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        검색결과 70

        21.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to evaluate the accumulation and distribution of hydrophobically modified glycol chitosan (HGC) as a degradable nanoparticle in the body. To determine the movement of degradable HGC nanoparticles in the body, 20 mg/kg of lutetium177-labeled HGC (Lu177-HGC) with the size ranging from 320 to 400 nm was injected intravenously into ICR mice, and the amount of radioactivity remaining in blood and several organs was measured at various time points during the period of 5 days. In the pharmacokinetics analysis using the Lu177 radioisotope, the free Lu177 was mainly distributed and accumulated in the order of kidney>liver>lung at 1 day after the injection of the radioisotope. However, the Lu177-HGC showed a high distribution of nanoparticles in the order of liver>spleen>kidney during the experimental period of 5 days. These results would provide a basic pharmacokinetics for the use of HGC as a drug carrier in drug delivery system.
        4,000원
        22.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The ultimate goal of this study is to assess the accumulation and distribution of hydrophobically modified glycol chitosan (HGC) as a degradable nanoparticle in the body. To understand the movement of degradable nanoparticle HGC in the body, we intravenously injected a dose of 20 mg/kg of Cy5.5-labeled HGC with size ranging from 320 to 400 nm into ICR mice, and measured the amount of fluorescence remaining in blood and several organs at various time intervals. In blood, the level of Cy5.5-labeled HGC was the highest at 15 min, then after 30 min it decreased rapidly and reached a plateau form 30 min to 28 days. In the tissue we confirmed the presence of nanoparticles at high levels in the order of kidney>liver>submandibular gland until 28 days after injection. However, we did not find the presence of the particles in the brain or testes. These results will provide basic information on HGC as a drug delivery agent.
        4,000원
        23.
        2014.10 구독 인증기관·개인회원 무료
        RDA(Rural Development Administration of Agriculture) and YIRI(Yecheon-gun Industrial Insect Research Institute) was development of 3 strains crossbred honey bee(Apis mellifera) for increasing honey production(HP). The overall goal of this research is to improve the honey production of queen honey bees. This will enhance the economic value of the nation’s honey bees for honey production, and hazard resistance. Our main objective of this research is to test of honey bees(A. mellifera) that have increased as well as being good honey producers and resistance of disease in jeon-nam province. The new honey bee(A. mellifera) stock were identified ability of increasing honey production by comparing with rearing practice colony. The new honey bee(A. mellifera) stock can produce more than 30~50% honey(HP; 12.31 kg) comparing with rearing practice colonies(control 1; 8.17 kg, and control 2; 9.53 kg). Furthermore, we are calculated the number of worker bee per colony. Population of worker bee in new honey bee(A. mellifera) stock are 2,849 (colony 1), 8,860 (colony 2) and 10,451 (colony 3), it was more then 1.2~3.7 fold comparing with controls.
        24.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        25.
        2012.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 심지층 처분장 부지선정 시에 고려되는 요소를 지질, 수리지질, 지화학 등으로 분류하고 그 첫 번째 단계로 지질분야의 세부 항목을 지형, 토양층, 암종, 구조지질, 역학적 안정성, 지질학적사건으로 분류하였으며, 이들 항목에 대한 국외 기준분석을 수행하였다. 부지선정요소(Siting factor)에 대한 기준(Criteria)은 각 국가의 처한 지질환경에 따라 다른 조건혹은 값을 제시하고 있다. 화산 및 지진활동이 빈번한 일본에서는 이에 대한 기준을 상대적으로 자세히 기술하고 있으며, 빙하작용이 예상되는 스웨덴에서는 빙하작용에 의한 지반 융기·침식에 대한 영향을 상세히 분석하였다. 따라서, 본 논문 결과는 향후 국내의 심지층 처분장 부지선정 기준 수립시에 중요한 참고자료로 활용될 수 있을 것으로 판단된다.
