• 약학회지
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• 제44권3호
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• pp.245-250
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• 2000

Because nonsteroidal anti-inflammatory drugs are reported to cause fluid retention and hypertension by inhibition of prostaglandin synthesis, the effects of piroxicam on pharmacodynamics and pharmacokinetics of nifedipine were studied in male spontaneously hypertensive rats. They received nifedipine (0.5 mg/kg) alone or combined with piroxicam (5 mg/kg) intravenously. Plasma levels norepinephrine, an index of sympathetic stimulation, were measured prior to each treatment and 5 min after drug administration. Changes in blood pressure were examined serially and blood samples for analysis of nifedipine were also taken for 6 hr following drug administration. Plasma nifedipine concentration were assayed by HPLC and pharmacokinetic parameters were calculated. Blood pressure was reduced (p<0.01), but plasma norepinephrine level was increased (p<0.05) by nifedipine administration. Anti-hypertensive effect of nifedipine was potentiated (p<0.05) by piroxicam coadministration, but effect of nifedipine on plasma norepinephrine level was not affected. In case of rats received nifedipine and piroxicam, plasma nifedipine concentrations were higher (p<0.05) than those from rats received nifedipine alone at 2,3,4,5 and 6 hours following drug administration. The area under the plasma concentration vs. time curve was increased (p<0.05), while the elimination rate constant was decreased (p<0.01) by piroxicam coadministration. No significant differences were observed in the plasma clearance, apparent volume of distribution and elimination half-life. Thus, piroxicam not only potentiated antihypertensive effect of nifedipine, but also altered nifedipine pharmacokinetics in the rats. It is concluded that the potentiation of nifedipine antihypertensive effect might correlate with the increment of its plasma concentration by piroxicam coadministration.

• 한국표면공학회지
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• 제29권5호
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• pp.363-370
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• 1996

Carbon nitride is one of the new carbon materials which show interesting properties. After the theoretical calculation by LIu and Cohen, many researchers are trying to prepare $\beta$-$C_3N_4$ which may be harder than diamond. Many carbon nitride films synthesized till now by various methods are amorphous and the N/C ratios in the films are usually below 0.5. First we review shortly the synthesis of carbon nitride thin films by plasma, ion and laser processing. Second we report on the preparation of amorphous carbon nitride thin films by shielded arc ion plating and the structural and mechanical properties of the films.

• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.406-414
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• 2010

A novel polyacrylamide grafted hydrous ferric oxide adsorbent composite has been synthesized by using glow discharge electrolysis plasma. To optimize the synthesis conditions, the following parameters were examined in detail: applied power, discharge time, post polymerization temperature, post polymerization time, amount of crosslinking agent and hydrous ferric oxide gel added and so on. The adsorbent was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The removal percentage of the adsorbent in Pb(II) solution was examined and the data obtained showed that the adsorbent composite has a high capacity for lead ion. For the use in wastewater treatment, the thermodynamic and kinetic of Pb(II)-capture were also studied. Results indicated that the adsorption reaction was a spontaneous and an endothermic process, and it seems to be obeyed a pseudo-secondorder rate model. Moreover, the adsorption isotherm of Pb(II)-capture is following the Langmuir and Freundlich isotherm models.

• Journal of Pharmaceutical Investigation
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• 제22권2호
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• pp.139-148
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• 1992

A prodrug of cefazolin pivaloyloxymethyl ester (CFZ-PV) was synthesized to improve oral absorption and bioavailability of parent drug by esterification of sodium cefazolin (CFZ) with chloromethyl pivalate. The successful synthesis of CFZ-PV was confirmed by spectroscopic analysis. Partition coefficient studies showed that CFZ-PV is more lipophilic than CFZ. The pharmacokinetic characteristics of CFZ-PV and CFZ preparations were compared following oral administrations of these compounds to rabbits. The analysis of CFZ in plasma was conducted by HPLC method. The ester compound (prod rug) was not detected in plasma following oral administration of CFZ-PV, and although CFZ-PV had not microbiological activity in vitro, the plasma taken after CFZ-PV administration had microbiological activity. From above observations, it was noted that CFZ-PV is rapidly hydrolyzed to CFZ in the body. And it was found that the oral absorption of CFZ-PV was increased, yielding 2-fold higher bioavailability than CFZ. From the results of this experiment, it was concluded that CFZ-PV could be a novel prodrug of CFZ which can improve the oral bioavailability of CFZ.

• 한국분말재료학회지
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• 제21권5호
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• pp.382-388
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• 2014

Fe-TiC composite powder was fabricated by high-energy milling of powder mixture of (Fe, TiC) and (FeO, $TiH_2$, C) as starting materials, respectively. The latter one was heat-treated for reaction synthesis of TiC phase after milling. Both powders were spark-plasma sintered at various temperatures of $680-1070^{\circ}C$ for 10 min. with sintering pressure of 70 MPa and the heating rate of $50^{\circ}C/min$. under vacuum of 0.133 Pa. Density and hardness of the sintered compact was investigated. Fe-TiC composite fabricated from (FeO, $TiH_2$, C) as starting materials showed better sintered properties. It seems to be resulted from ultra-fine TiC particle size and its uniform distribution in Fe-matrix compared to the simply mixed (Fe, TiC) powder.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2453-2459
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• 2014

Five novel cyanine dyes containing julolidine and indole moieties were synthesized. Several color compensating films for plasma display panels (PDP) were prepared using these dyes. The spectroscopic and physicochemical properties of the synthesized dyes in both solution and film state were evaluated. For each color compensating film, the optimum ratio of dye to binder was determined on the basis of transmittance, half band width, and photo-stability of the color compensating film. The five synthesized dyes showed sharp absorption peaks near 590 nm (orange light) and had molar extinction coefficients above $1{\times}10^5M^{-1}cm^{-1}$. The melting point of the dyes was above $200^{\circ}C$ and photo-stability of the color compensating films was improved by introducing substituents at the 5th position on the indole derivatives.

