• 한국식품영양과학회:학술대회논문집
• /
• 한국식품영양과학회 2004년도 Annual Meeting and International Symposium
• /
• pp.110-115
• /
• 2004

The immature fruits of Poncirus trifoliata L. or Ponciri fructus (PF), well known as 'Jisil' in Korea, have been used against allergic diseases for generations, and still occupy an important place in traditional Oriental medicine. Anti-allergic effects of this fruit have been investigated in a few experimental models. Immunoglobulin E (IgE) is the principal immunoglobulin involved in immediate hypersensitivities and chronic allergic diseases. The effect of an aqueous extract of PF on in vivo and in vitro IgE production was investigated. PF dose-dependently inhibited the active systemic anaphylaxis and serum IgE production induced by immunization with ovalbumin, Bordetelia pertussis toxin and aluminum hydroxide gel. PF strongly inhibited interleukin 4 (IL-4)-dependent IgE production by lipopolysaccharide-stimulated murine whole spleen cells. In the case of U266 human IgE-bearing B cells, Ponciri fructus also showed an inhibitory effect on the IgE production. On the other hand, mast cell hyperplasia can be causally related with chronic inflammation. Stem cell factor (SCF), the ligand of the c-kit protooncogene product, is a major regulator and ohernoattractant of mast cells. Ponciri fiuctus (1 mg/mL) significantly inhibited the SCF-induced migration of rat peritoneal mast cells (RPMCs). RPMCs exposed to SCF (50 ng/mL) resulted in a drastic shape change with a polarized morphology while the cells exposed to Ponciri fructus (1 mg/mL) remained resting, with little or no shape alteration. The drastic morphological alteration and distribution of polymerized actin were blocked by pretreatment with Ponciri fructus. In addition, Ponciri fructus inhibited both TNF-alpha and IL-6 secretion from RPMCs stimulated with SCF. These results suggest that Ponciri fructus has an anti-allergic activity by inhibition of IgE production from B cells. These findings also provide evidence that Ponciri fructu inhibits chemotactic response and inflammatory cytokines secretion to SCF in mast cells.

• Journal of Welding and Joining
• /
• 제30권1호
• /
• pp.72-77
• /
• 2012

Recently, according to the increase of income and development of quality of life, the leisure industry has been developed. In particular, the interest of design and manufacture technology of leisure yacht has significantly increased. However, domestic market of leisure ships is currently in its initiating stage. So research and development for structural strength of leisure yacht need to be investigated. In this study, lug of yacht's mast which is known for a critical damage region is explicitly considered. This paper deals with the estimation of stress concentration factors (SCFs) for lug of yacht's mast depending on dimensions of lug using hot spot stress. Also, SCF formulae is suggested using parametric study.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제4권1호
• /
• pp.51-56
• /
• 2002

A recombinant transfer vector pBacSCF was constructed by inserting huamn stem cell factor (hSCF) cDNA into plasmid pBacPAK8. BmN cells were co-transfected with modified Bombyx mori, nuclear polyhedrosis virus (BmBacPAK) DNA and the recmbinant transfer vector to construct a recombinant baculovirus containing hSCE gene. DNA dot blotting and RNA dot blotting demonstrated that the hSCE gene was contained in the recombinant virus and transcribed. The recombinant baculovirus was infectious to BmN cells and to silkworm. SDS-PAGE analysis showed a specific band of expressed product in the extract of infected cells and in the heamolymph of infected larvae. Bioactivity of the recombinant hSCE was determined with W-1 cell line and MTT colorimetric method in synergy with interlukin-3 (IL-3). These results revealed that the hSCF gene was over-expressed in cultured cells and lavae of silkworm.

• Bulletin of the Korean Chemical Society
• /
• 제19권5호
• /
• pp.539-544
• /
• 1998

A new theoretical method, named the SCF-DWB-IOS approximation, is suggested to investigate the vibrational predissociation of triatomic van der Waals complexes. The meta stable vibrational excited states are described with SCF (self-consistent-field) approximation and the fragmented diatomic continuum states are determined by using IOS (infinite order sudden) approximation. The dissociation process itself is studied by using DWB (distorted wave Born) approximation. As a test case, the predissociation rates, rotational state distributions of products, and the lifetimes of vibrationally excited states of $Ne-I_2$ are all computed which are in reasonable agreements with other theoretical and/or experimental results. The suggested SCF-DWB-IOS approximation scheme is found to be a very simple but efficient theoretical tool to investigate the vibrational predissociation dynamics of small van der Waals complexes.

