78 research outputs found

    Circulating irisin in nonalcoholic fatty liver disease: an updated meta-analysis

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    Introduction: Exogenous administration of recombinant irisin may reverse hepatic steatosis and steatohepatitis. However, it remains controversial as to whether nonalcoholic fatty liver disease (NAFLD) shows reduced circulating (serum/plasma) irisin levels. A meta-analysis was conducted to address this issue. Material and methods: A literature search of databases was performed up to June 2021. Observational studies that reported circulating irisin in NAFLD ascertained by any methods (e.g. ultrasonography or magnetic resonance) and compared with any controls were eligible for inclusion. Standardized mean differences (SMDs) and 95% confidence intervals (CIs) were obtained using a random-effects meta-analysis model. Results: Eleven studies enrolling 1277 NAFLD cases and 944 non-NAFLD controls were included. The approaches used for NAFLD ascertainment included ultrasonography (4 studies), magnetic resonance (3 studies), and liver biopsy (5 studies). Meta-analysis showed that circulating irisin in NAFLD was comparable to any non-NAFLD controls (10 studies with 11 datasets; SMD –0.09, 95% CI: –0.48 to 0.29), including the body mass index (BMI)-matched and lean controls (both p ≥ 0.80). Restricting studies to NAFLD ascertained by magnetic resonance or liver biopsy rather than ultrasonography showed that serum irisin was reduced in NAFLD (5 studies, SMD –0.63, 95% CI: –1.14 to –0.13). Meta-analysis also suggested that circulating irisin did not differ between mild and moderate-to-severe NAFLD (7 studies; SMD 0.02, 95% CI: –0.25 to 0.30), and this association was not significantly moderated by study location (Europe versus Asia). Conclusions: Circulating irisin in NAFLD did not differ from any non-NAFLD controls and was unlikely to be affected by disease severity or racial-ethnic difference

    Electronic properties of monolayer copper selenide with one-dimensional moir\'e patterns

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    Strain engineering is a vital way to manipulate the electronic properties of two-dimensional (2D) materials. As a typical representative of transition metal mono-chalcogenides (TMMs), a honeycomb CuSe monolayer features with one-dimensional (1D) moir\'e patterns owing to the uniaxial strain along one of three equivalent orientations of Cu(111) substrates. Here, by combining low-temperature scanning tunneling microscopy/spectroscopy (STM/S) experiments and density functional theory (DFT) calculations, we systematically investigate the electronic properties of the strained CuSe monolayer on the Cu(111) substrate. Our results show the semiconducting feature of CuSe monolayer with a band gap of 1.28 eV and the 1D periodical modulation of electronic properties by the 1D moir\'e patterns. Except for the uniaxially strained CuSe monolayer, we observed domain boundary and line defects in the CuSe monolayer, where the biaxial-strain and strain-free conditions can be investigated respectively. STS measurements for the three different strain regions show that the first peak in conduction band will move downward with the increasing strain. DFT calculations based on the three CuSe atomic models with different strain inside reproduced the peak movement. The present findings not only enrich the fundamental comprehension toward the influence of strain on electronic properties at 2D limit, but also offer the benchmark for the development of 2D semiconductor materials.Comment: 14 pages, 12 figures, 25 referenc

    Muscle strength and prediabetes progression and regression in middle‐aged and older adults: a prospective cohort study

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    Background: Prediabetes progression is associated with increased mortality while its regression decreases it. It is unclear whether muscle strength is related to prediabetes progression or regression. This study investigated the associations of muscle strength, assessed by grip strength and chair‐rising time, with prediabetes progression and regression based on the China Health and Retirement Longitudinal Study (CHARLS) enrolling middle‐aged and older adults. Methods: We included 2623 participants with prediabetes from CHARLS, who were followed up 4 years later with blood samples collected for measuring fasting plasma glucose and haemoglobin A1c. Grip strength (normalized by body weight) and chair‐rising time were assessed at baseline and categorized into tertiles (low, middle, and high groups). Prediabetes at baseline and follow‐up was defined primarily using the American Diabetes Association (ADA) criteria and secondarily using the World Health Organization (WHO) and International Expert Committee (IEC) criteria. Multinomial logistic regression analysis was applied to obtain the odds ratios (ORs) and 95% confidence intervals (CIs). Results: The mean age of included participants was 59.0 ± 8.6 years, and 46.6% of them were males. During follow‐up, 1646 participants remained as prediabetes, 379 progressed to diabetes, and 598 regressed to normoglycaemia based on ADA criteria. Participants who progressed to diabetes had lower normalized grip strength than those who remained as prediabetes (0.49 ± 0.15 vs. 0.53 ± 0.15, P < 0.001), but participants who regressed to normoglycaemia showed the opposite (0.55 ± 0.16 vs. 0.53 ± 0.15, P = 0.003). However, chair‐rising time was comparable across different groups (P overall = 0.17). Compared with participants in low normalized grip strength or high chair‐rising time group, those in high normalized grip strength or low chair‐rising time group had decreased odds of progression to diabetes (OR 0.62, 95% CI 0.44 to 0.87; and OR 0.69, 95% CI 0.51 to 0.93, respectively) after multivariable adjustment. However, both were unrelated to the odds of regression to normoglycaemia (OR 0.94, 95% CI 0.71 to 1.25; and OR 0.84, 95% CI 0.65 to 1.07, respectively). These outcomes remained generally comparable when prediabetes was defined by WHO or IEC criteria. Higher normalized grip strength but not lower chair‐rising time was prospectively associated with lower blood pressure, better glycaemic condition, and lower inflammation (all P ≤ 0.04). Conclusions: High muscle strength is associated with reduced odds of progression to diabetes but does not predict regression to normoglycaemia in prediabetes. Future studies are warranted to assess whether increases in muscle strength promote prediabetes regression

