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We fabricated successfully heterostructures of AlGaN/GaN and AlGaN/InGaN/GaN on AlN template/c-sapphire exhibiting the Shubnikov-de Haas (SdH) oscillation in the magnetic field at lower temperatures. In AlxGa1-xN/GaN system, the carrier density of two-dimensional electron gas (2DEG) was controlled from 4.0 × 1012 to 9.0 × 1012 cm−2, which was consistent with the theoretical simulation, with increase of Al composition in AlGaN barrier layer. In AlGaN/InGaN/GaN system, the surface morphology and alloy disorder on the InGaN were properly defined. The effective mass of 2DEG at the Al0.22Ga0.78N/In0.04Ga0.96N interface was estimated to be 0.24 m0 from the temperature dependence of SdH oscillation amplitude. Although the effective mass was comparable to that of AlGaN/GaN heterostructure, the mobility of 2DEG at the InGaN was drastically degraded in spite of the slight amount of indium incorporation. This reduction was attributed to larger scattering probably due to the interface roughness of InGaN layer caused by the step meandering and/or the potential fluctuation caused by random incorporation of indium atoms.

Background The bleeding risk after cold snare polypectomy in anticoagulated patients is not known. Objective To compare the bleeding risk after cold snare polypectomy or conventional polypectomy for small colorectal polyps in anticoagulated patients. Design Prospective randomized controlled study. Setting Municipal hospital in Japan. Interventions Anticoagulated patients with colorectal polyps up to 10 mm in diameter were enrolled. Patients were randomized to polypectomy with either cold snare technique (Cold group) or conventional polypectomy (Conventional group) without discontinuation of warfarin. The primary outcome measure was delayed bleeding (ie, requiring endoscopic intervention within 2 weeks after polypectomy). Secondary outcome measures were immediate bleeding and retrieval rate of colorectal polyps. Results Seventy patients were randomized (159 polyps): Cold group (n = 35, 78 polyps) and Conventional group (n = 35; 81 polyps). The patients' demographic characteristics including international normalized ratio and the number, size, and shape of polyps removed were similar between the 2 techniques. Immediate bleeding during the procedure was more common with conventional polypectomy (23% [8/35]) compared with cold polypectomy (5.7% [2/35]) ( P = .042). No delayed bleeding occurred in the Cold group, whereas 5 patients (14%) required endoscopic hemostasis in the Conventional group ( P = .027). Complete polyp retrieval rates were identical (94% [73/78] vs 93% [75/81]). The presence of histologically demonstrated injured arteries in the submucosal layer with cold snare was significantly less than with conventional snare (22% vs 39%, P = .023). Limitation Small sample size, single-center study. Conclusions Delayed bleeding requiring hemostasis occurred significantly less commonly after cold snare polypectomy than conventional polypectomy despite continuation of anticoagulants. Cold snare polypectomy is preferred for removal of small colorectal polyps in anticoagulated patients. (Clinical trial registration number: NCT 01553565.)

Formation of an inter-diffusion phase of gadolinium-doped ceria (GDC) and yttria-stabilized zirconia (YSZ) during high-temperature sintering is a significant issue to deteriorate the electrochemical performance of solid oxide fuel cell electrodes. In the present study, microstructural change of GDC particles on a YSZ substrate and formation of a secondary phase during high-temperature sintering was observed by an in-situ transmission electron microscopy (TEM). A TEM sample was fixed on Nano-Chip (Wildfire, DENSsolutions), and the in-situ observation was carried out at 1300 °C. For comparison, an additional observation by TEM was also carried out using the sample prepared in ex-situ condition. Formation of inter-diffusion phase was observed in both experiments. However, grain growth and interfacial microstructure were different in each experiment. Based on the differences between the two tests, mechanisms of microstructural evolutions of GDC and interfacial structure are discussed.

