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The influence of the dehydration by metal oxides on the synthesis of dimethyl carbonate (DMC) via oxidative carbonylation of methanol was studied. A Cu/Y-zeolite catalyst was prepared by the ion exchange method from CuCl 2 ·2H 2 O and the commercial NH 4 -form of the Y type zeolite. The catalyst was characterized by X-ray fluorescence (XRF), N 2 adsorption (BET method), X-ray diffraction (XRD), and temperature-programmed desorption of ammonia (NH 3 -TPD) to evaluate its Cu and Cl content, surface area, structure, and acidity. Reaction tests were carried out using an autoclave (batch reactor) for 18 h at 403 K and 5.5 MPa (2CH 3 OH + 1/2O 2 + CO ⇌ (CH 3 O) 2 CO + H 2 O). The influence of various dehydrating agents (ZnO, MgO, and CaO) was examined with the aim of increasing the methanol conversion ( X MeOH , MeOH conversion). The MeOH conversion increased upon addition of metal oxides in the order CaO >> MgO > ZnO, with the DMC selectivity ( S DMC ) following the order MgO > CaO > ZnO. The catalysts and dehydrating agents were characterized before and after the oxidative carbonylation of methanol by thermogravimetric and differential thermogravimetric (TG/DTG), and XRD to confirm that the dehydration reaction occurred via the metal oxide (MO + H 2 O → M(OH) 2 ). The MeOH conversion increased from 8.7% to 14.6% and DMC selectivity increased from 39.0% to 53.1%, when using the dehydrating agent CaO.

Experimental data on CO2 solubility in diisopropanolamine (DIPA) and methyldiethanolamine (MDEA) blended aqueous solutions were measured at different amine blending ratios and working temperatures. The successive (iterative) substitution method was implemented to calculate the molar fractions of all chemical species, including molecules and electrolytes, from equilibrium along with four material balances and one electroneutrality equation. The electrolyte universal quasi-chemical (electrolyte UNIQUAC) model was used to consider the nonideality in the liquid phase. The partial pressures of CO2 in the gas phase and molar fractions of all components in the liquid phase were recalculated using thermodynamic models. In addition, the effect of the blending ratio of DIPA, MDEA, and H2O was investigated and expressed using the newly applied triangular diagrams of pH, heat of absorption, and cyclic capacity of CO2 according to the absorption and stripping conditions.

Background and Aims The efficacy of palliative biliary drainage by using bilateral or unilateral self-expandable metal stents (SEMSs) for a malignant hilar biliary stricture (MHS) remains controversial. This prospective, randomized, multicenter study investigated whether bilateral drainage by using SEMSs is superior to unilateral drainage in patients with inoperable MHSs. Methods Patients with inoperable high-grade MHSs who underwent palliative endoscopic insertion of bilateral or unilateral SEMSs were enrolled. The main outcome measurements were the rate of primary reintervention for malfunction after successful placement of SEMSs, stent patency, technical and clinical success rates, adverse events, and survival duration. Results A total of 133 pathology-diagnosed patients were randomized to the bilateral group (n = 67) or the unilateral group (n = 66). The primary technical success rates were 95.5% (64/67) and 100% (66/66) in the bilateral and unilateral groups, respectively ( P = .244). The clinical success rates were 95.3% (61/64) and 84.9% (56/66), respectively ( P = .047). The primary reintervention rates based on the per-protocol analysis were 42.6% (26/61) in the bilateral group and 60.3% (38/63) in the unilateral group ( P = .049). The median cumulative stent patency duration was 252 days in the bilateral group and 139 days in the unilateral group. The risk of stent patency failure was significantly higher in the unilateral group (log-rank test; P P Conclusions Unilateral and bilateral drainage strategies by using SEMSs had similar technical success rates, but bilateral drainage resulted in fewer reinterventions and more durable stent patency in patients with inoperable high-grade MHSs. (Clinical trial registration number: NCT02166970.)

Numerous membrane models have been developed and tested for the simulation of membrane processes. However, these models are often either simplified or only validated with a narrow range of experimental data. For the model-based process design of membrane systems it is necessary to have a validated and accurate model which is accurate for the range of possible operating conditions under consideration. Hence, in this study a modeling framework is developed for hollow fiber membranes which can be adjusted systematically to accurately predict the performance of a given membrane. Mixed-gas (CO2/O2/N2 and CO2/N2) separation experiments are carried out over a range of different feed conditions to evaluate membrane performance and to provide reliable measurements of gas permeance. In particular the feed pressure (1–4 bar), permeate pressure (0.1–0.5 bar) and feed flow rates (0.096–0.4 N m3/h) are varied in these experiments (the ranges specified in brackets). Interpolation of these measured permeance allows for the accurate prediction of membrane performance at any conditions inside the measured range. A tanks-in-series modeling approach is employed here where the number of tanks (used to represent the membrane behavior in a numerical formulation) can be adjusted to calibrate and fit the membrane model to experimental results. For the membranes tested in this study it is found that using a relatively small number of tanks both minimizes the difference between model and experimental results and reduces the numerical complexity in the membrane model.

Recently developed crosslinked-thermally rearranged (XTR) polymeric membranes, which show enhanced gas separation, are applicable for CO2 separation from post-combustion gases. Moreover, the resulting thermally rearranged polybenzoxazole (TR-PBO) structure that is thermally induced from hydroxyl-polyimides (HPI) provides high thermal and chemical resistance, which is favorable for gas separation applications containing condensable gases such as water vapor. Herein, the influence of water vapor on the CO2 capture efficiency was evaluated using XTR poly(benzoxazole-co-imide) (XTR-PBOI) hollow fiber membrane modules which were compared with crosslinked HPI (XHPI) in mixture gas and single gases for CO2 and N2. The results revealed that the permeate CO2 flow rate in the hydrophobic XTR-PBOI module showed enhanced separation performance, whereas the flow rate severely decreased in the relatively hydrophilic XHPI module, reflecting more significant capillary condensation effect in the XHPI membranes. Both membrane modules showed excellent plasticization resistance, and the XTR-PBOI hollow fiber membrane module presented reasonable long-term stability over 240 h.

