• Molecules and Cells
• /
• 제43권12호
• /
• pp.989-1001
• /
• 2020

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a facultative intracellular pathogen that causes salmonellosis and mortality worldwide. S. Typhimurium infects macrophages and survives within phagosomes by avoiding the phagosome-lysosome fusion system. Phagosomes sequentially acquire different Rab GTPases during maturation and eventually fuse with acidic lysosomes. Lysophosphatidylcholine (LPC) is a bioactive lipid that is associated with the generation of chemoattractants and reactive oxygen species (ROS). In our previous study, LPC controlled the intracellular growth of Mycobacterium tuberculosis by promoting phagosome maturation. In this study, to verify whether LPC enhances phagosome maturation and regulates the intracellular growth of S. Typhimurium, macrophages were infected with S. Typhimurium. LPC decreased the intracellular bacterial burden, but it did not induce cytotoxicity in S. Typhimurium-infected cells. In addition, combined administration of LPC and antibiotic significantly reduced the bacterial burden in the spleen and the liver. The ratios of the colocalization of intracellular S. Typhimurium with phagosome maturation markers, such as early endosome antigen 1 (EEA1) and lysosome-associated membrane protein 1 (LAMP-1), were significantly increased in LPC-treated cells. The expression level of cleaved cathepsin D was rapidly increased in LPC-treated cells during S. Typhimurium infection. Treatment with LPC enhanced ROS production, but it did not affect nitric oxide production in S. Typhimurium-infected cells. LPC also rapidly triggered the phosphorylation of IκBα during S. Typhimurium infection. These results suggest that LPC can improve phagosome maturation via ROS-induced activation of NF-κB pathway and thus may be developed as a therapeutic agent to control S. Typhimurium growth.

• 한국기후변화학회지
• /
• 제10권3호
• /
• pp.237-242
• /
• 2019

Ammonia is main precursor gas of secondary particulate matter and contributes almost 78% of total ammonia emission from the agricultural sector in Korea. The current method of estimating ammonia emission from fertilizer application, which contributes 7% of the total emission, has high uncertainty and needs to be improved to better predict PM2.5 concentration. In this study, we suggest an improvement method for ammonia emission quantification from fertilizer application. The first improvement was in the emission factor of NPK fertilizer by conducting a field study to verify the currently used factor. The improved NPK emission factor of 52.2 kg NH ton-1N was confirmed by comparing with the value from the EEA (European Environment Agency) and adjusting the value for the Korean climate and soil conditions. We also improved the amount of fertilizer usage by including the sales amount to the fertilizer supply amount of the Korean Farmers Association, increasing total fertilizer usage by 39.8%. As the statistical data on fertilizer supply and sales are compiled yearly, we estimated monthly emission of ammonia by considering cultivated areas and timing of fertilization for each crop. In summary, we suggest a novel and practical method to improve estimation methodology of ammonia emission from the field of fertilizer application: 1) emission factor of NPK fertilizer was reconfirmed; 2) total amount of fertilizer use was revised considering fertilizer sales; and 3) monthly emission of ammonia was realized by considering different crop practices. A bottom-up approach to compile activity data is needed to increase the estimation accuracy of monthly emission of ammonia, which is very helpful for predicting PM2.5 concentration.

• 한국환경농학회지
• /
• 제42권4호
• /
• pp.444-449
• /
• 2023

The current study involved the calculation of air pollutant emission factors (EFs) generated from the incineration of agricultural residues. The process included sample collection, weight measurement, moisture measurement, incineration system configuration, and concentration measurement. The average CO emission factor of gaseous air pollutants from the incineration of barley and wheat agricultural residues was calculated as 0.08289 kg/kg and 0.06665 kg/kg, respectively, whereas the average NO_X emission factor for barley and wheat agricultural residues was determined to be 0.00518 kg/kg and 0.00185 kg/kg, respectively. In the existing air pollutant emission calculation manual, the EF is presented only for barley. Therefore, in this study, we have introduced the EF for wheat, previously absent in the calculation manual. Additionally, the air pollutant calculation manual presents the EF of air pollutants as one value, but in this study, EF values corresponding to 2.5% and 97.5% were presented in consideration of the distribution of experimental values as shown in EMEP/EEA data.

