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        검색결과 24

        1.
        2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hydrogen peroxide (H2O2) is widely used in bleaching treatments in the pulp and paper industry, in wastewater treatment, and as a food additive. However, H2O2 solutions are unstable and decompose slowly when subjected to external factors such as light, high temperatures, or metal compounds. Therefore, a simple and reliable method to measure the concentration of H2O2 is required for its proper use in various applications. We determined the concentration of an H2O2 solution by measurement at a single wavelength (249 nm) without any reagents or complex analytical procedures. In the present work, the measurable concentration of H2O2 was as low as 0.015 wt% (4.41 mM) and as high as 0.300 wt% (88.2 mM), with high linearity (99.99% at 249 nm) between the concentration of H2O2 and the optical density (OD) values. In addition, the method could be used to measure the concentration of H2O2 in a peracetic acid solution without interference from acetic acid and peracetate ion.
        4,000원
        3.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, the amount of heat generated in devices has been increasing due to the miniaturization and high performance of electronic devices. Cu-graphite composites are emerging as a heat sink material, but its capability is limited due to the weak interface bonding between the two materials. To overcome these problems, Cu nanoparticles were deposited on a graphite flake surface by electroless plating to increase the interfacial bonds between Cu and graphite, and then composite materials were consolidated by spark plasma sintering. The Cu content was varied from 20 wt.% to 60 wt.% to investigate the effect of the graphite fraction and microstructure on thermal conductivity of the Cu-graphite composites. The highest thermal conductivity of 692 W m−1K−1 was achieved for the composite with 40 wt.% Cu. The measured coefficients of thermal expansion of the composites ranged from 5.36 × 10−6 to 3.06 × 10−6 K−1. We anticipate that the Cu-graphite composites have remarkable potential for heat dissipation applications in energy storage and electronics owing to their high thermal conductivity and low thermal expansion coefficient.
        4,000원
        4.
        2018.04 구독 인증기관·개인회원 무료
        Gryllus bimaculatus is one of many cricket species known as field crickets. Also known as the African or Mediterranean field cricket or as the two-spotted cricket, it can be discriminated from other Gryllus species by the two dot-like marks on the base of its wings. G.bimaculatus is a subtropical insect and widely distributed from Africa to south Asia. After into the country, The species are popular for use as a food source for insectivorous animals like spiders and reptiles kept as pets. In 2016, G.bimaculatus was approved as a general food ingredient by Korean Ministry of Food and Drug Safety. However, domestic research on G.bimaculatus is still in its study is beginning stages. G.bimaculatus is possible species to year-round rearing without storage condition. but The aim of the present study prepares for in case of problems such as breeding space, labor cost etc. In the laboratory condition at 28±2℃ and 50% relative humidity under 10h light, 12h dark photoperiod, Adult crickets oviposit at soaked flower foam for 24 hours. The experiment on the hatching of the eggs showed that eggs could be stocked at 16℃ for 10 days with 7 day pre-period after laying, representing 85% hatchability.
        5.
        2018.04 구독 인증기관·개인회원 무료
        아메리카왕거저리의 사육기간을 단축과 기능성 향상을 위해 밀기울에 다양한 먹이를 보조사료로 공급하여 발륙기 간과 무게를 측정한 결과, 먹이종류별 아메리카왕거저리의 발육기간은 조단백질함량이 많은 배합사료와 밀기울에서 80.8일과 75.6일로 가장 짧았으며 버섯배지는 160일이상 소요되었으며 왕겨의 생충율은 85%로 가장 낮아 버섯폐배지 와 왕겨는 먹이원으로 적절하지 않았다. 보조 먹이원 선발을 위해 할맥, 압맥, 배추, 백련초, 파프리카, 개똥쑥을 20~80% 밀기울에 첨가한 결과 압맥과 할맥은 정상적으로 생장하지만 백련초, 개똥쑥 혼합에서는 접종 직후부터 죽은 개체들이 출현하여 생충율이 12.9%, 10.8%로 아주 낮게 나타났으며 배추와 파프리카도 24.2~38.8%로 낮아 보조사료로 적합하지 않았다. 들깨와 콩가루 역시 생충율이 높지 않아 1, 2차 시험결과 할맥, 압맥과 메밀이 보조사료로 적합하였다.
        6.
