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        검색결과 172

        81.
        2016.04 구독 인증기관·개인회원 무료
        Acetylcholinesterase 1 (AmAChE1) has low catalytic activity and is abundantly expressed in both neuronal and non-neuronal tissues. In previous experiments, we observed that AmAChE1 is rarely expressed in summer while highly expressed in winter. Through additional experiments, the expression of AmAChE1 was suggested to be associated with brood rearing status. Under the assumption that abnormal suppression of brood rearing activity may result in stressful condition in honey bee social community, it was further suggested that AmAChE1 is likely involved in stress management particularly during winter. We hypothesized that the increased docility usually observed in overwintering bees is likely an outcome of stress management in colony, which is mediated by AmAChE1 expression. To verify this, worker bees expressing abundant AmAChE1 were collected in early winter and injected with Amace1 dsRNA to knockdown Amace1. Then, the behavioral activity of the bees was investigated using the EthoVison video tracking system. Honey bees injected with Amace1 dsRNA showed significantly increased motility, which was strongly correlated with the suppressed expression level of AmAChE1 in the abdomen. No apparent reduced expression of AmAChE1 in the head was observed perhaps due to the limited efficacy of RNA interference in the blood-brain-barrier. Our finding suggests that behavioral activity can be regulated, at least, by AmAChE1 expression level in non-neuronal tissue (i.e., fatbody) perhaps via metabolic alteration.
        82.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study attempts to manufacture a Ni-Cr-Al-Y coating layer using a kinetic spray process and investigates the microstructure and physical properties of the manufactured layer. The Ni-22Cr-10Al-1Y (wt.%) composition powder is used, and it has a spherical shape with an average diameter of 23.7 μm. Cu plate is used as the substrate. Optical microscope, X-ray diffraction, scanning electron microscope and Vickers hardness test are carried out to characterize the macroscopic properties of the coating layer. Furthermore, the coating layer underwent vacuum heat treatment at temperatures of 400˚C and 600˚C for 1 hour to check the effect of heat treatment temperature on the properties. The manufactured coating layer is 1.5 mm thick, and featured identical phases to those found in the powder. The porosity of the coating layer is measured at 2.99%, and the hardness is obtained at 490.57 Hv. The layer shows reduced porosity as heat treatment temperature increased, and hardness is reduced at 400˚C but shows a slight increase at 600˚C. Based on the findings described above, this study also discusses possible manufacturing methods for a Ni-Cr-Al-Y coating layer using the kinetic spray process.
        4,000원
        83.
        2015.12 구독 인증기관 무료, 개인회원 유료
        The aim of the present study was to investigate sex- and age-associated clinico-metabolic characteristics of urinary stone patients. A retrospective review was performed on data from 2,009 consecutive patients presenting with their first urinary stone episode between 2005 and 2013. Of the 2,009 patients, 1,426 (71.0%) satisfied the inclusion criteria and were enrolled in the study. Patients were grouped by age (<60, ≥60 years old) and sex. The medical history and 24 hr urinary chemistry results of each patient were obtained. The mean age of the 165 (11.6%) patients aged 60 or over was 65.5 ± 4.2 years. Body mass index was greater in elderly females than in younger females (p=0.031). After stratification by sex and age, lower urinary excretion of calcium and uric acid was a protective factor for both sexes among the elderly (p<0.05, each, respectively). Low urine pH was a common risk factor for both sexes among the elderly (p=0.013 in males, p=0.047 in females, respectively), whereas lower citrate excretion was a risk factor for only the elderly female group (p=0.004). With regard to urinary metabolic abnormalities, elderly females showed higher incidence of hypocitraturia compared to younger females (p=0.049). In conclusion, this study demonstrated the sex- and age-associated clinico-metabolic characteristics of urinary stone patients. Thus, it is important to tailor metabolic evaluation and medical prevention therapies for patient according to sex and gender characteristics.
        4,000원
        84.
