检索结果-南通市图书馆

Preparation of High Purity Neodymium Oxide from Brazilian Monazite by Ion Exchange

Journal of Energy and Power Engineering 2015年第7期9卷 616-621页

作者： Carlos Alberto da silva Queiroz Jose Antonio Seneda Walter dos reis Pedreira Filho IPEN/CNEN-SP (Instituto de Pesquisas Energeticas e Nucleares/Comissao Nacional de Eneergia Nuclear-Sao Paulo) Cidade Universitaria Sao Paulo 05508-000. Brazil Fundacao Jorge Duprat Figueiredo de Seguranca e Medicina do Trabalho-FUNDACENTRO Sao Paulo 05409-002 Brazil

A simple and economical chemical process for obtaining high purity neodymium oxide is discussed. The raw material in the form of RE （rare earth） carbonates is produced industrially in Brazil from monazite. Using this concentrate as the feed material, ion exchange with a strong cationic resin, commonly used for water treatment, and without the use of retention ions was used for the fractionating of the REE （rare earth elements）. The eluent was ammonium salt of EDTA （ethylenediaminetetraacetic acid） at pH 4.0. The complex of EDTA-neodymium was transformed into neodymium oxides via oxalate precipitation. We produced 99.9% pure Nd203 in yields greater than or equal to 80%. Molecular absorption spectrophotometry was used to monitor the neodymium content during the process and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the neodymium oxides. The typical neodymium oxides obtained contained the followings contaminants in micrograms per gram： Sc （4.09）; Y （0.39）; La （0.78）; Ce （5.62）; Pr （4.56）; Sm （11.10）; Eu （1.10）; Gd （14.30）; Tb （29.3）; Dy （4.15）; Ho （8.39）; Er （13.80）; Tm （0.23）; Yb （2.29）; Lu （0.39）. High purity neodymium oxides obtained from this procedure replaced the imported product used in research and development work on rare earth at IPEN/CNEN-SP （Instituto de Pesquisas Energeticas e Nucleares/Comissfio Nacional de Eneergia Nuclear-Sao Paulo）.

关键词： Neodymium oxide elemental rare earths separation rare earths.

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

Urea breath test for Helicobacter pylori infection in adult dyspeptic patients: A meta-analysis of diagnostic test accuracy

引用

World Journal of Gastroenterology 2024年第6期30卷 579-598页

作者： Fabian Fellipe Bueno Lemos Caroline Tianeze de Castro Marcel silva Luz Gabriel reis Rocha Gabriel Lima Correa Santos Luís Guilherme de Oliveira silva Mariana Santos Calmon Cláudio Lima Souza Ana Carla Zarpelon-Schutz Kádima Nayara Teixeira Dulciene Maria de Magalhães Queiroz Fabrício Freire de Melo Instituto Multidisciplinar em Saúde Universidade Federal da BahiaVitória da Conquista 45029-094BahiaBrazil Instituto de Saúde Coletiva Universidade Federal da BahiaSalvador 40110040BahiaBrazil Campus Toledo Universidade Federal do ParanáToledo 85919-899ParanáBrazil Laboratory of Research in Bacteriology UFMGBelo Horizonte 30130-100Minas GeraisBrazil

BACKGROUND Helicobacter pylori(***)infection has been well-established as a significant risk factor for several gastrointestinal *** urea breath test(UBT)has emerged as a leading non-invasive method for detecting *** numerous studies confirming its substantial accuracy,the reliability of UBT results is often compromised by inherent *** findings underscore the need for a rigorous statistical synthesis to clarify and reconcile the diagnostic accuracy of the UBT for the diagnosis of *** *** To determine and compare the diagnostic accuracy of 13C-UBT and 14C-UBT for *** infection in adult patients with *** We conducted an independent search of the PubMed/MEDLINE,EMBASE,and Cochrane Central databases until April *** search included diagnostic accuracy studies that evaluated at least one of the index tests(^(13)C-UBT or ^(14)C-UBT)against a reference *** used the QUADAS-2 tool to assess the methodo-logical quality of the *** utilized the bivariate random-effects model to calculate sensitivity,specificity,positive and negative test likelihood ratios(LR+and LR-),as well as the diagnostic odds ratio(DOR),and their 95%confidence *** conducted subgroup analyses based on urea dosing,time after urea administration,and assessment *** investigate a possible threshold effect,we conducted Spearman correlation analysis,and we generated summary receiver operating characteristic(SROC)curves to assess ***,we visually inspected a funnel plot and used Egger’s test to evaluate publication *** both as reliable diagnostic tools in clinical *** In summary,our study has demonstrated that ^(13)C-UBT has been found to outperform the ^(14)C-UBT,making it the preferred diagnostic ***,our results emphasize the significance of carefully considering urea dosage,assessment timing,and measurement techniques for both tests to enh

