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Background/Aims: The utility of endoscopic ultrasonography (EUS) for differentiating gastrointestinal stromal tumors (GISTs) and leiomyomas of the stomach is not well known. We aimed to evaluate the ability of EUS for differentiating gastric GISTs and leiomyomas.Methods: We retrospectively reviewed the medical records of patients with histopathologically proven GISTs (n=274) and leiomyomas (n=87). In two consensus meetings, the inter-observer variability in the EUS image analysis was reduced. Using logistic regression analyses, we selected predictive factors and constructed a predictive model and nomogram for differentiating GISTs from leiomyomas. A receiver operating characteristic (ROC) curve analysis was performed to measure the discrimination performance in the development and internal validation sets.Results: Multivariate analysis identified heterogeneity (odds ratio [OR], 9.48), non-cardia (OR, 19.11), and older age (OR, 1.06) as independent predictors of GISTs. The areas under the ROC curve of the predictive model using age, sex, and four EUS factors (homogeneity, location, anechoic spaces, and dimpling or ulcer) were 0.916 (sensitivity, 0.908; specificity, 0.793) and 0.904 (sensitivity, 0.908; specificity, 0.782) in the development and internal validation sets, respectively.Conclusions: The predictive model and nomogram using age, sex and homogeneity, tumor location, presence of anechoic spaces, and presence of dimpling or ulcer on EUS may facilitate differentiation between GISTs and leiomyomas.

Cannulation of the portal vein is a rare complication of ERCP. This paper reports a case of portal vein catheterization during ERCP in a patient with choledocholithiasis. A 62-year-old man was admitted to the Presbyterian Medical Center with right upper quadrant pain and jaundice. ERCP was performed under the suspicion of obstructive jaundice caused by a radiolucent stone. Bile duct cannulation using a pull-type papillotome was attempted, but it failed. After needle-knife fistulotomy, wire-guided cannulation was performed successfully, and 10 mL contrast was injected. On the other hand, the fluoroscopy image showed that the contrast medium disappeared very quickly. Pure blood was collected when the catheter was aspirated to identify the bile reflux, indicating possible cannulation of the portal vein. The procedure was terminated immediately and abdominal computed tomography showed air in the portal vein. One day after, a follow-up CT scan showed no air in the portal vein. The patient underwent repeated ERCP, and the common bile duct was cannulated. In most cases, isolated portal vein cannulation does not result in severe morbidity. However, it is important to aware of this rare complication so that no further invasive procedure is performed on the patient.

Bougie or balloon dilation is a good short-term treatment for caustic esophageal strictures, although recurrence after dilation occurs in approximately 30% of these cases. Therefore, long-term treatment options are required in some cases, and endoscopic incisional therapy has been used for patients with an anastomotic stricture in the gastrointestinal tract. A 58-year-old woman presented with severe swallowing difficulty because of a caustic esophageal stricture, which was caused by accidental exposure to anhydrous acetic acid at infancy. She had undergone several previous bougie and balloon dilations but the stricture did not improve. We performed sequential treatment comprising incision with an insulated-tip knife, balloon dilation, and an oral steroid, which resulted in the patient's symptoms markedly improving. Thus, we report this case of an intractable caustic esophageal stricture, which was successfully treated using combined endoscopic sequential treatment.

In recent years, embedded systems such as various electronic devices equipped with a microprocessor, which acts as a brain of electronic devices, have been spreading due to the improvement of computational capability of system semiconductors and the generalization of large-capacity memory. However, as the requirements of the application using the embedded system increase, the number of the peripheral devices and the interfaces built in the embedded system increases. As a result, it takes much effort and time to develop the embedded system and verify the function. Therefore, in this paper, we propose and study a verification system that can efficiently test the interface to the embedded system.

Background/aims Proton pump inhibitors (PPIs) are frequently used to treat non-erosive reflux disease (NERD), but their effect is limited. It is not known whether a potential alternative, AlbisD, containing ranitidine hydrochloride, sucralfate hydrate, and tripotassium dicitrato bismuthate, is effective and safe in treating NERD. The aim of the study is to evaluate the efficacy and safety of AlbisD compared with omperazole in patients with NERD. Methods This was a multicenter, randomized, open-label, parallel-group, non-inferiority comparative study. A total of 126 patients with NERD were randomly allocated to either AlbisD twice daily or omeprazole 20 mg once daily for 4 weeks from February 2016 to August 2016. The study patients had histories of heartburn or regurgitation of moderate severity (> score 2) and a frequency of at least 2 episodes per week, and had no mucosal breaks of the esophagus on endoscopy. The primary efficacy variable was complete cure of heartburn at week 4. Secondary efficacy variables evaluating symptoms of heartburn and acid reflux as well as safety profiles were compared in the 2 groups at week 2 and 4 after treatment. Results A total of 113 patients completed the study (57 and 56 in AlbisD and omeprazole groups, respectively). The proportion of patients with complete cure of heartburn at week 4 was not significantly different between the AlbisD and omeprazole groups (35.1% vs 32.1% respectively, P = 0.740). There were no significant differences between the 2 groups in the any secondary variables including proportions of days without heartburn or acid reflux over 4 weeks (including daytime and nighttime). Adverse events were similarly reported in the 2 groups (7 [12.3%] vs 6 [10.7%]), and there were no serious adverse events. Conclusions The efficacy and safety of AlibsD in treating NERD patients are not inferior to those of omeprazole. Therefore, AlbisD can be an alternative to PPIs for NERD.

