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        검색결과 300

        82.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Calcium exerts antiproliferative effects on cellular targets through the promotion of differentiation and apoptosis. We investigated the influence of calcium on the formation of colonic aberrant crypt foci (ACFs), which were induced by exposure to azoxymethane (AOM) followed by dextran sodium sulfate (DSS), in ICR mice. Six-week-old ICR mice received 3 (weeks 0–2) intraperitoneal injections of AOM (10 mg/kg BW), followed by treatment with 2% DSS via drinking water for a week to induce preneoplastic lesions. The mice were then divided into 3 groups: the control (AOM/DSS), AOM/DSS + 1.0% Ca, and AOM/DSS + 2.0% Ca groups. Calcium (1.0 or 2.0%) was administered via drinking water for 12 weeks. After sacrificing the mice, the total numbers of aberrant crypts (ACs) and ACFs were measured in the colonic mucosa after methylene blue staining. The control group displayed 11.58 ± 2.43 ACFs/colon, which were composed of a total of 30.42 ± 5.18 ACs/colon. The number of ACFs with more than 3 ACs, which are likely to progress to colon cancer, was 2.37 ± 0.68. Compared to the control, 1.0% or 2.0% calcium treatment significantly decreased the number of total ACFs and ACs in a concentration-dependent manner. The decrease in ACFs or ACs after calcium treatment was associated with decreases in cell proliferation and β-catenin expression and an increase in apoptosis in colonic mucosal cells. These results suggest that calcium may exert a protective effect against colon cancer by inhibiting the development of ACFs/ACs in ICR mice.
        4,000원
        83.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 이산화탄소 고정화에 있어 이산화탄소 전환을 위해 MEA를 이용한 습식화학흡 수법의 셔틀메카니즘을 도입하였다. 또한 알칼리 무기물질을 다량 함유한 산업부산물을 습식탄산화법을 이용해 처리하고자 하였다. 즉, 산업부산물의 화학적 처리를 통해 칼슘이온을 용출하였다. 산성물질을 이용한 용출상징수를 ICP로 분석한 결과, 칼슘이온이 최대 17,900 ppm(1.79%)을 확보하였다. 또한 MEA를 이용한 습식 흡수공정을 통해 상온, 상압조건의 이산화탄소 분위기에서 94%의 전환률을 얻었 다. 슬러지의 액상탄산화를 통해 슬러지 mg 당 0.175 mg의 이산화탄소를 고정하였으며, 최종생성물의 XRD 분석결과 일반적인 탄산칼슘의 결정구조인 calcite 형상을 확인하였다.
        4,200원
        84.
        2014.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Calcium phosphate minerals are biologically important because of their application in the fields of orthopaedics and dentistry. Herein we have tried to synthesize calcium phosphate minerals from biowaste clam shells. A simple microwave method was used to synthesize a mixture of calcium phosphate minerals such as hydroxyapatite, tri-calcium phosphate, and monetite. The microwave induces vibration of the dipole ions in the reagent. The heating and rearrangement of ions and atoms occurs during the process. The phases obtained in the final powder were ascertained by X-ray diffraction; the morphology of each sample was checked using a scanning electron microscope. We were able to obtain a mixture of calcium phosphate minerals using the microwave method; the calcined powder showed a brick like morphology, which is different from the rod shape morphology of the hydroxyapatite obtained using the hydrothermal process.
        3,000원
        85.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        주간의 저온처리 방법이 팔레놉시스의 화경 발생과 엽 의 세포질 내 칼슘 농도 변화에 미치는 영향에 대하여 조사하였다. 주간 25oC의 항온저온 처리보다, 25 ~ 20oC 의 변온 처리가 화경 발생을 2주일 가량 단축시켰다. 그 원인은 주간의 평균 저온 때문이 아니라 변온처리 그 자 체의 효과 때문이었다. 저온 처리에 의한 엽의 세포질 내 Ca농도 증가 를 조사하기 위하여 PaCDPK1 유전자 발현 을 측정하였다. 화경 유도를 억제시키는 30oC 고온처리에 서의 PaCDPK1 유전자 발현은 25oC와 25 ~ 20oC 처리보 다 낮았다. 특히, PaCDPK1 유전자의 발현은 25 ~ 20oC 의 변온 저온 처리에서 다른 처리들 보다 3배 이상 높 았다. 이러한 결과들은 화경 발생 소요일수가 변온 저온 처리에 의해서 단축될 수 있으며, 화경 발생 소요일수의 단축은 세포질 내 Ca 농도의 변화와 관련이 있음을 말 해주고 있다.
