检索结果-南通市图书馆

Fractions of a chloroform extract of ajenjo leaves (Artemisiamendozana DC. var. mendozana) inhibit the proliferation,viability and clonogenicity of B16-F0 melanoma cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

BIOCELL 2020年第3期44卷 293-299页

作者： MARÍA ELISA MILLÁN MARÍA FERNANDA MARra LEONARDO ANDRÉS SALVARREDI EMILIO FERNANDO LIZARraGA luis ALBERTO LOPEZ Universidad Nacional de Cuyo MendozaArgentina Comisión Nacional de Energía Atómica Buenos AiresArgentina Fundación Escuela de Medicina Nuclear MendozaArgentina Fundación Miguel Lillo y Universidad Nacional de Tucumán San Miguel de TucumánArgentina

The ajenjo,Artemisia mendozana ***(Asteraceae),grows in the Andean foothills of Mendoza and San Juan,Argentina,and is used as a medicinal plant for its antispasmodic and antifungal *** aim of this work was to obtain fractions of a chloroform extract of ajenjo leaves and to evaluate the in vitro effects on proliferation,viability and clonogenicity of B16-F0 melanoma *** a silica.gel chromatography column,120 fractions were collected and grouped according to the chromatographic profile in 9 main fractions(F1–F9).Their major compounds identified were:terpenes(F1),terpenes and sesquiterpene lactones(F2–F3),sesquiterpenes(F4–F6)and phenols and sesquiterpenes(F7-9).B16-F0 cells were incubated for 72 h with DMSO(vehicle)or 0.1 mg/ml F1–*** 72 h of culture,F1 decreased both the growing index(GI)and cell viability.F2 and F3 both decreased GI and only F3 decreased clonogenic activity.F4 and F5 both decreased *** F5 decreased cell viability and F4 decreased ***,fractions F6–F8 did not affect any of the cell parameters assayed,while F9 decreased cell viability and inhibited clonogenicity.

关键词： Terpenes Sesquiterpene lactones Sesquiterpenes Phenols

Effect of Potassium on Sol-gel Cerium and Lanthanum Oxide Catalysis for Soot Combustion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modern Research in Catalysis 2015年第3期4卷 68-77页

作者： Daniela Salinas Gina Pecchi Vicente Rodríguez José luis García Fierro Department of Physical Chemistry Faculty of Sciences University of Concepcion Concepcion Chile Institute of Catalysis and Petrochemistry ICP-CSIC Cantoblanco Madrid Spain

The catalytic activity in the soot combustion is reported for a series of potassium-promoter alumina supported catalysts prepared by the sol-gel method to be used in the catalytic combustion of soot. The studied systems correspond to CeO2-Al2O3 and La2O3-Al2O3 with charges of 3 and 5 wt% of CeO2 and La2O3. Potassium impregnation is performed to reach 3 atoms of K per nm2 of the mixed oxide. The effect of the potassium incorporation increases its reducibility, decreases the surface area and forms a new type of oxygen that is stronger than the oxygen in mixed oxides with similar chemical nature. The existence of potassium oxides, K2O and oxygen responsible for the vacancies and/or lattice defects (O2−) are related to good catalytic activity. Additionally, the presence of alkali affects the structural and textural characteristics of the catalyst, promoting the catalytic activity in soot combustion.

关键词： Sol-gel Potassium Cerium Lanthanum Soot Combustion

Genotoxic Effects in Mice Exposed to radon Emissions in Indoor Conditions. Comparison between in utero and Neonatal Exposures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Life Sciences 2016年第2期10卷 66-76页

作者： Cristiano Foschi Manuel luis Orta Licia radicchi Germana Szpunar Mauro Cristaldi Department of Biology and Biotechnology Charles Darwin Faculty of Mathematical Physical and Natural Sciences University ofRome Rome 00161 Italy Department of Cell Biology Faculty of Biology University of Seville Seville 41012 Spain Civic Museum of Zoology via U. Aldrovandi 18 Rome 00197 Italy

The purpose of this study was to develop a biological model to evaluate the genotoxic effects of natural emissions of radon-222 and its decay products. To this aim, mice of the Swiss CD1 strain were exposed to radon for different periods （adult life, early postnatal and in utero exposure） and two simple but accurate mutagenicity tests （Micronucleus test and the Comet assay） were applied to the peripheral blood of mice. The study was carried out in two small towns in Latium region--ltaly, where radon pollution is notoriously present due to the volcanic soils. One experiment was carried out in the cellar of a house in Ciampino （Rome） and two experiments were performed in an old cellar in Vetralla （Viterbo）. The results showed that in all mice groups exposed to natural emissions of radon and its decay products, the micronucleated erythrocytes frequency （ME） was significantly higher than that observed in the mice control. The single cell gel electrophoresis （Comet assay） was performed in lymphocytes of adult mice in the last experiment. The results for this test also show that DNA damage was higher than in the cells of the mice control and the cells of mice exposed for a shorter period of time. To confirm these findings, the single cell gel electrophoresis （Comet assay） was performed in lymphocytes of adult mice in the last experiment. Similarly, this result could be linked to a greater sensitivity of neonatal mice to radon emissions compared with intrauterine mice. Further investigations on the effects of radon and its decay products during the intrauterine life and the first neonatal period should be performed to better clarify its genotoxic activity.

关键词： radon genotoxicity DNA damage micronucleus test comet assay.

Evaluation of a Voluntary Control Program for the Detection of Bovine Leukemia Virus Antibodies Based on Agar gel Immunodiffusion Test in Dairy Farms in Costa Rica

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Veterinary Medicine 2015年第12期5卷 229-233页

作者： Gaby Dolz Francine Huijsen Carlos Jiménez luis L. Rodríguez Escuela de Medicina Veterinaria Universidad Nacional Heredia Costa Rica

Cattle from 20 dairy farms were serologically tested over a five-year period using agar gel immunodiffusion test (AGIDT) as part of a voluntary Bovine Leukemia Virus (BLV) control program. After five years of removing infected animals from the herds based on BLV-AGIDT serological status, blood samples from 332 cattle in these farms were collected and analyzed side by side by AGIDT and enzyme-linked immunosorbent assay (ELISA) to detect antibodies against BLV. AGIDT detected 29.2% (97) and 16.0% (53) of the animals as positive and weak positive respectively, whereas ELISA detected 58.2% (193) cattle as positive. The prevalence of BLV-antibodies determined with AGIDT in the dairy farms oscillated between 0% and 86%, whereas prevalence determined by ELISA ranged between 28% and 100% in the same farms. Although both techniques showed similarly results in farms with high BLV-prevalence, ELISA detected a larger proportion of BLV-positive, especially in farms with low or no BLV-prevalence based on AGIDT, leading to wrong assumptions in terms of farm level control efforts. Our results strongly suggest that AGIDT alone is inadequate to implement BLV control programs and ELISA is a more adequate test for BLV surveillance and control programs.

关键词： BLV Serological Testing Control Programs

ACE-I inhibitory peptide fractions from enzymatic hydrolysates of velvet bean (<i>Mucuna pruriens</i>)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2013年第12期4卷 767-773页

作者： Maira Rubi Segura-Campos Carlos Paul Espadas-Alcocer luis Chel-Guerrero David Betancur-Ancona Facultad de Ingeniería Química Universidad Autónoma de Yucatán Mérida México

The hydrolysis of velvet bean (Mucuna pruriens) protein in the presence of Alcalase?-Flavourzyme? and Pepsin-Pancreatin was investigated. The results showed that Alcalase?-Flavourzyme? (29.08%) sequential system catalyzed the hydrolysis most efficiently that Pepsin-Pancreatin (24.78%). In addition, the higher ACE-I inhibitory activity was achieved with the sequential system Alcalase?-Flavourzyme? (33.13%). Furthermore, the concentration of peptides employing an ultrafiltration (UF) system or their purification by gel filtration chromatography showed that the oligomeric peptides with lower molecular weight registered the highest ACE-I inhibitory activity. It has been demonstrated that Mucuna pruriens protein hydrolysates could serve as a source of peptides with ACE inhibitory activity and this activity can be attributed mainly to the mixture of short peptides in the hydrolysate.

