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Gallbladder cancer is the most common cause of hilar biliary obstruction; however, it rarely causes combined biliary, duodenal, and colon triple obstruction. In this case, the quality of life for a patient with recurrent gallbladder cancer with combined duodenal, colonic, and biliary obstruction was improved by endoscopic and endosonographic palliation, despite its technical difficulty and complexity. Seven metal stents were implanted one by one using only endoscopic methods. Successful stent-in-stent placement and endoscopic ultrasound-guided stenting after failed ERCP improved the patient’s quality of life to the extent that there was no need for any external drainage.

A synthesis and patterning process of luminescent graphene quantum dots (GQDs) is highly desirable in applications to industrial- and bio-fields. In this paper, a novel strategy to obtain GQDs is proposed and demonstrated by an ion-beam assisted chemical vapor deposition (CVD). Ion-beam irradiation provides catalyst sources for the GQD creation. The luminescent GQDs are generated using a Fe-implanted Si wafer by a two-step annealing process: i) A formation step of nano-sized Fe catalyst particles and ii) a synthesis step of GQDs by a CVD method. Under the 1st annealing step of the Fe-implanted Si wafer, Fe nanoparticles (FeNPs) are created by the diffusion and aggregation of Fe atoms. Due to the high temperature atmosphere in the 2nd annealing step, FeNPs are then completely removed, and thus only high-purity and -quality GQDs are finally produced. In our work, patterned GQDs were fabricated by using a metallic mask during the ion-beam irradiation. Furthermore, various GQD patterns were also demonstrated by combining the conventional semiconductor manufacturing process and our ion-beam assisted CVD technique.

Background Monovalent meningococcal conjugate vaccines against serogroups A or C have resulted in significant reduction of pharyngeal carriage rates against the vaccine serogroups. However, the effect of the quadrivalent meningococcal conjugate vaccine on meningococcal carriage has not yet been evaluated. Methods We assessed changes in pharyngeal carriage rates of Neisseria meningitidis after introduction of the quadrivalent meningococcal conjugate vaccine in Korean military trainees. Two rounds of oropharyngeal swabs of Korean military trainees were obtained, at the beginning and the end of the army training period. The first oropharyngeal swabs were collected prior to vaccination; the second round was performed 5 weeks later. Results In 2013, the overall N. meningitidis carriage rate was higher at the end of the training period (13.8%, 60 of 434 participants) than upon entry into military service (8.9%, 39 of 434 participants). Although the carriage rates of nongroupable and serogroup X isolates increased over the 5-week interval, carriage of the serogroup strains included in the quadrivalent meningococcal vaccine was reduced, from 7 to 2 isolates, after vaccination. However, in 2014, the overall carriage rate of N. meningitidis was significantly lower at the end of the training period (5.2%, 23 of 443 participants) than on entry into military service (12.6%, 56 of 443 participants) (p = 0.028). Carriage of vaccine serogroups isolates was significantly decreased, compared to that of non-vaccine serogroup B over the 5-week interval. Carriage isolates belonging to the ST-178, ST-31 and ST-41/44 were frequently identified clonal complex. Meningococcal carriage rate before and after Meningococcal vaccination in Korean military trainees Conclusion Meningococcal vaccination in Korean military trainees could lead to reduce pharyngeal carriage rates of vaccine serogroup meningococci. Therefore, the quadrivalent meningococcal conjugate vaccine is likely to prevent carriage acquisition of meningococci in closed populations such as military trainees. Disclosures All Authors: No reported disclosures.

Summary Background Tegoprazan is a novel, fast‐ and long‐acting potassium‐competitive acid blocker that suppresses gastric acid secretion, which could benefit patients with non‐erosive reflux disease (NERD), a type of gastroesophageal reflux disease. Aim To evaluate the efficacy and safety profiles of tegoprazan compared with those of a placebo in Korean patients with NERD. Methods In this phase 3, double‐blind, placebo‐controlled, multicentre study, 324 Korean patients with NERD were randomised into three treatment groups: tegoprazan 50 mg, tegoprazan 100 mg and placebo. These drugs were provided once daily for 4 weeks. The primary endpoint was the proportion of patients with complete resolution of major symptoms (both heartburn and regurgitation) for the last 7 days of the 4‐week treatment period. Other outcomes related to efficacy, safety and tolerability were also evaluated. Results Among all, 42.5% (45/106), 48.5% (48/99) and 24.2% (24/99) of patients showed complete resolution of major symptoms at week 4 after receiving tegoprazan 50 mg, tegoprazan 100 mg, and placebo, respectively. Both doses of tegoprazan showed superior efficacy than the placebo (P = 0.0058 and P = 0.0004, respectively). The complete resolution rates of heartburn and proportions of heartburn‐free days (as other efficacy outcomes) were significantly higher in both tegoprazan groups than in the placebo group (P, Tegoprazan 50 and 100 mg showed superior therapeutic efficacy compared with the placebo, as well as a favourable safety profile in patients with non‐erosive reflux disease.

