221 research outputs found
Imaging the Kirkendall effect in pyrite (FeS2) thin films: cross-sectional microstructure and chemical features
This investigation provides novel data on the structure and chemical composition of pyrite thin films and new hints concerning their formation mechanism. From TEM-HAADF data, it has been found that the films are composed of two different layers: one is very compact and the other one is quite porous with many voids separating a few groups of grains. This porous layer is always in direct contact with the substrate, and its thickness is quite similar to that of the original Fe film. The average size of pyrite grains is equal in both layers, what suggests that the same process is responsible for their formation. Concentration profiles of sulfur, iron and some impurities (mainly sodium and oxygen from the glass substrate) through both layers are given in this work, and thus chemical inhomogeneities of the films are proved by the obtained stoichiometric ratios (S/Fe). Moreover, Na from sodalime glass substrates mainly accumulates at the pyrite grain boundaries and barely dopes them. The obtained results support the hypothesis that the iron sulfuration process essentially induces the diffusion of iron atoms, what leads to the porous layer formation as a manifestation of the Kirkendall Effect. Therefore, it seems that the same mechanisms that operate in the synthesis of surface hollow structures at the nanoscale are also active in the formation of pyrite thin films ranging from several tens to hundreds of nanometersMembers of MIRE Group acknowledge the financial support of the Spanish MICINN under project RTI2018-099794-B-I00. E. Flores acknowledges the intramural CSIC project 2D-MeSes funding and the service from the MiNa Laboratory at IMN, and funding from CM (project SpaceTec, S2013/ICE2822), MINECO (project CSIC13-4E1794) and EU (FEDER,FSE). Financial support through the project UMA18-FEDERJA-041 is gratefully acknowledge
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Scaling up cancer care for children without medical insurance in developing countries: The case of Mexico
Background: In 2006, the Mexican government launched the Fund for Protection Against Catastrophic Expenditures (FPGC) to support financially healthcare of high cost illnesses. This study aimed at answering the question whether FPGC improved coverage for cancer care and to measure survival of FPGC affiliated children with cancer. Procedure A retrospective cohort study (2006â2009) was conducted in 47 public hospitals. Information of children and adolescents with cancer was analyzed. The coverage was estimated in accordance with expected number of incident cases and those registered at FPGC. The survival was analyzed by using KaplanâMeier survival curves and Cox proportional hazards regression modeling. Results: The study included 3,821 patients. From 2006 to 2009, coverage of new cancer cases increased from 3.3% to 55.3%. Principal diagnoses were acute lymphoblastic leukemia (ALL, 46.4%), central nervous system (CNS) tumors (8.2%), and acute myeloid leukemia (AML, 7.4%). The survival rates at 36 months were ALL (50%), AML (30.5%), Hodgkin lymphoma (74.5%), Non-Hodgkin lymphoma (40.1%), CNS tumors (32.8%), renal tumors (58.4%), bone tumors (33.4%), retinoblastoma (59.2%), and other solid tumors (52.6%). The 3-year overall survival rates varied among the regions; children between the east and south-southeast had the higher risks (hazard ratio 3.0; 95% CI: 2.3â3.9) and 2.4; 95% CI: 2.0â2.8) of death from disease when compared with those from the central region. Conclusion: FPGC has increased coverage of cancer cases. Survival rates were different throughout the country. It is necessary to evaluate the effectiveness of this policy to increase access and identify opportunities to reduce the differences in survival
ExtracciĂłn secuencial de metales pesados en dos suelos contaminados (Andisol y Vertisol) enmendados con ĂĄcidos hĂşmicos
En suelos Andisoles y Vertisoles, bajo condiciones controladas, se evaluĂł el efecto de ĂĄcidos hĂşmicos purificados en concentraciones de 0%, 2.5% y 5% (peso/peso)) sobre la extracciĂłn secuencial de metales pesados despuĂŠs de incubaciĂłn a 60 y 90 dĂas. Â El fraccionamiento de los metales (Ni, Cu, Zn, Cd y Pb) en suelos contaminados y enmendados con ĂĄcidos hĂşmicos se realizĂł mediante extracciĂłn secuencial de Tessier. Â La movilidad de los metales se redujo con la adiciĂłn de dichos ĂĄcidos, con mayor retenciĂłn de Ni, Cu, Zn y Cd en la matriz del suelo (fracciĂłn residual). Â El Pb en ambos suelos y el Zn en Vertisol experimentaron incremento significativo en su movilidad, mayor biodisponibilidad y potencial de afectaciĂłn de diferentes componentes del medio-ambiente. Â El incremento del tiempo de incubaciĂłn permitiĂł la interacciĂłn de los metales con los componentes de los suelos, generando disminuciĂłn de su movilidad por mecanismos como formaciĂłn de complejos estables y/o incremento de la capacidad de intercambio catiĂłnico (CIC) de los suelos. Â Los ĂĄcidos hĂşmicos pueden ser utilizados, en general, como enmienda orgĂĄnica para la recuperaciĂłn de suelos contaminados con metales pesados
