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A lumen-apposing metal stent (LAMS) is a saddle-shaped stent with large flanges at both ends, thereby preventing stent migration and helping with approximation of the adjacent structures. We report the case of a 25-year-old female with remnant choledochal cyst which was successfully treated with LAMS after initial treatment failure with a plastic stent. Although complete excision of the cyst is the definite treatment of choledochal cysts, endoscopic ultrasonography-guided cystoduodenostomy can be considered in cases wherein surgery is not feasible and dysplasia is not present. LAMS may be preferred to plastic stents for effective resolution of remnant choledochal cyst and prevention of ascending infection.

Background Before total knee arthroplasty (TKA), rotational assessment of the distal femur can be performed using either magnetic resonance imaging (MRI) or computed tomography (CT). Until now, there has been no study comparing the two modalities regarding rotational assessment of the distal femur in the same patients. Methods We retrospectively reviewed the preoperative CT and MRI images of 110 knees in 110 patients who underwent TKA. In the axial planes of CT and MRI scan, the posterior condylar axis (PCA), anatomical transepicondylar axis (aTEA), and perpendicular line to anteroposterior axis (pAPA) were identified; the angles between these studied lines were calculated. During TKA, the angles measured on the preoperative CT and MRI were compared with the measurements obtained in the intraoperative field. Results The mean aTEA-PCA angle was 6.2 ± 1.9° with CT and 5.1 ± 1.8° with MRI. The mean pAPA-PCA angle was 4.7 ± 2.1° with CT and 3.5 ± 2.0° with MRI. The mean aTEA-PCA (1.1 ± 1.3°, p = 0.001) and pAPA-PCA (1.2 ± 1.2°, p = 0.012) angles significantly differed between CT and MRI. Intra-operatively, the mean aTEA-PCA angle was 4.7 ± 1.1° and the mean pAPA-PCA angle was 3.2 ± 0.9°. Reliability analysis between the preoperative CT/MRI and the intraoperative measurements gave kappa values of 0.72 for aTEA-PCA and 0.66 for pAPA-PCA with CT, and 0.82 for aTEA-PCA and 0.84 for pAPA-PCA with MRI. Conclusions Preoperative rotational assessment of the distal femur with CT may cause higher external rotation of femoral component in TKA.

A two-dimensional resistance temperature detector (RTD) array sensor for the measurement of temperature distribution inside a tissue-mimicking material was proposed to validate focused ultrasound (FUS) devices. The fully two-dimensional $10\times10$ RTD array sensor with 1 mm inter-RTD distance was fabricated on the $2.5~ \boldsymbol {\mu } \text{m}$ thick film and placed inside the tissue-mimicking material. The measurement uncertainty for the RTD array was 0.18 K. The temperature distribution inside the phantom caused by a FUS transducer was measured and compared depending on the input power and focal plane. A tissue-mimicking phantom with an implanted RTD array can be applied to validate the performance and safety of both high- and low-intensity focused ultrasound (HIFU and LIFU) devices.

Background/purpose Patients who undergo gastric surgery are prone to form postsurgical gallstones. Debates still exist about the need for prevention and the selection of preventive methods. No studies had been reported comparing the efficacy of prophylactic ursodeoxycholic acid (UDCA) and prophylactic cholecystectomy (PC) for lowering postsurgical gallstone formation and subsequent cholecystectomy (SC) in patients who have undergone gastric surgery. Methods We did a systematic review to identify studies from PUBMED, EMBASE, and the Cochrane database through June 30, 2020. We conducted direct and indirect comparisons of each prophylaxis using conventional and network meta-analysis. Studies with patients who have no history of cholecystectomy and who have not had preoperative gallstone were included. Results The excellent preventive effects of PC and UDCA were demonstrated for gallstone formation (odds ratio [OR] 0.05, [95% CI 0.01, 0.22] and 0.20, [95% CI 0.16, 0.24], respectively) and the need for SC (OR 0.10, [95% CI 0.02, 0.57] and OR 0.22, [95% CI 0.14, 0.35], respectively) than control group. The UDCA group showed a tendency to generate more gallstones (OR 3.74, [95% CI 0.88, 15.82]) and a greater need for SC (OR 2.19, [95% CI 0.47-10.14]) than did the PC group without statistical significance. Conclusions Prophylaxis for gallstone formation may be needed for patients who undergo gastric surgery to reduce troublesome morbidities. Prophylactic UDCA seem to be a reasonable preventive method for postsurgical gallstone formation to ensure clinical benefit while reducing the burden of subsequent cholecystectomy for the patient as compared to a PC.

This study aims to investigate the frequency-dependent characteristics of the focal length of an acoustic lens made of a material with a frequency-dependent acoustic refractive index (ARI). For this purpose, an exchangeable plano-spherical convex subsonic index lens (PSCSIL) was fabricated using a polydimethylsiloxane (PDMS) material. The ARI of the lens material was evaluated via the tone-burst through-transmission method over the frequency range of 1–10 MHz. The frequency dependence of the focal length of the fabricated PSCSIL was evaluated through graphical analysis of the acoustic field scanned by a hydrophone as well as of that simulated using the finite element method. The measured ARI and focal length were observed to be dependent on frequency. The simulated and measured focal lengths of the PSCSIL exhibited a great discrepancy with their respective values predicted using the conventional focal length equation. This discrepancy was further studied using the ray-tracing method and is described in the discussion section. In conclusion, the spherical curvature of PSCSIL does not induce the convergence of rays to meet in a point. The ray tracing method does not take into account the phase complexity of the near-field region inside the lens. This causes the actual focal length to be shorter than the predicted one.

Background There is a lack of studies regarding the optimal timing for endoscopic retrograde cholangiopancreatography (ERCP) in patients with cholangitis caused by distal malignant biliary obstruction (MBO). This study aims to investigate the optimal timing of ERCP in patients with acute cholangitis associated with distal MBO with a naïve papilla. Methods A total of 421 patients with acute cholangitis, associated with distal MBO, were enrolled for this study. An urgent ERCP was defined as being an ERCP performed within 24 h following emergency room (ER) arrival, and early ERCP was defined as an ERCP performed between 24 and 48 h following ER arrival. We evaluated both 30-day and 180-day mortality as primary outcomes, according to the timing of the ERCP. Results The urgent ERCP group showed the lowest 30-day mortality rate (2.2%), as compared to the early and delayed ERCP groups (4.3% and 13.5%) (P P = 0.006). A subgroup analysis showed that in both the primary distal MBO group, as well as in the moderate-to-severe cholangitis group, the urgent ERCP had significantly improved in both 30-day and 180-day mortality rates. However, in the secondary MBO and mild cholangitis groups, the difference in mortality rate between urgent, early, and delayed ERCP groups was not significant. Conclusions In patients with acute cholangitis associated with distal MBO, urgent ERCP might be helpful in improving the prognosis, especially in patients with primary distal MBO or moderate-to-severe cholangitis.

Chemical reactions typically have numerous controllable factors that need to be optimized to yield the desired products. Although traditional experimental methods are limited to explore possible combinations of these factors, artificial intelligence (AI) can provide the optimal solution based on chemical reaction data. In this study, we optimize the non-oxidative conversion of methane to C2 compounds using AI, such as machine learning (ML) to predict experimental results and metaheuristics to optimize reaction conditions. A decision tree-based machine learning method can reasonably predict the reaction outcomes (CH4 conversion, C2 yield, and selectivities for C2 and coke) with an error of < 5%. Trained ML models are applied to maximize the C2 yield by optimizing the reaction parameters with metaheuristics. We can simultaneously enhance the C2 yield and suppress the coke formation by improving the multi-objective function for the optimization. We believe that our method will be helpful to optimize the chemical reaction conditions with multiple targets.

The urethral catheter is used in various clinical situations such as diagnosing urologic disease, urine drainage in patients after surgery, and for patients who cannot urinate voluntarily. However, catheters can cause numerous adverse effects, such as catheter-associated infection, obstruction, bladder stones, urethral injury, and catheter-related bladder discomfort (CRBD). CRBD symptoms vary among patients from burning sensation and pain in the suprapubic and penile areas to urinary urgency. CRBD significantly reduces patient quality of life and can lead to several complications. CRBD is caused by catheter-induced bladder irritation due to muscarinic receptor-mediated involuntary contractions of bladder smooth muscle and also can be caused by mechanical stimulus of the urethral catheter. Various pharmacologic studies for managing CRBD, including antimuscarinic and antiepileptic agents and botulinum toxin injections have been reported. If urologists can reduce patients’ CRBD, their quality of life and recovery can improve.

To date, numerous studies have investigated the brain white matter abnormality in patients with alcohol dependence using diffusion tensor imaging (DTI). DTI has been primarily utilized to evaluate white matter integrity, it is now increasingly used to investigate microstructural changes of gray matter (GM), particularly the subcortical GM. We predicted that structural alterations may not only be restricted to the white matter but also found in subcortical GM in alcohol dependent patients (ADP). Possible relationships between brain microstructure assessed by magnetic resonance diffusion tensor imaging (DTI) and brain volumes were investigated in ADP. Diffusion and volumetric analyses were performed in 21 alcohol dependent men without neurological or somatic complications and in 21 healthy men. Raw volume and DTI parameters (i.e., fractional anisotropy, and diffusivity values) of six subcortical gray matter structures (amygdala, hippocampus, caudate, pallidum, putamen, thalamus) were measured in both hemispheres. Between-group (controls versus patients) comparisons of normalized volume, DTI parameters, as well as within-group correlation analyses between structural changes and clinical variables were carried out. Our results show that DTI measurements appear more sensitive than volume measurements, but the combination of the two methods can still be useful for detecting pathological changes. Major findings are change of macrostructures in left hippocampus and bilateral putamen and thalamus. ADP group exhibited significant volume reductions and change of microstructures in caudate and hippocampus, putamen. These findings can broaden our understanding of the neuroanatomical changes underlying ADP.

Molecular dynamics (MD) simulations are useful in understanding the interaction between solid materials and molecules. However, performing MD simulations is possible only when interatomic potentials are available and constructing such interatomic potentials usually requires additional computational work. Recently, generating interatomic potentials was shown to be much easier when machine learning (ML) algorithms were used. In addition, ML algorithms require new descriptors for improved performance. Here, we present an ML approach with several categories of atomic descriptors to predict the parameters necessary for MD simulations, such as the potential energies and the atomic forces. We propose several atomic descriptors based on structural information and find that better descriptors can be generated from eXtreme gradient boosting (XGBoost). Moreover, we observe fewer descriptors that perform better in predicting the potential energies and the forces during methane activation processes on a catalytic Pt(111) surface. These results were consistently observed in two different ML algorithms: fully-connected neural network (FNN) and XGBoost. Taking into account the advantages of FNN and XGBoost, we propose an efficient ML model for estimating potential energies. Our findings will be helpful in developing new ML potentials for long-time MD simulations.

