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      • Plant responses to nano and micro structured carbon allotropes: Water imbibition by maize seeds upon exposure to multiwalled carbon nanotubes and activated carbon

        Dasgupta-Schubert, N.,Tiwari, D.K.,Francis, E. Reyes,Martinez Torres, P.,Villasenor Cendejas, L.M.,Lara Romero, J.,Villasenor Mora, C. Techno-Press 2017 Advances in nano research Vol.5 No.3

        Multiwalled carbon-nanotubes (MWCNT) and micro-structured carbon, such as biochar or activated carbon (AC), have been seen to significantly increase the growth indices of certain plant species such as maize (Zea mays L.). Seed imbibition is the stage where environmental factors that affect water transport across the seed coat barrier, make a large impact. This work explores the effect on water imbibition by maize seeds when the aqueous environment surrounding the seed is diluted by small concentrations (10 and 20 mg/l) of pristine MWCNT (p-MWCNT), carboxylate functionalized MWCNT (COO-MWCNT) and AC. The degree of sensitivity of the process to (i) large structural changes is seen by utilizing the nano (the MWCNT) and the micro (the AC) allotropic forms of carbon; (ii) to small changes in the purity and morphology of the p-MWCNT by utilizing 95% pure and 99% pure p-MWCNTs of slightly differing morphologies; and (iii) to MWCNT functionalization by using highly pure (97%) COO-MWCNT. Water imbibition was monitored over a 15 hour period by Near Infrared Thermography (NIRT) and also by seed weighing. Seed surface topography was seen by SEM imaging. Analysis of the NIRT images suggests rapid seed surface topological changes with the quantity of water imbibed. While further work is necessary to arrive at a conclusive answer, this work shows that the imbibition phase of the maize seed is sensitive to the presence of MWCNT even to small differences in the purity of the p-MWCNT and to small differences in the physicochemical properties of the medium caused by the hydrophilic COO-MWCNT.

      • KCI등재

        Development of transient Monte Carlo in a fissile system with β-delayed emission from individual precursors using modified open source code OpenMC(TD)

        Romero-Barrientos J.,Molina F.,Márquez Damián J.I.,Zambra M.,Aguilera P.,López-Usquiano F.,Parra S. 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.5

        In deterministic and Monte Carlo transport codes, b-delayed emission is included using a group structure where all of the precursors are grouped together in 6 groups or families, but given the increase in computational power, nowadays there is no reason to keep this structure. Furthermore, there have been recent efforts to compile and evaluate all the available b-delayed neutron emission data and to measure new and improved data on individual precursors. In order to be able to perform a transient Monte Carlo simulation, data from individual precursors needs to be implemented in a transport code. This work is the first step towards the development of a tool to explore the effect of individual precursors in a fissile system. In concrete, individual precursor data is included by expanding the capabilities of the open source Monte Carlo code OpenMC. In the modified code e named Time Dependent OpenMC or OpenMC(TD)e time dependency related to b-delayed neutron emission was handled by using forced decay of precursors and combing of the particle population. The data for continuous energy neutron cross-sections was taken from JEFF-3.1.1 library. Regarding the data needed to include the individual precursors, cumulative yields were taken from JEFF-3.1.1 and delayed neutron emission probabilities and delayed neutron spectra were taken from ENDF-B/VIII.0. OpenMC(TD) was tested in a monoenergetic system, an energy dependent unmoderated system where the precursors were taken individually or in a group structure, and in a light-water moderated energy dependent system, using 6-groups, 50 and 40 individual precursors. Neutron flux as a function of time was obtained for each of the systems studied. These results show the potential of OpenMC(TD) as a tool to study the impact of individual precursor data on fissile systems, thus motivating further research to simulate more complex fissile systems

      • KCI등재

        Risk Factors for Mortality in Hospitalized Patients with COVID-19: An Overview in a Mexican Population

        ( Arturo Cortés-tellés ),( Stephanie López-romero ),( Roberto Mancilla-ceballos ),( Diana Lizbeth Ortíz-farías ),( Nelda Núñez-caamal ),( Esperanza Figueroa-hurtado ) 대한결핵 및 호흡기학회 2020 Tuberculosis and Respiratory Diseases Vol.83 No.-

