• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.528-530
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• 2002

Xanthmonas oryzae MGL21유래의 CFTase의 repeat영역을 deletion 시킨 ${\triangle}N{\triangle}C$ deletion mutant는 protein 정제결과 약 90kDa 이있으며 pH6.5, $45^{\circ}C$에서 최적 효소 반응을 하였다. 또한 Inulin과 반응시켰을 때 CFTase는 main product가 CF인데 비해 ${\triangle}N{\triangle}C$ deletion mutant는 main product가 fructooligosaccharide였다. 이러한 결과로부터 CFTase의 N말단 repeat영역과 C말단 repeat영역을 제거하였을 경우 endoinulinase와 활성이 유사하며, 유전자 크기 및 아미노산 서열도 유사함을 알 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제25권1호
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• pp.56-64
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• 1997

Since there are three hydroxyl groups on each anhydroglucose ring of the cellulose, the renewable resources, we can get various functional papers by the chemical modification of cellulose. The reaction involving the introduction of the ${\beta}$-cyanoethyl ($-CH_2-CH_2$-CN) group into organic substances containing reactive hydrogen atoms is known as cyanoethylation. Cellulose reacts with acrylonitrile in the presence of strong alkalis in a typical manner of primary and secondary alcohols to form cyanoethyl ethers. In cyanoethylation, important factors of reaction are temperature, concentration of the NaOH, and addition rate of acrylronitrile. FT-IR spectra of cyanoethyl group was confirmed at $2250cm^{-1}$, which corresponds the introduction of aliphatic nitrile group. Effect of cyanoethyl DS(degree of substitution) on strength properties was resulted that cyanoethylated BKP of DS 0.04 appeared to be the best choice for overall strength properties. Also, excellent thermal stability in aging characteristics was obtained.

• 대한수의학회지
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• 제52권3호
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• pp.157-162
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• 2012

Corneal injury is very common clinical condition in veterinary medicine and delayed or incomplete corneal healing has the potential of vision loss due to the loss of corneal transparency. For the reconstruction of corneal epithelium, tissue graft and cell transplantation have been prosperously investigated. The purpose of this study was to evaluate the clinical value and short-term safety of application of cultured allogenic mesenchymal stem cells (MSCs) in the treatment of canine experimental corneal defect. Corneal defects were surgically generated in the central corneas of healthy beagle dogs and cultured canine allogenic MSCs were transplanted via subconjunctival injection. Although mean healing time, the rate of epithelial regeneration, and the degree of corneal transparency were not significantly improved after MSC transplantation, significant immune reaction or incompatibility reaction was not detected except transient local irritation. These results propose the possibility of MSC application as a new regenerative medicine in canine ocular disorders.

• 한국세라믹학회지
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• 제36권7호
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• pp.698-704
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• 1999

Li rich Li1+xMn2-xO4(x=0.07) spinel powders were prepared by an oxalate precipitation of wet chemical methods at temperature lower than $600^{\circ}C$. The FTIR results showed that the powders prepared at $600^{\circ}C$ had high degree of crystal quality comparing with the spinel powders prepared by solid state reaction at 75$0^{\circ}C$ which was the lowest synthesis temperature of the solid state reaction method. The particle size of powders prepared by the oxalate precipitation at $600^{\circ}C$ was smaller than 0.2${\mu}{\textrm}{m}$ and the specific surface area was 11.01 m2/g A heat treatment over 90$0^{\circ}C$ formed second phase in the precipitates. It was shown that there were phase transitions at temperatures. T1,T2 and T2. The transitions involved weight loss and gain during heating and cooling. The low temperature synthesis below $600^{\circ}C$ avoided the second phase formation and the prepared powders showed improved compositional and physical properties for secondary lithium battery applications.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3312-3316
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• 2013

Single crystals of hexagonal graphenes were successfully grown on Cu foils using the atmospheric pressure chemical vapor deposition (CVD) method. We investigated the effects of reaction parameters, such as the growth temperature and annealing time, on the size, coverage, and density of graphene domains grown over Cu foil. The mean size of the graphene domains increased significantly with increases in both the growth temperature and annealing time, and similar phenomena were observed in graphene domains grown by low pressure CVD over Cu foil. From the comparison of micro Raman spectroscopy in the graphene films grown with different annealing times, we found that the nucleation and growth of the domains were strongly dependent on the annealing time and growth temperature. Therefore, we confirmed that when reaction time was same, the number of layers and the degree of defects in the synthesized graphene films both decreased as the annealing time increased.