Introduction The aim of this study was to evaluate the factors associated with recurrence after colpocleisis for pelvic organ prolapse in elderly women. Methods This was a retrospective cohort study of patients who underwent colpocleisis for stage 3 or 4 pelvic organ prolapse at a single tertiary center from January 2007 to December 2015. Results A total of 107 patients who underwent colpocleisis were reviewed. Duration from prolapse occurrence to surgery was significantly longer (24.6 ± 22.8 years vs 8.0 ± 12.9 years, p = 0.021) in patients who had recurrence after colpocleisis than in those without recurrence. Conclusion Duration of prolapse was longer in patients with recurrence than in those who had a successful outcome.

This study reports the performance of base-impregnated silica and activated carbons supplied by the University of Nottingham (UNOTT) have been tested in the bubbling fluidized-bed reactor and the two interconnected bubbling fluidized-beds in a continuous system. UNOTT has published several papers with polyethyleneimine (PEI)-silica sorbents using a bubbling fluidized-bed reactor, reporting that the average working capacity was around 8.0 wt.% and the regeneration heat was around 3.3 GJ/tCO 2 based on the cycle tests. In order to verify the performance of this silica adsorbent and to draw comparison with activated carbons that potentially offer have lower regeneration energies, KIER has carried out cycle experiments using a bubbling fluidized bed reactor and also used a continuous CO 2 capture system which consists of a bubbling fluidized-bed-type absorption and regeneration reactors. Further, the sorption characteristics, including equilibrium capacity, kinetics, surface area, pore size distribution, were determined using a volumetric (BET) and a gravimetric (MSB, magnetic suspension balance methods. The sorption mechanism of CO 2 on the sorbent surface was investigated by in situ FT-IR. The optical, physical and chemical characteristics were examined by SEM- EDAX, TGA before and after the sorption - desorption cyclic tests. Particle size distribution of the sorbent was also analyzed by laser diffraction particle size analyzer.

Separation characteristics and dynamic behavior of two binary mixtures, CO2/CH4 (50:50, vol%) and CH4/N2 (50:50, vol%), on methyltriethoxysilane templated silica (MTES) membrane were studied experimentally and theoretically. The permeation of the binary mixtures was compared with that of pure CO2, CH4, and N2 at 323–473 K and 300–600 kPa. The permeation flux of pure CO2, which has the strong adsorption affinity, was much higher than that of CH4. However, the permeation flux of the CO2/CH4 mixture was hindered by CH4 with large kinetic diameter. Although the permeation flux of pure N2 was higher than that of pure CH4, the permeation flux of CH4 in the CH4/N2 mixture was greater than that of N2 owing to the disturbance of N2 permeation by CH4 and the relatively weak adsorption affinity of N2. Because the molecular interactions, adsorption affinity, and kinetic diameter and structure of each component contributed to the separation, compared to the separation factors, the permselectivity was overestimated in the CO2/CH4 mixture, but somewhat underestimated in the CH4/N2 mixture. Due to its kinetic effects, the diffusion mechanism of CH4 needs to be investigated thoroughly in pore-controlled silica-based membranes. The transient permeation and separation behaviors of the binary mixtures on MTES membranes were successfully predicted by the generalized Maxwell–Stefan model, which incorporated the dusty gas model and Langmuir isotherm model.

SEWGS (Sorption Enhanced Water Gas Shift) process is one of options for pre-combustion CO 2 capture using dry absorbent and water gas shift catalyst. In this process, the thermodynamic equilibrium in the shift reaction can be enhanced to give more hydrogen yield by adding a CO 2 absorbent into the shift reactor. Total integrated system consists of coal gasifier, hot gas clean-up process (two interconnected fluidized bed desulfurizer), and one loop SEWGS process. In this presentation, continuous operation results of the hot gas clean-up process and one loop SEWGS process using dry absorbents at high temperature and pressure conditions were discussed. Dry absorbents (for desulfurization, CO 2 absorption) were produced by KEPCO RI (Korea Electric Power Corporation Research Institute) by means of spray-drying method. Continuous operation was performed at high pressure (21 bar for gasifier, 20 bar for hot gas clean-up process, and 18 bar for SEWGS process) and reaction temperature was 550 o C for desulfurizer and 236 o C for SEWGS reactor. Totally integrated operation was maintained up to 50 hours. We could get high sulfur capture efficiency (99.6%) in the desulfurizer, high CO conversion (98.9%) and CO 2 capture efficiency (98.0%) in the SEWGS reactor.

In this study, thermal efficiency of power plant has been evaluated by integrating the KIER-developed dry-sorbent CO 2 capture process (KIERDRY) with a pulverized coal-fired power plant using a commercial simulator, gPROMS. A simple basic KIERDRY model has been developed and connected it to PCPP (Pulverized Coal Power Plant) example in gCCS, a system modelling tool for support of design and operating decisions across the CCS chain. The PCPP capacity of 500 MWe and the KIERDRY capacity of 150 MW (125 tonCO 2 /hr based on captured amount) have been set as a base case. We consider HP steam(307 o C, 31 bar) and IP steam(461 o C, 14∼14.6 bar) as the utility steam of a regenerator in KIERDRY since the steam condition of a regenerator has been set to approximately 14.6∼15 bar, saturated. Totally 5 cases have been evaluated: (1-1) Use HP steam, use condensate to make a process steam, and return to condensate(1 bar); (1-2) Use HP steam and return to 5th feed water heater(12 bar); (2-1) Use IP steam, use condensate to make a process steam, and return to condensate(1 bar); (2-2) Use IP steam and return to 5th feed water heater(12 bar); (2-3) Use IP steam, do additional heat integration by preheating dry sorbents at loop-seal, and return to 5th feed water heater(12 bar). As a result, the condensate generated at the regenerator should be returned to the power plant rather than used to make a process steam, which is supplied as a reactant for the carbonation reaction. Based on several case studies, the reduction of the power output of the PCPP with KIERDRY has been varied from 29.2 MWe(minimum penalty) to 71.7 MWe(maximum penalty). Thus, it can be concluded that the energy penalty of KIERDRY has been significantly reduced by how heat has been integrated with PCPP.

