This paper presents the construction and characterization of an amperometric immunosensor based on the graphene/gold nanoparticles (AuNPs/GO) nanocomposite for the detection of the bladder cancer biomarker, apolipoprotein A1 (Apo-A1). The morphological analysis of the AuNPs/GO nanocomposite demonstrated an almost spherical shape of AuNPs and the successful coverage of their surface by graphene oxide. An increased G peak and decreased D peak after the association of AuNPs with GO, implied a reduction in graphene defects. The X-ray photoelectron spectroscopy (XPS) indicated a significant decrease in the quantity of oxygen-containing functional groups in the AuNPs/GO nanocomposite, as compared to the original GO. Furthermore, the developed sensor demonstrated commendable sensitivity and selectivity, with a wide linear range for Apo-A1 detection. Importantly, the immunosensor exhibited remarkable stability over a period of 14 days, signifying its potential for practical applications.
The purpose of study was to investigate university students’ attitudes towards English language learning apps and examine whether there is any significant difference in their attitudes depending on their personal variables such as their gender, major, grade, nationality, and so on. This study also explored students’ perceptions of English language learning apps that they have used. Participants were college students living in Korea and China. Data were collected by means of a questionnaire and an interview. Results showed that both Korean and Chinese students generally held positive attitudes towards English language learning apps, although Chinese students showed more positive attitudes than Koreans. The main reasons that they liked to use English language learning apps were their convenience, ubiquity, and rich resources. On the other hands, it was revealed that the lack of communication and feedback was the main problem of using such apps. Both Korean and Chinese students stated that it was an effective way to use English language learning apps to practice pronunciation, vocabulary, listening, and reading skills. Findings of this research suggest that English language learning apps should be developed to inspire users/students’ learning interest and foster learner autonomy.
This study was conducted to perform the suitability analysis of whole-crop rye (Secale cereale L.) based on the climatic information in the Republic of Korea to present useful information for producers and policy makers to determine the site-selection for the cultivation of the whole-crop rye. The criteria to analyze the climatic suitability of whole-crop rye was developed firstly. Then, the climatic suitability map for spatial analysis was developed through weighted overlaying the raster layers of climatic items in the evaluation criteria. Meanwhile, 16 geographically representative weather stations were selected to show examples of the calculation process of the climatic suitability score of a specific cultivation area. The results of the climatic suitability mapping indicated that the climatic conditions in most arable lands of the Republic of Korea such as the coastal, southern, western areas in the southern region of the Korean Peninsula and central areas in Jeju Island are suitable for the cultivation of whole-crop rye. The climatic suitability scores of the 16 weather stations were all in line with the results of the climatic suitability map.
Digital and social media has become an indispensable channel of promotion and marketing to the enterprises. For example, compared to other means of promotional channels, such as television advertising, newspapers, social network services (SNS) are more competitive, more convenient, and lower-cost. Because individuals compose or share those posts anytime, anywhere, information spreads fast and wide on social media. SNS posts can affect people's perception, thus affecting their purchase intention and behavior. A large number of researchers investigated academic issues involved SNS, such as the influence of eWOM in social media on consumers' purchase intentions (Erkan & Evans, 2016). According to Lin and Lu’s research (2011), which suggests that gender difference also exists in social media. In addition, a study identified attributes of social media messaging activities and examined the relationships among those perceived activities, value equity, relationship equity, brand equity, customer equity, and purchase intention through a structural equation model (Kim & Ko, 2012).