BACKGROUND The adjuvant treatment for patients with resected pancreatic cancer (PC) is not yet standardized. Because the prognosis differs according to the American Joint Committee on Cancer (AJCC) stage, a tailored approach to establish more aggressive treatment plans in high-risk patients is necessary. However, studies comparing the efficacy of adjuvant treatment modalities according to the AJCC stage are largely lacking. AIM To compare the efficacy of chemotherapy and chemoradiation therapy according to AJCC 8th staging system in patients with PC who underwent surgical resection. METHODS A total of 335 patients who underwent surgical resection and adjuvant treatment for PC were included. Patients were divided into three groups: Chemoradiation therapy (CRT) group, systemic chemotherapy (SCT) group and combined treatment of chemoradiation plus chemotherapy therapy (CRT-SCT) group. The primary outcomes were differences in overall survival (OS) between the three groups. The secondary outcomes were differences in recurrence-free survival, recurrence pattern and adverse events between the three groups. RESULTS Patients received CRT (n = 65), SCT (n = 62) and CRT-SCT (n = 208). Overall median OS was 33.3 mo (95% confidence interval (CI): 27.4-38.6). In patients with stage I/II, the median OS was 27.0 mo (95%CI: 2.06-89.6) in the CRT group, 35.8 mo (95%CI: 26.9-NA) in the SCT group and 38.6 mo (95%CI: 33.3-55.7) in the CRT-SCT group. Among them, there was no significant difference in OS between the three groups. In 59 patients with stage III, median OS in the SCT group [19.0 mo (95%CI: 12.6-NA)] and the CRT-SCT group [23.4 mo (95%CI: 22.0-44.4)] was significantly longer than that in the CRT group [17.7 mo (95%CI: 6.8-NA); P = 0.011 and P < 0.001, respectively]. There were no significant differences in incidence of locoregional and distant recurrences between the three groups (P = 0.158 and P = 0.205, respectively). Incidences of grade 3 or higher hematologic adverse events were higher in the SCT and CRT-SCT groups than in the CRT group. CONCLUSION SCT and CRT-SCT showed significantly longer OS and recurrence-free survival than CRT in patients with AJCC stage III, while there was no significant difference in OS between the CRT, SCT and CRT-SCT groups in patients with AJCC stage I/II. Different adjuvant therapy according to AJCC stage can be applied in patients with PC.

Background Two types of self-expandable metal stents (SEMS) are available for malignant distal biliary obstruction: fully covered SEMS (FCSEMS) and uncovered SEMS. FCSEMS can prevent stent ingrowth, but a major concern is spontaneous migration. This study aimed to determine whether the additional insertion of a double-pigtail plastic stent to anchor the FCSEMS can prevent migration. Methods 68 patients with unresectable, malignant, distal, biliary obstruction were included in this multicenter, randomized, superiority trial. The patients were randomly assigned to receive either the FCSEMS plus an anchoring plastic stent (n = 33) or an FCSEMS alone (n = 35). After placement of the FCSEMS, the anchoring stent was inserted inside the FCSEMS. The primary outcome was the rate of stent migration during the 6-month follow-up. The secondary outcomes were stent-related adverse events, stent patency, and survival rates. Results The baseline characteristics were similar between the two groups. The rate of stent migration at 6 months was significantly lower in patients with the FCSEMS plus anchoring stent (15 % vs. 40 %; P = 0.02). The mean stent patency was significantly longer in the FCSEMS plus anchoring group (237 days [95 % confidence interval [CI] 199 to 275] vs. 173 days [95 %CI 130 to 217]; P = 0.048). There were no significant differences in stent-related adverse events and overall survival rates at 6 months between the two groups. Conclusions Our data suggest that the additional double-pigtail plastic stent anchored the FCSEMS to prevent migration and prolonged patency without any serious adverse events.

The association between blood pressure (BP) defined by the 2017 American College of Cardiology/American Heart Association Hypertension Clinical Practice Guidelines with cardiovascular disease (CVD) and chronic kidney disease in patients with diabetes mellitus remains unclear. This study used the National Health Insurance Database of Korea that has health information of 8 922 940 persons who were screened from 2009 to 2014. We determined the BP status of 490 352 diabetes mellitus: level 1 (systolic

A hurdle to the commercialization of thermoelectrochemical cells (TECs) based on the redox reaction of hexacyanoferrate (HCF) to convert low-grade waste heat into electricity is the high manufactur...

Periarticular injection (PAI) can reduce pain and improve early outcomes following total knee arthroplasty (TKA). Although corticosteroid PAI has been reported to be safe and effective, investigations on the postoperative acute phase response (APR) are scarce.This retrospective cohort study with propensity score matching investigated two groups of patients after TKA: the steroid group (n = 50) received an intraoperative corticosteroid PAI (methylprednisolone 40 mg); the non-steroid group (n = 50) did not receive the corticosteroid. To evaluate the APR, C-reactive protein (CRP) levels and erythrocyte sedimentation rates (ESR) were determined preoperatively and on postoperative day (POD) 2, 4, 6, 14, and 28. A visual analogue scale (VAS) was used to measure pain on the night of surgery and on POD 1, 2, 4, and 6. Maximal flexion at discharge (POD 7), morphine equivalent dose (MED), and complications were also evaluated.The steroid group showed significantly lower CRP levels on POD 2 (P .05) and POD 4 (P .05) but a higher CRP level on POD 6 (P .05). However, ESR levels did not differ between the two groups in all measurements. Peak values in CRP and ESR in the steroid group (POD 4 and 6) appeared two days later compared with the non-steroid group (POD 2 and 4). The VAS pain score was significantly lower in the steroid group on POD 2 (P .05). Maximal flexion on discharge, MED and complication rate were similar in the two groups.Adding a corticosteroid to the PAI following TKA attenuated the APR, and also provided significant pain relief.

Background Although temporary endoscopic biliary stenting is considered effective for difficult common bile duct (CBD) stones, few studies have investigated the optimal conditions for complete stone clearance at the second endoscopic retrograde cholangiopancreatography (ERCP) after temporary biliary stenting. We aimed to evaluate factors associated with complete clearance. Methods Patients with difficult CBD stones (a large [≥ 20 mm] or multiple [≥ 3 sized ≥ 15 mm] CBD stones) were retrospectively enrolled from three institutions. Patients who underwent temporary biliary stenting at the first ERCP were analyzed. Double-pigtail plastic stents (7 or 10 Fr) were placed with the proximal ends above the stones. Complete clearance rate and stone size reduction at the second ERCP, and factors associated with complete clearance were evaluated using univariate and multivariate analyses. Results 85 patients were enrolled (mean age 74.5 years [SD 11.3]; 47 women). Stone size and CBD diameter significantly decreased during the interval. The overall complete stone clearance rate was 64.7 % (55/85) at the second ERCP. The mean stone size reduction was 5.6 mm (SD 6.8). In multivariate analysis, complete clearance rate was significantly lower in male patients, in patients aged > 80 years, and in stones > 25 mm initially, but was significantly higher when 7-Fr stents were placed and stone size was reduced by > 5 mm. Conclusion Use of 7-Fr rather than 10-Fr plastic stents was beneficial for complete clearance of difficult CBD stones after temporary biliary stenting; older male patients as well as patients with initial stones > 25 mm had a lower clearance rate.

