Instanton-noninstanton transition in nonintegrable tunneling processes: A renormalized perturbation approach

The instanton-noninstanton (I-NI) transition in the tunneling process, which has been numerically observed in classically nonintegrable quantum maps, can be described by a perturbation theory based on an integrable Hamiltonian renormalized so as to incorporate the integrable part of the map. The renormalized perturbation theory is successfully applied to the two quantum maps, the H\'enon and standard maps. In spite of different nature of tunneling in the two systems, the I-NI transition exhibits very common characteristics. In particular, the manifestation of I-NI transition is obviously explained by a remarkable quenching of the renormalized transition matrix element. The enhancement of tunneling probability after the transition can be understood as a sudden change of the tunneling mechanism from the instanton to quite a different mechanism supported by classical flows just outside of the stable-unstable manifolds of the saddle on the top of the potential barrier.Comment: 6 pages, 4 figure

Triaxial superdeformation in 40^{40}Ar

Superdeformed (SD) states in $^{40}$Ar have been studied using the deformed-basis antisymmetrized molecular dynamics. Low energy states were calculated by the parity and angular momentum projection (AMP) and the generator coordinate method (GCM). Basis wave functions were obtained by the energy variation with a constraint on the quadrupole deformation parameter $\beta$, while other quantities such as triaxiality $\gamma$ were optimized by the energy variation. By the GCM calculation, an SD band was obtained just above the ground state (GS) band. The SD band involves a $K^\pi = 2^+$ side band due to the triaxiality. The calculated electric quadrupole transition strengths of the SD band reproduce the experimental values appropriately. Triaxiality is significant for understanding low-lying states.Comment: 11 pages, 4 figure

Comparison of conservative treatment versus transcatheter arterial embolisation for the treatment of spontaneously ruptured hepatocellular carcinoma

Purpose: To elucidate the prognostic factors in the spontaneous rupture of hepatocellular carcinoma (HCC) and to determine whether transcatheter arterial embolisation (TAE) is associated with better prognosis compared to conservative treatment. Material and methods: A retrospective multicentre study was conducted involving 71 patients with spontaneous rupture of HCC. A conservative treatment group (Cons T group) included 20 patients, while a transcatheter arterial embolisation group (TAE group) included 51 patients. Results: The median survival time (MST) in the Cons T group was only 16 days and the survival rate was 39% at one month, whereas the MST in the TAE group was 28 days and the one month survival rate was 63%. However, there is no statistically significant difference in the overall survival between Cons T and TAE groups (p = 0.213). Multivariable analysis identified only the presence of distant metastasis as an independent prognostic factor (p = 0.023). A subanalysis including patients without distant metastasis showed that the presence of portal vein tumour thrombosis was a significant prognostic factor (p = 0.015). Conclusions: Distant metastasis appears to be a prognostic factor in spontaneous rupture of HCC. In cases without distant metastasis, portal vein tumour thrombosis could influence the prognosis. Our data failed to prove any benefit of TAE as the primary management

Experimental renal and hepatic artery embolization with a new embolic agent, atelocollagen, in a porcine model

PURPOSEWe aimed to investigate the potentiality of atelocollagen, a new embolic agent which is collagen type I in a porcine experimental model. MATERIALS AND METHODSThree pigs underwent transcatheter embolization of lower interlobular arteries of the renal artery (n=6) and one branch of the hepatic artery (n=3) with collagen type I. Angiography was performed prearterial, during, and postarterial embolization. After the procedure, samples from the embolized organs were evaluated by histological analysis. RESULTSSix lower interlobular renal arteries and three hepatic arteries were successfully embolized by administration of 0.8±0.3 mL and 2.9±1.2 mL, respectively, of the collagen type I. Histological findings of the embolized kidney specimens showed that the collagenous materials filled the arterial lumen, whose size ranged from 2.02 to 839.82 μm and reached the level of afferent arteries of glomerular tufts. Although the area of occluded arteries of the liver was smaller than the kidney, histological findings of the liver specimens showed that the collagenous materials filled small arterial lumens from 2.81 to 187.86 μm in diameter. CONCLUSIONAtelocollagen, a collagen type I, has the potential to be used to embolize the distal vessels of both renal and hepatic arteries

On-The-Fly Observing System of the Nobeyama 45-m and ASTE 10-m Telescopes

We have developed spectral line On-The-Fly (OTF) observing mode for the Nobeyama Radio Observatory 45-m and the Atacama Submillimeter Telescope Experiment 10-m telescopes. Sets of digital autocorrelation spectrometers are available for OTF with heterodyne receivers mounted on the telescopes, including the focal-plane 5 x 5 array receiver, BEARS, on the 45-m. During OTF observations, the antenna is continuously driven to cover the mapped region rapidly, resulting in high observing efficiency and accuracy. Pointing of the antenna and readouts from the spectrometer are recorded as fast as 0.1 second. In this paper we report improvements made on software and instruments, requirements and optimization of observing parameters, data reduction process, and verification of the system. It is confirmed that, using optimal parameters, the OTF is about twice as efficient as conventional position-switch observing method.Comment: 11 pages, 13 figures, accepted for publication in PAS

Hemosiderin Detection inside the Mammillary Bodies Using Quantitative Susceptibility Mapping on Patients with Wernicke-Korsakoff Syndrome

Hemorrhage inside the mammillary bodies (MMBs) is known to be one of the findings of Wernicke encephalopathy. Brain MRI of two patients with Wernicke-Korsakoff syndrome (WKS) demonstrated high susceptibility values representing hemosiderin deposition in MMBs by using quantitative susceptibility mapping (QSM). QSM provided additional information of susceptibility values to susceptibility-weighted imaging in diagnosis of WKS

High concentrations of omega-3 fatty acids are associated with the development of atrial fibrillation in the Japanese population

The favorable effect of fish oils rich in n-3 polyunsaturated fatty acids (PUFAs) on the development of atrial fibrillation (AF) is controversial. The relationship between the serum concentrations of n-3 PUFAs and the incidence of AF is unclear; therefore, in the present study, we aimed to elucidate this relationship. We evaluated the serum concentrations of n-3 PUFAs in 110 patients with AF, 46 patients with ischemic heart disease (IHD) and no AF, and 36 healthy volunteers. Thirty-six patients had a history of IHD (IHD-AF group) and 74 did not (L-AF group). The eicosapentaenoic acid (EPA) levels in the L-AF group were higher than those in the IHD-AF and control groups (117 +/- A 64, 76 +/- A 30, and 68 +/- A 23 mu g/ml, respectively); the docosahexaenoic acid (DHA) levels showed the same pattern (170 +/- A 50, 127 +/- A 27, and 126 +/- A 35 mu g/ml, respectively). In both the L-AF and IHD-AF groups, the EPA levels in patients with persistent and permanent AF were higher than those in patients with paroxysmal AF (L-AF 131 +/- A 74 vs. 105 +/- A 51 mu g/ml; IHD-AF 82 +/- A 28 vs 70 +/- A 33 mu g/ml). Multivariate analysis showed that cases of AF were associated with higher levels of EPA but not DHA. In this Japanese population study, the EPA and DHA levels in patients with L-AF were higher than those in normal subjects. In particular, the EPA level was associated with the incidence of AF. These findings suggest that an excess of EPA might be a precipitating factor of AF.ArticleHEART AND VESSELS. 28(4):497-504 (2013)journal articl

Enhancing effects of salicylate on tonic and phasic block of Na+ channels by class 1 antiarrhythmic agents in the ventricular myocytes and the guinea pig papillary muscle

AbstractObjective: To study the interaction between salicylate and class 1 antiarrhythmic agents. Methods: The effects of salicylate on class 1 antiarrhythmic agent-induced tonic and phasic block of the Na+ current (INa) of ventricular myocytes and the upstroke velocity of the action potential (Vmax) of papillary muscles were examined by both the patch clamp technique and conventional microelectrode techniques. Results: Salicylate enhanced quinidine-induced tonic and phasic block of INa at a holding potential of −100 mV but not at a holding potential of −140 mV; this enhancement was accompanied by a shift of the h∞ curve in the presence of quinidine in a further hyperpolarized direction, although salicylate alone did not affect INa. Salicylate enhanced the tonic and phasic block of Vmax induced by quinidine, aprindine and disopyramide but had little effect on that induced by procainamide or mexiletine; the enhancing effects were related to the liposolubility of the drugs. Conclusions: Salicylate enhanced tonic and phasic block of Na+ channels induced by class 1 highly liposoluble antiarrhythmic agents. Based on the modulated receptor hypothesis, it is probable that this enhancement was mediated by an increase in the affinity of Na+ channel blockers with high lipid solubility to the inactivated state channels