On the Strengthening Effects Affecting Tensile and Low Cycle Fatigue Properties of Low-Alloyed Seismic/Fire-Resistant Structural Steels

Jung‑Ho Sim,Tae‑Yeong Kim,Jun‑Yeon Kim,Chi‑Won Kim,Jun‑Ho Chung,Joonoh Moon,Chang‑Hoon Lee,Hyun‑Uk Hong 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

In the present study, low carbon ferritic and bainitic steels with different contents of Mo, Ti, and Nb were designed for bothseismic and fire-resistant applications. The microstructure of steels containing 0.3 wt% Mo–0.02 wt% Nb (‘A’ hereinafter)was mainly composed of bainite. By contrast, the microstructure of steels with 0.2 wt% Mo–0.13 wt% Ti (‘B’ hereinafter)consisted of ferrite with a high density of nano-sized (Ti,Mo)-rich MX precipitates. The results showed that the bainiticmicrostructure (‘A’ steel) was quite favorable to high-temperature strength and thermal stability. The yield strength of ‘A’ steelat both room and 600 °C temperatures increased consistently with increasing thermal exposure time (600 °C/200–1000 h),since the precipitation of NbC particles occurred while maintaining bainitic ferrite platelets with a high density of dislocationsduring exposure. In the ‘B’ steel, the formation of nano-sized (Ti,Mo)-rich MX particles was effective to impededislocation movement, leading to excellent plasticity (lower yield ratio) at room temperature. However, their contributionto precipitation hardening was not so much at 600 °C, as compared to the bainitic strengthening. During low cycle fatiguetests at room temperature, the main different feature between the two steels is that the ‘A’ steel showed cyclic softeningwhile cyclic hardening was evident in the ‘B’ steel. The bainitic microstructure showed a better fatigue life due to increasedductility manifested by cyclic softening, by which dislocation cell was developed.

서울의 PPNG 발생 빈도(1991-1992)

김재홍,윤기범,박평원,김영진,전경민,김영태,김중환,곽호,구상완,송민석,유옥,지혜구,김동원,문상은,박영립,정승호,성범진,성순제,엄주용,황정열,이기홍,이주협,전태진 대한화학요법학회 1994 대한화학요법학회지 Vol.12 No.1

The prevalence of PPNG among pretreated gonorrhea cases isolated at the STD clinic of Choong-Ku Public Health Center in Seoul has been studied and reported annually since 1981. In 1991, 123 strains of N.gonorrhoeae were isolated, among which 58(47.1%) were PPNG. In 1992, 98 starains of N.gonorrhoeae were isolated, among which 51(52.0%) were PPNG. In all, 109(49.3%) strains were found to be PPNG among 221 strains isolated between 1991-1992. The prevalence of PPNG in Seoul showed increased tendency till 1989, thereafter, it has been stationary or slightly decreasing.

Ethanol Extract of Ganoderma lucidum Augments Cellular Anti-oxidant Defense through Activation of Nrf2/HO-1

Lee, Yoo-hwan,Kim, Jung-hee,Song, Choon-ho,Jang, Kyung-jeon,kim, Cheol-hong,Kang, Ji-Sook,Choi, Yung-hyun,Yoon, Hyun-Min KOREAN PHARMACOPUNCTURE INSTITUTE 2016 Journal of pharmacopuncture Vol.19 No.1

Objectives: The mushroom Ganoderma lucidum has been widely used as a traditional herbal medicine for many years. Although several studies have focused on the anti-oxidative activity of this mushroom, the molecular mechanisms underlying its activity have not yet been clearly established. The present study investigated the cytoprotective effect of ethanol extract of Ganoderma lucidum (EGL) against oxidative stress (hydrogen peroxide, $H_2O_2$) and elucidated the underlying mechanisms in a C2C12 myoblast cell line. Methods: Oxidative stress markers were determined by using the comet assay to measure reactive oxygen species (ROS) generation and deoxyribonucleic acid (DNA) damage. Cell viability and Western blotting analyses were employed to evaluate the cellular response to EGL and $H_2O_2$ in C2C12 cells. Transfection with nuclear factor erythroid 2-related factor 2 (Nrf2)-specific small interfering ribonucleic acid (siRNA) was conducted to understand the relationship between Nrf2 expression and $H_2O_2$-induced growth inhibition. Results: The results showed that EGL effectively inhibited $H_2O_2$-induced growth and the generation of ROS. EGL markedly suppressed $H_2O_2$-induced comet-like DNA formation and phosphorylation of histone H2AX at serine 139 ($p-{\gamma}H2AX$), a widely used marker of DNA damage, suggesting that EGL prevented $H_2O_2$-induced DNA damage. Furthermore, the EGL treatment effectively induced the expression of Nrf2, as well as heme oxygenase-1 (HO-1), with parallel phosphorylation and nuclear translocation of Nrf2 in the C2C12 myoblasts. However, zinc protoporphyrin IX, a HO-1 inhibitor, significantly abolished the protective effects of EGL against $H_2O_2$-induced accumulation of ROS and reduced cell growth. Notably, transient transfection with Nrf2-specific siRNA attenuated the cytoprotective effects and HO-1 induction by EGL, indicating that EGL induced the expression of HO-1 in an Nrf2-dependent manner. Conclusion: Collectively, these results demonstrate that EGL augments the cellular anti-oxidant defense capacity through activation of Nrf2/HO-1, thereby protecting C2C12 myoblasts from $H_2O_2$-induced oxidative cytotoxicity.