        2017.06 구독 인증기관·개인회원 무료
        To determine the medicinal properties of Pleurotus cornucopiae and Safflower Oil (PS), the osteoblast effect was investigated. PS can prevent estrogen deficiency-induced bone loss. It was taken the measurements of biochemical factors such as serum osteocalcin, alkaline phosphatase, IGF-1, and bone status. Forty adult female Sprague-Dawley rats were randomly assigned to four equal groups for 12 weeks of treatment: (1) sham operation (SHAM) + vehicle; (2) ovariectomy (OVX) + vehicle; (3) OVX + 17β-estradiol (25 μg/kg); (4) OVX + PS (300 mg/kg/d, PO). At the end of the experiment, bone turnover, and trabecular microarchitecture were assessed by micro-computed tomography (micro-CT), and histopathology, respectively. Ovariectomized rats experienced remarkable increases in global volumetric bone density, and trabecular microarchitecture deterioration. These OVX-induced pathological changes are reversible in that most of them could be mostly corrected upon 17β-estradiol treatment. PNS treatment significantly prevented bone mass loss and microarchitecture deterioration. Moreover, PS enhanced osteoblast activity but suppressed osteoclast turnover, as evidenced by decreased levels of serum C-terminal telopeptides of type I collagen and elevated levels of alkaline phosphatase. PS mitigates estrogen deficiency-induced deterioration of trabecular microarchitecture.
        7.
        2016.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Pt@Cu/C core-shell catalysts were successfully prepared by impregnation of a carbon support with copper precursor, followed by transmetallation between platinum and copper. The Pt@Cu/C core-shell catalysts retained a core of copper with a platinum surface. The prepared catalysts were used for hydrogen production through catalytic dehydrogenation of decalin for eventual application to an onboard hydrogen supply system. Pt@Cu/C core-shell catalysts were more efficient at producing hydrogen via decalin dehydrogenation than Pt/C catalysts containing the same amount of platinum. Supported coreshell catalysts utilized platinum highly efficiently, and accordingly, are lower-cost than existing platinum catalysts. The combination of impregnation and transmetallation is a promising approach for preparation of Pt@Cu/C core-shell catalysts.
        4,000원
        8.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Autographa californica 핵다각체병 바이러스(AcNPV)의 다각체 단백질과 초록색 형광 단백질의 융합단백질의 특성을 분석하였다. 초록색 형광 단백질 유전자는 AcNPV의 완전한 다각체 단백질 유전자의 앞쪽과 뒤쪽에 융합하여 다각체 단백질 유전자의 프로모터 조절하에 도입하였다. 이렇게 작성된 재조합 바이러스를 각각 Ac-GFPPOL 또는 Ac-POLGFP이라고 명명하였다. 이들 재조합 바이러스에 의해 감염된 곤충세포주에서는 56kDa의 융합단백질이 발현되었다. 한편, 흥미롭게도 재조합 바이러스 Ac-POLGFP에 의해 감염된 세포주에서는 초록색 형광이 핵내에서만 다각체 유사 granular particle 형태로 관찰되었다. 반면에 Ac-GFPPOP에 의해 감염된 세포도주에서는 대부분 핵내에 존재하였지만, 세포질과 핵 모두에서 초록색 형광을 관찰할 수 있었다. 그러나 발현된 융합단백질은 분명히 다각체단백질을 포함하고 있음에도 다각체는 형성하지 않았다. 이러한 결과들은 융합단백질에서 다각체단백질의 위치와 관련이 있는 것으로 보여진다.
        4,000원
        9.
        1997.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        남부지방에서 분리한 곤충병원성곰팡이 Beauveria bassiana GY1-17균주를 이용하여 산림해충인 오리나무잎벌레(Agelastica coerulea), 밤나무혹나방(Meganola melancholica), 회양목명나방(Glyphodes perspectalis), 잔디해충인 등얼룩풍뎅이(Blitopertha orientalis), 채소해충인 배추좀나방(Plutella xylostella) 및 거세미나방(Agrotis segetum)의 생물적 방제 가능성을 알아보기 위하여 실험한 결과, 오리나무잎벌레와 배추좀나방유충은 7.0~2.0 conidia/ml 농도에서 처리 7일과 5일후 100%의 치사율을 나타내었다. 밤나무혹나방유충은 0.03875~3.1 conidia/ml 처리에서 66.7~100%의 높은 치사율을 보였으나 회양목명나방유충은 2.0~2.0conidia/ml 처리에서도 전혀 치사되지 않았다. 등얼룩풍뎅이유충은 3.7 conidia/ml 농도에서 46.7%의 치사율을 보였고, 거세미나방유충은 2.5 conidia/ml 농도에서 63.3% 치사율을 나타내었다.
        4,000원
        10.
