28 research outputs found

    Effects of different silica intermediate layers for hydrogen diffusion enhancement of palladium membranes applied to porous stainless steel support

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    Porous stainless steel (SUS) supports were modified with double intermediate layers, silicalite-1 and γ-alumina, to enhance the hydrogen diffusion of a thin palladium membrane. One of layers, silicalite-1, was prepared using the hydrothermal synthetic method on porous SUS supports. The differences in expansion/contraction behaviors caused by different thermal coefficients of expansion between silicalite-1 and the SUS resulted in a lowering of the durability of the membrane. Intermediates layers of mesoporous MCM-48 powders or commercial spherical non-porous silica particles were then applied to porous SUS supports via aspiration, γ-alumina was introduced by dip-coating, and the Pd membrane was subjected to electro-less plating. H2 permeance of the Pd membrane (membrane thickness: 11 μm) containing spherical silica particles was around 10 × 10−6 mol·m−2·s−1·Pa−1 at 600 °C, which was higher than that of the Pd membrane (membrane thickness: 7 μm) containing MCM-48. The durability of the Pd membrane containing spherical silica particles was higher than that of the version containing MCM-48 powders. These results suggest that commercial spherical non-porous silica particles will uniformly occupy the pores of the SUS tubes and enhance the H2 permeance and durability of the Pd membrane

    Intrafamilial clustering of genotypes of hepatitis C virus RNA.

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    Hepatitis C virus (HCV)-RNA in the blood was measured by polymerase chain reaction (PCR) in 37 subjects from eight families in which 2 or more persons tested seropositive for antibodies against C100-3 or CP9. HCV-RNA was positive in 17 of 37 subjects. Two or more HCV-RNA-positive subjects were observed in six of the families. Intrafamilial HCV infection was studied by determining the HCV-RNA type (I, II, III or IV) by PCR using type-specific primers. In two families, all of the subjects showed type III infection, and in three other families, all of the subjects showed type II infection, with different types of HCV infections being observed in only one family. The HCV type was uniform in all but one. These findings suggest a possibility of intrafamilial infection between husbands and wives and between members of the same household.</p

    Clinical characteristics and course of sporadic non-ampullary duodenal adenomas A multicenter retrospective study

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    Sporadic non-ampullary duodenal adenoma (SNADA) is a rare disease, and therefore, its clinical characteristics have not been comprehensively investigated. Furthermore, owing to the high complication rates and severity of endoscopic resection, treatment strategies vary among facilities. In the present study, we aimed to clarify the clinical characteristics and course of SNADA. We extracted clinical and histological records of SNADA cases diagnosed in 11 hospitals between September 1999 and August 2014. The patients were divided into "no-resection" and "resection" groups based on the initial treatment approach. We investigated the long-term outcome of the "no-resection" group and treatment results of the "resection" group, with particular interest in endoscopic resection. Overall, 299 patients were diagnosed with SNADA. The median age at diagnosis was 67 years (range, 31-88 years), with approximately twice as many men as women. The median tumor size was 8.0 mm (2-60 mm). In total, 161 patients were initially selected for no-resection and 138 underwent resection. Age >70 years and the presence of either severe illness or poor performance status were significantly related to opting for no-resection. In the no-resection group, 101 patients underwent endoscopic follow-up for at least 1 year. During the observational period (2.5 +/- 2.2 years), 27 lesions (27%) disappeared following cold forceps biopsy, and 13 lesions (14%) presented lateral growth. Four lesions (4%) changed to mucosal carcinoma, 3 were treated endoscopically, and 1 was surgically resected. Nineteen patients died; however, no one died of duodenal carcinoma. In the endoscopic resection group, en bloc resection was achieved in 78% of patients. However, the complication rate for perforation was 7%, and endoscopic submucosal dissection was associated with a 36% perforation rate. With the low incidence of cancer development and no disease specific death, the strategy of initially not performing resection could be considered especially for the older adults, poor-prognosis patients, or small lesions

    Combination of Diclofenac and Sublingual Nitrates Is Superior to Diclofenac Alone in Preventing Pancreatitis After Endoscopic Retrograde Cholangiopancreatography

