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1.
Chemistry ; 19(30): 9833-42, 2013 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-23794421

RESUMO

Improved synthetic approaches for preparing small-sized Ni nanoparticles (d=3 nm) supported on HBEA zeolite have been explored and compared with the traditional impregnation method. The formation of surface nickel silicate/aluminate involved in the two precipitation processes are inferred to lead to the stronger interaction between the metal and the support. The lower Brønsted acid concentrations of these two Ni/HBEA catalysts compared with the parent zeolite caused by the partial exchange of Brønsted acid sites by Ni(2+) cations do not influence the hydrodeoxygenation rates, but alter the product selectivity. Higher initial rates and higher stability have been achieved with these optimized catalysts for the hydrodeoxygenation of stearic acid and microalgae oil. Small metal particles facilitate high initial catalytic activity in the fresh sample and size uniformity ensures high catalyst stability.


Assuntos
Biocombustíveis , Nanopartículas Metálicas/química , Microalgas/química , Níquel , Zeolitas/química , Catálise , Tamanho da Partícula , Ácidos Esteáricos/química
2.
Micromachines (Basel) ; 13(5)2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35630166

RESUMO

W-particle-reinforced Al alloys were prepared on a 7075 aluminum alloy surface via laser melt injection to improve their wear resistance, and the microstructure, microhardness, and wear resistance of the W/Al layers were studied. Scanning electron microscopy (SEM) results confirmed that a W/Al laser melting layer of about 1.5 mm thickness contained W particles, and Al4W was formed on the surface of the Al alloys. Due to the reinforcement of the W particles and good bonding of the W and Al matrix, the melting layer showed excellent wear resistance compared to that of Al alloys.

3.
FEMS Yeast Res ; 11(2): 209-22, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21205158

RESUMO

Many transcriptional regulators play roles in morphogenesis of the human pathogen Candida albicans. Recently, Sfl2, a sequence homolog of C. albicans Sfl1, has been shown to be required for hyphal development. In this report, we show that, like Sfl1, Sfl2 could complement the phenotypes of the Saccharomyces cerevisiae sfl1 mutant, and green fluorescent protein-tagged Sfl2 localized in the nuclei of both yeast and hyphal cells in C. albicans, reflecting its role as a transcriptional regulator. In C. albicans, SFL2 expression was induced at a high growth temperature (37 °C) at both transcriptional and translational levels. The deletion of SFL2 impaired filamentation at a high temperature, whereas the overexpression of SFL2 promoted filamentous growth at a low temperature. Sfl2-activated hyphal development needs the existence of Efg1 and Flo8 under aerobic conditions. Thus, in contrast to Sfl1, which represses filamentation, Sfl2 acts as an activator of filamentous growth in C. albicans. Functional analysis of chimeric Sfl proteins demonstrated that the opposite actions of C. albicans Sfl1 and Sfl2 were mainly mediated by their heat shock factor domains. Furthermore, the deletion of SFL2 attenuated virulence in a mouse model of gastrointestinal colonization and dissemination, indicating that Sfl2 is important for virulence in the gastrointestinal model of candidiasis. Our results provide new insights into Sfl2 functions in C. albicans morphogenesis and pathogenesis.


Assuntos
Candida albicans/patogenicidade , Candidíase/microbiologia , Proteínas Fúngicas/metabolismo , Gastroenteropatias/microbiologia , Hifas/crescimento & desenvolvimento , Proteínas Repressoras/metabolismo , Fatores de Virulência/metabolismo , Animais , Candida albicans/crescimento & desenvolvimento , Candidíase/patologia , Modelos Animais de Doenças , Gastroenteropatias/patologia , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Teste de Complementação Genética , Camundongos , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae , Temperatura , Fatores de Transcrição/deficiência , Virulência
4.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 32(10): 1281-1285, 2018 10 15.
Artigo em Zh | MEDLINE | ID: mdl-30215495

RESUMO

Objective: To summarize the effectiveness of delayed skin-stretching device in treatment of skin and soft tissue defects. Methods: Between December 2014 and December 2016, 10 cases of skin and soft tissue defects were treated with delayed skin-stretching device. There were 6 males and 4 females with an average age of 53 years (range, 42-64 years). The skin and soft tissue defects were caused by acute trauma in 6 cases. The incision could not be closed directly after making incisions because of osseous fascia syndrome in 3 cases. The skin soft tissue defect caused after huge carbuncle incision and drainage in 1 case. The defect located at thigh in 4 cases, lower leg in 3 cases, upper arm in 2 cases, back in 1 case. The defect area ranged from 10 cm×4 cm to 22 cm×12 cm. Pinch test was performed on the wound margin, which confirmed that the wound could not be closed directly. Results: Tension blisters were found in 3 cases during traction, and no complications such as impaired blood circulation or skin necrosis occurred in all cases. Skin defects closed directly after continuously stretching for 7-18 days. No skin graft or free flap repair was performed in all patients. The wound healed well after operation. All the 10 patients were followed up 5-8 months (mean, 6.5 months). There was no necrosis around the wound margin and the scar was linear. The sensation and function were not affected. Conclusion: Delayed skin-stretching device is an effective method to treat skin and soft tissue defects, which has the advantages of simple operation, lower risk of operation, less complications, and reliable effectiveness.


