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        검색결과 339

        321.
        2020.12 KCI 등재 서비스 종료(열람 제한)
        The green synthesis of inorganic nanoparticles (NPs) using biomaterials has garnered considerable attention in recent years because of its eco-friendly, non-toxic, simple, and low-cost nature. In this study, we synthesized NPs of noble metals, such as Ag and Au using an aqueous extract of a marine seaweed, Ecklonia cava. The formation of AgNPs and AuNPs was confirmed by the presence of surface plasmon resonance peaks in UV-Vis absorption spectra at approximately 430 and 530 nm, respectively. Various properties of the NPs were evaluated using characterization techniques, such as dynamic light scattering, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. Phytochemicals in the seaweed extract, such as phlorotannins, acted as both reducing and stabilizing agents for the growth of the NPs. The green-synthesized AgNPs and AuNPs were found to exhibit high catalytic activity for the decomposition of organic dyes, including azo dyes, methylene blue, rhodamine B, and methyl orange.
        322.
        2018.10 서비스 종료(열람 제한)
        Background : For the green approach of nanoparticles synthesizing, plant based technology has been considered as cost-effective and eco-friendly mass production. The oriental medicinal crop, Kalopanax septemlobus (Thunb.) Koidz. (Korean name: 음나무), the deciduous tree and a family of Araliaceae. Endemic tree of Asian countries, K. septemlobus being used for the treatment of various diseases. Phytochemicals of K. septemlobus such as polyphenols has highly probability of reducing agent for biosynthesizing nanoparticles. Methods and Results : In this study, we applied K. septemlobus ZnO nanoparticles (Ks-ZnO NPs) with procedures including green approach one-pot synthesis. For the characterization of nanoparticles, UV–Vis, FTIR, XRD, SEM and TEM were used. The formation of ZnO nanoparticles, the aurface plasmon resonance were observed at 372 ㎚ in UV-Vis spectroscopy. The presence of functional groups which as a capping agent and formation of ZnO nanoparticles were confirmed in FTIR result. The crystallization and morphology showed by XRD, TEM and SEM respectively. The photocatalytic activity of ZnO nanoparticles, was determined using Methylene blue (MB) dye degradation under UV irradiation (365 ㎚) which resulted rate constant is (−k) 0.1215 with 97.5% of degradation in 30 min. Conclusion : The result shows that phytochemicals in K. septemlobus extract have a potential as a reducing agent to form ZnO nanoparticles. The ZnO NPs are capable to degrade MB with in brief time.
        323.
        2018.10 서비스 종료(열람 제한)
        Background : Codonopsis lanceolata is a perennial herb called as ‘Deodeok’ (더덕) in Korea. The roots of C. lanceolate has been reported to have some antioxidant and antimicrobial properties. The chemically reactive saponins of C. lanceolata might be used as a capping agent for the surface of ZnO nanoparticle, ultimately making it a highly efficient photocatalyst. Methods and Results : In this paper, we report the one-pot green synthesis of ZnO nanoparticles via precipitation method using root extract of C. lanceolata. The structure of green synthesized Cl-ZnO NPs was characterized using XRD, EDX, DLS and morphology using TEM. The FT-IR exhibited the information about the functional groups that capped the metal nanoparticle and the formation of metal NPs was confirmed by UV–vis spectra at 356nm. The Cl-ZnO NPs were evaluated for their catalytic activity by measuring the degradation of methylene blue (MB) dye in aqueous solution under UV light (365 ㎚). The result showed efficient degradation of MB, which was degraded 70% within 30 min by Cl-ZnO NPs. Conclusion : This study proves that the green route synthesized ZnO NPs from the root extract of C. lanceolata are low cost, time efficient, bio-degradable and non- toxic. The UVvis spectra confirmed the synthesis of ZnO NPs from C. lanceolata root extract. The Cl- ZnO NPs mediated catalysis exhibited high photocatalysis rate in short time. Ultimately, the green rapid synthesized Cl-ZnO NPs from root extract can be used as an efficient
        324.
