• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2769-2773
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• 2013

Red phosphors $Ca_{(1-1.5x)}Eu_xWO_4$ and $Ca_{(1-2x)}Eu^_xNa_xWO_4$ were synthesized with various concentrations x of $Eu^{3+}$ ions by using a solid-state reaction method. The crystal structure of the red phosphors were found to be a tetragonal scheelite structure with space group $I4_1/a$. X-ray diffraction (XRD) results show the (112) main diffraction peak centered at $2{\theta}=28.71^{\circ}$, and indicate that there is no basic structural deformation caused by the vacancies ${V_{Ca}}^{{\prime}{\prime}}$ or the $Eu^{3+}$ (and $Na^+$) ions in the host crystals. Densities of $Ca_{(1-1.5x)}Eu_xWO_4$ were measured on a (helium) gas pycnometer. Comparative results between the experimental and theoretical densities reveal that $Eu^{3+}$ (and $Na^+$) ions replace the $Ca^{2+}$ ions in the host $CaWO_4$. Also, the photoluminescence (PL) emission and photoluminescence excitation (PLE) spectra show the optical properties of trivalent $Eu^{3+}$ ions, not of divalent $Eu^{2+}$. Raman spectra exhibit that, without showing any difference before and after the doping of activators to the host material $CaWO_4$, all the gerade normal modes occur at the identical frequencies with the same shapes and weaker intensities after the substitution. However, the FT-IR spectra show that some of the ungerade normal modes have shifted positions and different shapes, caused by different masses of $Eu^{3+}$ ions (or $Na^+$ ions, or ${V_{Ca}}^{{\prime}{\prime}}$ vacancies) from $Ca^{2+}$.

• 한국미생물·생명공학회지
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• 제14권3호
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• pp.239-244
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• 1986

새로운 알카리내성 숙주균주를 개발하기 위하여 토양으로부터 알카리조건하에서 생육하는 미생물을 분리하고 이들 중에서 amylase활성과 Protease활성 및 항균력을 동시에 가지며 plasmid pUB 110이 형질전환 되어 이 plasmid가 안정하게 유지되는 균주를 선정하여 알카리내성 Bacillus sp. YA-14로 동정하였다. 분리균주의 amylase와 protease는 각각 pH 8.0과 pH 7.5에서 가장 활성이 높았으며 피검균으로 사용한 B. subtilis와 Sarcina lutea에 항균력을 나타내었다. 분리균주의 형질전환에는 0.4% MgSO$_4$ 가 함유된 modified SPI배지 (MSPI, pH8.0)를 사용하였으며 말기대수증식기의 균체가 적당하였다. Transformant는 20세대 계대배양 후에도 pUB,110plasmid가 안정하게 유지되어 형질발현되었다. 이 결과로부터 분리균주는 Bacillus속의 host-vector계에서 새로운 알카리내성 숙주균주로서 이용할 수 있는 가능성을 보여주었다.

• The Korean Journal of Physiology and Pharmacology
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• 제20권1호
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• pp.63-67
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• 2016

Severe graft-versus-host disease (GVHD) is an often lethal complication of allogeneic hematopoietic stem cell transplantation (HSCT). The safety of clinical-grade mesenchymal stem cells (MSCs) has been validated, but mixed results have been obtained due to heterogeneity of the MSCs. In this phase I study, the safety of bone marrow-derived homogeneous clonal MSCs (cMSCs) isolated by a new subfractionation culturing method was evaluated. cMSCs were produced in a GMP facility and intravenously administered to patients who had refractory GVHD to standard treatment resulting after allogeneic HSCT for hematologic malignancies. After administration of a single dose ($1{\times}10^6cells/kg$), 11 patients were evaluated for cMSC treatment safety and efficacy. During the trial, nine patients had 85 total adverse events and the rate of serious adverse events was 27.3% (3/11 patients). The only one adverse drug reaction related to cMSC administration was grade 2 myalgia in one patient. Treatment response was observed in four patients: one with acute GVHD (partial response) and three with chronic GVHD. The other chronic patients maintained stable disease during the observation period. This study demonstrates single cMSC infusion to have an acceptable safety profile and promising efficacy, suggesting that we can proceed with the next stage of the clinical trial.

