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        검색결과 1,173

        563.
        2011.10 구독 인증기관·개인회원 무료
        Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We studied the susceptibility of this biotype of B. tabaci to 21 isolates of Beauveria bassiana, 3 isolates of Isaria spp., 1 isolate of P. cateni,3 isolates of Lecanicillium lecanii, 1 isolate of L. attenuatum and 1 isolate of Aschersonia aleyrodes. These isolates were evaluated on pruned egg plant seedlings, at a concentration of 108conidia/ml (deposited at 6000±586 conidia mm-2). The mortality based on mycosis varied from 18 to 97% after 6 days. An Isaria sp. isolate, two B. bassiana isolates and a L. lecanii isolate were found the most effective. Furthermore, five isolates were chosen for concentration-mortality response assays and compared to B. bassiana GHA as a standard. The numbers of nymphs infected by fungi were correlated with the spore concentration. A L. lecanii isolate and Isaria sp. had the short LT50 at 6000±586 conidia mm-2. Mortality reduced and LT50s were longer as the concentration of conidia was reduced. The LD50 values were differed in isolates from 87 to 269 conidia mm-2. These results indicated that the Q biotype of sweetpotato whitefly was susceptible to the five isolates of entomopathogenic fungi and these isolates have potential to be developed as a microbial pesticide for whitefly control.
        564.
        2011.10 구독 인증기관·개인회원 무료
        Up to days, approximately 150 species of the subfamily scolytinae have been recorded from Korean peninsula. We have examined the collections of the Museum in Seoul National University, Korea Forest Research Institute, Research Institute of Forest Insects Diversity and National Plant Quarantine Service. And we have collected the bark beetles with Malaise traps and Lindgren funnel traps from 2007 to 2011 in the central part of the Korean peninsula. As a result of this study, we report 4 species, Hylurgus ligniperda (Fabricius 1787), Sueus niisimai (Eggers 1926), Scolytogenes expers (Blandford 1894) and Xylosandrus compactus (Eichhoff 1878) to Korean fauna with brief descriptions and illustrations of diagnostic characters.
        565.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Kenaf fibers, cellulose-based natural fibers, were used as precursor for preparing kenafbased carbon fibers. The effects of carbonization temperature (700℃ to 1100℃) and chemical pre-treatment (NaOH and NH4Cl) at various concentrations on the thermal change, chemical composition and fiber morphology of kenaf-based carbon fibers were investigated. Remarkable weight loss and longitudinal shrinkage were found to occur during the thermal conversion from kenaf precursor to kenaf-based carbon fiber, depending on the carbonization temperature. It was noted that the alkali pre-treatment of kenaf with NaOH played a role in reducing the weight loss and the longitudinal shrinkage and also in increasing the carbon content of kenaf-based carbon fibers. The number and size of the cells and the fiber diameter were reduced with increasing carbonization temperature. Morphological observations implied that the micrometer-sized cells were combined or fused and then re-organized with the neighboring cells during the carbonization process. By the pre-treatment of kenaf with 10 and 15 wt% NaOH solutions and the subsequent carbonization process, the inner cells completely disappeared through the transverse direction of the kenaf fiber, resulting in the fiber densification. It was noticeable that the alkali pre-treatment of the kenaf fibers prior to carbonization contributed to the forming of kenaf-based carbon fibers.
        4,000원
        566.
        2011.09 구독 인증기관 무료, 개인회원 유료
        Eugenol is an essential oil found in cloves and cinnamon that is used widely in perfumes. However, the significant anesthetic and sedative effects of this compound have led to its use also in dental procedures. Recently, it was reported that eugenol induces apoptosis in several cancer cell types but the mechanism underlying this effect has remained unknown. In our current study, we examined whether the cytotoxic effects of eugenol upon human melanoma G361 cells are associated with cell cycle arrest and apoptosis using a range of methods including an XTT assay, Hoechst staining, immunocytochemistry, western blotting and flow cytometry. Eugenol treatment was found to decrease the viability of the G361 cells in both a time- and dose-dependent manner. The induction of apoptosis in eugenol-treated G361 cells was confirmed by the appearance of nuclear condensation, the release of both cytochrome c and AIF into the cytosol, the cleavage of PARP and DFF45, and the downregulation of procaspase-3 and -9. With regard to cell cycle arrest, a time-dependent decrease in cyclin A, cyclin D3, cyclin E, cdk2, cdk4, and cdc2 expression was observed in the cells after eugenol treatment. Flow cytometry using a FACScan further demonstrated that eugenol induces a cell cycle arrest at S phase. Our results thus suggest that the inhibition of G361 cell proliferation by eugenol is the result of an apoptotic response and an S phase arrest that is linked to the decreased expression of key cell cycle-related molecules.
