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1.
Inorg Chem ; 63(19): 8925-8937, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38683480

RESUMO

The development of efficient urea oxidation reaction (UOR) catalysts helps UOR replace the oxygen evolution reaction (OER) in hydrogen production from water electrolysis. Here, we prepared Fe-doped Ni2P/NiSe2 composite catalyst (Fe-Ni2P/NiSe2-12) by using phosphating-selenizating and acid etching to increase the intrinsic activity and active areas. Spectral characterization and theoretical calculations demonstrated that electrons flowed through the Ni-P-Fe-interface-Ni-Se-Fe, thus conferring high UOR activity to Fe-Ni2P/NiSe2-12, which only needed 1.39 V vs RHE to produce the current density of 100 mA cm-2. Remarkably, this potential was 164 mV lower than that required for the OER under the same conditions. Furthermore, EIS demonstrated that UOR driven by the Fe-Ni2P/NiSe2-12 exhibited faster interfacial reactions, charge transfer, and current response compared to OER. Consequently, the Fe-Ni2P/NiSe2-12 catalyst can effectively prevent competition with OER and NSOR, making it suitable for efficient hydrogen production in UOR-assisted water electrolysis. Notably, when water electrolysis is operated at a current density of 40 mA cm-2, this UOR-assisted system can achieve a decrease of 140 mV in the potential compared to traditional water electrolysis. This study presents a novel strategy for UOR-assisted water splitting for energy-saving hydrogen production.

2.
Inorg Chem ; 63(8): 3702-3711, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38335057

RESUMO

A long-term goal of rechargeable zinc-air batteries (ZABs) has always been to design bifunctional electrocatalysts that are robust, effective, and affordable for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). It has become a feasible method to construct metal/metal oxide interfaces to achieve superior electrocatalytic performance for ORR and OER by enhanced charge transfer. In this study, Co/Co3O4 heterojunctions were successfully prepared and encased in porous N-doped mesoporous carbon (Co/Co3O4@NC) via a simple condensation-carbonization-etching method. The extensive specific surface area of Co/Co3O4@NC facilitates effective interaction between the electrolyte and the catalyst, thereby enabling sufficient exposure of active sites for the ORR and the OER, consequently enhancing the rate of transport of active species. The well-designed Co/Co3O4@NC delivers superior ORR catalytic activity with a half-wave potential of 0.82 V (vs RHE) and a low overpotential of 347 mV at 10 mA cm-2 for OER in alkaline solution. The power density of Co/Co3O4@NC-based alkaline aqueous ZAB (156.5 mW cm-2) is superior to the commercial Pt/C + IrO2-based alkaline aqueous ZAB, and the cycling stability of ZAB is up to 220 h. In addition, Co/Co3O4@NC-based ZAB shows a high power density (50.1 mW cm-2). The construction of metal/metal oxide heterojunction encased in N-doped mesoporous carbon provides a novel route for the design of bifunctional electrocatalysts for high-performance ZABs.

3.
RSC Adv ; 11(5): 2774-2782, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35747077

RESUMO

LC-HRMS/MS molecular networking enabled the targeted isolation of three new neoantimycin analogs (1, 3, 5) and two known ones (2, 4) from the culture broth of Streptomyces conglobatus RJ8. After derivatization into C1-hydroxyl form compounds (6-10) respectively, the absolute structures of 1-5 were clearly determined by analyzing the hydrolyzed components from 6-10. Compounds 2 and 3 were confirmed to be a pair of epimers with different stereochemistry at C-2, and so were 4 and 5. This is the first report of the isolation and characterization of epimers of NATs. The most abundant eight compounds we obtained were subjected to a cytotoxicity assay, 1 and 6 exhibited excellent cytotoxicity with the lowest IC50 value in the picomolar range against six human carcinoma cell lines while 7 and 8 showed potent cytotoxicity against PC-9 and PC-9/GR cell lines.

