Spheroidization of iron powders by radiative heat transfer

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999.Includes bibliographical references (leaves 45-46).by Rodrigo Javier Quintero de la Garza.S.M

Actitudes de los estudiantes hacia la enseñanza de la RSE en posgrados de negocios

El tipo de investigación es de tipo documental y cualitativo con carácter descriptivo y explicativo. Se utilizaron datos obtenidos del Aspen Institute Center for Business Education, basados en encuestas aplicadas a 15 escuelas de negocios para medir las actitudes de los estudiantes hacia la relación entre negocios y sociedad. En estos casos, se evaluaron y analizaron las siguientes dimensiones de estudio: Definición de Éxito en los Negocios, Liderazgo y Valores de Negocios y Preparación de la Escuela de Negocio

Influencia de los factores de implementación en la calidad de los sistemas de información para la satisfacción del usuario

This research studies the influence range of the organizational, planning and technical factors within the information quality, system quality and information systems services quality, in the user satisfaction, based on the designed model research for this purpose. The empirical study takes place in six Higher Education Institutes (94 questionnaires) by the Partial Least Square statistic tool. The results has shown that Organizational Factor (information needs, management support, institutional objectives satisfaction) is which has the most impact because its high correlation value (R=0.624; R=0.435 yR=0.428) and signifi cance (pEsta investigación estudia el nivel de influencia de los factores organizacional, planificación y técnico con la calidad de la Información, del sistema y de los servicios en la satisfacción del usuario, basado en un modelo diseñado para este propósito. El estudio empírico hecho en seis universidades mexicanas por medio de PLS, muestra que el Factor Organizacional es el que tiene un mayor impacto por sus altos valores de correlación (R=0.624; R=0.435 y R=0.428) y significancia en las tres hipótesis planteadas con una varianza explicada del 78.8% en la Satisfacción del Usuario, quienes piensan que la calidad de los sistemas les ayudan a aumentar la productividad en su toma de decisiones

Análisis de la escala etnocentrista CETSCALE en Cd. Victoria, Tamaulipas. Un estudio exploratorio

Ethnocentrism has become a relevant aspect for consumers because it is part of their self-identification with their country and the world. The purpose of this research is to identify ethnocentrism factors in the sector of alcoholic beverages (beer) using the CETSCALE measurement scale. To achieve this objective, a quantitative research was designed and a survey was applied to 469 consumers in Victoria, Tamaulipas. The methodology used for the statistical treatment of the data was performed using factor analysis. The results indicate that, in an exploratory phase and unlike previous research in Mexico, ethnocentrism in the Mexican context has three dimensions: protectionism, economic-moral, and preservation. Therefore in regards to beer, the CETSCALE becomes multidimensional.El etnocentrismo se ha convertido en un aspecto relevante para los consumidores ya que forma parte de su identidad con su nación y el mundo. El propósito de esta investigación es determinar los factores de etnocentrismo en el sector de bebidas alcohólicas (cerveza), mediante la utilización de la escala CETSCALE. Para lograr dicho objetivo se diseñó una investigación cuantitativa y se aplicó un cuestionario en Cd. Victoria, Tamaulipas a 469 consumidores. La metodología utilizada para el tratamiento estadístico de los datos se llevó a cabo mediante un análisis factorial. Los resultados indican que, en una fase exploratoria y a diferencia de lo indicado por investigaciones previas realizadas en México, el etnocentrismo en el contexto bajo estudio contiene tres dimensiones: proteccionista, económica-moral y preservación. Por lo tanto, en lo que respecta a la cerveza, el CETSCALE se convierte en un modelo multidimensional

Temporal relationship of serum markers and tissue damage during acute intestinal ischemia/reperfusion

OBJECTIVE: It is essential to identify a serological marker of injury in order to study the pathophysiology of intestinal ischemia reperfusion. In this work, we studied the evolution of several serological markers after intestinal ischemia reperfusion injury in rats. The markers of non-specific cell damage were aspartate aminotransferase, alanine aminotransaminase, and lactic dehydrogenase, the markers of inflammation were tumor necrosis factor alpha, interleukin-6, and interleukin-1 beta, and the markers of intestinal mucosal damage were intestinal fatty acid binding protein and D-lactate. We used Chiús classification to grade the histopathological damage. METHODS: We studied 35 Wistar rats divided into groups according to reperfusion time. The superior mesenteric artery was clamped for 30 minutes, and blood and biopsies were collected at 1, 3, 6, 12, 24, and 48 hours after reperfusion. We plotted the mean ± standard deviation and compared the baseline and maximum values for each marker using Student's t-test. RESULTS: The maximum values of interleukin-1 beta and lactic dehydrogenase were present before the maximal histopathological damage. The maximum tumor necrosis factor alpha and D-lactate expressions coincided with histopathological damage. Alanine aminotransaminase and aspartate aminotransferase had a maximum expression level that increased following the histopathological damage. The maximum expressions of interluken-6 and intestinal fatty acid binding protein were not significantly different from the Sham treated group. CONCLUSION: For the evaluation of injury secondary to acute intestinal ischemia reperfusion with a 30 minute ischemia period, we recommend performing histopathological grading, quantification of D-lactate, which is synthesized by intestinal bacteria and is considered an indicator of mucosal injury, and quantification of tumor necrosis factor alpha as indicators of acute inflammation three hours after reperfusion

