• Bulletin of the Korean Chemical Society
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• 제13권4호
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• pp.363-367
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• 1992

The crystal structure of (1,3,6,9,11,14-hexaazatricycol[12.2.1.$1^{6,9}$]octadecane)copper(Ⅱ) perchlorate, Cu($C_{12}H_{26}N_6$)$(ClO_4)_2$, has been determined by the X-ray diffraction methods. The crystal data are as follows: Mr=516.9, triclinic, ${\alpha}=8.572\;(2)$, b=8.499 (3), c=15.204 (3) ${\AA}$, ${\alpha}=80.42\;(5),\;{\beta}=73.57\;(3),\;{\gamma}=69.82\;(4)^{\circ},\;V=994.2\;{\AA}^3,\;D_C=1.726\;gcm^{-3}$, space group $P{\tilde{1}},\;Z=2,\;{\mu}=21.27\;cm^{-1}&, F(000)=534 and T=297 K. The structure was solved by direct methods and refined by full-matrix least-squares methods to and R value of 0.081 for 1608 observed reflections measured with graphite-mono-chromated Mo Ka radiation on a diffractometer. There are two independent complexes in the unit cell. The two copper ions lie at the special positions (1/2, 0, 0) and (0, 1/2, 1/2)and each complex possesses crystallographic center of symmetry. Each Cu ion is coordinated to four nitrogen donors if the hexaazamacrotricyclic ligand and weakly interacts with two oxygen atoms of the perchlorate ions to form a tetragonally distorted octahedral coordination geometry. The Cu_N (sec), Cu_N(tert) and Cu_O coordination distances are 1.985 (14), 2.055 (14) and 2.757 (13) ${\AA}$ for the complex A and 1.996 (10), 2.040 (11) and 2.660 (13) ${\AA}$ for the complex B, respectively. The macrocycles in the two independent cations assume a similar conformation with the average r.m.s. deviation of 0.073 ${\AA}$. Two 1,3-diazacyclopentane ring moieties of the hexaazamacrotricyclic ligand are placed oppositely and almost perpendicularly to the square coordination plane of the ruffled 14-membered macrocycle. The secondary N atoms are hydrogen-bonded to the perchlorate O atoms with distances of 3.017 (23) and 3.025 (19) ${\AA}$ for the complexes A and B, respectively.

• 구강생물연구
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• 제42권4호
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• pp.187-197
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• 2018

Chemical agents such as minocycline (MC) and citric acid (CA) were suggested in the treatment of contaminated implant surface. In this study, MC-HCl treatment was performed to enhance surface characteristics of titanium alloy surface. The purpose of this study was to assess the characteristics and the biocompatibility of Ti-6Al-4V surface treated by MC. Alpha-beta titanium alloy (Ti-6Al-4V) samples were prepared and they were divided into 6 groups according to chemical concentration and treatment time. These groups include 1) group I, non-treated smooth titanium alloy; 2) group II, MC 1.5 mg/mL for 1 hour; 3) group III, MC 1.5 mg/mL for 24 hours; 4) group IV, MC 15 mg/mL for 10 minutes; 5) group V, MC 100 mg/mL for 5 minutes; 6) group VI, pH1 CA for 3 minutes. The analysis of the surface characteristics of MC-treated titanium alloy was executed using scanning electron microscopy, roughness test, and X-ray photoelectron spectroscopy (XPS). Cell adhesion and MTT assay was done using MC3T3 cell. Titanium surfaces treated with MC indicated a more smoothened surface microstructure. For group II and III, the new peaks of rutile TiO2 were found. Group II and V have more basic group of Ti-OH form in XPS. In MTT assay, all MC-treated groups showed significantly higher cell viability compared to control. The surface roughness, crystal structure, surface hydrophilicity, cell viability of smooth titanium surface was improved by MC treatment. Compared with the control experiment and CA-treated group, smooth titanium surface treated with MC showed improved surface characteristics and cell biocompatibility.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.148-155
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• 2018

To get a better understanding of the effect of physicochemical properties and microstructure on $SO_2$ absorption behavior of DESs with different molar ratios of EmimCl and EG (from 2:1 to 1:2), densities (${\rho}$), viscosities (${\eta}$), speeds of sound (u), refractive indices ($n_D$), and thermal decomposition temperatures ($T_d$) of EmimCl-EG DESs were measured and used to obtain the other derived properties, such as thermal expansion coefficient (${\alpha}_p$) and activation energy for viscous flow ($E_{\eta}$). Moreover, FT-IR spectra and in situ variable-temperature NMR spectroscopy were employed to study the microstructures of DESs. Based on physicochemical and spectroscopic properties, the influence of the concentrations of EmimCl on the interactions in DESs was explored to be associated with their $SO_2$ absorption behavior. The results show that the interactions between $Emim^+$ and $Cl^-$ of EmimCl is gradually weakening with increasing the concentration of EG in DESs by forming of hydrogen bond interaction of $O-H{\cdots}Cl^-$, resulting in a decrease of ${\rho}$, ${\eta}$, u, $n_D$, and $T_d$ of DESs, and hindering the charge-transfer interaction of $SO_2$ with $Cl^-$ and deceasing $SO_2$ capture capacity. Moreover, the $SO_2$ absorption capacity of DESs is proportional to their ${\rho}$ and $E_{\eta}$, respectively.