Background and study aims During endoscopic ultrasound (EUS), patients may experience severe discomfort. The radial echoendoscope has a balloon around its tip. Balloon inflation prior to insertion may reduce contact injury and pharyngeal pain. The purpose of this study was to investigate the effect of balloon inflation on pharyngeal pain during insertion. Patients and methods Patients who underwent radial EUS for pancreatobiliary disease were randomized into standard insertion or balloon-inflated insertion. The primary outcome was the proportion of moderate-to-severe pharyngeal pain. Secondary outcomes were the degree of pharyngeal pain, risk factors for moderate pharyngeal pain, procedure-related adverse events, and pharyngeal pain depending on the experience of the endoscopist. Results A total of 481 patients were randomized into two groups: standard insertion (238) and balloon inflation (243). No statistically significant differences in proportion of moderate-to-severe pain were found (26.5 % vs. 20.2 %, P = 0.107). Balloon inflation (HR 0.65; 95 % CI (0.42–0.98, P = 0.041) was a protective factor against moderate pain. Balloon inflation reduced the proportion of patients with moderate-to-severe pain when performed by physicians with less than 3months of experience with EUS (44.7 % vs. 25.3 %, P = 0.012). Conclusion Balloon inflation did not reduce the absolute degree of post-procedural pain with EUS, but it reduced the number of patients with moderate-to-severe pain when performed by physicians with less than 3 months of experience.

We report two-terminal threshold devices that use niobium oxide (NbOx) thin films that were synthesized using atomic layer deposition (ALD) then pulsed-laser annealing. The ALD growth conditions for NbOx thin films were optimized using niobium(V) ethoxide and deionized water at 170 °C. As-deposited NbOx films were amorphous with Nb5+ valence state, but laser annealing led to partial conversion to NbO2 crystallites with Nb4+ valence states. This two-terminal device with ALD-NbOx exhibits excellent threshold switching with low off current ∼847 nA at 1 V, high on/off current ratio (∼103), high reliability, fast switching time ( 1 MHz).

Background Endoscopic retrograde biliary drainage (ERBD) is the treatment of choice for patients with malignant distal common bile duct (CBD) obstruction. Self-expandable metal stents (SEMS), which are commonly used in unresectable cases, have many clinical advantages, including longer stent patency. Although the expected patency of SEMS is around 8 months, it has recently been reported that the duration of SEMS’ patency in patients using aspirin is prolonged. Our study, therefore, aims to investigate the effect of aspirin on SEMS’ patency. Methods/design This is an investigator-initiated, prospective, multicenter, double-blind, randomized placebo-controlled trial that will be conducted from November 2017 in four tertiary centers in South Korea. We intend to include in our study 184 adult (aged ≥ 20 years) patients with malignant distal CBD obstruction for whom ERBD with SEMS was successfully performed. The patients will be randomly allocated to two groups, which will comprise patients who have either taken 100 mg aspirin or a placebo for 6 months after index ERBD. The primary outcome will be the rate of stent dysfunction, and the secondary outcomes will be the duration of patency, the rate of reintervention, and the occurrence of adverse events. Discussion The aspirin for metal stents in malignant distal common bile duct obstruction (AIMS) study should determine the efficacy of aspirin in maintaining metal-stent patency in patients with malignant distal CBD obstructive. Trial registration ClinicalTrials.gov, ID: NCT03279809. Registered on 5 September 2017.

Background and Objectives: The prevalence of choledocholithiasis in the high-risk group of choledocholithiasis has been reported to be slightly more than 50% when there is no definite cholangitis. Replacement of diagnostic endoscopic retrograde cholangiography (ERC) with an EUS-first approach may be beneficial in these patients. Materials and Methods: In this prospective, multicenter study, patients with dilated common bile duct and serum total bilirubin levels of 1.8–4 mg/dL were randomly allocated to undergo either EUS first, followed by subsequent ERC if necessary (EUS group) or ERC only (ERC group). The primary endpoint was the incidence of negative outcomes associated with a false-negative diagnosis of the choledocholithiasis or the endoscopic procedure. The secondary endpoints were the rate of diagnostic ERC and hospital stay length related to the endoscopic procedure. Results: Of 90 patients who were randomly assigned, the final analysis involved 42 in the EUS group and 44 in the ERC group. The negative outcomes were not significantly different between the EUS and ERC groups (2.4% vs. 6.8%; P = 0.62). The rate of diagnostic ERC was significantly lower in the EUS group (2.4% vs. 47.7%; P < 0.001). The hospital stay length related to the endoscopic procedure was significantly shorter in the EUS group (1.8 ± 1.0 vs. 2.5 ± 1.2 days; P = 0.001). Conclusion: In selected high-risk choledocholithiasis patients, an EUS-first strategy significantly decreased the rate of diagnostic ERC and hospital stay but did not achieve a significant reduction in negative endoscopic procedure outcomes.

