• Journal of Microbiology
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• 제41권1호
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• pp.1-6
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• 2003

The genetic relatedness of multidrug-resistant pneumococcal isolates of serotypes 19F and 23F was investigated. The DNA fragments digested with Sma I were resolved by pulsed-field gel electrophoresis (PFGE). PFGE analysis of 365. pneumoniae isolates showed 13 different patterns. Among 22 isolates of serotype 19F, 9 different PFGE patterns were present and 14 isolates of serotype 23F isolates represented 5 distinct PFGE patterns. Two isolates of serotype 19F and six isolates of serotype 23F shared the same PFGE pattern (Pattern I). Based on the genetic relatedness within the strains (one genetic cluster was defined as having more than 85% homology), we divided the pneumococcal strains into genefic clusters (Ⅰ, II, III, IV, V, and VI). The 22 strains of serotype 19F belonged to five distinct genetic clusters (I, II, III, IV, V and VI) and 14 strains of serotype 23F represented two genetic clusters (I and II ). These results showed that strains of serotype 19F are genetically more diverse than those of serotype 23F, Serotype 19F isolates with PFGE patterns H and I appeared to be less related to those of the remaining PFCE patterns (A to G) (less than 60% genetic relatedness), but those strains were genetically closely related with serotype 23f. These results suggest that the latter isolates originated from horizontal transfer of the capsular type 19F gene locus to 23F pneumococcal genotypes. In conclusion, the multidrug-resistant pneumococcal isolates of serotype 19f and 23F isolated in Korea are the result of the spread of a limited number of resistant clones.

• 미생물학회지
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• 제20권4호
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• pp.183-188
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• 1982

Clostidium botulinum type B가 생성하는 독소를 정제할 수 있는 방법을 연구하였다. 정제과정은 독소를 ammonium sulfate로 배양액에서 침전시켜 추출한후 Polymin P를 처리하여 핵산 및 기타 단백질을 최대한 제거한 후 Sephaex G-I00에서 gel fiItration을 시키고 DEAE-Sephadex로 이온교환 크로마토그래피를 시켰다. 이러한 과정으로 정제된 독소의 회수율은 17%였으며 SDS-polyacrylamide gel electrophoresis 결과 하나의 선을 나타내 동질성을 증명하였다. 정제된 독소의 분자량은 163,000이였으며 $\beta$-mercaptoethanol을 사용하여 환원시킨 결과 분자량 106,000과 56,000의 하위 단위체로 분리되었다.

• 한국안광학회지
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• 제3권1호
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• pp.21-25
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• 1998

Lead zirconate($PbZrO_3$, PZ) 박막의 광학적 성질을 조사하였다. 광학적 성질을 조사하기 위한 PZ 박막은 sol-gel 법으로 ITO glass 위에 제작되었다. 열처리온도 $T=700^{\circ}C$로 후열처리함에 의해 증착된 시료의 pyrochlore 상은 perovskite 상으로 변환되었다. 박막의 표면은 매우 평탄하였고, 투과율은 480~2000nm의 파장에서 60~80%였으며, 굴절률은 480~1000nm의 파장에 대하여 2.1~1.9 정도였다.

• The Korean Journal of Ceramics
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• 제1권3호
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• pp.152-154
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• 1995

A non-hydrolytic sol-gel process was developed to fabricate low-hydroxyl hard gels. The reaction of tert-butyl alcohol with silicon halides provided transparent low-hydroxyl hard gels. Some properties such as transparency, density, and refractive index was successfully doped into the hard gel matrices. The absorption spectrum of an erbium-doped methylsilsesquioxane was investigated to decide the pumping wavelength of an argon laser. The luminescence of the erbium-doped gel at 664 nm seems to be due to $4^F{9/2}\to 4^I_{15/2}$ transition.

• 한국세라믹학회지
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• 제40권12호
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• pp.1159-1164
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• 2003

Two processing routes (i.e., the gel casting and polymer preform routes) using polymer beads were studied to fabricate porous ceramics with a cellular structure. The gel casting route, comprising the gel casting of a ceramic slurry mixed with polymer beads, was found to be inadequate to produce porous ceramic bodies with a interconnected pore structure, due to complete coating of the slurry on the polymer beads, which left just isolated pores in the final sintered bodies. The polymer preform route, involving the infiltration of a polymer beads preform with the ceramic slurry, successfully produced porous ceramics with a highly interconnected network of spherical pores. The pore size of 250-300 $\mu\textrm{m}$ was demonstrated and the porosity ranged from 82 to 86%. This process is advantageous to control the pore size because it is determined by the sizes of polymer beads used. Another feature is the avoidance of hollow skeleton, giving a high strength.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1733-1736
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• 2008

