Glioblastoma multiforme (GBM) displays cellular hierarchies harboring a subpopulation of stem-like cells (GSCs). Enhancer of Zeste Homolog 2 (EZH2), the lysine methyltransferase of Polycomb ...repressive complex 2, mediates transcriptional repression of prodifferentiation genes in both normal and neoplastic stem cells. An oncogenic role of EZH2 as a transcriptional silencer is well established; however, additional functions of EZH2 are incompletely understood. Here, we show that EZH2 binds to and methylates STAT3, leading to enhanced STAT3 activity by increased tyrosine phosphorylation of STAT3. The EZH2-STAT3 interaction preferentially occurs in GSCs relative to non-stem bulk tumor cells, and it requires a specific phosphorylation of EZH2. Inhibition of EZH2 reverses the silencing of Polycomb target genes and diminishes STAT3 activity, suggesting therapeutic strategies.
•EZH2 activates STAT3 signaling via lysine methylation of STAT3•EZH2 and STAT3 preferentially interact in stem-like tumor cells•AKT serves as an upstream inducer of EZH2 to promote activation of STAT3•EZH2 inhibition reverses Polycomb-mediated silencing and decreases STAT3 activity
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Deep-air-staged combustion technology has been extensively used in coal-fired boilers under full-load conditions, which can help reduce the formation of nitrogen oxides (NOX). In this study, ...different proportions of deep-air-staging classification tests were conducted in a 550-MW tangentially fired boiler under a 50% load condition. To achieve a flexible adjustment of the boiler load, numerical simulations were conducted to evaluate the flow field distribution, combustion characteristics, and NOX emissions in a boiler under various air-staging configuration combustion conditions. The prediction results show that with an increase in the over-fire air (OFA) flow rate (i.e., close-coupled OFA (CCOFA) or separate OFA (SOFA)), the burner zone stoichiometric ratios are decreased, which is extremely important for improving the degree of burnout and reducing the NOX emissions. SOFA has a wall nozzle to better penetrate the updraft, and is thus better than the CCOFA effect in terms of coal burnout. SOFA also achieves a better pollutant emission reduction than CCOFA, and CCOFA plays a vital role in the combustion stability of a boiler combustion system. Finally, field measurements verified the effectiveness of the optimized air-staging classification scheme, which improved the combustion characteristics compared to a scheme without air-staging classification.
•Chieving high burnout and low gas emissions under 50%-load conditions•The CCOFA plays a vital role in the combustion stability of the boiler combustion system•The influence of various air-staging conditions on NOx/UBC is discussed•The SOFA burnout system has a better pollutant emission reduction effect than CCOFA
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Achieving combustion stability while reducing gas emissions under half-load conditions in boiler.•Furnace suffers from asymmetrical combustion due to various burner group arrangements.•The optimal ...CCOFA/SOFA ratio is 5% CCOFA and 15% SOFA.•The influence of excess air ratio on NOx/UBC is discussed.•Field tests are performed under optimal conditions.
The off-peak period of the grid load (i.e., deep peak load) prevents a power generation boiler from operating at full load. To achieve stable combustion of 550-MW tangentially fired pulverized coal boiler and ultra-low pollutant emissions (nitrogen oxides and unburned carbon) under half-load conditions, different operating parameters have been analyzed and optimized. In this study, under half-load conditions, the numerical method was used to simulate the flow field characteristics, combustion stability, and pollutant emissions of the boiler under various operating conditions. The operating conditions included various burner group arrangements, close-coupled overfire air (CCOFA)/separated overfire air (SOFA) distributions, and excess air ratios. The simulation prediction results showed that the middle burner group (BCDE) arrangement has a good flow field distribution. Compared with the upper burner group (CDEF) arrangement, this reduces NOX by approximately 62 ppm and also maintains a higher pulverized coal burnout rate than the lower burner group (ABCD) arrangement. Considering the stability of the combustion and lowest emissions, the ratio of CCOFA of 5% and SOFA of 15% were preferred as the operating conditions for the air-staging distribution. The high excess air caused an increase in NOX while the combustion temperature significantly reduced in the furnace, made the furnace exit gas temperature (FEGT) too low, and affected the steam temperature. In addition, the simulation results of the optimized scheme were in good agreement with the field test results.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Currently, a few of studies revealed that there is an association between mastication and cognitive impairment. There is no study of Korean adult representative samples in relation to mastication and ...cognitive decline. This study was to investigate the relationship between mastication and mild cognitive impairment in Korean adults.A population-based cross-sectional study was conducted in which a total of 7029 subjects (2987 men and 4042 women) over 45 years old were surveyed from the Korea Longitudinal Study on Aging (KLoSA), Round 5th survey. Logistic regression analysis was performed for the study data controlling for confounding factors such as age, gender, education, income, smoking, drinking, exercise, wearing denture, and the number of chronic diseases.Decreased chewing function is associated with mild cognitive impairment (odds ratio OR = 3.24, 95% confidence interval CI = 2.67-3.93) after controlling for confounding variables. In the participants who did not wear dentures, the reduction of chewing function was strongly correlated with mild cognitive impairment (OR = 3.97, 95% CI = 3.11-5.08).Mastication was associated with mild cognitive impairment. To prevent cognitive decline, health specialists should pay more attention to the decline of the mastication in people without dentures.
