• 대한금속재료학회지
• /
• 제49권8호
• /
• pp.628-634
• /
• 2011

SA508 Gr.4N Ni-Cr-Mo low alloy steel, in which Ni and Cr contents are higher than in commercial SA508 Gr.3 Mn-Mo-Ni low alloy steels, may be a candidate reactor pressure vessel (RPV) material with higher strength and toughness from its tempered martensitic microstructure. The inner surface of the RPV is weld-cladded with stainless steels to prevent corrosion. The goal of this study is to evaluate the microstructural properties of the clad interface between Ni-Cr-Mo low alloy steel and stainless weldment, and the effects of post weld heat treatment (PWHT) on the properties. The properties of the clad interface were compared with those of commercial Mn-Mo-Ni low alloy steel. Multi-layer welding of model alloys with ER308L and ER309L stainless steel by the SAW method was performed, and then PWHT was conducted at $610^{\circ}C$ for 30 h. The microstructural changes of the clad interface were analyzed using OM, SEM and TEM, and micro-Vickers hardness tests were performed. Before PWHT, the heat affected zone (HAZ) showed higher hardness than base and weld metals due to formation of martensite after welding in both steels. In addition, the hardness of the HAZ in Ni-Cr-Mo low alloy steel was higher than that in Mn-Mo-Ni low alloy steel due to a comparatively high martensite fraction. The hardness of the HAZ decreased after PWHT in both steels, but the dark region was formed near the fusion line in which the hardness was locally high. In the case of Mn-Mo-Ni low alloy steel, formation of fine Cr-carbides in the weld region near the fusion line by diffusion of C from the base metal resulted in locally high hardness in the dark region. However, the precipitates of the region in the Ni-Cr-Mo low alloy steel were similar to that in the base metal, and the hardness in the region was not greatly different from that in the base metal.

• Journal of Ginseng Research
• /
• 제45권1호
• /
• pp.126-133
• /
• 2021

Background: 20(S)-protopanaxadiol (20(S)-PPD), one of the aglycone derivatives of major ginsenosides, has been shown to have an anticancer activity toward a variety of cancers. This study was initiated with an attempt to evaluate its anti-cancer activity toward human endometrial cancer by cell and xenograft mouse models. Methods: Human endometrial cancer (HEC)-1A cells were incubated with different 20(S)-PPD concentrations. 20(S)-PPD cytotoxicity was evaluated using MTT assay. Apoptosis was detected using the annexin V binding assay and cell cycle analysis. Cleaved poly (ADP-ribose) polymerase (PARP) and activated caspase-9 were assessed using western blotting. HEC-1A cell tumor xenografts in athymic mice were generated by inoculating HEC-1A cells into the flank of BALB/c female mice and explored to validate 20(S)-PPD anti-endometrial cancer toxicity. Results: 20(S)-PPD inhibited HEC-1A cell proliferation in a dose-dependent manner with an IC50 value of 3.5 μM at 24 h. HEC-1A cells morphologically changed after 20(S)-PPD treatment, bearing resemblance to Taxol-treated cells. Annexin V-positive cell percentages were 0%, 10.8%, and 58.1% in HEC-1A cells when treated with 0, 2.5, and 5 μM of 20(S)-PPD, respectively, for 24 h. 20(S)-PPD subcutaneously injected into the HEC-1A cell xenograft-bearing mice three times a week for 17 days manifested tumor growth inhibition by as much as 18% at a dose of 80 mg/kg, which sharply contrasted to controls that showed an approximately 2.4-fold tumor volume increase. These events paralleled caspase-9 activation and PARP cleavage. Conclusion: 20(S)-PPD inhibits endometrial cancer cell proliferation by inducing cell death via a caspase-mediated apoptosis pathway. Therefore, the 20(S)-PPD-like ginsenosides are endowed with ample structural information that could be utilized to develop other ginsenoside-based anticancer agents.