• 한국균학회지
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• 제11권3호
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• pp.115-119
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• 1983

Aspergillus phoenicis에 의한 progesterone의 전환반응에 대하여 고찰하였다. 본 실험조건에서의 물질대사 결과 $11{\alpha}-hydroxyprogesterone$이 주생성물로 생성 되었다. $11{\alpha}-hydroxyprogesterone$의 농도는 반응시간에 따라 서서히 증가하였으나 40시간 이후부터는 점근값에 도달하였다. 반응액에의 glucose 첨가는 progesterone의 전환반응 속도를 증가시켜 점근값의 농도에 도달하는 시간이 괄목할 만큼 앞당겨졌다. Progesterone의 초기 농도를 증가시키는 것은 전환율이나 반응완결에 소요되는 시간에 큰 변화를 주지 않았으나 전환반응은 progesterone 농도에 대하여 1차반응 형태로 요약될 수는 없었다. 유기용매에 의한 효소 활성의 저하정도는 유기용매의 종류 및 그 농도에 의존하였으며, 낮은 유기용매의 농도에서는 acetone이 가장 높은 전환율을 나타내었다.

• 한국재료학회지
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• 제23권10호
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• pp.599-605
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• 2013

CSA, a cement mineral compound that is mainly composed of $3CaO{\cdot}3Al_2O_3{\cdot}CaSO_4$, generates ettringite as a hydration product after a reaction with glass (lime), gypsum and water to speed up the hardening process and enhance the strength and degree of expansion. When used as a cement admixture, there is increased production of ettringite, which can improve the initial strength in the first three days and ameliorate the reduction in the initial strength caused by the use of fly ash in particular. In this study, a hydrate analysis was performed using XRD and SEM after substitution with fly ash (30%) and CSA (8%) with the goal of observing the effect of CSA on the initial strength of a cement mixture containing fly ash. The results of the analysis showed that an addition of CSA promoted the production of ettringite and improved the initial strength, resulting in the generation of hydrates, which can effectively enhance the long-term strength of these materials.

• 대한물리치료과학회지
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• 제11권2호
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• pp.46-56
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• 2004

The purpose of this study was to investigate the effect of watsu therapy on muscle tone in adult hemiparesis patient after stroke. The subject was a 66 year old patient with left hemiparesis whose self gait was independent with minimal assist. The subject was ambulatory with some degree of limitation and demonstrated a little tremor and asymmetry in the body. A multiple treatment design(A-B-C-B) for a single-subject research was used for this study. The watsu therapy consisted of basic moves, head cradle, underfar leg, near leg cradle in watsu I (transition flow), for 25 minutes, which lasted 12 sessions for a total 21 sessions. A baseline was conducted for a first time and a general ROM exercise was conducted after the first watsu therapy. Tone assessment scale was tested : 1. posturing at rest 2. response to passive movement 3. associated reaction Comparing to the baseline and general ROM exercise, The results showed that the watsu therapy had some positive effects on improvement of three tests and there was a more positive effects of both response to passive movement and associated reaction.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.642-648
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• 2012

We determined the nucleotide sequence of the URA3 gene encoding orotidine-5'-phosphate decarboxylase (OMPDCase) of the erythritol-producing osmotolerant yeast Candida magnoliae by degenerate polymerase chain reaction and genome walking. Sequence analysis revealed the presence of an uninterrupted open-reading frame of 795 bp, encoding a 264 amino acid residue protein with the highest identity to the OMPDCase of the yeast Kluyveromyces marxianus. Phylogenetic analysis of the deduced amino acid sequence revealed that it shared a high degree of identity with other yeast OMPDCase homologs. The cloned URA3 gene successfully complemented the ura3 null mutation in Saccharomyces cerevisiae, revealing that it encodes a functional OMPDCase in C. magnoliae. An enzyme activity assay and reverse transcription polymerase chain reaction indicated that the expression level of the C. magnoliae URA3 gene in S. cerevisiae was not as high as that of the S. cerevisiae URA3 gene. The GenBank accession number for C. magnoliae URA3 is JF521441.

• Bulletin of the Korean Chemical Society
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• 제23권12호
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• pp.1702-1708
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• 2002

The synthesis and catalytic application of a new class of a new class of planar chiral ferrocenes, 1,2-ferrocenediylazaphosphinines (1 and 2) are described. They are powerful ligands for the copper(I)-catalyzed asymmetric cyclopropanation of a range of alkenes with diazo esters to exhibit an exceptionally high degree of diastereoselectivity(~100% de) in favor of trans isomers, regardless the structure of the olefins and the diazo compounds. Comparative studies between 1 and 2 reveal that the former works better in terms of diastereocontrol. In contrast, however, enantioselectivity is low with both 1 and 2 as a whole although, in certain cases with a proper combination of the olefin and the diazo ester, high optical yields (up to 100% ee) can be achieved. Other reaction parameters such as the reaction temperature and the structure of the ligand do exhibit some influence, although infinitestimal, on both chemical and optical yields.