• 제목/요약/키워드: B13

검색결과 7,807건 처리시간 0.041초

Thienobenzothiopyranones 111-New 4H-thieno[2,3-b][1]benzothiopyran-4-ones Carrying Different Heterocyclic Moieties of Expected Pharmacological Interest

  • El-Subbagh, H.I.;El-Emam, A.A.;El-Ashmawy, M.B.;Shehata, I.A.
    • Archives of Pharmacal Research
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    • 제13권1호
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    • pp.24-27
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    • 1990
  • Reaction of 2-formyl-4H-thieno [2, 3-b] benzothiopyran-4-one (1) with different heterocyclic amines afforded the corresponding Schiff's bases (2-4). Diethyl malonate, ethyl cyanoacetate and malononitrile were reached with 1 to afford compounds 5, 7 and 8, respectively. Compound 5 was cyclized to the pyrazolidin-3, 4-dione (6) by the action of hydrazine hydrate, whereas compound 7 was utilized for the synthesis of the thiazolin-4 one derivatives (9-13).

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차동 연결된 Varactor를 이용한 6Gbps CMOS 피드포워드 이퀄라이저 (A 6Gbps CMOS Feed-Forward Equalizer Using A Differentially-Connected Varactor)

  • 문용삼
    • 대한전자공학회논문지SD
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    • 제46권2호
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    • pp.64-70
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    • 2009
  • 0.13-um CMOS 공정을 이용하여 3GHz에서 6.2dB의 gain을 갖는 피드포워드 이퀄라이저를 구현하고 14.7dB의 감쇄를 갖는 7-m SATA 케이블을 통해 6Gbps의 데이터를 에러 없이 복원하였다. 제안한 이퀄라이저 회로는 varactor의 차동 연결을 통해서 기존 이퀄라이저에서 사용되는 varactor 면적의 1/4만을 사용하도록 설계되어 pad-frame에 집적할 수 있을 뿐만 아니라, 높은 동작 주파수 및 3.6mW의 낮은 전력 소모를 유지할 수 있다.

OSU89B에 의한 한반도 일원의 지오이드에 대한 연구 (A Study on the Geoid in and around the Korean Peninsula by analysing OSU89B)

  • 최광선
    • 한국측량학회지
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    • 제9권2호
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    • pp.67-72
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    • 1991
  • OSU89B를 이용하여 한반도 일원의 지오이드와 수직선편차에 대하여 연구하였다. 한반도 일원에서 지오이드는 GRS1980 지구타원체에 비해 +3m~+35m 범위의 변화를 나타내며, 전반적으로 서에서 동으로 높아져 감이 특징적이다. 수직선편차는 $\xi$가 -8.9"~8.0", $\eta$가 -13.1"~9.0"의 범위의 변화를 보이며 전반적으로 서편경향이 특징적이다.며 전반적으로 서편경향이 특징적이다.

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Crystal structure of the BAFF-BAFF-R complex and its implications for receptor activation

  • Lee, Jie-Oh
    • 한국결정학회:학술대회논문집
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    • 한국결정학회 2003년도 춘계학술연구발표회
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    • pp.13-13
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    • 2003
  • B-cell activating factor (BAFF) is a key regulator of B-lymphocyte development. Its biological role is mediated by the specific receptors BCMA, TACI, and BAFF-R. We have determined the crystal structure of BAFF-R extracellular domain bound to BAFF at a resolution of 3.3 ?. The cysteine-rich domain(CRD) of the BAFF-R extracellular domain adopts a b-hairpin structure and binds to the virus-like BAFF cage in a 1:1 molar ratio. The conserved DxL motif of BAFF-R is located on the tip of the b-turn, and plays an indispensable role in the binding of BAFF. The crystal structure shows that a unique dimeric contact occurs between the BAFF-R monomers in the virus-like cage complex. Both of the CRDs of TACI contain the DxL motifs and simultaneously interact with the BAFF dimer in the virus-like cage.

