385 research outputs found
High cycle fatigue of ARMCO iron severely deformed by ECAP
The high-cycle fatigue behavior of ARMCO iron severely deformed by Equal Channel Angular Pressing (ECAP) at room temperature through route Bc until 8 passes, with an average grain size of ~365 nm, was studied and compared with the same material in the annealed state with an average grain size of ~72 µm. The fatigue limit of the 8 passes ECAPed sample increased with respect to the annealed material by more than 250% rising from 274 MPa to 717 MPa. Striations and dimpled relief were observed on the fracture surfaces of the fatigued ultrafine and coarse grain fatigue samples. The microstructure was characterized by Electron Backscattered Diffraction (EBSD) before and after the fatigue tests and it was observed in both samples an increment in the fraction of Low Angle Grain Boundaries (LAGB) at high number of cycles to failure. A texture analysis for the materials after the fatigue failure was done. This study shown a preferential orientation towards the ¿ fiber for both conditions.Peer ReviewedPostprint (author's final draft
Study of the formation of Cu-24at.% Al by reactive milling
In this work, powders of Cu and Al were milled with a proportion equal to 24 atomic % Al, using low and medium energy mills. The initial, intermediate and final stages of the resulting powder are analyzed using scanning electron microscopy, X-ray diffraction and different transmission electron microscopy techniques. The structure and microstructure achieved in each step of the milling process are compared to the results of Cu-16at.%Al and Cu-30at.%Al obtained under the same conditions of reactive milling. At the final stage of milling, it was detected that the obtained intermetallic is not the equilibrium phase of the Cu-Al system.Fil: Giordana, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Muñoz Vásquez, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Garro González, M.. Universidad de Costa Rica; Costa RicaFil: Esquivel, Marcelo Ricardo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; ArgentinaFil: Zelaya, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentin
Advances in Understanding the Molecular Basis of the Mediterranean Diet Effect
Posted with permission from the Annual Review of Food Science and Technology, Volume 9 by Annual Reviews, http://www.annualreviews.org.Increasingly, studies showing the protective effects of the Mediterranean diet (MedDiet) on different diseases (cardiovascular, diabetes, some cancers, and even total mortality and aging indicators) are being published. The scientific evidence level for each outcome is variable, and new studies are needed to better understand the molecular mechanisms whereby the MedDiet may exercise its effects. Here, we present recent advances in understanding the molecular basis of MedDiet effects, mainly focusing on cardiovascular diseases but also discussing other related diseases. There is heterogeneity in defining the MedDiet, and it can, owing to its complexity, be considered as an exposome with thousands of nutrients and phytochemicals. We review MedDiet composition and assessment as well as the latest advances in the genomic, epigenomic (DNA methylation, histone modifications, microRNAs, and other emerging regulators), transcriptomic (selected genes and whole transcriptome), and metabolomic and metagenomic aspects of the MedDiet effects (as a whole and for its most typical food components). We also present a critical review of the limitations of the studies undertaken and propose new analyses and greater bioinformatic integration to better understand the most important molecular mechanisms whereby the MedDiet as a whole, or its main food components, may exercise their protective effects
Sharing gNB components in RAN slicing: A perspective from 3GPP/NFV standards
To implement the next Generation NodeBs (gNBs) that are present in every
Radio Access Network (RAN) slice subnet, Network Function Virtualization (NFV)
enables the deployment of some of the gNB components as Virtual Networks
Functions (VNFs). Deploying individual VNF instances for these components could
guarantee the customization of each RAN slice subnet. However, due to the
multiplicity of VNFs, the required amount of virtual resources will be greater
compared to the case where a single VNF instance carries the aggregated traffic
of all the RAN slice subnets. Sharing gNB components between RAN slice subnets
could optimize the trade-off between customization, isolation and resource
utilization. In this article, we shed light on the key aspects in the Third
Generation Partnership Project (3GPP)/NFV standards for sharing gNB components.
