• 한국환경농학회지
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• 제26권4호
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• pp.332-336
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• 2007

Pseudomonas stutzeri strain KCCM 34719 was used in this experiment to determine the effects of increasing Pb(II) concentrations on its growth rate. To obtain optimum growth conditions, strain KCCM 34719 was cultivated in nutrient broth under various conditions, such as temperature, pH, and NaCl concentration. Optimal conditions for cell growth were $30^{\circ}C$ of temperature, 8.0 of pH, and 3% of NaCl concentration, respectively. Growth response of bacterial cell to Pb(II) showed tolerance to concentrations ranging from 10 to 100 mg ${\ell}^{-1}$ in liquid culture, following a growth pattern similar to the control. Growth rate was greatly inhibited at 200 mg ${\ell}^{-1}$ of Pb(II).

• Journal of Photoscience
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• 제9권2호
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• pp.55-58
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• 2002

The reaction center Dl protein of photosystem II is the target of photodamage by excess illumination. The Dl protein is damaged by reactive oxygen species generated by photochemical reactions and then degraded by specific proteolytic enzymes. We found that the Dl protein also cross-links with the surrounding polypeptides, such as D2 and CP43 in isolated thylakoids or photosystem II-enriched membranes from spinach under the illumination with strong visible light. The cross-linking was observed in spinach leaf discs as well when they were illuminated at higher temperature (40°C). It was also shown that the cross-linked products are digested efficiently by a protease(s) in the stroma. Thus the cross-linking/digestion processes of the Dl protein seem to comprise a new pathway in the turnover of the photodamaged Dl protein. It should be noted, however, that the cross-linked products of the Dl protein and CP43 induced by endogenous cationic radicals in the donor-side photoinhibition are resistant to proteolytic digestion. Accumulation of these cross-linked products in the thylakoids may lead to the decay of the function of chloroplasts and finally to the death of plant cells. Thus, we suggest that the quality control of photosystem II, especially removal of the cross-linked products of the Dl protein, is crucial for the survival of chloroplasts under the light stress.

• 대한화학회지
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• 제24권2호
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• pp.121-128
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• 1980

Ambidentate 리간드인 isonitrosobenzoylacetone을 리간드로 하는 금속착물, tris(isonitrosobenzoylacetonato)cobalt(III) 및 bis(isonitrosobenzoylacetonato)palladium(II)을 합성한 후 분광학적 방법에 의하여 이들의 결합구조를 조사하였다. 즉 착물에서 리간드는 아세틸기의 산소 및 이소니트로소의 질소원자를 통하여 금속에 배위되어 5원의 킬레이트고리를 이루고 있음을 알 수 있었다. 이 결합구조는 Patel과 Haldar등이 얻었던 isonitrosoacetylacetone착물의 그 것들과 유사하다.

• 약학회지
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• 제44권5호
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• pp.399-405
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• 2000

We have synthesized a novel platinum (II) coordination complex containing trans-ι-1,2-diaminocyclohexane (DACH) as a carrier ligand and 1,2-bis (diphenylphosphino)ethane (DPPE) as a leaving group. In addition, nitrate was added to improve the water-solubility. A new series of [Pt (trans-ι-DACH) (DPPE)].2NO$_3$(PC) was evaluated for its cytotoxic activity on MKN-45 human gastric adenocarcinoma cells and normal primary cultured kidney cells. PC has demonstrated high levels of cytotoxicity against MKN-45/S, MKN-45/ADR and MKN-45/CDDP cells. The cytotoxicity of PC against rabbit proximal renal tubular cells, human renal cortical cells, and human renal cortical tissues, determined using the MTT assaying technique, the ($^3$H)-thymidine uptake and the glucose consumption tests, was found to be quite less than those of cisplatin. Based on these results, this novel platinum (II) coordination complex appears to be better for improving antitumor activities with low nephrotoxicity and is a valuable lead in the development of new clinically available anticancer chemotherapeutic agents.

