32 research outputs found

    Phenotypic and genotypic characteristics of tetracycline resistant Acinetobacter baumannii isolates from nosocomial infections at Tehran hospitals

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    Objective(s): To date, the most important genes responsible for tetracycline resistance among Acinetobacter baumannii isolates have been identified as tet A and tet B. This study was carried out to determine the rate of resistance to tetracycline and related antibiotics, and mechanisms of resistance. Materials and Methods: During the years 2010 and 2011, a total of 100 A. baumannii isolates were recovered from patients in different hospitals of Tehran, Iran. Antimicrobial susceptibility to tetracycline, minocycline, doxicycline and tigecycline was evaluated by E-test. Polymerase chain reaction (PCR) of the tet A and tet B genes was performed using specific primers, after which the isolates were subjected to Repetitive Extragenic Palindromic-PCR (PCR) to identify the major genotypes. Results: Of all isolates, 89 were resistant to tetracycline (MIC50 = 32 mu g/ml, MIC90 = 512 mu g/ml). Minocycline with the resistant rate of 35 (MIC50 = 16 mu g/ml, MIC90 = 32 mu g/ml) and doxicycline with the resistant rate of 25 (MIC50 = 16 mu g/ml, MIC90= 32 mu g/ml) have a good activity against A. baumannii isolates. All isolates were sensitive to tigecycline. Frequencies of tet B and tet A genes and coexistence of tet A and tet B among the isolates resistant to tetracycline, were 87.6, 2.2 and 1.1, respectively. Distribution of REP-types among A. baumannii isolates was types A (40), B (30), C (10), D (5) and E (5). Conclusion: It seems that tet A and tet B genes play an important role in the induction of resistance towards tetracyclines used in this study. It is suggested that further studies focus on other antimicrobial drugs and combinations in order to achieve a successful therapy against multi drug resistance (MDR) A. baumannii strains in Iran

    Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

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    BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

    Supply Chain Management: Supplier Selection Problem with Multi-objective Considering Incremental Discount

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    Supplier selection is the process by which firms identify, evaluate, and contract with suppliers. Supplier evaluation and selection are became an important but complex process due to the fact that they involve a large number of factors and decisions. In this paper, a multi-objective model is developed based on decision on quality, service level and cost of purchased goods. The difference of this research is considering discount into model. A numerical example for three proposed suppliers is defined and model has been solved in two steps. Firstly, single-objective and secondly multi-objective approach is employed to solve the model. An incremental discount is added to model to find out the optimum supplier selection. According to metric solution, results can predict optimum selection of suppliers as well as the purchased goods amount. The results show that single objective problem in and functions have better result rather than multi-objective function. According to the developed model, when an incremental offer from supplier is dedicated, the organization may lead to select the optimum supplier based on the constraint and multi objective as multiple products are supposed to supply

    Integrated extrusion‐enzymatic treatment of corn bran for production of functional cake

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    Corn bran, as one of the high‐fructose corn syrup industries’ by‐products, is a rich source of functional fibers. The major fraction of corn bran is insoluble arabinoxylan having lower functional properties than the minor soluble function. Therefore, the main aim of this research was to increase the soluble fiber content of corn bran and use it for functional cake production. In this regard, milled corn bran with three different sizes was exposed to one factor enzymatic treatment to select the best sieving size (the criterion for selecting the best product in each stage of assay was production of the highest amount of soluble fiber). Then, milled corn bran with the best particle size was exposed to nine different enzymatic treatments to select the best enzymatic treatment condition. Additionally, the extruder feed (corn bran) moisture was adjusted to three levels to select the best level of feed moisture content and use it for performing nine different extruding experiments. Concerning integrated extrusion‐enzymatic treatment, nine different extruding pretreatments were conducted on corn bran through selecting the optimum moisture level of extruding. Afterward, the product was milled and sieved to the optimum size for enzymatic treatment, and the nine pretreatments were combined with nine different enzymatic treatments. The product containing the highest soluble fiber was selected and used at various levels for functional cake production. Finally, some organoleptic and physicochemical properties (springiness, gumminess, hardness, cohesiveness, Bostwick number, density) of the produced product were analyze

