Wind Resistance Evaluation of Existing Standing Buddha Statue Using 3D Laser Scanning and CFD

Underestimating the aerodynamic forces acting on structures can lead to them sustaining severe damage. Currently, there are limited studies on the wind flow around complex-shaped tall structures such as the Buddha statue (Monywa, Myanmar) and the aerodynamic forces acting on them. This study discusses the applicability of three-dimensional (3D) terrestrial laser scanning in the 3D modeling of an existing complex-shaped standing Buddha statue. This study also aims to shed light on the wind resistance evaluation for the maintenance of a contemporary standing Buddha statue. Large-eddy simulation (LES), a turbulence model used in computational fluid dynamics, was utilized to calculate the wind flow around it. The results showed that there was no recirculation region at its top. The horseshoe vortex moved closer to the Buddha statue as the angle of attack (AOA) increased. However, the size of the wake region decreased. Sudden changes in the aerodynamic force coefficients and Strouhal number were observed in the Buddha statue—owing to vortices caused by the cross-sectional variations in shape and a setback. Finally, the most vulnerable parts of the Buddha statue that might require optimal maintenance and renovation are mentioned. Results from this study can be used in developing maintenance techniques for similar complex-shaped structures

Numerical evaluation of vortex-induced vibration amplitude of a box girder bridge using forced oscillation method

The evaluation of the amplitude of the vortex-induced vibration (VIV) of a long-span bridge is necessary to implement a wind-resistant design. The development of high-performance computing has led to the use of computational fluid dynamics (CFD) in this domain, but the evaluation of VIV amplitude using the free vibration method in CFD incurs a high computational cost because of the small negative aerodynamic damping in the wind speed region of VIV. In this study, the use of flutter derivatives based on the forced oscillation method with a large eddy simulation is proposed for evaluating the VIV amplitude to reduce computational cost. The heaving VIV amplitude of a box girder was evaluated using simulated flutter derivatives and the results were validated by corresponding free vibration wind tunnel tests. Because the aerodynamic damping obtained by the flutter derivatives showed a clear dependence on the oscillation amplitude, the VIV amplitude can be evaluated using the proposed method. The effects of the spanwise domain size and Reynolds number were also significant

Flow field control to mitigate airborne sea salt adhesion on bridge girders

In order to realise effective maintenance and enhanced durability of structures, it is important to also reduce corrosion of bridges by airborne sea salt. The objective of this study is to reduce airborne sea salt adhesion amount on steel girder bridges by employing aerodynamic countermeasures. The study bridge is a typical metropolitan highway bridge with 8 I-shaped steel girders located in Japan. Aerodynamic countermeasure devices are employed to change the flow field around the bridge structure in an attempt to reduce wind velocity normal to the bridge girders. Devices existing on urban bridges such as noise barriers, median barriers, and facilities for passage of drainage pipes and electric cables, modelled as horizontal plates, are modified and investigated for their ability to reduce airborne sea salt adhesion amount. As additional devices, vertical plates are installed to change the flow separation and their applicability is also studied. Computational fluid dynamics is employed for flow field simulations and airborne sea salt adhesion amount is estimated by the improved concentration flux method. Findings indicate that horizontal plates and vertical plates significantly reduce airborne sea salt adhesion amount. Noise barriers and median barriers can also reduce airborne sea salt adhesion amount

3Dマッピングシステムを用いた両心房Stimulus-V mapによる順行性速伝導路入口部の解剖学的位置並び特徴の検討

Purpose Previous studies examined the right atrial (RA) input site of the antegrade fast pathway (AFp) (AFpI). However, the left atrial (LA) input to the atrioventricular (AV) node has not been extensively evaluated. In this study, we created three-dimensional (3-D) bi-atrial stimulus-ventricle (St-V) maps and analyzed the input site and characteristics of the AFp in both the RA and LA. Methods Forty-four patients diagnosed with atrial fibrillation or WPW syndrome were included in this study. Three-dimensional bi-atrial St-V mapping was performed using an electroanatomical mapping system. Sites exhibiting the minimal St-V interval (MinSt-V) were defined as AFpIs and were classified into seven segments, four in the RA (F, S, M, and I) and three in the LA (M1, M2, and M3). By combining the MinSt-V in the RA and LA, the AFpIs were classified into three types: RA, LA, and bi-atrial (BA) types. The clinical and electrophysiological characteristics were compared. Results AFpIs were most frequently observed at site S in the RA (34%) and M2 in the LA (50%), and the BA type was the most common (57%). AFpIs in the LA were recognized in 75% of the patients. There were no clinical or electrophysiological indicators for predicting AFpI sites. Conclusions Three-dimensional bi-atrial St-V maps could classify AFpIs in both the RA and LA. AFpIs in the LA were frequently recognized. There were no significant clinical or electrophysiological indicators for predicting AFpI sites, and 3-D bi-atrial St-V mapping was the only method to reveal the precise AFp input site

