51 research outputs found
Use of refractory chromites for obtaining fluxes amassed employed in submerged arc welding (SAW)
11 páginas, 2 figuras, 8 tablal.[ES] En el presente trabajo se obtienen ferrocromo de alto carbono (ferrocromo de carga) y
escorias a partir del proceso de reducción de cromitas refractarias. Mediante la utilización
de un diseño de experimento de relaciones entre componentes, se estudia la obtención de
aleaciones y escorias. La composición química de ambas garantiza su aplicación para
la conformación de cargas aleantes y matrices de fundentes aglomerados, para el relleno
superficial mediante soldadura automática por arco sumergido (SAW). El proceso de
fusión-reducción se realiza en un horno eléctrico de arco.[EN] In the present work high carbon ferrochrome (load ferrochrome) and slags are obtained,
starting frora the métallurgie reductive processing of refractory chromites. The obtaining of
alloys and slags is studied using an experiment design based in the relationships among
components. The chemical compositions of alloys and slags guarantee their application for
the conformation of alloys loads and matrix fluxes amassed for the superficial filling by
means of submerged arc welding (SAW). The melting-reduction process is carried out in
an electric arc furnace.Peer reviewe
Plataforma neurotecnológica aplicada al estudio y entrenamiento de la actividad cognitiva del ajedrecista
RESUMEN
El ajedrez es un juego que demanda una continua actividad atencional en la solución de problemas. El entrenamiento adecuado de la atención en el ajedrecista mediante el empleo de técnicas psicológicas permite una mayor regulación de la precisión perceptiva, capacidad para integrar y procesar estímulos simultáneamente, fiabilidad de la respuesta, tiempo de reacción y concentración. En correspondencia con estos particulares la investigación tiene como objetivo diseñar una plataforma neurotecnológica que permita el estudio y entrenamiento de la actividad cognitiva de los ajedrecistas. El sistema neurotecnológico presentado es pertinente para el entrenamiento de los ajedrecistas en los marcos de los sistemas de entrenamientos contemporáneos. Su instrumentación permite la regulación del componente cognitivo, incrementa la tolerancia a la interferencia atencional, la concentración, el control espacial del tablero de ajedrez, la resistencia atencional y la velocidad de procesamiento de la información en la solución de problemas ajedrecísticos.
ABSTRACT
Chess is a game that demands a continuous attention activity in the solution of problems. The adequate training of the attention in the chess player through the use of psychological techniques allows a greater regulation of the perceptive precision, ability to integrate and process stimuli simultaneously, reliability of the response, reaction time and concentration. In correspondence with these individuals, the research aims to design a neurotechnological platform that allows the study and training of the cognitive activity of chess players. The neurotechnological system presented is relevant for the training of chess players in the frames of contemporary training systems. Its instrumentation allows the regulation of the cognitive component, it increases the tolerance to the attentional interference, the concentration, the spatial control of the chessboard, the attentional resistance and the speed of information processing in the solution of chess problems
Tissue compatibility of SN-38-loaded anticancer nanofiber matrices
Delivery of chemotherapy in the surgical bed has shown preclinical activity to control cancer progression upon subtotal resection of pediatric solid tumors, but whether this new treatment is safe for tumor-adjacent healthy tissues remains unknown. Here, Wistar rats are used to study the anatomic and functional impact of electrospun nano¿ber matrices eluting SN-38—a potent chemotherapeutic agent—on several body sites where pediatric tumors such as neuroblastoma, Ewing sarcoma, and rhabdomyosarcoma arise. Blank and SN-38-loaded matrices embracing the femoral neurovascular bundle or in direct contact with abdominal viscera (liver, kidney, urinary bladder, intestine, and uterus) are placed. Foreign body tissue reaction to the implants is observed though no histologic damage in any tissue/organ. Skin healing is normal. Tissue reaction is similar for SN-38-loaded and blank matrices, with the exception of the hepatic capsule that is thicker for the former although within the limits consistent with mild foreign body reaction. Tissue and organ function is completely conserved after local treatments, as assessed by the rotarod test (forelimb function), hematologic tests (liver and renal function), and control of clinical signs. Overall, these ¿ndings support the clinical translation of SN-38-loaded nano¿ber matrices to improve local control strategies of surgically resected tumorsPostprint (author's final draft
Conocimientos tradicionales relativos a la biodiversidad agrícola
La biodiversidad agrícola, a diferencia de la silvestre, requiere la acción continuada de los agricultores para su conservación, ya que las plantas cultivadas dependen de la intervención humana, con actividades como la selección, la siembra, el abonado, la poda u otras prácticas agrícolas para su supervivencia. Desde la revolución agrícola del Neolítico hasta la actualidad, estas prácticas y conocimientos han ido generando y conservando una gran diversidad, amenazada a partir de la segunda mitad del siglo XX por las causas que se han indicado anteriormente.Peer reviewe
Predictors of Survival After Head and Neck Squamous Cell Carcinoma in South America: The InterCHANGE Study.