• 대한금속재료학회지
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• 제46권11호
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• pp.730-736
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• 2008

$TiO_2$ nanotubes fabricated in aqueous HF-based electrolytes have been generally grown only to about 500nm in length because of the strong dissolubility of HF acid. In this paper, ethylene glycol solution has been applied for increasing the length of the anodic $TiO_2$ nanotubes, and the growth behaviors of the nanotubes according to water contents has been investigated. Anodization of Ti in ethylene glycol + 1 wt% $NH_4F$ (EG solution) with water additions up to 10 wt% were carried out at the constant voltage of 20 V. The results show that a thin titanium oxide layer is formed in the initial stage and the nanotube structure grows underneath the initial layer. And the length of $TiO_2$ nanotubes decreases with the increasing water content in the solution. It can be ascribed to the locally acidified circumstance around the barrier layer inside the nanopore due to $H^+$ ion originated from water. The XPS for the nanotubes suggests that the spectra of Ti2p and O1s are the major chemical bonding states of the $TiO_2$, and those for F1s, N1s and C1s come from the compound of $(NH_4)_2TiF_6$.

• Animal Bioscience
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• 제34권7호
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• pp.1146-1156
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• 2021

Objective: The aim of the study was to compare the effect of two plant additives, rich in polyphenolic compounds, supplemented to sheep diets on microorganisms and carbohydrate fermentation in rumen. Methods: In the experiment, 6 ewes of the Polish Mountain breed were fitted with ruminal cannulas. Sheep were divided into three feeding groups. The study was performed in a cross-over design of two animals in each group, with three experimental periods (n = 6 per each group). The animals were fed a control diet (CON) or additionally received 3 g of dry and milled lingonberry leaves (VVI) or oak bark (QUE). Additionally, plant material was analyzed for tannins concentration. Results: Regardless of sampling time, QUE diet increased the number of total protozoa, as well as Entodinium spp., Diplodinium spp. and Isotrichidae family, while decreased bacterial mass. In turn, a reduced number of Diplodinium spp. and increased Ophryoscolex spp. population were noted in VVI fed sheep. During whole sampling time (0, 2, 4, and 8 h), the number of protozoa in ruminal fluid of QUE sheep was gradually reduced as opposed to animals receiving CON and VVI diet, where rapid shifts in the protozoa number were observed. Moreover, supplementing sheep with QUE diet increased molar proportions of butyrate and isoacids in ruminal fluid. Unfortunately, none of the tested additives affected gas production. Conclusion: The addition of VVI or QUE in a small dose to sheep diets differently affected rumen microorganisms and fermentation parameters, probably because of various contribution of catechins in tested plant materials. However, it is stated that QUE diet seems to create more favorable conditions for growth and development of ciliates. Nonetheless, the results of the present study showed that VVI and QUE additives could serve as potential natural modulators of microorganism populations and, consequently, carbohydrate digestion in ruminants.

• Journal of Microbiology and Biotechnology
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• 제31권5호
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• pp.710-716
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• 2021

A risk analysis of Shiga toxin (Stx)-encoding bacteriophage was carried out by confirming the transduction phage to non-Stx-producing Escherichia coli (STEC) and subsequent expression of the Shiga toxin genes. The virulence factor stx1 was identified in five phages, and both stx1 and stx2 were found in four phages from a total of 19 phage isolates with seven non-O157 STEC strains. The four phages, designated as ϕNOEC41, ϕNOEC46, ϕNOEC47, and ϕNOEC49, belonged morphologically to the Myoviridae family. The stabilities of these phages to temperature, pH, ethanol, and NaClO were high with some variabilities among the phages. The infection of five non-STEC strains by nine Stx-encoding phages occurred at a rate of approximately 40%. Non-STEC strains were transduced by Stx-encoding phage to become lysogenic strains, and seven convertant strains had stx1 and/or stx2 genes. Only the stx1 gene was transferred to the receptor strains without any deletion. Gene expression of a convertant having both stx1 and stx2 genes was confirmed to be up to 32 times higher for Stx1 in 6% NaCl osmotic media and twice for Stx2 in 4% NaCl media, compared with expression in low-salt environments. Therefore, a new risk might arise from the transfer of pathogenic genes from Stx-encoding phages to otherwise harmless hosts. Without adequate sterilization of food exposed to various environments, there is a possibility that the toxicity of the phages might increase.