• The Plant Pathology Journal
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• 제23권4호
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• pp.251-259
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• 2007

Two isolates of Cucumber mosaic virus (CMV) originated from lily plants, named Ly2-CMV and Ly8-CMV, were compared with their pathological features in several host plants. Ly2-CMV and Ly8-CMV could induce systemic mosaic symptom in Nicotiana benthamiana, but Ly2-CMV could not systemically infect tomato and cucumber plants that have been used for CMV-propagative hosts. While Fny-CMV used as a control infected systemically the same host plants, producing typical CMV symptoms. Ly8-CMV could infect systemically two species of tobacco (N. tabacum cv. Xanthi-nc and N. glutinosa) and zucchini squash (Curcubita pepo), but Ly2 failed systemic infection on these plants. As resulted from tissue-print immunoblot assay, different kinetics of systemic movement between Ly2-CMV and Ly8-CMV were crucial for systemic infection in tobacco (cv. Xanthi-nc). Sequence analysis of full-length genome of two lily isolates showed Ly2 and Ly8 belonged to subgroup IA of CMV. The lily isolates shared overall 98 % sequence identity in their genomes. Coat protein, 3a protein, and 2b protein involved in virus movement was highly conserved in genomes of the isolates Ly2 and Ly8. Although there is the low frequency of recombinants and reassortants in natural CMV population, phylogenetic analysis of each viral protein among a number of CMV isolates suggested that genetic variation in a defined population of CMV lily isolates was stochastically produced.

• 한국응용곤충학회지
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• 제35권3호
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• pp.209-215
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• 1996

복숭아혹진딧물(Myzus persicae Sulzer)은 두가지 서로 다른 기주선호성을 가지는데 이 기주선호성과 형태적 특징에 기초하여 담배진닷물(Myzus nicotinae Blackman)과 담배 이외의 다른 채소류에 서식하는 복숭아 혹진딧물(M. persicae)로 분류하였지만(Blachmean, 1987) 이 분류 방법에 동의하지 않는 학자들도 많다. 이런 이유로 RAPD-PCR 기법을 이용하여 한국에 서식하는 복숭아혹진딧물에 대하여 그들의 2차 숙주선호성에 따른 DNA의 변이 정도를 살펴보았다. 실험곤충으로는 담배와 배추에서 채집하여 사육한 진딧물 각 4 clones 씩을 사용하였다. 각 clone은 한 개체를 사육하여 얻은 자손들과 그들의 후손으로 이루어졌으며, 사육한 진딧물에서 핵 DNA를 추출하고, 10개 nucleotide 길이의 random primer 100가지를 사용하여 PCR한 후 1 % agarose gel 전기영동법으로 분석하였다. 사용한 100종류의 random primer 중 83가지에서 DNA 단편이 합성되었다. 증폭된 1개의 primer당 단편의 수는 1개에서 22개였고 평균 단편 수는 약 13개였으며, 각 각 단편의 길이는 500에서 20,000 base pair사이에 분포하였다. 82가지 primer의 경우에 일부 단편의 짙기에는 차이가 있었으나 단편종류의 분포는 동일하게 나타났다. 한가지 primer경우에만 담배섭식형 1개 c clone에서 다른 7가지 clones에 없는 band가 1개 나타났다. 이때 나머지 7 clones의 단편 분포 형태는 모두 동일하였다. 따라서 이 band는 숙주 선호성과는 무관한 것으로 보인다. 결국 이 실험에 사용한 100종류의 primer에 기초하여 RAPD-PCR기법으로 DNA를 증폭한 결과 복숭아혹진딧물의 숙주선호성이 개체군간의 유전적인 차이점에 기인한다는 가설을 뒷받침할 만한 증거를 찾지 못하였다.

• 한국재료학회지
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• 제26권2호
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• pp.73-78
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• 2016

$TiO_2$ nanoparticles were synthesized by a sol-gel process using titanium tetra isopropoxide as a precursor at room temperature. Ag-doped $TiO_2$ nanoparticles were prepared by photoreduction of $AgNO_3$ on $TiO_2$ under UV light irradiation and calcinated at $400^{\circ}C$. Ag-doped $TiO_2$ nanoparticles were characterized for their structural and morphological properties by X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The photocatalytic properties of the $TiO_2$ and Ag-doped $TiO_2$ nanoparticles were evaluated according to the degree of photocatalytic degradation of gaseous benzene under UV and visible light irradiation. To estimate the rate of photolysis under UV (${\lambda}=365nm$) and visible (${\lambda}{\geq}410nm$) light, the residual concentration of benzene was monitored by gas chromatography (GC). Both undoped/doped nanoparticles showed about 80 % of photolysis of benzene under UV light. However, under visible light irradiation Ag-doped $TiO_2$ nanoparticles exhibited a photocatalytic reaction toward the photodegradation of benzene more efficient than that of bare $TiO_2$. The enhanced photocatalytic reaction of Ag-doped $TiO_2$ nanoparticles is attributed to the decrease in the activation energy and to the existence of Ag in the $TiO_2$ host lattice, which increases the absorption capacity in the visible region by acting as an electron trapper and promotes charge separation of the photoinduced electrons ($e^-$) and holes ($h^+$). The use of Ag-doped $TiO_2$ nanoparticles preserved the option of an environmentally benign photocatalytic reaction using visible light; These particles can be applicable to environmental cleaning applications.

