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Objectives This study aimed to investigate the utility of fluorodeoxyglucose (FDG) positron emission tomography for solid pseudopapillary neoplasm (SPN) diagnosis. Methods The subjects included 53 cases of SPN. We compared the maximal standardized uptake volume (SUVmax) with those of 25 cases of pancreatic duct cancer and 18 cases of pancreatic neuroendocrine neoplasm. In addition, immunopathological testing for SPN with regard to FDG uptake was undertaken. Results An increase in SUVmax was observed in all tumors with increased tumor diameter. Among tumors of 20 mm or smaller, the SUVmax of SPN was significantly higher than those of pancreatic duct cancer and pancreatic neuroendocrine neoplasm. The results of a pathological study of FDG uptake in SPN revealed increased glucose transporter protein type 1 expression with tumor enlargement. Furthermore, increased hypoxia-inducible factor-1 and vascular endothelial growth factor expression under hypoxic conditions were observed in the areas of necrosis. Conclusions In cases in which high FDG uptake is observed in small pancreatic tumors, FDG positron emission tomography is potentially useful for SPN differentiation. The factors involved in FDG uptake in SPN include cell density and glucose transporter protein expression, as well as hypoxia-inducible factor and vascular endothelia growth factor expression in the hypoxic environment of necrotic areas.

Background and Aim Although endoscopic nasopancreatic drainage (ENPD) is useful for collecting samples for pancreatic juice cytology and for treating leakage of pancreatic juice and occlusive pancreatitis, placement of the ENPD catheter is associated with complications such as post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP). We investigated whether an ENPD catheter with a smaller diameter could reduce the incidence of complications. Methods Patients requiring placement of an ENPD catheter (n = 254) were enrolled and randomly assigned to one of two catheter-size groups: the 4-Fr group or the 5-Fr group. The incidence of PEP, cholangitis, and spontaneous catheter displacement and the suitability of pancreatic juice cytology samples were compared between groups. In addition, univariate and multivariate analyses were conducted on factors associated with PEP. Results The incidence of PEP was significantly lower in the 4-Fr group compared with the 5-Fr group (4.1% vs 12.4%, respectively; P = 0.021). The rate of cholangitis and spontaneous catheter displacement and the suitability of pancreatic juice cytology samples did not differ between groups. Multivariate analysis revealed that the risk of PEP was 3.7 times higher when using a 5-Fr catheter than when using a 4-Fr catheter (P = 0.019). In addition, the risk of PEP was 4.1 times higher in patients with an intraductal papillary mucinous neoplasm than in those without (P = 0.0049) and 4.6 times higher in patients aged

Formation of metal hydrides is a signature chemical property of hydrogen and it can be leveraged to enact both storage and detection of this technologically important yet extremely volatile gas. Palladium shows particular promise as a hydrogen storage medium as well as a platform for creating rapid and reliable H2 optical sensor devices. Furthermore, alloying Pd with other noble metals provides a technologically simple yet powerful way of enacting control over the structural and catalytic properties of the resultant material. Similarly, in addition to alloying, different top-down and bottom-up Pd nanostructuring methods have been proposed and investigated specifically for creating optical H2 sensors. In this work it was determined that the hydrogen sensing ability of a series of Pd-Au alloy films could be improved by way of a hydrogen over exposure (HOE) treatment. Structural investigation showed that the HOE treatment, in addition to irreversibly altering the film morphology, results in a 1 to 2% expansion in the lattice constant of the metal. By combining a cyclic HOE treatment and alloy aging through annealing, the hydrogen detection sensitivity and response rates of Pd-Au films could be stabilized so that their performance would no longer be appreciably affected by repeated hydrogen uptake and release cycles. This work takes a further step towards routine all-optical detection of part-per-million level hydrogen gas concentrations in Pd-Au alloy films and discussion of ways to enhance response rates is provided.

Background and Aim. Endoscopic nasobiliary drainage (NBD) effects according to diameter remain unclear. We aimed to assess the drainage effects of the 4-Fr and 6-Fr NBD catheters. Methods. This prospective, multicenter, randomized, controlled study was conducted at Hiroshima University Hospital and related facilities within Hiroshima Prefecture. Endoscopic retrograde cholangiopancreatography (ERCP) in 246 patients revealed acute cholangitis, obstructive jaundice, and/or extrahepatic cholestasis; 4-Fr or 6-Fr NBD catheters were randomly allocated and placed in these patients. The primary endpoint was the efficacy of NBD based on the technical success rate and clinical success (rates of change in blood test and amount of bile output). Secondary endpoints included the spontaneous catheter displacement rate and nasal discomfort. Results. The technical success rate and clinical success did not differ significantly between groups. No spontaneous catheter displacement was noted in either group. Nasal discomfort due to catheter placement was significantly lower in the 4-Fr group versus the 6-Fr group (24 h after ERCP: 2.4 versus 3.5 cm, P=0.005; 48 h after ERCP: 2.2 versus 3.1 cm, P=0.01). Conclusion. The 4-Fr NBD catheter was not inferior to 6-Fr NBD catheter in terms of clinical success; the 4-Fr NBD catheter was useful to reduce nasal discomfort.

