• 제목/요약/키워드: B19'

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Ti-Ni-Cu 형상기억합금의 상변태 및 초탄성에 미치는 가공열처리의 영향 (Effect of Thermomechanical Treatment on the Phase Transformation and Superelasticity in Ti-Ni-Cu Shape Memory Alloy)

  • 이오연;박영구;천병선
    • 열처리공학회지
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    • 제7권4호
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    • pp.253-261
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    • 1994
  • Transformation behavior and superelastic behavior of Ti-Ni-Cu alloys with various Cu content has been investigated by means of electrical resistivity measurement, X-ray diffraction, tensile test and transmission electron microscopy. Two types of heat treatment are given to the specimens: i) Solutions treatment. ii) thermo-mechanical treatment. The transformation sequence in solution treated Ti-Ni-Cu Alloys substituted by Cu for Ni up to 5at.% occurs to $B2{\rightleftarrows}B19^{\prime}$ and it proceeds in two stages by addition of 10at.%Cu, i. e, $B2{\rightleftarrows}B19{\rightleftarrows}B19^{\prime}$. Also, it has been found that Ti-30Ni-20Cu alloy transformed in one stage : $B2{\rightleftarrows}B19$. The thermo-mechanically treated Ti-47Ni-3Cu alloy transformed in two stages: B2${\rightleftarrows}$rhomboheral phase${\rightleftarrows}B19^{\prime}$, while transformation sequence in Ti-45Ni-5Cu and Ti-40Ni-10Cu alloy transformed as same as solution treated specimens. The critical stress for inducing slip deformation in solution treated and thermo-mechanically treated Ti-40Ni-10Cu alloy is about 90MPa and 320Mpa respectively.

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생쥐에 있어서 에탄올의 면역독성에 미치는 메치오닌 식이의 영향 (Effects of Methionine Diets on the Immunotoxicity of Ethanol in ICR Mice)

  • 안영근;김정훈;구기범;문재규
    • 약학회지
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    • 제36권4호
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    • pp.303-314
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    • 1992
  • Experiments were performed on mice to investigate the effect of methionine diets (MET) on the immunotoxicity of ethanol. ICR female mice were divided into 5 groups, Met (Basal (B)+0.19% methionine(M), B+1.71% M and B+5.13%W) and ethanol(4%) were administered ad libitum for 21 days. The mice were evaluated for changes in immune status as measured by antibody titer, Arthus reaction, delayed type hypersensitivity (DTH), rosette forming cell(RFC) and plaque forming cell (PFC) to sheep red blood cells (S-RBC). To investigate the change of the non-specific immune response, the number of leukocytes in peripheral blood and phagocyte activity were measured. The results were summarized as follows: (1) The weight ratios of spleen and thymus to body weight were significantly increased by the B+0.19% M, B+0.57% M and B+1.71% M groups in comparison with control group(B), but B+5.13% M group was significantly decreased. (2) Humoral immune responses were significantly increased by the B+0.19% M and B+0.57% M groups in comparison with control group, but B+5.13% M group was significantly decreased. (3) Cellular immune responses were significantly decreased by the B+1.71% M and B+5.13% M groups in comparison with control group. (4) Phagocyte activities were significantly increased by the B+0.19% M, B+0.57% M and B+1.71% M groups in comparison with control groups, but B+5.13% M group was significantly decreased. (5) The number of circulating leukocyte was significantly increased in the B+0.19% M and B+0.57% M groups in comparison with control group, but B+5.13% M group was significantly decreased.

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The B2-B19-B19' Transformation in Ti-(45-x)Ni-5Cu-xMn (at%) (x = 0.5-2.0) Alloys

  • Jeon, Yeong-Min;Kim, Min-Gyun;Kim, Min-Su;Lee, Yong-Hee;Im, Yeon-Min;Nam, Tae-Hyun
    • Transactions on Electrical and Electronic Materials
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    • 제12권1호
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    • pp.24-27
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    • 2011
  • Effect of substitution of Mn for Ni on transformation behavior, shape memory characteristics and superelasticity of Ti45Ni-5Cu alloy has been investigated by means of electrical resistivity measurements, X-ray diffraction, thermal cycling tests under constant load and tensile tests. The one-stage B2-B19' transformation occurred when Mn content was 0.5 at%, above which the two-stage B2-B19-B19' transformation occurred. A temperature range where the B19 martensite exists was expanded with increasing Mn content because decreasing rate of Ms (60 K / % Mn) was larger than that of Ms' (40 K / % Mn). Ti-(45-x)Ni-5Cu-xMn alloys were deformed in plastic manner with a fracture strain of 60 % ~ 32 % depending on Mn content. Clear superelasticity was found in fully annealed Ti-(45-x)Ni-5Cu-xMn alloys with Mn content more than 1.0 at%, which was ascribe to a solid solution hardening by substitution of Mn for Ni.

