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Dielectric barrier discharge plasma actuators (DBD-PAs) have the potential to improve the performance of fluid machineries such as aircrafts and wind turbines by preventing flow separation. In this study, to identify the multiple flow control mechanisms in high Reynolds number flow, parametric experiments for an actuation parameter F+ with a wide range of Re values (105–106) for NACA0015 airfoil was conducted. We conducted wind tunnel tests by applying a DBD-PA to the flow field around a wing model at the leading edge. Lift characteristics, turbulent kinetic energy in the flow field, shear layer height, and the separation point of the boundary layer were evaluated based on pressure distributions on the wing surface and velocity of the flow field, with the effect of DBD-PA on the post-stall flow around the wing and the mechanism behind the increase in the lift coefficient CL analyzed based on these evaluation results. The following phenomena contributed to the increase in CL: (1) increase in turbulent kinetic energy; (2) increase in circulation; and (3) acceleration of the flow near the leading edge. Thus, this study effectively investigated the dependence of the increase in lift on F+ and the lift-increasing mechanism for a wide range of Re values.

Abstract Aim With the increased use of particle therapy for liver cancer, local recurrence after particle therapy increased. Salvage hepatectomy is an acceptable treatment option for local recurrence following particle therapy; however, its safety and effectiveness remain unclear. Therefore, this multi‐center study aimed to verify the feasibility and efficacy of salvage hepatectomy and assess clinical issues associated with its application. Methods We retrospectively assessed the perioperative outcomes, prognosis, and pathological characteristics of 15 patients who underwent salvage hepatectomy for local recurrence after particle therapy between 2006 and 2019. Results Hepatocellular carcinoma and metastatic liver tumors were noted in eight and seven patients, respectively. The mean total dose and number of fractions were 66.5 Gy and 12, respectively, and the mean interval between particle therapy and surgery was 30.1 months. Major hepatectomy was performed in seven cases. Moreover, the mortality rate was 0%, and surgical complications of Clavien‐Dindo grade IIIa or higher were observed in four cases (27%)—two bile leakages, one pleural effusion, and one refractory skin fistula. The median overall survival time and 5‐year overall survival rate after salvage hepatectomy were 29.9 months and 43.1%, respectively. Histological examination of the irradiated liver tissue surrounding the tumor showed sinusoidal dilatation, loss of hepatocyte, and fibrosis in most cases. Conclusion Salvage hepatectomy after particle therapy is a feasible therapy; however, the risk of refractory complications associated with particle therapy is relatively high. Therefore, the first‐line treatment for resectable liver cancer should be carefully determined considering second‐line treatment after local recurrence.

Abstract Background The use of surgical metal clips is crucial for ligating vessels in various operations. The currently available metal clips have several drawbacks; they are permanent and interfere with imaging techniques such as computed tomography (CT) or magnetic resonance (MR) imaging and carry the potential risk of endo-clip migration. We recently developed a novel magnesium (Mg) alloy for biodegradable clips that reduces artifacts on CT imaging. This study aimed to examine the tolerance, biodegradability, and biocompatibility of the Mg alloy clips compared with those of standard titanium (Ti) clips in hepatectomy. Methods Thirty Wistar rats were divided into two groups based on the clip used (groups A and B). The vascular pedicle, including hepatic artery, portal vein, bile duct, and hepatic vein of the left lateral lobe, was ligated with the Ti clip in group A or the Mg alloy clip in group B, and then the left lateral lobe was removed. The rats were sacrificed at 1, 4, 12, 24, and 36 weeks after surgery. Clinical and histological evaluations were performed. Absorption rate was calculated by measuring the clip volume. Results Although the Mg alloy clips showed biodegradability over time, there were no significant differences in the serum concentration of Mg between the two groups. The remaining volume ratio of Mg alloy clips was 95.5, 94.3, 80.0, 36.2, and 16.7% at 1, 4, 12, 24, and 36 weeks, respectively. No side effects occurred. Most of the microscopic changes were similar in both groups. Conclusions The new biodegradable Mg alloy clips are safe and feasible in vessel ligation for hepatectomy in a rat model and reduce artifacts in CT imaging compared with the standard Ti clips.

