Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 14 de 14
Filter
1.
J Colloid Interface Sci ; 675: 926-934, 2024 Jul 10.
Article in English | MEDLINE | ID: mdl-39002242

ABSTRACT

Mixed-dimensional van der Waals heterojunctions (MD-vdWhs), known for exceptional electron transfer and charge separation capabilities, remain underexplored in photocatalysis. In this study, we leveraged the synergistic effect of intermolecular π â†’ π* and D-π-A dual channels to fabricate novel MD-vdWhs. Owing to the synergistic effect, it exhibits superior electron transfer and delocalization ability, thereby enhancing its photocatalytic performance. The Optimal photocatalyst can degrade 98.78 % of 20 mg/L tetracycline (TC) within 15 min. Additionally, we introduced a novel proof strategy for investigating the photoelectron transfer path, creatively demonstrating the synergistic dual channels effect, which can be attributed to the carbonyl density and light-excitation degree. Notably, even under low-power light sources, it achieved complete inactivation of Escherichia coli within just 7 mins, far surpassing current cutting-edge research. This theoretical framework holds promise for broader applications within related studies.

2.
J Colloid Interface Sci ; 673: 346-353, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38878369

ABSTRACT

Employing electric energy to convert carbon dioxide (CO2) into valuable small molecules is a potentially practical method in energy storage and greenhouse gas alleviation. A huge challenge for electrocatalytic CO2 reduction is to reduce overpotential to improve energy efficiency. Herein, we demonstrate that doping alloy Pd49Ag30Te4 (PAT) with rare-earth element Tb is beneficial for selective exposure of (111) crystal plane, which is a highly active crystal plane for producing carbon monoxide (CO). The as-prepared Tb2.9PAT exhibited high electrocatalytic performance with 95.7 % CO faradic efficiency at - 0.8 V (vs RHE), far exceeding that of PAT, and coupled with good durability. In situ spectral study and theoretical calculations disclose that the introduction of Tb regulates the d-band center of PAT alloy, weakens the Pd - C bonding ability, and promotes the desorption of *CO in the rate-determining step. This study provides a method for doping induced selective exposure of crystal face, which provides new idea for improving catalytic performance.

3.
J Colloid Interface Sci ; 671: 1-14, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38788420

ABSTRACT

The widespread contamination of hexavalent chromium (Cr(VI)), pharmaceuticals and personal care products (PPCPs), and dyes is a growing concern. necessitating the development of convenient and effective technologies for their removal. Copper(I) phenylacetylide (PhC2Cu) has emerged as a promising photocatalyst for environmental remediation. In this study, we introduced a functional Cu-O bond into PhC2Cu (referred to as OrPhC2Cu) by creatively converting the adsorbed oxygen on the surface of PhC2Cu into a Cu-O bond to enhance the efficiency of Cr(VI) photoreduction, PPCPs photodegradation, and dyes photodegradation through a facile vacuum activating method. The incorporation of the Cu-O bond optimized the electron structure of OrPhC2Cu, facilitating exciton dissociation and charge transfer. The exciton dissociation behavior and charge transfer mechanism were systematically investigated for the first time in the OrPhC2Cu system by photoelectrochemical tests, fluorescence and phosphorescence (PH) techniques, and density functional theory (DFT) calculations. Remarkably, the enhanced visible-light response of OrPhC2Cu improved photon utilization and significantly promoted the generation of reactive species (RSs), leading to the highly efficient Cr(VI) photoreduction (98.52% within 25 min) and sulfamethazine photodegradation (94.65% within 60 min), with 3.91 and 5.23 times higher activity compared to PhC2Cu. Additionally, the photocatalytic efficiency of OrPhC2Cu in degrading anionic dyes surpassed that of cationic dyes. The performance of the OrPhC2Cu system in treating electroplating effluent or natural water bodies suggests its potential for practical applications.