Stroke is the leading cause of death and neurological disorders worldwide. However, diagnostic techniques and treatments for stroke patients are still limited for certain types of stroke. Intensive ...research has been conducted so far to find suitable diagnostic techniques and treatments, but so far there has been no success. In recent years, various studies have drawn much attention to the clinical value of utilizing the mechanism of exosomes, low toxicity, biodegradability, and the ability to cross the blood–brain barrier. Recent studies have been reported on the use of biomarkers and protective and recovery effects of exosomes derived from stem cells or various cells in the diagnostic stage after stroke. This review focuses on publications describing changes in diagnostic biomarkers of exosomes following various strokes and processes for various potential applications as therapeutics.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract Glycosaminoglycans (GAGs) and proteoglycans (PGs) are abundant structural components of the extracellular matrix in addition to collagen fibers. Hyaluronic acid (HA) one of GAGs, forms ...proteoglycan aggregates, which are large complexes of HA and HA-binding PGs. Their crosslinking to other matrix proteins such as the collagen network results in the formation of supermolecular structures and functions to increase tissue stiffness. Skin aging can be classified as intrinsic aging and photoaging based on the phenotypes and putative mechanism. While intrinsic aging is characterized by a thinned epidermis and fine wrinkles caused by advancing age, photoaging is characterized by deep wrinkles, skin laxity, telangiectasias, and appearance of lentigines and is mainly caused by chronic sun exposure. The major molecular mechanism governing skin aging processes has been attributed to the loss of mature collagen and increased matrix metalloproteinase expression. However, various strategies focusing on collagen turnover remain unsatisfactory for the reversal or prevention of skin aging. Although the expression of GAGs and PGs in the skin and their regulatory mechanisms are not fully understood, we and others have elucidated various changes in GAGs and PGs in aged skin, suggesting that these molecules are important contributors to skin aging. In this review, we focus on skin-abundant GAGs and PGs and their changes in human skin during the skin aging process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
SARS-CoV-2 induces illness and death in humans by causing systemic infections. Evidence suggests that SARS-CoV-2 can induce brain pathology in humans and other hosts. In this study, we used a canine ...transmission model to examine histopathologic changes in the brains of dogs infected with SARS-CoV-2. We observed substantial brain pathology in SARS-CoV-2–infected dogs, particularly involving blood–brain barrier damage resembling small vessel disease, including changes in tight junction proteins, reduced laminin levels, and decreased pericyte coverage. Furthermore, we detected phosphorylated tau, a marker of neurodegenerative disease, indicating a potential link between SARS-CoV-2–associated small vessel disease and neurodegeneration. Our findings of degenerative changes in the dog brain during SARS-CoV-2 infection emphasize the potential for transmission to other hosts and induction of similar signs and symptoms. The dynamic brain changes in dogs highlight that even asymptomatic individuals infected with SARS-CoV-2 may develop neuropathologic changes in the brain.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The low-density-lipoprotein receptor (LDLr) removes low-density lipoprotein (LDL), an endovascular transporter that carries cholesterol from the bloodstream to peripheral tissues. The maintenance of ...cholesterol content in the brain, which is important to protect brain function, is affected by LDLr. LDLr co-localizes with the insulin receptor and complements the internalization of LDL. In LDLr deficiency, LDL blood levels and insulin resistance increase, leading to abnormal cholesterol control and cognitive deficits in atherosclerosis. Defects in brain cholesterol metabolism lead to neuroinflammation and blood–brain-barrier (BBB) degradation. Moreover, interactions between endoplasmic reticulum stress (ER stress) and mitochondria are induced by ox-LDL accumulation, apolipoprotein E (ApoE) regulates the levels of amyloid beta (Aβ) in the brain, and hypoxia is induced by apoptosis induced by the LDLr defect. This review summarizes the association between neurodegenerative brain disease and typical cognitive deficits.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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•Understanding nitrogen transformation in wetland sediments is important.•Water level and vegetation affect nitrogen biogeochemical cycles in wetland sediments.•High water level and ...plant in wetland can provide DOC for microorganism in sediments.•Eco-hydrologic condition in wetland affects the microbial community in sediments.