        4,000원
        87.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        겨울철 눈이 내린 도로의 동결을 방지하기 위해 염화칼슘을 제설제로 사용하는데 이것은 용해되어 도로주변의 수목에 피해를 줄 수 있다. 본 연구는 겨울철 제설제로 이용되는 염화칼슘 처리에 따른 복자기의 생장과 생리적 반응을 알아보기 위해 생장 특성, 광색소함량, 광합성 효율, 엽록소형광반응을 측정하고 식물체 및 토양 분석을 하였다. 실험구는 무처리(대조구), 9mM(0.5%), 18mM(1.0%), 54mM(3.0%)의 총 4개의 처리구로 나누어 용해액을 신초가 나기 전, 일주일 간격으로 2회 500ml씩 살포하였다. 염화칼슘 처리 결과, 처리 후 30일째 염화칼슘 농도가 증가함에 따라 0.5% 처리구부터 총엽록소함량, 광합성율, 증산율, 기공전도도, 광계 II활성이 감소하였고 특히 3.0% 처리구에서 두드러졌다. 반면, 엽록소a/b는 염화칼슘 농도가 높아짐에 따라 증가하였고 수분이용효율은 1.0% 처리구에서부터 증가하였다. 처리 후 50일째 3.0% 처리구는 고사하여 측정할 수 없었고, 모든 처리구에서 대조구에 비해 엽록소a, 엽록소b, 총엽록소함량, 광계II활성, 광계II광화학효율이 감소하였다. 이러한 결과는 Ca2+와 Cl-이 잎과 토양에 축적되어 수분의 흡수와 전자전달의 방해에 기인한 것으로 염화칼슘 처리구에서 수고생장율의 50% 이상 저하를 가져왔다. 염화칼슘의 처리 농도와 시기에 따른 차이는 있었지만 모든 염화칼슘 처리구에서 생장율은 감소하고 생리적 활성은 둔화되었고 이는 시간이 경과함에 따라 심해졌다.
        4,000원
        88.
        2014.10 구독 인증기관·개인회원 무료
        Phospholipase A2 (PLA2) catalyzes an ester hydrolysis at sn-2 position of phospholipids. Various PLA2 genes are classified into at least 15 groups. However, on the basis of physiological functions, PLA2 genes are classified into calcium dependent cellular PLA2 (cPLA2), calcium independent cellular PLA2 (iPLA2) and secretary PLA2 (sPLA2). In insects, several sPLA2 genes are known to be associated with venom or immune functions. However, no known cellular PLA2 genes are identified. This study reports an iPLA2 (SeiPLA2) encoded in Spodoptera exigua. SeiPLA2 has an open reading frame of 2448 bp encoding a sequence of 816 amino acid residues. Its predicted protein is 89.55 KDa and 6.15 pI. SeiPLA2 is expressed in egg, larva, pupa and adult stages. In larval stage, SeiPLA2 is expressed in hemocytes, fat body, epidermis, gut, malpighian tubules and salivary gland. To understand its physiological function, its RNA interference is under investigation.
        89.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the effect of calcium (Ca) and vitamin D (vit. D) levels on metabolism of various minerals such as Ca, P, Mg, Fe, Zn, Cu, and Cr. The comparison was made on the rats that were placed on diet containing powdered skim milk with different Ca and vit. D levels for 5 weeks. A total of 42 5-week-old Sprague- Dawley rats were divided into 7 groups as follows: Control group consisted of normal Ca and normal vit. D (0.5% Ca, 1,000 IU vit. D); Experimental groups were divided into low (0.25%) and high (1.0%) calcium levels; and vit. D group was divided into low (10 IU), normal (1,000 IU), and high (5,000 IU) subgroups. The weight gain and food efficiency ratios of the rats were not significantly different with increasing dietary Ca levels. The absorption rates of 7 minerals (Ca, P, Mg, Fe, Zn, Cu, and Cr) were significantly decreased with increasing dietary Ca levels. Also, fecal excretion of P significantly increased with increasing dietary vit. D levels (p<0.05), and urine excretion of Fe was significantly increased with increasing dietary vit. D levels (p<0.001). The result indicated that higher Ca intake affected on bioavailability of other minerals, due to interactions among minerals in the process of intestinal absorption. However, vitamin D intake had no effect on bioavailability of several minerals. Therefore, it could be suggested that adequate Ca intake is important for balance of the minerals.
