• Fire Science and Engineering
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• v.33 no.2
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• pp.114-123
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• 2019

The paper relates to a study on the changes in performance of insulation sheath resulting from accelerated degradation of IV and HIV insulated wire. To assume insulation degradation of IV and HIV insulated wire, accelerated life tests using Arrhenius equation were conducted among accelerated life test models, and experimental samples of 0 year, 10 years, 20 years, 30 years, and 40 years in equivalent life were produced. Whereas the maximum tensile load were increased as accelerated degradation of IV and HIV insulated wire progressed, elongation percentage, rupture time, and flexibility of insulated wires were found to be gradually reduced. According to the additional surface analysis results for the insulated wires per equivalent life using a scanning electron microscope, mechanical properties of the insulator were observed to be reduced as insulation degradation resulting from aging progressed since phenomena such as formation of crystalline structures and perforation, etc. occurred on the sample surface with progression of accelerated degradation. Consequently, institutional replacement of insulated wires and preparation of repair times considering performance degradation of the insulator installed inside buildings are considered necessary in order to prevent in advance the risks of electrical fire resulting from degradation in insulation performance.

• Journal of Conservation Science
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• v.35 no.2
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• pp.177-186
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• 2019

A Termiticide that is applied to the soil treatment method, one of the methods for preventing termites in Korea's wooden cultural properties, will be subjected to the leaching of the effective ingredient in treated soil by the moisture behavior of rain. As a result, termiticide is deteriorated and needs to be reprocessed, but the standards and evaluation methods are nonexistent in korea. Accordingly, a basic indoor evaluation measure was proposed for the evaluation of the effectiveness of the termiticide chamber and the calculation of the reprocessing period. First, avoidance and contact toxicity were assessed at two concentrations of the same termiticide as a method for assessing termiticide suitability. The evaluation of mortality revealed that the soil termiticide used in this experiment was non-repellent, and that death from contact was confirmed. Afterwards, artificial rainfall and soil penetration tests were conducted to determine efficacy of termiticide in soil and the approximate reprocessing period was calculated by comparing the weather data. Persistence evaluation revealed perforation by termites after continuous water exposure of more than about 160 to 170mm of water injection condition. Based on the results, compared with weather data for the last five years, the termiticide of concentration used in this experiment is expected to remain effective for about one year if treated after September. The purpose of this study was to provide basic data for the establishment of a manual for the selection of termiticide for soil treatment by calculating the efficacy for termite mortality and the duration of the leaching effectiveness by water behavior in soil.

• Journal of Conservation Science
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• v.35 no.3
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• pp.227-235
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• 2019

In Korea, various methods are applied to prevent wooden structures from being damaged by termites. However, since there is no way to quickly bring toxic substances in contact with the termites inside the timber, it leads to the damage of wooden cultural property due to the prolonged period of controlling the termites. Accordingly, an indoor evaluation criteria study was conducted for the introduction of powder-type termiticides in Korea, which produced rapid control effects by drilling wood and directly contacting and transferring toxic substances inside the timber. First, contact toxicity and transfer ability of termite dusts were evaluated to establish the criteria for evaluation of effectiveness against Reticulitermes speratus. The contact toxicity confirmed 100% mortality of fipronil, deltamethrin and cyfluthrin termite dusts within 24 h of contact; however, differences occurred in the active ingredient transfer time to the sublethal. In addition, in the case of transfer ability evaluation, the rate of mortality gradually decreased under 1:9 and 1:25 ratio conditions; however, the difference in the reduction rate was identified depending on the type of termite dust. the results of the evaluation of compressive strength of the wood showed that the difference in the measured values between the control group and the conditions of perforation 1 to 3 times, which does not significantly affect the compressive strength of wood. In this study, the criteria of termite dust selection and evaluation method of dust-type termiticides were presented and the applicability of the method was identified.