ZnO thin films with preferred orientation along the (0 0 2) plane were fabricated by a sol-gel method. The effects of the annealing temperature, time, and thickness were studied by investigating UV-visible spectra, FT-IR spectra, and XRD of ZnO films. The films were dried and annealed ed at $100^{\circ}C,\;200^{\circ}C$, and $300^{\circ}C$ for 1hr, 2hrs, and 3hrs, respectively. The film showed the preferred (0 0 2) orientation and high transmittance near 90% in the visible range. Also, SEM images of the films exhibited very smooth surfaces without holes and cracks. Schottky diodes were fabricated by using ZnO sol-gel material. Au and Al were used as electrodes to make Ohmic and Schottky contacts, respectively. The annealing temperature, time and the thickness dependent I-V characteristics were presented in this article.

• 한국전기전자재료학회논문지
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• 제15권12호
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• pp.1033-1038
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• 2002

In this study, urethane acrylate macromer was synthesized and it was used in a gel polymer electrolyte (GPE), and then its electrochemical performances were evaluated. LiCoO$_2$/GPE/graphite cells were Prepared and their performances depending on discharge currents and temperatures were evaluated. The precursor consisting of urethane acrylate (UA), hexanediol dimethacrylate (HDDA) and benzoyl peroxide (BPO) had a low viscosity relatively ionic conductivity of the gel polymer electrolyte with UA at room temperature and -20$\^{C}$ was ca. 4.5 $\times$ 10$\^$-3/S$.$cm$\^$-1/ and 1.7 x 10$\^$-3/ S$.$cm$\^$-1/, respectively GPR was stable electrochemically up to potential of 4.i V vs. Li/Li$\^$+/. LiCoO$_2$/GPE/graphite cells showed good a high-rate and a low-temperature performance.

• 한국세라믹학회지
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• 제40권3호
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• pp.279-285
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• 2003

Sol-gel 법으로 200 nm 정도의 두께를 가진 강유전성 S $r_{0.9}$B $i_{2.1}$T $a_{1.8}$ N $b_{0.2}$ 박막을 Pt/Ti $O_2$/ $SiO_2$/Si 기판 위에 증착하였다. 본 실험에서는 Sr(O $C_2$ $H_{5}$)$_2$, Bi(TMHD)$_3$, Ta(O $C_2$ $H_{5}$)$_{5}$ 그리고, Nb(O $C_2$ $H_{5}$)$_{5}$를 출발 물질로 사용하였으며 2-methoxyethanol을 용매로 사용하였다. UV 노광과 급속열처리가 SBTN 박막의 구조와 전기적 특성에 어떤 영향을 주는 가를 연구하였다. UV 노광과 급속열처리를 한 후에 $650^{\circ}C$ 열처리한 SBTN 박막의 3V와 5V 인가 전압하에서의 잔류분극 값은 각각 8.49와 11.94 $\mu$C/$ extrm{cm}^2$이었다.

• KSBB Journal
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• 제14권5호
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• pp.600-605
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• 1999

본 연구는 도축 폐기물인 가축혈액을 이용하여 항고혈압 기능성 식품소재로서의 angiotensin I converting enzyme 저해 펩타이드 분획을 생산하기 위한 조건과 가능성을 조사하기 위하여 수행되었다. 산업적으로 이용 가능한 단백분해효소 중 Alcalase가 혈장 원액 및 그로부터 분리된 albumin에 대하여 가장 높은 활성의 가수분해물을 생성하였다. 특히 albumin의 Alcalase 가수분해물과 이를 gel chromatography를 통새 분획하여 얻은 고활성 분획의 $IC_50$값은 각각 0.5 및 0.02 mg/mL로서 지금까지 보고된 식품단백질 유래 펩타이드 혼합물들과 비교할 때 활성이 매우 높은 것에 속함을 알 수 있었다. 또한 이 고활성 펩타이드 분획은 혈장 원액으로부터 단순한 한외여과만을 거쳐도 얻을 수 있음을 확인함으로써 산업적 실용화 가능성이 높은 공정임을 알게 되었다.

• 미생물학회지
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• 제25권1호
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• pp.73-79
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• 1987

A restriction endonuclease, Kpn I has been isolated from Klebsiella pneumonia. Cells were broken by sonication. After ultracentrifugation the supernatant containing Kpn I activity was further purified by Sepharose-6B gel filtration, DEAD-Cellulose, Heparin-Agarose, and Aminohexyl-Agarose column chromatography. Final enzyme preparation was essentially free of contamination exonuclease and phosphatase, as judged by ligation-recut test. Total activity of the enzyme recovered from 10 grams of cells was $4.7\times 10^5$ units.