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        검색결과 1,173

        581.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        This study was carried out to investigate characteristic pattern of fruiting body of Ganoderma lucidum and their antioxidant activity. Mycelia of all strains were firstly inoculated into potato dextrose agar(PDA) and then transfered to a media of saw dust which contained 20% rice bran. These mycelia of saw dust were then inoculated into oak tree in polyethylene bags which has been sterilized for 8h at 120℃. The polyethylene bags were sent to a growth room for growth of fruit bodies. Antioxidant activities of each fruiting body were investigated by DPPH method.
        582.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        The Trichoderma disease, commonly referred to as green mold, has been previously considered as a problem in mushroom production, because it typically occurred in association with low-quality compost or poor hygiene. We studied growth of Trichoderma spp. (Trichoderma aggressivum, Trichoderma atroviride, Trichoderma harzianum, Trichoderma koningii, Trichoderma viride) is under the control of environment factors ; 15℃ - 35 ℃ of incubation temperature, pH 3 - pH 11 of medium and 55% - 75% moisture content of rice straw medium. At the temperature of incubation, Trichoderma spp. had the highest growth rate at 25 ℃ and had no growth at 35 ℃. At the pH of medium, Trichoderma spp. had the highest growth rate at pH 5 and had the lowest growth rate at pH 11. In the Moisture content of rice straw medium, Trichoderma spp. had the highest growth at 75% moisture content and had the lowest growth rate at 55% moisture content.
        583.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        Essential oil from Chamaecyparis obtusa leaves and water extract from Pseudotsuga menziesii sawdust were examined for antifungal activity against Trichoderma spp. (Trichoderma aggressivum, Trichoderma atroviride, Trichoderm harzianum. Trichoderma koningii, Trichoder-ma viride). Generally, essential oil and water extract inhibited the growth of Trichoderma spp. by about 25% and 33%, respectively, at 1000 ppm. Antifungal activity of water extract was slightly higher than essential oil at 1000 ppm. Antifungal activity was increased with increasing concentration of essential oil and water extract. This study was carried out the investigation of the chemical composition of essential oil from Chamaecyparis obtusa leaves and water extract from Pseudotsuga menziesii sawdust. The essential oil was analyzed by GC-MS and water extract analyzed by GC-MS/HS. Thirty-eight components were identified, of which terpinyl acetate (13.41%), elemol (11.86%) and isobornyl acetate (7.89%) were the main compounds in essential oil. Twenty-four components were identified, of which 2-Isopropoxy-ethylamine (46.45%), Epifluorohydrin (8.62%) and Trans-2,3-Dimethyloxirane (7.78%) were the main compounds in water extract. Based on all results described above, we conclude that the essential oil and water extact may have a potent in vitro antifungal activity against Trichoderma spp.
        590.
        2010.10 구독 인증기관·개인회원 무료
        The EAG (Electroantennogram) has been used to find out chemical substance effective to insect. We tried to use EAG recording for catching of responsible acoustic signals to Lirimyza trifolii (Diptera: Agromizidae). In fly auditory organ known as Johnston's organ located on antenna. Pure tone sounds (sine wave) and courtship songs of several kinds of species were broadcasted to excised head of the fly. Significant EAG signals were detected when released the 20 Hz pure tone sound and long pulse train patterns, which were courtship songs of Cryptonevra inquilina and Lipara japonica (Chloropidae). For conformation of it's effectiveness, we further analyzed movement behavior with the signal got from the EAG recording. Information entropy could represent the specimens activities of movement tracks. The entropy with sound was relatively lower than without sound. The combination of EAG responding and behavioral observation would be useful to analyze the response of insect pest against acoustic signals and develop acoustic pest managing tool in agriculture.
        592.
        2010.09 구독 인증기관 무료, 개인회원 유료
        In vivo redox reaction is involved in the processes of oxidative diseases. Thus, direct and non-invasive measurement of in vivo free radical reactions in living animals should be essential to understanding the roles of free radicals in pathophysiological phenomena. Electron spin resonance (ESR) technique has been utilized in analysis of free radicals, which are generated through imbalance of in vivo redox status. In vivo ESR/spin probe technique using nitroxide radicals as spin probes was developed for estimation of in vivo free radical reactions in whole living animals. This technique using a probe may become a powerful tool for use in clarifying mechanisms of disease and in monitoring pharmaceutical therapy. The application of ESR was introduced and discussed in this article.
