• Title/Summary/Keyword: V2C

Search Result 9,803, Processing Time 0.04 seconds

Determination of Costunolide from Aucklandiae Radix and Substitutive Herbs by Reversed-Phase HPLC (HPLC를 이용한 목향 및 유사 한약재에 함유된 Costunolide 비교)

  • Oh, Ju-Hee;Hong, Seon-Pyo;Choi, Ho-Young;Park, Yong-Ki;Lee, Je-Hyun
    • The Korea Journal of Herbology
    • /
    • v.23 no.3
    • /
    • pp.61-66
    • /
    • 2008
  • Objecives : Aucklandiae Radix is a root of Aucklandia lappa which has been widely used for regulating the flow of vital energy, invigorating the spleen, alleviating pain. Aucklandiae Radix contains the costunolide which is the main ingredient. The substitutive Aucklandiae Radix are Inulae helenii Radix, Aristolchiae Radix, Vladimiriae Radix, and Inulae racemosi Radix in Korea and China. This paper is analysised and compared the costunolide and HPLC pattern in Aucklandiae Radix and substitute herbs. Methods : Chromatographic separation performed using C18 column(Luna 5 u, 250 mm ${\times}$ 4.6 mm) with a mixture of methanol and water(65:35)(v/v). The analyses detected at UV(210 nm). Results : Optimal extraction condition of costunolide was 100% methanol for 2hr. Costunolide was detected in Aucklandiae Radix and Vladimiriae Radix, but other herbs were not detected. In Korea herbal market, Aristolchiae Radix merchandise was identified as the imported Inulae helenii Radix. Conclusions : According to above results, this method was useful identified to Aucklandiae Radix and substitutive herbs. In Korea herbal market, Aristolchiae Radix was identified as Inulae helenii Radix.

  • PDF

Quantitative Determination of Amitriptyline and Its Metabolite in Rat Plasma by Liquid Chromatography-tandem Mass Spectrometry

  • Chae, Jung-Woo;Baek, In-Hwan;An, Jung-Hwa;Kim, Eun-Jung;Kwon, Kwang-Il
    • Bulletin of the Korean Chemical Society
    • /
    • v.33 no.7
    • /
    • pp.2163-2167
    • /
    • 2012
  • A rapid, specific, and reliable LC-MS/MS-based bioanalytical method was developed and validated in rat plasma for the simultaneous quantitation of amitriptyline and its metabolite nortriptyline. Chromatographic separation of these analytes was achieved on a Gemini C18 column ($50{\times}4.60mm$, $5{\mu}m$) using reversed-phase chromatography. The mobile phase was an isocratic solvent system consisting of 1% formic acid in water and methanol (10:90, v/v), at a flow rate of 0.2 mL/min. The analytical range was set as 0.1-500 ng/mL for amitriptyline and 0.08-500 ng/mL for nortriptyline using a $200{\mu}L$ plasma sample. The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods. The validated method was successfully applied to a pharmacokinetic study in six rats after oral administration of amitriptyline (15 mg/kg). This method allows laboratory scientists to rapidly determine amitriptyline and nortriptyline concentrations in plasma.

Characteristics of Refractive Index Profiles at Different Temperatures in $LiNbO_3$ and $KTiOPO_4$ Waveguide Formed by 350 keV Light Ions

  • Wang, Ke-Ming;Feng Chen;Hui Hu;Xia, Hui-Hao;Wang, Xue-Lin;Shi, Bo-Rong;Lu, Qing-Ming
    • Journal of the Korean Vacuum Society
    • /
    • v.12 no.S1
    • /
    • pp.28-32
    • /
    • 2003
  • Both $LiNbO_3$ and $KTiOPO_4$ samples were implanted with 350 keY $H^+$ and $He^+$ ions at different doses ranging from $1 ${\times}$\times10^{16}$ to of $5 ${\times}$\times10^{16}$ ions/$\textrm{cm}^2$. Single and multi-energy implantations were performed at room temperature. Mono-mode or a few modes in both $LiNbO_3$ and $KTiOPO_4$ waveguides were observed. The effect of temperature on the refractive index profiles of $LiNbO_3$ and $KTiOPO_4$ waveguids was studied. The temperature covered from room temperature, $200^{\circ}C$, 194.5 K (dry ice) and 77K (liquid nitrogen). Different mechanisms are needed to interpret the observed behavior. A n, increased mono-mode $LiNbO_3$ waveguide was formed by multi-energy keV $He^+$ ions.

