• The Korean Journal of Physiology and Pharmacology
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• v.6 no.2
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• pp.87-91
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• 2002

The aim of this study was to investigate the role of $Ca^{2+}-channel$ blockers in norepinephrine (NE) release from rat hippocampus. Slices and synaptosomes were incubated with $[^3H]-NE$ and the releases of the labelled products were evoked by 25 mM KCl stimulation. Nifedipine, diltiazem, nicardipine, flunarizine and pimozide did not affect the evoked and basal release of NE in the slice. But, diltiazem, nicardipine and flunarizine decreased the evoked NE release with a dose-related manner without any change of the basal release from synaptosomes. Also, a large dose of pimozide produced modest decrement of NE release. ${\omega}-conotoxin$ (CTx) GVIA decreased the evoked NE release in a dose-dependent manner without changing the basal release. And ${\omega}-CTxMVIIC$ decreased the evoked NE release in the synaoptosomes without any effect in the slice, but the effect of decrement was far less than that of ${\omega}-CTxGVIA.$ In interaction experiments with ${\omega}-CTxGVIA,\;{\omega}-CTxMVIIC$ slightly potentiated the effect of ${\omega}-CTxGVIA$ on NE release in the slice and synaptosomal preparations. These results suggest that the NE release in the rat hippocampus is mediated mainly by N-type $Ca^{2+}-channels,$ and that other types such as L-, T- and/or P/Q-type $Ca^{2+}-channels$ could also be participate in this process.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.587-595
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• 2003

The aim of this study was to investigate trazodone's effect on vasorelaxation and blood pressure lowering and to examine its underlying mechanism of action in isolated thoracic aorta and anesthesized rats. Precontracted aortic rings with high KCl were relaxed with trazodone, at concentrations of $50{\mu}M$ or greater. However, precontracted rings with phenylephrine (PE) were relaxed with trazodone, at concentrations of $0.03{\mu}M$ or greater, in a concentration-dependent manner. These relaxant effects of trazodone on endothelium intact rat aortic rings were significantly greater than those on denuded rings. The trazodone-induced relaxations were suppressed by nitric oxide synthase (NOS) inhibitors, N(G)-nitro-L-arginine (L-NNA) and N(omega)-nitro-L-arginine methyl ester (L-NAME), guanylate cyclase inhibitors, methylene blue and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a $Ca^{2+}$-activated $K^+$ channel blocker, tetrabutylammonium (TBA), a $Ca^{2+}$ channel blocker, nifedipine, $Na^+$ channel blockers, lidocaine and procaine, and removal of extracellular $Na^+$, but not by aminoguanidine, 2-nitro-4-carboxyphenyl-n, n-diphenylcarbamate (NCDC), indomethacin, glibenclamide and clotrimazole. In vivo, infusion of trazodone elicited significant decrease in arterial blood pressure. Trazodone-induced decrease in blood pressure was markedly inhibited by pretreatment of intravenous injection of saponin, L-NNA, methylene blue, TBA, lidocaine or nifedipine. These findings suggest that the endothelium-dependent relaxation and decrease in blood pressure induced by trazodone is mediated by release of NO from the endothelium, activation of TBA-sensitive $Ca^{2+}$-activated $K^+$ channels or inhibition of $Ca^{2+}$ entry through voltage-gated channel.

• Journal of Chest Surgery
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• v.22 no.6
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• pp.1025-1035
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• 1989

Since we first performed open heart surgery on December 30, 1986, 126 cases were operated on up to August 31, 1989. Among the 126 cases, 65 cases were congenital heart disease of which 63 were acyanotic disease, and 61 cases were acquired heart disease, most of which were valvular heart disease. The age distribution of congenital heart disease was from 1 years 2 months to 48 years, and males had a slightly higher incidence. The age of acquired heart disease was from a minimum of 15 years to a maximum of 68 years, and the male to female ratio was 1;1.5. Midsternotomy was performed in all cases, and the aortic cannula was inserted through ascending aorta and the venous cannula inserted into the SVC and IVC through the right atrium. Vent was inserted through the right superior pulmonary vein. Cardioplegia solution was used in all cases; it was composed of sodium bicarbonate 3.5 ampule, KCL 14 mEq, 2% lidocaine 2.5 ml, 20 % albumin 50 ml and heparin 1000 units mixed to 950 ml with Hartman solution, and was made to 4oC and infused 10 ml per Kg every 20 minutes. The congenital heart disease had a variety of VSD in 32 cases, ASD 23 cases, PS 6 cases, PDA 2 cases, and one case each of Ebsteins anomaly and tricuspid atresia. The operations performed for acquired heart disease were 4 cases of OMC, 33 cases of MVR, and 5 cases of AVR, and 1 case of AVR with CABG. DVR was perfomed in 13 cases, and triple valve replacement was done in 1 case. Other than these, excision of LA myxoma was 2 cases, and repair of traumatic VSD and removal of a pulmonary embolism were one case each. The surgical mortality was 5 cases[4%], all of which occurred in valve replacement cases. Follow-up study revealed 2 late deaths. One died after a traffic accident and one died due to sepsis after he had received a gastrectomy for ulcer bleeding. The remaining patients were in good condition.

• Microbiology and Biotechnology Letters
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• v.15 no.2
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• pp.135-139
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• 1987

Aspergillus sp. MK-24 was cultured at 3$0^{\circ}C$ in the medium consisting of 2% glucose, 0.2% NaNO$_3$, 0.02% $K_2$HPO$_4$, 0.02% MgSO$_4$ 7$H_2O$, 0.02% KCl, and at initial pH of 5.0. The production of the inhibitor on venom proteinase reached to the maximum in 7 days. Sodium nitrate or potassium nitrate as a nitrogen source was favorable. The production of inhibitor was not affected by the addition of most of the inorganic salt used but depressed by lead, zinc, cobalt, mercuric or silver salts.

• Journal of the Mineralogical Society of Korea
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• v.20 no.1 s.51
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• pp.7-19
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• 2007

Four types of fluid inclusions are trapped within tourmaline from Daeyou pegmatite, Jangsu-Gun, Jeonllabukdo. They range $5{\sim}100\;{\mu}m$ in size and are grouped into I, II, III, and IV based on the phase behavior at the room temperature: (1) Type I inclusions are liquid-rich and NaCl equivalent salinity ranged $0{\sim}12\;wt%$, and the homogenization temperatures (Th) ranged $181{\sim}230^{\circ}C$ with eutectic temperatures (Te) $-54{\sim}-22^{\circ}C$. (2) Type II inclusions are vapor-rich and salinity ranged $3{\sim}8\;wt%$ NaCl, and Th ranged $177{\sim}304^{\circ}C$ also showing Te $-54{\sim}-29^{\circ}C$. (3) Type III inclusions contain a halite daughter mineral with $31{\sim}40\;wt%$ NaCl, Th $230{\sim}328^{\circ}C$. More than 90% of Type III homogenize by halite dissolution and are spatially associated with silicate melt inclusions. (4) Type IV inclusions are $CO_{2}$-bearing containing various daughter minerals such as sylvite and/or halite. The density of $CO_{2}$ system within the Type IV is $0.80{\sim}0.75\;g/cm^{3}$, Th $190{\sim}317^{\circ}C$, and salinity $2{\sim}35\;wt%$ NaCl. Type III fluid inclusions, considered as the earliest fluid, formed from the fluid exsolved from the crystallizing pegmatite. It is suggested that Type II fluid in the central part of tourmaline were exsolved earlier than Type I fluids in the margin indicating salinity fluctuation during the growth of tourmaline. It implies the fluctuation of the pressure since the salinity of fluid exsolved from the crystallizing melt is governed by the pressure. The last fluid was Type IV, which may be derived from the nearby limestone and metasedimentary rocks. It is suggested that Daeyou pegmatite containing muscovite without miarolitic cavities was formed by the partial melting resulted from the regional metamorphism. Subsequently, the exsolving fluids from the crystallizing melt were trapped in tourmaline at high pressure condition. The exsolved fluids contain various components such as $CaCl_{2}\;and\;MgCl_{2}$ as well as NaCl and KCl. The exsolution began at least at $2.7{\sim}5.3\;kbar\;and\;230{\sim}328^{\circ}C$ with the pressure fluctuation.

