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1.
World J Microbiol Biotechnol ; 40(2): 48, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38114804

RESUMO

Salmonella is a major cause of foodborne diseases and clinical infections worldwide. This study aimed to investigate the drug resistance, genomic characteristics, and protein expression of foodborne Salmonella in Shanxi Province. We isolated a strain of Salmonella Enteritidis from patient feces and designated it 31A. The drug resistance of 31A against 14 antibiotics was determined using an antimicrobial susceptibility test. Whole-genome sequencing and quantitative proteomic analysis were performed on the 31A strain. Functional annotation of drug resistance genes/proteins and virulence genes/proteins was conducted using various databases, such as VFDB, ARDB, CAZY, COG, KOG, CARD, GO, and KEGG. The focus of this study was understanding the mechanisms related to food poisoning, and the genetic evolution of 31A was analyzed through comparative genomics. The 31A strain belonged to ST11 Salmonella Enteritidis and showed resistance to ß-lactam and quinolone antibiotics. The genome of 31A had 70 drug resistance genes, 321 virulence genes, 12 SPIs, and 3 plasmid replicons. Functional annotation of these drug resistance and virulence genes revealed that drug resistance genes were mainly involved in defense mechanisms to confer resistance to antibiotics, while virulence genes were mainly associated with cellular motility. There were extensive interactions among the virulence genes, which included SPI-1, SPI-2, flagella, fimbriae, capsules and so on. The 31A strain had a close relationship with ASM2413794v1 and ASM130523v1, which were also ST11 Salmonella Enteritidis strains from Asia and originated from clinical patients, animals, and food. These results suggested minimal genomic differences among strains from different sources and the potential for interhost transmission. Differential analysis of the virulence and drug resistance-related proteins revealed their involvement in pathways related to human diseases, indicating that these proteins mediated bacterial invasion and infection. The integration of genomic and proteomic information led to the discovery that Salmonella can survive in a strong acid environment through various acid resistance mechanisms after entering the intestine with food and then invade intestinal epithelial cells to exert its effects. In this study, we comprehensively analyzed the drug resistance and virulence characteristics of Salmonella Enteritidis 31A using a combination of genomic and proteomic approaches, focusing on the pathogenic mechanism of Salmonella Enteritidis in food poisoning. We found significant fluctuations in various virulence factors during the survival, invasion, and infection of Salmonella Enteritidis, which collectively contributed to its pathogenicity. These results provide important information for the source tracing, prevention, and treatment of clinical infections caused by Salmonella Enteritidis.


Assuntos
Doenças Transmitidas por Alimentos , Salmonella enteritidis , Animais , Humanos , Salmonella enteritidis/genética , Proteômica , Antibacterianos/farmacologia , Genômica , Diarreia
2.
Int J Mol Sci ; 23(20)2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36293508

RESUMO

Bismuth ferrite-based heterojunction composites have been considered as promising visible-light responsive photocatalysts because of their narrow band gap structure; however, the synthetic methods reported in the literature were usually time-consuming. In this study, we report a facile and quick preparation of bismuth ferrite-based composites by the hydrothermal method, combined with spark plasma sintering (SPS), a technique that is usually used for the high-speed consolidation of powders. The result demonstrated that the SPS-assisted synthesized samples possess significant enhanced photoelectric and photocatalytic performance. Specifically, the SPS650 (sintered at the 650 °C for 5 min by SPS) exhibits a 1.5 times enhancement in the photocurrent density and a 3.8 times enhancement in the tetracycline hydrochloride photodegradation activity than the unmodified bismuth ferrite samples. The possible influence factors of SPS on photoelectric and photocatalytic performance of bismuth ferrite-based composites were discussed carefully. This study provides a feasible method for the facile and quick synthesis of a highly active bismuth ferrite-based visible-light-driven photocatalyst for practical applications.


