• 자원환경지질
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• 제43권2호
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• pp.177-184
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• 2010

시멘트 그라우트가 지반의 차수목적으로 사용될 경우 유동성, 입경 및 블리딩이 중요한 역할을 한다. 이들의 성질을 결정하는 가장 중요한 요소 중의 하나는 그라우트의 물시멘트비이며, 지반침투성능을 개선하기 위해서 보통포틀랜드 시멘트 외에 평균입경이 작은 마이크로 시멘트를 사용하고 있다. 또한, 주입효과는 지반조건뿐만 아니라 배합비 및 시멘트의 입경에 따라 좌우된다. 주입에 의한 침투효과를 평가하는 방법으로서는 실제 지반에서 시험 주입하는 것이 가장 확실한 방법이지만 이와 같은 시험주입은 많은 경비와 시간을 필요로 한다. 때문에 주입의 적합여부나 침투효과를 대략적으로 파악하기 위한 간단하고 실용적인 시험방법이 필요하게 된다. 우리나라의 경우 아직 실내에서 그라우트 주입을 재현할 수 있는 기준 및 장비가 전혀 없는 실정이다. 본 연구에서는 실내에서 여러 가지 그라우트의 주입을 일정하게 재현할 수 있는 가압침투주입장치를 개발하였으며 공시체 제작의 표준을 마련하였다. 가압침투주입시힘을 실시하여 자료를 분석한 결과 침투성능은 물시멘트비가 증가할수록 선형적으로 증가하였으며 재료의 평균입경이 작을수록 침투성능이 개선되었다. 또한 마이크로 시멘트인 마이셈 8000과 초미분말 시멘트인 콜로이드 슈퍼 시멘트의 침투성능을 비교한 결과 평균입경이 상대적으로 작은 콜로이드 슈퍼 시멘트가 침투성능이 좋은 것으로 나타났다.

• Journal of Astronomy and Space Sciences
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• 제33권3호
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• pp.185-196
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• 2016

New multiband BVRI light curves of NSVS 1461538 were obtained as a byproduct during the photometric observations of our program star PV Cas for three years from 2011 to 2013. The light curves indicate characteristics of a typical W-subtype W UMa eclipsing system, displaying a flat bottom at primary eclipse and the O'Connell effect, rather than those of an Algol/b Lyrae eclipsing variable classified by the northern sky variability survey (NSVS). A total of 35 times of minimum lights were determined from our observations (20 timings) and the SuperWASP measurements (15 ones). A period study with all the timings shows that the orbital period may vary in a sinusoidal manner with a period of about 5.6 yr and a small semi-amplitude of about 0.008 day. The cyclical period variation can be interpreted as a light-time effect due to a tertiary body with a minimum mass of 0.71 M_⊙. Simultaneous analysis of the multiband light curves using the 2003 version of the Wilson-Devinney binary model shows that NSVS 1461538 is a genuine W-subtype W UMa contact binary with the hotter primary component being less massive and the system shows a low mass ratio of q(m_c/m_h)=3.51, a high orbital inclination of 88.7°, a moderate fill-out factor of 30 %, and a temperature difference of ΔT=412 K. The O'Connell effect can be similarly explained by cool spots on either the hotter primary star or the cool secondary star. A small third-light corresponding to about 5 % and 2 % of the total systemic light in the B and V bandpasses, respectively, supports the third-body hypothesis proposed by the period study. Preliminary absolute dimensions of the system were derived and used to look into its evolutionary status with other W UMa binaries in the mass-radius and mass-luminosity diagrams. A possible evolution scenario of the system was also discussed in the context of the mass vs mass ratio diagram.