• 한국가축번식학회지
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• 제26권3호
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• pp.275-289
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• 2002

본 연구는 종모우의 정자수정능력 평가방법의 개발과 정자 기능 및 성상 변화에 영향을 미치는 요인을 알아보기 위하여 시행하였다. 동결-융해된 종모우 정액을 대상으로 정자의 운동성과 정자의 형태를 분석하였고, 정자의 기능 검 사 항목으로서 체외수정(IVF), HOST, Ca-ionophore에 의한 첨체반응율, 정자의 ROS 측정을 위한 luminol, lucigenin-dependent chemiluminescence, LPO 분석을 위한 malondialdehyde의 측정 및 TUNEL (terminal deoxynucleotidyl transferase(TdT) dUTP nick end labelling) 기법을 이용한 정자의 DNA fragmentation를 측정하였으며 이들 각각의 조사 항목들의 분석치들과 체외수정율 및 배발생율과의 상관관계를 조사하여 다음과 같은 결과를 얻었다. 1. 고수정군과 저수정군의 체외수정율과 배반포 발생율의 평균은 각각 64.4%와 34.3%, 18.50%와 6.2%였으며 두 군간에 통계학적으로 유의한 차이를 보였다(P<0.05). 고수정군과 저수정군의 정자운동성과 첨체반응률은 각각 평균79.0 %와 66.2%, 40.7%와 22.9%로 두 군간에 통계학적으로 유의한 차이를 보였으나(P<0.05), 정상형태 정자의 비율과 HOST는 각각 평균 94.6%와 92.7%, 69.4%와 59.8%로 두 군간 유의한 차이를 보이지 않았다. 2. Luminol dependent chemiluminescence, LPO 및 DNA fragmentation의 평균은 고수정군과 저수정군에 있어서 각각 6.4와 6.5, 2.Onmol와 3.Inmol 및 2.6%와 7.4%로 두 군간 통계학적으로 유의한 차이를 보였으나(P<0.05), lucigenin dependent chemiluminescence는 4.7와 4.6로 두 군간 유의한 차이를 보이지 않았다. 3. 체외 수정율은 정자의 운동성 및 첨체반응율과 통계학적으로 유의한 정(positive)의 상관관계(r=0.87, p<0.01; r=0.81, p<0.05)를 나타내었으며, luminol dependent chemiluminescence, lipid peroxldation 및 DNA fragmentation과는 통계학적으로 유의한 부(negative)의 상관관계 (r= -0.81, p<0.05; r: -0.74, p<0.05; r : 0.81, p<0.05)를 나타내었다. 그러나 체외수정율은 정상형태 정자의 비율, HOST 및 lucigenin dependent chemiluminescence와는 유의한 상관 관계를 나타내지 않았다. 4. 배반포 발생율은 첨체반응율과 통계학적으로 유의한 정의 상관관계(r=0.71, p<0.05)를 나타내었으며, luminol dependent chemiluminescence, lipid peroxidation 및 DNA fragmentation과는 통계학적으로 유의한 부의 상관관계(r= -0.71, p<0.05; r= -0.89, p<0.01; r= -0.71, P<0.05)를 나타내었다. 배반포 발생율은 정자의 운동성, 정상형태 정자의 비율 및 HOST, lucigenin dependent chemilumihescence와는 유의한 상관관계를 나타내지 않았다. 이상의 결과를 종합해 보면 정액질의 저하에 ROS의 영향이 밀접히 연관되어 있음을 알 수 있으며, 또한 본 연구에서 적용된 기법들은 정액질의 평가 및 정자 수정능력 향상을 위한 기술개발에 있어서 유용한 평가 방법으로 이용될 수 있을 것으로 사료된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권1호
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• pp.15-24
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• 2001

