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1.
Small ; 20(12): e2307843, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37948442

RESUMO

Covalent organic frameworks (COFs) with flexible periodic skeletons and ordered nanoporous structures have attracted much attention as potential candidate electrode materials for green energy storage and efficient seawater desalination. Further improving the intrinsic electronic conductivity and releasing porosity of COF-based materials is a necessary strategy to improve their electrochemical performance. Herein, the employed graphene as the conductive substrate to in situ grow 2D redox-active COF (TFPDQ-COF) with redox activity under solvent-free conditions to prepare TFPDQ-COF/graphene (TFPDQGO) nanohybrids and explores their application in both supercapacitor and hybrid capacitive deionization (HCDI). By optimizing the hybridization ratio, TFPDQGO exhibits a large specific capacitance of 429.0 F g-1 due to the synergistic effect of the charge transport highway provided by the graphene layers and the abundant redox-active centers contained in the COF skeleton, and the assembled TFPDQGO//activated carbon (AC) asymmetric supercapacitor possesses a high energy output of 59.4 Wh kg-1 at a power density of 950 W kg-1 and good cycling life. Furthermore, the maximum salt adsorption capacity (SAC) of 58.4 mg g-1 and stable regeneration performance is attained for TFPDQGO-based HCDI. This study highlights the new opportunities of COF-based hybrid materials acting as high-performance supercapacitor and HCDI electrode materials.

2.
Small ; 20(21): e2309353, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38098371

RESUMO

Defect engineering is recognized as an attractive method for modulating the electronic structure and physicochemical characteristics of carbon materials. Exploiting heteroatom-doped porous carbon with copious active sites has attracted great attention for capacitive deionization (CDI). However, traditional methods often rely on the utilization of additional heteroatom sources and strong corrosive activators, suffering from low doping efficiency, insufficient doping level, and potential biotoxicity. Herein, hydrogen-bonded organic frameworks (HOFs) are employed as precursors to synthesize N, O co-doped porous carbon via a simple and green reverse defect engineering strategy, achieving controllable heavy doping of heteroatoms. The N, O co-doping triggers significant pseudocapacitive contribution and the surface pore structure supports the formation of the electric double layer. Therefore, when HOF-derived N, O co-doped carbon is used as CDI electrodes, a superior salt adsorption capacity of 32.29 ± 1.42 mg g-1 and an outstanding maximum salt adsorption rate of 10.58 ± 0.46 mg g-1 min-1 at 1.6 V in 500 mg L-1 NaCl solution are achieved, which are comparable to those of state-of-the-art carbonaceous electrodes. This work exemplifies the effectiveness of the reverse nitrogen-heavy doping strategy on improving the carbon structure, shedding light on the further development of rational designed electrode materials for CDI.

3.
J Pak Med Assoc ; 74(1): 26-31, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38219160

RESUMO

Objectives: To evaluate the efficacy of miniprobe endoscopic ultrasonography for the diagnosis and adjuvant treatment of patients with colorectal submucosal lesions. METHODS: The retrospective study was conducted at the Beijing Chao-Yang Hospital, Capital Medical University, China, and comprised data from January 1, 2016, to July 31, 2021, related to patients of either gender with colorectal submucosal lesions who underwent miniprobe endoscopic ultrasonography. The findings were compared with biopsy specimens and clinical diagnoses. Diagnostic features of miniprobe endoscopic ultrasonography were assessed along with its accuracy. Data was analysed using R 4.1.2. RESULTS: Of the 237 patients, 121(51.1%) were female and 116(48.9%) were male. The overall mean age was 55.6±12.9 years. Miniprobe endoscopic ultrasonography successfully imaged all 237(100%) colorectal submucosal lesions, and 188(79.3%) had consistent results compared to histopathological findings. The majority of lesions were <10mm 102(43.4%) or 10-19mm 84(35.7%) in size. Those detected with high echogenicity were 126(53.2%) and those with low/low-medium echogenicity were 83(35.0%). Tumour size 10-19mm and uneven echo quality significantly increased the accuracy of miniprobe endoscopic ultrasonography (p<0.05). CONCLUSIONS: Miniprobe endoscopic ultrasonography was able to provide precise information about the size, layer of origin, echogenicity and border of colorectal submucosal lesions, and had a high accuracy in the differential diagnosis of such lesions.