• Journal of Aquaculture
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• v.8 no.3
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• pp.149-157
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• 1995

In order to obtain the basic knowledges concerned to the semen preservation of aquacultural fishes, studies on the physical and chemical properties of semen, and sperm motility with the different osmotic pressures making by adding $Na^+,\;K^+,\; Mg^{++},\;and\;Ca^{++}$ to artificial seawater (ASW) were conducted in black seabream, Acanthopagrus schlegeli. Average semen volume per fish in one strip was 1.97ml and sperm concentration was $2.33\pm1.30\times10^{10}$ sperm/ml. Spermatocrit and pH of semen were $90.6\pm5.0\;and\;8.3\pm0.1$, respectively, Osmotic pressures of rearing seawater, seminal fluid and plasma were $939\pm24,382\pm70\;and\;342\pm77$ mOsm/l, and $Na^+,\;K^+$ and $Cl^-$ concentrations of seminal fluid were $169.5\pm4.5,\;4.9\pm2.2,\;156.0\pm2.0\;mM/l$, respectively. When semen were diluted by using $Na^+,\;K^+,\;Mg^{++}\;and\;Ca^{++}$ free ASW, only $Na^+$ free ASW had no sperm motility. As raising osmotic pressure graduary by addition of 1M NaCl to the $Na^+$ free ASW, spermatozoa showed the high motilities in 457-1128 mOsm/l, but the low motilities in 1398-1736 mOsm/l. In the case of same treatments with 1M of KCl, $MgC1_2\;and\;CaC1_2$ to the $K^+,\;Mg^{++}\;and\;Ca^{++}$ free ASW, spermatozoa revealed the high motilities in $904\~1434,\;818\~1175\;and\;956\~1343$ mOsm/l, respectively.

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.31-37
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• 1997

Intergeneric hybrids between Aspergillus niger and Perricillium ch~y.sop~um(Tyr ), hyperlipolytic enzyne-producing fungi, were obtained by nuclear transfer technique:. Optimal conditions for formation of intergeneric hybrids were investigated. Maximum production of protoplasts were obtainrd by 1% Novozym 234 at $30^{\circ}C$ for 3 hrs and the most effective osmotic stabilizers for the isolation of protoplasts were 0.6 M KC]. Frequencies of hybrid formation by nuclear transfer were $1.3{\times}$10^{-3}$$ $-3.8{\times}$10^{-3}$$. From the chervation of genetic stability, conidial size, DNA content, ;md nuclear stain, it was suggested that their karyotypes are aneuploid. The hybrids showed 1.4-2.2 fold higher lipase activities than parental strains. It was strongly supported by results of this study that nuclear transfer technique is much more efficient in the formation of intergeneric hybrids than protoplast fusion and is very useful for the improvement of strains.

• Ocean and Polar Research
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• v.39 no.4
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• pp.269-277
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• 2017

