Search | SciELO

Need help?

Add field +

Search history

No documents were found for your search

Results: 19

au:"Barbosa, R."

Filters

Collection + Options

All
Brazil

13
Chile

3
Spain

2
Colombia

1

Journal + Options

All
Cerâmica

4
Brazilian Journal of Medical and Biological Research

3
Revista chilena de obstetricia y ginecología

3
Brazilian Journal of Biology

2
Actas Urológicas Españolas

1
Arquivos Brasileiros de Cardiologia

1
Brazilian Journal of Chemical Engineering

1
Diversitas: Perspectivas en Psicología

1
Journal of Microwaves, Optoelectronics and Electromagnetic Applications

1
Materials Research

1
Revista de la OFIL

1

Language

All
Portuguese

6

Publication Year + Options

All
2015

3
2005

2
2012

2
2013

2
2016

2
2017

2
2004

1
2006

1
2008

1
2010

1
2021

1
2022

1

SciELO Thematic Areas + Options

All
Health Sciences

9
Engineering

7
Biological Sciences

5
Human Sciences

1

WoS Subject Categories + Options

All
Biology

5
Materials

5
Science

5
Ceramics

4
Engineering

3
Experimental

3
Gynecology

3
Medicine

3
Obstetrics

3
Research

3
Chemical

2
Multidisciplinary

2
Cardiac

1
Cardiovascular

1
Electrical

1

Show all...

WoS Citation Index

All
Science Citation Index Expanded

8

Citables and non citables + Options

All
Citable

18
Non citable

1

Type of Literature + Options

All
Article

16
Article-commentary

1
Review article

1
Other

1

Order by

Page of 2 Next

Select this page

Print | Send to email | Export |

Facebook
Twitter
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

0 Selected itens

List all
Erase all

Behavioral observations of larvae and adults of Dinurothrips hookeri Hood, 1913 (Thysanoptera: Thripidae: Panchaetothripinae)
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Lima, É. F. B.

; Fontes, L .S.

; Silva, N. M. O.

; Barbosa, R. B.

Brazilian Journal of Biology

Journal Metrics
- Sobre o periódico
- SciELO Analytics

2022, Volume 82 elocation e238729

Abstract: En | Text: En | PDF: En

https://doi.org/10.1590/1519-6984.238729 349 downloads

Automatização em nutrição parentérica: controlo de qualidade antes e após a sua implementação
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Barbosa, R

; Capela, A

; Sampaio, C

; Fraga, S

; Soares, T

Revista de la OFIL

Journal Metrics
- Sobre o periódico
- SciELO Analytics

mar 2021, Volume 31 N. 1 Pages 24 - 27

Abstract: En Pt | Text: En Pt | PDF: En | PDF: Pt

SUMMARY Parenteral nutrition (PN) plays a vital role in critically ill patients and custom preparation is often necessary, adjusted to the needs of patients with specific needs. Compounding PN handling can be performed manually or automated, always requiring aseptic conditions and trained personnel. The implementation of an automated system requires a careful analysis of its need/ justification, so that, based on adequate rationale, a feasible execution plan may be structured. Monitoring the performance of the automated system is a key process which requires of pharmaceutical validation. In the Pharmaceutical Service of the Centro Hospitalar e Universitário de São João (CHUSJ), a study of gravimetric quality control was carried out before and after the implementation of the automated system, in order to monitor the accuracy of the results obtained for this verification test. As statistical results, the automated filling method was related to the lower average for the deviation to the theoretical weight, as well as lower standard deviation, corroborating a lower percentage of error but also a smaller dispersion of the results with this method. From the analysis of the results obtained, it was concluded that the implementation of automation resulted in improvements in the accuracy of results for the gravimetric control of nutritional bags, increasing the safety of the mixtures produced and, consequently, the quality of care provided to the patient. It is of highly importance that procedures for validating the performance of the automated system are implemented, as was the case, and these should be complemented by other types of evaluations, preferably performed by external entities to the institution in question.

