295 research outputs found
Analysis of the effects of excavation speed, ground condition and tunnel dimension variations on urban tunnel subsidence in Tehran tunnel dimension variations on urban tunnel subsidence in Tehran Niyayesh tunnel
Outcome selection and role of patient reported outcomes in contemporary cardiovascular trials: systematic review
Objectives To systematically assess the type of outcomes selected and the prevalence of patient reported outcomes in contemporary cardiovascular trials and to quantify any misuse or underuse of patient reported outcomes using a specially developed tool that would allow estimation of the relevance of such outcomes to clinical decision making
OkreĹlanie Optymalnej WartoĹci OdciÄcia ZawartoĹci Procentowej Pierwiastka UĹźytecznego W ZĹoĹźach Siarczku Miedzi
Optimum cut-off grades determination in mining life affects production planning and ultimate pit limit and it is also important from social, economical and environmental aspects. Calculation of optimum cut-off grades has been less considered for mines containing various mineral processing methods. In this paper, an optimization technique is applied to obtain optimum cut-off grades for both concentration and heap leaching processes. In this technique, production costs and different recoveries of heap leaching method directed into modeling different annual cash flows in copper mines. Considering the governing constraints, the Lagrange multiplier method is practiced to optimize the cut-off grades in which the objective function is supposed to maximize Net Present Value. The results indicate the effect of heap leaching process on the optimum cut-off grades of primary and secondary sulfide deposits
Study of gyrA S83R Mutation Rate in Vancomycin Resistant Entrococcus Faecium
Enterococci are among Gram-positive cocci and are common inhabitants of the human gastrointestinal tract and enough potent to cause serious infections such as bacteremia, urinary tract infections (UTIs) and endocarditis. Enterococci are not generally considered as highly infectious bacterium. However, the main reason for treatment failure in enterococcal infections is acquired resistance to glycopeptide antibiotics, specifically vancomycin. Most enterococcal infections in human such as gastroenteritis, intestinal infections, and endocarditis have been caused by E. faecalis and E. facieum. They are holding the second place of most frequent cause of hospital infections since 1990. In present study gyrA S83R polymorphism rate in vancomycin resistant Enterococcus faecium isolated from environment, food industries, and hospitals of Tehran were examined by ARMS-PCR technique. DNA was extracted from the bacterial colonies using standard column method, after separating the samples into two groups of antibiotic resistant and antibiotic susceptible by antibiogram test. A fragment of gyrA gene was amplified using PCR method to investigate point mutation of S83R position. ARMS-PCR technique was applied to detect the presence or absence of mutation using a set of specified primers which can be annealed when the mutation is present. The results were statistically analyzed by chi-square test (p < 0.05) using SPSS 19th version. The results showed that there was a significant correlation between the presences of S83R polymorphism with vancomycin resistance trait in Entrococcus faecium. Therefore, this technique could be used as a diagnostic tool to detect vancomycin resistance cases of E. faecium in patients and environment.HIGHLIGHTSâ˘There is a strong association between the presence of point mutation at the position of Ser83 and vancomycin resistant phenotype.â˘Resistance in Enterococcus spp. is highly mediated by mutations in gyrA gene which plays a major role in interaction with vancomycin.â˘Vancomycin is the only drug that can be consistently relied on for the treatment of infections caused by multidrug resistant enterococci.â˘VRE has presented a serious challenge for the Iranian medical community
Notch Fracture in Polymeric Specimens under Compressive Stresses: The Role of the Equivalent Material Concept in Estimating the Critical Stress of Polymers
ABSTRACT: n this paper, the fracture of notched polymeric specimens under compressive stresses was investigated both experimentally and theoretically. In the experimental section, to determine the load-carrying capacity (LCC) of U-notched specimens made of general-purpose polystyrene (GPPS) and polymethyl-methacrylate (PMMA) polymers, tests were performed on notched square samples under compression, i.e., negative mode I loading. In the observation of the nonlinear behavior of the two polymers in the standard compressive tests, for the first time, the equivalent material concept (EMC) was used under compressive loading to theoretically estimate the critical stresses of the two polymers, which were shown to be significantly different from the ultimate strengths obtained from the standard compression tests. By linking the EMC to the maximum tangential stress (MTS) and mean stress (MS) criteria, the LCC of the notched specimens was predicted. The outcomes are twofold: First, MTS, MS, EMC-MTS, and EMC-MS criteria provide accurate predictions of the experimental critical loads observed in the U-notched polymeric specimens; second, the combination of the EMC with the MTS and MS criteria, allow such predictions to be obtained without any need for experimental calibration
A prospective study of the effect of delivery type on neonatal weight gain pattern in exclusively breastfed neonates born in Shiraz, Iran
<p>Abstract</p> <p>Background</p> <p>In this exploratory study, the contribution of delivery type to the weight gain pattern for full-term infants with exclusive breastfeeding in the first month of infancy was determined. In addition, breastfeeding success among cesarean section (C-section) delivery mothers based on their neonate's weight gain at the end of the first month of infancy was evaluated.</p> <p>Methods</p> <p>A cohort of 92 neonates born in Shiraz, from July 10 to August 10, 2007 was followed longitudinally. The data were collected during the first month postpartum at three occasions: 3 to 7 days postpartum, 10-21 days postpartum and 24-31 days postpartum.</p> <p>Results</p> <p>Among 92 mothers in this study, 35 (38%) were delivered by C-section. Generalized estimating equation (GEE) showed that delivery type (p < 0.01), receipt of advice about breastfeeding (p = 0.03) and neonate's age (p < 0.01) significantly affected weight gain. GEE estimated the values of the parameters under study and the testing contribution of each factor to weight gain, leading to the conclusion that gender, parities and maternal education did not contribute to weight gain. The neonate's weight gain pattern for C-section deliveries lies below that of normal vaginal deliveries until 25 days postpartum, when weight gain for C-section deliveries became higher than that for normal vaginal deliveries.</p> <p>Conclusions</p> <p>Type of delivery contributes strongly to the weight gain pattern in the first month of infancy. In spite of greater weight loss among C-section birth neonates in the first days of life, at the end of the first month neonates showed a similar weight gain. Consequently, mothers with C-section delivery can successfully exclusively breastfeed.</p
