Showing papers by "Chung-Ang University published in 2013"
TL;DR: It is shown that introducing smart side-chain engineering to polymer semiconductors can facilitate intermolecular electronic communication and high hole mobility could be achieved even in devices fabricated using the polymers at room temperature.
Abstract: Charge carrier mobility is still the most challenging issue that should be overcome to realize everyday organic electronics in the near future. In this Communication, we show that introducing smart side-chain engineering to polymer semiconductors can facilitate intermolecular electronic communication. Two new polymers, P-29-DPPDBTE and P-29-DPPDTSE, which consist of a highly conductive diketopyrrolopyrrole backbone and an extended branching-position-adjusted side chain, showed unprecedented record high hole mobility of 12 cm2/(V·s). From photophysical and structural studies, we found that moving the branching position of the side chain away from the backbone of these polymers resulted in increased intermolecular interactions with extremely short π–π stacking distances, without compromising solubility of the polymers. As a result, high hole mobility could be achieved even in devices fabricated using the polymers at room temperature.
751 citations
TL;DR: Biofilm formation in dairy, fish processing, poultry, meat, and Ready-To-Eat foods industries are discussed, as well as the biofilm forming abilities' of various microorganisms and the influence of food contact surface materials on biofilm formation.
751 citations
TL;DR: This paper reviews two prominent areas; first: the pre-processing method for eliminating possible artifacts via appropriate preparation at the time of recording EMG signals, and second: a brief explanation of the different methods for processing and classifying EMG messages.
Abstract: Electromyography (EMG) signals are becoming increasingly important in many applications, including clinical/biomedical, prosthesis or rehabilitation devices, human machine interactions, and more. However, noisy EMG signals are the major hurdles to be overcome in order to achieve improved performance in the above applications. Detection, processing and classification analysis in electromyography (EMG) is very desirable because it allows a more standardized and precise evaluation of the neurophysiological, rehabitational and assistive technological findings. This paper reviews two prominent areas; first: the pre-processing method for eliminating possible artifacts via appropriate preparation at the time of recording EMG signals, and second: a brief explanation of the different methods for processing and classifying EMG signals. This study then compares the numerous methods of analyzing EMG signals, in terms of their performance. The crux of this paper is to review the most recent developments and research studies related to the issues mentioned above.
654 citations
TL;DR: In this article, the effects of chemical changes of alkaline activators on the compressive strength of mortar and analysis of the microstructure of the mortar through SEM, EDS, XRD, FT-IR and by porosity assessments were examined.
568 citations
TL;DR: In vitro pretreatment of A. muciniphila-derived EV ameliorated the production of a pro-inflammatory cytokine IL-6 from colon epithelial cells induced by Escherichia coli EV, and protected DSS-induced IBD phenotypes, such as body weight loss, colon length, and inflammatory cell infiltration of colon wall.
Abstract: Gut microbiota play an important part in the pathogenesis of mucosal inflammation, such as inflammatory bowel disease (IBD). However, owing to the complexity of the gut microbiota, our understanding of the roles of commensal and pathogenic bacteria in the maintenance of immune homeostasis in the gut is evolving only slowly. Here, we evaluated the role of gut microbiota and their secreting extracellular vesicles (EV) in the development of mucosal inflammation in the gut. Experimental IBD model was established by oral application of dextran sulfate sodium (DSS) to C57BL/6 mice. The composition of gut microbiota and bacteria-derived EV in stools was evaluated by metagenome sequencing using bacterial common primer of 16S rDNA. Metagenomics in the IBD mouse model showed that the change in stool EV composition was more drastic, compared to the change of bacterial composition. Oral DSS application decreased the composition of EV from Akkermansia muciniphila and Bacteroides acidifaciens in stools, whereas increased EV from TM7 phylum, especially from species DQ777900_s and AJ400239_s. In vitro pretreatment of A. muciniphila-derived EV ameliorated the production of a pro-inflammatory cytokine IL-6 from colon epithelial cells induced by Escherichia coli EV. Additionally, oral application of A. muciniphila EV also protected DSS-induced IBD phenotypes, such as body weight loss, colon length, and inflammatory cell infiltration of colon wall. Our data provides insight into the role of gut microbiota-derived EV in regulation of intestinal immunity and homeostasis, and A. muciniphila-derived EV have protective effects in the development of DSS-induced colitis.
