• Economic and Environmental Geology
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• 제27권5호
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• pp.441-449
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• 1994

The tourmalines distributed in the Sangdong area belong to the dravite-schorl series in terms of the cell dimensions and the chemical compositions. Geochemical characteristics of tourmalines indicate that Naedeogni granite and pegmatite appear to be derived from Li-poor and Fe-riched aplite rocks, but Nonggeori granite is derived from Ca-poor or Si-riched pelitic rocks. The Mg+Fe contents of tourmaline in Naedeogni granitoids are decreased from the granites to the pegmatites with the Fe contents increased while Mg contents decreased. It indicates the differentiation during the crystallization of tourmalines. These phenomena are coincided with the chemical variations from cores toward rims of the zonal tourmalines. Such a compositional variations in Nonggeori granite can not be observed.

• Mass Spectrometry Letters
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• 제11권4호
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• pp.108-112
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• 2020

A certified reference material (CRM) for the analysis of nutrient elements in an edible mushroom (Ganoderma lyceum) powder has been developed (KRISS CRM 108-10-011). The mass fractions of calcium (Ca), iron (Fe), and zinc (Zn) were measured by isotope dilution inductively coupled plasma mass spectrometry (ID ICP/MS). To dissolve the fungi cell wall of mushroom consisted of chitin fibers, sample preparation method by single reaction chamber type microwave-assisted acid digestion with acid mixtures was optimized. The mean measurement results obtained from 12 sample bottles were used to assign as the certified values for the CRM and the between-bottle homogeneities were evaluated from the relative standard deviations. The certified values were metrologically traceable to the definition of the kilogram in the International System of Units (SI). This CRM is expected to be used for validation of analytical methods or quality control of measurement results in analytical laboratories when they determine the mass fractions of elements in mushroom or other similar samples.

• Bulletin of the Korean Chemical Society
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• 제19권10호
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• pp.1095-1099
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• 1998

The crystal structure of an acetylene sorption complex of dehydrated fully Mn(Ⅱ)-exchanged zeolite X, Mn46Si100Al92O384·30C2H2 (a=24.705(3) Å) has been determined by single-crystal X-ray diffraction techniques. The structure was solved and refined in the cubic space group Fd3 at 21(l) ℃. The complex was prepared by dehydration at 380 ℃ and 2 x 10-6 Torr for 2 days, followed by exposure to 300 Torr of acetylene gas for 2 h at 24 ℃. The structure was refined to the final error indices, R1=0.060 and R2=0.054 with 383 reflections for which I > 3σ(Ⅰ). In the structure, Mn2+ ions are located at two different crystallographic sites; sixteen Mn2+ ions at site I are located at the centers of the double six rings and thirty Mn2+ ions are found at site Ⅱ in the supercage, respectively. Each of these latter Mn2+ ions is recessed ca. 0.385(2) Å into the supercage from its three-oxygen plane. Thirty acetylene molecules are sorbed per unit cell. Each Mn2+ ion at site Ⅱ lies on a threefold axis in the supercage of the unit cell, close to three equivalent trigonally arranged zeolite framework oxygen atoms (Mn(Ⅱ)-O=2.135(9) Å) and symmetrically to both carbon atoms of a C2H2 molecules. At these latter distances, the Mn(Ⅱ)-C interactions are weak (Mn(Ⅱ)-C=2.70(5) Å), probably resulting from electrostatic attractions between the divalent cations and the polarizable π-electron density of the acetylene molecules.

• Korean Journal of Soil Science and Fertilizer
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• 제46권4호
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• pp.260-269
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• 2013

Two single-crystals of fully dehydrated, partially $Li^+$-exchanged zeolites X (Si/Al = 1.09, crystal 1) and Y (Si/Al = 1.56, crystal 2), were prepared by flow method using 0.1 M $LiNO_3$ at 393 K for 48 h, respectively, followed by vacuum dehydration at 673 K and $1{\times}10^{-6}$ Torr. Their structures were determined by single-crystal X-ray diffraction techniques in the cubic space group $Fd\bar{3}$ and $Fd\bar{3}m$ at 100(1) K for crystals 1 and 2, respectively. They were refined to the final error indices $R_1/wR_2$ = 0.065/0.211 and 0.043/0.169 for crystals 1 and 2, respectively. In crystal 1, about 53 $Li^+$ ions per unit cell are found at three distinct positions; 9 at site I', 19 at another site I', and the remaining 25 at site II. The residual 25 $Na^+$ ions occupy three equipoints; 2 are at site I, 7 at site II, and 16 at site III'. In crystal 2, about 31 $Li^+$ ions per unit cell occupy sites I' and II with occupancies at 22 and 9, respectively; 3, 4, 23, and 3 $Na^+$ ions are found at sites I, I', II, and III', respectively. The extent of $Li^+$ ion exchange into zeolite X (crystal 1) is higher than that of zeolite Y (crystal 2), ca. 73% and 56% in crystals 1 and 2, respectively.