Abstract Background Hepatocellular carcinoma (HCC) can develop in patients who are negative for the hepatitis B surface antigen (HBsAg) in serum but positive for hepatitis B virus (HBV) DNA in the liver, referred to as occult HBV infection (OBI). Previous reports showed that HBV variants in OBI-related HCC are different from those in HBsAg-positive HCC. In the present study, HBV quasispecies based on the pre-S/S gene in OBI-related HCC patients were examined by high throughput sequencing and compared with those in HBsAg-positive HCC. Methods Nineteen tissue samples (9 OBI-related and 10 HBsAg-positive non-cancerous tissues) were collected at the time of surgery at Kobe University Hospital. The quasispecies with more than 1% variation in the pre-S/S region were isolated and analysed by ultra-deep sequencing. Results There were no significant differences in the major HBV populations, which exhibit more than 20% variation within the entire pre-S/S region, between OBI-related HCC and HBsAg-positive HCC. However, the prevalences of major populations with pre-S2 region mutations and of minor populations with polymerized human serum albumin-binding domain mutations were significantly higher in OBI-related HCC than in HBsAg-positive HCC. Moreover, the major variant populations associated with the B-cell epitope, located within the pre-S1 region, and the a determinant domain, located in the S region, were detected frequently in HBsAg-positive HCC. The minor populations of variants harbouring the W4R, L30S, Q118R/Stop, N123D and S124F/P mutations in the pre-S region and the L21F/S and L42F/S mutations in the S region were detected more frequently in OBI-related HCC than in HBsAg-positive HCC. Conclusions Ultra-deep sequencing revealed that the B-cell epitope domain in the pre-S1 region and alpha determinant domain in the S region were variable in HBsAg-positive HCC, although the quasispecies associated with the pre-S2 region were highly prevalent in OBI-related HCC. Trial registration Ref: R000034382/UMIN000030113; Retrospectively registered 25 November 2017.

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) often infiltrates to the adjacent major vasculatures; however, direct invasion of PDAC to the inferior vena cava (IVC) is uncommon. Case presentation We report our experience with three cases of PDAC directly invading the IVC wall. All three patients underwent pancreatoduodenectomy along with wedge resection of the IVC wall without severe postoperative complications. Histopathological studies revealed tumor infiltration to the adventitia of the IVC. All patients achieved negative surgical margins. One patient was still alive 26 months after surgery without tumor recurrence. Two patients experienced recurrence; one patient experienced liver metastasis but was still alive and in a stable condition without further tumor progression 12 months after surgery. Another patient experienced multiple liver metastasis 10 months after surgery and died 26 months after surgery. Conclusions Pancreatoduodenectomy along with wedge resection of the IVC wall for patients with PDAC directly invading the adventitia of the IVC can be performed safely. Further accumulation of cases is needed to elucidate the prognostic impact of IVC invasion.

Introduction In-vivo fluorescence imaging techniques using indocyanine green (ICG) to identify liver tumours and hepatic segment boundaries have been recently developed. The purpose of this study is to evaluate the efficacy of fusion ICG-fluorescence imaging for navigation during hepatectomy.Methods and analysis This will be an exploratory single-arm clinical trial; patients with liver tumours will undergo hepatectomy using the ICG-fluorescence imaging system. In total, 110 patients with liver tumours scheduled for elective hepatectomy will be included in this study. Preoperatively, ICG will be intravenously injected at a dose of 0.5 mg/kg body weight within 2 days. To detect liver tumours intraoperatively, the hepatic surface will be initially observed using the ICG-fluorescence imaging system. After identifying and clamping the portal pedicle corresponding to the hepatic segments, including the liver tumours to be resected, additional ICG will be injected intravenously at a dose of 0.5 mg/kg body weight to identify the boundaries of the hepatic segments. The primary outcome measure will be the success or failure of the ICG-fluorescence imaging system in identifying hepatic segments. The secondary outcomes will be the success or failure in identifying liver tumours, liver function indicators, operative time, blood loss, rate of postoperative complications and recurrence-free survival. The findings obtained through this study are expected to help to establish the utility of ICG-fluorescence imaging systems, and therefore contribute to prognostic outcome improvements in patients undergoing hepatectomy for various causes.Ethics and dissemination The protocol has been approved by the Kobe University Clinical Research Ethical Committee. The findings of this study will be disseminated widely through peer-reviewed publications and conference presentations.Trial registration number UMIN000031054 and jRCT1051180070