• Toxicological Research
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• 제34권3호
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• pp.221-229
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• 2018

Tenofovir nanoparticles are novel therapeutic intervention in human immunodeficiency virus (HIV) infection reaching the virus in their sanctuary sites. However, there has been no systemic toxicity testing of this formulation despite global concerns on the safety of nano drugs. Therefore, this study was designed to investigate the toxicity of Tenofovir nanoparticle (NTDF) on the liver and kidney using an animal model. Fifteen adult male Sprague-Dawley (SD) rats maintained at the animal house of the biomedical resources unit of the University of KwaZulu-Natal were weighed and divided into three groups. Control animals (A) were administered with normal saline (NS). The therapeutic doses of Tenofovir (TDF) and nanoparticles of Tenofovir (NTDF) were administered to group B and C and observed for signs of stress for four weeks after which animals were weighed and sacrificed. Liver and kidney were removed and fixed in formal saline, processed and stained using H/E, PAS and MT stains for light microscopy. Serum was obtained for renal function test (RFT) and liver function test (LFT). Cellular measurements and capturing were done using ImageJ and Leica software 2.0. Data were analysed using graph pad 6, p values < 0.05 were significant. We observed no signs of behavioural toxicity and no mortality during this study, however, in the kidneys, we reported mild morphological perturbations widening of Bowman's space, and vacuolations in glomerulus and tubules of TDF and NTDF animals. Also, there was a significant elevation of glycogen deposition in NTDF and TDF animals when compared with control. In the liver, there were mild histological changes with widening of sinusoidal spaces, vacuolations in hepatocytes and elevation of glycogen deposition in TDF and NTDF administered animals. In addition to this, there were no significant differences in stereological measurements and cell count, LFT, RFT, weight changes and organo-somatic index between treatment groups and control. In conclusion, NTDF and TDF in therapeutic doses can lead to mild hepatic and renal histological damage. Further studies are needed to understand the precise genetic mechanism.

• Journal of Animal Science and Technology
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• 제46권4호
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• pp.503-508
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• 2004

본 연구는 돼지의 일령별 체중자료를 이용한 개체별 체중 성장곡선 추정을 통해 성장 특성을 조사하고 육질 형질과의 상관 관계를 규명하고자 실시하였다. 축산연구소의 재래돼지와 랜드레이스를 기초축으로 조성한 F2집단 253두를 대상으로 일령별 체중기록과 육질 형질을 측정하여 개체별 성장곡선 모수와 성장 특성치를 추정하고 등지방 두께, 조지방 함량, 지방율 및 전단력과 성장곡선 모수간의 표현형 상관관계를 추정하였다. 대부분의 성장 특성치들은 기존 연구에서 제시된 재래돼지와 랜드레이스순종의 중간정도 능력을 나타내었으며, 상관관계의 추정 결과 조숙성의 개체일수록 성숙체중이 작았으며 만숙성인 개체일수록 지속적인 성장률의 증가로 인해 변곡점이 나타나는 월령이 늦어지며 최대 증체율이 커지는 것으로 나타났다. 성장곡선 모수와 육질형질 측정치들간의 상관 관계는 암수간에 일부에서 다소 상반되는 방향으로 추정되었으며 특히 전단력의 경우 모든 성장 특정치들과의 관계가 반대로 추정되었다. 최대 증체율과 등지방 두께 및 조지방 함량과의 상관은 비교적 높은 정의 상관정도를 보여 최대 증체율이 클수록 등지방 두께와 조지방 함량이 높아지는 것으로 나타났다.

• 정보관리연구
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• 제40권4호
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• pp.109-133
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• 2009

생명정보 중에서 미국의 국립생명공학정보센터(NCBI)에서 제공하는 GenBank는 전 세계적으로 연구자들이 가장 많이 사용하는 대표적인 유전자정보 데이터베이스이다. 한국과학기술정보연구원(KISTI)은 GenBank의 최신 버전을 데이터베이스로 재구축하여 Bio-KRISTAL 검색엔진을 이용하여 국내 생명과학 연구자들에게 제공하고 있다. 본 논문에서는 GenBank 데이터베이스를 활용하여 과학기술정보 통합서비스인 NDSL의 논문정보, 특허정보, 생물다양성정보 등의 콘텐트와 GenBank reference 필드와 organism 필드를 상호 연계하는 서비스 모델을 설계하고 프로토타입 시스템을 개발하였다. 이를 위하여 1) NCBI FTP 사이트에서 GenBank 데이터를 수집하여, 2) GenBank 텍스트 파일을 유전자 기본정보와 참고정보로 나누어 데이터베이스로 재구축하여, 3) GenBank reference 필드에서 논문 및 특허 정보 추출을 통한 새로운 테이블을 생성하여, 4) 데이터 맵핑 기술을 이용하여 GenBank 데이터와 NDSL 데이터가 상호 연계되어 서비스되는 프로토타입 시스템을 구현하여 이종의 콘텐트간 연계 및 융합 서비스의 가능성을 확인하였다.