• BMB Reports
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• 제49권1호
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• pp.57-62
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• 2016

Up-regulation of adhesion molecules plays an important role in the infiltration of leukocytes into the skin during the development of various inflammatory skin diseases, such as atopic dermatitis. In this study, we investigated the modulatory effects of 2,3-dimethoxy-2′-hydroxychalcone (DMHC) on tumor necrosis factor (TNF)-α-induced intercellular adhesion molecule-1 (ICAM-1) expression and monocyte adhesiveness, as well as the molecular mechanisms underlying its action in the HaCaT human keratinocyte cell line. Pre-treating HaCaT cells with DMHC significantly suppressed TNF-α-induced ICAM-1 expression and subsequent monocyte adhesiveness. DMHC inhibited TNF-α-induced activation of NF-ᴋB. In addition, DMHC induced HO-1 expression as well as NRF2 activation. Furthermore, HO-1 knockdown using siRNA reversed the inhibitory effect of DMHC on TNF-α-induced ICAM-1 expression and adhesion of monocytes to keratinocytes. These results suggest that DMHC may inhibit TNF-α-induced ICAM-1 expression and adhesion of monocytes to keratinocytes by suppressing the signaling cascades leading to NF-ᴋB activation and inducing HO-1 expression in keratinocytes. [BMB Reports 2016; 49(1): 57-62]

• BMB Reports
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• 제38권5호
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• pp.526-532
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• 2005

A lectin with in-vitro anticancer activity against established human cancer cell lines has been purified by affinity chromatography on asialofetuin-linked amino activated silica beads from the tubers of Arisaema tortuosum, popularly known as Himalayan Cobra lily, a monocot plant from the family Araceae. The bound Arisaema tortuosum lectin (ATL) was eluted with glycine-HCl buffer, pH 2.5. ATL was effectively inhibited by asialofetuin, a complex desialylated serum glycoprotein as well as by N-acetyl-D-lactosamine, a disaccharide. It gave a single band corresponding to a subunit molecular weight of 13.5 kDa in SDS-PAGE, pH 8.8 both under reducing and non reducing conditions. When subjected to gel-filtration on Biogel P-200, it was found to have a molecular weight of 54 kDa, suggesting a homotetramer structure, in which individual polypeptides are not bound to each other with disulfide bonds. ATL is a glycoprotein with 0.9% carbohydrate content, stable up to $55^{\circ}C$ and at pH 2 to 10. The lectin had no requirement for divalent metal ions i.e. $Ca^{2+}$ and $Mn^{2+}$ for its activity. However, as reported for other monocot lectins, ATL gave multiple bands in isoelectric focusing and Native PAGE, pH 8.3. The lectin was found to inhibit in vitro proliferation of human cancer cell lines HT29, SiHa and OVCAR-5.

• Korean Journal of Food Science and Technology
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• 제32권6호
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• pp.1389-1395
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• 2000

Cervical cancer has been one of the leading causes of female death from cancer worldwide with about 500,000 deaths per year. A strong association between certain human papillomaviruses (HPV types 16 and 18) and cervical cancer has been well known. An extract of natural products, Rhus, has been used to investigate whether this agent has the ability of inhibiting the oncogenes E6 and E7 of HPV type 16. This Rhus inhibited the proliferation of human cervical cancer cell lines (C-33A, SiHa, Caski) and HaCaT keratinocytes in a dose response manner. In vitro binding assay and ELISA showed that Rhus inhibited the in vitro binding of E6 and E6AP which are essential for the binding and degradation of the tumor suppressor p53. In addition, Rhus inhibited the in vitro binding of E7 and Rb which essential tumor suppressor for the control of cell cycle. The level of mRNA for E6 was also decreased by Rhus while that of E7 mRNA was not changed. Our data suggested that Rhus inhibited the oncogenecity of E6 and E7 of HPV 16 type, thus can be used as a putative anti-HPV agent for the treatment of cervical carcinomas by HPV.