RESUMO A nutrição parentérica (NP) desempenha um papel vital em doentes críticos, sendo muitas vezes necessária a sua preparação personalizada, ajustada às necessidades de doentes com carências específicas. A manipulação de NP poderá ser realizada de forma manual ou automatizada, requerendo sempre condições asséticas e pessoal treinado. A implementação de um sistema automatizado requer uma análise cuidada da sua necessidade/justificação, de forma a que, baseado em fundamentação adequada, se estruture um plano exequível. A monitorização do desempenho do sistema automatizado é um processo fundamental de validação farmacêutica. Nos Serviços Farmacêuticos (SF) do Centro Hospitalar e Universitário de São João (CHUSJ), elaborou-se um estudo de controlo de qualidade gravimétrico antes e após implementação do sistema automatizado, no sentido de monitorizar a precisão dos resultados obtidos para este ensaio de verificação. Como resultados estatísticos, o método de enchimento automatizado relacionou-se com a menor média para o desvio ao peso teórico, assim como menor desvio padrão, corroborando uma menor percentagem de erro e também uma menor dispersão dos resultados. Da análise dos resultados obtidos concluiu-se que a implementação da automatização se traduziu em melhorias a nível de precisão de resultados para o controlo gravimétrico das bolsas nutritivas, aumentando a segurança das misturas produzidas e, consequentemente, a qualidade dos cuidados prestados ao doente. É de elevada importância que se implementem procedimentos de validação do desempenho do sistema automatizado, como foi o caso, sendo que deverão ser complementados com outro tipo de avaliações, preferencialmente realizadas por entidades externas à instituição em causa.

https://doi.org/10.4321/s1699-714x2021000100006

An Improved Method for Acquisition of the Parameters of Jiles-Atherton Hysteresis Scalar Model Using Integral Calculus
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Mendes, Filomena Barbosa R.

; Leite, Jean V.

; Batistela, Nelson J.

; Sadowski, Nelson

; Suárez, Fredy M. S.

Journal of Microwaves, Optoelectronics and Electromagnetic Applications

Journal Metrics
- Sobre o periódico
- SciELO Analytics

mar 2017, Volume 16 N. 1 Pages 165 - 179

Abstract: En | Text: En | PDF: En

Abstract An accurate modeling of materials is essential to obtain reliable results in fields calculation. The Jiles-Atherton approach is widely used for modeling the magnetic hysteresis and depends on its set of five parameters to properly represent material. In this article is proposed an original methodology for obtaining this set of parameters avoiding the derivatives rough calculation and using the calculation of integrals. From the model equations, a new methodology with two nonlinear algebraic systems of five equations in five unknowns is obtained. The initial magnetization curve, the anhysteretic curve and filtering data are not necessary. The proposed methodology also does not restrict the search space of parameters. The parameters assume values in the interval (0,∞). Calculated data were compared with experimental data to validate the methodology. The simulations showed that the proposed method can obtain an accurate set of parameters from a single experimental hysteresis loop and with low computational effort.

https://doi.org/10.1590/2179-10742017v16i1880 1677 downloads

Effects of Lippia sidoides essential oil, thymol, p-cymene, myrcene and caryophyllene on rat sciatic nerve excitability
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Barbosa, R.

; Cruz-Mendes, Y.

; Silva-Alves, K.S.

; Ferreira-da-Silva, F.W.

; Ribeiro, N.M.

; Morais, L.P.

; Leal-Cardoso, J.H.