Effects of Esaxerenone on Diabetes-Induced Endothelial Dysfunction

Aims: Pharmacological blockade of mineralocorticoid receptors (MRs) is a potential therapeutic approach to reduce cardiovascular complications since MRs play a crucial role in cardiovascular regulation. Recent studies suggest that MR antagonists affect several extrarenal tissues, including vessel function. We investigated the effect of a novel nonsteroidal selective MR blocker, esaxerenone, on diabetes-induced vascular dysfunction. Methods: Diabetes was induced by a single dose of streptozotocin in 8-week-old male C57BL/6 mice. Esaxerenone (3 mg/kg/day) or a vehicle was administered by gavage to diabetic mice for 3 weeks. Metabolic parameters, plasma aldosterone levels, and parameters related to renal function were measured. Endothelium-dependent or -independent vascular responses of the aortic segments were analyzed with acetylcholine or sodium nitroprusside, respectively. Human umbilical vein endothelial cells (HUVECs) were used for the in vitro study. Results: Induction of diabetes elevated plasma aldosterone level (P＜0.05) and impaired endothelium-dependent vascular relaxation (P＜0.05). The administration of esaxerenone ameliorated the endothelial dysfunction (P＜0.01) without the alteration of metabolic parameters, blood pressure, and renal function. Esaxerenone improved the eNOSSer1177 phosphorylation in the aorta obtained from diabetic mice (P＜0.05) compared with that in the vehicle-treated group. Furthermore, a major MR agonist, aldosterone, decreased eNOSSer1177 phosphorylation and increased eNOSThr495 phosphorylation in HUVECs, which recovered with esaxerenone. Esaxerenone ameliorated the endothelium-dependent vascular relaxation caused by aldosterone in the aortic segments obtained from C57BL/6 mice (P＜0.001). Conclusion: Esaxerenone attenuates the development of diabetes-induced endothelial dysfunction in mice. These results suggest that esaxerenone has potential vascular protective effects in individuals with diabetes

Clinical clerkship students’ preferences and satisfaction regarding online lectures during the COVID-19 pandemic

Background: The COVID-19 pandemic has caused an unprecedented disruption in medical education. Students and lecturers had to adapt to online education. The current study aimed to investigate the level of satisfaction and future preference for online lectures among clinical clerkship students and elucidated the factors that affect these outcomes. Methods: We selected a sample of 114 medical students undergoing clinical clerkship during the COVID-19 pandemic. We conducted onsite lectures before the pandemic and online lectures after the outbreak. A survey was conducted, and the sample included students and 17 lecturers. The average scores of total satisfaction and future preference related to online lectures were computed. Results: Students’ scores on total satisfaction with online lectures and their future preference were higher than those for onsite lectures. Scores on the ease of debating dimension were low and those on accessibility of lectures in online lectures were higher than those in onsite lectures. There was no difference between the two groups in the scores on the comprehensibility and ease of asking questions dimensions. Results of the multiple regression analysis revealed that accessibility determined total satisfaction, and future preference was determined by comprehensibility as well as accessibility. Contrary to students’ future preferences, lecturers favored onsite lectures to online ones. Conclusion: Online lectures are an acceptable mode of teaching during the COVID-19 pandemic for students undergoing clinical clerkship. Online lectures are expected to become more pervasive to avoid the spread of COVID-19

