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        검색결과 121

        81.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        고무화합물 형태로 구성된 조영제의 병에 Syringe Connector의 Spike를 연결 시 고무의 찢김 정도를 알아보고 찢김 및 분쇄로 인한 합성고무의 혼입 유무와 분쇄된 합성고무가 검출 시 분쇄물의 크기를 실험을 통해 알아보고자 하였다. 그 결과 찢김 정도의 경우 Syringe Connector의 끝과 최초 접촉하는 앞면이 약 3.14±0.04 ㎜로 뒷면 보다 많이 찢겼으며, 실험 대상인 10 병의 조영제에서 평균 7 개에서 15 개로 모두 분쇄물이 검출되었다. 검출된 분쇄물을 이용하여 크기를 측정한 결과 평균크기는 약 7.89±0.31 ㎛이었다. 향 후 다양한 실험 및 분석방법을 통한 추가실험과 더불어 흡인된 분쇄물 차단을 위한 미세 필터타입 자동주입장치의 개발이 필요하며, 분쇄물 유입 시 치명적 사고를 대비하여 관련기관의 관심 또한 필요할 것으로 사료된다.
        82.
        2017.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        With increased human activity in space, the risk of re-entry and collision between space objects is constantly increasing. Hence, the need for space situational awareness (SSA) programs has been acknowledged by many experienced space agencies. Optical and radar sensors, which enable the surveillance and tracking of space objects, are the most important technical components of SSA systems. In particular, combinations of radar systems and optical sensor networks play an outstanding role in SSA programs. At present, Korea operates the optical wide field patrol network (OWL-Net), the only optical system for tracking space objects. However, due to their dependence on weather conditions and observation time, it is not reasonable to use optical systems alone for SSA initiatives, as they have limited operational availability. Therefore, the strategies for developing radar systems should be considered for an efficient SSA system using currently available technology. The purpose of this paper is to analyze the performance of a radar system in detecting and tracking space objects. With the radar system investigated, the minimum sensitivity is defined as detection of a 1-m2 radar cross section (RCS) at an altitude of 2,000 km, with operating frequencies in the L, S, C, X or Ku-band. The results of power budget analysis showed that the maximum detection range of 2,000 km, which includes the low earth orbit (LEO) environment, can be achieved with a transmission power of 900 kW, transmit and receive antenna gains of 40 dB and 43 dB, respectively, a pulse width of 2 ms, and a signal processing gain of 13.3 dB, at a frequency of 1.3 GHz. We defined the key parameters of the radar following a performance analysis of the system. This research can thus provide guidelines for the conceptual design of radar systems for national SSA initiatives.
        83.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to investigate the improvement of growth in Israeli carp (Cyprinus carpio), and the cross experiment was carried out with two strains of Israeli carp. Four combinations of Israeli carp from Jeonbuk fisheries farm and Songpu mirror carp from Heilong Jiang, China (KK; Jeonbuk ♀ × Jeonbuk ♂, KC; Jeonbuk ♀ × China ♂, CC; China ♀ × China ♂ and CK; China ♀ × Jeonbuk ♂) were developed and reared. Body length, body weight and condition factor were determined at 20, 40, 60 and 170 days post-hatch (DPH). The results showed that there were differences in growth rate of the four groups. Body length of four groups were CK > CC > KC > KK and body weight were CC > CK > KC > KK at 170 DPH. The growth perfomance of four groups were statistically significant difference (P<0.05). During the rearing, CC group had longer length and higher weight at 170 DPH compared to other three groups and also condition factor was highest in the CC group, but there was no significant difference in a survival rate. These results indicated that the growth performance mainly depended upon brooder combination but survival rate could not significantly affect brooder.
        84.