Background and Aims Perforation is the adverse event of greatest concern during colorectal endoscopic submucosal dissection (ESD). Accurate risk prediction of perforation may enable prevention strategies and selection of the most efficient therapeutic option. This study aimed to develop and validate a risk prediction model for ESD-induced perforation. Methods A multicenter cross-sectional study was performed on 2046 patients who underwent colorectal ESD at 9 Korean ESD Study Group–affiliated hospitals. The enrolled patients were randomly divided into either a derivation set or a validation set. In the derivation set, a prediction score was constructed to assess the risk of perforation using preoperative and procedural-related predictors selected via logistic regression. Discrimination and calibration of the prediction model was assessed using the validation set. Results An ESD-induced perforation occurred in 135 patients (6.6%). In the derivation set, multivariate logistic regression identified endoscopist experience (≥50 ESDs: odds ratio [OR] = 0.59; 95% confidence interval [CI], 0.35-1.00), tumor size (+1-cm increments: OR = 1.39; 95% CI, 1.19-1.62), colonic location (OR = 2.20; 95% CI, 1.24-3.89), and submucosal fibrosis (OR = 2.00; 95% CI, 1.04-3.87) as predictive factors (C-statistic = 0.678; 95% CI, 0.617-0.739). In the validation set, the model showed good discrimination (C-statistic = 0.675; 95% CI, 0.615-0.735) and calibration ( P = .635). When a simplified weighted scoring system based on the OR was used, risk of perforation ranged from 4.1% (95% CI, 2.8%-5.9%) in the low-risk group (score ≤4) to 11.6% (95% CI, 8.5%-15.6%) in the high-risk group (score >4). Conclusions This study developed and internally validated a score consisting of simple clinical factors to estimate the risk of colorectal ESD-induced perforation. This score can be used to identify patients at high risk before colorectal ESD.

Subepithelial tumors are frequently found in asymptomatic patients in Japan and Korea where cancer screening tests routinely include endoscopy. Most lesions are asymptomatic and clinically insignificant. However, carcinoid tumors, lymphomas, glomus tumor and gastrointestinal stromal tumors (GISTs) are malignant or have the potential to become malignant. Inflammation due to parasitic infestation by Anisakis and poorly differentiated adenocarcinomas in the stomach rarely present as subepithelial lesions. In contrast to the frequency of gastric GIST in the gastrointestinal system, they are uncommon in the duodenum and very rare in the esophagus. The prognosis of patients with GISTs in the stomach is relatively good compared with GISTs in other organs. Along with the location of the tumor, its size and mitotic count are major factors that determine the malignant potential of GIST. Small (

Background/aims The endoscopic forceps biopsy of gastric lesion may provide inadequate specimens for a correct diagnosis of the entire lesion. Therefore, a histologic discrepancy may exist between specimens obtained by forceps biopsy and by endoscopic resection. The aim of this study was to evaluate the endoscopic characteristics of an underestimation in gastric carcinomas initially diagnosed as adenomas by forceps biopsy. Materials and methods We retrospectively reviewed 431 lesions diagnosed as gastric adenomas by forceps biopsy and resected by endoscopic submucosal dissection (ESD) between January 2008 and December 2011. The endoscopic findings were reviewed for location, size, gross appearance, ulceration, and surface color. We compared these variables between the adenoma group and the carcinoma group, as defined by the post-resection pathological findings. Results The mean patient age was 65.63±9.30 years in the adenoma group and 64.75±10.30 years in the carcinoma group. The mean size of the lesion was 21.04±8.65 mm in the adenoma group and 22.06±7.46 mm in the carcinoma group. In the multivariate analysis, high-grade dysplasia from endoscopic forceps biopsy and red discoloration were significant variables associated with carcinoma in post-resection histology. Conclusion Gastric adenomatous lesions with endoscopic characteristics of surface redness and high-grade dysplasia on forceps biopsy should be resected completely by ESD because of the high possibility of an underestimation after ESD.