Brazilian Journal of Medical and Biological Research

Journal Metrics
- Sobre o periódico
- SciELO Analytics

2017, Volume 50 N. 12 elocation e6351

Abstract: En | Text: En | PDF: En

Lippia sidoides Cham is a typical herb species of Northeast Brazil with widespread use in folk medicine. The major constituents of the essential oil of L. sidoides (EOLs) are thymol, p-cymene, myrcene, and caryophyllene. Several studies have shown that the EOLs and its constituents have pharmacological effects, including antibacterial, anti-inflammatory, antioxidant and neuroprotective activity. Therefore, this work aimed to investigate the effects of the EOLs and their main constituents on rat sciatic nerve excitability. The sciatic nerves of adult Wistar rats were dissected and mounted in a moist chamber. Nerves were stimulated by square wave pulses, with an amplitude of 40 V, duration of 100 μs to 0.2 Hz. Both EOLs and thymol inhibited compound action potential (CAP) in a concentration-dependent manner. Half maximal inhibitory concentration for CAP peak-to-peak amplitude blockade were 67.85 and 40 µg/mL for EOLs and thymol, respectively. CAP peak-to-peak amplitude was significantly reduced by concentrations ≥60 µg/mL for EOLs and ≥30 µg/mL for thymol. EOLs and thymol in the concentration of 60 µg/mL significantly increased chronaxie and rheobase. The conduction velocities of 1st and 2nd CAP components were also concentration-dependently reduced by EOLs and thymol in the range of 30-100 µg/mL. Differently from EOLs and thymol, p-cymene, myrcene and caryophyllene did not reduce CAP in the higher concentrations of 10 mM. These data demonstrated that EOLs and thymol inhibited neuronal excitability and were promising agents for the development of new drugs for therapeutic use.

https://doi.org/10.1590/1414-431x20176351 1429 downloads

THE USE OF A HIGH LIMESTONE CONTENT MINING WASTE AS A SORBENT FOR CO2 CAPTURE
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Barbosa, R. C.

; Damasceno, J. J. R.

; Hori, C. E.

Brazilian Journal of Chemical Engineering

Journal Metrics
- Sobre o periódico
- SciELO Analytics

sep 2016, Volume 33 N. 3 Pages 599 - 606

Abstract: En | Text: En | PDF: En

Abstract In this work, a high limestone content waste was evaluated as a potential material for CO2 capture. The influence of calcination conditions on the CO2 capture capacity was evaluated using 5 cycles of calcination-hydration-carbonation reactions. A Central Composite Design of Experiments was set using calcination temperatures and time as variables. The response evaluated was the CO2 capture measured by thermogravimetric analysis. The results indicate that both calcination temperature and time influence the CO2 capture capacities in the initial cycles but, after a large number of cycles, the effect becomes less relevant. The optimum calcination temperature did not change significantly between cycles - about 893 °C in the first and 850 °C in the fourth cycle. However, the optimum calcination time decreased from 40.1 min in the first to 22.5 min in the fourth cycle. The maximum CO2 capture capacity declines over the reaction cycles due to the sorbent sintering, which becomes more noticeable. Moreover, the waste used in this work is suitable for separating CO2 from flue gas, achieving more than 0.2 g/g of capture capacity after five cycles.

https://doi.org/10.1590/0104-6632.20160333s20150111 2285 downloads

III DIRETRIZES DA SOCIEDADE BRASILEIRA DE CARDIOLOGIA SOBRE ANÁLISE E EMISSÃO DE LAUDOS ELETROCARDIOGRÁFICOS
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Pastore, CA

; Pinho, JA

; Pinho, C

; Samesima, N

; Pereira Filho, HG

; Kruse, JCL

; Paixão, A

; Pérez-Riera, AR

; Ribeiro, AL

; Oliveira, CAR

; Gomes, CIG

; Kaiser, E

; Galvão, F

; Darrieux, FCC

; França, FFAC

; Feitosa Filho, G

; Germiniani, H

; Aziz, JL

; Leal, MG

; Molina, M

; Oliveira, NMT

; Oliveira, PA

; Sanches, PCR

; Almeida, RM

; Barbosa, R

; Teixeira, RA

; Douglas, RAG

; Gundim, RS

; Atanes, SM

Arquivos Brasileiros de Cardiologia

Journal Metrics
- Sobre o periódico
- SciELO Analytics

apr 2016, Volume 106 N. 4 Pages 1 - 23

Abstract: Pt | Text: Pt | PDF: Pt

https://doi.org/10.5935/abc.20160054 79050 downloads

Prevalencia de complicaciones y factores predisponentes en cirugía ginecológica por patología benigna en el hospital universitario San Ignacio: Bogotá, Colombia
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Barbosa R, Gabriel