4.
Front Cardiovasc Med ; 10: 1132428, 2023.
Article in English | MEDLINE | ID: mdl-37265563

ABSTRACT

Background: On-pump valve surgeries are associated with high morbidity and mortality. The present study aimed to reliably predict a composite outcome of postoperative complications using a minimum of easily accessible clinical parameters. Methods: A total of 7,441 patients who underwent valve surgery were retrospectively analyzed. Data for 6,220 patients at West China Hospital of Sichuan University were used to develop a predictive model, which was validated using data from 1,221 patients at the Second Affiliated Hospital of Zhejiang University School of Medicine. The primary outcome was a composite of major complications: all-cause death in hospital, stroke, myocardial infarction, and severe acute kidney injury. The predictive model was constructed using the least absolute shrinkage and selection operator as well as multivariable logistic regression. The model was assessed in terms of the areas under receiver operating characteristic curves, calibration, and decision curve analysis. Results: The primary outcome occurred in 129 patients (2.1%) in the development cohort and 71 (5.8%) in the validation cohort. Six variables were retained in the predictive model: New York Heart Association class, diabetes, glucose, blood urea nitrogen, operation time, and red blood cell transfusion during surgery. The C-statistics were 0.735 (95% CI, 0.686-0.784) in the development cohort and 0.761 (95% CI, 0.694-0.828) in the validation cohort. For both cohorts, calibration plots showed good agreement between predicted and actual observations, and ecision curve analysis showed clinical usefulness. In contrast, the well-established SinoSCORE did not accurately predict the primary outcome in either cohort. Conclusions: This predictive nomogram based on six easily accessible variables may serve as an "early warning" system to identify patients at high risk of major complications after valve surgery. Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [NCT04476134].

5.
J Cell Physiol ; 238(1): 242-256, 2023 01.
Article in English | MEDLINE | ID: mdl-36538623

ABSTRACT

Myocardial hypertrophy is associated with a significant increase in intracellular Ca2+ , which can be induced by long-chain fatty acid. Palmitic acid methyl ester (PAME), a fatty acid ester released from adipose tissue, superior cervical ganglion, and retina, has been found to have anti-inflammation, antifibrosis, and peripheral vasodilation effects. However, the effects of PAME on cardiomyocytes are still unclear. The aim of this study was to determine whether PAME could disrupt the intracellular Ca2+ balance, leading to cardiomyocyte hypertrophy. Neonatal rat cardiomyocytes were treated with various concentrations (10-100 µM) of PAME for 1-4 days. Cytosolic Ca2+ and mitochondrial Ca2+ concentrations were examined using Fura-2 AM and Rhod-2, respectively. After treatment with PAME for 4 days, mitochondrial Ca2+ , an indicator of the state of mitochondrial permeability transition pore (MPTP), and cell death were monitored by flow cytometric analysis. ATP levels were detected using the ATP assay kit. Cardiomyocyte hypertrophy was analyzed by measuring the cardiac hypertrophy biomarker and cell area using quantitative real time-polymerase chain reaction, Western Blot analysis and immunofluorescence analysis. Our results show that PAME concentration- and time-dependently increased cytosolic and mitochondria Ca2+ through the mitochondrial calcium uniporter. Moreover, treatment with PAME for 4 days caused MPTP opening, thereby reducing ATP production and enhancing reactive oxygen species (ROS) generation, and finally led to cardiomyocyte hypertrophy. These effects caused by PAME treatment were attenuated by the G-protein coupled receptor 40 (GPR40) inhibitor. In conclusion, PAME impaired mitochondrial function, which in turn led to cardiomyocyte hypertrophy through increasing the mitochondrial Ca2+ levels mediated by activating the GPR40 signaling pathway.


Subject(s)
Calcium , Mitochondria , Palmitates , Receptors, G-Protein-Coupled , Animals , Rats , Adenosine Triphosphate/metabolism , Calcium/metabolism , Cardiomegaly/chemically induced , Cardiomegaly/metabolism , Mitochondria/metabolism , Myocytes, Cardiac/metabolism , Palmitates/pharmacology , Receptors, G-Protein-Coupled/metabolism , Cells, Cultured
6.
Front Cardiovasc Med ; 9: 996744, 2022.
Article in English | MEDLINE | ID: mdl-36176979

