544 research outputs found
Knowledge of medical professionalism in medical students and physicians at Shahid Beheshti University of Medical Sciences and affiliated hospitals-Iran
Although medical professionalism is a fundamental aspect of competence in medicine and a distinct facet of physicians' competence, evidence suggests that the subject of professionalism is not taught or assessed as part of medical students' curricula in Iran and many other countries. Assessing the knowledge of medical students and physicians about medical professionalism seems to be helpful in identifying the weaknesses of training in the field of professionalism and devise plans for future training on the subject. The present cross-sectional, quantitative, observational, and prevalence study recruited 149 medical interns, clinical residents, physicians, and professors working in hospitals selected through stratified random sampling using a questionnaire designed by the researchers and confirmed for its validity and reliability. The results were analyzed by Stata at a significance level of 0.05. Out of 149 cases, 61.64 were male with the mean age of 30.81 years. A total of 66 participants (44.29) (95 confidence interval CI: 36.44%-52.44%) had heard and 83 (55.70%) (95% CI: 47.55%-63.55%) had not heard the term 'medical professionalism' before the study. After adjusting for potential confounders, age and degree did not have statistically significant difference in assessed knowledge of medical professionalism, but sex had (mean difference: 5.88, P=0.045), and the mean of the female was significantly higher than that of the male participants. The mean percentage of correct answers was 47.67. The present study demonstrated that the medical professionals working in the national healthcare system have an unfavorable theoretical knowledge about medical professionalism in Iran; although this does not indicate that their practices are unethical, it should be noted that one of the prerequisites of possessing a high level of medical professionalism and for establishing a proper relationship between the medical community and the patients is to have a proper knowledge of this concept. Improving behaviors and performances in medical professions requires adequate training on the concepts of medical professionalism and consequently the assessment of the levels of professionalism achieved in medical professionals. © 2016 the Author(s). Published by Wolters Kluwer Health, Inc. All rights reserved
Analytical Characterization of Coverage Regions for STAR-RIS-aided NOMA/OMA Communication Systems
We provide an analytical characterization of the coverage region of simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS)-aided two-user downlink communication systems. The cases of orthogonal multiple access (OMA) and non-orthogonal multiple access (NOMA) are considered, under the energy-splitting (ES) protocol. Results confirm that the use of STAR-RISs is beneficial to extend the coverage region, and that the use of NOMA provides a better performance compared to the OMA counterpart. However, the effect of imperfect successive interference cancellation degrades the performance of NOMA and needs to be considered for a realistic analysis
Analytical Characterization of Coverage Regions for STAR-RIS-aided NOMA/OMA Communication Systems
We provide an analytical characterization of the coverage region of
simultaneously transmitting and reflecting reconfigurable intelligent surface
(STAR-RIS)-aided two-user downlink communication systems. The cases of
orthogonal multiple access (OMA) and non-orthogonal multiple access (NOMA) are
considered, under the energy-splitting (ES) protocol. Results confirm that the
use of STAR-RISs is beneficial to extend the coverage region, and that the use
of NOMA provides a better performance compared to the OMA counterpart
The architecture of the left ventricular myocytes relative to left ventricular systolic function
Objective: Mural thickening, combined with longitudinal and circumferential shortening, and apical along with basal twisting are critical components of the left ventricular systolic deformation that contribute to ventricular ejection. It is axiomatic that the spatial alignment of the actively contracting aggregates of myocytes must play a major role in the resulting ventricular deformation. The need to conserve functional global myocytic architecture, therefore, is an important aspect of the surgical manoeuvres affecting ventricular mass and geometry. To investigate the influence of the global alignment of the myocytes on ventricular contraction, we used a mathematical model simulating the large deformations produced by systolic contraction of the left ventricle of a human heart. Methods: The alignment and meshing of the myocytes within their supporting fibrous matrix cause mechanical anisotropy, which was included in the mathematical model in the form of a unit vector field, constructed from the measured trajectories of aggregated myocytes in an autopsied human heart. The relationship between ventricular structure and ventricular dynamics was assessed by analysing the influence of systematic deviations of the orientation of the myocytes from their original alignment, in longitudinal as well as radial directions, on the distribution of stress and strain within the myocardium, as well as on the ejection fraction. In addition, simplified idealised geometries were used to investigate the influence of the overall geometrical