关键词： Velvet Bean Mucuna pruriens ACE-I Inhibition Peptide Fractions Enzymatic Hydrolysis

In vitro effect of amoxicillin and clarithromycin on the 3' region of cagA gene in Helicobacter pylori isolates

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2013年第36期19卷 6044-6054页

作者： Javier Andrés Bustamante-Rengifo Andrés Januer Matta Alvaro Pazos luis Eduardo Bravo Registro Poblacional de Cáncer de Cali Department of Pathology School of Medicine Universidad del Valle Department of Biology Universidad de Nario

AIM:To evaluate the in vitro effect of amoxicillin and clarithromycin on the cag pathogenicity island(cag PAI).METHODS:One hundred and forty-nine clinical isolates of Helicobacter pylori(***)cultured from gastric biopsies from 206 Colombian patients with dyspeptic symptoms from a high-risk area for gastric cancer were included as study *** susceptibility was determined by the agar dilution *** isolates at baseline and in amoxicillin and clarithromycin serial dilutions were subjected to genotyping(cagA,vacA alleles s and m),Glu-Pro-Ile-Tyr-Ala(EPIYA)polymerase chain reaction and random amplified polymorphic DNA(raPD).Images of the raPD amplicons were analyzed by gel-Pro Analyzer *** analyses was done using SPSS 15.0statistical package,where each of the fingerprint bands were denoted as *** were designed by following Ward’s clustering method and the estimation of distances between each pair of *** isolates was calculated with the squared Euclidean ***:Resistance rates were 4%for amoxicillin and 2.7%for clarithromycin with 2%double *** evidenced a high prevalence of the genotype cagA-positive/vacA *** 3’region of cagA gene was successfully amplified in 92.3%(12/13)of the baseline resistant isolates and in 60%(36/60)of the resistant isolates growing in antibiotic *** observing the distribution of the number of EPIYA repetitions in each dilution with respect to baseline isolates,it was found that in 61.5%(8/13)of the baseline isolates,a change in the number of EPIYA repetitions lowered antibiotic *** gain and loss of EPIYA motifs resulted in a diversity of *** subclones after bacterial adjustment to changing conditions product of antibiotic *** PCR evidenced the close clonal relationship between baseline isolates and isolates growing in antibiotic ***:Antibiotic pressure does not induce loss of the cag pathoge

关键词： Helicobacter pylori Antimicrobial susceptibility cag pathogenicity island cagA 3’region random amplified polymorphic DNA-polymerase chain reaction

Study and Characterization of Organically Modified Silica-Zirconia Anti-Graffiti Coatings Obtained by Sol-gel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Chemistry and Chemical Engineering 2013年第2期7卷 120-131页

作者： M. Rosario Elvira M. Alejandra Mazo Aitana Tamayo Fausto Rubio Juan Rubio Jose luis Oteo Ceramic and Glass Institute CSIC Madrid 28049 Spain

In this work, it is presented the synthesis and characterization of transparent and colorless organic-inorganic hybrid anti-graffiti protective materials obtained by sol-gel method. This type of materials is based on MTES （methyltriethoxysilane）, TPOZ （tetrapropoxide of zirconium） and PDMS （polydimethylsiloxane）. The synthesis has been carried out at 25, 35 and 45 ℃ in order to evaluate the role of temperature in the structure, microstructure and anti-graffiti behavior as well. The incorporation of zirconium within the organic modified silica network, of sols after being gelled and dried, is evident by a shoulder which increased with temperature situated at 950 cml （Si-O-Zr bonds）, and it is homogenously dispersed inside the matrix avoiding the formation of large ZrO2 precipitates. As the temperature increases, the hydrolysis and condensation reactions occur in more extension and thus, the obtained sols are more cross-linked and present more Si-O-Zr linkages. The promising anti-graffiti beha＇4ior of the protectNe hybrids was qualitatively determined being the spot removal higher than 90%.

关键词： Sol-gel organic-inorganic hybrid anti-graffiti coatings hydrophobic materials.

Monitoring the autoproteolysis of hiv-1 protease by site-directed spin-labeling and electron paramagnetic resonance spectroscopy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Biophysical Chemistry 2011年第2期2卷 137-146页

作者： Jamie L. Kear luis Galiano a.gelo M. Veloro Laura S. Busenlehner Gail E. Fanucci Department of Chemistry University of Florida Gainesville Florida USA

Site-directed spin-labeling with continuous wave electron paramagnetic resonance spectroscopy was used to monitor autoproteolysis of HIV-1 protease, an enzyme essential for viral maturation. Two protein constructs were examined, namely subtype F and the circulating recombinant form CRF01_A/E. As the protease undergoes self-cleavage, protein unfolds and small peptide fragments containing the spin label are generated, which collectively give rise to a sharp spectral component that is easily discernable in the high-field resonance line in the EPR spectrum. By monitoring the intensity of this spectral component over time, the autoproteolytic stability of each construct was characterized under various conditions. Data were collected for samples stored at 4 °C, 25 °C, and 37 °C, and on a subtype F HIV-1 protease sample stored at 25 °C and containing the FDA-approved protease inhibitor Tipranavir. As expected, the rate of autoproteolysis decreased as the storage temperature was lowered. Minimal autoproteolysis was seen for the sample that contained Tipranavir, providing direction for future spectroscopic studies of active protease samples. When compared to standard methods of monitoring protein degradation such as gel electrophoresis or chromatographic analyses, spin-labeling with CW EPR offers a facile, real-time, non-consuming way to monitor autoproteolysis or protein degradation. Additionally, mass spectrometry studies revealed that the N-termini of both constructs are sensitive to degradation and that the sites of specific autoproteolysis vary.

关键词： HIV-1 Protease Autoproteolysis Self-Proteolytic Activity Site-Directed Spin-Labeling Electron Paramagnetic Resonance (EPR) Spectroscopy

Chemical Solution Deposition of YBa2Cu3O7 Films on YSZ （100） Substrates

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Chemistry and Chemical Engineering 2014年第6期8卷 547-551页

作者： Henry Elías Sanchez Comejo a.gel Bustamante Dominguez1 Ana María Osorio luis De Los Santos Valladares José Albino Aguiar Crispin H. W. Barnes Ceramics and Nanomaterials Laboratory Department of Physics Major National University of San Marcos Lima 14-0149 Peru Department of Chemistry and Chemical Engineering Major National University of San Marcos Lima 14-0149 Peru Superconductivity and Advanced Materials Laboratory Department of Physics Federal University of Pernambuco Recife50670-901 Brazil Cavendish Laboratory Department of Physics University of Cambridge Cambridge CB3 0HE United Kingdom

We report the epitaxial growth of YBCO （YBa2Cu3O7） films on YSZ （Yttria-stabilized Zirconia）（100） substrates by chemical solution deposition. The precursor solution was prepared by dissolving stoichiometric amounts of acetates of Y（OOCCH3）3·4H2O, Ba（OOCCH3）2 and Cu（OOCCH3）·2H2O in an aqueous solution of oxalic acid （H2C2O4） and following the sol-gel route. This solution was directly dripped onto YSZ （100） substrates with the help of a Fisher pipette. To form the YBCO film, the sample was crystallized by annealing at 860 ℃ for 12 h in an oxidizing atmosphere. The characterization was performed by XRD （X-ray diffraction） analysis which revealed high intensity （001） reflections and denoted that most of the grains were c-axis oriented. randomly oriented grains and other phases such as Y2BaCuO5 and CuO were also detected. The superconducting YBCO phase is demonstrated from the susceptibility versus temperature measurements which indicate a superconducting critical temperature ≈ 90 K. In addition, a surface morphology analysis was performed by optical microscopy and atomic force microscopy which revealed an average roughness of 0.2197 μm.

关键词： Sol-gel method epitaxial growth YBCO superconductor layers.