ABSTRACT

Objective: To compare the outcomes of four types of cardioplegia during cardiac surgery: del Nido (DN), blood cardioplegia (BC), histidine-tryptophan-ketoglutarate (HTK) and St. Thomas. Methods: Randomized controlled trials (RCTs) and observational cohort studies from 2005 to 2021 were identified in PubMed, Embase, and Cochrane databases. Data were extracted for the primary endpoint of perioperative mortality as well as the following secondary endpoints: atrial fibrillation, renal failure, stroke, use of an intra-aortic balloon pump, re-exploration, intensive care unit stay and hospital stay. A network meta-analysis comparing all four types of cardioplegia was performed, as well as direct meta-analysis comparing pairs of cardioplegia types. Results: Data were extracted from 18 RCTs and 49 observational cohort studies involving 18,191 adult patients (55 studies) and 1,634 children (12 studies). Among adult patients, risk of mortality was significantly higher for HTK (1.89, 95% CI 1.10, 3.52) and BC (RR 1.73, 95% CI 1.22, 2.79) than for DN. Risk of atrial fibrillation was significantly higher for BC (RR 1.41, 95% CI 1.09, 1.86) and DN (RR 1.51, 95% CI 1.15, 2.03) than for HTK. Among pediatric patients, no significant differences in endpoints were observed among the four types of cardioplegia. Conclusions: This network meta-analysis suggests that among adult patients undergoing cardiac surgery, DN may be associated with lower perioperative mortality than HTK or BC, while risk of atrial fibrillation may be lower with HTK than with BC or DN.

7.
Transl Cancer Res ; 11(7): 2122-2134, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35966299

ABSTRACT

Background: This study aims to discriminate risk factors associated with early death (died within 3 months) in metastatic small-cell lung cancer (SCLC) patients, and construct predictive nomograms to help physicians in guiding individual treatment. Methods: Surveillance, Epidemiology, and End Results (SEER) database was used to obtain records of deceased metastatic SCLC patients. The univariate and multivariate logistic regression methods were managed to identify risk factors for early death in overall patients and chemotherapy recipients. Predictive nomograms were developed and then validated by receiver operating characteristics curve (ROC) and calibration plots to verify its' precision. Results: A total of 13,229 patients were collected of which 5,832 of them encountered early death. The univariate and multivariate logistic regression analysis identified variables that were negatively associated with early death include sex, age, race, sequence, T stage, N stage, organ metastasis. Chemotherapy and radiotherapy implementation significantly decreased the odds of early death. For the chemotherapy recipients, white male patients with advanced age (over 80 years old), T4 stage, multiple organ metastasis, and without radiotherapy most likely died within 3 months. The area under the curve (AUC) of the nomograms for overall population and chemotherapy recipients' early death prediction was 0.839 and 0.653. Conclusions: Early death among metastatic SCLC patients was extremely common in clinical practice. The nomograms constructed were able to assist clinical physicians in discriminating high-risk SCLC patients for targeted intervention, and elderly white male patients diagnosed with advanced T stage and multiple organ metastasis might be exempted from systemic treatment to receive palliative care.

8.
Oxid Med Cell Longev ; 2022: 9523491, 2022.
Article in English | MEDLINE | ID: mdl-35082973

ABSTRACT

Ferroptosis is an iron-dependent form of cell death caused by the inactivation of glutathione peroxidase 4 (GPX4) and accumulation of lipid peroxides. Ferroptosis has been found to participate in the ischemia-reperfusion (I/R) injury, leading to heart dysfunction and myocardial cell death. Xanthohumol (XN), a prenylated flavonoid isolated from Humulus lupulus, has multiple pharmacological activities, such as anti-inflammatory and antioxidant. This study is aimed at investigating whether XN could attenuate the I/R-induced ferroptosis in cardiomyocytes and the underlying mechanisms. Cardiomyocytes were treated with Fe-SP and RSL3, and the rat hearts were treated with I/R. The results from the present study show that XN was able to protect cardiomyocytes against Fe-SP- and RSL3-induced ferroptotic cell death by decreasing the production of lipid peroxidation and ROS, chelating iron, reducing the NRF2 protein level, and modulating the protein levels of GPX4. Moreover, XN significantly decreased the mRNA levels of ferroptosis markers, Ptgs2 and Acsl4, and the protein levels of ACSL4 and NRF2 and modulated the protein levels of GPX4 in I/R-treated hearts. The findings from the present study suggest that XN might have the therapeutic potential for the I/R-induced ferroptosis injury.