AdsorciĂłn de metales pesados en Andisoles, Vertisoles y ĂĄcidos hĂşmicos
La presente investigaciĂłn estudiĂł la adsorciĂłn de cinco metales pesados (Cd, Cu, Ni, Pb y Zn) en tres adsorbentes, dos suelos agrĂcolas colombianos (Typic Melanudand y Epiaquert Ăşstico arcilloso fino isohipertĂŠrmico 1%) y ĂĄcidos hĂşmicos (AH) extraĂdos de leonardita, de EspaĂąa, mediante la metodologĂa descrita por Mosquera et al. (2007). A los suelos y a los AH se les determinaron propiedades quĂmicas como pH, Capacidad de Intercambio CatiĂłnico (CIC), carbono orgĂĄnico (%CO), bases intercambiables y contenido total de metales. La composiciĂłn quĂmica de los AH se determinĂł empleando tĂŠcnicas espectromĂŠtricas como ICP_MS, FTIR, UV-Vis, CPMAS 13C NMR y Py-GC/MS-THMA. Los resultados de la adsorciĂłn de metales se ajustaron al modelo de Freundlich, y muestran un comportamiento disĂmil de los absorbentes en relaciĂłn a los metales estudiados, es asĂ como la mĂĄxima capacidad de adsorciĂłn (K) y la fuerza de retenciĂłn (n) de los metales es significativamente diferente (pPbCuNiZn, Andisol: PbCuCdZnNi, y Vertisol: CdPbCuNiZn; y para n, Ăcidos HĂşmicos: PbZnCdCuNi, Andisol: CuNiZnPbCd, y Vertisol: ZnNiCuPbCd.This research studied the adsorption of five heavy metals (Cd, Cu, Ni, Pb and Zn) in three adsorbents, two Colombian agricultural soils (Typic Melanudand and fine clay 1% isohyperthermic-Ustic Epiaquert) and humic acids (HA) extracted from leonardite, of Spain. In both, HA and soils, the chemical properties determined were: pH, cation exchange capacity (CEC), organic carbon (% OC), exchangeable bases and total content of metals. The hemical composition of HA was determined using spectrometric techniques as ICP_MS, FTIR, UV-Vis, and CPMAS 13C NMR and Py-GC/MS-THMA. The results from the adsorption of metals in the three adsorbents were adjusted to Freundlich model, and these show a different behavior of the absorbers relative to the metals studied, in the same way the maximum adsorption capacity (K) and the retention force (n) of metals is significantly different (p 0.05). According to K and n of each adsorbent, the adsorption selectivity sequences of the metals has the following order of preference for K: In Humic Acids: Cd Pb Cu Ni Zn, Andisol: Pb Cu Cd Zn Ni, and Vertisol: Cd Pb Cu Ni Zn. For n, Humic Acids: Pb Zn Cd Cu Ni, Andisol: Cu Ni Zn Pb Cd, and Vertisol: Zn Ni Cu Pb C
Serum albumin level as a risk factor for mortality in burn patients
OBJECTIVE: Hypoalbuminemia is a common clinical deficiency in burn patients and is associated with complications related to increased extravascular fluid, including edema, abnormal healing, and susceptibility to sepsis. Some prognostic scales do not include biochemical parameters, whereas others consider them together with comorbidities. The purpose of this study was to determine whether serum albumin can predict mortality in burn patients. METHODS: We studied burn patients âĽ16 years of age who had complete clinical documentation, including the Abbreviated Burn Severity Index, serum albumin, globulin, and lipids. Sensitivity and specificity analyses were performed to determine the cut-off level of albumin that predicts mortality. RESULTS: In our analysis of 486 patients, we found that mortality was higher for burns caused by flame (pâ=â0.000), full-thickness burns (pâ=â0.004), inhalation injuries (pâ=â0.000), burns affecting >;30% of the body surface area (pâ=â0.001), and burns associated with infection (pâ=â0.008). Protein and lipid levels were lower in the patients who died (
DPYD pathogenic variants associated with fluoropyrimidines toxicity
Background: Genetic variants in dihydropyrimidine dehydrogenase gene (DPYD) coding for the key enzyme (DPD) of fluoropyrimidines (FPs) catabolism. DPYD contributes to the development of severe FPs-related toxicity, and pathogenic DPYD variants detection reduces side effects and complications associated with FP-toxicity. The allelic frequency of these variants in the Mexican population is currently unknown.
