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This paper reports an equivalent circuit model of self‐assembled electret (SAE) micro‐electro‐mechanical systems (MEMS) vibrational energy harvesters (VEHs). For the first time, a detailed equivalent circuit model of the SAE‐MEMS VEH has been implemented on a circuit simulator, considering the device energy diagram. The implemented equivalent circuit model allows analysis of the relationship between output current and SAE properties, device structures, and electrode materials. The validity of the model is confirmed by comparing the measurement and simulation results. Thus, the proposed model would be useful for the design of SAE‐MEMS VEHs. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The spontaneous orientation polarization (SOP) of 1,3,5,7-tetrakis(1-phenyl-1H-benzo[d]imidazol-2-yl)adamantane (TPBAD) and its photosensitivity were investigated and compared with those of 2,2′,2′′-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi), a prototypical molecule exhibiting SOP. Despite the large difference in the molecular shapes of TPBAD (tetragonal) and TPBi (disc-shaped), their vacuum-deposited films exhibited similarly high SOPs of +74.7 and +77.2 mV nm−1, respectively. Due to the non-conjugated adamantane core, TPBAD had a wider optical band gap (4.22 eV) than TPBi (3.50 eV). This reduced the sensitivity of SOP in TPBAD films to light irradiation, and the decay time constant was 10 times longer than that of TPBi films. Variable angle spectroscopic ellipsometry and two-dimensional grazing-incidence wide-angle X-ray scattering revealed that TPBAD films are optically isotropic with a lower packing order than TPBi films, suggesting that the subtle directional selectivity of the TPBAD molecules in the amorphous film generates large SOP. [ABSTRACT FROM AUTHOR]

Primary squamous cell carcinoma (SCC) of the liver is an extremely rare disease with a very poor prognosis. An 83-year-old woman was referred to our hospital with left abdominal pain. Laboratory data showed mildly elevated C-reactive protein and biliary enzymes. The tumor markers carcinoembryonic antigen, alpha-fetoprotein, and carbohydrate antigen 19-9 were within normal ranges. Contrast-enhanced computed tomography revealed a 60 mm-sized low-density mass with poor contrast enhancement located in the lateral segment of the liver. The tumor showed low signal on T1-weighted magnetic resonance imaging (MRI) and high signal on T2-weighted MRI. The cytology of bile juice showed no malignant findings. Endoscopic ultrasound-guided fine-needle aspiration biopsy was performed, which was suggestive of primary hepatic SCC. Tumor markers cytokeratin 19 fragment (CYFRA) and SCC-related antigen were elevated, at 25.2 ng/mL and 14.7 ng/mL, respectively. Left lobectomy and hilar lymph node dissection were performed. One month after surgery, the tumor marker values showed a marked decrease of 1.8 ng/mL for CYFRA and 0.3 ng/dL for SCC-related antigen. The patient has been without recurrence for more than one and half year postoperatively. SCC-related antigen and CYFRA were markedly decreased after tumor resection in this case, which may suggest their utility as tumor markers for SCC of liver origin. [ABSTRACT FROM AUTHOR]

