• 한국초전도ㆍ저온공학회논문지
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• 제22권1호
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• pp.1-6
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• 2020

This is a parameter study for the direct fabrication of a large grain YBCO bulk superconductors using Y₂O₃, BaCO₃ and CuO powders without any grinding step. The cracks, which have been formed due to volume contraction during calcination step, have been prevented by controlling the heating rate at 930~950 ℃. It has been observed that multi-grain growth has occurred due to the dissolution of Sm123 seed due to the retention of carbon in Ba-Cu-O melt. In order to accelerate the carbon release in prior calcination heat treatment, the reduction of pellet thickness and the drilling of artificial holes have been applied. Single-grain YBCO bulk superconductor has been successfully fabricated by stacking multiple thin slab. However, the crack formation has been rather prominent for the compact with artificial holes. The use of buffer pellet, which is supposed to act as diffusion barrier, has prevented the dissolution of Sm123 seed crystal and has led to the growth of single grain of high content of carbon containing specimen.

• The Korean Journal of Physiology and Pharmacology
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• 제14권5호
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• pp.299-304
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• 2010

Losartan is a selective angiotensin II (Ang II) type 1 ($AT_1$) receptor antagonist which inhibits vascular smooth muscle cells (VSMCs) contraction and proliferation. We hypothesized that losartan may prevent cell proliferation by activating AMP-activated protein kinase (AMPK) in VSMCs. VSMCs were treated with various concentrations of losartan. AMPK activation was measured by Western blot analysis and cell proliferation was measured by MTT assay and flowcytometry. Losartan dose- and time-dependently increased the phosphorylation of AMPK and its downstream target, acetyl-CoA carboxylase (ACC) in VSMCs. Losartan also significantly decreased the Ang II- or 15% FBS-induced VSMC proliferation by inhibiting the expression of cell cycle associated proteins, such as p-Rb, cyclin D, and cyclin E. Compound C, a specific inhibitor of AMPK, or AMPK siRNA blocked the losartan-induced inhibition of cell proliferation and the $G_0/G_1$ cell cycle arrest. These data suggest that losartan-induced AMPK activation might attenuate Ang II-induced VSMC proliferation through the inhibition of cell cycle progression.

• 생약학회지
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• 제36권1호통권140호
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• pp.17-20
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• 2005

We previously reported that the exogenous administration of cumambrin A, a sesquiterpene lactone from the dried flowers of Chrysanthemum boreale Makino has a pharmacological effect on normalization of blood pressure in the spontaneously hypertensive rats (SHR). In the present study, we further investigated the effect of cumambrin A on the relaxation of phenylephrine-induced precontracted rat aortic artery rings. The potency of cumambrin A was than compared to verapamil, a well known $Ca^{2+}-channel$ blocker. The results demonstrate that the isolated rat aortic arteries are relaxed to basal tension at a concentration of $5{\times}10^{-5}\;M$ cumambrin A treatment. The results also show that the phenylephrine-induced contraction is inhibited by a pretreatment of cumambrin A. Co-treatment of cumambrin A and verapamil showed a strong synergetic effect on the relaxation of rat aortic artery rings. Thus, these data demonstrate that cumambrin A is a potent relaxant of rat aortic smooth muscle and suggest that cumambrin A modulates intracellular or extracellular $Ca^{2+}$ mobilization.

• Molecules and Cells
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• 제26권3호
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• pp.265-269
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• 2008

Calumenin, a multiple EF-hand $Ca^{2+}$ binding protein is located in the SR of mammalian heart, but the functional role of the protein in the heart is unknown. In the present study, an adenovirus gene transfer system was employed for neonatal rat heart to examine the effects of calumenin over-expression (Calu-OE) on $Ca^{2+}$ transients. Calu-OE (8 folds) did not alter the expression levels of DHPR, RyR2, NCX, SERCA2, CSQ and PLN. However, Calu-OE affected several parameters of $Ca^{2+}$ transients. Among them, prolongation of time to 50% baseline ($T_{50}$) was the most outstanding change in electrically-evoked $Ca^{2+}$ transients. The higher $T_{50}$ was due to an inhibition of SERCA2-mediated $Ca^{2+}$ uptake into SR, as tested by oxalate-supported $Ca^{2+}$ uptake. Furthermore, co-IP study showed a direct interaction between calumenin and SERCA2. Taken together, calumenin in the cardiac SR may play an important role in the regulation of $Ca^{2+}$ uptake during the EC coupling process.

• 약학회지
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• 제45권1호
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• pp.78-84
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• 2001

Heme oxygenase is a rate-limiting enzyme in heme catabolism that cleaves heme to form biliverdin, iron, and carbon monoxide. Heme oxygenase-1 is expressed in many types of cells and tissues and is highly induced in response to oxidative stress. Carbon monoxide, one of the products of heme oxygenase, can stimulate soluble guanylate cyclase and dilate the vascular smooth muscle. So, the induction of heme oxygenase by lipopolysaccharide (LPS)-induced oxydative stress and the effect of the resultant carbon monoxide on aortic contractility were examined in this study. Zinc protoporphyrine IX (ZnPP), a inhibitor of heme oxygenase, elicited weak contraction of thoracic aortic ring, and this effect was more potent in aorta of LPS-treated rats than control and was blocked by methylene blue. The hyperreactivity to ZnPP in LPS-treated group was blocked by co-treatment with aminoguanidine. In the aortic ring of LPS-treated rats, ZnPP didn't change the vasoreactivity to phenylephrine or acetylcholine. ZnPP elicited hyper-tensive effect in concious rats, and pretreatment with LPS did not affect this effect. Prazosin significantly diminished the hypertensive effect of ZnPP. These results indicate that LPS induced heme oxygenase in aotra, and the resultant carbon monoxide diminished the aortic reactivity to vasoconstrictor.

• 대한물리치료과학회지
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• 제18권4호
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• pp.65-72
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• 2011

The purpose of this study was to investigate the responses of the trunk muscle during expected and unexpected sudden loadings of the hands on the sagittal plane. Twenty, young healthy adults(male 10, female 10) were participated to two different loading conditions : expected and unexpected sudden loadings. Different weights were dropped in hand : 5lb, 6lb, 7lb for male, and 3lb, 4lb, 5lb for female. EMG activity of rectus abdominalis and erector spine muscle were collected. Rectus abdominalis and lumbar erector spine muscle activity significantly increased in unexpected sudden loadings than expected sudden loadings(p<.05). This results indicate that co-contraction of abdominal and back muscle contribute for dynamic spinal stability during expected or unexpected activities of daily living. Preparatory adjustments can be made which reduce the postural perturbation to sudden load and prevent low back injuries.

• Biomolecules & Therapeutics
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• 제14권4호
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• pp.194-201
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• 2006

The general pharmacological properties of GCSB-5, a herbal formulation consisting of 6 Oriental herbs(Ledebouriellae Radix, Achyranthis Radix, Acanthopanacis Cortex, Cibotii Rhizoma, Glycine Semen and Eucommiae Cortex), were investigated in mice, rats, guinea pigs and rabbits. The administration of GCSB-5 had no effect on general behavior, and did not influence the central nervous system. Mean blood pressure, heat1 and respiratory rate and contractile response of the isolated guinea pig atrium were unaffected by the treatment of GCSB-5. Addition of GCSB-5 did not cause spontaneous relaxation and contraction of the isolated guinea pig ileum and rat uterus. And also, GCSB-5 had no effect on the gastrointestinal system and the blood system of the animals examined in this study. GCSB-5, at higher doses(1,000 and 3,000 mg/kg), increased the urinary excretion of electrolytes, however, the urine volume and pH in rats were unaffected. Taken together, these results indicate that GCSB-5 does not induce any adverse effects in experimental animals and is expected to have no significant general pharmacological activities.

• The Journal of Korean Physical Therapy
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• 제31권4호
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• pp.161-168
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• 2019

Most athletes with anterior cruciate ligament (ACL) ruptures undergo a surgical ACL reconstruction (ACLR) and rehabilitation. On the other hand, controversy still exists because neither a reconstruction nor rehabilitation have been proven to be superior in the management of ACL injury. This study reviewed the success rates of interventions to provide recommendations for the optimal management after an ACL injury. One of the most important considerations after an ACL injury is the timing and type of intervention. At the early stages, which involve the loss of volume and strength of quadriceps femoral muscle, weight bearing (closed kinetic chain) exercises with pain management followed by high velocity resistance exercises in an open kinetic chain environment are recommended to improve the quadriceps function. After that, it is important to apply intensive isokinetic exercise with a lower extension rate. In this case, it is important to apply overload to the muscles and to simultaneously lead the co-contraction of the hamstrings. Standards are essential because the timing and type of interventions are crucial to prevent re-injury and complications, such as osteoarthritis, as well as to confirm the successful outcome of the treatment. Different interventions recommended for ACL damage have yet to reach consensus. Further studies will be needed to observe the effects of the intervention through multidisciplinary approaches.

• 대한본초학회지
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• 제38권5호
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• pp.39-47
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• 2023

Objectives : The objective of present study was to investigate the vasorelaxant effects of 20 Korean native plants on isolated rat thoracic aorta precontracted with phenylephrine (PE). Methods : Dried 20 plant materials were extracted 3 times with water, ethanol, or methanol for 3h in the reflux apparatus at 70 ± 5℃. Male SD rats were anesthetized by ether inhalation, and their aorta rings were isolated and placed in 10 ㎖ Krebs Henseleit (KH) buffer. While using an isolated organ-chamber technique, the aorta rings were maintained by bubbling with a gas mixture of 95% O₂-5% CO₂ at 37℃. Changes in isometric tension of aorta rings were recorded via isometric transducers connected to a Powerlab Data Acquisition System. Results : Among the 20 native plants, Chrysanthemum indicum L. flower, Nelumbo nucifera Gaertn. rhizome, Schisandra chinensis (Turcz.) Baill. fruit, Anthriscus sylvestris (L.) Hoffm. root, Corydalis turtschaninovii Besser tuber, Corydalis decumbens (Thunb.) Pers. tuber, and Dolichos lablab L. seed showed significant vasorelaxant effect on the contraction of aorta rings induced by PE. In contrast, Mertensia maritima subsp. asiatica Takeda whole plant, Ajuga decumbens Thunb. whole plant, Trigonotis peduncularis (Trevis.) Benth. ex Baker & S.Moore whole plant, Dioscorea quinquelobate Thunb. rhizome, Allium microdictyon Prokh aerial part, Momordica charantia L. fruit, Carthamus tinctorius L. flower, and Clematis terniflora DC. root constricted more the aorta rings precontracted by PE Conclusion : These results suggest that the possibility as useful herbal resources for the development of functional foods or medicines for hypertension treatment.

• 한국축산식품학회지
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• 제44권1호
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• pp.216-224
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• 2024

The reduction of nitric oxide (NO) bioavailability in the endothelium induces endothelial dysfunction, contributing to the development of hypertension. Although Lactobacillus consumption decreases blood pressure, intracellular signaling pathways related to hypertension have not been well elucidated. Thus, this study examined the effect of spray-dried Lactiplantibacillus plantarum K79 (LpK79) on NO production, intracellular signaling pathways, and inflammatory responses related to vascular function and hypertension. NO production was assessed in human umbilical vein endothelial cells (HUVECs) treated with LpK79. Endothelial NO synthase (eNOS) and intracellular signaling molecules were determined using Western blot analysis. LpK79 dose-dependently increased NO production and activated eNOS via the phosphoinositide 3-kinase/Akt signaling pathway HUVECs. Moreover, LpK79 mitigated the activation of crucial factors pivotal for vascular contraction in smooth muscle cells, such as phospholipase Cγ, myosin phosphatase target subunit 1, and Rho-associated kinase 2. When HUVECs were treated with LpL79 in the presence of Escherichia coli lipopolysaccharide (LPS), LpK79 effectively suppressed mRNA and protein expression of pro-inflammatory mediators induced by E. coli LPS. These results suggest that LpK79 provided a beneficial effect on the regulation of vascular endothelial function.