• 한국식물학회:학술대회논문집
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• 한국식물학회 2002년도 춘계학술발표대회:발표눈문요지록
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• pp.62-72
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• 2002

This study has investigated the biosynthesis and function of the heavy metal binding peptides, the phytochelatins, in plants. PCs are synthesised enzymatically from glutathione by the enzyme PC synthase in the presence of heavy metal ions. Using Arabidopsis thaliana as a model organism cadmium-sensitive, phytochelatin-deficient mutants have been isolated and characterised in previous studies. The cadl mutants have wildtype levels of glutathione, are PC deficient and lack PC synthase activity. Thus, the CADl gene has been proposed to encode PC synthase. The CADl gene was isolated by a positional cloning strategy The gene was mapped and a candidate identified. Each of four cadl mutants had a single base pair change in the candidate gene and the cadmium-sensitive, cadl phenotype was complemented by the candidate gene. This demonstrated the CADl gene had been cloned. A homologous gene in the fission yeast, Schizosaccharomyces pombe was identified through database searches. A targeted-deletion mutation of this gene was constructed and the mutant, like cadl mutants of Arabidopsis, was cadmium-sensitive and PC-deficient. A comparison of the redicted amino acid sequences reveals a highly conserved N-terminal region Presumed to be the catalytic domain and a variable C-terminal region containing multiple Cys residues proposed to be involved in activation of the enzyme by metal ions. Similar genes were also identified in animal species. The Arabidopsis CADl/AtPCSl and S. pombe SpbPCS genes were expressed in E. coli and were shown to be sufficient for glutathione-dependent, heavy metal activate PC synthesis in vitro, thus demonstrating these genes encode PC synthase enzymes. Using RT-PCR, AtPCSl expression appeared to be independent of Cd exposure. However, at higher levels of Cd exposure a AtPCSl-CUS reporter gene construct appeared to be more highly expressed. Using the reporter gene construct, AtPCSl was expressed most tissues. Expression appeared to be greater in younger tissues and same higher levels of expression was observed in some regions, including carpels and the base of siliques. AtPCS2 was a functional gene encoding an active PC synthase. However, its Pattern of expression and the phenotype of a mutant (or antisense line) have not been determined. Assuming the gene is functional then it has clearly been maintained through evolution and must provide some selective advantage. This implies that, at least in some cells or tissue, it is likely to be the dominant PC synthase expressed. This remains to be determined

• Korean Journal of Acupuncture
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• 제22권3호
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• pp.119-135
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• 2005

Objectives : The aim of this study was to investigate the Asthma-suppressive and Immune-regulatory effect of AF-HA(Aristolochiae Fructus Herbal-acupuncture) at Joksamni(St36) in OVA(ovalbumin) induced asthma mouse model. Methods : C57BL/6 mice were sensitized and challenged with OVA(ovalbumin) for 12 weeks(once a week). The mice in the OVA-AF-HA group were treated with AF-HA at St36 for the later 8weeks(3times/week). The mice in the OVA-Needle-prick group were treated with single prick with an injection needle at St36 for the later 8 weeks(3times/week). Results : 1. The lung weight and the total cells in lung of the mice treated with AF-HA at St36 decreased significantly compared with those of the OVA-control group. 2. Total leukocytes and eosinophils in BALF of the mice group treated with AF-HA at St36 decreased remarkably compared with those of the OVA-control group. 3. The collagen accumulation in lung of OVA-AF-HA group decreased significantly compared with that of the OVA-control group, 4. The concentrations of IL-4, IL-5, IgE in BALF, and IL-4, IL-5, IL-13 in serum of the mice group treated with AF-HA at St36 decreased significantly compared with those of the OVA-control group. 5. The numbers of $Gr-1^+/CD11b^+\;and\;CD11b^+$ cells in lung of the mice group treated with AF-HA at St36 decreased significantly compared with those of the OVA-control group. 6. The numbers of $CCR3^+,\;CD4^+,\;CD8^+\;and \;CD3e^+/CD69^+$ cells in lung of the mice group treated with AF-HA at 5136 decreased significantly compared with those of the OVA-control group. 7. The mRNA expressions of $TNF-{\alpha}$, IL-4, IL-5, IL13 in lung of the mice group treated with AF-HA at St36 decreased significantly compared with those of the OVA-control group. Conclusion : These results suggest that Aristolochiae Fructus Herbal-acupuncture at Joksamni(St36) may be an effictive therapeutic method to treat asthma.