关键词： Helicobacter pylori Urea breath test Diagnosis Diagnostic test accuracy Meta-analysis

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

Evaluation of physicochemical properties as supporting information on quality control of raw materials and veterinary pharmaceutical formulations

引用

Journal of Pharmaceutical Analysis 2018年第3期8卷 168-175页

作者： Sara da silva Anacleto Marcella Matos Cordeiro Borges Hanna Leijoto de Oliveira Andressa reis Vicente Eduardo Costa de Figueiredo Marcone Augusto Leal de Oliveira Barbara Juliana Pinheiro Borges Marcelo Antonio de Oliveira Warley de Souza Borges Keyller Bastos Borges Departamento de Ciencias Naturals Universidade Federal de Sao Joao del-Rei Campus Dom Bosco Praca Dora Helvecio 74 Fabricas 36301-160 Sao Joao del-Rei Minas Gerais Brazil Departamento de Quimica Universidade Federal do Espirito Santo Avenida Fernando Ferrari 514 Goiabeiras 29075-910 Vitdria Espirito Santo Brazil Laboratorio de Analise de Toxicantes e Farmacos Faculdade de Ciencias Farmaceuticas Universidade Federal de Alfenas Rua Gabriel Monteiro da Silva 700 Centro 37130-000 Alfenas Minas Gerais Brazil Departamento de Quimica Universidade Federal de Juiz de Fora Rua Jose Lourenco Kelmer s/n 36036-330 Juiz de Fora Minas Gerais Brazil Centro de Ciencias da Saude Universidade Federal do Espirito Santo Avenida Marechal Campos 1468 Maruipe 29.043-900 Vitori Espirito Santo Brazil Centro Universitario Norte do Espirito Santo Universidade Federal do Espirito Santo Br 101 Norte Km 67 Sao Mateus Espirito Santo Brazil

This study aimed to show that the physicochemical proprieties obtained by Fourier transform infrared spectroscopy （FTIR）, thermogravimetry （TG）, and scanning electronic microscopy （SEM） can be useful tools for evaluating the quality of active pharmaceutical ingredients （APIs） and pharmaceutical products. In addition, a simple, sensitive, and efficient method employing HPLC-DAD was developed for simulta- neous determination of lidocaine （LID）, ciprofloxacin （CFX） and enrofloxacin （EFX） in raw materials and in veterinary pharmaceutical formulations. Compounds were separated using a Gemini Cm （250 mm×4.6 mm, 5μm） Phenomenex column, at a temperature of 25℃, with a mobile phase containing 10 mM of phosphoric acid （pH 3.29）： acetonitrile （85.7：14.3, v/v） and a flow rate of 1.5 mL/min. Physicochemical characterization by TG, FTIR, and SEM of raw materials of LID, CFX, and EFX provided information useful for the evaluation, differentiation, and qualification of raw materials. Finally, the HPLC method was proved to be useful for evaluation of raw material and finished products, besides satisfying the need for an analytical method that allows simultaneous determination of EFX, CFX, and LID, which can also be extended to other matrices and applications.

关键词： HPLC Physicochemical characterization Quality control Veterinary pharmaceutical formulation Raw material

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

Above-Optimum Temperature-Induced Differential Photosynthetic and Roots Morphometric Responses in Two Contrasting Rice Genotypes

引用

Journal of Agricultural Science and Technology(B) 2017年第5期7卷 309-319页

作者： Diogo da silva Moural Italo Lucas de Moraes Rodrigo da silva Armestol Rafael silva da silva Femanda Reolon Junior Borela Paulo Ricardo reis Fagundes Giovani Greigh de Brito Sidnei Deuner Institute of Biology Department of Botany Federal University of Pelotas (UFPel) Capao do Leao 96010-900 RS Brazil EMBRAPA Temperate Climate Brazilian Agricultural Research Corporation Pelotas 96010-971 RS Brazil

