• The Korean Journal of Pharmacology
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• v.22 no.2
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• pp.128-134
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• 1986

To determine the relationship between hydrochlorothiazide-induced diuretic action and cyclic nucleotides, the effects of hydrochlorothiazide (5 mg/kg, i.v.) on the renal tissue level of cyclic nucleotides and the renal adenylate cyclase and guanylate cyclase activity were investigated. Hydrochlorothiazide elecitied the maximal diuretic effect between 10 and 20 min after the injection of drug. The increased urine flow and urinary electrolytes excretion returned to the control levels 60 min after the injection of drug. 5 and 15 min after drug administration the cAMP level of renal tissue was significantly decreased, but 60 min after the cAMP level was not different from the control level. The cGMP level of renal tissue was not affected by hydrocholorothiazide. Hydrochlorothiazide $(5\;{\times};10^{-4}\;M)$ inhibited the renal adenylate cyclase but not affected the renal guanylate cyclase. These results suggest that cAMP may be involved in the renal action mechanism of hydrochlorothiazide and the involvement of cGMP is uncertain.

• YAKHAK HOEJI
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• v.41 no.3
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• pp.381-388
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• 1997

Metabolism of DWP401, recombinant juman epidermal growth factor, was examined in vivo and in vitro in rats. When $^{125}I$-labeled DWP401 was administered at a dose of 50 ${\mu}g$/kg by i.v. injection. $^{125}I$-labeled DWP401 was rapidly degraded within 30 minytes above 93%. Thin layer chromatography analysis of urine collected for 24 hr after i.v. administration of $^{125}I$-labeled DWP401 showed ohly one spot on a X-ray film which was considered as diiodo-tyrosine. This result suggests tha $^{125}I$-labeled DWP401 was completely digested into free amino acids without any specific intermediate polypeptides. About 42.1% of the administered iodine was recovered in 24 hr. For in vitro degradation study, $^{125}I$-labeled DWP401 was added to plama and tissue homogenates of rats and incubated at $37^{\circ}C$. Almost 98% of the added radioactivity recovered from the protein fraction of the liver, kidey, small intestine, stomach and spleen decreased rapidly. For examplem the recovery rates of $^{125}I$-labeled DWP401 were 58.6, 63.2, 39.9, 52.9 and 66.8% after 4hrs of incubation in respective organ homogenates.

• The Korean Journal of Pharmacology
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• v.12 no.2 s.20
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• pp.1-6
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• 1976

The effects of phenoxybenzamine and other related drugs were studied for their interaction with caerulein on gallbladder contraction in anesthetized animals and isolated gallbladder strips. Cholecystostomy and cystic duct ligation were made on anesthetized dog, cat and pig. Pressure changes of gallbladder were measured by a physiological pressure transducer connected to polygraph recorder. Isolated rabbit gallbladder strips were placed in a muscle chamber containing Locke-Ringer solution maintained at $38^{\circ}C$. The contractile responses were measured by a force-displacement transducer connected to polygraph recorder. Caerulein ($30{\sim}200$ ng/kg i.v.) produced marked contraction of gallbladder in situ and the cholecystokinetic potencies appear in decreasing order; dog, cat and pig. The response of caerulein was abolished by the large doses of phenoxybenzamine (15 mg/kg i.v.) but not affected with dibenamine, phentolamine or tolazoline. Cholecystokinetic effect of methacholine or barium chloride was also partially inhibited by phenoxybenzamine and the effect of caerulein was weakly inhibited intravenous injection of cyclophosphamide or papaverine. In isolated rabbit gallbladder strips, the response of contraction to caerulein were progressively inhibited by pretreatment of phenoxybenzamine along with time exposed. These results lead to the conclusion that phenoxytenzamine may inherently inhibit the contractile response of gallbladder to caerulein, and this effect was not related with ${\alpha}-adrenergic$ receptor blocking action.