• Clean Technology
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• v.15 no.4
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• pp.265-272
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• 2009

In this study the experiments on the static adsorption of benzene were carried out using activated carbon made from sewage sludge. The experiment was performed at 303.15 K, 318.15 K and 333.15 K under the pressure up to 7.999kPa. Isothermal adsorption curves were obtained using Langmuir isotherm, Freundlich isotherm and Toth isotherm for comparison. Based on fitting the adsorption quantity of Benzene (q), the isothermal adsorption curves obtained from Langmuir isotherm and Toth isotherm showed the higher accuracy. Although there was little difference in accuracy between result from Langmuir isotherm and that from Toth isotherm, the adsorption quantity of Benzene (q) was expressed in terms of Langmuir isotherm because less parameters were required for Langmuir isotherm than for Toth isotherm. Moreover SEM images of the activated carbon from sewage sludge and the commercial activated carbon were taken to observe the pore size development. The results showed that the perforation development of the commercial activated carbon (DARCO A.C., SPG-100 A.C.) was better than that of activated carbon from sewage sludge. Adsorption quantity of benzene on commercial activated carbon was confirmed to be higher than that on activated carbon from sewage sludge. However the maximum adsorption quantity of benzene on activated carbon from sewage sludge was close to that on SGP-100 A.C. at 303.15K. Therefore, we may conclude that it is feasible to commercialize the process to manufacturing activated carbon from sewage sludge.

• Journal of Digestive Cancer Research
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• v.3 no.2
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• pp.82-88
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• 2015

Gastric lymphoma comprises 1-6% of all gastric malignant neoplasms and among them 50% is gastric MALT lymphoma. The 60-70% of MALT lymphomas is diagnosed at early, localized diseased state. Gastric MALT lymphoma is assumed that it progress slowly with indolent course. It presents nonspecific symptoms such as epigastric pain, dyspepsia, nausea and vomiting. It is rarely associated with serious complication such as gastrointestinal bleeding or perforation. The definite diagnosis of gastric MALT lymphoma should be made with histopathologically. Wotherspoon score is used to differential diagnosis with Helicobacter pylori associated gastric inflammatory change. Gastric MALT lymphoma is associated with Helicobacter pylori infection with supported by epidemiologic and histopathologic studies. Gastric MALT lymphoma is characterized with genetic aberrations such as trisomy 3, trisomy 18, chromosomal translocations t(11;18), t(1;14), t(14;18), t(3;14). Appropriate clinical staging is essential to determine the optimal treatment strategy for gastric MALT lymphoma. Lugano International Conference classification has been applied widely. Helicobacter pylori eradication is used as the first line treatment for gastric MALT lymphoma independent of the stage. The complete remission has been achieved in 60-90% of the stage I/II1 patients with Helicobacter pylori eradication only. The treatment options for the patients with refractory to eradication are radiotherapy, chemotherapy and/or immunotherapy with the complete remission rate of 75% to 100%. The incidence of gastric MALT lymphoma can be expected to down by virtue of the decrease of Helicobacter pylori infection rate. Further basic and clinical research is necessary to advance in determine the pathogenesis and management.

• Journal of the Korean Society of Radiology
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• v.85 no.3
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• pp.661-667
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• 2024

Afferent loop syndrome (ALS) is a rare complication of gastrectomies and gastrointestinal reconstruction. This can predispose patients to fatal conditions, such as cholangitis, pancreatitis, and duodenal perforation with peritonitis. Therefore, emergency decompression is necessary to prevent these complications. Herein, we report two cases in which transcholecystic duodenal drainage, an alternative decompression treatment, was performed in ALS patients without bile duct dilatation. Two patients who underwent distal gastrectomy with Billroth II anastomosis sought consultation in an emergency department for epigastric pain and vomiting. On CT, ALS with acute pancreatitis was diagnosed. However, biliary access could not be achieved because of the absence of bile duct dilatation. To overcome this problem, a duodenal drainage catheter was placed to decompress the afferent loop after traversing the cystic duct via a transcholecystic approach. The patients were discharged without additional surgical treatment 2 weeks and 1 month after drainage.

• Journal of the Korean Society of Radiology
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• v.84 no.3
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• pp.653-662
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• 2023

Purpose This study aimed to determine the incremental value of using a structured report (SR) for US examinations of the pediatric appendix. Materials and Methods Between January 2009 and June 2016, 1150 pediatric patients with suspected appendicitis who underwent US examinations of the appendix were included retrospectively. In November 2012, we developed a five-point scale SR for appendix US examinations. The patients were divided into two groups according to the form of the US report: free-text or SR. The primary clinical outcomes were compared between the two groups, including the rate of CT imaging following US examinations, the negative appendectomy rate (NAR), and the appendiceal perforation rate (PR). Results In total, 550 patients were included in the free-text group and 600 patients in the SR group. The rate of additional CT examinations decreased by 5.3% in the SR group (8.2%, p = 0.003), and the NAR decreased by 8.4% in the SR group (7.8%, p = 0.028). There was no statistical difference in the appendiceal PR (37.6% vs. 48.0%, p = 0.078). Conclusion The use of an SR to evaluate US examinations for suspected pediatric appendicitis results in lower CT use and fewer negative appendectomies without an increase in appendiceal PR.