4.
J Org Chem ; 86(16): 10954-10961, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-33052677

RESUMO

Asperfloketals A (1) and B (2), two 1(10 → 6)-abeo-14,15-secosteroids featuring a novel trioxahexaheterocyclic ring system, were isolated from the sponge-associated fungus Aspergillus flocculosus 16D-1. Their structures were elucidated by extensive spectroscopic analysis and NMR chemical shifts calculations, supported by DP4+ probability analysis, and their absolute configurations were determined by ECD calculations and the modified Mosher's method. Asperfloketals A and B showed strong anti-inflammatory activity in the CuSO4-induced transgenic fluorescent zebrafish but displayed no cytotoxicity against HeLa, HepG2, and SW480 cell lines.


Assuntos
Aspergillus , Peixe-Zebra , Animais , Ergosterol/análogos & derivados , Estrutura Molecular
5.
Cell Death Dis ; 11(11): 971, 2020 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-33184264

RESUMO

Vagus nerve stimulation (VNS) restores autonomic balance, suppresses inflammation action and minimizes cardiomyocyte injury. However, little knowledge is known about the VNS' role in cardiomyocyte phenotype, sarcomere organization, and energy metabolism of infarcted hearts. VNS in vivo and acetylcholine (ACh) in vitro optimized the levels of α/ß-MHC and α-Actinin positive sarcomere organization in cardiomyocytes while reducing F-actin assembly of cardiomyocytes. Consistently, ACh improved glucose uptake while decreasing lipid deposition in myocytes, correlating both with the increase of Glut4 and CPT1α and the decrease of PDK4 in infarcted hearts in vivo and myocytes in vitro, attributing to improvement in both glycolysis by VEGF-A and lipid uptake by VEGF-B in response to Ach. This led to increased ATP levels accompanied by the repaired mitochondrial function and the decreased oxygen consumption. Functionally, VNS improved the left ventricular performance. In contrast, ACh-m/nAChR inhibitor or knockdown of VEGF-A/B by shRNA powerfully abrogated these effects mediated by VNS. On mechanism, ACh decreased the levels of nuclear translocation of FoxO3A in myocytes due to phosphorylation of FoxO3A by activating AKT. FoxO3A overexpression or knockdown could reverse the specific effects of ACh on the expression of VEGF-A/B, α/ß-MHC, Glut4, and CPT1α, sarcomere organization, glucose uptake and ATP production. Taken together, VNS optimized cardiomyocytes sarcomere organization and energy metabolism to improve heart function of the infarcted heart during the process of delaying and/or blocking the switch from compensated hypertrophy to decompensated heart failure, which were associated with activation of both P13K/AKT-FoxO3A-VEGF-A/B signaling cascade.


Assuntos
Proteína Forkhead Box O3/metabolismo , Insuficiência Cardíaca/metabolismo , Miócitos Cardíacos/metabolismo , Sarcômeros/metabolismo , Estimulação do Nervo Vago/métodos , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator B de Crescimento do Endotélio Vascular/metabolismo , Animais , Diferenciação Celular/fisiologia , Metabolismo Energético , Insuficiência Cardíaca/patologia , Masculino , Miócitos Cardíacos/patologia , Fenótipo , Ratos , Ratos Sprague-Dawley , Sarcômeros/patologia , Transdução de Sinais
6.
Org Lett ; 22(17): 6703-6708, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32701300

RESUMO

A neutral-loss scanning mass method was used to explore new kynurenine-containing cycloheptapeptides, phakefustatins A-C (1-3), from the marine sponge Phakellia fusca. Their structures were elucidated by spectroscopic analysis and the advanced Marfey's method. 1 was total synthesized via a final-stage ozonolysis strategy by the combination of solid/solution-phase synthesis. Phakefustatin A (1) was identified as a RXRα modulator to inhibit cancer cell growth, and its pharmacophores could be Kyn and guanidine groups.