Metallic V nanoparticles (NPs) were formed in silica glass by implantation with V + ions of 60 keV to a fluence of 1.0 × 10 17 ions/cm 2 . Annealing in oxygen gas at 800 °C transformed the metallic NPs to oxide NPs. While the mean diameter of the metal V NPs was 8.4 nm in the as-implanted state, the diameters steeply increased during oxidation, with some exceeding 100 nm. Since at least 15 different composition phases, such as V 2 O 3 , V 3 O 7 , V 6 O 13 , V 9 O 17 , etc., are known for vanadium oxides, identification of the oxide phase of the NPs was not easy. X-ray diffraction (XRD) was not a powerful tool for phase identification of the NPs, because the diffraction peaks were broad due to the nanometric sizes of the particles and readily shift due to stress effects. The temperature dependence of the optical absorption spectrum was measured. The observed spectra were almost unchanged between 3.3 and 370 K. Combining the spectral result and the XRD results, the candidates were narrowed down to three phases, V 2 O 5 , V 4 O 9 , and V 7 O 13 , from the 15 candidates. Among the three, the V 2 O 5 phase is the most probable because the absorption spectrum and the oxygen partial pressure for its formation were both consistent.

Thin single-crystal yttrium-stabilized zirconia (YSZ) substrate was prepared by indentation fracture and mechanical polishing. The specimen was analyzed in detail by transmission electron microscopy (TEM). The (110) edge surface was faceted, in contrast to the smooth (001) edge surface, and the facet surfaces were identified as {111}-type planes. Good cross-sectional TEM specimens comprised of crystalline Ni and NiO layers deposited on YSZ edge surface could be prepared by sputtering of a Ni support grid using Ar+ ion milling and subsequent re-deposiotion on the smooth (001) fracture surface of the YSZ specimen. The epitaxial growth of a pure Ni layer on the YSZ edge planes occurred during ion milling in vacuum. However, subsequent ion milling of the specimen after exposure in air for several minutes resulted in the formation of a NiO layer on top of the first Ni layer. Reduction of the NiO layer was confirmed by electron energy-loss spectroscopy after annealing at 973 K in a vacuum of 1.2 × 10−5 Pa. This Ni layer was re-oxidized upon annealing in air at 1073 K for 1 h. The deposition behavior of the Ni and NiO layers was discussed on the basis of the surface oxidation of Ni layer.

BACKGROUND & AIMS: Colonoscopy, using either a transparent retractable extension device or narrow band imaging, is thought to improve colon adenoma detection. We compared the abilities of a transparent retractable extension device and narrow band imaging to detect colorectal adenomas. METHODS: One hundred and seven patients with colonic adenomas that were detected by traditional colonoscopy were randomly assigned to groups that underwent a second colonoscopy that used either a transparent retractable extension or narrow band imaging; adenomas were removed. The principal outcome parameters were the number, size, shape, and location of adenomas detected. The patients’ demographic characteristics, indications for colonoscopy, and cecal intubation times were similar between groups. RESULTS: Use of the transparent retractable extension resulted in detection of 31% more adenomas than the initial procedure (P .0001). The majority of newly discovered adenomas were sessile (79%; 26/33) and less than 5 mm in size (73%; 24/33). There was no significant increase in adenoma detection (5%) between first colonoscopy and second colonoscopy using narrow band imaging. Additional adenomas were found in 40.7% of patients that were examined using the transparent hood (22/54) versus 13.2% of those examined using narrow band imaging (7/53) (P .0028). CONCLUSIONS: Colonoscopy with a transparent retractable extension significantly improved the adenoma detection rate compared with repeat colonoscopy using narrow band imaging.

Upon implantating of Xe ions into silicon nitride ceramic at 800 °C, the precipitation of Xe at grain boundaries (GBs) was observed. Transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, and electron energy-loss spectroscopy analyses showed that the precipitates at GBs were amorphous Xe nanoparticles. The Xe precipitates grew and coalesced with each other upon post implantation annealing. Crack paths that formed in the samples due to ex situ mechanical stress with and without Xe implantation were also investigated, and the change in crack paths by the presence or the evaporation of Xe precipitates at GB was confirmed.