; Garnica R, Lina

Revista chilena de obstetricia y ginecología

Journal Metrics
- Sobre o periódico
- SciELO Analytics

dec 2015, Volume 80 N. 6 Pages 456 - 461

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

Background: Surgical procedures involve risks and complications, a prompt diagnosis and appropriate managementcould modify patient's prognosis. Objective: To determine the prevalence of complications in gynecological surgery at Hospital San Ignacio and the associated factors. Methods: Cross-sectional study of 200 patients aged between 18-74 years who required gynecological surgery (open or laparoscopic approach) in Hospital San Ignacio from January to December 2013. A binomial logistic regression was performed to evaluate intraoperative and postoperative complications with the independent variables and a multivariate model was used to establish the related factors. Results: The most frequent procedure was abdominal hysterectomy (46%), the most common approach was abdominal in 65% of cases. Prevalence of surgical complications was 12.5%, 7.5% remained serious and 6% non-serious. Of the surgical complications that resulted, we found 1% had bladder injuries, 1% had bowel injuries, 4% required blood transfusions. The multivariate model showed a relationship with diabetes mellitus, anticoagulation, uterine fibroids, severe adherence syndrome and emergency surgical procedures. Conclusions: The incidence of complications in our institution is similar to other studies. Factors related to its occurrence were identified, however it's necessary to conduct further studies and research in order to develop prevention strategies.

Antecedentes: Los procedimientos quirúrgicos implican complicaciones de todo tipo, su pronto diagnóstico y manejo depende del pronóstico del paciente. Objetivo: Determinar la prevalencia de las complicaciones en cirugía ginecológica por patología benigna en el Hospital Universitario San Ignacio y los factores de riesgo predisponentes. Métodos: Estudio de corte transversal en 200 pacientes, entre 18 a 74 años, en las que se realizó procedimientos de cirugía ginecológica de patología benigna, tanto de abordaje abierto como laparoscópico desde enero a julio de 2013. Se hicieron regresiones logísticas binomiales de complicaciones intraoperatorias y postoperatorias con las variables independientes, posteriormente se aplicó un modelo multivariado para establecer los factores asociados. Resultados: El procedimiento más realizado fue la histerectomía abdominal total en un 46% y la vía de abordaje más utilizada fue la abdominal en el 65% de los casos. Se encontró una prevalencia de complicaciones del 12,5% siendo mayores el 7,5% y menores el 6%. Hubo un 1% de lesión vesical, 1% lesión intestinal y 4% de requerimiento de transfusión sanguínea. En cuanto a los resultados del modelo multivariado, se identificaron como variables relacionadas, la diabetes mellitus, la anticoagulación crónica, la miomatosis uterina, el síndrome adherencial severo y los procedimientos de urgencia. Conclusiones: El porcentaje de complicaciones en nuestra institución es similar a otros estudios y se determinaron factores relacionados a su aparición. Es pertinente continuar la investigación sobre este tema y su divulgación, así como diseñar estrategias de prevención.

6584 downloads

Essential oil of Lippia alba and its main constituent citral block the excitability of rat sciatic nerves
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Sousa, D.G.

; Sousa, S.D.G.

; Silva, R.E.R.

; Silva-Alves, K.S.

; Ferreira-da-Silva, F.W.

; Kerntopf, M.R.

; Menezes, I.R.A.

; Leal-Cardoso, J.H.

; Barbosa, R.

