ABSTRACT
Developing highly active electrocatalysts is crucial for the application of electrocatalytic water splitting. In this study, we prepared vanadium oxide-graphene carbon nanocomposites (VxOy/C) with abundant defects using a carbon- and oxygen-rich hexavanadate derivative Na2[V6O7{(OCH2)3CCH3}4] as a precursor without the addition of an extra carbon source. Subsequently, the VxOy/C was used as a catalyst support to load a small amount of Ir, forming the Ir/VxOy/C nanoelectrocatalyst. This catalyst exhibited low hydrogen evolution overpotentials of only 18.90 and 13.46 mV at a working current density of 10 mA cm-2 in 1.0 M KOH and 0.5 M H2SO4 electrolyte systems, outperforming the commercial Pt/C catalysts. Additionally, the catalyst showed excellent chemical stability and long-term durability. This work provides a new strategy for the design and synthesis of highly active electrocatalysts for water splitting.
ABSTRACT
To explore, highly active electrocatalysts are essential for water splitting materials. Polyoxometalates (POMs) have drawn interesting attention in recent years due to their abundant structure and unique electrocatalytic properties. In this study, by using a POM-based precursor Co2Mo10, novel bimetallic sulfide (CoS2-MoS2) nanocomposites are rationally designed and synthesized under hydrothermal conditions. The incorporation of Co2+ to the host electrocatalyst could effectively increase the exposure of active sites of MoS2. Compared to pure MoS2, the CoS2-MoS2 nanocomposite exhibited a perfect hydrogen evolution reaction (HER) ability, for it merely requires overpotentials of 120 and 153 mV for 10 mA cm-2 working current density toward the HER in 1 M KOH and 0.5 M H2SO4 electrolyte systems, respectively. Additionally, the nanocomposite exhibited outstanding chemical stability and long-term durability. This study presents a novel strategy that utilizes POMs to enrich the exposed edge sites of MoS2, resulting in the preparation of efficient electrocatalysts.
ABSTRACT
Developing inexpensive, efficient, and stable catalysts is crucial for reducing the cost of electrolytic hydrogen production. Recently, polyoxometalates (POMs) have gained attention and widespread use due to their excellent electrocatalytic properties. This study designed and synthesized three composite materials, NF/PMonW12-n, by using phosphomolybdic-tungstic heteropolyacids as precursors to grow in situ on nickel foam via the hydrothermal process and subsequent calcination. Then, their catalytic performances are systematically investigated. This work demonstrates that the NF/PMonW12-n catalysts generate more low valent oxides under the synergistic effect of Mo and W, further enhancing activity for hydrogen evolution reaction (HER). Among these electrocatalysts, NF/PMo6W6 exhibits the perfect HER performance, η10 is only 74 mV. It also shows great stability during long-term electrolysis. The current study introduces a fresh approach for producing electrocatalysts that are both cost-effective and highly efficient.
ABSTRACT
Polyoxometalates (POMs) are promising inorganic drug candidates for cancer chemotherapy. They are becoming attractive because of their easy accessibility and low cost. Herein, we report the synthesis and antitumor activity studies of four Lindqvist-type POMs with mixed-addenda atoms Na2[V4W2O16{(OCH2)3CR}] (R=-CH2OH, -CH3, -CH2CH3) and (Bu4N)2[V3W3{(OCH2)3CH2OOCCH2CH3}]. Compared with the current clinical applied antitumor drug 5-fluorouracil (5-FU) or Gemcitabine, analysis of MTT/CCK-8 assay, colony formation and wound healing assay revealed that the {V4W2} POMs had acceptable cytotoxicity in normal cells (293T) and significant inhibitory effects on cell proliferation and migration in three human tumor cell lines: human lung carcinoma cells (A549), human cervical carcinoma cells (HeLa), and human breast cancer cells (MCF-7). Interestingly, among the POMs analyzed, the therapeutic index (TI) of the {V4W2} POM with R= -CH2OH was relatively the most satisfactory. Thus, it was subsequently used for further studies. Flow cytometry analysis showed it prompted cellular apoptosis rate. qRT-PCR and Western blotting analysis indicated that multiple cell death pathways were activated including apoptosis, autophagy, necroptosis and pyroptosis during the POM-mediated antitumor process. In conclusion, our study shows that the polyoxotungstovanadate has great potential to be developed into a broad-spectrum antitumor chemotherapeutic drug.