        4,200원
        90.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Researches on the elimination of sulfur and nitrogen oxides with catalysts and absorbents reported many problems related with elimination efficiency and complex devices. In this study, decomposition efficiency of harmful gases was investigated. It was found that the efficiency rate can be increased by moving the harmful gases together with SPCP reactor and the catalysis reactor. Calcium hydroxide(Ca(OH)2), CaO, and TiO2 were used as catalysts. Harmful air polluting gases such as SO2 were measured for the analysis of decomposition efficiency, power consumption, and voltage according to changes to the process variables including frequency, concentration, electrode material, thickness of electrode, number of electrode winding, and additives to obtain optimal process conditions and the highest decomposition efficiency. The standard sample was sulfur oxide(SO2). Harmful gases were eliminated by moving them through the plasma generated in the SPCP reactor and the Ca(OH)2 catalysis reactor. The elimination rate and products were analyzed with the gas analyzer (Ecom-AC,Germany), FT-IR(Nicolet, Magna-IR560), and GC-(Shimazu). The results of the experiment conducted to decompose and eliminate the harmful gas SO2with the Ca(OH)2 catalysis reactor and SPCP reactor show 96% decomposition efficiency at the frequency of 10 kHz. The conductivity of the standard gas increased at the frequencies higher than 20 kHz. There was a partial flow of current along the surface. As a result, the decomposition efficiency decreased. The decomposition efficiency of harmful gas SO2 by the Ca(OH)2 catalysis reactor and SPCP reactor was 96.0% under 300 ppm concentration, 10 kHz frequency, and decomposition power of 20 W. It was 4% higher than the application of the SPCP reactor alone. The highest decomposition efficiency, 98.0% was achieved at the concentration of 100 ppm.
        4,000원
        91.
        2014.04 구독 인증기관 무료, 개인회원 유료
        With industrial development, energy demands continue to rise. Fossil fuels release more air pollutants to produce the same amount of energy compared with other types of fuel. The harmful exhaust gas exacerbated by the increasing uses of vehicles also makes a contribution to the worsening of air pollution. Thus there is a need for various processing methods and technologies to eliminate harmful gases such as sulfur oxides released into the air. Researches on the elimination of sulfur and nitrogen oxides with catalysts and absorbents reported many problems due to elimination efficiency and complex devices. In an attempt to supplement them, this study set out to increase the decomposition efficiency of harmful gases by moving them through the plasma generated in the SPCP reactor and the catalysis reactor specially designed and manufactured. The study used calcium hydroxide(Ca (OH)2),CaO,andTiO2 as catalysts. Harmful air polluting gases such as SO2 were measured for decomposition efficiency, power consumption, and voltage according to changes to the process variables including frequency, concentration, electrode material, thickness of electrode, number of electrode winding, and additives to obtain optimal process conditions and the highest decomposition efficiency. The standard sample was sulfur oxide(SO2). Harmful gases were eliminated by moving them through the plasma generated in the SPCP reactor and the Ca(OH)2 catalysis reactor. The elimination rate and products were analyzed with the gas analyzer (Ecom-AC,Germany), FT-IR(Nicolet, Magna-IR560), and GC-(Shimazu). The results of the experiment conducted to decompose and eliminate the harmful gas SO2with the Ca(OH)2 catalysis reactor and SPCP reactor show 96 decomposition efficiency at the frequency of 10kHz. The conductivity of the standard gas increased according to frequency at high voltage of 20 kHz or more. There was a partial flow of current along the surface. As a result, the decomposition efficiency decreased. The use of tungsten electrode resulted in the highest decomposition efficiency by the Ca(OH)2 catalysis reactor and SPCP reactor, and it was followed by the copper and aluminum electrode in the order. As for the impacts of thickness of electrode at electric discharge, the thicker the electrode was, the higher decomposition efficiency became. As for the number of electrode winding, the more it was wound, the higher decomposition efficiency became. The decomposition efficiency of harmful gas SO2 by the Ca(OH)2 catalysis reactor and SPCP reactor was 96.0% under the conditions of 300ppm concentration, 10kHz frequency, and decomposition power of 20W. It was higher than 92% when only the SPCP reactor was used. Decomposition efficiency was the highest at 98.0% when the concentration was 100ppm. As for the effects of additives to fit actual exhaust gases, the more methane (CH4) was added, the higher decomposition efficiency became over 99%. The higher the oxygen concentration was, the higher decomposition efficiency became, as well
        5,400원
        92.
