• 동의생리병리학회지
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• 제23권2호
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• pp.480-487
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• 2009

Atherosclerosis, slow progressing inflammatory lesion in arteries, is one of the major causes of cardiovascular diseases. As mortality due to cardiovascular disease keeps increasing in Korea, researches on pathological mechanism of atherosclerosis may be beneficial in fighting against cardiovascular diseases. It is known that migration and MMP-9 secretion of Vascular Smooth Muscle Cell(VSMC) play a significant part in pathogenesis of atherosclerosis, although detailed mechanism of entire process is not clarified. We investigated whether the seeds of Trichosanthes kirilowii maxim (TS), inhibit migration and MMP-9 production of HASMC(human aortic SMC), which were induced by TNF-${\alpha}$ treatment. Migration assay showed that TS inhibited the migration of HASMC induced by TNF-${\alpha}$, in dose dependent manner. Also by Zymography MMP-9 production of HASMC was found to be reduced by TS, both in time and in dose dependent manner. Western blotting results suggest TS suppress activity of MAPkinases.

• The Journal of Korean Physical Therapy
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• 제16권2호
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• pp.90-98
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• 2004

Traumatic brain injury is an insult to the brain caused by an external physical force, that may product a diminished or altered state of consciousness, which results in impairment of cognitive abilities or physical function. The purposes of this study were to overview injury mechanism and neural plasticity of traumatic brain injury. Injury mecanism includes exitotoxicity, production free radical, inflammation and apoptosis. Furthermore traumatic brain injury has protective mechanisms includes production of neural growth factor, heat shock protein, anti-inflammatory cytokines.

• 대한한의학회지
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• 제21권1호
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• pp.91-98
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• 2000

The water extract of Seongpungtang(SPT) has commonly been used for treatment of ischemic brain damage in Oriental traditional medicine. However, little is known about the mechanism by which the water extract of SPT rescues brain cells from ischemic damage. To elucidate the protective mechanism of ischemic induced cytotoxicity, the regulation of Lipopolysaccharide (LPS) and PMA (phobol-12-myristate-13-acetate) induced iNOS expression in microglial cells was investigated. LPS and PMA treatment for 48 hr in microglial cells markedly induced nitric oxide (NO), but treatment of the cells with the water extract of SPT decreased nitrite formation. In addition, LPS and PMA treatment for 48 hr induced severe cell death in microglial cells. However treatment of the cells with the water extract of SPT did not induce significant changes compared to the control cells. Furthermore, NO production was markedly decreased by treatment of nuclear factor kappa B(NF-kB) inhibitor, pyrrolidine dithiocarbamate(PDTC). According to the above results, it is suggested that the protective effects of the water extract of SPT against ischemic brain damage may be mediated by regulation of iNOS during ischemic condition.

• Environmental Analysis Health and Toxicology
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• 제18권3호
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• pp.165-174
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• 2003

Cr (Ⅵ) - containing compounds are well-established carcinogens, although the mechanism for chromium - induced carcinogenesis is still not well understood. The reduction of Cr (Ⅵ) to its lower oxidation states, par ticularly Cr (V) and Cr (IV), is an important step for the production of chromium-mediated reactive oxygen species (ROS). The persistent oxidative stress during the reduction process may play a key role in the mechanism of Cr (Ⅵ) -induced carcinogenesis. This paper summarizes recent studies on (1) the reduction of Cr (Ⅵ) to Cr (III) occur by a multiplicity of mechanisms depending on the nature of reducing agents including ascorbate, diol-and thiol-containing molecules, certain flavoenzymes, cell organelles, intact cells, and whole animals; (2) free-radical production with emphasis on hydroxy radical generation via Fenton or Haber-Weiss type reactions; and (3) free radical - induced cellular damage, such at DNA strand breaks, hydroxylation of 2'-deoxyguanosine, and activation of nuclear transcription factor kB.

• Animal Bioscience
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• 제34권3_spc호
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• pp.345-353
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• 2021

Phytobiotics, also known as phytochemicals or phytogenics, have a wide variety of biological activities and have recently emerged as alternatives to synthetic antibiotic growth promoters. Numerous studies have reported the growth-promoting effects of phytobiotics in chickens, but their precise mechanism of action is yet to be elucidated. Phytobiotics are traditionally known for their antioxidant activity. However, extensive investigations have shown that these compounds also have anti-inflammatory, antimicrobial, and transcription-modulating effects. Phytobiotics are non-nutritive constituents, and their bioavailability is low. Nonetheless, their beneficial effects have been observed in several tissues or organs. The health benefits of the ingestion of phytobiotics are attributed to their antioxidant activity. However, several studies have revealed that not all these benefits could be explained by the antioxidant effects alone. In this review, I focused on the bioavailability of phytobiotics and the possible mechanisms underlying their overall effects on intestinal barrier functions, inflammatory status, gut microbiota, systemic inflammation, and metabolism, rather than the specific effects of each compound. I also discuss the possible mechanisms by which phytobiotics contribute to growth promotion in chickens.