Assuntos
Antibacterianos , Bismuto , Bismuto/química , Antibacterianos/química , Tetraciclina , Catálise , Pós , Luz
3.
Xenobiotica ; 51(8): 871-876, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34082641

RESUMO

The effect of 4-O-galloylalbiflorin on the activity of cytochrome P450 enzymes (CYP450s) is an important factor that may induce drug-drug interaction.The effect of 4-O-galloylalbiflorin on the activity of CYP450s was evaluated in the presence of 0, 2.5, 5, 10, 25, 50, and 100 µM 4-O-galloylalbiflorin in pooled human liver microsomes. The inhibition model and corresponding parameters were assessed b fitting with Lineweaver-Burk plots. The time-dependent study was performed with the incubation time of 0, 5, 10, 15, and 30 min.4-O-galloylalbiflorin significantly inhibited the activity of CYP3A, 2C9, and 2 D in a concentration-dependent manner with the IC50 values of 8.2, 13, and 11 µM, respectively. The inhibition of CYP3A was found to be non-competitive and time-dependent with the Ki value of 4.0 µM and the KI/Kinact value of 2.2/0.030 (µM·min). The inhibition of CYP2C9 and 2 D was not affected by the incubation time but was found to be competitive with the Ki values of 6.7 and 6.6 µM, respectively.The inhibitory effect of 4-O-galloylalbiflorin on the activity of CYP3A, 2C9, and 2 D implying the potential drug-drug interaction between 4-O-galloylalbiflorin and the drugs metabolized by these CYP450s.


Assuntos
Inibidores das Enzimas do Citocromo P-450 , Microssomos Hepáticos , Citocromo P-450 CYP3A , Inibidores das Enzimas do Citocromo P-450/farmacologia , Sistema Enzimático do Citocromo P-450 , Glicosídeos , Humanos , Monoterpenos
4.
J Colloid Interface Sci ; 657: 728-737, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38071821

RESUMO

The exploration of highly efficient sunlight-assisted photocatalyst for photodegradation of organic contaminants or energy conversion is strongly encouraged. In this work, we designed a novel three-dimensional spindle-like Sv-ZIS@NMFe heterojunction made of amino functionalized NH2-MIL-88B(Fe) (NMFe) and ZnIn2S4 nanosheets with abundant sulfur vacancies (Sv-ZIS). The structural properties of NMFe materials, such as a clearly defined system of pores and cavities, were retained by the Sv-ZIS@NMFe composites. Additionally, the incorporation of sulfur vacancies, -NH2 functional groups, and well-matched energy level positions led to various synergistic effects that considerably enhanced internal electron transformation and migration, as well as improved adsorption performance. Consequently, under visible light irradiation, the optimized sample exhibited superior hydrogen production activity and tetracycline hydrochloride photodegradation performance. At last, density functional theory calculations was used to further elucidated the possible photoreactivity mechanism. This study demonstrates that the Sv-ZIS@NMFe heterojunction materials formed by ZnIn2S4 with suitable sulfur vacancies and amino functionalized Fe-MOFs have promising applications in photocatalysis.

