04) and a marginally significant decrease (p = 0.05), respectively, in TG/HDL and apo-B levels as compared to the initial values, and the TG/HDL ratio showed a significant decrease as compared to the control group (p = 0.047). CONCLUSION: Simultaneous administration of n-3FAs and VitC had no beneficial effects on the lipid profile of hyperlipidemic patients, but 1 g purified n-3FAs daily for 10 weeks is a beneficial supplement for decreasing TG without any increase in LDL-C, apo-B or MDA. Administration of 500 mg VitC for more than 10 weeks might decrease significantly TC and apo-B in hyperlipidemic patients.  相似文献   
89.
Data from 6246 participants aged 20–64 years (2339 males and 3907 females) in the cross-sectional phase of Tehran Lipid and Glucose Study (February 1999–May 2000) were used to determine distribution of serum lipid levels after 12–14 hour overnight fast. Mean total cholesterol (TC) concentration was 210 mg/dl. TC was significantly greater in females than males, 213 and 206 mg/dl, respectively (p < 0.0001). Thirty-one percent of population had TC values between 200 and 239 and 24% had values of 240 mg/dl or greater. Mean low-density lipoprotein cholesterol (LDL-C) was 129 and 135 mg/dl in males and females, respectively (p < 0.0001). Twenty-seven percent had LDL-C values between 130 and 159 and 23% had values 160 mg/dl or greater. The mean triglycerides (TGs) values were 190 and 162 mg/dl for males and females, respectively (p < 0.0001). The mean high-density lipoprotein cholesterol (HDL-C) was 39 in males and 45 mg/dl in females (p < 0.0001). The results showed higher levels of TC, LDL-C and TGs and slightly lower HDL-C in Tehranian adults than other studies in the industrialized countries.  相似文献   
90.
We report the use of CT angiography in the diagnosis and preoperative planning of a superficial temporal artery pseudoaneurysm. A 50-year-old man presented with a pulsatile preauricular mass 4 weeks after undergoing pterional craniotomy for aneurysm repair. CT angiography revealed a 2.5-cm pseudoaneurysm arising from the posterior margin of the right superficial temporal artery at the inferior margin of the craniotomy incision. To our knowledge, this is the first reported case showing the usefulness of CT angiography alone in the diagnosis and characterization of a superficial temporal artery pseudoaneurysm.  相似文献   
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