Microstructure and High Temperature Oxidation Property of Fe-Cr-B Based Metal/Ceramic Composite Manufactured by Powder Injection Molding Process

Yeun‑Ah Joo,Young‑Kyun Kim,윤태식,Kee‑Ahn Lee 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.2

This study investigated the microstructure and high temperature oxidation property of Fe–Cr–B metal/ceramic compositemanufactured using powder injection molding process. Observations of initial microstructure showed a unique structurewhere α-Fe and (Cr, Fe)2B form a continuous three-dimensional network. High temperature oxidation tests were performedat 900, 1000 and 1100 °C, for 24 h, and the oxidation weight gain according to each temperature condition was 0.13, 0.84and 6.4 mg/cm2, respectively. The oxidation results according to time at 900 and 1000 °C conditions represented paraboliccurves, and at 1100 °C condition formed a rectilinear curve. Observation and phase analysis results of the oxides identifiedCr2O3and SiO2at 900 and 1000 °C. In addition to Cr2O3and SiO2,CrBO3and FeCr2O4formed due to phase decompositionof boride were identified at 1100 °C. Based on the findings above, this study suggested the high temperature oxidationmechanism of Fe–Cr–B metal/ceramic composite manufactured using powder injection molding, and the possibility of itsapplication as a high temperature component material was also discussed.

식이섬유가 고콜레스테롤혈증 흰쥐의 지질농도에 미치는 영향

김명주,장주연,이미경,박지윤,박은미 한국식품영양학회 1999 韓國食品營養學會誌 Vol.12 No.1

에탄올 중독된 흰쥐의 간조직 중 지질대사에 미치는 셀렌과 메티오닌의 영향

김명주,이미경,장주연,박은미 한국식품영양학회 1999 韓國食品營養學會誌 Vol.12 No.1

산업체 급식소에서 생산직 근로자에게 제공되고 있는 음식의 적정 분량을 제시하기 위해 목포지역 생산직 근로자 240명을 대상으로 섭취량 측정과 설문지를 이용한 만족도 평가를 실시하였다. 조사대상 근로자의 연령은 30∼39세가 57.1%, 학력은 대부분 고졸이었으며, 건강상태는 52.1%가 건강하다고 하였다. 근로자의 좋아하는 식사의 형태는 한식이었고, 식품을 선택할 때 가장 중요하게 생각하는 것은 맛으로 나타났으며, 식사의 가치관은 조사대상 근로자의 37.1%가 공복을 채우는 것이라고 대답해서 생리적 욕구충족에 가치를 둔 비율이 가장 높았다. 산업체 급식소에서 제공된 음식의 섭취량과 섭취율은 밥류 238g(98.4%), 국류 212g(82.7%), 찌개류 230g(77.2%), 볶음류 40g(80.7%), 조림류 60g(83.5%), 무침류 42g(72.3%), 김치류 51g(75.9%), 일품요리류 406g(77.7%), 구이류 51g(72.6), 부침류 48g(48.7%)였다. 섭취량에 대한 만족도 평가 결과, 섭취량에 대해서 두 비교군 거의 모두가 '적은 양'이라고 대답하였다. 섭취량에 대한 만족도 평가를 기초로 음식의 적정량에 대해 밥류 240∼270g, 국류 270g, 찌개류 310g, 볶음류 60g, 조림류 75g, 무침류 76g, 김치류 67g, 일품요리류 470g, 구이류 80g, 부침류 50g으로 제시할 수 있다. The purpose of this study is to set up a appropriate portion by consumed size of food in industry food-service operation. The results were summarized as follows: 51.7% of the subjects were 30 to 39 years old, 83.3% of them had highschool education. They represented that taste of food was the most important point in food intake. Individual consumption sizes for physical workers in the industry foodservice were cooked rices 238g, soups 212g, pot stewes 230g, stir fries 40g, stewes 60g, fresh and boiled salad 42g, kimchies 51g, one course dishies 406g, grills 51g, meunieres 47g. Properly portioned meal sizes for physical workers based on a statistical data showed cooked rices 240∼270g, soups 270g, pot stewes 310g, stir fries 60g, stewes 75g, fresh and boiled salads 76g, kimchies 67g, one course dishies 470g, grills 80g and meunieres 50g in the foodservice industry.