Objective. To elucidate the optimum preoperative biliary drainage method for patients with pancreatic cancer treated with neoadjuvant chemotherapy (NAC).Material and Methods. From January 2010 through December 2014, 20 patients with borderline resectable pancreatic cancer underwent preoperative biliary drainage and NAC with a plastic or metallic stent and received NAC at Hiroshima University Hospital. We retrospectively analyzed delayed NAC and complication rates due to biliary drainage, effect of stent type on perioperative factors, and hospitalization costs from diagnosis to surgery.Results. There were 11 cases of preoperative biliary drainage with plastic stents and nine metallic stents. The median age was 64.5 years; delayed NAC occurred in 9 cases with plastic stent and 1 case with metallic stent (p=0.01). The complication rates due to biliary drainage were 0% (0/9) with metallic stents and 72.7% (8/11) with plastic stents (p=0.01). Cumulative rates of complications determined with the Kaplan-Meier method on day 90 were 60% with plastic stents and 0% with metallic stents (log-rank test,p=0.012). There were no significant differences between group in perioperative factors or hospitalization costs from diagnosis to surgery.Conclusions. Metallic stent implantation may be effective for preoperative biliary drainage for pancreatic cancer treated with NAC.

For hydrogen sensor and storage applications, films of Au and Pd were (i) co-sputtered at different rates or (ii) deposited in a sequential layer-by-layer fashion on a cover glass. Peculiarities of hydrogen uptake and release were optically monitored using 1.3 micrometers wavelength light. Increase of optical transmission was observed for hydrogenated Pd-rich films of 10-30 nm thickness. Up to a three times slower hydrogen release took place as compared with the hydrogen uptake. Composition ratio of Au:Pd and thermal treatment of films provided control over the optical extinction changes and hydrogen uptake/release time constants. Higher uptake and release rates were observed in the annealed Au:Pd films as compared to those deposited at room temperature and were faster for the Au-richer films. Three main parameters relevant for sensors: sensitivity, selectivity, stability (reproducibility) are discussed together with the hydrogenation mechanism in Au:Pd alloys., Comment: 8 figures

Objective. To evaluate the effectiveness of radiation protective curtains in reducing the occupational radiation exposure of medical personnel.Methods. We studied medical staff members who had assisted in 80 consecutive therapeutic endoscopic retrograde cholangiopancreatography (ERCP) procedures. Use of radiation protective curtains mounted to the X-ray tube was determined randomly for each procedure, and radiation doses were measured with electronic pocket dosimeters placed outside the protective apron.Results. When protective curtains were not used, the mean radiation doses to endoscopists, first assistants, second assistants, and nurses were 340.9, 27.5, 45.3, and 33.1 µSv, respectively; doses decreased to 42.6, 4.2, 13.1, and 10.6 µSv, respectively, when protective curtains were used (P<0.01). When the patient had to be restrained during ERCP (n=8), the radiation dose to second assistants without protective curtains increased by a factor of 9.95 (P<0.01) relative to cases in which restraint was not required.Conclusions. During ERCP, not only endoscopists, but also assistants and nurses were exposed to high doses of radiation. Radiation exposure to staff members during ERCP was reduced with the use of protective curtains.

Assessing and accurately predicting geological conditions ahead of a tunnel face are important in constructing mountain tunnels reasonably and safely. The authors have developed a new type of seismic tomography technique between tunnel and ground surface using a precise time synchronization wireless system with GPS, a vibration of blasting excavation and an automatic data acquisition system. This system enable to illustrate P-wave velocity contour ahead of a tunnel face without stopping an excavation. Based on its velocity distribution, not only a location but also a velocity value of geological change can be evaluated. This paper presents that details of each development and an actual employment of new technique to a construction site. 山岳トンネル工事において，切羽前方の地質状況を精度良く予測することは，安全かつ合理的な掘削を行う上で不可欠である．筆者らは，トンネルと地表面間における弾性波トモグラフィ探査により，切羽前方に分布する断層破砕帯や地層境界の位置だけでなく，その程度まで評価可能な探査手法を考案した．トモグラフィ解析を行うために，発受振システムの時刻同期に関する研究を行い，解析上問題とならない誤差で同期できることを確認した．さらに，掘削発破用トリガ検出装置と自動計測システムを考案し，切羽を止めず，自動的にデータ収録を可能とした．本手法を実現場へ適用した結果は，切羽状況や実施支保パターンと整合し，通常のトンネル掘削を行いながら，精度の高い施工中調査を行えるようになった．