• KSBB Journal
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• 제32권2호
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• pp.160-167
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• 2017

Coating of individual cells with organic or inorganic materials has drawn a great deal of attention, because it provides the cells with physicochemical durability, which would contribute to the development of bioreactors, biosensor, and lab-on-a-chip, as well as to the fundamental studies in single cell-based biology. Although many strategies have been developed for coating of microbial cells, limited methods are available to coat mammalian cells because most mammalian cells do not have a robust membrane or exoskeleton. Instead, they are enclosed in a lipid bilayer, which is fluidic and vulnerable to changes in its environments. It is more difficult to treat mammalian cells in vitro than microbial cells because the surfaces of mammalian cells are not protected or reinforced by a tough coat. In this work, we report a cytocompatible and degradable nanocoat for mammalian cells. Three types of mammalian cells (HeLa cells, NIH 3T3 fibroblasts, and Jurkat T cells) were individually coated within metal-polyphenol. To maintain the viability of the mammalian cells, we performed the whole processes under strictly physiological culture conditions, and carefully selected nontoxic materials.

• BMB Reports
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• 제44권12호
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• pp.811-815
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• 2011

Inhalational anthrax is caused by B. anthracis, a virulent sporeforming bacterium which secretes anthrax toxins consisting of protective antigen (PA), lethal factor (LF) and edema factor (EF). LF is a Zn-dependent metalloprotease and is the main determinant in the pathogenesis of anthrax. Here we report the identification of a lead small-molecule inhibitor of anthrax lethal factor by screening an available synthetic small-molecule inhibitor library using fluorescence-based high-throughput screening (HTS) approach. Seven small molecules were found to have inhibitory effect against LF activity, among which SM157 had the highest inhibitory activity. All theses small molecule inhibitors inhibited LF in a noncompetitive inhibition mode. SM157 and SM167 are from the same family, both having an identical group complex, which is predicted to insert into S1' pocket of LF. More potent small-molecule inhibitors could be developed by modifying SM157 based on this identical group complex.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2375-2380
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• 2013

Two metal-organic frameworks based on the connectivity co-effect between rigid benzenedicarboxylic acid and bridging ligand have been synthesized $[Zn_2(3-NO_2-bdc)_2(4,4'-bpy)_2H_2O]_n$ (1), $[Co(3-NO_2-bdc)(4,4'-bpy)H_2O]_n$ (2) (where $3-NO_2-bdcH_2$ = 3-nitro-1,2-benzenedicarboxylic acid, 4,4'-bpy = 4,4'-bipyridine). The two novel complexes were characterized by IR spectrum, elemental analysis, fluorescent properties, thermogravimetric analysis, single-crystal X-ray diffraction and powder X-ray diffraction (PXRD). X-ray structure analysis reveals that 1 and 2 are two-dimensional (2D) network structures. Complex 1 and complex 2 belong to triclinic crystal with P-1 space group. The luminescence measurements reveal that two complexes exhibit good fluorescent emissions in the solid state at room temperature. Also, thermal decomposition process and powder X-ray diffraction of complexes were investigated.

• 한국토양비료학회지
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• 제51권2호
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• pp.128-141
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• 2018

Industrial complex releasing huge amounts of dusts, fumes and wastewater containing heavy metal(loid)s could be a source of heavy metal(loid)s pollution in arable soil. Heavy metal(loid)s pollution in arable soil adversely affect crops safety, subsequently human being. Hence, it is important to accurately assess the heavy metal(loid)s pollution in soil using pollution indices. The objectives of this study are 1) to compare assessment methods of heavy metal(loid)s pollution in arable soils located near industrial complex in Gyeongsang provinces and 2) to determine the relationship between concentration of plant available heavy metal(loid)s and chemical properties of soil. Soil samples were collected from 85 sites of arable lands nearby 10 industrial complex in Gyeongsang provinces. The average total concentration of all heavy metal(loid)s of the studied soils was higher than that of Korean arable soils but did not exceed the warning criteria established by the Soil Environmental Conservation Act of Korea. Only six sites of arable soils for the total concentration of As, Cu and Ni exceeded the warning criteria (As: $25mg\;kg^{-1}$, Cu: $150mg\;kg^{-1}$, Ni: $100mg\;kg^{-1}$). The contamination factor (CF) and geoaccumulation index ($I_{geo}$) of the heavy metal(loid)s in arable soils varied among the sampling sites, and the average values of As and Cd were relatively higher than that of other metals. Results of integrated indices of As and Cd in arable soils located near industrial complex indicated that some arable soils were moderately or heavily polluted. The plant available concentration of heavy metal(loid)s was negatively related to the soil pH and negative charge of soil. Available Cd, Pb, and Zn concentrations had relatively high correlation coefficient with pH and negative charge of soil when compared with other heavy metal(loid)s. Based on the above results, it might be a good soil management to control pH with soil amendments such as lime and compost to reduce phytoavailability of heavy metal(loid)s in arable soil located near industrial complex.

