oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 6 )

2019 ( 238 )

2018 ( 414 )

2017 ( 411 )

Custom range...

Search Results: 1 - 10 of 256014 matches for " Carlos José de;Valenzuela "
All listed articles are free for downloading (OA Articles)
Page 1 /256014
Display every page Item
Control of strain in a flexible beam using Ni-Ti-Cu shape memory alloy wire actuators
Lima, Walber Medeiros;Araújo, Carlos José de;Valenzuela, Walter Andrés Vermehren;Rocha Neto, José Sérgio da;
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2012, DOI: 10.1590/S1678-58782012000500010
Abstract: in this paper the development of an experimental test bench to analyze and control the strain of a flexible aluminum beam subjected to external disturbances is described. in the proposed platform, strain-gauges are used to measure the strain of the beam in a single cantilever mode while ni-ti-cu shape memory alloy (sma) wires are used as force actuators. data acquisition and control system are implemented with an aduc microcontroller. the response of the structure in open-loop was used to identify the mathematical model of the system. to find the appropriate controller and to reach the best performance of the system, it was used techniques of direct tuning (pole-zero cancellation) in the identified model. the pi controller has been used to control the strain of the beam for different types of reference signals, as square, sinusoidal and triangular. the frequencies of the reference signals have been varied to observe to which bandwidth the system can respond. experimental results are used to demonstrate the usefulness of the pi controller in the proposed smart structure.
Diversidad genética y estructura de la población de Vibrio choierae en Colombia Genetic diversity and population structure of Vibrio choierae in Colombia
Ria?o Pachón Diego Mauricio,Valenzuela de Silva Emilia María,Mantilla Anayá José Ramón,Agudelo Carlos
Revista Colombiana de Biotecnología , 2003,
Abstract: Se realizó la electroforesis en gel por campo pulsado (PFGE) de los macrofragmentos de restricción de 34 aislamien-tos de Vibrio choierae pertenecientes a la epidemia de cólera que se presentó en Colombia entre 1991 y 1996, adicionalmente se analizaron 3 aislamientos de V. choierae no pertenecientes a esta epidemia y un aislamiento de V fluvialis. La diversidad genética observada para los 38 aislamientos tipificados fue de 0,95 valor muy similar al obtenido por Electroforesis de Enzimas Multilocus (MLEE). No se observó correlación entre las variables que carac-terizan a estos aislamientos (serotipo, origen [clínico o ambiental], departamento, tipo electroforético (MLEE) y perfil de macrofragmentos de restricción (PFGE)). No se obtuvo evidencia de desequilibrio de ligamiento al evaluar esta población con los marcadores genéticos PFGE y MLEE. Se sugiere que la población de Vibrio choierae en Colom-bia presenta una estructura genética sexual, hipótesis que está soportada por la falta de evidencia de desequilibrio de ligamiento y la ausencia de correlaciones entre las variables epidemiológicas, bioquímicas y moleculares a dispo-sición, y por el alto valor de diversidad genética obtenido, que puede ser el reflejo de la coexistencia de varias líneas de descendencia entre las cuales existe un alto flujo genético. Palabras clave: Vibrio choierae; Electroforesis en gel por campo pulsado; epidemiología molecular; genética de po-blaciones; desequilibrio de ligamiento. Pulsed field gel electrophoresis (PFGE) was used to study thirty-four Vibrio choierae isolates from the Colombian cholera epidemic between 1991 and 1996. Three Vchoierae isolates not belonging to the epidemic in Colombia and a Vfluvialis isolate were also analysed. The genetic diversity observed for the 38 isolates typified was 0.95, a very similar valué to that obtained by Multilocus Enzyme Electrophoresis (MLEE). No cor reía tion was observed be-tween the variables characterising these isolates (serotype, origin [clinical or environmental], state, electrophoretic type (MLEE) and restriction macro-fragment profile or pulsetype (PFGE)). No evidence of linkage disequilibrium was obtained on evaluating this population with PFGE and MLEE genetic markers. It is suggested that the Vibrio choierae population in Colombia presents a sexual genetic structure. The lack of evidence for linkage disequilibrium and the absence of correlation between the epidemiological, biochemical and molecular variables available sustains such a hypothesis. It is also sustained by the high valué for genetic diversity obtained wh
Caracterización molecular de aislamientos de Acinetobacter baumannii provenientes de la unidad de quemados de un hospital de tercer nivel de Bogotá
PINZóN,JANNETH ORQUíDEA; MANTILLA,JOSé RAMóN; VALENZUELA,EMILIA MARíA; FERNáNDEZ,FEDERICO; ARTURO áLVAREZ,CARLOS; OSORIO,ELKIN DE JESúS;
Infectio , 2006,
Abstract: objective.this study is a fenotypical and genetical description of acinetobacter baumannii carried out in a ten month follow-up at the unidad de quemados from the hospital simon bolívar in bogotá. materials and methods. 25 patient and 3 environmental isolates were typified by rep-pcr. hodge?s test and double disc sinergy were done for microbiologic carbapenemase detection. isoelectric points were determined by betalactamases isoelectric focusing. gene bla oxa23, bla oxa24, bla vim, bla imp detection was carried out through pcr. results. isolate genotypification allowed their classification in nine groups based on similarities greater than 0.85. the e group consisted of 39.2% of the isolates, a clone formed by three environmental isolates and two recovered from patients. 64.2% out 28 isolates displayed carbapenem resistance, and 66.6% of them were also resistant to betalactams, aminoglycosides and fluoroquinolones. oxacilinase carbapenemase presence was evident in 17 of 18 isolates resistant to imipenem. gene bla oxa23 and two betalactamases were detected in isolates resistant to imipenen, with 6.3 and 6.9 isoelectric points. conclusions. an endemic group of a. baumannii was detected in the 10 month study duration. oxa23 carbapenemase presence was an important factor for carbapenem resistance; however, microbiologic results allow us to assume the possible presence of other resistance mechanisms.
CARACTERIZACIóN MOLECULAR DE AISLAMIENTOS DE ENTEROBACTER CLOACAE MULTIRRESISTENTES, PRODUCTORES a-LACTAMASAS PROVENIENTES DE PACIENTES DE UN HOSPITAL DE TERCER NIVEL DE BOGOTá
García Romero,Ibonne Aydee; Valenzuela de Silva,Emilia María; Saavedra,Carlos Humberto; Leal Castro,Aura Lucía; Eslava Schmalbac,Javier; Mantilla Anaya,José Ramón;
Revista Facultad de Medicina de la Universidad Nacional de Colombia , 2005,
Abstract: background. enterobacter species were normal in gastrointestinal tract, but nowadays, its biology has changed and there are nosocomial agents with antibiotics resistance. objective. to make an epidemiological and molecular characterization of 20 isolates of enterobacter cloacae with third generation cephalosporin resistance, from a hospital of third level in bogotá-colombia. material and methods. isolates were identified with microscan and vitek, enterobacter asbureae was utilized as an inter-specie control. resistance was confirmed by agar diffusion and by blee techniques. isoelectric points were determined by ultrasound lyses and genotypication by versalovic′s system for gram negative bacteria. results. the isolates collected over the course of a year caused 15 cases of intra-hospital infection and two colonisations. all isolates presented resistance to cefotaxime, ceftazidime, ceftriaxone, aztreonam and ciprofloxacin, 95% to amikacin, gentamicin and chloramphenicol, 75% to trimethoprim/ sulphamethoxazole, 20% to cefepime and all were sensitive to imipenem. two isolates were confirmed as extended spectre a-iactamase (esbl) producers by microbiologic al combined disktechnique; two a-iactamases having 5.4 and 8.2 isoelectric points (pi) were presented by isoelectric focusing. between 2 and 4 a-iactamases having 5.4, 6.0, 7.0, 8.2 and >8.2 pl were detected in the 18 isolates which were not inhibited by clavulanic acid. third-generation cephalosporin-resistance was attributed to ampc hyper-production; pl values suggested simultaneous shv and tem a lactamase production. genotyping by three rep- pcr methodologies (eric, rep and box) grouped the population studied into 7clones; 6 were constitute d by a single isolate and the predominant e1/b1/r1 clone grouped 14 isolates causing infection in 10 patients. this work led to a multiresistant enterobacter cloacae clone being detected, considered endemic for the institution, in the studied surgical patients it was una predomin
Functional Transcriptomics of Wild-Caught Lutzomyia intermedia Salivary Glands: Identification of a Protective Salivary Protein against Leishmania braziliensis Infection
Tatiana R. de Moura equal contributor,Fabiano Oliveira equal contributor,Marcia W. Carneiro,José Carlos Miranda,Jorge Clarêncio,Manoel Barral-Netto,Cláudia Brodskyn,Aldina Barral,José M. C. Ribeiro,Jesus G. Valenzuela ,Camila I. de Oliveira
PLOS Neglected Tropical Diseases , 2013, DOI: 10.1371/journal.pntd.0002242
Abstract: Background Leishmania parasites are transmitted in the presence of sand fly saliva. Together with the parasite, the sand fly injects salivary components that change the environment at the feeding site. Mice immunized with Phlebotomus papatasi salivary gland (SG) homogenate are protected against Leishmania major infection, while immunity to Lutzomyia intermedia SG homogenate exacerbated experimental Leishmania braziliensis infection. In humans, antibodies to Lu. intermedia saliva are associated with risk of acquiring L. braziliensis infection. Despite these important findings, there is no information regarding the repertoire of Lu. intermedia salivary proteins. Methods and Findings A cDNA library from the Salivary Glands (SGs) of wild-caught Lu. intermedia was constructed, sequenced, and complemented by a proteomic approach based on 1D SDS PAGE and mass/mass spectrometry to validate the transcripts present in this cDNA library. We identified the most abundant transcripts and proteins reported in other sand fly species as well as novel proteins such as neurotoxin-like proteins, peptides with ML domain, and three small peptides found so far only in this sand fly species. DNA plasmids coding for ten selected transcripts were constructed and used to immunize BALB/c mice to study their immunogenicity. Plasmid Linb-11—coding for a 4.5-kDa protein—induced a cellular immune response and conferred protection against L. braziliensis infection. This protection correlated with a decreased parasite load and an increased frequency of IFN-γ-producing cells. Conclusions We identified the most abundant and novel proteins present in the SGs of Lu. intermedia, a vector of cutaneous leishmaniasis in the Americas. We also show for the first time that immunity to a single salivary protein from Lu. intermedia can protect against cutaneous leishmaniasis caused by L. braziliensis.
