• Title/Summary/Keyword: solvent effect

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Preparation and Characterization of Demineralized Bone Particle-loaded PLGA Scaffold for Tissue Engineered Bone (조직공학적 골재생을 위한 탈미넬화된 골분을 함유한 다공성 지지체의 제조 및 그 특성)

  • Jang Ji Wook;Lee Bong;Han Chang Whan;Kim Mun Suk;Cho Sun Hang;Lee Hai Bang;Khang Gilson
    • Polymer(Korea)
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    • v.28 no.5
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    • pp.382-390
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    • 2004
  • One of the significant natural bioactive materials is demineralized bone particle (DBP) whose has a powerful induce. of new bone growth. In this study, we developed the DBP loaded poly-lactide (PLA) and poly(L-lactide-co-glycolide) (PLGA) scaffolds for the possibility of the application of the tissue engineered bone. PLA/DBP and PLGA/DBP scaffolds were prepared by solvent casting/salt leaching method and were characterized by porosimeter, scanning electron microscopy. BMSCs were stimulated by osteogenic medium and characterized by histological stained Wright-Giemsa, Alizarin red, von Kossa, and alkaline phosphate activity (ALP). DBP impregnated scaffolds with BMSCs were implanted into the back of athymic nude mouse to observe the effect of DBP on the osteoinduction compared with control scaffolds. It can be observed that the porosity was above $90.2\%$ and the pore size was above 69.1$\mu$m. BMSCs could be differentiated into osteoprogenitor cells as result of wright-giemsa, alizarin red, von Kossa and ALP staining. In in vivo study, we could observed calcification region in PLA/DBP and PLGA/DBP groups, but calcification did not occur almost in control scaffolds. From these results, it seems that DBP as well as BMSCs play an important role for bone induction in PLA/DBP and PLGA/DBP scaffolds.

Preparation of PMSQ/TiO2 Composite Fine Powder by Sol-Gel Process (Sol-Gel Process를 이용한 PMSQ/TiO2 복합 미립자의 합성)

  • Lee, Dong Hyun;Koo, Sangman
    • Applied Chemistry for Engineering
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    • v.9 no.5
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    • pp.634-638
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    • 1998
  • Monodisperse, spherical $PMSQ/TiO_2$ composite fine powders were prepared by modified sol-gel process where 300 nm $TiO_2$ fine powders were used as seed particles for hetero-condensation with hydrolyzed MTMS (Methyltrimethoxysilane). The reaction was carried out under $N_2$ atmosphere at ambient temperature using $NH_3$ as a catalyst. Methanol was used as a solvent. Powder was obtained by the filtration of the solution with a glass filter and washing with acetone. The stirring rate, reaction temperature, $[H_2O]/[MTMS]$ and $[MTMS]/[TiO_2]$ ratio were varied to investigate shapes and sizes of particles. Monodisperse particles of $1-2{\mu}m$ diameter were obtained with [MTMS]=0.2 M, $[NH_3]=0.6M$, $[H_2O]/[MTMS]=100$, $[MTMS]/[TiO_2]=10-50$ at ambient temperature with mild stirring condition. These composite particles had a contact angle of almost 180 degree contact angle with water, which proves their excellent hydrophobicity. The study of UV absorption spectra showed that they have UV protecting effect.

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K+ Ion-Selective PVC Membrane Electrodes with Neutral Carriers (중성운반체를 이용한 K+ 이온선택성 PVC막 전극)

  • Kim, Yong-Ryul;Cho, Kyoung-Sub;Kang, An-Soo
    • Applied Chemistry for Engineering
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    • v.9 no.5
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    • pp.734-741
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    • 1998
  • Electrode characteristics were studied in the interface between sample solutions and $K^+$ ion selective PVC membrane electrodes containing neutral carriers, dibenzo-18-crown-6(D18Cr6) and valinomycin(Val). The effect of doping of base electrolytes, the chemical structure and the content of carrier, variation of plasticizer, membrane thickness, and concentration variation of sample solution on the response characteristics of electrode such as the measured Nernstian slope, the detection limit, the linear response range, and potentiometric selectivity coefficients, were studied. In order to synthesize the membrane D18Cr6 and Val as neutral carriers were used, and complex between the carrier and $K^+$ ions were used as active materials. PVC membrane electrodes were made of plasticizers (DBP, DOS, and DBS), the base electrolyte[potassium tetraphenylborate(KTPB)], and solvent(THF). The chemical structure of carrier D18Cr6 was best for electrode and ideal electrode characteristics were appeared especially in case of doping of TPB. The optimum carrier content was about 3.23 wt % in case of D18Cr6 and Val. DBP was best as a plasticizer. As membrane thickness decreased the electrode characteristics was improved. But its characteristics were lowered below the optimum membrane thickness because of the elution of carrier, deterioration of membrane strength, etc. In the case of D18Cr6, the selectivity coefficients by the mixed solution method for the $K^+$ ion were in the order of $NH_4{^+}>Ca^{2+}>Mg^{2+}>Na^+$.

