2,965 research outputs found
Semileptonic transition of P wave bottomonium to meson
Taking into account the two-gluon condensate contributions, the transition
form factors enrolled to the low energy effective Hamiltonian describing the
semileptonic
decay channel are calculated within three-point QCD sum rules. The fit function
of the form factors then are used to estimate the decay width of the decay mode
under consideration.Comment: 13 Pages, 3 Tables, 4 Figure
The role of the Rashba coupling in spin current of monolayer gapped graphene
In the current work we have investigated the influence of the Rashba
spin-orbit coupling on spin-current of a single layer gapped graphene. It was
shown that the Rashba coupling has a considerable role in generation of the
spin-current of vertical spins in mono-layer graphene. The behavior of the
spin-current is determined by density of impurities. It was also shown that the
spin-current of the system could increase by increasing the Rashba coupling
strength and band-gap of the graphene and the sign of the spin-current could be
controlled by the direction of the current-driving electric field
Properties of charmed-strange tensor meson
The mass and current coupling constant of the
charmed-strange meson is calculated in the framework of two-point QCD sum rule
approach. Although the quantum numbers of this meson is not exactly known, its
width and decay modes are consistent with , which we consider to
write the interpolating current used in our calculations. Replacing the light
strange quark with up or down quark we also compare the results with those of
charmed tensor meson and estimate the order of SU(3) flavor symmetry
violation.Comment: 9 Pages, 2 Figures and 1 Table, Some misprints are correcte
Non-adiabatic ionization with tailored laser pulses
Non-adiabatic photo-ionization is difficult to control as it relies on the derivatives of the envelope and not on phase-details of the short ionizing pulse. Here, we introduce a catalyzing state, whose presence render non-adiabatic ionization sensitive to phase-details of tailored pulses. Since a catalyzing state is in general easy to create, this opens a perspective for coherent control of ultra-fast ionization
Testing the accuracy of Foti's dental age estimation methods on a London UK sample
Background and aim: Tooth development and eruption are widely used in assessing dental age estimation, and one of the methods in using tooth development and eruption is Foti's method. However, the population used in the original study was French. Therefore, the aim of this study was to test the accuracy of Foti's four dental age estimation regression models against the East London population, mainly of the Bangladeshi and Caucasian ethnicity. These count the number of erupted teeth and tooth germs using a radiograph (Foti 1), absence of a radiograph (Foti 2), maxillary erupted teeth (Foti 3) and mandibular erupted teeth (Foti 4). Methods: The test sample was archived panoramic radiographs of 754 healthy patients aged 6–20 years (380 males and 374 females). The difference between dental and chronological ages was tested using a t-test. The mean absolute difference was also calculated for all models. The most accurate method was defined as the smallest mean difference, smallest standard deviation (SD) and mean absolute difference between dental and chronological ages. Results: Foti model 2 was most accurate with a mean difference of 0.11 years (SD 1.70 years) and a mean absolute difference of 1.33 years. Models 3 (maxillary erupted teeth) and 4 (mandibular erupted teeth) were marginally less accurate, whilst model 1 (radiograph) overestimated age on average by more than 5 years. Conclusion: Our findings show that estimating age using erupting teeth was most accurate using Foti model 2 (least bias)
Vasopressin attenuates ischemia-reperfusion injury via reduction of oxidative stress and inhibition of mitochondrial permeability transition pore opening in rat hearts
Aim of this study was to investigate the involvement of the mitochondrial permeability transition pore (MPTP) and oxidative stress in the cardioprotective effect of vasopressin (AVP) on ischemia/reperfusion (I/R) injury. Anesthetized male wistar rats were subjected to regional 30 min ischemia and 120 min reperfusion and randomly divided into nine groups: (1) Control; saline was administered intravenously before ischemia, (2) vasopressin was administrated 10 min prior to ischemia, (3, 4) Atractyloside as MPTP opener, was injected 5 min prior to reperfusion without and with vasopressin, (5, 6) Cyclosporine A as a MPTP closer, was injected 5 min prior to reperfusion without and with vasopressin, (7) mitochondria were isolated from control group and CaCl2 was added as MPTP opener and swelling inducer, (8) isolated mitochondria from Control hearts was incubated with Cyclosporine A before adding the CaCl2 (9) CaCl2 was added to isolated mitochondria from vasopressin group. Infusion of vasopressin decreased infarct size (18.6±1.7% vs. control group 37.6±2.4%), biochemical parameters [LDH (Lactate Dehydrogenase), CK-MB (Creatine Kinase-MB) and MDA (Malondialdehyde) plasma levels, PAB (Prooxidant-antioxidant balance)] compared to control group. Atactyloside suppressed the cardioprotective effect of vasopressin (32.5±1.9% vs. 18.6±1.7%) but administration of the Cyclosporine A without and with vasopressin significantly reduced infarct size to 17.7±4% (P<0.001) and 22.7±3% (P<0.01) respectively, vs. 37.6±2.4% in control group. Also, vasopressin, similar to Cyclosporine A, led to decrease in CaCl2-induced swelling. It seems that vasopressin through antioxidant effect and MPTP inhibition has created a cardioprotection against ischemia/reperfusion injuries. © 2015 Elsevier B.V. All rights reserved
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