• Proceedings of the Korean Magnestics Society Conference
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• 2010.06a
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• pp.96-96
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• 2010

We report the proper resistance-area products in the single crystalline bcc CoFe/MgO tunnel contact on nondegenerate n-Ge desirable for efficient spin injection and detection at room temperature. The electric properties of the crystalline CoFe(5 nm)/MgO(1.5,2.0,2.5 nm)/n-Ge(001) tunnel contacts have been investigated by I-V-T and C-V measurements. Interestingly, the tunnel contact with the 2-nm MgO exhibits the ohmic behavior with low resistance-area products, satisfying the theoretical conditions required for significant spin injection and detection. This result is ascribed to the presence of MgO layer between CoFe and n-Ge, enhancing the Schottky pinning parameter as well as shifting the charge neutrality level.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.6
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• pp.261-266
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• 2003

We investigated the effect of oxygen plasma treatment of indium-tin oxide(ITO) surface on the performance of electroluminescence(EL) devices. ITO surface treated oxygen plasma has been analyzed using atomic force microscope(AFM) and X-ray photoelectron spectroscopy(XPS), to investigate the relations between the properties of the ITO surface and the properties of the current-voltage-luminance(I-V-L) characteristics of the fabricated OLED with the structure of ITO(plasma treatment) / TPD / Alq$_3$/ Al. It is found that the oxygen plasma treatment of ITO anode improve the hole injection of the OLED due to the modification of the surface states. The treated ITO anode nay be low voltage with high luminance efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.11-13
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• 1992

The dielectric reliability of the Thin $SiO_2$ films of wet oxidation on n-type Si substrates has been studied by using self-healing method of breakdown and according to injection time high frequence C-V tests. These experiments have been performed to investigate the dielectric breakdown mechanism of a thin film in which positive charge generation during high-field Fowler-Nordheim tunneling are considered. In addition, The weak spots and robust areas are distinguished so that the localized dielectric breakdown could be described.

• BMB Reports
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• v.32 no.4
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• pp.339-344
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• 1999

We studied the effects of ginsenosides in immature rats based upon the previous results that ginseng has a suppressive or anticonvulsive activity. To examine the suppressive effect of ginsenosides on kainic acid-induced seizures, the severities and frequencies were observed for 4 h after injection of kainic acid (KA; i.p., 2 mg/kg b.w.) using 10-day-old male Sprague-Dawley rats ($22{\pm}2\;g$). Protopanaxadiol saponins such as ginsenoside-Rb1 (Rb1), ginsenoside-Rb2 (Rb2), ginsenoside-Rc (Rc), and ginsenoside-Rd(Rd) generally reduced the seizure activities while protopanaxatriol saponins such as ginsenoside-Rg1 (Rg1) and ginsenoside-Re (Re) rather increased stereotypic "paddling-like" movements. When vinyl-GABA (v-G) was injected together with Rb1 or Rc, KA-induced seizure severities were additionally reduced only by the injection of Rc, but not by Rb1. The level of gamma isozyme of protein kinase C (PKC-${\gamma}$) in the hippocampus increased about three times as much as that of normal rats at 4 h after KA injection. The increased level of PCK-${\gamma}$ by KA was significantly reduced to about 35% by the coinjection with v-G alone, but it was not changed by v-G together with Rb1 or Rc. The increased level of PKC-${\gamma}$ at 4 h after injection of KA was not consistent with the reduction of seizure severities between Rb1 and Rc. These results suggest that Rc and Rb1 may reduce seizure severity independent of PKC-${\gamma}$ levels, and Rc may additionally act with v-G regarding the GABA metabolism during the stage of KA-induced seizures in the immature rats.

