• Biomolecules & Therapeutics
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• v.2 no.3
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• pp.229-235
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• 1994

In dogs, renal denervation did not affect the diuretic action accompanied with renal hemodynamic chanties and inhibition of electrolytes reabsorption rates in renal tubules by methoxyverapamil infused into the vein or into a renal artery, while renal denervation blocked the antidiuretic action due to the decreased free water and osmolar clearances along with the reduced sodium amounts excreted in urine by methoxyverpamil infused into the carotid artery. These experimental results suggest that methoxyverapamil may cause diuresis by direct action in kidney but the antidiuretic action through central function mediated by renal nerves.

• YAKHAK HOEJI
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• v.29 no.1
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• pp.1-10
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• 1985

The ether fraction obtained from dry fruit of Cornus officinalis was investigated for the anti-inflammatory action, acute toxicity and central nervous system activities. From several pharmacological examinations, it was found that the ether fraction suppressed considerably carrageenin edema at the dose of 600mg/kg p.o. in rats, inhibited the granuloma formation in rats as given 100mg/kg p.o. for 7 days and decreased the swelling of both of complete adjuvant injected and noninjected (contralateral) paws of the rats at the dose of 100mg/kg p.o. given for 14 days. The $LD_{50}$ of the fraction are estimated to be more than 2,000mg/kg p. o. and 642mg/kg i. p. in mice. And the fraction did not show any sedative, stimulative, analgesic and anticonvulsant action but exhibited hypothermic action. These results might be concluded that the ether fraction of Corni fructus showed anti-inflammatory action in both of acute and chronic type models without any considerable central nervous depressant activity and exhibited very weak acute toxicity in mice.

• The Korean Journal of Physiology
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• v.19 no.2
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• pp.113-125
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• 1985

Electrophysiological difference of the central and peripheral area of the sinoatrial node in the rabbit was studied by glass microelectrode technique. Effects of $K^+,\;Na^+,\;Cs^+,$ adrenaline and ouabain on the action potential of the two areas were investigated, and transient hyperpolarization ($K^+-induced$ hyperpolarization) which developed following readmission of potassium after having pre-treated with $K^+-free$ Tyrode solution for 10 minutes was analyzed. The results obtained were as follows ; 1) The frequency of the spontaneous action potential recorded in the periphery of the SA node was faster than the central area. Reduction by $Cs^+$ and increase by O mM $K^+$, $10^{-6}M$ adrenaline and $10^{-6}M$ ouabain in the frequency of action potential were noticed more prominently in the peripheral than the central area. On the contrary, the frequency in the central area was more decreased than the Peripheral area by 13 mH $K^+$ and 1 mM $Co^{2+}$. 2) The amplitude of the K+_induced hyperpolarization was very small in the central area but large in the peripheral area. Transient hyperpolarization was abolished by ouabain and low sodium, and decreased by cooling the tissue $(17^{\circ}C)$. 3) By changing the concentration of $Ca^{2+}$ in the perfusate, the amplitude and the rate of transient hyperpolarization were increased in the high $Ca^{2+}$ concentration. It could be concluded that the central area of the SA node is less susceptible to the inhibition of Na-Pump and more susceptible to Ca-blocker and high concentration of $K^+$. The Na-Pump activity of the central area measured by means of transient hyperpolarization is found to be much less active than that of the peripheral area.

• YAKHAK HOEJI
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• v.45 no.4
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• pp.397-406
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• 2001

It has been demonstrated previously that R(-)-2,10,11-trihydroxy-N-n-propylnora porphine (TNPA), a dopamine D$_2$receptor agonist, produced the antidiuresis through changes of central friction in dog. This study was investigated about effects of renal denervation and raclopride, a dopamine D$_2$receptor antagonist, on the antidiuresis of TNPA in order to elicidate the mechanism involved in this central antidiuresis induced by TNPA. Antidiresis exhibited by TNPA given into the vein or into carotid artery was not influenced by renal denervation, whereas antidiuresis of TNPA administered into carotid artery was blocked almost perfectly by raclopride pretreated into carotid artery. From these observations it is concluded that central antidiuresis induced by TNPA is brought about through activation of dopamine D$_2$receptor localized in brain, not related to renal nerve activity.