An interpretable machine learning framework for measuring urban perceptions from panoramic street view images
The proliferation of street view images (SVIs) and the constant advancements in deep learning techniques have enabled urban analysts to extract and evaluate urban perceptions from large-scale urban streetscapes. However, many existing analytical frameworks have been found to lack interpretability due to their end-to-end structure and âblack-boxâ nature, thereby limiting their value as a planning support tool. In this context, we propose a five-step machine learning framework for extracting neighborhood-level urban perceptions from panoramic SVIs, specifically emphasizing feature and result interpretability. By utilizing the MIT Place Pulse data, the developed framework can systematically extract six dimensions of urban perceptions from the given panoramas, including perceptions of wealth, boredom, depression, beauty, safety, and liveliness. The practical utility of this framework is demonstrated through its deployment in Inner London, where it was used to visualize urban perceptions at the Output Area (OA) level and to verify against real-world crime rate
Studying the Status of Job Burnout and its Relationship with Demographic Characteristics of Nurses in Shiraz Nemazee Hospital
Background: Today, in order to provide desirable health care services, too much emphasis is placed on the physical and mental health of nurses, and job burnout among nurses is introduced as harmful elements to the health of nurses. Objective: This study was performed to evaluate job burnout in Shiraz Nemazee Hospital in relation to demographic characteristics. Methods: This research is a cross-sectional and descriptive-analytic study. The research community included all nurses in the whole sections of Nemazee Hospital out of which 245 were selected by classified random sampling as the study sample. A questionnaire was used to collect the data. After collection, data were entered in statistical package for social sciences SPSS software (version 18) and T-test, and analysis of variance (ANOVA) and Kruskal-Wallis tests were used to analyze the variables. Results: The mean score of emotional exhaustion, lack of personal accomplishment and job burnout were at an average level, and depersonalization was at a low level. As regards the intensity of burnout, most nurses were moderate. Between components of depersonalization of job burnout with marital status and age, there was a significant relationship (PConclusion: According to the findings of this study and in terms of the stressful nature of nursing profession, it is necessary that hospital managers and healthcare authorities pay attention to job burnout in nurses, its level, as well as provide and implement strategies for its prevention, thereby decreasing its effects and risks
Explaining the Challenges of the Iranian Health System in Fighting the Covid-19 Pandemic: a qualitative study
Introduction: The covid-19 pandemic has become a global threat for the general public and health care workers and it has created major challenges for all healthcare sectors. The challenges created by this disease can vary in different countries depending on cultural, social, and economic factors. To explain the challenges of the Iranian health system in fighting the covid-19 pandemic from the managersâ and executive authoritiesâ viewpoints.
Methods
The present study is a basic-applied research performed using a qualitative approach. It has studied 30 managers of the hospitals and medical centersâ managers, and deputies of the Ministry of Health, and the universities of medical sciences which were selected by purposive and snowball sampling with the maximum variety in March-September 2020. Data collection was done through semi-structured interviews and content analysis was used to explain the challenges of the Iranian health system in fighting the covid-19 pandemic (2020).
Results
Most of the interviewees (87%) had a Ph.D. degree (34%), and 40% of the participants were graduated in management and health economy and policymaking fields. Analysis and synthesis of the data collected from the interviews led to the creation of 19 sub-themes and 12 main themes classified into four general scopes including the organizational factors, resources, management factors, and other factors.
Conclusion
Identifying the mentioned challenges can provide useful information for the managers and policymakers to develop appropriate plans and take the necessary measures for resolving the challenges and using the available resources to provide the most effective services
The Global and Regional Prevalence of Abdominal Aortic Aneurysms:A Systematic Review and Modelling Analysis
Objective:
To estimate the global and regional prevalence and cases of abdominal aortic aneurysms (AAA) in 2019 and to evaluate major associated factors.
Summary Background Data:
Understanding the global prevalence of AAA is essential for optimizing health services and reducing mortality from reputed AAA.
Methods:
PubMed, MEDLINE and Embase were searched for articles published until Oct 11 2021. Population-based studies that reported AAA prevalence in the general population, defined AAA as an aortic diameter of 30mm or greater with ultrasonography or computed tomography. A multilevel mixed-effects meta-regression approach was used to establish the relation between age and AAA prevalence for high- socio-demographic index (H-SDI) and low-and middle-SDI (LM-SDI) countries. Odds ratios (ORs) of AAA associated factors were pooled using a random-effects method.
Results:
We retained 54 articles across 19 countries. The global prevalence of AAA among persons aged 30-79 years was 0.92% (95% confidence interval, CI: 0.65-1.30), translating to a total of 35.12 million (95% CI: 24.94-49.80) AAA cases in 2019. Smoking, male sex, family history of AAA, advanced age, hypertension, hypercholesterolemia, obesity, cardiovascular disease, cerebrovascular disease, claudication, peripheral artery disease, pulmonary disease and renal disease were associated with AAA. In 2019, the Western Pacific region (WPR) had the highest AAA prevalence at 1.31% (95% CI: 0.94-1.85), while the African region (AFR) had the lowest prevalence at 0.33% (95% CI: 0.23-0.48).
Conclusions:
A substantial proportion of people are affected by AAA. There is a need to optimise epidemiological studies to promptly respond to at-risk and identified cases to improve outcomes
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