        4,000원
        26.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study purposed to examine the effects of transcutaneous electrical nerve stimulation, self-stretching and functional massage on the recovery of muscle contraction force for muscle fatigue caused by sustained isotonic contraction. The subjects of this study were 45 healthy students. They were divided into transcutaneous electrical nerve stimulation group(n=15), self-stretching group(n=15) and functional massage group(n=15), and using Primus RS. We observed the pattern of changes in maximal voluntary isometric contraction force(MVIC) after causing muscle fatigue in quadriceps femoris muscle through sustained isotonic contraction. Maximal voluntary isometric contraction force(MVIC) were greatly increased after transcutaneous electrical nerve stimulation, self-stretching and functional massage. In the comparison of recovery rate of muscle contraction force for muscle fatigue caused by sustained isotonic contraction among the treatment groups, it did not show any significant differences. However, it showed that each treatment may be effective in recovery of muscle fatigue caused by sustained isotonic contraction.
        4,000원
        28.
        2012.10 구독 인증기관·개인회원 무료
        To identify whether higher expression of carboxylesterase (CbE) E4 in Myzus persicae is due to gene duplication, gene copy number was determined by quantitative real-time PCR. In addition, to determine the actual protein concentration of CbE E4 and it activity, Western blotting and activity staining were conducted. CbE gene copy number was highly correlated with carbamate resistance ratio (r2=0.934). However, CbE E4 expression level was little correlated with insecticide resistance ratio (r2<0.046) and no apparent correlation was observed among the gene copy number, protein quantity and total activity of CbE E4. Therefore, it was assumed that not only quantitative changing but also qualitative alteration of CbE E4 occurred in M. persicae. To investigate any potential alteration of CbE E4, mutation survey was conducted by sequencing of CbE E4 from various local strains of M. persicae. G137D and W251L mutations have been known as the main mutations associated with structural change leading to resistance. Interestingly, a new G134C mutation, which is in proximity of G137D mutation, was identified in the oxyanion hole of CbE E4. To predict the functional role of this mutation in resistance, 3-dimensional structure modeling was conducted. In summary, CbE E4 appears to be involved in resistance to both pyrethroids and carbamates as a nonspecific hydrolase or sequestration protein in M. persicae.
        29.
        2012.06 구독 인증기관·개인회원 무료
        Semen can be divided into two parts. One is cellular part which contains sperms the other is liquid part which is called by seminal plasma. The seminal plasma is a nutritive and protective medium for the sperms. Fructose, which is major energy source, is supplied to sperms swim to female oocyte. Alkalic property protects sperms from hostile environment of female reproductive organ. Also, seminal plasma induces tolerance to preexisted immune cells, and changes intra‐uterine environment to better conditions for fertilized embryos to implant. However, the effects of seminal plasma in in vitro culture of fertilized embryos are unclear. Second fraction of fresh semen was obtained from a normal farm pig. The semen was centrifuged to remove sperms, and then supernatant was filtrated. The filtered seminal plasma was stored in — 30℃. In this study, electrically activated and chemically activated porcine embryos were employed to investigate the developmental rate after 2 hours treatment of none, 0.1%, 0.5%, and 1% seminal plasma in culture media by two days of activation. Both electrically and chemically activated embryos, cleavage rate and cell numbers of blastocysts were not significant difference within four groups. Blastocyst formation rate of electrically activated embryos also did not show significant difference within any groups. However 0.1% seminal plasma treatment group showed significantly increase of blastocyst formation rate in chemically activated group (None; 24.8%, 0.1%; 31.7%, 0.5%; 19.4, and 1%; 16.5%, respectively. p<0.05).
        30.
