ABSTRACT
Direct ethanol fuel cell (DEFC) has attracted wide attention due to its wide range of fuel sources, cleanliness, and high efficiency. However, the problems of low catalytic efficiency and poor catalyst stability still exist in DEFC catalysts, which restrict its rapid development. With chloroplatinic acid (H2PtCl6·6H2O) as the precursor, Polyvinylpyrrolidone (PVP) plays the role of surfactant, stabilizer, and reducing agent in the experiment. Glycine is the surface control agent and co-reducing agent. Pt high-index facets nanocatalyst was prepared with the one-pot hydrothermal method by adjusting the amount of PVP and glycine. X-Ray Diffraction (XRD), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize the micro-structure of the nanocatalyst, and the influence of PVP and glycine on the synthesis of high-index facets catalyst was studied. The electrocatalytic performance of the catalyst was tested with an electrochemical workstation, and it was found that the performance of the prepared catalyst was better than that of the commercial catalyst. When the mass ratio of PVP and Pt was 50:1 and the molar ratio of glycine and Pt was 24:1, Pt nanocatalysts with {310}, {520} and {830} high exponential facets were prepared. The electrochemical test results showed that the peak current density of ethanol oxidation was 2.194 m2/g, and the steady-state current density was 0.241 mA/cm2, which was 5.7 times higher than that of commercial catalyst. The results of this paper show that due to the defects such as steps and kinks on the surface of the high-index facets, the active sites are increased, thus showing excellent electrocatalytic performance. This study provides a theoretical basis for the development and commercial application of high index facets nanocatalysts.
ABSTRACT
Although the electrochemical production of hydrogen has been considered as a promising strategy to obtain the sustainable resources, the sluggish kinetics of anodic oxygen evolution reaction (OER) hindered the sustainable energy development. Herein, we design mesoporous cobalt ferrite phosphides hybridized on reduced graphene oxide (rGO) as a highly efficient bifunctional catalyst through a simple nanocasting method. The hybrid catalyst possesses the abundant interface, which provides the large active sites, as well as the hybrid rGO accelerates the electron exchange and ion diffusion. Moreover, the mesoporous structure not only prevents the aggregation of actives sites, but also benefits for the rapid escape of bubbles during catalytical process, which can significantly improve the catalytic performance. Consequently, the resulting mCo0.5Fe0.5P/rGO shows superior catalytic performance with a low overpotential of 250 mV at a current density of 10 mA cm-2 for OER and outstanding long-term stability. More importantly, an electrolyzer with mCo0.5Fe0.5P/rGO as both anode and cathode catalysts shows a low voltage of 1.66 V to afford a current density of 10 mA cm-2. This work offers a new route for designing the highly efficient OER and overall water splitting electrocatalysts.
ABSTRACT
BACKGROUND: MicroRNAs (miRNAs) play a key role in mediating the action of insulin on cell growth and the development of diabetes. However, few studies have been conducted to provide a comprehensive overview of the miRNA-mediated signaling network in response to glucose in pancreatic beta cells. In our study, we established a computational framework integrating multi-omics profiles analyses, including RNA sequencing (RNA-seq) and small RNA sequencing (sRNA-seq) data analysis, inverse expression pattern analysis, public data integration, and miRNA targets prediction to illustrate the miRNA-mediated regulatory network at different glucose concentrations in INS-1 pancreatic beta cells (INS-1), which display important characteristics of the pancreatic beta cells. RESULTS: We applied our computational framework to the expression profiles of miRNA/mRNA of INS-1, at different glucose concentrations. A total of 1437 differentially expressed genes (DEGs) and 153 differentially expressed miRNAs (DEmiRs) were identified from multi-omics profiles. In particular, 121 DEmiRs putatively regulated a total of 237 DEGs involved in glucose metabolism, fatty acid oxidation, ion channels, exocytosis, homeostasis, and insulin gene regulation. Moreover, Argonaute 2 immunoprecipitation sequencing, qRT-PCR, and luciferase assay identified Crem, Fn1, and Stc1 are direct targets of miR-146b and elucidated that miR-146b acted as a potential regulator and promising target to understand the insulin signaling network. CONCLUSIONS: In this study, the integration of experimentally verified data with system biology framework extracts the miRNA network for exploring potential insulin-associated miRNA and their target genes. The findings offer a potentially significant effect on the understanding of miRNA-mediated insulin signaling network in the development and progression of pancreatic diabetes.