        4,000원
        567.
        2011.06 구독 인증기관 무료, 개인회원 유료
        Acute ischemic stroke results from sudden decrease or loss of blood supply to an area of the brain, resulting in a coinciding loss of neurological function. The antioxidant action of melatonin is an important mechanism among its known effects to protective activity during ischemic/reperfusion injury. The focus of this research, therapeutic efficacy of melatonin on recovery of neurological function following long term treatment in ischemic brain injured rats. Male Sprague-Dawley rats (n=40; 8 weeks old) were divided into the control group, and MCAo groups (Vehicle, MT7 : MCAo+ melatonin injection at 7:00, MT19 : MCAo+melatonin injection at 19:00, and MT7,19 : MCAo+melatonin injection at 7:00 and 19:00). Rat body weight and neurological function were measured every week for 8 weeks. After 8 weeks, the rats were anesthetized with a mixture of zoletil (40 mg/kg) and xylazine (10 mg/kg) and sacrificed for further analysis. Tissues were then collected for RNA isolation from brain tissue. Also, brain tissues were analyzed by histological procedures. We elucidated that melatonin was not toxic in vital organs. MT7,19 was the most rapidly got back to mild symptom on test of neurological parameter. Also, exogenous melatonin induces both the down-regulation of detrimental genes, such as NOSs and the up-regulation of beneficial gene, including BDNF during long term administration after focal cerebral ischemia. Melatonin treatment reduced the loss of primary motor cortex. Therefore, we suggest that melatonin could be act as prophylactic as well as therapeutic agent for neurorehabilitative intervention.
        4,000원
        568.
        2011.06 구독 인증기관 무료, 개인회원 유료
        To explore the role of histone deactylase (HDAC) activation in an in vivo model of hypertrophy, we studied the effects of Trichostatin A (TSA). TSA subjected to thoracic aortic banding (TAB)-induced pressure stress in mice. In histological observations, TAB in treated mice showed a significant hypertrophic response, whereas the sham operation remained nearly normal structure with partially blunted hypertrophy. TSA treatment had no effect (measured as HW/BW) on sham-operated animals. TAB animals treated with vehicle manifested a robust ~50% hypertrophic response (p<0.05 vs sham). TAB mice treated with 2 mg/kg/day TSA manifested a blunted growth responses, which was significantly diminished (p<0.05) compared with vehicle-treated TAB mice. TAB mice treated with a lower dose of TSA (0.5 mg/kg/day) manifested a similar blunting of hypertrophic growth (~25% increase in heart mass). Furthermore, to determine activity duration of TSA in vitro, 1 nM TSA was added to H9c2 cells. Histone acetylation was initiated at 4 hr after treatment, and it was peak up to 18 hr, then followed by significantly reduced to 30 hr. We also analyzed the expression of p53 following TSA treatment, wherein p53 expression was elevated at 4 hr, and it was maintained to 24 hr after treatment. ERK was activated at 8 hr, and maintained till 30 hr after treatment suggesting an intracellular signaling interaction between TSA and p53 expression. Taken together, it is suggested that HDAC activation is required for pressure-overload growth of the heart. Eventually, these data suggest that histone acetylation may be a novel target for therapeutic intervention in pressure-overloaded cardiac hypertrophy.
        4,000원
        569.
        2011.06 구독 인증기관 무료, 개인회원 유료
        Clinical arthritis is typically divided into rheumatoid arthritis (RA) and osteoarthritis (OA). Arthritis-induced muscle weakness is a major problem in aged people, leading to a disturbance of balance during the gait cycle and frequent falls. The purposes of the present study were to confirm fiber type-dependent expression of muscle atrophy markers induced by arthritis and to identify the relationship between clinical signs and expression of muscle atrophy markers. Mice were divided into four experimental groups as follows: (1) negative control (normal), (2) positive control (CFA+acetic acid), (3) RA group (CFA+acetic acid+type Ⅱ collagen), and (4) aging-induced OA group. DBA/1J mice (8 weeks of age) were injected with collagen (50 μg/kg), and physiological (body weight) and pathological (arthritis score and paw thickness) parameters were measured once per week. The gastrocnemius muscle from animals in each group was removed, and the expression of muscle atrophy markers (MAFbx and MuRF1) and myosin heavy chain isoforms were analyzed by reverse transcription-polymerase chain reaction. No significant change in body weight occurred between control groups and collagen-induced RA mice at week 10. However, bovine type Ⅱ collagen induced a dramatic increase in clinical score or paw thickness at week 10 (p<0.01). Concomitantly, the expression of the muscle atrophy marker MAFbx was upregulated in the RA and OA groups (p<0.01). A dramatic reduction in myosin heavy chain (MHC)-Iβ was seen in the gastrocnemius muscles from RA and OA mice, while only a slight decrease in MHC-Ⅱb was seen. These results suggest that muscle atrophy gene expression occurred in a fiber type-specific manner in both RA- and OA-induced mice. The present study suggests evidence regarding why different therapeutic interventions are required between RA and OA.