Benign biliary strictures (BBSs) are commonly caused by surgical injury, chronic pancreatitis, and inflammatory cholangiopathies. Although advanced imaging tests and tissue acquisition methods have been developed for evaluation of indeterminate biliary strictures, differentiation of BBSs from biliary malignancies remains a challenge to clinicians. The majority of BBSs have good response to nonsurgical treatment and surgical intervention mainly serves as a rescue when nonsurgical approaches fail. Endoscopic management is a safe, effective, and less-invasive treatment for BBSs compared with other approaches. Endoscopic biliary stricture dilation followed by placement of multiple plastic stents has been the first-line choice with good long-term ductal patency. Recently, covered self-expanding metal stents (CSEMSs) has been increasingly used in the management of BBSs with similar effectiveness but easier deployment, fewer endoscopic sessions compared with plastic stents. Moreover, other technologies are emerging in the diagnosis and management of BBSs. To assist clinicians in managing BBSs, the Asia-Pacific ERCP Club (APEC) has developed this statement through a systematic review of the literature.

Background/Aims Treatment for cholangitis without common bile duct (CBD) stones has not been established in patients with gallstones. We investigated the usefulness of endoscopic biliary drainage (EBD) without endoscopic sphincterotomy (EST) in patients diagnosed with gallstones and cholangitis without CBD stones by endoscopic retrograde cholangiopancreatography (ERCP) and intraductal ultrasonography (IDUS). Methods EBD using 5F plastic stents without EST was performed prospectively in patients with gallstones and cholangitis if CBD stones were not diagnosed by ERCP and IDUS. After ERCP, all patients underwent laparoscopic cholecystectomy. The primary outcomes were clinical and technical success. The secondary outcomes were recurrence rate of biliary events and procedure-related adverse events. Results Among 187 patients with gallstones and cholangitis, 27 patients without CBD stones according to ERCP and IDUS received EBD using 5F plastic stents without EST. The stents were maintained in all patients until laparoscopic cholecystectomy, and recurrence of cholangitis was not observed. After cholecystectomy, the stents were removed spontaneously in 12 patients and endoscopically in 15 patients. Recurrence of CBD stones was not detected during the follow-up period (median, 421 days). Conclusions EBD using 5F plastic stents without EST may be safe and effective for the management of cholangitis accompanied by gallstones in patients without CBD stones according to ERCP and IDUS.

Background and Aims Whether or not submucosal injection of a diluted epinephrine solution should be used to lift ampullary tumors during endoscopic snare papillectomy is unclear. This study aimed to investigate the clinical efficacy of a simple snaring method versus submucosal injection for papillectomy. Methods A prospective multicenter study was performed at 4 tertiary referral centers. Patients with papillary lesions were randomized to undergo either simple snare papillectomy (SSP) or submucosal injection papillectomy (SIP) using 1:10,000 diluted epinephrine. The main outcome measures were complete resection rate and post-papillectomy adverse events. Results A total of 50 patients with biopsy-proven papillary adenomas were enrolled. Complete resection rates in the SSP and SIP groups were 80.8% (21/26) and 50.0% (12/24), respectively ( P = .02). However, tumor persistence at 1 month (15.4% vs 8.3%, P = .62) and recurrence at 12 months (12.0% vs 9.5%, P = .58) did not differ despite initial differences in the prevalence of a positive resection margin. The mean tumor size was 12 mm in the SSP group and 9.29 mm in the SIP group. Post-papillectomy bleeding developed in 42.3% (11/26) and 45.8% (11/24) of patients, respectively ( P = .80). Delayed bleeding (>12 h) occurred in 27.3% (3/11) and 36.4% (4/11) of patients, respectively ( P = .50). Post-procedure pancreatitis occurred in 15.4% (4/26) and 25% (6/24) of patients, respectively ( P = .49). Pancreatitis severity did not differ between the groups, and there were no procedure-related mortalities. Conclusions Although the recurrence rate was similar between the SSP and SIP groups, SIP showed no advantage over SSP in terms of achieving complete resection or decreasing the frequency of post-papillectomy adverse events, such as bleeding. SSP may thus be a simpler and primarily recommendable technique. (Clinical trial registration number: NCT02165852.)

Background and Aim As society ages, the need for endoscopic retrograde cholangiopancreatography (ERCP) is increasing. This prospective comparative study evaluated the safety and efficacy of midazolam- versus propofol-based sedations by non-anesthesiologists during therapeutic ERCP in patients over 80 years of age. Methods A total of 100 patients over 80 years of age who required therapeutic ERCP were enrolled and randomly received midazolam + fentanyl (MF group) or propofol + fentanyl (PF group) sedation. Endoscopic sedation was titrated to a moderate level and carried out by trained registered nurses. Main outcome measurements were sedation safety in terms of cardiopulmonary components and efficacy measured on a 10-point visual analogue scale (VAS). Results Regarding safety, hypoxia occurred in seven (14%) in the MF group and in eight patients (16%) in the PF group (P = 0.779). Increased O2 supply was more frequent in the PF group (32% vs 42%), albeit not significantly so. There were no differences in the frequency of hypotension, bradycardia or tachycardia between the two groups. Mean VAS score for overall satisfaction with sedation by patients, endoscopists, and nurses and the scores for pain during the procedures were not different between the two groups. There was no significant difference in the procedure outcomes or rate of ERCP-related complications. Conclusions There were no significant differences of safety and efficacy between midazolam- and propofol-based sedation in patients over 80 years of age. Increased O2 supply was more frequent in the propofol group, but the prevalence of hypoxia did not differ significantly.

The permeation and separation of a CO2/CH4 mixture in an adsorbent/membrane hybrid (AMH) system, comprising zeolite 5A pellets packed into a tubular-type FAU-zeolite membrane, were compared to those in the FAU-zeolite membrane-only system. The separation factor of the AMH system was higher than that of the FAU-zeolite membrane under the same condition because of the difference in the propagation of each gas and the radial contact efficiency. The integration of two equilibrium separating media (zeolite 5A pellets as a bulk separator and FAU-zeolite membrane as a purifier) led to improved separation efficiency and reduced performance-fluctuation by varying input conditions because of the strong interaction between zeolite 5A and CO2. However, the permeation flux in the AMH was reduced due to the gas adsorption by the packed adsorbents. The dynamic behavior in the AMH system was well-predicted by integrating the mathematical models for an adsorbent-packed bed and a tubular-type membrane.

