• Smart Structures and Systems
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• v.21 no.5
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• pp.549-559
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• 2018

The dynamic behaviors of the bridge structures have great effects on the comfortability and safety of running high-speed trains, which can also reflect the structural degradation. This paper aims to reveal the characteristics of the dynamic behaviors induced by train loadings for a combined highway and railway bridge. Monitoring-based analysis of the acceleration and dynamic displacement of the bridge girder is carried out. The effects of train loadings on the vertical acceleration of the bridge girder are analyzed; the spatial variability of the train-induced lateral girder displacement is studied; and statistical analysis has been performed for the daily extreme values of the train-induced girder deflections. It is revealed that there are great time and spatial variabilities for the acceleration induced by train loadings for the combined highway and railway cable-stayed bridge. The daily extreme values of the train-induced girder deflections can be well fitted by the general extreme value distribution.

• Korean Journal of Pharmacognosy
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• v.15 no.4
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• pp.179-187
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• 1984

To investigate the recorded efficacy in Oriental medical references and effects in clinics, experimental studies were undertaken to estimate 'Palmiwhan' to the diuretic effect in normal rats, rabbits and rats with $HgCl_2-induced$ acute renal failure and hypotensive effects on the nephrogenous hypertension in rabbits with $HgCl_2-induced$ acute renal failure. The results of this study were summarized as follows; Increase in urinary volume, urinary $Na^+\;and\;Cl^-$ excretions were significantly recognized in normal rats and rabbits. Increase in urinary volume, urinary $Na^+\;and\;Cl^-$ excretions were significantly shown in rats with 2mg/kg $HgCl_2-induced$ acute renal failure. Although plasma electrolyte and creatinine levels were little affected, plasma urea nitrogen levels were significantly elevated in normal rats and 2mg/kg $HgCl_2-induced$ acute renal failure of rats. Although the blood pressure was not affected in normal rabbits and cats, hypotensive actions due to the diuretic effect were recognized in rabbits $HgCl_2-induced$ acute renal failure.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.3
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• pp.724-729
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• 2006

Many traditional herbal remedies exhibit several beneficial effects including anti-inflammation. The exact mechanism of the a-inflammato action of Panax notoginseng Buck F.H. Chen. however, has not been determined. In the present study, we have isolted the acting compound, emodin, from P. notoginseng and examined the effects of p. notoginseng and emodin on lipopolysaccharide (LPS)-induced nitric oxide (NO) production, and inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene expression in RAW264.7 macrophages. The results indicated that p. notoginseng concentration-dependently inhibited LPS-induced NO production. Furthermore, P. notoginseng inhibited the expression of LPS-induced iNOS and COX-2 proteins without an appreciable cytotoxic effect on RAW264.7 cells. Emodin also inhibited LPS-induced iNOS protein as potently as P. notoginseng. This was consistent with the findings that P. notoginseng but not emodin inhibited prostaglandin E2 synthesis induced Dy LPS.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.4
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• pp.471-477
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• 1998

Cyclosporin A (CsA), a widely used immunosuppressant, is well known to cause nephrotoxicity and hypertension as major side effects. The present study was aimed at investigating the effects of CsA-pretreatment on the activities of cytosolic guanylate cyclase (cGC) in relation to the alteration of relaxant responses in the rat thoracic aorta. CsA $(10\;{\mu}M)-preincubation$ for 90 min significantly attenuated the vasodilatation induced by sodium nitroprusside (SNP), a cytosolic guanylate cyclase activator, shifting the dose-response curve to the right. The increase in cGMP contents induced by SNP was markedly attenuated by CsA. SNP ($1\;{\mu}M{\sim}\;mM$) increased the cGC activity dose-dependently, and the increase was completely abolished by CsA. CsA attenuated the SNP-induced cGC activation dose-dependently. The abolishing effect of CsA-pretreatment on the SNP-induced cGC activation was not affected by washing the preparation, suggesting that the inhibition is irreversible. When CsA was added simultaneously with SNP, cGC activation was not attenuated. 1-(5-isoquinolinylsulfonyl)-2-methyl piperazine (H-7), a protein kinase C (PKC) inhibitor, decreased SNP-induced cGC activation and blocked the CsA-attenuation of cGC activation. These results suggest that CsA directly inhibits cGC participating in the CsA-induced impairment of vasodilatation, and that PKC is involved in the inhibitory action of CsA on cGC.

