• Journal of Welding and Joining
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• v.27 no.6
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• pp.55-61
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• 2009

This study aims for determination of cutting work envelope of an articular robot for H-beam cutting. The robot has its own work envelope. The cutting of piece with groove requires the specific position of the torch which contracts the work envelope. This study suggested the new method to determine the cutting work envelope for this case. The method simplified the problem by use of the combination of inverse kinematics and forward kinematics. The method was used for cutting the H-beam with groove. The cutting work envelope was determined easily. The result was verified by 3D simulation system which implements the articular robot with 6 axes and the H-beam in the virtual shop.

• IMMUNE NETWORK
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• v.4 no.3
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• pp.143-154
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• 2004

Background: CD27 is recently known as a memory B cell marker and is mainly expressed in activated T cells, some B cell population and NK cells. CD27 is a member of tumor necrosis factor receptor family. Like CD40 molecule, CD27 has (P/S/T/A) X(Q/E)E motif for interacting with TNF receptor-associated factors (TRAFs), and TRAF2 and TRAF5 bindings to CD27 in 293T cells were reported. Methods: To investigate the CD27 signaling effect in B cells, human CD40 extracellular domain containing mouse CD27 cytoplamic domain construct (hCD40-mCD27) was transfected into mouse B cell line CH12.LX and M12.4.1. Results: Through the stimulation of hCD40-mCD27 molecule via anti-human CD40 antibody or CD154 ligation, expression of CD11a, CD23, CD54, CD70 and CD80 were increased and secretion of IgM was induced, which were comparable to the effect of CD40 stimulation. TRAF2 and TRAF3 were recruited into lipid-enriched membrane raft and were bound to CD27 in M12.4.1 cells. CD27 stimulation, however, did not increase TRAF2 or TRAF3 degradation. Conclusion: In contrast to CD40 signaling pathway, TRAF2 and TRAF3 degradation was not observed after CD27 stimulation and it might contribute to prolonged B cell activation through CD27 signaling.

• The Korean Journal of Soil Zoology
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• v.6 no.1_2
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• pp.37-44
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• 2001

Scarabaeids and white grubs were investigated at Halla arboretum and nursery in Jeju province in 1999 and 2001. Scarabaeid pests were surveyed from 14 tree species of 12 families at Halla arboretum in Jeju in March, 1999 and from 55 species of 27 families in March and September, 2001 and from Taxus cuspidata at nursery in Seoguipo in March, 1999 and 18 tree species of 9 families at the same nursery in March and September, 2001. Six species of white grubs and scarabaeids were collected from Halla arboretum. At Halla arboretum, Holotrichia niponensis was collected from 28 tree species of 21 families, H. diomphalia from 27 tree species of 20 families, and an unidentified white grub from 27 tree species of 19 families. Maladera orientalis was collected from 4 tree species of 4 families and Aphodius sp. and Adoretus tenuimaculatus from Punica granatum and Carpinus sieboldiana. At Halla nursery in Seoguipo, H. niponensis were collected from 9 tree species of 6 families and H. diomphalia from 10 tree species of 6 families. White grub of Minela testaceopes was collected from Ternsstraemia japonica. H. niponensis, H. diomphalia and an unidentified white grub were dominant species out of collected white grubs and scarabaeids and these were collected from Cinamomum camphrora. H. niponensis was the most serious pest on T. cuspidata.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.260-263
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• 2001

Mechanical properties have been accepted to be major factor to improve wear resistance. The effect of mechanical properties on wear resistance of 0.27C-0.70Ni-1.42Cr-0.20Mo steel was studied under various test conditions. It is clear that yield strength, tensile strength, impact value, and hardness are strongly related each other. Wear resistance tests as pin on plate type and dry sand / rubber wheel type proved to be that wear depends on mechanical properties. Microstructures were also observed to make clear the wear properties. At quenching and low temperature tempering, the specimen has a good wear resistance.

• Natural Product Sciences
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• v.27 no.2
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• pp.122-127
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• 2021

A new steroidal saponin, (23S,24S)-spirosta-5,25(27)-diene-1𝛽,3𝛽,23,24-tetrol 1-O-((2,3-diacetyl-α-L-rhamnopyranosyl)-(1→2)-[𝛽-D-xylopyranosyl-(1→3)]-α-L-arabinopyranoside)-24-O-𝛽-D-glucopyranoside (humilisoside) together with the known 𝛽-sitosterol 3-O-glucopyranoside, adenosine, dioscin, and methylprotodioscin were isolated from the leaves of Dracaena humilis. Their structures were elucidated by spectral techniques including mass spectrometry (ESIMS, HRESIMS, tandem MS-MS), 1D NMR (¹H, ¹³C NMR), 2D NMR (HSQC, ¹H-¹H COSY, HMBC, NOESY), chemical method as well as by comparison with spectroscopic data reported in the literature. The chemotaxonomic significance of the isolation of these compounds is discussed. This is the first report on the phytochemical investigation of D. humilis.