Early diagnosis of pancreatic ductal adenocarcinoma (PDAC) is essential for improving prognosis; however, diagnosing PDAC at an early stage is challenging. In patients with localized high‐grade pancreatic intraepithelial neoplasia (HG‐PanIN), whose tumorous lesion is undetectable on cross‐sectional images such as computed tomography or magnetic resonance image, long‐term survival is expected. Pancreatic cystic lesions or main pancreatic duct (MPD) dilatation are important indirect findings for the initial diagnosis of HG‐PanIN. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound (EUS) should play important roles in detecting abnormal image findings, such as local irregular MPD stenosis, caliber MPD changes, small cystic lesions, or branch duct dilatation. Additionally, EUS could detect hypoechoic areas around the MPD stenosis in some patients with HG‐PanIN. Subsequently, endoscopic retrograde cholangiopancreatography (ERCP) and its associated pancreatic juice cytology, including serial pancreatic juice aspiration cytologic examination (SPACE) after placement of an endoscopic nasopancreatic drainage (ENPD) tube, may have high diagnostic accuracy for confirming the malignancy in HG‐PanIN. Although ERCP and its associated pancreatic cytology, including SPACE, may be associated with post‐ERCP pancreatitis (PEP), a recent randomized trial suggested that a 4‐Fr ENPD tube may reduce the incidence of PEP. In the future, further prospective multicenter studies are required to establish a standard method of SPACE. Additionally, further studies for novel biomarkers could help to establish evolutionary methods with duodenal fluid and pancreatic juice for the early and accurate diagnosis of early‐stage PDAC. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 <65 than in those aged ≥65 ( P = 0.0033). Conclusions A 4-Fr catheter is as useful as a 5-Fr catheter and is associated with a significantly lower incidence of PEP. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The effect of localized damage due to impact on compressive buckling as well as postbuckling behaviors of blade stiffened composite plates was numerically studied. A partial debonding between a skin panel and a flange and multiple delaminations in the skin panel were chosen as the localized damage. The three-dimensional composite elements used to analyze the compressive behavior of the stiffened panel with multiple delaminations was found to be suitable for this kind of complex composite structure. The contact problem between the skin and flange panels was approximated by a spring element with no restraint of the positive relative displacement and a strong restraint of the negative displacement. At the delaminations in the skin panel, which tended to close during compression, the normal relative displacement was constrained to prevent the delaminated portions from overlapping; this constraint made the convergence of the solution quite smooth compared to the case where the contact problem was exactly considered. When a debonded area only was located at the edge of the flange, no notable reduction of compressive buckling load was found until the size of the debonding reached a half wavelength of the buckling mode. The compressive buckling load dropped significantly when multiple delaminations, which were small in comparison to the half wavelength of the buckling mode, accompanied the skin-flange debonding. The energy release rate distributions at the damage edges, calculated using the virtual crack closure technique, increased quite rapidly, particularly in the transverse direction after buckling became sufficient to increase the delamination. [ABSTRACT FROM AUTHOR]

A direct-contact image sensor with an a-Si thin-film transistor (TFT) shift register and a sensor element for correcting shading due to a variation of a light source has been successfully fabricated and its properties have been evaluated. The Vt-shift of TFTs in the shift register was reduced by applying negative gate voltage during the rest period of the sensor. Because of this procedure, the sensor lifetime was prolonged. A bit rate of 500 kHz was obtained under the driving condition of 32 bits/block matrix driving and 15.6 kHz operation of the shift register. The sensor element is composed of a photoconductor for detecting the light from the light source and one for detecting the light reflecting from a document, which are serially connected. By matching photoconductivity exponents γ of the two photoconductors, the shading was corrected efficiently. [ABSTRACT FROM AUTHOR]

Early diagnosis of pancreatic cancer (PC) can improve patients' prognosis. We aimed to investigate the utility of endoscopic ultrasonography (EUS) for the early diagnosis of PC. This study included 64 patients with PC at an early stage treated at Onomichi General Hospital between January 2007 and January 2020. Diagnostic procedures included contrast computed tomography (CT), magnetic resonance cholangiopancreatography, EUS fine-needle aspiration, and endoscopic retrograde cholangiopancreatography (ERCP) for pancreatic juice cytology. The mean age was 71.3 years. In all, 32 patients were stage 0, and 32 were stage I. As for image findings, the main pancreatic duct (MPD) stenosis was detected in several cases, although CT and MRCP seldom detected tumors. EUS had a high detection rate for stage 0 tumor lesions. The median observation period was 3.9 years. In cases with stage 0, the 1 year and 5 year survival rates were 100% and 78.9%, respectively. In cases with stage I, the 1 year and 5 year survival rates were 96.4% and 66.7%, respectively. EUS has the highest sensitivity among all imaging modalities for detecting small pancreatic tumors. Cases with MPD dilation or stenosis, especially with tumors that cannot be identified on CT and MRI, should have EUS performed. In some cases, EUS was not able to detect any tumor lesions, and ERCP-based pancreatic juice cytology should be useful for pathological diagnosis. [ABSTRACT FROM AUTHOR]