检索结果-南通市图书馆

Gravity field Variations Associated with the Buried Geological Structures: San Marcos fault (nE Mexico) Case Study

Journal of Modern Physics 2012年第9期3卷 1236-1246页

作者： Vsevolod Yutsis Yaneth Quintanilla-López Konstantin Krivosheya Juan Carlos Montalvo-Arrieta Gabriel chávez-Cabello aculty of Earth Sciences Autonomous University of Nuevo Leon (UANL) Linares Mexico faculty of Earth Sciences Autonomous University of Nuevo Leon (UANL) Linares Mexico

Gravity data are sensitive to local vertical offsets across high-angle faults, where rocks with different densities are juxtaposed. Yet high densities in some Mesozoic sedimentary rocks just above the basement may smear out the subtle gravity signatures of basement faults. At this study the gravity data processing tends to avoid ill-described “black-box” techniques. The study area is situated in the Palomas site, Cuatrociénegas region, Coahuila, nE Mexico. The San Marcos fault is at least 300 km long and has WnW-ESE trend from the central part of nuevo león State through Coahuila, and finally to the eastern part of chihuahua State. Gravimetric data shows that the lowest values of free air and Bouguer anomalies are in the southern part of the area, and the highest values are in the western and central part of the area. Between these parts exists a zone of high horizontal gravity gradient. Configuration of linear elements of gravity field (gradient zones) delimited the San Marcos fault in the San Marcos valley below thickness of recent sedimentary cover. Two density models were carried out, which showed that the Cretaceous rocks are in discordant contact with the Paleo- zoic rocks that can be related to the San Marcos fault. The density was determinate using to nettleton’s method, which results highlight the presence of the San Marcos fault. Density models showed that the Quaternary sediments are in direct contact with the San Marcos fault.

关键词： Earth Gravity newton Potential Geophysical Prospecting Density Models free Air Anomaly Gravity field Variations

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Polyphenol Oxidase Inactivation by Microwave Oven and Its Effect on Phenolic Profile of Loquat (Eriobotrya japonica) fruit

引用

food and nutrition Sciences 2013年第9期4卷 87-94页

作者： Yanet chávez-Reyes Lidia Dorantes-Alvarez Daniel Arrieta-Baez Obed Osorio-Esquivel Alicia Ortiz-Moreno Departamento de Ingeniería Bioquímica Escuela Nacional de Ciencias Biológicas Instituto Politécnico Nacional México D.F. México Espectrometría de Masas y RMn Centro de nanociencias y Micro y nanoTecnología México D.F. México Instituto de Salud Pública Universidad de Chalcatongo Chalcatongo de Hidalgo Oaxaca México.

The objective of this research was investigated the effect of polyphenol oxidase microwave treatment on phenolic composition, antioxidant activity and microstructure of loquat fruit. Phenolic profile of methanolic extracts prepared from fresh, and microwave-treated samples were analyzed. Antioxidant activity was also evaluated by 2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS?+) and 1,1-diphenyl-2-picrylhydrazyl (DPPH+) methods. In addition, polyphenol oxidase inactivation was carried out using a response surface methodology to establish the optimal conditions of treatment. The phenolic content of fresh mesocarp was 311 ± 0.60 mg gallic acid equivalents (GAE)/100g dry weight (DW) and that of microwave-treated mesocarp was 1230 ± 0.36 mg GAE/100g DW. Total phenolic content of water/ methanol extract significantly increases after microwave treatment rather than methanolic extract of fresh loquat. five glycoside phenolics were identified by HPLC-DAD-MS as 3-caffeoylquinic acid, 3-p-coumaroylquinic acid, 5-caffeoylquinic acid and quercetin-3-O-sambubioside. Methanolic extract of microwave-treated mesocarp showed higher antioxidant activity than that of fresh mesocarp. Thus, polyphenol oxidase inactivation by microwave energy preserved the integrity of phenolic compounds as well as antioxidant activity in mesocarp extracts prepared from loquat fruit. It was also noted that phenolics were more abundant in the microwaved samples than in the fresh samples.

关键词： Loquat Phenolic Compounds Polyphenol Oxidase Microwave Eriobotrya japonica

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Phytochemical Composition, Anti-Inflammatory and Cytotoxic Activities of chloroform Extract of Senna crotalarioidesKunth

引用

American Journal of Plant Sciences 2021年第6期12卷 887-900页

作者： Roberto Serrano-Vega Salud Pérez-Gutiérrez francisco Alarcón-Aguilar Julio Almanza-Pérez Cuauhtémoc Pérez-González Marco Martín González-chávez Departamento de Sistemas Biológicos Universidad Autónoma Metropolitana-Xochimilco Mexico City México Departamento de Ciencias de la Salud Universidad Autónoma Metropolitana-Iztapalapa Mexico City México facultad de Ciencias Químicas Centro de Investigación y Estudios de Posgrado Universidad Autónoma de San Luis Potosí Zona Universitaria San Luis Potosí México

Senna crotalarioides is used in traditional medicine to treat inflammation. The aim of this work was to investigate the anti-inflammatory and cytotoxic activities and the possible mechanism of action of the chloroform extract washed with hexane of S. crotalarioides (CESC). The anti-inflammatory effect was tested on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema in mice. The levels of TNF-α, IL-1β, IL-6 and IL-10 were determined in macrophages J774A.1 stimulated by lipopolysaccharide (LPS). The cytotoxic activity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay against six human cancer cell lines: HeLa (cervical cancer), SKLU-1 and A549 (lung cancer), LNCaP (prostate cancer), SW620 (colon cancer) and MCF7 (breast cancer). The composition of the CESC was determined by GC-MS analysis, and standardized by HPLC-ELSD with ursolic acid as the phytochemical marker. CESC inhibited ear edema 61.45%. In chronic ear edema, CESC diminished the inflammation by 53.77%. CESC decreased TNF-α, IL-1β and IL-6 concentrations, and increased the concentration of IL-10. The extract showed IC50le="font-family:Verdana;"> values on HeLa, SKLU-1, A549, LnCaP, SW620 and MCf7 b

关键词： Senna crotalarioides Anti-Inflammatory Ursolic Acid Composition Cytotoxic

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carboxylesterase 1 family knockout alters drug disposition and lipid metabolism

引用

Acta Pharmaceutica Sinica B 2023年第2期13卷 618-631页

作者： changpei Gan Jing Wang Alejandra Martínez-chávez Michel Hillebrand niels de Vries Joke Beukers Els Wagenaar Yaogeng Wang Maria C.lebre Hilde Rosing Sjoerd Klarenbeek Rahmen Bin Ali Colin Pritchard Ivo Huijbers Jos H.Beijnen Alfred H.Schinkel Division of Pharmacology the Netherlands Cancer InstituteAmsterdam 1066 CXthe Netherlands Department of Pharmacy&Pharmacology the Netherlands Cancer InstituteAmsterdam 1066 CXthe Netherlands Division of Pharmacoepidemiology and Clinical Pharmacology Utrecht Institute for Pharmaceutical SciencesUtrecht UniversityUtrecht 3584 CSthe Netherlands Experimental Animal Pathology facility the Netherlands Cancer InstituteAmsterdam 1066 CXthe Netherlands Mouse Clinic for Cancer and Aging(MCCA)Transgenic facility the Netherlands Cancer InstituteAmsterdam 1066 CXthe Netherlands

The mammalian carboxylesterase 1(Ces1/CES1)family comprises several enzymes that hydrolyze many xenobiotic chemicals and endogenous *** investigate the pharmacological and physiological roles of Ces1/CES1,we generated Ces1 cluster knockout(Ces1^(-/-))mice,and a hepatic human CES1 transgenic model in the Ces1^(-/-)background(TgCES1).Ces1^(-/-)mice displayed profoundly decreased conversion of the anticancer prodrug irinotecan to Sn-38 in plasma and ***1 mice exhibited enhanced metabolism of irinotecan to Sn-38 in liver and ***1 and hCES1 activity increased irinotecan toxicity,likely by enhancing the formation of pharmacodynamically active ***1^(-/-)mice also showed markedly increased capecitabine plasma exposure,which was moderately decreased in TgCES1 ***1^(-/-)mice were overweight with increased adipose tissue,white adipose tissue inflammation(in males),a higher lipid load in brown adipose tissue,and impaired blood glucose tolerance(in males).These phenotypes were mostly reversed in TgCES1 ***1 mice displayed increased triglyceride secretion from liver to plasma,together with higher triglyceride levels in the male *** results indicate that the carboxylesterase 1 family plays essential roles in drug and lipid metabolism and ***1^(-/-)and TgCES1 mice will provide excellent tools for further study of the in vivo functions of Ces1/CES1 enzymes.

关键词： Ces1/CES1 enzymes Irinotecan Capecitabine Adipose tissue Lipid homeostasis Inflammation Triglyceride mobilization Mouse models

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sensing, Signal Processing, and Communication for WBAns

引用

ZTE Communications 2014年第3期12卷 3-12页

作者： Seyyed Hamed fouladi Raúl chávez-Santiago Pl Ander floor Ilangko Balasingham Tor A.Ramstad Department of Electronics and Telecommunications Norwegian University of Science and Technology The Intervention Center Oslo University Hospital Institute of Clinical Medicine University of Oslo

A wireless body area network （WBAn） enables real-time monitoring of physiological signals and helps with the early detection of life-threatening diseases. WBAn nodes can be located on, inside, or in close proximity to the body in order to detect vital signals. Measurements from sensors are processed and transmitted over wireless channels. Issues in sensing, signal processing, and com-munication have to be addressed before WBAn can be implemented. In this paper, we survey recent advances in research on sig-nal processing for the sensor measurements, and we describe aspects of communication based on IEEE 802.15.6. We also discuss state-of-the-art WBAn channel modeling in all the frequencies specified by IEEE 802.15.6 as well as the need for new channel models for new different frequencies.

关键词： wireless body area network IEEE 802.15.6 signal processing security channel modeling

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of cholesterol Enriched or fatty-Acid Diets on cholesterol and Lipid levels in Young Wistar Rats

引用

Advances in Bioscience and Biotechnology 2014年第10期5卷 846-852页

作者： Maribel Cortés-Ortiz Perla leal-Galicia Benjamín E. chávez-álvarez María del Carmen Cárdenas-Aguayo Marco Antonio Meraz-Ríos Departamento de Biomedicina Molecular Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Instituto Politécnico Nacional Mexico City Mexico

nutritional intake is a fundamental determinant of health. It is well known that cholesterol rich diets can induce several pathological conditions but detailed mechanism underlying these remains unknown. Wistar rats, an animal strain widely used in the research have been employed to study the effects of dietary interventions due to their metabolic characteristics, which are closer to the human compared to mice. The effect of some components of the western diet, combined with cholesterol in the lipid profile have been studied, but the impact of only cholesterol or fatty-acid diets in such a profile has not been yet characterized. Here we measured the effect of 6 or 16 weeks of dietary intervention with cholesterol enriched diet (CED) or fatty-acid diet (fAD) on cholesterol, triglyceride levels, high density lipoproteins (HDL) and low density lipoproteins (LDL). We observed significant differences in body weight only in animals treated with CED or fAD from Week 9 onwards as compared to animals fed the control diet. There were no differences between animals fed with CED or fAD in cholesterol levels at any time point nevertheless, triglyceride levels were significantly increased as compared to control diet in animals under both diets at early time points. finally, both CED and fAD induced a decrease in HDL as compared to control levels in treatments of more than 6 weeks, whereas LDL transiently increased in animals treated with fAD from 10 to 12 weeks, but after this period LDL levels returned to baseline, suggesting that young rats have a compensatory effect at least for the period of time analyzed here. Here we provide a temporal course on lipid profile of cholesterol, triglycerides, HDL and LDH in Wistar rats treated with CED and fAD diet that can be useful as reference for future studies.

关键词： cholesterol-Enriched Diet fatty-Acid Diet cholesterol Triglycerides Young Wistar Rat

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Meyer-neldel Rule in Plasma Polythiophene Thin films

引用

Open Journal of Polymer chemistry 2014年第3期4卷 31-37页

作者： J. Cuauhtemoc Palacios M. Guadalupe Olayo Guillermo J. Cruz J. A. chávez-Carvayar Departamento de física Instituto Nacional de Investigaciones Nucleares Ocoyoacac México facultad de Ingeniería Universidad Autónoma del Estado de México Toluca México.

In polymers, the electronic activation energy depends on the fragmentation, crosslinking, dopants, moisture and in general on the structure-environment interaction. This has a special importance in plasma polymers because fragmentation and crosslinking are usually higher than in other polymers. In this work, DC electrical conductivity of polythiophene thin films prepared by plasma (pPTh) was studied using the Meyer-neldel (Mn) rule to calculate the characteristic Mn energy and temperature as a function of moisture and metallic dopants. The experimental data for pPTh synthesized in different conditions indicated that EM = 32 meV and TM = 373 K, suggesting a thermally activated conduction mechanism;however, in polymer-metal matrices with metal concentration higher than the percolation threshold, the conduction mechanism is different causing that the Mn rule was only partially fulfilled. The congruence of the experimental data with the multiexcitation entropy model is discussed.

关键词： Polythiophene Plasma Conductivity Meyer-neldel Rule Multi-Excitation Entropy Model

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photoprotective Effect of the Hydroalcoholic Extract from Red and Black Peruvian Varieties of Phaseolus vulgarisL.

引用

Journal of Biosciences and Medicines 2020年第11期8卷 46-59页

作者： L. Papuico-Sánchez M. Santa-Cruz-Ermitanio Juana E. chávez-flores Richard A. Solórzano-Acosta facultad de farmacia y Bioquímica Universidad Norbert Wiener Lima Perú Departamento de fitotecnia Universidad Nacional Agraria La Molina Lima Perú

Introduction: Ultraviolet radiation can be harmful to the skin and can create serious problems when a protective substance or equipment is not used regularly, for this reason the present study set out to evaluate the ... 详细信息

ng>Introduction:ng> Ultraviolet radiation can be harmful to the skin and can create serious problems when a protective substance or equipment is not used regularly, for this reason the present study set out to evaluate the photoprotective effect of the hydroalcoholic extracts of the integument of the red and black varieties of pop beans (Phaseolus vulgaris). ng>Materials and Method: ng>The extracts were obtained by macerating the tegument of the two varieties of pop beans, black and red, in an ethanol/water (80:20) solution. The thin-layer chromatographic method was used to observe anti-tyrosinase activity, using the 0.05% kojic acid standard as a positive control. The photoprotective effect was evaluated in female mice of seven-week-old, Mus musculus Balb/c, with shaved back and exposed to UV-C radiation for 30 minutes once a day for thirty days to induce photo-damage in the skin. The treatments consisted in the application of extracts at 2% and 5% W/V in gel on the shaved area. Only the gel formulation, sunscreen or no treatment at all was used for the control group. Acute photodamage was quantified using the Draize scale, measuring the degree of erythema and edema;and the degree of photoaging using the Glogau scale at 7 days and 30 days. ng>Results:ng> It was found that the ethanolic extracts of the integument of both varieties of Phaseolus vulgaris, red and black, are practically non-toxic in mice by oral and dermal routes at a limit dose of 5000 mg/kg. The anti-tyrosinase effect at a qualitative level, evaluated by thin layer chromatography, showed the black variety were more active than the red one and both can be compared to the activity of the kojic acid. The two extracts of the two varieties showed photoprotective effect, however the extracts in 5% gel to a greater degree.ng> Conclusions: ng>It was concluded that the hydroalcoholic extract of the pop black beans tegument at 5% in gel has

关键词： Anti-Tyrosinase Effect Photoprotective Effect Phaseolus vulgaris

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Low serum levels of ghrelin are associated with gallstone disease

引用

World Journal of Gastroenterology 2006年第19期12卷 3096-3100页

作者： nahum Méndez-Sánchez Guadalupe Ponciano-Rodríguez Luisa Bermejo-Martínez Antonio R Villa norberto C chávez-Tapia Daniel Zamora-Valdés Raúl Pichardo-Bahena Blanca Barredo-Prieto Martha H Uribe-Ramos Martha H Ramos Héctor A Baptista-González Misael Uribe Liver Unit Biomedical Research Department Medica Sur Clinic and FoundationMexico CityMexico faculty of Medicine national Autonomous University of Mexico (UnAM) Mexico CityMexico Clinical Research Department national Institute of Perinatology Mexico CityMexico Clinical Epidemiology Unit national Institute of Medical Sciences and nutrition Mexico CityMexico

AIM： To explore the role of ghrelin in gallstone disease. METHODS： We carried out a cross-sectional study in 150 subjects, 38 with gallstones （cases） and 112 controls. We also did a real-time PCR-RT study in twenty gallbladder samples each. Body mass index （BnI）, serum insulin, ghrelin, and serum lipids were measured. Logistic regression analyses （univariate and multivariate） were conducted to estimate the probability of gallstone disease associated with serum ghrelin concentrations. RESULTS： Cases were statistically different from controls in gender distribution （P = 0.01）, age （53 vs 44 yr, P = 0.002）, BnI （28 vs 25; P = 0.004）, and glucose （5.26 vs 4.98 mmol/L; P = 0.05）. The prevalence of ghrelin serum levels above the third tercile was lower in subjects without metabolic syndrome （P 〈 0.05）. In a multivariate model, we found a protective effect, when ghrelin values were higher than the median value （OR = 0.27, 95%CI 0.09-0.82, P = 0.02）. Twenty （20%） gallbladder specimens expressed ghrelin mRnA. COnCLUSIOn： Serum ghrelin concentrations are associated with a protective effect of GD.

关键词： Gallstones Obesity Ghrelin Gallbladder Gastrointestinal hormones

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mitoepigenetics and hepatocellular carcinoma

引用

Hepatoma Research 2018年第6期4卷 11-24页

作者： María Guadalupe Lozano-Rosas Enrique chávez Alejandro Rusbel Aparicio-Cadena Gabriela Velasco-Loyden Victoria chagoya de Sánchez Department of Cellular Biology and Development Institute of Cellular PhysiologyNational Autonomous University of MexicoMexico City 04510Mexico

Mitochondria are the center of energy production in eukaryotic cells and are crucial for several cellular processes. Dysfunctional mitochondria have been associated with cancer progression. Mitochondria contain their own circular DnA (mtDnA), which codes for 13 proteins, 2rRnA, 22tRnA and non-coding RnAs. Recent evidence showed the presence of 5-methylcytosine and 5-hydroximethylcytosine in mtDnA suggesting that the level of gene expression could be modulated like a nuclear DnA by direct epigenetic modifications. Mitoepigenetics is a bidirectional phenomenon in the epigenetic regulation of mitochondrial genes encoded in both the nucleus and the mitochondrion. This process is affected by SAM-mediated methylation and hydroxymethylation of mtDnA and by nuclear chromatin modulators from mitochondria, such as Acetyl-CoA and nAD+. There is some information about physiological and pathological methylated profiles, but information is scarce for hepatocellular carcinoma (HCC). The aim of this review is to summarize the mitoepigenetic knowledge in HCC already reported so far, through a keywords search in Medline. In addition, the deregulation of energy intermediaries needed for the mitoepigenetic regulation is described. As this is a new area of study, a rigorous analysis and careful interpretation and integration of results are needed.

关键词： Hepatocellular carcinoma mitochondrial genome mitochondrial epigenome microRnAs

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：