Limpar
394 resultados

Acesso aberto

Tipo do recurso

Ano de criação

Produção nacional

Revisado por pares

Áreas

Idioma

Editores

Artigo Revisado por pares

Oswaldo Hernández‐González, Sergio Zarazúa, José Ignacio Veytia‐Bucheli, Marco Martín González‐Chávez, Cristian Jazmín Rodríguez‐Pinal, Susanna Edith Medellín‐Garibay, Edith Elena Uresti‐Rivera, Francisco Javier Pérez‐Vázquez, Diana Patricia Portales‐Pérez, Silvia Romano‐Moreno, Rosa del Carmen Milán‐Segovia,

Abstract The aim of this study was to establish and validate an alternative high‐performance liquid chromatography method for simultaneous quantification of pyrazinamide, isoniazid, acetyl‐isoniazid and rifampicin in plasma of patients under treatment for tuberculosis. The performed method was lineal ( r 2 > 0.99) in the range of 2.00–50.00 μg/mL for pyrazinamide, 0.50–20.00 μg/mL for both acetyl‐isoniazid and isoniazid, and 1.20–25.00 μg/mL for rifampicin. Precision and trueness were demonstrated with ...

Tópico(s): Pneumocystis jirovecii pneumonia detection and treatment

2020 - Wiley | Journal of Separation Science

Revisão Acesso aberto Revisado por pares

Mohammed H. Rashed, Emine Bayraktar, Gouda K. Helal, Mohamed F. Abd‐Ellah, Paola Amero, Arturo Chávez‐Reyes, Cristian Rodriguez‐Aguayo,

Intercellular communication via cell-released vesicles is a very important process for both normal and tumor cells. Cell communication may involve exosomes, small vesicles of endocytic origin that are released by all types of cells and are found in abundance in body fluids, including blood, saliva, urine, and breast milk. Exosomes have been shown to carry lipids, proteins, mRNAs, non-coding RNAs, and even DNA out of cells. They are more than simply molecular garbage bins, however, in that the molecules ...

Tópico(s): RNA Interference and Gene Delivery

2017 - Multidisciplinary Digital Publishing Institute | International Journal of Molecular Sciences

Artigo Revisado por pares

Valentina Valenzuela-Muñóz, Jacqueline Chávez-Mardones, Cristian Gallardo‐Escárate,

Azamethiphos is an organophosphate compound used in controlling Caligus rogercresseyi infestations in the Chilean salmon industry. The molecular target of organophosphates has traditionally been associated with acetylcholinesterase (AChE) activity in the nervous system. However, in arthropods these chemicals could induce complex genomic responses, which can involve different molecular pathways not exclusively related to the nervous system. Our study presents a transcriptomic analysis of C. rogercresseyi ...

Tópico(s): Insect Resistance and Genetics

2015 - Elsevier BV | Aquaculture

Artigo Revisado por pares

Jacqueline Chávez-Mardones, Cristian Gallardo‐Escárate,

Deltamethrin is an insecticide authorized for use against the ectoparasite Caligus rogercresseyi in salmon aquaculture. The biodegradation of this insecticide is principally catalyzed through P450 enzymes, carboxylesterases, and glutathione-S-transferase, increasing the amount of free radicals that could promote the activation of oxidative stress response. The present study identified and evaluated the transcriptomic expression of genes related to the antioxidant system in male and female C. rogercresseyi ...

Tópico(s): Insect Resistance and Genetics

2014 - Elsevier BV | Aquaculture

Artigo Revisado por pares

Jacqueline Chávez-Mardones, Cristian Gallardo‐Escárate,

Caspases play an important role in the different stages of programmed cell death, or apoptosis, which has been related to the immune response in multicellular organisms. The present study characterized an initiator caspase (HrCas8) and an effector caspase (HrCas3) from the red abalone Haliotis rufescens using the RACE method and qPCR analysis. HrCas8 showed a complete sequence of 2529 base pairs (bp) with an open-reading frame (ORF) of 1911 bp, a 5'UTR of 201 bp, and a 3'UTR of 417 bp. The estimated ...

