• 멤브레인
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• 제31권3호
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• pp.200-211
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• 2021

본 연구는 합성된 zeolitic imidazolate framework-7 (ZIF-7)을 poly(ether-b-amide) 2533 (PEBAX2533)에 혼합하여 혼합막을 제조하고, 단일기체(N₂, CO₂)를 투과하여 기체에 대한 성질을 조사하였다. FT-IR, XRD, FE-SEM을 통해 ZIF-7이 가지는 피크와 형상을 확인하였고, 합성이 잘 되었음을 판단하였다. TGA를 통해 ZIF-7이 우수한 열적 안정성을 가지는 것과 막 내에 혼입되었을 때 순수 PEBAX2533에 비해 열적 안정성이 향상되는 것을 확인하였다. BET를 통해 합성된 ZIF-7의 CO₂ 흡착 능력이 우수하고 CO₂/N₂ 흡착 선택도가 약 49.64로 높은 편이라는 것을 확인하였다. 기체 투과는 혼합막에서 ZIF-7 함량이 증가함에 따라 N₂ 투과도는 감소하고 CO₂ 투과도는 비교적 적게 감소하면서 CO₂/N₂ 선택도는 꾸준히 증가하는 모습을 보였다. 특히 ZIF-7 20 wt%이 첨가되었을 때 CO₂ 투과도가 크게 감소하지 않고 선택도가 상당히 증가하여 Robeson upper-bound에 근접하는 결과를 얻었다.

• 대한핵의학회지
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• 제7권2호
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• pp.1-12
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• 1973

The most commonly used methods for determining thyroxine binding globulin(TBG) concentration as the total thyroxine-binding capacity utilize electrophoretic seperation of serum. Although technically simple, the electrophoretic method is time consuming and is limited in the number of samples which can be run in a single assay. The author presented a single $T_4$ load ion exchange resin method as an approach to simplify the technique as with clinical practicability and results were analyzed. For construction of the standard curves, serum mixtures were diluted with barbital buffer.which effectively blocked $T_4$-binding to TBPA. For each serum dilution, a constant amount of $T_4-^{125}I$ and increments of unlabelled $T_4$ were added. After incubation in water bath, resin beads were dispensed to the samples which binded all $T_4$ not bound to TBG. The radioactivity in the supernatant was counted in the gamma scintillation counter. Each standard curve was plotted from the percent counts in the supernatant and total $T_4$ in each tube. Unknown samples were diluted to 1:40 and ran at a single $T_4$ loading concentration, and the TBG capacity of the samples was able to be read on the standard isobars. The following results were obtained. 1) Mean and standard deviation for TBG capacity in normal population was $28.6{\pm}5.09{\mu}g\;T_4/100ml$. 2) $24.9{\pm}3.87{\mu}g\;T_4/100ml$ in hyperthyroidism showed low TBG capacity comparing to normal population.(p<0.025) 3) $31.0{\pm}2.40{\mu}g\;T_4/100ml$ in hypothyroidism showed high TBG capacity tendency comparing to normal population. 4) Reversed correlationship existed between TBG capacity and $T_3$ resin uptake(r=-0.624), TBG capacity and serum $T_4$ value (r=-0.859), and TBG capacity and free thyroxine index(r=-0.623). The author assumes that this method of assay is considerably simpler in instrumentation and technique than any other assays traditionally being used, and seems to be more practical for routine clinical laboratory use.

• 한국환경농학회지
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• 제24권4호
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• pp.379-385
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• 2005

중금속으로 오염된 폐수를 처리하기 위하여 다양한 처리 방법들이 제시되고 있으나, 최근에는 미생물을 이용한 중금속 처리 방법에 대한 관심이 높아지고 있다. 따라서 중금속으로 오염된 토양에서 중금속에 대하여 강한 내성과 우수한 생물흡착능력을 동시에 가지고 있는 미생물 CPB를 분리하여 중금속에 대한 내성, 흡착 능력 및 흡착의 최적조건을 조사하였다. 중금속에 대한 내성은 전체적으로 $400mg{\ell}^{-1}$ 이상의 농도에서도 높은 내성을 보였으며, 생장 저해도는 단일 중금속 보다 중금속이 복합으로 존재 할 경우 더 크게 나타났다. 중금속 흡착 능력은 Pb>Cd>Cu>Zn의 순으로 흡착 능력이 나타났다. 외형적 흡착형태는 중금속의 종류에 따라 세포 표면 및 세포 막 부근에 electron dense particles들이 형성되었으며, 이는 EDS 분석을 통하여 중금속 화합물인 것으로 확인되었다. 중금속을 흡착하는데 있어 전반적인 최적 pH는 $5{\sim}7$범위였고, 최적 온도는 $25{\sim}35^{\circ}C$이다.