Brazilian Journal of Medical and Biological Research

Journal Metrics
- Sobre o periódico
- SciELO Analytics

aug 2015, Volume 48 N. 8 Pages 697 - 702

Abstract: En | Text: En | PDF: En

Lippia alba is empirically used for infusions, teas, macerates, and hydroalcoholic extracts because of its antispasmodic, analgesic, sedative, and anxiolytic effects. Citral is a mixture of trans-geranial and cis-neral and is the main constituent of L. alba essential oil and possesses analgesic, anxiolytic, anticonvulsant, and sedative effects. The present study evaluated the effects of the essential oil of L. alba (EOLa) and citral on compound action potentials (CAPs) in Wistar rat sciatic nerves. Both drugs inhibited CAP in a concentration-dependent manner. The calculated half-maximal inhibitory concentrations (IC50) of peak-to-peak amplitude were 53.2 µg/mL and 35.00 µg/mL (or 230 µM) for EOLa and citral, respectively. Peak-to-peak amplitude of the CAP was significantly reduced by 30 µg/mL EOLa and 10 µg/mL citral. EOLa and citral (at 60 and 30 µg/mL, values close to their respective IC50 for CAP blockade) significantly increased chronaxy and rheobase. The conduction velocity of the first and second CAP components was statistically reduced to ∼86% of control with 10 µg/mL EOLa and ∼90% of control with 3 µg/mL citral. This study showed that EOLa inhibited nerve excitability and this effect can be explained by the presence of citral in its composition. Both EOLa and citral showed inhibitory actions at lower concentrations compared with other essential oils and constituents with local anesthetic activity. In conclusion, these data demonstrate that EOLa and citral are promising agents in the development of new drugs with local anesthetic activity.

https://doi.org/10.1590/1414-431x20154710 1954 downloads

Prácticas de liderazgo y su relación con la cultura en un grupo de países latinoamericanos
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Espinosa M., Juan Carlos

; Contreras T., Francoise

; Barbosa R., David

Diversitas: Perspectivas en Psicología

Journal Metrics
- Sobre o periódico
- SciELO Analytics

jul 2015, Volume 11 N. 2 Pages 303 - 317

Abstract: Es En | Text: Es En | PDF: Es | PDF: En

El propósito de este estudio fue analizar, a través del MLQ 5X, los perfiles de liderazgo de 167 directivos de cuatro países latinoamericanos (Perú, Venezuela, Ecuador y Colombia), para observar si a pesar de la similitud cultural se presentan diferencias en los patrones de liderazgo. Se compararon estos perfiles con los obtenidos por otros autores en regiones culturalmente distintas, para finalmente confrontar los resultados con los de otra muestra colombiana. Se evidenciaron diferencias significativas en liderazgo, tanto entre países culturalmente distintos, como entre los mismos países latinoamericanos, a pesar de su similitud cultural. Finalmente, la muestra de directivos de este estudio difiere significativamente de la otra muestra colombiana, respecto a algunas variables del MLQ. Se discuten esos hallazgos.

The aim of this study was to analyze, by using the MLQ5X, the leadership profiles of 167 managers from four Latin American countries (Peru, Venezuela, Ecuador and Colombia), to see if there are different patterns of leadership despite cultural similarities. Likewise, these profiles were compared with results obtained by other authors from different regions. Finally, these results were compared with another Colombian sample. Significant differences in leadership were found, both in culturally different countries and in Latin American countries, despite their cultural similarities. Finally, the sample of managers in this study differs significantly from the other Colombian sample, in some variables of the MLQ. These findings are discussed.

https://doi.org/10.15332/s1794-9998.2015.0002.10 1538 downloads

10.

Study of aluminum nitride precipitation in Fe- 3%Si steel
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Alcântara, F.L.

; Barbosa, R.

; Cunha, M.A.