Tópico(s): Aquaculture Nutrition and Growth

2014 - Elsevier BV | Fish & Shellfish Immunology

Artigo Revisado por pares

Waleska Maldonado-Aguayo, Gustavo Núñez-Acuña, Valentina Valenzuela-Muñóz, Jacqueline Chávez-Mardones, Cristian Gallardo‐Escárate,

This study reports two kazal-type serine protease inhibitors (KPI) identified in a cDNA library from the surf clam Mesodesma donacium, and characterized through Rapid Amplification of cDNA Ends (RACE). The KPIs, denoted as MdSPI-1 and MdSPI-2, presented full sequences of 1139 bp and 781 bp respectively. MdSPI-1 had a 5′untranslated region (UTR) of 175 bp, a 3′UTR of 283 bp and an open reading frame (ORF) of 681 pb that encodes for 227 amino acids. MdSPI-2 showed a 5′UTR of 70 bp, a 3′UTR of 279 bp and ...

Tópico(s): Blood Coagulation and Thrombosis Mechanisms

2013 - Elsevier BV | Fish & Shellfish Immunology

Artigo Acesso aberto Revisado por pares

Roberto Goméz-Espina, Delia Rodríguez-Oroz, Manuel Chávez, Cristian Saavedra, María Jesús Bravo,

This paper collects and analyzes students' academic results related to the change in teaching methodologies used in different subjects of different science and engineering university courses between 2013 and 2016. This change means introducing active methodologies such as gamification and ICT instead of a traditional methodology. With this purpose the use of Socrative, a platform that has been designed for the educational field, was introduced during said period. Interaction with the Socrative platform ...

Tópico(s): Educational Innovations and Technology

2019 - Laureate Education | Higher Learning Research Communications

Artigo Revisado por pares

Carlos Ubeda, E. Vañó, Nemorino Riquelme, Daniel Aguirre, Héctor Vásquez, Cristian Chavez, Dandaro Dalmazzo,

This work presents patient radiation dose data for paediatric interventional cardiology procedures in a large paediatric hospital in Chile. This will contribute to setting national diagnostic reference levels (DRLs) for Chile in the near future. The dosimetric data collection period was from January 2018 to December 2018. The local DRLs were calculated as the 3rd quartile of patient dose data distributions for kerma area-product (Pka) values. The sample of collected clinical procedures (261) was divided ...

Tópico(s): Effects of Radiation Exposure

2019 - Elsevier BV | Radiation Physics and Chemistry

Artigo Revisado por pares

María Anel Fuentes-Valencia, Emma J. Fajer-Ávila, María Cristina Chávez‐Sánchez, Carlos A. Martínez‐Palacios, Carlos Cristian Martínez‐Chávez, G. Junqueira-Machado, Humberto H. Lara, Luciana Raggi, Bruno Gómez‐Gil, Alexey Pestryakov, Nina Bogdanchikova,

Ciliate ectoparasites are one of the most important groups of pathogens in fish culture, and the traditional treatments are sometimes harmful to the fish and the environment. Thus, the search for novel compounds that are effective at low concentrations and safe for fish are necessary to optimise treatments in aquaculture. The antiprotozoal capacity of silver nanoparticles (AgNPs) against the ciliate Tetrahymena has been documented; however, their toxicity may vary with the synthesis methodology and ...

Tópico(s): Nanoparticles: synthesis and applications

2019 - Elsevier BV | Experimental Parasitology

Revisão Revisado por pares

J Sequeiros, Aarón Rodríguez-Calienes, Sandra S. Chávez-Malpartida, Cristian Morán‐Mariños, Giancarlo Alvarado­-Gamarra, Marco Málaga, Alvaro Quincho-Lopez, Wendy Hernadez-Fernandez, Kevin Pacheco‐Barrios, Santiago Ortega‐Gutiérrez, Daniel Hoit, Adam S Arthur, Andrei V. Alexandrov, Carlos Alva‐Díaz, Lucas Elijovich,

Background In anterior circulation large vessel occlusion (LVO) in the extended time window, the guidelines recommend advanced imaging (ADVI) to select patients for endovascular therapy (EVT). However, questions remain regarding its availability and applicability in the real world. It is unclear whether an approach to the extended window EVT that does not use ADVI would be equivalent. Methods In April 2022, a literature search was performed to identified randomized controlled trials (RCT) and observational ...