In malignant biliary stricture (MBS), the diagnostic accuracy of ERCP‐based tissue sampling is insufficient. EUS‐guided fine needle aspiration biopsy (EUS‐FNAB) is emerging as a reliable diagnostic procedure. This study aimed to evaluate the usefulness of a diagnostic approach using ERCP‐guided transpapillary forceps biopsy (TPB) or EUS‐FNAB according to the characteristics of suspected MBS. Consecutive patients diagnosed with suspected MBS with obstructive jaundice and/or cholangitis were enrolled prospectively. ERCP with intraductal ultrasonography (IDUS) and TPB were performed as initial diagnostic procedures. Based on the results of imaging studies and IDUS, all MBS were classified as extrinsic or intrinsic type. If the malignancy was not confirmed by TPB, EUS‐FNAB for extrinsic type or second TPB for intrinsic type was performed. Among a total of 178 patients, intrinsic and extrinsic types were detected in 88 and 90 patients, respectively. The diagnostic accuracy of first TPB was significantly higher in the intrinsic than in the extrinsic type (81.8% vs. 67.8, P = 0.023). In 33 patients with extrinsic type and negative for malignancy on first TPB, the diagnostic accuracy of EUS‐FNAB was 90.9%. In 19 patients with intrinsic type and negative for malignancy on first TPB, the diagnostic accuracy of second TPB was 84.2%. The diagnostic accuracies of the combination of initial TPB with EUS‐FNAB and second TPB were 96.7% and 96.6%, respectively. A diagnostic approach using EUS‐FNAB or TPB according to the origin of MBS is considered effective to improve the diagnostic accuracy of MBS with negative for malignancy on first TPB. (Clinical trial registration number: UMIN000016886).

Two different aqueous amine solutions were applied to CO2 removal from simulated biogas in a lab.-scale continuous absorption process that can handle 5Nm3/hr of gas treatment. The effects of the gas-to-liquid ratio in the absorber and of the temperature of the reboiler on the CO2 removal were analyzed in aqueous MEA and AMP solutions. Since the CO2 loading ratio of AMP solutions is larger than that of MEA solutions for the same absorbent concentration, the AMP solutions have higher CO2 removal efficiency than that of MEA solutions for the same gas-to-liquid ratio and reboiler temperature. Also, the 30 wt% MEA solution has a higher CO2 removal efficiency than that of the 20 wt% MEA solution at the same gas-to-liquid ratio and reboiler temperature. To evaluate the feasibility of biogas upgrading, a commercial simulator, Aspen Plus®, was used to analyze the effects of absorbent concentration, absorbent flow rate at the absorption column, and absorber height on CO2 removal and CH4 purity; the regeneration energy was also evaluated. The results were applied to the design of a pilot-scale biogas upgrading plant that can handle 10,000Nm3/day of biogas treatment.

Background/Aims Controversy still exists regarding the benefits of covered self-expandable metal stents (SEMSs) compared to uncovered SEMSs. We aimed to compare the patency and stent-related adverse events of partially covered SEMSs (PC-SEMSs) and uncovered SEMSs in unresectable malignant distal biliary obstruction. Methods A total of 134 patients who received a PC-SEMS or uncovered SEMS for palliation of unresectable malignant distal biliary obstruction were reviewed retrospectively. The main outcome measures were stent patency, stent-related adverse events, and overall survival. Results The median stent patency was 118 days (range, 3 to 802 days) with PC-SEMSs and 105 days (range, 2 to 485 days) with uncovered SEMSs (p=0.718). The overall endoscopic revision rate due to stent dysfunction was 36.6% (26/71) with PC-SEMSs and 36.5% (23/63) with uncovered SEMSs (p=0.589). Tumor ingrowth was more frequent with uncovered SEMSs (4.2% vs 19.1%, p=0.013), but migration was more frequent with PC-SEMSs (11.2% vs 1.5%, p=0.04). The incidence of stent-related adverse events was 2.8% (2/71) with PC-SEMSs and 9.5% (6/63) with uncovered SEMSs (p=0.224). The median overall survival was 166 days with PC-SEMSs and 168 days with uncovered SEMSs (p=0.189). Conclusions Compared to uncovered SEMSs, PC-SEMSs did not prolong stent patency in unresectable malignant distal biliary obstruction. Stent migration was more frequent with PC-SEMSs. However, tumor ingrowth was less frequent with PC-SEMSs compared to uncovered SEMSs.

NH2-MIL-125 has been investigated as a water adsorbent because of its high hydrothermal stability and S-shaped water adsorption isotherm. Herein, we report the synthesis of NH2-MIL-125 with high surface area and water capacity for an adsorption heat transformation (AHT) system. NH2-MIL-125 derived from Ti(BuO)4 shows higher surface area and water uptake than those of Ti(iPrO)4-derived samples regardless of the synthesis method. In a sense of crystallinity, a solvothermal method with static conditions generated more distinct crystalline properties than the one synthesized by a reflux reaction as confirmed from powder X-ray diffraction analysis, UV–vis absorbance spectra, and scanning electron microscopy images. Considering it as an adsorbent for an AHT system, the Ti(BuO)4-derived sample synthesized by a solvothermal method shows an ideal S-shaped isotherm with a steep rise in water uptake at lower relative pressure (0.550 g/g at P/P0 = 0.30), which is attributed to narrow triangle apertures and hydrophili...