380 citations
TL;DR: Male sex, low anastomosis, preoperative chemoradiation, advanced tumor stage, perioperative bleeding, and multiple firings of the linear stapler increased the risk of AL after laparoscopic surgery for rectal cancer.
Abstract: Objective:To assess the risk factors for clinical anastomotic leakage (AL) in patients undergoing laparoscopic surgery for rectal cancer.Background:Little data are available about risk factors for AL after laparoscopic rectal cancer resection.Methods:This was a retrospective analysis of 1609 patient
337 citations
TL;DR: N- biochar had a highest adsorption capacity of all chemicals, suggesting that N-biochar derived from loblolly pine chip is a promising sorbent for agricultural and environmental applications.
298 citations
TL;DR: In this article, the adsorption behavior of ppb-level aqueous solutions of hexavalent chromium [Cr(VI)] on four different adsorbents was investigated as a function of pH, contact time, initial Cr(VI) concentration, adsorbent dose, and the copresence of competing anions.
291 citations
TL;DR: In this paper, a conceptual system framework for construction defect management that integrates ontology and augmented reality (AR) with building information modeling (BIM) is proposed to facilitate defect measures and rectifications as well as reduce the reoccurrence of the defect.
285 citations
TL;DR: In this paper, a composite membrane of sulfonated graphene oxide (s-GO) and SPEEK with various SGO contents was investigated, which significantly increased the proton conductivity of SGO membrane.
284 citations
TL;DR: This paper presents a distributed containment control approach for uncertain nonlinear strict-feedback systems with multiple dynamic leaders under a directed graph topology where the leaders are neighbors of only a subset of the followers.
TL;DR: Investigating the mediating role of consumer trust in an online merchant in the relationships between components of perceived risk and purchase intention concluded that efforts, made by online merchants, to lessen certain types of risk will first improve consumer trust, and then ultimately, increase consumer's intention to buy online.
TL;DR: A framework for a novel safety management and visualization system (SMVS) that integrates building information modeling, location tracking, augmented reality (AR), and game technologies is proposed that has a great potential to improve the identification of field safety risks, increase the risk recognition capacity of workers, and enhance the real-time communication between construction manager and workers.
TL;DR: In this paper, the use of these hybrid fillers was found to be effective for increasing the thermal conductivity of the composite, which was probably due to the enhanced connectivity offered by the structuring filler.
Abstract: Aluminum oxide and aluminum nitride with different sizes were used alone or in combination to prepare thermally conductive polymer composites. The composites were categorized into two systems, one including composites filled with large-sized aluminum nitride and small-sized aluminum oxide particles, and the other including composites filled with large-sized aluminum oxide and small-sized aluminum nitride. The use of these hybrid fillers was found to be effective for increasing the thermal conductivity of the composite, which was probably due to the enhanced connectivity offered by the structuring filler. At a total filler content of 58.4 vol.%, the maximum values of both thermal conductivities in the two systems were 3.402 W/mK and 2.842 W/mK, respectively, when the volume ratio of large particles to small particles was 7:3. This result was represented when the composite was filled with the maximum packing density and the minimum surface area at the same volume content. As such, the proposed thermal model predicted thermal conductivity in good agreement with experimental values.
TL;DR: RF ablation was effective in shrinking benign thyroid nodules and in controlling nodule-related problems over a 4-year follow-up and can be used as a non-surgical treatment for patients with benign non-functioning Thyroid nodules.