5.
Infect Drug Resist ; 16: 3271-3292, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37255882

RESUMO

Staphylococcus aureus is a common human pathogen with a variety of virulence factors, which can cause multiple infectious diseases. In recent decades, due to the constant evolution and the abuse of antibiotics, Staphylococcus aureus was becoming more resistant, the infection rate of MRSA remained high, and clinical treatment of MRSA became more difficult. The genetic diversity of MRSA was mainly represented by the continuous emergence of epidemic strains, resulting in the constant changes of epidemic clones. Different classes of MRSA resulted in different epidemics and resistance characteristics, which could affect the clinical symptoms and treatments. MRSA had also spread from traditional hospitals to community and livestock environments, and the new clones established a relationship between animals and humans, promoting further evolution of MRSA. Since the resistance mechanism of MRSA is very complex, it is important to clarify these resistance mechanisms at the molecular level for the treatment of infectious diseases. We firstly described the diversity of SCCmec elements, and discussed the types of SCCmec, its drug resistance mechanisms and expression regulations. Then, we described how the vanA operon makes Staphylococcus aureus resistant to vancomycin and its expression regulation. Finally, a brief introduction was given to the drug resistance mechanisms of biofilms and efflux pump systems. Analyzing the resistance mechanism of MRSA can help study new anti-infective drugs and alleviate the evolution of MRSA. At the end of the review, we summarized the treatment strategies for MRSA infection, including antibiotics, anti-biofilm agents and efflux pump inhibitors. To sum up, here we reviewed the epidemic characteristics of Staphylococcus aureus, summarized its classifications, drug resistance mechanisms of MRSA (SCCmec element, vanA operon, biofilm and active efflux pump system) and novel therapy strategies, so as to provide a theoretical basis for the treatment of MRSA infection.

6.
Front Microbiol ; 14: 1273397, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37808303

RESUMO

Staphylococcus aureus (S. aureus) is an important zoonotic pathogen that causes a high incidence rate and mortality worldwide. This study investigated the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) strains in a tertiary A hospital in Shanxi Province, China, in order to determine the major epidemic clones as well as their antibiotic resistance and virulence characteristics. A total of 212 S. aureus strains were collected in this hospital, and were subjected to antimicrobial susceptibility testing, detection of virulence genes, resistance genes, and efflux pump genes. Among them, 38 MRSA strains were further subjected to detection of biofilm genes, assessment of biofilm formation ability, MLST, spa typing, SCCmec typing, and phylogenetic analysis. The majority of S. aureus strains came from the neonatology department, with secretions and purulent fluid being the main source of samples. The strains showed high resistance to penicillin (98.11%), erythromycin (64.62%) and clindamycin (59.91%), while being sensitive to vancomycin and linezolid. The detection rates of efflux pump genes and resistance genes were high, and there was a significant correlation between resistance gene types and phenotypes, with mecA showing a close correlation with oxacillin. The detection rates of virulence genes and the toxin gene profiles of MSSA and MRSA strains showed significant differences. And the detection rate of biofilm genes in MRSA strains was relatively high, with 13.16% of MRSA strains showing strong biofilm formation ability. The most common epidemic clone of MRSA was ST59-SCCmecIV-t437, followed by ST59-SCCmecV-t437. The former had a higher detection rate of resistance genes and a stronger biofilm formation ability, while the latter had a higher positive rate for pvl gene and stronger pathogenicity, making it more likely to cause systemic infections. Phylogenetic analysis showed that all MRSA strains in this study clustered into three major branches, with distinct differences in antibiotic resistance and virulence characteristics among the branches. ST59-MRSA strains from different species showed consistency and inter-species transmission, but there were differences among ST59-MRSA strains from different geographical locations. In general, most MSSA and MRSA strains exhibited multidrug resistance and carried multiple resistance genes, virulence genes, and biofilm formation genes, warranting further research to elucidate the mechanisms of drug resistance and pathogenesis.

7.
Nanomicro Lett ; 15(1): 106, 2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37071313

RESUMO

Low-dimensional transition metal dichalcogenides (TMDs) have unique electronic structure, vibration modes, and physicochemical properties, making them suitable for fundamental studies and cutting-edge applications such as silicon electronics, optoelectronics, and bioelectronics. However, the brittleness, low toughness, and poor mechanical and electrical stabilities of TMD-based films limit their application. Herein, a TaS2 freestanding film with ultralow void ratio of 6.01% is restacked under the effect of bond-free van der Waals (vdW) interactions within the staggered 2H-TaS2 nanosheets. The restacked films demonstrated an exceptionally high electrical conductivity of 2,666 S cm-1, electromagnetic interference shielding effectiveness (EMI SE) of 41.8 dB, and absolute EMI SE (SSE/t) of 27,859 dB cm2 g-1, which is the highest value reported for TMD-based materials. The bond-free vdW interactions between the adjacent 2H-TaS2 nanosheets provide a natural interfacial strain relaxation, achieving excellent flexibility without rupture after 1,000 bends. In addition, the TaS2 nanosheets are further combined with the polymer fibers of bacterial cellulose and aramid nanofibers via electrostatic interactions to significantly enhance the tensile strength and flexibility of the films while maintaining their high electrical conductivity and EMI SE.This work provides promising alternatives for conventional materials used in EMI shielding and nanodevices.

