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        검색결과 283

        161.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to research how UCD(Ultra Constant Discharge) lamp lighting affects plant cultivation. To get the results within a short time, lettuce seedling was selected as a plant and nutrient hydroponic beds were used in a dark room for 100% artificial lighting. Two beds were installed for same distance lighting condition with UCD lamp and Hi-pressure Sodium lamp each and another two beds were installed for same light intensity condition with each type of lamp. After 15 days of cultivation, for both conditions, the yields under UCD lamp were weighed more than that under Hi-pressure Sodium lamp. The result can be analyzed that the spectrum of UCD lamp having near sunlight characteristic is much superior to that of Hi-pressure Sodium lamp having a line spectrum characteristic on yellow and red wavelengths for plant cultivation.
        4,000원
        162.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hydrophobically monoendcapped poly(sodium acrylate)s formed hydrophobic microdomains in water. This was concluded on poly(sodium acrylate)s with a linear C12-alkyl chain attached specifically at the end of the polymer. There was no well defined CMC (critical micelle concentration), but rather a gradual transition from a micelle free solution to a micelle solution. Steady state fluorescence spectroscopy indicates that the micro domains are rather hydrophobic. At pH 5 in the abscence of salt and at pH 9 in the prescence of 1 M sodium citrate the CAC (critical aggregation concentration) was in the range of 0.1 to 2.4 mM. However at pH 5 there was a linear increase in the transition concentration with a head-group size due to an increase in steric and electrostatic repulsions between polymer main chains. At pH 9 in the abscence of salt the transition concentration was in the range of 1 to 80 mM. For the larger polymers there was a effect which consisted of a concentration gradient of sodium counterion toward the hydrophobic domain. The effect was larger for the larger polymers because of the higher total sodium concentration and the less steep counterion concentration gradient.
        4,000원
        163.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to evaluate the anti-inlfammatory effects of glycyrrhiza glabra Linne extract on ulcerative colitis induced by 3% dextran sulfate sodium in mice. The experimental animals were divided into six groups: control(normal), DSS-induced colitis(control), 1㎎/㎏, 10㎎/㎏, and 100㎎/㎏ of glycyrrhiza glabra Linne extract, and 150㎎/㎏5-aminosalicylic acid(5-ASA)(positive control). We evaluated the pathological disease activity index(DAI), change in weight, colon mucosa damage and myeloperoxidase(MPO) in colon mucosa. Treatment with 10㎎/㎏ and 100㎎/㎏ of glycyrrhiza glabra Linne extract led to significant loss of body weight, the decrease of MPO activity and clinical symptoms such as DAI and histological change. In particular, 100㎎/㎏ Glycyrrhiza glabra Linne extract led to markedlygreater improvement than 150㎎/㎏ 5-ASA treatment. These results suggest that glycyrrhiza glabra mediated anti-inflammatory action on colorectal sites may be a useful therapeutic approach to ulcerative colitis.
        4,000원
        164.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Core-Shell polymers of silicone dioxide-styrene system were prepared by sequential emulsion polymerization. In inorganic/organic Core-Shell composite particle polymerization, silicone dioxide adsorbed by surfactant sodium dioctyl sulfosuccinate (EU-DO133L) was prepared initially and then core silicone dioxide was encapsulated emulsion by sequential emulsion polymerization using styrene at the addition of potassium persulfate (KPS) as an initiator. We found that SiO2 core shell of SiO2/styrene structure was formed when polymerization of styrene was conducted on the surface of SiO2 particles, and the concentration sodium dioctyl sulfosuccinate (EU-DO133L) was 0.5~2.0g. The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer and morphology of latex by scanning electron microscope(SEM).