• Biomolecules & Therapeutics
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• 제32권1호
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• pp.84-93
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• 2024

Rosmarinic acid (RA) is a phenolic ester that protects human keratinocytes against oxidative damage induced by ultraviolet B (UVB) exposure, however, the mechanisms underlying its effects remain unclear. This study aimed to elucidate the cell signaling mechanisms that regulate the antioxidant activity of RA and confirm its cyto-protective role. To explore the signaling mechanisms, we used the human keratinocyte cell line HaCaT and SKH1 hairless mouse skin. RA enhanced glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione synthetase (GSS) expression in HaCaT cells in a dose- and time-dependent manner. Moreover, RA induced nuclear factor erythroid-2-related factor 2 (NRF2) nuclear translocation and activated the signaling kinases protein kinase B (AKT) and extracellular signal-regulated kinase (ERK). Treatment with the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, the ERK inhibitor U0126, and small interfering RNA (siRNA) gene silencing suppressed RA-enhanced GCLC, GSS, and NRF2 expression, respectively. Cell viability tests showed that RA significantly prevented UVB-induced cell viability decrease, whereas the glutathione (GSH) inhibitors buthionine sulfoximine, LY294002, and U0126 significantly reduced this effect. Moreover, RA protected against DNA damage and protein carbonylation, lipid peroxidation, and apoptosis caused by UVB-induced oxidative stress in a concentration-dependent manner in SKH1 hairless mouse skin tissues. These results suggest that RA protects against UVB-induced oxidative damage by activating AKT and ERK signaling to regulate NRF2 signaling and enhance GSH biosynthesis. Thus, RA treatment may be a promising approach to protect the skin from UVB-induced oxidative damage.

• Biomolecules & Therapeutics
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• 제25권6호
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• pp.625-633
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• 2017

Sphingosylphosphorylcholine (SPC) is one of the bioactive phospholipids that has many cellular functions such as cell migration, adhesion, proliferation, angiogenesis, and $Ca^{2+}$ signaling. Recent studies have reported that SPC induces invasion of breast cancer cells via matrix metalloproteinase-3 (MMP-3) secretion leading to WNT activation. Thrombospondin-1 (TSP-1) is a matricellular and calcium-binding protein that binds to a wide variety of integrin and non-integrin cell surface receptors. It regulates cell proliferation, migration, and apoptosis in inflammation, angiogenesis and neoplasia. TSP-1 promotes aggressive phenotype via epithelial mesenchymal transition (EMT). The relationship between SPC and TSP-1 is unclear. We found SPC induced EMT leading to mesenchymal morphology, decrease of E-cadherin expression and increases of N-cadherin and vimentin. SPC induced secretion of thrombospondin-1 (TSP-1) during SPC-induced EMT of various breast cancer cells. Gene silencing of TSP-1 suppressed SPC-induced EMT as well as migration and invasion of MCF10A cells. An extracellular signal-regulated kinase inhibitor, PD98059, significantly suppressed the secretion of TSP-1, expressions of N-cadherin and vimentin, and decrease of E-cadherin in MCF10A cells. ERK2 siRNA suppressed TSP-1 secretion and EMT. From online PROGgene V2, relapse free survival is low in patients having high TSP-1 expressed breast cancer. Taken together, we found that SPC induced EMT and TSP-1 secretion via ERK2 signaling pathway. These results suggests that SPC-induced TSP-1 might be a new target for suppression of metastasis of breast cancer cells.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.199-199
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• 2016

Commercially pure titanium (cp-Ti) and Ti alloys (typically Ti-6Al-4V) display excellent corrosion resistance and biocompatibility. Although the chemical composition and topography are considered important, the mechanical properties of the material and the loading conditions in the host have, conventionally. Ti and its alloys are not bioactive. Therefore, they do not chemically bond to the bone, whereas they physically bond with bone tissue. The electrochemical deposition process provides an effective surface for biocompatibility because large surface area can be served to cell proliferation. Electrochemical deposition method is an attractive technique for the deposition of hydroxyapatite (HAp). However, the adhesions of these coatings to the Ti surface needs to be improved for clinical used. Plasma electrolyte oxidation (PEO) enables control in the chemical com position, porous structure, and thickness of the $TiO_2$ layer on Ti surface. In addition, previous studies h ave concluded that the presence of $Ca^{+2}$ and ${PO_4}^{3-}$ ion coating on porous $TiO_2$ surface induced adhesion strength between HAp and Ti surface during electrochemical deposition. Silicon (Si) in particular has been found to be essential for normal bone and cartilage growth and development. Zinc (Zn) plays very important roles in bone formation and immune system regulation, and is also the most abundant trace element in bone. The objective of this work was to study electrochemical characteristcs of Zn and Si coating on Ti-6Al-4V by PEO treatment. The coating process involves two steps: 1) formation of porous $TiO_2$ on Ti-6Al-4V at high potential. A pulsed DC power supply was employed. 2) Electrochemical tests were carried out using potentiodynamic and AC impedance methoeds. The morphology, the chemical composition, and the micro-structure an alysis of the sample were examined using FE-SEM, EDS, and XRD. The enhancements of the HAp forming ability arise from $Si/Zn-TiO_2$ surface, which has formed the reduction of the Si/Zn ions. The promising results successfully demonstrate the immense potential of $Si/Zn-TiO_2$ coatings in dental and biomaterials applications.