6,423 research outputs found
Formation and structures of cationic zirconium complexes in ternary systems rac-(SBI)ZrX2/AlBui3/[CPh3][B(C6F5)4(X = Cl, Me)
Src Utilizes Cas to Block Gap Junctional Communication Mediated by Connexin43
The Src tyrosine kinase phosphorylates Cas (Crk-associated substrate) to confer anchorage independence and invasive growth potential to transformed cells. Gap junctional communication is often lower between aggressive tumor cells compared with normal or benign precursors. The gap junction protein connexin43 (Cx43) is a tumor suppressor that can inhibit tumor cell growth. Src can phosphorylate Cx43 to block gap junctional communication between transformed cells. However, mechanisms by which this event actually closes intercellular channels have not been clearly defined. Here, we report that Src and Cas associate with each other at intercellular junctions. In addition, Cas is required for Src to reduce dye transfer and electrical coupling between cells expressing Cx43. Thus, Src utilizes Cas to inhibit gap junctional communication mediated by Cx43. This finding introduces a novel role of the Cas focal adhesion linker protein in the gap junction complex. This observation may help explain how gap junctional communication can be suppressed between malignant and metastatic tumor cells
Functional and Pharmacological Analysis of Cardiomyocytes Differentiated from Human Peripheral Blood Mononuclear-Derived Pluripotent Stem Cells
SummaryAdvances in induced pluripotent stem cell (iPSC) technology have set the stage for routine derivation of patient- and disease-specific human iPSC-cardiomyocyte (CM) models for preclinical drug screening and personalized medicine approaches. Peripheral blood mononuclear cells (PBMCs) are an advantageous source of somatic cells because they are easily obtained and readily amenable to transduction. Here, we report that the electrophysiological properties and pharmacological responses of PBMC-derived iPSC CM are generally similar to those of iPSC CM derived from other somatic cells, using patch-clamp, calcium transient, and multielectrode array (MEA) analyses. Distinct iPSC lines derived from a single patient display similar electrophysiological features and pharmacological responses. Finally, we demonstrate that human iPSC CMs undergo acute changes in calcium-handling properties and gene expression in response to rapid electrical stimulation, laying the foundation for an in-vitro-tachypacing model system for the study of human tachyarrhythmias
On the use of numerical models to predict/mitigate indoor radon levels in highly contaminated areas
The publication of the EURATOM directive BSS 2013/59 [1] has increased considerably the interest on radon studies in all EU countries. Certainly each member state has to establish a national action plan addressing long-term risks from radon exposures in dwellings, buildings with public access and workplaces for any source of radon ingress, whether from soil, building materials or water. The complexity generated by the number of parameters and processes affecting radon generation in the source, transport in source media, entry into dwellings, and its accumulation in the different rooms of the dwelling, makes the development of numerical models a very challenging exercise that might take also into account that the detailed information of the building-soil interface in an existing dwelling is normally not available. A new project funded by the Spanish Nuclear Safety Board (CSN) started in 2020. Its main goal is to establish and validate a numerical tool to predict and mitigate indoor radon levels in new and existing buildings in general, but paying special attention to the case of areas contaminated due to NORM industrial activities. Such a numerical tool might be of interest for Radiation Protection authorities to manage highly contaminated areas. In particular, 2 different numerical modelling strategies will be adapted to real sites and compared. The RAGENA [2] code, which was developed in the late 90s, will be updated with the last findings from experimental studies. This code allows modelling all radon sources and processes affecting radon accumulation indoors from a dynamic point of view in a very simple way, but lacks from spatial resolution. On the other hand, a CFD (computational fluid dynamics) model recently developed in Spain [3] numerically solves radon transport equation by finite elements with a good spatial resolution. The project focuses also on the experimental characterization of real sites. In this talk we will introduce the project, discuss the main features of both modelling approaches and describe in more detail the current status of the RAGENA code updating
Disnea en tercer día de puerperio: un caso de miocardiopatía periparto