Assuntos
Neoplasias Colorretais , Endossonografia , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Endossonografia/métodos , Estudos Retrospectivos , China , Diagnóstico Diferencial , Neoplasias Colorretais/diagnóstico por imagem , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/patologia
4.
Surg Endosc ; 36(11): 8021-8029, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35941305

RESUMO

BACKGROUND: Among all types of superficial gastrointestinal (GI) neoplasms, colorectal lesions are recognized as one of the most difficult locations to operate, due to the limited operation space, physiological bends, poor visualization of the submucosal dissection plane sheltered by colorectal crinkle wall, and the thin intestinal mucosa layer which is easy to perforation. The purpose of this prospective study is to evaluate the feasibility, efficacy, and safety of a novel endoscopic traction technique in assisting the endoscopic submucosal dissection (ESD) procedure in colorectal lesions. METHOD: A total of 117 patients with colonic lesions who underwent endoscopic treatment were enrolled between August 2020 and January 2021 at the endoscopic center of Beijing Chao-yang Hospital of Capital Medical University. Based on whether traction device was used during the operation, 60 and 57 patients were assigned to the conventional ESD group and clips and rubber band triangle traction-assisted ESD group (CRT-ESD, in which three clips and a rubber band were used to form an elastic triangular traction device), respectively. The total procedure time (TPT), submucosal dissection time (SDT), submucosal dissection speed (SDS), and rate of adverse events of the two groups were analyzed. RESULTS: After excluding patients who did not undergo treatment (conventional ESD, 1; CRT-ESD, 4), 112 patients were included in the study (conventional ESD, 59; CRT-ESD, 53). The baseline characteristics of the patients were well balanced between the two groups. The TPT (58.71 ± 26.22 min vs 33.58 ± 9.88 min, p < 0.001) and SDT (49.24 ± 23.75 min vs 26.34 ± 8.75 min, p < 0.001) were significantly different between the conventional ESD group and CRT-ESD group. The CRT-ESD group had significantly higher SDS than that of the traditional ESD group (0.54 ± 0.42 cm2/min vs 0.89 ± 0.40 cm2/min, p < 0.001). There were 4 (6.8%) cases of perforation in the traditional ESD group, and no perforation occurred in traction-assisted ESD. CONCLUSIONS: Compared with traditional ESD, CRT-ESD with clip and rubber band is both safer and more effective in the treatment of colorectal lesions.


Assuntos
Neoplasias Colorretais , Ressecção Endoscópica de Mucosa , Neoplasias Gastrointestinais , Humanos , Ressecção Endoscópica de Mucosa/métodos , Tração , Estudos Prospectivos , Resultado do Tratamento , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/patologia
5.
Reprod Health ; 19(1): 14, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-35057818

RESUMO

BACKGROUND: Inter-delivery interval (IDI) has been proven to be a factor associated with adverse maternal and neonatal outcomes. However, the optimal IDI in trial of labor after cesarean delivery (TOLAC) remains unclear. We aimed to investigate the association between IDI and major maternal and neonatal outcomes in women who underwent TOLAC. METHODS: A multicenter, retrospective cohort study including five hospitals was conducted between January 2018 and December 2019 in Foshan, China. This study included 1080 pregnant women with one or two cesarean deliveries who attempted a TOLAC. Data on maternal and neonatal outcomes were collected from the electronic record system. Maternal and neonatal outcomes in different groups of IDI were compared by univariate and multivariable analyses. RESULTS: A short IDI of < 24 months did not show a statistically significant association with uterine rupture in the univariate analysis (P = 0.668). In multivariable analysis, the incidences of postpartum hemorrhage (OR 19.6, 95% CI:4.4-90.9, P < 0.05), preterm birth (OR 5.5, 95% CI:1.5-21.3, P < 0.05), and low birth weight (OR 3.5, 95% CI:1.2-10.3, P < 0.05) were significantly increased in women with an IDI of < 24 months than in those with a normal interval (24-59 months). Infection morbidity (OR 1.8, 95% CI:1.4-7.9, P < 0.05), transfusion (OR 7.4, 95% CI:1.4-40.0, P < 0.05), and neonatal unit admission (OR 2.6, 95% CI:1.4-5.0, P < 0.05) were significantly increased in women with an IDI of 120 months or more than in those with a normal interval. Postpartum hemorrhage (P = 0.062) had a trend similar to that of a significant IDI of 120 months or more. We found no statistically significant difference in maternal and neonatal outcomes between 24-59 months and 60-119 months. CONCLUSIONS: An IDI of less than 24 months or 120 months or more increased the risk of major maternal and neonatal outcomes. We recommend that the optimal interval for women who underwent TOLAC should be 24 to 119 months.