Materials Research

Journal Metrics
- Sobre o periódico
- SciELO Analytics

oct 2013, Volume 16 N. 5 Pages 1039 - 1044

Abstract: En | Text: En | PDF: En

For good performance of electrical steels it is necessary a high magnetic induction and a low power loss when submitted to cyclic magnetization. A fine dispersion of precipitates is a key requirement in the manufacturing process of Fe- 3%Si grain oriented electrical steel. In the production of high permeability grain oriented steel precipitate particles of copper and manganese sulphides and aluminium nitride delay normal grain growth during primary recrystallization, causing preferential growth of grains with Goss orientation during secondary recrystallization. The sulphides precipitate during the hot rolling process. The aluminium nitride particles are formed during hot rolling and the hot band annealing process. In this work AlN precipitation during hot deformation of a high permeability grain oriented 3%Si steel is examined. In the study, transfer bar samples were submitted to controlled heating, compression and cooling treatments in order to simulate a reversible hot rolling finishing. The samples were analyzed using the transmission electron microscope (TEM) in order to identify the precipitates and characterize size distribution. Precipitate extraction by dissolution method and analyses by inductively coupled plasma optical emission spectrometry (ICP-OES) were used to quantify the precipitation. The results allowed to describe the precipitation kinetics by a precipitation-time-temperature (PTT) diagram for AlN formation during hot rolling.

5538 downloads

11.

Limb immobilization alters functional electrophysiological parameters of sciatic nerve
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics
- Dimensions
- PlumX
- Altmetric

Alves, J.S.M.

; Leal-Cardoso, J.H.

; Santos-Júnior, F.F.U.

; Carlos, P.S.

; Silva, R.C.

; Lucci, C.M.

; Báo, S.N.

; Ceccatto, V.M.

; Barbosa, R.

Brazilian Journal of Medical and Biological Research

Journal Metrics
- Sobre o periódico
- SciELO Analytics

aug 2013, Volume 46 N. 8 Pages 715 - 721

Abstract: En | Text: En | PDF: En

Immobilization, used in clinical practice to treat traumatologic problems, causes changes in muscle, but it is not known whether changes also occur in nerves. We investigated the effects of immobilization on excitability and compound action potential (CAP) and the ultrastructure of the rat sciatic nerve. Fourteen days after immobilization of the right leg of adult male Wistar rats (n=34), animals were killed and the right sciatic nerve was dissected and mounted in a moist chamber. Nerves were stimulated at a baseline frequency of 0.2 Hz and tested for 2 min at 20, 50, and 100 Hz. Immobilization altered nerve excitability. Rheobase and chronaxy changed from 3.13±0.05 V and 52.31±1.95 µs (control group, n=13) to 2.84±0.06 V and 59.71±2.79 µs (immobilized group, n=15), respectively. Immobilization altered the amplitude of CAP waves and decreased the conduction velocity of the first CAP wave (from 93.63±7.49 to 79.14±5.59 m/s) but not of the second wave. Transmission electron microscopy showed fragmentation of the myelin sheath of the sciatic nerve of immobilized limbs and degeneration of the axon. In conclusion, we demonstrated that long-lasting leg immobilization can induce alterations in nerve function.

https://doi.org/10.1590/1414-431X20132626 2104 downloads

12.

Caracterizações de argilas bentoníticas e síntese de argilas organofílicas para uso em nanocompósitos poliméricos: parte II
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Barbosa, R.

; Morais, D. D. S.

; Araújo, E. M.

; Mélo, T. J. A.

Cerâmica

Journal Metrics
- Sobre o periódico
- SciELO Analytics

dec 2012, Volume 58 N. 348 Pages 495 - 499

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

Nanocompósitos poliméricos tem atraído um considerável interesse, o que se deve a estes materiais oferecerem combinações incomuns de propriedades. As argilas esmectíticas são comumente utilizadas como fase dispersa na obtenção dos nanocompósitos, em particular destaque para as argilas bentoníticas. Neste trabalho, foram estudadas três argilas bentoníticas sem modificação e após a modificação ou organofilização com o sal cloreto de estearil dimetil amônio. A capacidade de troca catiônica (CTC) das argilas bentoníticas sem modificação foi realizada. A eficiência da organofilização foi avaliada por fluorescência de raios X e o grau de expansão das argilas organofílicas foram estudados por difração de raios X. A argila 1346 apresentou maior CTC em relação às demais argilas. Além disso, os resultados indicaram a organofilização das argilas com o sal quaternário de amônio, o que foi observado pela presença do sal no espaçamento basal das argilas e pela expansão basal na reflexão d001 das argilas.

