Aproximación exponencial para cálculo de capacitor en rectificador de onda completa

En este trabajo se presenta el análisis, cálculo y simulación del capacitor de salida de un rectificador de onda completa utilizando el método de aproximación exponencial.Este método de cálculo, resulta de utilidad si se desea obtener un rizado de voltaje en la salida de hasta el 60%. Otro método, basado en la aproximación a una función lineal, para el cálculo de éste capacitor está pensado para obtener rizados inferiores al 10%.Sin embargo, si se desea obtener un elevado rizado de voltaje, el método de aproximación lineal se vuelve inapropiado ya que con éste, se obtienen valores de capacitores que no corresponden con los valores deseados de rizado. En éste trabajo, se presenta el análisis de la forma de onda del voltaje de salida considerándola en su descarga como una señal exponencial. Con éste método, se obtienen resultados para rizados mayores al 10% del voltaje de salida con resultados satisfactorios. Para validar los cálculos y simulaciones, se han construido circuitos rectificadores con elevado rizado de voltaje, encontrando una correspondencia de los resultados obtenidos con los diseños y las simulaciones. Esta aproximación se utilizará para diseñar el rectificador de entrada de un convertidor CD-CD que alimentará un motor de 90V

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Naturaleza y cultura en Ámerica Latina

La concreción del XVIII Foro de Estudiantes Latinoamericanos de Antrología y Arqueología: Cultura y naturaleza en América Latina: escenarios para un modelo de desarrollo no civilizatorio, efectuado en Quito desde el 17 al 23 de julio del 2011, se constituyó en un acontecimiento sumamente significativo para la antropología latinoamericana debido a dos motivos. Primero porque coincidió con la emergencia del movimiento universitario estudiantil latinoamericano que expresaba sus tendencias, propuestas y exigencias de cambios tanto de las prácticas académicas como de los patrones civilizatorios que rigen las relaciones actuales. Segundo, porque se inscribía en un contexto de consolidación de las nuevas democracias de los países andinos, de carácter antineoliberal y basadas en los sujetos de derecho entre los cuales se incluye la naturaleza. Estos contextos determinaron que el Foro no ponga en escena certidumbres teóricas o metodológicas, ni se preste al exhibicionismo estéril de los avances disciplinares. Más bien, la convocatoria de la antropología y la arqueología fue apenas un pretexto para hablar, con su lenguaje, de nosotros mismos, de lo que somos, de lo que pensamos, de lo que aspiramos y sentimos sobre nuestra Latinoamérica. Lo que hemos visto, oído y compartido, en realidad, no han sido solamente ideas o conceptos sino opciones y toma de posiciones respecto a múltiples encrucijadas. Posición ante situaciones que amenazan la vida, la justicia y los derechos de todos, un desafío epistemológico todavía en ciernes y que no termina de cuajar aún en nuestras prácticas académicas

Measurement of the Higgs boson production rate in association with top quarks in final states with electrons, muons, and hadronically decaying tau leptons at s√=13TeV

The rate for Higgs (H) bosons production in association with either one (tH) or two (tt¯H) top quarks is measured in final states containing multiple electrons, muons, or tau leptons decaying to hadrons and a neutrino, using proton–proton collisions recorded at a center-of-mass energy of 13TeV by the CMS experiment. The analyzed data correspond to an integrated luminosity of 137fb−1. The analysis is aimed at events that contain H→WW, H→ττ, or H→ZZ decays and each of the top quark(s) decays either to lepton+jets or all-jet channels. Sensitivity to signal is maximized by including ten signatures in the analysis, depending on the lepton multiplicity. The separation among tH, tt¯H, and the backgrounds is enhanced through machine-learning techniques and matrix-element methods. The measured production rates for the tt¯H and tH signals correspond to 0.92±0.19(stat)+0.17−0.13(syst) and 5.7±2.7(stat)±3.0(syst) of their respective standard model (SM) expectations. The corresponding observed (expected) significance amounts to 4.7 (5.2) standard deviations for tt¯H, and to 1.4 (0.3) for tH production. Assuming that the Higgs boson coupling to the tau lepton is equal in strength to its expectation in the SM, the coupling yt of the Higgs boson to the top quark divided by its SM expectation, κt=yt/ySMt, is constrained to be within −0.9<κt<−0.7 or 0.7<κt<1.1, at 95% confidence level. This result is the most sensitive measurement of the tt¯H production rate to date.SCOAP

