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        검색결과 551

        121.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chlorella-derived activated carbon (CDAC) with a high specific surface area and hierarchical pore structure was prepared as a CO2 adsorbent and as a supercapacitor electrode material. During KOH activation of Chlorella-derived carbon, metallic K gas penetrated from the outer walls to the inner cells, and pores formed on the outer frame and the inner surface. Micropores were dominant in CDAC, contributing toward a high specific surface area (> 3500 m2/g) and a hierarchical pore structure owing to the cell walls. Consequently, CDAC exhibited a high CO2 adsorption capacity (13.41 mmol/g at 10 atm and room temperature) and afforded high specific capacitance (142 F/g) and rate capability (retention ratio: 91.5%) in supercapacitors. Compared with woody- and herbaceous-biomass-derived activated carbons, CDAC has a superior specific surface area when the precursors are used without any pretreatment under the same conditions due to their soft components such as lipids and proteins. Furthermore, developing microalgae into high-value-added products is beneficial from both economic and environmental perspectives.
        4,000원
        124.
        2019.04 구독 인증기관·개인회원 무료
        Developmental period of Trogoderma variabile can be affected by many factors. The larvae of Trogoderma variabile enter diapause in unfavorable conditions. In this study, a comparison will be made between feeds (wheat flour, mixture of wheat flour and bran, dried pollack) and humidity (15%, 60%) in the same temperature (30℃ ±0.5) for 6 months. In the results, there are differences between feeds. Feeding mixture of wheat flour and bran was the shortest developmental period. Feeding dried pollack took few months to emerge, although we could not observe emergence for wheat flour. Even though humidity makes differences for feeding dried pollack, there were no significant differences for mixture on the different humidity. From that results, we could assume that the strongest affect on the developmental period is feeding material. Additionally, depends on feeding material, the other factors may affect on the developmental period.
        125.
        2019.04 구독 인증기관·개인회원 무료
        For the setting of control timing, the number of overwintering eggs on host plants and population density of Metcalfa pruinosa nymphs and adults was surveyed in a sesame fields. According to a survey of the overwintering eggs density of M. pruinosa on host plants, they were many in the order of Mugunghwa trees, Oak trees, and Acacia trees. Examined sesame branches within the 50cm was not found population densities of M. pruinosa nymphs and adults, and it was also very low in the sticky trap. The peak density of the adult was highest at 0.13 per trap on 11 after being first investigated on July 3 in a string wrap survey, and then decreased. In a sesame fields, it is judged that the control of the M. pruinosa is due to be 35 days after the end of the insect hatching, and that distribution of host plants is more important in the outside region than inside region.
        126.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        American foulbrood (AFB) is caused by the bacterium Paenibacillus larvae, which is highly contagious and often lethal to honeybee broods. To control AFB, rapid diagnostic tools including those based on immunological methods are required. We produced several specific mouse monoclonal antibodies (MAbs) against P. larvae. Interestingly, a few of the MAbs were revealed to be an IgM-type antibody. To ascertain the effects of adjuvants on immunoglobulin isotype switching, BALB/c mice were immunized with various adjuvants, i.e., Freund's adjuvant (FA), Alum adjuvant, and AddaVax™ followed by the generation of hybridoma that secreted monoclonal antibodies to P. larvae. In the case of AddaVax™, all screened hybridoma clones secreted IgG-type MAbs, whereas hybridomas generated by Alum and FA secreted 91.25% (7/80) and 66.67% (11/33) respectively, IgG-type MAbs. Although the mechanism of incomplete immunoglobulin isotype switching associated with the P. larvae antigen needs further study, our results indicate that the applied adjuvants can have a significant effect on immunoglobulin isotype switching results.
        4,000원
        127.
        2019.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The incidence of stomach cancer has been found to be gradually decreasing; however, it remains one of the most frequently occurring malignant cancers in Korea. According to statistics of 2017, stomach cancer is the top cancer in men and the fourth most important cancer in women, necessitating methods for its early detection and treatment. Considerable research in the field of bioinformatics has been conducted in cancer studies, and bioinformatics approaches might help develop methods and models for its early prediction. We aimed to develop a classification method based on deep learning and demonstrate its application to gene expression data obtained from patients with stomach cancer. Data of 60,483 genes from 334 patients with stomach cancer in The Cancer Genome Atlas were evaluated by principal component analysis, heatmaps, and the convolutional neural network (CNN) algorithm. We combined the RNA-seq gene expression data with clinical data, searched candidate genes, and analyzed them using the CNN deep learning algorithm. We performed learning using the sample type and vital status of patients with stomach cancer and verified the results. We obtained an accuracy of 95.96% for sample type and 50.51% for vital status. Despite overfitting owing to the limited number of patients, relatively accurate results for sample type were obtained. This approach can be used to predict the prognosis of stomach cancer, which has many types and underlying causes.