An inter-delivery interval (IDI) that is too short or too long increases the risk of adverse maternal and neonatal outcomes. However, the optimal IDI for trial of labor after cesarean delivery (TOLAC) remains unclear. We performed a multicenter, electronic medical record-based, retrospective cohort study that included 1080 pregnant women who had one or two cesarean deliveries and underwent TOLAC. Data on maternal and neonatal outcomes were collected from the electronic record system. In multivariable analysis, the incidences of postpartum hemorrhage, preterm birth, and low birth weight were significantly increased in women with an IDI of < 24 months than in those with a normal interval (24­59 months). Infections, transfusion, and neonatal unit admission were significantly increased in women with an IDI of ≥ 120 months than in those with a normal interval. In conclusion, we found that an IDI < 24 months or ≥ 120 months increased the risk of major maternal and neonatal outcomes. We recommend that the optimal interval for women who underwent TOLAC should be 24 to 119 months.


Assuntos
Nascimento Prematuro , Nascimento Vaginal Após Cesárea , Cesárea , Feminino , Humanos , Recém-Nascido , Gravidez , Estudos Retrospectivos , Prova de Trabalho de Parto
6.
J Asian Nat Prod Res ; 22(1): 47-51, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30526090

RESUMO

Phytochemical investigation on the leaves of Rabdosia serra led to the isolation of two new abietane diterpenoids, raserranes A (1) and B (2), and four known phenylpropanoids (3-6). Their structures were determined by spectroscopic data. Compound 1 represented the rare examples of abietane diterpenoids featuring a 16-methoxycarbonyl group.


Assuntos
Isodon , Abietanos , Estrutura Molecular , Folhas de Planta
7.
Exp Cell Res ; 373(1-2): 132-144, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30321515

RESUMO

Pancreatic stellate cells (PSCs), when activated, are characterized by proliferation and collagen synthesis, and contribute to extracellular matrix deposition in pancreatic fibrosis. Concomitantly, fibrosis is linked with the loss of PTEN (phosphatase and tensin homolog) protein in several organs. This study investigated the association between PTEN protein levels and the activated or apoptotic status of PSCs in a rat model of chronic pancreatitis. In addition, the activation status and biological behaviors of culture-activated PSCs were analyzed after lentiviral transfection with wildtype or mutant (G129E) PTEN for upregulation, or PTEN short hairpin RNA for downregulation, of PTEN. In vivo, PTEN levels gradually decreased during pancreatic fibrosis, which positively correlated with apoptosis of activated PSCs, but negatively with PSC activation. In vitro, activated PSCs with wildtype PTEN showed less proliferation, migration, and collagen synthesis compared with control PSCs, and greater numbers were apoptotic; activated PSCs with mutant PTEN showed similar, but weaker, effects. Furthermore, AKT and FAK/ERK signaling was involved in this process. In summary, activated PSCs during pancreatic fibrosis in vivo have lower levels of PTEN. In vitro, PTEN appears to prevent PSCs from further activation and promotes apoptosis through regulation of the AKT and FAK/ERK pathways.