Introduction Chemo-responsiveness in pancreatic cancer is known to be dependent on fibrosis and vascularity. The purpose of this study was to assess vascular enhancement in advanced pancreatic adenocarcinoma with or without liver metastasis in computed tomography (CT) and to analyze the correlation between enhancement patterns and chemo-responsiveness. Methods Patients were assigned to either a responder group (partial response or stable disease) or a non-responder group (progressive disease) according to chemo-responsiveness assessed by CT before and after gemcitabine-based chemotherapy. Hounsefield unit (HU) was measured in pancreatic mass and the largest metastatic liver mass using region of interest (ROI). HU differences (ΔHU) between arterial and pre-contrast phase were calculated. Results Of the 101 study subjects, 78(77.2%) were assigned to the pancreas responder group {mean ΔHU (±SD), 36.7(±21.6)} and 23(22.8%) to the pancreas non-responder group {mean ΔHU (±SD), 20.6(±9.9)} (p = 0.001 for ΔHUs). Of the 46 study subjects with liver metastasis, 25(54.3%) were assigned to the liver metastasis responder group {mean ΔHU (±SD), 36.9(±21.0} and 21(45.7%) to the liver metastasis non-responder group {mean ΔHU (±SD), 17.1 (±24.0)}, (p = 0.005 for ΔHUs). Conclusion CT determined mass vascular enhancement patterns may predict chemoresponse in advanced pancreatic cancer.

Background and Aim It can be difficult to identify the cause of an enlarged ampulla of Vater (AOV). This study evaluated the accuracy of wire-guided intraduodenal ultrasonography (US) for the differential diagnosis of an enlarged AOV during endoscopic retrograde cholangiopancreatography (ERCP). Patients and Methods Thirty-four patients with enlarged AOVs of unknown cause identified on imaging studies or endoscopic observations underwent wire-guided intraduodenal US using a catheter probe. Results The final diagnoses were malignant or premalignant tumors in 10 patients (29.4%), stones in nine patients (26.5%), inflammation in 14 patients (41.2%), and cyst in one patient (2.9%). The overall diagnostic accuracy of intraduodenal US for enlarged AOVs was 91.2%. The diagnostic accuracies of stones, inflammation, and AOV tumors were 100.0%, 94.1%, and 91.1%, respectively. Conclusions Wire-guided intraduodenal US using a catheter probe is readily applicable during ERCP and may be useful in the differential diagnosis of enlarged ampullary lesions.

Background and Aim KRAS mutation analysis may provide ancillary diagnostic yield in an endoscopic ultrasound (EUS)-guided histopathological evaluation. We evaluated the clinical impact of KRAS mutation analysis with cytological and histological evaluations in EUS-guided tissue sampling, using a core biopsy needle for solid liver masses. Methods EUS-guided fine needle biopsy (EUS-FNB) using a core biopsy needle was performed in patients with primary or metastatic liver masses that were suspected malignancies. KRAS mutations were analyzed in all specimens obtained. The peptide nucleic acid (PNA)-mediated polymerase chain reaction (PCR) clamping method was compared with a next-generation sequencing (NGS) method for detecting KRAS mutations. Results EUS-FNB with a core biopsy needle was performed in 28 patients with solid liver masses located in the liver's left lobe. The diagnostic accuracies for malignancy of on-site cytology, cytology using Papanicolaou staining, and histology including immunohistochemical stains were 82.1%, 85.7%, and 89.3%, respectively. KRAS gene mutations were observed in 14.3% of patients by the PNA-PCR clamping method. The NGS method detected more KRAS mutations than the PNA-PCR clamping method: in 25% of patients. Adding the results of KRAS mutation analysis to the cytohistopathological evaluation, the overall diagnostic accuracy of EUS-guided tissue sampling was 96.4%. Conclusions EUS-guided tissue sampling for solid liver masses in the left lobe provided high diagnostic accuracy from cytological and histological evaluations. KRAS mutation analysis provided additional diagnostic yield in patients with inconclusive cytohistopathological results from EUS-guided tissue sampling. The NGS method detected additional KRAS mutations in patients with negative PNA-mediated PCR clamping test results.

Background and Aims Fully covered self-expanding metal stents (FCSEMSs) are considered to be more effective than plastic stents for the treatment of main pancreatic duct (MPD) strictures associated with chronic pancreatitis (CP) because of their larger diameter and exertion of a radial expansion force. However, the current FCSEMSs have several limitations. To overcome these, a novel modified nonflared FCSEMS was developed. In this study we conducted a prospective long-term follow-up evaluation of the efficacy of the novel FCSEMS for the treatment of refractory benign PD strictures in patients with CP. Methods Consecutive patients with symptomatic CP associated with refractory MPD strictures were enrolled prospectively in this single-arm study. The nonflared FCSEMS was placed intraductally or transpapillary according to the location and length of the stricture. Stent removal was performed at 3 months after placement. The primary outcome was the resolution of the pancreatic ductal stricture. Results Endoscopic placement of modified nonflared FCSEMSs was technically successful in all 25 patients. Intraductal FCSEMS placement was performed in 14 patients (56.0%). Stents of diameter 8 mm were used in 17 patients (68.0%). Stents of lengths 3 and 5 cm were inserted in 22 (88.0%) and 3 (12.0%) patients, respectively. In 1 patient (4.0%), stent migration developed. All other stents were removed successfully. After stent removal, resolution of the MPD stricture was confirmed in all patients, and no FCSEMS-related de novo stricture was observed. During the follow-up period (median, 34 months; interquartile range, 25-56) after the stents had been removed from the 25 patients, reintervention for recurrence of MPD stricture with abdominal pain was performed in 2 patients (8.0%). Conclusions Endoscopic placement of a novel modified nonflared FCSEMS resulted in long-term stricture resolution with pain relief and reduced the rate of stent-related adverse events, particularly stent migration and stent-induced de novo MPD stricture. (Clinical trial registration number: UMIN000035681.)

Although endoscopic intervention is the mainstay for palliation of malignant biliary obstruction, a percutaneous approach has been preferred, particularly in patients with advanced high-grade hilar malignant biliary obstruction, because of the technical difficulty and risk of complications. However, recently, primary endoscopic palliation using plastic or metal stents has had higher technical and clinical success with fewer adverse events than the percutaneous approach. Endoscopic interventions are being done more and more frequently because of advances in metal stents, accessories, and techniques. However, several concerns, such as optimal stent type, number, and deployment method, remain to be resolved. Therefore, we reviewed the literature in order to identify the optimal biliary stenting strategy for patients with hilar malignant biliary obstruction, focusing on stent type (plastic vs metal), number (unilateral [single] vs bilateral [multiple]), and deployment method (stent-in-stent vs stent-by-stent).

