1,080 research outputs found

    Auslander-Buchweitz approximation theory for triangulated categories

    Full text link
    We introduce and develop an analogous of the Auslander-Buchweitz approximation theory (see \cite{AB}) in the context of triangulated categories, by using a version of relative homology in this setting. We also prove several results concerning relative homological algebra in a triangulated category \T, which are based on the behavior of certain subcategories under finiteness of resolutions and vanishing of Hom-spaces. For example: we establish the existence of preenvelopes (and precovers) in certain triangulated subcategories of \T. The results resemble various constructions and results of Auslander and Buchweitz, and are concentrated in exploring the structure of a triangulated category \T equipped with a pair (\X,\omega), where \X is closed under extensions and ω\omega is a weak-cogenerator in \X, usually under additional conditions. This reduces, among other things, to the existence of distinguished triangles enjoying special properties, and the behavior of (suitably defined) (co)resolutions, projective or injective dimension of objects of \T and the formation of orthogonal subcategories. Finally, some relationships with the Rouquier's dimension in triangulated categories is discussed.Comment: To appear at: Appl. Categor. Struct. (2011); 22 page

    Possible Role of Nrf2 in Oxidative and Inflammatory Processes During Menopause

    Get PDF
    The increase in life expectancy leads to the possibility of development chronic diseases, from special physiological conditions as occurs in the menopause, which is defined as the permanent cessation of ovulation, marked by the end of menstruation. It has been related to decreased ovarian function that occurs around an age of 45 years. This event involves the reduction in estrogen production and may contribute to the development of chronic-degenerative diseases. Many diseases developed during menopause have been associated with oxidative stress, such as osteoporosis, hot flushes, cognitive impairment, insulin resistance, dry skin, obesity, and cardiovascular events. The knowledge about the participation of Nrf2 in diseases that occur during menopause is very limited. Here, only diseases such as osteoporosis, cardiovascular diseases and dry skin, which are present during menopause and its later stages have been described. The Nrf2 pathway involves the participation of PI3K/Akt, MAPK, and eNOS, which act as mediators for cytoprotection and antioxidation. Compounds such as equol, fitoestrogens, alkyl cathecols, or curcumin could be offered as options to antioxidant treatment, added the fact that they are present in fruits and vegetables which are rich in vitamins, minerals and calcium, thus including all the required nutrients for an adequate nutrition

    The orosomucoid 1 protein (α1 acid glycoprotein) is overexpressed in odontogenic myxoma

    Get PDF
    Odontogenic myxoma (OM) is a benign, but locally invasive, neoplasm occurring in the jaws. However, the molecules implicated in its development are unknown. OM as well as Dental Follicle (DF), an odontogenic tissue surrounding the enamel organ, is derived from ectomesenchymal/mesencyhmal elements. To identify some protein that could participate in the development of this neoplasm, total proteins from OM were separated by two-dimensional electrophoresis and the profiles were compared with those obtained from DF, used as a control

    Linfadenectomía inguinal robot asistida (LIRA) para cáncer de pene

    Get PDF
    ResumenIntroducciónEl carcinoma de células escamosas es una entidad que ocupa el 2-5% de los tumores urogenitales, siendo por tanto poco frecuente, sin embargo en instituciones como la nuestra y por un alto volumen de pacientes y centro de referencia, se logra tener entre 5-7 casos por año. Dentro del tratamiento de estas lesiones se encuentra la linfadenectomía inguinal, la cual en la actualidad es realizada con mayor frecuencia con mínima invasión. Presentamos el caso de un paciente con carcinoma epidermoide de pene al que se le realizó linfadenectomía inguinal superficial y profunda con cirugía robot asistida.ObjetivoDescribir la técnica quirúrgica para linfadenectomía inguinal robot asistida en cáncer de pene.Presentación del casoHombre de 73 años con padecimiento con un año y 6 meses de evolución con aumento de volumen a nivel del glande; previa toma de biopsia se le realizó penectomía radical con uretrostomía perineal con resultado histopatológico de carcinoma epidermoide bien diferenciado verrucoso que infiltra el cuerpo esponjoso y la uretra (T3, N0, M0, G1); se realizó linfadenectomía inguinal robot asistida a las 4 semanas.ConclusionesLa linfadenectomía inguinal robot asistida es una técnica factible en centros en los que se cuente con dicha tecnología, logrando disminuir la morbilidad, el sangrado y la estancia hospitalaria, sin embargo tiene como desventaja el costo del procedimiento.AbstractIntroductionSquamous cell carcinoma is a rare tumor, making up from 2 to 5% of the urogenital tumors. However, because our hospital is a referral center that manages large numbers of patients, approximately 5-7 cases are seen per year. Inguinal lymph node dissection is one of the treatments for these lesions and is being performed more frequently as a minimally invasive procedure.ObjectiveOur aim was to describe the surgical technique for robotic-assisted inguinal lymphadenectomy in cancer of the penis. We present herein the case of a 73-year-old man with symptom progression of one year and 6 months and increased volume at the level of the glans penis. A biopsy was taken, after which he underwent radical penectomy with perineal urethrostomy. The histopathologic study reported well differentiated verrucous squamous cell carcinoma that invaded the corpus spongiosum and the urethra (T3N0M0G1). Four weeks later he underwent robotic-assisted inguinal lymphadenectomy of the superficial and deep lymph nodes.ConclusionsRobotic-assisted inguinal lymphadenectomy, aside from its high cost, is a feasible technique when carried out in specialized centers that reduces morbidity, blood loss, and hospital stay

    Three-dimensional simulation of transient flows during the emptying of pipes with entrapped air

    Get PDF
    Two-and three-dimensional analyses of transient flows considering the air-water interaction have been a challenge for researchers due to the complexity in the numerical resolution of the multiphase during emptying in pressurized water pipelines. The air-water dynamic interaction of emptying processes can be analyzed using thermodynamic and hydraulic laws. There is a lack in the current literature regarding the analysis of those phenomena using 3D models. In this research, several simulations were performed to study the complex details of two-phase flows. A 3D model was proposed to represent the emptying process in a single pipeline, considering a PVoF model and two-equation turbulence model. The model was numerically validated through 12 experimental tests and mesh sensitivity analysis. The pressure pulses of the air pockets were evaluated and compared with the experimental results and existing mathematical models, showing how the 3D models are useful for capturing more detailed information, such as pressure and velocity patterns of discrete air pockets, distribution of air and water velocity contours, and the exploration of temperature changes for an air pocket expansion

    Management of a ruptured epidural catheter, an anesthesiologist's dilemma: a case report

    Get PDF
    Epidural anesthesia is a widely used anesthetic technique in lower extremity surgeries although it is a relatively safe procedure, it can have complications, such as rupture of the epidural catheter. This is a 69-year-old male patient with a diagnosis of Wagner IV diabetic foot is presented, which was scheduled for left supracondylar amputation in which after epidural block, retention of the catheter tip in the epidural space at level L2-L3 was seen, so hemi laminectomy was performed in a second surgical stage in L2 and removal of the epidural catheter. Ideally a broken needle should be removed as soon as possible
    corecore