        2018.10 서비스 종료(열람 제한)
        Background : Among medicinal plant sources, Abeliophyllum distichum is widely used in traditional Korean medicine. we report on the synthesis of nanostructured zinc oxide particles by both chemical and biological method. Highly stable and spherical zinc oxide nanoparticles are produced by using zinc nitrate and Abeliophyllum distichum leaf extract. Methods and Results : Zinc oxide (Ad-ZnONPs) nanoparticles synthesized from Abeliophyllum distichum at room temperature by aqueous extract of dried leaf and stem. The plant endemic in Korea alone and it is a monotypic flowering plant genus of olive family, Oleaceae. Catalytic and toxicity effect against human keratinocyte and adenocarcninomic human alveoloar. Ultra violet visible (UV-Vis) spectroscopy, field emission transmission electron microscopy (FE-TEM), energy-dispersive X-ray (EDX) spectroscopy, elemental mapping, X-Ray powder diffraction (XRD), selected area electron diffraction (SAED) and Fourier transform infrared (FTIR) spectroscopy were engaged to illustrate the biosynthesized nanoparticles. The Zn-AdNPs has the ability in catalytic action and the cytotoxicity agent against different cell lines as investigated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium bromide (MTT) assay Conclusion : The present studies reveals that facile approaching the biological synthesis of zinc oxide nanoparticles by using the A. distichum leaf and stem extract, which is revealed that recyclable method. The method is well suited for the green synthesis and dual function molecule as reducing agent and stabilizing agent for synthesis of nanoparticles. The nanoparticles also showing promising biological activities.
        325.
        2018.05 서비스 종료(열람 제한)
        Background : Ginseng root rot is a devastating disease caused by the fungus, Ilyonectria mors-panacis that generally attacks younger roots (-2 years), leading to defects in root quality, ginsenoside accumulation and also life cycle of the plant. Hence, there is an indispensable need to develop strategies resulting in tolerance against ginseng root rot. The protective role of silicon during pathogen infestation is well documented in other plant systems and a previous study demonstrated that silica nanoparticles are absorbed and accumulated more than the bulk silica in maize. However, the role of silica in ginseng-root rot pathosystem is unknown. Methods and Results : In the present study, we evaluated the effect of silica nanoparticles (N-SiO2) in Panax ginseng during I. mors-panacis infection. Long term analysis (30 dpi) revealed a striking 50% reduction in disease severity index upon 1 mM and 2 mM treatment of N-SiO2. However, N-SiO2 did not have any direct antifungal activity against I. mors-panacis. Candidate genes and metabolites based approach revealed jasmonic acid (JA) mediated sterol accumulation and incresed ginsenside biosyntesis as the key transcriptional reprogramming events orchestrated by N-SiO2 during the fungal infection. Conclusion : In a nut shell, N-SiO2 administration induces transcriptional reprogramming in ginseng roots, leading to increased phytosterol and ginsenosides synthesis resulting in enhanced tolerance against I. mors-panacis.
        326.
        2018.05 서비스 종료(열람 제한)
        Background : Anemarrhena asphodeloides has efficacy such as anti-fungal, anti-cancerous, anti-inflammatory, anti-diabetic, Anti-UV etc. Metal nanoparticles are used for photo imaging, cancer resection and drug delivery etc in medical field. Therefore A. asphodeloides nanoparticles will be expected better efficacy for therapeutic properties in medical field. Methods and Results : The water extract of A. asphodeloides mediated the synthesis of Aa-AgNPs and Aa-AuNPs. Their characterized by several physicochemical techniques such as UV-Vis spectrophotometry, FE-TEM, EDX spectroscopy, SAED pattern, DLS size analysis, XRD analysis, and FTIR analysis. Both Aa-Ag/AuNPs were evaluated for cytotoxicity towards 3T3-L1, A549, HT29 and MCF7. Aa-AgNPs and Aa-Au NPs were found to be spherical, face-centered cubic nanocrystals with hydrodynamic diameter of 190 and 258 ㎚. In vitro cytotoxic analysis revealed that up to 50 ㎍/㎖-1 concentration Aa-Au NPs did not exhibit any toxicity on 3T3-L1, HT29 and MCF7 cell lines, while being specifically cytotoxic to A549 cell line. On the contrary, Aa-Ag NPs displayed a significantly higher toxicity in all cell lines specially MCF7 cell line. ROS generation was not affected by Aa-Au NPs, but Aa-AgNPs has a higher potential to induce oxidative stress in A549 cells than HT29 and MCF7 cells. Aa-Au NPs have the potential for anticancer agent during lung cancer treatment. Aa-AgNPs is also exhibited to inhibit cell migration by induce oxidatie stress. Conclusion : The Aa-Au/AgNPs might have the anticancer potential and might be effective in the lung cancer therapy, however further evaluation is must needed.
