57 research outputs found

    Attenuating vibration transmission from a Town Board Station (TBS) to the neighbor residential building using an optimum isolator: A case study

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    Town Board Stations (TBS) are usually located in residential areas. Pressure reduction through reducing valves in these stations generates considerable amounts of sound and vibrations. These mechanical waves have undesired effects on the equipment such as reducing the fatigue life of the gas ransmission line. On the other hand, propagation of these wave in the residential area, auses discomfort for the neighbors of these stations. In this paper, vibrations enerated in a TBS and transmitted to the residential building in the area are investigated through modeling and analysis. The aim is to study and propose a method for reducing vibration transmission from the TBS to residential buildings by using a numerical model. A vibration isolator is designed for this purpose with ptimum parameters and considering the practical limitations of the problem. The performance of the isolator is verified with the help of the developed FEmodel. Results show the effectiveness of the designed vibration isolator for the operating range of the TBS.</span

    Can chronotropic incompetence predict life-threatening ventricular arrhythmias in patients with stable ischemic heart disease?

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    Background: Chronotropic incompetence has prognostic value of all-cause and cardiovascular mortality in both patients with asymptomatic and symptomatic ischemic heart disease (IHD), regardless of traditional risk factors. The aim of this study was to investigate the relationship between chronotropic response during exercise test and the development of ventricular arrhythmias. Methods: 153 patients with stable ischemic heart disease were screened and observed during the 24 months since October 2014 in a university hospital in Astana Kazakhstan. They underwent bedside electrocardiography, 24h heart rate Holter monitoring, echocardiography, exercise stress test (treadmill) for assessment of chronotropic index calculating at first contact. Holter- electrocardiography was repeated three times (at 3, 6, 12 months of follow-up period) to reveal life-threatening ventricular arrhythmias. Results: The quantity of the ventricular extrasystoles was higher in the group with low chronotropic index. Low chronotropic index increased the risk of high grade ventricular extrasystoles more than two times (P=0.015); episodes of non-sustained VT more than three times (p<0.001); and episodes of sustained VT more than nine times (p<0.001). Conclusions: Chronotropic index less than 35.6 increases the risk for life-threatening ventricular arrhythmias in patients with stable chronicle ischemic heart disease irrespectively of severe left ventricle systolic dysfunction

    A social accountable model for Iranian dentistry sciences education system: a qualitative study

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    IntroductionSocial accountability is a new paradigm in dental education and a sort of cultural change. This study is an attempt to elaborate on the process of social accountability in the Iranian dentistry education system.Materials and methodsThis study was carried out as a qualitative work based on a grounded theory approach. The participants were selected through purposive sampling and took part in deep semi-structured interviews, and data saturation was achieved with 14 interviews. The main interviews were private, and face-to-face interviews were held on different occasions (morning and afternoon) in a quiet and decent environment. The interviews were held by the author and voice-recorded with the permission of the interviewees. Data analyses were performed through the Strauss–Corbin method along with the interviews.ResultsThe results indicated that the process of social accountability featured three stages: antecedents, mechanisms, and outcomes consisting of 619 codes, 16 subcategories, and 7 categories. Updating the curriculum, qualified students, appropriate educational environment, appropriate educational technology, monitoring and feedback throughout educational activities, proper interaction with society, and accountability to society's needs were the main categories in the study. The concept of proper interaction with society was the core variable.ConclusionThe results indicated that the process of social accountability has major and effective requirements in the antecedent, mechanism, and outcome stages, and it has a good performance in fulfilling the current needs of society for dentistry services. However, to meet potential needs, it needs special attention and programming

    Dynamic changes in purine catabolism in patients with acute coronary syndrome that underwent percutaneous coronary intervention