In this study, we focus on the motivational antecedents of digital buzz on digital and social media. Among many performance metrics of digital marketing, the most important one that really matters to advertisers is click-through. Click-through is believed to reflect viewers’ interest in the product contents that are being shown on screen, and based on that assumption, it opens a new navigation tab, such as the advertiser’s web site that can provide information about products and services of an advertising company. However, there is a caveat here. Since advertisements in digital and social media are often placed on top of the contents that the viewers have already been reading, viewers can accidentally click on the internet advertisements in which they have no interests. Viewers are only annoyed by intrusive re-routing during their digital activities. Hence, it is important that the digital media marketer to be able to distinguish between the click-throughs, knowing the difference between the clicks that are genuinely reflective of a viewer’s interest, or the rest of clicks that are not. For this purpose, we propose consumer curiosity and anticipation as drivers of click-through that are meaningful to digital markers. Consumer curiosity is an important variable that results in click-through behavior, digital propagation or buzz, and further stimulates consumers' consumption activities. In recent years, there are many studies to verify this theory. Online atmospherics have an impact on customer emotions, and perceptual curiosity has a moderating effect existed in the two variables (Koo & Ju, 2010). However, the research about curiosity’s mediation effect on purchase intention aroused by SNS contents is still limited. In addition, the neural research in this field is still limited. The research seeks to understand how the SNS contents affect customer’s curiosity toward the product which the content mentioned. Furthermore, to find the relationship between curiosity and the purchase intention by using neuromarketing methodology. Our goal is to discover the neural signatures of consumers’ motivational state that leads to click-through, exploration of contents, and finally digital buzz behavior.
EEG and fMRI are commonly research approaches used in the neuroscience field. EEG detect electric activities in the brain waves and fMRI measures hemodynamic events to discover individuals’ cognitive and motivational states. After content-analyzing top 10 most shared posts in the fashion brands Facebook official account which included luxury brands such as GUCCI, Luis Vuitton, and Hermès), we extract the attractive posts’ content attributes to be the level of accuracy, graphic quality, and information value. Then, we create two different simulations of social media activities that instigates viewer curiosity at differing levels. By designing an online experiment that examines how different arrays of information can create different levels viewer curiosity in user posts, and by measuring viewers’ intention to propagate the posts, we are able to discover neural signatures of digital buzz. Potential implications to digital marketing of this research in establishing meaningful performance metrics for digital marketing are discussed.
Recently, semi-dried sweet potato is popular as a natural snake for children’s dessert. The drying condition was optimized to obtain high quality of sweet potato by oven drying process. The mashed yellow and chestnut sweet potato was dried using the oven drier at different temperature (50, 60, 70, and 80°C) then evaluated for the moisture content, appearance observation, texture properties, and sugar contents and sensory test in every 2, 6 and 12 hours. During the dehydration and drying process, the ending point of moisture content divided in three zone from 0-2 hour, 4-6 hour and 8-12 hour. The moisture content was dramatically decreased from 0 hour - 8 hour, but after 8 hour there is no significant decrease. Yellow sweet potato dried at 80°C for 6 hours was investigated as good product base on the sensory test, hardness value, and color appearances as compared to chestnut potato.
Excessive salt intake in body induces health risks resulting high blood pressure or heart diseases. Therefore, the low salt concentration and sale tasted food is needed by means of the modification of manufacturing process. The purpose of this study was to study the effect of inhomogeneous salt localization in bread to enhance the saltiness encapsulated salt. The 0, 0.5, 1, 1.5, and 2.0% of liposome encapsulated salt (LS) was added into the baking of white pan bread. The final salt concentration was adjusted at 2% by addition of salt. After baking the bread, the moisture content, loaf volume, fermentation rate, color, texture analysis, salt release rate and sensory test were measured. From this study, moisture content has no significant difference between control and treatments (p>0.05), except for 2.0% LS. Lightness of all treatments was higher than control (p<0.05), whereas, there were no significant difference in hardness (p>0.05). From the sensory test, the bread added 2.0% LS was showed the highest value from the salty taste. Moreover, it is related to the highest release rate of salt was represented at 2.0% LS. In conclusion, the salty intensity of bread can be enhanced by the salt localization using encapsulation of salt.