        4,000원
        593.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Domestic studies for identification of causality between children exposure to toxic chemicals, such as arsenic (As) and resulted hazardous effects were not implemented. This study was conducted to probabilistically estimate dietary As intake and health risk assessment for young children and all age-specific populations from the consumption of As-contaminated rice of Korea. Arsenic intakes for young children (1 to 6 years old) from As-contaminated rice were higher than other age-specific groups, based on a dose-per-body weight basis. Based on the current EPA cancer slope factor for As, estimated cancer risks (to the skin cancer) associated with dietary intake of As-contaminated rice for 1 to 2 years old group and 3 to years old group are 1.76 per 10,000 and 3.16 per 10,000, respectively, at the 50th percentile. Based on possible reference levels (0.005 mg/kg/day) for children, mean and 95th percentile value of HQ from rice for young children are very below 1.0, which is a regulatory limit of non-carcinogenic risks for human.
        4,000원
        594.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chronic exposure to Arsenic (As) causes significant human health effects including various cancers. Total As concentrations from 300 polished rice samples cultivated near the mining areas in Korea were analyzed to estimate a probabilistic assessment of human health risk from As-contaminated rice. The mean of total As concentrations in rice was 0.09 mg/kg and lognormal distribution model was set for total As concentrations. Human health risk for As in rice was estimated using gender-specific rice consumption data and average daily dose (ADD). While cancer risk (CR) and hazard quotient (HQ) were calculated using oral cancer slope factor (OCSF) and Reference dose (RfD) suggested by the U.S. EPA. Mean of CR posed by total As was 2.16 (for male) and 1.83 (for female) per 10,000. The HQ for general population from rice cultivated near the mining areas in Korea was below 1 as the 50th percentile of general population. However, less than 10% of general population consuming rice cultivated near the mining areas would exceed 1.0. This result is similar with those from each gender-specific group.
        4,000원
        595.
        2010.06 구독 인증기관 무료, 개인회원 유료
        Melatonin is induced by light information through the retina and leads to growth factor activation. Thus, we investigated the effects of melatonin by controlling the photoperiod of growing young rats. Male Sprague‐gDawley rats (n=6; 4 weeks old) were divided into two experimental groups: the L/D group (normal photoperiod; light/dark: 12/12 h; lights on at 9:00 a.m.) and the L/L group (light/light: 24 h). Rat body weight and food consumption were measured daily for 8 weeks. After 8 weeks, the rats were anesthetized with a mixture of ketamine (50 mg/kg) and xylazine (10 mg/kg) and sacrificed. Tissue was then collected for RNA isolation (from brain, heart, liver, kidney, adrenal gland, testis, tibia, hind limb muscles). Also, serum was isolated from blood using a centrifugal separation. The L/L group had significantly lower body weight than the L/D group from 4 to 6 weeks (p<0.05). The L/D group had increased tissue mass, compared with the L/L group, but the difference was not statistically significant. The L/D group had a significantly higher melatonin concentration than the L/L group between the hours of midnight and 2:00 a.m (p<0.01). These results indicate that photoperiod length may affect the secretion of melatonin from the pineal gland. Also, the reduction of nocturnal melatonin secretion may retard the development of growing young rats. In future studies, we plan to compare exogenous melatonin administration with endogenous melatonin concentration induced by photoperiod control. Moreover, we will confirm whether the effects seen in pathological animal models can be reversed by controlling the photoperiod.
        4,000원
        596.