• 한국전기전자재료학회논문지
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• 제30권9호
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• pp.602-608
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• 2017

Due to recent industry 4.0, manufacturing has changed a lot. In particular, it is necessary to control the controller and controller of the control system, to communicate various production information and measurement information, and to produce a database in accordance with the flexible production for a small quantity of various items, and to manage the trend of major parts of production facilities. In this paper, we developed a multiple wireless communication controller for small scale control system for smart factory by applying XBee and microcomputer. This controller is cheap and easy to build multi-radio communication environment of 1: N and can control and monitor control system. In addition, we tested multiple wireless communication controllers by using signal processing device and C++, and constructed network, control, and database for mechanism module, and confirmed effectiveness for industrial application.

• 한국연소학회지
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• 제9권4호
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• pp.28-34
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• 2004

Numerical simulations of freely propagating flames burning $H_2/HCl/Air$ Air mixtures were performed at atmospheric pressure in order to understand the effect of hydrogen chloride on flame structures. The chemical and physical effects of hydrogen chloride on flame structures were observed. A chemical kinetic mechanism was developed, which involved 26 gas-phase species and 198 forward elementary reactions. Under several equivalence ratios the flame speeds were calculated and compared with those obtained from the experiments, the results of which were in good agreement. As hydrogen chloride as additive was added into $H_2/Air$ flame, the flame speed, radical concentration and NO production rate were decreased. The chemical effect of hydrogen chloride caused the reduction of radical concentration, and then the decrease of the net rate of NO production. It was found that the influence in the reduction of $EI_{NO}$ with the addition of hydrogen chloride was attributed more due to the chemical effect than the physical effect.

• Applied Microscopy
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• 제28권4호
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• pp.539-549
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• 1998

The silk glands of the spiders are of several types. Among the several types of spider's silk glands, the principal fibers used in constructing the eggcase are products of the tubuliform glands (TBG), which are present only in females. Development of these glands parallels maturations of the ovaries and fat bodies. In order to understand the mechanism of eggcase-silk production, this paper has examined the fine structural changes of the TBG during the period of egg maturation in the garden spider, Argiope aurentia. Between the two kinds of secretory granules observed in the glandular epithelium of the mature TBG, the electron-dense granules which have paracrystalline structure are revealed to be the precursors of the eggcase silk fibers. During the production of eggcase, rapid release of the secretory product occurs at apical surface by the mechanism of apocrine secretion. Moreover, secondary lysosomes appear due to the rapid disorganization of cellular components during the eggcase formation. Examinations of formed fibers indicate a multicomponent internal structure, and electron micrographs reveal each fiber contains numerous electron lucent fibrils embedded in an amorphous electron dense matrix. The secretory precursors are produced as separated vesicles via well-oriented rER, and no Golgi complex has been found in the glandular epithelial cells.

• East Asian Economic Review
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• 제24권4호
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• pp.313-336
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• 2020

In this paper, I review evidence on changing global specialization in labor-intensive exporting. Production of apparel, footwear, furniture, and related products are how many low-income countries first enter export manufacturing. Just as China's rise as a powerhouse in these goods supplanted a role previously occupied by the East Asian Tigers, the world may again be on the cusp of significant change in where labor-intensive goods are produced. China's prowess in these sectors peaked in the early 2010s; its share in their global exports, while still substantial, is now in decline. Mechanisms through which the global economy may adjust to China's graduation into more technologically sophisticated activities include expanded labor-intensive export production in other emerging economies and labor-saving technological change in products currently heavily reliant on less-educated labor. Available evidence suggests that the first mechanism is operating slowly and the second hardly at all. As a third mechanism, China may in part replace itself by moving labor-heavy factories out of densely populated and expensive coastal cities and into the country's interior. Such a transition, though still in its infancy, would mirror the decentralization of manufacturing production in the U.S. and Europe, which occurred after World War II.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1996년도 춘계학술대회논문집
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• pp.110-120
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• 1996

A crank-slider mechanism is driven by the rotating disk with are crank-pin guide to be applied to the deep drawing and cold forging presses. Load characteristics for different presses are summarized to see the basics of deep drawing of sheet metal and forging in terms of load-stroke relationship. Several types of conventional deep drawing presses are also shown to be compared with the ratating disk-types press. Kinematic performances by thearc guide driving mechanism are anlayzed in terms of load capaicty, stroke, and slide velocity characteristics, and they are compared with those by conventional driving , e.g. Niagara-typepress and so on. Kinematically better performances is shown by arc guide drive than those by conventional ones. The new driving mechanism is also proven to be one of the best for mass production press in terms of short cycle time. Possible applications of the arc guide press to deep drawing and cold forging work are in terms of kinematics and load capacity.