The effect of time, temperature and P-chloro-mercuriphenylsulfonic acid during serum storage on HDLᵼ-C and HDL₃-C concentration

Background: Accurate measurement of clinical laboratory parameters plays an essential role in the correct interpretation of clinical biochemistry abnormalities. The purpose of this study was evaluation the time and temperature effect on HDLᵼ-C, HDL₂-C and HDL₃-C stability during storage.Material and Methods: 50 adult healthy subjects were participated. For the isolation of HDLᵼ-C, we used precipitation method and HDLᵼ-C data was analyzed by the Abell-Kendal cholesterol reference method. The remaining serum were dispensed into 12 sample tubes and divided into two groups. One of each group was stored upright at room temperature (approximately 25 ºC) while another at 4 ºC and the half of each group tubes were received p-chloro-mercuriphenylsulfonic acid (PCMPS). The stored serum aliquots from all temperature and time points were analyzed on 1, 2, 3 days post collection. Results: HDLᵼ-C concentration at the temperature of room in 24 hours is not changed significantly but over the time decreased (7.2% in 3 days). In addition of PCMPS inhibitor, the concentration is increased  by 17.3% in 3 days. But in 4ºC, with or without PCMPS, there is no a significant change in the HDLᵼ-C concentration. HDL₃-C was found to be the most stable lipoprotein studied because of non-significant effect of storage time and temperature on it. Conclusion: The results suggest 4ºC as the ideal storage condition for the preservation of human serum samples for HDLᵼ-C assay. Also it is suggested that HDL concentration estimation should be performed in the first 24 hours of samples collection. PCMPS addition didn’t affect HDL subtypes concentration in 4ºC

Ambiguity tolerance among medical students and its relationship with personality and participation in the mentoring program: A cross-sectional study

Background: Low ambiguity tolerance (AT) can lead to burnout and impact medical students� quality of life. Interventions are effective in increasing tolerance in ambiguous situations. Mentors can be facilitators in ambiguous situations. We aimed to determine the AT among Tehran University of medical sciences (TUMS) medical students and assess its relation with personality traits and mentor-seeking behavior. Methods: A cross-sectional study was designed. We used Budner AT questionnaire and the Ten Item Personality Inventory in our study. Questionnaires were sent to 350 randomly selected TUMS medical students in different years of education. Two hundred six students completed the questionnaires. The response rate was 58.85. Results: The mean AT score was 59.77 among TUMS medical students. No significant difference was seen between different genders and students with different marital statuses. Also, AT was constant among students at different years at medical school and at different education levels (P > 0.05). Students who had participated in the mentoring program were significantly more intolerant of novel situations (P = 0.01). However, they did not have significantly different scores in other subscales of AT scale and its total score than those who had not participated in the mentoring program (P > 0.05). Conclusion: Medical students are more intolerant of ambiguity at TUMS than medical students abroad, and there should be interventions to help them cope in ambiguous situations. Mentoring programs may also be considered for future interventions as participants who participate in the program are less tolerant of ambiguity in novel situations. © 202

Evaluation of the effect of one-stage transanal endorectal pull-through (TERPT) technique on defecation in patients with Hirschsprung’s Disease over the last 10 years in Tehran Pediatrics Medical Center

Introduction: One-stage Transanal Endorectal Pull-Through (TERPT) is one of the methods used for the treatment of Hirschsprung’s disease. The purpose of our study was to evaluate complications of surgery specially does related to defecation in patients undergoing pull-through surgery in Tehran Pediatrics Medical Center during the past 10 years.Materials and Methods: This descriptive study was performed on patients undergoing one-stage TERPT operation in Tehran Pediatrics Medical Center over the past 10 years. Exclusion Criteria included: the parent’s lack of consent to participate in the study, age below 3 years and inability to complete the checklist. For all patients, a check list was completed that included: Age, family history of the disease, readmission, follow-up period, presence of soiling, complete or partial fecal incontinence, constipation, use of laxative, use of boogie, presence or absence of RectoAnal Inhibitory Reflex (RAIR) in manometers, stricture in rectal examination and enterocolitis before and after surgery. Data analysis was performed using SPSS software version 19.Results: Our patients were 4.81% male and 3.9% of them had an underlying disease, such as heart or kidney disease. Only 6.81% of them had to be re-admitted due to enterocolitis. Soiling was found in 5.39% of patients, complete and partial fecal incontinence were noted in 3.2% and 7.4% of them respectively. The incidence of fecal incontinency was 7%. Constipation occurred in 6.11% of cases and 3.9% of cases did not have RAIR in manometry. The incidence of rectal stenosis was 7% and 93% of patients had transitional zone (TZ) in barium enema before the operation. The result showed that there was no significant relationship between post- operative complications in both sexes (p<0.05).Conclusion: This study shows that the complications of Endorectal Transanal pull-through surgery as a method for treatment of Hirschsprung disease are infrequent. Therefore, this method can be considered as a selective method. Further investigations are recommended to prove this matte

