784 research outputs found
Investigating Factors Affecting Electronic Word-Of-Mouth In The Open Market Context: A Mixed Methods Approach
Electronic Word-of-Mouth (eWOM) has been identified as one of key factors affecting online sales. There has been, however, lack of understanding about the factors leading to eWOM in the open market context. As many Internet vendors have adopted the open market business, it is essential to understand the factors leading to eWOM for the success of open market business. This study investigates factors affecting eWOM in the open market context based on a sequential combination of qualitative and quantitative research methods. The exploratory findings in the qualitative study become the basis for the quantitative study, survey research. The findings from the mixed methods explain the significance of three new factors (information sharing desire, self-presentation desire, and open market reward) and two other factors (open market satisfaction and open market loyalty) affecting eWOM directly and indirectly. This study contributes to research by adding to the broader literature on eWOM. The findings also can inform open market providers on how to promote and manage eWOM for their online business success
Dissolved Organic Matter Fractions and Their Removal in Full-Scale Drinking Water Treatment Process
Objectives The objective of this study is to investigate characteristics about removal of dissolved organic matter (DOM) and its fraction for improving operation efficiency in an advanced water treatment plant. Methods The monitoring of water quality was conducted at five processes such as raw water, pre-oxidation, after sedimentation, post-ozonation, after biological activated carbon (BAC) from July 2020 to August 2021 in advanced water treatment process (AWTP) supplying 180,000m3/day. The concentration of DOC (dissolved organic carbon) and number of algae were monitored and LC-OCD was used to fractionate DOC to four species, biopolymer (BP), humic substance (HS), building blocks (BB), and low molecular weights (LMWs). Results and Discussion The characteristics of raw water showed that the concentration of DOC and the number of algae increased with an increase in water temperature. The portion of BP and HS significantly increased at low and high water temperature, respectively, while BB and LMWs maintained the similar portion. The removal efficiency of DOC in the AWTP was achieved at 59% with each species of BP, HS, BB, and LMWs obtaining removal efficiency of 87%, 65%, 26%, and 52%, respectively. Coagulation/sedimentation/filtration showed removal efficiency of 84%, 56%, 20%, and 18% for BP, HS, BB, and LMWs, respectively, corresponding to their molecular weight. The effect of post-ozonation would be negligible except for BP. In BAC, removal efficiency of 49% and 12% were obtained for LMWs and BB (low molecular weight, respectively. As a result, the BP portion significantly decreased due to high removal efficiency, while BB portion was increased in the final treated water compared to raw water. Conclusion Most of DOM was removed in coagulation/sedimentation/filtration and BAC, whereas oxidation process such as pre-chlorination, pre-ozonation and post-oxidation did not have an effect on DOM removal. In coagulation/sedimentation/filtration, 84% and 54% of the BP and HS were removed, while BAC removed 49% and 12% of LMWs and BB, respectively. It has been recommended to improve the removal efficiency of BB, which obtained the lowest removal efficiency in AWTP, and to enhance the removal efficiency of LMWs in BAC to inhibit microbial regrowth in the distribution system
Cocoa polyphenols suppress TNF-α-induced vascular endothelial growth factor expression by inhibiting phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase kinase-1 (MEK1) activities in mouse epidermal cells
Cocoa polyphenols have antioxidant and anti-inflammatory effects. TNF-α is a pro-inflammatory cytokine that has a vital role in the pathogenesis of inflammatory diseases such as cancer and psoriasis. Vascular endothelial growth factor (VEGF) expression is associated with tumorigenesis, CVD, rheumatoid arthritis and psoriasis. We tested whether cocoa polyphenol extract (CPE) inhibited TNF-α-induced VEGF expression in promotion-sensitive JB6 mouse epidermal cells. CPE significantly inhibited TNF-α-induced up-regulation of VEGF via reducing TNF-α-induced activation of the nuclear transcription factors activator protein-1 (AP-1) and NF-κB, which are key regulators of VEGF expression. CPE also inhibited TNF-α-induced phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinase. CPE blocked activation of their downstream kinases, p70 kDa ribosomal protein S6 kinase and p90 kDa ribosomal protein S6 kinase. CPE suppressed phosphoinositide 3-kinase (PI3K) activity via binding PI3K directly. CPE did not affect TNF-α-induced phosphorylation of mitogen-activated protein kinase kinase-1 (MEK1) but suppressed TNF-α-induced MEK1 activity. Collectively, these results indicate that CPE reduced TNF-α-induced up-regulation of VEGF by directly inhibiting PI3K and MEK1 activities, which may contribute to its chemopreventive potentia
Methionine deprivation suppresses triple-negative breast cancer metastasis in vitro and in vivo