• BMB Reports
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• 제39권4호
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• pp.432-440
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• 2006

A tuber lectin from Arisaema jacquemontii Blume belonging to family Araceae was purified by employing a single step affinity chromatography using column of asialofetuin-linked amino activated silica beads and the bound lectin was eluted with 100 mM glycine-HCl buffer pH 2.5. The purified A. jacquemontii lectin (AJL) showed a single protein band with an apparent molecular mass of 13.4 kDa when submitted to SDS-polyacrylamide gel electrophoresis under reducing as well as non-reducing conditions. The native molecular mass of AJL determined by gel filtration on a Biogel P-200 column was 52 kDa and its carbohydrate content was estimated to be 3.40%. Thus AJL is a tetrameric glycoprotein. The purified lectin agglutinated erythrocytes from rabbit but not from human. Its activity was not inhibited by any of the mono- and disaccharides tested except N-acetyl-D-lactosamine having minimal inhibitory sugar concentration (MIC) 25 mM. Among the glycoproteins tested only asialofetuin was found to be inhibitory (MIC $125\;{\mu}g/mL$). A single band was obtained in native PAGE at pH 4.5 while PAGE at pH 8.3 showed two bands. Isoelectric focusing of AJL gave multiple bands in the pI range of 4.6-5.5. When incorporated in artificial diet AJL significantly affected the development of Bactrocera cucurbitae (Coquillett) larvae indicating the possibility of using this lectin in a biotechnological strategy for insect management of cucurbits. Larvae fed on artificial diet containing sub-lethal dose of AJL showed a significant decrease in acid phosphatase and alkaline phosphatase activity while esterase activity markedly increased as compared to larvae fed on diet without lectin. Out of various human cancer cell lines employed in sulphorhodamine B (SRB) assay, this lectin was found to have appreciable inhibitory effect on the in vitro proliferation of HCT-15, HOP-62, SW-620, HT-29, IMR-32, SKOV-3, Colo-205, PC-3, HEP-2 and A-549 cancer cell lines by 82, 77, 73, 70, 41, 41, 37, 29, 21 and 21% respectively.

• Bulletin of the Korean Chemical Society
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• 제28권1호
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• pp.41-48
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• 2007

Large colorless single crystals of sodium zeolite X, stoichiometry |Na80 |[Si112Al80O384]-FAU, with diameters up to 200 μm and Si/Al = 1.41 have been synthesized from gels with the composition of 2.40SiO2 : 2.00NaAlO2 : 7.52NaOH : 454H2O : 5.00TEA. One of these, a colorless octahedron about 200 μm in cross-section has been treated with aqueous 0.1 M KNO3 for the preparation of K+-exchanged zeolite X. The crystal structure of |K80|[Si112Al80O384]-FAU per unit cell, a = 24.838(4) A, dehydrated at 673 K and 1 × 10-6 Torr, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd at 294 K. The structure was refined using all intensities to the final error indices (using only the 707 reflections for which Fo > 4σ (Fo)) R1 = 0.075 (based on F) and R2 = 0.236 (based on F2). About 80 K+ ions per unit cell are found at an unusually large number of crystallographically distinct positions, eight. Eleven K+ ions are at the centers of double 6-rings (D6Rs, site I; K-O = 2.492(6) A and O-K-O (octahedral) = 88.45(22)o and 91.55(22)o). Site-I' position (in the sodalite cavities opposite D6Rs) is occupied by five K+ ions per unit cell; these K+ ions are recessed 1.92 A into the sodalite cavities from their 3-oxygen planes (K-O = 2.820(19) A, and O-K-O = 78.6(6)o). Twety-three K+ ions are found at three nonequivalent site II (in the supercage) with occupancies of 5, 9, and 9 ions; these K+ ions are recessed 0.43 A, 0.75 A, and 1.55 A, respectively, into the supercage from the three oxygens to which it is bound (K-O = 2.36(13) A, 2.45(13) A, and 2.710(13) A, O-K-O = 116.5(20)o, 110.1(17)o, and 90.4(6)o, respectively). The remaining sixteen, thirteen, and twelve K+ ions occupy three sites III' near triple 4-rings in the supercage (K-O = 2.64(3) A, 2.94(3) A, 2.73(5) A, 2.96(6) A, 3.06(4) A, and 3.08(3) A).

