AIM： To determine intestinal permeability, the serum tumor necrosis factor （TNF）-α level and urine nitric oxide （NO） metabolites are altered in liver cirrhosis （LC） with or without ascites. METHODS： Fifty-thr...AIM： To determine intestinal permeability, the serum tumor necrosis factor （TNF）-α level and urine nitric oxide （NO） metabolites are altered in liver cirrhosis （LC） with or without ascites. METHODS： Fifty-three patients with LC and 26 healthy control subjects were enrolled in the study. The intestinal permeability value is expressed as the percentage of polyethylene glycol （PEG） 400 and 3350 retrieval in 8-h urine samples as determined by high performance liquid chromatography. Serum TNF-α concentrations and urine NO metabolites were determined using an enzyme-linked immunosorbent assay （ELISA） and Greiss reaction method, respectively. RESULTS： The intestinal permeability index wassignificantly higher in patients with LC with ascites than in healthy control subjects or patients with LC without ascites （0.88 ± 0.12 vs 0.52 ± 0.05 or 0.53 ± 0.03, P 〈 0.05） and correlated with urine nitrite excretion （r = 0.98）. Interestingly, the serum TNF-α concentration was significantly higher in LC without ascites than in control subjects or in LC with ascites （198.9 ± 55.8 pg/mL vs 40.9 ± 12.3 pg/mL or 32.1 ± 13.3 pg/mL, P 〈 0.05）. Urine nitrite excretion was significantly higher in LC with ascites than in the control subjects or in LC without ascites（ 1170.9± 28.7 μmol/L vs 903.1 ± 55.1 μmol/L or 956.7 ± 47.7 μmol/L, P 〈 0.05）. COMCLUSIOM： Increased intestinal macromolecular permeability and NO is probably of importance in the pathophysiology and progression of LC with ascites, but the serum TNF-α concentration was not related to LC with ascites.展开更多
AIM： To determine the accuracy of 1.5-T magnetic resonance imaging （MRI） in the evaluation of gastric wall invasion and perigastric lymph node metastasis in gastric adenocarcinoma.METHODS： Twenty resected gastric ...AIM： To determine the accuracy of 1.5-T magnetic resonance imaging （MRI） in the evaluation of gastric wall invasion and perigastric lymph node metastasis in gastric adenocarcinoma.METHODS： Twenty resected gastric specimens containing 20 tumors were studied with a 1.5-T MR system using a commercial head surface coil. MR scanning was performed with a T1 weighted image （TR/TE = 500/20）, and a T2 weighted image （TR/TE = 2500/90）. MR findings were compared with pathologic findings.RESULTS： A T1-weighted image demonstrated three layers in the normal gastric wall. All of the gastric tumors were well demonstrated by lesions and location. In a MRI findings of gastric wall invasion, there was 1 case of T1, 7 of T2, 11 of T3. Pathologic results of resected specimens included 3 cases of pT1, 4 of pT2, and 12 of pT3. The accuracy of T staging with MRI was 74% （14 of 19）. MRI findings of lymph node metastasis included 6 cases of NO, 13 cases of N1. The accuracy of the N staging with MRI was 47% （9 of 19）.CONCLUSION： MRI has a high diagnostic accuracy in the evaluation of the T staging of gastric cancerin vitro and thus potentially enables preoperative histopathologic staging.展开更多
As a new class of two-dimensional materials, two-dimensional (2D) heterostructures constructed from metal chalcogenides (MCs) have been gaining tremendous attention due to their unprecedented physical and chemical phe...As a new class of two-dimensional materials, two-dimensional (2D) heterostructures constructed from metal chalcogenides (MCs) have been gaining tremendous attention due to their unprecedented physical and chemical phenomena, mainly originated from their distinct structural features such as composition, architecture type, spatial arrangement of each component, crystal structure, exposed facet and interface, dimensionality in their heterostructures. Towards the realization of practical applications, synthetic approaches need a rational design with a variety of architecture types including laterally-combined, vertically-aligned, and conformally-coated 2D MC heterostructures. Among various synthetic routes, solution-based synthesis is thought of as an alternative to fabrication through high-cost setups since it can control those structural features in a cheap fashion. This review presents recent progress on solution-based synthesis to produce various 2D MC heterostructures with a focus on the synthetic fundamentals in terms of thermodynamic and kinetic aspects related to the growth mechanism. Four different synthetic approaches are reviewed: seeded growth, cation exchange reaction, colloidal atomic layer deposition, direct synthesis including one-step process and modified electrochemical method. We also provide some representative applications of 2D MC heterostructures and their hybrid composites in various fields including optoelectronics, thermoelectrics, catalysis, and battery. Finally, we offer an insight into challenges and future directions in a synthetic improvement of 2D MC heterostructures.展开更多
Chronic activation of microglial cells endangers neuronal survival through the release of various proinflammatory and neurotoxic factors. The root of Paeonia lactiflora Pall has been considered useful for the treatmen...Chronic activation of microglial cells endangers neuronal survival through the release of various proinflammatory and neurotoxic factors. The root of Paeonia lactiflora Pall has been considered useful for the treatment of various disorders in traditional oriental medicine. Paeonol, found in the root of Paeonia lactiflora Pall, has a wide range of pharmacological functions, including anti-oxidative, anti-inflammatory and neuroprotective activities. The objective of this study was to examine the efficacy of paeonol in the repression of inflammation-induced neurotoxicity and microglial cell activation. Organotypic hippocampal slice cultures and primary microglial cells from rat brain were stimulated with bacterial lipopolysaccharide. Paeonol pretreatment was performed for 30 minutes prior to lipopolysaccharide addition. Cell viability and nitrite （the production of nitric oxide）, tumor necrosis factor-alpha and interleukin-lbeta products were measured after lipopolysaccharide treatment. In organotypic hippocampal slice cultures, paeonol blocked lipopolysaccharide-related hippocampal cell death and inhibited the release of nitrite and interleukin-lbeta. Paeonol was effective in inhibiting nitric oxide release from primary microglial cells. It also reduced the lipopolysaccharide-stimulated release of tumor necrosis factor-alpha and intefleukin-1β from microglial cells. Paeonol possesses neuroprotective activity in a model of inflammation-induced neurotoxicity and reduces the release of neurotoxic and proinflammatory factors in activated microglial cells.展开更多
The corrosion of metals can be induced by different environmental and operational conditions,and protecting metals from corrosion is a serious concern in many applicatiions.The developme nt of new materials and/or tec...The corrosion of metals can be induced by different environmental and operational conditions,and protecting metals from corrosion is a serious concern in many applicatiions.The developme nt of new materials and/or tech no logies to improve the efficie ncy of anti-corrosi on coati ngs has attracted ren ewed in terest.In this study,we develop a protective coati ng composed of a bilayer structure of reduced graphe ne oxide(RGO)/graphene oxide(GO)applied to Cu plates by spray-coating and subsequent annealing.The annealing of the GO/Cu plates at 120℃produces a bilayer structure of RGO/GO by the partial reducti on of the spray-coated GO layer.This in duces superior corrosion resista nee and adhesi on strength compared to those of GO/Cu and RGO/Cu plates because of the hydrophobic n ature of the RGO surface exposed to the surroundings and the formation of Cu-O bonds with the O-based functional groups of GO.This approach provides a viable and scalable route for using graphene coatings to protect metal surfaces from corrosion.展开更多