• Journal of Life Science
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• v.31 no.11
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• pp.995-1003
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• 2021

Chromatin remodeling regulates gene expression through epigenetic mechanisms. Aberrations in histone modification have been associated with depression-like behaviors in animal models. Additionally, growing evidence also indicates that epigenetic modification is associated with depression. p11 (S100A10) has been implicated in the pathophysiology of depression both in human and rodent models. In the present study, we investigated alterations in histone acetylation and methylation at the promoter of the p11 gene in the hippocampus of mice subjected to chronic unpredictable stress (CUS). C57BL/6 mice were exposed to CUS daily for 3 weeks. Depression-like behaviors were measured with the forced swimming test (FST). The levels of hippocampal p11 expression were analyzed by quantitative real-time polymerase chain reaction (PCR) and Western blotting. The levels of acetylated and methylated histone H3 at the promoter of p11 were measured by chromatin immunoprecipitation followed by real-time PCR. CUS-exposed mice displayed depression-like behaviors with prolonged immobility in FST. CUS led to significant decreases in the expression of p11 at both protein and mRNA levels. Meanwhile, there was a decrease in histone H3 acetylation (Ac-H3) and H3-K4 trimethylation (H3K4met3) and an increase in H3-K27 trimethylation (H3K27met3) at the p11 promoter. These results indicate that chronic stress causes the epigenetic suppression of p11 expression in the hippocampus.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.145-145
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• 2000

• Food Science of Animal Resources
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• v.27 no.1
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• pp.102-109
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• 2007

Lactobacillus salivarius subsp. salivarius CNU27 possessed a high level of ${\alpha}$-galactosidase activity. Purified ${\alpha}$-galactosidase was obtained after sonication of harvested cell pellet followed by DEAE-Sephadex A-50 and Mono Q anion exchange chromatography. The specific activity of the purified enzyme was 8,994 units/mg protein which is 17.09 times higher than that in crude extract. The native enzyme was a monomer with a molecular mass of 56,397.1 dalton. The optimum temperature and pH for the enzyme were $40^{\circ}C$ and 6.0, respectively. The enzyme was stable between 25 and $50^{\circ}C$. However, ${\alpha}$-galactosidase activity was lost rapidly below pH 4.5 and above pH 8.5. The enzyme activity decreased to 6.73% and 4.30% of the original activity by addition of $Cu^{2+}$ and $Hg^{2+}$, respectively. Other metal compounds did not affect the enzyme activity significantly. The enzyme liberated galactose from melibiose, raffinose, and stachyose. The rate of substrates hydrolysis was measured by HPLC. Raffinose, stachyose and melibiose were completely decomposed after 24 hr at $40^{\circ}C$.

• Food Science of Animal Resources
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• v.27 no.1
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• pp.110-116
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• 2007

Lactobacillus salivarius subsp. salivarius Nam27 with a high ${\beta}$-galactosidase activity was selected for enzymatic characterization. For purification, cell pellet was disrupted by Bead Beater, by DEAE-Sepharose and Mono-Q chromatography. The specific activity of the purified enzyme was 5,312 units/mg. The molecular weight of native monomeric ${\beta}$-galactosidase was estimated to be 30,000 dalton (monomer) by the SDS-PAGE. The optimum temperature and optimum pH were $50^{\circ}C$ and 5.0, respectively. This enzyme was stable between 35 and $55^{\circ}C$. ${\beta}$-galactosidase activity was lost rapidly above pH 7.0. But ${\beta}$-galactosidase was more stable at pH 4.0 (acidic conditions). And ${\beta}$-galactosidase activity was lost rapidly above $65^{\circ}C$ after 10 min incubation. $Ca^{2+}$ and $Zn^{2+}$ metal ions enhanced ${\beta}$-galactosidase activity by 164.09% and 127.37% while $Cu^{2+}$, $Fe^{3+}$ and $Mn^{2+}$ lowered ${\beta}$-galactosidase activity by 58.29%,85.10% and 77.66% respectively. Other metal ions didn't affect ${\beta}$-galactosidase activity significantly.

• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.663-666
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• 2006

Carnosine, homocarnosine and anserine might act as anti-oxidants and free radical scavengers in vivo. In the present study, the protective effects of carnosine and related compounds on the $H_2O_2$-mediated cytochrome c modification were studied. Carnosine, homocarnosine and anserine significantly inhibited the oligomerization of cytchrome c induced by $H_2O_2$. All three compounds also inhibited the formation of carbonyl compound and dityrosine during the incubation of cytochrome c with $H_2O_2$. These compounds effectively inhibited the peroxidase activity in the cytchrome c treated with $H_2O_2$. The results suggested that carnosine, homocarnosine, and anserine might protect cytochrome c against $H_2O_2$-mediated oxidative damage through a free radical scavenging.