• Computers and Concrete
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• 제21권6호
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• pp.727-739
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• 2018

Crack is the most common typical feature of concrete deterioration, so routine monitoring and health assessment become essential for identifying failures and to set up an appropriate rehabilitation strategy in order to extend the service life of concrete structures. At present, image segmentation algorithms have been applied to crack analysis based on inspection images of concrete structures. The results of crack segmentation offering crack information, including length, width, and area is helpful to assist inspectors in surface inspection of concrete structures. This study proposed an algorithm of image segmentation enhancement, named morphological segmentation based on edge detection-II (MSED-II), to concrete crack segmentation. Several concrete pavement and building surfaces were imaged as the study materials. In addition, morphological operations followed by cross-curvature evaluation (CCE), an image segmentation technique of linear patterns, were also tested to evaluate their performance in concrete crack segmentation. The result indicates that MSED-II compared to CCE can lead to better quality of concrete crack segmentation. The least area, length, and width measurement errors of the concrete cracks are 5.68%, 0.23%, and 0.00%, respectively, that proves MSED-II effective for automatic measurement of concrete cracks.

• Bulletin of the Korean Chemical Society
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• 제27권9호
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• pp.1293-1296
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• 2006

In this study, a solid phase extraction method has been developed for the preconcentration and separation of the elements Cr(III), Fe(III), Co(II) and Pb(II) at trace levels by using a column packed with Amberlite XAD-1180 resin loaded with 4-(2-pyridylazo)-resorcinol (PAR) reagent. After preconcentrating, the metals retained on the column were eluted with 20 mL of 3 mol/L $HNO_3$ and then determined by flame atomic absorption spectrometry (FAAS). The factors affecting the recovery of the elements, such as pH, type and concentration of eluent, volume of sample and elution solution, and matrix components, were also ascertained. The recoveries of Cr(III), Fe(III), Co(II) and Pb(II) were found to be $99\;{\pm}\;4,\;97\;{\pm}\;3,\;95\;{\pm}\;3$ and $98\;{\pm}\;4$%, respectively, under the optimum conditions at 95% confidence level and the relative standard deviations found by analyzing of nine replicates were $\leq4.4$%. The preconcentration factors for Cr(III), Fe(III), Co(II) and Pb(II) were found as 75, 125, 50 and 75 respectively. The detection limits (DL, 3s/b) were 3.0 $\mu g/L$ for Cr(III), 1.25 $\mu g/L$ for Fe(III), 3.3 $\mu g/L$ for Co(II), and 7.2 $\mu g/L$ for Pb(II). The recoveries achieved by adding of metals at known concentrations to samples and the analysis results of Buffalo river sediment (RM 8704) show that the described method has a good accuracy. The proposed method was applied to tap water, stream water, salt and street dust samples.

• 한국재료학회지
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• 제26권12호
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• pp.721-725
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• 2016

This work focuses on the electrical conduction mechanism in a lead free ($Na_{0.5}K_{0.5}NbO_3$ ; NKN) ceramics system with $LiNbO_3$ content of approximately critical concentration $x{\geq}0.2$. Lead free $(1-x)(Na_{0.5}K_{0.5})NbO_3-x(LiNbO_3)$, $NKN-LN_x$ (x = 0.1, 0.2) ceramics were synthesized by solid-state reaction method. Crystal structures are confirmed by X-ray diffraction. The electric-mechanical bond coefficient $k_p$ decreases and the phase transition temperature $T_c$ increases with increasing x content, as determined by dielectric and piezoelectric measurements. The value of the real dielectric constants ${\varepsilon}^{\prime}$ and $k_BT{\varepsilon}^{\prime\prime}$ showed anomalies around $T_c$ ($462^{\circ}C$ in the NKN-LN0.1 and $500^{\circ}C$ in the NKN-LN0.2). For the ionic conduction of mobile ions, the activation energies are obtained as $E_I=1.76eV$ (NKN-LN0.1) and $E_I=1.55eV$ (NKN-LN0.2), above $T_c$, and $E_{II}=0.78$ (NKNL-N0.1) and $E_{II}=0.81$ (NKN-LN0.2) below $T_c$. It is believed that the conduction mechanisms of NKN-LNx ceramics are related to ionic hopping conduction, which may arise mainly due to the jumping of $Li^+$ ions.