We propose a new heterogeneous reconfigurable energy harvester with an algorithm to control reconfiguration of energy harvester and receive mode, i.e., information decoding (ID) or energy harvesting (EH), so as to enhance EH efficiency and achievable rate for simultaneous wireless information and power transfer (SWIPT). Especially, we design the heterogeneous reconfigurable energy harvester which consists of low-power and high-power energy harvester (LP/HP-EH) blocks, each comprised of multiple EH circuits in parallel. Practical energy harvesters have their own favorable input range due to turn-on sensitivity and saturation effects. Considering this, we propose a heterogeneous reconfiguration algorithm which optimizes the number of EH circuits being activated and the power-splitting ratio. Further, an adaptive mode switching (MS) problem is formulated which maximizes the achievable rate under the energy-causality condition. Our proposed algorithm can be applied to low-power wide area network (LP-WAN) with wireless EH capability for self-sustainability, thereby realizing battery-free IoT network.

Background and aim Fully covered self-expandable metallic stent (FCSEMS) may be an effective modality for managing anastomotic biliary stricture (ABS) after liver transplantation. However, stent migration and stent-induced ductal injury are the main limitations. The objective of this study was to evaluate the usefulness of an unflared, intraductal FCSEMS that was designed to minimize migration and ductal injury for refractory ABS after living donor liver transplantation (LDLT). Methods A total of 32 consecutive patients with symptomatic ABS after LDLT unresolved by plastic stents with or without balloon dilation at four tertiary medical centers were prospectively enrolled. A short (3 or 5 cm) FCSEMS having long lasso (10 cm) used in this study had unflared convex ends to minimize tissue hyperplasia and smaller center portion to prevent migration. The FCSEMS was placed above the papilla and removed at 3-4 months after stenting. Results Technical and clinical success rates of intraductal placement with FCSEMS were 100% (32/32) and 81.2% (26/32), respectively. Early stent migration was observed in five (15.6%) patients. However, three patients with early stent migration had stricture resolution without needing additional intervention. Intended stent removal was successful in 27 (100%) patients (median, 101 days; range, 23-118 days). No stent-induced ductal change was observed in all patients. Stricture recurrence was observed in 11.5% (3/26) of patients during 639 days of median duration of follow-up (range, 366-2079 days). Conclusions Intraductal placement of an unflared short FCSEMS may be a promising option for refractory ABS after LDLT with minimal stent-induced ductal injury and stent migration.

Currently available peroral cholangioscopy (POC) is a duodenoscopy-assisted procedure that does not involve directly inserting an endoscope into the biliary tree. A prototype multibending (MB) ultra-slim endoscope has been developed as a dedicated cholangioscope to overcome the technical difficulties of direct POC. In this study, we evaluated the efficacy of the new MB ultra-slim endoscope compared with a conventional ultra-slim endoscope for free-hand insertion of an endoscope into the bile duct for direct POC without the assistance of accessories.Ninety-two patients with biliary disease requiring diagnostic and/or therapeutic direct POC were assigned randomly to groups examined using an MB ultra-slim endoscope (MB group, n=46) versus a conventional ultra-slim endoscope (conventional group, n=46). The primary outcome was the technical success of free-hand insertion of the endoscope during direct POC, defined as successful insertion of the endoscope through the ampulla of Vater and advancement of the endoscope up to the bifurcation or to the obstructed segment of the biliary tree without any accessories within 15 minutes.Free-hand biliary insertion of the endoscope for direct POC was technically successful in 41 patients (89.1%) in the MB group, which was significantly higher than the rate (14 patients, 30.4%) in the conventional group (P .001). The procedure time (mean ± standard deviation) of direct POC using free-hand biliary insertion of the endoscope was significantly shorter in the MB group than in the conventional group (3.2 ± 1.8 vs 6.0 ± 3.0 minutes, P = .004). Adverse events were observed in 3 patients (6.5%) in the MB group and 2 patients (4.3%) in the conventional group (P = .500), all of whom were treated conservatively. The technical success rates of the diagnostic or therapeutic intervention were not significantly different between the 2 groups in patients undergoing successful direct POC.Free-hand biliary insertion of the MB ultra-slim endoscope showed a high technical success rate without severe adverse events and effectively decreased procedure time compared with a conventional ultra-slim endoscope. Direct POC using the MB ultra-slim endoscope can be used for novel diagnostic and therapeutic procedures of the biliary tree without the assistance of another endoscope or accessory. (Clinical trial registration number: NCT02189421.).

In this paper, we implement transmitter-oriented dual mode simultaneous wireless information and power transfer (SWIPT) system in which two types (single/multi-tone) of communication mode are adopted to achieve the benefit of each communication mode. Duty-cycling operation is introduced for low-power consuming IoT devices to be self-powered. We propose a mixed-time scale based adaptive mode switching (MS) algorithm, in which a transmitter updates the MS threshold in long-term scale with deep recurrent neural networks (RNN) while deciding communication mode in short-term scale. The proposed algorithm enables the realization of battery-free IoT network.

Background A novel self-approximating lumen-apposing metallic stent (LAMS; Niti-S Spaxus, Taewoong Medical, Gyeonggi-do, Korea) has recently become available. The aim of the present study was to evaluate the outcomes for drainage of pancreatic fluid collections (PFC). Methods This was a prospective international multicentered study conducted in six high-volume institutions across Asia. Consecutive patients suffering from pancreatic pseudocyst or walled-off pancreatic necrosis (WOPN) requiring endoscopic ultrasonography-guided drainage were recruited. Outcomes included technical and clinical success, adverse events, procedural events, interventions through the stent and recurrence rates. Results Between August 2016 and November 2017, 59 patients were recruited to this study. Thirty-nine patients (66.1%) had WOPN and mean (SD) size of PFC was 11.5 (5.1) cm. Technical and clinical success rates were 100%. Mean (SD) procedural time was 35.0 (17.2) minutes. Sixteen-millimeter stents were used in 66.1% of the patients. Fifty-four sessions of necrosectomy were carried out with the stent in situ in 17 patients. Stent-related adverse event (AE) rate was 6.8%. Three patients (5.1%) suffered from bleeding after stenting and one required angiographic embolization. Two patients (3.4%) suffered from recurrence during a mean (SD) follow-up time of 325.6 (355.5) days. There were no differences in outcomes between those with pseudocysts or WOPN except for the duration of hospital stay (P = 0.012). Conclusion Use of a self-approximating LAMS for drainage of PFC was safe and effective. Endoscopic necrosectomy could be carried out through the stent with ease. The device was associated with a low rate of stent-related AE.

