215 research outputs found
On Level p
We give a simple formula for the Fourier coefficients of some degree-two Siegel cusp form with level p
Minimally Invasive Surgical Therapies for Atrial Fibrillation
Atrial fibrillation is the most common sustained arrhythmia and is associated with significant risks of thromboembolism, stroke, congestive heart failure, and death. There have been major advances in the management of atrial fibrillation including pharmacologic therapies, antithrombotic therapies, and ablation techniques. Surgery for atrial fibrillation, including both concomitant and stand-alone interventions, is an effective therapy to restore sinus rhythm. Minimally invasive surgical ablation is an emerging field that aims for the superior results of the traditional Cox-Maze procedure through a less invasive operation with lower morbidity, quicker recovery, and improved patient satisfaction. These novel techniques utilize endoscopic or minithoracotomy approaches with various energy sources to achieve electrical isolation of the pulmonary veins in addition to other ablation lines. We review advancements in minimally invasive techniques for atrial fibrillation surgery, including management of the left atrial appendage
Shaking Table Test Using Full-scale Model for Lateral Resistance Force of Ballasted Tracks During Earthquake
AbstractIn Japan where large earthquakes frequently occur, it is important to increase the resistibility of railway structures to earthquakes. The authors performed a shaking table test using a full-scale model to evaluate the lateral resistance force of the ballasted track during earthquakes. In this study, the shaking table test was attempted under test conditions under which the sleeper is given the lateral force to induce track buckling. Two kinds of cross sections of ballasted track for the full-scale model were applied: a straight track and a curved track to evaluate the influence of the difference of the cross section of ballasted track on the lateral resistance force. The results of the shaking table test clarified that the lateral resistance force of the ballasted track decreased during shaking, and the lateral sleeper displacement increased significantly by lateral force smaller than the lateral resistance force of the ballasted track after shaking. In addition, it is considered that the influence of the cross section of ballasted track on the lateral ballast resistance force during shaking and after shaking is small
Numerical method for evaluating the lateral resistance of sleepers in ballasted tracks
AbstractBallasted track sleepers have the important function of providing sufficient lateral resistance to prevent the lateral movement of rails. If the lateral force induced by the thermal expansion of steel rails overcomes the lateral resistance of sleepers, rail buckling may occur. More attention has been paid to this problem of lateral stability since the introduction of continuous welded rails. However, there is a high degree of uncertainty in the prediction of the lateral resistance of sleepers. In view of the foregoing, a series of laboratory tests was conducted on 1/5-scale models to evaluate the lateral resistance of sleepers. Single-sleeper pullout tests and track panel pullout tests were conducted on different types of concrete sleepers. The results of the pullout tests revealed the effects of the sleeper shape, the sleeper spacing, and the number of sleepers on the lateral resistance. Based on the model test results, a new numerical method for evaluating the lateral resistance of sleepers is proposed
Correlations of perioperative coagulopathy, fluid infusion and blood transfusions with survival prognosis in endovascular aortic repair for ruptured abdominal aortic aneurysm
Background: Factors associated with survival prognosis among patients who undergo endovascular aortic repair (EVAR) for ruptured abdominal aortic aneurysms (rAAA) have not been sufficiently investigated. In the present study, we examined correlations between perioperative coagulopathy and 24-h and 30-day postoperative survival. Relationships between coagulopathy and the content of blood transfusions, volumes of crystalloid infusion and survival.
Methods: This was a retrospective study of the medical records of all patients who underwent EVAR for rAAA at Chiba-Nishi General Hospital during the period from October 2013 to December 2015. Major coagulopathy was defined using the international normalized ratio or activated partial thromboplastin time (APTT) ratio of at least 1.5, or platelet count less than 50 × 10/l. We quantified the amounts of blood transfusions and crystalloid infusions administered from arrival to the hospital to admission to ICU following operations.
Results: Coagulopathy among patients with rAAA was found to progress even after they had presented at the hospital. No statistically significant correlation between preoperative coagulopathy and mortality was found, although a significantly greater degree of postoperative coagulopathy was seen among patients who died both within 24-h and 30 days postoperatively. Among patients with postoperative coagulopathy, lesser quantities of fresh frozen plasma (FFP) compared with red cell concentrate (RCC) were used during the period from hospital arrival to postoperative ICU entry. In both groups of patients who did not survive after 24-h and 30 days, FFP was used less than RCC. Large transfusions of crystalloids administered during the periods from hospital arrival to surgery and from hospital arrival to the end of surgery were associated with postoperative incidence of major coagulopathy, death within 24-h, and death within 30 days.