8.
Infect Drug Resist ; 16: 6567-6586, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37823028

RESUMO

Objective: This paper explores the drug resistance, genome and proteome expression characteristics of Salmonella from a food poisoning event. Methods: A multidrug-resistant Salmonella Enteritidis strain, labeled as 27A, was isolated and identified from a food poisoning patient. Antimicrobial susceptibility testing determined the resistance of 27A strain to 14 antibiotics. Then, WGS analysis and comparative genomics analysis were performed on 27A, and the functional annotation of resistance genes, virulence genes were performed based on VFDB, ARDB, COG, CARD, GO, KEGG, and CAZY databases. Meanwhile, based on iTRAQ technology, quantitative proteomic analysis was conducted on 27A to analyze the functions and interactions of differentially expressed proteins related to bacterial resistance and pathogenicity. Results: Strain 27A belonged to ST11 S. Enteritidis and was resistant to levofloxacin, ciprofloxacin, ampicillin, piperacillin, and ampicillin/sulbactam. There were 33 drug resistance genes, 384 virulence genes and 2 plasmid replicon, IncFIB(S) and IncFII(S), annotated by WGS. Proteomic analysis revealed significant changes in virulence and drug proteins, which were mainly involved in bacterial pathogenicity and metabolic processes. PPI prediction showed the relationship between virulence proteins and T3SS proteins, and PagN cooperated with proteins related to T3SS to jointly mediate the invasion of 27A strain on the human body. Phylogenetic analysis indicated that S. Enteritidis has potential transmission in humans, food, and animals. Conclusion: This study comprehensively analyzed the drug resistance and virulence phenotypes of S. Enteritidis 27A using genomic and proteomic approaches. These helps reveal the drug resistance and virulence mechanisms of S. Enteritidis, and provides important information for the source tracing and the prevention of related diseases, which lays a foundation for research on food safety, public health monitoring, and the drug resistance and pathogenicity of S. Enteritidis.

9.
ACS Appl Mater Interfaces ; 14(4): 5940-5950, 2022 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-35073693

RESUMO

The exploration of lightweight and compressible electromagnetic interference (EMI) shielding materials with outstanding shielding effectiveness (SE) is still a tremendous challenge in the elimination of electromagnetic pollution. Lightweight and highly compressible expandable polymer microsphere/silver nanowire (EPM/AgNW) composites with micron-sized closed pores and an interfacial AgNW conductive network are fabricated via a facile thermal expansion process in an enclosed space. The EPM/AgNW composites with AgNW loading of 0.127 vol % show low density (0.061 g/cm3), high compressibility and compression strength (4.25 MPa at 92.6% of compressive strain), and high EMI SE (over 40 dB, 1 mm) at a wideband of 8-40 GHz. Their EMI SE can be improved to a record 111.5 dB by increasing the AgNW content to 0.340 vol %, which corresponds to the surface-specific SE (SSE/d; SE divided by density and thickness) up to 13433 dB·cm2/g. The EMI shielding mechanism is further discussed using the finite-element analysis software COMSOL Multiphysics, and the application of the EPM/AgNW composites is visually demonstrated via near-field shielding in a practical antenna radiation. The overall properties of light weight, high elasticity, excellent mechanical strength, and outstanding EMI shielding performance suggest that the as-prepared EPM/AgNW composites have a great potential for applications in modern electronics.