Differential power processing (DPP) for photovoltaic (PV) systems can achieve high system efficiency and maintain maximum power production even under mismatched conditions. However, DPP converters applied to large-scale systems have challenges of complicated installation and high voltage ratings. The segmented DPP structure is introduced as a modular approach that utilizes groups of bidirectional DPP flyback converters to maximize PV power generation while minimizing converter power loss. Groups of four DPP converters are combined into a segmented DPP unit with maximum power point tracking (MPPT) control to maximize output power of the unit. The segmented DPP system and control algorithm are verified through simulation and hardware experimentation. Simulation results verify the effectiveness of the control algorithm with multiple segmented DPP units interacting with a typical inverter employing MPPT. Experimental results verify that system efficiency of the segmented DPP unit reaches 96.4% in even lighting conditions, reaches 92.7% in severe partial shading conditions, and shows an increase of up to 14.8% in uneven lighting conditions compared to an equivalent series-connected PV system.

A device approach to manage the emission color of the organic light-emitting diodes (OLEDs) which show two emission processes of thermally activated delayed fluorescence (TADF) and phosphorescence was developed by engineering the host of the emitter. The emitting material was phenyl(10-phenyl-10H-phenoselenazin-3-yl)methanone (PSeBz) which emitted at 496 nm by TADF process and at 559 nm by phosphorescence process. The phosphorescence of the PSeBz emitter was selectively switched by the host because the triplet excitons can be intentionally quenched by the low triplet energy host. Therefore, the color coordinate of the OLEDs could be tuned from (0.35, 0.52) to (0.41, 0.52) by just changing the host of the PSeBz emitter.

Evaluation of the safety and immunogenicity of new vaccine platforms is needed to increase public acceptance of coronavirus disease 2019 (COVID-19) vaccines. Here, we evaluated the association between reactogenicity and immunogenicity in healthy adults following vaccination by analyzing blood samples before and after sequential two-dose vaccinations of BNT162b2 and ChAdOx1 nCoV-19. Outcomes included anti-S IgG antibody and neutralizing antibody responses, adverse events, and proinflammatory cytokine responses. A total of 59 and 57 participants vaccinated with BNT162b2 and ChAdOx1 nCoV-19, respectively, were enrolled. Systemic adverse events were more common after the first ChAdOx1 nCoV-19 dose than after the second. An opposite trend was observed in BNT162b2 recipients. Although the first ChAdOx1 nCoV-19 dose significantly elevated the median proinflammatory cytokine levels, the second dose did not, and neither did either dose of BNT162b2. Grades of systemic adverse events in ChAdOx1 nCoV-19 recipients were significantly associated with IL-6 and IL-1β levels. Anti-S IgG and neutralizing antibody titers resulting from the second BNT162b2 dose were significantly associated with fever. In conclusion, systemic adverse events resulting from the first ChAdOx1 nCoV-19 dose may be associated with proinflammatory cytokine responses rather than humoral immune responses. Febrile reactions after second BNT162b2 dose were positively correlated with vaccine-induced immune responses rather than with inflammatory responses.

Patients with gastroesophageal reflux disease (GERD) frequently experience nighttime heartburn and sleep disturbance. Tegoprazan is a new potassium-competitive acid blocker that can rapidly block acid secretion. This study aims to evaluate the efficacy of tegoprazan compared with esomeprazole in relieving nighttime heartburn and sleep disturbances.Patients with erosive esophagitis, nighttime heartburn, and sleep disturbances were randomized to receive tegoprazan 50 mg or esomeprazole 40 mg for 2 weeks. The primary endpoint was time to first nighttime heartburn-free interval. The percentage of nighttime heartburn-free days was also compared between the 2 groups.A total of 46 patients were enrolled in this study. Time to the first nighttime heartburn-free interval was shorter with tegoprazan than with esomeprazole but the difference was not statistically significant (1.5 days vs 3 days,Tegoprazan may induce faster relief of nighttime heartburn symptoms and may improve sleep disorders associated with nighttime heartburn. Further large-scale studies are required to validate our findings.