        2015.12 구독 인증기관 무료, 개인회원 유료
        Recently, food delivery apps are seeing rapid growth into a market worth 1 trillion won under a simple but unique business model of connecting nearby restaurants with consumers via smartphone. Though basic similarities with social commerce exists in aspects such as mail-order sales intermediaries, startups, types of services and market competition structure, food delivery apps resemble social commerce in many ways in that they use excessive marketing to secure market dominance, causing a spike in consumer complaints. If the excessive marketing and increase in customer complaints are not rectified, the food delivery app could also see rapid decline as it gradually grows distant from consumers, just like social commerce. Accordingly, this study will identify the factors consumers recognize as important for continuous use vis-a-vis social commerce and food delivery apps to perform an empirical analysis on what areas need improvement. After deriving the four upper factors of product, information system and service along with eight sub-factors by referring to existing literature, the areas with opportunity for improvement were derived through satisfaction level and relative importance evaluation. The results of this study present a strategic direction for maintaining customers of social commerce and food delivery apps.
        4,000원
        89.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper we introduce the Plasma Physics of Active Galactic Nuclei project, which is an ongoing experiment with Korean VLBI Network (KVN) and KVN and VERA Array (KaVA) to study multi- frequency polarimetric properties on parsec scales of active galaxies. The goal of the project is to improve our understanding of fundamental jet physics, especially evolution of the relativistic out ow coupled with the large-scale magnetic field. We selected six radio-loud AGN as our targets. So far we (i) detected resolved emissions regions at 86 and 129 GHz on VLBI scales, (ii) constructed 2D spectral index maps of the out ows, and (iii) found polarizations at 22 and 43 GHz for a few targets. Here we present spectral index distributions of 3C 120 between 22 and 43 GHz and a linear polarization map of BL Lac at 43 GHz obtained with KVN.
        3,000원
        90.
        2015.06 구독 인증기관 무료, 개인회원 유료
        Dietary and lifestyle modifications are widely prescribed to prevent recurrence of urolithiasis, although little is known about the clinical and demographic factors associated with patient compliance and urinary metabolic changes. The present study assessed the clinical and demographic factors influencing compliance with a modified diet and lifestyle in first-time ureteric stone formers as well as determined the effects of compliance on urinary stone risk factors. We retrospectively reviewed the medical records of 53 patients presenting with ureteric calcium stones. Using a self-completed questionnaire, patients were classified according to compliance with seven recommendations for modifying diet and lifestyle into good compliance group (complied with ≥ three recommendations) and poor compliance group. Before (on a random diet) and after prescribing the modifications, 24 hour urine samples were collected from those in the good and poor compliance group. The stone size at presentation and initial treatment modality were closely associated with patient compliance (P=0.019, P=0.027, respectively). Citrate excretion significantly increased in the good compliance group after adopting modifications (P=0.012), whereas the poor compliance group did not show a statistically significant difference. Moreover, patients in the poor compliance group showed significantly increased urinary calcium excretion by the end of the study (P=0.040). After adjustments for age, sex, body mass index, and metabolic abnormality status, poor compliance was found to be an independent risk factor for persistence or development of hypocitraturia (OR: 3.885; 95% CI: 1.102~13.694; P=0.035). In conclusion, our results imply that patient education programs regarding diet and lifestyle should be tailored to the individual’s clinical and demographic characteristics.
        4,000원
        92.
        2013.12 구독 인증기관 무료, 개인회원 유료
        Muscle satellite cell (SC) is responsible for postnatal muscle growth, repair, and regeneration. Satellite cell is an im-portant source of multi-potent stem cell process and differentiation into adipogenic, myogenic, and osteoblastogenic. The objective of this study was to identify alter of transcriptome during differentiation in porcine satellite cell and to elevated transcriptome at different stages of postnatal development to gain insight into the differences in differ-entiated PSC. We used RNA-seq technique to investigate the transcriptomes during differentiation in pig muscle. Sequence reads were obtained from Illumina HiSeq2000. Differentially expressed genes (DEG) were detected by EdgeR. Gene ontology (GO) terms are powerful tool for unification among representation genes or products. In study of GO biological terms, functional annotation clustering involved in cell cycle, apoptosis, extracellular matrix, phosphoryla- tion, proteolysis, and cell signaling in differences stage. Taken together, these results would be contributed to a better understanding of muscle biology and processes underlying differentiation. Our results suggest that the source of DEGs could be better understanding of the mechanism of muscle differentiation and transdifferentiation.
        4,500원
        93.