10.
Nanomaterials (Basel) ; 11(1)2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33406718

RESUMO

Photocatalytic hydrogen evolution is a promising" green chemistry" route driven by sunlight for the direct water splitting into value-added hydrogen energy. Herein, with the object of exploring the effect of CuO loading on W18O49 photocatalytic activity, a 3D Urchin-like CuO modified W18O49 (CuO/W18O49) microspheres with different CuO loadings were synthesized via thermochemical precipitation combined with solvent-thermal method. The obtained CuO/W18O49 microspheres were analyzed by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL), etc. The results infer that the urchin-like 3D morphology with a high surface area and abundant 1D nanowires promotes electron transfer, the introduction of CuO further increases the number of active sites, thereby ensuring fast interfacial charge transfer to improve photocatalytic performance. During photocatalytic H2 evolution from water splitting, 5 wt.% CuO/W18O49 shows the optimal performance, the H2 yield is almost 3.22 times that of the undoped counterparts. This work presents that oxygen-vacancy-rich heterojunction nanocomposites can be used as a new strategy to design materials with high photocatalytic activity.

11.
Biomed Res Int ; 2020: 5481653, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33344641

RESUMO

Acute radiation enteritis (ARE) is a common complication with radiotherapy for pelvic and abdominal malignancy. This research is designed to investigate the efficacy of Tong-Xie-Yao-Fang (TXYF) on ARE and to explore the underlying mechanisms by microarray analysis. The ARE rat model was established by a single abdominal irradiation with a gamma-ray dose of 10 Gy. Next, the ARE rats were treated with distilled water, TXYF, and glutamine by gavage for 7 consecutive days according to the scheduled groups. For each group, the jejunal tissue was taken at 6 h after gastric lavage. The morphology of intestinal tissue was observed by hematoxylin and eosin (H&E) stain under a light microscope. The height of the villus and the thickness of the whole layer of the TXYF-treated groups were significantly ameliorative than that of the model control group. The transcriptome analysis was produced using the Agilent SurePrint G3 Rat GE V2.0 microarray. A total of 90 differentially expressed genes (DEGs), including 48 upregulated genes and 42 downregulated genes, were identified by microarray and bioinformatics analysis. Protein-protein interaction (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) were conducted to explore the possible mechanisms of DEGs taking part in the TXYF-mediated therapeutic process for ARE. In conclusion, we reveal that TXYF has a protective effect on the intestinal tissue of rats with ARE and summarize several DEGs, suggesting the possible mechanisms of TXYF-mediated efficacy for ARE.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Enterite/tratamento farmacológico , Mucosa Intestinal/patologia , Lesões por Radiação/tratamento farmacológico , Radioterapia/efeitos adversos , Transcriptoma , Animais , Biologia Computacional , Enterite/etiologia , Perfilação da Expressão Gênica , Inflamação , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Fitoterapia , Plantas Medicinais , Mapeamento de Interação de Proteínas , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
12.
Environ Sci Pollut Res Int ; 25(12): 11661-11669, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29435798

RESUMO

In this work, a field test was conducted to investigate the effects of heavy metal stabilizer addition on brown rice and microbial variables in a cadmium (Cd)-contaminated farmland from April to October in 2016. Compared with the control, red mud-based stabilizer (RMDL) effectively reduced the concentration of Cd in brown rice (with the removal rate of 48.14% in early rice, 20.24 and 47.62% in late rice). The results showed that adding 0.3 kg m-2 RDML in early rice soil or soil for both early and late rice increased the microbial biomass carbon (MBC), the number of culturable heterotrophic bacteria and fungi, and the catalase activity in soil at different stages of paddy rice growth. Furthermore, there was no notable difference in the diversity of the bacterial species, community composition, and relative abundance at phylum (or class) or operational taxonomic unit (OTU) levels between the control and treatment (RMDL addition) groups. In a word, RMDL could be highly recommended as an effective remediation stabilizer for Cd-contaminated farmland, since its continuous application in paddy soil cultivating two seasons rice soil could effectively decrease the Cd content in brown rice and had no negative impact on soil microorganisms.


