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        검색결과 28

        1.
        2023.10 구독 인증기관·개인회원 무료
        Honey bees are crucial pollinators for agricultural and natural ecosystems, but are experiencing heavy mortality in Korea due to a complex suite of factors. Extreme winter losses of honey bee colonies are a major threat to beekeeping but the combinations of factors underlying colony loss remain debatable. Finding solutions involves knowing the factors associated with high loss rates. To investigate whether loss rates are related to Varroa control and climate condition, we surveyed beekeepers in korea after wintering (2021–2022 to 2022–2023). The results show an average colony loss rate of 46%(2022) and 17%(2023), but over 40% colony loss before wintering at 2022. Beekeepers attempt to manage their honey bee colonies in ways that optimize colony health. Disentangling the impact of management from other variables affecting colony health is complicated by the diversity of practices used and difficulties handling typically complex and incomplete observational datasets. We propose a method to 1) Varroa mite population Control by several methods , and 2) Many nursing bee put in hive before wintering.
        2.
        2019.12 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the antimicrobial effects of Australia propolis against cariogenic and periodontopathic bacteria. Antimicrobial activity was determined by evaluating the minimal bactericidal concentration (MBC). Cell cytotoxicity of propolis extract on normal human gingival fibroblast (HGF-1) cells was observed using the methylthiazolyldiphenyl-tetrazolium bromide assay. The data indicated that, with the exception of Aggregatibacter actinomycetemcomitans (KCOM 1306), the MBC values of the propolis strains were 0.25–1% without HGF-1 cell cytotoxicity. These results suggest that propolis can be used to develop oral hygiene products for the prevention of oral infectious disease.
        3,000원
        3.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 이 설문 연구는 의료민영화와 안경원의 법인화 문제에 대한 일반 소비자의 인식도를 조사하고 그 결과를 안경사 집단에 대한 선행연구와 비교·분석하는 것을 목적으로 하였다. 방법 : 2018년 5월부터 6월까지 서울·경기 지역에서 150명의 일반 소비자를 대상으로 의료민영화와 안경원의 법인화 문제에 대하여 대면설문조사를 실시하고 응답 결과를 통계분석 하였다. 결과 : 일반 소비자 집단은 의료민영화 문제에 대하여 일관되게 부정적인 인식을 나타내었으나, 안경원의 법인화 문제에 대해서는 부정적인 인식이 많지 않고 중립적인 응답의 비율이 매우 높았다. 안경사 집단에 대한 유사한 설문 조사 결과와 비교했을 때, 의료민영화에 대한 인식은 두 집단이 비슷했으나 안경원 법인화에 대한 인식은 큰 차이를 보였다. 결론 : 반 소비자 집단의 안경원 법인화 문제에 대한 부정적인 인식도가 높지 않으므로, 안경사 집단은 일반 소비자 집단을 대상으로 안경원 법인화 문제에 대한 적극적인 홍보를 강화할 필요가 있다.
        4,200원
        4.
        2019.09 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the antimicrobial activity of the ethanol extract of Garcinia mangostana L. (mangosteen) against Cutibacterium acnes (6 strains) and Staphylococcus aureus (6 strains). The antimicrobial activity of the mangosteen extract was evaluated based on its minimal bactericidal concentration. Cytotoxicity of the mangosteen extract against human embryonic kidney 293 (HEK 293) cells was determined using the cell counting method. The data showed that the mangosteen extract was not toxic to HEK 293 cells at a concentration of up to 16 μg/mL and killed 87.0% and 99.9% of C. acnes and S. aureus after 10 minutes and 1 hour of treatment, respectively. These results suggest that ethanol extract of mangosteen can be used as an anti-acne agent.