BACKGROUND: Locally advanced (unresectable) pancreatic cancer (LAPC) is surgically unresectable and often treated with chemotherapy. Most of previous studies, that have evaluated conversion surgery after chemotherapy, included heterogeneous patients and chemotherapy regimens, making it challenging to determine the impact of FOLFIRINOX. The present study evaluated the survival benefit of conversion surgery in patients with LAPC who received FOLFIRINOX chemotherapy, and analyzed the prognostic factors. METHODS: Patients with LAPC who received FOLFIRINOX as first-line therapy for at least four cycles were included. During chemotherapy, surgical eligibility was determined based on radiologic and metabolic response to the treatment. Clinicopathologic characteristics were compared between the curative-intent surgery and non-resection groups, and the prognostic factors were analyzed. RESULTS: A total of 279 patients were included. The rates of partial response (PR) and stable disease (SD) were 34.1% and 51.4%, respectively, and 16.8% patients underwent curative-intent surgery. The median survival was significantly longer in the resection group than in the non-resection group (56 vs. 21 months, P

Pancreaticopleural fistula (PPF) a fistulous connection between the pancreas and pleural space due to prolonged chronic pancreatitis (CP). PPF is a very rare complication which presents in 0.4% of chronic pancreatitis cases, especially among children. We report a case involving a 3-year-old boy who presented with pleural effusion caused by a PPF, a complication of hereditary pancreatitis, which was, for the first time in Korea, successfully managed with endoscopic treatment. Chest radiography and computed tomography showed massive pleural effusion. Percutaneous catheter drainage was performed. High amylase levels were observed in the pleural fluid and serum, suggesting PPF. The patient was managed with bowel rest and octreotide infusion. Endoscopic retrograde cholangiopancreatography revealed CP, and pleural effusion was successfully managed with stent placement. PRSS1 genetic screening revealed R122H mutation.

Background Although several studies have suggested that aspirin and statins may help prevent pancreatic ductal adenocarcinoma (PDAC), this concept has been controversial. This study aimed to evaluate the association between use of statin or aspirin and PDAC in a nationwide large cohort. Methods In this nested case‐control study, we used data from a 12‐year nationwide longitudinal cohort in Korea. Cases with PDAC and controls who were matched to cases by age, sex, income, and index year at a 1:5 ratio were established. We used multivariate logistic regression analyses to identify the independent risk factors of PDAC. Results We identified a total of 827 patients with PDAC between 2007 and 2013, and included 4135 matched controls. Diabetes mellitus, chronic and acute pancreatitis, pancreatic cystic lesions, and cholelithiasis were independent risk factors for PDAC. Statin use (odds ratio [OR], 0.92; 95% confidence interval [CI] 0.76‐1.11; P = .344; adjusted OR [aOR], 0.70; 95% CI 0.56‐0.87; P = .001) was associated with a reduced risk of PDAC after correction of the confounding factors, but aspirin use (OR, 0.98; 95% CI 0.84‐1.15; P = .838; aOR 0.84; 95% CI 0.70‐1.01, P = .068) was not associated with PDAC. Among the patients with risk factors, both statin use (OR, 0.50; 95% CI 0.38‐0.66; P, The main contribution of our paper is to identify the association between use of statin or aspirin and pancreatic cancer in a nationwide large cohort, which is one of the worst prognostic cancers. In this nested case‐control study in the Korean nationwide cohort, we found that statin use was associated with a reduced risk of pancreatic cancer incidence but aspirin use was not. Both statin use and aspirin use were associated a reduced risk of pancreatic cancer incidence for patients with risk factors of pancreatic cancer.

Background Lymph-node (LN) metastasis is an important prognostic factor in resected pancreatic cancer. In this study, the prognostic value of American Joint Committee on Cancer (AJCC) 8th edition N stage, lymph-node ratio (LNR), and log odds of positive lymph nodes (LODDS) in resected pancreatic cancer was investigated. Methods Between January 2005 and December 2017, there were 351 patients with pancreatic cancer treated with R0 resection and adjuvant therapy at Seoul National University Hospital. Relationships between the three LN parameters and overall survival (OS) and recurrence-free survival (RFS) were evaluated using a log-rank test and Cox proportional hazard regression model. Each multivariate-adjusted LN parameter was internally validated by bootstrap-corrected Harrell’s C-index. Results The mean duration from surgery to adjuvant therapy was 47.6 ± 17.4 days. In total, the median OS and RFS was 31.7 (95% CI, 27.2-37.2) and 15.4 (95% CI, 13.5-17.7) months. The three LN classification systems were significantly correlated with OS and RFS in log-rank tests and multivariate-adjusted models (all p C–index = 0.65). LNR also showed the highest C-index in subgroup analysis, classified by adjuvant therapy modality. LNR and the AJCC 8th edition LN classification system were significantly associated with loco-regional recurrence (p = 0.026 and p = 0.027, respectively). Conclusions LNR, which showed the best prognostic performance and significant relationship with loco-regional recurrence, can help further stratify the patients and establish an active treatment plan.

Double raster scanning approach to 3D laser forming was investigated to obtain a large deformation with one-step laser irradiation, avoiding repetitive scanning. The magnitude of the deformation during raster scanning was found to be strongly dependent on the overlapping between adjacent passes, which can be controlled by changing their spacing and the beam diameter. Therefore, 3D deformation during raster scanning has been analyzed at various overlap ratios, whose effect on the temperature and strain distribution were discussed. As the heat transfer mode significantly influences the uniformity of the bending process, the variations in bending angles with negative and positive overlapping ratios have also been investigated. The ratio of the longitudinal and lateral curvatures decreased with the increasing overlap ratio. Therefore, the effect of the lateral side is more important for specifying the final symmetry of the part, playing a critical role in bending with higher overlap ratios. In a rectangular part, deformation of the lateral side was found to be more difficult, showing strong dependence on the length of the scanning track, compared with the space of the adjacent passes. Through process characterization, the double raster scanning process has been well understood and proved to be a feasible approach to 3D laser forming of rectangular parts. Keywords: Raster scanning, Laser forming, Curvature, Laser bending, Overlap, Heat transfer