        1993.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research aims to study the changes in gastrointestinal function attributed to aging in human. The thresholds for recognition and detection of flavors became elevated and salivary gland acinar cells decreased in the old age. But most esophageal function remained relatively intact. Although gastric emptying time has been slowed with aging, the total intestinal transit time did not differ. Atropic gastritis due to H. pylori in old man decreased secretion of acid and intrinsic factor and absorbability of calcium and iron. Pancreatic secretion is droped in older persons. Prevalence of gallstones rised with age. Liver size and portal blood flow decreased significantly with age. Mucosal surface area has been reported to be slightly diminished in the aging man. Glucose transporters decreased and insulin tolerance increased. Absorption of aromatic amino acid is diminished with age. Dietary protein in that aging human increased fecal nitrogen excretion. Vitamin A tolerance increased. Vitamin D receptor concentration decreased and resistance to 1, 25-(OH)_2D_3 action increased. Permeability of aging small intestine increased. Zinc balance dit not differ. Copper absorption appeared not to be significantly affected by age. Neurotensin secretion decreased thus slowed colonic peristaltic movements and intestinal mucosal growth.
        4,300원
        11.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        Present study aimed to determine the effect of ‘bitter melon’, a popularly used fruit in Bangladesh and several other Asian countries, on high-fat-diet-induced type 2 diabetes. To investigate the effect, ethanol extract from bitter melon (BME) as a dietary supplement with mouse chow was used. BME was found to significantly attenuate the high-fat diet (HFD) -induced body weight and total fat mass. BME also effectively reduced the insulin resistance induced by the HFD. Furthermore, dietary supplementation of BME was highly effective in increasing insulin sensitivity and reducing hepatic fat and obesity. These results indicate that BME could be effective in attenuating type 2 diabetes and could therefore be a preventive measure against type 2 diabetes.
        12.
        2017.05 서비스 종료(열람 제한)
        Background : Korean mountain ginseng (Panax ginseng C.A. Meyer) are difficult to industrially apply because of its scarcity and high cost. Advances in plant biotechnology have made it possible to produce mountain ginseng on a large scale using adventitious root cultures in bio-reactors. This study was conducted to develop a cosmetic emulsion using ginsenoside and physiological activity - enhanced raw materials by fermentation process. Methods and Results : Wild ginseng adventitious roots were fermented with Pediococcus pentosaceus HLJG 0702 (KACC 81017BP). ginsenoside contents was analysed by using HPLC. Antioxidant activity was measured by DPPH and ABTS radical scavenging activity and whitening effect was measured by tyrosinase inhibitory activity. After microfluidizer processing was performed to prepare emulsions with homogenized particles, particle size and distribution were measured through a transmission electron microscop e(TEM). Particle stability compares pH, viscosity, light and zeta potential. When fermented with Pediococcus pentosaceus HLJG 0702, the highest change rates of Rg3, Rk1 and Rg5 were shown and the antioxidant activity was increased. The whitening effect was 73.2 ± 0.9% when treated at 100 ㎍/㎖, 1.5 times higher than the control. The optimum particle size and distribution were shown to be 418.0 ± 14.9 ㎚ for 6 times treatment with 0 - 10 times microfluidizer treatment. Stability was about 3% in pH, viscosity and light test. the zeta potential was found to be homogeneous at –33.33 mV. Conclusion : Pediococcus pentosaceus HLJG 0702 Fermented Wild ginseng adventitious roots were found to have effective ingredients and improved physiological activity. We have also developed emulsions that exhibit optimal particle size and distribution
        13.
        2017.05 서비스 종료(열람 제한)
        Background : The study about cultured wild ginseng root (Panax ginseng C. A. Meyer) have been reported mainly ginsenosides in saponins family. However metabolites of fermented wild ginseng roots by microorganisms was not reported yet. Methods and Results : Cultured wild ginseng roots were used for fermentation of ginseng roots using Pediococcus pentosaceus and other bacterial strains. We analyzed different types of ginsenoside contents, metabolite and enzyme contents, and gene expression by using microorganisms. Results showed considerable differences in ginseonoside contents specially Rk1 and Rg5. The highest enzyme activity level was by Glutathione reductase (GR) and Glutathione S transferase (GST) in fermented ginseng roots than control (non-fermented), whereas Glutathione peroxidase (GPX) and Peroxidase (POD) contents were reduced. Score plots and loading plots of principal components 1 of the PCA result obtained from the data on 43 metabolites in fermented wild ginseng root of five conditions. The concentration of metabolite such as β-alanin and 4-aminobutyric acid (GABA), which is used to improve memory were increased in fermented ginseng roots than control. We found functional gene in wild ginseng root related with metabolic process. The APX gene expression gradually increased in fermented ginseng root with respect to fermentation times. Conclusion : In this study, accumulation of functional metabolite in cultured ginseng r
        14.
