1,085 research outputs found
Comparación entre la cirugía convencional, minilaparotomía y la reparación endovascular en el manejo de aneurismas de aorta abdominal
Un Aneurisma de Aorta Abdominal (AAA) es definido como una dilatación de la arteria aorta de al menos 1.5 veces el diámetro medido a nivel de las arterias renales. En muchos individuos el valor normal a este nivel es de 2.0 cm (rango 1.4 a 3.0 cm); un diámetro mayor de 3.0 cm es generalmente considerado aneurisma. La historia natural de estos aneurismas es la de expansión y eventual ruptura. Los aneurismas se expanden una tasa promedio de 0.3 a 0.4 cm por año 1-8.
La resección electiva es considerada para AAA que han alcanzado un diámetro de 5.0 a 5.5 cm 9-12, para aquellos que incrementan en diámetro más de 0.5 cm dentro de un periodo de 6 meses, o para aquellos que son sintomáticos (mayor sensibilidad o dolor abdominal y/o lumbar) 11, 13. Sin embargo, el riesgo de intervención quirúrgica debe ser valorado contra el potencial beneficio. La mortalidad perioperatoria para reparación quirúrgica de aneurisma aórtico varía entre 2.7 y 5.8% 14,15. La mortalidad se incrementa sustancialmente cuando la cirugía es realizada de emergencia debido a ruptura, y en el marco de condiciones comórbidas tales como edad avanzada, insuficiencia renal, cirrosis o enfermedad cardiopulmonar 8,16-18.Tesis de segunda especialida
Climate Change Mitigation in Livestock Production: Nonconventional Feedstuffs and Alternative Additives
Livestock production has widely contributed to increase global production of greenhouse gases (GHG), mostly through digestive fermentation in ruminants. Moreover, emissions derived from livestock are estimated over 14% of the total anthropogenic GHG emissions to atmosphere. In addition, methane emitted from ruminal enteric fermentation is responsible for 25% of the total global methane emissions, which turns livestock activity into a main promoter of the climate change effect. However, these emissions may be diminished by modifying livestock diets through alterations in forage-concentrate ratios, the supplementation of feed additives, and the inclusion of alternative feedstuffs not commonly used as forage and protein sources in farm animal feeding. Additionally, the use of nonconventional feedstuffs is highly recommended since their production does not compete with human feeding and may provide metabolites used as methanogenesis suppressors. Likewise, agricultural by-products should be considered as potential feedstuffs for animal production by increasing the livestock efficiency and reducing the energy losses due to methane synthesis
Endoplasmic Reticulum Stress during Mammalian Follicular Atresia
Follicles are ovarian structures that contain a single germ cell. During the mammalian reproductive lifetime, ovarian follicles mature through the process of follicular development, with the aim of selecting oocytes for ovulation. As part of this process, several follicles are eliminated by means of follicular atresia, a mechanism that mainly involves apoptosis. Nevertheless, it has been shown that there are other routes of programmed cell death in the ovary including autophagy, paraptosis, and necroptosis. Surprisingly, the endoplasmic reticulum is involved in these different programmed cell death pathways. Moreover, there are several evidences for the pathways triggered by intra- and extracellular signals in endoplasmic reticulum-induced cell death. Thus, it is important to analyze the participation of endoplasmic reticulum in follicular atresia
Resumen de PAR-MEX en IberLEF 2022: Tarea Compartida para la Detección de Paráfrasis en Español