Background & Aims: Therapeutic endoscopic retrograde cholangiopancreatography requires selective cannulation of the relevant ductal system. The aim of this study was to evaluate the efficacy and safety of 3 different precutting techniques for difficult bile duct access on the basis of the characteristics of the major duodenal papilla (MDP). Methods: The patients were classified into small MDP, large MDP, or swollen MDP groups on the basis of the characteristics of the MDP. The precutting technique was based on MDP characteristics: transpancreatic sphincterotomy for small MDPs, needle-knife precut sphincterotomy for large MDPs, and needle-knife fistulotomy for swollen MDPs. The success rate of bile duct cannulation and the complication rates were compared. Results: A total of 86 patients (58 men; mean age, 76 years) with difficult bile duct cannulation required precutting technique; 48 had transpancreatic sphincterotomy, 30 had needle-knife precut sphincterotomy, and 8 had needle-knife fistulotomy. With precutting, the procedure was successful in 46 of 48 (96%), 27 of 30 (90%), and 8 of 8 patients (100%), respectively. The overall success rate of biliary cannulation after 2 endoscopic retrograde cholangiopancreatography attempts was 100%. The overall complication rate was 4.7% (4 of 86) (2 mild bleeding and 2 mild pancreatitis). Conclusions: Selection of the precutting technique on the basis of the characteristics of the MDP resulted in a high degree of success and a low complication rate in cases of difficult bile duct cannulation.

Human decorin was expressed in Spodoptera frugiperda 21 (Sf21) insect cells. A full-length cDNA encoding preprodecorin of 359 amino acids from a human fibroblast library was cloned into baculovirus transfer vector pVL1392, and transfected into Sf21 insect cells. The infected cells secreted the mature decorin into the culture medium. The secreted decorin lacked glycosaminoglycan but was N-glycosylated, whereas the unmodified decorin was present in the cell lysates, suggesting that N-glycosylation is required for decorin secretion from Sf21 cells. The recombinant decorin was then efficiently purified from the conditioned medium by two chromatographic procedures, hydroxyapatite Sepharose and Con A-Agarose, under nondenaturing conditions. The purified decorin was more potent, as evaluated by the inhibition of collagen fibrillogenesis, than that obtained from bovine tissues under denaturing conditions. The final yield of recombinant decorin was 1.5 mg in 200 ml culture medium of 3 × 10 8 cells. The biologically active decorin produced in Sf21 cells is a potentially useful probe for investigating the molecular interactions of this protein with other extracellular matrix proteins and may also have therapeutic applications.

Background and Aims: Fibroscan (Echosens,France) is a new non invasive tool for measuring liver stiffness and steatosis. It has mainly developed to evaluate chronic liver disease in adult, but usefulness and appropriate inspection method in children has not been established. We report our experience of Fibroscan to evaluate liver stiffness and steatosis in children. Methods: Pediatric patients diagnosed or suspected to have liver disease were evaluated for controlled attenuation parameter (CAP) and elasticity value (E value) using Fibroscan from August 2013 to November 2014. Results: In total, 20 procedures were performed for 19 patients (14 male, average age 11.5 year). CAP was 100 to 348 dB/m, and E value was 3.2 to 21.3 kPa. E values were higher than 10 kPa in three patients, one after receiving liver transplantation, one post Fontan procedure and one Alstrom syndrome. Liver biopsy was performed in four of them (2 Non-alcoholic steatohepatitis:NASH), 1 congenital liver fibrosis, 1 Wilson's disease) at almost the same time and E value was correlated with histological fibrosis stage (F 1-2) in them. CAP and the degree of steatosis in the liver tissue were correlated in NASH patients. After treatment not only the blood data such as transaminase and HOMA-IR but also CAP and E value of the patient of NASH were improved (CAP 323 to 299 dB/m, E value 7.7 to 4.5 kPa). Conclusion: Fibroscan might be useful for evaluating and following up liver stiffness and steatosis of children with liver disease as well as adult.

Background: The life expectancy of the population is rising. The number of octogenarian (80 years or older) undergoing endoscopy evaluation is rising. The utility of double balloon enteroscopy (DBE) procedure in Octogenarians have not been previously reported. Aim: To determine the safety and diagnostic yield of DBE procedure in the octogenarians. Methods: We reviewed our large prospectively collected DBE database from 2006 to 2011. The octogenarian patients aged 80 years or older were included in our study analysis. Patients' demographics along with DBE procedure indication, findings, and complications were recorded. The safety and diagnostic yield of DBE procedure was calculated by the frequency statistics. Results: A total of 1218 DBE procedure were performed from 2006 to 2011 at our tertiary referral center. Out of these DBE procedures, 108 DBE (60 antegrade and 48 retrograde approaches) performed in 86 different patient encounters among 68 octogenarian (54.4% Male) were included in our study analysis. The average age of these patients was 84 (80-95) years and BMI was 26.2 (18.6-45.13) kg/m2. The most common indication for DBE was overt bleeding 29.6% (See table below). The most common finding during these DBE was bleeding AVM (arterio-venous malformation) among 38% (n=33) encounters. The overall diagnostic (pertinent positive findings) or therapeutic yield of DBE was found to be 91.86% (79/86 encounters). The diagnostic and therapeutic yield was found to be 91% (71/ 78 encounters) for evaluation of gastrointestinal bleeding and 100% (5/5 encounters) for evaluation of suspected mass or bowel stricture among octogenarian. There was no immediate (