• 한국응용곤충학회지
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• 제42권3호
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• pp.173-184
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• 2003

2000년 3월부터 11월까지 부산항으로 수입된 목재류에서 검출된 나무좀과(Scolytidae), 긴나무좀과(Platypodidae), 개나무좀과(Bostrichldae), 가루나무좀과(Lyctidae)의 종류 및 검출된 기주와 수입국을 조사하여 국내 유입의 가능성이 있는 해충을 파악하는 한편, 이들 해충의 국내 유입을 차단하기 위한 자료로 활용 하고자 본 조사를 실시하였다. 부산항의 수입재에서 검출된 나무좀과, 긴나무좀과, 개나무좀과, 가루나무좀과는 총 23속 52종이었으며, 검출된 수입재는 15개 국에서 수입한 13과 19종의 원목, 제재목, 기타 등이었다. 나무좀과에서는 3아과 16속 35종이 검출되었다. Xyleborus속에서 12종, Ips속에서 6종, Trpodendron속에서 3종, Arixyleborus속에서 2종, 그 외 Alniphagus속 등에서 12속에서 각각 1종씩 검출되었다. 검출된 수종은 말레이시아를 비롯한 11개국에서 수입한 13속 16종이었으며, 남양재인 말레이시아산 나왕류에서 2속 13종의 가장 많은 종이 검출되었다. 긴나무좀과는 Platypus cupulatus, P. curtus 등 1아과 1속9종이 채집되었다. 검출된 수종은 호주, 파푸아 뉴기니아 등 6개국에서 수입한 4속6종이었고, 말레이시아산 나왕류에서 6종이 검출되었다. 개나무좀과는 2아과4속5종이 검출되었다. Herernbostrychus aequalis, Dinoderus bifoveoratus 등이 검출되었다. 검출된 수종은 말레이시아, 엘살바도르등 4개국에서 수입한 4속 6종이었으며 말레이시아산 나왕류에서 4종이 검출되었다. 가루나무좀과는 Trogoxylon sp., Minthea rugicoliis, Minthea sp. 등 2속 3종이 검출되었다. 검출된 수종은 필리핀 등을 비롯한 3개 국에서 수입한 2속 3종이었다.an으로 강한 $T_2$ 대조도를 갖는 128x128의 고해상도 EPI 영상을 얻을 수 있었다. 결론 : 제안한 Half Fourier기법을 이용하여 기존의 $64{\times}64$ 영상보다 해상도를 높인 $128{\times}128$ EPI영상을 single scan으로 얻을수 있었으며, 에코의 적절한 배치를 통해 임상에서 널리 사용되는 $T_2$ 대조도를 얻을 수 있었다. 제안한 방법은 특별한 하드웨어의 추가 없이, 펄스 시퀀스와 tuning 및 재구성 알고리즘 등의 소프트웨어적인 방법만으로 구현이 가능하여 많은 임상 응용이 기대된다.체 실험을 통하여 확인하였다.les, ranged from 0.02 to 40 MHz, and dominated by contribution from bound pool, which is bound to macromolecule regardless of binding ratios. In addition, as more Gd-chelate bound to macromolecule, sharp increase of relaxivity at higher field occurs. The NMRD profiles for different values of τS show the enormous increase of low field profile whereas relaxivity at high field is not affected by τS. On the other hand, the change in τV does not affect low field profile but strongly in fluences on both inflection fie이 and the maximum relaxivity value. The results

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.746-751
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• 2003

A method of measuring the length of defects on the wall of the spent nuclear fuel pool using the image processing and a laser slit beam is proposed. Since the defect monitoring camera is suspended by a crane and hinged to the crane hook, the camera viewing direction can not be adjusted to the orientation that is exactly perpendicular to the wall. Thus, the image taken by the camera, which is horizontally rotated along the axis of the camera supporting beam, is distorted and thus, the precise length can not be measured. In this paper, by using the LASER slit beam generator, the horizontally rotated angle of the camera is estimated. Once the angle is obtained, the distorted image can be easily reconstructed to the image normal to the wall. The estimation algorithm adopts a 3-dimensional coordinate transformation of the image plane where both the laser slit beam and the original image of the defects exist. The estimation equation is obtained by using the information of the beam projected on the wall and the parameters of this equation are experimentally obtained. With this algorithm, the original image of the defect taken at arbitrary rotated angle can be reconstructed to an image normal to the wall. From the result of a series of experiments, the accuracy of the defect is measured within 0.6 and 1.3 % error bound of real defect size in the air and underwater, respectively under 30 degree of the inclined angle of the laser slit beam generator. Also, the error increases as the inclined angle increases upto 60 degree. Over this angle, the defect length can not be measured since the defect image disappears. The proposed algorithm enables the accurate measurement of the defect length only by using a single camera and a laser slit beam.