    Pancreatic Stellate Cells: A Rising Translational Physiology Star as a Potential Stem Cell Type for Beta Cell Neogenesis

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    The progressive decline and eventual loss of islet β-cell function underlies the pathophysiological mechanism of the development of both type 1 and type 2 diabetes mellitus. The recovery of functional β-cells is an important strategy for the prevention and treatment of diabetes. Based on similarities in developmental biology and anatomy, in vivo induction of differentiation of other types of pancreatic cells into β-cells is a promising avenue for future diabetes treatment. Pancreatic stellate cells (PSCs), which have attracted intense research interest due to their effects on tissue fibrosis over the last decade, express multiple stem cell markers and can differentiate into various cell types. In particular, PSCs can successfully differentiate into insulin- secreting cells in vitro and can contribute to tissue regeneration. In this article, we will brings together the main concepts of the translational physiology potential of PSCs that have emerged from work in the field and discuss possible ways to develop the future renewable source for clinical treatment of pancreatic diseases

    Prediabetes Progression and Regression on Objectively- Measured Physical Function: A Prospective Cohort Study

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    Prediabetes leads to declines in physical function in older adults, but the impact of prediabetes progression or regression on physical function is unknown. This study assessed this longitudinal association, with physical function objectivelymeasured by grip strength, walking speed, and standing balance, based on the Health and Retirement Study enrolling United States adults aged >50 years. Participants with prediabetes were followed-up for 4-year to ascertain prediabetes status alteration (maintained, regressed, or progressed), and another 4-year to assess their impacts on physical function. Weak grip strength was defined as <26 kg for men and <16 kg for women, slow walking speed was as <0.8 m/sec, and poor standing balance was as an uncompleted fulltandem standing testing. Logistic and linear regression analyses were performed. Of the included 1,511 participants with prediabetes, 700 maintained as prediabetes, 306 progressed to diabetes, and 505 regressed to normoglycemia over 4 years. Grip strength and walking speed were declined from baseline during the 4-year followup, regardless of prediabetes status alteration. Compared with prediabetes maintenance, prediabetes progression increased the odds of developing weak grip strength by 89% (95% confidence interval [CI], 0.04 to 2.44) and exhibited larger declines in grip strength by 0.85 kg (95% CI, -1.65 to -0.04). However, prediabetes progression was not related to impairments in walking speed or standing balance. Prediabetes regression also did not affect any measures of physical function. Prediabetes progression accelerates grip strength decline in aging population, while prediabetes regression may not prevent physical function decline due to aging

    Analysis of age-related differences in hypoxia-related factors in yak brain tissue