Tópico(s): Venous Thromboembolism Diagnosis and Management

2022 - BMJ | Journal of NeuroInterventional Surgery

Artigo Acesso aberto Revisado por pares

Leandro Tamini, Rubén F. Dellacasa, Leandro N. Chavez, Cristian Marinao, María Eva Góngora, R Crawford, Esteban Frere,

Abstract Seabird bycatch in fisheries, and the development of effective mitigation to minimize this, have been subject to increasing research attention over the past three to four decades. Trawl fisheries represent a particular challenge, as bird mortalities (especially highly threatened albatrosses and large petrels, Procellariforms) occur primarily through difficult-to-detect collisions with warp and net monitoring cables. Effectiveness of bird-scaring lines (BSLs) as a mitigation measure can be ...

Tópico(s): Wildlife Ecology and Conservation

2023 - Oxford University Press | ICES Journal of Marine Science

Artigo Revisado por pares

Guillermo A. Corona‐Herrera, Silvia E. Arranz, Carlos A. Martínez‐Palacios, Pamela Navarrete‐Ramírez, Elva Mayra Toledo‐Cuevas, Juan José Valdez-Alarcón, Carlos Cristian Martínez‐Chávez,

The present study evaluates the influence of continuous light on phenotypic sex ratios in Chirostoma estor , a temperature sex determination animal model. Relative gene expression levels of 5 day old larvae were performed on two early gonad differentiation genes ( sox9 and foxl2 ), two stress axis activation genes ( gcr1 and crf ) and four reactive oxygen species (ROS) antagonist effector genes ( sod2, ucp2, gsr and cat ). Two light treatments were applied from fertilization; control (12L:12D) simulated natural photoperiod ...

Tópico(s): Animal Behavior and Reproduction

2018 - Wiley | Journal of Fish Biology

Artigo Brasil Produção Nacional Revisado por pares

Cristian A. Chávez, Hugo Leonardo Souza Lara Leão, Gherhardt Ribatski,

The present study concerns an experimental evaluation of the performance of hydrocarbon refrigerants during flow boiling in a microchannels array heat sink. The heat sink is composed of fifty channels with cross sectional areas of 123 × 494 μm2 and length of 15 mm manufactured in a copper block. Heat transfer coefficient and pressure drop data were obtained for refrigerants R600a, R290 and R1270, mass velocities from 165 to 823 kg/m2 s, heat fluxes up to 400 kW/m2, liquid subcooling at the inlet of ...

Tópico(s): Refrigeration and Air Conditioning Technologies

2016 - Elsevier BV | Applied Thermal Engineering

Artigo Acesso aberto Revisado por pares

F. Nimmo, Douglas P. Hamilton, W. B. McKinnon, P. Schenk, Richard P. Binzel, C. J. Bierson, R. A. Beyer, J. M. Moore, S. A. Stern, H. A. Weaver, C. B. Olkin, L. A. Young, K. Ennico Smith, J. M. Moore, W. B. McKinnon, J. R. Spencer, R. A. Beyer, Richard P. Binzel, M. W. Buie, B. Buratti, Andrew Cheng, D. P. Cruikshank, C. M. Dalle Ore, A. M. Earle, G. R. Gladstone, W. M. Grundy, A. D. Howard, Tod R. Lauer, Ivan Linscott, F. Nimmo, J. W. Parker, Simon Porter, H. J. Reitsema, D. Reuter, J. H. Roberts, S. J. Robbins, P. Schenk, M. Showalter, K.E. Singer, D. F. Strobel, M. E. Summers, Len Tyler, O. L. White, O. M. Umurhan, M. E. Banks, O. Barnouin, V. J. Bray, B. Carcich, A. Chaikin, Cristian F. Chavez, C. Conrad, Douglas P. Hamilton, Carly Howett, J. D. Hofgartner, Joshua A. Kammer, C. M. Lisse, Annie Marcotte, A. H. Parker, K. D. Retherford, M. Saina, Kirby Runyon, Rebecca Schindhelm, J. A. Stansberry, A. J. Steffl, T. Stryk, H. B. Throop, C. C. C. Tsang, A. Verbiscer, Helene Winters, A. M. Zangari, S. A. Stern, H. A. Weaver, C. B. Olkin, L. A. Young, K. Ennico Smith,

The deep nitrogen-covered basin on Pluto, informally named Sputnik Planitia, is located very close to the longitude of Pluto's tidal axis and may be an impact feature, by analogy with other large basins in the Solar System. Reorientation of Sputnik Planitia arising from tidal and rotational torques can explain the basin's present-day location, but requires the feature to be a positive gravity anomaly, despite its negative topography. Here we argue that if Sputnik Planitia did indeed form as a result ...