        2012.06 구독 인증기관·개인회원 무료
        In the present study, we investigated the effect of porcine follicular fluid (PFF) concentration (10% vs. 1%) and protein-free media (PFF 0%) on maturation of porcine oocytes in vitro and analysed difference in gene expression in resulting blastocysts following parthenogenetic activation. Three groups were tested; 1) 10% PFF: Tissue culture medium (TCM) 199+10% PFF; 2) 1% PFF: TCM 199+1% PFF; and 3) 0.1% PVA: TCM 199+0.1 PVA. Cumulus-oocyte-complexes were cultured in the respective media containing gonadotrophin (1 ug/ml), epidermal growth factor (10 ng/ml), cystein (0.57 mM), sodium pyruvate (0.91 mM), insulin (5 ug/ml), 9-cis retinoic acid (5 nM) for 20~22 h and then without hormonal supplements for an additional 20-22 h. Data was analyzed using statistical analysis system(SAS) program. There was no significant difference in oocyte maturation rate. However, significantly higher (p<0.05) proportions of embryos developed to the blastocyst stage when oocytes were matured in 10% PFF group (45%) than in the 1% PFF group (31.1%). The total cell numbers were not significantly different among groups (52 ± 1.3 vs. 54.6±3.1 vs. 54.4±2.5, respectively). The relative abundance (ratio to beta-actin mRNA) of gene transcripts related to apoptosis in blastocysts was measured by real- time PCR. The expression of anti-apoptotic gene (BclxL) was up-regulated and the expression of pro-apoptotic gene (Bax) was down-regulated in 10% PFF group than in the other groups. Therefore, it can be concluded that supplementation of 10% PFF during in vitro maturation improves embryo development by reduction of apoptosis. * This study was supported by IPET (#311011-05-1-SB010), RNL Bio (#550-20120006), MKE (#10033839-2011-13), Institute for Veterinary Science, the BK21 program and TS Corporation.
        31.
        2012.06 구독 인증기관·개인회원 무료
        Embryo transfer (ET) is the final procedure for getting pregnancy through assisted reproductive technology such as IVF (in vitro fertilization), SCNT (somatic cell nuclear transfer). In our laboratory, the porcine cloned embryos loaded in ET medium are carried for 3 hours by portable incubator because of the great distance from the laboratory to the experimental farm. Thus, before transferring into recipient, porcine cloned embryos are exposed in vitro condition for long time. Medium which is used in this process is the TALP (Tyrode’s medium supplemented with 10 mM HEPES), but it includes little nutrients for embryo. Thus, the aim of this study is to determine whether ET media containing nutrients affect the in vitro development of embryos compared to TALP. For the experiment, porcine zygote medium (PZM)-5 which has amino acids for developing embryo was chosen as ET medium containing nutrients, added 10 mM Hepes as PZM-5 does not contain buffering system. For experiment, we carried out parthenogenesis through a chemical method using Thi/DTT. Parthenogenetic embryos were cultured in PZM-5 for 2 days, and then they were randomly divided into two group; loaded in a straw with TALP or PZM-5-Hepes, respectively. They were stored in a portable incubator for 3 hours to simulate the time consumed in ET, thereafter embryos in both TALP and PZM-5-Hepes groups were respectively cultured in PZM-5 for additional 5 days. All experiments were repeated 5 times. In result, blastocyst formation rate were 22.46%±1.47 and 23.17%± 2.13, respectively and total cell number were 32.9±2.22 and 37.09±2.18, respectively. There is no significant difference between TALP and PZM-5-Hepes groups. * Further study will investigate effect of PZM-5-Hepes on in vivo development of porcine cloned embryo. This study was supported by IPET (#311011-05-1-SB010), RNL Bio (#550-20120006), Institute for Veterinary Science, the BK21 program and TS Corporation.
        32.