The Viable But Nonculturable State of Kanagawa Positive and Negative Strains of Vibrio parahaemolyticus

  • Bates, Tonya C.;Oliver, James D.
    • Journal of Microbiology
    • /
    • v.42 no.2
    • /
    • pp.74-79
    • /
    • 2004
  • Ingestion of shellfish-associated Vibrio parahaemolyticus is the primary cause of potentially severe gas-troenteritis in many countries. However, only Kanagawa phenomenon (hemolysin) positive (KP$\^$+/) strains of V. parahaemolyticus are isolated from patients, whereas >99% of strains isolated from the environment do not produce this hemolysin (i.e. are KP$\^$-/). The reasons for these differences are not known. Following a temperature downshift, Vibrio parahaemolyticus enters the viable but noncultur-able (VBNC) state wherein cells maintain viability but cannot be cultured on routine microbiological media. We speculated that KP$\^$+/ and KP$\^$-/ strains may respond differently to the temperature and salinity conditions of seawater by entering into this state which might account for the low numbers of cul-turable KP$\^$+/ strains isolated from estuarine waters. The response of eleven KP$\^$+/ and KP$\^$-/ strains of V. parahaemolyticus following exposure to a nutrient and temperature downshift in different salinities, similar to conditions encountered in their environment, was examined. The strains included those from which the KP$\^$+/ genes had been selectively removed or added. Our results indicated that the ability to produce hemolysin did not affect entrance into the VBNC state. Further, VBNC cells of both biotypes could be restored to the culturable state following an overnight temperature upshift.

Optical properties of InxGa1-xN/GaN epilayers (InxGa1-xN/GaN 박막의 광학적 특성)

  • Jun, Yong-Ki;Chung, Sang-Jo
    • Korean Journal of Materials Research
    • /
    • v.12 no.1
    • /
    • pp.54-57
    • /
    • 2002
  • We have grown undoped $In_ xGa_{1-x}N,\; In_xGa_{1-x}N:Si\;and\;In_{0.1}Ga_{0.9}N:Zn$ thin films by MOCVD at temperature between 880 and $710^{\circ}C which endows various In composition in the epilayer from 0.07 to 0.22 as examined using X-ray diffraction, optical absorption(OA), photocurrent (PC) and photoluminescence (PL). The In molar fraction estimated from PL results is higher than that from the OA, PC, and X-ray data for $X{\le}0.22$, which may be caused by phase separation. However, the In molar fraction estimated by X-ray diffraction, OA, PC and PL for $In_xGa_{1-x}N:Si$ does not show discrepancy. With the appropriate Zn doping in undoped $In_{0.1}Ga_{0.9}N$, the emission peak is shifted from 3.15 eV which originates from the band edge emission peak to 2.65 eV which resulted from the conduction band to acceptor transition due to a deep acceptor level.

The thermal cycling stability of V-Ti based alloy

  • Park, Jeoung-Gun;Kim, Dong-Myung;Jang, Kuk-Jin;Han, Jai-Sung;Lee, Jai-Young
    • Journal of Hydrogen and New Energy
    • /
    • v.9 no.3
    • /
    • pp.111-118
    • /
    • 1998
  • The intrinsic degradation behavior of $(V_{0.53}Ti_{0.47})_{0.925}Fe_{0.075}$ alloy with BCC structure and the two plateau regions (the low and high plateau region) has been investigate during the temperature-induced hydrogen absorption-desorption cycling (thermal cycling). After 400 thermal cycles between room temperature and $600^{\circ}C$ under 10atm $H_2$, the total reversible hydrogen absorption capacity decreased by about 40%. From thermal desorption analysis it was found that the degradation behavior at each plateau region was different. In addition, XRD analysis showed that the crystal structure of the sample in de-hydrided state was changed from BCC to BCT after degradation, and that of the sample in hydrided state it was maintained as FCC although peaks were broadened after degradation. From the result of static isothermal hydrogenation treatment it were found that crystal structure change from BCC to BCT was caused by the thermal energy. TEM analysis showed that the peak broadening was due to the formation of an amorphous phase in FCC matrix.

  • PDF

A Study of Development on Waterfront of Fishing Village National Harbor and Swimming Beach - Foused on Anmock Harbor in Gangwon Province - (어촌어항과 해수욕장의 워터프론트 개발 계획에 관한 연구 - 강원 안목항을 중심으로 -)

  • Cho, Won-Seok;Kim, Heung-Gee
    • Journal of the Korean Institute of Rural Architecture
    • /
    • v.10 no.2
    • /
    • pp.37-44
    • /
    • 2008
  • Both environments and landscape can be checked in development of waterfront, Nevertheless this conditions does not control at the programming phase as much as necessary in absorption speed of development. Therefore this paper aims to analyze for the environmental space and sustainable landscape. In case of Anmock Harvor, our team carried out interview method by satisfaction level and attractiveness to take requirements of users. This research is to provide that fishing village-national harbor and swimming beach based on the waterfront scale, consists of pedestrian mall, promenade circulation, various water friendly park and beautiful pier. This study proposes two strategies for better life by waterfront space: first, renewal guideline is necessary to masterplan: second, systematic comprehensive plan can be established regal procedures(District Unit Plan & Agreement of Landscape) by participation of regional resident. This survey of waterfront spatial data is expected to use for environmental improvement of fishing village, harbor and swimming beach.

