•Quantitative investigation of curing temperature for FA-based geopolymer strength.•Various micro-observation results through EDA, XRD, SEM, MIP.•Strength grading contour considering ...alkali-activators, Ms values, and curing temperatures.•Relationship between strength and changes in macro-pore structure.•Pre-curing effect with different temperature and duration on strength.
Many researches have been performed on performance improvement of geopolymer considering low calcium materials and alkaline solutions. In the binder of geopolymer, OPC (Ordinary Portland Cement) which can cause environmental load such as CO2 emission is not used. The mechanical properties of geopolymer are directly affected by various parameters like binder types, SiO2/Na2O molar ratios, alkali activator concentrations, and curing conditions (temperature and period), but very limited researches have been performed on comprehensive evaluation of the influencing parameters.
In the work, compressive strength in FA (Fly Ash)-based geopolymer is evaluated considering four test variables covering Na2O content, SiO2/Na2O molar ratios, curing temperature/period, and pre-curing temperature/period. The results reveal that higher compressive strength can be obtained with higher Na2O content, higher curing temperatures, and longer pre-curing periods at the relatively low temperature (23°C). On the other hand, an extension of curing period at high temperatures leads to strength reduction due to increasing macro-pores over 50nm. Through the various tests, strength grade contours considering SiO2/Na2O molar ratios, Na2O content, and curing temperatures are obtained, which can be utilized for an effective mix design for FA-based geopolymer.
Antifibrotic agent for the treatment of liver fibrosis has not been developed so far. Long term treatment of chronic hepatitis B patients with antiviral drugs tenofovir disoproxil fumarate (TDF) and ...entecavir (ETV) results in the regression of liver fibrosis, but the underlying mechanism has not been clarified. Therefore, we aimed to investigate the direct impact of TDF and ETV on liver fibrosis.
Activated hepatic stellate cell (HSC) cell lines were used to evaluate the effects of TDF and ETV. After treatment with each antiviral agent, cell viability, morphology, apoptotic features, autophagy and antifibrosis signalling pathways were examined. Then, collagen deposition, fibrosis markers and activated HSCs were measured in liver tissues of the liver fibrosis model mice.
After TDF treatment, the viabilities of LX2 and HSC-T6 cells were decreased, and the cells exhibited apoptotic features, but ETV did not induce these effects. Cleavage of PARP and Caspase-3 and the inhibition of the antiapoptotic gene Bcl-xl indicated activated HSC apoptosis following TDF treatment. TDF simultaneously increased autophagy, which also regulated apoptosis through crosstalk. TDF inactivated the PI3K/Akt/mTOR signalling pathway, which was associated with the activation of both apoptosis and autophagy. In the liver fibrosis mouse model, the fibrotic area and activated HSC markers were decreased by TDF but not ETV treatment. Additionally, apoptotic cells were concentrated in the periportal fibrotic area after TDF treatment, which indicated the specific antifibrotic effect of TDF.
TDF directly ameliorates liver fibrosis by downregulating the PI3K/Akt/mTOR signalling pathway, which results in the apoptosis of activated HSCs. The antifibrotic effects of TDF indicate that it may be a therapeutic agent for the treatment of liver fibrosis.