        330.
        2017.02 KCI 등재 서비스 종료(열람 제한)
        Green synthesis of gold nanoparticles(GNPs) considered more ecofriendly and cost effective than other chemical methods use of dangerous reagents and solvents, improved material and energy efficiency and enhanced design of non-toxic products. In this study, we developed a green synthesis method for using Caulis in Taeniam (BCT). BCT were characterized by UV-vis, Zetasizer, TEM, XRD, and FTIR. The antioxidant activity of BCT was determined by DPPH and ABTS radical-scavenging assays, and heme oxygenase-1 induction in RAW 264.7 macrophages. The resulting BCT appeared spherical with an average diameter of 67.171.39 nm The aAntioxidant activity was increased in a dependent manner. To conclude, the green synthesis of BCT-GNPs was successful, and it appers to be useful in the for future applications.
        331.
        2016.11 KCI 등재 서비스 종료(열람 제한)
        이 연구는 γ선 및 x선 조사 시 AuNPs 입자의 방사선감수성의 향상을 생물물리학적으로 평가하기 위해 두 가지 실험을 시행하였다. 생물학적 방사선 감수성의 평가에 앞서 6시간, 12시간, 18시간, 24시간 incubation한 후 세포생존율(surviving Fraction, SF)값을 비교하여 AuNPs 입자의 독성 여부와 세포질에 입자의 균일 된 분포 여부를 확인 해 보았다. incubation time에 따라 세포생존율(surviving Fraction, SF)이 낮아지지 않음을 확인한 다음 γ선 및 x선 조사 후 Clonogenic assay 실시하고 세포생존율(surviving Fraction, SF)을 구하여 방사선 감수성을 비교 평가하였다. 방사선량 증가 시 세포생존율(surviving Fraction, SF)이 계속해서 낮아졌고 8Gy 조사 시 최대치로 약 30%의 차이가 있음을 확인하였다. 또한 Gate v6.1을 사용하여 몬테카를로 시뮬레이션 후 percent depth dose(PDD)를 구한 뒤 선량 평가하여 약 40% Dose Enhancement가 있음을 확인하였다. 두 가지 실험에 따라 생물물리학적으로 AuNPs 입자는 방사선 감수성이 향상되도록 하며 이는 nanoparticle을 이용한 방사선 병합 치료 시 치료 성적 향상에 큰 도움이 될 것으로 보인다.
        332.
        2016.04 KCI 등재 서비스 종료(열람 제한)
        In order to treat groundwater containing high levels of nitrate, nitrate reduction by nano sized zero-valent iron (nZVI) was studied using batch experiments. Compared to nitrate removal efficiencies at different mass ratios of nitrate/Fe0, the removal efficiency at the mass ratio of 0.02% was the highest(54.59%). To enhance nitrate removal efficiency, surface modification of nZVI was performed using metallic catalysis such as Pd, Ni and Cu. Nitrate removal efficiency by Cu-nZVI (at catalyst/Fe0 mass ratio of 0.1%) was 66.34%. It showed that the removal efficiency of Cu-nZVI was greater than that of the other catalysts. The observed rate constant (kobs) of nitrate reduction by Cu-nZVI was estimated to 0.7501 min-1 at the Cu/Fe mass ratio of 0.1%. On the other hand, TEM images showed that the average particle sizes of synthetic nZVI and Cu-nZVI were 40~60 and 80~100 nm, respectively. The results imply that catalyst effects may be more important than particle size effects in the enhancement of nitrate reduction by nZVI.