        2012.06 구독 인증기관·개인회원 무료
        Adipose tissue-derived mesenchymal stem cells (ASCs) are very interesting in several laboratory animals and humans because they are easy to harvest and expand to generate millions of cells from a small quantity of fat. ASCs are known as useful materials for clinical applications in human cell therapy and as a donor cell in somatic cell nuclear transfer (SCNT). Here, we investigated if 1) minipig ASCs can be isolated, self-renewed and differentiated into multiple tissue lineages, 2) ASCs can be a suitable donor cell type for generation of cloned pig. In order to isolate ASC, adipose tissues were collected from inguinal region of a 6-year-old female minipig. The ASCs were attached to the culture dish with a fibroblast-like morphology. They expressed cell-surface marker characteristics of stem cell, underwent osteogenic, adipogenic, myogenic, neurogenic and chondrogenic differentiation when exposed to specific differentiation-inducing conditions. To investigate its potential as donor cell for cloning, we respectively carried out SCNT using ASC, adult skin fibroblast (ASF) and fetal fibroblast (FF) derived from same minipig. The ratio of blastocysts to 2-cell embryos and total cell number of blastocysts were monitored as experimental parameters. In results, cleavage and developmental competence to blastocysts rate showed no significant difference among the three groups. On the other hand, total cell numbers of blastocysts derived from ASC and FF were significantly higher than in ASF (89±7.9 and 105±5.5 vs. 57.5±5.2, respectively). Our results demonstrated that ASC have potential compared to ASF and FF in terms of the in vitro development and blastocyst formation ability. In further study, we will investigate the in vivo developmental ability of ASC as donor cell for pig cloning. * This study was supported by IPET (#311011-05-1-SB010), RNL Bio (#550-20120006), Institute for Veterinary Science, the BK21 program, TS Corporation and Optifarm Solution.
        33.
        2011.10 구독 인증기관·개인회원 무료
        The green peach aphid (Myzus persicae) is a cosmopolitan pest of agricultural and horticultural crops and causes serious economic damages. M. persica has rapidly developed resistance to a wide variety of insecticides, including pyrethroids. Target site insensitivity mechanism mediated by two mutations (L1014F and M918T) on the para-type voltage-sensitive sodium channel (vssc) is mainly responsible for pyrethroid resistance. To predict the vssc resistance allele frequency, quantitative sequencing (QS) protocol was established. Frequency prediction equations generated from the plots of signal ratios and amplification critical time showed a high correlation coefficient (r2>0.993), indicating its high accuracy in prediction. QS results revealed that the kdr-type L1014F mutation is only present in Pyeongchang strain. No field strains of M. persicae possessed the super-kdr type M918T mutation. However, a novel M918L mutation was found by genotyping approach. The allele frequencies of M918L and L1014F were 0% to 53% in populations examined, and the level of M918L mutation frequency was closely related with pyrethroid resistance. Therefore, QS-based detection of M918L mutation frequency should faciltate the monitoring of pyrethroid resistance in the field.
        34.
        2011.10 구독 인증기관·개인회원 무료
        The green peach aphid (Myzus persicae) is a serious pest of agricultural and horticultural crops all over the world. M. persica has rapidly developed resistance to a wide variety of insecticides, including carbamates. The E4/FE4 carboxylesterase is known to be involved in carbamate resistance. To compare the E4/FE4 carboxylesterase gene copy number, as a genetic resistance marker, between seven field strains, quantitative real-time PCR (qPCR) was performed. In addition, quantitative sequencing (QS) was employed to predict the frequencies of acetylcholinesterase (AChE) mutations (A301S and S431F) that are associated with target site insensitivity. All M. persica strains examined possessed the S431F mutation in the heterozygous state except for a susceptible strain, implying the possibility of AChE duplication. In contrast, no A301S mutation was found. Frequency prediction equation was generated from the plots of signal ratios and amplification critical time, which showed a high correlation (r2>0.996). QS analysis of M. persicae populations revealed that the allele frequency of S431F ranged 4% to 63%. Taken together, the AChE resistance allele frequencies determined by QS and the E4/FE4 gene copy number by qPCR should facilitate the detection and monitoring of carbamate resistance in M. persicae in the field.
        35.