        2013.12 구독 인증기관 무료, 개인회원 유료
        Satellite cells were derived from muscular tissue in postnatal pig. Satellite cell is an important to growth and development in animal tissues or organs. However, the progress underlying induced differentiation is not clear. The aim of this study was to evaluate the morphologic and the transcriptome changes in porcine satellite cell (PSC) treated with insulin, rosiglitazone, or dexamethasone respectively. PSC was obtained from postnatal muscle tissue. In study 1, for study the effect of insulin and FBS on the differentiated satellite cells, cells were cultured at absence or presence of insulin treated with FBS. Total RNA was extracted for determining the expression levels of myo-genic PAX3, PAX7, Myf5, MyoD, and myogenin genes by real-time PCR. Myogenic genes decreased expression levels of mRNA in treated with insulin. In study 2, in order to clarify the relationship between rosiglitazone and lipid in differentiated satellite cells, we further examined the effect of FBS on lipid accumulation in the presence or absence of the rosiglitazone and lipid. Significant differences were observed between rosiglitazone and lipid by FBS. The mRNA of FABP4 and PPARγ increased in rosiglitazone treatment. In study 3, we examined the effect of dexame-thasone on osteogenic differentiation in PSC. The mRNA was increased osteoblasotgenic ALP and ON genes treated with dexamethasone in 2% FBS. Dexamethasone induces osteoblastogenesis in differentiated PSC. Taken together, in differentiated PSCs, FABP4 and PPARγ increased to rosiglitazone. Whereas, no differences to FBS and lipid. These results were not comparable with previous reports. Our results suggest that adipogenic, myogenic, and osteoblasto-genic could be isolated from porcine skeletal muscle, and identify culture conditions which optimize proliferation and differentiation formation of PSC.
        4,000원
        94.
        2013.12 구독 인증기관 무료, 개인회원 유료
        Muscular satellite cell (SC), which is stem cell of postnatal pig, is an important for study of differentiation into adipogenesis, myogenesis, and osteoblastogenesis. In this study, we isolated and examined from pig muscle tissue to determine capacity in proliferate, differentiate, and expression of various genes. Porcine satellite cells (PSC) were isolated from semimembranosus (SM) muscles of 90∼100 days old pigs according to standard conditions. The cell proliferation increased in multi-potent cell by Masson’s, oil red O, and Alizarin red staining respectively. We per-formed the expression levels of differentiation related genes using real-time PCR. We found that the differentiation into adipocyte increased expression levels of both fatty acid binding protein 4 (FABP4) and peroxisome proliferator- acti-vated receptor gamma (PPARγ) genes (p<0.01). Myocyte increased the expression levels of the myosin heavy chain (MHC), myogenic factor 5 (Myf5), myogenic regulatory factor (MyoD), and Myogenic factor 4 (myogenin) (p<0.01). Osteo-blast increased the expression levels of alkaline phosphatase (ALP) (p<0.01). Finally, porcine satellite cells were indu-ced to differentiate towards adipogenic, myogenic, and osteoblastogenic lineages. Our results suggest that muscle satellite cell in porcine may influence cell fate. Understanding the progression of PSC may lead to improved strat-egies for augmenting meat quality.
        4,000원
        95.
        2013.10 구독 인증기관·개인회원 무료
        Most traditional genome sequencing projects involving infectious viruses include culturing and purification of the virus. This can present difficulties as an analysis of multiple populations from multiple locations may be required to acquire sufficient amount of high-quality DNA for sequence analysis. The electrophoretic method provides a strategy whereby the genomic DNA sequences of the Korean isolate of Pieris rapae granulovirus (PiraGV-K) were analyzed by purifying it from host DNA by pulsed-field gel electrophoresis, thus simplifying sampling and labor time. The genomic DNA of infected P. rapae was embedded in agarose plugs, digested with a restriction nuclease and methylase, and pulsed-field gel electrophoresis (PFGE) was used to separate PiraGV-K DNA from the DNA of P. rapae, followed by mapping of fosmid clones of the separated viral DNA. The double-stranded circular genome of PiraGV-K encodes 120 open reading frames (ORFs), covering 92% of the sequenced genome. BLAST and ORF arrangement showed the presence of 78 homologs to other genes in the database. The mean overall amino acid identity of PiraGV-K ORFs was highest with the Chinese isolate of PiraGV (~99%), followed up with Choristoneura occidentalis ORFs at 58%. PiraGV-K ORFs were grouped, according to function, into 10 genes involved in transcription, 11 involved in replication, 25 structural protein genes, and 15 auxiliary genes. Genes for Chitinase (ORF 10) and cathepsin (ORF11), involved in the liquefaction of the host, were found in the genome. The recovery of PiraGV-K DNA genome by pulse-field electrophoretic separation from host genomic DNA had several advantages, compared with its isolation from particles harvested as virions or inclusions from the P. rapae host. We have sequenced and analyzed the 108,658 bp PiraGV-K genome purified by the pulsed field electrophoretic method. The method appears to be applicable to the analysis of genomes of large viruses. The chitinase, identified by PiraGV-K genome sequence, was functionally characterized by quantitative PCR, Western blot analysis, immunohistochemistry and transmission electron microscopy.
