Comparison of Vocal Tract Discomfort Symptoms and Acoustic Features in Patients with Gastro Esophageal Reflux (GER) and Laryngo Pharyngeal Reflux (LPR)

Introduction: Gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) are associated with voice disorders, which cause changes in the structure of the vocal cords and subsequently changes in the voice quality and unpleasant feelings. Since LPR is stronger and has more direct impact on the laryngopharyngeal mucosa and vocal cords than the GERD, it is supposed to create more stable sensory symptoms and acoustic features. Therefore, this study aimed to examine and compare patients with LPR and GERD as well as their acoustic features and vocal tract discomfort (VTD) symptoms. Materials and Methods: This cross-sectional descriptive-analytic study included 17 patients with GERD and 18 patients with LPR. The voices of patients were recorded in an acoustic room (noise 28 dB). Besides, both groups of patients were asked to complete the VTDs. Then, acoustic features were analyzed using praat software. In addition, the frequency and severity scores of the VTDs were analyzed via SPSS software. Results: Baseline frequency, jitter (local), and shimmer (local), and also harmonic-to-noise ratio were not significantly different between the two groups. Meanwhile, the severity of soreness and the frequency and severity of pain were significant between the two groups. Conclusion: The severity and the frequency of pain and the frequency of soreness are more prevalent in patients suffering from LPR than the patients with GERD. LPR has more destructive effects on the acoustic features and the vocal tracts of patients with LPR, due to its stronger involvement with the laryngopharyngeal space. Therefore, patients with voice disorders indicating higher scores than normal in VTD must be examined for LPR, although they do not show symptoms of heartburn or acid reflux

Interns\' View About Basic Medical Sciences: Their Knowledge And Attitude To National Comprehensive Exam And Basic Medical Courses In Isfahan University Of Medical Sciences

Introduction: Medical education in Iran has four stages: Basic Medical Science (BMS), Pathophysiology, Clinical Clerkship, and Internship. The relevance of basic medical course contents to professional practice needs is considered to be a problem in such traditional curriculum. Also, diminished retention of the content is another problem. These two problems are explored in this study. Methods: One of the national comprehensive BMS exams was given to interns. The participant's previous score in a similar (but not identical) exam was assumed as the previous knowledge state. Their attitude toward clinical relevance of each question and different BMS courses were assessed using statements with five point Likert scale. Results: 70% of participants claimed that they filled questionnaires precisely. Mean of scores in the present exam was 25% less than the previous one (four year interval). Mean scores for clinical relevance of exam items was 3.7 out of 5.Knowledge scores didn't correlate with demographic variables. Present knowledge scores were directly correlated to the previous exam score and intern's average. Score for clinical relevance of a given exam item did not correlate with the knowledge score about it. Maximum knowledge scores were for questions of Health, Histology, and Pathology. The highest scores of clinical relevance were for questions of Nutrition, Health, Physiology, Pathology, Bacteriology, Parasitology, and English language. The highest scores of clinical application were for Nutrition, Health and Physiology. There was a miss-match between interns view about clinical relevance of some BMS courses (Genetics and Medical Physics) and clinical application of their exam items. Conclusions: The causes of 25% decline in knowledge retention should be explored more. The observed miss-match between clinical relevance of some BMS courses and clinical application of exam items as well as knowledge scores suggests that BMS course contents and exams should be revised according to professional practice needs

Human Bone Marrow Mesenchymal Stem Cell Behaviors on PCL/Gelatin Nanofibrous Scaffolds Modified with A Collagen IV-Derived RGD-Containing Peptide

Objective: We introduce an RGD (Arg-Gly-Asp)-containing peptide of collagen IV origin that possesses potent cell adhesion and proliferation properties. Materials and Methods: In this experimental study, the peptide was immobilized on an electrospun nanofibrous polycaprolactone/gelatin (PCL/Gel) hybrid scaffold by a chemical bonding approach to improve cell adhesion properties of the scaffold. An iodine-modified phenylalanine was introduced in the peptide to track the immobilization process. Native and modified scaffolds were characterized with scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR). We studied the osteogenic and adipogenic differentiation potential of human bone marrow-derived mesenchymal stem cells (hBMSCs). In addition, cell adhesion and proliferation behaviors of hBMSCs on native and peptide modified scaffolds were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 4',6-diamidino-2-phenylindole (DAPI) staining, and the results compared with tissue culture plate, as the control. Results: FTIR results showed that the peptide successfully immobilized on the scaffold. MTT assay and DAPI staining results indicated that peptide immobilization had a dramatic effect on cell adhesion and proliferation. Conclusion: This peptide modified nanofibrous scaffold can be a promising biomaterial for tissue engineering and regenerative medicine with the use of hBMSCs

Experimental Investigation on Improvement of Wet Cooling Tower Efficiency with Diverse Packing Compaction Using ANN-PSO Algorithm

In this study, a numerical and empirical scheme for increasing cooling tower performance is developed by combining the particle swarm optimization (PSO) algorithm with a neural network and considering the packing’s compaction as an effective factor for higher accuracies. An experimental setup is used to analyze the effects of packing compaction on the performance. The neural network is optimized by the PSO algorithm in order to predict the precise temperature difference, efficiency, and outlet temperature, which are functions of air flow rate, water flow rate, inlet water temperature, inlet air temperature, inlet air relative humidity, and packing compaction. The effects of water flow rate, air flow rate, inlet water temperature, and packing compaction on the performance are examined. A new empirical model for the cooling tower performance and efficiency is also developed. Finally, the optimized performance conditions of the cooling tower are obtained by the presented correlations. The results reveal that cooling tower efficiency is increased by increasing the air flow rate, water flow rate, and packing compaction

Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021

BackgroundEstimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period.Methods22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution.FindingsGlobal all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations.InterpretationGlobal adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic