检索结果-南通市图书馆

Relaxant effect and possible mechanism of 17-nor-subincanadine E in rabbit corpora cavernosa

Asian Journal of Andrology 2011年第5期13卷 747-753页

作者： Otacilio D Benvindo nilberto rf nascimento Claudia F Santos Manasses C Fonteles Edilberto R Silveira Daniel E Uchoa Adriana R Campos Karina MA Cunha Flavia A Santos Vietla S Rao Department of Physiology and Pharmacology Faculty of Medicine Federal University of Ceara PO Box 3157 60430-270 Fortaleza CE Brazil Superior Institute of Biomedicine Caara State University Fortaleza CE Brazil Detriment of Organic and Inorganic Chemistry Federal University of Ceara 60455-760 Fortaleza CE Brazil

Compounds with dual action on cyclic adenosine monophosphate （cAMP） and cyclic guanosine monophosphate （cGMP） may be a treatment option for erectile dysfunction, as they not only promote penile erection but also prevent the upregulation of phosphodiesterase-5. In this study, we examined the possible relaxant effect and mechanism of 17-nor-subincanadine E （SEC, 0.2-200 pmol I^-1）, a plant-derived alkaloid, in rabbit corpus cavernosum （RbCC） strips that had been precontracted by exposure to phenylephrine （10 pmol I^- 1） or a high concentration of K＋（60 mmol I^- 1） in vitro. In addition to SEC＇s effect on cAMP and cGMP levels, electrical field stimulation （EFS） in phenylephrine-precontracted RbCC and calcium chloride （1-100 mmol I^-1） evoked responses in depolarized RbCC were analysed. SEC relaxed the phenylephrine-precontracted RbCCs in a concentration-dependent manner. Atropine, guanethidine and N-co-nitro-L-arginine methyl ester （L-NAME） did not have any effect on the relaxation of RBCCs. When 1H-1,2,4oxadiazole[4,3-a] quinoxalin-1-one （ODQ） was added, it effectively blocked the relaxant response of SEC. Although SEC enhanced the maximal relaxation produced by sodium nitroprusside （SNP） and forskolin in phenylephrine-precontracted cavernosal smooth muscle, it caused a decrease in the maximal contractile response induced by calcium chloride in depolarized RbCCs. The relaxant effect of SEC was paralleled by an increase in the tissue levels of the Cyclic nucleotides cAMP and cGMP. We conclude that SEC promotes the relaxation of RbCC, possibly favouring cAMP and cGMP accumulation and calcium blockade. This novel mechanism could be useful for patients who do not benefit from phosphodiesterase inhibitors and for those with endothelial and nitrergic dysfunction, such as patients with diabetes, hypertension and dyslipidaemias.

关键词： 17-nor-subincanadine E cyclic nucleotides electrical field stimulation nitric oxide rabbit corpus cavernosum smoothmuscle relaxation

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

Colon and rectal cancer:An emergent public health problem

引用

World Journal of Gastroenterology 2024年第7期30卷 644-651页

作者： Marina Pinheiro David nascimento Moreira Michele Ghidini LAQV REQUIMTEDepartment of ChemistryFaculty of PharmacyUniversity of Porto4050-313 PortoPortugal Unidade de Saúde Pública Unidade Local de Saúde Barcelos/EsposendeBarcelinhos 4755-069BragaPortugal Medical Oncology Unit Fondazione IRCCS Ca’Granda Ospedale Maggiore PoliclinicoMilan 20122Italy

Colorectal cancer ranks third globally,with a high mortality *** the United States,and different countries in Europe,organized population screenings exist and include people between 50 and 74 years of *** screenings have allowed an early diagnosis and consequently an improvement in health *** and rectal cancer(CRC)is a disease of particular interest due to the high global burden associated with it and the role attributed to prevention and early diagnosis in reducing morbidity and *** study is a review of CRC pathology and includes the most recent scientific evidence regarding this pathology,as well as a diagnosis of the epidemiological situation of ***,the recommendation from a public health perspective will be discussed in detail taking into account the context and the most current recommendations.