PURPOSE: Head and neck squamous cell carcinoma (HNSCC) incidence is high in South America, where recent data on survival are sparse. We investigated the main predictors of HNSCC survival in Brazil, Argentina, Uruguay, and Colombia. METHODS: Sociodemographic and lifestyle information was obtained from standardized interviews, and clinicopathologic data were extracted from medical records and pathologic reports. The Kaplan-Meier method and Cox regression were used for statistical analyses. RESULTS: Of 1,463 patients, 378 had a larynx cancer (LC), 78 hypopharynx cancer (HC), 599 oral cavity cancer (OC), and 408 oropharynx cancer (OPC). Most patients (55.5%) were diagnosed with stage IV disease, ranging from 47.6% for LC to 70.8% for OPC. Three-year survival rates were 56.0% for LC, 54.7% for OC, 48.0% for OPC, and 37.8% for HC. In multivariable models, patients with stage IV disease had approximately 7.6 (LC/HC), 11.7 (OC), and 3.5 (OPC) times higher mortality than patients with stage I disease. Current and former drinkers with LC or HC had approximately 2 times higher mortality than never-drinkers. In addition, older age at diagnosis was independently associated with worse survival for all sites. In a subset analysis of 198 patients with OPC with available human papillomavirus (HPV) type 16 data, those with HPV-unrelated OPC had a significantly worse 3-year survival compared with those with HPV-related OPC (44.6% v 75.6%, respectively), corresponding to a 3.4 times higher mortality. CONCLUSION: Late stage at diagnosis was the strongest predictor of lower HNSCC survival. Early cancer detection and reduction of harmful alcohol use are fundamental to decrease the high burden of HNSCC in South America
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Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
The original version of this article unfortunately contained a mistake
Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
Characterization of a manganese ore to define the use in the fluxes synthesis for submerged arc welding
9 páginas, 3 figuras, 10 tablas.[ES] Se realiza la caracterización química, el análisis térmico diferencial y termogravimétrico
(ATD y TG), la determinación de las fases por difractóme tría de rayos-X y el análisis
granulométrico del mineral de manganeso del yacimiento "Margarita de Cambute", en
Cuba. Sobre la base de los resultados de caracterización, se establece un plan de síntesis del
fundente consistente en definir como condición básica el rango de valores de la relación
MnO/Si02. La estrategia planteada se corrobora experimentalmente, mediante la
obtención de un prototipo de fundente en homo eléctrico del arco acoplado a una fuente
de corriente continua y la realización de ensayos del fundente en la soldadura.[EN] Chemical analysis, thermal analysis (DTA and TG), phase determination by X-ray
diffraction and granulometric analysis of the manganese ore from the location "Margarita
de Cambute" in the eastern part of Cuba were carried out. Based on these characterization
results, a flux synthesis strategy was established, comprising the definition, as a basic
condition, of the MnO/Si02 range of values. This strategy was confirmed experimentally
by obtaining a flux prototype in an electric arc furnace connected to direct current source
and the carrying out of the flux in submerged arc welding tests.Peer reviewe
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