        99.
        2012.10 구독 인증기관·개인회원 무료
        We investigated the molecular and kinetic properties of two acetylcholinesterases (AmAChE1 and AmAChE2) from the Western honey bee, Apis mellifera. Western blot analysis revealed that AmAChE2 has most of catalytic activity rather than AmAChE1, further suggesting that AmAChE2 is responsible for synaptic transmission in A. mellifera, in contrast to most other insects. AmAChE2 was predominately expressed in the ganglia and head containing the central nervous system (CNS), while AmAChE1 was abundantly observed not only in the CNS but also in the peripheral nervous system/non-neuronal tissues. Both AmAChEs exist as homodimers; the monomers are covalently connected via a disulfide bond under native conditions. However, AmAChE2 was associated with the cell membrane via the glycophosphatidylinositol anchor, while AmAChE1 was present as a soluble form. The two AmAChEs were functionally expressed with a baculovirus system. Kinetic analysis revealed that AmAChE2 has approximately 2,500-fold greater catalytic efficiency toward acetylthiocholine and butyrylthiocholine than AmAChE1, supporting the synaptic function of AmAChE2. In addition, AmAChE2 likely serves as the main target of the organophosphate (OP) and carbamate (CB) insecticides as judged by the lower IC50 values against AmAChE2 than against AmAChE1. When OP and CB insecticides were pre-incubated with a mixture of AmAChE1 and AmAChE2, asignificant reduction in the inhibition of AmAChE2 was observed, suggesting a protective role of AmAChE1 against xenobiotics. Taken together, based on their tissue distribution pattern, molecular and kinetic properties, AmAChE2 plays a major role in synaptic transmission, while AmAChE1 has non-neuronal functions, including chemical defense.
        100.
        2012.06 구독 인증기관 무료, 개인회원 유료
        Iron is an essential trace element for normal functions of the body. Restriction of iron availability directly limits erythropoiesis. The objective of this experiment was to compare the bioavailability of iron nanoparticles (Fe-NPs) with iron-microparticles (Fe-MPs) in anemic mice. There were four experimental groups, including the normal control group, iron-deficiency anemia (IDA) group, Fe-NPs group, and Fe-MPs group. Animals in the normal group fed on an adequate iron-containing diet (45 ppm Fe). Meanwhile, animals in the other three groups fed on a low Fe diet (4.5 ppm Fe) for seven weeks. Double deionized water was supplied as drinking water ad libitum. After feeding for three weeks with the low Fe diet, animals in the Fe-NPs and Fe-MPs groups received oral administration of Fe-NPs or Fe-MPs at a daily dose of 40 mg/kg for four weeks. The IDA group showed markedly decreased red blood cell (RBC) count, hematocrit (Hct), and hemoglobin (Hb) values compared with the normal group throughout the experimental periods. Treatments with Fe-NPs or Fe-MPs for four weeks resulted in restoration of the decreased RBC count and hematological values similar to normal values. The Fe-NPs group showed faster restoration in values than Fe-MPs with passage of time. The iron contents of the upper small intestine in the Fe-NPs and Fe-MPs groups were higher than in the normal group at weeks 2 and 4. Treatment with Fe-NPs and Fe-MPs resulted in a significant increase in hepatic iron contents and lipid peroxidation, compared with the IDA group with passage of time. The iron contents in liver and ferritin deposits in spleen were identified in the Fe-NPs and Fe-MPs groups, similar to the normal group. These results indicate that oral administration of both Fe-NPs and Fe-MPs can result in recovery from anemia and Fe-NPs is more absorbable and available in the body than Fe-MPs.
        4,600원
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