This experiment was carried out to figure out the growth and yield of waxy corn after cultivating the hairy vetch which was mostly used as a green manure crop. The waxy corn showed the growth and yield efficiency relative to conventional culture after the hairy vetch was returned to as the green manure and the amount of nitrogen fertilizer increased, and the LAI was similar to the conventional culture when less than 18 kg. Length of ear slightly decreased compared to 188 mm of conventional culture when the hairy vetch was used as the green manure and the amount of nitrogen fertilizer was less than 9 kg, but the length of ear increased relative to the conventional culture when the amount of applied nitrogen fertilizer was more than 18 kg. The highest 100-kernel weight was 35.4 g with the hairy vetch and 27 kg of nitrogen fertilizer treatment. The lowest 100-kernel weight was 27.4 g with the hairy vetch and 0 kg of nitrogen fertilizer treatment. Quantity with the hairy vetch and 9 kg of the nitrogen fertilizer treatment was similar the conventional culture. Suger content with the hairy vetch and more than 18 kg of the nitrogen fertilizer treatment was higher than the conventional culture. Thickness of pericarp showed no difference among treatments.

Secondary involvement of the gallbladder by systemic lymphoma is exceedingly rare and relapsed diffuse large B cell lymphoma of the gallbladder has not been reported. A 78-year-old man was admitted to the hospital due to epigastric pain and jaundice. His past medical history was remarkable for diagnosis with diffuse large B-cell lymphoma of the ileum 5 years ago. He underwent right hemicolectomy and three cycles of adjuvant chemotherapy and had complete remission. Abdominal computed tomography showed choledocholithiasis and focal thickening at fundus of the gallbladder. The patient underwent open cholecystectomy. Pathologic examination revealed diffuse large B-cell lymphoma. We report a case of solitary, relapsed diffuse large Bcell lymphoma of the gallbladder with literature review. Korean J Pancreatobiliary 2015;20(3):151-155

Background and aim Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is commonly used to obtain tissue external to the gastrointestinal tract. EUS-FNA is relatively safe, but occasionally adverse events have been reported. There is scarcity of data on risk factors of adverse events. The aim of this study is to identify risk factors associated with EUS-FNA. Methods In this multicenter case-control study, we retrospectively reviewed 4,097 cases between 2009 and 2012 at 15 hospitals in Korea. Among the patients there were 104 cases (2.5%) who had adverse events of which 12 (0.29%) were severe. We matched 520 controls (1:5 ratios) stratified by hospital to analyze the potential risk factors. Results The most common adverse events were pancreatitis (45/104, 43.3%) and infection (46/104, 44.2%). Endoscopic retrograde cholangiopancreatography (ERCP) on the same day was a risk factor of all adverse events [OR = 2.41, 95% CI (1.41, 4.12)], pancreatitis [OR = 2.31, 95% CI (1.02, 5.25)], and infection [OR = 2.75, 95% CI (1.31, 5.78)]. More than 15 to-and-fro movements during puncture increased the risk of pancreatitis [OR = 2.30, 95% CI (1.11, 4.77)] and infection [OR = 3.65, 95% CI (1.55, 8.59)]. A higher number of punctures was positively correlated with pancreatitis [OR = 1.34, 95% CI (1.08, 1.67)] but negatively correlated with infection [OR = 0.66, 95% CI (0.48, 0.89)]. Conclusions EUS-FNA is a safe procedure in which serious adverse events are rare. We define some risk factors of adverse events during EUS-FNA, including ERCP on the same day, a higher number of punctures, and more than 15 to-and-fro movements.

Misoprostol is reported to prevent non-steroidal anti-inflammatory drug (NSAID)-associated gastroduodenal complications. There is, however, limited information regarding the efficacy of DA-9601 in this context. We performed a comparative study on the relative efficacy of DA-9601 and misoprostol for prevention of NSAID-associated complications. In this multicenter, double-blinded, active-controlled, stratified randomized, parallel group, non-inferiority trial, 520 patients who were to be treated with an NSAID (aceclofenac, 100 mg, twice daily) over a 4-week period were randomly assigned to groups for coincidental treatment with DA-9601 (60 mg, thrice daily) (236 patients for full analysis) or misoprostol (200 μg, thrice daily) (242 patients for full analysis). A total of 236 patients received DA-9601 and 242 received misoprostol. The primary endpoint was the gastric protection rate, and secondary endpoints were the duodenal protection rate and ulcer incidence rate. Endpoints were assessed by endoscopy after the 4-week treatment period. Drug-related adverse effects, including gastrointestinal (GI) symptoms, were also compared. At week 4, the gastric protection rates with DA-9601 and misoprostol were 81.4 % (192/236) and 89.3 % (216/242), respectively. The difference between the groups was −14.2 %, indicating non-inferiority of DA-9601 to misoprostol. Adverse event rates were not different between the two groups; however, the total scores for GI symptoms before and after administration were significantly lower in the DA-9601 group than in the misoprostol group (−0.2 ± 2.8 vs 1.2 ± 3.2; p