Assuntos
Cinurenina/química , Peptídeos Cíclicos/química , Poríferos/química , Animais , Estrutura Molecular , Análise Espectral
7.
Org Lett ; 22(5): 1825-1829, 2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-32057246

RESUMO

Three unusual chlorinated PKS-NRPS hybrid metabolites, flavipesides A-C (1-3), were isolated from a strain of marine sponge symbiotic fungus Aspergillus flavipes 164013. Their structures were determined by spectroscopic data analysis, and absolute configurations were assigned by single-crystal X-ray diffraction with ECD spectral analysis. Flavipesides A-C showed potent pancreatic lipase (PL) inhibitory activity with IC50 values of 0.07-0.23 µM.


Assuntos
4-Butirolactona/análogos & derivados , Aspergillus/química , Inibidores Enzimáticos/farmacologia , Fungos/química , Lipase/metabolismo , 4-Butirolactona/química , 4-Butirolactona/isolamento & purificação , 4-Butirolactona/farmacologia , Animais , Cristalografia por Raios X , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Fungos/metabolismo , Lipase/química , Estrutura Molecular , Poríferos/química , Análise Espectral
8.
J Nat Prod ; 82(4): 970-979, 2019 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-30844272

RESUMO

Four new cycloheptapeptides, fuscasins A-D (1-4), were isolated from the marine sponge Phakellia fusca collected from the South China Sea. Their planar structures were fully characterized by spectroscopic methods, and the absolute configurations of amino acid residues were determined using the advanced Marfey's method. Structurally, 1 is a unique cycloheptapeptide with a backbone bearing a pyrrolidine-2,5-dione unit. Among the isolated compounds, 1 exhibited potent growth-inhibitory activity against HepG2 cells with an IC50 value of 4.6 µM, whereas it did not show apparent inhibitory effects against the other five human cancer cell lines, MCF-7, HeLa, NCI-H460, PC9, and SW480. Encouragingly, 1 exhibited no cytotoxicity against nonmalignant cells even with a concentration up to 100 µM. These findings suggest that 1 may display a selective inhibitory effect on the growth of HepG2 cells.


Assuntos
Peptídeos Cíclicos/isolamento & purificação , Poríferos/química , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Biologia Marinha
9.
Org Lett ; 21(3): 767-770, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30676034

RESUMO

Three unusual meroterpenoids, septosones A-C (1-3), were isolated from the marine sponge Dysidea septosa. The structures were determined by analysis of spectroscopic data combined with single-crystal X-ray diffraction and ECD calculations. Septosone A (1) features an unprecedented "septosane" carbon skeleton, whereas septosones B (2) and C (3) share a rare spiro[4.5]decane motif. Septosone A showed in vivo anti-inflammatory activity in CuSO4-induced transgenic fluorescent zebrafish likely through inactivation of the NF-κB signaling pathway.


Assuntos
Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Carbono/química , Dysidea/química , Terpenos/química , Terpenos/farmacologia , Animais , Células HEK293 , Humanos , Modelos Moleculares , Conformação Molecular , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Peixe-Zebra
10.
Int J Syst Evol Microbiol ; 69(3): 715-720, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30605079

RESUMO

A novel marine actinomycete, designated LHW63014T, isolated from a marine sponge, Craniella species, collected in the South China Sea, was examined using a polyphasic approach. The 16S rRNA gene sequence of strain LHW63014T showed highest similarities to Jishengella endophytica 202201T (98.9 %), Micromonospora olivasterospora DSM 43868T (98.7 %), Micromonospora maris AB-18-032T (98.6 %) and Micromonospora gifhornensis DSM 44337T (98.6 %). Phylogenetic analyses of the family Micromonosporaceae based on the 16S rRNA and gyrB gene sequences indicated that strain LHW63014T and J. endophytica 202201T located within the genus Micromonospora. Morphological and chemotaxonomic characteristics confirmed their affiliation to the genus Micromonospora. Based on phenotypic characteristics, phylogenetic data and digital DNA-DNA hybridization results, strain LHW63014T could be distinguished from its closest taxa, representing a novel species of the genus Micromonospora, for which the name Micromonospora craniellae sp. nov., is proposed, with the type strain LHW63014T (=DSM 106193T=CCTCC AA 2018012T). It is also proposed that J. endophytica be transferred to genus Micromonospora as Micromonospora endophytica comb. nov. (type strain 202201T =CGMCC 4.5597T=DSM 45430T).