        4,000원
        5.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the effects of freeze dried placenta supplementation on reproductive performance, colostrum and plasma biochemical composition in pregnant sows. Eleven Landrace × Large white sows were fed with corn-soybean meal diets supplemented with or without 1% freeze dried placenta powder from 10 days before their expected farrowing dates until 10 days postpartum. The colostrum protein content was significantly higher(P=0.043) in the treatment group than in the control group. Compared to the control group, the immunoglobulin G(IgG) concentration in the colostrum was significantly higher(P=0.004) in the treatment. In day 25 piglets plasma, the IgG concentration was higher(P=0.184) in the treatment than the control. The mortality rate was lower(P=0.102), and the piglet weight gain was higher(P=0.35) in the treated group. Overall, the treatment group showed greater levels of protein and IgG concentration in the colostrum, when compared to control group. Therefore, the freeze dried placenta supplementation on pregnant sows can enhance its colostrum composition, hence decrease the mortality and increase the growth rate of piglets.
        4,000원
        6.
        2015.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The effect of precursor concentration on the structural, morphological, and optical properties of TiO2nano-flowers was investigated in this study. An increase in crystallite size was observed with an increase in the concentration of the precursor (titanium butoxide). The FE-SEM micrographs of the as-prepared samples show a three-dimensional flower-like morphology. The flowers consist of several nanorods coming out of a single core and have very sharp edges. Also, the variation in the aspect ratio of the nanostructure was observed with the concentration of the precursor. The photocatalytic properties of the samples show that the sample that has a high aspect ratio (AR~9) has a much better photocatalytic activity compared to the nano-crystal with a low aspect ratio (AR~6.1). It is believed that the excellent photocatalytic performance and short time synthesis of TiO2nano-flowers using the microwave hydrothermal method can have potential applications in the field of photocatalysis.
        4,000원
        7.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The fact that flip-flops, one of many different types of unstable shoes, are light and relatively easy to put on, accounts for their popularity among people. But because flip-flops rely heavily on the support of a single thong between your first and second toes, they impose a huge amount of pressure onto lower leg. Thus in the following experiment we tried to examine the different effects of flip-flops and running shoes in terms of their effect on muscle activity and fatigue of tibialis anterior and gastrocnemius during walking. In order to measure an electromyogram we used Free EMG system. 10 men and 10 women in running shoes ran on treadmills for 15 minutes at 4.8km/h, 2 days later the same experiment was carried out, but this time, in flip-flops. p value turned out to be greater than .05 and thus there was no considerable difference between the effects of flip-flops and running shoes on muscle activity and fatigue during walking. Therefore we conclude that despite the fact that flip-flops are considered unstable, their effects on muscle activity and fatigue of tibialis anterior and gastrocnemius are negligible.
        3,000원
        8.
        2011.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to examine the effects of gait training using functional electrical stimulation on the improvement of hemiplegic patients' functions for balance and gait velocity. The subjects of the experiment were determined to be 10 each hemiplegic patients who had been diagnosed with stroke or brain damage six months or longer earlier assigned to an experimental group and a control group respectively. The subjects were evaluated before the experiment using Tetrax and 10M gait tests, received gait training five times a week for four weeks using functional electrical stimulation and were evaluated after the experiment in the same method as used in the evaluation before the experiment. In order to examine differences between the experimental group that received gait training using functional electrical stimulation and the control group that was treated by functional electrical stimulation and received gait training thereafter, differences between before and after the experiment were analyzed using paired sample t-tests and differences in changes after the experiment between the experimental group and the control group were analyzed using independent sample t-tests in order to compare the two groups with each other. Experimental results showed significant differences in weight bearing, balance and gait velocity between before and after the experiment in the experimental group(p<.05). In the control group, whereas weight bearing and gait velocity did not show any significant difference between before and after the experiment(p>.05), balance showed significant differences(p<.05). Weight bearing, balance and gait velocity change rates showed significant differences between the experimental group and the control group(p<.05). In conclusion, it was indicated that gait training using functional electrical stimulation is effective for enhancing stroke patients' weight bearing rates, balance abilities and gait velocity.
        4,000원
        9.
