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1.
J Hazard Mater ; : 124203, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33268207

RESUMO

Plasma catalysis technology has been demonstrated to be effective for the decomposition of volatile organic compounds (VOCs). It is highly desired to explore the effect of supports on VOCs oxidation processes during plasma catalysis. In this work, four supports of SiO2, ZSM-5-300, ZSM-5-38 and γ-Al2O3 loading with transition metal oxides were used to decompose toluene at room temperature. It was found that toluene decomposition with 1 wt%Mn/γ-Al2O3 was highest, which was strongly proportional to the ozone decomposition ability of the catalyst. The plasma catalytic decomposition of toluene over 1 wt% MnO2 on different supports were characterized using in situ plasma diffuse reflectance infrared Fourier transform spectrometer. The results showed that 1 wt%Mn/γ-Al2O3 could further catalyze toluene to carbonate and bicarbonate via the breakage of C-C bonds from benzoic acid, while that was difficult for 1 wt% Mn/SiO2, 1 wt%Mn/ZSM-5-300 and 1 wt%Mn/ZSM-5-38. The reaction mechanism of toluene decomposition on different catalysts were proposed.

2.
Nano Lett ; 20(9): 6899-6907, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32786941

RESUMO

Thin layers of cobalt and ruthenium polypyridyl-oligomers with thicknesses between 2 and 8 nm were deposited on gold by electrochemical reduction of diazonium salts. A scanning tunneling microscope was used to create single-molecule junctions (SMJs). The charge transport properties of the Au-[Co(tpy)2]n-Au (n = 1-4) SMJs do not depend markedly on the oligomer length, have an extremely low attenuation factor (ß âˆ¼ 0.19 nm-1), and do not show a thickness-dependent transition between two mechanisms. Resonant charge transport is proposed as the main transport mechanism. The SMJ conductance decreases by 1 order of magnitude upon changing the metal from Co to Ru. In Au-[Ru(tpy)2]n-Au and Au-[Ru(bpy)3]n-Au SMJs, a charge transport transition from direct tunneling to hopping is evidenced by a break in the length-dependent ß-plot. The three different mechanisms observed are a clear molecular signature on transport in SMJs. Most importantly, these results are in good agreement with those obtained on large-area molecular junctions.

3.
J Biol Chem ; 295(37): 12975-12992, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32690606

RESUMO

Pancreas/duodenum homeobox protein 1 (PDX1) is an important transcription factor that regulates islet ß-cell proliferation, differentiation, and function. Reduced expression of PDX1 is thought to contribute to ß-cell loss and dysfunction in diabetes. Thus, promoting PDX1 expression can be an effective strategy to preserve ß-cell mass and function. Previously, we established a PDX1 promoter-dependent luciferase system to screen agents that can promote PDX1 expression. Natural compound tectorigenin (TG) was identified as a promising candidate that could enhance the activity of the promoter for the PDX1 gene. In this study, we first demonstrated that TG could promote the expression of PDX1 in ß-cells via activating extracellular signal-related kinase (ERK), as indicated by increased phosphorylation of ERK; this effect was observed under either normal or glucotoxic/lipotoxic conditions. We then found that TG could suppress induced apoptosis and improved the viability of ß-cells under glucotoxicity and lipotoxicity by activation of ERK and reduction of reactive oxygen species and endoplasmic reticulum (ER) stress. These effects held true in vivo as well: prophylactic or therapeutic use of TG could obviously inhibit ER stress and decrease islet ß-cell apoptosis in the pancreas of mice given a high-fat/high-sucrose diet (HFHSD), thus dramatically maintaining or restoring ß-cell mass and islet size, respectively. Accordingly, both prophylactic and therapeutic use of TG improved HFHSD-impaired glucose metabolism in mice, as evidenced by ameliorating hyperglycemia and glucose intolerance. Taken together, TG, as an agent promoting PDX1 expression exhibits strong protective effects on islet ß-cells both in vitro and in vivo.

4.
J Hazard Mater ; 396: 122730, 2020 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-32344365

RESUMO

Plasma-catalytic oxidation of particulate matter (PM) has potential applications for diesel exhaust cleaning. There is a grand requirement to explore the mechanism of carbonaceous PM oxidation for the development of plasma catalysts. Herein, Au/γ-Al2O3 was used to catalyze the gasification of the graphitic carbon. A modified diffuse reflectance infrared Fourier transform spectrometer equipped with a mass spectrometer was originally utilized to in situ characterize the surface intermediates of graphite on Au/γ-Al2O3 and the gaseous products during the discharges processes in the O2-He balanced gases. It was found that O atoms and O3 play important roles in the formation of surface oxygen complexes (SOCs) and facilitate the gasification of SOCs to CO2 in the presence of Au/γ-Al2O3. The findings are helpful to understand the plasma-catalytic oxidation mechanism of PM and further develop efficient plasma catalysts.