关键词： Colon and rectal neoplasia Colon and rectal tumor Mortality Morbidity

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

Catalytic combustion of soot over Ru-doped mixed oxides catalysts

引用

Journal of Rare Earths 2014年第7期32卷 610-620页

作者： L.F.nascimento R.F.Martins O.A.Serra Department of Chemistry Faculdade de FilosofiaCiências e Letras de Ribeirao PretoUniversity of Sao PauloAv.Bandeirantes 3900CEP 14040-901 Ribeirao PretoSPBrazil

We employed modified substrates as outer heterogeneous catalysts to reduce the soot originating from the incomplete diesel combustion. Here, we proposed that ceria（CeO2）-based catalysts could lower the temperature at which soot combustion occurred from 610 oC to values included in the operation range of diesel exhausts（270–400 oC）. Here, we used the sol-gel method to synthesize catalysts based on mixed oxides（ZnO：CeO2） deposited on cordierite substrates, and modified by ruthenium nanoparticles. The presence of ZnO in these mixed oxides produced defects associated with oxygen vacancies, improving thermal stability, redox potential, sulfur resistance, and oxygen storage. We evaluated the morphological and structural properties of the material by X-ray diffraction（XRD）, Brumauer-emmett-teller method（BET）, temperature programmed reduction（H2-TPR）, scanning electron microscopy（SEM）, and transmission electron microscopy（TEM）. We investigated how the addition of Ru（0.5 wt.%） affected the catalytic activity of ZnO：CeO2 in terms of soot combustion. Thermogravimetric analysis（TG/DTA） revealed that presence of the catalyst decreased the soot combustion temperature by 250 oC, indicating that the oxygen species arose at low temperatures, which was the main reason for the high reactivity of the oxidation reactions. Comparative analysis of soot emission by diffuse reflectance spectroscopy（DRS） showed that the catalyst containing Ru on the mixed oxide-impregnated cordierite samples efficiently oxidized soot in a diesel stationary motor： soot emission decreased 80%.

关键词： soot combustion ceria mixed oxides ruthenium nanoparticles rare earths

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

A High-Order Localized Artificial Diffusivity Scheme for Discontinuity Capturing on 1D Drift-Flux Models for Gas-Liquid Flows

引用

Advances in Applied Mathematics and Mechanics 2024年第1期16卷 47-74页

作者： Adyllyson H.nascimento Eugenio S.Rosa Department of Energy School of Mechanical EngineeringUniversity of CampinasCampinasBrazil

A computational code is developed for the numerical solution of onedimensional transient gas-liquid flows using drift-flux models,in isothermal and also with phase change *** these two-phase models,classical upwind schemes such as Roe-and Godunov-type schemes are generally difficult to derive and expensive to use,since there are no treatable analytic expressions for the Jacobian matrix,eigenvalues and eigenvectors of the system of *** the other hand,the highorder compact finite difference scheme becomes an attractive alternative on these occasions,as it does not make use of any wave propagation information from the system of *** present paper extends the localized artificial diffusivity method for high-order compact finite difference schemes to solve two-phase flows with *** numerical method has simple formulation,straightforward implementation,low computational cost and,most importantly,*** numerical methodology proposed is validated by solving several numerical examples given in the *** simulations are sixth-order accurate and it is shown that the proposed numerical method provides accurate approximations of shock waves and contact *** is an essential property for simulations of realistic mass transport problems relevant to operations in the petroleum industry。

关键词： Compressible two-phase flows drift-flux model localized artificial diffusivity highorder numerical methods

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

Catalytic combustion of soot over ceria-zinc mixed oxides catalysts supported onto cordierite

引用

Journal of Environmental Sciences 2014年第3期26卷 694-701页

作者： Leandro Fontanetti nascimento Renata Figueredo Martins Rodrigo Ferreira Silva Osvaldo Antonio Serra Department of Chemistry FFCLRP University of Sao Paulo

Modified substrates as outer heterogeneous catalysts was employed to reduce the soot generated from incomplete combustion of diesel or diesel/biodiesel blends, a process that harms the environment and public health. The unique storage properties of ceria （CeO2） makes it one of the most efficient catalysts available to date. Here, we proposed that ceria-based catalysts can lower the temperature at which soot combustion occurs; more specifically, from 610℃ to values included in the diesel exhausts operation range （300-450℃）. The sol-gel method was used to synthesize mixed oxide-based catalysts （CeO2：ZnO）; the resulting catalysts were deposited onto cordierite substrates. In addition, the morphological and structural properties of the material were evaluated by XRD, BET, TPR-H2, and SEM. Thermogravimetric （TG/DTA） analysis revealed that the presence of the catalyst decreased the soot combustion temperature by 200℃ on average, indicating that the oxygen species arise at low temperatures in this situation, promoting highly reactive oxidation reactions. Comparative analysis of soot emission by diffuse reflectance spectroscopy （DRS） showed that catalyst-impregnated cordierite samples efficiently oxidized soot in a diesel/biodiesel stationary motor： soot emission decreased by more than 70%.