Paraphrase detection is an important unresolved task in natural language processing; especially in the Spanish language. In order to address this issue, and contribute to the creation of high-performance paraphrase detection automated systems, we propose a shared task called PAR-MEX. For this task, we created a corpus, in Spanish, with topics in the domain of Mexican gastronomy. Afterwards, the participants in this task submitted their classification results on our corpus. In this paper we explain the steps followed for the creation of the corpus, we summarize the results obtained by the various participants, and propose some conclusions regarding the paraphrase-detection task in Spanish.La detección de paráfrasis es una tarea importante no resuelta en procesamiento del lenguaje natural; especialmente en la lengua española. Para atacar este problema, y para contribuir a la creación de sistemas de detección automática que obtengan resultados competitivos, proponemos la tarea compartida llamada PAR-MEX. Para esto, creamos un corpus en español con temas dentro del campo semántico de gastronomía mexicana. Después los participantes en esta tarea enviaron los resultados de sus sistemas de clasificación sobre nuestro corpus. En este paper explicamos los pasos seguidos para la creación del corpus, resumimos los resultados obtenidos por los participantes, y proponemos algunas conclusiones al respecto de la detección de paráfrasis en español.We acknowledge the support of the projects CONACyT CB A1-S-27780, and DGAPA-UNAM PAPIIT references TA400121 and TA101722
The Gould's Belt Very Large Array Survey III. The Orion region
We present results from a high-sensitivity (60 Jy), large-scale (2.26
square degree) survey obtained with the Karl G. Jansky Very Large Array as part
of the Gould's Belt Survey program. We detected 374 and 354 sources at 4.5 and
7.5 GHz, respectively. Of these, 148 are associated with previously known Young
Stellar Objects (YSOs). Another 86 sources previously unclassified at either
optical or infrared wavelengths exhibit radio properties that are consistent
with those of young stars. The overall properties of our sources at radio
wavelengths such as their variability and radio to X-ray luminosity relation
are consistent with previous results from the Gould's Belt Survey. Our
detections provide target lists for followup VLBA radio observations to
determine their distances as YSOs are located in regions of high nebulosity and
extinction, making it difficult to measure optical parallaxes.Comment: Accepted for publication in ApJ; 51 pages, 15 figures, 5 table
The Gould's Belt Very Large Array Survey II: The Serpens region
We present deep (Jy) radio continuum observations of the Serpens
molecular cloud, the Serpens south cluster, and the W40 region obtained using
the Very Large Array in its A configuration. We detect a total of 146 sources,
29 of which are young stellar objects (YSOs), 2 are BV stars and 5 more are
associated with phenomena related to YSOs. Based on their radio variability and
spectral index, we propose that about 16 of the remaining 110 unclassified
sources are also YSOs. For approximately 65% of the known YSOs detected here as
radio sources, the emission is most likely non-thermal, and related to stellar
coronal activity. As also recently observed in Ophiuchus, our sample of YSOs
with X-ray counterparts lies below the fiducial G\"udel & Benz relation.
Finally, we analyze the proper motions of 9 sources in the W40 region. This
allows us to better constrain the membership of the radio sources in the
region.Comment: Accepted in The Astrophysical Journa
Filamin B Regulates Chondrocyte Proliferation and Differentiation through Cdk1 Signaling
Humans who harbor loss of function mutations in the actin-associated filamin B (FLNB) gene develop spondylocarpotarsal syndrome (SCT), a disorder characterized by dwarfism (delayed bone formation) and premature fusion of the vertebral, carpal and tarsal bones (premature differentiation). To better understand the cellular and molecular mechanisms governing these seemingly divergent processes, we generated and characterized FlnB knockdown ATDC5 cell lines. We found that FlnB knockdown led to reduced proliferation and enhanced differentiation in chondrocytes. Within the shortened growth plate of postnatal FlnB−/− mice long bone, we observed a similarly progressive decline in the number of rapidly proliferating