60 research outputs found

    Ca2+ Cycling in Heart Cells from Ground Squirrels: Adaptive Strategies for Intracellular Ca2+ Homeostasis

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    Heart tissues from hibernating mammals, such as ground squirrels, are able to endure hypothermia, hypoxia and other extreme insulting factors that are fatal for human and nonhibernating mammals. This study was designed to understand adaptive mechanisms involved in intracellular Ca2+ homeostasis in cardiomyocytes from the mammalian hibernator, ground squirrel, compared to rat. Electrophysiological and confocal imaging experiments showed that the voltage-dependence of L-type Ca2+ current (ICa) was shifted to higher potentials in ventricular myocytes from ground squirrels vs. rats. The elevated threshold of ICa did not compromise the Ca2+-induced Ca2+ release, because a higher depolarization rate and a longer duration of action potential compensated the voltage shift of ICa. Both the caffeine-sensitive and caffeine-resistant components of cytosolic Ca2+ removal were more rapid in ground squirrels. Ca2+ sparks in ground squirrels exhibited larger amplitude/size and much lower frequency than in rats. Due to the high ICa threshold, low SR Ca2+ leak and rapid cytosolic Ca2+ clearance, heart cells from ground squirrels exhibited better capability in maintaining intracellular Ca2+ homeostasis than those from rats and other nonhibernating mammals. These findings not only reveal adaptive mechanisms of hibernation, but also provide novel strategies against Ca2+ overload-related heart diseases

    Relationship between a Novel Polymorphism of the C5L2 Gene and Coronary Artery Disease

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    C5L2 has been demonstrated to be a functional receptor of acylation-stimulating protein (ASP), which is a stimulator of triglyceride synthesis or glucose transport. However, little is known about the variations in the coding region of the C5L2 gene and their association with coronary artery disease (CAD). = 0.047, OR = 2.602, 95% CI: 1.015–6.671).The 698CT genotype of C5L2 may be a genetic maker of CAD in the Han and Uygur population in western China

    Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants

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    Background: Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories.Methods: We used data from 1990 to 2019 on people aged 30-79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age.Findings: The number of people aged 30-79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306-359) million women and 317 (292-344) million men in 1990 to 626 (584-668) million women and 652 (604-698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55-62) of women and 49% (46-52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43-51) of women and 38% (35-41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20-27) for women and 18% (16-21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran.Interpretation: Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings.Copyright (C) 2021 World Health Organization; licensee Elsevier.</p

    Feasibility of Partial Nitrification Combined with Nitrite-Denitrification Phosphorus Removal and Simultaneous Nitrification-Endogenous Denitrification for Synchronous Chemical Oxygen Demand, Nitrogen, and Phosphorus Removal

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    A combination of partial nitrification and nitrite-denitrifying phosphorus removal and simultaneous nitrification-endogenous denitrification (nDNPR-SNED) in two sequencing batch reactors was developed for synchronous chemical oxygen demand (COD), nitrogen (N), and phosphorus (P) removal by regulating dissolved oxygen (DO) and influent nitrite concentrations. COD, total nitrogen, and P removal efficiencies of 87.4 ± 0.5, 91.6 ± 1.1, and 97.8 ± 0.6% were obtained after 112 days of anaerobic/anoxic/aerobic operation. Mass balance analysis confirmed that 91.9% of the COD was stored as intracellular carbon at the anaerobic stage, and 99.6% of PO43-P and 99.8% of NO2-N were eliminated via the nDNPR process at the anoxic stage, and at the aerobic stage, the SNED process contributed to 68.7% nitrogen removal. Genera of Candidatus Competibacter, Dechloromonas, Ellin6067, and Nitrospirae were the dominant consortia with a relative abundance of 26.5, 16.5, 1.0, and 1.1%, respectively. In the metabolic pathway model, β-hydroxybutyrate was the main endogenous driving force for nitrogen and phosphorus removal. Compared with conventional biological nitrogen and phosphorus removal processes, the combined process could achieve 6.7% saving in the total cost. The proposed approach provides an economic and technical alternative for C-, N-, and P-laden wastewater treatment, reducing both carbon demand and aeration consumption

    Coal rapid pyrolysis in a transport bed under steam-containing syngas atmosphere relevant to the integrated fluidized bed gasification

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    An integrated fluidized bed (IFB) consisting of an upper transport bed section and a bottom fluidized bed section was adopted to investigate the transport bed coal pyrolysis by varying its reaction temperature and reaction atmosphere adjusted to simulate steam-containing syngas produced by the bottom fluidized bed char gasification. Steam and syngas, in comparison with N-2, as the reaction atmosphere little affected the tar yield below 600 degrees C but significantly decreased it for the former and increased it for the latter at rather higher temperatures. The presence of H-2 in the syngas increased tar yield significantly because it could suppress polymerization and condensation reactions through providing H as radical stabilizer and hydrogenation agent. In the steam-containing syngas atmosphere, the tar yield obtained from transport bed rapid pyrolysis increased rapidly with raising temperature to a peak value of 10.5 wt.% (daf) at 600 degrees C, about 1.1 wt.% higher than the Gray-King assay yield, and then decreased due to the excessive secondary reactions. Analyzing tar composition further showed that steam-containing syngas combined their respective advantages that syngas improved the yields of both light and heavy tars while steam reduced the heavy tar yield, especially at temperatures above 600 degrees C. The steam-containing syngas atmosphere also promoted CH4 production in comparison with syngas atmosphere below 700 degrees C. (C) 2016 Elsevier Ltd. All rights reserved
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