Temporal relationship of serum markers and tissue damage during acute intestinal ischemia/reperfusion

OBJECTIVE: It is essential to identify a serological marker of injury in order to study the pathophysiology of intestinal ischemia reperfusion. In this work, we studied the evolution of several serological markers after intestinal ischemia reperfusion injury in rats. The markers of non-specific cell damage were aspartate aminotransferase, alanine aminotransaminase, and lactic dehydrogenase, the markers of inflammation were tumor necrosis factor alpha, interleukin-6, and interleukin-1 beta, and the markers of intestinal mucosal damage were intestinal fatty acid binding protein and D-lactate. We used Chius classification to grade the histopathological damage. METHODS: We studied 35 Wistar rats divided into groups according to reperfusion time. The superior mesenteric artery was clamped for 30 minutes, and blood and biopsies were collected at 1, 3, 6, 12, 24, and 48 hours after reperfusion. We plotted the mean ¡ standard deviation and compared the baseline and maximum values for each marker using Student’s t-test. RESULTS: The maximum values of interleukin-1 beta and lactic dehydrogenase were present before the maximal histopathological damage. The maximum tumor necrosis factor alpha and D-lactate expressions coincided with histopathological damage. Alanine aminotransaminase and aspartate aminotransferase had a maximum expression level that increased following the histopathological damage. The maximum expressions of interluken-6 and intestinal fatty acid binding protein were not significantly different from the Sham treated group. CONCLUSION: For the evaluation of injury secondary to acute intestinal ischemia reperfusion with a 30 minute ischemia period, we recommend performing histopathological grading, quantification of D-lactate, which is synthesized by intestinal bacteria and is considered an indicator of mucosal injury, and quantification of tumor necrosis factor alpha as indicators of acute inflammation three hours after reperfusion

Towards precision medicine: defining and characterizing adipose tissue dysfunction to identify early immunometabolic risk in symptom-free adults from the GEMM family study

Interactions between macrophages and adipocytes are early molecular factors influencing adipose tissue (AT) dysfunction, resulting in high leptin, low adiponectin circulating levels and low-grade metaflammation, leading to insulin resistance (IR) with increased cardiovascular risk. We report the characterization of AT dysfunction through measurements of the adiponectin/leptin ratio (ALR), the adipo-insulin resistance index (Adipo-IRi), fasting/postprandial (F/P) immunometabolic phenotyping and direct F/P differential gene expression in AT biopsies obtained from symptom-free adults from the GEMM family study. AT dysfunction was evaluated through associations of the ALR with F/P insulin-glucose axis, lipid-lipoprotein metabolism, and inflammatory markers. A relevant pattern of negative associations between decreased ALR and markers of systemic low-grade metaflammation, HOMA, and postprandial cardiovascular risk hyperinsulinemic, triglyceride and GLP-1 curves was found. We also analysed their plasma non-coding microRNAs and shotgun lipidomics profiles finding trends that may reflect a pattern of adipose tissue dysfunction in the fed and fasted state. Direct gene differential expression data showed initial patterns of AT molecular signatures of key immunometabolic genes involved in AT expansion, angiogenic remodelling and immune cell migration. These data reinforce the central, early role of AT dysfunction at the molecular and systemic level in the pathogenesis of IR and immunometabolic disorders

Hispanic health in the USA: a scoping review of the literature

Hispanics are the largest minority group in the USA. They contribute to the economy, cultural diversity, and health of the nation. Assessing their health status and health needs is key to inform health policy formulation and program implementation. To this end, we conducted a scoping review of the literature and national statistics on Hispanic health in the USA using a modified social-ecological framework that includes social determinants of health, health disparities, risk factors, and health services, as they shape the leading causes of morbidity and mortality. These social, environmental, and biological forces have modified the epidemiologic profile of Hispanics in the USA, with cancer being the leading cause of mortality, followed by cardiovascular diseases and unintentional injuries. Implementation of the Affordable Care Act has resulted in improved access to health services for Hispanics, but challenges remain due to limited cultural sensitivity, health literacy, and a shortage of Hispanic health care providers. Acculturation barriers and underinsured or uninsured status remain as major obstacles to health care access. Advantageous health outcomes from the “Hispanic Mortality Paradox” and the “Latina Birth Outcomes Paradox” persist, but health gains may be offset in the future by increasing rates of obesity and diabetes. Recommendations focus on the adoption of the Health in All Policies framework, expanding access to health care, developing cultural sensitivity in the health care workforce, and generating and disseminating research findings on Hispanic health