        2013.11 구독 인증기관 무료, 개인회원 유료
        In this study, the air pollutant removal such as sulfur oxides was studied. A combination of the plasma discharge in the reactor by the reaction surface discharge reactor Calcium hydroxides catalytic reactor and air pollutants, hazardous gas SOx, changes in gas concentration, change in frequency, the thickness of the electrode, kinds of electrodes and the addition of simulated composite catalyst composed of a variety of gases, including decomposition experiments were performed by varying the process parameters. The experimental results showed the removal efficiency of 98% in the decomposition of sulfur oxides removal experiment when Calcium hydroxides catalysts and the tungsten(W) electrodes were used. It was increased 3% more than if you do not have the catalytic. If added to methane gas was added the removal efficiency increased decomposition.
        4,600원
        94.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The diagnostic assay of calcium ion was sought using a modified sensor with square-wave stripping voltammetry (SWSV) and cyclic voltammetry (CV). In this study, simple graphite pencil was used as working, reference, and auxiliary electrodes. By coating the working electrodes with DNA, their sensitivity was very much improved, and good results were yielded. Moreover, clean seawater was used as an electrolyte solution instead of acid and base electrolytes to lessen the expenses involved in the experiment. The analytical optimum conditions were also examined. These conditions were attained at the low detection limit of 0.6ugL1. After that, the results were applied to drinking water of milk contain.
        4,000원
        95.
        2013.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to determine the effects of partial replacement (40.0%) of sodium chloride by potassium chloride, potassium lactate and calcium ascorbate on quality characteristics of cooked pork ham during cold storage. The cooked pork hams with partial replacement of sodium chloride by potassium chloride and potassium lactate had lower lightness (L*) and higher bitterness than others (p <0.05). However, redness (a*), yellowness (b*) and overall acceptability of sensory properties were not different among the treatments (p >0.05). The partial replacement of sodium chloride by all substitutes leads to increase tenderness (p <0.05). There are no problems in microbiological stability and lipid oxidation of cooked pork hams with 40% replacement of sodium chloride by potassium chloride, potassium lactate and calcium ascorbate during cold storage. Therefore, it is possible to use potassium chloride, potassium lactate and calcium ascorbate as partial substitutes of sodium chloride in cooked pork ham.
        4,000원
        96.
        2013.03 구독 인증기관 무료, 개인회원 유료
        Recent studies indicate that reactive oxygen species (ROS) can act as modulators of neuronal activity, and are critically involved in persistent pain primarily through spinal mechanisms. In this study, we investigated the effects of NaOCl, a ROS donor, on neuronal excitability and the intracellular calcium concentration ([Ca2+]i) in spinal substantia gelatinosa (SG) neurons. In current clamp conditions, the application of NaOCl caused a membrane depolarization, which was inhibited by pretreatment with phenyl-N-tert-buthylnitrone (PBN), a ROS scavenger. The NaOCl-induced depolarization was not blocked however by pretreatment with dithiothreitol, a sulfhydrylreducing agent. Confocal scanning laser microscopy was used to confirm whether NaOCl increases the intracellular ROS level. ROS-induced fluorescence intensity was found to be increased during perfusion of NaOCl after the loading of 2′,7′-dichlorofluorescin diacetate (H2DCF-DA). NaOCl-induced depolarization was not blocked by pretreatment with external Ca2+ free solution or by the addition of nifedifine. However, when slices were pretreated with the Ca2+ ATPase inhibitor thapsigargin, NaOCl failed to induce membrane depolarization. In a calcium imaging technique using the Ca2+-sensitive fluorescence dye fura-2, the [Ca2+]i was found to be increased by NaOCl. These results indicate that NaOCl activates the excitability of SG neurons via the modulation of the intracellular calcium concentration, and suggest that ROS induces nociception through a central sensitization.