Background Recent evidence suggests that prenatal maternal distress increases the risk of allergic diseases in offspring. However, the effect of prenatal maternal depression and anxiety on atopic ...dermatitis (AD) risk remains poorly understood. Objective We investigated whether prenatal maternal distress is associated with AD risk in offspring and whether the mechanism is mediated by reactive oxygen species. Methods Two general population-based birth cohorts formed the study. One cohort (Cohort for Childhood Origin of Asthma and Allergic Diseases COCOA) consisted of 973 mother-baby dyads, and the other (Panel Study on Korean Children PSKC) consisted of 1531 mother-baby dyads. The association between prenatal distress and AD was assessed by using Cox proportional hazards and logistic regression models. In COCOA placental 11β-hydroxysteroid dehydrogenase type 2 and glutathione levels and serum IgE levels in 1-year-old children were measured. Results In COCOA and PSKC AD occurred in 30.6% (lifetime prevalence) and 11.6% (1 year prevalence) of offspring, respectively. Prenatal maternal distress increased the risk of AD in offspring, both in COCOA (hazard ratio for depression, 1.31 95% CI, 1.02-1.69; hazard ratio for anxiety, 1.41 95% CI, 1.06-1.89) and PSKC (odds ratio for distress, 1.85 95% CI, 1.06-3.25). In COCOA both prenatal maternal depression and anxiety scores were positively related to the predicted probability of AD ( P < .001 in both). Prenatal distress decreased placental glutathione to glutathione disulfide ratios ( P = .037) and, especially in those who later had AD, decreased placental 11β-hydroxysteroid dehydrogenase type 2 levels ( P = .010) and increased IgE levels at 1 year of age ( P = .005). Conclusion Prenatal maternal depression and anxiety promote risk of AD in offspring. Maternal distress increases the predicted probability of AD. The mechanism might involve chronic stress, abnormal steroid levels, and reactive oxygen species.
Although cesarean delivery and prenatal exposure to antibiotics are likely to affect the gut microbiome in infancy, their effect on the development of atopic dermatitis (AD) in infancy is unclear. ...The influence of individual genotypes on these relationships is also unclear. To evaluate with a prospective birth cohort study whether cesarean section, prenatal exposure to antibiotics, and susceptible genotypes act additively to promote the development of AD in infancy.
The Cohort for Childhood of Asthma and Allergic Diseases (COCOA) was selected from the general Korean population. A pediatric allergist assessed 412 infants for the presence of AD at 1 year of age. Their cord blood DNA was subjected to interleukin (IL)-13 (rs20541) and cluster-of-differentiation (CD)14 (rs2569190) genotype analysis.
The combination of cesarean delivery and prenatal exposure to antibiotics associated significantly and positively with AD (adjusted odds ratio, 5.70; 95% CI, 1.19-27.3). The association between cesarean delivery and AD was significantly modified by parental history of allergic diseases or risk-associated IL-13 (rs20541) and CD14 (rs2569190) genotypes. There was a trend of interaction between IL-13 (rs20541) and delivery mode with respect to the subsequent risk of AD. (P for interaction = 0.039) Infants who were exposed prenatally to antibiotics and were born by cesarean delivery had a lower total microbiota diversity in stool samples at 6 months of age than the control group. As the number of these risk factors increased, the AD risk rose (trend p<0.05).
Cesarean delivery and prenatal antibiotic exposure may affect the gut microbiota, which may in turn influence the risk of AD in infants. These relationships may be shaped by the genetic predisposition.
Ginseng, a perennial plant belonging to the genus Panax of the Araliaceae family, is well known for its medicinal properties that help alleviate pathological symptoms, promote health, and prevent ...potential diseases. Among the active ingredients of ginseng are saponins, most of which are glycosides of triterpenoid aglycones. So far, numerous saponins have been reported as components of Panax ginseng, also known as Korean ginseng. Herein, we summarize available information about 112 saponins related to P. ginseng; >80 of them are isolated from raw or processed ginseng, and the others are acid/base hydrolysates, semisynthetic saponins, or metabolites.
Previous studies have rarely investigated the role of non-vitamin K oral anticoagulants (NOAC) and warfarin in the secondary prevention of ischemic stroke patients with nonvalvular atrial ...fibrillation (NVAF). In this study, we compared the effectiveness and safety of NOAC and warfarin for secondary prevention in Korean ischemic stroke patients with NVAF. Based on the Korean National Health Insurance Service Database, this study included 21,064 oral anticoagulants-naïve acute ischemic stroke patients with NVAF between July 2015 and June 2019. The main study outcomes included ischemic stroke, systemic embolism, major bleeding, and death. During the observational periods, NOAC users had a significantly decreased risk of ischemic stroke + systemic embolism (adjusted hazard ratio aHR 0.86; 95% confidence interval CI 0.78-0.95), ischemic stroke (aHR 0.89; 95% CI 0.81-0.99), major bleeding (aHR 0.78; 95% CI 0.68-0.89), and all-cause death (aHR 0.87; 95% CI 0.81-0.93). Standard-dose NOAC users had a lower risk of ischemic stroke, systemic embolism, and major bleeding events than warfarin users. In contrast, low-dose NOAC users did not differ in risk from warfarin users for all outcomes. In conclusion, NOACs were associated with a lower risk of secondary thromboembolic events and bleeding complications in Korean ischemic stroke patients with NVAF than warfarin.