• Journal of Ginseng Research
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• 제45권1호
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• pp.163-175
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• 2021

Background: Ginsenosides, which have strong biological activities, can be divided into polar or less-polar ginsenosides. Methods: This study evaluated the phytochemical diversity of the saponins in Panax ginseng (PG) root, American ginseng (AG) root, and Panax notoginseng (NG) root; the stem-leaves from Panax ginseng (SPG) root, American ginseng (SAG) root, and Panax notoginseng (SNG) root as well as the saponins obtained following heating and acidification [transformed Panax ginseng (TPG), transformed American ginseng (TAG), transformed Panax notoginseng (TNG), transformed stem-leaves from Panax ginseng (TSPG), transformed stem-leaves from American ginseng (TSAG), and transformed stem-leaves from Panax notoginseng (TSNG)]. The diversity was determined through the simultaneous quantification of the 16 major ginsenosides. Results: The content of ginsenosides in NG was found to be higher than those in AG and PG, and the content in SPG was greater than those in SNG and SAG. After transformation, the contents of polar ginsenosides in the raw saponins decreased, and contents of less-polar compounds increased. TNG had the highest levels of ginsenosides, which is consistent with the transformation of ginseng root. The contents of saponins in the stem-leaves were higher than those in the roots. The transformation rate of SNG was higher than those of the other samples, and the loss ratios of total ginsenosides from NG (6%) and SNG (4%) were the lowest among the tested materials. In addition to the conversion temperature, time, and pH, the crude protein content also affects the conversion to rare saponins. The proteins in Panax notoginseng allowed the highest conversion rate. Conclusion: Thus, the industrial preparation of less-polar ginsenosides from SNG is more efficient and cheaper.

• 대한본초학회지
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• 제36권1호
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• pp.41-49
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• 2021

Objective : Citrus unshiu peel (Citri Unshius Pericarpium) has been prescribed to suppress coughing and phlegm in Korean medicine. In this study, the effect of ethanol extract of Citrus unshiu peel (CEE) on apoptosis was investigated using cadmium chloride (CdCl2) treated HepG2 cells. Methods : CEE was prepared by extracting 300 g of Citri Unshius Pericarpium in 3 L of ethanol for 72 h. Apoptosis was determined by the TUNEL assay. The mitochondrial membrane potential (MMP) was monitored using the membrane-permeable fluorescent dye Rh123. The expression level of each protein was monitored by Western blot analysis. Results : CEE protected HepG2 cells from apoptosis as determined by the TUNEL assay. A decrease in MMP was observed in cells exposed to cadmium, indicating that mitochondria are involved in the induction of apoptosis. However, CEE recovered the reduction in MMP caused by cadmium. In addition, decreased expression of B-cell lymphoma 2 (Bcl-2), procaspase, and poly(ADP-ribose) polymerase (PARP) by cadmium was increased by CEE. The anti-apoptotic effect of CEE was found to be associated with inhibition of JNK and p38 phosphorylation when examining the expression of phosphorylated MAPK by Western blot. Conclusion : This study showed that CEE exerted anti-apoptotic effects in cadmium-induced HepG2 cells by inhibiting the reduction of MMP and changes in the expression level of apoptotic proteins. These results suggest the potential for CEE to be used for heavy metal-induced liver damage.

• 한국컴퓨터정보학회논문지
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• 제26권2호
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• pp.183-191
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• 2021

설탕은 비만, 당뇨병 등의 원인이 되므로 저당화 식품섭취가 필요하며, 저당화 식품에 올리고당, 대체 감미료와 같은 저열량 감미소재를 이용하는 방안이 대두되고 있다. 최근 항산화작용이 높은 베리류가 각광 받기 시작하면서 아로니아의 국내 재배면적 및 소비량이 지속적으로 증가하고 있다. 떫은맛을 지닌 아로니아는 주로 생과나 동결건조시킨 가루로 이용되며, 천연색소나 주스, 잼, 와인 등과 같은 가공제품도 증가하는 추세에 있어 아로니아의 단점을 개선한 다양한 가공 상품 개발이 시급하다. 이에 본 연구는 아로니아의 선명한 색은 살리면서 떫은맛을 완화시킨 저당 아로니아청으로 아로니아시럽을 제조하였다. 설탕 첨가량을 줄이고 단맛을 대체할 감미료로서 아스파탐을 첨가한 아로니아청을 제조하고, 여기에 올리고당을 첨가하여 개발한 아로니아시럽의 이화학적 특성과 생리활성능을 연구하였다. 아로니아시럽은 음료 등 다양한 음식개발에 활용이 가능하며, 생리활성기능을 가진 아로니아로 인하여 건강을 증진시킬 수 있을 것이다.