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    Background: Cardiovascular diseases are global problems. They are causes of death in about 43 of people worldwide and may become the most widespread reason of death by 2020. The prognosis is directly dependent to immediate diagnosis and on time treatment. Introduction of new biochemical markers as the early diagnosis of complications after coronary revascularization is very important in this period. Herein, we assayed the changes of purine catabolites in patients with acute coronary syndrome (ACS) before and after percutaneous coronary intervention (PCI) in comparison with control group. Methods: Thirty five ACS patients (20 males and 15 females) were included (57&#177;17 years old) in the study. The determination of intermediates of purine catabolism as guanine, hypoxanthine (GCS), adenine, xanthine (Kc) and uric acid (MK) were assayed before and 3 days after PCI. Conditionally, 35 healthy-matched persons were included in the control group. Purine catabolites were determined in plasma through the method of Oreshnikov E.V (2008). Results: In ACS patients, prior to PCI, there was a tendency to increase the concentration of guanine (P=0.001), hypoxanthine (P=0.002) adenine (P=0.0003), xanthine (P=0.000003) and uric acid (P=-0.000001) relative to the upper limits of normal ranges. And on the third day after PCI, there was the second tendency to increase the levels of guanine (P=0.000001), hypoxanthine (P=0.000001) adenine (P=0.0000001), xanthine (P=0.000001) and uric acid (P=0.0000001) relative to upper limits of normal ranges. Conclusion: Increment of plasma purine catabolites can be a marker of inflammation and instability of coronary artery plaques and may be used as a restenosis marker in patients with history of PCI. &#160

    Underlying risk factors and their relationship with extent of coronary vessel involvement in patients undergoing coronary angiography in North of Iran

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    Background: Coronary artery disease (CAD) is one of the most progressive and life-threatening diseases and is the first leading cause of death affecting both genders in Iran. The present study aimed to determine the extent of coronary vessel involvement and relevant relationship with several underlying risk factors. Methods: In this cross-sectional study, 1452 patients undergoing angiography who met the inclusion criteria were recruited consecutively in Babol, Iran during 2016. Data collection was performed through a questionnaire including demographic and clinical characteristics and information on underlying diseases via an interview with the patient and looking into the patients’ records. Results: Of these patients, 459 (31.6%) had normal coronary arteries, 220 (15.1%) suffered from non-obstructive CAD and 773 (53.3%) had one, two or three-vessel obstructive involvement. The results of multiple logistic regression showed that the chances of having coronary artery involvement in patients with diabetes (OR=1.55, p=0.012), age> 60 years old (OR=3.52, P=0.001), male gender (OR=2.54, P=0.001), history of heart attack (OR=3.16, P=0.001), and history of hospitalization because of cardiac problem (OR=1.51, P=0.021) significantly increased. Conclusions: Diabetes, male gender, age over 60 years old, history of myocardial infarction and history of hospitalization due to cardiac problem were related to the extent of coronary vessels involvement. Therefore, it is recommended to practice preventive measures more extensively in this regard

    Prevalence, awareness, treatment, and control of type 2 diabetes mellitus among the adult residents of tehran: Tehran Cohort Study.

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    BACKGROUND The prevalence of type 2 diabetes mellitus has increased in the past decades. We investigated the prevalence of diabetes and its awareness, treatment, and control among adult residents of Tehran. METHODS We used the recruitment phase data of the Tehran Cohort study, enrolling a random sample of adult residents of Tehran aged ≥35 years. Diabetes was defined as self-report, current use of glucose-lowering medications, and/or fasting plasma glucose (FPG) ≥126mg/dl. Impaired fasting glucose (IFG) was defined as an FPG of 100-125mg/dl. Awareness was defined as diabetes self-report, treatment as receiving glucose-lowering medications, and glycemic control as FPG <126mg/dl. The age- and sex-weighted estimates were calculated using the 2016 national census. Logistic regression models were used to determine the factors associated with diabetes awareness, treatment, and control. RESULTS A total of 8151 participants were included. Age- and sex-weighted prevalence of diabetes mellitus and IFG were 16.7% (95% CI: 15.1-18.4) and 25.1% (95% CI: 23.1-27.1), respectively. Diabetes was more prevalent in the eastern and central districts of Tehran. Advanced age (OR per 1-year increase: 1.026, 95% CI: 1.021-1.030), male sex (OR: 1.716, 95% CI: 1.543-1.909), higher BMI levels (OR for BMI ≥35 vs. <20 kg/m2: 4.852, 95% CI: 3.365-6.998), pre-existing hypertension (OR: 1.552, 95% CI: 1.378-1.747), dyslipidemia (OR: 1.692, 95% CI: 1.521-1.883), and chronic kidney disease (OR: 1.650, 95% CI: 1.019-2.673) were associated with an increased odds of diabetes mellitus. On the contrary, diabetes mellitus was less likely in current tobacco (OR: 0.872, 95% CI: 0.765-0.994) and alcohol users (OR: 0.836, 95% CI: 0.703-0.994) compared to non-users. Among diabetic individuals, 82.8% were aware of their condition, 71.9% received treatment, and 31.7% of treated patients had adequate glycemic control. Advanced age and pre-existing comorbidities, including hypertension and dyslipidemia, were associated with higher diabetes awareness and treatment. Furthermore, advanced age, higher levels of education, and female sex were determinants of better glycemic control among treated diabetic participants. CONCLUSION There is a high prevalence of diabetes and IFG among adult residents of Tehran. Additionally, more than two-thirds of treated diabetics living in Tehran remain uncontrolled