In this study, a lab.-scale twin bubbling fluidized-bed system (TBS) has been used continuously to test the performance for CO2 adsorption of silica-PEI (S.PEI) adsorbents, containing 40 wt.% of PEI, which were supplied by the University of Nottingham (UNOTT). The TBS comprises bubbling-bed adsorption and desorption reactors, a riser for pneumatic conveying of solids from the adsorption to the desorption reactor, and a cyclone for solid-gas separation. The adsorbent prepared using PEI with a molecular mass of 800 (S.PEI-0.8K) was a preliminarily tested for almost 24 h at the given operating conditions by varying the inlet sorbent/CO2 mass ratio at the adsorber to analyse the CO2 removal efficiency in the adsorption reactor and the dynamic sorption capacity of the adsorbent. A 180-h continuous test was then carried out by changing various experimental conditions such as the H2O concentration, reaction temperature, solid layer height, reaction gas flow rate, and inlet sorbent/CO2 mass ratio at the adsorber using PEI with a molecular mass of 5000 (S.PEI-5K) adsorbent. In this test, a CO2 removal efficiency of above 80% and a dynamic sorption capacity greater than 6.0 wt.% were achieved.

Isostructural [M

The purpose of this study was to determine the glucose metabolism at delay phase measured by pretreatment dual-time-point 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/ computed tomography (CT) provides prognostic information independent of well-known prognostic factors in patients with intrahepatic or perihilar cholangiocarcinoma (ICC or PCC). From July 2012 to December 2017, 55 patients (men 27, women 28, mean age 68 ± 11 years) with pathologically proven ICC or PCC were enrolled in this retrospective study. The dual-time-point 18F-FDG PET/CT as part of a staging workup was performed in all patients. The patient's data includes age, sex, serum CA19-9, presence of LN or distant metastasis, early SUVmax (early maximum standardized uptake value [eSUV]), delay SUVmax (delay maximum standardized uptake value [dSUV]), retention index of SUVmax (percent change of maximum standardized uptake values [ΔSUV]), neutrophil to lymphocyte ratio (NLR) and histopathology including pCEA, p53, Ki-67 index. The analysis of the relationship between metabolic parameters and survival was done using the Kaplan–Meier curve and Cox proportional hazards regression model. Median survival for all patients was 357 days. Median early and delay SUVmax was 5.2 (range: 2.0–21.4) and 6.5 (range 2.7–24.5), respectively. The overall survival was found to be significantly related to eSUV, dSUV, ΔSUV, age, serum CA19-9 and NLR in univariate analysis. In multivariate analysis, dSUV (P = .014, 95%CI; 1.30–10.7, HR 3.74) and ΔSUVmax (P = .037, 95%CI; 1.05–6.12, HR 2.5) were independent factors of overall survival. Kaplan–Meier curve analysis clearly showed the significant difference of overall survival between 2 groups (high eSUV, low eSUV + high ΔSUV vs low eSUV and ΔSUV, P

Polyethyleneimine (PEI)/silica adsorbents have been considered as a promising candidate for post-combustion CO2 capture, but the limited process study has been performed on a pilot-scale unit. Herein we report the 150 h continuous test results using a 100 kg sample of silica-PEI on a fluidized bed continuous unit. The CO2 removal efficiency and dynamic sorption capacity were evaluated continuously by changing a number of variables. For the sorption reactor, the changing variables were inlet H2O concentrations of 0–8.3 vol%, inlet CO2 concentrations of 12.0–21.5 vol%, bed temperatures of 50–70 °C and the bed differential pressures of 176–370 mmH2O. For the desorption reactor operated at the bed temperature of 129–130 °C, inlet H2O concentrations of 8.0–13.5 vol%, inlet CO2 concentrations of 14.6–81.2 vol% and bed differential pressures of 430–580 mmH2O were used. During continuous operation, CO2 removal efficiencies of over 90% were achieved with dynamic sorption capacities of 7.5 wt%. Solid sample collected during continuous operation were analyzed by TGA and 13C NMR to identity the decrease of CO2 adsorption capacity and the extent of thermo-oxidative side reactions. Slow oxidative degradation of the silica-PEI occurred because the transporting adsorbent was exposure to the non-humidified air in the solid transport system.

In this letter, we propose a new architecture for simultaneous wireless information and power transfer (SWIPT) which utilizes multi-sine waveforms for energy transfer and their distinct peak-to-average-power-ratios (PAPR) for information transmission. The new form of SWIPT proposed is based on an innovative idea of conveying information using the different levels of PAPR which can be measured at the output of the rectifier for energy harvesting, enabling a low-energy combined receiver. The latter is very crucial for batteryless operation of low-energy wireless devices relying much on the harvested energy. We demonstrate how the proposed idea works in terms of the information decoding via distinct PAPR, as well as the rate-energy tradeoff for a varying number of multiple tones.