• 혜화의학회지
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• 제4권2호
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• pp.335-336
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• 1996

Artemisinin, a new antimalarial to treat patients infected with strains of Plasmodium jalciparum, derived from the plant Artemisia annua Linn, has immunopharmacologic actions such as enhence the PHA -induced lymphocyte transformation rate, increased the weight of spleen but reduced the weight of thymus, reduced phagocytic function of peritoneal macrophage, remarkably reduced the level of serum IgG and hemolysin fonning capacity (sentitized with SRBC), inhibited the activity of Ts cells of donor mice by supraoptimal immunuization(SOI), but enhenced activity of Ts cells of recipient mice by SOI. These results suggested that Ts cells may be the target cells of artemisinin. To the serum complement C3 level of plasmodium berghei-infeted mice, artemisinin (i. m,) could remarkly increase it. The artemisinin also obviously reduced the prostaglandin E(PGE) in the mouse hind paw swelling induced by carrageenin. Numerous studies have demonstrated that pharmacologic doses of PGE attenuate the development of immunocomplex nephritis. Some autologous immune mechanisms may be invoolved In the pathogensis of some types of glomurulonephritis. Glomerular abnormalities can be induced in animals by variety of immunological manipulations. The resulting disorder has many clinical and pathogical similarities to the disease in human. Our purpose was therefore to test the ability of the artemisinin to lessen the severity of rabbit IgG accelerated nephrotoxic serum glomerulonephritis in mice model. Mice which had treated with rabbit IgG and NTS, administrated with saline, showed Significant inceases of urinary protein, cholesterol level, and decrease of serum albumin in NS group. On the contrary, By i.g. adminstration of artemisinin at dose of 12.5, 25 and 50 mg/kg for 14 days after NTS injection, shown that artemisinin inhibited the nephritic changes in some parameters by means of urinary protein(p<0.05, p<0.01) and serum choleterol(p<0.05, p<0.01) and albumin (p<0.05, p<0.01), blood urea nitrogen (p<0.05, p<0.01), serum albumin(p<0.05, p<0.01); Cyclophosphamide(i.p. 10mg/kg for 14d) had almost same effect as the artemisinin had. Morphological studies shown that The picture of kidney from the mouse with NTS-nephritis accerated with rabbit IgG, treated with i.g. saline as the control, the mesangiocapillary were enlarged and proliferated; There were inflammatory cells infiltrating around the glomeruli; The ethelial cell were proliferated in the wall of Bowman's capsule. Histopatholological picture of kidney from the NTS-nephritis accerated with rabbit IgG mouse treated with i.p. 10mg/kg cyclophosphamide as the positive control. No siginicant histopathological evidence were found. Treaded with i.p. 12.5mg/kg artemisinine, the picture shown that mesangiocapillary were lightly proliferated; There were inflammatory cells infiltrating around the glomeruli; Treaded with i.p. 25mg/kg artemisinine, The picture shown that the mesangiocapillary were lightly proliferated; Treaded with i.p. 50mg/kg artemisinine, The picture shown that both the mesangiocapillary proliferated and the inflammatory cells infiltrating around the glomeruli are less than treated with saline, 12.5 and 25 mg/kg artemisinine. On the basis of these studies we conclude that the artemisinin can relieve pathological change caused by NTS-nephritis aacerated with rabbit IgG.