• Steel and Composite Structures
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• v.30 no.4
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• pp.337-350
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• 2019

The objective of this paper is to investigate the confinement coefficient of concrete-filled square stainless steel tubular (CFSSST) stub columns under axial loading. A fine finite 3D solid element model was established, which utilized a constitutive model of stainless steel considering the strain-hardening characteristics and a triaxial plastic-damage constitutive model of concrete with features of the parameter certainty under axial compression. The finite element analysis results revealed that the increased ultimate bearing capacity of CFSSST stub columns compared with their carbon steel counterparts was mainly due to that the composite action of CFSSST stub columns is stronger than that of carbon steel counterparts. A further parametric study was carried out based on the verified model, and it was found that the stress contribution of the stainless steel tube is higher than the carbon steel tube. The stress nephogram was simplified reasonably in accordance with the limit state of core concrete and a theoretical formula was proposed to estimate the ultimate bearing capacity of square CFSSST stub columns using superposition method. The predicted results showed satisfactory agreement with both the experimental and FE results. Finally, the comparisons of the experimental and predicted results using the proposed formula and the existing codes were illustrated.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.2
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• pp.217-219
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• 2004

Stimulation of fecundity following female antennal amputation has been reported for the first time in silkworm. Antennal amputation caused significant increase in fecundity in two newly evolved multivoltine silkworm breeds viz., BL 67 and 96A. This study indicated better chances for increasing egg yield and the increase in fecundity may be attributed to the action of some neurohormones. Significance of antennal amputation in silkworm has been discussed.

• YAKHAK HOEJI
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• v.37 no.6
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• pp.631-637
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• 1993

In the previous report, it was described that the butanol fraction of the root bark extract of Aralia elata had potent antigastritic and antiulcerative effects in rats, In this pharmacological profile, the fraction revealed low acute toxicities in mice and rats, no central nervous system activities, moderate analgesic action, weak inhibitory action in carrageenin edema of rats and no direct effects on isolated smooth muscles of rats and guinea-pigs. Slight lowering of blood pressure as given i.v. in rabbit was observed.

• YAKHAK HOEJI
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• v.37 no.6
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• pp.561-570
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• 1993

Renal action of domperidone known as dopamine receptor blocker and effect of domperidone on renal function of dopamine were investigated in dog. Domperidone, when administered into vein, produced diuretic action by the improvement of renal hemodynamic state, when given into a renal artery, elicited diuretic action accompanied with natriuresis in only experimental kidney, whereas domperidone given into carotid artery exhibited antidiuretic action by the decrease of Na$^{+}$ excretion in urine. Diuretic action of dopamine was not influenced by domperidone given into vein or into a renal artery, was blocked by domperidone given into carotid artery. Above results suggest that domperidone produced both peripheral diuretic and central antidiuretic action, and domperidone do not block diuretic action by renal hemodynamic improvement of dopamine in kidney.

• Steel and Composite Structures
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• v.23 no.2
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• pp.229-238
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• 2017

This paper presents a combined numerical and theoretical study on the composite action between steel and concrete of circular steel tube confined concrete (STCC) stub columns under axial compressive loading with a full theoretical elasto-plastic model and finite element (FE) model in comparison with experimental results. Based on continuum mechanics, the elasto-plastic model for STCC stub columns was established and the analysis was realized by a FORTRAN program and the three dimensional FE model was developed using ABAQUS. The steel ratio of the circular STCC columns were defined in range of 0.5% to 2% to analyze the composite action between steel tube and concrete, and make a further study on the advantages of the circular STCC columns. By comparing the results using the elasto-plastic methods with the parametric analysis result of FE model, the appropriate friction coefficient between the steel tube and core concrete was defined as 0.4 to 0.6. Based on ultimate balance theory, the formula of ultimate load capacity applying to the circular STCC stub columns was developed.

• Steel and Composite Structures
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• v.26 no.6
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• pp.693-703
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• 2018

To better understand the influence of hollow ratio on the hollow concrete-filled circular steel tubular (H-CFT) stub columns under axial compression and to propose the design formula of ultimate bearing capacity for H-CFT stub columns, 3D finite element analysis and laboratory experiments were completed to obtain the load-deformation curves and the failure modes of H-CFT stub columns. The changes of the confinement effect between core concrete and steel tube with different hollow ratios were discussed based on the finite element results. The result shows that the axial stress of concrete and hoop stress of steel tube in H-CFT stub columns are decreased with the increase of hollow ratio. AfteGr the yield of steel, the reduction rate of longitudinal stress and the increase rate of circumferential stress for the steel tube slowed down. The confinement effect from steel tube on concrete also weakened slowly with the increase of hollow ratio. Based on the limit equilibrium method, a simplified formula of ultimate bearing capacity for the axially loaded H-CFT stub columns was proposed. The predicted results showed satisfactory agreement with the experimental and numerical results.