• Journal of Pharmaceutical Investigation
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• 제25권4호
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• pp.323-330
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• 1995

Ceftezole pivaloyloxymethyl ester(CFZ-PV) was synthesized to improve oral absorption and bioavailability of parent drug by esterification of ceftezole(CFZ) with chloromethyl pivalate. The successful synthesis of CFZ-PV was conformed by spectroscopic analysis. Partition coefficient studies showed that CFZ-PV is more lipophillic than CFZ. The pharmacokinetic characteristics of CFZ-PV and CFZ were compared following oral administrations of these compounds to rabbits. The amount of CFZ in plasma was determined with an HPLC method. The ester compound (prodrug) was not detected in plasma following oral administration of CFZ-PV, and although CFZ-PV had not microbiological activity in vitro, the plasma taken after oral administration of CFZ-PV had microbiological activity. From above observations, it was noted that CFZ-PV is rapidly hydrolyzed to CFZ in the body. And the oral absorption of CFZ-PV was increased by yielding 2-fold bioavailability rather than CFZ. Therefore, CFZ-PV could be a novel prodrug of CFZ which can improve the oral bioavailability of CFZ.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2001년도 정기총회 및 봄 학술발표회 초록집
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• pp.238-239
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• 2001

The egg-yolk precursor vitellogenin(VTG) is secreted by the liver of female and male fish, in response to estrogenic compound. Carp(Cryprinus carpio) vitellogenin of one major protein is 160kDa, two minor proteins is 110kDa and 170kDa. We were induced vitellogenin by inject of 17-estradiol and purified in a two step procedure by separating it from plasma protein precipitated by 35% saturated ${(NH_4)}_2SO_4$ and then from the remainder by Mono-Q chromatography. We found major carp(Cyprinus carpio) vitellogenin band at 160kDa. Effect of different concentration of oestrogen on vitellogenin synthesis in carp(Cyprinus carpio) exposed for 4 weeks. Show differential effects on vitellogenin synthesis 7 days after treatment. Plasma vitellogenin was measured 3 times for each by an enzyme linked immunosorbent assay(ELISA). ELISA was developed for the detection of the egg yolk precursor vitellogenin in plasma of carp(Cyprinus carpio). The ELISAS performance was optimized and characterized.

• Journal of Nutrition and Health
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• 제29권8호
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• pp.874-880
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• 1996

The effects of an anabolic steroid, nandrolone phenylpropionate(NPP), on body weight gain and body protein, and muscle protein metabolism were inestigated in adrenocorticotrophic hormone(ACTH)-treated male and female rats. Daily injections of 100ug/day of ACTH for 7-8 days caused a cessation of growth in females and a net loss of body weight in males which were associated with significant reductions in body protein content. However, food intake was not affected by ACTH in either sex. The weight, protein content and fractional rate of protein synthesis, measured in vivo, of gastrocnemius muscle were all significantly reduced in both sexes. NPP at a dose of 4mg/kg body weight prevented the reduction in body weight gain in ACTH-treate females but not in males. However, boy protein content was increased by NPP in both sexes which was associated with increases in the weight, protein content and fractional rate of protein synthesis of gastrocnemius muscle. ACTH treatment caused a marked increase in plasma concentrations of corticosterone in both sexes. NPP suppressed much of the increases in corticosterone concentrations in both sexes. The results of the present study suggest that NPP exerts at least part of its anabolic effect by reducing plasma concentrations of catabolic glucocorticoid hormones, through suppressing the response of the adrenals to ACTH.

• 한국정밀공학회지
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• 제24권6호
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• pp.113-120
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• 2007

Chemical vapor deposition (CVD) is one of the various synthesis methods that have been employed for carbon nanotube (CNT) growth. In particular, Ren et al reported that large areas of vertically aligned multi-wall carbon nanotubes could be grown using a direct current (dc) PECVD system. The synthesis of CNT requires a metal catalyst layer, etchant gas, and a carbon source. In this work, the substrates consists of Si wafers with Ni-deposited film. Ammonia $NH_3$) and acetylene ($C_2H_2$) were used as the etchant gases and carbon source, respectively. Pretreated conditions had an influence on vertical growth and density of CNTs. And patterned growth of CNTs could be achieved by lithographical defining the Ni catalyst prior to growth. The length of single CNT was increased as niclel dot size increased, but the growth rate was reduced when nickel dot size was more than 200 nm due to the synthesis of several CNTs on single Ni dot. The morphology of the carbon nanotubes by TEM showed that vertical CNTs were multi-wall and tip-type growth mode structure in which a Ni cap was at the end of the CNT.