Severe tibiofemoral (TF) subluxation 10 mm is a contraindication for high tibial osteotomy (HTO). However, the relationship between the degree of preoperative TF subluxation at 10 mm and postoperative radiographic/clinical outcomes remains unclear.Sixty-seven patients who underwent open wedge HTO with a planned postoperative mechanical femorotibial angle (mFTA) of three degrees valgus were retrospectively studied. The minimal subluxation (MIN) group included 39 patients with TF subluxation 5 mm, while the moderate subluxation (MOD) group included 28 patients with TF subluxation of five to 10 mm. The preoperative and one-year postoperative mFTA, TF subluxation, medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), preoperative Kellgren-Lawrence (K-L) grade and varus-valgus laxity were evaluated. Clinical scores and pain visual analogue scale (VAS) were also analyzed.The mean preoperative TF values in the MIN and MOD groups were 3.1±1.0 mm and 6.7±1.6 mm (mean±standard deviation, p 0.001), respectively, with no significant difference in K-L grades. The MIN group demonstrated a significantly smaller varus preoperative mFTA (p 0.001), larger MPTA (p = 0.011), smaller JLCA (p = 0.004), and less varus laxity (p = 0.023). Postoperative TF subluxation, MPTAs, and JLCAs did not differ significantly between the two groups, while the postoperative mFTA was significantly different (p = 0.001), with unintended overcorrection in the MOD group. No significant difference in clinical scores and VAS were observed.After HTO, compared to patients with TF subluxation 5 mm, patients with TF subluxation of five to 10 mm were more likely to demonstrate unintended valgus overcorrection on one-year postoperative radiography.

The frequency of incidental detection of pancreatic cystic lesions (PCLs) is increasing because of the frequent use of cross-sectional imaging. The appropriate treatment for PCLs is challenging, and endoscopic ultrasound-guided ablation for PCLs has been reported in several studies. Although the feasibility and efficacy of this therapeutic modality have been shown, the safety issues associated with the procedure are still a concern. We present a case of a 61-year-old man who underwent ultrasound-guided ethanol ablation for PCL and needed repeated endoscopic balloon dilatation for severe duodenal stricture caused by necrotizing pancreatitis after the cyst ablation therapy.

Purpose To identify the association between nocturia and obstructive sleep apnea (OSA), we compared results of polysomnography (PSG) with the presence or absence of nocturia in patients with suspected OSA. Methods Patients underwent PSG for suspected OSA. The International Prostate Symptom Score and quality of life (IPSS/QoL) questionnaire was evaluated to assess voiding symptoms that may affect sleep quality. The results of PSG were compared between patient groups with or without nocturia. Results In logistic regression analysis, age (odds ratio [OR], 1.052; P=0.004), diabetes mellitus (OR, 6.675; P

Background: Monocyte-to-lymphocyte ratio (MLR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) have been reported to be prognostic markers in various cancers. However, the prognostic value of these inflammatory biomarkers, particularly MLR, in gallbladder cancer remains to be determined. Methods: From 2005 to 2016, 178 patients with histologically confirmed gallbladder adenocarcinoma who underwent palliative chemotherapy were queried in this study. The association between survival and various clinical and laboratory variables, including MLR, NLR, and PLR, was investigated. The optimal cutoff values for MLR, NLR, and PLR were determined using the maxstat package of R. Results: Patients with high MLR (>0.24) were expected to have shorter progression-free survival [PFS; hazard ratio (HR), 2.100; 95% confidence interval (CI), 1.397–3.157; P < 0.001] and overall survival (OS; HR, 2.533; 95% CI, 1.664–3.856; P < 0.001) compared with patients with low MLR (≤0.24). In multivariate Cox model, CA 19-9, stage, and MLR were independent factors for PFS. MLR was also an independent predictor of OS along with PLR, age, and CA 19-9, whereas NLR was not significantly associated with OS. Time-dependent receiver operating characteristic (ROC) analysis showed that the area under the curve of MLR for predicting OS was greater than that of NLR and PLR at most time points. Conclusions: MLR independently predicts survival in gallbladder cancer patients undergoing chemotherapy. Future prospective studies are needed to validate its value as a prognostic biomarker. Impact: MLR is an inexpensive and easily available biomarker for predicting prognosis in patients with gallbladder cancer undergoing chemotherapy.

Background/Aims Recurrent pyogenic cholangitis (RPC) is a chronic progressive disease frequently accompanied by cholangiocarcinoma (CCA). This study aimed to investigate the natural course of RPC and identify factors associated with CCA. Methods From January 2005 to December 2016, 310 patients diagnosed with RPC at Seoul National University Hospital were included. Complications and management during follow-up were recorded. CCA-free probability was estimated by Kaplan-Meier method, and risk factors associated with CCA were analyzed using log-rank test and Cox’s proportional hazard regression model. Results Mean age at diagnosis was 59.1±10.9 years and mean follow-up duration was 84.0±64.1 months. An intrahepatic duct stone was found in 253 patients (81.6%). Liver atrophy was identified in 185 patients (59.7%) and most commonly located at the left lobe (65.4%). Acute cholangitis, liver abscesses, cirrhotic complications, and CCA developed in 41.3%, 19.4%, 9.7%, and 7.4%, respectively. During follow-up, complete resolution rate after hepatectomy, biliary bypass surgery, and choledocholithotomy with T-tube insertion reached 82.3%, 55.2%, and 42.1%, respectively. None of the patients who maintained complete resolution by the last follow-up day developed CCA. In univariate analysis, female, both-sided intrahepatic duct stones, and liver atrophy at any location were associated with increased risk of CCA. Multivariate analysis revealed that both-sided atrophy significantly increased risk of CCA (hazard ratio, 4.56; 95% confidence interval, 1.48 to 14.09; p=0.008). In 21 patients who developed intrahepatic CCA, tumor was located mostly in the atrophied lobe (p=0.023). Conclusions In RPC patients, acute cholangitis, liver abscess, cirrhotic complications, and CCA frequently developed. Both-sided liver atrophy was a significant risk factor for developing CCA.