Background and Aims Delayed bleeding is an important adverse event after colorectal endoscopic submucosal dissection (ESD). We aimed to investigate the incidence and risk factors of delayed bleeding after colorectal ESD and to develop a risk-scoring model for predicting delayed bleeding. Methods This retrospective study was performed at 5 centers. The derivation and validation cohorts comprised 1189 patients from 1 center and 415 patients from the other 4 centers. We investigated the incidence and risk factors of delayed bleeding. Then, we developed a risk-scoring model for predicting delayed bleeding by using the data of the derivation cohort. We validated the scoring system in the validation cohort. Results Delayed bleeding occurred in 34 patients (2.9%) in the derivation cohort. In multivariate analysis, the risk factors of delayed bleeding were tumor location in the rectosigmoid colon (odds ratio [OR], 6.49; 95% confidence interval [CI], 1.96-21.42; P = .002), large tumor (≥30 mm) (OR, 2.10; 95% CI, 1.01-4.40; P = .048), and use of antiplatelet agents except for aspirin alone (OR, 4.04; 95% CI, 1.44-11.30; P = .008). These 3 factors were incorporated into a risk-scoring model for prediction of delayed bleeding. As the score based on this system increased, the incidence of delayed bleeding increased in the validation cohort. Conclusion The risk-scoring model incorporating tumor location, tumor size, and use of antiplatelet agents can quantitatively predict the risk of delayed bleeding after colorectal ESD.

OBJECTIVE. Endoscopic ultrasonography (EUS)-guided fine-needle aspiration (EUS-FNA) may facilitate tissue sampling for histopathological diagnosis of subepithelial tumors (SETs) in the gastrointestinal (GI) tract. However, immunohistochemistry is not always feasible using EUS-FNA samples due to the low quality of specimens often obtained by aspiration. This study aimed to compare the use of 22-gauge (G) EUS-guided fine-needle biopsy (EUS-FNB) with 22G EUS-FNA for core sampling used for histopathological examination, including immunohistochemistry, in patients with GI SETs. METHODS. Twenty-eight patients with GI SETs ≥2 cm in size were prospectively enrolled at five university hospitals in Korea between January and June 2013. They were randomized to undergo either EUS-FNB or EUS-FNA. RESULTS. A total of 22 patients was finally analyzed in this study: 10 and 12 patients underwent EUS-FNA and EUS-FNB, respectively. Compared to the EUS-FNA group, the EUS-FNB group had a significantly lower median number of needle passes to obtain macroscopically optimal core samples (4 vs. 2, p = 0.025); higher yield rates of macroscopically and histologically optimal core samples with three needle passes (30% vs. 92%, p = 0.006; 20% vs. 75%, p = 0.010, respectively); and a higher diagnostic sufficiency rate (20% vs. 75%, p = 0.010). No technical difficulties were encountered in either group. CONCLUSIONS. This study shows that EUS-FNB has a better ability to obtain histological core samples and a higher diagnostic sufficiency rate than EUS-FNA and that EUS-FNB is a feasible, safe, and preferable modality for adequate core sampling for histopathological diagnosis of GI SETs.

In this letter, we analyze the outage performance of the signal-to-noise ratio (SNR)-based selective relaying in a relay network, where the relay terminal may retransmit the received signal or remain silent based on the received SNR of the link from the source to the relay. For the proposed relaying scheme, we derive the exact outage probability.

Cronkhite-Canada syndrome (CCS) is a rare nonfamilial polyposis syndrome characterized by epithelial disturbances both in the gastrointestinal tract and in the epidermis. The pathologic finding of the polyp is usually a hamartomatous polyp of the juvenile type; however, the possibility of serrated adenoma associated malignant neoplasm was reported in some Japanese cases. Up till now in South Korea, 13 CCS cases have been reported, but there was no case accompanied by the colon cancer. We report the first case of CCS associated with malignant colon polyp and serrated adenoma in Korea. A 72-year-old male patient who complained of diarrhea and weight loss was presented with both hands and feet nail dystrophy, hyperpigmentation, and alopecia. Endoscopic examination showed numerous hamartomatous polyps from the stomach to the colon. The pathologic results confirmed colon cancer and serrated adenoma. Helicobacter pylori eradication and prednisolone was used. Thus, the authors report this case along with a literature review.