• Clinics in Shoulder and Elbow
• /
• 제24권1호
• /
• pp.21-26
• /
• 2021

Background: To evaluate the demographics, clinical and radiographic features of calcific tendinitis of the shoulder in the Korean population, specifically focusing on the incidence of coexisting rotator cuff tear. Methods: Between October 2014 and January 2015, we performed a prospective multicenter study with 506 patients from 11 training hospitals in Korea. We collected data of demographics and radiographic analysis based on simple radiographs, clinical assessments based on visual analog scale (VAS) and the American Shoulder Elbow Surgeons (ASES) score, and treatment modalities that are used currently. We also evaluated coexisting rotator cuff tear by ultrasonography (US) or magnetic resonance imaging (MRI) images. Results: There were 402 female patients (79%) with mean age of 55 years (range, 31-87 years). Mean duration of symptoms was 16 months. Mean size of calcific materials was 11.4 mm (range, 0-35 mm). Mean value of VAS and ASES scores were 6.5 (range, 1-10) and 47 (range, 8-95), respectively. Of 383 patients (76%), 59 (15%) had rotator cuff tear including 15 full-thickness tears on US or MRI. Patients with rotator cuff tears were significantly associated with older age, recurrent symptoms, menstrual disorders in females, and having undergone calcification removal surgery and rotator cuff repair (all p<0.05). Conclusions: This study reported demographic, radiographic, and clinical features of calcific tendinitis of the shoulder in Korean population, which were not different from those of Western population. Coexisting rotator cuff tear was found with 15% incidence in this large series, suggesting that further radiographic study to evaluate rotator cuff tear might be needed in some calcific tendinitis patients of older age and presenting with recurrent symptoms.

• 벤처창업연구
• /
• 제15권6호
• /
• pp.115-133
• /
• 2020

최근 4차 산업혁명을 비롯해 산업의 패러다임의 급속한 변화에 따라 중소·벤처기업의 생존과 지속 가능한 성장은 더욱 어려운 환경에 직면하게 되었는데, 시장에 대한 기업의 적응능력은 더욱 중요하다. 대부분 선행연구 결과는 기업역량은 조직역량을 통해서 경영성과 간에 긍정적인 상호연관성을 확인 하였고, 이들 상호 간에 최적의 조합을 이를 때 최고의 기업성과가 이뤄진다는 것이다. 그런데 조직역량, 시장적응역량, 기업성과에 관계에 대한 연구는 미흡하다. 따라서 매우 중요한 역할을 수행하고 있는 조직역량이 경영성과에 어떠한 영향을 미치는지, 그리고 이러한 관계에 있어 시장적응역량이 어떠한 역할을 하는지를 파악할 필요가 있다. 본 연구는 기존의 조직역량, 시장적응역량에 관련 연구를 고찰하고, 이를 바탕으로 조직역량을 재구성하여 조직역량 및 기업성과에 미치는 영향에 대한 이론적인 연구모형을 개발하였다. 본 연구는 실증분석 결과에 따라 첫째, 흡수역량은 민첩성에 유의한 영향을 미치는 것으로 나타났다. 둘째, 혁신역량은 유연성에 유의한 영향을 미치는 것으로 나타났다. 셋째, 혁신역량은 기업성과에 유의한 영향을 미치는 것으로 나타났다. 넷째, 유연성은 기업성과에 유의한 영향을 미치는 것으로 나타났다. 다섯째, 조직역량과 기업성과간의 유연성의 매개효과를 검증하였다. 따라서 회사의 혁신역량과 유의성이 회사의 성과 향상 시키는게 매우 중요하다. 회사가 외부의 지식과 기술을 빠르게 흡수하여 내부 지식과 통합해 경쟁력 있는 새로운 제품과 기술을 혁신하고 개발할 수 있도록 하는 것이 중요하다. 불확실한 환경에 직면한 회사가 신속하게 대응하고 시간을 단축해 새로운 환경에 적응하면 궁극적으로 회사의 재무 및 비 재무성과에 긍정적인 영향을 미친다.