Although electrical stimulation is therapeutically applied for neural regeneration in patients, it remains unclear how electrical stimulation exerts its effects at the molecular level on spinal cord injury （SCI）. To...Although electrical stimulation is therapeutically applied for neural regeneration in patients, it remains unclear how electrical stimulation exerts its effects at the molecular level on spinal cord injury （SCI）. To identify the signaling pathway involved in electrical stimulation improving the function of injured spinal cord, 21 female Sprague-Dawley rats were randomly assigned to three groups： control （no surgical intervention, n = 6）, SCI （SCI only, n = 5）, and electrical simulation （ES; SCI induction followed by ES treatment, n = 10）. A complete spinal cord transection was performed at the 10^th thoracic level. Electrical stimulation of the injured spinal cord region was applied for 4 hours per day for 7 days. On days 2 and 7 post SCI, the Touch-Test Sensory Evaluators and the Basso-Beattie-Bresnahan locomotor scale were used to evaluate rat sensory and motor function. Somatosensory-evoked potentials of the tibial nerve of a hind paw of the rat were measured to evaluate the electrophysiological function of injured spinal cord. Western blot analysis was performed to measure p38-RhoA and ERK1/2-Bcl-2 pathways related protein levels in the injured spinal cord. Rat sensory and motor functions were similar between SCI and ES groups. Com- pared with the SCI group, in the ES group, the latencies of the somatosensory-evoked potential of the tibial nerve of rats were significantly shortened, the amplitudes were significantly increased, RhoA protein level was significantly decreased, protein gene product 9.5 expression, ERK1/2, p38, and Bcl-2 protein levels in the spinal cord were significantly increased. These data suggest that ES can promote the recovery of electrophysiological function of the injured spinal cord through regulating p38-RhoA and ERK1/2-Bcl-2 pathway-related protein levels in the injured spinal cord.展开更多
Brain delivery of macromolecular therapeutics (e.g., proteins) remains an unsolved problem because of the formidable blood brain bather (BBB). Although a direct pathway of nose-to-brain transfer provides an answer to ...Brain delivery of macromolecular therapeutics (e.g., proteins) remains an unsolved problem because of the formidable blood brain bather (BBB). Although a direct pathway of nose-to-brain transfer provides an answer to circumventing the BBB and has already been intensively investigated for brain delivery of small drugs, new challenges arise for intranasal delivery of proteins because of their larger size and hydrophilicity. h order to overcome the bathers and take advantage of available pathways (e.g., epithelial tight junctions, uptake by olfactory neurons, transport into brain tissues, and intra-brain diffusion), a low molecular weight protamine (LMWP) cell-penetrating peptide was utilized to facilitate nose-to-brain transport. Cell-penetrating peptides (CPP) have been widely used to mediate macromolecular delivery through many kinds of biobarriers. Our results show that conjugates of LMWP proteinsare able to effectively penetrate into the brain after intranasal administration. The CPP-based intranasal method highlights a promising solution for protein therapy of brain diseases. (C) 2016 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.展开更多
The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and...The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and Cu_(2)O/Ni O/NF electrodes via in situ pulsed laser irradiation in liquids(PLIL)for the bifunctional electrocatalysis of oxygen evolution reaction(OER)and furfural oxidation reaction(FOR),respectively.Simultaneous oxidation of NF surface to NiO and deposition of CoO and/or Cu_(2)O on NF during PLIL offer distinct advantages for enhancing both the OER and FOR.CoO/NiO/NF electrocatalyst provides a consistently low overpotential of~359 m V(OER)at 10 m A/cm^(2),achieving the maximum FA yield(~16.37 m M)with 61.5%selectivity,79.5%carbon balance,and a remarkable Faradaic efficiency of~90.1%during 2 h of FOR at 1.43 V(vs.reversible hydrogen electrode).Mechanistic pathway via in situ electrochemical-Raman spectroscopy on CoO/NiO/NF reveals the involvement of phase transition intermediates(NiOOH and CoOOH)as surface-active centers during electrochemical oxidation.The carbonyl carbon in FF is attacked by hydroxyl groups to form unstable hydrates that subsequently undergo further oxidation to yield FA products.This method holds promise for large-scale applications,enabling simultaneous production of renewable building materials and fuel.展开更多
OBJECTIVE: To assess Atractylodis Rhizoma Alba extract(ARE) neuroprotective function in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-treated mice and related genes. METHODS: Examined m RNA-DNA methylation change...OBJECTIVE: To assess Atractylodis Rhizoma Alba extract(ARE) neuroprotective function in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-treated mice and related genes. METHODS: Examined m RNA-DNA methylation changes induced by ARE in MPTP-induced Parkinson's disease(PD) model's substantia nigra. RESULTS: ARE mitigated MPTP-induced motor impairment in rotarod and open field tests and preserved tyrosine hydroxylase-positive neuronal cells in substantia nigra and striatum. Genome RNA-Sequencing and Methyl-Sequencing in substantia nigra of vehicle/ARE-treated MPTP-induced PD mice showed 84 differentially expressed genes(DEGs) and 1804 differentially methylated regions(DMRs). Upregulated genes involved zinc ion homeostasis, cilium protein localization, and transcription;downregulated genes linked to ephrin receptor signaling, somitogenesis, and gene expression regulation. Hyper/hypomethylated DMRs post-ARE treatment associated with Wnt signaling, mitochondrial organization, dopamine biosynthesis, and hindbrain development. No significant correlation between DEGs and methylated genes related to PD pathogenesis. CONCLUSION: This research has identified the epigenetic targets of ARE's therapeutic action and gives insight on how ARE protects neurons in Parkinson's disease.展开更多
Herein,we propose a simple and rapid approach for synthesizing a CuS/Ru composite that serves as a bifunctional electrocatalyst to promote hydrogen production and concurrently convert sulfion into a value-added sulfur...Herein,we propose a simple and rapid approach for synthesizing a CuS/Ru composite that serves as a bifunctional electrocatalyst to promote hydrogen production and concurrently convert sulfion into a value-added sulfur product.This composite comprises Ru nanoclusters supported on the CuS nanostructure,achieved through simple pulsed laser irradiation in liquid approach.The optimized CuS/Ru-30 electrocatalyst demonstrates remarkable bifunctional electrocatalytic activity,exhibiting a negligible working potential of 0.28 V(vs.RHE)for the anodic sulfion oxidation reaction(SOR)and a minimal overpotential of 182 m V for cathodic hydrogen evolution reaction(HER)to achieve 10 mA cm^(-2)of current density.Moreover,the Cu S/Ru-30 electrocatalyst shows exceptional selectivity for converting sulfion into valuable sulfur during anodic oxidation reactions.Remarkably,in a two-electrode electrolyzer system utilizing Cu S/Ru-30 as both the anode and cathode,the SOR+HER coupled water electrolysis system demands only 0.52 V to reach 10 mA cm^(-2),which is considerably lesser compared to the OER+HER coupled water electrolysis(1.85 V).The experimental results and density function theory(DFT)calculations reveal that the strong electron interaction between CuS and Ru nanoclusters generates a built-in electric field,greatly enhancing electron transfer efficiency.This significantly boosts the HER performance and facilitates the adsorption and production of sulfur intermediates.This study presents a rapid and simple strategy for synthesizing a dual-functional catalyst suitable for low-voltage hydrogen generation while facilitating the recovery of valuable sulfur sources.展开更多