Temperature thresholds during the rice （Oryza sativa L.） cycle development have been reported to affect plant metabolism Therefore, this study aimed to evaluate the effects of the above-optimal temperature on photosynthetic and morphometric parameters in two contrasting irrigated rice genotypes （BRS Quer^ncia--sensitive and Nagina 22 （N22）~tolerant）. Plants of both genotypes were grown in rhizotrons and always maintained under two temperature conditions： Out--under environmental temperature conditions, and In--rhizotrons inside a plastic structure, which increased the temperature about 3 ~C to 5 ~C above the external one. In the genotype N22, there was an increase （twofold higher） in CO2 assimilation in plants cultivated under elevated temperature （In）. In BRS Quer^ncia, the stomatal conductance （gs） and transpiration rate （E） decreased upon high temperature. The rise in the temperature also negatively impacted in the modulated fluorescence parameters in both genotypes. Increases in root dry weight （RDW） and shoot dry weight （SDW） were also observed in the genotype N22 when compared to BRS Quer^ncia upon temperature rise. In general, the N22 genotype showed greater response to the above-optimal temperature due to its intrinsic thermotolerance traits over BRS Quer^ncia. Thus, N22 appeared as a potential donor of heat tolerance genes aiming to obtain new cultivar to face current global wanning.

关键词： Oryza sativa L. heat thermotolerance photosynthesis root system.

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

Production of Soybean Oil Nanoemulsion (SONE) and Evaluation of Angiogenic and Embryotoxic Activity

引用

Journal of Biomaterials and Nanobiotechnology 2020年第3期11卷 161-178页

作者： Tamíris Augusto Marinho Patrícia silva Nunes Paulo Roberto de Melo-reis Mônica Rodrigues Ferreira Machado Nelson Jorge silva Júnior Programa de Pós-Graduaç o Doutorado em Biotenologia e Biodiversidade (PGBB) Universidade Federal de Goiás (UFG) Goiania Brasil Núcleo de Estudos e Pesquisas em Promoç o da Saúde (NUPPS) Instituto Federal de Educa&#231 o Ciência e Tecnologia de Goiás (IFG) Goiania Brasil Programa de Pós-Graduaç o Mestrado em Genética Goiania Brasil Departamento de Ciências Biológicas Laboratório de Pesquisa e Reprodu&#231 o de Zebrafish (LABFISH) Universidade Federal de Jataí (UFJ) Jataí Brasil

The SONE oil/water was prepared using the pseudo-ternary phase diagram, using a low energy method with phase inversion by changing the composition. In order to optimize the preparation of SONE, three speeds were used in the agitator arm and two different rods. The particle size and polydispersity index were determined by Dynamic Light Scattering (DLS) and the stability test by the freeze-thaw cycle. Angiogenesis in chicken embryo egg chorioallantoic membrane and zebrafish (Danio rerio) embryotoxicity was performed. The lower stirring speed and propeller shaft induced smaller particle size (550.2 nm). Regarding angiogenesis, there was a statistically significant difference for all the evaluated parameters (length, caliber, junctions, and number of blood vessel complexes) and the result was higher in SONE when compared to the inhibition control (Dexamethasone), but lower than the induction control (Regederm®) and there was no statistically significant difference between SONE and distilled water. It was observed that the exposure of the zebrafish embryos to SONE caused an increase in the mortality rate dependent on time and concentration. The LC50 for SONE decreased statistically with increasing exposure (p-value = 0.046). Heart rate decreased significantly with increasing concentration at all exposure times (p-value rogressive embryo mortality. The hatching rate was late until the concentration of 0.0193 mg/mL and no hatching rate was verified from that concentration. Exposure of zebrafish embryos to different concentrations of SONE induced malformations such as spinal changes, pericardial edema and yolk sac edema, but there was no significant difference in the malformation rate of embryos exposed to SONE when compared to the control group. The SONE produced remained stable in the freeze-thaw cycle, with c

关键词： Soybean Oil Angiogenesis Inducing Agents Toxicity Biotechnology Nanotechnology

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

Chromate and the Environment： Removal and Utilization of Industrial Waste

引用

Journal of Chemistry and Chemical Engineering 2016年第3期10卷 147-152页

作者： Femando B. Mainier Pedro Paulo B. Leite Marcone F. reis Thiago Teobaldo silva Engineering School Federal Fluminense University(UFF) Niteroi Rio de Janeiro 24220-261 Brazil