First, we identify four possible scenarios for sharing gNB components. Then, we
analyze the impact of sharing on the customization level of each RAN slice
subnet. Later, we determine the main factors that enable isolation between RAN
slice subnets. Finally, we propose a 3GPP/NFV-based description model to define
the lifecycle management of shared gNB componentsComment: Article accepted for publication in IEEE Conference on Standards and
Networking (CSCN) 201
Microstructural and mechanical study in the plastic zone of ARMCO iron processed by ECAP
Plastic deformation of ARMCO iron processed by ECAP up to a maximum equivalent strain of sixteen (i.e., 1, 4, 8, and 16 ECAP passes) following route Bc was investigated by analyzing its microstructure and the stress-strain curves obtained after tensile tests at different levels of deformation. Three values of deformation (two in the plastic region taking into account the modified Crussard-Jaoul analysis and one after failure) were considered. Fractions of LAGB and HAGB, grain size and grain aspect ratio were calculated and compared for the different ECAP passes and tensile deformation levels. The dislocation density evolution calculated by the Bergström model for both the tensile curves and the ECAP curve showed a higher increase in the amount of dislocations during the initial stages of deformation than at higher values of deformation due to higher probabilities of dislocations annihilation. The strain hardening exponents calculated via the Bergström model for each ECAP pass shows that there is a continuous decrease in the strain hardening capacity until the eighth pass where a small increase with a subsequent stabilization was found. The dislocation densities calculated by the Estrin model presented a good correlation with values reported in bibliography for iron especially with those calculated by X-ray diffraction. This latter model predicted well the strain hardening evolution for stages III, IV and V for ARMCO iron processed by ECAP, where the main increments in hardening for stages IV and V were coming from the cell interiors.Preprin
Dislocation study of ARMCO iron processed by ECAP
The aim of this work was to study the deformation behavior of an Armco iron after severe plastic deformation by equal channel angular pressing (ECAP). Particular attention was paid to predict the dislocation density by different approaches like the model proposed by Bergström. Experimental measures of dislocation density by different techniques are used in the discussion. Cylindrical samples of ARMCO iron (8mm of diameter, 60mm of length) were subjected to ECAP deformation using a die with an intersecting channel of F=90° and outer arc of curvature of ¿= 37° die. Samples were deformed for up to 16 ECAP passes following route Bc. The mechanical properties of the material were measured after each pass by tensile tests. The original grain size of the annealed iron (70 µm) was drastically reduced after ECAP reaching grain sizes close to 300nm after 16 passes.Peer ReviewedPostprint (author's final draft
Kesici-delici alet yaralanmalarında penetran kardiyak travma: Kardiyak bölgenin doğru tanısına ilişkin bir çalışma
BACKGROUND: Stab wounds (SW) to the thorax raises suspicion for cardiac injuries; however, the topographic description is variable. The present study aims to evaluate different topographical descriptions within the thorax and establish their diagnostic value in penetrating cardiac trauma by SW.
METHODS: Medical records of all patients admitted to our center with thoracic SW from January 2013 to June 2016 were included in this study. Diagnostic value potential was measured using different areas of the thorax described in the literature.
RESULTS: In this study, we analyzed 306 cases. Thirty-eight (12.4%) patients had a cardiac injury managed surgically. Death by cardiac injury occurred in seven (18.4%) patients. The cardiac area defined between the right mid-clavicle line until the left anterior axillary line, and between 2nd and 6th intercostal spaces was the more accurate. It has sensitivity of 97.3%, specificity 72%, positive predictive value 33%, negative predictive value 99.4% and accuracy 75.1% for penetrating cardiac trauma. ROC was 0.894 IC 95% (0.760–0.901).
CONCLUSION: Among the thoracic areas, topographical limits between the right mid-clavicle line and the left anterior axillary line, and between 2nd and 6th intercostal spaces are the more accurate and are highly indicative of cardiac injury in patients with SW to the thorax
Identifying Topics in Social Media Posts using DBpedia
This paper describes a method for identifying topics in text published in social media, by applying topic recognition techniques that exploit DBpedia. We evaluate such method for social media in Spanish and we provide the results of the evaluation performed
Early and sustained increase in time in range 1 year after initiation of hybrid close loop therapy via telemedicine in type 1 diabetes patients
La evidencia respalda la eficacia y seguridad del sistema Hybrid Close Loop (HCL) en pacientes con diabetes tipo 1 (DT1). Sin embargo, hay datos limitados disponibles sobre los resultados a largo plazo de los pacientes que reciben HCL con seguimiento por telemedicina.
Métodos
Un estudio de cohorte observacional prospectivo que incluyó pacientes con diabetes Tipo 1 que estaban actualizando al sistema HCL. La capacitación virtual y el seguimiento se realizaron a través de telemedicina. Los datos de MCG se analizaron para comparar el tiempo inicial dentro del rango (TIR), el tiempo por debajo del rango (TBR), la variabilidad glucémica y el modo automático (AM), con mediciones realizadas a los 3, 6 y 12 meses.
