Modelling the Leipzig Wind Profile with a (k-ε) model

Hiraoka, H. Techno-Press 2001 Wind and Structures, An International Journal (WAS Vol.4 No.6

The Leipzig Wind Profile is generally known as a typical neutral planetary boundary layer flow. But it became clear from the present research that it was not completely neutral but weakly stable. We examined whether we could simulate the Leipzig Wind Profile by using a ($k-{\varepsilon}$) turbulence model including the equation of potential temperature. By solving analytically the Second Moment Closure Model under the assumption of local equilibrium and under the condition of a stratified flow, we expressed the turbulent diffusion coefficients (both momentum and thermal) as functions of flux Richardson number. Our ($k-{\varepsilon}$) turbulence model which included the equation of potential temperature and the turbulent diffusion coefficients varying with flux Richardson number reproduced the Leipzig Wind Profile.

Functional Abnormalities of HERG Mutations in Long QT Syndrome 2 (LQT2)

Hiraoka, Masayasu The Korean Society of Pharmacology 2001 The Korean Journal of Physiology & Pharmacology Vol.5 No.5

The chromosome 7-linked long QT syndrome (LQT2) is caused by mutations in the human ether-a- go-go-related gene (HERG) that encodes the rapidly activating delayed rectifier $K^+$ current, $I_{Kr},$ in cardiac myocytes. Different types of mutations have been identified in various locations of HERG channel. One of the mechanisms for the loss of normal channel function is due to membrane trafficking of channel protein. The decreased channel function in some deletion mutants appears to be due to loss of coupling with wild type HERG to form the functional channel as the tetramer. Most of missense mutants with few exceptions could interact with wild type HERG to form functional tetramer and caused dominant negative suppression with co-injection with wild type HERG showing variable effects on current amplitude, voltage dependence, and kinetics of activation and inactivation. Two missense mutants at pore regions of HERG found in Japanese LQT2 (A614V and V630L) showed accentuated inward rectification due to a negative shift in steady-state inactivation and fast inactivation. One mutation in S4 region (R534C) produced a negative shift in current activation, indicating the S4 serving as the voltage sensor and accelerated deactivation. The C-terminus mutation, S818L, could not express the current by mutant alone and did not show dominant negative suppression with co-injection of equal amount of wild type cRNA. Co-injection of excess amount of mutant with wild type produced dominant negative suppression with a shift in voltage dependent activation. Therefore, multiple mechanisms are involved in different mutations and functional abnormality in LQT2. Further characterization with the interactions between various mutants in HERG and the regulatory subunits of the channels (MiRP1 and minK) is to be clarified.

Appropriate Color Enhancement Settings for Blue Laser Imaging Facilitates the Diagnosis of Early Gastric Cancer with High Color Contrast

Hiraoka, Yuji,Miura, Yoshimasa,Osawa, Hiroyuki,Nomoto, Yoshie,Takahashi, Haruo,Tsunoda, Masato,Nagayama, Manabu,Ueno, Takashi,Lefor, Alan Kawarai,Yamamoto, Hironori The Korean Gastric Cancer Association 2021 Journal of gastric cancer Vol.21 No.2

Purpose: Screening image-enhanced endoscopy for gastrointestinal malignant lesions has progressed. However, the influence of the color enhancement settings for the laser endoscopic system on the visibility of lesions with higher color contrast than their surrounding mucosa has not been established. Materials and Methods: Forty early gastric cancers were retrospectively evaluated using color enhancement settings C1 and C2 for laser endoscopic systems with blue laser imaging (BLI), BLI-bright, and linked color imaging (LCI). The visibilities of the malignant lesions in the stomach with the C1 and C2 color enhancements were scored by expert and non-expert endoscopists and compared, and the color differences between the malignant lesions and the surrounding mucosa were assessed. Results: Early gastric cancers mainly appeared orange-red on LCI and brown on BLI-bright or BLI. The surrounding mucosae were purple on LCI regardless of the color enhancement but brown or pale green with C1 enhancement and dark green with C2 enhancement on BLI-bright or BLI. The mean visibility scores for BLI-bright, BLI, and LCI with C2 enhancement were significantly higher than those with C1 enhancement. The superiority of the C2 enhancement was not demonstrated in the assessments by non-experts, but it was significant for experts using all modes. The C2 color enhancement produced a significantly greater color difference between the malignant lesions and the surrounding mucosa, especially with the use of BLI-bright (P=0.033) and BLI (P<0.001). C2 enhancement tended to be superior regardless of the morphological type, Helicobacter pylori status, or the extension of intestinal metaplasia around the cancer. Conclusions: Appropriate color enhancement settings improve the visibility of malignant lesions in the stomach and color contrast between the malignant lesions and the surrounding mucosa.