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    BACKGROUND & AIMS: Acute pancreatitis is a major adverse event of endoscopic retrograde cholangiopancreatography (ERCP). Rectal administration of nonsteroidal anti-inflammatory drugs (NSAIDs) decreases the incidence of post-ERCP pancreatitis (PEP). Little is known about the combined effects of sublingual nitrate and NSAIDs. We performed a randomized trial to assess whether the combination of NSAIDs and sublingual nitrate is more effective than NSAIDs alone in preventing PEP. METHODS: In a prospective superiority trial, eligible patients underwent ERCP at 12 endoscopic units in Japan, from March 2015 through May 2018. Patients were randomly assigned to groups given diclofenac suppositories (50 mg) within 15 minutes after the endoscopic procedure alone (diclofenac-alone group, n = 442) or in combination with sublingual isosorbide dinitrate (5 mg) 5 minutes before the endoscopic procedure (combination group, n = 444). The primary endpoint was the occurrence of PEP. RESULTS: PEP developed in 25 patients in the combination group (5.6%), and in 42 patients in the diclofenac-alone group (9.5%) (relative risk 0.59; 95% confidence interval 0.37-0.95; P = .03). Moderate to severe pancreatitis developed in 4 patients (0.9%) in the combination group, and 10 patients (2.3%) in the diclofenac-alone group (relative risk 0.12; 95% confidence interval 0.13-1.26; P = .12). There was no serious adverse event related to the additional administration of sublingual nitrate. CONCLUSIONS: In a randomized controlled trial, we found that prophylaxis with rectal diclofenac and sublingual nitrate significantly reduces the overall incidence of PEP compared with diclofenac suppository alone. ClinicalTrials.gov, no: UMIN 000016274

    Effectiveness, safety, and factors associated with the clinical success of endoscopic biliary drainage for patients with hepatocellular carcinoma: a retrospective multicenter study

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    Background Only a few reports have assessed the effectiveness of endoscopic biliary drainage (EBD) in hepatocellular carcinoma (HCC) patients with obstructive jaundice and liver dysfunction. Methods This was a retrospective study based on the clinical databases from the Okayama University Hospital and 10 affiliated hospitals. All patients received EBD for jaundice or liver dysfunction. The indication for EBD was aggravation of jaundice or liver dysfunction with intrahepatic bile duct (IHBD) dilation. The technical and clinical success rate, complications, factors associated with clinical failure, and survival duration were evaluated. Results A total of 107 patients were enrolled in this study. Technical success was achieved in 105 of 107 patients (98.1%). Clinical success was achieved in 85 of 105 patients (81%). Complications related to endoscopic retrograde cholangiography (ERC) occurred in 3 (2.8%) patients. Child–Pugh class C (odds ratio 3.90, 95% confidence interval [CI] 1.47–10.4, p = 0.0046) was the only factor associated with clinical failure, irrespective of successful drainage. The median survival duration was significantly longer in patients with clinical success than in those without clinical success (5.0 months vs. 0.93 months; hazard ratio [HR] 3.2, 95% CI 1.87–5.37). HCC Stage I/II/III (HR 0.57, CI 0.34–0.95, p = 0.032), absence of portal thrombosis (HR 0.52, CI 0.32–0.85, p = 0.0099), and clinical success (HR 0.39, CI 0.21–0.70, p = 0.0018) were significant factors associated with a long survival. Conclusions EBD for obstructive jaundice and liver dysfunction in patients with HCC can be performed safely with a high technical success rate. Clinical success can improve the survival duration, even in patients expected to have a poor prognosis

    Effect of Glue-line Flexibility on Cleavage Fracture Toughness of Wood-Epoxy Resin Bond System

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    この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。The paper concerns with effect of the mechanical properties of glue-line on the cleavage fracture toughness of wood-epoxy resin bond systems. Tensile stress-strain relations of the resin films flexibilized with polysulfide in various grades were tested at a range of head speed 0.09 mm/min to 180 mm/min and temperature 20℃ to 60℃. Resins containing 20 to 40 parts per hundred of resin (phr) behaved like elasto-plastic material and that of 60 phr like rubber. Numerical analysis of stress distribution in cleavage fracture toughness test specimens of wood-flexibilized epoxy resin bond system was made by using the values of mechanical properties of resin films obtained above. Less stress concentration was found on the tip of a crack in thicker and more flexible glue-line. Higher stress concentration was found on thinner and more rigid glue-line arid on lower density adherend. Test results on cleavage fracture toughness G_ of wood-epoxy resin bond specimens showed clearly that increasing flexibility and thickness of glue-line could effectively improve cleavage fracture toughness of wood-glue bond system
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