AIM： To assess the diagnostic performance of follow- up liver computed tomography （CT） for the detection of high-risk esophageal varices in patients treated with Io- coregional therapy for hepatocellular carcinoma ...AIM： To assess the diagnostic performance of follow- up liver computed tomography （CT） for the detection of high-risk esophageal varices in patients treated with Io- coregional therapy for hepatocellular carcinoma （HCC）. METHODS： We prospectively enrolled 100 patients with cirrhosis who underwent transcatheter arterial chemoembolization, radiofrequency ablation or both procedures for HCCs. All patients underwent upper endoscopy and subsequently liver CT. Three radiolo- gists independently evaluated the presence of high-riskesophageal varices with transverse images alone and with three orthogonal multiplanar reformation （MPR） images, respectively. With endoscopic grading as the reference standard, diagnostic performance was as- sessed by using receiver operating characteristic （ROC） curve analysis. RESULTS： The diagnostic performances （areas under the ROC curve） of three observers with transverse im- ages alone were 0.947 ± 0.031, 0.969 ± 0.024, and 0.916 ＋ 0.038, respectively. The mean sensitivity, spec- ificity, positive predicative value （PPV）, and negative predicative value （NPV） with transverse images alone were 90.1%, 86.39%, 70.9%, and 95.9%, respectively. The diagnostic performances, mean sensitivity, specific- ity, PPV, and NPV with three orthogonal MPR images （0.965 ± 0.025, 0.959 ± 0.027, 0.938 ± 0.033, 91.4%, 89.5%, 76.3%, and 96.6%, respectively） were not su- perior to corresponding values with transverse images alone （P 〉 0.05）, except for the mean specificity （P = 0.039）. CONCLUSION： Our results showed excellent diagnos- tic performance, sensitivity and NPV to detect high-risk esophageal varices on follow-up liver CT after Iocore- gional therapy for HCC,展开更多
We investigated the role of metal atomization and solvent decomposition into reductive species and carbon clusters in the phase formation of transition-metal carbides(TMCs;namely,Co_(3)C,Fe_(3)C,TiC,and MoC)by pulsed ...We investigated the role of metal atomization and solvent decomposition into reductive species and carbon clusters in the phase formation of transition-metal carbides(TMCs;namely,Co_(3)C,Fe_(3)C,TiC,and MoC)by pulsed laser ablation of Co,Fe,Ti,and Mo metals in acetone.The interaction between carbon s-p-orbitals and metal d-orbitals causes a redistribution of valence structure through charge transfer,leading to the formation of surface defects as observed by X-ray photoelectron spectroscopy.These defects influence the evolved TMCs,making them effective for hydrogen and oxygen evolution reactions(HER and OER)in an alkaline medium.Co_(3)C with more oxygen affinity promoted CoO(OH)intermediates,and the electrochemical surface oxidation to Co_(3)O_(4)was captured via in situ/operando electrochemical Raman probes,increasing the number of active sites for OER activity.MoC with more d-vacancies exhibits strong hydrogen binding,promoting HER kinetics,whereas Fe_(3)C and TiC with more defect states to trap charge carriers may hinder both OER and HER activities.The results show that the assembled membrane-less electrolyzer with Co_(3)C∥Co_(3)C and MoC∥MoC electrodes requires~2.01 and 1.99 V,respectively,to deliver a 10 mA cm−2 with excellent electrochemical and structural stability.In addition,the ascertained pulsed laser synthesis mechanism and unit-cell packing relations will open up sustainable pathways for obtaining highly stable electrocatalysts for electrolyzers.展开更多
AIM:To track intravascularly transplanted mesenchymal stem cells (MSCs) labeled with superparamagnetic iron oxide (SPIO) by using magnetic resonance imaging (MRI) in an experimental rabbit model of hepatic failure.MET...AIM:To track intravascularly transplanted mesenchymal stem cells (MSCs) labeled with superparamagnetic iron oxide (SPIO) by using magnetic resonance imaging (MRI) in an experimental rabbit model of hepatic failure.METHODS:Human MSCs labeled with FDA-approved SPIO particles (Feridex) were transplanted via the mes-enteric vein into rabbits (n=16) with carbon tetrachloride-induced hepatic failure.Magnetic resonance (MR) examinations were performed with a 3.0 T clinical scanner immediately before and 2 h and 1,3,and 7 d after transplantation.Signal intensity (SI) changes on T2weighted MRI were measured,and correlation between MR findings and histomorphologic findings was also investigated.RESULTS:SI on T2-weighted MRI decreased significantly in the liver 2 h after injection of human MSCs and returned gradually to the levels found before injection in 7 d.Changes in SI in the liver at 2 h,1,3,and 7 d were 41.87% ± 9.63%,10.42% ± 4.3%,5.12% ± 1.9%,3.75% ± 1.2%,respectively (P < 0.001).Histologic analyses confirmed the presence of MSCs in the liver,localized mainly in the sinusoids in early period (2 h and 1 d) and concentrated to the border zone in late period (3 and 7 d).The number of iron-positive cells in the liver at 2 h and on 1,3 and 7 d after transplantation was 29.2 ± 4.8,10.1 ± 3.7,6.7 ± 2.2,and 5.8 ± 2.1,respectively (P=0.013).CONCLUSION:Intravascularly injected SPIO-labeled MSCs in an experimental rabbit model of hepatic failure can be detected and followed with MRI.展开更多
OBJECTIVE: To investigate whether scorpion extract elicits a neuroprotective effect in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-treated mice models, and the genes associated with the therapeutic effects usin...OBJECTIVE: To investigate whether scorpion extract elicits a neuroprotective effect in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-treated mice models, and the genes associated with the therapeutic effects using RNA sequencing(seq)analysis.METHODS: This study investigated the changes in interaction between messenger ribonucleic acid(m RNA) expression and deoxyribonucleic acid(DNA) methylation related to the protective effects of scorpion extracts, in the substantia nigra(SN)region of a MPTP-induced Parkinson's disease(PD)model.RESULTS: In this model, scorpion extracts attenuated the motor impairment as demonstrated by the rotarod and open field tests. Scorpion extracts consistently attenuated the decrease of tyrosine hydroxylase(TH) positive neural cells in the SN and striatum of mice. We profiled genomewide DNA methylation using Methyl-Seq and measured the transcriptome using RNA-Seq in murine SN in the following groups: vehicle-treated MPTP-induced PD mice and scorpion extracttreated MPTP-induced PD mice. In total, 13 479 differentially expressed genes were identified in association with the anti-PD effect of the scorpion extract, mainly in the promoter and coding regions.Among them, 47 were negatively correlated downregulated genes. Nineteen genes out of 47 downregulated genes were negatively correlated with the expression of the other 28 genes. Among these genes, SGSM1 was related to dopaminergic neurons including dopamine transporters, TH, dihydroxyphenylalanine decarboxylase, and dopamine D2 receptor.CONCLUSION: This study provides insights into the anti-parkinsonian effects of scorpion extract and reveals the epigenetic targets in its therapeutic mechanism.展开更多
Population studies have suggested an association between diabetes and the symptoms of testosterone deficiency. Recently, the expression of the androgen receptor （AR） has been shown to be decreased in diabetic patien...Population studies have suggested an association between diabetes and the symptoms of testosterone deficiency. Recently, the expression of the androgen receptor （AR） has been shown to be decreased in diabetic patients. Furthermore, diabetes has been shown to induce global methylation. In this study, we used an animal model to investigate whether diabetes results in increased methylation of the AR promoter and whether these changes are associated with the decreased expression of AR in penile cavernosal smooth muscle tissue. Twenty C57BL/6J mice were divided into two groups, receiving either high- （mature diabetic） or low- （mature control） caloric meals for 14 weeks. Another 10 mice were killed at 1 week （young control）. Animals in the mature diabetic group showed decreased testosterone levels, although this was not statistically significant. In both control groups, no significant methylation was observed in the AR promoter region CpG island （-85 to ＋339）. In the mature diabetic group, significant methylation was observed at ＋ 185 and ＋200 of the AR promoter. These changes were associated with increased homeostatic model assessment for insulin resistance （HOMA-IR） and decreased corpus cavernosal tissue mass and expression of AR mRNA and protein. We conclude that in these animals, insulin resistance increased the methylation of the GC-rich regions of the AR promoter, leading to decreased AR expression.展开更多