Assuntos
PTEN Fosfo-Hidrolase/metabolismo , Pâncreas/patologia , Células Estreladas do Pâncreas/enzimologia , Animais , Apoptose , Movimento Celular , Proliferação de Células , Células Cultivadas , Colágeno/metabolismo , Fibrose , Humanos , Masculino , Pâncreas/enzimologia , Células Estreladas do Pâncreas/citologia , Células Estreladas do Pâncreas/metabolismo , Células Estreladas do Pâncreas/fisiologia , Ratos Wistar , Transdução de Sinais
8.
Int J Nurs Pract ; 24(2): e12628, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29498139

RESUMO

BACKGROUND: Evidence-based nursing has been highlighted and highly developed in recent decades in mainland China. Nevertheless, little is known about its overall development. AIMS: To gain insights on the overall development of evidence-based nursing in the most recent 5 years and to inform future evidence-based nursing research in mainland China. METHOD: Four Chinese and four English databases were searched with the search terms "evidence-based practice," "nurse or nursing," and "China or Chinese" from 2012 to 2016. Bibliometric and co-word cluster analysis were conducted with the final included publications. RESULTS: A total of 9036 papers published by 13 808 authors in 606 journals were included. Publication numbers were increasing. None of the top ten journals publishing evidence-based nursing papers were core nursing journals. The research hot spots on evidence-based nursing in the recent five years were cardiovascular disease, mental health, and complication prevention. However, little attention has been paid to education for evidence-based nursing. CONCLUSION: Evidence-based nursing has penetrated into various nursing branches in mainland China and become a well-recognized and relatively mature research domain. More importance should be attached to the study design, methodological, and reporting quality of evidence-based nursing projects.


Assuntos
Enfermagem Baseada em Evidências/estatística & dados numéricos , Pesquisa em Enfermagem/estatística & dados numéricos , Editoração/estatística & dados numéricos , Bibliometria , China , Humanos
9.
Langmuir ; 32(43): 11321-11327, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27491270

RESUMO

Water nanobubbles manifest fascinatingly higher mechanical strength, higher thermal stability, and longer lifetime than macroscopic bubbles; thus, they provide an important impact in applications in the biomedical and chemical industries. However, a detailed understanding of the mechanism behind these mysteries of nanobubbles remains a challenge. Consistency between quantum computations and Raman spectrometric measurements confirmed our predictions that a nanobubble skin shares the same supersolidity with molecular clusters, skins of bulk water, and water droplets because of molecular undercoordination (fewer than four nearest molecular neighbors). Molecular undercoordination (coordination number Zcluster < Zsurface < Zbubble < Zbulk = 4) shortens/extends the H-O/O:H bond and stiffens/softens its corresponding stretching phonons, whose frequency shift is proportional to the square root of the cohesive energy and inversely proportional to the segmental length. The strongly polarized O:H-O bond slows the molecular dynamics and increases the viscosity. The freezing temperature is lowered by the softened O:H bond, and the melting temperature is enhanced by the stiffened H-O bond. Therefore, the supersolid skin makes the nanobubbles thermally more stable, less dense, and stiffer and slows the dynamics of their molecular motion.

11.
Phys Chem Chem Phys ; 16(45): 24666-71, 2014 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-25325235

RESUMO

Infrared spectroscopy and contact-angle measurements revealed that NaCl salting has the same effect as heating on O:H phonon softening and H-O phonon stiffening, but has the opposite effect on skin polarization of liquid water. The mechanics of thermal modulation of O-O Coulomb repulsion [Sun, et al., J. Phys. Chem. Lett., 2013, 4, 3238] may suggest a possible mechanism for this NaCl involved Hofmeister effect, aqueous solution modulated surface tension and its abilities in protein dissolution, from the perspective of Coulomb mediation of interaction within the O:H-O bond.


Assuntos
Temperatura Alta , Cloreto de Sódio/química , Água/química , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular
12.
ACS Omega ; 9(2): 2657-2663, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38250417

RESUMO

This study explores the production of flash graphene (AC-FG) from anthracite coal by using the flash Joule heating (FJH) method. This study demonstrates that AC-FG can be derived from anthracite coal by precisely controlling the system parameters, specifically the pulse voltage. The FJH process requires no catalyst. The produced material was characterized by using Raman, XRD, XPS, TG, SEM, TEM, and XPS techniques. The results reveal that the degree of graphitization of coal reaches its peak at 190 V. From an energy perspective, FJH provides a straightforward and cost-effective method for graphene preparation, offering a substantial avenue for the efficient utilization of coal resources and the cost-effective application of graphene.