Linked Color Imaging Demonstrates Characteristic Findings in Semi-Pedunculated Gastric Adenocarcinoma in Helicobacter pylori-Negative Normal Mucosa

Yuji Hiraoka,Yoshimasa Miura,Hiroyuki Osawa,Mio Sakaguchi,Masato Tsunoda,Alan Kawarai Lefor,Hironori Yamamoto 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.1

BRIEF REPORT

Complementary Discriminant Analysis for Classification of Double Attributes

Kazuyuki Hiraoka,Taketoshi Mishima 대한전자공학회 2002 ITC-CSCC :International Technical Conference on Ci Vol.2002 No.7

Efficacy of restarting anti-tumor necrosis factor α agents after surgery in patients with Crohn’s disease

Sakiko Hiraoka,Shiho Takashima,Yoshitaka Kondo,Toshihiro Inokuchi,Yuusaku Sugihara,Masahiro Takahara,Seiji Kawano,Keita Harada,Wakayama Medical University,Hiroyuki Okada 대한장연구학회 2018 Intestinal Research Vol.16 No.1

Background/Aims: The efficacy of anti-tumor necrosis factor α (anti-TNFα) antibodies for postoperative Crohn’s disease(CD) in patients who were treated with these agents prior to surgery is largely unknown. Methods: CD patients who underwentintestinal resection and received anti-TNFα agents after surgery were divided into 2 groups according to the presence orabsence of preoperative anti-TNFα treatment: anti-TNFα restart group or anti-TNFα naïve group. Endoscopic recurrence aftersurgery was examined according to the preoperative conditions, including administration of anti-TNFα agents before surgery. Results: Thirty-six patients received anti-TNFα antibody after surgery: 22 in the anti-TNFα restart group and 14 in the anti-TNFα naïve group. Endoscopic recurrence after surgery was more frequently observed in the anti-TNFα restart group than inthe anti-TNFα naïve group (68% vs. 14% , P <0.001). Multivariate analysis revealed the following significant risk factors of endoscopicrecurrence after surgery: anti-TNF restart group (odds ratio [OR], 28.10; 95% CI, 3.08−722.00), age at diagnosis <23 years(OR, 24.30; 95% CI, 1.67−1,312.00), serum albumin concentration at surgery <3.3 g/dL (OR, 34.10; 95% CI, 1.72–2,804.00), andpresence of inflammation outside of the surgical site (OR, 21.40; 95% CI, 1.02−2,150.00). Treatment intensification for patientswith endoscopic recurrence in the anti-TNFα restart group showed limited responses, with only 1 of 12 patients achieving endoscopicremission. Conclusions: The efficacy of restarting anti-TNFα antibody treatment after surgery was limited, and treatmentintensification or a change to different classes of biologics should be considered for those patients.

The novel latex agglutination turbidimetric immunoassay system for simultaneous measurements of calprotectin and hemoglobin in feces

( Sakiko Hiraoka ),( Shiho Takashima ),( Toshihiro Inokuchi ),( Asuka Nakarai ),( Masahiro Takahara ),( Keita Harada ),( Yasuhiro Seki ),( Katsunori Watanabe ),( Jun Kato ),( Hiroyuki Okada ) 대한장연구학회 2019 Intestinal Research Vol.17 No.2

Background/Aims: Fecal calprotectin (Fcal) as well as the fecal immunochemical test (FIT) are useful biomarkers for detecting activity and mucosal healing in inflammatory bowel diseases. Here, we report the performance of simultaneous measurements of Fcal and FIT for ulcerative colitis (UC) patients using the newly-developed latex agglutination turbidimetric immunoassay (LATIA) system. Methods: Fcal and hemoglobin were measured by the LATIA system in 152 UC patients who underwent colonoscopy. Fcal was also quantified with a conventional enzyme-linked immunosorbent assay (ELISA). Fecal markers were evaluated in conjunction with the mucosal status of UC, which was assessed via the Mayo endoscopic subscore (MES) classification. Results: The LATIA system could quantify calprotectin and hemoglobin simultaneously with the same fecal samples within 10 minutes. The values of the Fcal-LATIA closely correlated with those of the Fcal-ELISA (Spearman rank correlation coefficient, r=0.84; P<0.0001). The values of Fcal for each assay and the FIT all significantly correlated with the MESs (Spearman rank correlation coefficient, Fcal-LATIA: r=0.58, Fcal-ELISA: r=0.55, and FIT: r=0.72). The mucosal healing predictability (determined by an MES of 0 alone) of the Fcal-LATIA, Fcal-ELISA, and FIT-LATIA with the cutoffs determined by receiver operating characteristic curve analysis was 0.79, 0.78, and 0.92 for sensitivity, respectively, and 0.78, 0.69, and 0.73 for specificity, respectively. Conclusions: The performance of the novel Fcal-LATIA was equivalent to that of the conventional Fcal assay. Simultaneous measurements with FITs would promote the clinical relevance of fecal biomarkers in UC. (Intest Res 2019;17:202-209)