Recent increases in the frequency of extreme floods and droughts associated with climate change can affect fluctuating groundwater or wetland water levels and wetland plant growth, and consequently cause redox condition changes in nitrogen dynamics in wetland sediments. Here, we studied the fate of nitrate (NO3-), dissolved organic carbon (DOC), and the microbial characteristics at different sediment depths in response to water levels (i.e., 5 or 2.5 cm) above the sediment surface and in the presence or absence of plants (Phragmites communis Trin) for four months in three wetland mesocosms. Results showed that mesocosm A (MA) with a high water level (5 cm above the surface) and plants had significantly higher DOC concentrations (17.57 ± 8.22 mg/L) in sediment that were actively consumed by microorganisms than other mesocosms with low water level (MB) and without plant (MC) (8.77 ± 2.38 mg/L and 7.87 ± 2.72 mg/L in MB and MC, respectively). Consequently, the most of influent NO3- (20 mg-N/L) dramatically reduced in the vicinity of plant roots (-20 to -15 cm sediment depth) where active denitrification was expected in MA. Moreover, the functional genes involved in denitrification such as narG (2.4 × 108 –3.5 × 108 copies·g-1) and nirS (5.6 × 106–1.1 × 107 copies·g-1) were more abundant in this mesocosm. The profile of the microbial community structure at the class level revealed that Alphaproteocbacteria (MA: 14.19 ± 1.19%; MB: 14.01 ± 0.51%; MC: 15.21 ± 2.76%) and Actinobacteria (MA: 8.21 ± 1.91%; MB: 13.91 ± 2.13%; MC: 11.75 ± 3.43%) were predominant in all three mesocosms. Interestingly, the clustered heatmap supported the obvious difference in microbial composition of MA from other mesocosms showing relatively more abundant Clostridia (6.71 ± 1.54%) and Deltaproteobacteria (7.05 ± 0.68%). These results can provide an insight to understand the biogeochemical nitrogen cycle associated with climate change in wetland systems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A new combustion system promoted the combustion stability of the boiler.•Combination of corner SOFA (70%) and clockwise wall SOFA (30%) had best performance.•Industrial experiments were carried out ...using a 500 MW retrofit boiler.•NOx emissions and unburned carbon in fly ash reduced by 66% and 2.9%, respectively.
Retrofitting of an aging 500 MW tangential coal-fired boiler with high pollutant emissions in South Korea was investigated to achieve low nitrogen oxide (NOX) emissions and high combustion efficiency. This study evaluated and analyzed the combustion and emission characteristics of five arrangements to optimize the position and direction of a separated overfire air (SOFA) installation using a computational fluid dynamics (CFD) simulation. The results show that the air injection of SOFA at the center of the boiler wall causes substantial obstruction of the rising airflow below, causing unstable combustion behavior in the boiler, and increasing the amount of unburned carbon (UBC). However, combining the wall injection with corner SOFA helps reduce the formation of NOX and has the effect of promoting the burnout of UBC. For the direction of the wall injection under combined conditions, a clockwise airflow helps to reduce the formation of NOX with increasing UBC. Otherwise, the counter-clockwise airflow weakens the flow rate of the ascending airflow, increasing the residence time of unburned particles, increasing the coal burnout rate, and increasing the furnace exit gas temperature (FEGT). Among the five SOFA arrangements studies, this study recommends Case 4, which has a clockwise wall SOFA (30%) with corner SOFA (70%). This case has the best performance in terms of combustibility, NOX emission, UBC, and FEGT. The proposed condition was verified through a field test, and the results indicate that NOX emissions decreased from 169 ppm to 57 ppm, the UBC content decreased from 3.64% to 0.7%, and the boiler efficiency increased by 2%.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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