        2016.10 서비스 종료(열람 제한)
        Background : The minor saponins produced by the hydrolysis of a major saponins sugar. The minor saponins has high absorption and efficacy compared to major saponin. The acid treatment, heat treatment and fermentation with minor saponin research has been actively conducted. This study was performed in order to investigate the bioconversion of ginsenoside Rg5 of fermented wild ginseng adventitious roots by using lactic acid bacteria. Methods and Results : 20g adventitious roots of ginseng was added to water (10-fold v/w). 10% (v/v) of lactic acid bacteria (Pediococcus pentosaceus HLJG0702[KACC 81017BP]) were inoculated with wild ginseng adventitious roots. For the fermentation process the inoculated samples were transferred to culture room for 1, 3 and 5 days. The fermented samples were dried at room temperature and extracted with 70% ethanol. Extract was concentrated completely at 50 ℃ and Rg5 was analysed by using HPLC. Results showed no significant difference the dry weight of non-fermented and fermented wild ginseng adventitious roots. During the fermentation process, the pH changed from 5.7 to 4.2. HPLC analysis showed higher ginsenoside Rg5 (39.588 mg/g) at 3 days. Conclusion : The fermentation of ginseng root can increase the Rg5 contents and minor saponin composition. This process may be used to enhance the minor saponin thereby increasing in fermented property of wild ginseng adventitious roots.
        15.
        2016.10 서비스 종료(열람 제한)
        Background : The study about ginseng cultured roots have been reported mainly ginsenosides in saponins family. Other phytochemical such as non-saponins of fatty acid has been revealed its bioactive activity including anti-oxidation, whitening, anti-cancer. Supercritical extraction (SE) process mainly refer to the extraction with CO2, is usually from a solid matrix, is a sample preparation step for analytical purposes. SE produce no residual solvent and possess high stability of the extract component, which is advantageous for fatty acid analysis. Methods and Results : Fermented ginseng cultured roots used in the experiment were used for fermentation using Pediococcus pentosaceus. SE performed at different temperature, pressure and extraction time using non-fermented and fermented ginseng roots. Further we fractionated from fermented ginseng using Methanol, Hexane, Ethanol, Ethyl acetate and Butanol. We compared fatty acids contents ginseng extractions by GC analysis. Methyl linoleate contents was 44% of fatty acids supercritical extraction contained. The contents of Methyl linoleate was the most dominant component among 37 types of fatty acids by SE and other extractions solvent. Total fatty acids contents obtained by SE process from fermented ginseng (1325.61ppm) was twice than from non-fermented ginseng (618.47ppm). Conclusion : Fatty acids contents by SE was increased at high pressure. The best condition for fatty acids contents extraction was 60℃, 350bar and 3h.
        16.
        2016.10 서비스 종료(열람 제한)
        Background : Perilla frutescens L. is valuable as a medicinal plant as well as a natural medicine and functional food. Limonene perilla collected from various places showed 60% limonene compounds. However biological activity of these accession has not been reported before. Therefore, this study was conducted to investigate the biological activity of limonene perilla. Methods and Results : Fractional solvent extracts were obtained by using organic solvents such as n-hexane, chloroform, ethyl acetate, n-BuOH, and aqueous solvent from different parts of limonene perilla extracted initially in 70% EtOH. We investigated the effects of limonene perilla on total phenol and flavonoid contents, FRAP (Ferric Reducing Antioxidant Power), total saponin contents and tyrosinase inhibition activity. Leaves of limonene perilla produced the highest total phenolic contents (29.88 mg·CAE/g), flavonoid (8.39 mg·QE/g) and saponin contents (47.77 mg·GIE/g) than stems and roots of limonene perilla. FRAP of leaves was 823.00±3.58 μM·FeSO4·E/mg. Tyrosinase inhibition activity rate was 40.31% in 70% ethanol extracts from leaves of limonene perilla. Conclusion : This results suggest that leaf of limonene perilla fractions has significant antioxidant activity. Also, limonene perilla could be used as a functional biomaterial in developing cosmetics and functional foods.
        17.