Methods: The study was carried out at the Centro Universitario Contra el CĂĄncer (CUCC) of the Universidad AutĂłnoma de Nuevo LeĂłn (UANL) in Monterrey MĂŠxico. Genomic DNA was isolated from 154 subjects using the QIAamp DNA Blood Midi kit (QIAGEN) following the manufacturer\u27s recommendations. We analyze the variants c.1156G-\u3eT, c.2846A-\u3eT, and c.1129-5923C-\u3eG by qPCR using predesigned probes. For the remaining genomic variants (c.1905+1G-\u3eA, c.1679T-\u3eG, c.1898delC and c.299_302delTCAT), we design sequencing oligos using the software Oligo Primer v.7ÂŽ. The allele frequency was calculated for each variant.
Results: We analyzed a total of 154 samples to detect the seven variants analyzed. So far, only 2 samples have been found that presented the variant c.1129-5923C\u3eG in a state of heterozygosis, representing 1.2987% of the total of our population.
Conclusions: The allele frequency for the variant c.1129-5923C-\u3eG was higher than reported in other populations. So this allele is more common in our population, which could attribute to the large percentage of side effects in our patients. However, more studies and increasing the number of samples are needed to establish DPYD the allele frequency more precisely
Initial CONNECT Architecture
Interoperability remains a fundamental challenge when connecting heterogeneous systems which encounter and spontaneously communicate with one another in pervasive computing environments. This challenge is exasperated by the highly heterogeneous technologies employed by each of the interacting parties, i.e., in terms of hardware, operating system, middleware protocols, and application protocols. The key aim of the CONNECT project is to drop this heterogeneity barrier and achieve universal interoperability. Here we report on the development of the overall CONNECT architecture that will underpin this solution; in this respect, we present the following contributions: i) an elicitation of interoperability requirements from a set of pervasive computing scenarios, ii) a survey of existing solutions to interoperability, iii) an initial view of the CONNECT architecture, and iv) a series of experiments to provide initial validation of the architecture
Mejoramiento del parque Juan Aldama - AutoconstrucciĂłn de techo verde de bambĂş en vivienda social, Puerto Vallarta, Jalisco
El proyecto RegeneraciĂłn socioambiental del rĂo Pitillal en Puerto Vallarta, ha sido desarrollado por los equipos del PAP desde la primavera de 2021 y contempla una metodologĂa que combina la producciĂłn social del hĂĄbitat (Ortiz. E, 2012) con la autoconstrucciĂłn con materiales locales (Comunal, 2019). Se han desarrollado investigaciones para generar diagnĂłsticos, posteriormente se han desarrollados propuestas tĂŠcnicas que se han validado con los habitantes de la zona. Se busca actualmente pasar a la etapa de la acciĂłn participativa, buscando motivar el involucramiento de los actores locales y beneficiarios de las zonas en las que se da el acompaĂąamiento.
Se presenta aquĂ el reporte del proceso de la realizaciĂłn de dos lĂneas de investigaciĂłn que dan continuidad a procesos que se originaron en semestres anteriores del PAP en el escenario de Puerto Vallarta:AUTOCONSTRUCCIĂN DE CUBIERTA DE BAMBĂ Y FORESTACIĂN EN PARQUE JUAN ALDAMA y AUTOCONSTRUCCIĂN DE CUBIERTA DE BAMBĂ Y FORESTACIĂN EN AZOTEA DE VIVIENDA EN VALLARTA VILLAS.ITESO, A.C
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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