The single-pot production of Pd@Pt core-shell structures is a promising approach as it offers large surface area,catalytic capability,and stability.In this work,we established a single-pot process to produce Pd@Pt cor...The single-pot production of Pd@Pt core-shell structures is a promising approach as it offers large surface area,catalytic capability,and stability.In this work,we established a single-pot process to produce Pd@Pt core-shell nanodendrites with tunable composition,shape and size for optimal electrochemical activity.Pd@Pt nanodendrites with diverse compositions were synthesized by tuning the ratios of Pd and Pt sources in an aqueous environment using cetyltrimethylammonium chloride,which functioned as both the surfactant and the reducing agent at an elevated temperature(90°C).The synthesized Pd5@Pt5 nanodendrites showed exceptional electrochemical action toward the methanol oxidation reaction related with another compositional Pd@Pt nanodendrites and conventional Pt/C electrocatalysts.In addition,Pd5@Pt5 nanodendrites exhibited good CO tolerance owing to their surface features and the synergistic effect among Pt and Pd.Meanwhile,nanodendrites with a Pt-rich surface provided exceptional catalytic active sites.Compared with the conventional Pt/C electrocatalyst,the anodic peak current obtained by Pd5@Pt5 nanodendrites was 3.74 and 2.18 times higher in relations of mass and electrochemical active surface area-normalized current density,respectively.This approach offers an attractive strategy to design electrocatalysts with unique structures and outstanding catalytic performance and stability for electrochemical energy conversion.展开更多
The effects of hydro co-extrusion on the microstructure changes of aluminum hybrid duo-cast Al 3003/Al 4004 clad materials were studied. The specimen of duo-cast Al 3003/Al 4004 clad materials was in circle shape, and...The effects of hydro co-extrusion on the microstructure changes of aluminum hybrid duo-cast Al 3003/Al 4004 clad materials were studied. The specimen of duo-cast Al 3003/Al 4004 clad materials was in circle shape, and was composed of Al 3003(outside) and Al 4004(inside) materials. The specimen was extruded by the hydro co-extrusion equipment. The manufacturing conditions of the specimen were 423 K in temperature and 5 in extrusion ratio. The dimensions of the specimen were 80 mm in diameter of the Al 4004 material and 35 mm in thickness of the Al 3003 material before the hydro co-extrusion process, and 30 mm in diameter and about 5 mm in thickness after the extrusion process, respectively. The microstructure and the hardness for two specimens were investigated. The hardness value of cross section in the duo-cast Al 3003/Al 4004 clad materials before the extrusion process was increased in form of the parabola toward the center. However, after the extrusion process, it was almost constant in the portion of Al 4004 material. Lots of big voids above 1 mm in diameter in the specimen existed in the interfacing region of Al 3003 and Al 4004 materials before the extrusion process. These big voids disappeared after the process of hydro co-extrusion.展开更多
Here,CuO nanorods fabricated via pulsed laser ablation in liquids were decorated with Ir,Pd,and Ru NPs(loading~7 wt%) through pulsed laser irradiation in the liquids process.The resulting NPs-decorated CuO nanorods we...Here,CuO nanorods fabricated via pulsed laser ablation in liquids were decorated with Ir,Pd,and Ru NPs(loading~7 wt%) through pulsed laser irradiation in the liquids process.The resulting NPs-decorated CuO nanorods were characterized spectroscopically and employed as multifunctional electrocatalysts in OER,HER,and the furfural oxidation reactions(FOR).Ir-CuO nanorods afford the lowest overpotential of~345 mV(HER) and 414 mV(OER) at 10 mA cm^(-2),provide the highest 2-furoic acid yield(~10.85 mM) with 64.9% selectivity,and the best Faradaic efficiency~72.7% in 2 h of FOR at 1.58 V(vs.RHE).In situ electrochemical-Raman analysis of the Ir-CuO detects the formation of the crucial intermediates,such as Cu(Ⅲ)-oxide,Cu(OH)_(2),and Ir_x(OH)_y,on the electrode-electrolyte surface,which act as a promoter for HER and OER.The Ir-CuO ‖ Ir-CuO in a coupled HER and FOR-electrolyzer operates at~200 mV lower voltage,compared with the conventional electrolyzer and embodies the dual advantage of energy-saving H_(2) and 2-furoic acid production.展开更多
The influence of the dehydration by metal oxides on the synthesis of dimethyl carbonate （DMC） via oxidative carbonylation of methanol was studied. A Cu/Y-zeolite catalyst was prepared by the ion exchange method from...The influence of the dehydration by metal oxides on the synthesis of dimethyl carbonate （DMC） via oxidative carbonylation of methanol was studied. A Cu/Y-zeolite catalyst was prepared by the ion exchange method from CuCl2.2H2O and the commercial NH4-form of the Y type zeolite, The catalyst was characterized by X-ray fluorescence （XRF）, N2 adsorption （BET method）, X-ray diffraction （XRD）, and temperature-programmed de- sorption of ammonia （NH3-TPD） to evaluate its Cu and Cl content, surface area, structure, and acidity. Reaction tests were carried out using an autoclave （batch reactor） for 18 h at 403 K and 5.5 MPa （2CH3OH ＋ 1/2O2 ＋ CO （CH3O）2CO ＋ H2O）. The influence of various dehydrating agents （ZnO, MgO, and CaO） was examined with the aim of increasing the methanol conversion （XMeOH, MeOH conversion）. The MeOH conversion increased upon addition of metal oxides in the order CaO 〉〉 MgO 〉 ZnO, with the DMC selectivity （SDMC） following the order MgO 〉 CaO 〉 ZnO. The catalysts and dehydrating agents were characterized before and after the oxidative carbonylation of methanol by thermogravimetric and differential thermogravimetric （TG/DTG）, and XRD to con- firm that the dehydration reaction occurred via the metal oxide （MO ＋ H2O →M（OH）2）. The MeOH conversion increased from 8.7% to 14.6% and DMC selectivity increased from 39.0% to 53.1%, when using the dehydrating azent CaO.展开更多
基金A grant from the National R&D Program for Cancer Control,Ministry of Health & Welfare,Republic of Korea,No.0520190-1
文摘AIM： To determine intestinal permeability, the serum tumor necrosis factor （TNF）-α level and urine nitric oxide （NO） metabolites are altered in liver cirrhosis （LC） with or without ascites. METHODS： Fifty-three patients with LC and 26 healthy control subjects were enrolled in the study. The intestinal permeability value is expressed as the percentage of polyethylene glycol （PEG） 400 and 3350 retrieval in 8-h urine samples as determined by high performance liquid chromatography. Serum TNF-α concentrations and urine NO metabolites were determined using an enzyme-linked immunosorbent assay （ELISA） and Greiss reaction method, respectively. RESULTS： The intestinal permeability index wassignificantly higher in patients with LC with ascites than in healthy control subjects or patients with LC without ascites （0.88 ± 0.12 vs 0.52 ± 0.05 or 0.53 ± 0.03, P 〈 0.05） and correlated with urine nitrite excretion （r = 0.98）. Interestingly, the serum TNF-α concentration was significantly higher in LC without ascites than in control subjects or in LC with ascites （198.9 ± 55.8 pg/mL vs 40.9 ± 12.3 pg/mL or 32.1 ± 13.3 pg/mL, P 〈 0.05）. Urine nitrite excretion was significantly higher in LC with ascites than in the control subjects or in LC without ascites（ 1170.9± 28.7 μmol/L vs 903.1 ± 55.1 μmol/L or 956.7 ± 47.7 μmol/L, P 〈 0.05）. COMCLUSIOM： Increased intestinal macromolecular permeability and NO is probably of importance in the pathophysiology and progression of LC with ascites, but the serum TNF-α concentration was not related to LC with ascites.