        4,000원
        97.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Calcium is an essential nutrient generally obtained from dietary foods. However, its metabolism is a complex biological network requiring an effective analytical tool. In this review, a few notable calcium mechanistic models are assessed, emphasizing the power of mechanistic modeling in analyzing biological systems because no publication has reviewed them in a single place. Reviewed models are categorized by target systems: calcium absorption, calcium excretion, bone turnover, and whole calcium homeostasis. In the calcium absorption model, two transport systems carrying calcium from intestine to blood have been mechanistically described. Since urine calcium excretion is poorly understood, its model has not been explicitly developed although it is modeled as a part of the whole calcium metabolic system. Cell-based bone turnover model has been conceived to describe the mechanism under bone cell regulation. Finally, whole calcium metabolism has been a target to explain the metabolic control of calcium homeostasis that is linked to the endocrine system. Reviewed models focus on explaining how the calcium metabolic system behaves in response to conditional perturbations by involving effective factors such as endocrine system. We expect that not only will this study provide comprehensive information for future studies in calcium metabolism, but also that it will suggest what the concepts of biosystem modeling are and how they can be used for assessing the target system.
        4,000원
        98.
        2012.12 구독 인증기관 무료, 개인회원 유료
        Vital pulpotomy is a very useful method for disarming of canine tooth, tooth fracture, periodontitis, and malocclusion in veterinary dentistry. Calcium hydroxide is the material commonly used as a liner during vital pulpotomy. This creates a mineralized barrier by stimulating osteoblastic hard tissue repair, arrests the inflammatory response, and soothes dentin. However, the powder or mix type calcium hydroxide materials have many disadvantages due to complicated procedures for use and are hard to handle when vital pulpotomy is followed under general anesthesia in animals. This study was conducted in order to compare the effect of mix and premixed paste type calcium hydroxide as a liner in vital pulpotomy. Six beagle dogs underwent hemisection on the mesial root of the mandibular first molar and vital pulpotomy on the distal root of the first molar. On the distal root of the left and right mandibular first molar, mix type (DYCAL®, Dentsply, USA) and premixed paste type calcium hydroxide (VITAPEX®, Morita, Japan) were used as liners, respectively. Radiological evaluation was performed at immediate, 4, 12, and 20 weeks after vital pulpotomy. According to the results, all teeth had well-formed dentinal bridges, and there were no periradicular lucency, lamina dura loss, or anomalies of the pulp cavity. According to these results, on vital pulpotomy in animals, premixed paste type calcium hydroxide was easy to handle and decreased the anesthesia period due to a more convenient application procedure. A further study of many clinical cases is needed for evaluation of side effects and other problems.
        4,000원
        99.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        환경친화적인 농산물 살균소독 세척방법으로 소성칼슘 및 열처리에 의한 신선편이 브로콜리 저장 중 품질 및 미생물적인 안전성 향상 효과를 구명하기 위하여 본 연구를 수행하였다. 브로콜리를 절단한 뒤 수돗물, 50μL·L-1 염소수 및 1.5g·L-1 소성칼슘 용액과 45℃의 수돗물 열처리, 열처리와 살균소독제를 혼합한 45℃의 1.5g·L-1 소성칼슘 용액에서 각각 2분 세척하였다. 그리고 신선편이 브로콜리를 50μm PE 필름에 포장하여 5℃에서 9일 저장하면서 기체조성, 전기전도도, 미생물수, 색 및 관능적인 품질을 조사하였다. 포장내부의 기체조성은 열처리에서 O2 농도가 낮고, CO2 농도는 높았으나 비열처리구에서는 살균소독 방법 간에 차이가 없었다. 소성칼슘 및 염소수 살균소독처리는 수돗물 처리보다 신선편이 브로콜리의 미생물 감소에 효과적이었고 열처리는 저장 3일까지는 효과가 있었으나 6일 이후에는 나타나지 않았다. 전기전도도는 소성칼슘 + 열처리에서 높게 나타났고, 색은 저장기간이 지나면서 명도가 낮아지고 황색도는 증가하였으나 살균소독 처리간에는 차이가 나타나지 않았다. 신선편이 브로콜리 저장 중 미생물수는 소성칼슘 단독처리가 염소수와 비슷한 수준으로 저장 9일 동안 일반세균수 제어효과를 나타냈고, 대장균군도 수돗물 처리보다 저장기간 내내 적게 나타났다. 또한 브로콜리 절단면의 변색 억제에는 열처리가 효과적이었으나 이취는 높게 나타났으며, 비열처리구에서 소성칼슘 용액처리는 염소수와 같이 수돗물보다 외관이 우수하고, 이취가 적게 나타났다. 따라서 소성칼슘 처리는 환경친화적인 방법으로서 신선편이 브로콜리의 염소 살균소독 세척을 대체할 수 있는 방법으로 판단되었다.
        4,000원
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