        4,000원
        128.
        2019.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Intensive Monitoring Survey of Nearby Galaxies (IMSNG) is a high cadence observation program monitoring nearby galaxies with high probabilities of hosting supernovae (SNe). IMSNG aims to constrain the SN explosion mechanism by inferring sizes of SN progenitor systems through the detection of the shock-heated emission that lasts less than a few days after the SN explosion. To catch the signal, IMSNG utilizes a network of 0.5-m to 1-m class telescopes around the world and monitors the images of 60 nearby galaxies at distances D < 50 Mpc to a cadence as short as a few hours. The target galaxies are bright in near-ultraviolet (NUV) with MNUV < - 18.4 AB mag and have high probabilities of hosting SNe (0.06 SN yr-1 per galaxy). With this strategy, we expect to detect the early light curves of 3.4 SNe per year to a depth of R  19:5 mag, enabling us to detect the shock-heated emission from a progenitor star with a radius as small as 0.1 R . The accumulated data will be also useful for studying faint features around the target galaxies and other science projects. So far, 18 SNe have occurred in our target fi elds (16 in IMSNG galaxies) over 5 years, confi rming our SN rate estimate of 0.06 SN yr-1 per galaxy.
        4,200원
        129.
        2018.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A coelostat is often used for solar observations, because it corrects the image rotation auto- matically by guiding sunlight into a fixed telescope with two plane mirrors. For the purposes of education and spectroscopic observation, the solar group at Seoul National University (SNU) plans to develop the SNU coelostat (SNUC) and install it in the SNU Astronomical Observatory (SAO). Requirements of the SNUC are < 1′′ positioning accuracy with 30 cm beam size on the entrance pupil in the compact dome. To allow for installation in the small dome, we design a compact slope type coelostat with a 45 cm primary plane mirror and a 39 cm secondary plane mirror. The motion of the SNUC is minimized by fixing the position of the slope frame. Numerical simulations of the available observational time of the designed coelostat shows that the sun can be observed ay all times from June to early August and at least three hours in other months. Since the high accuracy driving motors installed in the SNUC can be affected by external environment factors such as humidity and temperature variations, we design a prototype to test the significance of these effects. The prototype consists of a 20 cm primary plane mirror, a 1 m slope rail, a direct drive motor, a ballscrew, a linear motion guide, an AC servo motor, a reduction gear and a linear encoder. We plan to control and test the accuracy of the prototype with varying atmospheric conditions in early 2019. After testing the prototype, the SNUC will be manufactured and installed in SAO by 2020.
        4,000원
        130.
        2018.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Osteoporosis is a major worldwide public health problem that poses a great economic burden to society. Puerariae Radix, the dried root of Pueraria lobata (Wild.) Ohwi, has been widely used in Asia. This study investigated the effects of Puerariae Radix (PR) on bone loss in ovariectomized (OVX) mice. C3H/HeN mice (10 weeks old) were divided into sham and OVX groups. The OVX mice were treated with vehicle, 17β-estradiol (E2), PR (oral administration, 250 mg/ kg/day) or PR (intraperitoneal administration, 50 mg/ kg/every other day) for 6 weeks. Grip strength, uterus weight, serum alkaline phosphatase (ALP), estradiol concentration and osteoclast surface levels were measured. Tibiae were analyzed using microcomputed tomography. There were no significant differences in the degree of grip strength, body weight and uterine weight between OVX group and PR-treated group. As compared with the OVX group, the serum estradiol levels were significantly increased in the PR-treated group. PR (i.p.) significantly preserved trabecular bone volume, trabecular bone number, structure model index and bone mineral density of proximal tibiae metaphysic. The administration of PR lowered serum ALP and osteoclast surface levels in OVX mice, suggesting that PR can reduce the bone turnover rate in mice. The results indicate that the supply of PR can prevent OVX-induced bone loss in mice.
        4,000원
        133.
