2,485 research outputs found

    Towards a metallic top contact electrode in molecular electronic devices exhibiting a large surface coverage by photoreduction of silver cations

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    In this contribution the photoreduction of silver ions coordinated onto a Langmuir–Blodgett monolayer is presented as an effective method for the deposition of the top contact electrode in metal/monolayer/metal devices. Silver cations were incorporated from an aqueous AgNO3 sub-phase of Langmuir films of 4,4'-(1,4-phenylenebis(ethyne-2,1-diyl))dibenzoic acid upon the transference of these films onto a metallic substrate. Subsequent irradiation of the silver-ion functionalized Langmuir–Blodgett films with 254 nm light results in the photoreduction of silver cations to produce metallic silver nanoparticles, which are distributed over the organic monolayer and exhibit a surface coverage as large as 76% of the monolayer surface. Electrical properties of these metal/monolayer/metal devices were determined by recording I–V curves, which show a sigmoidal behaviour indicative of well-behaved junctions free of metallic filaments and short-circuits. The integrity of the organic monolayer upon the irradiation process and formation of the silver top-contact electrode has also been demonstrated through cyclic voltammetry experiments

    Cutaneous metastases in renal cell carcinoma: a case report

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    Renal cell carcinoma is the most common form of malignant renal tumour and is extremely lethal. About 25% of the patients develop metastasis at the time of diagnosis, and in many cases during the course of the disease, affecting the lung, lymphatic ganglions, liver, and bone, with skin metastases being quite rare

    Trace gases detection by photoacoustic technique based on a lineal chirp excitation scheme

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    We present a new photoacoustic gas-trace measurement setup, based on a chirped optical chopper. This method combines features of the resonant and pulsed techniques. To show the advantages of this setup, we carried out a comparison with the resonant method in samples of NO2 contained in a one-dimensional acoustic resonator. The results show the chirped technique allows carrying out short-term acquisitions with good signal-to-noise ratio

    Detección de gases traza por técnica fotoacústica basada en un esquema de excitación chirp lineal

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    We present a new photoacoustic gas-trace measurement setup, based on a chirped optical chopper. This method combines features of the resonant and pulsed techniques. To show the advantages of this setup, we carried out a comparison with the resonant method in samples of NO2 contained in a one-dimensional acoustic resonator. The results show the chirped technique allows carrying out short-term acquisitions with good signal-to-noise ratio.En este trabajo se presenta un nuevo esquema de medición para espectroscopía fotoacústica de gases traza basado en un esquema de excitación up-chirp. Esta forma combina las ventajas de los esquemas resonante y pulsado. Para mostrar el potencial de esta técnica se la comparó con un esquema de excitación resonante sobre la medición de muestras de dióxido de nitrógeno en aire contenidas en una resonador acústico de alumnio. Los resultados mostraron que la técnica chirp permite realizar mediciones de corta duración con muy buena relación señal a ruido

    Cluster randomized trial in smoking cessation with intensive advice in diabetic patients in primary care : ITADI Study

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    Background: It is a priority to achieve smoking cessation in diabetic smokers, given that this is a group of patients with elevated cardiovascular risk. Furthermore, tobacco has a multiplying effect on micro and macro vascular complications. Smoking abstinence rates increase as the intensity of the intervention, length of the intervention and number and diversity of contacts with the healthcare professional during the intervention increases. However, there are few published studies about smoking cessation in diabetics in primary care, a level of healthcare that plays an essential role in these patients. Therefore, the aim of the present study is to evaluate the effectiveness of an intensive smoking cessation intervention in diabetic patients in primary care. Methods/Design: Cluster randomized trial, controlled and multicentric. Randomization unit: Primary Care Team. Study population: 546 diabetic smokers older than 14 years of age whose disease is controlled by one of the primary care teams in the study. Outcome Measures: Continuous tobacco abstinence (a person who has not smoked for at least six months and with a CO level of less than 6 ppm measured by a cooximeter) , evolution in the Prochaska and DiClemente's Transtheoretical Model of Change, number of cigarettes/day, length of the visit. Point of assessment: one- year post- inclusion in the study. Intervention: Brief motivational interview for diabetic smokers at the pre-contemplation and contemplation stage, intensive motivational interview with pharmacotherapy for diabetic smokers in the preparation-action stage and reinforcing intevention in the maintenance stage. Statistical Analysis: A descriptive analysis of all variables will be done, as well as a multilevel logistic regression and a Poisson regression. All analyses will be done with an intention to treatment basis and will be fitted for potential confounding factors and variables of clinical importance. Statistical packages: SPSS15, STATA10 y HLM6. Discussion: The present study will try to describe the profile of a diabetic smoker who receives the most benefit from an intensive intervention in primary care. The results will be useful for primary care professionals in their usual clinical practice