• Journal of Gastric Cancer
• /
• 제5권4호
• /
• pp.246-251
• /
• 2005

목적: 위악성 종양으로 위전절제술 및 식도공장문합술을 시행 받은 환자에서 발생할 수 있는 문합부 양성협착의 빈도와, 위험인자 및 이에 대한 치료에 대해 알아보고자 하였다. 대상 및 방법: 1998년 3월부터 2001년 2월까지 근치적 위전절제술 후 자동문합기를 사용하여 루앙와이 식도공장 문합술을 시행 받은 658명에서 추적관찰 기간 중 내시경 검사를 시행한 436명을 대상으로 후향적으로 분석하였다. 협착은 직경 9mm 내시경의 통과여부로 정의하였다. 결과: 남자는 292명, 여자는 144명이었고, 평균(mean) 나이는 53.7세$(23{\sim}81)$세였다. 436명 중 33명에서 문합부 협착이 진단되었으며 이 중 재발에 의해 협착이 발생한 9명을 제외한 24명을 대상으로 분석하였다. 성별, 나이, 자동문합기의 직경, 항암화학요법, 방사선치료, 역류성 식도염 여부, 당뇨 및 고혈압 등의 위험인자들과 양성협착 사이에 통계학적으로 의미 있는 결과를 보이지 않았다. 문합부 양성협착이 발견된 모든 환자에서 풍선확장술을 시행하였으며, 시행 후 모든 환자에서 증상의 호전을 보였다. 결론: 위험인자들과 문합부 양성협착의 발생빈도 사이의 관계를 조사한 결과 통계학적으로 의미 있는 인자는 없었으나 문합부 혈류와 관계된 인자들에 대해 추가적인 조사가 필요할 것으로 생각된다. 증상의 호전을 위하여 내시경 풍선 확장 시술을 시행하고 1회의 시술로 증상의 호전을 보이지 않는 경우가 있어 지속적인 내시경 추적검사가 요구된다.

• Journal of Nutrition and Health
• /
• 제48권4호
• /
• pp.371-379
• /
• 2015

본 연구는 우리나라 노인세대가 겪는 사회환경요인이 에너지 섭취 부족에 어떠한 영향을 주는지 알아보고자 제5기 1차년도 (2010) 국민건강영양조사 자료를 바탕으로 분석을 실시하였으며, 결과를 요약하면 다음과 같다. 1) 남녀 모두 연령이 70세 이상이고, 경제활동을 하지 않는 경우, 활동제한이 있는 경우 에너지 섭취 부족 비율이 높은 것으로 나타났다. 그 밖에 남자는 배우자는 없이 가족과 동거하는 경우, 학력, 그리고 가구소득, 여자는 자살생각 여부가 에너지 섭취량에 영향을 주는 것으로 분석되었다. 2) 에너지 필요 추정량의 75% 미만으로 섭취하는 노인의 비율은 남자는 23.7% (196명), 여자는 31.1% (324명)으로 나타났으며 에너지 섭취량이 75% 미만인 그룹의 경우 탄수화물 섭취 비율이 유의적으로 높은 것으로 분석되었다. 3) 에너지 섭취가 부족한 그룹의 경우 남녀 모두 돼지고기와 소고기가 10위 안에 포함되지 않았고 배추김치와 된장이 20위 안의 주요 급원식품에 들었다. 4) 최종적으로 남녀 모두 학력 (남자: OR = 1.480, 여자: OR = 1.614)과 경제활동 여부 (남자: OR = 1.751, 여자: OR = 1.464)가 에너지 섭취 부족에 영향을 주는 요인으로 분석되었으며, 이 외에도 남자는 70세 이상의 고령 (OR = 1.475), 여자는 배우자 없이 가족과 동거하는 경우 에너지 섭취 부족일 확률이 1.496배로 나타났다. 이상의 연구 결과 노인의 에너지 섭취량은 노화로 인한 신체적 생리적 변화 외에도 노인이 속한 사회환경, 사회구조적 변화에 민감하게 반응한다는 것을 확인할 수 있었다. 효과적인 노년기 영양관련 정책 수립을 위해서는 사회환경의 변화에 따른 영양취약계층을 선별하는 것이 무엇보다 중요하므로, 본 연구에서 확인한 노인의 에너지 섭취 부족과 관련된 요인들은 노년기 영양정책을 계획하는 데 있어 기초자료로 활용될 수 있을 것으로 사료된다.