Objective To evaluate the usefulness of maternal serum c-reactive protein (CRP), lipid peroxide, and oxygen radical absorbance capacity (ORAC), to predict the interval between membrane rupture and delivery in patients with preterm premature rupture of membranes (PPROM). Methods The present prospective study included patients with singleton pregnancies experiencing PPROM at earlier than 34 weeks of pregnancy who underwent spontaneous vaginal delivery between August 1, 2010 and July 31, 2013 at Chonnam National University Hospital, Republic of Korea. Patients were categorized based on whether delivery occurred within 3 days of PPROM or after. CRP levels, lipid peroxide (using malondialdehyde levels), ORAC, protein carbonyl, and other potential risk factors were compared between the groups. Results There were 72 patients included. Maternal serum CRP levels, malondialdehyde levels, and Bishop Score were higher in patients who underwent delivery within 3 days (all P

Background/aims The covered self-expandable metal stent (CMS) was developed to prevent tumor ingrowth-induced stent occlusion during the treatment of malignant biliary obstruction. However, complications such as cholecystitis, pancreatitis, and stent migration can occur after the endoscopic insertion of CMSs. The aim of the present study was to assess the efficacy and safety of a double-layered CMS (DCMS) for the management of malignant bile duct obstruction. Methods DCMSs were endoscopically introduced into 59 patients with unresectable malignant extrahepatic biliary obstruction at four tertiary referral centers, and the patient medical records were retrospectively reviewed. Results Both the technical and functional success rates were 100%. Procedure-related complications including pancreatitis, cholangitis, stent migration, and liver abscess occurred in five patients (8.5%). The median follow-up period was 265 days (range, 31 to 752 days). Cumulative stent patency rates were 68.2% and 40.8% at 6 and 12 months, respectively. At the final follow-up, the rate of stent occlusion was 33.9% (20/59), and the median stent patency period was 276 days (range, 2 to 706 days). Conclusions The clinical outcomes of DCMSs were comparable to the outcomes previously reported for CMSs with respect to stent patency period and complication rates.

In this study, ceriabased catalysts were prepared for dimethyl carbonate (DMC) synthesis and reaction conditions were evaluated for finding the optimal reaction route. In order to find optimal catalysts for DMC synthesis, calcination temperature and Cu(II) impregnation amount were evaluated. The oxidative carbonylation using methanol, carbon monoxide and oxygen and the direct synthesis using methanol and carbon dioxide were introduced for producing DMC. Following the law of Le Chatelier, the dehydration reaction was applied for enhancing the reactivity (methanol conversion) as removing water during the reaction. 2-cyanopyridine, as a chemical dehydration agent, was used. In the case of the oxidative carbonylation, methanol conversion rate increased from 15.1% to 38.7% and the DMC selectivity increased from 0% to 98.8%. In the case of the direct synthesis, methanol conversion rate increased from 1.0% to 77.8% and the DMC selectivity increased from 41.2% to 100.0%.

Walled-off necrosis (WON) is a new term for encapsulated necrotic tissue after severe acute pancreatitis. Various terminologies such as pseudocyst, necroma, pancreatic abscess, and infected necrosis were previously used in the literature, resulting in confusion. The current and past terminologies must be reconciled to meaningfully interpret past data. Recently, endoscopic necrosectomy was introduced as a treatment option and is now preferred over surgical necrosectomy when the expertise is available. However, high-quality evidence is still lacking, and there is no standard management strategy for WON. The consensus meeting aimed to clarify the diagnostic criteria for WON and the role of endoscopic interventions in its management. In the Consensus Conference, 27 experts from eight Asian countries took an active role and examined key clinical aspects of WON diagnosis and endoscopic management. Statements were crafted based on literature review and expert opinion, employing the modified Delphi method. All statements were substantiated by the level of evidence and the strength of the recommendation. We created 27 consensus statements for WON diagnosis and management, including details of endoscopic procedures. When there was not enough solid evidence to support the statements, this was clearly acknowledged to facilitate future research. Proposed management strategies were formulated and are illustrated using flow charts. These recommendations, which are based on the best current scientific evidence and expert opinion, will be useful for guiding endoscopic management of WON. Part 2 of this statement focused on the endoscopic management of WON.

Walled-off necrosis (WON) is a relatively new term for encapsulated necrotic tissue after severe acute pancreatitis. Various terminologies such as pseudocyst, necroma, pancreatic abscess, and infected necrosis were previously used in the literature, resulting in confusion. The current and past terminologies must be reconciled to meaningfully interpret past data. Recently, endoscopic necrosectomy was introduced as a treatment option and is now preferred over surgical necrosectomy when the expertise is available. However, high-quality evidence is still lacking, and there is no standard management strategy for WON. The consensus meeting aimed to clarify the diagnostic criteria for WON and the role of endoscopic interventions in its management. In the Consensus Conference, 27 experts from eight Asian countries took an active role and examined key clinical aspects of WON diagnosis and endoscopic management. Statements were crafted based on literature review and expert opinion, employing the modified Delphi method. All statements were substantiated by the level of evidence and the strength of the recommendation. We created 27 consensus statements for WON diagnosis and management, including details of endoscopic procedures. When there was not enough solid evidence to support the statements, this was clearly acknowledged to facilitate future research. Proposed management strategies were formulated and are illustrated using flow charts. These recommendations, which are based on the best current scientific evidence and expert opinion, will be useful for guiding endoscopic management of WON. Part 1 of this statement focused on the epidemiology, diagnosis, and timing of intervention.

[Mg2(DOBDC)] (Mg-MOF-74 or CPO-27-Mg) with open metal sites showed an exceptionally high CO2 uptake at low partial pressure and room temperature. The single-crystal structure of [Mg2(DOBDC)], however, has not been reported so far. In this work, we synthesized the crystalline product of [Mg2(DOBDC)(DMF)2] (1) and determined its single-crystal structure by synchrotron X-ray diffraction analysis. To improve the chemical stability and fabrication of the adsorbent, the composite of 1 and polystyrene (PS) was prepared by a simply solution-mixing method. Powder X-ray diffraction pattern of 1@PS revealed that the crystallinity of 1 is intact after incorporating PS. TGA of the composite revealed that 2.2 wt% of PS are incorporated to 1. CO2 sorption isotherms of activated 1@PS were measured in the temperature range between 283 and 303 K. The enthalpy of CO2 adsorption for activated 1@PS estimated by the virial equation at zero coverage is 43.9 kJmol−1, which is comparable to the reported value (47 kJmol−1) of activated 1. Interestingly, this composite showed high moisture stability after 90% humidity exposure for 1 day.