• Journal of Korean Medicine for Obesity Research
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• v.15 no.2
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• pp.55-67
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• 2015

Objectives: This study was to evaluate the effect of Palmijihwang-whan (PMJHW) aqueous extract in the regulation of hypothyroidism related reproductive organ damages in propylthiouracil (PTU)-induced rat model. Methods: PMJHW aqueous extract (yield=17.90%) were administered, once a day for 42 days from 2 weeks before start of PTU treatment as oral doses of 500, 250, and 125 mg/kg (body weight), and hypothyroidism was induced by daily subcutaneous treatment of PTU 10 mg/kg for 28 days. Results: PTU-induced hypothyroidism and related male reproductive organ damages-atrophic changes of testis, epididymis and prostate, were favorably and dose-dependently inhibited by treatment of PMJHW 500, 250, and 125 mg/kg. They also effectively regulated the PTU-induced abnormal antioxidant defense system changes in the testis. Although levothyroxine also favorably inhibited PTU-induced hypothyroidism, it deteriorated the hypothyroidism related male reproductive organ damages through testicular oxidative damages. The results suggest that oral administration of 125, 250, and 500 mg/kg of PMJHW has favorable effects on the hypothyroidism and related reproductive organ damages through augmentation of antioxidant defense system in the testis. Conclusions: This study suggest that PMJHW may be help to ameliorate the hypothyroidism and related organ damages in clinics.

• YAKHAK HOEJI
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• v.43 no.4
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• pp.535-540
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• 1999

Glutamate (Glu) receptor-mediated excitoxicity has been implicated in many acute and chronic types of neurological disorders. Exposure of mature rat cortical neurons (15-18 days in culture) to the various concentrations of Glu resulted in a marked neuronal death, whereas immature rat cortical neurons (4∼5 days in culture) were resistant to the Glu-induced toxicity. Glu receptor subtype-specific agonists showed differential extent of toxicity in the immature neurons. The neurons treated with NMDA or kainate (KA) did not exhibit damage. However, quisqualate (QA) treatment induced a considerable cell death (36.1%) in immature enurons. The non-NMDA antagonist DNQX did not reduce this response. Interestingly, the QA-induced toxicity was potentiated by spermine in a concentration-dependent manner. Again, the spermine-enhanced damage was not altered by the polyamine antagonist ifenprodil. Taken together, unlike NMDA or KA, QA can induce neurotoxicity in immature rat cortical neurons and the QA-induced toxicity was potentiated by spermine. The lack of antagonizing effects of DNQX and ifenprodil on QA-induced toxicity and the potentiated toxicity by spermine, respectively, implies that both QA receptor and the polyamine site of NMDA receptor may not mediate the neurotoxicity observed in this study, and that a distinct mechanism(s) may be involved in excitotoxicity in immature neurons.

• Archives of Pharmacal Research
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• v.29 no.10
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• pp.904-910
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• 2006

The inhibitory effects of paeonol, a major compound of Paeoniae radix, on the development of locomotor sensitization, conditioned place preference (CPP) and dopamine receptor supersensitivity induced by the repeated administration of morphine were investigated through behavioral experiments. A single administration of morphine produces hyperlocomotion. Repeated administration of morphine develops sensitization (reverse tolerance), a progressive enhancement of locomotion, which is used as a model for studying the drug-induced drug-seeking behaviors, and CPP, which is used as a model for studying drug reinforcement. Paeonol inhibited morphine-induced hyperlocomotion, sensitization and CPP. In addition, paeonol inhibited the development of postsynaptic dopamine receptors supersensitivity, which may be an underlying common mechanism that mediates the morphine-induced dopaminergic behaviors such as sensitization and CPP. Apomorphine (a dopamine agonist)-induced climbing behaviors also were inhibited by a single direct administration of paeonol. These results provide evidence that paeonol exerts anti-dopaminergic activity, and it is suggested that paeonol may be useful for the prevention and therapy of these adverse actions of morphine.

• YAKHAK HOEJI
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• v.37 no.2
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• pp.163-171
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• 1993

In order to study the functions of vascular endothelial nitric oxide(NO) generating system, we examined the effects of monomethylarginine(MMA) and dimethylarginine(DMA)(asym., sym.), arginine analogues, on modulation of vascular tone. Also, the concentrations of endogenous arginie and MMA were measured by HPLC in rat aortic tissues. The results were as follows. 1. The maximum relaxation induced by Ach (1.5$\times$10$^{-6}$M) was 80% of the contractility of rings of rat aorta induced by phenylephrine and L-Arg causes endothelium-dependent relaxation of the aorta precontracted with phenylephrine and these relaxation were concentration-dependent. 2. Endothelium-dependent contractility of rings of rat aorta induced by MMA (100 $\mu{M}$), DMA (asym., 100 $\mu{M}$) and DMA (sym., 100 $\mu{M}$) were 25.5%, 27.5% and 16.5% of that induced by phenylephrine respectively. 3. The relaxation of rat aortic ring induced by L-Arg was inhibited by MMA, DMA(asym.) and DMA(sym.). The degrees of inhibition induced by MMA, DMA(asym.) and DMA(sym.) were 45.7%, 37.1% and 18.3%, respectively. 4. The endogenous arginine and monomethylarginine contents in rat aorta were 83 pmoles/mg wet tissue, and 34.9 pmoles/mg wet tissue. After stimulation with Ach, the concentrations of L-Arg and MMA were significantly decreased. These results suggest that there are the strong relationships between the endogenous L-Arg and methylated arginines and NO-generating system.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1556-1560
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• 2006

The effects of the methanol subfraction from Pueraria Radix on hydrogen peroxide-induced lipid peroxidation and cadmium-induced cytotoxicity were investigated in NIH 3T3 fibroblast cells. After the methanol subfraction treatment, the content of MDA induced by 600 ${\mu}g$ $H_2O_2$ significantly decreased in proportion to the subfraction concentrations as well as 50 ${\mu}M$ $CdCl_2$-induced cytotoxicity. Especially, 200 ${\mu}g/mL$ concentration of methanol subfraction was strongly shown inhibition of lipid peroxidation and detoxification of cadmium. These results suggest that the methanol subfraction from Pueraria Radix retains a potential antioxidant and protective effect against cadmium.

• Journal of Environmental Health Sciences
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• v.45 no.5
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• pp.520-528
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• 2019

Objectives: This study assessed the cytotoxicity of the metallic mordant cupric acetate (CA) and the protective effect of Albizzia julibrissin (AJ) leaf extract on CA-induced cytotoxicity in NIH3T3 fibroblasts. Methods: For this study, cell viability and antioxidative effects such as the inhibitory activity of lipid peroxidation (LP) and superoxide anion-radical (SAR) scavenging activity were assessed. Results: CA significantly decreased cell viability in a dose-dependent manner, and the $XTT_{50}$ value was measured as $55.0{\mu}M$ of CA. The cytotoxicity of CA was determined as highly toxic by Borenfreund and Puerner's toxic criteria. The catalase antioxidant significantly increased cell viability diminished by CA-induced cytotoxicity in these cultures. Regarding the protective effect of AJ leaf extract on CA-induced cytotoxicity, AJ leaf extract remarkably increased the SAR scavenging ability and the inhibitory ability of LP. From these findings, it is suggested that oxidative stress is involved in the cytotoxicity of CA, and AJ leaf extract effectively protected CA-induced cytotoxicity via antioxidative effects. Conclusions: Natural resources like AJ leaf extract may be a putative therapeutic agent for treatment or alleviation of the toxicity induced by CA metallic mordant.