Although radar and AIS alarm functions have been used as support measures for collision prevention in many ships, they lacked the function to identify actual collision risk ships and inform the degree of risk and did not provide information on avoidance routes. This study aims to design a newly developed safer new optimal route for anti-collision based on the Collision Risk Zone assessment method, targeting mainly very small-sized ships that caused most of the collision accidents due to human errors. Designing a safer new optimal route is composed of three segments according to the ship’s characteristics. That is, empirical method for small-sized ships, collision risk zone method for larger ships and then combination method between empirical and collision risk method. In addition, this study analyzed the collision risk of various scenarios according to the navigation relationships and speed conditions between the two meeting ships. As a result, the model proposed in this study numerically calculated the risk of collision according to the navigation situation and could provide a safe optimal avoidance path accordingly. Therefore, this model can be applied to build the collision avoidance model of not only the current ship but remote-controlled ship, which is under compliance with COLREG regulations and involves the possibility of human error in an operation.

Vessels experience additional resistance by waves during navigation, which becomes a factor that increases energy consumption and exhaust gas emissions. Proper estimation and understanding of this additional resistance is an important task in the marine industry. In this study, we propose a machine-learning model that predicts added resistance in arbitrary wave headings using basic ship parameters. First, extensive model experimental data on added resistance for different ship types and sizes of ships were acquired. To build a proper machine learning model, algorithms such as extreme gradient boosting (XGB), random forest (RF), artificial neural network (ANN), k-nearest neighbor (ANN), gaussian process regression (GPR), and support vector regression (SVR) were considered. Through nested cross-validation, the evaluation and hyperparameter tuning of algorithms were performed together. As a result, SVR was selected among the candidate models due to high accuracy with robustness to the outliers. In the validation with test data of head waves and all wave headings, the R2 scores of the selected model were 0.6738–0.7584 and 0.6744–0.7449, respectively, which was better than estimation methods for added resistance in head waves such as STAWAVE-2 and Cepowski (2020), and similar accuracy to those applicable in arbitrary wave headings. Even estimation of added resistance in irregular waves of sea states, the relative deviation with the semi-empirical methods for arbitrary waves was not large, on average 10%.

The methyl iodide (CH3I) removal performance of tri-ethylene-di-amine impregnated activated carbon (TEDA-AC) used in the air cleaning unit of nuclear power plants (NPPs) should be maintained at least 99% between 24 month-performance test period. In order for evaluating the effectiveness of TEDA-AC on the removal performance of CH3I in nuclear power plant during the operation of NPPs, the long-term test for up to 15 months was carried out under the simulated operating conditions (e.g., 25 °C, RH 50%, ppb level poisoning gases injection) at nuclear power plants (NPPs). The TEDA-AC samples were analyzed with the Brunauer-Emmett-Teller (BET) specific surface area and TEDA content as well as CH3I penetration test. It is clearly evident that more than 99% of CH3I removal performance of TEDA-AC was observed in the TEDA-AC samples during 15 months of long-term operation under the simulated NPP operating conditions including the ppb level of organic and oxide form of poisoning gases. BET specific surface area and TEDA content that can affect the CH3I removal performance of TEDA-AC were also maintained as those in new TEDA-AC during 15 months of long-term operation.

In this paper, we perform a comprehensive study of various semi-empirical methods using publicly accessible experimental data on added resistance in waves with different ship types and conditions. Based on the analysis results, a new method (So-called “Combined method”) is proposed, combining two existing methods, which are available in arbitrary wave headings. The results from the two methods are combined smoothly using a tangent hyperbolic function according to wavelengths and wave headings. The coefficients constituting the function are tuned to minimize mean squared error between predictions and model experiments. Finally, the new Combined method is verified by full-scale measurements of a general cargo ship and a container ship, and it seems to give good agreement with measurements in all analysis areas, compared to existing semi-empirical methods. Especially, it showed better performance in estimating added wave resistance at high waves, resonance frequencies, arbitrary waves, and low speeds.

A UVC photo-Fenton advanced oxidation process (AOP) was studied to develop a process for the decomposition of oxalic acid waste generated in the chemical decontamination of nuclear power plants. The oxalate decomposition behavior was investigated by using a UVC photo-Fenton reactor system with a recirculation tank. The effects of the three operational variables―UVC irradiation, H2O2 and Fenton reagent―on the oxalate decomposition behavior were experimentally studied, and the behavior of the decomposition product, CO2, was observed. UVC irradiation of oxalate resulted in vigorous CO2 bubbling, and the irradiation dose was thought to be a rate-determining variable. Based on the above results, the oxalate decomposition kinetics were investigated from the viewpoint of radical formation, propagation, and termination reactions. The proposed UVC irradiation density model, expressed by the first-order reaction of oxalate with the same amount of H2O2 consumption, satisfactorily predicted the oxalate decomposition behavior, irrespective of the circulate rate in the reactor system within the experimental range. Keywords: AOP, UVC photo-Fenton, Chemical decontamination waste, Oxalic acid