文摘AIM： To determine the accuracy of 1.5-T magnetic resonance imaging （MRI） in the evaluation of gastric wall invasion and perigastric lymph node metastasis in gastric adenocarcinoma.METHODS： Twenty resected gastric specimens containing 20 tumors were studied with a 1.5-T MR system using a commercial head surface coil. MR scanning was performed with a T1 weighted image （TR/TE = 500/20）, and a T2 weighted image （TR/TE = 2500/90）. MR findings were compared with pathologic findings.RESULTS： A T1-weighted image demonstrated three layers in the normal gastric wall. All of the gastric tumors were well demonstrated by lesions and location. In a MRI findings of gastric wall invasion, there was 1 case of T1, 7 of T2, 11 of T3. Pathologic results of resected specimens included 3 cases of pT1, 4 of pT2, and 12 of pT3. The accuracy of T staging with MRI was 74% （14 of 19）. MRI findings of lymph node metastasis included 6 cases of NO, 13 cases of N1. The accuracy of the N staging with MRI was 47% （9 of 19）.CONCLUSION： MRI has a high diagnostic accuracy in the evaluation of the T staging of gastric cancerin vitro and thus potentially enables preoperative histopathologic staging.
文摘As a new class of two-dimensional materials, two-dimensional (2D) heterostructures constructed from metal chalcogenides (MCs) have been gaining tremendous attention due to their unprecedented physical and chemical phenomena, mainly originated from their distinct structural features such as composition, architecture type, spatial arrangement of each component, crystal structure, exposed facet and interface, dimensionality in their heterostructures. Towards the realization of practical applications, synthetic approaches need a rational design with a variety of architecture types including laterally-combined, vertically-aligned, and conformally-coated 2D MC heterostructures. Among various synthetic routes, solution-based synthesis is thought of as an alternative to fabrication through high-cost setups since it can control those structural features in a cheap fashion. This review presents recent progress on solution-based synthesis to produce various 2D MC heterostructures with a focus on the synthetic fundamentals in terms of thermodynamic and kinetic aspects related to the growth mechanism. Four different synthetic approaches are reviewed: seeded growth, cation exchange reaction, colloidal atomic layer deposition, direct synthesis including one-step process and modified electrochemical method. We also provide some representative applications of 2D MC heterostructures and their hybrid composites in various fields including optoelectronics, thermoelectrics, catalysis, and battery. Finally, we offer an insight into challenges and future directions in a synthetic improvement of 2D MC heterostructures.
文摘Chronic activation of microglial cells endangers neuronal survival through the release of various proinflammatory and neurotoxic factors. The root of Paeonia lactiflora Pall has been considered useful for the treatment of various disorders in traditional oriental medicine. Paeonol, found in the root of Paeonia lactiflora Pall, has a wide range of pharmacological functions, including anti-oxidative, anti-inflammatory and neuroprotective activities. The objective of this study was to examine the efficacy of paeonol in the repression of inflammation-induced neurotoxicity and microglial cell activation. Organotypic hippocampal slice cultures and primary microglial cells from rat brain were stimulated with bacterial lipopolysaccharide. Paeonol pretreatment was performed for 30 minutes prior to lipopolysaccharide addition. Cell viability and nitrite （the production of nitric oxide）, tumor necrosis factor-alpha and interleukin-lbeta products were measured after lipopolysaccharide treatment. In organotypic hippocampal slice cultures, paeonol blocked lipopolysaccharide-related hippocampal cell death and inhibited the release of nitrite and interleukin-lbeta. Paeonol was effective in inhibiting nitric oxide release from primary microglial cells. It also reduced the lipopolysaccharide-stimulated release of tumor necrosis factor-alpha and intefleukin-1β from microglial cells. Paeonol possesses neuroprotective activity in a model of inflammation-induced neurotoxicity and reduces the release of neurotoxic and proinflammatory factors in activated microglial cells.
文摘The corrosion of metals can be induced by different environmental and operational conditions,and protecting metals from corrosion is a serious concern in many applicatiions.The developme nt of new materials and/or tech no logies to improve the efficie ncy of anti-corrosi on coati ngs has attracted ren ewed in terest.In this study,we develop a protective coati ng composed of a bilayer structure of reduced graphe ne oxide(RGO)/graphene oxide(GO)applied to Cu plates by spray-coating and subsequent annealing.The annealing of the GO/Cu plates at 120℃produces a bilayer structure of RGO/GO by the partial reducti on of the spray-coated GO layer.This in duces superior corrosion resista nee and adhesi on strength compared to those of GO/Cu and RGO/Cu plates because of the hydrophobic n ature of the RGO surface exposed to the surroundings and the formation of Cu-O bonds with the O-based functional groups of GO.This approach provides a viable and scalable route for using graphene coatings to protect metal surfaces from corrosion.
