41 research outputs found

    Prospective Acid Reflux Study of Iran (PARSI): Methodology and study design

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    <p>Abstract</p> <p>Background</p> <p>Gastroesophageal reflux disease is a common and chronic disorder but long term, prospective studies of the fate of patients seeking medical advice are scarce. This is especially prominent when looking at non-erosive reflux disease (NERD) patients.</p> <p>Methods</p> <p>We designed a prospective cohort to assess the long term outcome of GERD patients referring to gastroenterologists. Consecutive consenting patients, 15 years of age and older, presenting with symptoms suggestive of GERD referring to our outpatient clinics undergo a 30 minute interview. Upper gastrointestinal endoscopy is performed for them with protocol biopsies and blood samples are drawn. Patients are then treated according to a set protocol and followed regularly either in person or by telephone for at least 10 years.</p> <p>Discussion</p> <p>Our data show that such a study is feasible and follow-ups, which are the main concern, can be done in a fairly reliable way to collect data. The results of this study will help to clarify the course of various subgroups of GERD patients after coming to medical attention and their response to treatment considering different variables. In addition, the basic symptoms and biological database will fuel further molecular epidemiologic studies.</p

    The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

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    Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

    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

    Premenstrual Disorders: Prevalence and Associated Factors in a Sample of Iranian Adolescents

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    BACKGROUND: Premenstrual disorders usually refer to Premenstrual Syndrome (PMS) and Premenstrual Dysphoric Disorder (PMDD). This study was designed to find out the frequency of premenstrual disorders and evaluate the associated factors in a sample of Iranian adolescents. OBJECTIVES: This study was conducted to investigate the frequency of premenstrual disorders (PMS and PMDD) based on Premenstrual Assessment Scale (PAS) and also to determine the association of some demographic and menstrual characteristics with these disorders in adolescent girls. PATIENTS AND METHODS: This was a cross sectional study. A sample of adolescent school girls aged between 14 and 19 years were included in the study. Diagnostic assessments were based on Premenstrual Assessment Scale (PAS). The data were analyzed in a descriptive fashion and were compared among subgroups of the study sample. In addition, demographic and menstrual factors associations with premenstrual disorders were assessed. RESULTS: In all 1379 female students were included in the study. About 99.5 % of the students reported at least one premenstrual symptom. Of these, 66.3% was mild, 31.4% moderate and 2.3% severe. A total of 814 girls (59%) met the diagnostic criteria for premenstrual dysphoric disorder (PMDD). Most frequently reported symptoms were back pain, lethargy, fatigue and anxiety. Early menarche, lower education was associated with higher scores on PAS. CONCLUSION: Premenstrual disorders are common in adolescent girls. Preventive and treatment strategies are highly recommended

    A modified proportional guidance law for homming missiles by using of nonlinear filters

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    In this paper two nonlinear estimation techniques, i.e. particle filter (PF) and unscented Kalman filter (UKF), are used for estimation of the states of a passive homming missile. The estimated states including the range between missile and target are used as the elements of proportional navigation guidance (PNG) law. Previous methods such as extended Kalman filter (EKF), measurements based on line of sight angle and its rate of change have demonstrated some difficulties due to limitations of extended Kalman filter as well as unobservability of the states of the system. Besides, in the paper the problem of observability of states of the system is investigated and unobservability of some of the states of this system is resolved by proposing a new measurable variable which can be used in real implementations of such missiles. The performances of these two nonlinear estimation techniques are compared with that of extended Kalman filter from root mean square error point of view by Monte-Carlo simulations. The computational complexity and the question that the algorithms are realizable or not are also considered in this study

    Exact Solution of Time-Fractional Partial Differential Equations Using Sumudu Transform

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    Abstract: In this study, we propose a new algorithm to find exact solution of nonlinear time- fractional partialdifferential equations. The new algorithm basically illustrates how two powerful algorithms, the homotopy pertur-bation method and the Sumudu transform method can be combined and used to get exact solutions of fractionalpartial differential equations. We also present four different examples to illustrate the preciseness and effectivenessof this algorithm

    Exact Solution of Time-Fractional Partial Differential Equations Using Sumudu Transform

    No full text
    Abstract: In this study, we propose a new algorithm to find exact solution of nonlinear time- fractional partialdifferential equations. The new algorithm basically illustrates how two powerful algorithms, the homotopy pertur-bation method and the Sumudu transform method can be combined and used to get exact solutions of fractionalpartial differential equations. We also present four different examples to illustrate the preciseness and effectivenessof this algorithm

    Using Spectral Descriptive Signatures for Industrial Plume Detection

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    This paper presents a novel approach for anomaly detection base on computing and utilizing descriptive spectral signatures. The goal of the work is to distinguish between contaminated and normal water areas within a region of investigation. A site-independent approach was developed by considering descriptive spectral signatures characterising normal sweat lake water as reference spectral features. Thereafter, it was possible to detect and determine the distribution of industrial outlet plumes which usually have spectral characteristics that deviate from the surrounding unaffected normal waters. The method was evaluated on airborne hyperspectral remotely-sensed image-data acquired over the region of Norrsundet, Sweden. In this region, areas of different water types were found, such as riverine sweet water, coastal salt seawater, as well as waste water discharged from paper-pulp industries. The work aimed at identifying these types of waters and their distributions. The needed reference descriptive spectral signatures of uncontaminated normal water were generated by using a dataset consisting of laboratory measurements of chlorophyll-a and phaeophytine-a concentrations and the corresponding field reflectance spectra collected at 22 sampling stations in Lake Erken, Sweden. The final results, showing the locations and distributions of contaminated and normal water areas, are in full agreement with field observations in the investigated region.QC 20130718</p
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