Abstract: To evaluate the clinical outcomes and safety of radiofrequency (RF) ablation for benign non-functioning thyroid nodules over a 4-year follow-up. We evaluated 126 benign non-functioning thyroid nodules of 111 patients treated with RF ablation and followed-up more than 3 years. RF ablation was performed using the Cool-Tip RF system and an internally cooled electrode. Nodule volume and cosmetic and symptom scores were evaluated before treatment and during follow-up. Complications and factors related to efficacy were evaluated. The mean follow-up duration was 49.4 ± 13.6 months. Thyroid nodule volume decreased significantly, from 9.8 ± 8.5 ml before ablation to 0.9 ± 3.3 ml (P < 0.001) at final evaluation: a mean volume reduction of 93.4 ± 11.7 %. The mean cosmetic (P < 0.001) and symptom scores (P < 0.001) improved significantly. Factors related to efficacy were initial solidity and volume. The overall recurrence rate was 5.6 % (7/126). The overall complication rate was 3.6 % (4/111). RF ablation was effective in shrinking benign thyroid nodules and in controlling nodule-related problems over a 4-year follow-up. There were no life-threatening complications or sequelae. Therefore, RF ablation can be used as a non-surgical treatment for patients with benign non-functioning thyroid nodules. • Radiofrequency (RF) ablation provides a non-surgical option for benign non-functioning thyroid nodules
• RF ablation reduced non-functioning thyroid nodular volume by 93.5 % after 49 months
• Initial solidity and volume influenced the efficacy of RF ablation
• Larger thyroid nodules required more treatment sessions to achieve appropriate volume reduction
• Complete treatment of the periphery of the nodule is important in preventing marginal regrowth
TL;DR: From the Lyapunov stability theorem, it is shown that the consensus errors are cooperatively semiglobally uniformly ultimately bounded and converge to an adjustable neighborhood of the origin.
Abstract: In this brief, we study the distributed consensus tracking control problem for multiple strict-feedback systems with unknown nonlinearities under a directed graph topology. It is assumed that the leader's output is time-varying and has been accessed by only a small fraction of followers in a group. The distributed dynamic surface design approach is proposed to design local consensus controllers in order to guarantee the consensus tracking between the followers and the leader. The function approximation technique using neural networks is employed to compensate unknown nonlinear terms induced from the controller design procedure. From the Lyapunov stability theorem, it is shown that the consensus errors are cooperatively semiglobally uniformly ultimately bounded and converge to an adjustable neighborhood of the origin.
TL;DR: The experimental results demonstrate that the proposed feature selection method improves the classification performance to a great extent and has proved to be a useful method in selecting features for multi-label classification problems.
TL;DR: A conceptual framework that integrates BIM with augmented reality (AR) so as to enable the physical context of each construction activity or task to be visualized in real-time is proposed.
TL;DR: The results showed that the size of the silver nanoparticles did not affect their tissue distribution, and biological barriers, such as the blood–brain barrier and blood-testis barrier, seemed to play an important role in the silver clearance from these tissues.
Abstract: Silver nanoparticles are known to be distributed in many tissues after oral or inhalation exposure. Thus, understanding the tissue clearance of such distributed nanoparticles is very important to understand the behavior of silver nanoparticles in vivo. For risk assessment purposes, easy clearance indicates a lower overall cumulative toxicity. Accordingly, to investigate the clearance of tissue silver concentrations following oral silver nanoparticle exposure, Sprague–Dawley rats were assigned to 3 groups: control, low dose (100 mg/kg body weight), and high dose (500 mg/kg body weight), and exposed to two different sizes of silver nanoparticles (average diameter 10 and 25 nm) over 28 days. Thereafter, the rats were allowed to recover for 4 months. Regardless of the silver nanoparticle size, the silver content in most tissues gradually decreased during the 4-month recovery period, indicating tissue clearance of the accumulated silver. The exceptions were the silver concentrations in the brain and testes, which did not clear well, even after the 4-month recovery period, indicating an obstruction in transporting the accumulated silver out of these tissues. Therefore, the results showed that the size of the silver nanoparticles did not affect their tissue distribution. Furthermore, biological barriers, such as the blood–brain barrier and blood-testis barrier, seemed to play an important role in the silver clearance from these tissues.
TL;DR: Evidence is provided that the NAC (for NAM, ATAF1/2, and CUC2) TF ANAC096 cooperates with the bZIP-type TFs ABRE binding factor and ABREbinding protein (ABF/AREB) to help plants survive under dehydration and osmotic stress conditions.