• 정보처리학회논문지A
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• 제10A권6호
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• pp.635-642
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• 2003

최근 네트워크 기술의 비약적인 발전은 고속 그리고 저가의 클러스터 시스템을 구축할 수 있는 기본 토대를 제공하여 주었다. 이러한 기존 클러스터 시스템은 안정화된 고속의 지역 네트워크를 기반으로 일정 수준의 시스템으로 구성되는 것이 일반적인 경향이다. 본 논문에서 제안하는 다중 분산 웹 클러스터 그룹은 개방 네트워크상에 존재하는 저가, 저속의 시스템 노드를 대상으로 하여, 주어진 작업에 대한 병렬수행 및 SC-Sever의 공유메모리를 통한 효율적인 작업 분배와 시스템 노드간의 상호 협조 작업을 통하여 고성능, 고효율 그리고 고가용성을 얻을 수 있는 웹 클러스터 모델이다. 이를 위하여 다중 분산 웹 클러스터 그룹은 복수개의 시스템 노드를 단일한 가상 네트워크로 묶어 놓은 서브 클러스터 그룹으로 구성하고, 서브 클러스터 그룹내의 효율적인 자료전송을 위하여 분산 공유 메모리를 이용한다. 제안된 모델은 사용자로부터 요구되는 대규모의 작업에 대하여 분산 공유 메모리를 기반으로 한 부하분배 및 병렬 컴퓨팅 방식을 이용하므로 처리 효율을 높일 수 있다.

• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.749-755
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• 2005

The ccpA gene encoding catabolite control protein A (CcpA) of Leuconostoc mesenteroides SYl, a strain isolated from kimchi, was cloned, sequenced, analyzed for transcript, and overexpressed in Escherichia coli. The ccpA ORF (open reading frame) is 1,011 bp in size, which can encode a protein of 336 amino acid residues with a molecular mass of 36,739 Da. The transcription start site was mapped at a position 49 nucleotides upstream of the start codon, and promoter sequences were also identified. The putative cre site overlapped with the -35 promoter sequence. The deduced amino acid sequence of the CcpA contained the helix-turn-helix motif found in many DNA-binding regulatory proteins. CcpA from 1. mesenteroides SY1 had $54.6\%$ identity with CcpA from Lactobacillus casei. The Northern blot experiment showed that ccpA was transcribed as a single 1.1 kb transcript, and transcription was repressed when grown on media containing glucose. CcpA was overproduced in E. coli BL21(DE3) cells using the pET expression vector, and purified to an apparent homogeneity. Gel Mobility Shift Assay with purified CcpA and a DNA fragment containing the ere sequence of the $\alpha$-galactosidase gene (aga) from L. mesenteroides SY1 revealed that CcpA bound specifically to the cre site of aga.

• Journal of Microbiology and Biotechnology
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• 제19권3호
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• pp.277-285
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• 2009

The nucleotide sequence of the Paenibacillus curdlanolyticus B-6 xyn10A gene, encoding a xylanase Xyn10A, consists of 3,828 nucleotides encoding a protein of 1,276 amino acids with a predicted molecular mass of 142,726 Da. Sequence analysis indicated that Xyn10A is a multidomain enzyme comprising nine domains in the following order: three family 22 carbohydrate-binding modules (CBMs), a family 10 catalytic domain of glycosyl hydrolases (xylanase), a family 9 CBM, a glycine-rich region, and three surface layer homology (SLH) domains. Xyn10A was purified from a recombinant Escherichia coli by a single step of affinity purification on cellulose. It could effectively hydrolyze agricultural wastes and pure insoluble xylans, especially low substituted insoluble xylan. The hydrolysis products were a series of short-chain xylooligosaccharides, indicating that the purified enzyme was an endo-$\beta$-1,4-xylanase. Xyn10A bound to various insoluble polysaccharides including Avicel, $\alpha$-cellulose, insoluble birchwood and oat spelt xylans, chitin, and starches, and the cell wall fragments of P. curdlanolyticus B-6, indicating that both the CBM and the SLH domains are fully functioning in the Xyn10A. Removal of the CBMs from Xyn10A strongly reduced the ability of plant cell wall hydrolysis. These results suggested that the CBMs of Xyn10A play an important role in the hydrolysis of plant cell walls.