Switching surge reduction of a bi-directional dual active bridge DC-DC converter with a digital operation

Recently, the bi-directional dc-dc converter has been focused on because of the huge demand for diversification of power supply network including battery. The dual active bridge (DAB) dc-dc converter is one of the most popular circuits for bi-directional applications because of its simple structure. However, power efficiency at light load is the intrinsic problem of a bi-directional DAB DC-DC converter. In this paper, the simple solution with digital operation for the problem is proposed and experiments are performed with 1kW system. This method can reduce a switching surge without other circuits such as snubber and improve power efficiency at light load. Therefore it can reduce loss of switching surge, and improve power efficiency. From the results, 37% maximum power efficiency improvement at light load is confirmed. Furthermore, this method is capable for control in the conventional method in the heavy load range. Consequently, it is possible to reduce the switching surge and realize high power efficiency in a wide load range.2013 15th European Conference on Power Electronics and Applications, EPE 2013; Lille; France; 2 September 2013 through 6 September 201

A static characteristic analysis of proposed bi-directional dual active bridge DC-DC converter

Recently, the power supply network with energy storage devices such as battery has been focused. This network topology uses bi-directional isolated DC-DC converter of low or medium capacity is required for the diversification of power supply network. The dual active bridge (DAB) DC-DC converter is one of the effective bi-directional isolated DC-DC converters. However, the circuit has some instinct problems such as degradation of power efficiency and the occurrence of the surge in light-load operation. In this paper, we have been done a static characteristic analysis and highly power-efficient technique for DAB DC-DC Converter at light load. Also the analysis results and the proposed technique are verified with some experimental results.7th International Power Electronics Conference, IPEC-Hiroshima - ECCE Asia 2014; Hiroshima; Japan; 18 May 2014 through 21 May 201

A power efficiency improvement technique for a bi-directional dual active bridge DC-DC converter at light load

Recently, the bi-directional dc-dc converter has been focused on because of the huge demand for diversification of power supply network including battery. The dual active bridge (DAB) dc-dc converter is one of the most popular circuits for bi-directional applications because of its simple structure. However, power efficiency at light load is the intrinsic problem of a bi-directional DAB DC-DC converter. In this paper, the simple solution with digital operation for the problem is proposed and experiments are performed with 1kW system. This method can reduce a switching surge without other circuits such as snubber and improve power efficiency at light load. Therefore it can reduce loss of switching surge and, improve power efficiency. From the results, 37% maximum power efficiency improvement at light load is confirmed. Furthermore, this method is capable of control in the conventional method in the heavy load range. Consequently, it is possible to reduce the switching surge and realize high power efficiency in a wide load range.5th Annual IEEE Energy Conversion Congress and Exhibition, ECCE 2013; Denver, CO; United States; 15 September 2013 through 19 September 2013; Category numberCFP13ECD-US

Parathyroid hormone 1 (1-34) acts on the scales and involves calcium metabolism in goldfish

金沢大学環日本海域環境研究センターThe effect of fugu parathyroid hormone 1 (fugu PTH1) on osteoblasts and osteoclasts in teleosts was examined with an assay system using teleost scale and the following markers: alkaline phosphatase (ALP) for osteoblasts and tartrate-resistant acid phosphatase (TRAP) for osteoclasts. Synthetic fugu PTH1 (1-34) (100 pg/ml-10 ng/ml) significantly increased ALP activity at 6 h of incubation. High-dose (10 ng/ml) fugu PTH1 significantly increased ALP activity even after 18 h of incubation. In the case of TRAP activity, fugu PTH1 did not change at 6 h of incubation, but fugu PTH1 (100 pg/ml-10 ng/ml) significantly increased TRAP activity at 18 h. Similar results were obtained for human PTH (1-34), but there was an even greater response with fugu PTH1 than with human PTH. In vitro, we demonstrated that both the receptor activator of the NF-κB ligand in osteoblasts and the receptor activator NF-κB mRNA expression in osteoclasts increased significantly by fugu PTH1 treatment. In an in vivo experiment, fugu PTH1 induced hypercalcemia resulted from the increase of both osteoblastic and osteoclastic activities in the scale as well as the decrease of scale calcium contents after fugu PTH1 injection. In addition, an in vitro experiment with intramuscular autotransplanted scale indicated that the ratio of multinucleated osteoclasts/mononucleated osteoclasts in PTH-treated scales was significantly higher than that in the control scales. Thus, we concluded that PTH acts on osteoblasts and osteoclasts in the scales and regulates calcium metabolism in goldfish. © 2011 Elsevier Inc. All rights reserved

Analysis of prophylactic Bakri balloon tamponade failure in patients with placenta previa

Objective: Recently, Bakri balloon (BBT) was effective for women with placenta previa to reduce hemorrhage. However, about 10% of women needed to receive an invasive strategy. Thus, the identification of risk factors and the development of additional measurements for BBT failure was needed. The aim of our study is to investigate the cause and measurements of failing prophylactic BBT in women with placenta previa. Materials and methods: Women with placenta previa who underwent cesarean section and had a prophylactic BBT inserted during the operation at our institution between January 2015 and December 2017 were enrolled. Patients requiring additional procedures after cesarean section for massive hemorrhage were defined as BBT failures. Additionally, the patterns and risk factors of BBT failure were retrospectively evaluated. Results: Seventy women met the inclusion criteria. Of them, 9 (13%) were in the balloon failure group and 61 (87%), in the balloon success group. Between two groups, the median of postoperative blood loss was 1153 g vs. 70 g (p < 0.01) and the total blood loss 2409 g vs. 971 g (p < 0.01). There were two types of failures in the balloon failure group: balloon prolapse in eight patients (89%) and accidental placental retention in one patient (11%). The hemorrhage was controlled in all patients with balloon prolapse by reinsertion and inflation of the balloon. The patient with placental retention required a uterine artery embolization (UAE). Although three patients required a blood transfusion, none required a hysterectomy. The logistic regression for the risk of balloon failure revealed classification of major previa to be the highest risk factor (Hazard Ratio; 19.1, 95% Confidence Interval; 3.17–367.9, p < 0.01). Conclusion: The major cause of BBT failure was balloon prolapse. It could be treated with non-invasive methods; however, patients with placental retention could not avoid invasive treatment to stop the hemorrhage. Keywords: Bakri balloon, Cesarean section, Placenta previa, Postpartum hemorrhage, Uterine aton

【夜、寝ている時に起こる異常行動】 睡眠関連てんかん

出版社版睡眠中の異常言動の背景には、さまざまな疾患・病態がある。その中でも、てんかんは見逃してはならない重要な疾患である。てんかん発作の出現様式を睡眠・覚醒サイクルの観点から分類すると、睡眠関連てんかん(睡眠てんかん)(発作は睡眠中、とくに入眠直後と起床直前の2時間以内に起こりやすい)、覚醒てんかん(発作は朝方の起床直後と夕方に起こりやすい)、および汎発性てんかん(発作は睡眠中と覚醒中のいずれでも起こる)に分類される。睡眠てんかんは、どの年齢でも発症し、側頭葉てんかんと前頭葉てんかんで認められやすく、とくにNREM睡眠のstage 2から起こりやすい。睡眠中の異常行動をてんかんと確定診断するためには、本症を念頭に置いた医療面接、脳画像検査、通常の脳波検査に加えて、長時間Video-Polysomnographyを積極的に行うことが重要である