Resultados
Se incluyeron 134 pacientes con A1c basal 7,6% ± 1,1. El 40,5% tuvo algún evento de hipoglucemia grave en el último año. La TIR inicial, medida dos semanas después de comenzar AM, fue de 78,6 ± 9,94 %. No se observaron cambios evidentes a los tres (diferencia de medias − 0,15; IC-2,47; 2,17; p = 0,96), seis (MD-1,09; IC-3,42, 1,24; p = 0,12) y 12 meses (MD-1,30; IC-3,64). <1,04; p = 0,08). No se encontraron cambios significativos en la TBR ni en la variabilidad glucémica a lo largo del seguimiento. El uso de AM fue de 85,6 ± 17,5% y el porcentaje de uso de sensor fue de 88,75 ± 9,5% a los 12 meses. No se informaron eventos de hipoglucemia (SH) graves.
Conclusiones
Los sistemas HCL permiten mejorar TIR, TBR y variabilidad glucémica de forma segura, temprana y sostenida hasta 1 año de seguimiento en pacientes con DM1 y alto riesgo de hipoglucemia seguidos a través de telemedicina.Q1Background and Aims
Evidence supports the efficacy and safety of the Hybrid Close loop (HCL) system in patients with type 1 diabetes (T1D). However, limited data are available on the long-term outcomes of patients on HCL with telemedicine follow-up.
Methods
A prospective observational cohort study including T1D patients, who were upgrading to HCL system. Virtual training and follow-up were done through telemedicine. CGM data were analyzed to compare the baseline time in range (TIR), time below range (TBR), glycemic variability and auto mode (AM), with measurements performed at 3, 6 and 12 months.
Results
134 patients were included with baseline A1c 7.6% ± 1.1. 40.5% had a severe hypoglycemia event in the last year. Baseline TIR, measured two weeks after starting AM was 78.6 ± 9.94%. No changes were evident at three (Mean difference − 0.15;CI-2.47,2.17;p = 0.96), six (MD-1.09;CI-3.42,1.24;p = 0.12) and 12 months (MD-1.30;CI-3.64,1.04;p = 0.08). No significant changes were found in TBR or glycemic variability throughout the follow-up. Use of AM was 85.6 ± 17.5% and percentage of use of sensor was 88.75 ± 9.5% at 12 months. No severe hypoglycemic (SH) events were reported.
Conclusions
HCL systems allow to improve TIR, TBR and glycemic variability safely, early and sustained up to 1 year of follow-up in patients with T1D and high risk of hypoglycemia followed through telemedicine.Revista Internacional - IndexadaS
Microstructure characterization of metallic materials processed by Equal Channel Angular Pressing (ECAP): an Electron Backscatter Diffraction (EBSD) analysis
This overview article discusses the Equal Channel Angular Pressing (ECAP) processing of different metallic materials. Particular emphasis is given to the microstructural evolution from the coarse grain (CG) to the ultrafine-grained (UFG) states throughout the electron backscattering diffraction (EBSD) technique. Iron-based alloys, such as duplex and 1020 low-carbon steels reached higher hardening with a lower deformation and lower non-ultrafine average grain sizes than the ultrafine pure iron condition due to fast grain fragmentation, i.e., more geometrically necessary dislocation (GND) grouping. Moreover, due to the magnesium adhesion, copper alloys reached superior mechanical properties compared to pure copper even when the initial grain size for as-cast alloys was over 1000 µm. On the other hand, low melting temperature (T MP) materials processed at 250°C, like the ZK60 magnesium and AA6082 aluminum alloys (i.e., homologous temperatures (TH) of 0.38T MP and 0.37T MP, respectively), showed grain refinement without reaching the ultrafine regime and mechanical softening due to the static and dynamic recrystallization phenomena. CP titanium also displayed heterogeneous grain sizes with average values of above 1 µm after four ECAP passes for temperatures ranging between 150°C and 400°C (TH between 0.09T MP ¹ 0.24TMP). The evolution of the GNDs suggested that the initial deformation stages of severe plastic deformation (SPD) by ECAP produced the most notorious density increments from 10 12 m¹2 to 1014 m¹2 , which level up at high deformations (more than four ECAP passes) around 1014 1015 m¹2 , explaining the fast and slow grain size reduction rates, respectively. The ECAP processing on different metallic material systems showed a larger grain fragmentation capacity in high melting points and alloyed materials, giving rise to steep yield strength increases and low ductility. The low ductility and grain size saturation correspond to a low capacity to create new grain boundaries manifested by the GNDs saturation in the UFG range.Peer ReviewedPostprint (published version
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