For organic farming, green manure crops such as leguminous forages and barley have been broadly used to improve soil fertility and soil physical and chemical properties by repeatedly cutting and mulching them directly as winter crop in the field in the rotation. In this investigation we selected 78 agricultural farm corporations as well as individual organic farmhouses related to crop rotation from greenmanure crops to main crops in order to analyze the relationship of cropping system between main crops and green manure crops. The results showed that the green manure crops were divided into two groups as leguminous and nonleguminous crops, representing that those are limited to specific climate and farming systems of regions. Also the 10 or less green manure crops including sudangrass, hairyvetch, italian ryegrass, sorghun, buckwheat, oat, pea, rye, clover, and canola which belong to leguminous crops which are presently cultivated from the organic farmhouses within the rotational crop system. We also confirmed that the major main crops are sweet potato, soybean, corn, tobacco, spinach from usage frequency analyzed by NetMiner H 2.6 which was used to estimate the rotational cropping system among the green manure crops and main crops.

In this paper, we design the physical layer of Guardian modem for wireless public networks. The physical layer is composed of a dual-band RF (Radio Frequency) transceiver and a baseband-processor with quasi-orthogonal codes. The 2.4/5GHz dual-band RF transceiver can overcome the communication difficulty of dense 2.4GHz band for wireless public environment. Also the quasi-orthogonal code can reduce the required ASIC (Application Specific Integrated Circuit) design area. Finally, we analyze the performance of the developed system in viewpoint of data rate, BER (Bit Error Rate), PER (Packet Error Rate). Moreover we verify the performance of the dual-band RF communication.

In this paper, we first introduce our own binary CDMA technology. Then we propose a wireless distribution automation system using the binary CDMA technology. The major research items are the binary CDMA distribution automation system, piconet configuration for remote control and monitoring, scheduling for the transmission and reception of data, and ways of applying encryption to protect wireless packet. To verify the possibility of applying wireless transmission to the distribution automation system, we experiment the implemented system in terms of the transmission rate by applying it to a real-world environment.

In this paper, we propose a WFAN (Wireless Fighter Area Network) system based on Koinonia modems is proposed. Also, we suggest that the proposed Koinonia WFAN system is a suitable solution for indoor and outdoor wireless network of fighters. Additionally we compare the Koinonia WFAN system with the overseas ASMT (Advanced SubMiniature Telemetry). Finally we show the communication experiment results, the system requirements, and the implementation methodology of the Koinonia MFAN.

Background The Korean College of Helicobacter and Upper Gastrointestinal Research has studied Helicobacter pylori (H. pylori) prevalence since 1998 and found a dynamic change in its prevalence in Korea. The aim of this study was to determine the recent H. pylori prevalence rate and compare it with that of previous studies according to socioeconomic variables. Methods We planned to enroll 4920 asymptomatic Korean adults from 21 centers according to the population distribution of seven geographic areas (Seoul, Gyeonggi, Gangwon, Chungcheong, Kyungsang, Cholla, and Jeju). We centrally collected serum and tested H. pylori serum IgG using a chemiluminescent enzyme immunoassay. Results We analyzed 4917 samples (4917/4920 = 99.9%) from January 2015 to December 2016. After excluding equivocal serologic results, the H. pylori seropositivity rate was 51.0% (2414/4734). We verified a decrease in H. pylori seroprevalence compared with previous studies performed in 1998, 2005, and 2011 (P

The CSMA/CA driven MAC protocols withhold packet transmissions from exposed stations when they detect carrier signal above a certain threshold. This is to avoid collisions at other receiving stations. However, this conservative scheme often exposes many stations unnecessarily, and thus minimizes the utilization of the spatial spectral resource. In this paper, we demonstrate that remote estimation of the status at the active receivers is more effective at avoiding collisions in wireless networks than the carrier sensing. We apply a new concept of the interference range, named as n-tolerant interference range, to guarantee reliable communications in the presence of n (n ≥ 0) concurrent transmissions from outside the range. We design a distributed interference preventive MAC (IP-MAC) using the n-tolerant interference range that enables parallel accesses from the noninterfering stations for an active communication. In IP-MAC, an exposed station goes through an Interference Potentiality Check (IPC) to resolve whether it is potentially interfering or noninterfering to the active communication. During the resolve operation, IPC takes the capture effect at an active receiver into account with interfering signals from a number of possible concurrent transmissions near that receiver. The performance enhancement offered by IP-MAC is studied via simulations in different environments. Results reveal that IP-MAC significantly improves network performance in terms of throughput and delay.