Abstract: Multiple transcription factors (TFs) play essential roles in plants under abiotic stress, but how these multiple TFs cooperate in abiotic stress responses remains largely unknown. In this study, we provide evidence that the NAC (for NAM, ATAF1/2, and CUC2) TF ANAC096 cooperates with the bZIP-type TFs ABRE binding factor and ABRE binding protein (ABF/AREB) to help plants survive under dehydration and osmotic stress conditions. ANAC096 directly interacts with ABF2 and ABF4, but not with ABF3, both in vitro and in vivo. ANAC096 and ABF2 synergistically activate RD29A transcription. Our genome-wide gene expression analysis revealed that a major proportion of abscisic acid (ABA)–responsive genes are under the transcriptional regulation of ANAC096. We found that the Arabidopsis thaliana anac096 mutant is hyposensitive to exogenous ABA and shows impaired ABA-induced stomatal closure and increased water loss under dehydration stress conditions. Furthermore, we found the anac096 abf2 abf4 triple mutant is much more sensitive to dehydration and osmotic stresses than the anac096 single mutant or the abf2 abf4 double mutant. Based on these results, we propose that ANAC096 is involved in a synergistic relationship with a subset of ABFs for the transcriptional activation of ABA-inducible genes in response to dehydration and osmotic stresses.
TL;DR: This work developed a chitosan-conjugated Pluronic-based nano-carrier with a specific target peptide for the brain (rabies virus glycoprotein; RVG29) and applied for the protein delivery to the brain, and showed that the Pluronics-based Nano-carriers conjugated with both chitOSan and the peptide was very efficient for the accumulation in brain tissue and was remarkably better than the nano- carrier conjug
Samsung Medical Center1, Chungbuk National University2, Seoul National University3, Konyang University4, Korea Electric Power Corporation5, Yeungnam University6, Sungkyunkwan University7, Chung-Ang University8, Gyeongsang National University9, The Catholic University of America10, Kyungpook National University Hospital11, Korea University12, Catholic University of Daegu13, Kyungpook National University14
TL;DR: Ischemic postconditioning did not improve myocardial reperfusion in patients with ST-segment–elevation myocardIAL infarction undergoing primary PCI with current standard practice.
Abstract: Background—Ischemic postconditioning has been reported to reduce infarct size in patients with ST-segment–elevation myocardial infarction. However, cardioprotective effects of postconditioning have not been demonstrated in a large-scale trial. Methods and Results—We performed a multicenter, prospective, randomized, open-label, blinded end-point trial. A total of 700 patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment–elevation myocardial infarction within 12 hours after symptom onset were randomly assigned to the postconditioning group or to the conventional primary PCI group in a 1:1 ratio. Postconditioning was performed immediately after restoration of coronary flow as follows: The angioplasty balloon was positioned at the culprit lesion and inflated 4 times for 1 minute with low-pressure ( 70%) measured at 30...
TL;DR: In this article, the authors established temporal decay estimates for weak solutions to the Hall-magnetohydrodynamic equations and obtained algebraic time decay for higher order Sobolev norms of small initial data solutions.
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TL;DR: In this article, a Keller-Segel model coupled with the incompressible Navier-Stokes equations in spatial dimensions two and three is considered and the local existence of regular solutions is established.
Abstract: We consider a Keller-Segel model coupled to the incompressible Navier-Stokes equations in spatial dimensions two and three.
We establish the local existence of regular solutions and present some blow-up criteria for both cases that equations of oxygen concentration is of parabolic or hyperbolic type. We also prove global existence and decay estimate in time under the some smallness conditions of initial data.
TL;DR: It is demonstrated that a graphene oxide (GO) film is an efficient platform for modulating structure and function of human adipose-derived stem cells (hASCs) and the GO film proved to be a suitable environment for the time-dependent viability of hASCs.
Abstract: Nanoscale topography of artificial substrates can greatly influence the fate of stem cells including adhesion, proliferation, and differentiation. Thus the design and manipulation of nanoscale stem cell culture platforms or scaffolds are of great importance as a strategy in stem cell and tissue engineering applications. In this report, we propose that a graphene oxide (GO) film is an efficient platform for modulating structure and function of human adipose-derived stem cells (hASCs). Using a self-assembly method, we successfully coated GO on glass for fabricating GO films. The hASCs grown on the GO films showed increased adhesion, indicated by a large number of focal adhesions, and higher correlation between the orientations of actin filaments and vinculin bands compared to hASCs grown on the glass (uncoated GO substrate). It was also found that the GO films showed the stronger affinity for hASCs than the glass. In addition, the GO film proved to be a suitable environment for the time-dependent viability of hASCs. The enhanced differentiation of hASCs included osteogenesis, adipogenesis, and epithelial genesis, while chondrogenic differentiation of hASCs was decreased, compared to tissue culture polystyrene as a control substrate. The data obtained here collectively demonstrates that the GO film is an efficient substratum for the adhesion, proliferation, and differentiation of hASCs.