        2010.10 구독 인증기관·개인회원 무료
        The pinewood nematode (PWN, Bursaphelenchus xylophilus) is known to be a major pathogen of the pine wilt disease (PWD). However molecular pathology of B. xylophilus is not completely understood, the pathogenecity of PWD is related to cell wall-degrading enzymes such as endoglucanases, expansins and pectate lyases (PELs). Recently, we developed stage-specific expressed tag library of B. xylophilus and identified a novel PEL, Bx-PEL3. We cloned Bx-PEL3 gene with RT-PCR, which showed high similarity to previously reported Bx-PELs. Phylogenetic analysis revealed that PEL3 was much closer to PELs of B. xylophilus than any other PELs. PEL3 has a conserved intron site as found in Bx-PEL2 in the genomic DNA analysis. Quantitative real-time PCR analysis revealed that Bx-PEL1 and Bx-PEL2 were more predominantly expressed than the Bx-PEL3 in B. xylophilus. The difference of expression level among Bx-PELs according to growth condition suggests that each Bx-PEL plays different biochemical role in the pathogenesis of the PWD.
        10.
        2010.05 구독 인증기관·개인회원 무료
        tasks that require nematode extraction and microscopic examination. To develop a more efficient detection method for Bursaphelenchus xylophilus, we first generated monoclonal antibodies (MAbs) specific to B. xylophilus. Among 2,304 hybridoma fusions screened, a hybridoma clone named 3-2A7-2H5 recognized a single protein from B. xylophilus specifically. We finally selected the MAb clone 3-2A7-2H5-D9-F10 (D9-F10) for further studies. To identify the antigenic target of MAb-D9-F10, we analyzed proteins in spots, fractions or bands via nano liquid chromatography electrospray ionization quadrupole ion trap mass spectrometry (nano-LC-ESI-Q-IT-MS). Peptides of galactose-binding lectin-1 of B. xylophilus (Bx-LEC-1) were commonly detected in several proteomic analyses, demonstrating that this LEC-1 is the antigenic target of MAb-D9-F10. The localization of MAb-D9-F10 immunoreactivities at the area of the median bulb and esophageal glands suggested that the Bx-LEC-1 may be involved in food perception and digestion. The Bx-LEC-1 has two non-identical galactose-binding lectin domains important for carbohydrate binding. The affinity of the Bx-LEC-1 to D-(+)-raffinose and N-acetyllactosamine were much higher than that to L-(+)-rhamnose. Based on this combination of evidences, MAb-D9-F10 is the first identified molecular biomarker specific to the Bx-LEC-1.
        11.
        2010.05 구독 인증기관·개인회원 무료
        Three acetylcholinesterases (AChEs) were identified from the pinewood nematode, Bursaphelenchus xylophilus. Sequence comparison with known AChEs in conjunction with three-dimensional structure analysis suggested that all BxAChEs share typical characteristics of AChE at the major catalytic structures. BgAChE3 was most predominantly transcribed and then followed by AChE1 and AChE2. Immunohistochemistry using anti-BxAChEs antibodies revealed that BxAChE1 is most widely distributed whereas BxAChE2 exhibits more localized distribution in neuronal tissues. BxAChE3 was detected from entire body together with some limited tissues, including mouth parts and alimentary lining, and determined to be the only soluble AChE, suggesting its localization in hemolymph or/and extracellular space. Kinetic analysis of in vitro expressed BxAChEs revealed that BxAChE1 has the highest substrate specificity whereas BxAChE2 has the highest catalytic efficiency with BxAChE3 having the lowest catalytic efficiency. Interestingly, presence of BxAChE3 in the pool of BxAChEs significantly reduced the inhibition of BxAChE1 and BxAChE2 by inhibitors. Knockout of BxAChE3 by RNAi significantly increased the toxicity of nematicides, suggesting the protective role of BxAChE3 against these toxicants. Based on several features, including tissue distribution, expression level, substrate kinetics and inhibition property, it appeared that BxAChE1 is the major AChE with the function of postsynaptic transmission whereas BxAChE3 has been evolved to acquire the function of chemical defense, perhaps intrinsically against secondary toxic compounds from host pine trees, such as α-pinene and limonene. BxAChE2 appears to play a role in post-synaptic transmission in specialized neurons but its detailed physiological function still remains to be elucidated.
        12.
