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        검색결과 10

        1.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To solve the problem of water pollution, researchers have proposed a photocatalytic degradation technology, in which the key factor is the development of efficient photocatalytic materials. Graphitic carbon nitride (g-C3N4), an n-type semiconductor, has been widely studied due to its suitable band gap (2.7 eV), low cost, easy preparation, non-toxicity, and high photostability. However, the pure-phase g-C3N4 still has defects such as low specific surface area, insufficient visible light absorption, low charge mobility, few active sites for interfacial reaction, and easy recombination of photogenerated electron–hole pairs, which leads to the lower photocatalytic activity of g-C3N4. Aiming at the problems mentioned above, this paper focus on the synthesis of g-C3N4-based composites with high photocatalytic activity via lemon juice induction method. Thiourea and lemon juice were selected as precursors, and carbon quantum dots (CQDs) as electron mediators were introduced anchoring on the surface of g-C3N4 to build g-C3N4/CQDs with compact interface. The results showed that small-sized CQDs are uniformly distributed on the surface of g-C3N4, and the g-C3N4/CQDs composite has a 2D0D structure, which reduces the recombination of photogenerated electron–hole pairs. The photocatalytic degradation efficiency of 4% g-C3N4/CQDs for RhB reaches the highest data of 90.9%, and the photocatalytic degradation rate is 0.016 min− 1, which is about 2.3 times that of g-C3N4. After four cycles of photocatalytic reaction, the photocatalytic degradation efficiency of the material remained at 81.7%. Therefore, the g-C3N4/CQDs synthesized via lemon juice induction has a more stable microstructure, and the charge separation efficiency is greatly improved, which is suitable for practical photocatalytic environmental protection.
        4,300원
        2.
        2022.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Organic reagent is considered as one of the most promising reductants for deeply removing vanadium (V) trichloride oxide ( VOCl3) from crude titanium tetrachloride ( TiCl4). Nevertheless, indeterminate active component and unclearly removal mechanisms appear to be the obstacles to separate VOCl3 from TiCl4 using organic reagent. Herein we conduct the experiment to explore it. Firstly, the organic reagents are obtained from enterprise (noted as EOR1– EOR7), and then it is determined that carbon aromatic ( CA) is the active component for removing VOCl3. Furthermore, modified organic reagents (noted as MOR1– MOR4) are prepared via adding aromatic hydrocarbon oil and stearic acid to EOR7, then indicating that MOR3 is endowed with the best capacity to remove VOCl3. In addition, the residues obtained from distillation experiment are comprehensively analyzed (using X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM) etc.), revealing that porous amorphous carbon that deriving from MOR, plays an excellent role in removing VOCl3 from TiCl4 system. Therefore, the removal mechanisms can be explained like that porous amorphous carbon reduces VOCl3 into insoluble vanadium (III) chloride ( VCl3) and vanadium (IV) oxide dichloride ( VOCl2), and then they are separated via adsorption process, with the help of porous amorphous carbon.
        4,500원
        3.
        2018.07 구독 인증기관 무료, 개인회원 유료
        Introduction How to evaluate quality of advertising? Previous behavioral studies have mainly focused on subjective reports of survey and interview containing social and cognitive bias, or objective data of sell changes suffering huge temporal and monetary cost. Recently, increasing researchers have proposed that techniques of neuro-imaging could provide an objective and effective way to examine cognitive neural mechanisms underlying consumer behavior (referred to as consumer neuroscience) (Karmarkar & Yoon, 2016), and several studies have measured consumer's brain responses to advertising and movie trailer in both single- and two-brain frames (Barnett & Cerf, 2017; Venkatraman et al., 2015). However, still little is known about cognitive neural mechanisms underlying comprehension of advertising. Functional near-infrared spectroscopy (fNIRS) is a non-invasive technique of brain-imaging measuring changes in the hemodynamic properties of human brain. Compared with fMRI and EEG, fNIRS is portable, has few physical constraints on participants with reasonable spatial and temporal resolution, and is tolerant to electromagnetic noise and motion artifact. Therefore, fNIRS is a suitable tool for research of human behavior in daily-life contexts (Liu et al., in press), which is a trends in neuroimaging (Hasson & Honey, 2012) and consumer neuroscience as weill. Methods To examine the neural responses to different quality of advertisings, in the present study we measured 14 undergraduate students' frontal activations while watching 20 advertisings in Study 1 and listening 30 music demos in Study 2 using a portable fNIRS device, and analyzed interpersonal neural network across all participants based on graph theory. Figure 1 shows positions of the fNIRS channels. Positions of the fNIRS channels were measured by a 3D magnetic digitizer. In a pilot study, another group of participants were recruited to score 30 advertisings from three dimensions: degree of liking, degree of willing to pay (WTP), and degree of understanding, and finally top-10 and bottom-10 scored adverting were remained for the final experiment in Study 1. Concerning the music demos used in Study 2, we selected the top-15 and bottow-15 ranking music in the ‘Billboard 2014 hot 100’. During the experiment, participants were asked to score their degree of liking and WTP to the advertising or the music immediately after each stimulus was displayed. After the experiment, they were also instructed to score and report their understanding on each advertising or music. Results and Discussion In Study 1, the intra-brain activations revealed higher medial prefrontal cortex (mPFC) activation when participants watched low-scored advertisings than watched high-scored ones (Fig. 2), and the mPFC activations showed a positive relationship with participants’ understanding on the meaning of the advertisings. This result only suggests that low-scored advertisings were relatively hard for participants to understand the intentions of the adverting, requiring more cognitive resources of mentalizing (Lieberman, 2007). Importantly, when we considered all participants' brains as a network, and then calculated the interpersonal neural connectivity (INS) across the network (defined as the number of participant pairs who showed significant positive inter-brain neural synchronization across them indicating shared understanding) (Hasson et al., 2012), only the network connectivity in the right inferior frontal gyrus (IFG) had significantly positive relationships with participants' scores of attitude towards the advertisings (defined as mean of the scores of liking and WTP) (Fig. 3). Study 2 confirmed the result showing significantly positive relationship between the network connectivity across all participants' brains and their scores of attitude towards the song demos. More importantly, the network connectivity in the right IFG of the small group of participants also significantly predicted the public's attitude towards the songs assessed by the rating scores on Douban website (Fig. 4). Conclusion The right IFG is a core area of mirror neuron system and is closely associated with empathy (Lamm et al., 2007). Thus, the present results suggest that high-scored advertisings may activate consumer's empathic response to simulate and experience their contents and intentions. And the network connectivity across consumers' brains in the right IFG may be a critical index evaluating quality of experiential advertisings. Practically, advertising should invite consumers to experience their products, and then could convey information and emotion more effectively.