A novel nanocomposite LDPE film with UV protective properties was developed for active packaging applications. Initially, undoped and Mn-doped TiO2 nanoparticles (NPs) were synthesized by the sol-gel method and the resulting particles were characterized. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images revealed an agglomerated nature and spherical morphology. X-ray diffraction (XRD) studies indicated that all products were crystalline and in the form of rutile. The reflectance spectrum of undoped TiO2 NPs demonstrated a characteristic sharp edge at 410 nm. Subsequently, nanocomposite (NC) LDPE samples were prepared with the NPs by solvent precipitation followed by film casting. The optical and thermal properties of the NC samples were investigated. Incremental increases in Mn concentration from 0.25 mol % to 1.00 mol % were associated with progressive decreases in light transmission in the UV region. The melting and maximum decomposition temperatures of all NCs were 107 and 442-449 °C, respectively. The UV protective LDPE-based NC films exhibited superior photostability. Absorption in the FTIR spectra at 1716 and 1734 cm-1 changed after 4-wk exposure to UV for all film samples as a consequence of photodegradation. Finally, the photooxidation of perilla oil was assessed as an example of a UV protective packaging application. After 12 days, protection with 1.00 mol% Mn-doped TiO2-LDPE was associated with a gradual increase in PV, while protection with TiO2-LDPE was associated with a significant increase and protection with the control treatment was associated with a dramatic increase in PV. Hence, a 1.00 mol% Mn-doped TiO2-LDPE NC showed promise for UV shielding packaging applications.
Makgeolli is rich in nutrients such as beneficial microbial species, essential amino acids, oligosaccharides, and organic acids. The lactic acid bacteria contained in Makgeolli provides a healthy function as probiotics for customers. The purpose of this study was to enhance the nutritional properties, lactic acid bacteria propagation and alcohol contents of makgeolli by controlling redox potential balance. An automatic control system was created using ORP sensor, Labview control kit, and air supplier, in which air concentration was controlled by on & off mode. Makgeolli was fermented at three different redox potentials -50 mV, -100 mV, -150 mV. Regulating of aeration according to the redox potentials could give prominence to nutritional benefits of Makgeolli. The profiles of redox potential appeared bathtub curves, and related to lactic acid bacteria growth curve and byproducts. We could find the optimum redox potential balance that affects the factors such as LAB’s, alcohol contents and byproducts. In conclusion it was essential to control redox potential balance in order to produce nutrients rich Makgeolli.
Time-temperature indicators or integrators (TTIs) indicate food quality changes based on time-temperature history. Whilst many types of TTIs have been developed and commercialized, educated consumers often refuse to purchase food products with attached TTI labels showing even a slight color change. In this study, a novel on-off diffusion-based TTI coupled with polydiacetylene/silica nanocomposites has been proposed. The prototype TTI tag has a multilayer structure comprised of a self-adhesive base layer, a middle microporous sheet, and an upper opaque white layer coupled with a square reservoir of Tween 20 attached to an activation stripe. At the end of the diffusion path, polydiacetylene/silica nanocomposites were injected into a loading site as a fine blue stripe. After activation, Tween 20 diffused and reached the loading site, where it rapidly changed from blue-to-red via solvatochromism. This alternative and innovative TTI continuously showed a blue color until reaching the end point, at which stage a red color rapidly appeared, indicating product rejection. Thus, this novel TTI it is of great benefit to the brand owner. The developed prototype was characterized and evaluated for its ability to monitor microbial quality based on published, isothermal, microbial growth data of modified-atmosphere packaged minced beef, Mediterranean fish, and ground pork. The diffusion of Tween 20 in the TTI system was measured under various isothermal conditions and a kinetic model, based on the association between diffusion and time-temperature, was investigated. The Gaussian-estimated activation energy value was 51.082kJ mol-1. Tween 20 diffusion of 6.10, 5.15 and 6.15mm along the TTI systems were considered to be end points and the 95% confidence interval between the times taken for TTI to display OFF and for the foods to reach their deterioration thresholds were 23.30-23.70, 23.00-23.50 and 23.44-24.05h for total aerobic bacteria, Shewanella putrefaciens, and Pseudomonas spp. respectively. The TTI performance test for reproducibility and accuracy revealed a normal frequency distribution with 35004.90, 1200.254.82 and 549.811.09min at 0, 11 and 25C, respectively in accordance with the investigation of diffusion in the TTI.