• 환경영향평가
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• 제29권1호
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• pp.8-25
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• 2020

산업화는 도로축적퇴적물(road-deposited sediment, RDS)의 발생과 중금속 오염을 증가시켰고, 이는 비점오염을 통해 주변 수환경에 심각한 영향을 끼칠 수 있다. RDS의 오염과 입자 크기와의 관계는 오염관리를 위해 중요하나, 이에 대한 정보는 매우 부족하다. 본 연구에서는 시화호 및 주변 하천의 주요한 비점오염원으로 판단되는 시화산업단지 내 25개 정점에서 수거된 RDS 시료의 입도에 따른 중금속 분포특성과 환경영향에 대한 연구를 수행하였다. 농집지수(I_geo)는 RDS가 주로 Zn, Cu, Pb, Sb에 의해 오염되었음을 보여주었고, 이들의 농도범위는 Zn, Cu, Pb, Sb이 각각 633-3605, 130-1483, 120-1997, 5.5-50 mg/kg이었다. 이는 국내외 다른 도시에 비해 매우 높은 수준이었다. 대부분의 중금속은 농도와 입도와의 높은 음의 상관관계를 보였다. 250 ㎛ 이하의 분율은 전체에 대한 질량 부하와, 오염 기여율이 각각 평균 78.6, 70.4%로 매우 지배적이었다. 강우 유출을 통해 인근 하천으로 유입될 확률이 높을 것으로 간주되는 125 ㎛ 이하의 입자 분율에 대한 오염평가 결과, 이는 저서생물에 독성을 나타낼 수 있는 매우 오염된 수준이었다. 입자 크기별로 나누어 RDS의 금속원소에 대한 주성분 및 요인분석을 실시한 결과, 250 ㎛ 보다 큰 RDS는 주변의 산업시설이, 250 ㎛ 보다 작은 RDS는 차량운행이 중금속오염의 주요 요인일 것으로 나타났다. 본 연구 결과, 시화산업단지 내 RDS의 중금속오염 및 인근 수역으로의 비점오염의 효율적인 저감을 위해서는 125에서 250 ㎛ 이하의 미세한 RDS 입자의 제어가 매우 중요한 것으로 나타났다.

• 광물과 암석
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• 제34권2호
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• pp.107-120
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• 2021