Assuntos
Procedimentos de Cirurgia Plástica , Transplante de Pele , Lesões dos Tecidos Moles , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transplante de Pele/métodos , Dispositivos para Expansão de Tecidos , Resultado do Tratamento , Cicatrização
5.
Artigo em Inglês | MEDLINE | ID: mdl-25218220

RESUMO

Two novel complexes [Cu(L)2(Ac)2]·3H2O (1) (L=N-2-methyl benzimidazole demethylcantharate imide, C16H15N3O3, Ac=acetate, C2H3O2) and [Cu(bimz)2(DCA)] (2) (bimz=benzimidazole, C7H6N2; DCA=demethylcantharate, C8H8O5) were synthesized and characterized by elemental analysis, infrared spectra and X-ray diffraction techniques. Cu(II) ion was four-coordinated in complex 1, Cu(II) ion was five-coordinated in complex 2. A large amount of intermolecular hydrogen-bonding and π-π stacking interactions were observed in these complex structures. The DNA-binding properties of these complexes were investigated using electronic absorption spectra, fluorescence spectra, viscosity measurements and agarose gel electrophoresis. The interactions between the complexes and bovine serum albumin (BSA) were investigated by fluorescence spectra. The antiproliferative activities of the complexes against human hepatoma cells (SMMC7721) were tested in vitro. And the results showed that these complexes could bind to DNA in moderate intensity via partial intercalation, and complexes 1 and 2 could cleave plasmid DNA through hydroxyl radical mechanism. Title complexes could effectively quench the fluorescence of BSA through static quenching. Meanwhile, title complexes had stronger antiproliferative effect compared to L and Na2(DCA) within the tested concentration range. And complex 1 possessed more antiproliferative active than complex 2.


Assuntos
Antineoplásicos/química , Benzimidazóis/química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Complexos de Coordenação/química , Cobre/química , Substâncias Intercalantes/química , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Benzimidazóis/síntese química , Benzimidazóis/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Bovinos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , Cobre/farmacologia , Cristalografia por Raios X , DNA/metabolismo , Humanos , Substâncias Intercalantes/síntese química , Substâncias Intercalantes/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Modelos Moleculares , Soroalbumina Bovina/metabolismo
7.
Artigo em Inglês | MEDLINE | ID: mdl-24220672

RESUMO

Two novel copper(II) complexes with Schiff base of benzimidazole [Cu(L)Cl]2·CH3OH have been synthesized. HL(1) (N-(benzimidazol-2-ymethyl)-5-chlorosalicylideneimine, C15H11ClN3O) and HL(2) (N-(benzimidazol-2-ymethyl)-salicylideneimine, C15H12N3O) are ligands of complex (1) and complex (2), respectively. The complexes were characterized by elemental analysis, IR, UV-Vis, TGA and X-ray diffraction. Within the complexes, Cu(II) ions were four coordinated by two nitrogen atom of azomethine and imine, one phenolic oxygen atom from HL and one chloride atom. A distorted quadrilateral structure was formed. Complex (1) crystallized in the triclinic crystal system. Results showed that π-π stacking effect occurred due to the existence of aromatic ring from Schiff base and hydrogen bonding between methanol and adjacent atoms. The DNA binding properties of the complexes were investigated by electronic absorption spectra, fluorescence spectra and viscosity measurements. Results indicated that complexes bound to DNA via partial intercalation mode. The DNA binding constants Kb/(L mol(-1)) were 1.81×10(4) (1), 1.37×10(4) (2), 6.27×10(3) (HL(1)) and 3.14×10(3) (HL(2)) at 298 K. The title complexes could quench the emission intensities of EB-DNA system significantly. The results of agarose gel electrophoresis indicated complex (1) could cleave supercoiled DNA through the oxidative mechanism. The inhibition ratios revealed that complex (1) and HL(1) had strong antiproliferative activities against human breast cancer cells (MCF-7) lines and human colorectal cancer cells (COLO205) lines in vitro. The antiproliferative activities of complex (1) against MCF-7 lines (IC50=16.9±1.5 µmol L(-1)) and against COLO205 lines (IC50=16.5±3.4 µmol L(-1)) is much stronger than that of HL(1), which had the potential to develop anti-cancer drug.


Assuntos
Benzimidazóis/síntese química , Benzimidazóis/farmacologia , Cobre/farmacologia , DNA/metabolismo , Bases de Schiff/síntese química , Bases de Schiff/farmacologia , Absorção , Benzimidazóis/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cobre/química , Cristalografia por Raios X , Humanos , Conformação Molecular , Plasmídeos/metabolismo , Bases de Schiff/química , Espectrometria de Fluorescência , Termogravimetria , Viscosidade/efeitos dos fármacos
8.
Artigo em Inglês | MEDLINE | ID: mdl-23557779

RESUMO

Three new transition metal complexes [Mn2(DCA)2(bipy)2]·5H2O (1), [M2(DCA)2(bipy)2(H2O)]·10H2O(M=Ni(II)(2);Zn(II)(3)), (DCA=demethylcantharate, 7-oxabicyclo[2,2,1]heptane-2,3-dicarboxylate, C8H8O5) were synthesized and characterized by elemental analysis, molar conductance, infrared spectra and X-ray diffraction techniques. Each metal ion was six-coordinated in complexes. Complex 1 has a Mn2O2 center. Complexes 2 and 3 have asymmetric binuclear structure. Great amount of intermolecular hydrogen-bonding and π-π(*) stacking interactions were formed in these complex structures. The DNA-binding properties of complexes were investigated by electronic absorption spectra and viscosity measurements. The DNA binding constants Kb/(Lmol(-1)) were 1.71×10(4) (1), 2.62×10(4) (2) and 1.59×10(4) (3) at 298 K. The complexes could quench the intrinsic fluorescence of bovine serum albumin (BSA) strongly through static quenching. The protein binding constants Ka/(L mol(-1)) were 7.27×10(4) (1), 4.55×10(4) (2) and 7.87×10(4) L mol(-1) (3) and binding site was one. The complexes bind more tightly with DNA and BSA than with ligands. Complexes 1 and 3 had stronger inhibition ratios than Na2(DCA) against human hepatoma cells (SMMC-7721) lines and human gastric cancer cells (MGC80-3) lines in vitro. Complex 3 showed the strongest antiproliferative activity against SMMC-7721 (IC50=29.46±2.12 µmol L(-1)) and MGC80-3 (IC50=27.02±2.38 µmol L(-1)), which shows potential in anti-cancer drug development.


Assuntos
2,2'-Dipiridil/farmacologia , Antineoplásicos/farmacologia , Cantaridina/análogos & derivados , Complexos de Coordenação/farmacologia , Manganês/farmacologia , Níquel/farmacologia , Zinco/farmacologia , 2,2'-Dipiridil/química , 2,2'-Dipiridil/metabolismo , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Cantaridina/química , Cantaridina/metabolismo , Cantaridina/farmacologia , Bovinos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Cristalografia por Raios X , DNA/metabolismo , Humanos , Manganês/química , Manganês/metabolismo , Modelos Moleculares , Neoplasias/tratamento farmacológico , Níquel/química , Níquel/metabolismo , Soroalbumina Bovina/metabolismo , Zinco/química , Zinco/metabolismo
9.
FEBS Lett ; 585(5): 797-802, 2011 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-21315072

RESUMO

Candida albicans, the most prevalent human fungal pathogen, can switch stochastically between white and opaque phases. In this study, we identified Zcf37, a zinc finger protein, as a new regulator of white-opaque switching. Deletion of ZCF37 increased white-to-opaque switching frequency and stabilized the opaque state. Overexpression of ZCF37 promoted conversion of opaque cells to white phase, but needed existence of Efg1, a key regulator required for maintenance of the white state. Deletion of EFG1 abolished the effect of ectopically expressed Zcf37 on opaque-to-white switching, whereas ectopic expression of EFG1 promoted white cell formation without presence of Zcf37. Our results suggest that Zcf37 acts as an activator of white cell formation and a repressor of opaque state and functions upstream of Efg1.


Assuntos
Candida albicans/citologia , Candida albicans/metabolismo , Proteínas Fúngicas/metabolismo , Genes de Troca , Dedos de Zinco , Candida albicans/genética , Proteínas de Ligação a DNA/metabolismo , Deleção de Genes , Dosagem de Genes/genética , Genes Fúngicos/genética , Genes Supressores , Genes de Troca/genética , Mutação/genética , Proteínas Nucleares/genética , Proteínas de Saccharomyces cerevisiae/genética , Transativadores/genética , Fatores de Transcrição/metabolismo
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