13.
Gut Microbes ; 16(1): 2329147, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38528729

RESUMO

BACKGROUND: Inflammatory bowel disease (IBD) is characterized by immune-mediated, chronic inflammation of the intestinal tract. The occurrence of IBD is driven by the complex interactions of multiple factors. The objective of this study was to evaluate the therapeutic effects of IAA in colitis. METHOD: C57/BL6 mice were administered 2.5% DSS in drinking water to induce colitis. IAA, Bifidobacterium pseudolongum, and R-equol were administered by oral gavage and fed a regular diet. The Disease Activity Index was used to evaluate disease activity. The degree of colitis was evaluated using histological morphology, RNA, and inflammation marker proteins. CD45+ CD4+ FOXP3+ Treg and CD45+ CD4+ IL17A+ Th17 cells were detected by flow cytometry. Analysis of the gut microbiome in fecal content was performed using 16S rRNA gene sequencing. Gut microbiome metabolites were analyzed using Untargeted Metabolomics. RESULT: In our study, we found IAA alleviates DSS-induced colitis in mice by altering the gut microbiome. The abundance of Bifidobacterium pseudolongum significantly increased in the IAA treatment group. Bifidobacterium pseudolongum ATCC25526 alleviates DSS-induced colitis by increasing the ratio of Foxp3+T cells in colon tissue. R-equol alleviates DSS-induced colitis by increasing Foxp3+T cells, which may be the mechanism by which ATCC25526 alleviates DSS-induced colitis in mice. CONCLUSION: Our study demonstrates that IAA, an indole derivative, alleviates DSS-induced colitis by promoting the production of Equol from Bifidobacterium pseudolongum, which provides new insights into gut homeostasis regulated by indole metabolites other than the classic AHR pathway.


Assuntos
Bifidobacterium , Colite , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Camundongos , Animais , Equol/metabolismo , Equol/farmacologia , Equol/uso terapêutico , RNA Ribossômico 16S/genética , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/metabolismo , Ácidos Indolacéticos/metabolismo , Doenças Inflamatórias Intestinais/patologia , Inflamação/patologia , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Fatores de Transcrição Forkhead/farmacologia , Sulfato de Dextrana/toxicidade , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Colo/metabolismo
14.
Ann Med ; 56(1): 2337712, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38614128

RESUMO

Background: Ulcerative colitis (UC), which is characterized by chronic relapsing inflammation of the colon, results from a complex interaction of factors involving the host, environment, and microbiome. The present study aimed to investigate the gut microbial composition and metabolic variations in patients with UC and their spouses. Materials and Methods: Fecal samples were collected from 13 healthy spouses and couples with UC. 16S rRNA gene amplicon sequencing and metagenomics sequencing were used to analyze gut microbiota composition, pathways, gene expression, and enzyme activity, followed by the Kyoto Encyclopedia of Genes and Genomes. Results: We found that the microbiome diversity of couples with UC decreased, especially that of UC patients. Bacterial composition, such as Firmicutes, was altered between UC patients and healthy controls, but was not significantly different between UC patients and their spouses. This has also been observed in pathways, such as metabolism, genetic information processing, organismal systems, and human diseases. However, the genes and enzymes of spouses with UC were not significantly different from those of healthy individuals. Furthermore, the presence of Faecalibacterium correlated with oxidative phosphorylation, starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, and the bacterial secretion system, showed a marked decline in the UC group compared with their spouses, but did not vary between healthy couples. Conclusion: Our study revealed that cohabitation with UC patients decreased differences in the gut microbiome between healthy individuals and patients. Not only was the composition and diversity of the microbiota diminished, but active pathways also showed some decline. Furthermore, Firmicutes, Faecalibacterium, and the four related pathways may be associated with the pathological state of the host rather than with human behavior.