        4,000원
        570.
        2011.06 구독 인증기관 무료, 개인회원 유료
        Arthritis is a common disease in aged people, and is clinically divided into rheumatoid arthritis (RA) and osteoarthritis (OA). Although common symptoms such as pain are present, the underlying pathological mechanisms are slightly different. Therefore, the objectives of the present study were to compare joint damage induced by RA and OA by analyzing the major morphological and molecular differences, and to propose a suitable therapeutic intervention based on the pathophysiological conditions of bones and joints. For the RA animal model, 8-week-old DBA1/J mice were immunized with bovine type II collagen emulsified in complete Freund’s adjuvant (CFA). Normal C57BL/6 mice (over 2 years of age) were used for OA. The clinical arthritis score was calculated using a subjective scoring system, and paw thicknesses were measured using calipers. The serum TNFα level was analyzed using an ELISA kit. Micro- CT was used to identify pathological characteristics and morphological changes. In collagen-induced RA mice, there were increased ankle joint volumes and clinical scores (p<0.01). The concentration of TNFα was significantly increased from 3 to 7 weeks after immunization. Micro-CT images showed trabecular bone destruction, pannus formation, and subchondral region destruction in RA mice. OA among aged mice showed narrowed joint spaces and breakdown of articular cartilage. This study suggests that a careful therapeutic intervention between RA and OA is required, and it should be based on morphological alteration of bone and joint.
        4,000원
        571.
        2011.06 구독 인증기관 무료, 개인회원 유료
        In all living organisms, respiration may lead to oxidative stress, a state where increased formation of reactive oxygen species overwhelms host protection and subsequently induces DNA damage, lipid peroxidation, and protein denaturation. As a phenolic acid, chlorogenic acid occurs ubiquitously in food. It has been proven to have a number of biological effects in vitro and in vivo, including antioxidant, anti-inflammatory, and anticarcinogenic properties. Therefore, to some extent, chlorogenic acid can promote human health, and hopefully provide new methods for treatment of chronic disease. Recent studies have focused on the antioxidant properties of dietary polyphenols. The in vitro data often conflict with results obtained from in vivo studies on the antioxidant capacity of plasma or the resistance of plasma and lipoproteins to oxidation ex vivo after consumption of polyphenol-rich foods by human subjects. These inconsistencies are likely explained by the limited bioavailability of dietary polyphenols and their extensive metabolism in humans. Polyphenols exert multifaceted actions, and any clinical application using these substances should be based on a precise understanding of the physiologically relevant mechanisms.
        4,000원
        573.
        2011.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A primary purpose of this paper is to critically evaluate Professor P. Singh’s Article, “Colonised’s Madness, Colonisers’Modernity and International Law: Mythological Materialism in the East-West Telos”published in Volume 3, Number 1 of the Journal of East Asia and International Law. In his article, Singh attempted to overlap various conceptions of modernity taken from a wide range of academic disciplines, and experimentally collapse them into one with a post-colonial point of view. In spite of incomplete argumentation and obscurity in the conceptual formulation, I found his original ideas on the internal connection of modernity with the operating mode of international law to be highly impressive. The most critical point against him was the firm and stereotypical dichotomy of the colonizer and the colonized without any potentiality of sublating the state of colonization, that is, disconnecting the colonizers with their colony and liberating the colonized from their colony. By such sublation (Aufheben) of the existing oppressive relation between the colonizers and the colonized, we can plan to build a new world of peaceful coexistence between the colonizers and the colonized of the past. But although Singh’s conception of modernity is dangerously one-sided, I expect his further research to penetrate into the deep life-reality of the Indian subaltern, which would make a great contribution to the establishment of the new vision of international law in this global society.
        4,000원
        574.
        2011.05 구독 인증기관·개인회원 무료
        The emulsion and micro-encapsuled formulation from three essential oils, cassia, thyme white and lemon grass were tested for their insecticidal activities against Lycoriella ingenua (Dufour) adults at 0.3% concentration. As a result, the micro-encapsules than emulsion formulation was confirmed to show greater activity. Based on this result, insecticidal activities at several levels of concentration were examined, resulting in more than 80% insecticidal activity after 30 minutes at 0.6% level of cassia formulation. And also, insecticidal activity of three oil-based micro-encapsuled formulations lasted for up to 12 hours at 0.9% concentration. The main ingredients derived from three essential oils were evaluated on the insecticidal activity against Lycoriella ingenua. As a result, in case of thymol from thyme white, it showed more than 80% mortality after over 30 minutes at 0.25%, and in cinnamic aldehyde and citral, exhibited 88% and 82% mortality after 30 minutes at the 0.5% level, respectively. These three compounds were examined for whether the insecticidal activity was maintained depending on being over time. In case of thymol, it maintained good insecticidal activity against Lycoriella ingenua at 0.5% level until 120 hours, while cinnamic aldehyde and citral showed lower activity after 12 hours.
