检索结果-南通市图书馆

Development and characterization of α-tricalcium phosphate/monocalcium aluminate composite bone cement

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 Biomedical Science and Engineering 2012年第8期5卷 448-456页

作者： Loreley Morejón-Alonso Raúl García Carrodeguas luis Alberto dos Santos Ceramic Department Instituto de Cerámica y Vidrio-CSIC Madrid Spain Engineering School Materials Department Universidade Federal do Rio Grande do Sul Porto Alegre RS Brazil General Chemistry Department Chemistry Faculty Havana University Cuba

Calcium phosphate cements have received much attention in recent decades owing to their biocompatibility, in situ handling, and shaping abilities. However, their low initial mechanical strength is still a major limitation. On the other hand, calcium aluminate cements (CACs) set fast and have a high initial strength and good corrosion resistance in contact with body fluids, making them excellent dental restorative materials. Therefore, the chemical, mechanical and biological properties of new-TCP/CA cement after aging in simulated body fluid (SBF) were investigated. The results indicated that the composites have setting times not appropriated for immediate applications and have degradation rates higher than those of the traditional CPCs. Moreover, the compressive strength of composite was lower than 5MPa and did not increase with SBF immersion. However, the α-TCP/CA composites showed a higher bioactivity at early stages and were not only more biocompatible but also more noncytotoxic.

关键词： Calcium Phosphate Cements Calcium Aluminate Cements Hydroxyapatite In Vitro

Corticosteroids for severe influenza pneumonia: A critical appraisal

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 Critical Care Medicine 2016年第1期5卷 89-95页

作者： Wagner luis Nedel David Garcia Nora Jorge Ibrain Figueira Salluh Thiago Lisboa Pedro Póvoa Intensive Care Unit Hospital Nossa Senhora da Concei??o Intensive Care Unit Vila Franca de Xira Hospital D’or Institute for Research and Education Critical Care Department Hospital de Clinicas de Porto Alegre Post-Graduation Program (PPG) Pneumology Universidade Federal do Rio Grande do Sul Polyvalent Intensive Care Unit S?o Francisco Xavier Hospital Centro Hospitalar de Lisboa Ocidental Nova Medical School CEDOC New University of Lisbon

Influenza pneumonia is associated with high number of severe cases requiring hospital and intensive care unit(ICU) admissions with high mortality. Systemic steroids are proposed as a valid therapeutic option even though its effects are still controversial. Heterogeneity of published data regarding study design, population demographics, severity of illness, dosing, type and timing of corticosteroids administered constitute an important limitation for drawing robust conclusions. However, it is reasonable to admit that, as it was not found any advantage of corticosteroid therapy in so diverse conditions, such beneficial effects do not exist at all. Its administration is likely to increase overall mortality and such trend is consistent regardless of the quality as well as the sample size of studies. Moreover it was shown that corticosteroids might be associated with higher incidence of hospital-acquired pneumonia and longer duration of mechanical ventilation and ICU stay. Finally, it is reasonable to conclude that corticosteroids failed to demonstrate any beneficial effects in the treatment of patients with severe influenza infection. Thus its current use in s evere influenza pneumonia should be restricted to very selected cases and in the setting of clinical trials.

关键词： Influenza Mechanical ventilation Pneumonia Corticosteroids Respiratory failure

Dynamic Modelling of Dengue Epidemics in Function of Available Enthalpy and Rainfall

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 Epidemiology 2016年第1期6卷 50-79页

作者： Hugo Abi Karam Julio Cesar Barreto da Silva Augusto José Pereira Filho José luis Flores Rojas Instituto de Geociências IGEO-CCMN-UFRJ Universidade Federal do Rio de Janeiro Rio de Janeiro Brasil Departmento de Estatística CCET-UFRN Universidade Federal do Rio Grande do Norte Natal Brasil Instituto de Astronomia Geofísica e Ciências Atmosféricas IAG-USP Universidade de Sao Paulo SP Brasil