        Background: Currently, Mexico ranks third worldwide in mortality due to coronavirus disease pandemic 2019 (COVID-19) and reliable information is scarce, with the available data focused on epidemiological characteristics. This study aimed to identify the risk factors associated with mortality and outcomes in hospitalized Mexican patients with COVID-19. Methods: We prospectively assessed patients admitted to a COVID-19 reference center in southeast Mexico between March 28 and June 30, 2020. Mortality was defined as survivors or non-survivors and univariate and multivariate logistic regression analyses were performed to explore the association of the clinical characteristics and laboratory parameters with mortality. Results: We included 200 patients with a mean age of 55 years, 69% were men and 72% had at least one chronic comorbidity. Eighty-six patients required invasive mechanical ventilation (IMV) with an overall mortality rate of 82.5%. Only 51% of the patients with IMV were admitted to the intensive care unit (ICU), with a survival rate of 27.3%, but only 7.2% for patients without ICU admissions (p=0.014). The multivariate analysis found that a neutrophil-to-lymphocyte ratio ≥9 (odds ratio [OR], 4.64; 95% confidence interval [CI], 2.05-10.53) albumin <3.5 g/dL (OR, 3.76; 95% CI, 1.56-9.07), lactate dehydrogenase (LDH) level ≥725 U/L (OR, 5.45; 95% CI, 2.36-12.57), and IMV (OR, 64.7; 95% CI, 15.20-275.39) were independent risk factors associated with mortality. Conclusion: Neutrophil-to-lymphocyte ratio, LDH, albumin, and IMV were independent risk factors for mortality in Mexican patients with COVID-19. Also, the availability of ICU resources is invaluable for better outcomes in critically ill patients. Our results could provide clinical information for timely decision-making in low-and-middle income countries to overcome the pandemic.

      • KCI등재

        Intra-aneurysmatic thrombectomy in a distal anterior cerebral artery aneurysm

        Juan Luis Gómez-Amador,Leoncio Alberto Tovar-Romero,Andrea Castillo-Matus,Ricardo Marian-Magaña,Jorge Fernando Aragón-Arreola,Marcos Vinicius Sangrador-Deitos,Alan Hernández-Hernández,Germán López-Val 대한뇌혈관외과학회 2023 Journal of Cerebrovascular and Endovascular Neuros Vol.25 No.4

        Thrombectomy procedures following intra-aneurysmatic lesions are extremely rare, and few cases have been reported. This article describes a microsurgical intra-aneurysmatic thrombectomy (MIaT) for a distal anterior cerebral artery (DACA) aneurysm. We present the case of a 48-year-old female that was admitted to the emergency room, showing neurologic deterioration with focal deficits. A computed tomography angiography (CTA) scan revealed an aneurysm located in the distal segment of the left anterior cerebral artery. During the surgical procedure, after clipping, a wellformed clot was visualized through the aneurysm’s wall obstructing the left DACA flow. We proceeded to open the aneurysm’s dome to remove the thrombus and clip the aneurysm neck, re-establishing the flow of the left DACA.Intra-aneurysmatic thrombosis can occur as a complication during clipping, obstructing the distal flow of vital arteries and causing fatal results in the patient’s postoperative status. MIaT is a good technique for restoring the flow of the affected vessel and allows a secure aneurysm clipping after thrombus removal.

      • KCI등재

        Preparation of Hybrid Devices Containing Nylon/M(II)Pc-TTF (M=Cu, Zn) Films with Potential Optical and Electrical Applications

        María Elena Sánchez-Vergara,Diana Monserrat López-Romero,Pablo Vidal-García,Christian Jiménez-Jarquín,Aline Hernandez-García,Omar Jiménez-Sandoval 대한금속·재료학회 2017 ELECTRONIC MATERIALS LETTERS Vol.13 No.3

        Hybrid devices consisting of metallophthalocyanines, MPcs(M=Zn, Cu), doped with a Tetrathiafulvalene (TTF) derivativeand dispersed in nylon 11 have been prepared by using a thermalevaporation technique. The effects of thermal relaxation on thestructure and morphology of the samples were studied by FT-IRspectroscopy, SEM and X-ray diffraction. The thermalrelaxation in nylon 11 produced a crystalline arrangement in theα- and β-form MPc molecules. Changes in conductivity of thedevices suggest the formation of alternative paths for carrierconduction. It was found that the temperature-dependent electriccurrent in Zn devices showed a semiconductor behavior. Finally,the optical direct and indirect band gap of these hybrid deviceswas evaluated from optical absorption measurements. The bandgap values were found to decrease from 3.7 to 1.38 eV (for theZnPc device), and from 1.9 to 1.1 eV (for the CuPc device), withthe addition of TTF in the polymeric matrix.