modifications. Results: Left ventricular function proved to be robust with respect to small-to-moderate rotational variations in myocytic alignment, up to 14°, a finding which we attribute to an equalising effect of the non-uniform anisotropic pattern found in a real heart involving substantial local irregularities in the architecture of the aggregated myocytes. Severe deterioration of function occurred only when deviations in alignment exceeded 30°. Conclusions: Our findings substantiate the concept of the myocardial walls representing a continuous three-dimensional meshwork, with the absence of any intermediate structures such as discrete bands or tracts extending over the ventricles, which could be destroyed surgically, thereby adversely affecting systolic function. With appropriate indications, they also support the validity of the surgical procedures performed to reduce ventricular radius and therefore to reduce mural stres
Prevalence and associated factors of cardio-metabolic risk factors in Iranian seafarers
BACKGROUND: Since Iran's economy is based on the sale of petroleum products, seafaring is considered a crucial job. Little research has been done on issues related to seafarers' health in Iranian maritime industry. The present study investigated the prevalence and associated factors of cardio-metabolic risk factors in seafarers of National Iranian Tanker Company (NITC). MATERIALS AND METHODS: A cross-sectional study was performed on 234 Iranian male seafarers of NITC in 2015. Metabolic syndrome (MetS) was diagnosed according to the reports of National Committee of Obesity. Three main blood parameters (of elevated total cholesterol, elevated low-density lipoprotein cholesterol, and elevated very low-density lipoprotein cholesterol) and general obesity were included as additional cardio-metabolic risk factors. RESULTS: The mean age of the participants was 36.0 ± 10.3 years. The prevalence of MetS was 14.9. The common cardio-metabolic risk factors were excess weight (51.1), abdominal obesity (38.5), and smoking (27.8) among Iranian seafarers. In multivariate analysis, age (OR: 1.05, 95 CI: 1.01-1.09) and body mass index (OR: 1.14, 95 CI: 1.01-1.27) were associated with the increase in hypertension risk. CONCLUSIONS: Our finding showed that the current prevalence of MetS among Iranian male seafarers working on tankers can affect negatively their health and career at sea
Acute effect of nitroglycerin on cyclosporine-induced hypertension after cardiac transplantation
BACKGROUND: Cyclosporine represents a milestone in immunosuppression following organ transplantation. Its use, however, comes at the cost of significant side effects, such as arterial hypertension which is rarely controllable by currently available anti-hypertensive drugs. The aim was to investigate the effect of acute administration of nitroglycerin in heart-transplanted patients with cyclosporine-induced hypertension. METHODS: The sample included 18 cyclosporine-induced hypertensive patients (HTX group) scheduled for elective cardiac catheterization following heart transplantation, as well as 6-matched essential hypertensive patients (HT group). The blood pressure (BP) in the aorta and pulmonary artery, before and after administration of nitroglycerin, was measured simultaneously. RESULTS: After injection of 50 microg and 100 microg nitroglycerin, BP significantly decreased both in HTX (systolic (s) BP p = 0.0001; diastolic (d) BP p = 0.0001) and in controls (sBP p = 0.006; dBP p = 0.05). This reduction was more pronounced in HTX (sBP p = 0.022; dBP p = 0.018 for group-comparison). Following analysis of the data in relation to its individual baseline, a significantly higher reduction of the BP induced by 100 microg nitroglycerin was observed in the HTX group compared to the HT group (p = 0.02 for sBP and p = 0.03 for dBP). 8 +/- 3 minutes after the last nitrate infusion, BP remained significantly reduced compared to baseline in HTX (p <0.001), whereas it came back to baseline in controls. The reduction in sBP was correlated to cyclosporine A levels (p = 0.04 after 50microg nitroglycerin; p = 0.05 after 100 microg nitroglycerin). CONCLUSION: After application of nitroglycerin, sBP is reduced immediately in HTX with uncontrolled cyclosporine-induced hypertension. Further studies are needed to evaluate the long-term effect of nitrates in these patients
Prevalence and associated factors of cardio-metabolic risk factors in Iranian seafarers
BACKGROUND: Since Iran's economy is based on the sale of petroleum products, seafaring is considered a crucial job. Little research has been done on issues related to seafarers' health in Iranian maritime industry. The present study investigated the prevalence and associated factors of cardio-metabolic risk factors in seafarers of National Iranian Tanker Company (NITC). MATERIALS AND METHODS: A cross-sectional study was performed on 234 Iranian male seafarers of NITC in 2015. Metabolic syndrome (MetS) was diagnosed according to the reports of National Committee of Obesity. Three main blood parameters (of elevated total cholesterol, elevated low-density lipoprotein cholesterol, and elevated very low-density lipoprotein cholesterol) and general obesity were included as additional cardio-metabolic risk factors. RESULTS: The mean age of the participants was 36.0 ± 10.3 years. The prevalence of MetS was 14.9. The common cardio-metabolic risk factors were excess weight (51.1), abdominal obesity (38.5), and smoking (27.8) among Iranian seafarers. In multivariate analysis, age (OR: 1.05, 95 CI: 1.01-1.09) and body mass index (OR: 1.14, 95 CI: 1.01-1.27) were associated with the increase in hypertension risk. CONCLUSIONS: Our finding showed that the current prevalence of MetS among Iranian male seafarers working on tankers can affect negatively their health and career at sea