에탄올성 간손상 흰쥐의 유해산소 생성효소계에 미치는 칡 추출물의 영향

조수열,김명주,박은미,박지윤,장주연 한국노화학회 2001 한국노화학회지 Vol.11 No.1

임플란트 hexagon 높이에 따른 임플란트와 주위 조직의 응력분포 평가

박성재,김주현,김소연,윤미정,고석민,허중보 대한치과보철학회 2012 대한치과보철학회지 Vol.50 No.1

PURPOSE. To analyze the stress distribution of the implant and its supporting structures through 3D finite elements analysis for implants with different hexagon heights and to make the assessment of the mechanical stability and the effect of the elements. MATERIALS AND METHODS. Infinite elements modeling with CAD data was designed. The modeling was done as follows; an external connection type ∅4.0 mm×11.5 mm OsstemUSII (Osstem Co., Pusan, Korea) implant system was used, the implant was planted in the mandibular first molar region with appropriate prosthetic restoration, the hexagon (implant fixture’s external connection) height of 0.0, 0.7, 1.2, and 1.5 mm were applied. ABAQUS 6.4 (ABAQUS, Inc., Providence, USA) was used to calculate the stress value. The force distribution via color distribution on each experimental group’s implant fixture and titanium screw was studied based on the equivalent stress (von Mises stress). The maximum stress level of each element (crown, implant screw, implant fixture, cortical bone and cancellous bone) was compared. RESULTS. The hexagonal height of the implant with external connection had an influence on the stress distribution of the fixture, screw and upper prosthesis and the surrounding supporting bone. As the hexagon height increased, the stress was well distributed and there was a decrease in the maximum stress value. If the height of the hexagon reached over 1.2 mm, there was no significant influence on the stress distribution. CONCLUSION. For implants with external connections, a hexagon is vital for stress distribution. As the height of the hexagon increased, the more effective stress distribution was observed. 연구 목적: 본 연구는 hexagon 높이에 따른 임플란트 각 부위와 주위 지지조직의 응력분포를 3차원 유한요소 해석을 통해 평가하여 hexagon 높이가 기계적 안정성에 미치는 영향을 평가하고자 시행되었다. 연구 재료 및 방법: 외측 연결 형태의∅L4.0 mm×11.5 mm USII (Osstem Co., Pusan, Korea) 임플란트 시스템을 이용하여 하악 제 1대구치 부위에 임플란트를 식립하여 보철 수복한 경우를 연구 모델로 가정하고 임플란트 고정체의 외측 연결부인 hexagon의 높이를 각각 0.0 mm, 0.7 mm, 1.2 mm, 1.5 mm로 적용한 CAD data를 유한요소 모형화하였다. ABAQUS 6.4 (ABAQUS Inc., Providence, RI, USA)를 이용하여 산출된 응력 값 중에서 등가응력을 기준으로 각 요소(상부 치관, 지대주 나사, 고정체, 치밀골, 해면골)에서 나타나는 최대 응력 값을 비교 하였다. 결과:외측 연결을 갖는 임플란트의 hexagon의 높이는 고정체, 지대주 나사, 상부 보철물 그리고 주위 지지골에 대해 응력 분산에 영향을 주었다. Hexagon의 높이가 증가할 수록 임플란트의 응력 분산은 더 잘 이루어졌으며, 최대 응력 값의 감소를 보였다. Hexagon의 높이가 1.2 mm 이상이 되면 응력 분포에 더 이상 크게 기여하지 않았다. 결론: 외측연결을 갖는 임플란트에서 hexagon은 응력 분산에 필수적인 요소이며 그 높이가 증가할수록 더욱 효과적인 응력의 분산이 나타났다.

