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When using vacuum interrupters to switch capacitive current, the degree of insulation between the contacts tends to degrade as the broken welds are formed on the contact by making and opening operation. These broken welds locally enhance the electric field between contact by roughening the contact surface. Previous studies have found that the amplitude of the current has a major impact on breakdown electric field, while the impacts of arcing time and total arc energy remain ill-understood. This article reports an investigation of the impact of arcing time on the insulation between contacts. The arcing time affects the electric field in two distinct regions. Breakdown electric field decreases as arcing time increases for arcing times less than 1ms. On the other hand, breakdown electric field does not necessary degrade with further long arcing time. This trend is explained by vacuum arc diffusion. The equivalent current density of the vacuum arc decreases over time during each discharge process. The temperature of the contacts was calculated from the diffusion radius of vacuum arc observed using high speed cameras. These calculations reveal that the melted volume of the contacts increases for arcing times 1 ms, and subsequently declines with increasing arcing time. The resulting increased melted volume decreases the electric field. These results show that the relationship between electric field and total arc energy is complicated, as high arc energies do not necessary result in poor insulation performance.

Background: L-asparaginase (L-Asp)-associated thromboembolisms are serious complications in pediatrics patients with acute lymphoblastic leukemia (ALL), especially at ≥10.0 years old, but the pathogenesis remains to be clarified. Procedure: We conducted a multicenter, prospective study of 72 patients with ALL aged 1.0 to 15.2 years treated with either a Berlin-Frankfurt-Münster (BFM) 95-ALL oriented regimen or Japan Association of Childhood Leukemia Study ALL-02 protocol. We divided patients into each treatment protocol and investigated the dynamic changes in coagulation and fibrinolysis using simultaneous thrombin and plasmin generation assay. Patients' plasma samples were collected at the prephase (T0), intermittent phase (T1), and postphase of L-Asp therapy (T2), and postinduction phase (T3). Measurements of endogenous thrombin potential (T-EP) and plasmin peak height (P-Peak) were compared to normal plasma. Results: None of the cases developed thromboembolisms. Median ratios of T-EP and P-Peak for the controls in the JACLS group were 1.06 and 0.87 (T0), 1.04 and 0.71 (T1), 1.02 and 0.69 (T2), and 1.20 and 0.92 (T3), respectively, while those in the BFM group were 1.06 and 1.00 (T0), 1.04 and 0.64 (T1), 1.16 and 0.58 (T2), and 1.16 and 0.85 (T3), respectively. In particular, P-Peak ratios were depressed at T1 and T2 compared to T0 in the BFM group (P < .01). Moreover, P-Peak ratios in patients ≥10.0 years old were lower at T1 in the BFM group (P = .02). Conclusions: The results demonstrated that hemostatic dynamics appeared to shift to a hypercoagulable state with marked hypofibrinolysis associated with L-Asp therapy, especially in patients ≥10.0 years old following the BFM regimen., 博士（医学）・甲第722号・令和元年12月5日, © 2019 Wiley Periodicals, Inc., This is the pre-peer reviewed version of the following article: [https://onlinelibrary.wiley.com/doi/full/10.1002/pbc.28016], which has been published in final form at [https://doi.org/10.1002/pbc.28016]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.

In this paper, the authors report the relation between the arc rotation and the temperature of contact surface. The interruption tests were performed with the vacuum chamber equipped with spiral-type contacts. The rotation of vacuum arc was observed with high speed cameras from two different directions. The temperature of the contact surface was estimated from emission intensity measured by high speed camera with the infrared band-pass filter. Local surface overheating occurs with slow-speed arc rotation, whereas surface temperature rises homogeneously with high-speed arc rotation. In addition, differences of arc behavior certainly effects on the interrupting performance.

A 44-year-old female was admitted because of gross hematuria six years after beginning hemodialysis for chronic renal failure. There was a past history of hematuria one year before admission. Retrograde pyelography, computed tomographic scan and angiography had been performed, and a probable malignant tumor of left renal pelvis had been found in 1986. We recommended surgery at the time, but she refused treatment and was followed up. On June 22, 1987, the patient had a second attack of gross hematuria resulting in bladder tamponade, and hematuria from the left ureteric orifice was confirmed at cystoscopy. Ultrasound showed left obstructive nephropathy. Left nephrectomy was performed because of the presumptive diagnosis of malignant tumor. The histological diagnosis was transitional cell carcinoma of the left renal pelvis. Two courses of M-VAC (methotiexate, vinblastine, adriamycin and cisplatin) chemotherapy were accordingly given postoperatively. The incidence of renal pelvic tumor and its chemotherapy in patients with chronic renal failure are discussed.

A 44-year-old female was admitted because of gross hematuria six years after beginning hemodialysis for chronic renal failure. There was a past history of hematuria one year before admission. Retrograde pyelography, computed tomographic scan and angiography had been performed, and a probable malignant tumor of left renal pelvis had been found in 1986. We recommended surgery at the time, but she refused treatment and was followed up. On June 22, 1987, the patient had a second attack of gross hematuria resulting in bladder tamponade, and hematuria from the left ureteric orifice was confirmed at cystoscopy. Ultrasound showed left obstructive nephropathy. Left nephrectomy was performed because of the presumptive diagnosis of malignant tumor. The histological diagnosis was transitional cell carcinoma of the left renal pelvis. Two courses of M-VAC (methotiexate, vinblastine, adriamycin and cisplatin) chemotherapy were accordingly given postoperatively. The incidence of renal pelvic tumor and its chemotherapy in patients with chronic renal failure are discussed.

Purpose: The purpose of this study is to compare response rates of lenvatinib and atezolizumab plus bevacizumab, in first-line real-world setting. Methods: Overall cohort included Western and Eastern hepatocellular carcinoma (HCC) patient populations from 46 centres in 4 countries (Italy, Germany, Japan, and Republic of Korea). Results: 1312 patients were treated with lenvatinib, and 823 patients were treated with atezolizumab plus bevacizumab. Objective response rate (ORR) was 38.6% for patients receiving lenvatinib, and 27.3% for patients receiving atezolizumab plus bevacizumab (p < 0.01; odds ratio 0.60). For patients who achieved complete response (CR), overall survival (OS) was not reached in both arms, but the result from univariate Cox regression model showed 62% reduction of death risk for patients treated with atezolizumab plus bevacizumab (p = 0.05). In all multivariate analyses, treatment arm was not found to be an independent factor conditioning OS. Comparing ORR achieved in the two arms, there was a statistically significant difference in favor of lenvatinib compared to atezolizumab plus bevacizumab in all subgroups except for Eastern patients, Child-Pugh B patients, presence of portal vein thrombosis, α-feto-protein ≥ 400 ng/mL, presence of extrahepatic disease, albumin-bilirubin (ALBI) grade 2, and no previous locoregional procedures. Conclusion: Lenvatinib achieves higher ORR in all patient subgroups. Patients who achieve CR with atezolizumab plus bevacizumab can achieve OS so far never recorded in HCC patients. This study did not highlight any factors that could identify patient subgroups capable of obtaining CR.