• 한국건설안전학회 논문집
• /
• 제3권1호
• /
• pp.1-8
• /
• 2020

농어촌 민박 이용객의 증가와 정부의 관련 정책에 대한 다양한 지원이 이루어지고 있다. 그러나 농어촌 민박의 숙박 서비스에 대한 안전기준이나 안전지표가 부족하여 2018년 12월 강릉 펜션 일산화탄소 누출사고, 2020년 1월 동해 펜션 가스폭발사고 등 대형사고가 발생하고 있으며 국민의 안전을 위협하고 있다. 숙박업소와 달리 농어촌 민박의 경우 소화기와 화재경보기 등의 일정 요건을 갖추면 영업이 가능하도록 되어있다. 농림축산식품부는 농어촌 민박 제도개선 대책으로 농어촌정비법 개정을 통해 가스와 전기안전 전문가가 안전점검을 하고 그 확인서를 제출하는 제도를 도입하고 있다. 본 연구의 목적은 농어촌 민박의 숙박시설에 대한 안전기준과 안전지표를 제시하여 농어촌 민박과 관련한 지방자치단체와 정부의 운영관리와 점검에 필요한 기준을 제시하는 데 있다. 숙박시설의 안전관리는 국민의 가장 기본적인 안전과 직결된다. 따라서 농어촌 민박에 대한 적절한 안전기준을 제시하고 신고필증을 배부할 필요가 있으며 지속적인 수시점검과 안전교육 및 소방, 질식사고 등에 대한 사전예방을 위한 대책을 세울 필요가 있다. 본 연구를 통해 농어촌 민박의 안전관리 실태에 대한 조사와 분석 결과를 바탕으로 안전관리 기준 및 안전지표, 수시점검 방법, 사고예방 교육을 제공하고 제도화 할 필요성이 있는 것으로 나타났다. 농어촌 민박의 숙박이용 국민에 대한 안전확보를 위해 반드시 안전관리 기준과 교육을 제도화하는 것이 시급한 것으로 보인다.

• Journal of Neurogastroenterology and Motility
• /
• 제25권3호
• /
• pp.343-362
• /
• 2019

Background/Aims There has been major progress in our understanding of the irritable bowel syndrome (IBS), and novel treatment classes have emerged. The Rome IV guidelines were published in 2016 and together with the growing body of Asian data on IBS, we felt it is timely to update the Asian IBS Consensus. Methods Key opinion leaders from Asian countries were organized into 4 teams to review 4 themes: symptoms and epidemiology, pathophysiology, diagnosis and investigations, and lifestyle modifications and treatments. The consensus development process was carried out by using a modified Delphi method. Results Thirty-seven statements were developed. Asian data substantiate the current global viewpoint that IBS is a disorder of gut-brain interaction. Socio-cultural and environmental factors in Asia appear to influence the greater overlap between IBS and upper gastrointestinal symptoms. New classes of treatments comprising low fermentable oligo-, di-, monosacharides, and polyols diet, probiotics, non-absorbable antibiotics, and secretagogues have good evidence base for their efficacy. Conclusions Our consensus is that all patients with functional gastrointestinal disorders should be evaluated comprehensively with a view to holistic management. Physicians should be encouraged to take a positive attitude to the treatment outcomes for IBS patients.

• 한국산학기술학회논문지
• /
• 제22권2호
• /
• pp.440-451
• /
• 2021

본 연구는 영유아기 자녀를 양육하고 있는 부모의 부모 역할 책임을 확인할 수 있는 평가 척도를 개발하고자 하였다. 본 연구 조사 대상자는 어린이집에 재원 중인 자녀를 둔 301명의 부모이다. 부모의 양육 책임 척도는 문항 양호도, 타당도, 신뢰도 기준에 따라 11개 하위요인, 총 60문항으로 선정되었다 (i.e., factor load ≥ 0.5; AVE ≥ 0.5; CR ≥ 0.7; Cronbach's alpha ≥ 0.7). 부모의 양육 책임 척도는 '위생관리'(4문항), '신체활동'(6문항), '생존 및 건강관리'(6문항), '인지발달'(5문항), '정서적 안정감'(5문항), '사회적 기술' (6문항), 사회규범 및 가치관' (7문항), '물리적 환경'(5문항), '보호'(5문항), '가족공동체 의식과 가풍'(4문항), '기관이용 부모의 역할과 책임'(7문항)이 최종 확정되었다. 영유아기 자녀를 둔 부모의 양육 역할 책임에 대한 지표를 한국의 실정에 맞도록 검증하여 개발하였다는 데 의의가 있다. 이 척도를 통하여 부모 역할 책임의 특성을 파악할 수 있으며, 부모와 육아 지원 기관과의 원활한 의사소통의 기초자료가 될 수 있을 것이라 기대한다.