        4,000원
        165.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The influence of sodium hypochlorite and ethephon on the germination of narrow-leaved purple coneflower (Echinacea angustifolia) was investigated. Treatment of seeds with ethephon (1 mM) for 2 h followed by soaking in 0.525% sodium hypochlorite greatly increased germination (>90%). The treatment of seed with a combination of sodium hypochlorite and ethephon shortened number of days required to reach 50% of the final germination (T₅₀) from 4.2 days in control to 1.1 days. Seedlings grown from ethephon-treated seeds had shorter and thicker hypocotyls and roots with higher dry weights compared to the control. The same trend was observed during seedling emergence from soil. Ethephon treatment longer than 2 h resulted in weaker seedlings, probably due to leaf senescence. Anthocyanin content in seedling leaves increased linearly from 0.04 mg/g fresh weight in control to 3.72 mg/g fresh weight in 24 h treatment as the time of seed exposure to ethephon increased. Seed treatment with bleach and ethephon may well be practiced to facilitate the establishment of E. angustifolia in the field.
        4,000원
        166.
        2010.05 구독 인증기관·개인회원 무료
        Sodium-potassium-chloride co-transporter (NKCC) is a membrane bound channel protein that plays a prominent role in a variety of epithelial absorptive, secretory processes and a direct role in cell volume regulation, in which NKCC transports sodium, potassium, and chloride ions across the cell membrane. It has been known that prostaglandin E2 (PGE2) induces an acute cell lysis of specific hemocyte type, oenocytoid, to release prophenoloxidase into the plasma and ouabain (a specific sodium pump inhibitor) inhibits the oenocytoid cell lysis resulting in preventing phenoloxidase activation. However, it is not clear how the intracellular signaling pathway leads to oenocytoid cell lysis in response to PGE2. This study was designed to analyze functional role of NKCC in the cell lysis to release prophenoloxidase. A gene structure of NKCC was derived from cDNA library of Spodoptera exigua hemocyte, NKCC was expressed in all developmental stages and tissues. A real time quantitative RT-PCR showed that bacterial challenge significantly induced its expression. Specific inhibitors of NKCC, bumetanide and chlorothiazide, clearly prevented the cell lysis in a dose dependent manner. When RNA interference using double stranded RNA (dsRNA) specific to NKCC suppressed its expression, the oenocytoid lysis and PO activation was significantly inhibited in response to PGE2. It also reduced nodule formation to bacterial challenge. These results indicate that NKCC is associated with oenocytoid cell lysis probably by increasing cell volume through inward transport of ions in response to PGE2.
        168.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This survey was conducted to monitor the total sugar, sodium, and artificial sweetener contents of light meals from the school zone in Gwangju, from November, 2008 to April, 2009. A total of 100 samples were tested. HPLC/ELSD was used for the determination of total sugar contents and AAS for sodium contents. Total sugar amounts were the sum of both mono-and disaccharide according to nutritional information standard defined by the Korea Food and Drug Administration. The results were as follows by the form of total sugar content(sodium content): 5.7 ± 1.9%(4.6 ± 1.6 mg/g) for Tteokbokki, 7.6 ± 5.1%(5.4 ± 2.7 mg/g) for Chicken(skewed), 15.4 ± 3.2%(3.0 ± 0.9 mg/g) for Bun(fish-shaped), 0.6 ± 0.3%(3.7 ± 1.0 mg/g) for Sundae, 0.9 ± 0.3%(7.4 ± 1.4 mg/g) for Oden(with broth), 20.5 ± 6.2%(2.9 ± 0.6 mg/g) for Waffle, 6.8 ± 2.2%(4.7 ± 1.0 mg/g) for Hotdog, 14.2 ± 2.8%(3.1 ± 1.6 mg/g) for Hotteok, 6.6 ± 2.1%(3.9 ± 0.6 mg/g) for Toast, 10.1 ± 3.7%(2.3 ± 0.7 mg/g) for Fry(sweet potato), 1.6 ± 0.7% (4.0 ± 0.7 mg/g) for Fry(etc), and 9.3 ± 2.4%(4.0 ± 0.6 mg/g) for Doughnut. In addition, sodium saccharin, one of the artificial sweeteners, was tested. Among 60 samples from February to April, 2009, 11 samples had sodium saccharin(6.7~101.0 mg/kg).