  • PDF

A study on the fabrication and characteristics of the scaled MONOS nonvolatile memory devices for low voltage EEPROMs (저전압 EEPROM을 위한 Scaled MONOS 비휘발성 기억소자의 제작 및 특성에 관한 연구)

  • 이상배;이상은;서광열
    • Electrical & Electronic Materials
    • /
    • v.8 no.6
    • /
    • pp.727-736
    • /
    • 1995
  • This paper examines the characteristics and physical properties of the scaled MONOS nonvolatile memory device for low programming voltage EEPROM. The capacitor-type MONOS memory devices with the nitride thicknesses ranging from 41.angs. to 600.angs. have been fabricated. As a result, the 5V-programmable MONOS device has been obtained with a 20ms programming time by scaling the nitride thickness to 57.angs. with a tunneling oxide thickness of 19.angs. and a blocking oxide thickness of 20.angs.. Measurement results of the quasi-static C-V curves indicate, after 10$\^$6/ write/erase cycles, that the devices are degraded due to the increase of the silicon-tunneling oxide interface traps. The 10-year retention is impossible for the device with a nitride less than 129.angs.. However, the MONOS memory device with 10-year retentivity has been obtained by increasing the blocking oxide thickness to 47.angs.. Also, the memory traps such as the nitride bulk trap and the blocking oxide-nitride interface trap have been investigated by measuring the maximum flatband voltage shift and analyzing through the best fitting method.

  • PDF

Terbia Addition Effects on Accelerated aging Characteristics of (Pr, Co, Cr)-doped ZnO Varistors ((Pr, Co, Cr)-doped ZnO 바리스터의 가속열화특성에 테르비아 첨가효과)

  • Nahm, Choon-Woo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.20 no.6
    • /
    • pp.508-513
    • /
    • 2007
  • The electrical properties and stability of $ZnO-Pr_6O_{11}-CoO-Cr_2O_3-based$ varistors were investigated for different $Tb_4O_{11}$ amounts in the range of $0{\sim}1.0\;mol%$. As the $Tb_4O_{11}$ amount increased, the sintered density increased in the range of $99.1{\sim}101.1%$ of theoretical density and the average grain size decreased in the range of $7.7{\sim}4.8{\mu}m$. The varistor voltage increased in the range of $280.9{\sim}715.8V/mm$ and the nonlinear coefficient increased in the range of $26.4{\sim}44.4$ with the increased of $Tb_4O_{11}$ amount. The 0.25 mol% $Tb_4O_{11}$-doped varistors exhibited the high electrical stability, with -0.1% in variation rate of varistor voltage, -0.7% in variation rate of nonlinear coefficient, and +17.4% in variation rate of leakage current for specified dc accelerated aging stress of $0.95V_{1mA}/150^{\circ}C/24h$.

A Study on the manufacturing of porous membrane by the aluminum anodizing (알루미늄 양극산호를 이용한 다공성 견막 제조에 관한 연구)

  • Yoon, Jae-Hwan;Kang, Tak
    • Journal of Surface Science and Engineering
    • /
    • v.13 no.4
    • /
    • pp.221-227
    • /
    • 1980
  • When anodizing the Al in the acid electrolyte, it is well known that the parallel pores grow continuously perpendicular to the surface. This fact can be used for the manufacturing of the porous membrane, if thc pores pass through the anodized foil. Anodizing both surfaces of the Al-foil spontaneously in 20$^{\circ}C$, 2% oxalic acid under tile potentiostatic condition, it is found that the harrier layer remaining in the midst of the foil finally disappears and thc pores pass through the foil. And examined the porous structure change when the voltage is changed during the anodizing treatment. From the result, it is revealed that the new pores and cell grow, adjusting themselves to the final voltage. The characteristic of the porous membrane is greatly dependent upon the diameter of the pore and the cell. So studied the relationship between the voltage and the diameter of the pore and the cell quantitatively with the aid of field-assisted dissolution concept. And derived the following two equation, Pi = 8.32Vi, Ci = 26.80Vi. These equations are in good accord with the experimental data above 30V, but do not accord nuder 30V.

  • PDF