        2018.11 구독 인증기관·개인회원 무료
        Ovarian folliculogenesis and the production of fertilizable oocytes depend on gap junctional intercellular communication within both the developing and the mature follicle. Gap junctions connect oocytes with granulosa cells and granulosa cells with each other. Various nutritional bio-molecules are known to be transferred to the growing oocyte from the granulosa cells via gap junction. Signals that regulate meiotic maturation of fully-grown oocytes pass through the oocyte-granulosa cell gap junctions. Gap junctions also play a critical role in regulating uterine blood flow, contributing to the maternal recognition and also implantation during pregnancy. Due to the challenge of various stressors the in vitro embryo developmental potentials are still suboptimal compared to in vivo. To identify the molecular mechanism of these stressors and to improve the existing embryo developmental potentials, the singlet oxygens quencher lycopene was added to the culture media to counterbalance the oxidative damage caused by ROS. In this study, we have patterned connexin like Cx43, Cx37, Cx32 and Cx26 at protein and transcription level during follicular growth, atresia and blastocyst stage by using immunohistochemistry, conventional PCR and RT-qPCR. Lycopene (0.2 μM) significantly (P < 0.05) increased the gap junctional communication protein (connexin) expression of Cx43, Cx37, Cx32, Cx26 as compared to the control group at both transcription and translation level during follicular growth, atresia and blastocyst stage. Lycopene potentiates ovarian folliculogenesis, provides the production of fertilizable oocytes and improved embryo developmental capabilities by increasing gap junctional intercellular communication.
        135.
        2018.10 구독 인증기관·개인회원 무료
        Tenebrio molitor beetles have been widely used in traditional and folklore medicines to treat various human diseases worldwide. Alzheimer’s disease (AD) is a neurodegenerative disorder and the most prevalent form of dementia in developed and developing countries. The human β-amyloid cleaving enzyme (BACE-1) is a target for AD treatments. This study was performed to determine BACE-1 inhibitory activity of 12 compounds that were extracted from T. molitor adults and their 65 related compounds using a fluorescence resonance energy transfer-based enzyme assay. The results were compared with those of two positive controls for BACE-1, the cell-permeable isophthalamide BACE-1 inhibitor IV and the natural BACE-1 inhibitor, epigallocatechin gallate (EGCG). Based on IC50 values, linoleic acid, ergosterol, palmitoleic acid, and tryptopol (28.41‒46.16 μM) were the most potent BACE-1 inhibitors and the anti-BACE-1 activity of these compounds was lower than either inhibitor IV (13.13 μM) or EGCG (1.12 μM). Multiple regression analysis of the anti-BACE-1 activities of compounds was examined using their IC50 values and the values of the physical parameters (molecular weight (MW), log P, and molecular refraction (MR)) for the 41 fatty acids (R2 = 0.674 (P = 0.044)) and 29 flavonoids (R2 = 0.587 (P = 0.063)). Correlation coefficient (r) analysis showed that MW, log P, and MR may be positively correlated with IC50 of the fatty acids (MW, r = 0.658; log P, r = 0.471; and MR, r = 0.713) and IC50 of the flavonoids (MW, r = 0.547; log P, r = 0.644; and MR, r = 0.591). Further studies will warrant possible applications of T. molitor adults as therapeutic BACE-1 blocker.
        136.
        2018.10 구독 인증기관·개인회원 무료
        Whitefly (Hemiptera: Aleyrodidae) pests, including the tobacco whitefly, Bemisia tabaci, and the greenhouse whitefly, Trialeurodes vaporariorum, are economically important in agriculture. With the annual growth of the domestic fresh fruit export market, various quarantine treatment methods are being used to export strawberries of better quality. The objective of the present study was to evaluate the effects of gamma rays on the development and reproductive sterility of B. tabaci and T. vaporariorum. In both species, the eggs were completely inhibited from hatching at 50 Gy, and the emergence of 3rd instar nymphs was completely suppressed at 150 Gy. Some adult B. tabaci and T. vaporariorum spawning occurred at 100 Gy and 70 Gy, respectively; however, at these irradiation levels, F1 hatchability was completely inhibited. Dosimetry results showed that the penetrating power of gamma ray in the strawberry-filled box was the lowest at the mid-box position. Therefore, B. tabaci and T. vaporariorum were placed in the middle of the strawberry-filled box and irradiated. A gamma-ray irradiation of 100 Gy suppressed the development and reproduction of eggs and adults in both B. tabaci and T. vaporariorum. However, the development of 3rd instar nymphs was inhibited at 300 Gy for B. tabaci and 200 Gy for T. vaporariorum. Our data suggest that at least 300 Gy should be used for the control of these two types of whitefly for strawberry export.
