Proton Decay from Excited States in Spherical Nuclei

Based on a single particle model which describes the time evolution of the wave function during tunneling across a one dimensional potential barrier we study the proton decay of $^{208}$Pb from excited states with non-vanishing angular momentum $\ell$. Several quantities of interest in this process like the decay rate $\lambda$, the period of oscillation $T_{osc}$, the transient time $t_{tr}$, the tunneling time $t_{tun}$ and the average value of the proton packet position $r_{av}$ are computed and compared with the WKB results.Comment: 12 pages, 4 figure

Decay Rate of Triaxially-Deformed Proton Emitters

The decay rate of a triaxially-deformed proton emitter is calculated in a particle-rotor model, which is based on a deformed Woods-Saxon potential and includes a deformed spin-orbit interaction. The wave function of the $I=7/2^{-}$ ground state of the deformed proton emitter $^{141}$Ho is obtained in the adiabatic limit, and a Green's function technique is used to calculate the decay rate and branching ratio to the first excited 2$^{+}$ state of the daughter nucleus. Only for values of the triaxial angle $\gamma$ $<5^{\circ}$ is good agreement obtained for both the total decay rate and the 2$^{+}$ branching ratio.Comment: 19 pages, 4 figure

Time-dependent properties of proton decay from crossing single-particle metastable states in deformed nuclei

A dynamical study of the decay of a metastable state by quantum tunneling through an anisotropic, non separable, two-dimensional potential barrier is performed by the numerical solution of the time-dependent Schrodinger equation. Initial quasi- stationary proton states are chosen in the framework of a deformed Woods-Saxon single-particle model. The decay of two sets of states corresponding to true and quasi levels-crossing is studied and the evolution of their decay properties as a function of nuclear deformation is calculated around the crossing point. The results show that the investigation of the proton decay from metastable states in deformed nuclei can unambiguously distinguish between the two types of crossing and determine the structure of the nuclear states involved.Comment: 15 pages, 9 figures, submitted to Phys. Rev.

Role of dynamical particle-vibration coupling in reconciliation of the d3/2d_{3/2} puzzle for spherical proton emitters

It has been observed that decay rate for proton emission from $d_{3/2}$ single particle state is systematically quenched compared with the prediction of a one dimensional potential model although the same model successfully accounts for measured decay rates from $s_{1/2}$ and $h_{11/2}$ states. We reconcile this discrepancy by solving coupled-channels equations, taking into account couplings between the proton motion and vibrational excitations of a daughter nucleus. We apply the formalism to proton emitting nuclei $^{160,161}$Re to show that there is a certain range of parameter set of the excitation energy and the dynamical deformation parameter for the quadrupole phonon excitation which reproduces simultaneously the experimental decay rates from the 2$d_{3/2}$, 3$s_{1/2}$ and 1$h_{11/2}$ states in these nuclei.Comment: RevTex, 12 pages, 4 eps figure

Effect of combination antihypertensive therapy, including renin-angiotensin-aldosterone system inhibitors, on oxidative stress and arterial remodeling in hypertensive patients with heart failure with preserved ejection fraction

Aim. To study the effect of triple combination therapy on oxidative stress and arterial remodeling in hypertensive patients with heart failure with preserved ejection fraction (HFpEF).Material and methods. The study involved 76 people with diagnosed HFpEF. After a comprehensive examination, patients were randomized into two equal groups: first group — patients who received perindopril 10 mg, indapamide 2,5mg and amlodipine 5 mg; second — patients who received losartan 100 mg, indapamide 2,5 mg, amlodipine 5 mg. Before and 16 weeks after the therapy initiation, cardiac ultrasound, assessment of endothelial function with estimating endothelium-dependent vasodilation, assessment of vascular stiffness by photoplethysmography and compression oscillometry were carried out. The plasma concentration of oxidative stress marker 8-isoprostane was studied.Results. During the follow-up period, a significant improvement in endothelial function was noted: in the first group — from 8,1% to 11,4% (p=0,001), in the second — from 5,8% to 8,3% (p=0,0007). In both groups, there was an improvement in microvessel elasticity: a significant decrease in specific peripheral vascular resistance, as well as a significant decrease in total peripheral resistance in the first group (p&lt;0,002) and a tendency to decrease in the second one (p&gt;0,05). There was a significant increase in the stiffness of the aorta and muscular arteries in both groupsю In the first group, a stiffness index decreased from 10,38 m/s to 8,33 m/s (p&lt;0,0001), in the second — from 10,6 m/s to 9,3 m/s (p&lt;0,01). In addition, resistance index in the first group decreased from 71,5% to 60% (p&lt;0,0001), while in the second — from 68% to 60% (p=0,006). Also, both groups showed a significant decrease in the left atrial diastolic dimension and the left atrial volume index. A decrease in the 8-isoprostane plasma levels was noted, which indicates a decrease in oxidative stress.Conclusion. Oxidative stress, which develops due to chronic systemic inflammation, plays a key role in the pathogenesis of HFpEF. The results obtained show an improved endothelial function as a result of decrease in oxidative stress, which is accompanied by an improvement in vessel wall elasticity, thereby slowing down the heart failure progression