• Clinical Endoscopy
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• v.55 no.5
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• pp.655-664
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• 2022

Background/Aims: Endoscopic submucosal dissection (ESD) for residual or recurrent colorectal lesions after incomplete resection is challenging because of severe fibrosis. This study aimed to compare the efficacy of the pocket-creation method (PCM) with a traction device (TD) with that of conventional ESD for residual or recurrent colorectal lesions. Methods: We retrospectively studied 72 patients with residual or recurrent colorectal lesions resected using ESD. Overall, 31 and 41 lesions were resected using PCM with TD and conventional ESD methods, respectively. We compared patient background and treatment outcomes between the PCM with TD and conventional ESD groups, respectively. The primary endpoints were en bloc resection and R0 resection rates. The secondary endpoints were the dissection speed and incidence of adverse events. Results: En bloc resection was feasible in all cases with PCM with TD, but failed in 22% of cases of conventional ESD. The R0 resection rates for PCM with TD and conventional ESD were 97% and 66%, respectively. Dissection was significantly faster in the PCM with TD group (13.0 vs. 7.9 mm²/min). Perforation and postoperative bleeding were observed in one patient in each group. Conclusions: PCM with TD is an effective method for treating residual or recurrent colorectal lesions after incomplete resection.

• Clinical Endoscopy
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• v.55 no.6
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• pp.801-809
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• 2022

Background/Aims: Current society guidelines recommend antibiotic prophylaxis for 3 to 5 days after endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of pancreatic cystic lesions (PCLs). The overall quality of the evidence supporting this recommendation is low. In this study, we aimed to assess cyst infection and adverse event rates after EUS-FNA of PCLs among patients treated with or without postprocedural prophylactic antibiotics. Methods: We retrospectively reviewed all patients who underwent EUS-FNA of PCLs between 2015 and 2019 at two large-volume academic medical centers with different practice patterns of postprocedural antibiotic prophylaxis. Data on patient demographics, cyst characteristics, fine-needle aspiration technique, periprocedural and postprocedural antibiotic prophylaxis, and adverse events were retrospectively extracted. Results: A total of 470 EUS-FNA procedures were performed by experienced endosonographers for the evaluation of PCLs in 448 patients, 58.7% of whom were women. The mean age was 66.3±12.8 years. The mean cyst size was 25.7±16.9 mm. Postprocedural antibiotics were administered in 274 cases (POSTAB+ group, 58.3%) but not in 196 cases (POSTAB- group, 41.7%). None of the patients in either group developed systemic or localized infection within the 30-day follow-up period. Procedure-related adverse events included mild abdominal pain (8 patients), intra-abdominal hematoma (1 patient), mild pancreatitis (1 patient), and perforation (1 patient). One additional case of pancreatitis was recorded; however, the patient also underwent endoscopic retrograde cholangiopancreatography. Conclusions: The incidence of infection after EUS-FNA of PCLs is negligible. Routine use of postprocedural antibiotics does not add a significant benefit.

• Clinical and Experimental Pediatrics
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• v.52 no.4
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• pp.446-452
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• 2009

Purpose : This study was performed to demonstrate the usefulness of early endoscopy for predicting the development of stricture following corrosive ingestion in children. Methods : We conducted a retrospective study on 34 children who were brought to Seoul National University Childrens Hospital and Seoul National University Bundang Hospital for corrosive ingestion from 1989 to 2007. Results : The corrosive burns were classified as grade 0 in 8 patients, grade 1 in 2, grade 2a in 7, grade 2b in 13, and grade 3 in 4. There was no significant correlation between the presence of esophageal injury and symptoms including vomiting, dysphagia, and drooling. There was a statistically significant relation between the presence of oropharyngeal injury and esophageal injury (P=0.014). There were no complications including hemorrhage and perforation related to endoscopy. Strictures of the esophagus or the stomach developed in 12 patients (36.4%). Esophageal stricture was observed in 11 patients and pyloric stenosis in 1 patient. The endoscopic grade of mucosal injury was significantly related to the frequency of development of esophageal stricture (P=0.002). Two of eleven patients with esophageal stricture responded to repeated dilation. The remaining seven patients underwent surgery. Conclusion : Early esophagogastroduodenoscopy is not only a safe and useful diagnostic tool for children with accidental caustic ingestion but also a necessity for determining the degree and the extent of caustic burns and for predicting the development of late complications.