Subject(s)
Gene Expression Regulation/genetics , Gene Regulatory Networks/genetics , Insulin/metabolism , MicroRNAs/genetics , Humans , Signal TransductionABSTRACT
Controllable synthesis and rational design of ordered nanostructures are crucial for their renewable energy applications. In this work, a mesoporous CoP/Fe2 P doped with 5 % Ce by a simple nanocasting method is designed as a superior electrocatalyst for the oxygen evolution reaction (OER). The well-designed composite delivers an efficient electrocatalytic activity with a low overpotential of 250â mV at 10â mA cm-2 and excellent long-term stability with no degradation after 10â h of electrochemical OER test, superior to that of the state-of-the-art RuO2 electrocatalyst in alkaline electrolyte. A comprehensive analysis demonstrates that the outstanding OER performance is due to the desirable combination of the highly exposed active centers in the Ce-doped bimetallic phosphides, efficient mass transfer, and effective electron conduction owing to the hierarchically mesoporous hybridization. Furthermore, the synergistic effect between Ce and CoP/Fe2 P accelerates the migration rate of electrons/ions and increases the electrochemical active area. This excellent OER performance observed by Ce doping of CoP/Fe2 P makes them possible candidates toward OER in alkaline electrolytes.
ABSTRACT
Healing of the chronic diabetic ulceration and large burns remains a clinical challenge. Therapeutic fasting has been shown to improve health. Our study tested whether fasting facilitates diabetic and burn wound healing and explored the underlying mechanism. Methods: The effects of fasting on diabetic and burn wound healing were evaluated by analyzing the rates of wound closure, re-epithelialization, scar formation, collagen deposition, skin cell proliferation and neovascularization using histological analyses and immunostaining. In vitro functional assays were conducted to assess fasting and refeeding on the angiogenic activities of endothelial cells. Transcriptome sequencing was employed to identify the differentially expressed genes in endothelial cells after fasting treatment and the role of the candidate genes in the fasting-induced promotion of angiogenesis was demonstrated. Results: Two times of 24-h fasting in a week after but especially before wound injury efficiently induced faster wound closure, better epidermal and dermal regeneration, less scar formation and higher level of angiogenesis in mice with diabetic or burn wounds. In vitro, fasting alone by serum deprivation did not increase, but rather reduced the abilities of endothelial cell to proliferate, migrate and form vessel-like tubes. However, subsequent refeeding did not merely rescue, but further augmented the angiogenic activities of endothelial cells. Transcriptome sequencing revealed that fasting itself, but not the following refeeding, induced a prominent upregulation of a variety of pro-angiogenic genes, including SMOC1 (SPARC related modular calcium binding 1) and SCG2 (secretogranin II). Immunofluorescent staining confirmed the increase of SMOC1 and SCG2 expression in both diabetic and burn wounds after fasting treatment. When the expression of SMOC1 or SCG2 was down-regulated, the fasting/refeeding-induced pro-angiogenic effects were markedly attenuated. Conclusion: This study suggests that fasting combined with refeeding, but not fasting solely, enhance endothelial angiogenesis through the activation of SMOC1 and SCG2, thus facilitating neovascularization and rapid wound healing.
