Optimización del Tratamiento Térmico de Productos Tubulares de Acero

[Optimization of Heat Treatment of Steel Tubular Products] El problema a abordar es el de la optimización del tratamiento térmico de productos tubulares de acero, presente en la empresa siderúrgica Tenaris. Más específicamente, se estudia el problema de dar un tratamiento adecuado a cargas retenidas en el horno de revenido. En este caso, el tratamiento térmico se compone de un primer calentamiento de los tubos a temperaturas cercanas a los 900°C, en el que se austeniza el material, seguido por un enfriamiento rápido en el que el material se transforma en martensita. Esta etapa constituye el templado del acero. Para lograr las propiedades metalúrgicas finales especificadas para el producto se realiza un segundo calentamiento a temperaturas entre 500 y 700°C, que se denomina revenido. Para simplificar el análisis, en este trabajo se considera una única propiedad metalúrgica, la dureza, que para el producto que se analiza debe estar en el rango de 270-300 Hv

Influence of Clocking Strategies on the Design of Low Switching-Noise Digital and Mixed-Signal VLSI Circuits

This communication shows the influence of clocking schemes on the digital switching noise generation. It will be shown how the choice of a suited clocking scheme for the digital part reduces the switching noise, thus alleviating the problematic associated to limitations of performances in mixed-signal Analog/Digital Integrated Circuits. Simulation data of a pipelined XOR chain using both a single-phase and a two-phase clocking schemes, as well as of two nbit counters with different clocking styles lead, as conclusions, to recommend multiple clock-phase and asynchronous styles for reducing switching noise

Antagonistic Interaction of Selenium and Cadmium in Human Hepatic Cells Through Selenoproteins

Cadmium (Cd) is a highly toxic heavy metal for humans and animals, which is associated with acute hepatotoxicity. Selenium (Se) confers protection against Cd-induced toxicity in cells, diminishing the levels of ROS and increasing the activity of antioxidant selenoproteins such as glutathione peroxidase (GPx). The aim of this study was to evaluate the antagonistic effect of selenomethionine (SeMet) against Cd toxicity in HepG2 cells, through the modulation of selenoproteins. To this end, the cells were cultured in the presence of 100 µM SeMet and 5 µM, 15 µM, and 25 µM CdCl2 and a combination of both species for 24 h. At the end of the experiment, cell viability was determined by MTT assay. The total metal content of Cd and Se was analyzed by triple-quadrupole inductively coupled plasma–mass spectrometry (ICP-QqQ-MS). To quantify the concentration of three selenoproteins [GPx, selenoprotein P (SELENOP), and selenoalbumin (SeAlb)] and selenometabolites, an analytical methodology based on column switching and a species-unspecific isotopic dilution approach using two-dimensional size exclusion and affinity chromatography coupled to ICP-QqQ-MS was applied. The co-exposure of SeMet and Cd in HepG2 cells enhanced the cell viability and diminished the Cd accumulation in cells. Se supplementation increased the levels of selenometabolites, GPx, SELENOP, and SeAlb; however, the presence of Cd resulted in a significant diminution of selenometabolites and SELENOP. These results suggested that SeMet may affect the accumulation of Cd in cells, as well as the suppression of selenoprotein synthesis induced by Cd.This work was supported by the projects PG2018-096608-B-C21 from the Spanish Ministry of Economy and Competitiveness (MINECO). SR-A thanks the Spanish Ministry of Economy and Competitiveness for a PhD scholarship (BES-2016-076364). The authors are grateful to FEDER (European Community) for financial support, grant UNHU13-1E-1611

Estrogen receptors α and β and progesterone receptors in normal bovine ovarian follicles and cystic ovarian disease

The purpose of this study was to determine by immunohistochemistry the expression of estrogen and progesterone receptors in ovarian follicular structures from cows with cystic ovarian disease (COD) and to compare these with normal ovarian structures. Secondary, tertiary, atretic, and cystic follicles were evaluated. The follicular cysts of animals with COD presented a significantly higher expression of estrogen receptor a in all follicular layers than secondary, tertiary, and atretic follicles in both groups (P < .05). The intensity of estrogen receptor β in the granulosa cell layer was stronger in tertiary than in secondary and atretic follicles in normal animals (P < .05) and in growing and cystic follicles in animals with COD (P < .05). Theca cells were scarcely stained in the 2 groups. Growing follicles and cysts from COD animals were less stained than tertiary follicles from normal animals (P < .05). Differences did not exist between the 2 groups with regard to the progesterone receptor. Ovaries of animals with COD exhibited altered estrogen receptors expression compared with that in normal animals.Facultad de Ciencias Veterinaria

Interaction of 8 He with 208Pb at near-barrier energies: 4 He and 6 He production

Spanish Ministry of Economy and Competitiveness-FPA-2010-22131-CO2-01 (FINURA) y FPA2013-47327-C2-1-RMinistry of Science and Higher Education of Poland-N202 033637National Science Centre of Poland-2013/08/M/ST2/00257 (LEA-COPIGAL) y 2014/14/M/ST2/00738 (COPIN-INFN Collaboration)European Science Foundation-EUI2009-04163432 (EUROGENESIS