    Critical Thinking Level among Medical Sciences Students in Iran

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    Background. Critical thinking is one of the most important missions of the educational planning system of medical sciences universities around the world. Hence, identifying the level of critical thinking skills and tendency of medical sciences students to think critically is of great importance. Therefore, the aim of this systematic review was to examine the critical thinking level in medical sciences students in Iran. Methods. To extract published studies in the field of critical thinking in Iran, a search was conducted in the databases of PubMed, Web of Science, Scopus, ERIC, and Magiran. The keywords of critical thinking, medical sciences, and Iran were used for the purpose of the search in the two languages of Persian and English and without any time limit. The PRISMA flow diagram was applied for the selection of articles, and the Newcastle–Ottawa Scale was used for the evaluation of these papers. Results. After evaluating the quality of searched articles, 80 articles were finally selected for the final analysis. The total sample of the articles included 12,578 students. The results indicated that out of 51 articles conducted in the field of critical thinking skills, 48 articles reported these skills at a low level, 2 papers at a medium level, and only 1 paper at a high level in the medical sciences students. Among 29 articles in the field of the level of critical thinking disposition, 13 articles reported their tendency level at a low level, 11 articles at a medium level, and 5 articles at a high level. Conclusion. In general, based on most articles, the level of critical thinking skills in the medical sciences students in Iran was reported to be at a low level and their tendency to critical thinking at a moderate level and low level. Therefore, given the importance of critical thinking for medical sciences students, future studies should consider factors influencing the increase of the critical thinking level in these students. In this regard, formation of some training workshops can also be promising. Furthermore, reviewing the medical sciences curriculum should be taken into consideration by the policymakers and educational planners so as to strengthen the level of critical thinking in the medical sciences students

    Predictors of decline in kidney function in the general population: a decade of follow-up from the Tehran Lipid and Glucose Study

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    AbstractBackground and aims We aimed to assess the potential socio-demographic, clinical, and lifestyle-related risk factors for kidney function decline (KFD), defined as ≥30% estimated glomerular filtration rate (eGFR) decline, in an Iranian cohort study.Methods 7190 participants (4049 women) aged 20–90 years with 2–5 eGFR data from examinations (2001–2005 to 2015–2018) were included. Cox proportional hazard models were used to examine the association between potential risk factors and eGFR decline.Results During 11.5 years of follow-up, 1471 (889 women) participants had incident KFD with a crude incidence rate of 192.1 (182.6–202.2) per 10,000 person-year. Among the total population, older age, female gender, prehypertension, hypertension, diabetes, widowed/divorced states, higher triglycerides (TG), prevalent cardiovascular diseases (CVD), and higher baseline eGFR were significantly associated with higher, while moderate physical activity and a positive family history of diabetes were associated with lower risk of KFD (all p values <.05). Prevalent CVD in women but not men, diabetes, and hypertension among postmenopausal than premenopausal women were significant risk factors of KFD. According to the presence of chronic kidney disease (CKD) at baseline, higher eGFR decreased the risk of KFD in patients with CKD and increased KFD risk in those without CKD (all p for interactions <.05).Conclusion KFD is associated with multiple modifiable risk factors among the Iranian urban population that is affected by gender, menopausal status, and initial kidney function. Interventions targeting these factors might potentially help reduce the burden of KFD.Key messages:Menopausal status may influence the relationship between cardiometabolic risk factors and KFD;The impact of higher baseline eGFR on the risk of KFD differed between subjects with preserved kidney function and CKD patients.The interaction between gender, menopausal status, and baseline kidney function with different risk factors on KFD may help to make renal risk prediction scores to identify those in the general population at risk who may benefit from early prevention

    The clinical value of metabolic syndrome and its components with respect to sudden cardiac death using different definitions: Two decades of follow-up from the Tehran Lipid and Glucose Study

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    Abstract Background To evaluate the impact of different definitions of metabolic syndrome (MetS) and their components on the risk of sudden cardiac death (SCD) among the Iranian population according to the World Health Organization (WHO), International Diabetes Federation (IDF), Adult Treatment Panel III (ATP III), and Joint Interim Statement (JIS) criteria. Methods The study population included a total of 5,079 participants (2,785 women) aged ≥ 40 years, free of cardiovascular disease (CVD) at baseline. Participants were followed for incident SCD annually up to 20 March 2018. Multivariable Cox proportional hazards regression models were applied to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of MetS and its components for incident SCD. Results The prevalence of MetS ranged from 27.16% to 50.81%, depending on the criteria used. Over a median of 17.9 years of follow-up, 182 SCD events occurred. The WHO, IDF, and JIS definitions were strong predictors of SCD with multivariable-adjusted HRs (95% CI) of 1.68 (1.20–2.35), 1.51 (1.12–2.03), and 1.47 (1.08–1.98), respectively; these associations significantly attenuated after further adjustment for MetS components. MetS by the ATP III definition was not associated with the risk of SCD after controlling for antihypertensive, glucose-lowering, and lipid-lowering medication use. Among the components of MetS, high blood pressure (WHO definition), high waist circumference (using the national cutoff of ≥ 95 cm), and high glucose component by the JIS/IDF definitions remained independent predictors of SCD with HRs of 1.79 (1.29–2.48), 1.46 (1.07–2.00), and 1.52 (1.12–2.05), respectively. Conclusions The constellation of MetS, except for when defined with ATP III definition, is a marker for identifying individuals at higher risk for SCD; however, not independent of its components. Among MetS components, abdominal obesity using the population-specific cutoff point, high glucose component (JIS/IDF definitions), and high blood pressure (WHO definition) were independent predictors of SCD