Multicode code-division multiple access (MC-CDMA) and variable processing gain CDMA (VPG-CDMA) are very appealing techniques for achieving high bit-rate data transmission and providing significant capacity gain in wireless channels. This letter provides the peak-to-average power ratio (PAPR) reduction scheme by using a code selective allocation (CSA) in a MC VPG-CDMA system. From simulation results, the MC VPG-CDMA system experiences a reduced PAPR thanks to the CSA algorithm and maintains an acceptable performance degradation even if encountered with nonlinear distortions introduced by a level clipper.

This letter presents a timing synchronization method of high-rate wireless personal area network (WPAN) systems encountered with a multipath fading channel. Two-stage timing synchronization using constant amplitude zero auto-correlation (CAZAC) training symbols and correlation techniques is adopted. At the same time, a simple way of setting a reliable threshold used to estimate WPAN timing is provided.

In this paper a multi-coded variable spreading gain (MC-VSG) CDMA system employing a binary transmission of MC signals by introducing a level clipper termed MC-VSG BNet system, is proposed for the candidate of wireless personal area network (WPAN) and 3G cellular applications. With an emphasis on the MC-VSG BNet physical layer we address the concise specification of the MC-VSG BNet system including the spreading code, level clipping, modulation, coding, frame format, and its applications. From the receiver performance based on simulation results, in addition to simple receiver structure, an acceptable performance degradation of the MC-VSG BNet system over the existing DS/CDMA system is observed, while guaranteeing a high bit rate transmission.

This study compared the efficacy of DA-9601 (Dong-A ST Co., Seoul, Korea) and its new formulation, DA-5204 (Dong-A ST Co.), for treating erosive gastritis. This phase III, randomized, multicenter, double-blind, non-inferiority trial randomly assigned 434 patients with endoscopically proven gastric mucosal erosions into two groups: DA-9601 3 times daily or DA-5,204 twice daily for 2 weeks. The final analysis included 421 patients (DA-5204, 209; DA-9601, 212). The primary endpoint (rate of effective gastric erosion healing) and secondary endpoints (cure rate of endoscopic erosion and gastrointestinal [GI] symptom relief) were assessed using endoscopy after the treatment. Drug-related adverse events (AEs), including GI symptoms, were also compared. At week 2, gastric healing rates with DA-5204 and DA-9601 were 42.1% (88/209) and 42.5% (90/212), respectively. The difference between the groups was −0.4% (95% confidence interval, −9.8% to 9.1%), which was above the non-inferiority margin of −14%. The cure rate of gastric erosion in both groups was 37.3%. The improvement rates of GI symptoms with DA-5204 and DA-9601 were 40.4% and 40.8%, respectively. There were no statistically significant differences between the two groups in both secondary endpoints. AEs were reported in 18 (8.4%) patients in the DA-5204 group and 19 (8.8%) in the DA-9601 group. Rates of AE were not different between the two groups. No serious AE or adverse drug reaction (ADR) occurred. These results demonstrate the non-inferiority of DA-5204 compared to DA-9601. DA-5204 is as effective as DA-9601 in the treatment of erosive gastritis. Registered randomized clinical trial at ClinicalTrials.gov (NCT02282670), Graphical Abstract

In this letter, we present a simple way of estimating the integer frequency offset of orthogonal frequency division multiplexing (OFDM) system over a rapidly time-varying channel. By utilizing the channel responses of neighboring subcarriers within one pilot symbol, the frequency offset estimator is derived. We show by simulation that the proposed estimator can accurately estimate the integer frequency offset with reduced computational burden.

One of the most important prognostic factors in esophageal carcinoma is lymph node metastasis, and in particular, the number of affected lymph nodes, which influences long-term outcomes. The esophageal lymphatic system is connected longitudinally and transversally; thus, the pattern of lymph node metastases is very complex. Early esophageal cancer frequently exhibits skipped metastasis, and minimal surgery using sentinel node navigation cannot be performed. In Korea, most esophageal cancer cases are squamous cell carcinoma (SCC), although the incidence of adenocarcinoma has started to increase recently. Most previous reports have failed to differentiate between SCC and adenocarcinoma, despite the fact that the Union for International Cancer Control (7th edition) and American Joint Committee on Cancer staging systems both consider these separately because they differ in cause, biology, lymph node metastasis, and outcome. Endoscopic tumor resection is an effective and safe treatment for lesions with no associated lymph node metastasis. Esophageal mucosal cancer confined to the lamina propria is an absolute indication for endoscopic resection, and a lesion that has invaded the muscularis mucosae can be cured by local resection if invasion to the lymphatic system has not occurred.

Background/aims Endoscopic submucosal dissection (ESD) has become accepted as a minimally invasive treatment for gastric neoplasms. However, the development of synchronous or metachronous gastric lesions after endoscopic resection has become a major problem. We investigated the characteristics of multiple gastric neoplasms in patients with early gastric cancer (EGC) or gastric adenoma after ESD. Methods In total, 512 patients with EGC or gastric adenoma who had undergone ESD between January 2008 and December 2011 participated in this study. The incidence of and factors associated with synchronous and metachronous gastric tumors were investigated in this retrospective study. Results In total, 66 patients (12.9%) had synchronous lesions, and 13 patients (2.5%) had metachronous lesions. Older (> 65 years) subjects had an increased risk of multiple gastric neoplasms (p = 0.012). About two-thirds of the multiple lesions were similar in macroscopic and histological type to the primary lesions. The median interval from the initial lesions to the diagnosis of metachronous lesions was 31 months. The annual incidence rate of metachronous lesions was approximately 3%. Conclusions We recommend careful follow-up in patients of advanced age (> 65 years) after initial ESD because multiple lesions could be detected in the remnant stomach. Annual surveillance might aid in the detection of metachronous lesions. Large-scale, multicenter, and longer prospective studies of appropriate surveillance programs are needed.

Bacterial pericarditis has been recognized as a rare disease since the development of antibiotics. Usually, the disease is associated with underlying conditions or a seeding of infection elsewhere to the pericardium. Here we describe a case of group G streptococcal pericarditis as an initial presentation of colon cancer. A 52-yr-old man was admitted because of dyspnea. An electrocardiogram showed a diffuse ST-segment elevation and a two-dimensional echocardiogram showed a large amount of pericardial effusion. A pericardiocentesis was done and purulent fluid was drained. Group G streptococci was cultured in pericardial fluid. The patient was treated with antibiotics and pericardiostomy with saline irrigation. A colonoscopy revealed a small mass with moderately differentiated adenocarcinoma in rectosigmoid colon. He underwent a mucosectomy and was recovered without any complication.

This article is concerned with a Bluetooth receiver with the channel estimation and DC-offset estimation. Each of the Bluetooth devices in the connection state knows the access codes used in the ad-hoc networks, which is utilized as a reference signal for the parameter estimation. The proposed estimators can be implemented without degradation of frame and spectral efficiency thanks to using the access code specified for the Bluetooth system.

This research analyzed design considerations for the mechanical harvesting of Bokbunja (Rubus coreanus Miquel) berries and manufactured a prototype mechanical Bokbunja harvester to selectively harvest mature berries. The most critical design factors for mechanical harvesting are the shape of the bushes, the cane training methods, and the selective harvesting of mature berries. The height of the bushes is around 120 – 150 cm from the ground and the width is approximately 120 cm. The canes are 150 cm long and typically entangle each other despite being trained. Mature Bokbunja berries are picked by hands five to six times each harvesting season. The berries are very soft with thin skin.

In this study, we propose a new routing and scheduling algorithm for a relay network of Koinonia V2.0 in which each station transmits either multimedia data or multimedia streaming. Different from previous related works, all stations are used by altruistic users who don’t want to cooperate with each other. With the proposed algorithm, master stations compute paths for each single slave station and allocate divisible wireless resources to each slave station. The system with the proposed scheme reaches Nash Equilibrium Points (NEPs) per every single superframe. Simulation results show that the proposed scheme provides all slave stations with the best path which efficiently balances the capacities of relay users in the two hops.

As wireless network cannot dispense with a proper security measure due to its inborn vulnerability, a new security measure has been developed with an advent of new wireless network technology. Each security measure properly serves the security needs of its associated wireless network as it was intended to. Quality of Protection (QoP) estimates the stability of individual network system by quantifying security intensity. So, it can work as an evaluation standard for the security of network. This paper considers Historical Vulnerability Measure (HVM) and relative weight in total reward function for the improved QoP model. HVM is objectively organized by Flow-based Abnormal Traffic Detection Algorithm for utility function.

An ad hoc network is multi-hop wireless formed by mobile node with no infrastructure. Due to the mobility of nodes in mobile ad hoc networks, the topology of network changes frequently. In this environments, multicast protocols are faced with the challenge of producing multi-hop routes and limitation of bandwidth. We compare the performance of two multicast routing protocols for mobile ad hoc networks - serial multiple disjoint tree multicast routing protocol (serial MDTMR) and adapted core multicast routing protocol (ACMRP). The simulator is implemented with GloMoSim.

