3,536 research outputs found
Study Majorana Neutrino Contribution to B-meson Semi-leptonic Rare Decays
B meson semi-leptonic rare decays are sensitive to new physics beyond
standard model. We study the process and
investigate the Majorana neutrino contribution to its decay width. The
constraints on the Majorana neutrino mass and mixing parameter are obtained
from this decay channel with the latest LHCb data. Utilizing the best fit for
the parameters, we study the lepton number violating decay , and find its branching ratio is about
, which is consistent with the LHCb data reported recently.Comment: 10 pages, 3 figure
Genome-Wide Analysis of WRKY Genes and Their Response to Hormone and Mechanic Stresses in Carrot
The WRKY gene family plays a vital role in plant development and environment response. Although previous studies suggested that the WRKY genes in carrot (Kuroda type) involved in biotic and abiotic stress responses, the information of WRKY genes in the latest version of the carrot genome (Daucus carota v2.0, Nantes type carrot) and their response to hormone and injury stresses have not been reported. In this study, we performed a genome-wide analysis of WRKYs using a chromosome-scale genome assembly of carrot (Daucus carota subsp. sativus L.). We identified a total of 67 WRKY genes, which were further classified into the three groups. These WRKY genes are unevenly distributed on carrot chromosomes. We found that more than half of them were derived from whole-genome duplication (WGD) events, suggesting that WGDs have played a major role during the evolution of the WRKY gene family. We experimentally ascertained the expression divergence existed between WGD-derived WRKY duplicated gene pairs, which is indicative of functional differentiation between duplicated genes. Our analysis of cis-acting elements indicated that WRKY genes were transcriptionally regulated upon hormone and mechanic injury stresses. Gene expression analyses by qRT-PCR further presented that WRKY genes were involved in hormone and mechanic injury stresses
Modified Hertz-damp model for base-isolated structural pounding simulation under near-fault earthquakes
Pounding phenomenon between base-isolated structures under near-fault earthquakes has been widely investigated with various impact models around the world. Firstly, the existing impact analysis models are summarized and discussed in this paper. For the Hertz-damp impact model, the damping constant does not coincide with its physical fact. Then, the damping constant in the Hertz-damp impact analysis model was modified based on the Hertz theory. Next, the approximate formula of the damping constant is theoretically derived, and the effectiveness is verified by a simulation analysis. The numerical results show that the pounding can significantly increase the floor acceleration, especially at the isolation layer. In addition, the impact stiffness has a significant effect on the acceleration response, and the inter-story drifts are also sensitive to the variety of impact stiffness. The simulation results indicate that excessive flexibility at the base-isolated system may lead to a susceptible pounding with a limited seismic gap
Diagnosis and treatment characteristics of radioactive optic neuropathy
AIM: To explore the diagnosis and treatment methods of radioaction-induced optic neuritis(RION)through the clinical dates of 17 patients. <p>METHODS: It was a retrospective case series study. From August 2008 to October 2013, 17 cases(24 eyes)of Rion clinical dates from Chinese PLA General Hospital were studied. The diagnosis methods including visual acuity, pupil, fundus, visual field, fundus fluorescein angiography(FFA), visual electrophysiological testing, and head MRI. To analysis the clinical date of patients with diagnosis of RION by statistical description.<p>RESULTS: The deterioration degree of vision: 13 eyes were classified as â…£, 9 eyes as â…¢, 2 eyes as â…¡. Ten eyes RAPD(+), visual electrophysiology is extinguished. The retina of 5 eyes showed flame hemorrhages and cotton wool spots exudation. Optic nerve head edema in one eye. T1-weighted MRI enhanced in 19 eyes which showed optic nerve of the intracranial and intratubal segments abnormal changed, optic chiasm and pituitary stalk signal abnormalities and enhancement of the optic nerve. Tortuous optic nerves and rough edges were observed in 5 eyes. Treatment effect: 4 eyes of visual acuity improved, 1 eye from blindness to light perception,1 eye from 0.08 to 0.2, 1 eye from 0.4 to 0.6,1 eye from 0.04 to 0.15, the rest of the cases did not see any improvement.<p>CONCLUSION: The unique clinical manifestation of RION can provide objective basis for clinical diagnosis in time, but there have not been proven any effective treatments
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