Enhanced Leishmania braziliensis Infection Following Pre-Exposure to Sandfly Saliva
Tatiana R. de Moura,Fabiano Oliveira,Fernanda O. Novais,José Carlos Miranda,Jorge Clarêncio,Ivonise Follador,Edgar M. Carvalho,Jesus G. Valenzuela,Manoel Barral-Netto,Aldina Barral,Cláudia Brodskyn,Camila I. de Oliveira
PLOS Neglected Tropical Diseases , 2007, DOI: 10.1371/journal.pntd.0000084
Abstract: Background Sand fly saliva has an array of pharmacological and immunomodulatory components, and immunity to saliva protects against Leishmania infection. In the present study, we have studied the immune response against Lutzomyia intermedia saliva, the main vector of Leishmania braziliensis in Brazil, and the effects of saliva pre-exposure on L. braziliensis infection employing an intradermal experimental model. Methodology/principal findings BALB/c mice immunized with L. intermedia salivary gland sonicate (SGS) developed a saliva-specific antibody response and a cellular immune response with presence of both IFN-γ and IL-4. The inflammatory infiltrate observed in SGS-immunized mice was comprised of numerous polymorphonuclear and few mononuclear cells. Mice challenged with live L. braziliensis in the presence of saliva were not protected although lesion development was delayed. The inoculation site and draining lymph node showed continuous parasite replication and low IFN-γ to IL-4 ratio, indicating that pre-exposure to L. intermedia saliva leads to modulation of the immune response. Furthermore, in an endemic area of cutaneous leishmaniasis, patients with active lesions displayed higher levels of anti-L. intermedia saliva antibodies when compared to individuals with a positive skin test result for Leishmania. Conclusion These results show that pre-exposure to sand fly saliva plays an important role in the outcome of cutaneous leishmaniasis, in both mice and humans. They emphasize possible hurdles in the development of vaccines based on sand fly saliva and the need to identify and select the individual salivary candidates instead of using whole salivary mixture that may favor a non-protective response.
Using Recombinant Proteins from Lutzomyia longipalpis Saliva to Estimate Human Vector Exposure in Visceral Leishmaniasis Endemic Areas
Ana Paula Souza,Bruno Bezerril Andrade,Dorlene Aquino,Petter Entringer,José Carlos Miranda,Ruan Alcantara,Daniel Ruiz,Manuel Soto,Clarissa R. Teixeira,Jesus G. Valenzuela,Camila Indiani de Oliveira,Cláudia Ida Brodskyn,Manoel Barral-Netto,Aldina Barral
PLOS Neglected Tropical Diseases , 2010, DOI: 10.1371/journal.pntd.0000649
Abstract: Background Leishmania is transmitted by female sand flies and deposited together with saliva, which contains a vast repertoire of pharmacologically active molecules that contribute to the establishment of the infection. The exposure to vector saliva induces an immune response against its components that can be used as a marker of exposure to the vector. Performing large-scale serological studies to detect vector exposure has been limited by the difficulty in obtaining sand fly saliva. Here, we validate the use of two sand fly salivary recombinant proteins as markers for vector exposure. Methodology/principal findings ELISA was used to screen human sera, collected in an area endemic for visceral leishmaniasis, against the salivary gland sonicate (SGS) or two recombinant proteins (rLJM11 and rLJM17) from Lutzomyia longipalpis saliva. Antibody levels before and after SGS seroconversion (n = 26) were compared using the Wilcoxon signed rank paired test. Human sera from an area endemic for VL which recognize Lu. longipalpis saliva in ELISA also recognize a combination of rLJM17 and rLJM11. We then extended the analysis to include 40 sera from individuals who were seropositive and 40 seronegative to Lu. longipalpis SGS. Each recombinant protein was able to detect anti-saliva seroconversion, whereas the two proteins combined increased the detection significantly. Additionally, we evaluated the specificity of the anti-Lu. longipalpis response by testing 40 sera positive to Lutzomyia intermedia SGS, and very limited (2/40) cross-reactivity was observed. Receiver-operator characteristics (ROC) curve analysis was used to identify the effectiveness of these proteins for the prediction of anti-SGS positivity. These ROC curves evidenced the superior performance of rLJM17+rLJM11. Predicted threshold levels were confirmed for rLJM17+rLJM11 using a large panel of 1,077 serum samples. Conclusion Our results show the possibility of substituting Lu. longipalpis SGS for two recombinant proteins, LJM17 and LJM11, in order to probe for vector exposure in individuals residing in endemic areas.
Air Quality Monitoring and Its Implication on the Environmental Licensing Process in Brazil  [PDF]
José Carlos de Moura Xavier, Wilson Cabral de Sousa Junior
Journal of Environmental Protection (JEP) , 2014, DOI: 10.4236/jep.2014.51001
Abstract:

In the state of Sao Paulo, Brazil, public policies regarding the air quality aimed at the welfare of the population are strongly dependent on monitoring conducted by the Sao Paulo State Environmental Company (CETESB), which can be influenced by faulty monitors and equipment support and cuts in power supply, among others. A research conducted from 1998 to 2008 indicated that a significant portion of the air quality automatic stations in the state of Sao Paulo did not meet the criterion of representativeness of measurements of PM10, NO2, O3, CO and SO2 concentrations which resulted in the classification of some municipalities as the nonattainment area, a situation evidenced for PM10 and O3 parameters. The network unavailability for each parameter was estimated and compared with the monitoring networks operated in Canada and the UK. This paper discusses the implications of the lack of representativeness of measurements in the environmental licensing process of pollution sources from 2008, when by the effect of state law, municipalities have been qualified according to their air quality nonattainment level.

Gest?o da mudan?a da qualidade de produto
Toledo, José Carlos de;
Gest?o & Produ??o , 1994, DOI: 10.1590/S0104-530X1994000200001
Abstract: the dynamic of the competitive environment, rapid changes in consumer necessities and sometimes, even legal constraints, lead firms to continually try to improve the quality of their existing products. as a result, the ability to constantly keep products up to date, in the face of the requirements of economic and technological environments, has been an important source of competitive advantage. performance in this area depends on firms' ability to manage the process of development and improvement of products and also on their ability to interact with the market and with the technological innovation sources. this paper presents the concept of change in product quality, related to the concept of technological innovation. this change occurs according to dimensions that embrace the total product quality, often adding value to it. it proposes a model that can be used as a guideline to structure and plan the necessary activities in the process of changing the product quality in a firm. it also provides a set of propositions that can contribute to both an efficacious and efficient management of this changing process.
Compostos biologicamente ativos em invertebrados marinhos
Freitas, José Carlos de;
Boletim do Instituto Oceanográfico , 1980, DOI: 10.1590/S0373-55241980000200036
Abstract: the author has reviewed the classification, the nomenclature and the ecological aspects of biologically active compounds, emphasizing the freyvogel & perret's (1973) concepts of venomous and poisonous organisms. the literature involving the phyla annelida, mollusca and arthropoda was also reviewed. the author's pharmacological studies performed with the polychaete eurytlioe camplanata, which revealed a dializable principle, active in the guinea pig's ileum and dorsal muscle ot polvchaete itself are also commented. this principle differs from acetylcholine and serotonin. pharmacologically studies in the sea-hares (genus aplysia) were also focused, including the author's contribution. in the glands os aplysia brasiliana, namely the mid-gut-gland, the opaline gland and the purple gland, the author confirmed presence of cholinesters, which are discussed in the review. toxicity of arthropods are also discussed, mainly in decapod crustaceans. in some brazilian crabs studies revealed a pharmacological activity of the gastric secretion expelled with an apparently defensive purpose and its ecological importance is focused in terms of the community. the relatively scarce studies of chemical ecology of marine organisms in latin america and the importance of these studies were finally emphasized.
Page 1 /256014
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.