The objective of this study was to construct Italian ryegrass (IRG) dry matter yield (DMY) estimation models in South Korea based on climatic data by locations. Obviously, the climatic environment of Jeju Island has great differences with Korean Peninsula. Meanwhile, many data points were from Jeju Island in the prepared data set. Statistically significant differences in both DMY values and climatic variables were observed between south areas of Korean Peninsula and Jeju Island. Therefore, the estimation models were constructed separately for south areas of Korean Peninsula and Jeju Island separately. For south areas of Korean Peninsula, a data set with a sample size of 933 during 26 years was used. Four optimal climatic variables were selected through a stepwise approach of multiple regression analysis with DMY as the response variable. Subsequently, via general linear model, the final model including the selected four climatic variables and cultivated locations as dummy variables was constructed. The model could explain 37.7% of the variations in DMY of IRG in south areas of Korean Peninsula. For Jeju Island, a data set containing 130 data points during 17 years were used in the modeling construction via the stepwise approach of multiple regression analysis. The model constructed in this research could explain 51.0% of the variations in DMY of IRG. For the two models, homoscedasticity and the assumption that the mean of the residuals were equal to zero were satisfied. Meanwhile, the fitness of both models was good based on most scatters of predicted DMY values fell within the 95% confidence interval.
The objective of this study was to construct a forage rye (FR) dry matter yield (DMY) estimation model based on climate data by locations in South Korea. The data set (n = 549) during 29 years were used. Six optimal climatic variables were selected through stepwise multiple regression analysis with DMY as the response variable. Subsequently, via general linear model, the final model including the six climatic variables and cultivated locations as dummy variables was constructed as follows: DMY = 104.166SGD + 1.454AAT + 147.863MTJ + 59.183PAT150 4.693SRF + 45.106SRD 5230.001 + Location, where SGD was spring growing days, AAT was autumnal accumulated temperature, MTJ was mean temperature in January, PAT150 was period to accumulated temperature 150, SRF was spring rainfall, and SRD was spring rainfall days. The model constructed in this research could explain 24.4 % of the variations in DMY of FR. The homoscedasticity and the assumption that the mean of the residuals were equal to zero was satisfied. The goodness-of-fit of the model was proper based on most scatters of the predicted DMY values fell within the 95% confidence interval.
There are a lot of types of wild vegetables such as Colocasia esculenta (L.) Schott stem in Korea. However, the consumption of these wild vegetables is restricted because their storage decreased dramatically after harvest. To maintain original quality of vegetables, pre-treatments such as blanching and drying are important. But conditions for these treatments were still not optimized for many vegetables including Colocasia esculenta (L.) Schott stem. Thus, the objective of this study was to set up an optimal pre-treatment method for freezing storage. Colocasia esculenta (L.) Schott stems were peeled and cut equally (10 cm) for sample preparation. Dried samples (D) were dried at 90℃ for 3 h. Blanched samples (B) were blanched in hot water at 100℃ for 2 min. Blanched and dried samples (BD) were blanched and dried as same protocol. Physicochemical properties were analyzed to evaluate the quality including texture, moisture content, total color difference and viable cell count. Raw sample had 6.85 kg/cm 3 of hardness and 78.75 of chewiness whereas B was 6.83 kg/cm 3 of hardness and 7.8 of chewiness. B had the similar value compared to raw samples. Moisture content of raw sample was 94.4% and that of B was 94.1%, though there were not any significant differences between them. ΔE value of B showed lower value than those of the others. Viable cell counts and total coliforms were not detected after treatment, while raw sample had 5.39 log CFU/g of viable cell count without total coliform. Therefore, pre-treatments are essential for microbial safety of samples. All results considered, it is supposed that blanching is the optimal pre-treatment to sustain its original quality of Colocasia esculenta (L.) Schott stems before freezing.