• 전자공학회논문지SC
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• 제48권6호
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• pp.43-50
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• 2011

바이오인식 기술은 패스워드나 IC 카드와 같이 분실의 우려가 없어 다양한 분야에 응용되고 있으나, 변조가 가능하며 측정방식에 따라 측정자에게 거부감을 줄 수 있다는 단점을 가지고 있다. 이러한 문제점을 해결하기 위해 심전도(ECG)를 이용한 바이오인식 기술에 대한 연구가 진행되고 있으나, 기존의 심전도 바이오인식기술은 심장질환을 측정하는 정형화된 심전도 리드 II 파형을 이용했기 때문에 바이오인식에는 적합하지 못했다. 따라서 본 논문에서는 심전도 리드 III 파형을 이용한 새로운 바이오인식 기술을 제안한다. 측정된 심전도 리드 III 파형은 잡음을 제거하기 위해 필터링을 한 후 AAV 알고리즘을 이용하여 파형의 정점을 찾고, 그 정점을 기준으로 원신호에서 파형을 분류하였다. 추출된 파형을 4가지 타입으로 정의하고 그를 기반으로 꼭짓점 및 세부파형모양, 파형진폭 및 간격 등 총 22가지의 특징들을 추출하였다. 추출된 특징은 오류역전파 신경회로 망인식기를 통해 분류되었다. 심전도 리드 III 파형을 이용한 바이오인식을 위해 31명의 측정자와 데이터베이스에 없는 5명의 측정자, 총 36명을 대상으로 심전도 바이오인식을 실험한 결과 특이도(specificity) 100%, 민감도(sensitivity) 95.59%, 정확도(accuracy) 99.17%의 특성을 보였다.

• 보존과학회지
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• 제32권1호
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• pp.63-73
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• 2016

본 연구는 거창 정장리 유적에서 복원이 불가능한 유리구슬 편 24점과 완형 유리구슬 26점에 대하여 형태적 특성 관찰과 화학 조성 분석을 통해 재질 및 특성을 밝히고자 하였다. 유리구슬의 형태적 특성은 색상, 크기, 풍화 상태, 제작 기법에 따라 크게 다섯 가지 유형으로 구분된다. 화학 조성에 따른 분류에서 첫 번째와 두 번째 유형은 소다유리군, 세 번째 유형은 포타쉬유리군, 네 번째와 다섯 번째 유형은 납바륨유리군으로 확인된다. 이를 통해 거창 정장리 유적의 유리구슬은 형태적 특성에 따라 화학 조성이 변화되는 양상을 보이며 다양한 화학 조성이 확인되었다. 본 유적의 유리문화의 흐름을 살펴보면 납바륨유리군 II형과 포타쉬유리군 I, II형이 나타나는 유구는 비교적 선행 시기인 목곽묘 단계, 소다유리군과 납바륨유리군 III형이 나타나는 유구는 비교적 후행 시기인 목곽묘 단계의 유리 문화가 형성된 것으로 추정할 수 있다.

• 분석과학
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• 제27권5호
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• pp.248-253
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• 2014

이 연구는 Mn과 Pb의 노출이 면역체계에 미치는 영향을 파악하고자 하였다. 연구대상자는 남성 근로자 42 명으로, 대상자 중 13명은 사무직 근로자(실험군 I), 21 명은 제조업 사업장 근로자(실험군 II), 8명은 용접 작업자(실험군 III)였다. 대상자의 혈액 중 Mn과 Pb 농도는 실험군별로 유의한 차이를 보였다. 실험군 I 대상자의 CD19+와 total lymphocytes 농도는 기타의 실험군 대상자에서보다 유의하게 높았으나 다른 T lymphocytes subpopulation의 농도는 차이가 없었다. Mn과 Pb 농도는 T lymphocytes subpopulation과 음의 상관관계를 보였으나, Mn은 CD4+CD45RO+와 자연살해세포를 제외한 T lymphocytes subpopulation과 유의한 음의 상관관계를 보였다. Pb 농도는 단지 total lymphocytes 농도와 유의한 음의 상관관계를 보였다. 이 연구에서 Mn과 Pb의 직업적인 노출은 세포성면역계에 영향을 미칠 수 있음을 제시하였다.