Tópico(s): Geology and Paleoclimatology Research

2016 - Nature Portfolio | Nature

Artigo Brasil Produção Nacional Revisado por pares

Carlos T. Salinas, Cristian A. Chávez, Rubén A. Ananías, Diego Elustondo,

This article reports an experimental and numeric methodology for studying the development of internal stresses during drying of solid wood. For validation purposes, tests were performed for drying of radiata pine at the equivalent of constant air-drying conditions at 44°C dry-bulb and 36°C wet-bulb temperatures. The methodology involves the simulation of drying stresses caused by the development of internal moisture content gradients during drying, where the moisture content gradients are also simulated ...

Tópico(s): Textile materials and evaluations

2015 - Taylor & Francis | Drying Technology

Artigo Brasil Produção Nacional Revisado por pares

Hugo Leonardo Souza Lara Leão, Cristian A. Chávez, Francisco Júlio do Nascimento, Gherhardt Ribatski,

The present study concerns an experimental investigation of flow boiling of R245fa in a 50 parallel rectangular 123.3 × 494.2 μm2 microchannels heat sink. Heat transfer coefficient and pressure drop results were obtained for footprint heat fluxes up to 300 kW/m2, mass velocities from 300 to 1000 kg/m2 s, liquid subcoolings at the test section inlet of 5 and 10 °C and saturation temperature of 30 °C. The heat sink performance was evaluated for its footprint area horizontally positioned (HP), its footprint ...

Tópico(s): Heat Transfer Mechanisms

2015 - Elsevier BV | Applied Thermal Engineering

Artigo Acesso aberto Revisado por pares

Elva Mayra Toledo‐Cuevas, Francisco Javier Moyano, Dariel Tovar‐Ramírez, Carlos Augusto Strüssmann, Carlos Alfonso Álvarez‐González, Carlos Cristian Martínez‐Chávez, Carlos A. Martínez‐Palacios,

The early development of the digestive biochemistry of three cultured Atherinopsids (two Odontesthes species and Chirostoma estor) was investigated. Relatively high lipolytic and high alkaline proteolytic activities were found in all species. In addition, gene expression of lipase and trypsin during the early development of C. estor not only indicates an early onset of the lipase activity but also demonstrates a major importance of protein digestion in this species. However, despite all of them share ...

Tópico(s): Aquaculture disease management and microbiota

2011 - Wiley | Aquaculture Research

Artigo Revisado por pares

Cristian A. Chávez, Enrique Romero, Eduardo Alonso Pérez de Ágreda,

Abstract This paper describes the development of a new triaxial cell specifically built to test coarse granular material under partially saturated conditions. The partial saturation is achieved by imposing a total suction that is correlated with the relative humidity. Relative humidity control was achieved by water vapor transfer using a forced convection system, which is driven by an air pump transporting the air humidity to the sample, and it is controlled by saturated saline solutions placed ...

Tópico(s): Geotechnical Engineering and Soil Stabilization

2009 - ASM International | Geotechnical Testing Journal

Artigo Acesso aberto Revisado por pares

Carlos Cristian Martínez‐Chávez, Hervé Migaud,

The aim of this work was to confirm previous findings suggesting that the eyes are required for night-time melatonin production in Nile tilapia and further characterise this divergent circadian organisation. To do so, melatonin levels were firstly measured in eyecups and plasma to determine circadian patterns of melatonin production. Secondly, the effect of partial ophthalmectomy on the suppression of melatonin production was determined in vivo as well as ex vivo pineal light/dark sensitivity. Finally, ...