关键词： soot oxidation mixed oxides ceria

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

Tree structure and diversity of lowland Atlantic forest fragments：comparison of disturbed and undisturbed remnants

引用

Journal of Forestry Research 2016年第3期27卷 605-609页

作者： Fabricio Alvim Carvalho Joao Marcelo Alvarenga Braga Marcelo Trindade nascimento Departamento de Botanica Universidade Federal de Juiz de Fora. Campus Universitario s/n Sao PedroJuiz de Fora-MG 36036-900 Brazil Instituto de Pesquisas do Jardim Botanico do Rio de Janeiro. Rio de Janeiro-RJ Brazil Laboratorio de Ciencias Ambientais CBB Universidade Estadual do Norte Fluminense Campos dos Goytacazes-RJ 28013-602 Brazil

This study describes the tree community structure of three moist lowland Atlantic Forest fragments in Rio de Janeiro State, southeastern Brazil. Two fragments were disturbed and an undisturbed one was used as reference. Our hypothesis was that disturbed fragments show distinct structural patterns in comparison with undisturbed stands due to past disturbance practices and forest fragmentation. Four 100 ×5 m sampling plots were demarcated in each fragment and all live and dead trees with DBH C 5 cm were located, measured and identified. The results supported our hypothesis, due to the high values found for standing dead trees, an increase of dominance of a few pioneer species, lower values of large trees and species richness in disturbed fragments in comparison with the undisturbed one. The advanced fragmentation process in the Southern Brazilian lowland areas and the high species richness in undisturbed areas highlight these forest fragments as priority areas for conservation and management.

关键词： Phytosociology Tree community Forestfragmentation . Hotspot Brazil

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

Rat cardiomyocyte H9c2(2-1)-based sulforhodamine B assay as a promising in vitro method to assess the biological component of effluent toxicity

引用

Journal of Environmental Sciences 2020年第10期32卷 163-170页

作者： Elsa T Rodrigues Susana F nascimento Maria Joao Moreno Paulo J Oliveira Miguel A Pardal University of Coimbra Centre for Functional EcologyDepartment of Life SciencesCalcada Martim de FreitasCoimbra 3000-456Portugal University of Coimbra Coimbra Chemistry CenterDepartment of ChemistryCoimbra 3004-535Portugal Centre for Neuroscience and Cell Biology Uniuersity of CoimbraUC BiotechBiocant ParkCantanhede 3060-197Portugal

The treatment of wastewaters is crucial to maintain the ecological status of receiving waters,and thereby guarantee the protection of aquatic life and human *** quality evaluation is conventionally based on physicochemical parameters,but increasing attention has been paid to integrate physicochemical and biological ***,the regulatory use of fish in biological testing methods has been subject to various ethical and cost concerns,and in vitro cell-based assays have thus become an important topic of ***,the present study intends:(a) to evaluate the efficiency of two different sample pre-concentration techniques (lyophilisation and solid phase extraction) to assess the toxicity of municipal effluents on rat cardiomyoblast H9c2(2-1) cells,and (b) maximizing the use of the effluent sample collected,to estimate the environmental condition of the receiving *** gathered results demonstrate that the H9c2(2-1) sulforhodamine B-based assay is an appropriate in vitro method to assess biological effluent toxicity,and the best results were attained by lyophilising the sample as *** to its response,the H9c2(2-1) cell line might be a possible alternative in vitro model for fish lethal testing to assess the toxicity of municipal *** physicochemical status of the sample suggests a high potential for eutrophication,and iron exceeded the permissible level for wastewater discharge,possibly due to the addition of ferric chloride for wastewater *** general,the levels of carbamazepine and sulfamethoxazole are higher than those reported for other countries,and both surpassed the aquatic protective values for long-term exposure.

关键词： Municipal wastewater treatment plant effluent Lyophilisation Solid phase extraction Cell-based assays H9c2(2-1)cell line SRB assay

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

Predictive factors associated with hepatitis C antiviral therapy response

引用

World Journal of Hepatology 2015年第12期7卷 1617-1631页

作者： Lourianne nascimento Cavalcante André Castro Lyra Hospital Sao Rafael-Gastro-Hepatology Service Department of Medicine Federal University of Bahia