LncRNA H19 Drives Proliferation of Cardiac Fibroblasts and Collagen Production via Suppression of the miR-29a-3p/miR-29b-3p-VEGFA/TGF-β Axis

  • Guo, Feng;Tang, Chengchun;Huang, Bo;Gu, Lifei;Zhou, Jun;Mo, Zongyang;Liu, Chang;Liu, Yuqing
    • Molecules and Cells
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    • 제45권3호
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    • pp.122-133
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    • 2022
  • The aim of this study was to investigating whether lncRNA H19 promotes myocardial fibrosis by suppressing the miR-29a-3p/miR-29b-3p-VEGFA/TGF-β axis. Patients with atrial fibrillation (AF) and healthy volunteers were included in the study, and their biochemical parameters were collected. In addition, pcDNA3.1-H19, si-H19, and miR-29a/b-3p mimic/inhibitor were transfected into cardiac fibroblasts (CFs), and proliferation of CFs was detected by MTT assay. Expression of H19 and miR-29a/b-3p were detected using real-time quantitative polymerase chain reaction, and expression of α-smooth muscle actin (α-SMA), collagen I, collagen II, matrix metalloproteinase-2 (MMP-2), and elastin were measured by western blot analysis. The dual luciferase reporter gene assay was carried out to detect the sponging relationship between H19 and miR-29a/b-3p in CFs. Compared with healthy volunteers, the level of plasma H19 was significantly elevated in patients with AF, while miR-29a-3p and miR-29b-3p were markedly depressed (P < 0.05). Serum expression of lncRNA H19 was negatively correlated with the expression of miR-29a-3p and miR-29b-3p among patients with AF (rs = -0.337, rs = -0.236). Moreover, up-regulation of H19 expression and down-regulation of miR-29a/b-3p expression facilitated proliferation and synthesis of extracellular matrix (ECM)-related proteins. SB431542 and si-VEGFA are able to reverse the promotion of miR-29a/b-3p on proliferation of CFs and ECM-related protein synthesis. The findings of the present study suggest that H19 promoted CF proliferation and collagen synthesis by suppressing the miR-29a-3p/miR-29b-3p-VEGFA/TGF-β axis, and provide support for a potential new direction for the treatment of AF.

Transformation Behavior of Ti-(45-x)Ni-5Cu-xCr (at%) (x = 0.5-2.0) Shape Memory Alloys

  • Im, Yeon-Min;Jeon, Young-Min;Kim, Min-Su;Lee, Yong-Hee;Kim, Min-Kyun;Nam, Tae-Hyun
    • Transactions on Electrical and Electronic Materials
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    • 제12권1호
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    • pp.28-31
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    • 2011
  • Transformation behavior and shape memory characteristics of Ti-(45-x)Ni-5Cu-xCr (x=0.5-2.0) alloys have been investigated by means of electrical resistivity measurements, differential scanning calorimetry, X-ray diffraction and thermal cycling tests under constant load. Two-stage B2-B19-B19' transformation occurred in Ti-(45-x)Ni-5Cu-xCr alloys. The B2-B19 transformation was separated clearly from the B19-B19' transformation in Ti-44.0Ni-5Cu-1.0Cr and Ti-43.5Ni-5Cu-1.5Cr alloys. A temperature range where the B19 martensite exists was expanded with increasing Cr content because decreasing rate of Ms (85 K / % Cr) was larger than that of Ms' (17 K / % Cr). Ti-(45-x)Ni-5Cu-xCr alloys were deformed in plastic manner with a fracture strain of 68% ~ 43% depending on Cr content. Substitution of Cr for Ni improves the critical stress for slip deformation in a Ti-45Ni-5Cu alloy due to solid solution hardening.