Polymeric nanocomposites have attracted considerable interest because this material offers unusual combination of properties. The smectite clays are commonly used as the dispersed phase to obtain nanocomposites, in particular, bentonite clays. In this work three bentonite clays without modification and after modification with salt or organophilization stearyl dimethyl ammonium chloride were studied. The cation exchange capacity (CEC) of bentonite clay was carried out without modification. The efficiency of organophilization was evaluated by X-ray fluorescence and the degree of expansion of the organoclay by X-ray diffraction. The 1346 clay shows higher CEC than that of other clays. In addition, the results indicate that organophilization clays with quaternary ammonium salt, which was observed by the presence of salt in the basal spacing of clay and the expansion of the basal reflection d001 clays.

2400 downloads Cited 1 time in SciELO

13.

Caracterizações de argilas bentoníticas e síntese de argilas organofílicas para uso em nanocompósitos poliméricos: parte II
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Barbosa, R.

; Morais, D. D. S.

; Araújo, E. M.

; Mélo, T. J. A.

Cerâmica

Journal Metrics
- Sobre o periódico
- SciELO Analytics

sep 2012, Volume 58 N. 347 Pages 363 - 367

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

Polymeric nanocomposites have attracted considerable interest due to this material offers unusual combinations of properties. The smectite clays are commonly used as the dispersed phase to obtain nanocomposites, in particular, bentonite clays. esthearildimethyl ammonium chloride. In this work three bentonite clay without modification and after modification with salt or organophilization stearyl dimethyl ammonium chloride were studied. The cation exchange capacity (CEC) of bentonite clay was carried out without modification. The efficiency of organophilization was evaluated by X-ray fluorescence and the degree of expansion of the organoclay by X-ray diffraction. The 1346 clay showed higher CEC than that of other clays. In addition, the results indicated that organophilization clays with quaternary ammonium salt, which was observed by the presence of salt in the basal spacing of clay and the expansion of the basal reflection d001 clays.

2680 downloads Cited 1 time in SciELO

14.

Avaliação da estabilidade térmica de sais quaternários de amônio para uso em argilas organofílicas nacionais: Parte I
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Barbosa, R.

; Souza, D. D.

; Araújo, E. M.

; Mélo, T. J. A.

Cerâmica

Journal Metrics
- Sobre o periódico
- SciELO Analytics

dec 2010, Volume 56 N. 340 Pages 376 - 380

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

A grande propagação da nanotecnologia nos tempos atuais requer estudos cada vez mais específicos para entender a evolução desses materiais. A obtenção de boas propriedades em nanocompósitos polímero/argila faz com que estudos mais aprofundados sejam realizados sobre a estabilidade térmica dos surfactantes nas temperaturas de processamento destes materiais. Neste trabalho, a estabilidade térmica de quatro sais quaternários de amônio, tais como brometo de hexadeciltrimetil amônio, cloreto de alquildimetilbenzil amônio, cloreto de estearildimetil amônio e cloreto de hexadeciltrimetil amônio foi avaliada, visando sua posterior intercalação em argilas bentoníticas nacionais, com o propósito de torná-las organofílicas para uso em nanocompósitos poliméricos. Os sais foram caracterizados termicamente por calorimetria exploratória diferencial e termogravimetria sob Ar e N2. Os resultados indicaram que os sais à base do ânion cloreto se degradaram em temperaturas similares e o sal à base do ânion brometo se degradou em temperatura superior. Além disso, este estudo indicou que o sal cloreto de estearildimetil amônio provavelmente terá sucesso na utilização como surfactante para o uso em nanocompósitos.