Subject(s)
Ferroptosis/drug effects , Flavonoids/therapeutic use , Myocardial Reperfusion Injury/drug therapy , Myocardium/pathology , Propiophenones/therapeutic use , Animals , Flavonoids/pharmacology , Propiophenones/pharmacology , Rats , Rats, Sprague-Dawley
9.
Environ Pollut ; 295: 118669, 2022 Feb 15.
Article in English | MEDLINE | ID: mdl-34921941

ABSTRACT

Iron (III) co-precipitation with dissolved organic matter (DOM) is pervasive in many natural environments. However, the effects of DOM on the formation of Fe(III) hydroxysulfate (FHS) and its environmental implications are poorly understood. In this study, fulvic acid (FA) was used as a model DOM compound, and experiments were devised to investigate the effects of FA on the formation of FHS. In addition, the Pb(II) adsorption capabilities of FHSs biosynthesized under various FA dosages, including kinetics and sorption isotherm experiments, were conducted. These experiments showed that co-precipitation of FA promoted the formation of Fe-FA composites, FA-doped schwertmannite, and small particles of jarosite. Co-precipitates are more enriched in carboxyl (-COOH) functional groups due to their preferential binding with FHS. The adsorption kinetics, isotherms and mechanisms of Pb onto the biosynthesized FHSs were then comprehensively characterized and modeled. Though the specific surface area decreased with increasing FA loading, the introduction of FA into FHSs increased Pb(II) adsorption, with the highest concentration of FA addition improving the removal capacity of Pb(II) to 91.54%. Kinetics studies and intra-particle diffusion models indicated that the adsorption of Pb(II) onto the FHSs was correlated with the number of active sites, and two adsorption steps: surface adsorption and the diffusion of Pb(II) in channels inside the biosynthesized FHSs, are suggested. The adsorption mechanism was attributed to cation exchange between Pb(II) and -OH and -COOH functional groups, and the co-precipitated FA provided additional sites for Pb(II) adsorption by FHS.


Subject(s)
Dissolved Organic Matter , Ferric Compounds , Adsorption , Benzopyrans , Kinetics
10.
Biomolecules ; 11(11)2021 11 10.
Article in English | MEDLINE | ID: mdl-34827665

ABSTRACT

Myocardial ischemia/reperfusion (I/R) injury has been associated with ferroptosis, which is characterized by an iron-dependent accumulation of lipid peroxide to lethal levels. Gossypol acetic acid (GAA), a natural product taken from the seeds of cotton plants, prevents oxidative stress. However, the effects of GAA on myocardial I/R-induced ferroptosis remain unclear. This study investigated the ability of GAA to attenuate I/R-induced ferroptosis in cardiomyocytes along with the underlying mechanisms in a well-established rat model of myocardial I/R and isolated neonatal rat cardiomyocytes. H9c2 cells and cardiomyocytes were treated with the ferroptosis inducers erastin, RSL3, and Fe-SP. GAA could protect H9c2 cells against ferroptotic cell death caused by these ferroptosis inducers by decreasing the production of malondialdehyde and reactive oxygen species, chelating iron content, and downregulating mRNA levels of Ptgs2. GAA could prevent oxygen-glucose deprivation/reperfusion-induced cell death and lipid peroxidation in the cardiomyocytes. Moreover, GAA significantly attenuated myocardial infarct size, reduced lipid peroxidation, decreased the mRNA levels of the ferroptosis markers Ptgs2 and Acsl4, decreased the protein levels of ACSL4 and NRF2, and increased the protein levels of GPX4 in I/R-induced ex vivo rat hearts. Thus, GAA may play a cytoprotectant role in ferroptosis-induced cardiomyocyte death and myocardial I/R-induced ferroptotic cell death.