Subject(s)
Diabetes Mellitus, Experimental/diet therapy , Fasting , Neovascularization, Physiologic , Osteonectin/metabolism , Re-Epithelialization , Secretogranin II/metabolism , Animals , Burns/therapy , Cell Line , Cell Proliferation , Cicatrix/metabolism , Endothelial Cells , Humans , Male , Mice , Mice, Inbred C57BL , Skin/metabolism , Skin/pathologyABSTRACT
Rational construction of MnCo2O4-based core-shell nanomaterials with distinctive and desirable architectures possesses great potential in the advanced electrode material of high-performance supercapacitors. Here, a new class of hierarchical core-shell nanowire arrays (NWAs) with a shell of NiWO4 nanoparticles and a core of MnCo2O4 nanowires is reported, which can significantly improve the electrochemical energy storage properties of supercapacitors. The unique core-shell structure endows the MnCo2O4@NiWO4 NWAs electrode with a high areal specific capacitance of 5.09 F cm-2 at a current density of 1 mA cm-2 and a superior cyclic retention of 96% after 5000 charge-discharge cycles, which are more preferable than those of MnCo2O4 NWAs electrode. More importantly, an aqueous electrochemical energy storage device (core-shell MnCo2O4@NiWO4 NWAs as the positive electrode and active carbon as the negative electrode, MnCo2O4@NiWO4//AC ASC) was assembled and shows a high energy density of 0.23 mWh cm-2 at a power density of 2.66 mW cm-2, and 0.09 mWh cm-2 at 16.00 mW cm-2, indicating hopeful potential for practical applications. This work highlights the significance of NiWO4 as a shell for hierarchical core-shell nanostructures, which can further improve the electron transport characteristic of the electrode material, thereby achieving performance breakthroughs in energy storage devices.
ABSTRACT
Accurate and sensitive detection of dopamine (DA) is fundamental to monitor and diagnose certain neurological diseases. Herein, highly ordered mesoporous ZnFe2O4 (OM-ZnFe2O4) is prepared via a facile nanocasting method and shows the highly sensitive in the electrochemical detection of DA. The optimized OM-ZnFe2O4-40 shows the most excellent activity for DA oxidation in a wide linear range from 2 to 600â¯nM with a quick response time of 5â¯s, high sensitivity of 0.094â¯nAâ¯nM-1 and a lower detection limit of 0.4â¯nMâ¯(S/Nâ¯=â¯3). The electrode modified with OM-ZnFe2O4 is further successfully used to monitor the increase of DA concentration induced by K+-stimulation of living PC12â¯cells in a neurological environment. This work offers a simple and powerful strategy for designing electrodes for detecting DA in biological systems.
Subject(s)
Dopamine/analysis , Electrochemical Techniques/instrumentation , Ferric Compounds/chemistry , Zinc Compounds/chemistry , Animals , Electrochemical Techniques/methods , Equipment Design , Limit of Detection , PC12 Cells , Porosity , RatsABSTRACT
The dysbiosis of human gut microbiota is strongly associated with the development of colorectal cancer (CRC). The dysbiotic features of the transition from advanced polyp to early-stage CRC are largely unknown. We performed a 16S rRNA gene sequencing and enterotype-based gut microbiota analysis study. In addition to Bacteroides- and Prevotella-dominated enterotypes, we identified an Escherichia-dominated enterotype. We found that the dysbiotic features of CRC were dissimilar in overall samples and especially Escherichia-dominated enterotype. Besides a higher abundance of Fusobacterium, Enterococcus, and Aeromonas in all CRC faecal microbiota, we found that the most notable characteristic of CRC faecal microbiota was a decreased abundance of potential beneficial butyrate-producing bacteria. Notably, Oscillospira was depleted in the transition from advanced adenoma to stage 0 CRC, whereas Haemophilus was depleted in the transition from stage 0 to early-stage CRC. We further identified 7 different CAGs by analysing bacterial clusters. The abundance of microbiota in cluster 3 significantly increased in the CRC group, whereas that of cluster 5 decreased. The abundance of both cluster 5 and cluster 7 decreased in the Escherichia-dominated enterotype of the CRC group. We present the first enterotype-based faecal microbiota analysis. The gut microbiota of colorectal neoplasms can be influenced by its enterotype.
