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        검색결과 257

        1.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Compound characters in oracle bone inscriptions refer to the form of two or three oracle bone characters combined together. These characters, formed after combination, are called compound characters and represent one of the structural features of oracle bone scripts. The phenomenon of compound characters is prevalent among river names in oracle bone inscriptions. Based on this observation, we propose that the formation of river names in oracle bone inscriptions was initially the combinations of geographic names and rivers, and these compound character forms have generally gone through a development process from separate characters to compound characters. Through the study of the structure formation of river names in oracle bone inscriptions, a deeper understanding of the people’s perceptions of river systems and geographical environments during the Shang Dynasty can be obtained, as well as the relationship between geographic names and rivers.
        6,000원
        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hypertension is characterized by excessive renin-angiotensin system activity, leading to blood vessel constriction. Several synthetic compounds have been developed to inhibit renin and angiotensin-converting enzyme (ACE). These drugs often have adverse side effects, driving the exploration of plant protein-derived peptides as alternative or supplementary treatments. This study assessed the phenolic compound and amino acid content and the antioxidant and antihypertensive activity of 5 South Korean staple crops. Sorghum had the highest phenolic compound content and exhibited the highest antioxidant activity. Millet grains, particularly finger millet (38.86%), showed higher antihypertensive activity than red beans (14.42%) and sorghum (17.16%). Finger millet was found to contain a large proportion of branched-chain, aromatic, and sulfur-containing amino acids, which are associated with ACE inhibition. In particular, cysteine content was positively correlated with ACE inhibition in the crops tested (r=0.696, p<0.01). This study confirmed that the amino acid composition was more correlated with the antihypertensive activity of grains than the phenolic compound content. Finger millet mainly contained amino acids, which have higher ACE inhibitory activity, resulting in the strongest antihypertensive activity. These findings underscore the antihypertensive potential of select crops as plant-based food ingredients, offering insight into their biological functions.
        4,200원
        3.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To produce an intestinal immunomodulatory beverage containing Centella asiatica extract (CAE), three types of CAE-added beverage prototypes were prepared, and their immunomodulatory activities and marker compounds were analyzed. As a result of the cytotoxicity assessment, all the beverages did not show significant toxicity compared to the control group. Next, the immunomodulatory activities of the beverage prototype were evaluated using the inflammatory model of IL-1β-induced intestinal epithelial cell line. All the samples significantly reduced the production of IL-6, IL-8, and MCP-1 in a CAE concentration-dependent manner. In addition, CAE-added beverages inhibited NO, IL-6, and IL-12 production in LPS-induced RAW 264.7 cells. When the major triterpenoids, as marker compounds for the production of CAE-added beverages, were analyzed by HPLC-DAD, only asiaticoside was detected beyond the limit of quantification, while madecassoside, madecassic acid, and asiatic acid were not detected. The amounts of asiaticoside in CAE-added beverage prototypes were confirmed in No. 1 (19.39 μg/mL), 2 (19.25 μg/mL), and 3 (19.98 μg/mL). In conclusion, the results of this study suggested that CAE-added beverage prototypes induced immunomodulatory effects in the intestinal inflammatory cell line models and asiaticoside could be used as a marker compound for CAE-added beverage production.
        4,000원
        4.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We determined physicochemical characteristics and antioxidant activities of cookies prepared by replacing wheat flour with 0, 3, 6, and 9% freeze-dried burdock powder instead of wheat flour. The leavening and loss rates of the cookies decreased in proportion to the amount of burdock powder added to the dough. The moisture content of the cookies increased in proportion to the amount of burdock powder added and the crude protein and hardness were higher in the burdock-added group compared to the control. The lightness and yellowness of the cookies decreased, and the redness increased in proportion to the amount of burdock powder added. The total flavonoid and polyphenol compounds in the cookies increased in proportion to the amounts of burdock powder added. The antioxidant activities also tended to increase in proportion to the amount of burdock powder added. Based on the above results, adding burdock powder to cookies can increase antioxidant activity by increasing the content of antioxidant components, such as polyphenols and flavonoids. In addition, it is believed that adding burdock powder at levels of 3 to 9% of the weight of flour would result in cookies with spreadability, swelling power, and hardness similar to those of regular cookies.
        4,000원
        6.