Estrogen receptors α and β and progesterone receptors in normal bovine ovarian follicles and cystic ovarian disease

The purpose of this study was to determine by immunohistochemistry the expression of estrogen and progesterone receptors in ovarian follicular structures from cows with cystic ovarian disease (COD) and to compare these with normal ovarian structures. Secondary, tertiary, atretic, and cystic follicles were evaluated. The follicular cysts of animals with COD presented a significantly higher expression of estrogen receptor a in all follicular layers than secondary, tertiary, and atretic follicles in both groups (P < .05). The intensity of estrogen receptor β in the granulosa cell layer was stronger in tertiary than in secondary and atretic follicles in normal animals (P < .05) and in growing and cystic follicles in animals with COD (P < .05). Theca cells were scarcely stained in the 2 groups. Growing follicles and cysts from COD animals were less stained than tertiary follicles from normal animals (P < .05). Differences did not exist between the 2 groups with regard to the progesterone receptor. Ovaries of animals with COD exhibited altered estrogen receptors expression compared with that in normal animals.Facultad de Ciencias Veterinaria

Impact of an intermittent and localized cooling intervention on skin temperature, sleep quality and energy expenditure in free-living, young, healthy adults

Where people live and work together it is not always possible to modify the ambient temperature; ways must therefore be found that allow individuals to feel thermally comfortable in such settings. The Embr Wave (R) is a wrist-worn device marketed as a 'personal thermostat' that can apply a local cooling stimulus to the skin. The aim of the present study was to determine the effect of an intermittent mild cold stimulus of 25 degrees C for 15-20 s every 5 min over 3.5 days under free-living conditions on 1) skin temperature, 2) perception of skin temperature, 3) sleep quality and 4) resting energy expenditure (REE) in young, healthy adults. Ten subjects wore the device for 3.5 consecutive days. This intervention reduced distal skin temperature after correcting for personal ambient temperature (P = 0.051). Thus, this intermittent mild cold regime can reduce distal skin temperature, and wearing it under free-living conditions for 3.5 days does not seem to impair the perception of skin temperature and sleep quality or modify REE.The study was funded by the Spanish Ministry of Economy and Competitiveness via the Fondo de Investigacion Sanitaria del Instituto de Salud Carlos III (PI13/01393 and CB16/10/00239) and PTA 12264-I, Retos de la Sociedad (DEP2016-79512-R), and European Regional Development Funds (ERDF). Other funders included the Spanish Ministry of Education (FPU 16/05159, 15/04059 and 19/02326), the Fundacion Iberoamericana de Nutricion (FINUT), the Redes Tematicas De Investigacion Cooperativa RETIC (Red SAMID RD16/0022), the AstraZeneca Health Care Foundation, the University of Granada Plan Propio de Investigacion 2016 (Excellence actions: Unit of Excellence on Exercise, Nutrition and Health [UCEENS]), and by the Junta de Andalucia, Consejeria de Conocimiento, Investigacion y Universidades (ERDF, SOMM17/6107/UGR). AMT was supported by Seneca Foundation through grant 19899/GERM/15 and the Ministry of Science Innovation and Universities RTI2018-093528-B-I0, as well as DJP (MINECO; RYC-2014-16938). BMT was supported by an individual postdoctoral grant from the Fundacion Alfonso Martin Escudero. We thank Dr. Matt Smith of Embr Labs Inc. for configuring the Embr Wave (R) devices used in this experiment

Effect of lanthanum on the catalytic properties of PtSn/γ-Al2O3 bimetallic catalysts prepared by successive impregnation and controlled surface reaction.

Bimetallic PtSn/γ -Al2O3–La2O3 catalysts were prepared by two comparative methods, successive impregnation (SI) and controlled surface reaction (CSR). FTIR-pyridine adsorption revealed a decrease in support acidity as a function of lanthanum content. Oxidized Pt2+ was identified by CO-FTIR chemisorption and by XPS spectra on catalysts prepared by SI. When the CSR preparation method was used, reduced Pt0 was observed and oxidized Pt2+ was not detected. As the lanthanum content increased a diminution in cyclohexane dehydrogenation and n-heptane conversion was observed. Low hydrogenolysis and high selectivity to C7-olefins were obtained in both preparations. It is proposed that lanthanum in SI catalysts stabilizes the platinum in an oxidation state, Pt2+, and diminishes the support acidity. In CSR preparations the lanthanum effect is limited to inhibit the support acidity and hence to the bifunctional reactions occurring during the n-heptane conversion