Subject(s)
Antineoplastic Agents , Carcinoma , Humans , Antineoplastic Agents/pharmacology , Fluorouracil/pharmacology , Fluorouracil/therapeutic use , Apoptosis , Cell Line, Tumor , Cell Proliferation , Carcinoma/drug therapyABSTRACT
Ammonia (NH3 ) is a promising hydrogen (H2 ) carrier for future carbon-free energy systems, due to its high hydrogen content and easiness to be liquefied. Inexpensive and efficient catalysts for ammonia electro-oxidation reaction (AOR) are desired in whole ammonia-based energy systems. In this work, ultrasmall delafossite (CuFeO2 ) polyhedrons with exposed high-index facets are prepared by a one-step NH3 -assisted hydrothermal method, serving as AOR pre-catalysts. The high-index CuFeO2 facet is revealed to facilitate surface reconstruction into active Cu-doped FeOOH nanolayers during AOR processes in ammonia alkaline solutions, which is driven by the favorable Cu leaching and terminates as the 2p levels of internal lattice oxygen change. The reconstructed heterostructures of CuFeO2 and Cu-doped FeOOH effectively activate the dehydrogenation steps of NH3 and exhibit a potential improvement of 260 mV for electrocatalytic AOR at 10 mA cm-2 compared to the pre-restructured phase. Further, density functional theory (DFT) calculations confirm that a lower energy barrier of the rate-determining step (*NH3 to *NH2 ) is presented on high-index CuFeO2 facets covered with Cu-doped FeOOH nanolayers. Innovatively, lattice oxygen atoms in Fe-based oxides and oxyhydroxide are involved in the dehydrogenation steps of AOR as a proton acceptor, broadening the horizons for rational designs of AOR catalysts.
ABSTRACT
The electrocatalytic nitrogen reduction reaction (NRR) to synthesize NH3 under ambient conditions is a promising alternative route to the conventional Haber-Bosch process, but it is still a great challenge to develop electrocatalysts' high Faraday efficiency and ammonia yield. Herein, a facile and efficient exfoliation strategy to synthesize ultrathin 2D boron and nitrogen co-doped porous carbon nanosheets (B/NC NS) via a metal-organic framework (MOF)-derived van der Waals superstructure, is reported. The results of experiments and theoretical calculations show that the doping of boron and nitrogen can modulate the electronic structure of the adjacent carbon atoms; which thus, promotes the competitive adsorption of nitrogen and reduces the energy required for ammonia synthesis. The B/NC NS exhibits excellent catalytic performance and stability in electrocatalytic NRR, with a yield rate of 153.4 µg·h-1 ·mg-1 cat and a Faraday efficiency of 33.1%, which is better than most of the reported NRR electrocatalysts. The ammonia yield of B/NC NS can maintain 92.7% of the initial NRR activity after 48 h stability test. The authors' controllable exfoliation strategy using MOF-derived van der Waals superstructure can provide a new insight for the synthesis of other 2D materials.
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Pseudouridine synthase 7 (PUS7) may play key roles in cancer development. However, few studies have been conducted in this area. In the present study, we explored the function and potential mechanisms of PUS7 in colorectal cancer (CRC) progression. We found that PUS7 had higher expression in CRC tissues and cell lines. Clinically, high expression of PUS7 was associated with an unfavorable prognosis for CRC patients. Functionally, knockdown of PUS7 suppressed the proliferation of CRC cells in vitro and inhibited tumorigenicity in vivo. Mechanistically, RNA sequencing and coimmunoprecipitation (Co-IP) indicated that PUS7 exhibited oncogenic functions through the interaction of Sirtuin 1 (SIRT1) and activated the Wnt/ß-catenin signaling pathway. Thus, our findings suggest that PUS7 promotes the proliferation of CRC cells by directly stabilizing SIRT1 to activate the Wnt/ß-catenin pathway.