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청미래덩굴 뿌리에서 추출한 순차분획물의 항균활성과 성분 분석 (Antimicrobial Activity and Composition of Extract from Smilax china Root)

  • 박인호;송종호;권혁동;이원구
    • 한국식품영양과학회지
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    • 제27권4호
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    • pp.574-584
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    • 1998
  • Antimicrobial activities, extraction yields and chemical compositions of the extract from the powder of vacuum dried Smilax china root on various solvents were investigated. Antimicrobial activities against. A rhizogenes, A. tumefaciens, C. utilis, S. cerevisiae, B. megaterium, B. subtilis and E. coli were measured by disc diffusion method. Methanol, chloroform, ethylacetate and butanol extracts exhibited potent antimicrobial activities against B. megaterium and B. subtilis. Also, methanol, ethylacetate and butanol extracts had the activities against A. rhizogenes, and chloroform and ethylacetate extracts against A. tumefacciens. The extraction yields were 13.10%, 8.71%, 2.73%, 0.83%, 0.54% and chemical compositions of their extracts were very different according to the kinds of solvents. The main chemical groups of ethylacetate, methanol, chloroform and butanol extracts were 45.99% phenolics, 36.10% acids, 29.13% phenolics and 18.96% phenolics, respectively.

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A Dual-Band CMOS Low-Noise Amplifier

  • 오태현;전희석;정영호;신형철
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.489-490
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    • 2006
  • This paper presents a switch type 2.4/5.8 GHz dual band low-noise amplifier, designed with $0.13{\mu}m$ RF CMOS technology. Using MOS switch allows the LNA to have two different input transconductance and output capacitance modes. Given supply voltage of 1.2 V, the simulation exhibits gains of 8.1 dB and 17.1 dB, noise figures of 3.1 dB and 2.57 dB and power consumptions of 13.0 mW and 10.2 mW at 2.4 GHz and 5.8 GHz, respectively.

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Analysis of Physical Characteristics on Compound Semiconductor $B_{13}P_2$ using APCVD

  • 홍근기;정예초;김철주
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.473-474
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    • 2006
  • Boron Phosphide films were deposited on (111) Si substrate at $650^{\circ}C$, by the reaction of B2H6 with PH3 using APCVD. N2 was carried out as carrier gas. The optimal gas rates were $20\;m{\ell}/min$ for B2H6, $60\;m{\ell}/min$ for PH3 and $1\;{\ell}/min$ for N2. After as grown the films were insitu annealed for 1hour in N2 ambient at $550^{\circ}C$ and measured. The measurement of AFM shows that the RMS is $29.626{\AA}$ for the reaction temperature at $650^{\circ}C$. The measurement of XRD shows that the films have the orientation of (101). Also, the measurement of AES is shown that the films have B13P2 stoichiometry.

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EFFECT OF FLASH ANNEALING ON MAGNETIC PROPERTIES OF Fe-BASED NANOCRYSTALLINE ALLOYS

  • Yu, Xiaojun;Quan, Baiyun;Sun, Guiqin;Narita, Kenji
    • 한국자기학회지
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    • 제5권5호
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    • pp.507-510
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    • 1995
  • A heat-treatment method of pre-annealing and then flash annealing(FA) has been used to improve the soft magnetic properties of nanocrystalline $Fe_{76}CuSi_{13}B_{10}$ and $Fe_{74}CuNb_{3}Si_{12}B_{10}$ alloys. Outstanding magnetic properties of nanocrystalline $Fe_{74}CuNb_{3}Si_{12}B_{10}$ alloy were attained by flash-annealing in air after annealed at $500^{\circ}C$ for 0.5hr below the crystallization temperature. The same results were obtained for $Fe_{74}CuSi_{13}B_{10}$ alloy. The measurment of relief of stress and X-ray diffraction were used to analyze the effect of flashannealing.