• 한국대기환경학회지
• /
• 제25권3호
• /
• pp.188-195
• /
• 2009

Generally. mobile sources of air pollution were classified in on-road and non-road. Due to increased registration number of construction equipment in Korea. updated emission factors for non-road mobile sources, such as construction machinery. should be developed. NONROAD model of U.S. EPA already has introduced transient adjustment factors and sulfur adjustment factors for emission factors of diesel powered engine. In addition to this. European Environment Agency (EEA) has proposed emission factors for off-road machinery including several types of construction equipment. In this study. six types of construction equipment, such as excavator. forklift, loader, crane, roller and bulldozer, were studied to estimate emission factors based on total registration status in Korea. Total 445 construction equipments between 2004 and 2007 model year were tested with KC1-8 mode and air pollutants (CO, THC, $NO_x$, and PM) were measured. After statistical estimation and calculation, emission factors for CO, THC, $NO_x$, and PM for excavator, forklift, loader, crane, roller and bulldozer were provided and compared with previous emission factors. Moreover, updated emission factors for six types of construction equipment in this study were verified after comparison with emission factors of U.S. EPA. Finally, estimated emission amounts of four air pollutants were suggested according to six types of construction equipment.

• Journal of Chest Surgery
• /
• 제34권11호
• /
• pp.843-847
• /
• 2001

배경: 식도질환의 수술 후 식도재건술은 아직도 식도수술에 관여하는 외과의사에게 해결해야 될 부분이 많이 있다. 1996년 1월부터 1999년 12월가지 흉부식도암환자 27명에서 흉부식도절제술 후 15예의 식도-위 문합술과 12예의 유리총장 이식술을 시행하였다. 저자들은 식도암 수술 후 문합부 누출, 문합부위의 협착, 역류성식도염, 수술시간, 호흡기 합병증 등을 양 군을 나누어 비교하였다. 대상 및 방법: 고식적 우회술 또는 식도인공삽입술, 인두식도와 식도 위 결합부위의 암은 본 연구에서 제외하였다. 우측 개흉술로 식도를 절제하였고, 자동봉합기를 사용하여 식도-위 문합을 시행하였다. 유리공장이식술의 경우 근위부의 식도는 6예에서 자동봉합기를 사용하였으며, 6예의 근위부와 12예의 원위부는 수기통합하였다. 모든 식도 재건술은 후종격동을 경유하였다. 결과: 3예의 수술사망을 포함하여 3예의 문합부 누출, 2예의 이식공장괴사 등 중한 합병증과 11예의 역류성 식도염, 5예의 문합부 협착이 발생되었다. 식도-위 문합술의 평균 수술시간은 300$\pm$160분, 유리공장이식술은 550$\pm$280분이었다. 결론: 역류성 식도염은 식도-위 문합군에서 더 많았고, 수술시간은 유리공장이식군에서 더 길었다(p<0.05). 적절한 환자의 선택과 장시간의 수술에 따르는 술 후 합병증을 줄일 수 있다면, 식도재건수술후의 역류식도염을 감소시키는 수술로 유리공장이식술이 우수하다고 판단된다.

• 한국대기환경학회지
• /
• 제28권2호
• /
• pp.211-221
• /
• 2012

The Ministry of Environment will enforce air quality standards for $PM_{2.5}$ in 2015 because it affects human health as well as climate change and brings about other adverse effects. Until recently, even though a number of researches have reported $PM_{2.5}$ emissions according to sources, they have not precisely considered the emission factors correspondent to each source for emission estimation. For the sake of establishing $PM_{2.5}$ emission inventories, this study was undertaken using activity data of each source taken from CAPSS (Clean Air Policy Support System) multiplied by each emission factor of U.S. EPA Speciate or EEA CORINAIR. The 2008's total annual $PM_{2.5}$ emission (73.971 ton/yr) can be apportioned into five sources, such as fuel combustion facilities (62.2%), mobiles (33.8%), production processes (3.2%), fires (0.4%), and waste treatments (0.3%). The results show that fuel combustion facilities and mobiles are the predominant sources of $PM_{2.5}$, and they should be taken into great account in establishing $PM_{2.5}$ standards. In addition, it is necessary and urgent to develop effective measures for reduction of $PM_{2.5}$ emissions from those two main sources as well.