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Isolation and Identification of an Antioxidant Substance from Ethanol Extract of Wild Grape (Vitis coignetiea) Seed (머루종자 에탄올 추출물로부터 항산화활성물질 분리 및 동정)

  • Kim, Nan-Young;Choi, Jae-Ho;Kim, Young-Guk;Jang, Mi-Young;Moon, Jea-Hak;Park, Geun-Hyung;Oh, Deog-Hwan
    • Korean Journal of Food Science and Technology
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    • v.38 no.1
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    • pp.109-113
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    • 2006
  • Antioxidant compound(s) were identified from the ethanol extract of wild grape (Vitis coignetiea) seed. Organic solvent fractions of n-hexane, chloroform, ethyl acetate and butanol were obtained from the ethanol extract of wild grape seed, among which ethyl acetate fraction showed the strongest reducing power. Ethyl acetate fraction was further purified through ODS column chromatography and HPLC, and isolated antioxidative active compound was identified through $^1H-NMR$ as (+)-catechin (52.7 g/100 g). (+)-Catechin and ethyl acetate fraction both showed approximately 80% scavenging effect. These results indicated (+)-catechin in the ethyl acetate fraction synergetically interacts with unknown antioxidative compound(s).

Extraction & Separation Behavior of Light Rare Earth Elements from the Mixed Solutions by Cyanex 572 (경희토류(La, Ce, Pr, Nd, Sm) 혼합용액에서 Cyanex 572에 의한 추출·분리 거동 고찰)

  • Cho, Yeon-Chul;Lee, Joo-Eun;So, Hong-Il;Ahn, Jae-Woo;Kim, Hong-In;Lee, Jin-Young
    • Resources Recycling
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    • v.26 no.4
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    • pp.79-87
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    • 2017
  • Extraction and separation behaviors of La, Ce, Pr, Nd and Sm from light rare earth multi - component mixed solutions by Cyanex 572 were studied. As extractant concentration increased, the $pH_{50}$ values of all the five components decreased. When extractant concentration was larger than 0.6 M, the separation factor of La and Ce, Nd and Sm was higher than 10, while the separation factor between Ce and Pr, Pr and Nd was as low as 0.5~2.2. Addition of TBP to the 0.6 M Cyanex 572 had little synergistic effect on the phase separation rate and separation factor. From the analysis of experiment results, group separation of [La]/[Pr, Nd, Sm] and [Pr, Nd]/[Sm] could be possible, but in case of the group separation between [La, Ce] and [Pr, Nd] was not available because of the low separation factor between Ce and Pr.

Pancreatic Lipase Inhibitory and Antioxidant Activities of Zingiber officinale Extracts (생강 추출물의 pancreatic lipase 저해 및 항산화 활성)

  • Bae, Jong-Sup;Kim, Tae-Hoon
    • Food Science and Preservation
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    • v.18 no.3
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    • pp.390-396
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    • 2011
  • Ginger (Zingiber officinale) is a well-known herb that is widely consumed as spice for the flavoring of foods. As part of our continuing search for bioactive materials, the in vitro pancreatic lipase inhibition and antioxidant properties of an aqueous ethanolic extract of Z. officinale were investigated. The total phenolic content was determined using a spectrophotometric method. The antioxidant efficacies of the extract was studied with radical scavenging assays using DPPH and $ABTS^+$ radicals. Further more, the antiobesity effect of the extract was evaluated by porcine pancreatic lipase assay. In particularly, the pancreatic lipase inhibitory activity of the ethyl acetate (EtOAc)-soluble portion from Z. officinale was significantly higher than that of the other solvent-soluble portions. The results suggest that Z. officinale may have therapeutic potential that may be useful in development of an anti-obesity agent or its precursors.

Acaricidal and Repellent Activities of Cnidium officinale-derived Compounds Against Haemaphysalis longicornis (Acari: Ixodidae) (작은소피참진드기에 대한 다양한 식물체 및 천궁유래물질의 살비 및 기피 효과)

  • Ahn, Hyeonmo;Shin, Eungyeong;Kim, Hyun Kyung;Kim, Gil-Hah
    • Korean journal of applied entomology
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    • v.60 no.3
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    • pp.315-322
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    • 2021
  • This study investigated the acaricidal and repellent activities of various plant extracts and Cnidium officinale-derived materials against Haemaphysalis longicornis. Among the 24 methanolic plant extracts, C. officinale showed the highest acaricidal activity (93.3%) against H. longicornis. Platycodon grandiflorus, Phytolacca americana, Magnolia denudata, Houttuynia cordata, C. officinale, and Pueraria montana showed significant differences in their repellent activity. Consequently, the activity of solvent-fractionated materials and the derived material of the C. officinale, was investigated and a 90% acaricidal effect was observed three days after hexane fraction treatment, indicating that the repellent response was statistically significant. Butylidenephthalide, which is a C. officinale-derived compound, showed 90% acaricidal activity seven days after treatment. Additionally, all H. longicornis moved to the untreated area in the t-tube olfactometer experiment, confirming the repellent activity of butylidenephthalide. Therefore, the results of this study suggest the use of C. officinale crude extract and butylidenephthalide as potent acaricidals and repellents against H. longicornis, respectively.