      • KCI등재

        Work Ability Index: Psychometric Testing in Aeronautical Industry Workers

        González-Domínguez María Eugenia,Fernández-García Elena,Paloma-Castro Olga,González-López Regina María,Rivas Pérez María Paz,López-Molina Luis,García-Jiménez Jesús,Romero-Sánchez José Manuel 한국산업안전보건공단 산업안전보건연구원 2024 Safety and health at work Vol.15 No.1

        Background The Work Ability Index (WAI) is an instrument that measures work ability. The wide dispersion of the WAI internationally has led to its adaptation for use in different countries. This study aimed to evaluate the psychometric properties of the Spanish version of the WAI. Methods A methodological design was used over an opportunistic sample of 233 workers in the aeronautical industry in Spain. Reliability was evaluated through internal consistency. Factorial validity, known groups, and convergent validity were tested. Results The Cronbach's alpha and item-total correlation indicated an adequate internal consistency. The confirmatory factor analysis, performed to evaluate the factorial validity, found adequate fit indices for a two-factor solution with a high correlation between the factors. Factor 1, “Subjectively estimated work ability and resources”, was composed of 3 subscales and factor 2, “Ill-health-related”, of 2 subscales. Subscales 4 and 6 had loading in both factors. Workers under 45 years of age obtained higher significant scores than older ones. Convergent validity was also evidenced since WAI was highly correlated with self-assessment of health status. Conclusions The Spanish version of the WAI has shown evidence of reliability and validity in this study, supporting its use in individual and collective health surveillance by occupational health professionals. The factorial solution that was found has previously been reported in another international context. However, further research is needed to resolve the discrepancies detected in the role of some subscales between other national and international studies. Background The Work Ability Index (WAI) is an instrument that measures work ability. The wide dispersion of the WAI internationally has led to its adaptation for use in different countries. This study aimed to evaluate the psychometric properties of the Spanish version of the WAI. Methods A methodological design was used over an opportunistic sample of 233 workers in the aeronautical industry in Spain. Reliability was evaluated through internal consistency. Factorial validity, known groups, and convergent validity were tested. Results The Cronbach's alpha and item-total correlation indicated an adequate internal consistency. The confirmatory factor analysis, performed to evaluate the factorial validity, found adequate fit indices for a two-factor solution with a high correlation between the factors. Factor 1, “Subjectively estimated work ability and resources”, was composed of 3 subscales and factor 2, “Ill-health-related”, of 2 subscales. Subscales 4 and 6 had loading in both factors. Workers under 45 years of age obtained higher significant scores than older ones. Convergent validity was also evidenced since WAI was highly correlated with self-assessment of health status. Conclusions The Spanish version of the WAI has shown evidence of reliability and validity in this study, supporting its use in individual and collective health surveillance by occupational health professionals. The factorial solution that was found has previously been reported in another international context. However, further research is needed to resolve the discrepancies detected in the role of some subscales between other national and international studies.

      • KCI등재

        Enteroparasitism and Risk Factors Associated with Clinical Manifestations in Children and Adults of Jalisco State in Western Mexico

        María de la Luz Galván-Ramírez,Ana Luisa Madriz-Elisondo,Jorge de Jesús Romero Rameño,Dania Araceli de la O Carrasco,Marco Antonio Cardona López,Cynthia Guadalupe Temores Ramírez 질병관리본부 2019 Osong Public Health and Research Persptectives Vol.10 No.1