Numerical simulation of non-reacting diesel fuel sprays under low temperature late injection operating condition

AbstractAccurate simulations on combustion and emission characteristics of direct injection diesel engines are highly dependent on detailed prediction of equivalence ratio distribution inside the combustion chamber. In this study, Open-FOAM and Lib-ICE multi-dimensional CFD frameworks were used in order to model engine flow, liquid diesel fuel spray, break-up, evaporation and mixing. Simulations were conducted on the basis of experimental data from SANDIA optical engine. Initial simulation results showed tangible discrepancy with the experimental equivalence ratio data in distribution of fuel-rich zones. Investigations on three different injection angles in three different combustion chamber bowl geometries showed that cavitation phenomenon was most probably occurred in injector nozzle during the experiments. Onset of cavitation in injector nozzle internal flow can noticeably change the spray break-up length and cause asymmetric spray angle later inside the combustion chamber. Taking cavitation effects into account, simulations were performed by corrected values of spray break-up length and injection angle based on experimental injection pressure and nozzle orifice dimensions. Final spray simulations showed better agreement with experimental results for all of three bowl geometries. This enhanced accuracy of numerical prediction without unacceptable tuning of spray sub-model parameters

Modelling compression ignition engines by incorporation of the flamelet generated manifolds combustion closure

Tabulated chemistry models allow to include detailed chemistry effects at low cost in numerical simulations of reactive flows. Characteristics of the reactive fluid flows are described by a reduced set of parameters that are representative of the flame structure at small scales so-called flamelets. For a specific turbulent combustion configuration, flamelet combustion closure, with proper formulation of the flame structure can be applied. In this study, flamelet generated manifolds (FGM) combustion closure with progress variable approach were incorporated with OpenFOAM® source code to model combustion within compression ignition engines. For IC engine applications, multi-dimensional flamelet look-up tables for counter flow diffusive flame configuration were generated. Source terms of non-premixed combustion configuration in flamelet domain were tabulated based on pressure, temperature of unburned mixture, mixture fraction, and progress variable. A new frozen flamelet method was introduced to link one dimensional reaction diffusion space to multi-dimensional Computational Fluid Dynamics (CFD) physical space to fulfill correct modelling of thermal state of the engine at expansion stroke when charge composition was changed after combustion and reaction rates were subsided. Predictability of the developed numerical framework were evaluated for Sandia Spray A (constant volume vessel), Spray B (light duty optical Diesel engine), and a heavy duty Diesel engine experiments under Reynolds averaged Navier Stokes turbulence formulation. Results showed that application of multi-dimensional FGM combustion closure can comprehensively predict key parameters such as: ignition delay, in-cylinder pressure, apparent heat release rate, flame lift-off, and flame structure in Diesel engines

A novel multilevel network slacks-based measure with an application in electric utility companies

In this paper, we developed an alternative Network Slacks-Based Data Envelopment Analysis Measure (NSBM) wherein the overall efficiency is expressed as a weighted average of the efficiencies of the individual processes. The advantage of this new model is that both overall efficiency and multi-divisional efficiencies have been calculated with a unified framework. The major merits of the proposed model are its ability to provide appropriate measure of efficiency, obtaining weight of processes from model, simultaneous assessment of intermediate variables considering them as both input and output. Finally, an application in electric power companies shows the practicality of the proposed model

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

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

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

Background Disorders 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. Methods We 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. Findings Globally, 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. Interpretation As 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. Funding Bill & Melinda Gates Foundation