Hepatitis C virus(HCV) infection may lead to significant liver injury, and viral, environmental, host, immunologic and genetic factors may contribute to the differences in the disease expression and treatment response. In the early 2000 s, dual therapy using a combinationof pegylated interferon plus ribavirin(PR) became the standard of care for HCV treatment. In this PR era, predictive factors of therapy response related to virus and host have been identified. In 2010/2011, therapeutic regimens for HCV genotype 1 patients were modified, and the addition of NS3/4a protease inhibitors(boceprevir or telaprevir) to dual therapy increased the effectiveness and chances of sustained virologic response(SVR). Nevertheless, the first-generation triple therapy is associated with many adverse events, some of which are serious and associated with death, particularly in cirrhotic patients. This led to the need to identify viral and host predictive factors that might influence the SVR rate to triple therapy and avoid unnecessary exposure to these drugs. Over the past four years, hepatitis C treatment has been rapidly changing with the development of new therapies and other developments. Currently, with the more recent generations of pangenotipic antiviral therapies, there have been higher sustained virologic rates, and prognostic factors may not have the same importance and strength as before. Nonetheless, some variables may still be consistent with the low rates of non-response with regimens that include sofosbuvir, daclatasvir and ledipasvir. In this manuscript, we review the predictive factors of therapy response across the different treatment regimens over the last decade including the new antiviral drugs.

关键词： Hepatitis C Direct acting antivirals Antiviraltherapy Interferon Sustained virologic response

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

Soot combustion; Ceria; Ternary mixed oxide; Cordierite coating; Diesel particulate filter

引用

Journal of Environmental Sciences 2018年第11期30卷 58-68页

作者： Leandro Fontanetti nascimento Juliana Fonseca Lima Paulo Cesar de Sousa Filho Osvaldo Antonio Serra Department of Chemistry FFCLRP University of Sao Paulo 14040-901 Ribeirao Preto Sao Paulo Brazil Institute of Chemistry Rio de Janeiro State University 20550-900 Rio de Janeiro Rio de Janeiro Brazil Institute of Chemistry Uniuersity of Campinas 13083-970 Campinas Silo Paulo Brazil Center of-Natural and Human Sciences Federal Uniuerty of ABC 09210-580 Santo Andre Sao Paulo Brazil

We report the application of a solid lanthanum-ceria-zinc catalyst in the catalytic regeneration of diesel particulate filters （DPF） in diesel engines. We synthesized a CeO2- ZnO-La2O3 （Ce-Zn-La） mixed oxide by a lactic acid-mediated sol-gel method, which efficiently coated cordierite substrates for soot capture and combustion. We studied the effects of La loading on the physicochemical and catalytic properties of Ce-Zn mixed oxide during lowtemperature soot combustion processes. We characterized the synthesized catalysts by X-ray diffraction （XRD）, Fourier-transform infrared spectroscopy （FTIR）, N2 adsorption, Raman spectroscopy, oxygen storage capacity （OSG）, and scanning and transmission electron microscopy （SEM and TEM）. Thermogravimetric and differential thermal analysis （TGA/DTA） confirmed that the catalysts effectively reduced the soot oxidation temperature. The ternary Ce-Zn-La mixed oxide catalyst with Ce/Zn/La atomic ratio of 2：1：0.5 had the highest catalytic activity and promoted soot oxidation at temperatures below 390℃. This indicated that the large number of oxygen vacancies in the catalyst structure generated oxygen species at low temperatures. Raman spectroscopy measurements revealed the presence of oxygen vacancies and lattice defects in Ce-Zn-La samples, which were key parameters concerning the stability and redox properties of the prepared catalysts.

关键词： Soot combustion Ceria Ternary mixed oxide Cordierite coating Diesel particulate filter

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

Sex recognition does not modulate aggression toward nest intruders in a paper wasp

引用

Current Zoology 2023年第3期69卷 324-331页

作者： Andre Rodrigues de Souza Wilson Franca Amanda Prato Fabio Santos do nascimento Departamento de Biologia Faculdade de Filosofia Ciencias e Letras de Ribeirao PretoUniversidade de Sao PauloSao PauloBrazil

During social interactions,the behavior of an individual often depends on the sex of its social *** animal societies have males and females that play very different behavioral roles,although they coexist and interact *** specific phases of the colony cycle,social wasp females and males are contemporaries within a nest,they often interact,although mating occurs mostly off the nest,therefore providing an opportunity to test sex discrimination in contexts other than classical sexual *** performed a lure presentation experiment to test if Mischocyttarus metathoracicus discriminate between conspecifics of the 2 sexes during on-nest social *** wasps discriminated conspecific sex during experimentally simulated nest *** and chemical cues may account for this sex *** sex discrimination(evidenced by differential inspective behavior from the nest females toward the female and the male lures),female wasps were as aggressive toward lures of both *** the female-dominated hymenopteran societies,males are often subordinate and not aggressive on nest,resulting in females directing less aggression to them compared to other ***,*** males and females are both aggressive toward nestmates,so they might be perceived as similar threat during on-nest social interactions.

关键词： chemical cues Mischocyttarus sex discrimination social interactions social wasps visual cues

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：