        2023.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study focuses on how the partial substitution of copper by nickel nanoparticles affects the electrical and structural properties of the Bi2Ba2Ca2Cu2.9Ni0.1O10+δ, Bi2Ba2Ca2Cu2.8Ni0.2O10+δ and Bi2Ba2Ca2Cu2.6Ni0.4O10+δ compounds. Approximate values of crystallization size and crystallization percentage for the three compounds were calculated using the Scherer, modified Scherer, and Williamson-Hall methods. A great similarity was observed in the crystal size values from the Scherer method, 243.442 nm, and the Williamson-Hall method, 243.794 nm for the second sample. At the same time this sample exhibited the highest crystal size value for the three methods. In the examination of electrical properties, the sample with 0.1 partial substitution, Bi2Ba2Ca2Cu2.9Ni0.1O10+δ was determined to be the best with a critical temperature of 100 K and an energy gap of 6.57639 × 10-21 MeV. Using the SEM technique to analyze the structural morphology of the three phases, it was discovered that the size of the granular forms exceeds 25 nm. It was determined that the samples’ shapes alter when nickel concentration rises. The patterns that reveal the distribution of the crystal structure also exhibit clear homogeneity.
        4,000원
        7.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 천연 항균, 항산화 물질인 망고스틴의 크산톤 화합물로 코팅된 콘택트렌즈를 제조하여 안과적 질환 예 방을 위한 기능성 콘택트렌즈의 물리·화학적 특성을 연구하였다. 방법 : 콘택트렌즈를 제조하여 IPN기술을 통해 감마망고스틴을 코팅하였다. 제조된 렌즈를 ISO와 식약처기준 을 참고하여 광투과율, 함수율, 산소투과율(Dk/t), 항균, 항산화성 실험을 진행하였다. 결과 : 감마망고스틴 코팅 콘택트렌즈의 가시광선투과율은 93%이다. 자외선은 70% 이상 청광은 30% 이상 차 단한다. 항균 실험에서는 감마망고스틴 코팅 콘택트렌즈의 항균성이 일반렌즈에 비해 5배 이상 효과 있고, 항산화 는 시험별 17.49, 28.46, 36.99%의 항산화율을 보였다. 결론 : 감마망고스틴으로 코팅된 콘택트렌즈는 UV와 청광의 차단율이 일반렌즈에 비해 매우 뛰어나다. 또한, 일반렌즈에 없는 항균, 항산화 활성을 보여 안과적 질환을 예방할 수 있을 것으로 보인다.
        4,200원
        8.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: A breast cancer is the second leading cause of cancer death in women worldwide and among different types of breast cancers, triple-negative breast cancer (TNBC) has a poor prognosis. Methods: We investigated the potential of ginsenoside compound K (CK), an active ingredient in the bio-transformed ginsenoside, to be used as a therapeutic ingredient by examining the effects of CK on cell proliferation, apoptosis, and cancer-related gene expressions in breast cancer cells. Results: From the results of treating MCF-7, an ER and PR-positive breast cancer cells, and MDA-MB-231 (TNBC) with CK at a concentration of 0-100 μM, the half maximal inhibitory concentration (IC50) values for each cell were 52.17 μM and 29.88 μM, respectively. And also, it was confirmed that cell migration was inhibited above the IC50 concentration. In addition, fluorescence analysis of Apoptosis/Necrosis showed that CK induced apoptosis rather than necrosis of breast cancer cells. Through qPCR, it was confirmed that the expression of genes related to apoptosis and cell cycle arrest was increased in CK-treated breast cancer cells, and it acted more effectively on TNBC. However, the expression of genes related to tumor invasion and metastasis is also increased, so it is necessary to consider the timing of application of CK as a potential therapeutic anticancer compound. Conclusions: CK showed a stronger inhibitory effect in TNBC with poor prognosis but considering the high tumor invasion and metastasis-related gene expression, the timing of application of CK should be considered.
        4,000원
        9.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we analyzed the changes in concentrations of volatile fatty acids (VFA), phenols, and indoles, as well as odor contribution in pig slurry. The pig slurry was stored for approximately two months after the manure excretion of pigs which had been fed 3% level of peat moss additive. The investigation was carried out through lab-scale experiments simulating slurry pit conditions within pig house. Throughout the storage period, the concentration of VFA exhibited a tendency to be 11%-32% higher in the pig manure treated with peat moss as compared to the control group. From a concentration perspective, phenol and acetic acid accounted for the majority of the total odor compounds produced during the pig slurry storage period. However, their significance diminished when the concentration of odoros compounds are converted into odor activity value and odor contribution. Despite the odor reduction effect of the ammonia (NH3) adsorption by peat moss, if it cannot effectively reduce the high odor-contributing compounds such as indoles and p-cresol, the sole use of peat moss may not be considered an effective means of mitigating odors produced by pig slurry. According to this study, indoles, p-cresol, skatole, and valeric acid were consistently revealed as major odor-contributing substances during the two-month storage of pig slurry. Therefore, a comprehensive odor mitigation methodology should be proposed, taking into consideration the odor generation characteristics (including temporal concentration and odor contribution) of pig slurry-derived odors during storage.