• Journal of Chest Surgery
• /
• 제32권10호
• /
• pp.924-929
• /
• 1999

Background: The use of the stapler n esophageal reconstruction after esophageal resection for benign or malignant esophageal diseases has become popular because it has less leakage at the anastomotic site and shorter operation time than manual sutures. However, the use of classic circular stapler has some complications such as stenosis and dysphagia that requires additional treatment. Such complications are closely related to the inner diameter of the anastomotic sites. In this study, the diameter of anastomotic site was compared after the use of circular stapler(EEA) and straight endoscopic stapler(endo GIA). Material and Method: The patients who received esophageal reconstruction by stapler from August 1995 to September 1997 were reviewed. The patients were divided into 2 groups. One group need the circular stapler, and the other group the straight endo GIA(14 cases with endo GIA 30mm, 24 with endo GIA 45mm). After a cervical esophago-enteric anastomosis, the stricture of anastomotic site and the incidence of dysphagia were compared between the 2 groups using an esophagography and the patient's symptoms. The follow-up period was 12months in average. Result: In the former group in which the circular stapler was used, 2 cases of anastomotic stenosis were reported. In comparison, none were reported in the latter group. Dysphagia were reported in 8 cases of the former group, and in 3 cases of the latter group(1 case in endo GIA 30 mm, 2 cases in endo GIA 45 mm). Conclusion: The use of endo GIA in esophago-enteric anastomosis resulted in a wider diameter of the anastomotic site, lesser stricture, and lesser incidence of dysphagia compared to the use of former circular stapler. Therefore, it is thought to be a better method in esophageal reconstructions.

• 대한인간공학회지
• /
• 제32권3호
• /
• pp.279-291
• /
• 2013

Objective: The aim of this study was to compare old standard EN 954-1 and new standard EN ISO 13849-1 through case study and provide necessity of adaptation of EN ISO 13849-1 in Korea. Background: International and EU harmonized standard EN ISO 13849 "safety of machinery - Safety-related parts of control system" is classified into Part 1: General principles for design and Part 2: Validation. EN ISO 13849-1 standard was introduced in Official Journal of the European Union on September 8, 2009 as harmonized standard, and old standard EN 954-1 was withdrawn on December 31, 2011. So, EU decided to use of EN ISO 13849-1 standard forcibly from January 1, 2012 for safety of machinery. New machines need to be CE marked if they are to be placed on the market in the European Economic Area(EEA), Switzerland or Turkey, and Korean machine builder should apply EN ISO 3849-1 standard for safety of machinery accordingly. However, current Korean Safety Certification system(KCs mark) for dangerous machinery is not referred to EN ISO 13849-1 standard as safety standard. There is a need of research for adaptation of EN ISO 13849-1 standard in Korea as safety standards for new design of safety-related control system which use mostly electronic components. Method: Five case studies of representative designs for safety-related control system in accordance with EN 954-1were selected according to safety category from B to 4. And these five representative designs were tried to change new design in accordance with EN ISO 13849-1 standard. The results of comparison were analyzed in aspect of economy and technical complexity. Results: The results showed that EN ISO 13849-1 provided quantitative method of application and it enabled designers to create safety-related control systems that require fewer components and less wiring, with many of the components being to a lower specification and, therefore, less costly. Conclusion: EN ISO 13849-1 standard is good for electronic safety-related control systems compare to EN 954-1. By considering the importance of application of EN ISO 13849-1 and benefits, the application of EN ISO 13849-1 as safety standard for safety of machinery is urgent in Korea. Application: The results of comparing EN 954-1 and EN ISO 13849-1 standard might help to determine the adaptation of EN ISO 13849-1 standard for safety of industrial machinery in Korea.