한국 12-23개월 소아에서 7가 폐구균 단백결합 백신 추가접종으로 유도된 6B와 19F 혈청형 특이 방어항체의 교차혈청형 6A, 6C, 19A에 대한 교차 반응 (Cross-reaction of 6B and 19F Specific Antibodies to Serotypes 6A, 6C, and 19A after Immunization with 7-valent Pneumococcal Conjugate Vaccine in Korean Children Aged 12-23 Months)

  • 김경효;양주연;박인호;임수영
    • Pediatric Infection and Vaccine
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    • 제20권2호
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    • pp.53-62
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    • 2013
  • 목 적 : 폐구균 단백결합 백신의 교차혈청형에 대한 교차방어 능력에 대한 연구는 매우 부족하다. 본 연구는 12-23개월 연령 소아에게 PCV7 추가접종 후 얻어진 면역혈청에서 교차혈청형 6A, 6C, 19A에 대한 교차 항체의 혈청학적 특성을 연구하기 위해 수행하였다. 방 법 : 백신 혈청형 6B, 19F와 교차혈청형 6A, 6C, 19A의 IgG, IgM 항체 농도와 옵소닌 인덱스를 ELISA와 OPA를 통해 측정하였다. 혈청군 6과 19에 대한 방어항체의 혈청학적 특성과 항원 특이도는 면역혈청내 IgM 제거, OPA, cOPA를 통해 확인하였다. 결 과 : 대조군 혈청에 비교하여 IgM 제거 면역혈청의 6B와 19F에 대한 옵소닌 인덱스가 감소하였고, 6A, 6C, 19A에 대한 옵소닌 인덱스도 역시 감소하였다. cOPA에서 6B 다당질, 19F다당질은 백신 혈청형 6B, 19F 뿐 아니라 6A, 6C, 19A의 방어 면역도 완전히 억제하였다. 결 론 : 6B, 19F를 포함한 PCV7은 교차혈청형 6A, 6C, 19A에 대한 IgG 및 IgM 교차방어 항체를 유도하였다. IgM 방어항체는 IgG 항체와 비교하여 백신 혈청형뿐 아니라 백신-연관 혈청형에 대해 더 높은 옵소닌 인덱스를 나타내었다. 향후 더 많은 소아와 성인의 면역 혈청으로 연구가 필요하다.

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LncRNA H19/miR-29b-3p/PGRN Axis Promoted Epithelial-Mesenchymal Transition of Colorectal Cancer Cells by Acting on Wnt Signaling

  • Ding, Dayong;Li, Changfeng;Zhao, Tiancheng;Li, Dandan;Yang, Lei;Zhang, Bin
    • Molecules and Cells
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    • 제41권5호
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    • pp.423-435
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    • 2018
  • This investigation was aimed at working out the combined role of lncRNA H19, miR-29b and Wnt signaling in the development of colorectal cancer (CRC). In the aggregate, 185 CRC tissues and corresponding para-carcinoma tissues were gathered. The human CRC cell lines (i.e. HT29, HCT116, SW480 and SW620) and normal colorectal mucosa cell line (NCM460) were also purchased. Si-H19, si-NC, miR-29b-3p mimics, miR-29b-3p inhibitor, si-PGRN and negative control (NC) were, respectively, transfected into the CRC cells. Luciferase reporter plasmids were prepared to evaluate the transduction activity of $Wnt/{\beta}-catenin$ signaling pathway, and dual-luciferase reporter gene assay was arranged to confirm the targeted relationship between H19 and miR-29b-3p, as well as between miR-29b-3p and PGRN. Finally, the proliferative and invasive capacities of CRC cells were appraised through transwell, MTT and scratch assays. As a result, overexpressed H19 and down-expressed miR-29b-3p displayed close associations with the CRC patients' poor prognosis (P < 0.05). Besides, transfection with si-H19, miR-29b-3p mimic or si-PGRN were correlated with elevated E-cadherin expression, decreased snail and vimentin expressions, as well as less-motivated cell proliferation and cell metastasis (P < 0.05). Moreover, H19 was verified to directly target miR-29b-3p based on the luciferase reporter gene assay (P < 0.05), and miR-29b-3p also bound to PGRN in a direct manner (P < 0.05). Finally, addition of LiCl ($Wnt/{\beta}-catenin$ pathway activator) or XAV93920 ($Wnt/{\beta}-catenin$ pathway inhibitor) would cause remarkably altered E-cadherin, c-Myc, vimentin and snail expressions, as well as significantly changed transcriptional activity of ${\beta}-catenin/Tcf$ reporter plasmid (P < 0.05). In conclusion, the lncRNA H19/miR-29b-3p/PGRN/Wnt axis counted a great deal for seeking appropriate diagnostic biomarkers and treatment targets for CRC.