Assuntos
Colite Ulcerativa , Microbioma Gastrointestinal , Microbiota , Humanos , Microbioma Gastrointestinal/genética , Colite Ulcerativa/genética , RNA Ribossômico 16S/genética , Inflamação
15.
J Colloid Interface Sci ; 657: 921-930, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38091915

RESUMO

As a typical spinel oxide, nickel cobaltite (NiCo2O4) is considered to be a promising and reliable oxygen evolution reaction (OER) catalyst due to its abundant oxidation states and the synergistic effect of multiple metal species. However, the electrocatalytic OER performance of NiCo2O4 has always been limited by the low specific surface area and poor intrinsic conductivity of spinels. Herein, the hedgehog-like molybdenum-doped NiCo2O4 (Mo-NiCo2O4) catalyst was prepared as an efficient OER electrocatalyst via a facile hydrothermal method followed with high-temperature annealing. The Mo-NiCo2O4-0.075 with Mo doping concentration of âˆ¼ 1.95 wt% exhibits excellent OER performance with a low overpotential of 265 mV at a current density of 10 mA·cm-2and a Tafel slope of 126.63 mV·dec-1, as well as excellent cyclingstability.The results demonstrated that the hedgehog-like structure provides Mo-NiCo2O4 with the high surface area and mesopores that enhance electrolyte diffusion and optimal active site exposure. The in-situ Raman spectra and density functional theory calculations show that the Mo cations doping improve the intrinsic conductivity of the NiCo2O4 while modulating the chemisorption of intermediates. Meanwhile, the energy barriers of *OH and O* formation decrease significantly after Mo doping, effectively facilitating water dissociation and optimizing the reaction kinetics.

16.
Chem Commun (Camb) ; 60(22): 3067-3070, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38386357

RESUMO

MnO2-Mn3O4 heterostructure materials are applied in aqueous magnesium ion energy storage for the first time. The heterostructure yields an exceptionally high pseudocapacitance contribution, resulting in a specific capacitance of 313.5 F g-1 at 1 A g-1, which contrasts with that of MnO2 (108.8 F g-1) and Mn3O4 (123.5 F g-1). Additionally, it shows potential for practical applications as a cathode for magnesium ion hybrid supercapacitors (MHS).

17.
Dalton Trans ; 53(4): 1640-1647, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38167672

RESUMO

Manganese oxides are commonly employed as a cathode for magnesium ion storage in aqueous magnesium ion hybrid supercapacitors (MHS). However, sluggish reaction kinetics still hinders their practical application. Herein, we designed K-birnessite-MnO2 and electrostatically spun mulberry-like carbon composites (K-MnO2/HMCs) via an in situ growth technique. Benefiting from the 3D conductive carbon network substrate, the in situ fabricated K-MnO2 exhibits more active sites and provides more interfacial contact area between the electrode material and the electrolyte. This improvement enhances its conductivity, facilitating the rapid transfer of electrons, diffusion of ions, and redox reactions. As a result, K-MnO2/HMC-based MHS achieves a specific capacity of 168 mA h g-1 at 0.5 A g-1, simultaneously exhibiting a superior energy density of 111.1 W h kg-1 at a power density of 505 W kg-1. Furthermore, it demonstrates excellent high rate performance and a long cycling life for aqueous magnesium ion storage, offering new insights for MHS applications.