Nutrient deprivation strategies have been proposed as an adjuvant therapy for cancer cells due to their increased metabolic demand. We examined the specific inhibitory effects of amino acid deprivation on the metastatic phenotypes of the human triple-negative breast cancer (TNBC) cell lines MDA-MB-231 and Hs 578T, as well as the orthotopic 4T1 mouse TNBC tumor model. Among the 10 essential amino acids tested, methionine deprivation elicited the strongest inhibitory effects on the migration and invasion of these cancer cells. Methionine deprivation reduced the phosphorylation of focal adhesion kinase, as well as the activity and mRNA expression of matrix metalloproteinases MMP-2 and MMP-9, two major markers of metastasis, while increasing the mRNA expression of tissue inhibitor of metalloproteinase 1 in MDA-MB-231 cells. Furthermore, methionine restriction downregulated the metastasis-related factor urokinase plasminogen activatior and upregulated plasminogen activator inhibitor 1 mRNA expression. Animals on the methionine-deprived diet showed lower lung metastasis rates compared to mice on the control diet. Taken together, these results suggest that methionine restriction could provide a potential nutritional strategy for more effective cancer therapy
Relationship of Vertigo and Postural Instability in Patients With Vestibular Schwannoma
Objectives Growth of vestibular schwannomas (VS) causes progressive vestibular symptoms and postural instability. Since the tumor grows slowly, compensation of decaying vestibular input may decrease subjective symptoms of dizziness. This study aims to estimate the relationship of subjective vestibular symptoms and objective postural instability in patients with VS. Methods A retrospective review of 18 patients newly diagnosed with VS and with subjective vertigo symptoms was performed. The results of vestibular function tests including the sensory organization test (SOT) using computerized dynamic posturography, caloric test, and self-report measures of subjective dizziness handicap (Dizziness Handicap Inventory) and visual analogue scale were compared according to the onset of vertigo symptoms. Results In VS patients, SOT showed decreased equilibrium score for all vestibular function related conditions, condition (C) 5 and 6, and composite (COMP) score. COMP scores were not correlated with visual analogue scale or Dizziness Handicap Inventory scores. Acute onset group included six patients and insidious onset group, 12 patients. Equilibrium scores for C5 and C6, and COMP scores were lower for insidious onset group, but the difference was not statistically significant. Conclusion Our findings confirmed postural instability is prevalent in VS patients. SOT parameters did not differ significantly between acute onset and insidious onset groups, but increased tumor size and canal weakness were noted in the insidious onset group. Clinicians should consider that postural instability is likely present even in patients who do not complain of acute vertigo, and appropriate counseling should be discussed with the patients
Enhancement of Biological Activated Carbon (BAC) Process to Improve Removal Efficiency of Micropollutants
Objectives In this study, the removal efficiency of micropollutants in the biological activated carbon (BAC) process was investigated, and a method for improving the removal efficiency of micropollutants in the BAC process of water treatment plants was proposed. Methods Dibromo-methylparaben (Br2-MP) was selected as the target micropollutant. Batch and lab-scale column experiments were conducted to evaluate the removal efficiencies of Br2-MP in the conventional BAC process and the BAC with enhanced biofilm properties by the addition of phosphorus (P) and hydrogen peroxide (H2O2). Biodegradation kinetics were evaluated using results from batch and lab scale column experiments. Results and Discussion As a result of comparing the removal efficiency of Br2-MP in a batch experiment with the same biomass concentrations (2.0±0.2×107 cells), the biodegradation rate constant (kbio) of the enhanced BAC process was found to be 1.2 times higher than that of the conventional BAC process due to its higher biological activity (enhanced BAC: 3.4±0.3 mg·C/g·hr, conventional BAC: 2.9±0.4 mg·C/g·hr). Comparison of removal efficiencies of Br2-MP in batch experiments with the same wet weight of BAC (1 g) showed that the biodegradation rate constant (kbio) of the enhanced BAC process was 1.9 times higher than that of conventional BAC process due to higher biomass (enhanced BAC: 3.5±0.4 µg·ATP/g·GAC, conventional BAC: 2.3±0.2 µg·ATP/g·GAC). Through the batch experiments, the enhanced BAC process was efficient in removing Br2-MP via increasing both biomass concentrations and activity of attached microorganisms. Lab-scale column experiments conducted under different water temperatures (5 and 25℃) and empty bed contact time (EBCT: 5-40 min) conditions showed higher removal efficiency of Br2-MP in the enhanced BAC process than the conventional BAC process throughout the entire period of operation. In particular, the removal efficiency of Br2-MP between the enhanced and conventional BAC processes showed significant differences at low temperature (5℃) and short EBCT (5 min). At 5℃ and 25℃, the kbio of the conventional BAC process was 0.0229 min-1 and 0.0612 min-1, respectively, and the kbio of the enhanced BAC process was 0.0470 min-1 and 0.1421 min-1, respectively, These results showed that the enhanced BAC process had two times higher biodegradability of Br2-MP than the conventional BAC process. These results showed a similar trend to the results from the batch experiment. In an experiments simulating the impact of frequent EBCT changes during summer, the enhanced BAC process maintained a relatively stable removal efficiency of Br2-MP compared to the conventional BAC process. Conclusion The enhanced BAC process showed superior biodegradation of micropollutant compared to the conventional BAC process. Considering economic costs (e.g., costs of adding phosphate and hydrogen peroxide) and water quality, it appears to be an efficient alternative to operate the enhanced BAC process intermittently, limited to cases where EBCT is shortened, such as summer, or when water temperature is low, such as in winter