Chromate and dichromate sodium as a function of oxidizer characteristics are used in several industrial areas; for example, in surface protection of coated parts of cadmium, zinc and aluminum （chromate coated treated）, corrosion inhibitors, the treatment of leather, the manufacture of pigments, etc. However, the use of such products has been questioned due to the problems of toxicity and pollution that can be caused in the environmental. The Brazilian environmental agency has established that the concentrations of chromate in water courses are less than 0.5 ppm. In order to reuse chromate （CrO42） from industrial effluent, laboratory experiments have been proposed based on chemical reduction or electrolytic processes, in order to transform these chromate ions in a final mix of oxides （in solid form）, which can then be packed and sent to the production process of sodium chromate. The results of these experiments have become useful industrially （without regard to costs） considering the environmental reuse and the life cycle of the chemical compound.

关键词： Chromate dichromate contamination chemical reduction electrolytic process.

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

Prevalence of sarcopenia using different methods in patients with non-alcoholic fatty liver disease

引用

World Journal of Hepatology 2022年第8期14卷 1643-1651页

作者： Naiade Silveira Almeida Raquel Rocha Claudineia Almeida de Souza Ana Carolina Sirelli da Cruz Bruna dos reis Ribeiro Luiza Valois Vieira Carla Daltro Rafael silva Manoel Sarno Helma Pinchemel Cotrim Programa de Pós-Graduação em Medicina e Saúde Universidade Federal da BahiaSalvador 40110-060BABrazil Departamento de Ciência da Nutrição Escola de NutriçãoUniversidade Federal da BahiaSalvador 40110-060Brazil Caliper Clínica e Escola de Imagem Salvador 41810-012Brazil

BACKGROUND Sarcopenia is a clinical condition associated with several liver diseases and it includes non-alcoholic fatty liver disease(NAFLD)in its broad spectrum as steatosis,steatohepatitis and ***,the criteria to define sarcopenia are diverse,and even those established in consensus have been discussed regarding their performance in making an accurate *** To evaluate the prevalence of sarcopenia,using different methods,in patients with NAFLD,and its association with clinical-anthropometric *** This was an observational study of outpatients with *** was defined by the European Working Group Consensus on Sarcopenia in Older People of 2010(EWGSOP1)and 2018(EWGSOP2).The skeletal muscle index was used to estimate muscle mass,handgrip strength was assessed using the dynamometer and physical performance by walking a distance of four meters at usual walking *** non-invasive fibrosis scores,fibrosis-4(FIB-4)index and Aspartate aminotransferase to platelet ratio index(APRI),were used to assess the absence and presence of *** Fifty-seven individuals with NAFLD were evaluated,the mean age(SD)was 52.7(11.3)years and 75.4%were *** assessed by FIB-4 and APRI was observed in 3.7%and 16.6%of patients with NAFLD,*** diagnosis of sarcopenia was identified only by EWGSOP1 in 3.5%of NAFLD patients,and the prevalence of probable/pre-sarcopenia was higher using the EWGSOP2 consensus at 26.3%,when compared to 1.8%with *** defined by EWGSOP1,was associated with grade I steatosis,but without overweight(P0.05).EWGSOP2 showed a greater number of patients with probable sarcopenia,and who were overweight(12(80.0%)),with a higher degree of steatosis[11(73.3%)and presence of fibrosis(1(6.7%),FIB-4 and 3(20.0%),APRI]compared to EWGSOP1[1(100%),0(0.0%),0(0.0%),FIB-4 and 0(0.0%),APRI,respectively].CONCLUSION The presen

关键词： Non-alcoholic fatty liver disease Sarcopenia Muscle strength Physical performance Liver fibrosis

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

Laser texturing of piston ring for tribological performance improvement

引用

Friction 2023年第10期11卷 1895-1905页

作者： Rita FERREIRA Óscar CARVALHO Luís SOBRAL Sandra CARVALHO Filipe silva CMEMS-UMinho University of MinhoGuimarães 4800058Portugal LABBELS-Associate Laboratory Guimarães 4800058Portugal CEMMPRE-Center for Mechanical Engineering Materials and ProcessesUniversity of CoimbraRua Luís Reis SantosCoimbra 3030-788Portugal MAHLE Componentes de MotoresS.A.Núcleo Industrial de MurtedeCantanhede 3060-372Portugal

The radial surface coating layer of compression piston rings is used to improve their wear resistance during the internal combustion engine ***,at top dead centers,the friction coefficient of the piston ring–cylinder liner pair is detrimental to the engine’s tribological *** this work,dimples with different texture dimensions and densities were tested in a home-developed *** friction coefficient was measured for all samples,and for those with the best results,their wear resistance was *** texture with an aspect ratio of 0.25 and a density area of 15%reported the best tribological results.