•Cold joint effect on chloride diffusion is investigated for normal concrete.•GGBFS effect on chloride diffusion is also evaluated.•Compressive and tensile stress effects on diffusion are ...quantitatively evaluated.•The total effect of joint, GGBFS, and loading level is evaluated on diffusion.•Diffusion increases linearly in cold joint concrete under compressive region.
RC (Reinforced Concrete) structures undergo deterioration and the initiated corrosion in the steel is considered as one of the most critical problems. For efficient construction of structures, construction joint should be installed, however cold joint occurs reluctantly due to delayed concrete placing and poor condition of the old concrete surface. The chloride ingress in cold joint concrete is more rapid than that in sound concrete, and it is also affected by loading conditions. This paper presents a quantitative evaluation on chloride diffusion coefficient considering the effects of cold joint and loading conditions. For the work, concrete samples with 0.6 of w/b (water to binder) ratio are prepared. Compressive and tensile stresses are induced with 30% and 60% of ultimate strength, respectively. The chloride diffusion coefficients in accelerated condition are measured under loading, and the effects of cold joint and loading levels are evaluated. In order to investigate an effect of GGBFS (Ground Granulated Blast Furnace Slag) on chloride diffusion, 40% of GGBFS replacement ratio is considered for OPC (Ordinary Portland Cement) and the GGBFS effect is evaluated considering cold joint and loading levels. The effects of stress level, pore structure improvement through GGBFS, and cold joint on chloride diffusion coefficient are quantitatively investigated.
Lipotoxicity, induced by saturated fatty acid (SFA)-mediated cell death, plays an important role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). The KEAP1 (kelch like ECH associated ...protein 1)-NFE2L2/NRF2 (nuclear factor, erythroid 2 like 2) pathway is a pivotal defense mechanism against lipotoxicity. We previously reported that SQSTM1/p62 has a cytoprotective role against lipotoxicity through activation of the noncanonical KEAP1- NFE2L2 pathway in hepatocytes. However, the underlying mechanisms and physiological relevance of this pathway have not been clearly defined. Here, we demonstrate that NFE2L2-mediated induction of SQSTM1 activates the noncanonical KEAP1-NFE2L2 pathway under lipotoxic conditions. Furthermore, we identified that SQSTM1 induces ULK1 (unc-51 like autophagy activating kinase 1) phosphorylation by facilitating the interaction between AMPK (AMP-activated protein kinase) and ULK1, leading to macroautophagy/autophagy induction, followed by KEAP1 degradation and NFE2L2 activation. Accordingly, the activity of this SQSTM1-mediated noncanonical KEAP1-NFE2L2 pathway conferred hepatoprotection against lipotoxicity in the livers of conventional sqstm1- and liver-specific sqstm1-knockout mice. Moreover, this pathway activity was evident in the livers of patients with nonalcoholic fatty liver. This axis could thus represent a novel target for NAFLD treatment.