        137.
        2018.10 구독 인증기관·개인회원 무료
        For the setting of control timing, the number of overwintering eggs on host plants and population density of Metcalfa pruinosa nymphs and adults was surveyed in the three peach orchards. According to a survey of the overwintering eggs density (∅2~3㎝, 20㎝ branches) of M. pruinosa on host plants, 221.8 in Mugunghwa trees, 189.3 Oak trees, and 152.7 Acacia trees, and 57.0 Peach showed the number of eggs laid. Examined peach branches within the 50cm (∅1~5cm) was not found population densities of M. pruinosa nymphs and adults, and it was also very low in the sticky trap. The peak density of the adult was highest at 5.4 per trap on August 7 after being first investigated on July 16 in a string wrap survey, and then decreased. In the peach orchard, it is judged that the control of the M. pruinosa is due to be 20 days after the end of the insect hatching, and that distribution of host plants is more important in the outside region than inside region.
        138.
        2018.10 구독 인증기관·개인회원 무료
        Trogoderma variabile B. is one species of well-known stored product insect. This study was conducted to test the perforation ability of larvae of T. variabile on different packaging films which has been widely used in food industry at different thickness. The tested packaging films are polypropylene (PP) 20μm, low density polyethylene (LDPE) 20μm, polyethylene terephthalate (PET) 12μm, PP 30μm and PP 40μm. This investigation was carried out for 7 days. In the same order as the films mentioned above, the perforation rate are 33.33%, 0%, 14.81%, 29.62%, 0%. From these results, the easiest film to perforate among PP, LDPE, PET is PP, and there are significant differences on thickness. Therefore, different type of materials and thickness would be considered to be used for food packaging.
        139.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Somatic cell nuclear transfer (SCNT) is a useful biotechnological tool for animal cloning. Until now, SCNT has been inefficient, especially in dog. It is believed that an embryo developmental block in SCNT embryos is cause of low production efficiency. However, no studies have been performed on canines for embryo developmental block. In this study, we attempted to evaluate the beneficial role of EDTA in canine parthenogenic (PA) embryos development to overcome embryo developmental block. The PA embryos were divided into 0.01 mM EDTA treated and non-treated groups. Embryo developmental efficiency was measured by activating chemically parthenote. After EDTA induction, PA embryos were evaluated for embryonic development, Reactive Oxygen Species (ROS) activity, mitochondrial integrity, ATP production and genomic activation. The EDTA treated PA embryos showed significantly higher survival rate and improved cavity formation compared to non-treated. Furthermore, cytoplasmic ROS level was mitigated and mitochondrial membrane potential was found significantly higher in EDTA treated group followed by higher ATP production. Moreover, major embryonic genomic activation specific markers/factors were also elevated in EDTA treated group. Conclusively, we elucidated that EDTA showed substantially positive effect to overcome embryo developmental block in canine.
        4,000원
        140.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although the concept of “common sense” is often taken for granted, judging whether behavior or knowledge is common sense requires a complex series of mental processes. Additionally, different perceptions of common sense can lead to social conflicts. Thus, it is important to understand how we perceive common sense and make relevant judgments. The present study investigated the dynamics of neural representations underlying judgments of what common sense is. During functional magnetic resonance imaging, participants indicated the extent to which they thought that a given sentence corresponded to common sense under the given perspective. We incorporated two different decision contexts involving different cultural perspectives to account for social variability of the judgments, an important feature of common sense judgments apart from logical true/false judgments. Our findings demonstrated that common sense versus non-common sense perceptions involve the amygdala and a brain network for episodic memory recollection, including the hippocampus, angular gyrus, posterior cingulate cortex, and ventromedial prefrontal cortex, suggesting integrated affective, mnemonic, and social functioning in common sense processing. Furthermore, functional connectivity multivariate pattern analysis revealed that interactivity among the amygdala, angular gyrus, and parahippocampal cortex reflected representational features of common sense perception and not those of non-common sense perception. Our study demonstrated that the social memory network is exclusively involved in processing common sense and not non-common sense. These results suggest that intergroup exclusion and misunderstanding can be reduced by experiencing and encoding long-term social memories about behavioral norms and knowledge that act as common sense of the outgroup.
        5,500원