        Objectives: To determine the prevalence and risk factors associated with intestinal parasites in the population of San Juan Cosala, Jalisco, Mexico. Methods: A total of 277 samples from 104 participants were analysed using direct smear, flotation, formaldehyde/ethyl acetate, and modified Kinyoun’s acid-fast stain methods. The Graham method was applied only for samples from children under 12 years of age for the diagnosis of Enterobius vermicularis. Results: The prevalence of parasite infections in the study population was 77.9% including: Entamoeba histolytica/E. dispar/E. moshkovskii/E. bangladeshi (37.5%), Giardia intestinalis (11.5%); commensals: Endolimax nana (44.2%), Entamoeba coli (27.9%), Chilomastix mesnili (6.7%) and Iodamoeba bütschlii, (2.9%); emerging intestinal protozoans: Blastocystis spp. (49%), Cryptosporidium spp. (7.7%) and Cyclospora cayetanensis (2.9%); and helminths: Enterobius vermicularis (18.3%) and Ascaris lumbricoides (5.8%). The results also showed that 58.64% of the studied population presented polyparasitism. A significant association was found between protozoan infections and housewives, and houses that were not built with concrete ceilings, brick walls and cement floors (p < 0.05). Conclusion: Polyparasitism was observed in over half the study population. The most prevalent parasite was Blastocystis spp, whilst the prevalence of helminths was less than that of protozoans. The risk factors for infection to intestinal parasites were being a housewife and not having solid brick, cement and concrete materials for house construction.

      • KCI등재

        Boundaries for an algebra of bounded holomorphic functions

        L. A. Moraes,L. Romero Grados 대한수학회 2004 대한수학회지 Vol.41 No.1

        Let Ab(BE) be the Banach algebra of all complex valued bounded continuous functions on the closed unit ball BE of a complex Banach space E, and holomorphic in the interior of BE, endowed with the sup norm. We present some sufficient conditions for a set to be a boundary for Ab(BE) in case E belongs to a class of Banach spaces that includes the pre-dual of a Lorentz sequence space studied by Gowers in [6]. We also prove the non-existence of the Shilov boundary for Ab(BE) and give some examples of boundaries.

      • SCIESCOPUSKCI등재

        BOUNDARIES FOR AN ALGEBRA OF BOUNDED HOLOMORPHIC FUNCTIONS

        Moraes, L.A.,Grados, L.-Romero Korean Mathematical Society 2004 대한수학회지 Vol.41 No.1

        Let $A_b(B_E)$ be the Banach algebra of all complex valued bounded continuous functions on the closed unit ball $B_E$ of a complex Banach space E, and holomorphic in the interior of $B_E$, endowed with the sup norm. We present some sufficient conditions for a set to be a boundary for $A_b(B_E)$ in case E belongs to a class of Banach spaces that includes the pre-dual of a Lorentz sequence space studied by Gowers in [6]. We also prove the non-existence of the Shilov boundary for $A_b(B_E)$ and give some examples of boundaries.

      • KCI등재

        Origin of congenital coronary arterio-ventricular fistulae from anomalous epicardial and myocardial development

        Palmquist-Gomes P.,Ruiz-Villalba A.,Guadix J. A.,Romero J. P.,Bessiéres B.,MacGrogan D.,Conejo L.,Ortiz A.,Picazo B.,Houyel L.,Gómez-Cabrero D.,Meilhac S. M.,de la Pompa J. L.,Pérez-Pomares J. M. 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

        Coronary Artery Fistulae (CAFs) are cardiac congenital anomalies consisting of an abnormal communication of a coronary artery with either a cardiac chamber or another cardiac vessel. In humans, these congenital anomalies can lead to complications such as myocardial hypertrophy, endocarditis, heart dilatation, and failure. Unfortunately, despite their clinical relevance, the aetiology of CAFs remains unknown. In this work, we have used two different species (mouse and avian embryos) to experimentally model CAFs morphogenesis. Both conditional Itga4 (alpha 4 integrin) epicardial deletion in mice and cryocauterisation of chick embryonic hearts disrupted epicardial development and ventricular wall growth, two essential events in coronary embryogenesis. Our results suggest that myocardial discontinuities in the embryonic ventricular wall promote the early contact of the endocardium with epicardial-derived coronary progenitors at the cardiac surface, leading to ventricular endocardial extrusion, precocious differentiation of coronary smooth muscle cells, and the formation of pouch-like aberrant coronary-like structures in direct connection with the ventricular lumen. The structure of these CAF-like anomalies was compared with histopathological data from a human CAF. Our results provide relevant information for the early diagnosis of these congenital anomalies and the molecular mechanisms that regulate their embryogenesis.

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