We report a case of a woman in the third day after delivery with acute heart failure. She’s diagnosed by transthoracic echocardiography of peripartum cardiomyopathy. Treatment of heart failure was started and the patient’s condition improved. Peripartum cardiomyopathy is the left ventricular systolic dysfunction that occurs in the final month of pregnancy and up to 5 months after delivery in abscense of another identifiable cause for the heart failure. Peripartum cardiomyopathy is the major cause of pregnancy-induced heart failure. Although the incidence is low, morbidity and mortality rates are high. Therefore, it’s necessary to take into consideration this pathology in the differential diagnosis.Presentamos un caso de una paciente en tercer día de puerperio que presenta clínica de insuficiencia cardíaca (IC). Tras descartar otras etiologías es diagnosticada mediante ecocardiografía transtorácica de miocardiopatía periparto. Se instaura tratamiento de IC evolucionando favorablemente. La miocardiopatía periparto es la disfunción del ventrículo izquierdo producida en el último mes de embarazo y los 5 meses posparto, sin otra causa que justifique la IC. Es la principal causa de fallo cardíaco en el embarazo y si bien tiene baja incidencia puede presentar una elevada morbimortalidad por lo que es necesario tenerla en cuenta en el diagnóstico diferencial
Fracaso renal agudo como manifestación de estenosis de la arteria renal
We report a case of a 77 year old woman with history of renovascular hypertension because of stenosis of right renal artery which has an acute renal failure. After abdominal Doppler-ultrasounds and abdominal CT with contrast, a bilateral stenosis of renal artery was demonstrated, with acute occlusion of left artery.Presentamos un caso de una paciente de 77 años con antecedentes de hipertensión arterial renovascular por estenosis de la arteria renal derecha que presenta un fallo renal agudo, y tras realización de ecografía abdominal que demuestra flujo Doppler alterado se realiza TC abdominal con contraste que demuestra estenosis de arteria renal bilateral, con oclusión aguda de arteria renal izquierda
Study of secondary muons detected within the tunnels of the Cholula pyramid
The pyramid of Cholula was built at the beginning of 100 B.C. and during of period of 500 years it was finished, had several new constructions, based on the previous constructions. The primarily material of construction is the adobe. Early in 1931 archaeological excavations began with the intention of exploring the interior of the pyramid, excavations were stopped in 1971, and to date no further excavations have been carried out. This work shows the first measurements of muons, particles that are very penetrating, these are generated by primary cosmic rays that was incoming in the atmosphere and these generates a rain of secondary particles, among them the muons. To measure this kind of particles was implemented a detector system, it is formed by a scintillator plastic coupled to a tube photomultiplier; the signals were acquired by mean of an oscilloscope. The detector was collocated near of the center of the pyramid; the location belongs to the maxima concentration in mass over the detector. Graphs of the charge distribution, maximum amplitude and characteristic rise times of the generated pulses in a plastic scintillator are shown, this is scintillator was synthesized in the materials laboratory of the FCFM-BUAP. In addition the optical characterization of the same was realized
Air and wet bulb temperature lapse rates and their impact on snowmaking in a Pyrenean ski resort
A set of 17 air temperature and relative humidity sensors were used to analyze the temporal variability of surface air temperature
(Tair), wet bulb temperature (Twb), and daily snowmaking hours (SM, number of hours per day with Twb < − 2 °C), lapse rates,
and the occurrence of thermal inversions at the Formigal ski resort (Spanish Pyrenees) from December to March during three
consecutive ski seasons (2012–2013, 2013–2014, and 2014–2015). The Tair and Twb lapse rates showed strong hourly and daily
variability, with both exhibiting almost identical temporal fluctuations.
The Twb exhibited average lapse rates that were slightly steeper (− 5.2 °C/km) than those observed for Tair (− 4.9 °C/km). The
less steep lapse rates and most thermal inversions were observed in December. Days having less (more) steep Tair and Twb lapse
rates were observed under low (high) wind speeds and high (low) relative humidity and air pressure. The temporal dynamics of
the SM lapse rates was more complex, as this involved consideration of the average Tair in the ski resort, in addition to the driving
factors of the spatio-temporal variability of Twb. Thus, on a number of cold (warm) days, snowmaking was feasible at all
elevations at the ski resort, independently of the slopes of the lapse rates. The SM exhibited an average daily lapse rate of
8.2 h/km, with a progressive trend of increase from December to March.
Weather types over the Iberian Peninsula tightly control the driving factors of the Tair, Twb, and SM lapse rates (wind speed,
relative humidity, and Tair), so the slopes of the lapse rates and the frequency of inversions in relation to elevation for the three
variables are very dependent on the occurrence of specific weather types. The less steep lapse rates occurred associated with
advections from the southeast, although low lapse rates also occurred during advections from the east and south, and under
anticyclonic conditions. The steepest Tair and Twb lapse rates were observed during north and northwest advections, while the
steepest rates for SM were observed during days of cyclonic circulation and advections from the northeast.This study was funded by the research project CGL2014-52599-P "Estudio del manto de nieve en la montaña española y su respuesta a la variabilidad y cambio climatico" (Ministry of Economy and Development, MINECO)
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