Conclusion: Coagulopathy progressed during care in the emergency outpatient clinic and operations. Postoperative coagulopathy was associated with poorer outcomes. Smaller FFP/RCC ratios and larger volumes of crystalloid infusion were associated with development of coagulopathy and poorer prognosis of survival
Tailoring graft strategy to calcification severity of aorta in off-pump coronary artery bypass grafting
埼玉医科大学平成28年
Heme-dependent autophosphorylation of a heme sensor kinase, ChrS, from Corynebacterium diphtheriae reconstituted in proteoliposomes
AbstractCorynebacterium diphteriae employs the response regulator, ChrA, and the sensor kinase, ChrS, of a two-component signal transduction system to utilize host heme iron. Although ChrS is predicted to encode a heme sensor, the sensing mechanism remains to be characterized. In this report, ChrS expressed in Eshcherichia coli membranes was solubilized and purified using decylmaltoside. ChrS protein incorporated into proteoliposomes catalyzed heme-dependent autophosphorylation by ATP. Other metalloporphyrins and iron did not stimulate kinase activity. The UV–Vis spectrum of hemin in the ChrS–proteoliposomes indicated that heme directly interacts with ChrS. This is the first functional reconstitution of a bacterial heme-sensing protein
CIN after endovascular aortic repair
Objective : This study aimed to determine the perioperative predictors of contrast medium-induced nephropathy (CIN) after endovascular aortic repair (EVAR). Materials and Methods : The data of 203 consecutive patients who underwent elective EVAR for thoracic and abdominal aortic aneurysm between January 2014 and September 2014 were retrospectively analyzed. CIN was defined according to the diagnostic criteria of the European Society of Urogenital Radiology. Results : Fourteen patients (6.9%) developed CIN after EVAR. Contrast medium volume (CV), preoperative serum creatinine, estimated glomerular filtration rate (eGFR), and the CV/eGFR ratio were significantly related with CIN development after EVAR. The CV/eGFR ratio was significantly higher in patients with CIN than those without CIN. Receiver operator characteristic curve analysis showed that the area under the curve of the CV/eGFR ratio was 0.782, indicating that it was the most important predictor. The appropriate CV/eGFR ratio cutoff was >1.62. Sensitivity and specificity were 85.7% and 65.6%, respectively. Conclusions : The CV/eGFR ratio was a useful predictor of contrast medium-induced nephropathy after EVAR. It is possible that the score can be used in patients when managing the EVAR techniques and contrast medium volume
Coil volume embolization ratio for preventing recanalization after portal vein embolization
PURPOSEThe purpose of this study was to evaluate the optimum volume embolization ratio (VER) for the prevention of recanalization after portal vein embolization (PVE) and the influence of recanalization on future liver remnant (FLR) function using technetium-99m galactosyl human serum albumin single-photon emission computed tomography (99mTc-GSA SPECT/CT) fusion imaging.METHODSWe analyzed procedural data of 18 patients who underwent PVE from 2015 to 2018. A total of 29 portal branches were embolized (12 anterior branch, 11 posterior branch, 4 left branch, 2 right branch) with absolute ethanol and coils. Portal vein recanalization was evaluated three weeks after PVE by contrast-enhanced CT. We classified the treated portal branches as non-recanalized and recanalized. VER was compared between the groups. In addition, for each patient, we calculated and evaluated the ratio of FLR volume to total liver volume (volumetric %FLR), FLR count to total liver count on 99mTc-GSA SPECT/CT fusion imaging (functional %FLR), and functional-volumetric ratio (functional %FLR/ volumetric %FLR).RESULTSTwenty-six portal branches showed no recanalization (non-recanalized group, n=26, 89.7%), while three portal branches showed recanalization (recanalized group, n=3, 10.3%). The median VER was 4.94% (3.12%–11.1%) in the non-recanalized group and 3.49% (2.76%–4.32%) in the recanalized group, which was significantly different between the groups (p = 0.045, Mann-Whitney U test). The median functional-volumetric ratio was 1.16 (1.03–1.50) in non-recanalized patients (n=15, 83.3%) and 1.01 (0.96–1.13) in recanalized patients (n=3, 16.7%), and it was significantly higher in the non-recanalized patients (p = 0.021, Mann-Whitney U test).CONCLUSIONThe VER for preventing recanalization after PVE was approximately 5% (> 4.94%). 99mTc-GSA SPECT/CT fusion imaging revealed a decrease in FLR function due to recanalization after PVE
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