        2016.10 서비스 종료(열람 제한)
        Background : Gentinae Macrophyllae Radix is one of the traditional medicines originated from the roots of multiple plants, Gentiana macrophylla Pall., Gentiana straminea Maxim., Gentiana crassicaulis Duthie ex Burkill and Gentiana dahurica Fisch., in Gentianaceae. Multi-origin traditional medicine usually has adulteration problem based on the morphological similarity and/or misunderstanding the species. Therefore, accurate and reliable identification criteria to ensure drug safety and quality is necessary. Methods and Results : We collected four original species of Gentinae Macrophyllae Radix from plantations and markets in China and Korea. DNA barcoding with four barcoding markers (Internal Transcribed Spacer (ITS), rbcL, trnL intron, trnL-F intergenic sapcer) was performed. Intra-specific variation was observed in ITS nucleotide sequence however, successfully distinct four original species based on the nucleotide discrepancy while trnL intron has no difference. trnL-F intergenic spacer has two transitions(T→C and A→G) sites only in G. crassicaulis and rbcL shows one transition(C→T) site in G. dahurica and G. macrophylla. Phylogenetic relationship analysis of the Gentinae Macrophyllae Radix revealed two major clades – clade I including three groups, G. macrophylla, G. straminea and G. dahurica, and clade II including G. crassicaulis. This aspects was shown more clear with multi-region combined analysis. Conclusion : DNA barcoding will be accurate and powerful criteria for the analysis the origin of Gentinae Macrophyllae Radix. However, single region analysis might be deficient such as trnL intron, rbcL and trnL-F intergenic spacer results in this research. Multi-region combined analysis based on the multiregional DNA barcode markers will be overcome the disadvantage and also increase the precision.
        85.
        2016.10 서비스 종료(열람 제한)
        Background : This study, the fraction for testing the efficacy of the Astragalus extract was concentrated active ingredient. The concentrated fraction was applied to a cosmetic material that Astragalus testing results confirmed that the improved efficacy. Methods and Results : The fractions were performed using an n-butanol solvent for increasing the efficacy of the Astragalus extract, by using the material fractions collected to compare and ultimately an increase in whitening and wrinkle efficacy. The solvent to be used in the fractions was used for the n-butanol good dissolution to the effective substance(Astragaloside, Isoflavonoid). It increased approximately 6.5 times the sample extract and the n-butanol fraction of the Astragalus as a result Astragaloside 15 ppm, 97 ppm respectively analyzed by HPLC equipment, isoflavonoid content was confirmed by an increase in the content of the fractions increased 4.5 times to 280 ppm, 1,260 ppm. Tyrosinase inhibitory effect, respectively IC50 5.70 mg/mL, IC50 1.02 mg/mL to, Collagenase producing ability is IC50 4.88 mg/mL, IC50 0.93 mg/mL with n-butanol fraction was good whitening, anti-wrinkle efficacy than the extract. Sensory evaluation was conducted in the same amount of sample, using a purified Astragalus cosmetics received high marks. Stability evaluation(MTT assay) was checked for more than 100% cell viability at the concentration 2,000 ppm. Conclusion : n-butanol fraction of Astragalus was subjected to a component analysis and In vitro test, it was confirmed an increase active ingredient content. The results of sensory evaluation and stability evaluation, it was confirmed been made to improve qualities as a cosmetic materials.
        86.