5.
Int J Biol Sci ; 15(7): 1472-1487, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31337977

RESUMO

A decrease in islet ß-cell mass is closely associated with the development and progression of diabetes. Therefore, protection against ß-cell loss is an essential measure to prevent and treat diabetes. In this study, we investigated the protective effects of non-photoactivated hypericin, a natural compound, on ß-cells both in vitro and in vivo. In vitro, hypericin greatly improved INS-1 cell viability under high-glucose and high-fatty-acid conditions by inhibiting glucotoxicity- and lipotoxicity-induced apoptosis and nitric oxide (NO) production. Then, we further demonstrated that hypericin elicited its protective effects against glucotoxicity and lipotoxicity in INS-1 cells by attenuating the reduction in pancreatic duodenal homeobox-1 (PDX1) expression and Erk activity. In vivo, prophylactic or therapeutic use of hypericin inhibited islet ß-cell apoptosis and enhanced the anti-oxidative ability of pancreatic tissue in high-fat/high-sucrose (HFHS)-fed mice, thus alleviating ß-cell loss and maintaining or improving ß-cell mass and islet size. More importantly, hypericin treatment decreased fasting blood glucose, improved glucose intolerance and insulin intolerance, and alleviated hyperinsulinaemia in HFHS-fed mice. Therefore, hypericin showed preventive and therapeutic effects against HFHS-induced onset of type II diabetes in mice. Hypericin possesses great potential for development as an anti-diabetes drug in the future.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glucose/metabolismo , Proteínas de Homeodomínio/metabolismo , Células Secretoras de Insulina/metabolismo , Perileno/análogos & derivados , Transativadores/metabolismo , Animais , Antioxidantes/metabolismo , Apoptose , Linhagem Celular , Sobrevivência Celular , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Inibidores Enzimáticos/farmacologia , Ácidos Graxos/química , Células Secretoras de Insulina/efeitos dos fármacos , Insulinoma/metabolismo , Lipídeos/química , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Perileno/farmacologia , Ratos
6.
J Phys Chem Lett ; 10(15): 4164-4169, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31265312

RESUMO

Various architectures have been generated and observed by STM at a solid/liquid interface resulting from an in situ chemical reaction between the bipyridine terminal groups of a ditopic ligand and Co(II) ions. Large monodomains of one-dimensional (1D) double wires are formed by Co(II)/ligand coordination, with polymer lengths as long as 150 nm. The polymers are organized as parallel wires 8 nm apart, and the voids between wires are occupied by solvent molecules. Two-dimensional (2D) grids, showing high surface mobility, coexist with the wires. The wires are formed from linear chain motifs where each cobalt center is bonded to two bipyridines. 2D grids are generated from a bifurcation node where one cobalt bonds to three bipyridines. Surface reconstruction of the grids and of the 1D wires was observed under the STM tip. As an exciting result, analysis of these movements strongly indicates surface reactions at the solid/liquid interface.

7.
Sci Rep ; 8(1): 1479, 2018 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-29367618

RESUMO

Prohibitin 2 (PHB2), as a conserved multifunctional protein, is traditionally localized in the mitochondrial inner membrane and essential for maintenance of mitochondrial function. Here, we investigated the role of PHB2 in human rhabdomyosarcoma (RMS) RD cells and found substantial localization of PHB2 in the nucleolus. We demonstrated that PHB2 knockdown inhibited RD cell proliferation through inducing cell cycle arrest and suppressing DNA synthesis. Meanwhile, down-regulation of PHB2 also induced apoptosis and promoted differentiation in fractions of RD cells. In addition, PHB2 silencing led to altered nucleolar morphology, as observed by transmission electron microscopy, and impaired nucleolar function, as evidenced by down-regulation of 45S and 18S ribosomal RNA synthesis. Consistently, upon PHB2 knockdown, occupancy of c-Myc at the ribosomal DNA (rDNA) promoter was attenuated, while more myoblast determination protein 1 (MyoD) molecules bound to the rDNA promoter. In conclusion, our findings suggest that nucleolar PHB2 is involved in maintaining nucleolar morphology and function in RD cells by regulating a variety of transcription factors, which is likely to be one of the underlying mechanisms by which PHB2 promotes tumor proliferation and represses differentiation. Our study provides new insight into the pathogenesis of RMS and novel characterizations of the highly conserved PHB2 protein.


Assuntos
Nucléolo Celular/metabolismo , Proliferação de Células , RNA Ribossômico/genética , Proteínas Repressoras/metabolismo , Rabdomiossarcoma/patologia , Transcrição Genética , Apoptose , Diferenciação Celular , Humanos , Proteína MyoD/metabolismo , RNA Interferente Pequeno/genética , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/genética , Rabdomiossarcoma/genética , Rabdomiossarcoma/metabolismo , Células Tumorais Cultivadas
8.
Int J Mol Sci ; 18(4)2017 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-28394269

