• 제목/요약/키워드: Ta-N

검색결과 652건 처리시간 0.025초

New Zealand White 토끼의 생식세포 및 체세포 분열에 의한 염색체 분석 (Chromosomal Analysis of Meiosis and Mitosis in New Zealane White Rabbit)

  • 신선희;김희수;최영현;이원호
    • 생명과학회지
    • /
    • 제11권4호
    • /
    • pp.354-361
    • /
    • 2001
  • Chromosomal characteristics of New Zealane White rabbit was studied at meiosis and mitosis. The meiotic chromosomal preparations were mad with the modified air-drying method and karyotype analysis was performed with the G-banding technique, using isolated mitotic metapase chromosomes of the New Zealand White rabbit. Chromosomes, sex vesicles and centromeres could be classified in the zygotene and the pachytene of the meiosis I. The hair-like processes projecting laterally from the axes of bivalent chromosomes at the mid-to-late pachytene were observed and made the appearance of the lampbrush chromosome structure. Chromosomes could be classified onthe basis of the numbers and locations of chiasma in the diakinesis. Twenty-one autosomal bivalents and a single unequal terminally associated X-Y bivalent were observe during the late prophase and the metaphase of the meiosis I. Most of the bivalent types observed in the New Zealand White rabbit spermatrocytes were 1CH, 1TAl, and 2TA bivalents. The mean chiasma frequency(CF) of the male New Zealand White rabbit was 30.2 and it was found that the CF value tended to decrease through diakinesis and the metaphase I. The karyotype of the New Zealand White rabbit was a male chromosome number of 44(2n=44) comprising 8 pairs of metacentric, 9 pairs of submetacentric, 4 pairs o acrocentric autosomes, metacentric X chromosome and acrocentric Y chromosome.

  • PDF

마우스 대식세포에서 스테로이드 호르몬과 세포내 $Ca^{++}$ 타우린수송체의 활성에 미치는 영향 (Effect of Steroid Hormones and Intracellular $Ca^{++}$ on Taurine Transporter Activity in Murine Macrophage Cell Line)

  • 김하원;안혜숙;이선민;이은진;현진원;박건구;박태선;김병각
    • Biomolecules & Therapeutics
    • /
    • 제9권1호
    • /
    • pp.40-45
    • /
    • 2001
  • The activity of taurine transporter is affected by various extracellular stimuli such as ion, hormone and stress. To assess effects of steroid hormones antral cyclosporin A (CsA) on the taurine transporter activity, murine monocytic RAW264.7 cell line was stimulated with dexamethasone (DM), triamcinolone (TA), cortisone (CS), hydrocortisone (HCS), prednisone (PSN), prednisolone (PSL) and methylprednisolone (MPSL) in the presence of 12-0-tetradecanoylphorbol-13-acetate(TPA). Treatment of TPA on the cell line led to significant reduction of taurine transporter activity. However, in case of stimulation of the cells with steroid hormones in the presence of TPA, all of them recovered TPA-induced reduction of the taurine transporter activity. Treatment of the cells with CsA led to significant reduction of the taurine transporter activity. Ionomycin (IM) recovered the reduced taurine transporter activity by CsA, but failed in the presence of EDTA, a calcium chelating agent. These results showed that glucocorticoid hormone recovered TPA-induced reduction of taurine transporter activity and that IM recovered CsA-induced reduction of the transporter activity by increasing intracellular free $Ca^{++}$ concentration.n.

  • PDF

하소온도변화에 따른 (Na,K)NbO3계 무연 압전세라믹스의 압전 및 유전특성 (Piezoelectric and Dielectric Characteristics of Lead-free (Na,K)NbO3 Piezoelectric Ceramic System according to Calcination Temperature)

  • 류성림;정광현;류주현;이병률;정영호
    • 한국전기전자재료학회논문지
    • /
    • 제18권9호
    • /
    • pp.821-826
    • /
    • 2005
  • In this paper, in order to develop lead-free piezoelectric ceramics, $(Li_{0.04}Na_{0.44}K_{0.52)(Nb_{0.86}Ta_{0.10}Sb_{0.04})O_3$ ceramics were fabricated with the variation of calcination temperature and sintering temperature. The ceramics couldn't be sintered at temperature less than $1110^{\circ}C$ and showed the highest density at calcination temperature of $800^{\circ}C$. Crystal structure of the ceramics showed pseudo-tetragonal phase. At the calcination temperature of $800^{\circ}C$ and sintering temperature of $1110^{\circ}C$, the optimal values of $density=4.64g/cm^3,\;kp=0.45,\;{\varepsilon}r=1336,\;d_{33}=254pC/N\;and\;Tc=335^{\circ}C$ were obtained.