        4,000원
        171.
        2008.12 구독 인증기관 무료, 개인회원 유료
        The sodium bicarbonate cotransporter (NBC) protein is functionally expressed in salivary glands. In this experiment, we examined the role of NBC in HCO₃-formation in human parotid gland acinar cells. Intracellular pH (pHi) was measured in 2'-7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF)-loaded cells. Acetazolamide (0.1 mM) and 4,4'-diisothio cyanatostilbene-2,2'-disulphonic acid (DIDS, 0.5 mM) were used as specific inhibitors of carbonic anhydrase and NBC, respectively. The degree of inhibition was assessed by measuring the pHi recovery rate (△pHi/min) after cell acidification using an ammonium prepulse technique. In control experiments, △pHi/min was 1.40±0.06. Treatment of cells with 0.5 mM DIDS or 0.1 mM acetazolamide significantly reduced △pHi/min to 1.14±0.14 and 0.74±0.15, respectively. Simultaneous application of DIDS and acetazolamide further reduced △pHi/min to 0.47±0.10. Therefore, DIDS and acetazolamide reduced △pHi/min by 19% and 47%, respectively, while simultaneous application of both DIDS and acetazolamide caused a reduction in △pHi/min of 67%. These results suggest that in addition to carbonic anhydrase, NBC also partially contributes to HCO₃- formation in human parotid gland acinar cells.
        4,000원
        172.
        2008.12 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to examine the effect of caffeine and sodium bicarbonate in a fertilization medium on the fertilizability of boar spermatozoa that were frozen in straws. Boar spermatozoa were extended with Beltsville F5 extender and frozen in 0.25‐ml straws. In vitro matured porcine oocytes were fertilized in vitro (IVF) with frozen‐thawed boar spermatozoa for 6 h in a modified tris‐buffered medium (mTBM) or in its modified medium by substituting the tris with 25 mM sodium bicarbonate (modified bicarbonate‐buffered medium; mBBM). Some of inseminated oocytes were fixed and stained for examination of sperm penetration. IVF embryos were cultured in a North Carolina State University‐23 medium for embryo development. The percentage of live sperm was 47±4% and morphological abnormality of acrosome was found in 14±3% of spermatozoa. Optimal sperm concentration for IVF was 0.75~1.0×106 sperms/ml when mTBM containing 5 mM caffeine was used as the fertilization medium. Sperm penetration was significantly (p<0.05) stimulated by increasing caffeine concentration in the IVF medium. In addition, mBBM significantly (p<0.05) increased sperm penetration (92%) compared to mTBM (65%). More (p<0.05) blastocysts (22% vs. 32%) developed from the oocytes that were fertilized in mBBM containing 1 mM caffeine than from those fertilized in mTBM with 5 mM caffeine. Our results indicate that boar spermatozoa can be frozen successfully in straws with holding their normal fertilizability and that caffeine and sodium bicarbonate stimulates sperm penetration in vitro.
        4,000원
        173.
        2008.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The transformation of the liquid crystal complex made by binding of anionic surfactant, sodium dodecyl sulfate (SDS), into high charge density cationic polymer, the homopolymer of diallyldimethylammonium chloride (PDADMAC) was induced by adding of nonionic surfactants and investigated by means of microscopy and FE.SEM. Among nonionic surfactants in this experiments polyethylene glycol (3 mol) ether of lauryl alcohol (laureth-3) made variation in the complex. The laureth-3 transformed the complex into spherulite vesicle with the size of ca.100μm. This change increased the viscosity and the turbidity of the solution phase separated originally. Microscope showed that they are spherulite particles and polarized microscope suggested they are multi.lamellar liquid crystals. FE-SEM also proved that explicitly.
        4,000원
        174.