Background and Aims: The epidemiology of gastrointestinal disorder is poorly described among Japanese children. Our aim is to clarify the trend of GI diseases' prevalence at Pediatric GI practice in Japan over the last decade. Methods: Children and adolescents with GI symptoms from 2001 to 2011 were identified by endoscopic databases at Shinshu University Hospital and Showa Inan General Hospital. Procedures were performed by pediatric GIs and routine biopsies were taken from every landmark. The prevalence of newly diagnosed GI disorders, especially Helicobacter pylori related disorders, eosinophilic gastrointestinal diseases (EGIDs) and inflammatory bowel disorder (IBD), are evaluated. Results: In total, 772 procedures (534 esophagogastroduodenoscopy[EGD] and 237 colonoscopy[CS]) were performed for 552 Japanese children and adolescents (54% female, average 11.47±4.57 year). Of 552 patients, 93 (18%) had H. pylori infection, and 27 (29%) of H. pylori positive subjects had peptic ulcer (22 duodenal ulcer and 5 gastric ulcer). Twenty-two patients (4%) were diagnosed as EGIDs (11 eosinophilic gastroenteritis, 11 eosinophilic colitis and no patient of eosinophilic esophagitis despite routine biopsies from esophagus). Twelve patients were diagnosed as IBD (10 Ulcerative colitis and 2 Crohn's disease). The trend of each disorder was shown in Figure 1. Conclusion: EGIDs have increased dramatically in a few years. On the other hand, H. pyori infection decreased almost one-fifth over 10 years in Japanese children.

Comparison of Nurse Administered Propofol and Midazolam for Endoscopic Procedures in Very Elderly Or High-Risk Patients Akira Horiuchi, Yoshiko Nakayama Objectives: Propofol is a sedative agent that is superior to benzodiazepines with regard to rapid induction of sedation and faster recovery. However the possibility of serious adverse effects such as respiratory and cardiovascular depression have made many endoscopists reluctant to use propofol. We compared nurse-administered propofol to midazolam for sedation in very elderly (O85) or high-risk patients with chronic pulmonary disease (PaO2 ! 55 torr at rest) undergoing endoscopic procedures. Methods: During a 12-month period, 40 very elderly (O85) or high-risk patients were randomized to receive propofol or midazolam for sedation undergoing percutaneous endoscopic gastrostomy. After initial intravenous administration of 20 mg propofol, the dose was titrated in increments of 10 mg against clinical response. Midazolam was administered at a single set dose of 4 mg. The mean dose of each drug, procedure time, recovery time, and complications were evaluated. The blood levels of the drugs were measured before and at 30, 60, 120, and 180 after the injection of each drug. Results: The mean doses of propofol and midazolam administered were 35 mg (range, 20-40 mg) and 4 mg, respectively. Procedure times and the level of sedation achieved between the groups were similar: propofol 15 C 1.9 min; midazolam, 14 C 2.1 min) (p Z 0.22). Time to full recovery was faster in the propofol group: 44.9 C 11 min vs. 123 C 23 min) (p ! 0.001). No major complications occurred in either group. There was, however, an increased risk for a short oxygen desaturation (!90%) with midazolam (5.6%) compared to 1.7% with propofol in the very elderly group (p Z 0.036). Neither had a pronounced influence on arterial pressure or heart rate. Propofol concentrations ranged from 34 to 96 ng/ml (mean 55 ng/ml) 60 min post injection whereas midazolam ranged from 0.12 to 1.6 mg/L (mean 0.55 mg/L) at 180 min. Conclusions: There was faster recovery and a lower incidence of respiratory depression with propofol than with midazolam in very elderly or highrisk patients undergoing endoscopy. Nurse-administered propofol is a safe and reasonable sedation method for endoscopy in very elderly (O85) or high-risk patients.