        4,000원
        4.
        2016.10 구독 인증기관·개인회원 무료
        α-solanine is toxic to human health by disturbing digestive and central nervous systems. However, little information has been focused on investigated with respect to α-solanine influence in mammal oocyte maturation and quality. In this study, we investigated the effects of α-solanine on oocyte maturation, quality and possible molecular mechanisms in a pig model. Porcine Cumulus-oocyte complexes (COCs) were treated with increasing concentration (0, 1, 10, 20, 50 μM) of α-solanine subjected to further in vitro maturation culture. The result showed that α-solanine significantly inhibited cumulus cells expansion and increased oocyte death rates when the concentration of α-solanine more than 10 μM. After cell cycle and cytoskeleton analysis, the results showed that α-solanine (10 μM) disturbed meiotic resumption, increased abnormal spindle formation and cortical granules (CGs) distribution rates when compared with the untreated group. α-solanine (10 μM) triggered autophagy by increasing the expression of autophagy-related genes (LC3, ATG7, LAMP2) and accumulation of LC3-specific puncta (an autophagy maker). TUNEL staining assay showed that α-solanine significantly increased apoptosis in porcine oocytes confirmed by up-regulated the levels of BAX and CAPS3 genes. Further study revealed that exposure α-solanine (10 μM) to porcine oocytes induced ROS generation, reduced mitochondrial membrane potential. In addition, our results suggested that α-solanine (10 μM) significantly increased the levels of H3K36me3 and H3K27me3 in porcine oocytes. Taken together, these data indicated that α-solanine toxic impaired oocyte maturation and quality by inhibited cumulus cells expansion, increased abnormal spindle and CGs distribution rates, triggered autophagy/apoptosis occur, accumulated ROS, decreased mitochondrial membrane potential, and changed epigenetic modifications.
        5.
        2015.05 구독 인증기관 무료, 개인회원 유료
        Pigs are considered an ideal source of human disease model due to their physiological similarities to humans. However, the low efficiency of in vitro embryo production (IVP) is still a major barrier in the production of pig offspring with gene manipulation. Despite ongoing advances in the associated technologies, the developmental capacity of IVP pig embryos is still lower than that of their in vivo counterparts, as well as IVP embryos of other species (e.g., cattle and mice). The efficiency of IVP can be influenced by many factors that affect various critical steps in the process. The previous relevant reviews have focused on the in vitro maturation system, in vitro culture conditions, in vitro fertilization medium, issues with polyspermy, the utilized technologies, etc. In this review, we concentrate on factors that have not been fully detailed in prior reviews, such as the oocyte morphology, oocyte recovery methods, denuding procedures, first polar body morphology and embryo quality.
        4,000원
        7.
        2012.06 구독 인증기관·개인회원 무료
        The objective of the present study was to investigate the effects of different concentrations of sorbitol supplementation for in vitro maturation medium and in vitro culture medium, on porcine cumulus oocyte complexe(COC) maturation and subsequent developmental capacity after parthenogenetic activation. Porcine COC were cultured for 44 h(0~ 22 h termed MI stage and 22~44 h termed MII stage) in TCM199 without(— ) or with(+) sorbitol (20 μM, 100 μM, 200 μM), and the resultant metaphase II oocytes cultured in PZM-3 for 7 days following activation. Our results showed that supplementation with appropriate concentrations of sorbitol (20 μM) during full term maturation culture(MI+/MII+) significantly(p<0.05) improved blastocyst formation rates and total cell number. When the concentration of sorbitol were increased to 100 μM and 200 μM during maturation culture, the maturation rate of COC were significantly reduced compared with 20 μΜ or control groups. Also blastocyst formation rates significantly(p<0.05) reduced with increasing concentration of sorbitol(200 μM). Supplementation with sorbitol(20 μM, 50 μM, 100 μM) into PZM-3 for in vitro culture significantly(p<0.05) inhibited blastocyst formation compared with control group. However, the blastocyst formation rates start to rise again when 50 μ M sorbitol was used for the first 48 hours and then cultured in PZM-3 without sorbitol. There was no significant difference in cell number between control and sorbitol treated groups. When the activated oocytes were cultured in PZM-3 for 48h and then cultured in PZM-3 with sorbitol, interestingly, the blastocyst formation rate was similar to that of PZM-3 with sorbitol for in vitro culture and significantly lower than control group. These results suggest that addition of low concentrations of sorbitol(20 μM) during oocyte maturation is beneficial for subsequent blastocyst development and improved embryo quality. However, treatment with sorbitol supplementation during in vitro culture medium is negative effect to blastocyst formation.