TL;DR: These cases represent artificial pulmonary embolisms and infarct after IV injection of hASC and follow-up chest CT showed spontaneous resolution of lesions in all three patients.
Abstract: The therapeutic potential of human multipotent mesenchymal stromal cells, especially human adipose tissue-derived stem cells (hASC), is promising. However, there are concerns about the safety of infusion of hASC in human. Recently, we have experienced pulmonary embolism and infarct among family members who have taken multiple infusions of intravenous autologous hASC therapy. A 41-year-old man presented with chest pain for one month. Chest CT showed multiple pulmonary artery embolism and infarct at right lung. Serum D-dimer was 0.8 µg/mL (normal; 0-0.5 µg/mL). He had received intravenous autologous adipose tissue-derived stem cell therapy for cervical herniated intervertebral disc three times (one, two, and three months prior to the visit). His parents also received the same therapy five times and their chest CT also showed multiple pulmonary embolism. These cases represent artificial pulmonary embolisms and infarct after IV injection of hASC. Follow-up chest CT showed spontaneous resolution of lesions in all three patients.
TL;DR: The effects of restrictive mediation on online time and online risks were greater for a child with low self-control, and was significantly associated with reduced online risks and reduced time spent online.
Abstract: The purpose of this study was to identify predictors of parental restrictive mediation and to examine the effects of restrictive mediation on children’s internet use. Data were obtained through a survey of Korean children from fourth to ninth grade, and their parents. According to the findings, the age of a child, parental perception of the negative influence of the internet, parental perception of their child’s low self-control, and parental internet skills were significant predictors of restrictive mediation. Restrictive mediation was significantly associated with reduced online risks and reduced time spent online, and was not associated with addictive use. In particular, the effects of restrictive mediation on online time and online risks were greater for a child with low self-control. This study advances the understanding of the effects, predictors and moderators of restrictive mediation.
TL;DR: Cell and gene therapy based on stem cells, particularly using neurons and glia derived from iPSCs, ESCs or NSCs, will become a routine treatment for patients suffering from neurodegenerative diseases and also stroke and spinal cord injury.
Abstract: Human neurodegenerative diseases such as Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS) and Alzheimer's disease (AD) are caused by a loss of neurons and glia in the brain or spinal cord. Neurons and glial cells have successfully been generated from stem cells such as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs) and neural stem cells (NSCs), and stem cell-based cell therapies for neurodegenerative diseases have been developed. A recent advance in generation of a new class of pluripotent stem cells, induced pluripotent stem cells (iPSCs), derived from patients' own skin fibroblasts, opens doors for a totally new field of personalized medicine. Transplantation of NSCs, neurons or glia generated from stem cells in animal models of neurodegenerative diseases, including PD, HD, ALS and AD, demonstrates clinical improvement and also life extension of these animals. Additional therapeutic benefits in these animals can be provided by stem cell-mediated gene transfer of therapeutic genes such as neurotrophic factors and enzymes. Although further research is still needed, cell and gene therapy based on stem cells, particularly using neurons and glia derived from iPSCs, ESCs or NSCs, will become a routine treatment for patients suffering from neurodegenerative diseases and also stroke and spinal cord injury.
TL;DR: In this article, the performance of the H-RGO/MnO2 composites was investigated using cyclic voltammetry and galvanostatic charge/discharge tests and electrochemical impedance spectroscopy in a three-electrode experimental setup.
TL;DR: This work has investigated the release of active sites blocked by bubbles attached on the surface of catalysts during the oxygen evolution reaction (OER) in alkaline water electrolysis via the modulation of the wetting properties of the four different morphologies of a nickel catalyst.