        2011.10 구독 인증기관·개인회원 무료
        Rhynchium brunneum is a widely distributed wasp species in South Eastern Asia. R. brunneum females were collected from rural provinces of Cambodia, and their total RNA and venom were extracted on site. To search for novel substances in venom, a subtracted cDNA library specific to the venom gland and sac was constructed. A total of 1118 expressed sequenced sequence tags (ESTs) were sequenced and assembled into 349 contigs (107 multiple sequences and 242 singletons). In this result, we found the putative neurotoxin (DTX protein precursor), antimicrobial peptides (teratocyte-specific caboxylesterase) together with typical major components of wasp venom (venom hyaluronidase, arginine kinase, phospholipase A2, serine/theonine protein phosphatase). Additional in-depth annotation would be required for further characterization of many unidentified genes found in the EST library.
        37.
        2011.05 구독 인증기관·개인회원 무료
        Vespa tropica is a tropical species of Vespa found in Southeast Asia. V. tropica wasps were collected from rural provinces of Cambodia, and their total RNA and venom were extracted on site. To search for novel substances in venom, a subtracted cDNA library specific to the venom gland and sac was constructed and venom protein was analyzed by nano-LC-MS/MS. A total of 1127 expressed sequenced sequence tags (ESTs) were sequenced and assembled into 572 contigs (152 multiple sequences and 420 singletons). The short venom peptides were identified to be encoded from 5 contigs (43 ESTs) by proteomic analysis. In addition, putative antimicrobial peptides together with typical major components of wasp venom (venom allergen 5, mastoparan-like peptide, serine protease, and hyaluronidase) were identified in the EST Library. Additional in-depth annotation would be required for further characterization of many unidentified genes found in the EST library.
        38.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        World wide mushroom productions have been increased to 10-20% and more various mushrooms have been attempted to cultivate. Similar trends were also observed in Korea. More diverse mushroom varieties such as Pleurotus eryngii, Hericium erinaceus and Agrocybe aegerita have been attempted to cultivate in larger areas. In these days, 235 varieties of 33 different mushroom species have been cultivated. However only 50 varieties were protected by the law. Since 1960s, mushroom industry had been considered as one of the major export industries in Korea and mushroom production has been rapidly increased. In 2008, total mushroom production was about 198,209 ton, which were about 800 billion won (one trillion won if include mushroom factory products). Major cultivated species are Pleurotus ostreatus, P. eryngii, Flammulina velutipes, Lentinula edodes and Agaricus bisporus, which cover 90% of total production. We believed that the protection of mushroom vavarieties by the law is one of the main problems to be solved. Also, more studies to develop better mushroom production methods with low cost and improve the distribution structures are certainly required. In these days, the export of mushroom has been increased in Korea. We imported more mushrooms than exported for last 4 years, however, it has been changed that export is getting bigger in these days. Because we developed the liquid spawning and automatic cultivation systems, which lead the reduction of mushroom production cost and resulted in the increasement of export. If we develop better post-harvest system, it is certain that the mushroom export should be more important in the future. As an alternative way, some Korean companies are planning to build the plants in main export countries. Mushroom industry has promising future because mushroom is good for your health.
        40.
        2010.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to reveal how EA affects BAX and NF-kB involved in cell deaths from global ischemia, and to do this, observes the changes of BAX and NF-kB caused by EA application after transient global ischemia. The experimental method is to give rise to global ischemia and apply EA to 27 SD rats with the particulars of being six-week-old, male, around-300 gram-weighing, and adapted to laboratory environment for more than a week, and divide them into three groups, that is, GV20 EA group(n=9), L14 EA group(n=9), no-treatment GI group(n=9), and then observe their changes of BAX and NF-kB at the time lapse of 6 hours, 9 hours and 12 hours after ischemia, using western blotting. The numerical decrease of BAX expression at the time lapse of 9 hours after EA application, though not statistically significant, was observed in GV20 EA group and L14 EA group, and the NF-kB expression appeared statistically significant decrease in GV20 EA group and L14 EA group, but the expression was higher in the group with EA application. Therefore, EA application at the early phase of global ischemia is considered to affect BAX and NF-kB and play a positive role in decreasing apoptosis and cell deaths by inflammation.
        4,000원
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