In this work, we present results of an investigation of environmental precursors of infectious epidemic of dengue fever in the Metropolitan Area of Rio de Janeiro, RJ, Brazil, obtained by a numerical model with representation of infection and reinfection of the population. The period considered extend between 2000 and 2011, in which it was possible to pair meteorological data and the reporting of dengue patients worsening. These data should also be considered in the numerical model, by assimilation, to obtain simulations of Dengue epidemics. The model contains compartments for the human population, for the vector Aedes aegypti and four virus serotypes. The results provide consistent evidence that worsening infection and disease outbreaks are due to the occurrence of environmental precursors, as the dynamics of the accumulation of water in the breeding and energy availability in the form of metabolic activation enthalpy during pre-epidemic periods.

关键词： Modelling Dengue Epidemics Environmental Enthalpy Environmental Precursors of Dengue Epidemics

Unsteady Fluidynamic Behavior of Gas Bubbles Flowing in Curved Pipes: A Numerical Study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Chemical Engineering and Science 2012年第2期2卷 283-291页

作者： Jose luis Gomes Marinho Ramdayal Swarnakar Severino Rodrigues de Farias Neto Antonio Gilson Barbosa de Lima Department of Chemical Engineering Center of Sciences and Technology Federal University of Campina Grande Campina Grande Brazil Department of Mechanical Engineering Center of Sciences and Technology Federal University of Campina Grande Campina Grande Brazil

Petroleum is considered as one of the factors for the development of a nation as well as a cause of economic and political conflicts around the world because of the diversity of products obtained with their derivatives such as fuel for automotives and aviation, and manufacturing plastic parts, among others. The crude petroleum (usually oil, water and gas) found in an underground reservoir is transported to the surface by pipes, and has drawn the attention of researchers because of the problems generated in the pipeline with particular attention to the loss of pressure, friction and bubbles. For a fluid flow in plug regime, where many of the bubbles formed coalesce and produce bigger ones of sizes almost equal to the pipe diameter (Taylor bubble), severe instability in the flow is caused. In this context, the objective of this research has been to study the Taylor bubble flow in curved ducts using the software CFX. Results of the transient effects of the air concentration on the bubble air volumetric fraction, of the viscosity on bubble format, and pipe angle of 90? on bubble symmetry are presented and interpreted.

关键词： Slug Flow Taylor Bubbles Curved Pipe CFD Oil Simulation

ON THE CONSTITUTIVE CRITERIA FOR THE FAULT:INFLUENCE OF SIZE AND TENSILE CRACKS GENERATION DURING RUPTURE

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

ON THE CONSTITUTIVE CRITERIA FOR THE FAULT:INFLUENCE OF SIZE...

Feasibility Study of a Hydro PV Hybrid System Operating at a Dam for Water Supply in Southern Brazil

第十八届国际反应堆结构力学大会

作者： Jorge Daniel Riera Letícia Fleck Fadel Miguel luis Angel Dalguer Gudiel Departamento de Engenharia Civil Universidade Federal do Rio Grande do Sul Departamento de Engenharia Civil Universidade Federal do Rio Grande do Sul Department of Geological Science San Diego State University

＜正＞ Several models have been used in the dynamic analysis of the fault region in order to predict features of the rupture process that gives rise to seismic excitation. The simplest and understandably more often employed laws are the slip-weakening laws and the so-called velocity or rate-weakening laws. In this paper, the region adjacent to the fault surface was modeled, including material non-homogeneities as well as the possibility of generation of new tensile cracks. By means of Monte Carlo simulation, the macro constitutive relations for the fault, which correlate the static （mean normal and shear stresses） with kinetic

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Power and Energy Engineering 2015年第9期3卷 70-83页