Subject(s)
Adenoma/microbiology , Colorectal Neoplasms/microbiology , Gastrointestinal Microbiome , Adenoma/pathology , Aeromonas/genetics , Aeromonas/pathogenicity , Aged , Bacteroidaceae/genetics , Bacteroidaceae/pathogenicity , Colorectal Neoplasms/pathology , Enterococcus/genetics , Enterococcus/pathogenicity , Escherichia/genetics , Escherichia/pathogenicity , Female , Fusobacterium/genetics , Fusobacterium/pathogenicity , Haemophilus/genetics , Haemophilus/pathogenicity , Humans , Male , Middle Aged , RNA, Ribosomal, 16S/geneticsABSTRACT
Dopamine (DA) detection is significant for the prevention of unfavorable neuronal illness. However, the detection of DA with low concentration still face tremendous challenges. In this study, highly ordered mesoporous Fe3O4 materials were synthesized as a biosensor by using mesoporous silica KIT-6 with different aging temperature as hard template. The ordered mesoporous Fe3O4 with high surface area modified glassy carbon electrode shows the high sensitivity for detecting DA. Fe3O4-40 mesoporous material modified electrode has the highest catalytic activity to DA with a sensitivity of 0.053â¯nAâ¯nM-1 and a detection limit of 0.8â¯nM (S/Nâ¯=â¯3). The results indicating that the mesoporous Fe3O4 material modified electrode exhibits high sensitivity to determine DA at low levels, which can be used for DA real-time monitoring in neutral biological media.
Subject(s)
Biosensing Techniques/methods , Dopamine/analysis , Ferrosoferric Oxide/chemistry , Animals , Biosensing Techniques/instrumentation , Carbon/chemistry , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Electrodes , Ferrosoferric Oxide/chemical synthesis , Limit of Detection , PC12 Cells , Porosity , Rats , Silicon Dioxide/chemistryABSTRACT
The ubiquitous and emerging physiology function of endogenous nitric oxide in vascular, myocardial, immune, and neuronal systems prompts chemists to develop a prodrug for the controlled delivery of ·NO in vivo and for the translational biomedical application. Inspired by the discovery of natural [Fe(NO)2] motif, herein, we develop the synthetic dinitrosyl iron complexes (DNICs) [Fe2(µ-SR)2(NO)4] (1) as a universal platform for the O2-triggered release of ·NO, for the regulation of ·NO-release kinetics (half-life = 0.6-27.4 h), and for the activation of physiological function of ·NO. Using C. elegans as a model organism, the ·NO-delivery DNIC 1 regulates IIS signaling pathway, AMPK signaling pathway, and mitochondrial function pathway to extend the lifespan and to delay the aging process based on the lifespan analysis, SA-ßgal activity assay, and next-generation RNA sequencing analysis. This study unveils the anti-aging effect of ·NO and develops DNICs as a chemical biology probe for the continued discovery of unprecedented NO physiology.
