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        검색결과 11

        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.
        2018.10 구독 인증기관·개인회원 무료
        Tetranychus urticae and Myzus persicae are one of the most serious insect pests in many crops, vegetables, flowers, and fruit trees worldwide. Many insecticides have been developed to control green peach aphid and two spotted spider mite, but resistance to almost all insecticides has reduced their control effect. Particular groups of plant-beneficial microbials are not only root colonizers that provide plant disease suppression, but in addition are able to infect and kill insect larvae. Antimicrobial compounds produced by biocontrol microbes are effective weapons against a vast diversity of organisms such as fungi, nematodes, and viruses. In this study, we evaluated the effectiveness of mixtures plant extracts and improvement of culture process biocontrol microbials on insecticidal activity. Azadirachta indica and Derris elliptica mixed with micorbials, which are nutrient sources of mung bean extract and lecithin, were more effective than other the mixtures. Leaf spraying with the mixture of Pseudomonas fluorescens significantly showed the highest insecticidal power in vivo for 24 hours after treatment. The effect of spraying mixture was more than 50% at 2000 times dilution, and the spraying concentration of 90% or more showed a dilution of up to 500 times. Our results indicated that the nutrient sources of microbe act as a key antimicrobial metabolite in biocontrol of insect pests, and mixing with plant extracts can provide synergistic effects as an optimal usage of the biocontrol agents.
        3.
        2008.09 구독 인증기관 무료, 개인회원 유료
        수평 배향 액정 모드는 양의 유전율 이방성과 음의 유전융 이방성 액정을 사용한 프린지 필드 스위칭과 양의 유전율 이방성 액정을 사용한 인플래인 스위칭 모드가 대표적이다 . 이 대표적인 세 구동 방식의 화질 특성을 비교하기 위하여 각각의 최척화된 위상지연 값 조건하에서 밝기, 명암대비율과 색 특성을 조사하였다. 그 결과 양액정과 음액정을 사용한 프린지 필드 스위칭 모드가 밝기와 명암대비율 면에 있어서 인플래인 스위칭 모드보다 우수한 특성을 보인다. 또한 양액정을 사용한 프린지 필드 스위 칭 모드는 시야각 방향에서 적은 색 변이 특성을 보인다.
        4,000원
        4.
        2017.08 서비스 종료(열람 제한)
        Spinal cord is a posterior part of central nervous system, developmentally produced by the folding of the neural plate via an embryonic process called neurulation. Defects in neurulation is one of the most common birth defects in human, raising the importance to develop in vitro model recapitulating human neurulation. The advent of organoid technology, which can produce 3D structure resembling parts of organs from human embryonic stem cells/induced pluripotent stem cells (ESCs/iPSCs), has offered new tools to model human diseases. Recently, we developed organoid model exhibiting morphogenetic features of spinal cord development, such as neural plate formation, neural folding, and neural tube closure and profound production of spinal cord-type motor neurons. Human spinal cord organoids will be a useful tool for assessing genetic and environmental factors affecting spinal cord development, and screening ‘personalized drugs’ for spinal cord diseases such as Amyotrophic Lateral Sclerosis (ALS).
        5.
        2014.09 서비스 종료(열람 제한)
        The patent ductus arteriosus (PDA) is a vascular structure connecting the proximal descending aorta to the roof of the main pulmonary artery, near the origin of the left branch pulmonary artery. Transcatheter closure has become the treatment of choice for most cases of PDA in both children and adults; however, measurement of the exact size and morphology of the shunt in adult cases using only contrast fluoroscopy is difficult. We report on a case of a 49-year-old woman who underwent transcatheter closure of PDA with intravascular ultrasound (IVUS) guideance. In the current case, IVUS is feasible and helpful for measuring the exact size and shape of the PDA.
        6.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        Neural stem cells are found in adult mammalian brain regions including the subgranular zone (SGZ) of the dentate gyrus (DG) and the subventricular zone (SVZ). In addition to these two regions, other neurogenic regions are often reported in many species. Recently, the subcallosal zone (SCZ) has been identified as a novel neurogenic region where new neuroblasts are spontaneously generated and then, by Bax-dependent apoptosis, eliminated. However, the development of SCZ in the postnatal brain is not yet fully explored. The present study investigated the precise location and amount of neuroblasts in the developing brain. To estimate the importance of programmed cell death (PCD) for SCZ histogenesis, SCZ development in the Bax-knockout (KO) mouse was examined. Interestingly, an accumulation of extra neurons with synaptic fibers in the SCZ of Bax-KO mice was observed. Indeed, Bax-KO mice exhibited enhanced startle response to loud acoustic stimuli and reduced anxiety level. Considering the prevention of PCD in the SCZ leads to sensory-motor gating dysfunction in the Bax-KO mice, active elimination of SCZ neuroblasts may promote optimal brain function.
        8.
        2011.09 서비스 종료(열람 제한)
        Apoptosis of the cell is one of the key steps in tissue remodeling and functional differentiation. At the time of implantation there are dramatically remodeling and functional differentiations of uterine endometrium. Decidualization is the process by which the uterine stromal cells proliferate and differentiation into morphologically and functionally distinct decidual cells. Bax is one of the key molecules in apoptotic process during that time. It is known that Bax expression have characters of time specificity and tissue specificity but the role of implantation is not largely unknown. The aim of this study was to examine the embryo implantation and decidualization reaction in order to understand the role of pro-apoptotic Bax gene as a major regulator of apoptosis of decidual cells. Some of Bax knockout mice have coat pigmentation defects involving white color. The number of blue bands after embryo transfer (ET) was not different between the control and Bax-knockout (Bax-KO) black coat (BC) and white coat (WC). Decidua were normally differentiated in both control and Bax-KO BC, but deciuda were not detected in Bax-KO WC at 96 hr post ET. Moreover, embryos of Bax-KO WC stayed in dormant stage on the embryonic day 7.5 and day 9.5. These results suggest that Bax and its related unknown genes may be a key molecule in implantation and uterine decidual reaction.