This study aims to develop an optimization-based framework to systematically analyze and assess carbon utilization strategies. To achieve this goal, we generated a superstructure consisting of a number of carbon utilization strategies, which included a series of technologies (separation and reaction) to convert carbon sources into final products. We then estimated the technical and economic parameters of all the included technologies using interactive process models. The flow and relationship information in the superstructure and the technical and economic parameters from the process models are used to develop optimization models capable of assessing the carbon utilization strategies with four different criteria: product quantity, energy efficiency, production cost, and revenue. With the proposed framework, we can answer a range of interesting questions about carbon utilization – what is the best strategy for the production of a certain product or for the utilization of a given carbon source? The capability of the proposed framework is illustrated with a coke oven gas case study. As a result, the optimal production strategies of hydrogen, methane, methanol and liquid fuels are identified using four different criteria.

This study aims to develop novel high energy-efficient and economically viable methanol production processes form coke oven gas. To pursue this goal, two process schemes for the coke oven gas utilization, namely a highly integrated polygeneration of methanol, power, and heat, are proposed. The optimal system configuration and operating conditions for maximizing methanol amount or the total energy production were identified through the development of rigorous process models. The capability of the proposed processes was analyzed with different criteria: energy efficiency, carbon balance and minimum selling price of the produced methanol. As a result, the energy efficiency of the proposed processes is analyzed to range from 53 to 71%, which are greatly improved compared to the base process (38%). An economic evaluation study revealed that the minimum selling price of the methanol of the proposed processes was 0.23–0.29 USD/kg, which are competitive with conventional methanol production processes.

The bit-patterned media (BPM) technology is a promising approach for developing high-density memory devices. Porous templates such as anodized aluminum oxide and self-assembled block copolymer films have been explored for use in BPM. In this work, in order to further increase the pore density, we used a mesoporous silica thin film (MSTF) with 8 nm sized regularly ordered pores and 4 nm thick walls as a template to grow CoPt3 nanoparticles (NPs) into two-dimensional hexagonal arrays. The use of a Au(111)/SiO2 substrate induced epitaxial growth of single-crystalline CoPt3 NPs in the face-centered cubic structure, as evidenced by high-resolution transmission electron microscopy and grazing-incidence X-ray scattering data. Direction-dependent magnetic measurements showed that the CoPt3 NPs had out-of-plane magnetic polarization. Magnetic force microscopy (MFM) data indicated that individual CoPt3 NPs could be addressed independently. First-principles electronic structure calculations indicated that the observ...

Computational fluid dynamics (CFD) studies have been carried out for CO2 reforming of methane in both a packed-bed reactor (PBR) and a membrane reactor (MR) with a heating tube as a heat source at the center of a reactor. The effect of a reactor geometry on the temperature and H2 and CH4 concentration profiles within a PBR and a MR have been investigated numerically by changing the distance of membranes from the center of a heating tube (Dcenter = radial distance between the center of the reactor and the center of the membrane) for a given heating tube temperature. The distances of the center of the membranes in a MR from the reactor center were 0.028 m, 0.03 m, 0.033 m, 0.035 m, 0.038 m, 0.04 m, 0.042 m, 0.044 m and 0.045 m. With the help of COMSOL Multiphysics® modeling software, it was possible to visualize temperature and concentration profiles both axially and radially. Interestingly, it was found that H2 enhancement is proportional to both Dcenter and the magnitude of the H2 flux. Further studies for the effect of a heating tube radius proposed an optimum radius for a maximum H2 yield enhancement in a MR. Consequently, it turned out that CFD studies can be used as a critical guideline for an efficient reactor design focusing on a reactor geometry in a MR for given conditions.

Process simulation and design as well as economic analysis were carried out to evaluate technical and economic feasibility of steam reforming of methanol in a membrane reactor (MR) for ultra-pure H2 production. Using a commercial process simulator, Aspen HYSYS®, comparative studies were conducted to investigate the effect of operating conditions including the H2 permeance (1 × 10−5 - 6 × 10−5 mol m−2 s−1 Pa−1), a H2O sweep gas flow rate (1–20 kmol h−1), and a reaction temperature (448–493 K) in a conventional packed-bed reactor (PBR) and the MR using a previously reported reaction kinetics. Improved performances such as methanol conversions and H2 yields were observed in the MR compared to the PBR and several design guidelines for the MR were obtained to develop H2 separation membranes with optimal H2 permeance and to select a suitable H2O sweep gas flow rate. In addition, economic analysis based on itemized cost estimations was conducted for a small-sized H2 fueling station by calculating a unit H2 production cost for both the PBR and the MR reflecting a current economic status in Korea. As a result, a cost saving of about 23% was obtained in the MR (7.24 $ kgH2−1) compared to the PBR (9.37 $ kgH2−1) confirming the benefit of employing the MR for ultra-pure H2 production.

This paper addresses the low-frequency noise characterization of Z2-FET structures. These double-gated p-i-n diode devices have been fabricated at STMicroelectronics in an ultrathin body and box (UTBB) 28-nm FDSOI technology and designed to operate as 1T-DRAM memory cells, although other applications, as for example electro static discharge (ESD) protection, have been reported. The experimentally extracted power spectral density of current reveals that the high-diode series resistance, carrier number fluctuations due to oxide traps, and gate leakage current are the main noise contributors at high-current regimes. These mechanisms are expected to contribute to the degradation of cell variability and retention time. Higher flicker noise levels have been reported when increasing the vertical electric field. A simple model considering the contribution of the main noise sources is proposed., This work was supported in part by the European REMINDER 687931 Grant, in part by the Consejeria de Economia, Conocimiento, Empresas y Universidad de la Junta de Andalucia and European Regional Development Fund (ERDF), under Grant SOMM17/6109/ UGR, and in part by the TEC2017-89800-R Projects

Neural network-based generative models have been actively investigated as an inverse design method for finding novel materials in a vast design space. However, the applicability of conventional generative models is limited because they cannot access data outside the range of training sets. Advanced generative models that were devised to overcome the limitation also suffer from the weak predictive power on the unseen domain. In this study, we propose a deep neural network-based forward design approach that enables an efficient search for superior materials far beyond the domain of the initial training set. This approach compensates for the weak predictive power of neural networks on an unseen domain through gradual updates of the neural network with active transfer learning and data augmentation methods. We demonstrate the potential of our framework with a grid composite optimization problem that has an astronomical number of possible design configurations. Results show that our proposed framework can provide excellent designs close to the global optima, even with the addition of a very small dataset corresponding to less than 0.5% of the initial training dataset size.