Assuntos
Cádmio/toxicidade , Recuperação e Remediação Ambiental , Fazendas , Microbiologia do Solo , Poluentes do Solo/toxicidade , Solo , Bactérias/efeitos dos fármacos , Bactérias/enzimologia , Biomassa , Cádmio/análise , China , Fungos/efeitos dos fármacos , Fungos/enzimologia , Oryza/crescimento & desenvolvimento , Estações do Ano , Poluentes do Solo/análise
13.
Chemosphere ; 189: 224-238, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28942248

RESUMO

In recent years, advanced oxidation processes (AOPs), especially sulfate radical based AOPs have been widely used in various fields of wastewater treatment due to their capability and adaptability in decontamination. Recently, metal-free carbon materials catalysts in sulfate radical production has been more and more concerned because these materials have been demonstrated to be promising alternatives to conventional metal-based catalysts, but the review of metal-free catalysts is rare. The present review outlines the current state of knowledge on the generation of sulfate radical using metal-free catalysts including carbon nanotubes, graphene, mesoporous carbon, activated carbon, activated carbon fiber, nanodiamond. The mechanism such as the radical pathway and non-radical pathway, and factors influencing of the activation of sulfate radical was also be revealed. Knowledge gaps and research needs have been identified, which include the perspectives on challenges related to metal-free catalyst, heterogeneous metal-free catalyst/persulfate systems and their potential in practical environmental remediation.


Assuntos
Metais/química , Modelos Químicos , Oxirredução , Sulfatos/química , Carbono , Fibra de Carbono , Catálise , Radicais Livres , Grafite , Nanotubos de Carbono , Eliminação de Resíduos Líquidos , Águas Residuárias
14.
Bioresour Technol ; 245(Pt A): 266-273, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28892700

RESUMO

Highly efficient simultaneous removal of Cu(II) and tetracycline (TET) from aqueous solution was accomplished by iron and zinc doped sawdust biochar (Fe/Zn-biochar). The mutual effects and inner mechanisms of their adsorption onto Fe/Zn-biochar were systematically investigated via sole and binary systems, sorption isotherm and adsorption kinetics models. The liquid-film diffusion step might be the rate-limiting step for tetracycline, the interaction of Cu(II) was more likely controlled by both intra particle diffusion model and liquid film diffusion model. The fitting of experimental data with kinetic models, Temkin model indicates that the adsorption process of tetracycline and Cu(II) involve chemisorption, and physico-chemical adsorption, respectively. There exists site competition and enhancement of Cu(II) and tetracycline on the sorption to Fe/Zn-biochar. The results of this study indicate that modification of biochar derived from sawdust shows great potential for simultaneous removal of Cu(II) and tetracycline from co-contaminated water.


Assuntos
Carvão Vegetal , Tetraciclina , Poluentes Químicos da Água , Adsorção , Cobre , Cinética
15.
Eur J Obstet Gynecol Reprod Biol ; 198: 22-26, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26773244

RESUMO

OBJECTIVE: The aim of this study is to determine whether caspase activity and oxidative stress of granulosa cells are associated with the viability and developmental potential of vitrified immature oocytes. STUDY DESIGN: Oocytes from mice were exposed to genistein or/and Z-VAD-FMK with or without vitrification. Ultrastructural alterations of granulosa cells in vitrified immature oocytes were observed. Moreover, the level of superoxide dismutase (SOD) in granulosa cells, incidence of apoptotic follicles, the viability of vitrified-warmed oocytes and their subsequent developmental competence were measured. RESULTS: Ultrastructural alterations of granulosa cells vitrified in the presence of genistein or Z-VAD-FMK were slighter than that of granulosa cells vitrified in the absence of genistein or Z-VAD-FMK. The incidence of apoptotic follicles vitrified in the presence of genistein or Z-VAD-FMK was significantly lower than that of immature oocytes vitrified in the absence of genistein or Z-VAD-FMK, whereas, the level of SOD in granulosa cells, the viability and developmental competence of immature oocytes vitrified in the presence of genistein or Z-VAD-FMK were significantly higher than that of immature oocytes vitrified in the absence of genistein or Z-VAD-FMK. CONCLUSION: Both antioxidant (genistein) and caspase inhibition (Z-VAD-FMK) improve the viability and developmental competence of vitrified immature oocytes. Genistein is superior to Z-VAD-FMK in improving the efficacy of immature oocyte vitrification.