    Towards molecular electronic devices based on 'all-carbon' wires

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    Nascent molecular electronic devices based on linear ‘all-carbon’ wires attached to gold electrodes through robust and reliable C–Au contacts are prepared via efficient in situ sequential cleavage of trimethylsilyl end groups from an oligoyne, Me3Si–(C[triple bond, length as m-dash]C)4–SiMe3 (1). In the first stage of the fabrication process, removal of one trimethylsilyl (TMS) group in the presence of a gold substrate, which ultimately serves as the bottom electrode, using a stoichiometric fluoride-driven process gives a highly-ordered monolayer, Au|C[triple bond, length as m-dash]CC[triple bond, length as m-dash]CC[triple bond, length as m-dash]CC[triple bond, length as m-dash]CSiMe3 (Au|C8SiMe3). In the second stage, treatment of Au|C8SiMe3 with excess fluoride results in removal of the remaining TMS protecting group to give a modified monolayer Au|C[triple bond, length as m-dash]CC[triple bond, length as m-dash]CC[triple bond, length as m-dash]CC[triple bond, length as m-dash]CH (Au|C8H). The reactive terminal C[triple bond, length as m-dash]C–H moiety in Au|C8H can be modified by ‘click’ reactions with (azidomethyl)ferrocene (N3CH2Fc) to introduce a redox probe, to give Au|C6C2N3HCH2Fc. Alternatively, incubation of the modified gold substrate supported monolayer Au|C8H in a solution of gold nanoparticles (GNPs), results in covalent attachment of GNPs on top of the film via a second alkynyl carbon–Au σ-bond, to give structures Au|C8|GNP in which the monolayer of linear, ‘all-carbon’ C8 chains is sandwiched between two macroscopic gold contacts. The covalent carbon–surface bond as well as the covalent attachment of the metal particles to the monolayer by cleavage of the alkyne C–H bond is confirmed by surface-enhanced Raman scattering (SERS). The integrity of the carbon chain in both Au|C6C2N3HCH2Fc systems and after formation of the gold top-contact electrode in Au|C8|GNP is demonstrated through electrochemical methods. The electrical properties of these nascent metal–monolayer–metal devices Au|C8|GNP featuring ‘all-carbon’ molecular wires were characterised by sigmoidal I–V curves, indicative of well-behaved junctions free of short circuits

    Índice de provisión de hábitat potencial para la biodiversidad de controladores biológicos en un paisaje de interfase urbano rural en Mendoza, Argentina