Subject(s)
Colorectal Neoplasms , Intramolecular Transferases , Sirtuin 1 , Wnt Signaling Pathway , Humans , beta Catenin/genetics , beta Catenin/metabolism , Cell Line, Tumor , Cell Movement , Cell Proliferation/genetics , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Gene Expression Regulation, Neoplastic , Sirtuin 1/genetics , Sirtuin 1/metabolism , Wnt Signaling Pathway/genetics , Intramolecular Transferases/genetics , Intramolecular Transferases/metabolismABSTRACT
The emerging edge computing paradigm has given rise to a new promising mobile network architecture, which can address a number of challenges that the operators are facing while trying to support growing end user's needs by shifting the computation from the base station to the edge cloud computing facilities. With such powerfully computational power, traditional unpractical resource allocation algorithms could be feasible. However, even with near optimal algorithms, the allocation result could still be far from optimal due to the inaccurate modeling of interference among sensor nodes. Such a dilemma calls for a measurement data-driven resource allocation to improve the total capacity. Meanwhile, the measurement process of inter-nodes' interference could be tedious, time-consuming and have low accuracy, which further compromise the benefits brought by the edge computing paradigm. To this end, we propose a measurement-based estimation solution to obtain the interference efficiently and intelligently by dynamically controlling the measurement and estimation through an accuracy-driven model. Basically, the measurement cost is reduced through the link similarity model and the channel derivation model. Compared to the exhausting measurement method, it can significantly reduce the time cost to the linear order of the network size with guaranteed accuracy through measurement scheduling and the accuracy control process, which could also balance the tradeoff between accuracy and measurement overhead. Extensive experiments based on real data traces are conducted to show the efficiency of the proposed solutions.
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We successfully employed bisphenol A and several different formyl-containing monomers as useful building blocks to construct a series of hydroxy-group-containing porous organic polymers in a sealed tube at high temperature. Fourier transform infrared and solid-state 13C CP/MAS NMR spectroscopy are utilized to characterize the possible structure of the obtained polymers. The highest Brunauer-Emmet-Teller specific surface area of the phenolic-resin porous organic polymers (PPOPs) is estimated to be 920 m2 g-1. The PPOPs exhibit a highest carbon dioxide uptake (up to 15.0 wt % (273 K) and 8.8 wt % (298 K) at 1.0 bar), and possess moderate hydrogen storage capacities ranging from 1.28 to 1.04 wt % (77 K) at 1.0 bar. Moreover, the highest uptake of methane for the PPOPs is measured as 4.3 wt % (273 K) at 1.0 bar.
ABSTRACT
Facile preparation of microporous conjugated polycarbazoles via carbazole-based oxidative coupling polymerization is reported. The process to form the polymer network has cost-effective advantages such as using a cheap catalyst, mild reaction conditions, and requiring a single monomer. Because no other functional groups such as halo groups, boric acid, and alkyne are required for coupling polymerization, properties derived from monomers are likely to be fully retained and structures of final polymers are easier to characterize. A series of microporous conjugated polycarbazoles (CPOP-2-7) with permanent porosity are synthesized using versatile carbazolyl-bearing 2D and 3D conjugated core structures with non-planar rigid conformation as building units. The Brunauer-Emmett-Teller specific surface area values for these porous materials vary between 510 and 1430 m(2) g(-1) . The dominant pore sizes of the polymers based on the different building blocks are located between 0.59 and 0.66 nm. Gas (H2 and CO2 ) adsorption isotherms show that CPOP-7 exhibits the best uptake capacity for hydrogen (1.51 wt% at 1.0 bar and 77 K) and carbon dioxide (13.2 wt% at 1.0 bar and 273 K) among the obtained polymers. Furthermore, its high CH4 /N2 and CO2 /N2 adsorption selectivity gives polymer CPOP-7 potential application in gas separation.