Assuntos
Micromonospora/classificação , Filogenia , Poríferos/microbiologia , Animais , Técnicas de Tipagem Bacteriana , China , DNA Bacteriano/genética , Genes Bacterianos , Micromonospora/isolamento & purificação , Micromonosporaceae/classificação , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
11.
Acta Paul. Enferm. (Online) ; 31(2): 162-169, Mar.-Abr. 2018. tab, graf
Artigo em Inglês | LILACS, BDENF - Enfermagem | ID: biblio-949274

RESUMO

Abstract Objective This study aimed to determine the differences in learning style preferences among bachelor degree nursing students at Central South University and associate degree nursing students at the Vocational Health School in China. Methods This study was a cross-sectional survey using the Chinese version of the VARK questionnaire to assess preferred learning styles: 159 enrolled bachelor degree nursing students and 199 enrolled associate degree nursing students completed the questionnaire with a response rate of 96.8%. Results The bachelor degree nursing students tend to prefer a multimodal learning style (58.49%), which significantly differed from that of associate degree nursing students (45.77%). The kinaesthetic modality was the predominant unimodal learning style among the bachelor degree and associate degree nursing students (18.20% and 33.67%), and the read-write modality was the least popular modality (2.5% and 4.02%). Conclusion There are both differences and similarities between the learning style preferences of bachelor degree and associate degree nursing students. Educational background is one of the most critical factors that influence the learning style preference of nursing students. This finding may be necessary and beneficial for carrying out future curricula reform. In addition, further comprehensive research should be conducted to examine the relationships between learning style preferences and academic performance, as well as learning style preferences and teaching methods.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Adulto Jovem , Estudantes de Enfermagem , Ensino , Inquéritos e Questionários , Bacharelado em Enfermagem , Aprendizagem , China , Estudos Transversais
12.
Res Microbiol ; 165(8): 639-46, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25261719

RESUMO

The utilization of amorphous µ-S and orthorhombic α-S8 by thermoacidophile Sulfobacillus thermosulfidooxidans was firstly investigated in terms of cell growth and sulfur oxidation behavior. The morphology and surface sulfur speciation transformation were evaluated by using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), Raman spectroscopy and sulfur K-edge X-ray absorption near edge structure (XANES) spectroscopy. The results showed that the strain grown on µ-S entered slower (about 1 day later) into the exponential phase, while grew faster in exponential phase and attained higher maximal cell density and lower pH than on α-S8. After bio-corrosion, both sulfur samples were evidently eroded, but only µ-S surface presented much porosity, while α-S8 maintained glabrous. µ-S began to be gradually converted into α-S8 from day 2 when the bacterial cells entered the exponential phase, with a final composition of 62.3% µ-S and 37.7% α-S8 on day 4 at the stationary phase. α-S8 was not found to transform into other species in the experiments with or without bacteria. These data indicated S. thermosulfidooxidans oxidized amorphous µ-S faster than orthorhombic α-S8, but the chain-like µ-S was transformed into cyclic α-S8 by S. thermosulfidooxidans.


Assuntos
Bactérias Gram-Positivas/crescimento & desenvolvimento , Bactérias Gram-Positivas/metabolismo , Enxofre/química , Enxofre/metabolismo , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Oxirredução , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Espectroscopia por Absorção de Raios X , Difração de Raios X
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