• 대한조선학회지
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• 제27권4호
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• pp.58-66
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• 1990

기계적 체결방법은 분해 및 조립이 용이하고 본드접착에 의한 결합보다 신뢰도가 높은 장점이 있으나 원공으로 인한 높은 응력집중을 초래하고 국부적으로 집중된 응력 재분포의 메카니즘이 등방성 재료와는 달리 매우 복잡하고 실적 데이타 및 실험자료가 거의 없어, 복합재료구조물의 결합방법으로 많은 연구 검토를 필요로 하고 있다. 본 연구에서 사용한 시편은 $[0^{\circ}/45^{\circ}90^{\circ}/-45^{\circ}]_s$ 적층판으로 W(시편의 폭)/d(핀의 직경) 및 L(edge의 거리)/d를 변화시키면서 실험을 수행하여 기하학적 형상 및 적층강도 변화에 따른 파손강도 및 파손양상을 측정하여 그 결과를 이론해석 값과 비교하였다. 실험결과에 따라 최적기법으로 만든 새로운 변수 $\alpha,\;\beta,\;\gamma$를 재료상수로 취급하여 W/d및 L/d와 체결강도와의 관계식을 이용하면, 동일한 재료로 제작한 적층판의 체결강도를 8%이내의 오차로 예측 가능하다. 초음파 탐상법(Ultrasonic C-scanning)으로는 손상영역 탐색 및 손상영역 확대과정을 파악하고, X-ray로는 몇 단계 하중상태에서 손상부를 촬영하였고, SEM(Scanning electron microscopes)을 이용 원공주위 파손부의 균열의 진전상태를 미시적으로 관찰하였다. 파손강도 및 파손양상에 대한 실험결과와 FEM이론해석 모델에 예측한 값과의 차이는 $L/D=2{\sim}3$인 경우를 제외하고는 대부분 일치하였다.

• Restorative Dentistry and Endodontics
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• 제18권1호
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• pp.1-26
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• 1993

The purpose of this study was to investigate the effect of acid etching on the surface appearance and fracture toughness of five glass ionomer cements. Five kinds of commercially available glass ionomer cements including chemical curing filling type, chemical curing lining type, chemical curing metal reinforced type, light curing tilling type and light curing lining type were used for this study. The specimens for SEM study were fabricated by treating each glass ionomer cement with either visible light curing or self curing after being inserted into a rubber mold (diameter 4mm, depth 1mm). Some of the specimens were etched with 37% phosphoric acid for 0, 15, 30, 60, go seconds, at 5 minutes, 1 hour and 1 day after mixing of powder and liquid. Unetched ones comprised the control group and the others were the experimental groups. The surface texture was examined by using scanning electron microscope at 20 kV. (S-2300, Hitachi Co., Japan). The specimens for fracture toughness were fabricated by curing of each glass ionomer cement previously inserted into a metal mold for the single edge notch specimen according to the ASTME399. They were subjected to a three-point bend test after etching for 0, 30, 60, and 90 seconds at 5 minutes-, 1 hour-and 1 day-lapse after the fabrication of the specimens. The plane strain fracture toughness ($K_{IC}$) was determined by three-point bend test which was conducted with cross-head speed of 0.5 mm/min using Instron universal testing machine (Model No. 1122) following seven days storage of the etched specimens under $37^{\circ}C$, 100% humidity condition. Following conclusions were drawn. 1. In unetched control group, crack was present, but the surface was generally smooth. 2. Deterioration of the surface appearance such as serious dissolving of gel matrix and loss of glass particles occured as the etching time was increased beyond 15 s following Immediate etching of chemical curing type of glass ionomer cements. 3. Etching after 1 h, and 1 d reduced surface damage, 15 s, and 30s etch gave rough surface appearance without loss of glass particle of chemical curing type of glass ionomer cements. 4. Light curing type glass ionomer cement was etched by acid, but there was no difference in surface appearances according to various waiting periods. 5. It was found that the value of plane stram fracture toughness of glass ionomer cements was highest in the light curing filling type as $1.79\;MNm^{-1.5}$ followed by the light curing lining type, chemical curing metal reinforced type, chemical curing filling type and chemical curing lining type. 6. The value of plane stram fracture toughness of the chemical curing lining type glass ionomer cement etched after 5 minutes was lower than those of the cement etched after 1 hour or day or unetched (P < 0.05). 7. Light curing glass ionomer cement showed Irregular fractured surface and chemical curing cement showed smooth fractured surface.