高血圧患者におけるアンジオテンシン II-レニンフィードバック機構に対するL/N型カルシウムチャネル拮抗薬の影響

Objectives. Cilnidipine, an L-/N-type calcium channel blocker (CCB), has unique organ-protective properties due to suppression of hyperactivity in the sympathetic nervous system and renin-angiotensin system (RAS). In this study, we hypothesized that cilnidipine might exert a renoprotective effect by suppressing the RAS. Methods. A total of 25 hypertensive patients receiving a RAS inhibitor were randomly assigned to a cilnidipine (n = 12) or amlodipine (n = 13) group. The effects of cilnidipine on proteinuria and angiotensin II–renin feedback were assessed. Results. After 6 months of treatment, both systolic and diastolic blood pressures were significantly reduced to a similar extent in both groups. The urine albumin-to-creatinine ratio was significantly lower in the cilnidipine group (p < 0.05) than in the amlodipine group. Amlodipine increased plasma angiotensin I and angiotensin II levels (p < 0.05), whereas cilnidipine did not. Interestingly, the cilnidipine group had a higher ratio of angiotensin-(1–7) (Ang-(1–7)) to angiotensin II in plasma than the amlodipine group (p < 0.05). Conclusions. The L-/N-type CCB cilnidipine, but not amlodipine, decreased urinary albumin excretion in hypertensive patients. Cilnidipine also increased the ratio of Ang-(1–7) to angiotensin II in plasma, which might be one factor underlying its beneficial effects

Coronary Artery Disease/Effects of Ablation on Cardiac Reserve

The effects of catheter ablation on exercise tolerance and quality of life in patients with atrial fibrillation (AF) have been reported. We assessed cardiac function in more detail using the leg positive pressure (LPP) technique and found that contractile reserve is particularly important in relation to exercise tolerance and prognosis. In this study, we used the LPP technique to examine changes in contractile reserve immediately after ablation and 6 months later. We prospectively enrolled patients who underwent catheter ablation for AF at 2 institutes. We performed LPP stress echocardiography 2 to 3 days after (FU-1) and 6 months after (FU-2) ablation to examine changes in cardiac function indexes. The primary end point was improvement in contractile reserve. Ultimately, 109 patients (mean age 67.4 ± 9.6 years; 70% men) underwent 2 sessions of LPP stress echocardiography. The median CHA2DS2-VASC score was 2 (interquartile range 13). From FU-1 to FU-2, the change in the stroke volume index after the LPP maneuver increased in patients with paroxysmal and persistent AF with low CHA2DS2-VASC scores (both p <0.05). Regardless of AF subtype, contractile reserve at FU-2 improved in patients with low CHA2DS2-VASC scores compared with that at FU-1. In contrast, patients with high CHA2DS2-VASC scores had no change. In conclusion, patients with AF with a low CHA2DS2-VASC score had improved contractile reserve after ablation, whereas patients with high scores did not show any improvement. Aggressive interventions in patients with high scores may lead to better management after catheter ablation

J wave due to diagonal branch ischemia

The culprit lesion of acute myocardial infarction could be predicted by electrocardiogram findings. However, we experienced some cases with coronary angiographic finding in the area of ST-T elevation that was different from that predicted. The lambda-like J wave could be caused by ischemia although the mechanism has not been fully elucidated. We report a case of acute myocardial infarction that showed discrepancy between ST-T elevation with lambda-like ischemic J wave in a broad area and coronary angiographical finding of diagonal branch occlusion

左前下行枝冠動脈周囲の局所心外膜脂肪厚は簡便な冠動脈疾患の予測因子である : フラミンガムリスクスコアと組み合わせた新しい予測モデル

Background: Compared with global cardiac adiposity, the local accumulation of fat surrounding coronary arteries might have a more direct impact on coronary artery disease (CAD). Here, we compared the local epicardial adipose tissue (EAT) thickness and global cardiac adiposity volumes for predicting CAD. Methods and Results: A total of 197 consecutive subjects underwent 320-slice multi-detector computed tomography coronary angiography and were segregated into CAD (≥1 coronary artery branch stenosis ≥50%) and non-CAD groups. EAT thickness was measured at the right coronary artery (EATRCA), the left anterior descending artery (EATLAD), and the left circumflex artery (EATLCX). Although EATRCA and EATLCX were similar between the 2 groups, EATLAD was larger in the CAD group than in the non-CAD group (5.45±2.16 mm vs. 6.86±2.19 mm, P<0.001). EATLAD, after correcting for confounding factors, was strongly associated with CAD (r=0.276, P<0.001) and Gensini score (r=0.239, P<0.001). On multiple regression analysis, Framingham risk score combined with EATLAD was a strong predictor of CAD (adjusted R2=0.121; P<0.001). Conclusions: The local fat thickness surrounding the LAD is a simple and useful surrogate marker for estimating the presence, severity, and extent of CAD, independent of classical cardiovascular risk factors