作者： luis E.Teixeira Johan Caux Alexandre Beluco Ivo Bertoldo JoséAntonio S.Louzada Ricardo C.Eifler Instituto de Pesquisas Hidráulicas Universidade Federal do Rio Grande do SulPorto AlegreBrazil Ecole Nationale Superieure de l’Energie l’Eau et l’EnvironnementGrenoble INPGrenobleFrance Companhia Riograndense de Saneamento Santa MariaBrazil Companhia Estadual de Energia Elétrica Salto do JacuíBrazil

Dams for water supply usually represent an untapped hydroelectric potential. It is a small energetic potential, in most situations, usually requiring a particular solution to be viable. The use of pumps as power turbines often represents an alternative that enables the power generation in hydraulic structures already in operation, as is the case of dams in water supply systems. This potential can be exploited in conjunction with the implementation of PV modules on the water surface, installed on floating structures, both operating in a hydro PV hybrid system. The floating structure can also contribute to reducing the evaporation of water and providing a small increase in hydroelectric power available. This paper presents a pre-feasibility study for implementation of a hydroelectric power plant and PV modules on floating structures in the reservoir formed by the dam of Val de Serra, in southern Brazil. The dam is operated to provide drinking water to about 60% of the population of the city of Santa Maria, in the state of Rio grande do Sul, in southern Brazil. The pre-feasibility study conducted with Homer software, version Legacy, indicated that the hydroelectric plant with a capacity of 227 kW can operate together with 60 kW of PV modules. This combination will result (in one of the configurations considered) in an initial cost of USD$ 1715.83 per kW installed and a cost of energy of USD$ 0.059/kWh.

关键词： Hydro PV Hybrid System PV Floating Cover Water Supply Dam Software Homer

Characterization of goat whey proteins and their bioactivity and toxicity assay

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Food Bioscience 2022年第2期46卷 833-843页

作者： Maria Isabel Ferreira Campos Paula Perazzo de Souza Barbosa Laura Junqueira Camargo Luciano Da Silva Pinto Bianca Mataribu Catarina Serr˜ao luis Fernando Marques-Santos Jos´e Hon´orio Lopes Julia Mariano Caju de Oliveira Carlos Alberto de Almeida Gadelha Tatiane Santi-Gadelha Programa de P´os-Graduaç˜ao em Ciˆencia e Tecnologia de Alimentos Universidade Federal da ParaíbaJo˜ao PessoaParaíbaBrazil Departamento de Biologia Molecular Universidade Federal da ParaíbaJo˜ao PessoaParaíbaBrazil Centro de Desenvolvimento Tecnol´ogico Universidade Federal de PelotasRio Grande do SulBrazil Programa de P´os-Graduaç˜ao em Ciˆencias da Nutriç˜ao Universidade Federal da ParaíbaJo˜ao PessoaParaíbaBrazil

Goat whey is an industry-discarded dairy by-product that has interesting nutritional value and a nutrient composition with important functional potential,where proteins have a high biological value and play an important role in the organism’s ***,the aim of this study was to identify,quantify,concentrate and investigate the capacity of goat whey proteins to perform different biological activities and to evaluate their acute *** proteins were quantified and identified by Bradford,Kjehdal and SDS-PAGE *** activity was performed against Listeria monocytogenes,Salmonella spp.,Staphylococcus aureus,Pseudomonas aeruginosa and Escherichia coli microorganisms and showed MIC ranging from 15 to 120μg mL-1,with the highest inhibition for *** *** activity was performed against human malignant melanoma cells and their proliferation inhibition was up to 66.8%within 72 h of *** highest antioxidant capacity was obtained at concentration 2 mg that showed 29.69%of inhibition of DPPH radical *** acute toxicity test was performed using Artemia franciscana larvae in which whey proteins were able to preserve larval survival throughout ***,we can conclude that goat’s whey has proteins that can play a positive effect on health,with antimicrobial activity and without *** present study highlights the great potential of goat’s whey to be developed as a safe biopreservative or as a functional ingredient in the food industry.