FOLFIRINOX is currently one of the standard chemotherapy regimens for pancreatic cancer patients, but little is known about the factors that can predict a response to it. We performed a study to discover novel DNA damage repair (DDR) gene variants associated with the response to FOLFIRINOX chemotherapy in patients with pancreatic cancer. We queried a cohort of pancreatic cancer patients who received FOLFIRINOX chemotherapy as the first treatment and who had tissue obtained through an endoscopic ultrasound-guided biopsy that was suitable for DNA sequencing. We explored variants of 148 DDR genes based on whole exome sequencing and performed multivariate Cox regression to find genetic variants associated with progression-free survival (PFS). Overall, 103 patients were included. Among 2384 variants of 141 DDR genes, 612 non-synonymous variants of 123 genes were selected for Cox regression analysis. The multivariate Cox model showed that rs2228528 in ERCC6 was significantly associated with improved PFS (hazard ratio 0.54, p = 0.001). The median PFS was significantly longer in patients with rs2228528 genotype AA vs. genotype GA and GG (23.5 vs. 16.2 and 8.6 months, log-rank p &lt, 0.001). This study suggests that rs2228528 in ERCC6 could be a potential predictor of response to FOLFIRINOX chemotherapy in patients with pancreatic cancer.

Background FOLFIRINOX (FFX) and Gemcitabine plus nab-paclitaxel (GnP) have been recommended as the first-line chemotherapy for metastatic pancreatic cancer (mPC). However, the evidence is lacking comparing not only two regimens, but also sequential treatment (FFX–GnP vs. GnP–FFX). Methods Data of 528 patients (FFX, n = 371; GnP, n = 157) with mPC were collected retrospectively. Propensity score matching was conducted to alleviate imbalance of the two groups. Overall survival (OS), progression free survival (PFS), and toxicity of patients were analyzed. Results In the whole population, OS (12.5 months vs. 10.3 months, P = 0.05) and PFS (7.1 months vs. 5.8 months, P = 0.02) were longer in the FFX group before matching and after matching (OS: 11.8 months vs. 10.3 months, P = 0.02; PFS: 7.2 months vs. 5.8 months, P P P = 0.03). Conclusions FFX achieved a longer overall survival than GnP in mPC, but not in the comparison for sequential treatment. More frequent adverse events followed by treatment interruptions during GnP might lead to a poor survival outcome. Therefore, FFX would be a better first-line treatment option than GnP for mPC.

Lignin directly derived from lignocellulosic biomass has been named a promising source of platform chemicals for the production of bio-based polymers. This review discusses potentially relevant routes to produce renewable aromatic aldehydes (e.g., syringaldehyde and vanillin) from lignin feedstocks (pre-isolated lignin or lignocellulose) that are used to synthesize a range of bio-based polymers. To do this, the processes to make aromatic aldehydes from lignin with their highest available yields are first presented. After that, the routes from such aldehydes to different polymers are explored. Challenges and perspectives of the production the lignin-derived renewable chemicals and polymers are also highlighted.

Mesoporous metal oxides consisting of fully interconnected network structures with small pores (20–50 nm) have high surface areas and decreased ion intercalation distances, making them ideal for use in high-performance electrochromic supercapacitors (ECSs). Evaporation-induced self-assembly (EISA), which combines sol–gel chemistry and molecular self-assembly, is a powerful method for the fabrication of mesoporous metal oxides through a solution phase synthesis. Herein, we introduce ultrafast sub-1 s ECSs based on an amorphous mesoporous tungsten trioxide (WO3) that is prepared by EISA. Compared to that of a compact-WO3 film-based device, the performances of an ECS with mesoporous WO3 exhibits a large optical modulation (76% at 700 nm), ultrafast switching speeds (0.8 s for coloration and 0.4 s for bleaching), and a high areal capacitance (2.57 mF/cm2), even at a high current density (1.0 mA/cm2). In addition, the excellent device stability during the coloration/bleaching and charging/discharging cycles is observed under fast response conditions. Moreover, we fabricated a patterned mesoporous WO3 for ECS displays (ECSDs) via printing-assisted EISA (PEISA). The resulting ECSDs can be used as portable energy-storage devices, and their electrochromic reflective displays change color according to their stored energy level. The ECSDs in this work have enormous potential for use in next-generation smart windows for buildings and as portable energy storage displays. Networks of tiny holes improve the energy storage properties of materials that can also be used for smart windows. In electrochromic materials, the fraction of light passing through the material can be controlled using an electrical voltage. This is useful for smart windows which electrically switch from being transparent to opaque. This change is associated with the storage or release of energy, so the same materials are being investigated for energy storage. Keon-Woo Kim from Pohang University of Science and Technology, South Korea, and co-workers have developed an improved electrochromic supercapacitor made from tungsten trioxide. They used an evaporation-induced self-assembly process to deposit a film of tungsten trioxide containing pores approximately 30 nanometers across. This porous structure increased the material’s switching speed and capacitance compared to a conventional tungsten trioxide thin film. Ultra-fast electrochromic supercapacitors (ECSs) are demonstrated based on mesoporous WO3 prepared by evaporation-induced self-assembly (EISA). Mesoporous WO3 based ECSs show excellent electrochromic and supercapacitor performances under fast operating condition. Furthermore, printing assisted EISA is introduced to produce patterned mesoporous WO3 for ECS displays (ECSDs). The resulting ECSDs have great potential as next-generation smart electrochemical components.