Radiologic results of additional single screw fixation with lateral locking plate after hybrid closed-wedge high tibial osteotomy

( Nobuyuki Hiraoka ),( Shuji Nakagawa ),( Eigo Otakara ),( Hiroaki Inoue ),( Kenji Takahashi ),( Yuji Arai ) 대한슬관절학회 2020 대한슬관절학회지 Vol.32 No.-

Background: Hybrid closed-wedge high tibial osteotomy (hybrid CWHTO) is an effective surgical treatment for medial compartment osteoarthritis of the knee. Our study investigated whether the combination of a lateral locking plate and a single medial screw promoted bone union after hybrid CWHTO. Methods: The study cohort consisted of 30 patients (15 men and 15 women) who underwent hybrid CWHTO for medial compartment osteoarthritis or spontaneous osteonecrosis of the knee. Sixteen knees were fixed with a lateral locking plate (LP group), and 17 were fixed with both a lateral locking plate and a cannulated cancellous screw on the medial side of the tibia (LPS group). The times to bone union, radiolucency, and callus formation at the osteotomy site were evaluated radiographically. Results: The mean postoperative time to radiographic confirmation of bone union was 5.5 ± 2.6 months in the LP group and 3.4 ± 1.5 months in the LPS group. Radiolucency at the osteotomy site and excess callus formation on the posterior side of the tibia were lower in the LPS group than in the LP group. Conclusions: This modified hybrid CWHTO combining a lateral locking plate and a cannulated cancellous screw on the medial side of the tibia improves the stability of the osteotomy site and shortens the period of bone union.

Experimental Evaluation on Effect of Steering Reactive Torque of SBW Vehicle on Driving Behavior

Toshihiro Hiraoka,Hidenori Kusabe,Hiromitsu Kumamoto 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

Steering reactive torque presentation is important for drivers of a steer-by-wire(SBW) vehicle to inform of the driving environment such as the road surface condition and the working state of the SBW controller. However, we have to solve the problem how to decide the steering reactive torque gain. Therefore, in the present paper, the driving simulator experiments which simulate the actual driving environment are performed to verify the effect of the steering reactive torqueo the driving behavior and the subjective evaluation.

Radiologic results of additional single screw fixation with lateral locking plate after hybrid closed-wedge high tibial osteotomy

( Nobuyuki Hiraoka ),( Shuji Nakagawa ),( Eigo Otakara ),( Hiroaki Inoue ),( Kenji Takahashi ),( Yuji Arai ) 대한슬관절학회 2021 대한슬관절학회지 Vol.33 No.-

Background: Hybrid closed-wedge high tibial osteotomy (hybrid CWHTO) is an effective surgical treatment for medial compartment osteoarthritis of the knee. Our study investigated whether the combination of a lateral locking plate and a single medial screw promoted bone union after hybrid CWHTO. Methods: The study cohort consisted of 30 patients (15 men and 15 women) who underwent hybrid CWHTO for medial compartment osteoarthritis or spontaneous osteonecrosis of the knee. Sixteen knees were fixed with a lateral locking plate (LP group), and 17 were fixed with both a lateral locking plate and a cannulated cancellous screw on the medial side of the tibia (LPS group). The times to bone union, radiolucency, and callus formation at the osteotomy site were evaluated radiographically. Results: The mean postoperative time to radiographic confirmation of bone union was 5.5 ± 2.6 months in the LP group and 3.4 ± 1.5 months in the LPS group. Radiolucency at the osteotomy site and excess callus formation on the posterior side of the tibia were lower in the LPS group than in the LP group. Conclusions: This modified hybrid CWHTO combining a lateral locking plate and a cannulated cancellous screw on the medial side of the tibia improves the stability of the osteotomy site and shortens the period of bone union.