29 research outputs found
Decay spectroscopy of Cd-129
Excited states of In populated following the -decay of
Cd were experimentally studied with the GRIFFIN spectrometer at the
ISAC facility of TRIUMF, Canada. A 480-MeV proton beam was impinged on a
uranium carbide target and Cd was extracted using the Ion Guide Laser
Ion Source (IG-LIS). - and -rays following the decay of
Cd were detected with the GRIFFIN spectrometer comprising the plastic
scintillator SCEPTAR and 16 high-purity germanium (HPGe) clover-type detectors.
%, along with the -particles were detected with SCEPTAR. From the
-- coincidence analysis, 32 new transitions and 7 new
excited states were established, expanding the previously known level scheme of
In. The values deduced from the -feeding intensities
suggest that some of the high-lying states were populated by the allowed Gamow-Teller (GT) transition, which
indicates that the allowed GT transition is more dominant in the Cd
decay than previously reported. Observation of fragmented Gamow-Teller
strengths is consistent with theoretical calculations.Comment: 13 pages, 9 figures, to be published in Physical Review
High-precision branching ratio measurement and spin assignment implications for Ga-62 superallowed beta decay
Plasticity of skin water permeability and skin thickness in the amphibious mangrove rivulus Kryptolebias marmoratus
Sildenafil Alleviates Bronchopulmonary Dysplasia in Neonatal Rats by Activating the Hypoxia-Inducible Factor Signaling Pathway
The development of the O2-sensing system in an amphibious fish: consequences of variation in environmental O2 levels
Angiotensin II inhibits insulin-stimulated GLUT4 translocation and Akt activation through tyrosine nitration-dependent mechanisms.
Angiotensin II (Ang II) plays a major role in the pathogenesis of insulin resistance and diabetes by inhibiting insulin's metabolic and potentiating its trophic effects. Whereas the precise mechanisms involved remain ill-defined, they appear to be associated with and dependent upon increased oxidative stress. We found Ang II to block insulin-dependent GLUT4 translocation in L6 myotubes in an NO- and O(2)(*-)-dependent fashion suggesting the involvement of peroxynitrite. This hypothesis was confirmed by the ability of Ang II to induce tyrosine nitration of the MAP kinases ERK1/2 and of protein kinase B/Akt (Akt). Tyrosine nitration of ERK1/2 was required for their phosphorylation on Thr and Tyr and their subsequent activation, whereas it completely inhibited Akt phosphorylation on Ser(473) and Thr(308) as well as its activity. The inhibitory effect of nitration on Akt activity was confirmed by the ability of SIN-1 to completely block GSK3alpha phosphorylation in vitro. Inhibition of nitric oxide synthase and NAD(P)Hoxidase and scavenging of free radicals with myricetin restored insulin-stimulated Akt phosphorylation and GLUT4 translocation in the presence of Ang II. Similar restoration was obtained by inhibiting the ERK activating kinase MEK, indicating that these kinases regulate Akt activation. We found a conserved nitration site of ERK1/2 to be located in their kinase domain on Tyr(156/139), close to their active site Asp(166/149), in agreement with a permissive function of nitration for their activation. Taken together, our data show that Ang II inhibits insulin-mediated GLUT4 translocation in this skeletal muscle model through at least two pathways: first through the transient activation of ERK1/2 which inhibit IRS-1/2 and second through a direct inhibitory nitration of Akt. These observations indicate that not only oxidative but also nitrative stress play a key role in the pathogenesis of insulin resistance. They underline the role of protein nitration as a major mechanism in the regulation of Ang II and insulin signaling pathways and more particularly as a key regulator of protein kinase activity.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe