Wave Packet Propagation and Electric Conductivity of Nanowires

We compute the electric conductivity of nanowires in the presence of magnetic domain walls by the method of wave packet propagation. We demonstrate that the propagation through the wire depends on the initial state used in the wave packet simulation. We propose a procedure, based on the Landauer formula, to reduce this dependence. Direct numerical calculations of the Kubo formula for small individual systems are used as reference data for the proposed procedure. The enhancement of the conductivity in the magnetic domain wall is found in the present method in accordance with the previous perturbative analysis.Comment: 20 pages, 9 figure

Wave Packet Propagation and Electric Conductivity of Nanowires

We compute the electric conductivity of nanowires in the presence of magnetic domain walls by the method of wave packet propagation. We demonstrate that the propagation through the wire depends on the initial state used in the wave packet simulation. We propose a procedure, based on the Landauer formula, to reduce this dependence. Direct numerical calculations of the Kubo formula for small individual systems are used as reference data for the proposed procedure. The enhancement of the conductivity in the magnetic domain wall is found in the present method in accordance with the previous perturbative analysis

Sleep Quality is associated with Central Arterial Stiffness in Postmenopausal Women : A Cross-sectional Pilot Study

This study aimed to investigate the associations between sleep quality and arterial stiffness in healthy postmenopausal women. A total of 31 healthy postmenopausal women aged between 50 and 74 years participated in this study. Objectively and subjectively measured sleep quantity and quality were concomitantly obtained by a waist-worn actigraphy, Pittsburgh Sleep Quality Index (PSQI) questionnaire, and daily sleep diary. Carotid-femoral pulse wave velocity (cfPWV), brachial-ankle PWV (baPWV), and femoral-ankle PWV (faPWV) were measured as indices of arterial stiffness. Based on the PSQI score, the participants were divided into good (PSQI 5.5; n = 10) sleepers. Self-reported sleep duration was significantly longer in poor sleepers than in good sleepers. However, there was no difference in total sleep time measured by actigraphy between the two groups. Additionally, sleep latency and wake after sleep onset significantly increased, and sleep efficiency significantly decreased in poor sleepers than in good sleepers. The cfPWV and baPWV were significantly higher in poor sleepers than in good sleepers, even after adjustment for risk factors (i.e., age, blood pressure, and physical activity), but no difference in faPWV. These results suggest that decreased sleep quality is associated with an increase in central arterial stiffness in postmenopausal women

定期的な有酸素性運動は中高齢男性における勃起不全を改善するか？

科学研究費助成事業 研究成果報告書：挑戦的萌芽研究2015-2017課題番号 : 15K1269

Mineralocorticoid receptor stimulation induces urinary storage dysfunction via upregulation of epithelial sodium channel expression in the rat urinary bladder epithelium

AbstractWe aimed to evaluate mineralocorticoid receptor (MR) expression in rat bladder and the physiological role of the MR-epithelial sodium channel (ENaC) pathway in controlling bladder function in 10–12-week-old, male Sprague–Dawley rats. First, we examined the mRNA expression of MR and localization of MR and ENaC-α proteins in the urinary bladder. MR mRNA expression was observed in untreated-rat urinary bladders, and MR and ENaC-α proteins were localized in the epithelium. Next, rats were treated with vehicle (controls) or fludrocortisone (an MR agonist) for 3 days, and ENaC-α protein expression levels and bladder function were evaluated on day 4. ENaC-α protein expression was significantly higher in fludrocortisone-treated rats than in controls. In addition, cystometry was performed during intravesical infusion of saline and amiloride (an ENaC inhibitor). While intercontraction intervals (ICIs) during saline infusion were significantly shorter in the fludrocortisone group than in the controls, infusion of amiloride normalized the ICIs in the fludrocortisone group. However, no intra- or inter-group differences in maximum intravesical pressure were observed. Taken together, MR protein is localized in the rat urinary bladder epithelium, and may regulate ENaC expression and bladder afferent input. The MR-ENaC pathway may be a therapeutic target for ameliorating storage symptoms

Photoluminescence Enhancement of β-FeSi2 Nanocrystals Controlled by Transport of Holes in Cu-doped n-type Si Substrates

We have investigated PL behavior of β-FeSi2 nanocrystals controlled by transport of holes in Cu-doped n-type Si substrates. PL enhancement was observed and PCI-PL measurements revealed that PL enhancement was attributed to a transport process of holes with a larger time constant in Cu-doped n-Si substrate in which an interval trap process is controlled by Cu doping.International Conference and Summer School on Advanced Silicide Technology 2014, July 19–21, 2014, Tokyo, Japa

Histological Observation of Regions around Bone Tunnels after Compression of the Bone Tunnel Wall in Ligament Reconstruction

The objectives of this study were to investigate the time-course of influence of compression of bone tunnel wall in ligament reconstruction on tissue around the bone tunnel and to histologically examine the mechanism of preventing the complication of bone tunnel dilation, using rabbit tibia. A model in which the femoral origin of the extensor digitorum longus tendon was cut and inserted into a bone tunnel made proximal to the tibia was prepared in the bilateral hind legs of 20 Japanese white rabbits. In each animal, a tunnel was made using a drill only in the right leg, while an undersized bone tunnel was made by drilling and then dilated by compression using a dilator to the same tunnel size as that in the right leg. Animals were sacrificed at 0, 2, 4, 8 and 12 weeks after surgery (4 animals at each time point). Observation of bone tunnels by X-ray radiography showed osteosclerosis in the 2- and 4-week dilation groups. Osteosclerosis appeared as white lines around the bone tunnel on X-ray radiography. This suggests that dilation promotes callus formation in the bone tunnel wall and prevents the complication of bone tunnel enlargement after ligament reconstruction

RESULTS OF EATON AND LITTLER'S LIGAMENT RECONSTRUCTION FOR INSTABILITY OF THE FIRST CARPOMETACARPAL JOINT

This study presents the cases of Eaton and Littler's ligament reconstruction for the treatment of instability of lst CM joint resulting from early stage osteoarthritis (Group OA), trauma (Group T), and a part of generalized joint laxity (Group GJL) in 21 joints of 20 cases. Omitting six cases with less than one year follow-up, 15 joints in 14 cases were analyzed. Clinically, hypermobility pain was improved in all joints. However, eight out of 14 patients felt their joints stretched, but still had the normal range of motion. Grip power and pinch power was significantly improved (P＜0.01, P＜0.05). Comparing each group, only Group T revealed a significant difference between preoperative and postoper- ative grip power (P＜0.01). In increase of grip power, Group T were more significantly improved than Group OA (P＜0.01) and Group GJL (P＜0.05). Radiographically, postoper- ative stages of 4 joints in 4 cases out of 8 cases which felt stretched progressed from their preoperative stages. We assumed that the newly reconstructed ligament may be strong enough to maintain the stability of 1st CM joint and ligament reconstruction is most effective in treating post-traumatic instability

Relationship between Aortic Compliance and Impact of Cerebral Blood Flow Fluctuation to Dynamic Orthostatic Challenge in Endurance Athletes

Aorta effectively buffers cardiac pulsatile fluctuation generated from the left ventricular (LV) which could be a mechanical force to high blood flow and low-resistance end-organs such as the brain. A dynamic orthostatic challenge may evoke substantial cardiac pulsatile fluctuation via the transient increases in venous return and stroke volume (SV). Particularly, this response may be greater in endurance-trained athletes (ET) who exhibit LV eccentric remodeling. The aim of this study was to determine the contribution of aortic compliance to the response of cerebral blood flow fluctuation to dynamic orthostatic challenge in ET and age-matched sedentary (SED) young healthy men. ET (n = 10) and SED (n = 10) underwent lower body negative pressure (LBNP) (−30 mmHg for 4 min) stimulation and release the pressure that initiates a rapid regain of limited venous return and consequent increase in SV. The recovery responses of central and middle cerebral arterial (MCA) hemodynamics from the release of LBNP (~15 s) were evaluated. SV (via Modeflow method) and pulsatile and systolic MCA (via transcranial Doppler) normalized by mean MCA velocity (MCAv) significantly increased after the cessation of LBNP in both groups. ET exhibited the higher ratio of SV to aortic pulse pressure (SV/AoPP), an index of aortic compliance, at the baseline compared with SED (P < 0.01). Following the LBNP release, SV was significantly increased in SED by 14 ± 7% (mean ± SD) and more in ET by 30 ± 15%; nevertheless, normalized pulsatile, systolic, and diastolic MCAv remained constant in both groups. These results might be attributed to the concomitant with the increase in aortic compliance assessed by SV/AoPP. Importantly, the increase in SV/AoPP following the LBNP release was greater in ET than in SED (P < 0.01), and significantly correlated with the baseline SV/AoPP (r = 0.636, P < 0.01). These results suggest that the aortic compliance in the endurance athletes is able to accommodate the additional SV and buffer the potential increase in pulsatility at end-organs such as the brain