RESUMO

Ginkgolide A (GA) is a natural compound isolated from Ginkgo biloba and has been used to treat cardiovascular diseases and diabetic vascular complications. However, only a few studies have been conducted on the anti-inflammatory effects of GA. In particular, no related reports have been published in a common inflammation model of lipopolysaccharide (LPS)-stimulated macrophages, and the anti-inflammatory mechanisms of GA have not been fully elucidated. In the present study, we extensively investigated the anti-inflammatory potential of GA in vitro and in vivo. We showed that GA could suppress the expression of pro-inflammatory mediators (cyclooxygenase-2 (COX-2) and nitric oxide (NO) and pro-inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1ß) in LPS-treated mouse peritoneal macrophages, mouse macrophage RAW264.7 cells, and differentiated human monocytes (dTHP-1) in vitro. These effects were partially carried out via downregulating Nuclear factor kappa-B (NF-κB), Mitogen-activated protein kinases (MAPKs) (p38 mitogen-activated protein kinase and extracellular signal-regulated kinase (ERK), but not c-Jun N-terminal kinase (JNK), and activating the AMP-activated protein kinase (AMPK) signaling pathway also seems to be important. Consistently, GA was also shown to inhibit the LPS-stimulated release of TNF-α and IL-6 in mice. Taken together, these findings suggest that GA can serve as an effective inflammatory inhibitor in vitro and in vivo.


Assuntos
Ginkgolídeos/farmacologia , Inflamação/prevenção & controle , Lactonas/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Animais , Western Blotting , Linhagem Celular , Linhagem Celular Tumoral , Ciclo-Oxigenase 2/metabolismo , Citocinas/sangue , Citocinas/genética , Citocinas/metabolismo , Feminino , Expressão Gênica/efeitos dos fármacos , Humanos , Inflamação/sangue , Inflamação/induzido quimicamente , Mediadores da Inflamação/sangue , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos , Macrófagos/metabolismo , Macrófagos Peritoneais/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos
9.
Zhonghua Yu Fang Yi Xue Za Zhi ; 46(12): 1095-8, 2012 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-23363966

RESUMO

OBJECTIVE: To analyze the key indicators of China Comprehensive AIDS Response Program (China CARES) and the effects of this program during 2008 and 2011. METHODS: Data were obtained from National AIDS Comprehensive Prevention and Control Information System. The general population HIV test rate and spouse of people living with HIV or AIDS (PLWHA) HIV test rate were chosen as the indicators for HIV testing expansion; anti-retroviral therapy (ART) coverage and PLWHA CD4 test rate during the past 6 months as the indicators for treatment expansion; femal sex worker (FSW) intervention coverage and injection drug users (IDU) intervention coverage as the Indicators for behavior intervention expansion. The Key working quality indicators of 309 program sites were calculated and the results were compared. RESULTS: During 2008 and 2011, for China CARES, the Median of general population HIV test rate were 1.8%, 2.5%, 3.2% and 5.5%, the Median of spouse of PLWHA HIV test rate were 80.9%, 85.7%, 91.8% and 100.0%, the Median of ART coverage were 60.0%, 66.7%, 76.1% and 92.0%, the Median of PLWHA CD4 test rate during the past 6 months were 27.7%, 45.4%, 58.6% and 75.3%, the Median of FSW intervention coverage were 43.8%, 67.8%, 73.3% and 90.9%, the Median of IDU intervention coverage were 18.2%, 24.0%, 34.0% and 72.4%. The indicators of China CARES increased steadily from 2008 to 2011 in HIV testing expansion, treatment expansion and behavior intervention expansion; Compared to 2008, the percentage of the China CARES which had great progress of the 6 indicators were 98.4% (304/309), 98.3% (286/291), 94.0% (281/299), 93.5% (288/308), 91.8% (279/304) and 90.0% (223/247). in 2008, 3 indicators which were ART coverage, PLWHA CD4 test rate during the past 6 months and FSW intervention coverage were lower than national average (6.9%, 17.9% and 30.9%), the general population HIV test rate, spouse of PLWHA HIV test rate and IDU intervention coverage were higher than national average (3.4%, 64.3% and 22.8%), with the China CARES project going on, in 2011, key indicators which were general population HIV test rate, spouse of PLWHA HIV test rate, ART coverage, PLWHA CD4 test rate during the past 6 months, FSW intervention coverage and IDU intervention coverage were all higher than national average (6.5%, 80.6%, 81.9% and 55.9%).the proportions of China CARES sites whose 6 indicators were higher than national average in 2008 were 32.7% (101/309), 60.6% (149/246), 37.4% (99/265), 61.1% (181/296), 64.0% (174/270) and 45.3% (73/161), and the proportions increase annually to 2011 were 44.0% (136/309), 89.3% (260/291), 76.6% (229/299), 77.9% (240/308), 91.4% (278/304) and 64.8% (160/247). CONCLUSION: An obvious achievements have been made in the areas of HIV/AIDS prevention and control among China CARES sites during 2008 and 2011 than the national average.


Assuntos
Síndrome de Imunodeficiência Adquirida/prevenção & controle , Indicadores de Qualidade em Assistência à Saúde , Síndrome de Imunodeficiência Adquirida/tratamento farmacológico , Síndrome de Imunodeficiência Adquirida/epidemiologia , Antirretrovirais/uso terapêutico , China/epidemiologia , Humanos
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