Electro-acupuncture at acupoint ST36 reduces inflammation and regulates immune activity in Collagen-Induced Arthritic Mice
This study aimed to investigate the anti-inflammatory, anti-arthritic and immuno-regulatory effects of electro-acupuncture (EA) at ST36 on Collagen-induced arthritis (CIA) in mice. Male DBA/1J mice were divided into five groups: Normal, Control, NR (needle retention), EAI and EAII. All mice except those in the normal group were immunized with Collagen II for arthritis induction. Acupuncture needles were inserted into mice ST36 and electrical currents at a frequency of 2 Hz in a continuous rectangular wave form were conducted through the needles for 15 min, 3 times a week. EA treatments were administered for 5 weeks in the EAI group and for 9 weeks in the EAII group. The mice in the NR group were acupunctured in the same manner as the EA groups and the needles were retained for 15 min without electrical stimulation. CIA incidence analysis, ELISA, histological analysis and FACS analysis were performed to evaluate the effect of EA on CIA. EA at ST36 significantly reduced CIA incidence, IL-6, TNF-a, INF-γ, collagen II antibody, IgG and IgM levels in CIA mice serum and prevented knee joint destruction. EA at ST36 also reduced CD69+/CD3e+ cells and CD11a+/CD19+ cells in CIA mice lymph nodes, and CD11b+/Gr1+ cells in CIA mice knee joints. The ratios of CD3e+ cells to CD19+ cells, and CD8+ cells to CD4+ cells were maintained closer to the normal range in the EA groups as compared with the control group or the NR group. EAII was more effective than EAI throughout all the measurements. The NR was effective as well, though less effective than EA. EA at ST36 may have an anti-inflammatory, anti-arthritic and immuno-regulatory effects on CIA in mice. The effectiveness is stronger when EA starts earlier and is applied longer. Needle retention without electrical stimulation may be effective on CIA as well, however less effective than EA. Electrical stimulation and acupoint ST36 may have synergistic effects on CIA
Lattice-patterned LC-polymer composites containing various nanoparticles as additives
In this study, we show the effect of various nanoparticle additives on phase separation behavior of a lattice-patterned liquid crystal [LC]-polymer composite system and on interfacial properties between the LC and polymer. Lattice-patterned LC-polymer composites were fabricated by exposing to UV light a mixture of a prepolymer, an LC, and SiO2 nanoparticles positioned under a patterned photomask. This resulted in the formation of an LC and prepolymer region through phase separation. We found that the incorporation of SiO2 nanoparticles significantly affected the electro-optical properties of the lattice-patterned LC-polymer composites. This effect is a fundamental characteristic of flexible displays. The electro-optical properties depend on the size and surface functional groups of the SiO2 nanoparticles. Compared with untreated pristine SiO2 nanoparticles, which adversely affect the performance of LC molecules surrounded by polymer walls, SiO2 nanoparticles with surface functional groups were found to improve the electro-optical properties of the lattice-patterned LC-polymer composites by increasing the quantity of SiO2 nanoparticles. The surface functional groups of the SiO2 nanoparticles were closely related to the distribution of SiO2 nanoparticles in the LC-polymer composites, and they influenced the electro-optical properties of the LC molecules. It is clear from our work that the introduction of nanoparticles into a lattice-patterned LC-polymer composite provides a method for controlling and improving the composite's electro-optical properties. This technique can be used to produce flexible substrates for various flexible electronic devices
Validation of the ECOS-16 Questionnaire in Koreans with Osteoporosis
Study DesignProspective study.PurposeTo evaluate the reliability and validity of the adapted Korean version of the Quality of Life Questionnaire of the European Foundation for Osteoporosis (ECOS-16).Overview of LiteratureThe validity of the Korean version of ECOS-16 has not been completely demonstrated.MethodsTranslation/retranslation of the English version of ECOS-16, and full cross-cultural adaptation were performed. The Korean version of a visual analog scale measure of pain, and the Korean versions of ECOS-16 and of the previously validated short form-36 (SF-36) were mailed to 158 consecutive patients with osteoporosis. Factor analysis and reliability assessment using kappa statistics of agreement for each item, intraclass correlation coefficient, and Cronbach's α were done. Construct validity was evaluated by comparing responses to ECOS-16 with responses to SF-36 using Pearson's correlation coefficient.ResultsFactor analysis extracted three factors. All items had a kappa statistics of agreement >0.6. The ECOS-16 showed good test/re-test reliability (0.8469) and internal consistency of Cronbach's α (0.897). The Korean version of ECOS-16 showed significant correlation with SF-36 total scores and with single SF-36 domains scores.ConclusionsThe adapted Korean version of the ECOS-16 was successfully translated and showed acceptable measurement properties. It is considered suitable for outcome assessments in Korean patients with osteoporosis
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