        2009.10 구독 인증기관·개인회원 무료
        A cDNA of PBAN receptor (Plx-PBANR) isolated from female pheromone gland of the diamondback moth encodes 338 amino acids and has 7 transmembranes, belonging to G-protein coupled receptor family. The fact that Plx-PBANR expression was only found in female pheromone gland revealed that pheromone gland is the only molecular target of Plx-PBAN. Plx-PBANR expressing cells increased level of Ca2+ influx when challenged with PBANs. When RNAi fragment for PBANR was injected into pupae, suppression of PBANR expression was maintained for at least 2 days at post-emergence. Injection of RNA fragment for inhibition of Plx-PBANR expression also inhibited mating behavior and suppressed sex pheromone production, suggesting that some molecular target was affected by reduced Plx-PBANR expression. We cloned partial Δ9 and Δ11 desaturase gene and investigated expression level in Plx-PBANR-RNAi moth. It is of interest that desaturases expression was reduced by RNA fragment injection. These results suggest of PBANR expression affects the molecular biological events of PBAN and eventually suppresses mating behavior.
        13.
        2009.09 구독 인증기관 무료, 개인회원 유료
        Effects of Vegemil® containing soybean proteins and isoflavones on the growth and bone density of broiler chickens were investigated. One-week-old male and female Arbor Acres broiler chickens were fed on Vegemil® A containing 3% soybean proteins and 162 ppm isoflavones, instead of water, for 30 days and their growth indices (body weight, leg weight and femur length) and bone density were analyzed. The body weight gains in male and female chickens were increased by 15.6% and 31.7%, respectively, following feeding Vegemil® A compared to normal water. Vegemil® A increased leg weight as well as femur length of females by 22.9% and 15.0%, respectively. In addition, Vegemil® A feeding enhanced femoral bone density by 21.3% in comparison with water feeding. Therefore, it is suggested that Vegemil® A not only facilitates body growth, but also strengthens bone density of normal chickens, and that it could be a promising candidate for the improvement of infant growth and for the prevention of menopausal osteoporosis.
        4,000원
        14.
        2009.05 구독 인증기관·개인회원 무료
        The pinewood nematode (PWN, Bursaphelenchus xylophilus) is known as a virulent factor of the pine wilt disease, transmitted to pinewoods by the pine sawyer beetle, Monochamus alternatus. It is very hard to discriminate B. xylophilus from B. mucronatus because these Bursaphelenchus species are genetically and biochemically very close. Therefore, it has been necessary to detect PWN-infected trees for the prevention of pine wilt disease transmission in a short time. We developed polyclonal antibodies against B. xylophilus in BalbC mice and primarily screened with ELISA. Positive clones releasing polyclonal antisera revealed B. xylophilus-specific immuno-reactivity, which were at least two times higher than that of B. mucronatus. Two clones, D9-F10 and 1F3, were finally selected and exhibited specific immuno-reactivity for B. xylophilus, not for B. mucronatus in Western blot analysis. D9-F10 clone was reactive with a 43-kDa whereas 1F3 clone with two proteins, 40- and 45-kDa. Their isotypes against mouse Ig family were identical, kappa-light chain. These results suggest that these monoclonal antibodies can be useful for the development of diagnostic kit for the pine wilt disease.
        15.
        2009.05 구독 인증기관·개인회원 무료
        Varroa destructor is an ecto-parasite mite and worldwide pest of the honey bee Apis mellifera L. The pyrethroid tau-fluvalinate (Apistan), an acaricide that is tolerated by honey bees, has been used for varroa mite control since the mid 1980s. Even though various resistances to tau-fluvalinate in varroa mites have been reported from Europe, Israel, and USA, the nature of tau-fluvalinate resistance in varroa mites in Korea has never been investigated. To investigate and understand tau-fluvalinate resistance in varroa mites in Korea, we conducted bioassay in several apiaries located different regions in Korea. To understand the molecular mechanisms underlying the difference of tau-fluvalinate resistances in varroa mites, partial genomic DNA fragments of a voltage-sensitive sodium channel gene from varroa mites were cloned and sequenced, since tau-fluvalinate is known to act on the sodium channels directly. Two novel mutations in sodium channels of varroa mites were present in eight apiaries. Two mutations might be a geographical polymorphism of sodium channel of varroa mites in Korea.
        16.