        2008.06 구독 인증기관 무료, 개인회원 유료
        This study examined the effects of lactic acid spray, hot water spray, or their combined treatment, as well as the effects of acidified sodium chlorite (ASC), for the decontamination of Escherichia coli on beef carcass surfaces using a commercial intervention system. With this system, the effects of 2 or 4% lactic acid (v/v), hot water (89±1oC), or their combined treatment, were examined in terms of reducing inoculated E. coli. ASC (266 ppm), which was adjusted to pH 2.5 using acetic acid or citric acid, was applied using a hand-held spray system. When the beef carcasses were treated with 2 or 4% lactic acid for 10.4 s, less than 1 log reductions of inoculated E. coli were observed. A hot water spray treatment for 9.8 s resulted in a 2.1 log reduction of inoculated E. coli. However, when the hot water was followed with either 2 or 4% lactic acid, no difference in E. coli reduction was found between the hot water alone or the combined treatment with lactic acid. When ASC was adjusted to pH 2.5 with acetic acid and citric acid, 3.8 and 4.1 log reductions of E. coli were observed, respectively. Overall, the lactic acid spray treatment was least effective, and the ASC treatment was most effective, for the E. coli decontamination of beef carcasses. Therefore, these data suggest that ASC would be a more effective intervention against E. coli than most of the methods currently being used. However, more research is required to evaluate the effects of ASC on other organisms, as well as to identify application methods that will not affect meat quality.
        4,000원
        176.
        2008.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고랭지에서 재배되는 주요 양채류의 기능성 향상을 위한 적정 셀레늄처리 방법을 구명하고자, sodium selenate처리 농도, 처리시기 및 처리 횟수에 따른 작물생육과 작물체내 무기성분, ascorbic acid, nitrate 및 셀레늄 함량에 미치는 영향을 조사하였다. Sodium selenate 1, 2, 5 및 20mg·L-1처리구에서 공시작물 모두 초기생육은 큰 차이가 없었으나, 처리 60일 후부터 5mg·L-1 이상의 고농도에서는 생육이 크게 억제되어, 무처리구에 비해 5mg·L-1처리구에서도 결구상추는 33%, 브로콜리는 47%, 파슬리는 74% 생체중이 감소한대 비해 비트와 셀러리는 고농도에서도 생육억제 현상이 크지 않아 20mg·L-1농도에서 생체중이 20%와 15% 감소하였다. sodium selenate 처리에 따른 작물체내 ascorbic acid 함량은 결구상추의 경우 셀레늄처리 농도가 높아질수록 증가하는 경향을 보여 20mg·L-1처리구는 무처리구에 비해 약 1.2배 높았고, 셀러리와 비트도 같은 농도에서 약 10% 정도 함량 증가를 보였으나, 브로콜리와 파슬리는 셀레늄처리에 따른 통계적 유의차는 없었다. 식물체내 nitrate함량은 무처리구에 비해 모든 작물에서 감소하였으며, 처리농도가 증가할수록 감소의 폭은 큰 경향을 나타내었다. 작물별 질산염의 함량 저하는 결구상추에서 가장 현저하였으며, 그 다음이 비트, 셀러리 순이었다. 무기성분 K, Ca, Mg의 함량은 공시작물 모두 처리농도가 높아질수록 감소하는 경향을 보였다. 성분별로는 K성분이 모든 작물에서 고도의 부(負) 상관관계를 나타냈으나, Mg와 Ca함량이 감소는 농도간의 차이에 유의성이 없었다. Sodium selenate 처리에 따른 식물체내 셀레늄함량은 처리 농도가 증가함에 따라 모든 공시작물에서 비례적으로 증가하여, 고농도인 20mg·L-1 처리구에서 브로콜리는 무처리구 보다 24.4배, 셀러리는 76.4배, 파슬리는 560배의 높은 함량을 보였으며, 결구상추, 비트도 같은 경향을 보였다. 작물의 생육단계별 처리에서는 생육초기에 후기보다 결구상추는 1.3배, 브로콜리는 1.4배 높았으나, 파슬리와 셀러리는 생육중기에 처리한 것이 가장 높은 함량을 보였다. 처리 횟수별 Se 함량은 파슬리, 셀러리 및 결구상추는 처리 횟수에 비례하여 증가하다가 10회 이상이 되면 셀레늄의 축적량이 둔감해지는 경향을 나타냈으나, 브로콜리는 처리횟수가 많으면 많아질수록 셀레늄의 축적량도 지속적으로 증가하는 경향을 나타냈다.