두경부 종양세포주에 대한 Mithramycin A의 세포자멸사 유도성 및Cisplatin 항암작용 증가효과

이강대,손성환,박종욱,김영록,이봉주,김주연 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.1

Background and Objectives : Cisplatin (CP) is a major chemotherapeutic agent for head and neck cancer. However, cancer cells can get drug resistance through recovering the DNA damage by CP. Mithramycin A (MA) can inhibit gene expression of multidrug resistance gene 1, c-myc or h-ras. The goal of this study is to evaluate the therapeutic effect of MA alone and combination of MA and CP on head and neck cancer cell lines. Materials and Methods : Two head and neck cancer cell lines (AMC-HN4, AMC-HN7) were treated with MA. The cellular proliferation, apoptosis and protein expression were measured with XTT assay, FACS analysis, and western blotting, respectively after MA treatment in cell lines. In order to know the combination effect of MA with CP, the cancer cell lines were treated with MA, CP, and MA/CP combination, and cellular proliferation, apoptosis and expression of apoptosis-associated proteins were measured. Results : MA inhibited the proliferation of head and neck cancer cells and induce dapoptosis. Increase of caspase activation, PLC-?1 fragmentation and percent apoptosis by MA treatment was blocked by z-VAD-fms, but not blocked by N-Acetyl Cystein. Combination of MA and CP significantly inhibited cancer cell growth and increased apoptosis compared to MA and CP alone, and it also suppressed the expression of anti-apoptotic proteins such as XIAP and Mcl-1. Conclusions : The present study suggests that MA alone andMA/CP combination chemotherapy could be a potential regiment for the control of the head and neck cancer.

산국의 수량과 유효성분에 대한 NPK의 효과

이경동,양민석,정연규,손보균,조주식,이성태,김필주 한국농화학회 2003 Applied Biological Chemistry (Appl Biol Chem) Vol.46 No.2

본 연구는 3요소(N-PO_2O_5-K_2O)처리가 산국(Chysanthemum boreale M.)의 수량과 유효성분에 미치는 효과를 조사하여 효과적인 재배시스템을 개발하고자하였다. 처리구는 무처리, NPK(250-160-160), NK(250-0-160), PK(0-160-160kg/ha)의 5처리로 설정하여 산국을 재배한 결과, 건물수량은 NPK처리구가 PK처리구에 비하여 4.0배의 증수가 있었으며, 다른 처리구보다 무기이온의 흡수율, 생육 및 수량에서 NPK처리구가 가장 우수하였다. 식용으로 많이 쓰이는 꽃의 주요 아미노산은 proline, glutamic acid과 aspartic acid이였고, 다른 처리구들에 비하여 NPK처리구가 높은 함량을 보였다. 혈압강하효과가 우수한 cumambrin A는 PK처리구에 비하여 NPK처리구가 6.2배의 증수효과가 있었다. NK처리구는 NP처리구보다 cumambrin A의함량을 높이기 위해서는 인산의 시용보다 칼리의 시용이 더 요구되며, 야외포장에서의 인산과 칼리의 적정 시비량의 설정이 필요하다고 판단된다. To establish the fertilization condition to increase the productivity of Chrysanthemum boreale M. with high quality, the effects of three nutrients (N, P, K) on the yields and the effective components were investigated in the pot scale. NPK was applied by chemical fertilizers with N-P_2O_5-K_2O = 250-160-160 kg/ha as a main treatment, and NP (N-P_2O_5 = 250-160 kg/ha), NK (N-KO = 250-160 kg/ha), and PK (PO_2-KO_5 = 160-160 kg/ha) treatments were settled as comparison. Dry yields of C. boreale M. was increased significantly to 4 fold higher by nitrogen. Nitrogen increased apparently plant growth and inorganic nutrient uptake. In the flower, which is most useful and edible part as a herbal medicine, main amino acids were glutamic acid and aspartic acids, and the total content was increased significantly by three elements of application. In addition, the content of cumambrin A, which is known to have the effect of blood-pressure reduction, was increased source to 6.2 times by nitrogen higher than that in PK treatment. Potassium was more effective in biosyndiesis of cumatnbrin A than phosphorus, but the biological pathway was not clear, still.

A resonance frequency analysis of sandblasted and acid-etched implants with different diameters: a prospective clinical study during the initial healing period

Kim, Hyun-Joo,Kim, Yeun-Kang,Joo, Ji-Young,Lee, Ju-Youn Korean Academy of Periodontology 2017 Journal of Periodontal & Implant Science Vol.47 No.2