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    The brain is an important part of the mammalian nervous system, is highly sensitive to hypoxia, and plays an important role in the adaptation of the body to hypoxic environments. This study was conducted to study the distribution and expression of hypoxia-related factors (hypoxia-inducible factor 1α, HIF-1α; erythropoietin, EPO; vascular endothelial growth factor, VEGF; vascular cell adhesion molecule, VCAM) in the cerebellum, cerebrum, medulla oblongata, and corpora quadrigemina in yaks of different ages (4d, 6-months-old and adult). Paraffin sections were obtained from the cerebellum, cerebrum, medulla oblongata, and corpora quadrigemina of healthy yak for 4-day-old, 6-months-old and adult yaks. Histological characteristics were assessed by haematoxylin staining. Immunohistochemical staining was performed to detect the distribution and expression of HIF-1α, EPO, VEGF and VCAM proteins. Immunohistochemical results showed that HIF-1α, EPO, VEGF, and VCAM were expressed in the pyramidal cell layer of the yak cerebrum, and distributed in the cerebellum granulose cell layer, Purkinje cell layer and medulla layer, and were mainly positive in Purkinje cells and medulla. It is expressed in the cell bodies of the medulla oblongata and the quadrimatous neurons. The expression level in the medulla oblongata was higher, indicating may play a crucial role in functional cohesion. The expression of HIF-1α in 4 d cerebellar tissues was higher than that in other age groups, and the expression of HIF-1α in the medulla oblongata increased with age. In addition, the expression levels of EPO and VEGF in the 6-month-old group were slightly higher than those in the other age groups. It is speculated that EPO and VEGF have obvious protective effects on brain tissue in the 6-month-old age group; VCAM showed no significant differences in the cerebrum, cerebellum, medulla oblongata, or corpora quadrigemina of the yaks. This study provides basic data for further exploration of the adaptive mechanism of plateau yak brain tissue

    Association between night blindness history and risk of diabetes in the Chinese population: a multi-center, cross sectional study

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    Aims Night blindness (NB), an important manifestation of VA deficiency, may be associated with the odds of diabetes. The aim of this study was to explore the probable association between NB history and diabetes in Chinese community-dwelling adults. Methods This multi-center, cross-sectional study enrolled a total of 5664 participants aged 18–82 years from eight sites in China. Information on demographics and medical history was collected using a standardized questionnaire. Diabetes was diagnosed based on the oral glucose tolerance test or a self-reported history. NB history was ascertained by a face-to-face interview with reference to the recommendation by the World Health Organization. Logistic regression analysis was used to evaluate the association between NB history and the odds of diabetes. Results A total of 5049 participants were finally included, with 252 ascertained with NB history and 1076 with diabetes. The mean age of included participants was 52.9 years, and the percentage of participants with NB history was significantly higher in participants with diabetes than those without (7.0% vs. 4.5%). The multivariable adjusted odds ratio for diabetes was 1.41 (95% confidence interval 1.06, 1.89) in participants with NB history compared with those without. Furthermore, mediation analysis showed that obesity, as assessed by waist-height ratio, partially mediated the relationship between NB history and increased odds of diabetes. Conclusions The results suggest that NB history might be associated with increased odds of diabetes in Chinese community-dwelling adults

    Transport Accessibility and Poverty Alleviation in Guizhou Province of China: Spatiotemporal Pattern and Impact Analysis

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    Both transport development and poverty alleviation are vital for sustainable development. However, due to the lack of long-term, comparable, county-level transport accessibility and poverty incidence data, the spatiotemporal patterns of these factors have rarely been accurately revealed in the poverty-stricken regions of China, causing the impacts of transport accessibility on poverty alleviation to be difficult to quantify. Taking Guizhou Province in China as the study area, this study revealed the spatiotemporal patterns of transport accessibility and poverty alleviation in 88 counties from 2000 to 2018 based on multisource data, including nighttime light data, LandScan population data, and transport network data. It was found that the transport accessibility decreased from 4.9 h to 3.3 h, and the poverty index decreased from 0.75 to 0.29 on average. All these factors exhibited a &ldquo;core&ndash;periphery&rdquo; spatial pattern. Furthermore, the panel data regression analysis suggested that transport accessibility has played a dominant role in poverty alleviation, with an elasticity coefficient of 0.839. In the future, policies concerned to integrate transport development with rural industries such as agriculture, e-commence, and tourism are recommended for poverty alleviation and rural revitalization, which are especially significant for promoting sustainable development, securing a win&ndash;win of economic growth and social equity

    Numerical Study on Effects of High-Frequency Arrayed Energy Deposition on Scramjet Combustor Performance

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    For the supersonic flows have large momentum, it is difficult to get higher penetration depth because of the influence of transverse jet on incoming flow so as to affect the mixing and combustion efficiency of jet in scramjet combustor. In this paper, a method to improve the mixing and combustion efficiency of scramjet combustor by using high-frequency energy deposition and thermal disturbance is proposed, and verified by a numerical simulation. The effects of two types of high-frequency arrayed energy deposition, respectively distributed upstream and downstream of the fuel jet orifice, on a scramjet combustor with a cavity are studied by solving the N-S equations with the energy source term and the chemical reaction source term. It is found that the energy deposition can improve the mixing performance of the combustor for increasing the scale of the jet-induced stream-wise vortexes. The energy deposition can improve the combustion efficiency of the combustor, and that distributed downstream of the jet orifice is of more combustion efficiency increasing about 29% compared with the baseline condition. Total pressure recovery coefficient of the combustor is almost negligible for addition of the energy deposition
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