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1.
Molecules ; 29(12)2024 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-38930819

RESUMO

The selective hydrogenation of the biomass platform molecule furfural (FAL) to produce furfuryl alcohol (FA) is of great significance to alleviate the energy crisis. Cu-based catalysts are the most commonly used catalysts, and their catalytic performance can be optimized by changing the preparation method. This paper emphasized the effect of calcination atmosphere on the performance of a Cu/Al2O3 catalyst for the selective hydrogenation of FAL. The precursor of the Cu/Al2O3 catalyst prepared by the ammonia evaporation method was treated with different calcination atmospheres (N2 and air). On the basis of the combined results from the characterizations using in situ XRD, TEM, N2O titration, H2-TPR and XPS, the Cu/Al2O3 catalyst calcined in the N2 atmosphere was more favorable for the dispersion and reduction of Cu species and the reduction process could produce more Cu+ and Cu0 species, which facilitated the selective hydrogenation of FAL to FA. The experimental results showed that the N2 calcination atmosphere improved the FAL conversion and FA selectivity, and the FAL conversion was further increased after reduction. Cu/Al2O3-N2-R exhibited the outstanding performance, with a high yield of 99.9% of FA after 2 h at 120 °C and an H2 pressure of 1 MPa. This work provides a simple, efficient and economic method to improve the C=O hydrogenation performance of Cu-based catalysts.

2.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 32(1): 175-80, 2015 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-25997288

RESUMO

Trying to provide ultrasonic image-aid measures for quantitative diagnosis and dynamic monitoring of liver fibrosis, we propose two scoring methods for liver fibrosis tissue in vivo , based on ultrasound radio frequency (RF) time series in this paper. Firstly, RF echo signals of human liver were recorded in this study. Then one of the recorded frame RF data was demodulated to be B model image. After that, a region of interest (ROI) in the B model image was selected. For each point in the ROI, its all frame data were acquired so that RF time series were formed. An SMR (size measure relationship) fractal dimension and six spectral features were extracted from RF time series in the ROI. With relative deviation and Fisher's discriminant ratio, seven features were weighted and summed so that the liver tissues' scores were obtained, Score-rd and Score-fisher, respectively. Area under ROC curve (AUC) and a support vector machine (SVM) were used to evaluate whether these scoring methods would be useful in distinguishing normal and cirrhosis tissues. Experimental results are shown as follows: Score-rd's AUC was 0.843, while Score-fisher was 0.816, SVM classification accuracies were both up to 87.5%. This proved that our proposed scoring methods were effective in distinguishing normal and cirrhosis tissues. Score-rd and Score-fisher have potential for clinical applications. They can also provide quantitative references for liver fibrosis diagnosis.


Assuntos
Cirrose Hepática/diagnóstico por imagem , Área Sob a Curva , Fractais , Humanos , Cirrose Hepática/classificação , Ondas de Rádio , Máquina de Vetores de Suporte , Ultrassonografia
3.
Antiviral Res ; 80(3): 295-301, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18662724

RESUMO

Coxsackievirus A16 (CA16) is a major causative agent of hand, foot, and mouth disease (HFMD). It can cause myocarditis, pericarditis and fatal shock. There is no effective therapy against CA16. RNA interference (RNAi) is a powerful tool to silence gene expression. The small interfering RNA (siRNA) that induces RNA degradation has recently been used as an anti-virus agent to inhibit virus replication. In this study, we established the complete nucleotide sequence of CA16 strain Shzh05-1, and then compared the nucleotide sequences of Shzh05-1 with sequences of other CA16 strains in GenBank. We chose conserved regions between Shzh05-1 and the two other CA16 strains to design 30 siRNAs and construct siRNA-encoding plasmids. Thirteen siRNAs targeting conserved regions of the virus could effectively block replication of CA16 in cultured cells. Combination transfection of these 13 effective siRNAs could also produce a high inhibitory effect. These strategies and results suggest that RNAi has potential therapeutic use for suppression of CA16 infection.


Assuntos
Enterovirus Humano B/genética , Doença de Mão, Pé e Boca/genética , Doença de Mão, Pé e Boca/terapia , RNA Interferente Pequeno/genética , Replicação Viral , Animais , Linhagem Celular , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Enterovirus Humano B/metabolismo , Terapia Genética , Vetores Genéticos/genética , Doença de Mão, Pé e Boca/virologia , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Interferência de RNA , Células Vero
4.
Antivir Ther ; 11(4): 431-8, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16856616

RESUMO

Influenza B virus is a cause of substantial morbidity and mortality in humans and current vaccination strategies and antiviral drugs only provide limited protection. Here, we report the evaluation of small interfering RNA (siRNA) for repression of viral replication in cultured cells as well as in chicken embryos. Several siRNAs targeting conserved regions of the virus (in chemically synthesized or plasmid-encoded forms) were found to effectively block the replication of the influenza B virus. The siRNAs were found to offer broad protection over several strains of influenza B virus (B/Beijing/76/98, B/Beijing/37/99 and B/Jiangsu/10/03) that differ substantially in their genetic content. The antiviral effects of 500 ng siRNA-encoding plasmids or 60 nmoles synthetic siRNA were found to be comparable to that of 3.6 microg ribavirin. These results indicated that RNA interference warrants further study for management of influenza B virus infections.


Assuntos
Vírus da Influenza B/fisiologia , Interferência de RNA , RNA Interferente Pequeno/genética , Proteínas Virais/genética , Replicação Viral/efeitos dos fármacos , Animais , Linhagem Celular , Embrião de Galinha , Humanos , Vírus da Influenza B/classificação , Vírus da Influenza B/genética , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/farmacologia , RNA Viral/genética , RNA Viral/metabolismo , Fatores de Tempo , Proteínas Virais/metabolismo
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