Recursive Sample-Entropy Method and Its Application for Complexity Observation of Earth Current

Shohei Shimizu,Koichi Sugisaki,Hiromitsu Ohmori 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

The effectiveness of Sample-Entropy was practically shown as the measure index of irregularity from time series, by the development of research to quantify complexity. This Sample-Entropy calculated from at least 100 sample points, can classify a various system which contains a deterministic chaos system and/or a stochastic system, and is strong against noise. Therefore it is applied to the wide fields such as the ecology, finance, the medical treatment, etc. In this paper, the recursive Sample-Entropy technique is proposed and it is applied to the earthquake forecast. The earthquake forecast is generally performed by using the vibration wave, however it is extremely short that time from the forecast to the occurrence. Then, in this research, I use the earth current data based on the technique called the VAN method that used an abnormal earth current that is the one of the macroscopic anomalies that the difference of time until the earthquake occurrence is long. As a result, it is confirmed that there is a possibility that the precursor of an earthquake are able to be observed in real time.

Percutaneous transsplenic obliteration of ectopic varices following pancreaticoduodenectomy with portal vein resection and splenic vein ligation

Shohei Chatani,Yozo Sato,Nozomi Okuno,Takaaki Hasegawa,Shinichi Murata,Hidekazu Yamaura,Kazuo Hara,Yasuhiro Shimizu,Yoshitaka Inaba 소화기인터벤션의학회 2021 Gastrointestinal Intervention Vol.10 No.2

Left-sided portal hypertension following pancreaticoduodenectomy (PD) with portal vein resection and splenic vein ligation may cause ectopic variceal formation, potentially resulting in life-threatening bleeding. We report of a 79-year-old male suffering from severe anemia and melena after PD. Emergency endoscopy and contrast-enhanced computed tomography (CECT) revealed ectopic varices at the anastomosis site of pancreaticojejunostomy. An interventional radiology approach was preferred over surgical and endoscopic treatment because of the poor general condition and altered anatomy. In the first procedure, percutaneous transhepatic retrograde obliteration was performed using the coaxial double balloon-occlusion technique. Although hemostasis was obtained, re-bleeding occurred two months later. CECT revealed the development of another collateral pathway and the recurrence of varices. Insufficient embolization of the afferent vein was considered the cause of recurrence. Therefore, a percutaneous transsplenic approach was used, and complete embolization of varices was achieved. When transhepatic retrograde obliteration is not effective, transsplenic antegrade obliteration can be a useful therapeutic option.

Percutaneous transsplenic obliteration of ectopic varices following pancreaticoduodenectomy with portal vein resection and splenic vein ligation

Shohei Chatani,Yozo Sato,Nozomi Okuno,Takaaki Hasegawa,Shinichi Murata,Hidekazu Yamaura,Kazuo Hara,Yasuhiro Shimizu,Yoshitaka Inaba 소화기인터벤션의학회 2021 International journal of gastrointestinal interven Vol.10 No.2

Left-sided portal hypertension following pancreaticoduodenectomy (PD) with portal vein resection and splenic vein ligation may cause ectopic variceal formation, potentially resulting in life-threatening bleeding. We report of a 79-year-old male suffering from severe anemia and melena after PD. Emergency endoscopy and contrast-enhanced computed tomography (CECT) revealed ectopic varices at the anastomosis site of pancreaticojejunostomy. An interventional radiology approach was preferred over surgical and endoscopic treatment because of the poor general condition and altered anatomy. In the first procedure, percutaneous transhepatic retrograde obliteration was performed using the coaxial double balloon-occlusion technique. Although hemostasis was obtained, re-bleeding occurred two months later. CECT revealed the development of another collateral pathway and the recurrence of varices. Insufficient embolization of the afferent vein was considered the cause of recurrence. Therefore, a percutaneous transsplenic approach was used, and complete embolization of varices was achieved. When transhepatic retrograde obliteration is not effective, transsplenic antegrade obliteration can be a useful therapeutic option.

Power Consumption/Supply Control Using Neural Network for Micro Grids

Tsunashi Kaneko,Shohei Shimizu,Hiromitsu Ohmori 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

This paper proposes the control scheme using neural network for micro grids with isolated operation mode. Normally, the micro grid operates in interconnected mode with the medium voltage network, however when the power go down, the micro grid must have the ability to operate stably autonomously. So this paper evaluates the stability of the micro grids with isolated operation mode using the feedback error learning scheme in neural networks.