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    La expansión urbana sobre paisajes agrícolas genera interfases urbano-rurales. La coexistencia de usos del suelo agrícolas y residenciales puede promover conflictos en torno al uso de plaguicidas. En Mendoza, Argentina, la escasez del recurso hídrico limita el traslado de la agricultura más allá de las áreas irrigadas, por lo que es importante mejorar esta convivencia. Para disminuir el uso de plaguicidas se necesitan estrategias asentadas en funciones ecosistémicas como el control biológico de plagas por conservación. Esta estrategia depende de la biodiversidad funcional presente en el paisaje; en especial, de las comunidades vegetales con capacidad de brindar hábitat a especies de artrópodos, parasitoides y depredadores generalistas. El objetivo de este trabajo fue construir un índice para evaluar la capacidad de proveer hábitat potencial para los controladores biológicos (IHPB) en diferentes ambientes de un paisaje, con el fin de aportar conocimientos para el ordenamiento ambiental territorial de áreas de interfase. El IHPB se construyó a partir de 5 indicadores y se puso a prueba en el distrito de Lunlunta (Maipú, Mendoza). Se clasificó el área de estudio en 6 unidades de paisaje (UP): Natural de secano, Natural de ribera, Seminatural, Agrícola convencional, Agrícola biodiverso y Urbana. En ellas se realizaron censos de vegetación para calcular los indicadores. El valor más alto de IHPB ocurrió en la UP Natural de secano por la alta diversidad y la cobertura total y de especies arbóreas y arbustivas nativas presentes en su comunidad vegetal; el IHPB más bajo ocurrió en la UP Agrícola convencional. Su aplicación confirmó la importancia de las áreas naturales en cuanto a su potencialidad para sostener a la entomofauna benéfica base para el control biológico de plagas, y la necesidad de mejorar las condiciones de hábitat en los ambientes agrícolas.Urban sprawl over agricultural landscapes generates urban-rural interfaces. The coexistence of agricultural and residential land uses can promote conflicts over the use of pesticides. In Mendoza (Argentina), the scarcity of water resources is a constraint for moving agriculture beyond irrigated areas, so it is important to improve this coexistence. In order to reduce the use of pesticides, strategies based on ecosystem functions such as biological pest control through conservation are necessary. This strategy depends on the functional biodiversity present in the landscape, especially on plant communities with the capacity to provide habitat for arthropod species, parasitoids and generalist predators. The objective of this work was to construct an index to evaluate the capacity to provide potential habitat for biological controllers (IHPB) in different areas of a landscape, in order to provide knowledge for the territorial environmental management of interface areas. The IHPB was constructed from five indicators and evaluated in the Lunlunta district (Maipú, Mendoza). The study area was classified into six landscape units (UP): Dryland natural, Riverside natural, Semi-natural, Conventional agricultural, Biodiverse agricultural and Urban, in which vegetation censuses were conducted for the calculation of the indicators. The IHPB showed the highest value in the Dryland natural UP due to the high diversity, total cover and native tree and shrub species present in its plant community; the lowest was registered in Conventional agriculture. Its application confirmed the importance of natural areas in terms of their potential to sustain the beneficial entomofauna base for the biological control of pests, and the need to improve habitat conditions in agricultural environments.EEA MendozaFil: Del Barrio, Lucia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Fruitos, Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Junin; ArgentinaFil: Fruitos, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sarandon, Santiago. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. CIC-LIRA; ArgentinaFil: Portela, Jose Antonio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; ArgentinaFil: D'Amario, Julieta. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Martin Velasco, Maria J. Universidad Nacional de Mar del Plata. Instituto de Geología de Costas y del Cuaternario; ArgentinaFil: Perez, Martin Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentin

    The Relationship between PM2.5 and Health Vulnerability in Argentina in 2010

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    This study aimed to further explore the concept of health vulnerability in Argentina, including environmental pollution in 2010. To this end, we developed a geo-referenced database of PM2.5 concentrations and emissions data from the national emissions inventory to analyze possible correlations with the demographic, activity, education, and health data from the 2010 national census. In addition, to provide a more complete picture of health vulnerability in Argentina, an extended index (SVI + PM2.5) was constructed and mapped, including PM concentration. We obtained data for annual PM2.5 values emissions and air concentrations in Argentina from public sources (GEEA-AEIv3.0M for emissions and the Atmospheric Composition Analysis Group V5.GL.03 dataset for surface PM2.5). We evaluated health vulnerability using the “Sanitary Vulnerability Index” (SVI). PM2.5 emissions are concentrated in urban and intensive agricultural areas of Argentina. PM2.5 air concentrations were acceptable (≤10 µg/m3) in only 15% of the Argentinean territory. The newly developed SVI + PM2.5 index showed that exposure to particulate material significantly increases the vulnerability shown by SVI in almost all census blocks. These results indicate that the new SVI + PM2.5 index might help identify populations that are at risk because of social issues or air pollution.Fil: Bullo, Manuela. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; ArgentinaFil: Lakkis, Gabriela. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; Argentina. Universidad Tecnológica Nacional; ArgentinaFil: Pustilnik, Martin. Universidad Nacional de Hurlingham; ArgentinaFil: Bonfiglio, Juan Ignacio. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; ArgentinaFil: Di Pasquale, Ricardo. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; ArgentinaFil: Gonzalez, Luciana Marisol. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; ArgentinaFil: Gonzalez Alemán, Gabriela. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; ArgentinaFil: Lamas, María Cristina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; ArgentinaFil: Salvia, Hector Agustin. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Langsam, Martín. No especifíca;Fil: Olego, Tomás Alberto. No especifíca;Fil: Starosta, Valentín. No especifíca;Fil: Perez Lloret, Santiago. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    CD44 Modulates Cell Migration and Invasion in Ewing Sarcoma Cells