        4,200원
        11.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        High-temperature and high-pressure post-processing applied to sintered thermoelectric materials can create nanoscale defects, thereby enhancing their thermoelectric performance. Here, we investigate the effect of hot isostatic pressing (HIP) as a post-processing treatment on the thermoelectric properties of p-type Bi0.5Sb1.5Te3.0 compounds sintered via spark plasma sintering. The sample post-processed via HIP maintains its electronic transport properties despite the reduced microstructural texturing. Moreover, lattice thermal conductivity is significantly reduced owing to activated phonon scattering, which can be attributed to the nanoscale defects created during HIP, resulting in an ~18% increase in peak zT value, which reaches ~1.43 at 100oC. This study validates that HIP enhances the thermoelectric performance by controlling the thermal transport without having any detrimental effects on the electronic transport properties of thermoelectric materials.
        4,000원
        12.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Centella asiatica (C. asiatica) has been widely used in food, cosmetics, and pharmaceutical industry as a functional material. In a previous study, we have investigated not only pharmacological effects such as antioxidative and anti-inflammatory effects, but also analyzed various functional ingredients. In this study, triterpenoids were analyzed using HPLC-DAD to determine marker compounds among functional ingredients. When triterpenoids were analyzed, asiaticoside from C. asiatica was determined as an optimal marker compound. Next, specificity, linearity, limited of detection (LOD), limited of quantification (LOQ), precision, accuracy, and range were evaluated using HPLC-DAD to determine asiaticoside contents in C. asiatica juice and extracts. The specificity was elucidated by chromatogram and retention time using an established analytical method. The coefficient of correlation obtained was 0.9996. LOD was 4.99 μg/mL and LOQ was 15.12 μg/mL. Intra- and inter-day precision of asiaticoside were determined to be 0.48~1.68% and 0.08~1.09%, respectively. Furthermore, the recovery rate of asiaticoside was 98.88% and the analytical range of Field-70E was determined to be 0.625~10 mg/mL. As a results of evaluating ABTS, DPPH, and FRAP antioxidative effect, Field-70E showed potent antioxidant activities. Results of this study could be used as basic data for quality standardization of C. astiatica juice and extracts.
        4,000원
        15.
        2023.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A mixture of elemental Co50Si50 powders was subjected to mechanical alloying (MA) at room temperature to prepare a CoSi thermoelectric compound. Consolidation of the Co50Si50 mechanically alloyed powders was performed in a spark plasma sintering (SPS) machine using graphite dies up to 800 °C and 1,000 °C under 50 MPa. We have revealed that a nanocrystalline CoSi thermoelectric compound can be produced from a mixture of elemental Co50Si50 powders by mechanical alloying after 20 hours. The average grain size estimated from a Hall plot of the CoSi intermetallic compound prepared after 40 hours of MA was 65 nm. The degree of shrinkage of the consolidated samples during SPS became significant at about 450 °C. All of the compact bodies had a high relative density of more than 94 % with a metallic glare on the surface. X-ray diffraction data showed that the SPS compact produced by sintering mechanically alloyed powders for 40-hours up to 800 °C consisted of only nanocrystalline CoSi with a grain size of 110 nm.
        4,000원
        16.
        2023.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In order to broaden the range of application of light weight aluminum alloys, it is necessary to enhance the mechanical properties of the alloys and combine them with other materials, such as cast iron. In this study, the effects of adding small amounts of Cu and Zr to the Al-Si-Mg based alloy on tensile properties and corrosion characteristics were investigated, and the effect of the addition on the interfacial compounds layer with the cast iron was also analyzed. Although the tensile strength of the Al-Si-Mg alloy was not significantly affected by the additions of Cu and Zr, the corrosion resistance in 3.5 %NaCl solution was found to be somewhat lowered in this research. The influence of Cu and Zr addition on the type and thickness of the interfacial compounds layer formed during compound casting with cast iron was not significant, and the main interfacial compounds were identified to be Al5FeSi and Al8Fe2Si phases, as in the case of the Al-Si-Mg alloys.
        4,000원
        20.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Various kinds of friction materials were manufactured by adding 10%, 20%, and 30% of reduced iron, respectively, which has been obtained during the reduction process of blast furnace sludge extracted from the blast furnace, and its iron oxide, instead of existing barium sulfate(BaSO4) among the components of automobile brake friction materials. Fundamental physical property test and friction performance test, etc., using a brake dynamometer were carried out against these friction materials. Furthermore, when the expensive filling material, BaSO4 was substituted by reduced iron and added to the friction material, the added content of reduced iron for an excellent friction characteristic considering the heat emission temperature, wear, etc., was 10%. In the fundamental physical property test, as the added content of blast furnace sludge or reduced iron increased, and as the content increased, the shear strength and bonding strength of friction materials decreased, but both of them indicated sufficient strengths to be applied to a friction material. Even in the frictional performance test using a brake dynamometer, as the added content of blast furnace sludge or reduced iron increased, the friction coefficient reacted insensibly to brake deceleration, and its stability was improved.
        4,000원
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