Purpose: The possibility of immediate or early loading has become popular in implant dentistry. A prerequisite for the immediate or early loading of an implant prosthesis is the achievement of initial stability in the implant. Moreover, in response to clinicians' interest in verifying clinical stability to determine the optimal time point for functional loading, a non-invasive method to assess implant stability has been developed on the basis of resonance frequency analysis (RFA). The primary objective of this study was to monitor the stability of sandblasted, large-grit, and acid-etched (SLA) implants with different diameters during the early phases of healing by RFA. The secondary objective was to evaluate how the initial stability of implants varied depending on different surface modifications and other contributing factors. Methods: Thirty-five implants (25 SLA implants and 10 resorbable blasting media [RBM] implants) placed in 20 subjects were included. To measure implant stability, RFA was performed at baseline and at 1, 2, 3, 4, 6, and 10 weeks after surgery. Results: The longitudinal changes in the implant stability quotient (ISQ) values were similar for the SLA implants with different diameters and for the RBM implants. During the initial healing period, the ISQ decreased after installation and reached its lowest values at 1 week and 2 weeks, respectively. The mean ISQ values in the SLA implants were significantly higher in ${\varnothing}5.0mm$ implants than in ${\varnothing}4.0mm$ implants. Men showed a higher ISQ than women. Mandibular sites showed a higher ISQ than maxillary sites. Conclusions: All implants used in this study are suitable for immediate or early loading under appropriate indications. A wider diameter and SLA surface treatment of implants could improve the stability, if the implant is fixed with at least 30 Ncm of insertion torque.

Molecular genetic characteristics of X-linked retinoschisis in Koreans

Kim, So Yeon,Ko, Hyun Soo,Yu, Young Suk,Hwang, Jeong-Min,Lee, Jong Joo,Kim, Sung Yeun,Kim, Ji Yeon,Seong, Moon-Woo,Park, Kyu Hyung,Park, Sung Sup Molecular Vision 2009 Molecular vision Vol.15 No.-

<P><B>Purpose</B></P><P>X-linked retinoschisis (XLRS) is a recessively inherited disorder that causes macular degeneration and resultant visual defect in young males. Many genetic studies had focused on the patients in Western countries. We characterized the mutational spectrum of the <I>RS1</I> gene in Korean patients with XLRS, and aimed to provide genetic information of XLRS in an Asian population.</P><P><B>Methods</B></P><P>This study enrolled 17 unrelated probands and their mothers for molecular genetic evaluation. All exons and the flanking intronic regions of <I>RS1</I> were analyzed by direct sequencing. We performed gene dosage analysis by semiquantitative multiplex PCR to rule out the possibility of duplication in a patient without a sequence variation. We also tried RT–PCR analysis in a case with a putative splicing mutation.</P><P><B>Results</B></P><P>Genetic tests revealed 16 Korean patients (94.1%) had <I>RS1</I> mutations. In one patient, neither sequence variation nor deletion or duplication in <I>RS1</I> was detected. One case with de novo mutation was confirmed by familial analysis. Identified were 14 causative mutations, three of which were novel: one missense mutation (c.227T>G, p.V76G) and two splice-site mutations (c.78+1G>T and c.78+5G>A). No obvious genotype-phenotype relationship was observed.</P><P><B>Conclusions</B></P><P>A missense mutation was the predominant type, and common or founder mutations were not observed in the Korean patients in this study who had XLRS. This study provides molecular genetic characteristics about an Asian population previously unexplored. The genetic characteristics of Korean XLRS will be helpful for understanding the worldwide spectrum of <I>RS1</I> mutation.</P>

Dual Oxidase 2 is Essential for the Toll-Like Receptor 5-Mediated Inflammatory Response in Airway Mucosa

Joo, Jung-Hee,Ryu, Ji-Hwan,Kim, Chang-Hoon,Kim, Hyun Jik,Suh, Mi-Sun,Kim, Jin-Oh,Chung, Seung Yeun,Lee, Sang Nam,Kim, Hwan Mook,Bae, Yun Soo,Yoon, Joo-Heon Mary Ann Liebert 2012 ANTIOXIDANTS AND REDOX SIGNALING Vol.16 No.1

<P>Airway mucosa is constantly exposed to various airborne microbes, and epithelial host defense requires a robust innate immunity. Recently, it has been suggested that NADPH oxidase (NOX) isozymes serve functional roles in toll-like receptor (TLR)-mediated innate immune responses. However, the molecular mechanism between TLR and NOX-mediated reactive oxygen species (ROS) production in human airway mucosa has been poorly understood.</P>