The Prevalence of Needle sticks injuries among health care workers at a hospital in Tehran
ABSTRACT
Needle stick injuries (NSIs) are one of the most significant and preventable hazards in relation to Healthcare workers (HCWs). Such injuries have been shown to be of high prevalence within developing countries. To determine the prevalence and circumstances pertaining to the occurrence of NSIs among HCWs employed at a special hospital. The study conducted was a cross-sectional study on HCWs and was carried out in one of Tehran's special hospitals in the year 2012. In this study, in order to identify and determine hazardous potential due to needle stick, HFMEA method was chosen. This resulted in the collection of 240 valid and reliable questionnaires. The validity and reliable nature of the questionnaires was confirmed by experts and by means of the test re-test method. The gathered data was analyzed with SPSS software, version 16.From the analysis of the data it was shown that, a total of 97 (40.42%) HCWs had suffered NSIs in the last year. The patient ward showed the highest prevalence of NSIs (47.42%) in the hospital. Nurses had the highest risk of suffering NSIs (56.7%) in comparison with the other occupational groups. All in all 175 NSIs occurred for the 240 HCWs trialed during the selected period of clinical practice. Of those that received injuries, only roughly 1 in 3 (38.14%) reported it to their infection control officer. Just over a quarter (26.80%) of the injured HCWs used post exposure prophylaxis (PEP) against HIV. Almost all (88.75%) of the HCWs had received a safe injection course. In general, NSIs and their subsequent underreporting are commonplace among hospital healthcare professionals. Significantly, more than two-thirds of the injured HCWs did not use post-exposure prophylaxis (PEP) against HIV. Improved prevention and reporting strategies are needed if the occupational health and safety of healthcare workers is to improve
Copula-based Performance Analysis for Fluid Antenna Systems under Arbitrary Fading Channels
In this letter, we study the performance of a single-user fluid antenna system (FAS) under arbitrary fading distributions, in which the fading channel coefficients over the ports are correlated. We adopt copula theory to model the structure of dependency between fading coefficients. Specifically, we first derive an exact closed-from expression for the outage probability in the most general case, i.e., for any arbitrary choice of fading distribution and copula. Afterwards, for an important specific case, we analyze the performance of the outage probability under correlated Nakagami- m fading channels by exploiting popular Archimedean copulas, namely, Frank, Clayton, and Gumbel. The results confirm that the spatial correlation dependency structure for the FAS is a key factor to determine its performance, which is natively captured through the choice of copula
An analysis of the spatial arrangement of the myocardial aggregates making up the wall of the left ventricle
Objective: We used the technique of peeling of myocardial aggregates, usually described as ‘fibres', to determine the spatial arrangement of the myocytes in the left ventricular wall of a healthy autopsied human heart. Methods: We digitised the left ventricular outer and inner boundaries, as well as the pathways in space, of almost 3000 aggregates harvested from the left ventricular myocardium. During the process of gradual peeling, we sought to identify the myocardial aggregates as uniformly as possible. Despite this, interpolation was necessary to complete the pattern so as to construct a unit vector field that represented the preferred direction of the myocardial aggregates throughout the entirety of the walls of the left ventricle of this individual human heart. Results: Apart from the overall systematic arrangement of the aggregates necessary to achieve physiologic ventricular contraction, we documented substantial local heterogeneities in the orientation of the myocardial aggregates. In particular, a significant proportion of aggregates was found to intrude obliquely with respect to the ventricular boundaries, with markedly heterogeneous distribution. Moreover, the distribution of the helical angle of the aggregates relative to the ventricular base varied notably throughout the left ventricular free walls and the septum. Within the generally quite uniform and continuous structure of the ventricular mass, we were, however, unable to identify any organised tracts or functional subunits such as a ‘helical ventricular band', nor did we find radial fibrous lamellas coursing across the ventricular wall. Conclusion: We suggest that the impact of local anatomical inhomogeneities, associated with gradients in regional contractile function on global ventricular dynamics, has been systematically underestimated in the past. Our analysis confirms furthermore the continuous nature of the myocardium associated with an overall gross organisation of the fibre direction field; however, there is no evidence of substructures compartmentalising the ventricle
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