647 research outputs found

    Critical Review of Credit Bank System in South Korea: A New Mediator for Lifelong Learning?

    Get PDF
    This study critically analyzes Credit Bank System (CBS) as an emerging open higher education system in South Korea by using critical theory. Specifically, it examines the meaning of CBS degree in Korean credentialism circumstances and reflects CBS meeting needs rationale assumption. Based on the findings, conclusions and implications are discussed

    Selectively enhanced expression of prophenoloxidase activating enzyme 1 (PPAE1) at a bacteria clearance site in the white shrimp, Litopenaeus vannamei

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The prophenoloxidase-activating (PO activating) system plays an important role in the crustacean innate immunity, particularly in wound healing and pathogen defense. A key member of this system is prophenoloxidase-activating enzyme (PPAE), which is the direct activator of prophenoloxidase (proPO). Despite their importance in crustacean PO activating system, the studies on them remain limited.</p> <p>Results</p> <p>Here we report on a PPAE of white shrimp, <it>Litopenaeus vannamei </it>(lvPPAE1), which showed 94% similarity to PPAE1 of <it>Penaeus monodon</it>. We found that lvPPAE1 in fluid hemocytes was down regulated after challenge by <it>Vibrio harveyi </it>but was enhanced when shrimps were exposed to a bacteria-rich environment for long-term. In <it>vivo </it>gene silence of lvPPAE1 by RNAi can significantly reduce the phenoloxidase activity (PO) and increase the susceptibility of shrimps to <it>V. harveyi</it>. Although lvPPAE1 was down-regulated in fluid hemocytes by <it>Vibrio </it>challenge, its expression increased significantly in gill after bacteria injection, which is the primary bacteria-clearance tissue.</p> <p>Conclusion</p> <p>Suppressed expression in fluid hemocytes and enhanced expression in gill indicates selectively enhanced expression at the bacterial clearance site. This is a novel feature for PPAE expression. The results will contribute to our understanding of the PO activating system in crustaceans.</p

    Discrimination of cultivation ages and cultivars of ginseng leaves using Fourier transform infrared spectroscopy combined with multivariate analysis

    Get PDF
    AbstractTo determine whether Fourier transform (FT)-IR spectral analysis combined with multivariate analysis of whole-cell extracts from ginseng leaves can be applied as a high-throughput discrimination system of cultivation ages and cultivars, a total of total 480 leaf samples belonging to 12 categories corresponding to four different cultivars (Yunpung, Kumpung, Chunpung, and an open-pollinated variety) and three different cultivation ages (1 yr, 2 yr, and 3 yr) were subjected to FT-IR. The spectral data were analyzed by principal component analysis and partial least squares-discriminant analysis. A dendrogram based on hierarchical clustering analysis of the FT-IR spectral data on ginseng leaves showed that leaf samples were initially segregated into three groups in a cultivation age-dependent manner. Then, within the same cultivation age group, leaf samples were clustered into four subgroups in a cultivar-dependent manner. The overall prediction accuracy for discrimination of cultivars and cultivation ages was 94.8% in a cross-validation test. These results clearly show that the FT-IR spectra combined with multivariate analysis from ginseng leaves can be applied as an alternative tool for discriminating of ginseng cultivars and cultivation ages. Therefore, we suggest that this result could be used as a rapid and reliable F1 hybrid seed-screening tool for accelerating the conventional breeding of ginseng

    Sound waves delay tomato fruit ripening by negatively regulating ethylene biosynthesis and signaling genes

    Get PDF
    AbstractRegulation of tomato fruit ripening may help extend fruit shelf life and prevent losses due to spoilage. Here, tomato fruit were investigated whether sound treatment could delay their ripening. Harvested fruit were treated with low-frequency sound waves (1kHz) for 6h, and then monitored various characteristics of the fruit over 14-days at 23±1°C. Seven days after the treatment, 85% of the treated fruit were green, versus fewer than 50% of the non-treated fruit. Most of the tomato fruit had transitioned to the red ripening stage by 14 days after treatment. Ethylene production and respiration rate were lower in the sound-treated than non-treated tomatoes. Furthermore, changes in surface color and flesh firmness were delayed in the treated fruit. To investigate how sound wave treatment effects on fruit ripening, the expression of ethylene-related genes was analyzed by quantitative real-time RT-PCR analysis. The expression level of several ethylene biosynthetic (ACS2, ACS4, ACO1, E4 and E8) and ripening-regulated (RIN, TAGL1, HB-1, NOR, CNR) genes was influenced by sound wave treatment. These results indicated that sound wave treatment delays tomato fruit ripening by altering the expression of important genes in the ethylene biosynthesis and ethylene signaling pathways

    Edge-functionalized graphene-like platelets as a co-curing agent and a nanoscale additive to epoxy resin