Abbreviations: ACACA: acetyl-CoA carboxylase alpha; ACTB: actin beta; BafA1: bafilomycin A
1
; CM-H2DCFDA:5-(and-6)-chloromethyl-2ʹ,7ʹ-dichlorodihydrofluorescein diacetate; CQ: chloroquine; CUL3: cullin 3; DMSO: dimethyl sulfoxide; FASN: fatty acid synthase; GSTA1: glutathione S-transferase A1; HA: hemagglutinin; Hepa1c1c7: mouse hepatoma cells; HMOX1/HO-1: heme oxygenase 1; KEAP1: kelch like ECH associated protein 1; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3; MEF: mouse embryonic fibroblast; MTORC1: mechanistic target of rapamycin kinase complex 1; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; NAC: N-acetyl-L-cysteine; NAFLD: nonalcoholic fatty liver disease; NASH: nonalcoholic steatohepatitis; NFE2L2/NRF2: nuclear factor, erythroid 2 like 2; NQO1: NAD(P)H quinone dehydrogenase 1; PA: palmitic acid; PARP: poly (ADP-ribose) polymerase 1; PRKAA1/2: protein kinase AMP-activated catalytic subunits alpha1/2; RBX1: ring-box 1; ROS: reactive oxygen species; SESN2: sestrin 2; SFA: saturated fatty acid; siRNA: small interfering RNA; SQSTM1/p62: sequestosome 1; SREBF1: sterol regulatory element binding transcription factor 1; TBK1: TANK binding kinase 1; TUNEL: terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling; ULK1: unc-51 like autophagy activating kinase.
X-linked adrenoleukodystrophy (X-ALD), caused by an ABCD1 mutation, is a progressive neurodegenerative disorder associated with the accumulation of very long-chain fatty acids (VLCFA). Cerebral ...inflammatory demyelination is the major feature of childhood cerebral ALD (CCALD), the most severe form of ALD, but its underlying mechanism remains poorly understood. Here, we identify the aberrant production of cholesterol 25-hydroxylase (CH25H) and 25-hydroxycholesterol (25-HC) in the cellular context of CCALD based on the analysis of ALD patient-derived induced pluripotent stem cells and ex vivo fibroblasts. Intriguingly, 25-HC, but not VLCFA, promotes robust NLRP3 inflammasome assembly and activation via potassium efflux-, mitochondrial reactive oxygen species (ROS)- and liver X receptor (LXR)-mediated pathways. Furthermore, stereotaxic injection of 25-HC into the corpus callosum of mouse brains induces microglial recruitment, interleukin-1β production, and oligodendrocyte cell death in an NLRP3 inflammasome-dependent manner. Collectively, our results indicate that 25-HC mediates the neuroinflammation of X-ALD via activation of the NLRP3 inflammasome.
To understand the mechanisms underlying tooth morphogenesis, we examined the developmental roles of important posttranslational modification, O‐GlcNAcylation, which regulates protein stability and ...activity by the addition and removal of a single sugar (O‐GlcNAc) to the serine or threonine residue of the intracellular proteins. Tissue and developmental stage‐specific immunostaining results against O‐GlcNAc and O‐GlcNAc transferase (OGT) in developing tooth germs would suggest that O‐GlcNAcylation is involved in tooth morphogenesis, particularly in the cap and secretory stage. To evaluate the developmental function of OGT‐mediated O‐GlcNAcylation, we employed an in vitro tooth germ culture method at E14.5, cap stage before secretory stage, for 1 and 2 days, with or without OSMI‐1, a small molecule OGT inhibitor. To examine the mineralization levels and morphological changes, we performed renal capsule transplantation for one and three weeks after 2 days of in vitro culture at E14.5 with OSMI‐1 treatment. After OGT inhibition, morphological and molecular alterations were examined using histology, immunohistochemistry, real‐time quantitative polymerase chain reaction, in situ hybridization, scanning electron microscopy, and ground sectioning. Overall, inhibition of OGT resulted in altered cellular physiology, including proliferation, apoptosis, and epithelial rearrangements, with significant changes in the expression patterns of β‐catenin, fibroblast growth factor 4 (fgf4), and sonic hedgehog (Shh). Moreover, renal capsule transplantation and immunolocalizations of Amelogenin and Nestin results revealed that OGT‐inhibited tooth germs at cap stage exhibited with structural changes in cuspal morphogenesis, amelogenesis, and dentinogenesis of the mineralized tooth. Overall, we suggest that OGT‐mediated O‐GlcNAcylation regulates cell signaling and physiology in primary enamel knot during tooth development, thus playing an important role in mouse molar morphogenesis.
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