        2010.06 구독 인증기관 무료, 개인회원 유료
        Our objective of current study was to investigate the development of bone and heart in association with diabetes mellitus (DM). DM was induced by administering an intraperitoneal injection of streptozotocin (STZ; 60 mg/kg) to 4‐gweek‐gold Sprague‐gDawley rats. Body weight and blood glucose were monitored, and rats were sacrificed after 2 or 5 weeks. The left ventricle (LV), including the interventricular septum, was weighed, and body weight and tibial bone length were assessed. Young diabetic rats showed reduced growth in terms of tibial length and body weight compared to controls. Moreover, diabetic males showed more significant growth suppression and reduced LV size than diabetic females. Morphometric analysis of tibiae from diabetic rats revealed suppressed bone growth at 2 and 5 weeks, with no difference between genders. STZ‐ginduced diabetes decreased bone growth and retarded pre‐gpubertal heart development. As a result, diabetes may increase cardiovascular risk factors and lead to eventual heart failure. Therefore, new therapeutic approaches are required for diabetic children exhibiting growth retardation. Heart growth factor, exercise, and cardiopulmonary physical therapy may be required to promote heart development and physiological function.
        4,000원
        598.
        2010.05 구독 인증기관·개인회원 무료
        Apolipophorin-III (apoLp-III) is a hemolymph protein whose function is to facilitate lipid transport in an aqueous medium in insects. Recently, apolipophorin-III in Galleria mellonella and Hyphantria cunea was shown to play an unexpected role in insect immune activation. We show here a novel possible function/role of the apoLp-III in insects. To investigate the genes which have a relationship with apoLp-III in fall webworm larvae, we reduced endogenous Hc apoLp-III mRNA levels in larvae via RNA interference (RNAi). The RNAi-mediated Hc apoLp-III reduction resulted in the reduction of antioxidants, like MnSOD, catalase, and glutathione S transferase as well as immune proteins. In particular, expression of MnSOD commonly decreased in fat body, midgut, and hemocytes following the knockdown of Hc apoLp-III, which induced an elevated level of superoxide anion in Hyphantria cunea larvae. The observed effect of Hc apoLp-III RNAi suggests that Hc apoLp-III is related to the action/expression of antioxidants, especially MnSOD.
        599.
        2010.05 구독 인증기관·개인회원 무료
        Previous studies indicated that Matsumuraeses phaseoli and M. falcana (Lepidoptera: Tortricidae) are separate species since a few differences were observed in genitalia morphology and female sex pheromone composition. A clear difference was detected in the DNA sequences of cytochrome oxidase I of the two species separately collected in different plants and regions. A hybridization test also showed that a post-zygotic reproductive isolation occurred between the species. In field monitoring, however, both species have been caught simultaneously and together in the separate sex pheromone traps installed for the two species around neighboring soybean and red bean fields. Molecular marker-assisted identification with several adults sampled from the trapped insects showed that only ca. 40% of M. phaseoli adults identified as the species by genitalia morphology was the M. phaseoli, while ca. 97% of M. falcana adults identified as the species was the M. falcana. The result indicated that the observation of genitalia did not make a decisive criterion for classification of the insects. Conclusively, it suggested that the sex pheromones of the two species should be studied more precisely although there is a possibility that the two species are hybridized in fields as in laboratory, and speciation is under process.
        600.
        2010.05 구독 인증기관·개인회원 무료
        Mosquito-borne viral pathogens infect millions of people worldwide, often resulting in fatal infections. Our research interests in mosquito vector biology focuses on understanding of the molecular and genetic basis of mosquito resistance to arbovirus infections. Unlike mammalian cells including humans, for instance, mosquito cells do not show pathologic symptoms when infected by arboviruses. This observation led us to embarking a microarray study to investigate mosquito-virus interactions using Anopheles gambiae and o’nyong-nyong virus (ONNV) as a model system. As a result, we found that transcription of the hsc70B gene is increased about 2.6-fold in ONNV-infected An. gambiae compared to non-infected controls. Subsequently, in vivo RNAi silencing of the hsc70B transcript caused enhanced ONNV replication in female mosquitoes. Therefore, these results suggest that the hsc70B protein has an inhibitory effect on ONNV replication. A promoter analysis of the hsc70B locus further demonstrated that the hsc70B promoter is able to induce transcription of hsc70B in response to ONNV infection. In addition, hsc70B transcription was also induced by West Nile or La Crosse virus infection. Collectively, our findings indicate that hsc70B plays a role in suppressing virus replication as a general antiviral mechanism. Implications of hsc70B research and our other research endeavors toward the control of mosquito-borne infectious diseases will be discussed.