En el musculo liso de las vías aéreas el ATP favorece la entrada de ca2+ al retículo sarcoplasmico vía receptores P2X e induce contracción a través de receptores P2Y epiteliales /

 tesis que para obtener el grado académico de Doctor en Ciencias presenta LQC. Edgar Flores Soto ; director de tesis: Dr. Luis Manuel Montano Ramírez116 páginas : diagramasDoctorado en Ciencias Biomédicas UNAM, Facultad de Medicina, 201

Bacillus amyloliquefaciens as a plant growth promoting bacteria with the interaction with of grass salt Distichlis palmeri (Vasey) under field conditions, in desert of Sonora, Mexico

The halophyte Distichlis palmeri (Vasey) is a plant resource with high potential to be harvested in the coastal areas of northwestern Mexico; enlarge the knowledge and domestication for its incursion into the agricultural sector, plays an important role for arid areas with saline intrusion problems. However, its productivity depends on the supplementary supply of nitrogen, as well as other essential macro and micronutrients. The microorganisms considered beneficial are an alternative to chemical fertilization, highlighting those Plant Growth Promoting Bacteria (PGPB). In the present study, the inoculation of the Bacillus amyloliquefaciens (B.a.) as a halobacterium PGPB was evaluated to know the response in seeds of Distichlis spicatai obtained from natural population from colorado river in Delta north of the Gulf of California. Wild seed was collected and germinated previously inoculated with B. a., and sowed in germinated beds. Later, seedlings were planted under field and salinity conditions in the coast of Hermosillo, Sonora. Three treatments were examined (T1: B.a., T2: Chemical fertilization, T3: Negative control), with four repetitions each treatment. Each repetition consisted of experimental plots of 5 x 5 m, with a separation of 1 m between them. The harvest was carried out 600 days after sowing. The results indicate that treatments inoculated with halobacteria B.a., showed significant results in crude protein, non-protein nitrogen, neutral detergent fiber and acid detergent fiber, as well as spike length and number of seeds. The results obtained suggests the feasibility of biofertilizers where biomass and seed production are significant compared to non-inoculated controls

Influence of Deposition Parameters on Structural and Electrochemical Properties of Ti/Ti₂N Films Deposited by RF-Magnetron Sputtering

The titanium nitride (Ti2N) films have good mechanical properties, such as high hardness and chemical stability, giving Ti2N good resistance to wear and corrosion. The properties of films deposited by PVD techniques are determined by their structure, microstructure, composition, and morphology that depend on the deposition parameters, such as substrate temperature, vacuum pressure, and the distance between the target and the substrate. The influence of these parameters has been studied individually. This work studied the structure, morphology, composition, and electrochemical behavior of Ti/Ti2N films deposited by RF-magnetron sputtering on carbon steel, such as a function of the power of the RF source, substrate temperature, and the target to substrate distance and the Ar/N2 ratio. The film structure was analyzed by X-ray diffraction (XRD), the morphology of cross-section by SEM, the semi-quantitative composition by EDS, and the electrochemical properties was studied by open circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques. The films showed two phases of Ti and Ti2N. The SEM-EDS exhibited a morphology according to the Stranski–Krastanov or layer-plus-island growth model. The substrate temperature of 450 °C strongly influences the electrochemical properties

Synthesis, Crystal Structure, DFT Studies and Optical/Electrochemical Properties of Two Novel Heteroleptic Copper(I) Complexes and Application in DSSC

New copper(I) compounds of compositions [Cu(HL)(PPh3)2]·H2O (1) and [Cu(HL)POP]·CH2Cl2 (2), where HL = monoanion of pyridine-2,5-dicarboxylic acid, PPh3 = triphenylphosphine and POP = bis [2-(diphenylphosphine)phenyl]ether), are documented. The complexes were characterized by elemental analysis, spectroscopic techniques (IR, 1H/31P RMN and UV–VIS), cyclic voltammetry, and thermogravimetric analysis. Single-crystals for 1 and 2 enabled X-ray diffraction analysis, revealing distorted tetrahedral geometries for Cu(I) centers embedded in NOP2 environments. The crystal structures are stabilized by O−H∙∙∙O, C−H∙∙∙O, C−H∙∙∙π and π∙∙∙π interactions that were analyzed by inspection of the Hirshfeld surfaces and fingerprint plots. Compounds 1 and 2 show interesting optical/electrochemical properties, which were studied experimentally in solution by UV–Vis spectroscopy and cyclic voltammetry, as well as theoretically using Time-Dependent Density Functional Theory (TD-DFT). Additionally, in combination with the ruthenium complex N719, their efficiency as co-sensitizers in dye-sensitized solar cells (DSSCs) was assessed, showing good activity