다양한 열처리 조건에 따른 SBT 박막의 전기적 특성 (Electric Properties of SBT Thin Films with various Annealing Conditions)

  • 조춘남;김진사;오용철;신철기;박건호;최운식;김충혁;홍진웅;이준웅
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
    • /
    • pp.589-592
    • /
    • 2002
  • The $Sr_{0.7}Bi_{2.3}Ta_2O_9$(SBT) thin films are deposited on Pt-coated electrode(Pt/TiO2/SiO2/Si) using RF magnetron sputtering method. The structural and electric properties of SBT capacitors were influenced with annealing atmosphere. In the XRD pattern, the SBT thin films in all annealing atmosphere had (105) orientation. In the SEM images, Bi-layered perovskite phase was crystallized in all annealing atmosphere and grains largely grew in oxygen annealing atmosphere. The maximum remanent polarization and the coercive electric field in oxygen annealing atmosphere are $12.40{\mu}C/cm^2$ and 48kV/cm respectively. The dielectric constant and leakage current density annealing in oxygen atmosphere are 340 and $6.81{\times}10^{-10}A/cm^2$ respectively. The fatigue characteristics of SBT capacitors did not change up to $10^{10}$ switching cycles.

  • PDF

열처리 온도에 따른 Pt/SBT/Pt 커패시터의 피로특성 (Fatigue Properties of SBT capacitor with annealing temperatures)

  • 조춘남;김진사;오용철;신철기;최운식;김충혁;송민종;이준용
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2001년도 기술교육위원회 창립총회 및 학술대회 의료기기전시회
    • /
    • pp.5-8
    • /
    • 2001
  • The $Sr_{0.8}Bi_{2.4}Ta_{2}O_{9}(SBT)$ thin films are deposited on Pt-coated electrode$(Pt/TiO_{2}/SiO_{2}/Si)$ using RF magnetron sputtering method. With increasing annealing tempera ture from $600[^{\circ}C]$ to $850[^{\circ}C]$, Bi-layered perovskite phase was crystallized above $650[^{\circ}C]$. The dielectric constant is 213 at annealing temperature of $750[^{\circ}C]$ and dielectric loss have a stable value within 0.1. Leakage current density is $1.01{\times}10^{-8} A/cm^{2}$ at annealing temperature of $750[^{\circ}C]$ The fatigue characteristics of SBT thin films did not change up to $10^{10}$ switching cycles.

  • PDF

열처리에 따른 SBT 캐패시터의 분극특성 (Polarization properties of SBT capacitor with annealing temperatures)

  • 조춘남;김진사;신철기;정일형;이상극;이동규;정동회;김충혁;이준웅
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2001년도 기술교육위원회 창립총회 및 학술대회 의료기기전시회
    • /
    • pp.9-12
    • /
    • 2001
  • The $Sr_{0.8}Bi_{2.4}Ta_2O_9(SBT)$ thin films are deposited on Pt-coated electrode($Pt/TiO_2/SiO_2/Si$) using RF magnetron sputtering method. With increasing post-annealing temperature from $600[^{\circ}C]$ to $850[^{\circ}C]$, Bi-layered perovskite phase was crystallized above $650[^{\circ}C]$. The maximum remanent polarization and the coercive electric field is 11.60[${\mu}C/cm^{2}$] 48[kV/cm] respectively. The leakage current density of SBT capacitor at post-annealing temperature of $750[^{\circ}C]$ is $1.01{\times}10^{-8}A/cm^2$ at 100[kV/cm]

  • PDF

Protective effect of methanolic extract of Ganoderma lucidum P. Karst. Reishi from South India against doxorubicin-induced cardiotoxicity in rats