TNF-α로 유도된 혈관내피세포의 혈관염증에 미치는 오적산(五積散)의 억제 효과

한병혁 ( Byung Hyuk Han ),윤정주 ( Jung Joo Yoon ),김혜윰 ( Hye Yoom Kim ),안유미 ( You Mee Ahn ),홍미현 ( Mi Hyeon Hong ),손찬옥 ( Chan Ok Son ),나세원 ( Se Won Na ),이윤정 ( Yun Jung Lee ),강대길 ( Ho Sub Lee ),이호섭 대한본초학회 2018 大韓本草學會誌 Vol.33 No.4

Objectives : Ojeoksan, originally recorded in an ancient Korean medicinal book named “Donguibogam” and has been used for the treatment of circulation disorder of blood which was called blood accumulation (血積) in Korean medicine. Therefore, this study was carried out to investigate the beneficial effect of OJS on vascular inflammation in HUVECs. Methods : We evaluated the effect of OJS on the expression of cell adhesion molecules and protective role in HUVEC stimulated by TNF-α by using Western blot. Results : Pretreatment with OJS decreased the adhesion of HL-60 cells to TNF-α-induced HUVEC. OJS suppressed TNF-α-induced expression level of cell adhesion molecules such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1(VCAM-1), and endothelial cell selectin (E-selectin). Moreover, OJS significantly decreased TNF-α-induced production of intracellular reactive oxygen species (ROS); and inhibited the phosphorylation of IκB-α in the cytoplasm compared to the experimental group. Pretreatment with OJS inhibited the trans-location of NF-κB p65 to the nucleus. OJS also inhibited phosphorylation of MAPKs compared to the experimental group. OJS significantly increased the protein expression of Nrf2 and HO-1. Conclusions : Ojeoksan has a protective effect on vascular inflammation, and might be a potential therapeutic agent for early atherosclerosis.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

공급 사슬 환경에서의 고객주문만족 시스템

장지홍,정호상,정봉주 연세대학교 산업기술연구소 2000 논문집 Vol.32 No.2

기업의 틀을 뛰어넘어 고객과 공급자까지 자사를 중심으로 통합하는 공급 사슬 환경에 있어서 고객 만족 수준을 향상시키는 것은 매우 중요하다. 고객 만족 수준을 높이기 위해서는 우선 정확한 수요예측을 통하여 주문에 대비해야 하며, 주문이 들어올 경우 고객에게 정확한 납기회신을 제공해야 한다. 물류, 정보, 자금 등의 흐름을 총괄하는 공급 사슬 환경의 특성상, 정확한 수요예측과 납기회신을 제공하기 위해서는 제품의 공급자, 고객을 포함한 공급 사슬내의 여러 파트너 들에 대한 종합적인 고려가 이루어져야 한다. 본 연구에서는 일반적인 공급 사슬 환경에서 사용 가능한 수요계획 시스템을 구축하는데 필요한 모델과, 고객의 주문에 대한 납기 제시를 위한 납기회신 알고리듬을 제시하고자 한다. : 공급사슬관리, 수요계획, 납기회신

