2,110 research outputs found
Congenital teratomas at the Hospital Universitario San Ignacio, case series
Los tumores en niños tienen menor incidencia que en los adultos. Los tumores en fetos y en recién nacidos son aún más raros. Se reporta una serie de tres tumores germinales, uno en un recién nacido vivo, uno en un feto mortinato y el tercero presente en las membranas ovulares. Se revisa la información disponible sobre los tumores en este grupo de edad.Reporte de caso442-451Tumor incidence in children is lower than in adults. In fetuses and newborns it is even
rarer. We report a series of three cases of germ cell tumors;
the first one present
in a
newborn child, the second one in a stillborn, and a third tumor present in placenta
membranes. We also present the results of a review of the literature of similar cases
of tumors
Insights into the mechanism of activation of the phosphorylation-independent response regulator NblR. Role of residues Cys69 and Cys96
Cyanobacteria respond to environmental stress conditions by adjusting their photosynthesis machinery. In Synechococcus sp. PCC 7942, phycobilisome degradation and other acclimation responses after nutrient or high light stress require activation by the phosphorylation-independent response regulator NblR. Structural modelling of its receiver domain suggested a role for Cys69 and Cys96 on activation of NblR. Here, we investigate this hypothesis by engineering Cys to Ala substitutions. In vivo and in vitro analyses indicated that mutations Cys69Ala and/or Cys96Ala have a minor impact on NblR function, structure, size, or oligomerization state of the protein, and that Cys69 and Cys96 do not seem to form disulphide bridges. Our results argue against the predicted involvement of Cys69 and Cys96 on NblR activation by redox sensing.This work was supported by the Spanish Ministerio de Ciencia e Innovación (grants BFU2009-07371 to A.C., BIO2009-10872 and BIO2010-15424 to A.M. and SAF2008-05742-C02-01 and CSD2008-00005 to J.L.N.) and the Generalitat Valenciana (grants ACOMP2006/083 and ACOMP2011/211 to A.C., ACOMP2010/114 and ACOMP2011/113 to J.L.N.). M.L. López-Redondo was a fellow of the Fundación Mutua Madrileña Automovilística
GHG Balance of Agricultural Intensification & Bioenergy Production in the Orinoquia Region, Colombia
Energy crop expansion can increase land demand and generate displacement of food crops, which impacts greenhouse gas (GHG) emissions mainly through land-use change (LUC). Increased agricultural productivity could compensate for this. Our study aims to evaluate the regional combined GHG emissions of increasing agricultural yields for food crop and beef production and using the generated surplus land for biomass production to replace fossil fuels in the Orinoquia region of Colombia until 2030. The results show that surplus land for biomass production is obtained only when strong measures are applied to increase agricultural productivity. In the medium and high scenario, a land surplus of 0.6 and 2.4 Mha, respectively, could be generated. Such intensification results in up to 83% emission reduction in Orinoquia’s agricultural sector, largely coming from increasing productivity of cattle production and improving degraded pastures. Biofuel potential from the surplus land is projected at 36 to 368 PJ per year, with a low risk of causing indirect LUC, and results in GHG emission reductions of more than 100% compared to its fossil fuel equivalent. An integrated perspective of the agricultural land use enables sustainable production of both food and bioenergy
Knockout of the BK β2 subunit abolishes inactivation of BK currents in mouse adrenal chromaffin cells and results in slow-wave burst activity
Rat and mouse adrenal medullary chromaffin cells (CCs) express an inactivating BK current. This inactivation is thought to arise from the assembly of up to four β2 auxiliary subunits (encoded by the kcnmb2 gene) with a tetramer of pore-forming Slo1 α subunits. Although the physiological consequences of inactivation remain unclear, differences in depolarization-evoked firing among CCs have been proposed to arise from the ability of β2 subunits to shift the range of BK channel activation. To investigate the role of BK channels containing β2 subunits, we generated mice in which the gene encoding β2 was deleted (β2 knockout [KO]). Comparison of proteins from wild-type (WT) and β2 KO mice allowed unambiguous demonstration of the presence of β2 subunit in various tissues and its coassembly with the Slo1 α subunit. We compared current properties and cell firing properties of WT and β2 KO CCs in slices and found that β2 KO abolished inactivation, slowed action potential (AP) repolarization, and, during constant current injection, decreased AP firing. These results support the idea that the β2-mediated shift of the BK channel activation range affects repetitive firing and AP properties. Unexpectedly, CCs from β2 KO mice show an increased tendency toward spontaneous burst firing, suggesting that the particular properties of BK channels in the absence of β2 subunits may predispose to burst firing
Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV
The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8 TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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