Subject(s)
Caenorhabditis elegans/physiology , Iron/chemistry , Longevity , Nitric Oxide/administration & dosage , Nitrogen Oxides/chemistry , Adenylate Kinase/metabolism , Animals , Caenorhabditis elegans/genetics , Half-Life , Kinetics , Molecular Structure , Nitric Oxide/chemistry , Sequence Analysis, RNA , Signal Transduction , Spectrum Analysis/methodsABSTRACT
Elevated serum haptoglobin (Hp) is identified as a prognostic marker in multiple types of solid tumors, which is correlated with poor prognosis. HCC is one of the major causes of cancer deaths in worldwide, which remains poor prognosis and is clinically urgent for discovering early diagnostic markers. However, except for serum Hp, the correlation of tumor Hp expression with hepatocellular carcinoma (HCC) progression is still unclear. In this study, we evaluated and identified the tissue Hp expression as a prognostic marker to predict the survival rate of HCC patients. To evaluate the prognostic value of Hp expression for HCC, two cohorts were enrolled in our study, including total 130 matched pair tissue sections (both adjacent non-tumorous and tumor tissue derived from same patient) of HCC patients from Changhua Christian Hospital (CCH) and total 316 RNA-seq data with clinical information of HCC patients from The Cancer Genome Atlas (TCGA) database. In contrast to other types of cancers, HCC tumor tissues have lower Hp protein expression in CCH cohort and have lower Hp mRNA expression in TCGA cohort as compared with adjacent non-tumorous tissues (p < 0.001). Moreover, lower Hp expression is significantly correlated with different stages of HCC cancer differentiation in CCH cohort (one-way ANOVA, p < 0.001). Most importantly, lower Hp expression is highly correlated with poor five-year overall survival rate in TCGA cohort (p < 0.01). Based on our data, we conclude that tissue Hp expression positively correlates with better HCC tumor differentiation and increased five-year overall survival rate of HCC patients. The results indicated that tissue Hp is potentially a prognostic marker for HCC patients. Our findings may further provide a new insight of effective treatments along with biopsy diagnosis of HCC patients.
Subject(s)
Biomarkers, Tumor , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/mortality , Gene Expression , Haptoglobins/genetics , Liver Neoplasms/genetics , Liver Neoplasms/mortality , Aged , Carcinoma, Hepatocellular/pathology , Female , Gene Expression Profiling , Haptoglobins/metabolism , High-Throughput Nucleotide Sequencing , Humans , Immunohistochemistry , Liver Neoplasms/pathology , Male , Middle Aged , Neoplasm Grading , Neoplasm Staging , PrognosisABSTRACT
The materials of Ni nanoparticles/carbon nanofibers (Ni NPs/CNFs) and carbon nanofibers (CNFs) were prepared by electrospinning the Ni doped precursor solutions. The Ni doped nanofibers with the diameter of 200-300 nm possess the uniform morphology and smooth surface. These nanofibers were carbonized at 600 degrees C for 2 h. The Ni NPs/CNFs composite was characterized with SEM (scanning electro microscope), XRD (X-ray diffraction) and FT-IR (Infrared spectroscopy). The Ni NPs/CNFs electrode was investigated through the cyclic voltammetry measurement. The average specific capacity was calculated to be 113 F x g(-1) at the scan rate of 2 mV x s(-1). The high specific capacity was larger than the CNFs owing to the Ni NPs. The specific capacity retention also maintains 72% after 5 cycles, suggesting that the electrode possess good reversibility. The Ni NPs/CNFs composite material with excellent electrochemical properties will be a promising material which can be used for energy storage.
ABSTRACT
A simple one-step solution-phase synthesis of cobalt phosphide nanorods (NRs) and hollow nanoparticles (NPs) has been reported in this paper. The phase and morphology evolutions of cobalt phosphide were researched by varying the reaction conditions. The detailed research confirms that oleylamine (OAm) in the reaction firstly reduces Co(acac)2 to the Co phase and the reaction between P atoms from TOP and Co atoms results in the Co2P phase. The as-synthesized NRs and NPs show superparamagnetic behavior at room temperature and ferromagnetic properties at 2 K. The current route provides a new and general chemical method for tunable preparation of cobalt phosphide nanostructures, which are important for further magnetic and catalytic studies.
ABSTRACT
In an attempt to test Kandell's proposition that internet dependents used the internet as a coping mechanism against underlying psychological issues, this study investigated the extent to which the fifth and sixth Eriksonian crises (identity, intimacy), were related to internet dependence (online chatting, gaming) among college students. Students spending more than 10 hours per week on chatting/gaming were classified as dependents. On the basis of a national sample of freshmen in Taiwan, this study found that the dependents scored significantly lower on most of the measures that reflected the successful resolution of the crises, and higher on the measures that reflected unsuccessful resolution of the crises. Kandell's proposition was supported.