基金supported by a grant from Wonkwang Institute of Clinical Medicine in 2011
文摘Although electrical stimulation is therapeutically applied for neural regeneration in patients, it remains unclear how electrical stimulation exerts its effects at the molecular level on spinal cord injury （SCI）. To identify the signaling pathway involved in electrical stimulation improving the function of injured spinal cord, 21 female Sprague-Dawley rats were randomly assigned to three groups： control （no surgical intervention, n = 6）, SCI （SCI only, n = 5）, and electrical simulation （ES; SCI induction followed by ES treatment, n = 10）. A complete spinal cord transection was performed at the 10^th thoracic level. Electrical stimulation of the injured spinal cord region was applied for 4 hours per day for 7 days. On days 2 and 7 post SCI, the Touch-Test Sensory Evaluators and the Basso-Beattie-Bresnahan locomotor scale were used to evaluate rat sensory and motor function. Somatosensory-evoked potentials of the tibial nerve of a hind paw of the rat were measured to evaluate the electrophysiological function of injured spinal cord. Western blot analysis was performed to measure p38-RhoA and ERK1/2-Bcl-2 pathways related protein levels in the injured spinal cord. Rat sensory and motor functions were similar between SCI and ES groups. Com- pared with the SCI group, in the ES group, the latencies of the somatosensory-evoked potential of the tibial nerve of rats were significantly shortened, the amplitudes were significantly increased, RhoA protein level was significantly decreased, protein gene product 9.5 expression, ERK1/2, p38, and Bcl-2 protein levels in the spinal cord were significantly increased. These data suggest that ES can promote the recovery of electrophysiological function of the injured spinal cord through regulating p38-RhoA and ERK1/2-Bcl-2 pathway-related protein levels in the injured spinal cord.
基金the National Basic Research Program of China(973 Program Nos.2013CB932503 and 2014CB931900)National Natural Science Foundation of China(Nos.81172996,81373357,81422048 and 81361140344)
文摘Brain delivery of macromolecular therapeutics (e.g., proteins) remains an unsolved problem because of the formidable blood brain bather (BBB). Although a direct pathway of nose-to-brain transfer provides an answer to circumventing the BBB and has already been intensively investigated for brain delivery of small drugs, new challenges arise for intranasal delivery of proteins because of their larger size and hydrophilicity. h order to overcome the bathers and take advantage of available pathways (e.g., epithelial tight junctions, uptake by olfactory neurons, transport into brain tissues, and intra-brain diffusion), a low molecular weight protamine (LMWP) cell-penetrating peptide was utilized to facilitate nose-to-brain transport. Cell-penetrating peptides (CPP) have been widely used to mediate macromolecular delivery through many kinds of biobarriers. Our results show that conjugates of LMWP proteinsare able to effectively penetrate into the brain after intranasal administration. The CPP-based intranasal method highlights a promising solution for protein therapy of brain diseases. (C) 2016 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.
基金supported by the Korea Basic Science Institute(National research Facilities and Equipment Center)grant funded by the Ministry of Education(2019R1A6C1010042,2021R1A6C103A427)the financial support from the National Research Foundation of Korea(NRF)(2022R1A2C2010686,2022R1A4A3033528,2021R1I1A1A01060380,2021R1C1C2010726,2019H1D3A1A01071209)。
文摘The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and Cu_(2)O/Ni O/NF electrodes via in situ pulsed laser irradiation in liquids(PLIL)for the bifunctional electrocatalysis of oxygen evolution reaction(OER)and furfural oxidation reaction(FOR),respectively.Simultaneous oxidation of NF surface to NiO and deposition of CoO and/or Cu_(2)O on NF during PLIL offer distinct advantages for enhancing both the OER and FOR.CoO/NiO/NF electrocatalyst provides a consistently low overpotential of~359 m V(OER)at 10 m A/cm^(2),achieving the maximum FA yield(~16.37 m M)with 61.5%selectivity,79.5%carbon balance,and a remarkable Faradaic efficiency of~90.1%during 2 h of FOR at 1.43 V(vs.reversible hydrogen electrode).Mechanistic pathway via in situ electrochemical-Raman spectroscopy on CoO/NiO/NF reveals the involvement of phase transition intermediates(NiOOH and CoOOH)as surface-active centers during electrochemical oxidation.The carbonyl carbon in FF is attacked by hydroxyl groups to form unstable hydrates that subsequently undergo further oxidation to yield FA products.This method holds promise for large-scale applications,enabling simultaneous production of renewable building materials and fuel.
基金the Development of Sustainable Application for Standard Herbal Resource by the Korea Institute of Oriental Medicine (No. KSN2012320)。
文摘OBJECTIVE: To assess Atractylodis Rhizoma Alba extract(ARE) neuroprotective function in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-treated mice and related genes. METHODS: Examined m RNA-DNA methylation changes induced by ARE in MPTP-induced Parkinson's disease(PD) model's substantia nigra. RESULTS: ARE mitigated MPTP-induced motor impairment in rotarod and open field tests and preserved tyrosine hydroxylase-positive neuronal cells in substantia nigra and striatum. Genome RNA-Sequencing and Methyl-Sequencing in substantia nigra of vehicle/ARE-treated MPTP-induced PD mice showed 84 differentially expressed genes(DEGs) and 1804 differentially methylated regions(DMRs). Upregulated genes involved zinc ion homeostasis, cilium protein localization, and transcription;downregulated genes linked to ephrin receptor signaling, somitogenesis, and gene expression regulation. Hyper/hypomethylated DMRs post-ARE treatment associated with Wnt signaling, mitochondrial organization, dopamine biosynthesis, and hindbrain development. No significant correlation between DEGs and methylated genes related to PD pathogenesis. CONCLUSION: This research has identified the epigenetic targets of ARE's therapeutic action and gives insight on how ARE protects neurons in Parkinson's disease.
基金supported by the Korea Basic Science Institute(National research Facilities and Equipment Center)grant funded by the Ministry of Education(No.2019R1A6C1010042)the financial support from the National Research Foundation of Korea(NRF)(2022R1A2C2010686,2022R1A4A3033528,2021R1C1C2010726)。
文摘Herein,we propose a simple and rapid approach for synthesizing a CuS/Ru composite that serves as a bifunctional electrocatalyst to promote hydrogen production and concurrently convert sulfion into a value-added sulfur product.This composite comprises Ru nanoclusters supported on the CuS nanostructure,achieved through simple pulsed laser irradiation in liquid approach.The optimized CuS/Ru-30 electrocatalyst demonstrates remarkable bifunctional electrocatalytic activity,exhibiting a negligible working potential of 0.28 V(vs.RHE)for the anodic sulfion oxidation reaction(SOR)and a minimal overpotential of 182 m V for cathodic hydrogen evolution reaction(HER)to achieve 10 mA cm^(-2)of current density.Moreover,the Cu S/Ru-30 electrocatalyst shows exceptional selectivity for converting sulfion into valuable sulfur during anodic oxidation reactions.Remarkably,in a two-electrode electrolyzer system utilizing Cu S/Ru-30 as both the anode and cathode,the SOR+HER coupled water electrolysis system demands only 0.52 V to reach 10 mA cm^(-2),which is considerably lesser compared to the OER+HER coupled water electrolysis(1.85 V).The experimental results and density function theory(DFT)calculations reveal that the strong electron interaction between CuS and Ru nanoclusters generates a built-in electric field,greatly enhancing electron transfer efficiency.This significantly boosts the HER performance and facilitates the adsorption and production of sulfur intermediates.This study presents a rapid and simple strategy for synthesizing a dual-functional catalyst suitable for low-voltage hydrogen generation while facilitating the recovery of valuable sulfur sources.