  • Sheena, N;Ajith, TA;Janardhanan, KK
    • Advances in Traditional Medicine
    • /
    • 제5권1호
    • /
    • pp.62-68
    • /
    • 2005
  • Doxorubicin is a powerful anticancer antibiotic extensively used in the treatment of several types of cancers. Long-term administration of this drug results in cumulative dose related cardiotoxicity due to enhanced production of free radicals leading to oxidative stress. Our earlier investigations have demonstrated significant antioxidant, anti-inflammatory and antitumour properties of Ganoderma lucidum extracts. We extended our investigations to evaluate the protective effect of Ganoderma lucidum extract against doxorubicin-induced cardiotoxicity. Administration of 3 doses of doxorubicin, 6 mg/kg body weights, i.p. per each dose, alternative days, showed dear signs of cardiotoxicity in rats. The drug enhanced serum creatine kinase (CK) activity and lipid peroxidation in tissue drastically. The drug also induced significant decrease in GSH level and activities of CAT, SOD and GPx. Administration of methanolic extract of G.lucidum (500 and 1,000 mg/kg body weight) significantly increased the level of GSH and activities of CAT, SOD and GPx. Activity of CK was significantly lowered in a dose dependent manner. The treatment also caused significant decrease in lipid peroxidation (MDA). The results thus indicated that methanolic extract of G.lucidum prevented oxidative stress caused by doxorubicin administration and the increase in serum CK activity and lipid peroxidation in the tissue. The experimental findings suggest the therapeutic potential of G.lucidum as adjuvant in cancer chemotherapy.

Properties of $Sr_{0.8}Bi_{2.3}{(Ta_{1-x}Nb_{x})}_{2}O_{9+{\alpha}}$ Thin Films

  • Park, Sang-Jun;Jang, Gun-Eik
    • Transactions on Electrical and Electronic Materials
    • /
    • 제1권1호
    • /
    • pp.22-25
    • /
    • 2000
  • Polycrystalline SBTN layered ferroelectric thin film with various Nb mole ratios were prepared by sol-gel method Pt/ $SiO_2$/Si (100) substrates. The films were annealed at different temperature and characterized in terms of phase and microstructure. The films were crystallized with a high (105) diffraction intensity and had rodike structure, SBTN films fired at 800$^{circ}C$ revealed standard hysteresis loops with no fatigue for up to 10$^{10}$ cycles. At an applied voltage of 5V the dielectric constant($varepsilon$) , dissipation factor (tan $delta$), remanent polarization(ZPr) and coercive field(Ec) of typical S $r_{0.8}$B $i_{2.3}$(T $a_{1-x}$ N $b_{x}$) $O_{9+}$$alpha$/ thin film(x=0.1) prepared on Pt/ $SiO_2$/Si (100) were about 277.7, 0.042, 3.74$mu$C/$textrm{cm}^2$, and 24.8kv/cm respectively.ly.y. respectively.ly.y.y..

  • PDF

Fabrication of MFISFET Compatible with CMOS Process Using $SrBi_2Ta_2O_9$(SBT) Materials

  • You, In-Kyu;Lee, Won-Jae;Yang, Il-Suk;Yu, Byoung-Gon;Cho, Kyoung-Ik
    • Transactions on Electrical and Electronic Materials
    • /
    • 제1권1호
    • /
    • pp.40-44
    • /
    • 2000
  • Metal-ferroelectric-insulator-semoiconductor field effect transistor (MFISFETs) were fabricated using CMOS processes. The Pt/SBT/NO combined layers were etched for forming a conformal gate by using Ti/Cr metal masks and a two step etching method, By the method, we were able to fabricate a small-sized gate with the dimension of $16/4{\mu}textrm{m}$ in the width/length of gate. It has been chosen the non-self aligned source and drain implantation process, We have deposited inter-layer dielectrics(ILD) by low pressure chemical vapor deposition(LPCVD) at $380^{circ}C$ after etching the gate structure and the threshold voltage of p-channel MFISFETs were about 1.0 and -2.1V, respectively. It was also observed that the current difference between the $I_{ON}$(on current) and $I_{OFF}$(off current) that is very important in sensing margin, is more that 100 times in $I_{D}-V_{G}$ hysteresis curve.

  • PDF

열처리 온도에 따른 Pt/SBT/Pt 캐패시터의 유전특성 (Dielectric Properties of SBT capacitor with annealing temperatures)

  • 조춘남;오용철;정일형;김진사;신철기;최운식;김충혁;이준웅
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2001년도 하계학술대회 논문집 C
    • /
    • pp.1546-1548
    • /
    • 2001
  • The $Sr_{0.8}Bi_{2.4}Ta_2O_9$(SBT) thin films are deposited on Pt-coated electrode(Pt/$TiO_2$/ $SiO_2$/Si) using RF magnetron sputtering method. With increasing annealing temperature from 600[$^{\circ}C$] to 850[$^{\circ}C$], Bi-layered perovskite phase was crystallized above 650[$^{\circ}C$]. The dielectric constant is 213 at annealing temperature of 750[$^{\circ}C$] and dielectric loss have a stable value within 0.1. Leakage current density is $1.01{\times}10^{-8}A/cm^2$ at annealing temperature of 750[$^{\circ}C$].

  • PDF