• 한국식생활문화학회지
• /
• 제36권1호
• /
• pp.92-102
• /
• 2021

There is little information on the nutrient intake according to the city size and small town in Korean elderly. This study analyzed the nutritional consumption of older people in metropolitan, middle and small cities, and rural areas according to four income levels. The recent data from the 2016~2018 Korean National Health and Nutrition Survey, Centers for Disease Control and Prevention were used. The final analysis included 4,325 individuals (Male: 1,856, Female: 2,469) over 65 years old. Multivariable regression with a complex sample design was conducted to compare the nutrient intake among the groups. In a comparison within regions, the nutrition status of the elderly in small towns was more vulnerable than metropolitan and middle & small cities. The energy intakes were similar between the groups. The carbohydrate intake of middle & small cities was significantly higher than the other regions. The intake of other nutrients in metropolitan and middle & small cities appeared to be higher than in rural areas. The number of nutrients with statistical significance between low and high-income levels were 19 in metropolitan, 11 in middle & small cities, and 5 in rural areas. Each contribution of carbohydrate, fat, and protein to the total energy intake was lower in the low-income level than the high-income level in metropolitan and middle & small cities. On the other hand, in rural areas, only the contribution of protein to energy intake was lower in the low-income level than the high-income level. Cities with higher levels of urbanization had more severe nutritional inequality in relation to the income level. There was also nutritional inequality present in rural areas but it was to a lesser extent. Moreover, the generally low level of nutrient intake was problematic in rural areas. These findings could be used as fundamental evidence for developing community nutritional policies for the elderly.

• The Korean Journal of Pain
• /
• 제34권2호
• /
• pp.229-233
• /
• 2021

Background: Iliotibial band friction syndrome (ITBFS) is a common disorder of the lateral knee. Previous research has reported that the iliotibial band (ITB) thickness (ITBT) is correlated with ITBFS, and ITBT has been considered to be a key morphologic parameter of ITBFS. However, the thickness is different from inflammatory hypertrophy. Thus, we made the ITB cross-sectional area (ITBCSA) a new morphological parameter to assess ITBFS. Methods: Forty-three patients with ITBFS group and from 43 normal group who underwent T1W magnetic resonance imaging were enrolled. The ITBCSA was measured as the cross-sectional area of the ITB that was most hypertrophied in the magnetic resonance axial images. The ITBT was measured as the thickest site of ITB. Results: The mean ITBCSA was 25.24 ± 6.59 ㎟ in the normal group and 38.75 ± 9.11 ㎟ in the ITBFS group. The mean ITBT was 1.94 ± 0.41 mm in the normal group and 2.62 ± 0.46 mm in the ITBFS group. Patients in ITBFS group had significantly higher ITBCSA (P < 0.001) and ITBT (P < 0.001) than the normal group. A receiver operator characteristic curve analysis demonstrated that the best cut-off value of the ITBT was 2.29 mm, with 76.7% sensitivity, 79.1% specificity, and area under the curve (AUC) 0.88. The optimal cut-off score of the ITBCSA was 30.66 ㎟, with 79.1% sensitivity, 79.1% specificity, and AUC 0.87. Conclusions: ITBCSA is a new and sensitive morphological parameter for diagnosing ITBFS, and may even be more accurate than ITBT.

• 디지털융복합연구
• /
• 제19권3호
• /
• pp.453-463
• /
• 2021

본 연구는 코로나19가 공연예술계에 가져온 국내·외의 변화를 살펴보고 그 대응방안을 도출하기 위하여 언론리뷰와 문헌조사를 통하여 내용 분석을 실시하였으며 다음과 같은 결론을 도출하였다. 첫째, 코로나19 이후 세계 모든 극단과 공연장은 공연 스트리밍에 적극적인 입장을 취한 것으로 나타났다. 둘째, 공연 영상화가 적극적으로 이루어졌으며, 이러한 공연 영상화는 기존 극장 공연의 보완재가 되고 있었다. 셋째, 공연 제작 소비 행태의 변화에서는 빈익빈 부익부의 현상이 나타났으며, 다양한 공연들을 온라인으로 경험할 수 있는 기회를 제공하는 것으로 나타났다. 넷째, 코로나19 이후 영국의 경우 직원 고용유지 지원책과 자영업자 및 프리랜서 지원책, 영국 문화예술위원회의 긴급 지원금 정책이 있으며. 한국 정부는 공연예술관람료, 예술인을 위한 창작 준비금, 학교예술강사 생계유지를 위한 강사비 등의 제도가 발표, 집행 중에 있다. 다섯째, 코로나19 이후의 대응방안으로는 공연 영상화에 꾸준히 자본과 기술을 투입하여 온라인과 오프라인이 상생할 수 있는 구조 마련이 시급하며 해외 유수 공연 단체와의 전략적 제휴와 플랫폼 공유 전략이 필요하다고 분석되었다.