        575.
        2011.05 구독 인증기관·개인회원 무료
        The Korean record of Scolytoplatypus mikado Blandford 1893 is originated from Murayama (1929) whereas Wood(1989) synonimyzed S. sinensis Tsai & Huang 1965 as a junior synonym of S. mikado Blandford 1893. In 2010, the authors collected several specimens from Korea and Japan and found considerable morphological differences between S. sinensis and S. mikad the process on the prosternum, the pubescences on the procoxae, and the shape of the male elytral declivity. Comparing the Cytochrome Oxidase I and 16S rRNA gene, we also found the genetical gap between the South Korean specimens (= S. sinensis, with the Japanese sample from Mt. Tsukubasan) and the sample from Mt. Yamizosan, Japan (= S. mikado). Accordingly, S. sinensis Tsai & Huang 1965 is here reinstated.
        578.
        2011.03 구독 인증기관 무료, 개인회원 유료
        Sepsis is a clinical syndrome defined as a systemic inflammatory response to infection. Eritoran is a synthetic lipid A derivative that competes with lipopolysaccharide in binding to the identical site of myeloid differentiation-2/toll-like receptor 4 complex. Eritoran is effective in decreasing the septic mortality of Gram-negative bacteria-infected animals. Eritoran has been highlighted as a candidate drug for treatment of endotoxemia in phase I clinical studies with healthy human volunteers. A phase II trial of eritoran has been conducted in patients with severe sepsis. Intravenous infusion of eritoran reduced the mortality rate, as compared with the placebo group, in sepsis patients at a high risk of mortality according to acute physiology and chronic health evaluation-II scores. A phase III study of eritoran was completed in 2011. The results appear to be disappointing as no statistically significant difference in all-cause mortality was observed between the eritoran treatment group and the placebo group on day 28 in sepsis patients with a high risk of death. In this review, we focus on the rationale for the use of eritoran in treatment of sepsis as well as its clinical applications.
        4,000원
        579.
        2011.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present a deep CCD imaging in B and V bands which allows us to analyze the vertical structure of NGC 4631. We derive the scale heights of the thin and thick disks at a variety of positions along the major axis of the disk. The scale heights of the thin disk are nearly constant while those of the thick disk tend to increase with increasing galactocentric distance. The mean scale heights of the thin disk derived from B and V images are similar to each other (~ 450 pc). Instead, those of the thick disk show a strong east-west asymmetry which is caused by the diffuse stellar emission that is most prominent in the north west regions above the disk plane. The ratio of scale heights (z_thick/zthin) is about 2.5 in the east side of the disk. However, this ratio is greater than 4 for the thick disk above the disk plane in the west side of the galaxy.
        4,000원
        580.
        2011.01 구독 인증기관·개인회원 무료
        Dasan (茶山) Jung, Yak-Yong (丁若鏞, 1762-1836) who compiled the Practical Thought in the latter period of Chosun dynasty had asserted the acceptance of foreign advanced culture for the people's utilization and welfare. He, in Giyeron, asserted that Chosun should introduce the hi-tech culture of Chung dynasty for people's utilization and welfare including all the technical skill and new institutional systems. And he asserted that we should learn the merits of Japan, as it were (1) the strengthening of the national defence (2) the excellent shipbuilding technology (3) the lattice window of the official residences. Dasan criticized that Shin, Yu-Han (申維翰) who had dropped in Japan as a communication man hadn't surveyed on “the elaborateness of their industry and various training exercises" in Valhaesagyunmunrok (跋海槎見聞錄). He, in prefaces for declaration, asserted that the import of diverse hi-tech industry is the second obligation of the ambassador. Dasan who had classified the ambassador into two kinds as like (1) the style of Yi, Ki-Yang (李基讓) had contributed to the people's welfare by introducing their thrashing fan machine for raw cotton <prefaces for declaration>, (2) the style of Shin, Wi (申緯) had purchased oddly shaped stones for individual taste <Jaejaesukdo (題載石圖)> judged the latter more highly. He won the highest praise on Yi, Ki-Yang that his achievement could be stood beside Moon, Yik-Jum (文益漸) who had contributed a lot to the people's welfare by importing the cottonseed first. Dasan's assertion for the acceptance of foreign advanced culture had aimed just to the people's easy utilization and welfare had been derived from his realism and practicalism.