ABSTRACT
Periplocoside NW (PSNW) with pregnane glycoside skeleton is a novel insecticidal compound isolated from the root bark of Periploca sepium Bunge. This compound has a potent stomach poisoning activity against several insect pests. In this study, we observed the intoxication symptoms, investigated the histopathological effects and carried out immuno-electron microscopic localization of PSNW on the midgut epithelium of oriental armyworm Mythimna separata Walker larvae for better understanding its action mechanism against insects. Ultrastructural observations showed that cell damages caused by PSNW in the midgut of M. separata larvae are related to the degeneration of brush border microvilli. The dissolution of cytoskeletal structures in the interior and on the surface of microvilli was responsible for the decrease in size and eventual disappearance of microvilli when bubbles of cytoplasmic substances protrude into the midgut lumen of M. separata, thus resulting in cell death. The immuno-electron microscopic localization research showed that gold particle appeared on the microvilli layer of the midgut of M. separate larvae firstly. The density of gold particle gradually added with the time, and finally microvilli layer was destructed severely. Meantime, the gold particles were also presented to the intracellular organelle membrane and the organelles also were destructed. Therefore, we proposed that this membrane system on insect midgut epithelium cells is the initial acting site of PSNW against insects.
Subject(s)
Glycosides/toxicity , Insecticides/toxicity , Moths/drug effects , Periploca/chemistry , Plant Extracts/toxicity , Pregnanes/toxicity , Animals , Digestive System/chemistry , Digestive System/drug effects , Digestive System/ultrastructure , Epithelium/chemistry , Epithelium/drug effects , Epithelium/ultrastructure , Histology , Larva/chemistry , Larva/drug effects , Larva/ultrastructure , Microscopy, Immunoelectron , Microvilli/chemistry , Microvilli/drug effects , Microvilli/ultrastructure , Moths/chemistry , Moths/ultrastructureABSTRACT
OBJECTIVES: This study aimed to pool the efficacy in bowel movement and explore the change of gut microbiota on adult functional constipated patients after probiotics-containing products treatment. DESIGN: Systematic review and meta-analysis. DATA SOURCES: PubMed, Cochrane Library for published studies and ClinicalTrials.gov for 'grey' researches were independently investigated for randomised controlled trials up to November 2022. ELIGIBILITY CRITERIA, DATA EXTRACTION AND SYNTHESIS: The intervention was probiotics-containing product, either probiotics or synbiotics, while the control was placebo. The risk of bias was conducted. The efficacy in bowel movement was indicated by stool frequency, stool consistency and Patient Assessment of Constipation Symptom (PAC-SYM), while the change of gut microbiota was reviewed through α diversity, ß diversity, change/difference in relative abundance and so on. The subgroup analysis, sensitivity analysis and random-effect meta-regression were conducted to explore the heterogeneity. The Grading of Recommendations Assessment Development and Evaluation was conducted to grade the quality of evidence. RESULTS: 17 studies, comprising 1256 participants, were included with perfect agreements between two researchers (kappa statistic=0.797). Compared with placebo, probiotics-containing products significantly increased the stool frequency (weighted mean difference, WMD 0.93, 95% CI 0.47 to 1.40, p=0.000, I²=84.5%, 'low'), improved the stool consistency (WMD 0.38, 95% CI 0.05 to 0.70, p=0.023, I²=81.6%, 'very low') and reduced the PAC-SYM (WMD -0.28, 95% CI: -0.45 to -0.11, p=0.001, I²=55.7%, 'very low'). In subgroup analysis, synbiotics was superior to probiotics to increase stool frequency. Probiotics-containing products might not affect α or ß diversity, but would increase the relative abundance of specific strain. CONCLUSIONS: Probiotics-containing products, significantly increased stool frequency, improved stool consistency, and alleviated functional constipation symptoms. They increased the relative abundance of specific strain. More high-quality head-to-head randomised controlled trials are needed.
Subject(s)
Constipation , Gastrointestinal Microbiome , Probiotics , Adult , Humans , Constipation/therapy , Defecation , Probiotics/therapeutic use , SynbioticsABSTRACT
Objective: This study explores the correlation between coping style, quality of life, and illness uncertainty in the family caregivers of patients with liver cancer. Methods: Employing convenience sampling, 210 family caregivers of patients with liver cancer who met the admission criteria were selected from a grade A infectious disease hospital in Beijing between January and December 2022. A cross-sectional survey was conducted using the Simplified Coping Style Questionnaire, Caregiver Quality of Life, and the Mishel Uncertainty in Illness Scale for Family Members. This study analysed the correlations between coping styles, quality of life, and illness uncertainty in these caregivers. Results: The study found that family caregivers of patients with liver cancer had average scores for illness uncertainty (83.44 ± 11.86), coping style (33.19 ± 9.79; both positive [23.02 ± 6.81] and negative [10.17 ± 5.05]), and quality of life (169.53 ± 32.46). A negative association was observed between illness uncertainty in these caregivers and positive coping style (r = -0.207, p = 0.003), physical status (r = -0.182, p = 0.008), psychological status (r = -0.200, p = 0.004), and social adaptation (r = -0.229, p = 0.001). Conclusion: The study concludes that illness uncertainty in family caregivers of patients with liver cancer is at a moderate level. Furthermore, there is a notable correlation between illness uncertainty, coping style, and quality of life in these caregivers.
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Functional materials that can quickly absorb and degrade mustard gas are essential for chemical warfare emergency response kits. In this study, a fiber membrane with excellent adsorption and catalytic degradation activity was developed by solution blow spinning polystyrene (PS)/polyurethane (PU) and hydrothermal in situ growth of a zirconium-based MOF (MOF-808). The mechanical properties of the PS/PU fibers were improved by adding a trimethylolpropane tris (2-methyl-1-aziridine propionate) (TTMA) cross-linking agent. Moreover, the CâO bonds in TTMA provided abundant growth sites for MOF-808 in the hydrothermal process, thereby greatly increasing the loading capacity. The fiber surface was completely covered with the MOF-808 particles within 24 h. The PS/PU/TTMA/MOF-808 fiber membrane was used for the catalytic degradation of 2-chloroethyl ethyl sulfide (CEES). The degradation efficiency reached 97.7% after 72 h, indicating its great application potential in emergency wiping cloths for mustard gas adsorption and degradation.
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Smoking is the primary cause of lung cancer and is linked to 85% of lung cancer cases. However, how lung cancer develops in patients with smoking history remains unclear. Systems approaches that combine human protein-protein interaction (PPI) networks and gene expression data are superior to traditional methods. We performed these systems to determine the role that smoking plays in lung cancer development and used the support vector machine (SVM) model to predict PPIs. By defining expression variance (EV), we found 520 dynamic proteins (EV>0.4) using data from the Human Protein Reference Database and Gene Expression Omnibus Database, and built 7 dynamic PPI subnetworks of lung cancer in patients with smoking history. We also determined the primary functions of each subnetwork: signal transduction, apoptosis, and cell migration and adhesion for subnetwork A; cell-sustained angiogenesis for subnetwork B; apoptosis for subnetwork C; and, finally, signal transduction and cell replication and proliferation for subnetworks D-G. The probability distribution of the degree of dynamic protein and static protein differed, clearly showing that the dynamic proteins were not the core proteins which widely connected with their neighbor proteins. There were high correlations among the dynamic proteins, suggesting that the dynamic proteins tend to form specific dynamic modules. We also found that the dynamic proteins were only correlated with the expression of selected proteins but not all neighbor proteins when cancer occurred.
Subject(s)
Lung Neoplasms/metabolism , Protein Interaction Mapping , Protein Interaction Maps , Smoking/adverse effects , Databases, Genetic , Databases, Protein , Humans , Lung Neoplasms/etiology , Lung Neoplasms/pathology , Support Vector MachineABSTRACT
Ammonia (NH3) is one of the hydrogen carriers that has received extensive attention due to its high hydrogen content and carbon-free nature. The ammonia electro-oxidation reaction (AOR) and the liquid AOR (LAOR) are integral parts of an ammonia-based energy system. The exploration of low-cost and efficient electrocatalysts for the AOR and LAOR is very important but very difficult. In this work, a novel self-supporting AOR and LAOR bifunctional electrocatalyst of a Ag3CuS2 film is synthesized by a simple hydrothermal method. The Ag3CuS2 film without a substrate shows efficient catalytic activity and enhanced stability for NH3 electrolysis in both aqueous ammonia solution and liquid ammonia, including an onset potential of 0.7 V for the AOR and an onset potential of 0.4 V for the LAOR. The density functional theory calculations prove that compared to Cu atoms, Ag atoms with appropriate charge density on the surface of Ag3CuS2 are more electrocatalytically active for NH3 splitting, including the low energy barrier in the rate-determining *NH3 dehydrogenation step and the spontaneous tendency in the N2 desorption process. Overall, the foamed Ag3CuS2 film is one of prospective low-cost and stable electrocatalysts for the AOR and LAOR, and the self-supporting strategy without a substrate provides more perspectives to tailor more meaningful and powerful electrocatalysts.