Effect of alirocumab on mortality after acute coronary syndromes. An analysis of the ODYSSEY OUTCOMES randomized clinical trial

Background: Previous trials of PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitors demonstrated reductions in major adverse cardiovascular events, but not death. We assessed the effects of alirocumab on death after index acute coronary syndrome. Methods: ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) was a double-blind, randomized comparison of alirocumab or placebo in 18 924 patients who had an ACS 1 to 12 months previously and elevated atherogenic lipoproteins despite intensive statin therapy. Alirocumab dose was blindly titrated to target achieved low-density lipoprotein cholesterol (LDL-C) between 25 and 50 mg/dL. We examined the effects of treatment on all-cause death and its components, cardiovascular and noncardiovascular death, with log-rank testing. Joint semiparametric models tested associations between nonfatal cardiovascular events and cardiovascular or noncardiovascular death. Results: Median follow-up was 2.8 years. Death occurred in 334 (3.5%) and 392 (4.1%) patients, respectively, in the alirocumab and placebo groups (hazard ratio [HR], 0.85; 95% CI, 0.73 to 0.98; P=0.03, nominal P value). This resulted from nonsignificantly fewer cardiovascular (240 [2.5%] vs 271 [2.9%]; HR, 0.88; 95% CI, 0.74 to 1.05; P=0.15) and noncardiovascular (94 [1.0%] vs 121 [1.3%]; HR, 0.77; 95% CI, 0.59 to 1.01; P=0.06) deaths with alirocumab. In a prespecified analysis of 8242 patients eligible for ≥3 years follow-up, alirocumab reduced death (HR, 0.78; 95% CI, 0.65 to 0.94; P=0.01). Patients with nonfatal cardiovascular events were at increased risk for cardiovascular and noncardiovascular deaths (P<0.0001 for the associations). Alirocumab reduced total nonfatal cardiovascular events (P<0.001) and thereby may have attenuated the number of cardiovascular and noncardiovascular deaths. A post hoc analysis found that, compared to patients with lower LDL-C, patients with baseline LDL-C ≥100 mg/dL (2.59 mmol/L) had a greater absolute risk of death and a larger mortality benefit from alirocumab (HR, 0.71; 95% CI, 0.56 to 0.90; Pinteraction=0.007). In the alirocumab group, all-cause death declined wit h achieved LDL-C at 4 months of treatment, to a level of approximately 30 mg/dL (adjusted P=0.017 for linear trend). Conclusions: Alirocumab added to intensive statin therapy has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for ≥3 years, if baseline LDL-C is ≥100 mg/dL, or if achieved LDL-C is low. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01663402

Increasing the lifetime of a couple of cutting blades for pipe

Badania mają na celu zwiększenie trwałości noży do cięcia rur. Średnia trwałość pary noży wynosi około dwie zmiany, po czym następują wykruszenia i zużycie powodujące złą jakość powierzchni cięcia i przestoje linii produkcyjnej. Obecnie noże te są wykonane ze stali D2 (1,5% C, 12% Cr, 1% V). Stal ta jest odporna na zużycie, ale krucha i niezbyt sprawdzająca się w warunkach dynamicznych procesu cięcia. Poszukując poprawy właściwości mechanicznych, a w szczególności lepszej udarności zaproponowano obróbkę kriogeniczną (podzerową), która powinna zwiększyć odporność na ścieranie stali D2 do 10 razy, zmniejszając również jej kruchość. Obróbka podzerowa prezentuje również dobre wyniki w przypadku innych badanych materiałów (S7, H13, M2, Cr8). Dodatkowo dla zwiększenia trwałości noży zastosowano różne pokrycia PVD, które powodują wielokrotny wzrost odporności na zużycie. Badania tribologiczne zostały wykonane na maszynie T-05 (blok on ring) zaprojektowanej i wyprodukowanej w Instytucie Technologii Eksploatacji w Radomiu.This investigation seeks to increase the lifetime of a couple of cutting blades pipe. The average life of this pair of blades is about two working shifts, and these blades have fracture and wear problems, which result in line stoppage and bad cuts in the pipes. These blades are currently made of D2 steel (1.5% C, 12% Cr, 1% V), which is a strong but brittle steel, and the process is quite fast and is under severe impact conditions. Searching to increase the mechanical properties, such as toughness and impact resistance, the utilization of a cryogenic treatment (sub-zero) has been proposed. The investigated cryogenic treatment increases the wear resistance in steel D2 ten times and also presents good results in other investigated materials (S7, H13, M2, Cr8) applying different PVD coatings in which the lifetime increases to reach 200%. The tribological tests were done with the T-05 (block on ring) equipment designed by the Institute for Sustainable Technologies in Radom, Poland, to analyse the eroded volume for each specimen