        2016.10 서비스 종료(열람 제한)
        Background : ROS produced by oxidative stress damaged endothelial cells, and cause a variety of vascular complications. In diabetic hyperglycemia state, ROS increase. The polyol pathway occur in diabetic complications, the excess glucose is absorbed into the polyol pathway when aldose reductase increased, NADPH changes it to sorbitol. Glutathione (GSH) removes ROS. GSH level is reduced by glutathione reductase, using NADPH as an electron donor. Activation of the polyol pathway decrease NADPH, and GSH also reduced. As a result, ROS is increased. In diabetic hyperglycemia state, Glycolysis increases. Effects of increased glycolysis, protein kinase C (PKC) is increased. NAD(P)H oxidase, stimulated by PKC-dependent pathway, increases ROS in the cell. In this study, we measured the ROS scavenging activity of 5 natural products (Lycii fructus, Astragalus membranaceus, Cassia Tora, Polygonatum odoratum, Rubus Coreanus), to confirm the efficacy as diabetic antioxidants. Methods and Results : We extracted 5 natural product by distilled water and ethanol. DPPH radical scavenging activity was significantly higher in Lycii fructus, Rubus coreanus. ABTS radical scavenging activity was better Rubus coreanus, Lycii fructus, Cassia Tora. In addition to, Rubus coreanus, Cassia Tora, Lycii fructus was comparatively higher reducing power activity than other natural products. And total phenolic and flavonoid contents were much higher in Rubus coreanus compared with other extracts. Conclusion : These results suggest that Lycii fructus, Rubus coreanus can be applied as diabetic antioxidant that prevent vascular complications caused by ROS.
        87.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        Early life stage mortality in fish is one of the problems faced by loach aquaculture. However, our understanding of immune system in early life stage fish is still incomplete, and the information available is restricted to a few fish species. In the present work, we investigated the expression of immune-related transcripts in loach during early development. In fishes, recombination-activating gene 1 (RAG-1) and sacsin (SACS) have been considered as immunological function. In this study, the expression of the both genes was assessed throughout the early developmental stages of loach using real-time PCR method. maRAG-1 mRNA was first detected in 0 dph, observed the increased mostly until 40 dph. Significant expression of maRAG-1 was detected in 0 to 40 dph. These patterns of expression may suggest that the loach start to develop its function after hatching. On the other hand, maSACS was detected in unfertilized oocyte to molura stages and 0 to 40 dph. maSACS mRNA transcripts were detected in unfertilized oocytes, suggesting that they are maternally transferred.
        88.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        This study investigated possible involvement of photoperiodic regulation in reproductive endocrine system of female olive flounder. To investigate the influence on brain-pituitary axis in endocrine system by regulating photoperiod, compared expression level of Kisspeptin and sbGnRH mRNA in brain and FSH-β, LH-β and GH mRNA in pituitary before and after spawning. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from Aug. 2013 to Jun. 2014. Continuous long photoperiod treatment from Aug. (post-spawning phase) was inhibited gonadal development of female olive flounder. In natural photoperiod group, the Kiss2 expression level a significant declined in Mar. (spawning period). And also, FSH-β, LH-β and GH mRNA expression levels were increasing at this period. However, in long photoperiod group, hypothalamic Kiss2, FSH-β, LH-β and GH mRNA expression levels did not show any significant fluctuation. These results suggest that expression of hypothalamic Kiss2, GtH and GH in the pituitary would change in response to photoperiod and their possible involvement of photoperiodic regulation in reproductive endocrine system of the BPG axis.
        89.
        2014.09 서비스 종료(열람 제한)
        The isolated single coronary artery is a rare congenital anomaly, in which both coronary arteries arise from a solitary ostium. Diagnosis of coronary anomalies and identification of the exact anatomy of coronary arteries has significant clinical importance, hence, myocardial ischemia or sudden cardiac death is usually related to its course of anomalous coronary artery. Most patients with a single coronary artery are asymptomatic and have normal electrocardiogram and negative stress tests. However, if the patient has other structural abnormalities, for example, ventricular hypertrophy, the exam is determined. This report describes a case of single coronary artery, where the right coronary artery originated from the distal left circumflex artery in a patient with hypertrophic ardiomyopathy.
        90.