The large propagation of nanotechnology in modern times requires more studies to meet their specific development. For obtaining good properties of polymer/clay nanocomposites more comprehensive studies on the thermal stability of surfactants in the processing temperatures of these materials are necessary. In this work, the thermal stability of four quaternary ammonium salts such as hexadecyltrimethyl ammonium bromide, alkyldimethylbenzyl ammonium chloride, esthearildimethyl ammonium chloride and hexadecyltrimethyl ammonium chloride was evaluated for their intercalation into national bentonite clay, with the aim to enable organophilic for using in polymer nanocomposites. The salts were thermally characterized by differential scanning calorimetry and thermogravimetryunder Ar and N2. The results indicate that the salts based on chloride ion degraded at similar temperatures and the based on the bromide anion degraded at higher temperature. Besides, these studies indicated that the esthearildimethyl ammonium chloride salt may be successful in obtaining as surfactant for the use in nanocomposite.

5729 downloads

15.

PANCREATITIS AGUDA PUERPERAL TRAS CESÁREA
Facebook Twitter

Other social networks
Google+
LinkedIn
Reddit
StambleUpon
CiteULike
Mendeley
Other networks

Metrics
- SciELO Analytics

Díaz M, Virginia

; Moral P, José María

; Zapardiel G, Ignacio

; Bartolomé V, Alicia

; Barbosa R, José Luís

; García M, Pedro

Revista chilena de obstetricia y ginecología

Journal Metrics
- Sobre o periódico
- SciELO Analytics

2008, Volume 73 N. 5 Pages 337 - 340

Abstract: En Es | Text: En Es | PDF: En | PDF: Es

Acute pancreatitis is an uncommon complication during pregnancy which is associated with great morbimor-tality and its prevalence increases during the third trimester and early puerperium. We report a case of acute pancreatitis following to caesarean section in a patient with an unremarkable medical history. Diagnosis was done by means of imaging techniques and its treatment was carried out by a multidisciplinar/ team.

La pancreatitis aguda es una complicación poco frecuente en el embarazo, pero que presenta una gran morbimortalidad, siendo su prevalencia mayor en el tercer trimestre y puerperio inmediato. Presentamos un caso de pancreatitis aguda post cesárea en una paciente sin antecedentes, a cuyo diagnóstico se llegó por el apoyo de pruebas diagnósticas de imagen. El tratamiento fue llevado por un equipo multidisciplinario que logró la remisión completa de la enfermedad.

18745 downloads

Showing

itens per page

Page of 2 Next

Select one or more results

All Alphabetic

Results

Comparative chart Download CSV

Statistics of

Send result

To*

Use ; (semicolon) to insert more emails.

Send to email

This page

Selected records

All references (max. 300)

Your email

Subject

Comments

Export format:

RIS (for EndNote, ProCite, Reference Manager, RefWorks, Citavi, etc.)

BibTeX

Citation

CSV (for Excel, etc)

Export:

This page

Selected itens

All references (max. 2000)

Sem resultados

No documents were found for your search

Glossary and search help

You can enrich your search in a very simple way. Use the search indexes combined with the connectors (AND or OR) and specify more your search.

For example, if you want to search for articles about
cases of dengue in Brasil in 2015, use:
ti:dengue and publication_year:2015 and aff_country:Brasil

See below the complete list of search indexes that can be used:

Index code	Element
ti	article title
au	author
kw	article keywords
subject	subject (title words, abstract and keywords)
ab	abstract
ta	journal short title (e.g. Cad. Saúde Pública)
journal_title	journal full title (e.g. Cadernos de Saúde Pública)
la	publication language code (e.g. pt - Portuguese, es - Spanish)
type	document type
pid	publication identifier
publication_year	publication year of publication
sponsor	sponsor
aff_country	country code of the author's affiliation
aff_institution	author affiliation institution
volume	article volume
issue	article issue
elocation	elocation
doi	DOI number
issn	journal ISSN
in	SciELO colection code (e.g. scl - Brasil, col - Colômbia)
use_license	article usage license code

SciELO - Scientific Electronic Library Online
Rua Dr. Diogo de Faria, 1087 – 9º andar – Vila Clementino 04037-003 São Paulo/SP - Brasil
Email: scielo@scielo.org

All the contents of this site www.scielo.br, except where otherwise noted, is licensed under a Creative Commons Attribution License.
more »