Percutaneous metallic stent placement for malignant afferent loop syndrome via the blind end of the jejunal limb after biliary reconstruction

Yozo Sato,Shohei Chatani,Takaaki Hasegawa,Shinichi Murata,Takamichi Kuwahara,Kazuo Hara,Yasuhiro Shimizu,Yoshitaka Inaba 소화기인터벤션의학회 2021 Gastrointestinal Intervention Vol.10 No.1

Background: Malignant afferent loop syndrome occurs after biliary reconstruction and is difficult to treat because of the complicated anatomical changes. The aim of this study was to investigate the safety and efficacy of percutaneous metallic stent placement for malignant afferent loop syndrome via the blind end of the jejunal limb after biliary reconstruction. Methods: Percutaneous metallic stent placement via the jejunal limb was performed in five male patients (median age, 68 years; range, 51–88 years) with malignant afferent loop syndrome following pancreatoduodenectomy or bile duct resection with reconstruction at our institute from June 2009 to April 2019. Reconstruction was performed using a modified Child’s method or the Roux-en-Y method, and blind end of the jejunal limb was surgically fixed to the abdominal wall. Percutaneous drainage of the afferent loop was performed via the blind end of the jejunal limb. Subsequently, percutaneous metallic stent placement was performed via the same route. Technical success, clinical success, and complications were retrospectively evaluated. Results: Percutaneous metallic stent placement via the blind end of the jejunal limb was successfully achieved in all six procedures. Additional metallic stent placement was performed due to tumor ingrowth in a patient. Drainage catheters were removed from three patients, clamped in one, and could not be removed in one. Clinical success was achieved in four patients (80%) without major complications. Conclusion: Percutaneous metallic stent placement for malignant afferent loop syndrome via the blind end of the jejunal limb after biliary reconstruction could be a safe and effective procedure.

Percutaneous metallic stent placement for malignant afferent loop syndrome via the blind end of the jejunal limb after biliary reconstruction

Yozo Sato,Shohei Chatani,Takaaki Hasegawa,Shinichi Murata,Takamichi Kuwahara,Kazuo Hara,Yasuhiro Shimizu,Yoshitaka Inaba 소화기인터벤션의학회 2021 International journal of gastrointestinal interven Vol.10 No.1

Background: Malignant afferent loop syndrome occurs after biliary reconstruction and is difficult to treat because of the complicated anatomical changes. The aim of this study was to investigate the safety and efficacy of percutaneous metallic stent placement for malignant afferent loop syndrome via the blind end of the jejunal limb after biliary reconstruction. Methods: Percutaneous metallic stent placement via the jejunal limb was performed in five male patients (median age, 68 years; range, 51–88 years) with malignant afferent loop syndrome following pancreatoduodenectomy or bile duct resection with reconstruction at our institute from June 2009 to April 2019. Reconstruction was performed using a modified Child’s method or the Roux-en-Y method, and blind end of the jejunal limb was surgically fixed to the abdominal wall. Percutaneous drainage of the afferent loop was performed via the blind end of the jejunal limb. Subsequently, percutaneous metallic stent placement was performed via the same route. Technical success, clinical success, and complications were retrospectively evaluated. Results: Percutaneous metallic stent placement via the blind end of the jejunal limb was successfully achieved in all six procedures. Additional metallic stent placement was performed due to tumor ingrowth in a patient. Drainage catheters were removed from three patients, clamped in one, and could not be removed in one. Clinical success was achieved in four patients (80%) without major complications. Conclusion: Percutaneous metallic stent placement for malignant afferent loop syndrome via the blind end of the jejunal limb after biliary reconstruction could be a safe and effective procedure.

Solvent- and temperature-dependent conformational changes between H?ckel antiaromatic and M?bius aromatic species in meso-trifluoromethyl substituted [28]hexaphyrins.

Yoon, Min-Chul,Kim, Pyosang,Yoo, Hyejin,Shimizu, Soji,Koide, Taro,Tokuji, Sumito,Saito, Shohei,Osuka, Atsuhiro,Kim, Dongho American Chemical Society 2011 The Journal of physical chemistry B Vol.115 No.50

<P>We investigated the photophysical properties of figure-eight-like meso-hexakis(trifluoromethyl) [26]- and [28]hexaphyrins(1.1.1.1.1.1) denoted as TFM26H and TFM28H, respectively, using steady-state and time-resolved spectroscopy along with theoretical calculations to explore their electronic and magnetic natures depending on their molecular aromaticity. TFM26H exhibited a well-resolved absorption feature and intense fluorescence, both of which were neither solvent- nor temperature-dependent. These optical properties were in agreement with its H?ckel's [4n + 2] aromaticity as observed in typical aromatic porphyrinoids. The S(1)-state lifetime of ~50 ps for TFM26H in solution was shorter than those in planar aromatic hexaphyrins (>100 ps) presumably due to nonplanar figure-eight geometry of TFM26H. However, TFM28H exhibited remarkable changes in solvent- and temperature-dependent absorption spectra as well as excited-state lifetimes indicating that a dynamic equilibrium occurs between the two conformational species. With the help of quantum mechanical geometry optimization and vertical excitation energy calculations, we found that the figure-eight double-sided conformer observed in the solid-state and single-sided distorted one could be the best candidates for the two conformers, which should be H?ckel antiaromatic and M?bius aromatic species, respectively, based on their optical characteristics, molecular orbital structures, and excited-state lifetimes. Conformational dynamics between these two conformers of TFM28H was scrutinized in detail by temperature-dependent (1)H NMR spectra in various solvents, which showed that the conformational equilibrium was quite sensitive to solvents and that a conformational change faster than the NMR time-scale occurs even at 173 K.</P>