• Journal of Electrical Engineering and Technology
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• v.1 no.3
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• pp.359-365
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• 2006

Since the start of the KSTAR (Korea Superconducting Tokamak Advanced Research) project, Instrumentation and Control (I&C) of the Neutral Beam Test Facility (NB-TF) has been striving to answer diverse requests arising from various facets during the project's development and construction phases. Hard-wired electrical circuits have been designed, tested, fabricated, and finally installed to the relevant parts of the system. In relation to the vacuum system I&C, controlling functions for the rotary pumps, a Roots pump, two turbomolecular pumps, and four cryosorption pumps have been constructed. I&C for the ion source operation are the temperature and flow rate signal monitoring, Langmuir probe signal measurements, gradient grid current measurements, and arc detector circuit. For the huge power system to be monitored or safely operated, many temperature measurement functions have also been implemented for the beam line components like the neutralizer, bending magnet, ion dump, and calorimeter. Nearly all of the control and probe signals between the NB test stand and the control room were made to be transmitted through the optical cables. Failures of coolant flow or beam line vacuum pressure were made to be safely blocked from influencing the system by an appropriate interlock circuit that will shut down the extraction voltage application to the system or prevent damages to the vacuum components. Preliminary estimation of the beam power through the calorimetric measurement shows that 87.9% of the total power of the 60kV/18A beam with 200 seconds duration is absorbed by the calorimeter surface. Most of these I&C results would be highly appropriate for the construction of the main NBI facility for the KSTAR national fusion research project.

• The Korean Journal of Pharmacology
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• v.23 no.2
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• pp.87-94
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• 1987

The role of central adrenergic activity in the genesis of stress ulcers was investigated by intracerebroventricular (i.c.v.) administration of catecholamines and clonidine in pylorus-ligated rats restrained for 4 hours at a temperature of $4^{\circ}C$. 1. The stress-induced ulceration was markedly decreased by the i.c.v. administration of norepinephrine, epinephrine, dopamine or low dose of clonidine. 2. After an i.c.v. administration of norepinephrine or epinephrine, the volume of gastric juice, and both acid and pepsin secretion were markedly decreased. 3. Dopamine or a low dose of clonidne decreased the volume of gastric juice and acid secretion but did not affect pepsin secretion. 4. Isoproterenol caused a decrease in the volume of gastric juice and acid secretion, however, the ulcerogenesis was similar to that of the control. 5. Gastric function as well as ulcerogenesis was little affected by a high dose of clonidine. From the above results, it is suggested that central adrenergic activation inhibits cold-restraint induced ulcerogenesis via adrenergic alpha and dopaminergic receptors, and that this effect may be mediated by a decrease in gastric acid secretion. It is also suggested that other factors may be involved in this antiulcerogenic effect.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.283-283
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• 2011

The n-doping effect by doping metal carbonate into an electron-injecting organic layer can improve the device performance by the balanced carrier injection because an electron ohmic contact between cathode and an electron-transporting layer, for example, a high current density, a high efficiency, a high luminance, and a low power consumption. In the study, first, we investigated an electron-ohmic property of electron-only device, which has a ITO/$Rb_2CO_3$-doped $C_{60}$/Al structure. Second, we examined the I-V-L characteristics of all-ohmic OLEDs, which are glass/ITO/$MoO_x$-doped NPB (25%, 5 nm)/NPB (63 nm)/$Alq_3$ (32 nm)/$Rb_2CO_3$-doped $C_{60}$(y%, 10 nm)/Al. The $MoO_x$doped NPB and $Rb_2CO_3$-doped fullerene layer were used as the hole-ohmic contact and electron-ohmic contact layer in all-ohmic OLEDs, respectively, Third, the electronic structure of the $Rb_2CO_3$-doped $C_{60}$-doped interfaces were investigated by analyzing photoemission properties, such as x-ray photoemission spectroscopy (XPS), Ultraviolet Photoemission spectroscopy (UPS), and Near-edge x-ray absorption fine structure (NEXAFS) spectroscopy, as a doping concentration at the interfaces of $Rb_2CO_3$-doped fullerene are changed. Finally, the correlation between the device performance in all ohmic devices and the interfacial property of the $Rb_2CO_3$-doped $C_{60}$ thin film was discussed with an energy band diagram.