28,303 research outputs found
Heterodimerization of apelin receptor and neurotensin receptor 1 induces phosphorylation of ERK1/2 and cell proliferation via Gαq-mediated mechanism
Dimerization of G protein-coupled receptors (GPCRs) is crucial for receptor function including agonist affinity, efficacy, trafficking and specificity of signal transduction, including G protein coupling. Emerging data suggest that the cardiovascular system is the main target of apelin, which exerts an overall neuroprotective role, and is a positive regulator of angiotensin-converting enzyme 2 (ACE2) in heart failure. Moreover, ACE2 cleaves off C-terminal residues of vasoactive peptides including apelin-13, and neurotensin that activate the apelin receptor (APJ) and neurotensin receptor 1 (NTSR1) respectively, that belong to the A class of GPCRs. Therefore, based on the similar mode of modification by ACE2 at peptide level, the homology at amino acid level and the capability of forming dimers with other GPCRs, we have been suggested that APJ and NTSR1 can form a functional heterodimer. Using co-immunoprecipitation, BRET and FRET, we provided conclusive evidence of heterodimerization between APJ and NTSR1 in a constitutive and induced form. Upon agonist stimulation, hetrodimerization enhanced ERK1/2 activation and increased proliferation via activation of Gq α-subunits. These novel data provide evidence for a physiological role of APJ/NTSR1 heterodimers in terms of ERK1/2 activation and increased intracellular calcium and induced cell proliferation and provide potential new pharmaceutical targets for cardiovascular disease. © 2014 The Authors
Fiber Based Multiple-Access Optical Frequency Dissemination
We demonstrate a fiber based multiple-access optical frequency dissemination
scheme. Without using any additional laser sources, we reproduce the stable
disseminated frequency at an arbitrary point of fiber link. Relative frequency
stability of 3E10^{-16}/s and 4E10^{-18}/10^4s is obtained. A branching fiber
network for highly-precision synchronization of optical frequency is made
possible by this method and its applications are discussed.Comment: 5 pages, 3 figure
Impurity scattering and Friedel oscillations in mono-layer black phosphorus
We study the effect of impurity scattering effect in black phosphorurene (BP)
in this work. For single impurity, we calculate impurity induced local density
of states (LDOS) in momentum space numerically based on tight-binding
Hamiltonian. In real space, we calculate LDOS and Friedel oscillation
analytically. LDOS shows strong anisotropy in BP. Many impurities in BP are
investigated using -matrix approximation when the density is low. Midgap
states appear in band gap with peaks in DOS. The peaks of midgap states are
dependent on impurity potential. For finite positive potential, the impurity
tends to bind negative charge carriers and vise versa. The infinite impurity
potential problem is related to chiral symmetry in BP
Searching for high- isomers in the proton-rich mass region
Configuration-constrained potential-energy-surface calculations have been
performed to investigate the isomerism in the proton-rich mass
region. An abundance of high- states are predicted. These high- states
arise from two and four-quasi-particle excitations, with and
, respectively. Their excitation energies are comparatively
low, making them good candidates for long-lived isomers. Since most nuclei
under studies are prolate spheroids in their ground states, the oblate shapes
of the predicted high- states may indicate a combination of isomerism
and shape isomerism
Chinese Herbal Medicine: A Safe Alternative Therapy for Urinary Tract Infection in Patients with Renal Insufficiency
We have used reduced doses of Chinese herbs for estimation of urinary tract infections (UTIs) patients with stable impairment of renal function. A total of 33 adult female patients with moderately impaired renal function and symptomatic UTIs were included in this study. Urine cultures were carried out. Patients were monitored clinically and with various laboratory tests. Chinese herbal concoction divided by milligrams of creatinine per 100 ml were orally administrated for ten days. Three patients were excluded from final analysis. Most of the patients responded symptomatically to treatment. Chinese herbs eradicated the primary pathogen in 68.7% of the patients at the day 10 of treatment. Two patients relapsed (one had abbreviated courses of therapy) 6 to 8 days posttreatment. Organisms which recurred included Escherichia coli and Pseudomonas aeruginosa. Bacterial reinfections occurred 5 to 8 days posttreatment in four patients. Adverse reactions observed among the 30 patients were rare. Nausea (6.67%) and mild elevation of hepatic enzymes (3.33%) were probably drug related. Nausea disappeared when the therapy ended. Elevated hepatic enzymes resumed at the 2-week follow-up. Two patients demonstrated slight increases in serum creatinine on day 10 of treatment. One patient had a 12.5% elevation over baseline and the other had a 13.0% elevation. Serum creatinine values had improved in these two patients at 4-week follow-up. Chinese herbal medicine was effective and safe in the treatment of UTIs with renal insufficiency.Key words: Chinese herbs; Urinary tract infection; Renal insufficiency; Dose adjustment
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