• Archives of Pharmacal Research
• /
• 제22권2호
• /
• pp.108-112
• /
• 1999

Recombinant murine stem cell factor (rmSCF) or recombinant murine nerve growth factor (rmNGF) induced the morphological change of large numbers of rat peritoneal mast cells (RPMC). We investigated the role of phosphatidylinositol $3^{l}-kinase$ (PI3-kinase) in receptors-mediated morphological change in RPMC. Exposure of RPMC to PI3-kinase inhibitor, wortmannin, before the addition of rmSCF and rmNGF antagonized those factors-induced morphological change. These results suggest that the PI3-kinase is involved in the signal transduction pathway responsible for morphological change following stimulation of rmSCF and rmNGF and that wortmannin blocks these responses.

• Ocean Systems Engineering
• /
• 제12권1호
• /
• pp.1-22
• /
• 2022

The majority of tubular joints commonly found in offshore jacket structures are multi-planar. Investigating the effect of loaded out-of-plane braces on the values of the stress concentration factor (SCF) in offshore tubular joints has been the objective of numerous research works. However, due to the diversity of joint types and loading conditions, a number of quite important cases still exist that have not been studied thoroughly. Among them are internally ring-stiffened two-planar TT-joints subjected to axial loading. In the present research, data extracted from the stress analysis of 243 finite element (FE) models, verified against available numerical and experimental data, was used to study the effects of geometrical parameters on the chord-side SCFs in two-planar tubular TT-joints reinforced with internal ring stiffeners subjected to two types of axial loading. Parametric FE study was followed by a set of nonlinear regression analyses to develop six new SCF parametric equations for the fatigue analysis and design of axially-loaded two-planar TT-joints reinforced with internal ring stiffeners.

• 대한임상검사과학회지
• /
• 제36권2호
• /
• pp.163-172
• /
• 2004

Mast cells (MCs) have been implicated in the pathogenesis of tissue fibrosis. However, the role of MC in the development of liver fibrosis has not been fully elucidated. Stem cell factor (SCF) is known to recruit MCs to the liver following injury as it induces mast cell proliferation, survival and differentiation from resident tissue precursors. This study examines the interaction between activated hepatic stellate cells (HSCs) and MCs in rat fibrotic liver, and SCF production by HSCs during culture in vitro. Rats were studied 4, 7, 14 and 21 days after bile duct ligation (BDL). Fibrogenesis was assessed by a measurement of collagen stained with sirius red F3B. Activated HSCs and MCs were identified by ${\alpha}$-smooth muscle actin (${\alpha}-SMA$) immunohistochemical and alcian blue staining and measured by a computerized image analysis system. SCF production was determined in rat HSC cultures using Western blotting. Mild fibrotic changes were noted in BDL rat livers as early as 4 days after induction of cholestasis. Significant expansion and organization of fibrous tissue has occurred in day 14 BDL rats which progressed to bridging fibrosis by day 21. In BDL rats, both a large number of activated HSCs and MCs were detected in portal tracts and fibrous septa. Both area of activated HSCs infiltration and density of MCs were significantly higher in all BDL group compared with Shams. In BDL rats, both areas of activated HSCs infiltration and density of MCs were no significant difference between day 4 and 7 and were significantly higher in day 14. However, the areas of activated HSCs infiltration were significantly lesser in day 21 and the densities of MCs were significantly higher in day 21 compared with day14 BDL. In BDL rats, both areas of activated HSCs infiltration and density of MCs were highly correlated with areas of fibrosis. Western blotting showed that SCF protein was consistently produced in activated HSCs by culture on plastic and freshly isolated HSCs expressed relatively little 30kD SCF compared to late primary culture activated HSCs (day 14) and passaged HSCs. These results suggest that HSCs activated in vitro produce SCF, and may play an important role in recruiting mast cells to the liver during injury and fibrosis.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
• /
• pp.1521-1524
• /
• 1987

The performance of SCF can be improved with the Op-AMP which has the properties of high speed, large slew rate, and lower power dissipation. The OP-AMP used for SCF will be presented. For illustration, using this OP-AMP 5-th order LPF is designed.

• 대한화학회지
• /
• 제46권6호
• /
• pp.541-544
• /
• 2002

높은 순도의 14-알킬-14H-다이벤조[a,j]잔텐의 합성법과 AM1 SCF MO 계산을 보고하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 F
• /
• pp.1896-1898
• /
• 1998

Balanced differential SCF with common-mode reject fully differential SC network is introduced. Through simulation, performance of balanced differential bandpass SCF and its potentiality of practical application is proposed.