基金Supported by Grant from the Samsung Medical Center Clinical Research Development Program,No. CRS108-12-1
文摘AIM： To assess the diagnostic performance of follow- up liver computed tomography （CT） for the detection of high-risk esophageal varices in patients treated with Io- coregional therapy for hepatocellular carcinoma （HCC）. METHODS： We prospectively enrolled 100 patients with cirrhosis who underwent transcatheter arterial chemoembolization, radiofrequency ablation or both procedures for HCCs. All patients underwent upper endoscopy and subsequently liver CT. Three radiolo- gists independently evaluated the presence of high-riskesophageal varices with transverse images alone and with three orthogonal multiplanar reformation （MPR） images, respectively. With endoscopic grading as the reference standard, diagnostic performance was as- sessed by using receiver operating characteristic （ROC） curve analysis. RESULTS： The diagnostic performances （areas under the ROC curve） of three observers with transverse im- ages alone were 0.947 ± 0.031, 0.969 ± 0.024, and 0.916 ＋ 0.038, respectively. The mean sensitivity, spec- ificity, positive predicative value （PPV）, and negative predicative value （NPV） with transverse images alone were 90.1%, 86.39%, 70.9%, and 95.9%, respectively. The diagnostic performances, mean sensitivity, specific- ity, PPV, and NPV with three orthogonal MPR images （0.965 ± 0.025, 0.959 ± 0.027, 0.938 ± 0.033, 91.4%, 89.5%, 76.3%, and 96.6%, respectively） were not su- perior to corresponding values with transverse images alone （P 〉 0.05）, except for the mean specificity （P = 0.039）. CONCLUSION： Our results showed excellent diagnos- tic performance, sensitivity and NPV to detect high-risk esophageal varices on follow-up liver CT after Iocore- gional therapy for HCC,
基金National Research Foundation of Korea,Grant/Award Numbers:2019H1D3A1A01071209,2021R1I1A1A01060380,2022R1A2C2010686,2022R1A4A3033528Korea Basic Science Institute,Grant/Award Numbers:2019R1A6C1010042,2021R1A6C103A427。
文摘We investigated the role of metal atomization and solvent decomposition into reductive species and carbon clusters in the phase formation of transition-metal carbides(TMCs;namely,Co_(3)C,Fe_(3)C,TiC,and MoC)by pulsed laser ablation of Co,Fe,Ti,and Mo metals in acetone.The interaction between carbon s-p-orbitals and metal d-orbitals causes a redistribution of valence structure through charge transfer,leading to the formation of surface defects as observed by X-ray photoelectron spectroscopy.These defects influence the evolved TMCs,making them effective for hydrogen and oxygen evolution reactions(HER and OER)in an alkaline medium.Co_(3)C with more oxygen affinity promoted CoO(OH)intermediates,and the electrochemical surface oxidation to Co_(3)O_(4)was captured via in situ/operando electrochemical Raman probes,increasing the number of active sites for OER activity.MoC with more d-vacancies exhibits strong hydrogen binding,promoting HER kinetics,whereas Fe_(3)C and TiC with more defect states to trap charge carriers may hinder both OER and HER activities.The results show that the assembled membrane-less electrolyzer with Co_(3)C∥Co_(3)C and MoC∥MoC electrodes requires~2.01 and 1.99 V,respectively,to deliver a 10 mA cm−2 with excellent electrochemical and structural stability.In addition,the ascertained pulsed laser synthesis mechanism and unit-cell packing relations will open up sustainable pathways for obtaining highly stable electrocatalysts for electrolyzers.
基金Supported by Innovative Research Institute for Cell Therapy,No.A062260Contract grant sponsor:National R&D Program for Cancer Control,Ministry of Health and Welfare,No.0920030+1 种基金Basic Science Research Program Through the National Research Foundation funded by the Ministry of Education,Science and Technology,No.20090080219Korea Healthcare Technology R&D Projects,Ministry for Health,Welfare and Family Affairs,Republic of Korea,No.A091001
文摘AIM:To track intravascularly transplanted mesenchymal stem cells (MSCs) labeled with superparamagnetic iron oxide (SPIO) by using magnetic resonance imaging (MRI) in an experimental rabbit model of hepatic failure.METHODS:Human MSCs labeled with FDA-approved SPIO particles (Feridex) were transplanted via the mes-enteric vein into rabbits (n=16) with carbon tetrachloride-induced hepatic failure.Magnetic resonance (MR) examinations were performed with a 3.0 T clinical scanner immediately before and 2 h and 1,3,and 7 d after transplantation.Signal intensity (SI) changes on T2weighted MRI were measured,and correlation between MR findings and histomorphologic findings was also investigated.RESULTS:SI on T2-weighted MRI decreased significantly in the liver 2 h after injection of human MSCs and returned gradually to the levels found before injection in 7 d.Changes in SI in the liver at 2 h,1,3,and 7 d were 41.87% ± 9.63%,10.42% ± 4.3%,5.12% ± 1.9%,3.75% ± 1.2%,respectively (P < 0.001).Histologic analyses confirmed the presence of MSCs in the liver,localized mainly in the sinusoids in early period (2 h and 1 d) and concentrated to the border zone in late period (3 and 7 d).The number of iron-positive cells in the liver at 2 h and on 1,3 and 7 d after transplantation was 29.2 ± 4.8,10.1 ± 3.7,6.7 ± 2.2,and 5.8 ± 2.1,respectively (P=0.013).CONCLUSION:Intravascularly injected SPIO-labeled MSCs in an experimental rabbit model of hepatic failure can be detected and followed with MRI.
基金Supported by the Korea Institute of Oriental Medicine:the Verification of Efficacy and Safety for Chung-bu Medicinal Materials Described in the Dong Ui Bo Gam (K18411)Applicational Development of Standardized Herbal Resources (KSN1911420)。
文摘OBJECTIVE: To investigate whether scorpion extract elicits a neuroprotective effect in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-treated mice models, and the genes associated with the therapeutic effects using RNA sequencing(seq)analysis.METHODS: This study investigated the changes in interaction between messenger ribonucleic acid(m RNA) expression and deoxyribonucleic acid(DNA) methylation related to the protective effects of scorpion extracts, in the substantia nigra(SN)region of a MPTP-induced Parkinson's disease(PD)model.RESULTS: In this model, scorpion extracts attenuated the motor impairment as demonstrated by the rotarod and open field tests. Scorpion extracts consistently attenuated the decrease of tyrosine hydroxylase(TH) positive neural cells in the SN and striatum of mice. We profiled genomewide DNA methylation using Methyl-Seq and measured the transcriptome using RNA-Seq in murine SN in the following groups: vehicle-treated MPTP-induced PD mice and scorpion extracttreated MPTP-induced PD mice. In total, 13 479 differentially expressed genes were identified in association with the anti-PD effect of the scorpion extract, mainly in the promoter and coding regions.Among them, 47 were negatively correlated downregulated genes. Nineteen genes out of 47 downregulated genes were negatively correlated with the expression of the other 28 genes. Among these genes, SGSM1 was related to dopaminergic neurons including dopamine transporters, TH, dihydroxyphenylalanine decarboxylase, and dopamine D2 receptor.CONCLUSION: This study provides insights into the anti-parkinsonian effects of scorpion extract and reveals the epigenetic targets in its therapeutic mechanism.