        333.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        나노입자의 응용은 1970년대부터 발전되어 왔다. 금속 나노입자에 빛을 조사하면 나노입자 표면에서 플라즈몬 공명(SPR, surface plasmon resonance)을 일으킨다. SPR 효과는 금속표면에 입사한 빛에너지에 의해 전자가 여기하며 공명을 일으켜 진동을 발생시키는 현상을 말한다. 여기 된 전자들이 금속원자들과 충돌을 일으키며 열에너지로 전환될 수 있는데 이를 금속의 광열효과(photothermal effect)라고 한다. 우리는 광열 효과를 이용하여 온열 화장품의 개발 가능성을 제시하고자 한다. 온열 화장품의 개발을 위해 생체 독성이 적은 금 나노입자를 선택하여 광열 효과에 있어서의 세포 생체적합성과 열효율을 살펴보았다. 금 나노입자의 합성 상태는 금 나노입자가 갖는 독특한 흡광 스펙트럼으로 확인하였으며, 금 나노입자의 농도는 원자 흡광분석기로 측정하였다. 세포의 독성평가는 MTT assay와 이중 염색법을 사용하였으며, 금 나노입자의 광열 효과는 제논 램프를 광원으로 하여 금 나노입자의 농도의 증가에 따른 광열 효과증대를 적외선-열화상 카메라로 확인하였다. 금 나노입자의 광열 효과를 온열 화장품에 적용한다면 한대 지방의 기후, 또는 겨울철에 태양 에너지를 열에너지로 전환시켜 피부에 손실된 열을 공급, 피부온도 유지에 도움이 되고 피부건강에 긍정적 효과를 주리라 사료된다.
        334.
        2012.12 KCI 등재 서비스 종료(열람 제한)
        본 연구는 초상자성 산화철 나노입자 (SPIONs)의 세포독성평가 및 SPIONs를 uptake한 뇌신경교종 (glioblastoma multiforme, GBM) 세포의 방사선 세포생존곡선을 구하기 위해 수행되었으며, 본 연구의 결과는 양성자선과 SPIONs 이용한 GBM의 양성자선 치료선량 정보 등 양성자선 치료효과를 개선하기 위한 기초자료로 활용될 수 있을 것이다.SPIONs의 세포독성을 평가는 in vitro 실험 후 MTT 분석법을 이용하여 수행하였다. 독성평가 결과 1~100μg/ml의 농도에서는 세포생존율의 유의한 차이가 나타나지 않았다. 하지만 200μg/ml의 농도에서는 세포생존율이 74.2%로 감소하며 세포독성을 나타냈다. SPIONs가 uptake 된 U373MG세포와 uptake 되지 않은 U373MG세포에 0~5 Gy의 양성자선을 조사하여 각각에 대한 세포생존곡선을 측정한 결과를 분석하여 SPIONs가 uptake된 U373MG세포의 세포생존율이 더 급격히 감소함을 알 수 있었다. 결론적으로 SPIONs가 uptake 된 세포에서는 보다 적은 선량으로도 세포사멸을유도할 수 있음을 알 수 있었다. 따라서 GBM에 SPIONs를 타겟팅하면 양성자선을 이용한 뇌신경교종 치료효과를 개선할 수 있음을 보였다.
        335.
        2010.05 KCI 등재 서비스 종료(열람 제한)
        The generation of TiO2 nanoparticles by a thermal decomposition of titanium tetraisopropoxide (TTIP) was carried out experimentally using a tubular electric furnace at various synthesis temperatures (700, 900, 1100 and 1300℃) and precursor heating temperatures (80, 95 and 110℃). Effects of degree of crystallinity, surface area and anatase mass fraction of those TiO2 nanoparticles on photocatalytic properties such as decomposition of methylene blue was investigated. Results show that the primary particle diameter obtained from thermal decomposition of TTIP was considerably smaller than the commercial photocatalyst (Degussa, P25). Also, those specific surface areas were more than 134.4 m2/g. Resultant TiO2 nanoparticles showed improved photocatalytic activity compared with Deggusa P25. This is contributed to the higher degree of crystallinity, surface area and anatase mass fraction of TiO2 nanoparticles compared with P25.
        337.