Assuntos
Caspases/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Oócitos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Clorometilcetonas de Aminoácidos , Animais , Apoptose/efeitos dos fármacos , Feminino , Genisteína/farmacologia , Células da Granulosa/efeitos dos fármacos , Células da Granulosa/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Oócitos/efeitos dos fármacos , Capacitação Espermática/fisiologia , Superóxido Dismutase/metabolismo , Vitrificação
16.
Sci Rep ; 4: 7045, 2014 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-25391987

RESUMO

Self-doping TiO2 has recently attracted considerable attention for its high photocatalytic activity under visible-light irradiation. However, the literature reported synthetic methods until now were very time-consuming. In this study, we establish a quick and facile method for obtaining self-doping TiO2 with the use of directly treated commercial P25 at a desired temperature for only 5 min through spark plasma sintering technology. With the using of this method, the modified P25 samples exhibit significantly high photoelectric and photocatalytic performance. Furthermore, the sample prepared at 600 °C exhibits the optimum catalytic activity. The photodegradation and H2 evolution rates of this samples are significantly higher than those of unmodified P25 sample under visible-light irradiation. The physical origin of the visible-light absorption for the modified P25 samples is investigated in detail according to their structural, optical, and electronic properties. This work will provide a quick and facile method for the large-scale synthesis of visible-light driven photocatalyst for practical applications.

17.
ACS Appl Mater Interfaces ; 5(13): 6201-7, 2013 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-23767991

RESUMO

In this work, a novel photocatalyst, polypyrrole (PPy)-decorated Ag-TiO2 nanofibers (PPy-Ag-TiO2) with core-shell structure, was successfully synthesized using an electrospinning technique, followed by a surfactant-directed in situ chemical polymerization method. The results show that a PPy layer was formed on the surface of Ag-TiO2 nanofiber, which is beneficial for protecting Ag nanoparticles from being oxidized. Meanwhile, the PPy-Ag-TiO2 system exhibits remarkable light absorption in the visible region and high photocurrent. Among them, the 1%-PPy-Ag-TiO2 sample shows the highest photoactivity, which is far exceeds that of the single- and two-component systems. This result may be due to the synergistic effect of Ag, PPy, and TiO2 nanostructures in the ternary system.

18.
ACS Appl Mater Interfaces ; 2(4): 1173-6, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20423136

RESUMO

The photocatalytic activity of TiO(2) is enhanced mainly through heightening absorption of UV-vis light and improving the separation efficiency of photoinduced electrons and holes. The recent new theoretical research revealed that the TiO(2) codoped with Mo + C is considered to be an optimal doping system. On the basis of this theory, the Mo + C codoped TiO(2) powders were first experimentally synthesized by thermal oxidizing a mixture of TiC and MoO(3) powders in the air. The XRD patterns and the XPS survey spectrum showed that carbon (C) acted as a Ti-O-C band structure and molybdenum (Mo) existed as Mo(6+) in anatase TiO(2). The Mo+C codoped TiO(2) had a 32 nm red shift of the spectrum onset compared with pure anatase TiO(2), and its band gap was reduced from 3.20 to 2.97 eV. The photocurrent of the Mo + C codoped TiO(2) was about 4 times as high as that of pure anatase TiO(2), and its photocatalytic activity on decomposition of methylene blue was enhanced.

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