Prolactin secretion in high altitude natives

Objetivos: Determinar el efecto de la hipoxia crónica sobre la secreción de prolactina. Diseño: Estudio comparativo. Institución: Servicio de Endocrinología, Hospital Nacional Arzobispo Loayza, Lima, Perú. Participantes: Hombres jóvenes nativos de Lima y Cerro de Pasco. Intervenciones: Se estudió en forma dinámica tres grupos de hombres jóvenes normales de edad (X24a) y estado nutricional comparable, nativos de diferentes altitudes: 150 m.s.n.m. (Lima, N=10), 3 000 m.s.n.m. (Tarma, N= 10), 4 200 m.s.n.m. (Cerro de Pasco, n=11); y tres pacientes con mal de montaña crónico (MMC) nativos de Cerro de Pasco; todos clínicamente eutiroideos y sin bocio. En cada sujeto se determinó por RIA los niveles séricos basales de PRL y su respuesta. Principales medidas de resultados: Diferencia de niveles séricos de prolactina y su respuesta máxima a la hormona liberadora de tirotropina en sujetos a nivel del mar y en la altura. Resultados: Los niveles séricos basales de prolactina (PRL) y su respuesta máxima a la hormona liberadora de tirotropina (TRH) fueron significativamente menores en los nativos de altura en comparación con los del nivel del mar. La causa subyacente sería la hipoxia crónica, pudiendo estar implicados un incremento de la actividad dopaminérgica del sistema túbero – infundibular o una alteración a nivel del receptor o posreceptor del lactotrofo en los nativos de altura. Este hecho puede ser un mecanismo de adaptación para la conservación de la fertilidad en los hombres nativos de las grandes alturas. El escaso número de pacientes con mal de montaña crónico no permitió obtener resultados concluyentes, pero se observó persistencia de la menor secreción de prolactina, con una respuesta más tardía a la TRH. Se requiere más investigaciones en pacientes con MMC, para definir estas observaciones. Conclusiones: Los niveles séricos basales de prolactina y su respuesta máxima a la hormona liberadora de tirotropina fueron significativamente menores en los nativos de altura en comparación con los del nivel del mar.Objectives: To determine the effect of chronic hypoxia on prolactin (PRL) secretion. Design: Comparative study. Setting: Endocrinology service, Hospital Nacional Arzobispo Loayza, Lima, Peru. Participants: Native young men from Lima and Cerro de Pasco. Interventions: Three groups of normal young men age (X24a) with comparable nutritional status, natives from different altitudes: 150 m.a.s.l. (Lima, N=10), 3 000 m.a.s.l. (Tarma, N= 10), 4 200 m.a.s.l. (Cerro de Pasco, n=11); and three patients with chronic mountain disease (CMD) natives from Cerro de Pasco were studied. All subjects were euthyroid and without goiter. RIA determinations of PRL basal serum levels and PRL response to thyrotrophin releasing hormone (TRH) 200 μg I.V. were carried out on each subject. Main outcome measures: Difference of serum prolactin levels and highest response to thyrotrophin releasing hormone in subjects at sea level and at high altitude. Results: Prolactin basal serum levels and the highest response to TRH were significatively less (P&lt;0.05) in high altitude natives when compared to those at sea level. Underlying cause would be chronic hypoxia including either tubero-infundibular dopaminergic system activity increase or lactotrophs’ receptor or post-receptor alteration in high altitude natives. This may be an adaptation mechanism for fertility preservation in high altitude natives. The few patients with chronic mountain disease studied did not allow concluding results, but persistence of less prolactin secretion was observed with late response to TRH. Further investigations in patients with MMD are required to define these observations. Conclusions: Prolactin basal serum levels and highest response to thyrotropin releasing hormone were significatively less in high altitude natives compared with those at sea level

Intra-Abdominal Pressure as a Marker of Enteral Nutrition Intolerance in Critically Ill Patients. The PIANE Study

To determine whether elevated intra-abdominal pressure (IAP) is associated with a higher rate of enteral nutrition-related gastrointestinal (GI) complications; to assess the value of IAP as a predictor of enteral nutrition (EN) intolerance. Intensive Care Unit (ICU) patients on mechanical ventilation requiring at least 5 days of EN were recruited for a prospective, observational, non-interventional, multicenter study. EN was performed and GI complications were managed with an established protocol. IAP was determined via a urinary catheter. Patients who developed any GI complications were considered as presenting EN intolerance. Variables related to EN, IAP and GI complications were monitored daily. Statistical analysis compared patients without GI complications (group A) vs. GI complications (group B). 247 patients were recruited from 28 participating ICUs (group A: 119, group B: 128). No differences between groups were recorded. Patients in group B (p < 0.001) spent more days on EN (8.1 ± 8.4 vs. 18.1 ± 13.7), on mechanical ventilation (8.0 ± 7.7 vs. 19.3 ± 14.9) and in the ICU (12.3 ± 11.4 vs. 24.8 ± 17.5). IAP prior to the GI complication was (14.3 ± 3.1 vs. 15.8 ± 4.8) (p < 0.003). The best IAP value identified for EN intolerance was 14 mmHg but it had low sensitivity and specificity. Although a higher IAP was associated with EN intolerance, IAP alone did not emerge as a good predictor of EN intolerance in critically ill patients