Numerical and experimental studies of heat and flow characteristics in a laminar pipe flow of nanofluid

Thermal performance of energy systems can be improved by adding metal or metal-oxide nanoparticles to a base fluid, thereby increasing heat-transfer efficiency. Laminar pipe flow of a Cu–water nanofluid was studied using discrete phase model numerical simulation and experimental methods. The forces including thermophoretic and Brownian forces were considered to solve the particles governing equation. A two-step method was employed in the preparation of the nanofluid. The influences of Reynolds number, fluid temperature, and particle volume fraction on the flow pressure drop and convective heat-transfer coefficient of the nanofluid have been studied. The results demonstrated that adding nanoparticles to a base fluid significantly enhanced convective heat transfer in a pipe and increased energy loss. The pressure drop increased with increasing Reynolds number. A critical nanoparticle volume fraction existed, beyond which the pressure drop changed from increasing to decreasing with increasing nanoparticle volume fraction. This is attributed to competition between slip of particles on the pipe wall and the effect of a drag force on the particles. The deposition efficiency of nanoparticle changing with the particle size and volume fraction also has been illustrated

Burden of epilepsy in China and its provinces, 1990 to 2019: findings from the Global Burden of Disease Study 2019

Abstract. Background:. Epilepsy accounts for a significant portion of the global disease burden. However, little is known about the disease burden of epilepsy in China and its provinces. Methods:. We assessed the burden of epilepsy in China and its provinces, municipalities, and autonomous regions from 1990 to 2019. Burden was measured as incidence, prevalence, deaths, years lived with disability, years of life lost, and disability-adjusted life years (DALYs), by age, sex, year, and province. We used the Socio-Demographic Index (SDI) to determine the association between the provincial development level and age-standardized DALY rates of epilepsy from 1990 to 2019. Results:. In 2019, epilepsy caused 1367.51 thousand (95% uncertainty interval [UI]: 979.92–1837.61 thousand) DALYs, and the age-standardized DALY rate was 99.77 (95% UI: 71.33–133.52)/100,000. The age-standardized incidence and prevalence rates for epilepsy in China were 24.65/100,000 and 219.69/100,000, increased by 45.00% (95% UI: 8.03–98.74%) and 35.72% (95% UI: 0.47–86.19%) compared with that in 1990, respectively. From 1990 to 2019, the proportion of DALY caused by epilepsy in the age group under 25 years steadily decreased. The proportion of DALYs caused by epilepsy in people aged 50 years and over increased from 9.45% and 10.22% in 1990 to 29.01% and 32.72% for male and female individuals in 2019, respectively. The highest age-standardized mortality rates were seen in Tibet (4.26 [95% UI: 1.43–5.66]/100,000), Qinghai (1.80 [95% UI: 1.15–2.36]/100,000), and Yunnan (1.30 [95% UI: 0.88–1.62]/100,000), and the lowest mortality rates were in Guangdong (0.48 [95% UI: 0.39–0.64]/100,000), Zhejiang (0.56 [95% UI: 0.44–0.70]/100,000), and Shanghai (0.57 [95% UI: 0.41–0.73]/100,000). The age-standardized DALY rates across the country and in provinces, municipalities, and autonomous regions generally decreased as their SDI increased. Conclusions:. The disease burden of epilepsy is still heavy in China, especially in the western provinces. The incidence and prevalence of epilepsy increased between 1990 and 2019, and the burden of epilepsy in the elderly increases gradually. This study provides evidence on epilepsy prevention and care of different regions in China

Establishing and Verifying a Robust Liquid Chromatography-Tandem Mass Spectrometry Method to Simultaneously Measure Seven Androgens Present in Plasma Samples

Objectives: To develop a robust liquid chromatography-tandem mass spectrometry (LC–MS/MS) method to simultaneously measure seven human plasma androgens, namely testosterone (T), dihydrotestosterone (DHT), androstenedione (A4), dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), 11-ketotestosterone (11-KetoT), and 11β-hydroxytestosterone (11β-OHT). Design and Methods: Plasma was extracted via a solid phase extraction method, and the analytical performance of the assay was validated according to the Clinical & Laboratory Standards Institute guidelines. Overall, 73 apparently healthy volunteers were recruited to evaluate the distribution of these seven androgens; their levels in 25 females with acne and 33 obese females were also evaluated. Results: The developed method exhibited a good precision, with the total coefficient variations (CV) and the intra-assay CVs being within 10%. Furthermore, the recoveries of T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11β-OHT were 90.3–105.8, 88.7–98.1, 92.4–102.5, 90.5–106.7, 87.6–99.9, 93.3–105.3, and 90.2–104.4%, respectively, and no significant matrix effect was observed after internal standard correction (<20%). Moreover, the limits of quantification were 0.01, 0.01, 0.01, 0.10, 5.00, 0.02, and 0.02 ng/mL for T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11β-OHT, respectively, which are adequate for their accurate measurement in human plasma samples. It was also determined that patients diagnosed with acne had significantly higher levels of DHT, A4, and DHEAS, while those suffering from obesity had significantly higher levels of T and A4 but lower levels of DHT. Conclusions: A robust LC-MS/MS method for the simultaneous determination of seven androgens in plasma samples was successfully established and validated, which plays important roles in clinical application