Anti-cancer and Anti-microbial Effect of the Fraction Isolated from Pyrus ussuriensis Leaves (산돌배나무(Pyrus ussuriensis) 잎 분획물의 항암 및 항균활성에 관한 연구)

  • Lee, Chang-Eon;Kim, Young-Hun;Lee, Byung-Guen;Lee, Do-Hyung
    • Journal of Korean Society of Forest Science
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    • v.100 no.2
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    • pp.136-141
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    • 2011
  • This study was conducted to confirm the application as ingredients of cosmetics through an examination of the function for anti-cancer and anti-microbial of the fraction isolated from Pyrus ussuriensis leaves. The dried leaf of P. ussuriensis were extracted with acetone-$H_{2}O$ (6:4, v/v), concentrated and fractionated with the upper layer of acetone on a separatory funnel. Each fraction was freeze dried, then a portion of acetone soluble powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol as eluents and also used the MIC-gel using a series of aqueous methanol as developing solvent. The isolated compounds were identified by silica-gel TLC. The growth inhibition activity was measured using the MTT assay by the mouse meltioma (B16F10) cell. The cancer cell growth inhibition rate of fractions isolated from P. ussuriensis leaf was 80%. In anti-microbial activity test, the fraction of P. ussuriensis with 0.25 mg/disc resulted in the clear zone of 1.3 cm and 2 cm for Staphylococcus aureus and S. epidermidis of gram positive bacillus, respectively. In Escherichia coli of gram negative bacillus, the fraction with 0.5 mg/disc resulted in the clear zone of 1.1 cm~1.5 cm each fraction. From these results, we confirmed that acetate fraction of P. ussuriensis has a great potential as a natural ingredients with a anti-cancer and anti-microbial source.

Anti-inflammation and Anti-aging Effect of Lactic Acid Bacteria Fermented Lycium chinense Extracts (젖산균 발효 구기자(Lycium chinense ) 추출물의 항염증 및 항노화 효능 연구)

  • Han, Dong-Geun;Lee, Ju-Seong;Gal, Gyeok;Park, Nam-Wan;Kim, Hyun-Jeong;An, Bong-Jeon
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.48 no.2
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    • pp.113-121
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    • 2022
  • In this study, fermented Lycium chinense (L. chinense) extract was used to analyze the efficacy of nitric oxide (NO) and anti-aging inhibition to verify its usefulness as a functional cosmetic material. L. chinense was extracted with hydrothermal and 70% ethanol as a solvent, fermented, concentrated, and freeze-dried to prepare a sample, followed by MTT assay, NO inhibition assay, western blot assay, and UPLC analysis.As a result of the analysis of NO inhibitory efficacy, fermented L. chinense water extract (FLW) and fermented L. chinense 70% ethanol extract (FLE) showed excellent NO inhibitory efficacy of 47.96% and 56.71%, respectively. As a result of measuring the expression patterns of the wrinkle-related proteins MMP-1, and TRPV-1 through Western blot, both FLW and FLE confirmed the inhibitory efficacy of MMP-1 and TRPV-1. Based on the results of the experiment, the fermented L. chinense extract is expected to have a high application value as a functional cosmetic material related anti-inflammatory, and anti-aging.

Kinetics of CO2 Absorption in Aqueous DETA and DEEA Solutions by Wetted-Wall Column (젖은 벽탑을 이용한 디에틸렌트리아민과 디에틸에탄올아민 수용액의 CO2 흡수속도 측정)

  • You, Jong Kyun;Lee, Jun;Hong, Yeon Ki
    • Korean Chemical Engineering Research
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    • v.60 no.4
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    • pp.582-587
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    • 2022
  • Biphasic solvents are attracting attention as energy-reducing solvents for capturing CO2 from flue gas in combustion process. In this study, considering diethylenetriamine (DETA) and diethylethanolamine (DEEA) mixed solvents, one of the biphasic solvents by blending of two types of amines, the CO2 absorption rates of DETA and DEEA was measured by wetted wall column. The effects of DETA and DEEA concentrations and operating temperature on the overall mass transfer coefficient were investigated. As a result, the overall mass transfer coefficient was proportional to the DETA concentration. However, in the case of the DEEA concentration, the effect was small and when the concentration was exceeded, the overall mass transfer coefficient decreased. The DETA aqueous solution showed little change in the overall mass transfer coefficient with the operating temperature, whereas the DEEA aqueous solution increased the overall mass transfer coefficient with the operating temperature. As a result of obtaining the observed reaction rate constant under the pseudo-first-order reaction assumption, it was found that the observed reaction rate constant in DETA aqueous solution was proportional to the DETA concentration, but DEEA did not fit the pseudo-first-order reaction assumption.