Recently an induction heating system comprising a pair of no-insulation high-temperature superconductor (HTS) racetrack coils was built and now it is commercially available. It generates a direct current (dc) magnetic field in which a conductive metallic billet rotates at a high speed. Most dc induction machines accommodate a “single” billet per operation. This paper proposes an alternative concept of a “multiple-billet” induction heater, where the multiple billets can be simultaneously heated. The system consists of eight pairs of HTS racetrack coils that are placed in a circular pattern. An arbitrary number of billets may be placed and rotate at the same time in the space between racetrack coil pairs. The main goal in this paper is to theoretically demonstrate the principle of operation of the new multibillet system. The paper presents: first, overall system configuration and the principle of operation; second, electromagnetic design of the eight-pole HTS magnet; third, analyses with key operation parameters to estimate the multibillet heater performance. Due to the “positive” mutual inductance among neighbor racetrack coils, the multibillet system is estimated to deliver a larger heating power per billet than that of its single-billet counterpart for given operating conditions. Also, due to the eddy-currents induced in each billet, the power per billet reduces when the number of billets increases beyond an optimal value.

In accordance with the decommissioning plan for the Kori Unit 1 NPP, the reactor coolant system will be chemically decontaminated as soon as possible after permanent shutdown. This study developed the chemical decontamination process though the development project of decontamination technology of reactor coolant system and dismantled equipment for NPP decommissioning, which has been carried out since 2014. In this study, Oxidation/reduction process was conducted using system decontamination process development equipment of lab scale and was divided into unit and continuous processes. The optimal process time was derived from the unit process, and decontamination agent and the number of process were derived through the continuous processes. Through the unit process, the oxidation process took 5 hours and the reduction process took 4 hours. As optimum decontamination agent, the oxidizing agent was 200 mg·L-1 Permanganic acid + 200 mg·L-1 Nitric acid and the reducing agent was 2000 mg·L-1 Oxalic acid. In the case of the number of processes, all oxide films were removed during the two-cycle chemical decontamination process of STS304 and SA508. In the case of Alloy600, all oxide films were removed when chemical decontamination was performed for three cycles or more.

Background Fecal calprotectin, an indicator of colonic inflammation, is associated with nonconstipated irritable bowel syndrome. Rifaximin is an antibiotic used to treat nonconstipated irritable bowel syndrome. We performed a retrospective review of patient charts to investigate the changes in fecal calprotectin levels and intestinal symptoms following treatment with rifaximin in patients with nonconstipated irritable bowel syndrome with elevated fecal calprotectin. Methods This study included 198 patients presenting with gastrointestinal complaints consistent with Rome III criteria for irritable bowel syndrome. We treated them with rifaximin for 4-12 weeks, until fecal calprotectin levels were normalized, and divided these into 4-, 8-, and 12-week groups according to the treatment period. Fecal calprotectin levels and gastrointestinal symptoms were assessed following rifaximin therapy. Results A total of 162 subjects achieved normalized fecal calprotectin values. Of these, most patients who used rifaximin for 8 or 12 weeks showed a significant improvement in gastrointestinal symptoms by the fourth week of treatment, and gradually improved symptoms after 4 weeks. Fecal calprotectin levels were reduced with concomitant improvement of clinical symptoms. In addition, 36 patients who had elevated fecal calprotectin even after 12 weeks of rifaximin treatment showed a gradual reduction in gastrointestinal symptoms and fecal calprotectin during the course of treatment for 12 weeks. Conclusions These findings suggest that fecal calprotectin might be a useful biomarker for measuring the effect of rifaximin therapy in nonconstipated irritable bowel syndrome patients with elevated fecal calprotectin values.

As interest in eco-friendly ships increases, methods for status monitoring and forecasting using in-service data from ships are being developed. Models for predicting the energy efficiency of a ship in real time need to effectively process the operational data and be optimized for such an application. This paper presents models that can predict fuel consumption using in-service data collected from a 13,000 TEU class container ship, along with statistical and domain-knowledge methods to select the proper input variables for the models. These methods prevent overfitting and multicollinearity while providing practical applicability. To implement the prediction model, either an artificial neural network (ANN) or multiple linear regression (MLR) were applied, where the ANN-based models showed the best prediction accuracy for both variable selection methods. The goodness of fit of the models based on ANN ranged from 0.9709 to 0.9936. Furthermore, sensitivity analysis of the draught under normal operating conditions indicated an optimal draught of 14.79 m, which was very close to the design draught of the target ship, and provides the optimal fuel consumption efficiency. These models could provide valuable information for ship operators to support decision making to maintain efficient operating conditions.