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    The chimeric EWSR1::FLI1 transcription factor is the main oncogenic event in Ewing sarcoma. Recently, it has been proposed that EWSR1::FLI1 levels can fluctuate in Ewing sarcoma cells, giving rise to two cell populations. EWSR1::FLI1low cells present a migratory and invasive phenotype, while EWSR1::FLI1high cells are more proliferative. In this work, we described how the CD44 standard isoform (CD44s), a transmembrane protein involved in cell adhesion and migration, is overexpressed in the EWSR1::FLI1low phenotype. The functional characterization of CD44s (proliferation, clonogenicity, migration, and invasion ability) was performed in three doxycycline-inducible Ewing sarcoma cell models (A673, MHH-ES1, and CADO-ES1). As a result, CD44s expression reduced cell proliferation in all the cell lines tested without affecting clonogenicity. Additionally, CD44s increased cell migration in A673 and MHH-ES1, without effects in CADO-ES1. As hyaluronan is the main ligand of CD44s, its effect on migration ability was also assessed, showing that high molecular weight hyaluronic acid (HMW-HA) blocked cell migration while low molecular weight hyaluronic acid (LMW-HA) increased it. Invasion ability was correlated with CD44 expression in A673 and MHH-ES1 cell lines. CD44s, upregulated upon EWSR1::FLI1 knockdown, regulates cell migration and invasion in Ewing sarcoma cells.This project was funded by Instituto de Salud Carlos III, grant numbers PI20CIII/00020, DTS18CIII/00005, Asociación Pablo Ugarte, grant numbers TRPV205/18; Asociación Candela Riera, Asociación Todos Somos Iván & Fundación Sonrisa de Alex, grant numbers TVP333-19, TVP-1324/15; ASION, grant number TVP141/17. Enrique Fernández-Tabanera is supported by Asociación Candela Riera, Asociación Todos Somos Iván & Fundación Sonrisa de Alex, Saint T. Cervera is supported by Asociación Pablo Ugarte and Raquel M. Melero is supported by a CIBERER contract.S

    Assessment of ataxia rating scales and cerebellar functional tests : critique and recommendations

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    Background: We assessed the clinimetric properties of ataxia rating scales and functional tests, and made recommendations regarding their use. Methods: A systematic literature search was conducted to identify the instruments used to rate ataxia symptoms. The identified rating scales and functional ability tests were reviewed and ranked by the panel as "recommended," "suggested," or "listed" for the assessment of patients with discrete cerebellar disorders, using previously established criteria. Results: We reviewed 14 instruments (9 rating scales and 5 functional tests). "Recommended" rating scales for the assessment of symptoms severity were: for Friedreich's ataxia, the Friedreich's Ataxia Rating Scale, the International Cooperative Ataxia Rating Scale (ICARS), and the Scale for the Assessment and Rating of Ataxia (SARA); for spinocerebellar ataxias, ICARS and SARA; for ataxia telangiectasia: ICARS and SARA; for brain tumors, SARA; for congenital disorder of glycosylation-phosphomannomutase-2 deficiency, ICARS; for cerebellar symptoms in multiple sclerosis, ICARS; for cerebellar symptoms in multiple system atrophy: Unified Multiple System Atrophy Rating Scale and ICARS; and for fragile X-associated tremor ataxia syndrome, ICARS. "Recommended" functional tests were: for Friedreich's ataxia, Ataxia Functional Composite Score and Composite Cerebellar Functional Severity Score; and for spinocerebellar ataxias, Ataxia Functional Composite Score, Composite Cerebellar Functional Severity Score, and SCA Functional Index. Conclusions: We identified some "recommended" scales and functional tests for the assessment of patients with major hereditary ataxias and other cerebellar disorders. The main limitations of these instruments include the limited assessment of patients in the more severe end of the spectrum and children. Further research in these populations is warranted
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