        2016.10 서비스 종료(열람 제한)
        Background : This study, the fraction for testing the efficacy of the Astragalus extract was concentrated active ingredient. The concentrated fraction was applied to a cosmetic material that Astragalus testing results confirmed that the improved efficacy. Methods and Results : The fractions were performed using an n-butanol solvent for increasing the efficacy of the Astragalus extract, by using the material fractions collected to compare and ultimately an increase in whitening and wrinkle efficacy. The solvent to be used in the fractions was used for the n-butanol good dissolution to the effective substance(Astragaloside, Isoflavonoid). It increased approximately 6.5 times the sample extract and the n-butanol fraction of the Astragalus as a result Astragaloside 15 ppm, 97 ppm respectively analyzed by HPLC equipment, isoflavonoid content was confirmed by an increase in the content of the fractions increased 4.5 times to 280 ppm, 1,260 ppm. Tyrosinase inhibitory effect, respectively IC50 5.70 mg/mL, IC50 1.02 mg/mL to, Collagenase producing ability is IC50 4.88 mg/mL, IC50 0.93 mg/mL with n-butanol fraction was good whitening, anti-wrinkle efficacy than the extract. Sensory evaluation was conducted in the same amount of sample, using a purified Astragalus cosmetics received high marks. Stability evaluation(MTT assay) was checked for more than 100% cell viability at the concentration 2,000 ppm. Conclusion : n-butanol fraction of Astragalus was subjected to a component analysis and In vitro test, it was confirmed an increase active ingredient content. The results of sensory evaluation and stability evaluation, it was confirmed been made to improve qualities as a cosmetic materials.
        18.
        2016.10 서비스 종료(열람 제한)
        Background : Plants are the rich source of antioxidants, which plays a very important role in maintaining human health. Their antioxidant property protects cells of different organs of human beings against free radicals and free radical mediated diseases. Even though, there is lack of knowledge on the antioxidant effect of lutein present in plants. In the present study, lutein was isolated from the GreenTea leaves (Camellia sinensis) which is used as a dietary source. Methods and Results : The procedure adopted for the isolation and purification of lutein using acetone extraction and preparative high performance liquid chromatography (HPLC) is simple and less time consuming. Free radicals scavenging activity of isolated lutein from acetone extract of GreenTea was assessed by DPPH radical scavenging assay and reducing power. The isolated lutein scavenged 79% of DPPH radicals at 20 ㎍/㎖ and two fold lower concentration compared to the standard antioxidants (α-tocopherol). No significant differences were found between the reducing power of the lutein and BHT when their concentrations were high. However, significant differences were observed at relatively low concentrations, the reducing power of lutein was isolated from the GreenTea leaves was stronger than those of their acetone extract and standard antioxidants (BHA). Both electron spin resonance (ESR) and in vitro assay confirmed that lutein was isolated from the GreenTea leaves, exhibited a greater capacity for scavenging superoxide (O2 •-) and hydroxyl (OH •) radicals than standard antioxidants β-carotene and α-tocopherol respectively. Conclusion : The results proven that lutein isolated from GreenTea leaves has an efficient antioxidant ability, it could serve as an antioxidant to scavenge reactive oxygen species.
        19.
        2016.10 서비스 종료(열람 제한)
        Background : Lutein, a xanthophyll, consists of chains with 8 conjugated double bounds containing closed rings on each end of the chain. This carotenoid is found in fruits and vegetables, especially dark green leafy vegetables such as green tea. In this study, we investigated the anticancer effects of purified lutein from green tea on human cancer cell lines containing prostate carcinoma cancer cells (LNCaP). Methods and Results : Prostate carcinoma cancer cells (LNCaP) were cultured and evaluated the inhibitory effect of lutein isolated from green tea compared other carotenoids (β-carotene and lycopene) on cell proliferation. Cyclin D1 and PCNA were evaluated as cell differentiation. In results, PCNA/cyclin regulates the initiation of cell proliferation by mediating DNA polymerase. Under cultural conditions, lycopene remarkably suppressed the PCNA expression prostate cancer cell line LNCaP in higher doses (20 μM - 100 μM) statistically. However, β-carotene and lutein presented the less inhibitory effects on PCNA expression. Determination of PCNA expression in control and treated cells demonstrates that lycopene did affect proliferation in LNCaP cancer cells in dose-dependent manner. However, β-carotene and lutein suppressed the cyclin D1 expression in dose-dependent manner but no in lycopene group. These results indicate that differ carotenoids presented the various suppressive ability of PCNA and cyclin D1 expression in cell proliferation. Conclusion : In conclusion, lutein suppressed the carcinogenesis of induced prostate cancer cell line by acting as a suppressor for inhibiting the expression of cyclin D.
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