    A Linear Parameter Varying Control Approach for DC/DC Converters in All-Electric Boats

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    Utilization of renewable energies in association with energy storage is increased in different applications such as electrical vehicles (EVs), electric boats (EBs), and smart grids. A robust controller strategy plays a significant role to optimally utilize the energy resources available in a power system. In this paper, a suitable controller for the energy resources of an EB which consists of a 5 kW solar power plant, 5 kW fuel cell, and 2 kW battery package is designed based on the linear parameter varying (LPV) controller design approach. Initially, all component dynamics are augmented, and by exploiting the sector-nonlinearity approach, the LPV representation is derived. Then, the LPV control method determines the suitable gains of the states’ feedbacks to provide the required pulse commands of the boost converters of the energy resources to regulate the DC-link voltage and supply the power of EB loads. Comparing with the state-of-the-art nonlinear control methods, the developed control approach assures the stability of the overall system, as it considers all component dynamics in the design procedure. The real-time simulation results demonstrate the performance of the designed controller in the creation of a constant DC-link voltage

    Changes in Fasting plasma glucose status and risk of mortality events in individuals without diabetes over two decades of Follow-up: a pooled cohort analysis

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    Abstract Background We aimed to assess the gender-specific impact of 3-year changes in fasting plasma glucose (FPG) status on the risk of all-cause, cardiovascular (CV), and cancer mortality in individuals without type 2 diabetes (T2DM) during an 18-year follow-up. Methods The study population included 14,378 participants aged 30–60 years (8272 women) from three population-based cohort studies, including Atherosclerosis Risk in Communities, Multi-Ethnic Study of Atherosclerosis, and Tehran Lipid and Glucose Study. Subjects were classified into six categories based on the approximately three-year changes in FPG status: (1) normal FPG (NFG) to NFG (reference category); (2) NFG to impaired fasting glucose (IFG) (i.e., 126 > FPG ≥ 100 mg/dl); (3) NFG to T2DM; (4) IFG to NFG; (5) IFG to IFG; (6) IFG to T2DM. Multivariable stratified Cox regression, adjusting for age, body mass index (BMI), BMI-Change, smoking status, hypertension, and hypercholesterolemia was used to estimate hazard ratios (HRs (95% CI)) for all-cause and cause-specific mortality events. Women-to-men ratios of HRs (RHRs) for each category were also estimated. Results During follow-up, 2,362 all-cause mortality events were recorded. Among women, all categories of FPG change, excluding IFG-NFG (HR, 95%CI 1.24 (0.98–1.57), p = 0.07), were associated with a higher risk of all-cause mortality compared to the NFG-NFG category. Moreover, women in IFG-T2DM group were at increased risk for CV mortality (2.21 (1.42–3.44)). We also found that women in NFG-IFG (1.52 (1.20–1.91)), NFG-T2DM (2.90 (1.52–5.51)), and IFG-IFG (1.30 (1.02–1.66)) categories had a higher risk for cancer mortality. However, among men, a higher risk of all-cause mortality was found for only two groups of NFG-T2DM (1.78 (1.15–2.74)) and IFG-T2DM (1.34 (1.04–1.72)). Women with IFG-IFG had a 24% higher risk for all-cause mortality events than their men counterparts (RHR; 1.24 (1.01–1.54)). After further adjustment for physical activity, results were in line with the main findings, excluding T2DM up to six years after the measurement period and early mortality events. Conclusion In women, the IFG status, whether as incident, persistent, or converted to T2DM, had a higher risk for mortality events; however, among men, only conversion to T2DM conferred an excess risk of all-cause mortality
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