남극지역의 대기오염 측정체계 구축을 위한 기초조사

정의석,김선태,김선규,홍성민,정호성 大田大學校 環境問題硏究所 2002 환경문제연구소 논문집 Vol.6 No.-

From January through February 2000, the SO_2. NO_2, and VOCs (Volatile organic compounds) concentrations were measured at the total 15 sites (between 6213S and 6214S, between 5846W and 5848W) around the King Sejong Station located in King George Island. The badge type of SO_2 and NO_2 passive diffusion samplers impregnated with 5% Na_2CO_3 and TEA, respectively and VOC passive samplers including activated carbon filter were used. The samplers brought back to the laboratory were analyzed with IC or GC after extracting by distilled pure water, H_2O_2, or CS_2. Considering that the concentration level of each compound analyzed are very low in Antarctica, the blanks and instrumental detection limits were also determined. The blanks of SO_2 and NO_2 sampler were found to be 0.63 ppb and 0.49 ppb, respectively. Measured concentrations range from <LOD to 1.58 ppb for NO_2 and from <LOD to 0.44 ppb for SO_2. For ten species of VOCs investigated, on the other hand, most of compounds except for toluene and benzene could not be detected because of extremely low concentrations below the instrumental detection limits. Measured concentrations range from <LOD to 0.96ppb for toluene and from <LOD to 0.22 ppb for benzene. Although the concentrations of most gaseous contaminants investigated are observed to be very low, our results clearly show that anthropogenic emissions at King Sejong Station affect the concentrations of several of these compounds. The limited but valuable data presented in this study will be helpful to establish the systematic air monitoring system in the near future.

한국인 선천성 난청에서 Connexin 26의 분자유전학적 분석

박홍준,박기현,송정환,정영훈,최호석 대한이비인후과학회 2000 대한이비인후과학회지 두경부외과학 Vol.43 No.4

Burkitt림프종 환아의 증례 보고

홍현진,최병재,이제호,윤정훈,손흥규 대한소아치과학회 2001 大韓小兒齒科學會誌 Vol.28 No.2

Burkitt 림프종은 중앙아프리카 지역의 어린이 악골에서 흔하게 나타는 악성 종양으로 림프조직으로부터 발생되며 매우 빠른 성장 양상을 보인다. 임상적으로는 7∼8세 아동에 주로 호발하며 악골에 발생하는 경우 안면부 종장이 나타날 수 있으며 유지의 비정상적 동요 및 구치부 조기 맹출등이 나타날 수 있다. 방사선 소견으로는 경계가 불규칙한 방사선투과성 병소로 나타나며 조직학적으로는 종양세포들 사이에 대식세포가 분포되어 "starry-sky" appearance치 특징적인 양상이 관찰된다. 본 증례는 좌측 안면부 종창을 동반한 유구치의 심한 동요도를 주소로 내원한 3세 남환아에서 임상 및 방사선 검사와 조직학적 검사를 통해 Burkitt 림프종으로 진단하였고 항암 화학요법에 의해 치료중이며 양호한 치료 결과론 얻고 있다. Burkitt's lymphoma is a malignant tumor that commonly occurs in the jaws of children of Central Africa. It originates from the lymphatic tissue. and it shows rapid growth Clinically. It is commonly found in children between age of 3 and 8. When it is found in the jaw, facial swelling, mobility of deciduous teeth. and early eruption of posterior teeth can also be found. Upon radiographic examination, radiolucent lesions with irregular border can be observed Histologically, macrophage can be seen among tumor ce11s, and this special pattern is called "starry-sky" appearance. In this case, 3 year-old male patient came to our hospital with left facial swelling and severe mobility of deciduous molars. He was diagnosed as Burkitt's lymphoma based on clinical, radiographic, and histologlc examination. He is being treated with chemotherapy and progress seems promising.

Memory 소자 응용을 위한 BST(Ba_xSr_1-_xTiO_3) 강유전체 박막과 전극과의 계면특성

정민재,조정희,홍석민,김호건,김옥경 漢陽大學校 工學技術硏究所 1997 工學技術論文集 Vol.6 No.1

BaxSr1-xTiO3 powders were prepared by changing stoichiometry of Ba and Sr. After they were calcined and sintered at 1,200℃ and 1,300℃ respectively, BST sputtering targets were made in 3inch mould. For MIM structure capacitors. Pt-based structures such as Pt/TiN/SiO2/Si, Pt/Ti/Si3N4/Si, Pt/SiO2/Si, Ru/SiO2/Si and Ru/Si3N4/Si were used for bottom electrodes, and subsequently, the BaxSrl-xTiO3 thin films were sputtered on them. After the analysis of their structures by XRD, Al was evaporated on the BST films for MIM capacitor. We found that the structures of the films showed good crystallinity above 550℃ from the results of XRD measurements. The largest dielectric constant of films was obtained with 0.7mol% of Ba. The electric properties of the capacitors were very good with Pt/TiN/SiO2/Si electrodes.