검덕 연-아연 광상은 한반도에서 가장 규모가 큰 연-아연 광상으로 지체구조상 고원생대의 마천령층군이 포함된 Jiao Liao Ji belt내 혜산-리원 광화대에 위치한다. 이 광상의 주변지질은 고원생대의 마천리층군 변성퇴적암류와 이를 관입한 중생대의 만탑산 관입암체 및 신생대의 현무암으로 구성된다. 이 광상은 고원생대의 마천리층 변성퇴적암류내에 층상광체 및 맥상광체로 산출되며 퇴적분기형 광상에 해당된다. 이 광상에서 산출되는 돌로마이트들은 산출 광물조합 및 정출순서를 기초로 1)모암인 돌로마이트(D₀), 2)각섬암상의 변성작용에 의한 초기의 돌로마이트(투각섬석, 양기석, 투휘석, 섬아연석, 방연석 등)(D₁), 3)각섬암상의 변성작용에 의한 말기의 돌로마이트(활석, 방해석, 석영, 섬아연석, 방연석 등)(D₂), 4)석영맥과 함께 산출되는 돌로마이트(백색운모, 녹니석, 섬아연석, 방연석 등)(D₃)으로 산출된다. 이들 돌로마이트의 화학조성은 각각 Ca_1.00-1.20Mg_0.80-0.99Fe_0.00-0.01Zn_0.00-0.02(CO₃)₂(D₀), Ca_1.00-1.02M_0.97-0.99Fe_0.00-0.01Zn_0.00-0.02(CO₃)₂(D₁), Ca_0.99-1.03Mg_0.93-0.98Fe_0.01-0.05Mn_0.00-0.01As_0.00-0.01(CO₃)₂(D₂) 및 Ca_0.95-1.04Mg_0.59-0.68Fe_0.30-0.36Mn_0.00-0.01(CO₃)₂(D₃)로써 이론적인 돌로마이트의 화학조성보다 미량원소들의 함량이 높다. 이 미량원소들은 FeO, MnO, HfO₂, ZnO, PbO, Sb₂O₅ 및 As₂O₅ 원소들이며 광화작용이 진행됨에 따라 FeO, MnO, ZnO, Sb₂O₅ 및 As₂O₅ 원소들의 함량이 증감 변화가 있으나 HfO₂와 PbO 원소들의 함량은 증감 변화가 없다. 검덕광상의 D_o, D₁ 및 D₂는 Ferroan 돌로마이트에 해당되며 D₃는 Ferroan 돌로마이트와 철백운석(ankerite)에 해당된다. 따라서 1)모암인 돌로마이트(D₀)는 고원생대(2012~1700 Ma) 해양증발환경에서 실리카와 함께 퇴적된 후 계속적인 속성작용에 의해 돌로마이트화 작용에 의해 형성되었다. 2)초기의 돌로마이트(D₁)는 고원생대의 리원암군 관입(1890~1680 Ma)에 의한 변성작용(최소 각섬암상)에 의한 열수교대작용에 의해 형성되었다. 3)말기의 돌로마이트(D₂)는 각섬암상의 변성작용에 의한 계속적인 온도와 압력의 감소에 의해 잔존 유체로부터 형성되었다. 또한 4)석영맥의 돌로마이트(D₃)는 중생대의 만탑산 관입암체의 관입(213~181 Ma)에 의해 형성되었다.

• 대한화학회지
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• 제28권2호
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• pp.121-129
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• 1984

원료가 서로 다른 세종류의 국산활성탄을 사용하여 니켈 및 아연이온에 관한 할로겐과 시안이온의 활성탄 흡착에 대한 공존효과를 살펴보았다. 수용액중에서 니켈 및 아연이온은 할로겐이나 시안이온의 공존으로 착음이온 형태로 활성탄에 용이하게 흡착됨을 알 수 있었으며 니켈이온은 pH $6.0{\sim}7.0$에서, 아연이온은 pH $6.5{\sim}7.0$의 범위가 가장 적합함을 알았다. 또한 니켈이온과의 착음이온을 만들기 위한 음이온은$ 1{\times}10^{-2}mol/l$에서 그 최대치를 나타내었다. 실온에서 구한 이들의 흡착등온선은 거의 직선으로 Freundlich의 흡착등온식게 따랐으며, 시안이온 공존시의 기울기는 활성탄 A, B, C에 대해 각각 1.7, 5.4, 7.1로서 활성탄 A가 흡착제로서 매우 양호한 것을 알 수 있다.

• 한국환경과학회지
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• 제13권5호
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• pp.479-488
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• 2004

Five sediment cores from the tidal flat of artificial Lake Shihwa are analyzed in terms of sedimentology and geochemistry to evaluate the heavy metal contamination and redox condition of surficial sediment following the Shihwa seawall construction. The variability of concentrations of various elements depends on the depositional environment, and reflects the various redox conditions and sediment provenances. The amounts of Ti and Al and their ratio of Ti/ Al with respect to Li clearly indicate that there is an anthropogenic contribution to the surficial sediment. The high concentrations of heavy metals suggest an anthropogenic contribution at ST. 34 and ST. 22. Concentrations of most elements (Cr, Cu, Zn and Pb) are higher near the Shihwa-Banwol industrial complex than in the central part of Lake Shihwa. Concentrations of heavy metal in surficial sediment near the Shihwa-Banwol industrial complex are two to eight times higher than in the center of Lake Shihwa. Enrichment factors (EF), which are normalized by the unpolluted shale, suggests a significant metallic contamination near the Shihwa-Banwol industrial complex (SBIC). The redox condition is divided into two anoxic and mixed oxi $c_oxic zones based on the carbon:sulfur (C/S) ratios of organic matter and elemental relationships. Correlations among geochemical elements Mn, U and Mo are significantly different from site to site, and may therefore be an indicator of the spatial redox condition. Controlling factors for switching anoxic/oxic conditions are thought to be water depth and the differences in industrial effluent supply. The variations of the Cu/Mn ratio in the sediments confirms above mentioned spatial differences of a redox condition in part, and therefore shows a location-dependence redox condition in sediments at four other sites. The redox condition of the surficial sediment characteristics of the Shihwa Lake are controlled by its geographic location and water depth.th.