chondrocytes and premature differentiation characterized by an enlarged prehypertrophic zone, a widened Col2a1+/Col10a1+ overlapping region, but relatively reduced hypertrophic zone length. The reduced chondrocyte proliferation and premature differentiation were, in part, attributable to enhanced G2/M phase progression, where fewer FlnB deficient ATDC5 chondrocytes resided in the G2/M phase of the cell cycle. FlnB loss reduced Cdk1 phosphorylation (an inhibitor of G2/M phase progression) and Cdk1 inhibition in chondrocytes mimicked the null FlnB, premature differentiation phenotype, through a β1-integrin receptor- Pi3k/Akt (a key regulator of chondrocyte differentiation) mediated pathway. In this context, the early prehypertrophic differentiation provides an explanation for the premature differentiation seen in this disorder, whereas the progressive decline in proliferating chondrocytes would ultimately lead to reduced chondrocyte production and shortened bone length. These findings begin to define a role for filamin proteins in directing both cell proliferation and differentiation through indirect regulation of cell cycle associated proteins
Growth hormone in males at different altitude
Objetivos: Determinar los niveles de hormona de crecimiento (GH) en sujetos varones adultos, a nivel del mar (Lima, 150 msnm) y en la altura (Cajamarca: 2 750 msnm; Huancayo: 3 280 msnm; Morococha: 4 540 msnm). Diseño: Estudio descriptivo, observacional, transversal y prospectivo. Lugar: Ciudades de Lima, Cajamarca, Huancayo y Morococha, Perú. Participantes: Adultos varones, nativos de localidades de diferentes altitudes. Intervenciones: Previo consentimiento informado, a 41 adultos varones nativos de su localidad de origen [12 sujetos alnivel del mar (Lima 150 m), 10 sujetos en Cajamarca (2 750 m), 12 sujetos en Huancayo (3 280 m) y 7 sujetos en Morococha (4 540 m)] se tomó muestras de sangre en ayunas y en condiciones de reposo. Principales medidas de resultados: Niveles sanguíneos de hormona de crecimiento (GH) en sangre. Resultados: La edad promedio de los participantes fue 28 años (rango de 20 a 35 años). Los valores promedios de GH encontrados fueron: a 4 540 m, 3,87 ± 0,16 ng/mL; a 3 280 m, 1,31 ± 0,09 ng/mL; a 2 750 m, 0,63 ± 0,08 ng/mL; y a 150 m, 0,54 ± 0,04 ng/mL. Hubo diferencia significativa (p < 0,05) entre los valores de GH encontrados en la altura a 4 540 m y 3 280 m con respecto al nivel del mar 150 m. No se encontró diferencia significativa entre los valores encontrados a 2 750 m con respecto a 150 m. Conclusiones: Los niveles de GH son mayores en los sujetos nativos a 3 280 m (Huancayo, n=12) y 4 540 m (Morococha, n=7) respecto a los sujetos que viven a 150 m (Lima, n=12).Objectives: To determine growth hormone (GH) serum levels in adult males at sea level (Lima, 150 msnm) and high altitude (Cajamarca: 2 750 msnm, Huancayo: 3 280 msnm, Morococha: 4 540 msnm). Design: Descriptive, observational, transversal and prospective study. Location: Lima, Cajamarca, Huancayo y Morococha, Peru. Participants: Male adult natives of different altitude settings. Interventions: With informed consent blood samples were obtained from the forearm in fasting and resting conditions from 41 young adult male subjects 20 to 35 years old [12 subjects at sea level (Lima 150 m), 10 subjects in Cajamarca (2 750 m), 12 subjects in Huancayo (3 280 m), and 7 subjects in Morococha (4 540 m)]. Main outcome measures: Serum growth hormone (GH) levels. Results: GH mean values found were at 4 540 m: 3,87 ± 0,16 ng/mL; at 3 280 m: 1,31 ± 0,09 ng/mL; at 2 750 m: 0,63 ± 0,08 ng/mL; and at 150 m: 0,54 ± 0,04 ng/mL. There was significant difference (p <0,05) between values found at altitudes 4 540 m and 3 280 m above sea level (150 m). No significant difference was found between values found at 2 750 m and 150 m. Conclusions: Adult male growth hormone serum levels were higher at Huancayo (3 280 msnm, n=12) and Morococha (4 540 msnm, n=7) than at sea level (Lima 150 msnm, n=12)
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