        4,000원
        177.
        2008.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        강원도 고랭지 지역의 재배토양과 주요 양채류의 셀레늄 함량을 조사하고 관비재배시 sodium selenate첨가가 작물생육과 셀레늄함량 증가에 미치는 영향을 조사하였다. 고랭지 지역의 토양의 셀레늄 함량은 0.024~0.038mg·kg-1의 분포를 보여 전반적으로 낮은 함량을 나타냈다. 각 지역에서 재배된 브로콜리의 셀레늄 함량은 적게는 10.5mg에서 많게는 17.9 mg·kg-1DW로 나타났으며, 토양내 셀레늄 함량이 높을수록 재배 작물체내의 함량도 높아지는 경향을 보였다. 셀러리의 셀리늄 함량은 6.02 mg·kg-11이었고, 비트, 결구상추 및 파슬리는 1mg 전후로 매우 낮은 함량을 나타내었다. 관비재배시 sodium selenate 2mg·L-1처리구는 무처리구(대조구)에 비해 생육및 작물체내 셀레늄함량을 증진시켰다. 2mg·L-1농도 60일간 관비재배한 결과 양채류의 Se 함량은 브로콜리 76.2mg·L-1, 파슬리 69.1mg·L-1, 셀러리 63.2mg·L-1, 비트 54.2mg·L-1, 결구상추 8.3mg·L-1순이었으며 브로콜리는 대조구보다 4.2배, 셀러리는 10.5배, 파슬리는 62.5배가 증가하였다.
        4,000원
        179.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        분리층 두께가 5 μm이며 Si/Al 몰비가 1.5인 Na형 faujasite 제올라이트 분리막을 이차성장 공정에 의하여 제조하였고, 투과부에 13X 제올라이트 흡착제 충진 전후의 진공모드에서의 CO2/N2 분리거동을 CO2/N2 몰비가 1인 혼합기체에 대하여 30℃에서 평가하였다. 충진된 13X 제올라이트 흡착제는 CO2 투과도와 CO2/N2 선택도를 동시에 증진시켰다. 이 현상은 13X 제올라이트 흡착제 충진이 다공성 α-알루미나 지지체의 기공채널을 통한 CO2 탈출을 증진시킴으로써 faujasite 제올라이트/α-알루미나 상계면에서의 CO2 탈착을 증진시켰기 때문으로 설명되었다. 본 논문으로부터 흡착제와 분리막의 혼성화는 일반적으로 보여지는 선택도와 투과도의 역비례 관계를 획기적으로 개선할 방법임이 확인되었다.
        4,000원
        180.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        다양한 재료특성(Si/Al 몰비, 두께, 구조적 불완전성)을 갖는 Na형 faujasite 제올라이트 분리층을 다공성 α-알루미나 튜브 표면에 수열조건에서 이차성장 시키고 CO2/N2 분리거동을 CO2/N2 몰비가 1인 혼합기체에 대하여 30℃에서 평가하였다. 수열조건 중에서 수열용액 내의 SiO2 양은 형성된 제올라이트 분리층의 재료특성에 가장 큰 영향을 주는 변수임을 확인하였다. 즉, 수열용액 내의 SiO2 양이 증가함에 따라서 형성된 제올라이트 분리층의 Si/Al 몰비, 두께, 구조적 불완전성(discontinuity)은 동시에 증가하였다. 본 논문에서는 불완전한 치밀화에 의해 잔존하는 결정립간 공극(void), GIS Na-P1 상에 의해 형성된 균열(crack) 등 구조적 불완전성이 CO2/N2 분리에 가장 큰 영향을 주는 재료특성이며, 투과부에서의 CO2 탈착이 전체 CO2 투과의 율속단계(rate-determining step)임을 확인하였다.
        4,800원