    Get PDF
    A newly developed method for the edge-selective functionalization of "pristine" graphite with 4-aminobenzoic acid was applied for the synthesis of 4-aminobenzoyl-functionalized graphite (AB-graphite) through a "direct" Friedel-Crafts acylation in a polyphosphoric acid (PPA)/phosphorus pentoxide medium (P(2)O(5)). The AB moiety at the edge of the AB-graphite played the role of a molecular wedge to exfoliate the AB-graphite into individual graphene and graphene-like platelets upon dispersion in polar solvents. These were used as a co-curing agent and a nanoscale additive to epoxy resin. The physical properties of the resulting epoxy/AB-graphite composites were improved because of the efficient load transfer between the additive and epoxy matrix through covalent links.close191

    Admission levels of high-density lipoprotein and apolipoprotein A-1 are associated with the neurologic outcome in patients with out-of-hospital cardiac arrest

    Get PDF
    Objective To investigate whether serum levels of high-density lipoprotein (HDL) and apolipoprotein A-1 (ApoA1), after the return of spontaneous circulation, can predict the neurologic outcome in patients with out-of-hospital cardiac arrest (OHCA). Methods This was a retrospective observational study conducted in a single tertiary hospital intensive care unit. All adult OHCA survivors with admission lipid profiles were enrolled from March 2013 to December 2015. Good neurologic outcome was defined as discharge cerebral performance categories 1 and 2. Results Among 59 patients enrolled, 13 (22.0%) had a good neurologic outcome. Serum levels of HDL (56.7 vs. 40 mg/dL) and ApoA1 (117 vs. 91.6 mg/dL) were significantly higher in patients with a good outcome. Areas under the HDL and ApoA1 receiver operating curves to predict good outcomes were 0.799 and 0.759, respectively. The proportion of good outcome was significantly higher in patients in higher tertiles of HDL and ApoA1 (test for trend, both P=0.003). HDL (P=0.018) was an independent predictor in the multivariate logistic regression model. Conclusion Admission levels of HDL and ApoA1 are associated with neurologic outcome in patients with OHCA. Prognostic and potential therapeutic values of HDL and ApoA1 merit further evaluation in the post-cardiac arrest state, as in other systemic inflammatory conditions such as sepsis

    Endoscopic Submucosal Dissection Followed by Concurrent Chemoradiotherapy in Patients with Early Esophageal Cancer with a High Risk of Lymph Node Metastasis

    Get PDF
    Endoscopic submucosal dissection is recommended as an alternative therapy for early esophageal cancer. However, achieving curative resection in this procedure remains controversial since precise prediction of lymph node metastasis can be difficult. Here, we present the preliminary results of endoscopic submucosal dissection followed by concurrent chemoradiotherapy for early esophageal cancer with a high risk of lymph node metastasis. From May 2006 to January 2014, six patients underwent concurrent chemoradiotherapy after endoscopic submucosal dissection with a median follow-up period of 63 months. No complications were encountered during concurrent chemoradiotherapy. Although local recurrence did not occur in all patients, two patients were diagnosed with metachronous cancer. Overall, the survival rate was 100%. Thus, endoscopic submucosal dissection followed by concurrent chemoradiotherapy may be a feasible treatment for early esophageal cancer in patients with a high risk of lymph node metastasis. Future prospective large-scale studies are warranted to confirm our results

    Assessment of Esophageal Reconstruction via Bioreactor Cultivation of a Synthetic Scaffold in a Canine Model

    Get PDF
    Objectives Using tissue-engineered materials for esophageal reconstruction is a technically challenging task in animals that requires bioreactor training to enhance cellular reactivity. There have been many attempts at esophageal tissue engineering, but the success rate has been limited due to difficulty in initial epithelialization in the special environment of peristalsis. The purpose of this study was to evaluate the potential of an artificial esophagus that can enhance the regeneration of esophageal mucosa and muscle through the optimal combination of a double-layered polymeric scaffold and a custom-designed mesenchymal stem cell-based bioreactor system in a canine model. Methods We fabricated a novel double-layered scaffold as a tissue-engineered esophagus using an electrospinning technique. Prior to transplantation, human-derived mesenchymal stem cells were seeded into the lumen of the scaffold, and bioreactor cultivation was performed to enhance cellular reactivity. After 3 days of cultivation using the bioreactor system, tissue-engineered artificial esophagus was transplanted into a partial esophageal defect (5×3 cm-long resection) in a canine model. Results Scanning electron microscopy (SEM) showed that the electrospun fibers in a tubular scaffold were randomly and circumferentially located toward the inner and outer surfaces. Complete recovery of the esophageal mucosa was confirmed by endoscopic analysis and SEM. Esophagogastroduodenoscopy and computed tomography also showed that there were no signs of leakage or stricture and that there was a normal lumen with complete epithelialization. Significant regeneration of the mucosal layer was observed by keratin-5 immunostaining. Alpha-smooth muscle actin immunostaining showed significantly greater esophageal muscle regeneration at 12 months than at 6 months. Conclusion Custom-designed bioreactor cultured electrospun polyurethane scaffolds can be a promising approach for esophageal tissue engineering
    corecore