        2014.07 서비스 종료(열람 제한)
        Mungbean (Vigna radiata) is a fast-growing, warm-season legume crop that is primarily cultivated in developing countries of Asia. We constructed a draft genome sequence of mungbean to facilitate genome research into the subgenus Ceratotropis and to enable a better understanding of the evolution of leguminous species. The draft genome sequence covers 80% of the estimated genome, of which 50.1% consists of repetitive sequences. In total, 22,427 high confidence protein-coding genes were predicted. Based on the de novo assembly of additional wild mungbean species, the divergence of what was eventually domesticated and the sampled wild mungbean species appears to have predated domestication. Moreover, the de novo assembly of a tetraploid Vigna species (Vigna reflexo-pilosa var. glabra) provided genomic evidence of a recent allopolyploid event. To further study speciation, we compared de novo RNA-seq assemblies of 22 accessions of 18 Vigna species and protein sets of Glycine max and Cajanus cajan. The species tree was constructed by a Bayesian Markov chain Monte Carlo method using highly confident orthologs shared by all 24 accessions. The present assembly of V. radiata var. radiata will facilitate genome research and accelerate molecular breeding of the subgenus Ceratotropis.
        91.
        2013.12 서비스 종료(열람 제한)
        Neutropenic enterocolitis (NE), the most serious gastrointestinal complication, has been reported as a clinical syndrome that occurs in the setting of disease- or chemotherapy-induced neutropenia. Complications of NE include bowel necrosis with perforation, fistula, stenosis, massive bleeding, abscess formation, and pneumatosis intestinalis (PI). Most physicians recommend initial conservative management with bowel rest, intravenous fluids, total parenteral nutrition, broad-spectrum antibiotics, and normalization of neutrophil counts. Surgical intervention is recommended in the event of obstruction, perforation, persistent gastrointestinal bleeding despite correction of thrombocytopenia and coagulopathy, or clinical deterioration. We experienced a patient whose abdominal computed tomography scan showed pneumoretroperitoneum, intramural gas in the colon, and inferior vena caval gas. Her condition improved after treatment with granulocyte colony-stimulating factor and broad-spectrum antibiotics. We report on this case along with a review of the literature.
        92.
        2013.03 서비스 종료(열람 제한)
        Acinetobacter baumannii is usually considered an opportunistic pathogen that it responsible for a variety of nosocomial infections, such as, pneumonia, tracheobronchitis, meningitis, endocarditis, peritonitis, skin and soft tissue infections, and urinary tract infections. However, over the years, the organism has developed substantial antimicrobial resistance, and thus, the management of infections has become more difficult. The less common infective endocarditis is one of the more serious consequences of nosocomial bacteremia. Here, we report the successful treatment of the first case of multidrug-resistant A. baumannii endocarditis in a 33-year-old patient.
        93.
        2012.07 서비스 종료(열람 제한)
        R genes are a key component of genetic interactions between plants and biotrophic bacteria and are known to regulate resistance against bacterial invasion. The most common R proteins contain a nucleotide-binding site and a leucine-rich repeat (NBS-LRR) domain. Some soybean NBS-LRR genes have also been reported to function in disease resistance. A total of 319 genes were determined to be putative NBS-LRR genes in the soybean genome. The number of NBS-LRR genes on each chromosome was highly correlated with the number of disease resistance QTL in the 2-Mb flanking regions of NBS-LRR genes. In addition, the recently duplicated regions contained duplicated NBS-LRR genes and duplicated disease resistance QTL, and possessed either an uneven or even number of NBS-LRR genes on each side. The significant difference in NBS-LRR gene expression between a resistant near-isogenic line (NIL) and a susceptible NIL after inoculation of Xanthomonas axonopodis pv. glycines supports the conjecture that NBS-LRR genes have disease resistance functions in the soybean genome. The number of NBS-LRR genes and disease resistance QTL in the 2-Mb flanking regions of each chromosome was significantly correlated, and several recently duplicated regions that contain NBS-LRR genes harbored disease resistance QTL for both sides. In addition, NBS-LRR gene expression was significantly different between the BLP-resistant NIL and the BLP-susceptible NIL in response to bacterial infection. From these observations, NBS-LRR genes are suggested to contribute to disease resistance in soybean. Moreover, we propose models for how NBS-LRR genes were duplicated, and apply Ks values for each NBS-LRR gene cluster.
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