关键词： piston ring surface texture friction wear

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

Management of the Innovation Process of a Small Amazonian Company in the Food Sector

引用

Sociology Study 2011年第7期1卷 491-504页

作者： Joao Bosco Lissandro reis Botelho Joesia Moreira Juliao Pacheco Andre Luiz Nunes Zogahib Andreza de Souza silva Erasmus University Rotterdam The Netherlands EmbrapaWestern Amazonia Brazil Federal University of rio de Janeiro/Amazonas EducationTechnology Center Brazil Federal University of Minas Gerais/State University ofAmazonas Brazil La SaUe College Brazil

The present article broaches aspects related to the management of the innovation process of a small company that works in the food industry of Manaus; the authors focus on the current types and levels of technological competencies existent in the company, describe their technological learning process and emphasize the innovation system that provides the organizational development support. This paper is based on a specific individual study and on empirical evidence collected using various techniques. It demonstrates how the management of the technological learning process and the innovation system boost the growth trajectory in a small company, by the fact that they contribute to the effective development of technological competencies considered fundamental to perfect the level of competitiveness of the company.

关键词： Technological capability technological learning innovation system

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

Concerns about the application of resistance exercise with blood-flow restriction and thrombosis risk in hemodialysis patients

引用

Journal of Sport and Health Science 2024年第4期13卷 548-558,F0003页

作者： Hugo de Luca Correa Lysleine Alves Deus Dahan da Cunha Nascimento Nicholas Rolnick Rodrigo Vanerson Passos Neves Andrea Lucena reis Thais Branquinho de Araujo Carmen Tzanno-Martins Fernanda Silveira Tavares Luiz Sinesio silva Neto Claudio Avelino Rodrigues Santos Paolo Lucas Rodrigues-silva Fernando Honorato Souza Vitoria Marra da Motta Vilalva Mestrinho Rafael Lavarini dos Santos Rosangela Vieira Andrade Jonato Prestes Thiago dos Santos Rosa Post-graduate Program of Physical Education Catholic University of BrasıliaBrasılia 71966-700Brazil The Human Performance Mechanic Lehman CollegeNew YorkNY 10011USA Clinical Group Home Dialysis Center and RenalClass Sao Paulo 01239-040Brazil Department of Medicine Catholic University of BrasıliaBrasılia 71966-700Brazil Faculty of Medicine Federal University of TocantinsTocantins 77001-090Brazil Embrapa Genetic Resources and Biotechnology Brasılia 70770-917Brazil Graduate Program of Genomic Sciences and Biotechnology Brasılia 71966-700Brazil

Background:Hemodialysis(HD) per se is a risk factor for *** the growing body of evidence on blood-flow restriction(BFR) exercise in HD patients,identification of possible risk factors related to the prothrombotic agent D-dimer is required for the safety and feasibility of this training *** aim of the present study was to identify risk factors associated with higher D-dimer levels and to determine the acute effect of resistance exercise(RE) with BFR on this ***:Two hundred and six HD patients volunteered for this study(all with a glomerular filtration rate of 70 years old),and HD ***,RE+BFR significantly increases D-dimer after 4 *** with borderline baseline D-dimer levels(400-490 ng/mL) displayed increased risk of elevating D-dimer over the normal range(≥500 ng/mL).Conclusion:These results identified factors associated with a heightened prothrombotic state and may assist in the screening process for HD patients who wish to undergo RE+BFR.D-dimer and/or other fibrinolysis factors should be assessed at baseline and throughout the protocol as a precautionary measure to maximize safety during RE+BFR.

关键词： Blood-flow restriction Chronic kidney disease Coagulation Hemodialysis Vascular occlusion exercises

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

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：