We present the design and simulation of an adaptive MAC protocol based on the path-diversity routing information for ad hoc networks. As a routing protocol, a multipath routing protocol based on SPAFAR is used, where a route discovery algorithm finds multiple paths significantly reduce the delay in finding an alternate path. The information about multiple paths discovered in the network layer is exploited by the MAC layer in order to forward a frame over the best hop out of multiple hop choices. The performance of our approach is compared with IEEE 802.11 MAC through the simulation. The results show that our scheme exhibits a significantly better performance rather than the IEEE 802.11 MAC protocol in terms of packet overhead and end-to-end throughput.

In mobile ad hoc networks, the large amount of control overheads associated with discovering and maintaining end-to-end routing path information may not be tolerable. In this paper, we present the design and simulation of a new approach for IEEE 802.11 MAC based on the multipath routing information for ad hoc networks. The routing information about multiple paths discovered in the network layer is exploited by the MAC layer in order to forward a frame over the best hop out of multiple hop choices. The performance of our approach is compared with the one of the IEEE 802.11 MAC protocol via simulation. The results show that our proposed scheme exhibits a remarkable performance improvement over the IEEE 802.11 MAC protocol in terms of packet overhead and end-to-end throughput.

Cholangitis and cholecystitis are intra-abdominal infections that show poor prognosis upon progression to sepsis and multiorgan failure. Administration of antibiotics with high antimicrobial susceptibility and removal of infected bile at the initial treatment are important. After undergoing ERCP for diagnostic purposes, a 58-year-old man developed acute cholangitis and cholecystitis accompanied by rhabdomyolysis, multi-organ failure, and severe sepsis. Broad-spectrum antibiotics with bedside endoscopic nasobiliary drainage were administered, but clinical symptoms did not improve. Therefore, bedside EUS-guided transgastric gallbladder aspiration and lavage was performed, resulting in successful treatment of the patient. We report the above described case along with a discussion of relevant literature.

Endosonography (EUS) enables the acquisition of clear images of the gastrointestinal tract wall and the surrounding structures. EUS enables much greater accuracy for staging decisions compared to computed tomography. Surgery for esophageal cancer has a high rate of morbidity and mortality, and it is important to decide on an appropriate treatment method through pre-surgical evaluation. Minimal invasive surgery is widely used for the treatment of gastrointestinal cancer, and endoscopic submucosal dissection is a safe treatment method for early cancer of the gastrointestinal tract that does not result in lymph node metastasis. EUS is essential for pre-surgical evaluation for all esophageal cancers. The use of EUS can effectively reduce unnecessary surgeries and thereby allow for appropriate treatment planning for patients. A number of different diagnostic modalities are available, but EUS is still the mainstay for pre-surgical evaluation of esophageal cancer. The role of EUS for early stomach cancer treatment as a tool for determining the need for endoscopic resection and for pre-surgical assessment is increasing.

High data-rate wireless personal area networks such as WiMedia are ideal for enabling wireless connectivity and real-time streaming among numerous multimedia applications. However, wireless channels have higher error rates and burstier error patterns than wireline links. In this paper, we propose forward error correction protocol which includes a novel code selection scheme, and addresses two important issues in the transmission of real-time traffic on wireless channels: (1) Adaptability to channel conditions, through prompt reactions to channel variations; and (2) QoS provision, especially throughput and packet error rate. Then, we evaluate the performance of the proposed AFEC. Performance evaluation shows that the proposed technique guarantees the target PER.

IEEE 802.15.3 high-rate Wireless Personal Area Networks (WPANs) is a short range communication technology, in which devices (DEVs) of a piconet communicate with a Piconet Coordinator (PNC). An extension of the communication area in WPAN via formation of a multi-piconet is one of the most challenging issues. Although a concept of multi-piconet has been defined in the IEEE 802.15.3 WPAN standard, a detailed formation mechanism of multi-piconet is not presented. In this paper, we propose efficient multi-piconet formation algorithms, Piconet Coordinator To Device (PCTD) and Device To Piconet Coordinator (DTPC). We evaluate the performance of the algorithms via simulations. The proposed algorithms are shown to extend the communication area with one to three levels and to provide sufficient Channel Time Allocations (CTAs) for subsidiary piconets in IEEE 802.15.3 WPAN.

The IEEE 802.15.3 standard does not specify how to schedule CTA (Channel Time Allocation)s in CTAP (Channel Time Allocation Period) of a superframe. In this paper, we propose a novel scheduling algorithm for channel time allocation of 802.15.3-based HR-WPAN (High Rate Wireless Personal Area Networks), named WFCTA (Weighted Fair Channel Time Allocation). The proposed WFCTA inherently has properties which are necessary for various QoS provisioning, because it is based on TDMA, applied by WFQ algorithm. We explain and compare four implementation cases of WFCTA. We also analyze its worst-case performance in terms of both link utilization and fairness and verify it by simulation.