        2008.10 구독 인증기관·개인회원 무료
        The pine sawyer beetle, Monochamus alternatus, transmits the pinewood nematode (PWN, Bursaphelenchus xylophilus), causing the pine wilt disease (PWD), which gives rise to enormously economic as well as forest damage. However, PWN has been identified as a pathogen of PWD, it is very difficult to discriminate B. xylophilus from B. mucronatus in a short time, which are genetically and morphologically very similar. Therefore, it has been necessary to detect and eliminate PWN-infected trees in the forest area for the prevention of PWD transmission. Up to date, there is no report on biomarkers such as DNA and protein for the diagnosis of B. xylophilus. In this study, we produced a B. xylophilus monoclonal antiserum (D9-F10) from BalbC mice and screened its specificity with various proteins extracts. Western blot analysis revealed that the D9-F10 is only reactive with B. xylophilus protein extract among other tested protein extracts, indicating that the D9-F10 is specific for a B. xylophilus protein. Furthermore, two-dimensional electrophoresis showed the D9-F10 detects a very highly acidic protein, pI≒3.5. These results suggest that the D9-F10 monoclonal antibody is useful for the development of a diagnostic kit for the pine wilt disease.
        17.
        2008.05 구독 인증기관·개인회원 무료
        The pinewood nematode (PWN, Bursaphelenchus xylophilus) causes the pine wilt disease, transmitted to pinewoods by the pine sawyer beetle, Monochamus alternatus. It is very difficult to discriminate B. xylophilus from B. mucronatus. Therefore, it has been necessary to detect PWN-infected trees for the prevention of pine wilt disease transmission in a short time. The development of biomarkers such as DNA and protein is important for diagnosis of B. xylophilus. However, there have been no reports regarding biomarker identifications of B. xylophilus. In this study, polyclonal antisera were raised against whole proteins of B. xylophilus in BalbC mice and were primarily screened with ELISA. Twenty five among over 500 cell lines releasing polyclonal antisera revealed B. xylophilus-specific immuno-reactivity, which was at least three times higher than that of B. mucronatus. Three cell lines among them were secreting monoclonal antibody through further screening. These cell lines only detect about a 33-kDa protein in B. xylophilus in the western blot. These results suggest that these monoclonal antibodies will be useful for the development of diagnostic kit for the pine wilt disease.
        18.
        2008.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 확산에 의해 발생하는 시멘트 방벽의 변질 과정을 반응성용질이동 모델링을 통해 장기간 동안 예측하고자 하였다. 모델링 결과 50,000년 후 시멘트의 변질은 30cm까지 진행되었다. pH는 13.0에서 11.86까지 감소하였으며 이는 알칼리 이온의 감소, 포틀랜다이트(portlandite)와 CSH (Calcium Silicale Hydrate)광물의 용해/침전반응에 의해 결정되고 있었다. 공극률 또한 portlandite와 의 용해에 의해 가장 큰 영향을 받고 있었으며 최고 약 0.3 점도 증가하였다. 우라늄의 용해도 역시 증가하고 있었으며 이는 pe의 증가에 기인하고 있었다. 본 연구 결과는 장기간의 시멘트 변질이 pH, pe, 공극률을 변화시킴으로서 핵종의 이동을 증가시킬 수 있음을 보여주고 있다.
        4,000원
        19.
        2008.03 구독 인증기관 무료, 개인회원 유료
        Pronuclear DNA microinjection has been the most universal method in transgenic animal production but its success rate of transgenesis in mammals are extremely low. To address this long-standing problem, we used retrovirus- and lentivirus-based vectors carrying the enhanced green fluorescent protein (EGFP) gene under the control of ubiquitously active cytomegalovirus (CMV) promoter to deliver transgenes to bovine embryos. The rate of transgenesis was evaluated by counting EGFP positive blastocysts after injection of concentrated virus stock into the perivitelline space of the bovine oocytes in metaphase II. Among two different types of lentivirus vectors derived from FIV (feline immunodeficiency virus) and HIV (human immunodeficiency virus), the former scored the higher gene transfer efficiency; almost 100% of the blastocysts developed from the oocytes infected with FIV-based vector were EGFP positive. As for the vectors derived Com HIV lentivirus, the transgenesis rate of the blastocysts was reduced to 39%.
        4,900원
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