An extended GS method for dense linear systems

AbstractDavey and Rosindale [K. Davey, I. Rosindale, An iterative solution scheme for systems of boundary element equations, Internat. J. Numer. Methods Engrg. 37 (1994) 1399–1411] derived the GSOR method, which uses an upper triangular matrix Ω in order to solve dense linear systems. By applying functional analysis, the authors presented an expression for the optimum Ω. Moreover, Davey and Bounds [K. Davey, S. Bounds, A generalized SOR method for dense linear systems of boundary element equations, SIAM J. Comput. 19 (1998) 953–967] also introduced further interesting results. In this note, we employ a matrix analysis approach to investigate these schemes, and derive theorems that compare these schemes with existing preconditioners for dense linear systems. We show that the convergence rate of the Gauss–Seidel method with preconditioner PG is superior to that of the GSOR method. Moreover, we define some splittings associated with the iterative schemes. Some numerical examples are reported to confirm the theoretical analysis. We show that the EGS method with preconditioner PG(γopt) produces an extremely small spectral radius in comparison with the other schemes considered

A case of neurogenic myocardial stunning presenting transient left ventricular mid-portion ballooning simulating atypical takotsubo cardiomyopathy

SummaryA 57-year-old female patient, who was initially suspected to have subarachnoid hemorrhage, was admitted to our hospital. She experienced severe dyspnea and chest pain owing to pneumonia on the fourth admission day. Electrocardiography showed ST-segment elevation in leads V2 through V5, and echocardiography revealed hypokinetic left ventricular wall motion. No stenosis was found in the coronary arteries by urgent coronary angiography. However, left ventriculography revealed that the basal and apical areas were hyperkinetic and the mid portion was akinetic. After a month, left ventricular wall motion was improved and coronary artery spasm provocation tests were negative. Although the clinical course of this patient was similar to that of neurogenic myocardial stunning, the shape of her left ventricle was not typical

Oscillating focus of SopA associated with filamentous structure guides partitioning of F plasmid

The F plasmid is actively partitioned to daughter cells by the sopABC gene. To elucidate the partitioning mechanisms, we simultaneously analysed movements of the plasmid and the SopA ATPase in single living cells. SopA, which is a putative motor protein assembled densely near nucleoid borders and formed a single discrete focus associated with less dense filamentous distribution along the long axis of the cell. The dense SopA focus oscillates between cell poles. The direction of the plasmid motion switches as the SopA focus switches its position. The velocity of the plasmid motion stays constant while it oscillates moving towards the SopA focus. The low density filamentous distribution of SopA persisted throughout the SopA oscillation. The focus associated with filamentous distribution of SopA was also observed in a cell without nucleoid. The SopA filament may guide the movement of the plasmid as a railway track and lead it to cell quarters

Lipid control profile in patients with acute coronary syndrome at Tokushima Prefectural Central Hospital

In Japan atherosclerosis society guideline, it is recommended for secondary prevention of acute coronary syndrome to manage lipid. In particular, hyper-LDLemia is known to develop and promote atherosclerosis, and lowering the LDL-C level leads to suppression of recurrence of atherosclerosis. We investigated the profile of lipid control in patients who succeeded in percutaneous coronary intervention for acute coronary syndrome（ACS）at our hospital, and examined by high risk patients（chronic kidney disease, diabetes, obesity）. The achievement rate of LDL-C <１００ at discharge was６２％ of all cases, and the achievement rate of LDL-C <７０was only１６％. In particular, only１２％ of obese patients achieved LDL-C <７０. In recent years, it has been shown that additional administration of ezetimibe or PCSK９ inhibitor to statins further lowers LDL-C and significantly reduces the risk of developing cardiovascular disease. We should recognize that some ACS patients have not reached their goals and actively treat them for secondary prevention

α‑Glucosidase inhibitor miglitol attenuates glucose fluctuation, heart rate variability and sympathetic activity in patients with type 2 diabetes and acute coronary syndrome : a multicenter randomized controlled (MACS) study

Background: Little is known about clinical associations between glucose fluctuations including hypoglycemia, heart rate variability (HRV), and the activity of the sympathetic nervous system (SNS) in patients with acute phase of acute coronary syndrome (ACS). This pilot study aimed to evaluate the short-term effects of glucose fluctuations on HRV and SNS activity in type 2 diabetes mellitus (T2DM) patients with recent ACS. We also examined the effect of suppressing glucose fluctuations with miglitol on these variables. Methods: This prospective, randomized, open-label, blinded-endpoint, multicenter, parallel-group comparative study included 39 T2DM patients with recent ACS, who were randomly assigned to either a miglitol group (n = 19) or a control group (n = 20). After initial 24-h Holter electrocardiogram (ECG) (Day 1), miglitol was commenced and another 24-h Holter ECG (Day 2) was recorded. In addition, continuous glucose monitoring (CGM) was performed throughout the Holter ECG. Results: Although frequent episodes of subclinical hypoglycemia (≤4.44 mmo/L) during CGM were observed on Day 1 in the both groups (35% of patients in the control group and 31% in the miglitol group), glucose fluctuations were decreased and the minimum glucose level was increased with substantial reduction in the episodes of subclinical hypoglycemia to 7.7% in the miglitol group on Day 2. Holter ECG showed that the mean and maximum heart rate and mean LF/HF were increased on Day 2 in the control group, and these increases were attenuated by miglitol. When divided 24-h time periods into day-time (0700–1800 h), night-time (1800–0000 h), and bed-time (0000–0700 h), we found increased SNS activity during day-time, increased maximum heart rate during night-time, and glucose fluctuations during bed-time, which were attenuated by miglitol treatment. Conclusions: In T2DM patients with recent ACS, glucose fluctuations with subclinical hypoglycemia were associated with alterations of HRV and SNS activity, which were mitigated by miglitol, suggesting that these pathological relationships may be a residual therapeutic target in such patients

Bicuspid aortic valve endocarditis complicated by perivalvular abscess

A 37-year-old man presenting with fever and chest pain was admitted to our hospital. Electrocardiogram showed sinus tachycardia and complete left bundle branch block. Transthoracic echocardiogram showed infective endocarditis in the bicuspid aortic valve, complicated by multiple hyperechoic vegetations and severe aortic regurgitation. Blood cultures were negative and intravenous empiric antibiotic therapy was begun. However, fever lasted for 7 days and follow-up echocardiography revealed a newly emerged perivalvular abscess. The patient eventually underwent an urgent aortic root replacement that confirmed the echocardiographic findings. Our case report emphasizes that all patients with suspected aortic valve endocarditis should undergo early and followup echocardiographic studies

Day Surgery ヒガエリ シュジュツ ノ ゲンジョウ

From May 1999, the Day Surgery for the operations of inguinal hernia, cholecystolithiasis and benign thyroid tumor were introduced in our department. Twenty nine patients (5 inguinal hernia repairs in children, 11 tension free inguinal hernia repairs in adults, 8 laparoscopic cholecystectomies, 3 extirpations of benign thyroid tumors, 1 extirpation of giant breast tumor, 1 extirpation of skin tumor in child) were attempted to put the Day Surgery into practice. 2 cases (one : inguinal hernia of child, another inguinal hernia of adult) were not successful because of postoperative complications like wound pain. The day surgery for 27 cases were successfully carried out. As the Day Surgery has benefits of cutting down on expenses, saving time and reducing mental fatigue, the feelings of satisfaction of all of these patients were remarkably high. The system of the Day Surgery was almost established in our department , so we actively would like to extend the kinds of operations suitable for the Day Surgery