Subject(s)
Myocardial Reperfusion Injury , Animals , Ferroptosis , Gossypol/analogs & derivatives , Male , Rats
12.
Mol Microbiol ; 75(2): 426-39, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19943898

ABSTRACT

The ability of some microbial species to oxidize monomethylamine via glutamate-mediated pathways was proposed in the 1960s; however, genetic determinants of the pathways have never been described. In the present study we describe a gene cluster essential for operation of the N-methylglutamate pathway in the methylotrophic beta-proteobacterium Methyloversatilis universalis FAM5. Four major polypeptides from protein fractions displaying high activities of N-methylglutamate synthetase, N-methylglutamate dehydrogenase and gamma-glutamylmethylamide synthetase were selected for mass spectrometry-based identification. The activities of enzymes were associated with the presence of peptides identified as ferredoxin-dependent glutamate synthase (GltB2), large subunit of putative heterotetrameric sarcosine oxidase (SoxA) and glutamine synthetase type III (GSIII) respectively. A gene cluster (8.3 kb) harbouring gltB2, soxA and gsIII-like genes was amplified from M. universalis FAM5, sequenced and assembled. Two partial and six complete open reading frames arranged in the order soxBDAG-gsIII-gltB132 were identified and subjected to mutational analysis, functional and metabolic profiling. We demonstrated that gltB-like and sox-like genes play a key role in methylamine utilization and encode N-methylglutamate synthetase and N-methylglutamate dehydrogenase respectively. Metabolic, enzymatic and mutational analyses showed that the gsIII-like gene encodes gamma-glutamylmethylamide synthetase; however, this enzyme is not essential for oxidation of methylamine.


Subject(s)
Betaproteobacteria/genetics , Glutamic Acid/metabolism , Methylamines/metabolism , Alanine/metabolism , Bacterial Proteins/genetics , Betaproteobacteria/drug effects , Betaproteobacteria/growth & development , Betaproteobacteria/metabolism , DNA Mutational Analysis/methods , Gene Expression Profiling/methods , Glutamate Synthase/genetics , Glutamate Synthase/metabolism , Glutamic Acid/genetics , Glutamic Acid/pharmacology , Glutamine/metabolism , Kinetics , Multigene Family , Open Reading Frames , Oxidation-Reduction , Peptide Fragments/chemistry , Peptide Fragments/metabolism
13.
Cyberpsychol Behav ; 11(5): 603-5, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18785821

ABSTRACT

Based on information systems acceptance literature, this study develops an integrated model to predict and explain behavioral intention to use mobile booking (m-booking). Data collected from 201 users in Taiwan are tested against the research model, using the structural equation modeling approach. The proposed model is mostly supported by the empirical data. The findings of this study provide several crucial implications for m-booking service practitioners and researchers.


Subject(s)
Attitude to Computers , Cell Phone , Commerce , Diffusion of Innovation , Models, Psychological , Consumer Behavior , Humans , Intention , Psychometrics , Travel
14.
Cyberpsychol Behav ; 11(4): 405-13, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18721088

ABSTRACT

IT-related self-efficacy has been found to have a critical influence on system use. However, traditional measures of computer self-efficacy and Internet-related self-efficacy are perceived to be inapplicable in the context of mobile computing and commerce because they are targeted primarily at either desktop computer or wire-based technology contexts. Based on previous research, this study develops and validates a multidimensional instrument for measuring mobile computing self-efficacy (MCSE). This empirically validated instrument will be useful to researchers in developing and testing the theories of mobile user behavior, and to practitioners in assessing the mobile computing self-efficacy of users and promoting the use of mobile commerce systems.


Subject(s)
Computer Literacy , Computers, Handheld , Internet , Self Efficacy , Task Performance and Analysis , Adolescent , Adult , Attitude to Computers , Equipment Design , Female , Humans , Male , Middle Aged , Psychometrics , Reference Values , Reproducibility of Results , Sensitivity and Specificity , Statistics, Nonparametric , User-Computer Interface
SELECTION OF CITATIONS
SEARCH DETAIL
...