Establishing and Verifying a Robust Liquid Chromatography-Tandem Mass Spectrometry Method to Simultaneously Measure Seven Androgens Present in Plasma Samples

Objectives: To develop a robust liquid chromatography-tandem mass spectrometry (LC&ndash;MS/MS) method to simultaneously measure seven human plasma androgens, namely testosterone (T), dihydrotestosterone (DHT), androstenedione (A4), dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), 11-ketotestosterone (11-KetoT), and 11&beta;-hydroxytestosterone (11&beta;-OHT). Design and Methods: Plasma was extracted via a solid phase extraction method, and the analytical performance of the assay was validated according to the Clinical &amp; Laboratory Standards Institute guidelines. Overall, 73 apparently healthy volunteers were recruited to evaluate the distribution of these seven androgens; their levels in 25 females with acne and 33 obese females were also evaluated. Results: The developed method exhibited a good precision, with the total coefficient variations (CV) and the intra-assay CVs being within 10%. Furthermore, the recoveries of T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11&beta;-OHT were 90.3&ndash;105.8, 88.7&ndash;98.1, 92.4&ndash;102.5, 90.5&ndash;106.7, 87.6&ndash;99.9, 93.3&ndash;105.3, and 90.2&ndash;104.4%, respectively, and no significant matrix effect was observed after internal standard correction (&lt;20%). Moreover, the limits of quantification were 0.01, 0.01, 0.01, 0.10, 5.00, 0.02, and 0.02 ng/mL for T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11&beta;-OHT, respectively, which are adequate for their accurate measurement in human plasma samples. It was also determined that patients diagnosed with acne had significantly higher levels of DHT, A4, and DHEAS, while those suffering from obesity had significantly higher levels of T and A4 but lower levels of DHT. Conclusions: A robust LC-MS/MS method for the simultaneous determination of seven androgens in plasma samples was successfully established and validated, which plays important roles in clinical application

Utilization of five data mining algorithms combined with simplified preprocessing to establish reference intervals of thyroid-related hormones for non-elderly adults

Abstract Background Despite the extensive research on data mining algorithms, there is still a lack of a standard protocol to evaluate the performance of the existing algorithms. Therefore, the study aims to provide a novel procedure that combines data mining algorithms and simplified preprocessing to establish reference intervals (RIs), with the performance of five algorithms assessed objectively as well. Methods Two data sets were derived from the population undergoing a physical examination. Hoffmann, Bhattacharya, Expectation Maximum (EM), kosmic, and refineR algorithms combined with two-step data preprocessing respectively were implemented in the Test data set to establish RIs for thyroid-related hormones. Algorithm-calculated RIs were compared with the standard RIs calculated from the Reference data set in which reference individuals were selected following strict inclusion and exclusion criteria. Objective assessment of the methods is implemented by the bias ratio (BR) matrix. Results RIs of thyroid-related hormones are established. There is a high consistency between TSH RIs established by the EM algorithm and the standard TSH RIs (BR = 0.063), although EM algorithms seems to perform poor on other hormones. RIs calculated by Hoffmann, Bhattacharya, and refineR methods for free and total triiodo-thyronine, free and total thyroxine respectively are close and match the standard RIs. Conclusion An effective approach for objectively evaluating the performance of the algorithm based on the BR matrix is established. EM algorithm combined with simplified preprocessing can handle data with significant skewness, but its performance is limited in other scenarios. The other four algorithms perform well for data with Gaussian or near-Gaussian distribution. Using the appropriate algorithm based on the data distribution characteristics is recommended

Additional file 1 of Immune characteristics of kidney transplant recipients with acute respiratory distress syndrome induced by COVID-19 at single-cell resolution

Additional file 1: Figure S1. The intercellular communication of cytokines. cirPlot visualizing the intercellular communication events within cell subpopulations in patients with (A) COVID-19-induced ARDS and (B) COVID-19-induced ARDS after kidney transplantation. (C) CCL5 expression in naïve T cells and CD8+ T cells