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Synthesis and Characterization of 14-Membered Tetraaza Macrocycles with N-Ethyl Groups and their Nickel(Ⅱ) and Copper(Ⅱ) Complexes

  • Kang Shin-Geol;Kweon Jae Keun
    • Bulletin of the Korean Chemical Society
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    • 제13권3호
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    • pp.256-259
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    • 1992
  • The 14-membered tetraaza macrocyclic ligand 1,8-diethyl-5,12-dimethyl-1,4,8,11-tetraazacyclote tradeca-4,11-diene(B) can be synthesized as its dihydroperchlorate salt by the one-pot reaction of 2-ethylaminoethylamine, methylvinyl ketone, and perchloric acid in absolute ethanol. The reaction of Ni(II) or Cu(II) ion and the salt yields $[M(B)]^{2+}$ (M = Ni(II) or Cu(II)), which reacts with $NaBH_4$ to produce $[M(D)]^{2+}$ (D = 1,8-diethyl-5,12-dimethyl-1,4,8,11-tetraazacyclote tradecane). The complexes $[M(L)]^{2+}$ (L = B or D) have planar geometry and contain two ethyl groups at the donor nitrogen atoms of the ligands. The red solids $[Cu(B)](X)_2(X)$ = $ClO_4-$ or $PF_6^-$) react with water molecules of atmospheric moisture to produce the purple solids in which water molecules are coordinated to the metal ion. Synthesis, characterization, and the properties of the new N-ethylated macrocyclic ligands and their Ni(II) and Cu(II) complexes are reported.

A Cell-Based Assay System for Monitoring NF-$\kappa$B Activity in Human Epidermal Keratinocytes: A Screening Tool of the Antioxidants and Anti-inflammatories for Dermatological Purpose

  • Moon, Ki-Young;Hahn, Bum-Soo;Lee, Jinseon;Kim, Yeong-Shik
    • 대한화장품학회지
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    • 제27권1호
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    • pp.17-27
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    • 2001
  • A cell-based assay system for monitoring NF-$textsc{k}$B activity was developed to determine the influence of activated NF-$textsc{k}$B in human HaCaT cells. The pNF-$textsc{k}$B-SEAP-NPT plasmid that permits expression of the secreted alkaline phosphatase (SEAP) reported gene in response to the NF-$textsc{k}$B activity and contains neomycin phosphotransferase (NPT) gene for the geneticin resistance in host cells was constructed and transfected into human keratinocyte cell line HaCaT. Human HaCaT transfectant cells secreted the SEAP enzyme into the culture medium in a time-dependent manner until 72h. NF-$textsc{k}$B activities were measured in the SEAP reporter gene assay using a fluorescent detection method. The treatment of HaCaT cell transfectants with known antioxidants [e.g., N-acetyl-L-cysteine and vitamin C] showed inhibition of NF-$textsc{k}$B activity in a time-and concentration-dependent manner. The phorbol 12-myristate 13-acetate (PMA) known as a stimulator of NF-$textsc{k}$B expression demonstrated that it increased NF-$textsc{k}$B activity in a time- and concentration-dependent manner. This assay system could be used to determine the quantitative measurement of NF-$textsc{k}$B activity in the human skin and allow the screening of anti-inflammatory agents from various synthetic chemicals and natural products for dermatological purpose. Abbrevitions used: NF-$textsc{k}$B, nuclear factor kappa B; I-$textsc{k}$B, Inhibitory kappa B; SEAP, secreted alkaline phosphatase; NPT, neomycin phosphotransferease; PCR, polymerase chain reaction: dNTP, deoxynucleoside triphosphates; DMEM, dulbecco’s modified eagle medium; FBS, fetal bovine serum; PBs, phosphate-buffered saline; MUP, 4-methylumbellifery phosphate; NAC, N-acetyl-L-cysteine; DMSO, dimethyl sulfoxide; PMA, phorbol 12-myristate 13-acetate.

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