18.
J Colloid Interface Sci ; 656: 289-296, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-37995399

RESUMO

Currently, the development of economical and effective non-noble metal electrocatalysts is vital for advancing hydrogen evolution reaction (HER) and enabling its widespread applications. The customizable pore structure and enormous surface area of metal-organic frameworks (MOFs) have made them to become promising non-noble metal electrocatalysts for HER. However, MOFs have some challenges, including low conductivity and instability, which can result in them having high overpotentials and slow reaction kinetics in electrocatalytic processes. In this work, we present an innovative approach for synthesizing cost-effective and high-efficient Zr-MOF-derived pH-universal electrocatalysts for HER. It entails creating the interfaces of the electrocatalysts with suitable proportions of phosphide nanostructures. Zr-MOF/Ni2P@nickel foam (NF) electrodes with interface regulated by Ni2P nanostructures were successfully developed for high-efficient pH-universal HER electrocatalysts. The presence of Ni2P nanostructures with abundant active sites at the Zr-MOFs@NF interfaces boosted the electronic conductivity and local charge density of the hybrid electrocatalysts. This helped to improve their reaction kinetics and electrocatalytic activity. By optimizing the Ni2P amount, Zr-MOF/Ni2P@NF demonstrated impressive stability and superior HER activities, with a low overpotential of 149 mV (acidic electrolytes) and 143 mV (alkaline electrolytes) at 10 mA cm-2. The proven strategy in this work can be expanded to many types of MOF-based materials for wider practical applications.

19.
Tob Induc Dis ; 222024.
Artigo em Inglês | MEDLINE | ID: mdl-38686042

RESUMO

INTRODUCTION: This study aimed to investigate the effects of nicotine on the activation of pancreatic stellate cells (PSCs) and pancreatic fibrosis in chronic pancreatitis (CP), along with its underlying molecular mechanisms. METHODS: This was an in vivo and in vitro study. In vitro, PSCs were cultured to study the effects of nicotine on their activation and oxidative stress. Transcriptome sequencing was performed to identify potential signaling pathways involved in nicotine action. And the impact of nicotine on mitochondrial Ca2+ levels and Ca2+ transport-related proteins in PSCs was analyzed. The changes in nicotine effects were observed after the knockdown of the mitochondrial calcium uniporter (MCU) in PSCs. In vivo experiments were conducted using a mouse model of CP to assess the effects of nicotine on pancreatic fibrosis and oxidative stress in mice. The alterations in nicotine effects were observed after treatment with the MCU inhibitor Ru360. RESULTS: In vitro experiments demonstrated that nicotine promoted PSCs activation, characterized by increased cell proliferation, elevated α-SMA and collagen expression. Nicotine also increased the production of reactive oxygen species (ROS) and cellular malondialdehyde (MDA), exacerbating oxidative stress damage. Transcriptome sequencing revealed that nicotine may exert its effects through the calcium signaling pathway, and it was verified that nicotine elevated mitochondrial Ca2+ levels and upregulated MCU expression. Knockdown of MCU reversed the effects of nicotine on mitochondrial calcium homeostasis, improved mitochondrial oxidative stress damage and structural dysfunction, thereby alleviating the activation of PSCs. In vivo validation experiments showed that nicotine significantly aggravated pancreatic fibrosis in CP mice, promoted PSCs activation, exacerbated pancreatic tissue oxidative stress, and increased MCU expression. However, treatment with Ru360 significantly mitigated these effects. CONCLUSIONS: This study confirms that nicotine upregulates the expression of MCU, leading to mitochondrial calcium overload and exacerbating oxidative stress in PSCs, and ultimately promoting PSCs activation and exacerbating pancreatic fibrosis in CP.

20.
Nanomaterials (Basel) ; 14(12)2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38921884

RESUMO

Photocatalysis represents a sustainable strategy for addressing energy shortages and global warming. The main challenges in the photocatalytic process include limited light absorption, rapid recombination of photo-induced carriers, and poor surface catalytic activity for reactant molecules. Defect engineering in photocatalysts has been proven to be an efficient approach for improving solar-to-chemical energy conversion. Sulfur vacancies can adjust the electron structure, act as electron reservoirs, and provide abundant adsorption and activate sites, leading to enhanced photocatalytic activity. In this work, we aim to elucidate the role of sulfur vacancies in photocatalytic reactions and provide valuable insights for engineering high-efficiency photocatalysts with abundant sulfur vacancies in the future. First, we delve into the fundamental understanding of photocatalysis. Subsequently, various strategies for fabricating sulfur vacancies in photocatalysts are summarized, along with the corresponding characterization techniques. More importantly, the enhanced photocatalytic mechanism, focusing on three key factors, including electron structure, charge transfer, and the surface catalytic reaction, is discussed in detail. Finally, the future opportunities and challenges in sulfur vacancy engineering for photocatalysis are identified.

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