Synthetic Studies on Carbapenam Skeletons

  • 구양모;서민효;이윤영
    • Bulletin of the Korean Chemical Society
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    • 제17권10호
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    • pp.909-918
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    • 1996
  • Syntheses of carbapenam skeletons were achieved from 1,3-propanediol through 1,3-dipolar cycloaddition. 3-(Tetrahydropyran-2-yloxy)-(10) and 3-(t-butyldimethylsilyloxy) propanal (13) were obtained from 1,3-propanediol. 3-Hydroxypropanals (10, 13, 14) were reacted with N-hydroxyglycine esters to give C-(2-hydroxyethyl)-N-alkoxycarbonylmethylnitrones (15a-15d). 1,3-Dipolar cycloaddition of the nitrones with methyl acrylate or ethyl crotonate gave 3-(2-hydroxyethyl)isoxazolidines (16a-16b, 17a-17b, 18, 19a-19b). 3-(2-Hydroxyethyl)isoxazolidines (17a, 17c, 19a, 19b) were converted to 3-(2-iodoethyl)isoxazolidines (21a-21d) or 3-phenylthiocarbonylmethylisoxazolidines (25a-25d) which were cyclized to give 2-oxa-1-azabicyclo[3.3.0]octanedicarboxylates (22a-22d, 26a-26d). 2-Oxa-1-azabicyclo[3.3.0]octane-4,8-dicarboxylates (22c-22d, 26c-26d) were transformed to 6-(l-hydroxyethyl)carbapenam-3-carboxylates (30a-30b, 31a-31b).

K대역용 인터디지털 대역통과 필터분석 (The Analysis of Interdigital Bandpass Filter for K-band)

  • 심재우;이영철;김영진
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2000년도 추계종합학술대회
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    • pp.186-189
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    • 2000
  • 본 논문에서는 K대역 무궁화 위성통신 하향변환기에 적용을 위한 대역통과 필터를 설계하였다. 중심 주파수가 19.6GHz에서 25~30%대역만을 통과시키기 위해 6차 인터디지털 대역통과 필터를 마이크로 스트립라인으로 구성하였다. 최적화 과정을 통한 모의실험 결과 통과대역 주파수에서 삽입손실은 -0.275dB, 반사계수는 -20.95dB을 보였다. 실제 제작후 측정결과 중심주파수는 19.15GHz 삽입손실은 -4.1dB, 입력반사계수는 -l5dB, 출력반사계수는 -l6dB임을 확인하였다.

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COVID-19 대응 군 간부의 소진, 이차적 외상성 스트레스 및 공감만족 (Burnout, Secondary Traumatic Stress, and Compassion Satisfaction of Military Officers Responding to COVID-19)

  • 백서영;황신우
    • 지역사회간호학회지
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    • 제33권2호
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    • pp.217-227
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    • 2022
  • Purpose: The purpose of this study was to identify individual and occupational factors influencing burnout, secondary traumatic stress, and compassion satisfaction in military officers who experienced supporting civilians in responding to COVID-19. Methods: This descriptive study was conducted on 140 special forces' military officers who experienced responding to disasters within 3 months. Data were collected through an online survey from September to November 2021. Results: The mean scores for burnout, secondary traumatic stress, and compassion satisfaction were 21.67±6.03, 20.54±8.21, and 39.72±8.12 out of 50, respectively. The significant factors that influenced burnout and secondary traumatic stress were 'higher passive stress copying styles' (B=0.17, p<.001; B=0.31, p=<.001, respectively) and 'lower social support (B=-0.11, p=.031; B=-0.10, p=.001, respectively). The compassion satisfaction was more significantly associated with 'higher self-efficacy' (B=0.37, p=<.001), 'higher active stress copying styles' (B=0.19, p=.006), and 'education responding to disasters' (B=2.04, p=.029). Conclusion: The results suggest that the strategies to increase social support, self-efficacy, and active stress coping styles should be considered in developing educational programs for military officers responding to disasters to minimize burnout, secondary traumatic stress and to improve compassion satisfaction.