Introduction Multimodal treatment prolongs the survival of patients with biliary tract cancer (BTC). However, the chemotherapy choices for this disease are few, and completing each chemotherapy session is important. Adjuvant chemotherapy has been attempted for BTC, but has only had a 75% completion rate. Body weight loss and cholangitis are reasons for the interruption of chemotherapy. Previous reports suggested that nutritional intervention with omega-3 fatty acids maintained body weight and improved the completion rate for chemotherapy. Moreover, omega-3 fatty acids have an anti-inflammatory effect. Therefore, we theorised that omega-3 fatty acids would improve the completion rate of adjuvant chemotherapy in patients with BTC. The aim of this study is thus to evaluate the effectiveness of omega-3 fatty acids for patients planning adjuvant chemotherapy for BTC.Method and analysis This study is a single-centre, open-label, single-arm, historically controlled study with a planned enrolment of 55 participants. Protocol treatment consists of four courses of S-1 adjuvant chemotherapy and an oral omega-3 fatty acid pharmaceutic adjuvant (LOTRIGA 2 g (Takeda Pharmaceutical Co.)), which includes 2 g of omega-3 fatty acids from day 1 until day 168 of the treatment period. The primary endpoint is the completion rate of four total courses of S-1. Secondary endpoints are postoperative cholangitis, time to recurrence or distant metastasis, changes in nutritional index, changes in the lymphocyte blast transformation test induced by phytohaemagglutinin, and concanavalin A and diamine oxidase serum activity during adjuvant chemotherapy. All adverse events will be evaluated.Ethics and dissemination This protocol was approved by the Institutional Review Board of Kobe University Hospital. The findings from this study will be presented at national and international conferences and published in peer-reviewed journals.Trial registration number UMIN000031247.

Pregenomic RNA (pgRNA) is generated from covalently closed circular DNA (cccDNA) and plays important roles in viral genome amplification and replication. Hepatic pgRNA and cccDNA expression levels indicate viral persistence and replication activity. This study was aimed to measure hepatic pgRNA and cccDNA expression levels in various states of hepatitis B virus (HBV) infection. Thirty-eight hepatocellular carcinoma (HCC) patients, including 14 positive for hepatitis B surface antigen (HBsAg) and 24 negative for HBsAg but positive for anti-hepatitis B core (anti-HBc) antibody, were enrolled in this study. In HBsAg-negative but anti-HBc-positive group, HBV-DNA was detected in 20 of 24 (83%) noncancerous liver tissues for at least two genomic regions based on polymerase chain reaction (PCR) analysis. pgRNA and cccDNA expression levels in occult HBV-infected patients were significantly lower than those in HBsAg-positive patients (P

Introduction Bile leak is still a major complication after liver resection to be improved. To intraoperatively detect this adverse complication, leak test is commonly performed after hepatic resection. However, by the conventional leak test, it is often difficult to know whether the test reagent reaches to intrahepatic bile duct near cut surface of liver with adequate volume and pressure to identify the existence of bile leak. Thus, in order to perform leak test more accurately, this study aims to evaluate the efficacy and safety of the leak test using contrast-enhanced intraoperative ultrasonic cholangiography (CE-IOUSC), which was reported by our group as a procedure for detection of bile duct. Methods and analysis The current study is a nonrandomised, prospective, off-label, single-arm clinical trial for patients who undergo liver resection. A total of 100 patients will be enrolled. After completion of liver resection, the leak test is performed with CE-IOUSC using Sonazoid as a contrast agent to visualise dye injection into the intrahepatic bile duct. The primary endpoint is the success of the leak test, defined as clear visualisation of intrahepatic bile duct around cut surface by ultrasonography that indicates enough volume of dye injection. Secondary endpoints are postoperative bile leak and all adverse events related to CEIOUSC. The findings obtained through this study will establish this procedure to assist surgeons for adequately performing the leak test, precisely detecting intraoperative biliary leak strictly and reducing postoperative bile leak. Ethics and dissemination The protocol is approved by Institutional Review Boards of Kobe University Hospital (No.290069). Our findings will be widely disseminated through conference presentations and peer-reviewed publications. [ABSTRACT FROM AUTHOR]

Background: Elevations in blood lactate levels have been associated with poor postoperative outcome. The aim of the present study was to determine if preoperative supplementation with branched-chain amino acids (BCAA) decreases postoperative blood lactate levels in patients undergoing pancreatoduodenectomy. Methods: The cases of 223 consecutive patients who underwent pancreatoduodenectomy were retrospectively reviewed. Postoperative blood lactate levels in patients who were treated with BCAA supplementation before pancreatoduodenectomy (December 2011-December 2014) were compared with levels in patients who were not pretreated (January 2008-November 2011). Results: Postoperative lactate levels were significantly lower in patients who received preoperative BCAA supplementation than in patients who did not (2.6 vs 3.1 mmol/L, P = .005), although preoperative blood lactate levels were statistically equivalent between the groups. In the univariate analysis, preoperative BCAA supplementation, preoperative lactate levels, operation time, and postoperative glucose levels were associated with postoperative lactate levels. A multiple regression analysis was performed among the 4 factors, and the preoperative use of BCAA supplementation was independently correlated with postoperative lactate levels (P = .046). Conclusions: Preoperative BCAA supplementation decreased postoperative blood lactate levels. These results suggest that preoperative BCAA supplementation may help patients recover after surgery. (JPEN J Parenter Enteral Nutr. 2018;42:960-964) [ABSTRACT FROM AUTHOR]