        2008.09 KCI 등재 서비스 종료(열람 제한)
        비정질 규산염 나노입자는 지각에 풍부한 규소와 산소로 이루어진 비다공성 나노입자로서 광물학을 포함한 지구환경과학과 산업적 측면에서 모두 중요한 물질이다. 본 연구에서는 1H과 29Si MAS NMR분광분석을 통해 7 nm와 14 nm 규산염 나노입자의 규소와 수소 원자 환경을 측정하고, 입자 크기에 따른 규산염 나노입자 원자 환경 변화를 규명하였다. NMR 스펙트럼의 화학적 이동 값의 이론적 배경을 이해하기 위해 양자화학계간을 통해 Si3O6H6, Si4O5H10, Si5O4H12 분자계간모델의 화학 차폐를 계산하였다. 29Si MAS NMR의 결과, 이중 실라놀(geminal silanol)과 단일 실라놀(single silanol), 실록산(siloxane) 구조의 Si 원자 환경에 해당하는 Q2, Q3, O4가 구분되어 나타나며 입자 크기에 따라 Q2, Q3, O4가 7 nm규산염 나노입자에는 7±1%, 27±2%, 66±2%, 14 nm 규산염 나노입자에는 6±1%, 21±2%, 73±2%의 분포를 갖는다. Q2, Q3 구조는 나노 입자의 표면적에 대부분 존재하는 것으로 예상되었으나, 두 규산염 나노입자의 표면적 차이에 비해 Q2, Q3 양의 차이가 적으며, 이는 입자 표면 뿐 아니라 입자 내부에도 Q2, Q3 구조가 존재함을 의미한다. 1H MAS NMR 스펙트럼은 물리흡착 된 물(physisorbed water), 수소결합 된 수산기(hydrogen bended silanol), 비 수소결합 된 수산기(non-hydrogen bonded silanol)를 구분하여 나타낸다. 14 nm 비정질 규산염 나노입자에 비해 7nm 나노입자에 약 3.4 배의 수소 원자가 존재하며, 더 강한 수소결합 세기를 갖는다. 전체 수산기 중에서 비 수소결합 된 수산기가 차지하는 비율이 7 nm 규산염 나노입자 보다 14 nm 규산염 나노입자에서 더 높으며, 이는 수소 원자간의 상대적 거리(proximity)가 14 nm 임자에서 더 긴 것을 지시한다. 본 연구결과를 통하여 현재까지 알려지지 않은 규산염 나노입자의 입자의기에 의한 다양한 원자 구조의 변화를 규명하였다.
        338.
        2008.09 KCI 등재 서비스 종료(열람 제한)
        생체 친화성 에칠셀룰로오스 막제를 사용하여 자발적인 유화확산에 의하여 레티닐 팔미테이트를 봉입한 나노 입자를 제조하였다. 분산매인 유화제로는 폴리소르베이트 20, 폴리소르베이트 60, 피피지-26-부테스-26/피이지-40 하이드로제네이티드캐스터오일를 이용하여 제조하였으며, 본 결과로서 나노크기 입자를 제조하기에 가장 적절하며 안정한 조건은 1 w/v% 에칠셀룰로오스와 3 w/v% 폴리소르베이트 60 수용액을 이용한 것이었으며, 레티닐 팔미테이트의 봉입률을 최대화하기 위한 조건은 2 w/v% 에칠셀룰로오스와 1 w/v% 폴리소르베이트 60 수용액을 이용한 제조 조건이었다. 또한 이 최적 조건에 다른 유효성분에도 적용 가능한 것을 확인하였다.
        339.
        2008.07 KCI 등재 서비스 종료(열람 제한)
        The use of support materials on the nanoparticle synthesis and applications has advantages in many aspects; resisting the aggregation and gelation of nanoparticles, providing more active sites by dispersing over the supports, and facilitating a filtering process. In order to elucidate the influence of the supports on the nitrate reduction reactivity, the supported iron nanoparticles were prepared by borohydride reduction of an aqueous iron salt in the presence of supports such as activated carbon, silica and polyethylene. The reactivity for nitrate reduction decreased in the order of unsupported Fe(0) > activated carbon(AC) supported Fe(0) > polyethylene(PE) supported Fe(0) ≥ silica supported Fe(0). Rate constants decrease with increasing initial nitrate concentration implying that the reaction is limited by the surface reaction kinetics.
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