关键词： Goat whey proteins Malignant cells Antimicrobial Antioxidant capacity Whey protein functionality

pRB expression in esophageal mucosa of individuals at high risk for squamous cell carcinoma of the esophagus

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 2007年第11期13卷 1728-1731页

作者： Simone S Contu Paulo C Contu Daniel C Damin Renato B Fagundes Fabiano Bevilacqua Aline S Rosa Joo C Prolla luis F Moreira Post-Graduate Program in Surgery Hospital de Clínicas de Porto Alegre Federal University of Rio Grande do Sul Brazil University Hospital-Division of Gastroenterology Federal University of Santa Maria Brazil

AIM: To investigate the pRb expression in a large group of patients with history of chronic exposure to the main risk factors for development of squamous cell carcinoma of the esophagus. METHODS: One hundred and seventy asymptomatic individuals at high risk for esophageal squamous cell carcinoma (consumption of more than 80 g of ethanol and 10 cigarettes/d for at least 10 years) underwent upper gastrointestinal endoscopy with biopsies of the esophageal mucosa. As a control group, specimens of esophageal mucosa obtained from 20 healthy subjects were also studied. Immunohistochemical assessment of the tissues was performed using a monoclonal antibody anti-pRB protein. RESULTS: Absence of the pRB staining, indicating loss of RB function, was observed in 33 (19.4%) of the individuals at risk for esophageal cancer, but in none of the healthy controls (P < 0.02). Loss of pRb expression increased in a stepwise fashion according to the severity of the histological findings (P < 0.005): normal mucosa (11/97 or 11.3%), chronic esophagitis (17/60 or 28.3%), low-grade dysplasia (3/10 or 30%), high-grade dysplasia 1/2 or 50%) and squamous cell carcinoma (1/1 or 100%). CONCLUSION: Our findings suggest that abnormal expression of the pRB protein may be implicated in the process of esophageal carcinogenesis. Additional studies are warranted to define the role of the pRBprotein as a biomarker for development of esophageal squamous cell carcinoma in individuals at high risk for this malignancy.

关键词： Esophageal cancer Squamous cell carcinoma Risk factors pRB Carcinogenesis

An Emergy-Based Approach to Assess and Valuate Ecosystem Services of Tropical Wetland Pastures in Brazil

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 Ecology 2020年第5期10卷 303-319页

作者： Sandra Aparecida Santos Fabio Takahashi Evaldo luis Cardoso Claudio Flores Luiz Orcirio Fialho de Oliveira Geraldo da Silva e Souza Eliane Goncalves Gomes Enrique Ortega Embrapa Pantanal CorumbaMSBrasil Universidade de Vicosa FlorestalMGBrasil Embrapa Gado de Corte Campo GrandeMSBrasil Embrapa Sede BrasiliaDFBrasil Universidade de Campinas Barao GeraldoSPBrasil

Wetland grasslands are important ecosystems for raising beef cattle, because they are highly productive and present forages with high quality. Most of these ecosystems are threatened by overgrazing or by being replaced by exotic pastures. Emergy synthesis approach was used to assess and value the services provided by native pastures wetland under three conservation status and also to compare them to exotic pastures on wetlands. The ecosystem service that was assessed included forage provision for calves production estimated from grazing capacity of cow with calf at the foot. Habitat maintenance to plant diversity and wild herbivores were also evaluated. The results showed that natural wetland pastures with better conservation status provided valuable ecosystem services and are highly renewable. Data envelopment analysis (DEA) showed that regardless of the conservation state of the natural pastures, wet native grasslands were more efficient than wet exotic grasslands. Replacing native pastures by exotic ones may reduce plant diversity and the renewability of the system. The proposed method has a holistic approach to pasture ecosystems and is able to help decision-makers to define sustainable management practices and to subsidise public policies when it comes to payments regarding ecosystem services.

关键词： Data Envelopment Analysis Forage Resources Natural Pasture Plant Diversity Sustainability