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A novel trimethylolethane (TME)-substituted polyoxovanadate (POV) was designed as a precursor to prepare ultrasmall vanadium carbide nanoparticles, which markedly promoted the hydrogen evolution reaction and oxygen evolution reaction of iridium (Ir)-based electrocatalysts. This work is the first example employing organic ligand-substituted POV as the precursor for metal carbide, and is also the first combination of Ir and vanadium carbide, providing new insights into the design of excellent electrocatalysts.
ABSTRACT
The hydrogen evolution reaction (HER) through electrocatalysis is promising for the production of clean hydrogen fuel. However, designing the structure of catalysts, controlling their electronic properties, and manipulating their catalytic sites are a significant challenge in this field. Here, we propose an electrochemical surface restructuring strategy to design synergistically interactive phosphorus-doped carbon@MoP electrocatalysts for the HER. A simple electrochemical cycling method is developed to tune the thickness of the carbon layers that cover on MoP core, which significantly influences HER performance. Experimental investigations and theoretical calculations indicate that the inactive surface carbon layers can be removed through electrochemical cycling, leading to a close bond between the MoP and a few layers of coated graphene. The electrons donated by the MoP core enhance the adhesion and electronegativity of the carbon layers; the negatively charged carbon layers act as an active surface. The electrochemically induced optimization of the surface/interface electronic structures in the electrocatalysts significantly promotes the HER. Using this strategy endows the catalyst with excellent activity in terms of the HER in both acidic and alkaline environments (current density of 10 mA cm-2 at low overpotentials, of 68 mV in 0.5 M H2SO4 and 67 mV in 1.0 M KOH).
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Novel glucosamine hydrochloride functionalized water-soluble conjugated polyfluorene was easily synthesized through Cu(I)-catalyzed azide/alkyne "click" ligation and Suzuki coupling polymerization. The water-solubility and biocompatibility of the polymer were improved after grafting glucosamine hydrochloride to the side chains of the conjugated polymer. As a fluorescent model system of chitosan, its interaction with single-stranded DNA was studied by spectrofluorometric titration.
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Gastric adenocarcinoma (GAC), also known as stomach adenocarcinoma (STAD), is one of the most lethal malignancies in the world. It is vital to classify and detect the hub genes and key pathways participated in the initiation and progression of GAC. In this study, we collected and sequenced 15 pairs of GAC tumor tissues and the adjacent normal tissues. Differentially expressed genes (DEGs) were analyzed and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) analysis were used to annotate the unique biological significance and important pathways of enriched DEGs. Moreover, we constructed the protein-protein interaction (PPI) network by Cytoscape and conducted KEGG enrichment analysis of the prime module. We further applied the TCGA database to start the survival analysis of these hub genes by Kaplan-Meier estimates. Finally, we obtained total 233 DEGs consisted of 64 up-regulated genes and 169 down-regulated genes. GO enrichment analysis found that DEGs most significantly enriched in single organism process, extracellular region, and extracellular region part. KEGG pathway enrichment analysis suggested that DEGs most significantly enriched in Protein digestion and absorption, Gastric acid secretion, and ECM-receptor interaction. Furthermore, the PPI network showed that the top 10 hub genes in GAC were IL8, COL1A1, MMP9, SST, COL1A2, TIMP1, FN1, SPARC, ALDH1A1, and SERPINE1 respectively. The prime gene interaction module in PPI network was enriched in protein digestion and absorption, ECM receptor interaction, the PI3K-Akt signaling pathway, and pathway in cancer. Survival analysis based on the TCGA database found that the expression of the FN1, SERPINE1, and SPARC significantly predicted poor prognosis of GAC. Collectively, we identified several hub genes and key pathways associated with GAC initiation and progression by analyzing the microarray data on DEGs, which provided a detailed molecular mechanism underlying GAC occurrence and progression.