Tópico(s): Neurobiology and Insect Physiology Research

2009 - Elsevier BV | Brain Research

Artigo Acesso aberto Revisado por pares

Carlos Cristian Martínez‐Chávez, Matteo Minghetti, Hervé Migaud,

The Kiss1/GPR54 system has recently been shown to play a key role in the onset of puberty in mammals. Growing evidence suggests that this system is also conserved across vertebrates although very few studies so far have been performed in lower vertebrates. The aims of this study were firstly in the teleost Nile tilapia to screen tissues for GPR54 expression levels, secondly to measure the expression patterns of GPR54 and GnRH I receptor (rGnRH I) in whole brains during the onset of puberty and finally ...

Tópico(s): Reproductive biology and impacts on aquatic species

2008 - Elsevier BV | General and Comparative Endocrinology

Artigo Acesso aberto Revisado por pares

Hervé Migaud, Andrew Davie, Carlos Cristian Martínez‐Chávez, Sami Al-Khamees,

Abstract: The aim of this study was to compare the circadian control of melatonin production in teleosts. To do so, the effects of ophthalmectomy on circulating melatonin rhythms were studied along with ex vivo pineal culture in six different teleosts. Results strongly suggested that the circadian control of melatonin production could have dramatically changed with at least three different systems being present in teleosts when one considers the photic regulation of pineal melatonin production. ...

Tópico(s): Sleep and Wakefulness Research

2007 - Wiley | Journal of Pineal Research

Artigo Acesso aberto Revisado por pares

Charles R. Howell,

... oxysporum f. sp. physali InfectionJosé Luis Chaves-Gómez, Cristian Camilo Chavez-Arias, Alba Marina Cotes Prado, Sandra Gómez-Caro, ...

Tópico(s): Plant and soil sciences

2006 - American Phytopathological Society | Phytopathology

Artigo Acesso aberto Revisado por pares

Cristian A. Chávez, Eduardo Alonso Pérez de Ágreda,

The mechanical response of rockfill is largely dominated by particle breakage, which is controlled by stress level and the prevailing relative humidity (RH) in the large rockfill voids. The paper presents a model for rockfill behaviour under triaxial stress states, which is based on: (a) existing knowledge on rockfill compressibility, (b) experimental and theoretical developments on sand behaviour and (c) a series of suction-controlled triaxial tests performed in a new large-diameter triaxial cell, ...

Tópico(s): Geotechnical Engineering and Soil Stabilization

2003 - Elsevier BV | SOILS AND FOUNDATIONS

Artigo Revisado por pares

Rodolfo Farlora, Valentina Valenzuela-Muñóz, Jacqueline Chávez-Mardones, Cristian Gallardo‐Escárate,

Aquaporins are small integral membrane proteins that function as pore channels for the transport of water and other small solutes across the cell membrane. Considering the important roles of these proteins in several biological processes, including host-parasite interactions, there has been increased research on aquaporin proteins recently. The present study expands on the knowledge of aquaporin family genes in parasitic copepods, examining diversity and expression during the ontogeny of the sea ...

Tópico(s): Aquatic Invertebrate Ecology and Behavior

2016 - Elsevier BV | Gene

Artigo Revisado por pares

Gustavo Núñez-Acuña, Andrea Aguilar-Espinoza, Jacqueline Chávez-Mardones, Cristian Gallardo‐Escárate,

Ubiquitin-conjugated E2 enzyme (UBE2) is one of the main components of the proteasome degradation cascade. Previous studies have shown an increase of expression levels in individuals challenged to some pathogen organism such as virus and bacteria. The study was to characterize the immune response of UBE2 gene in the gastropod Concholepas concholepas through expression analysis and single nucleotide polymorphisms (SNP) discovery. Hence, UBE2 was identified from a cDNA library by 454 pyrosequencing, ...

Tópico(s): interferon and immune responses

2012 - Elsevier BV | Fish & Shellfish Immunology

Artigo Revisado por pares

Cristian A. Chávez, Nelson O. Moraga, Carlos Salinas, Roberto C. Cabrales, Rubén A. Ananías,

This work presents a predictive transient two-dimensional model describing the evolution of heat, mass and mechanical stresses during wood dehydration inside an experimental drying chamber. The history of the distributions of moisture content and temperature and the effects produced by its gradients on the stresses were simultaneously modeled. The non-linear coupled differential equations of heat, mass and stresses were integrated by the Control Volume Finite Element method using triangular elements ...

Tópico(s): Natural Fiber Reinforced Composites

2021 - Elsevier BV | International Communications in Heat and Mass Transfer