The purpose of this study is to evaluate the tissue response in applying of various bone substitutes included toothash-plaster mixture, resorbable hydroxylapatite (HA) and demineralized freeze-dried bone and to show the clinical usefulness of toothash-plaster mixture for the repair of craniomaxillofacial bone defect. For this experiment, 100 Sprague-Dawley rats weighing 200gm or more were used. There were four experimental groups: group I, toothash-plaster mixture; group II, demineralized freeze-dried bone; group III, resorbable HA; and group IV, control group. A full thickness, round bone defect measuring 10mm in diameter was created in the midcranium, and the substitutes cited above were embedded in the experimental rats based on their group assignment. Blood clot was filled in the rats assigned to the control group. Experimental rats were sacrificed on the 1st, 3rd, 5th, 8th, 12th and 24th week after implantation and stained with the hematoxylineosin, Masson's Trichrome, using Van Gieson's stain method, and were examined under light microscope. The results were as follows: 1. In all the groups, prominent inflammatory reaction and the infiltration of multinucleated giant cells were noted during the early stage. Gradual healing decreased this reaction. 2. Among the rats in the experimental group II, which were given demineralized freeze-dried bone implants, active formation of new bone traveculae manifested. Chondroid tissues appeared, and it was suggested that the defect was filled with newly formed bone by virtue of osteoinductive activity. On the 12th week after the experiments, most of the defect was filled with newly formed bone trabeculae. 3. In experimental groups I and III, it was noted that HA manifested a healing process similar to that characterized by the toothash-plaster mixture, but inflammatory reaction was more prominent in experimental group I. Active osteoblasts were observed along the periphery of osteoid tissues, while newly formed bone trabeculae appeared adjacent to the implanted materials three weeks later. Formation increased to the extent that newly formed bone trabeculae fused directly with the host bone. Increase in new bone ingrowth into the filling materials was revealed by both experimental groups. 4. In the control group, new bone formation adjacent to the host bone was observed, but most of the defect was filled with mature connective tissue 24 weeks after the experiments.

• 대한수의학회지
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• 제13권2호
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• pp.119-129
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• 1973

A hypothesis that is a stress condition in animal may cause either enhancement or reduction of the host resistance against microbial infection was experimentally studied. Among of many processes for stress formation an experimental electrization in mice was devised, on the bases of blood picture analysis, and studied the effect of experimental electrization of mice on E. coll infection. The results obtained were as follows. 1. Electrization with ordinary current, A. C. 60 cps., on the path of symmetrical line of both posterior limbs at 20 to 100 volts (less than 10 mA) for 15 to 30 seconds was able to induce a stress reaction in blood pattern without showing any dangers of electrocution, electric burns and other residual signs, and no correlation between blood pattern of the reaction and an amount of current between 20 to 100 volts was observed. As the electrodes, two of 21 gauge hypodermic needles were used, when the electrization each of them were inserted into the center of toe tissue of the both legs. 2. Serum protein fractions following the experimental electrization showed a tendency of a low A/G ratio and a high value of ${\alpha}$-globulin. 3. In the studies on the effect of electrical stress on the pathogenesis of E. coli in mice, a group in which a simultaneous electrization and infection, and a group infected two hours after electrization showed 80 per cent mortality. On the other hand, infection after 20 hours electrization and control groups showed their mortality of 40 and 60 per cent respectively.

• 한국재료학회지
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• 제14권9호
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• pp.627-633
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• 2004

Lithium titanate whiske($Li_{x}Ti_{4}O_9$) was prepared by an ion-exchange reaction. To this end, the initial material, potassium tetratitanate ($K_{2}Ti_{4}O_9{\cdot}nH_{2}O$) was prepared by calcination of a mixture of $K_{2}CO_3\;and\;TiO_2$ with a molar ratio of 2.8 at $1050^{\circ}C$ for 3 h, followed by boiling water treatment of the calcined products for 10 h. Fibrous potassium tetratitanate could be transformed into layered hydrous titanium dioxide ($H_{2}Ti_{4}O_9{\cdot}nH_{2}O$) through an exchange of $K^{+}\;with\;H^{+}$ using 0.075 M HCl. Also, lithium titanate whisker was finally prepared as $Li^{+}\;and\;H^{+}$ ions were exchanged by adding 20 mL of a mixture solution of LiOH and $LiNO_3$ to 1g whisker and stirring for $5\~15$ days. The average length and diameter of the $Li_{x}Ti_{4}O_9$ whiskers were $10\~20{\mu}m\;and\;1\~3{\mu}m$, respectively.