Medium compositions for the hyperthermophilic archaeon, Thermococcus onnurineus NA1 was statistically optimized to enhance formate-driven hydrogen ($H_2$) production by using response surface methodology. From the Plackett-Burman design-based experiment, it was confirmed that among the minor components of medium such as KCl, $MgSO_4$, $NH_4Cl$, Cystein-HCl, trace elements, Fe-EDTA and $CaCl_2$, the trace elements were screened as the only positively effective components with respect to $H_2$ production. Subsequently, the optimal concentrations of the trace elements and the major components of a medium such as NaCl, yeast extract and sodium formate were determined from the five-level central composite design (CCD)-based experiment. The resulting quadratic model predicted the maximum $H_2$ production of 46.6 mmol/L in serum bottle and it was validated experimentally using the optimal medium initially supplemented with 26.70 g/L of NaCl, 9.81 g/L of sodium formate, 3.50 g/L of yeast extract and 4.59 mL/L of trace elements. From the duplicate batch cultivations in the fermentor using the optimized medium, the a maximum $H_2$ production rate up to 71.8 mmol/L/h could be obtained, which was a 65% enhanced value compared with that obtained using the control medium, showing the high efficiency of the optimized medium.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.597-606
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• 2003

Although the antidepressant effects of imipramine (IMI) have been well known in several studies, the effects on cardiovascular system, particularly the vasorelaxant effects, have not known clearly. We hypothesis that IMI-induced vasorelaxation involves NO (nitrie oxide), activation of guanylate cyclase (GC) and $Ca^{2+}$ channel. The possible roles of the endothelium and $Ca^{2+}$ in IMI-induced responses were investigated using isolated rings of rat thoracic aorta and anesthesized rats. In KCl-precontracted rings. IMI produces endothelium-dependent and endothelium-independent relaxations in intact (+E) as well as endothelium-denuded (-E) rat aorta in a concentration-dependent manner. In phenylephrine (PE)-precontracted rings, the IMI-induced relaxation was significantly greater in +E rings. The IMI-induced relaxations were suppressed by nitric oxide synthase (NOS) inhibitors, N(G)-nitro-L-arginine (L-NNA), N(omega)-nitro-L-arginine methyl ester (L-NAME) and aminoguanidine, a non-selective GC inhibitor, methylene blue, $Na^+$ channel blockers, lidocaine and procaine, or $Ca^{2+}$ channel blockers, nifedipine and verapamil, in PE-precontracted +E rings, but not in PE-precontracted -E rings. These relaxations were also suppressed by lidocaine or procaine in -E aortic rings. However, IMI-induced relaxations were not inhibited by a PLC inhibitor 2-nitro-4-carboxyphenyl-n,n-diphenylcarbamate (NCDC), an inositol monophosphatase inhibitor, lithium, indomethacin and dexamethasone in +E and -E rings. In vivo, infusion of IMI elicited significant decrease in arterial blood pressure. After intravenous injection of saponin, NOS inhibitors. MB and nifedipine, infusion of IMI inhibited the IMI-lowered blood pressure markedly. These findings suggest that the endothelium-dependent relaxation induced by IMI is mediated by activation of NO/cGMP signaling cascade or inhibition of $Ca^{2+}$ entry through voltage-gated channel, and this mechanism may contribute to the hypotensive effects of IMI in rats.

• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1201-1207
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• 2020

This study explored whether MXene (Ti₃C₂T_x) could remove radioactive Cs⁺ from model nuclear wastewater. Various adsorption tests were performed and the physical aspects of the interaction were investigated. We varied the MXene dosage, Cs⁺ initial concentration, solution pH, solution temperature and exposure time. MXene adsorption exhibited very fast kinetics, based on the fact that equilibrium was achieved within 1 h. MXene exhibited an outstanding adsorption capacity (148 mg g^-1) at adsorbent and adsorbate concentrations of 5 and 2 mg L^-1, respectively, at neutral pH condition (i.e., pH 7). We explored Cs⁺ adsorption by MXene in the presence of four different ions (NaCl, KCl, CaCl₂ and MgCl₂) and three different organic acids (sodium oleate, oxalic acid, and citric acid). The Cs⁺ removal rate changed in the presence of these components; adsorption of Cs⁺ by MXene thus involved ion exchange, supported by both Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. We confirmed that MXene was re-usable for at least four cycles. MXene is cost-effective and practical when used to adsorb radionuclides (e.g., Cs⁺) in nuclear wastewater.