• Bulletin of the Korean Chemical Society
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• 제23권5호
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• pp.688-692
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• 2002

The aminomethylation of phenols with para-substituents by the Mannich reaction has successfully been accomplished to produce the Mannich bases 2-6. The compounds 7-8 have also been synthesized in order to identify the effect of the side arms and t he macrocycle in the complex formation. Protonation constants and stability constants of the double armed diaza-18-crown-6 ethers 2-7 with metal ions have been determined by potentiometric method at 25 $^{\circ}C$ in 95 % methanol solution. Under a basic condition (pH > 8.0), the double-armed crown ethers 2-6 revealed stronger interaction with divalent metal ions than the simple diazacrown ether 1. The stability constants with these metal ions were Co 2+ < Ni2+ < Cu2+ > Zn 2+ in increasing order, which are in accordance with the order of the Williams-Irving series. The stability constants with alkali earth metal ions were Ca 2+ < Sr 2+ < Ba 2+ in increasing order, which may be explained by the concept of size effect. It is noteworthy that the hosts 2-6, which have phenolic side arms and a macrocycle, bind stronger with metal ions than the hosts 1 and 7. On the other hand, the host 8, which has phenolic side arms with a pyperazine ring,provided comparable stability constants to those with the host 3. These facts demonstrate that phenolic side arms play a more important role than the azacrown ether ring in the process of making a complex with metal ions especially in a basic condition. In particular, the log KML values for complexation of divalent metal ions with the hosts 2-6 had the sequence, i.e., 2 (R=OCH3) < 3 (R=CH3) < 4 (R=H) < 5 (R=Cl) < 6 (R=CF3). The stability constants of the hosts 5 and 6 containing an electron-withdrawing group are larger than those of the hosts 2 and 3 containing an electron-donating group. This substituent effect is attributed to the solvent effect in which the aryl oxide with an electron-donating group has a tendency to be tied strongly with protic solvents.

• 한국자기공명학회논문지
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• 제19권2호
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• pp.67-73
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• 2015

The microcystin is a cyclic heptapeptide from metabolites of cyanobacteria in the genera mycrocystis, anabaeba as a result of eutrophication. It has been known that microcystin-LR is a potent inhibitor of the catalytic subunits of protein phosphatase-1 (PP-1) as well as powerful tumor promoter. The active site of microcystin actually has two metal ions $Fe^{2+}/Zn^{2+}$ close to the nucleophilic portion of PP-1-microcystin complex. We report the isolation and purification of this microcystin-LR from cyanobacteria (blue-green algae) obtained from Daechung Dam in Chung-cheong Do, Korea. Microcystin-LR was extracted from solid-phase extraction (SPE) sample preparation using a CN cartridge. The cyanobacteria extract was purified to obtain microcystin-LR by HPLC method and identified by LC/MS. The detail structural studies that can elucidate the possible role of monovalent and divalent metal ions in PP-1-microcystin complexation were carried out by utilizing molecular dynamics. Conformational changes in metal binding for ligands were monitored by molecular dynamic computation and potential of mean force (PMF) using the method of the free energy perturbation. The microcystin-metal binding PMF simulation results exhibit that microcystin can have very stable binding free energy of -10.95 kcal/mol by adopting the $Mg^{2+}$ ion at broad geometrical distribution of $0.5{\sim}4.5{\AA}$, and show that the $K^+$ ion can form a stable metal complex rather than other monovalent alkali metal ions.