    α1-FANGs: Protein Ligands Selective for the α-Bungarotoxin Site of the α1-Nicotinic Acetylcholine Receptor

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    Nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels that play a central role in neuronal and neuromuscular signal transduction. Here, we have developed FANG ligands, fibronectin antibody-mimetic nicotinic acetylcholine receptor-generated ligands, using mRNA display. We generated a 1 trillion-member primary e10FnIII library to target a stabilized α1 nicotinic subunit (α211). This library yielded 270000 independent potential protein binding ligands. The lead sequence, α1-FANG1, represented 25% of all library sequences, showed the highest-affinity binding, and competed with α-bungarotoxin (α-Btx). To improve this clone, a new library based on α1-FANG1 was subjected to heat, protease, binding, off-rate selective pressures, and point mutations. This resulted in α1-FANG2 and α1-FANG3. These proteins bind α211 with KDvalues of 3.5 nM and 670 pM, respectively, compete with α-Btx, and show improved subunit specificity. α1-FANG3 is thermostable (T_m = 62 °C) with a 6 kcal/mol improvement in folding free energy compared with that of the parent α1-FANG1. α1-FANG3 competes directly with the α-Btx binding site of intact neuromuscular heteropentamers [(α1)_2β1γδ] in mammalian culture-derived cellular membranes and in Xenopus laevis oocytes expressing these nAChRs. This work demonstrates that mRNA display against a monomeric ecto-domain of a pentamer has the capability to select ligands that bind that subunit in both a monomeric and a pentameric context. Overall, our work provides a route to creating a new family of stable, well-behaved proteins that specifically target this important receptor family

    α1-FANGs: Protein Ligands Selective for the α-Bungarotoxin Site of the α1-Nicotinic Acetylcholine Receptor

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    Nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels that play a central role in neuronal and neuromuscular signal transduction. Here, we have developed FANG ligands, fibronectin antibody-mimetic nicotinic acetylcholine receptor-generated ligands, using mRNA display. We generated a 1 trillion-member primary e10FnIII library to target a stabilized α1 nicotinic subunit (α211). This library yielded 270000 independent potential protein binding ligands. The lead sequence, α1-FANG1, represented 25% of all library sequences, showed the highest-affinity binding, and competed with α-bungarotoxin (α-Btx). To improve this clone, a new library based on α1-FANG1 was subjected to heat, protease, binding, off-rate selective pressures, and point mutations. This resulted in α1-FANG2 and α1-FANG3. These proteins bind α211 with KDvalues of 3.5 nM and 670 pM, respectively, compete with α-Btx, and show improved subunit specificity. α1-FANG3 is thermostable (T_m = 62 °C) with a 6 kcal/mol improvement in folding free energy compared with that of the parent α1-FANG1. α1-FANG3 competes directly with the α-Btx binding site of intact neuromuscular heteropentamers [(α1)_2β1γδ] in mammalian culture-derived cellular membranes and in Xenopus laevis oocytes expressing these nAChRs. This work demonstrates that mRNA display against a monomeric ecto-domain of a pentamer has the capability to select ligands that bind that subunit in both a monomeric and a pentameric context. Overall, our work provides a route to creating a new family of stable, well-behaved proteins that specifically target this important receptor family

    Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017

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    A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1–70.8) million) to 6.4% (58.3 (47.6–70.7) million), but is predicted to remain above the World Health Organization’s Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8–38.5) million) in 2000 to 6.0% (55.5 (44.8–67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic

    Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens
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