文摘Population studies have suggested an association between diabetes and the symptoms of testosterone deficiency. Recently, the expression of the androgen receptor （AR） has been shown to be decreased in diabetic patients. Furthermore, diabetes has been shown to induce global methylation. In this study, we used an animal model to investigate whether diabetes results in increased methylation of the AR promoter and whether these changes are associated with the decreased expression of AR in penile cavernosal smooth muscle tissue. Twenty C57BL/6J mice were divided into two groups, receiving either high- （mature diabetic） or low- （mature control） caloric meals for 14 weeks. Another 10 mice were killed at 1 week （young control）. Animals in the mature diabetic group showed decreased testosterone levels, although this was not statistically significant. In both control groups, no significant methylation was observed in the AR promoter region CpG island （-85 to ＋339）. In the mature diabetic group, significant methylation was observed at ＋ 185 and ＋200 of the AR promoter. These changes were associated with increased homeostatic model assessment for insulin resistance （HOMA-IR） and decreased corpus cavernosal tissue mass and expression of AR mRNA and protein. We conclude that in these animals, insulin resistance increased the methylation of the GC-rich regions of the AR promoter, leading to decreased AR expression.
基金the Basic Science Research Program of the National Research Foundation(NRF)of Korea(Nos.2019R1A6A1A11053838,2022R1A4A3033528,and 2022R1F1A1063285)Korea Agency for Infrastructure Technology Advancement(KAIA)funded by the Ministry of Land,Infrastructure,and Transport(No.21CTAP-C163795-01)Prof.M.Y.Choi acknowledges the Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Ministry of Education(Nos.2019R1A6C1010042 and 2021R1A6C103A427).
文摘The single-pot production of Pd@Pt core-shell structures is a promising approach as it offers large surface area,catalytic capability,and stability.In this work,we established a single-pot process to produce Pd@Pt core-shell nanodendrites with tunable composition,shape and size for optimal electrochemical activity.Pd@Pt nanodendrites with diverse compositions were synthesized by tuning the ratios of Pd and Pt sources in an aqueous environment using cetyltrimethylammonium chloride,which functioned as both the surfactant and the reducing agent at an elevated temperature(90°C).The synthesized Pd5@Pt5 nanodendrites showed exceptional electrochemical action toward the methanol oxidation reaction related with another compositional Pd@Pt nanodendrites and conventional Pt/C electrocatalysts.In addition,Pd5@Pt5 nanodendrites exhibited good CO tolerance owing to their surface features and the synergistic effect among Pt and Pd.Meanwhile,nanodendrites with a Pt-rich surface provided exceptional catalytic active sites.Compared with the conventional Pt/C electrocatalyst,the anodic peak current obtained by Pd5@Pt5 nanodendrites was 3.74 and 2.18 times higher in relations of mass and electrochemical active surface area-normalized current density,respectively.This approach offers an attractive strategy to design electrocatalysts with unique structures and outstanding catalytic performance and stability for electrochemical energy conversion.
基金supported by the project of Fundamental Materials Development funded by the Korean Ministry of Knowledge Economy
文摘The effects of hydro co-extrusion on the microstructure changes of aluminum hybrid duo-cast Al 3003/Al 4004 clad materials were studied. The specimen of duo-cast Al 3003/Al 4004 clad materials was in circle shape, and was composed of Al 3003(outside) and Al 4004(inside) materials. The specimen was extruded by the hydro co-extrusion equipment. The manufacturing conditions of the specimen were 423 K in temperature and 5 in extrusion ratio. The dimensions of the specimen were 80 mm in diameter of the Al 4004 material and 35 mm in thickness of the Al 3003 material before the hydro co-extrusion process, and 30 mm in diameter and about 5 mm in thickness after the extrusion process, respectively. The microstructure and the hardness for two specimens were investigated. The hardness value of cross section in the duo-cast Al 3003/Al 4004 clad materials before the extrusion process was increased in form of the parabola toward the center. However, after the extrusion process, it was almost constant in the portion of Al 4004 material. Lots of big voids above 1 mm in diameter in the specimen existed in the interfacing region of Al 3003 and Al 4004 materials before the extrusion process. These big voids disappeared after the process of hydro co-extrusion.
基金supported by the Korea Basic Science Institute (National research Facilities and Equipment Center) grant funded by the Ministry of Education. (2019R1A6C1010042, 2021R1A6C103A427)the financial support from the National Research Foundation of Korea (NRF), (2022R1A2C2010686, 2022R1A4A3033528, 2021R1I1A1A01060380, 2019H1D3A1A01071209)。
文摘Here,CuO nanorods fabricated via pulsed laser ablation in liquids were decorated with Ir,Pd,and Ru NPs(loading~7 wt%) through pulsed laser irradiation in the liquids process.The resulting NPs-decorated CuO nanorods were characterized spectroscopically and employed as multifunctional electrocatalysts in OER,HER,and the furfural oxidation reactions(FOR).Ir-CuO nanorods afford the lowest overpotential of~345 mV(HER) and 414 mV(OER) at 10 mA cm^(-2),provide the highest 2-furoic acid yield(~10.85 mM) with 64.9% selectivity,and the best Faradaic efficiency~72.7% in 2 h of FOR at 1.58 V(vs.RHE).In situ electrochemical-Raman analysis of the Ir-CuO detects the formation of the crucial intermediates,such as Cu(Ⅲ)-oxide,Cu(OH)_(2),and Ir_x(OH)_y,on the electrode-electrolyte surface,which act as a promoter for HER and OER.The Ir-CuO ‖ Ir-CuO in a coupled HER and FOR-electrolyzer operates at~200 mV lower voltage,compared with the conventional electrolyzer and embodies the dual advantage of energy-saving H_(2) and 2-furoic acid production.
文摘The influence of the dehydration by metal oxides on the synthesis of dimethyl carbonate （DMC） via oxidative carbonylation of methanol was studied. A Cu/Y-zeolite catalyst was prepared by the ion exchange method from CuCl2.2H2O and the commercial NH4-form of the Y type zeolite, The catalyst was characterized by X-ray fluorescence （XRF）, N2 adsorption （BET method）, X-ray diffraction （XRD）, and temperature-programmed de- sorption of ammonia （NH3-TPD） to evaluate its Cu and Cl content, surface area, structure, and acidity. Reaction tests were carried out using an autoclave （batch reactor） for 18 h at 403 K and 5.5 MPa （2CH3OH ＋ 1/2O2 ＋ CO （CH3O）2CO ＋ H2O）. The influence of various dehydrating agents （ZnO, MgO, and CaO） was examined with the aim of increasing the methanol conversion （XMeOH, MeOH conversion）. The MeOH conversion increased upon addition of metal oxides in the order CaO 〉〉 MgO 〉 ZnO, with the DMC selectivity （SDMC） following the order MgO 〉 CaO 〉 ZnO. The catalysts and dehydrating agents were characterized before and after the oxidative carbonylation of methanol by thermogravimetric and differential thermogravimetric （TG/DTG）, and XRD to con- firm that the dehydration reaction occurred via the metal oxide （MO ＋ H2O →M（OH）2）. The MeOH conversion increased from 8.7% to 14.6% and DMC selectivity increased from 39.0% to 53.1%, when using the dehydrating azent CaO.
