• Journal of Animal Science and Technology
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• v.65 no.3
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• pp.652-663
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• 2023

The rumen fluids contain a wide range of bacteria, protozoa, fungi, and viruses. The various ruminal microorganisms in the rumen provide nutrients by fermenting the forage they eat. During metabolic processes, microorganisms present in the rumen release diverse vesicles during the fermentation process. Therefore, in this study, we confirmed the function of rumen extracellular vesicles (EVs) and their interaction with the host. We confirmed the structure of the rumen EVs by transmission electron microscope (TEM) and the size of the particles using nanoparticle tracking analysis (NTA). Rumen EVs range in size from 100 nm to 400 nm and are composed of microvesicles, microparticles, and ectosomes. Using the Caenorhabditis elegans smart animal model, we verified the interaction between the host and rumen EVs. Exposure of C. elegans to rumen EVs did not significantly enhance longevity, whereas exposure to the pathogenic bacteria Escherichia coli O157:H7 and Staphylococcus aureus significantly increased lifespan. Furthermore, transcriptome analysis showed gene expression alterations in C. elegans exposed to rumen EVs, with significant changes in the metabolic pathway, fatty acid degradation, and biosynthesis of cofactors. Our study describes the effect of rumen EV interactions with the host and provides novel insights for discovering biotherapeutic agents in the animal industry.

• Applied Chemistry for Engineering
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• v.35 no.2
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• pp.115-121
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• 2024

This study analyzed the influence of process variables affecting the thermodynamic equilibrium and fluid dynamics of interfaces such as reverse micelle, salt concentration, interfacial tension, and viscosity of fluids to optimize the microencapsulation process using the W1/O/W2 double emulsion method. The process variable with the greatest impact on encapsulation efficiency was found to be the difference in osmotic pressure between the W1 and W2 phases. It was observed that increasing the salt concentration in the W2 phase or decreasing the ascorbic acid concentration in the W1 phase resulted in higher encapsulation efficiency. Additionally, a larger difference in osmotic pressure led to increased damage to the surface of the microparticles, as confirmed by SEM images. The introduction of reverse micelles, which was anticipated to increase encapsulation efficiency, either had a low contribution or even decreased encapsulation efficiency. The yield of microcapsules was expressed as a universal function, applicable to all process conditions or solution compositions. According to this universal function, no further increase in yield was observed beyond the Ca (capillary number) of approximately 20.

• Journal of Life Science
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• v.24 no.9
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• pp.1030-1038
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• 2014

Platelet products are used to treat hemorrhagic or platelet dysfunction diseases. Plateletpheresis involves collecting the platelet components of blood using an apheresis blood-collection system. Various indicators are available for evaluating the qualities of the apheresis platelets. The productivity of platelet collection is evaluated through both the collection efficiency and collection rates. Platelet storage quality can be evaluated in vitro using several indicators, including visual appearance, metabolic activities, volume, platelet count, white blood cell count, microparticles, and various platelet activation markers. Platelet activation markers have been used as indicators of storage quality in various studies. Post-transfusion platelet quality can be evaluated based on the corrected count increment and the percentage of platelet recovery. Although various studies have investigated the aspects of plateletpheresis, no article has systemically presented assessments of the platelet products obtained from different plateletpheresis devices. The present study provides a review of plateletpheresis, including the specifics of the process, the types of devices employed, the platelet quality, the overall efficacy, and the evaluation indicator qualities. Furthermore, the differences in functionality among the different apheresis devices are discussed. Although adverse reactions to the citrate anti-coagulant have been reported, apheresis processing may provide a safer option for donors who are at a high risk for presyncopal or syncopal reactions related to whole blood collection.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.215-225
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• 2015

Recently, the importance of energy saving and alternative energy is significantly increasing due to energy depletion and the phase change material (PCM) research for saving energy is also actively investigating. In this research, the membrane emulsification using SPG membrane was used to make various microencapsulated phase change material (MPCM) particles which were comprised of $Rubitherms^{(R)}$ (RT-21 and RT-24) core and silica coating. We investigated the pressure of the dispersion phase, the concentration of surfactant, and the ratio of $Rubitherm^{(R)}$ and silica to prepare various MPCM particles. The DSC and TGA were used to examine the heat stability and latent heat properties. Also, PSA, SEM, and optical microscopy were used to confirm the size of $Rubitherm^{(R)}$ particles and the thickness of silica shell. The average of particle size was $7-8{\mu}m$. And, FT-IR was also used to enforce the qualitative analysis. Finally, the MPCM particles obtained from membrane emulsification showed monodispersed size distribution and the heat stability and latent heat were kept up to 80% compared to pure $Rubitherm^{(R)}$. So, it can be effectively used for wallpaper, buildings and interior products for energy saving as PCMs.

• Analytical Science and Technology
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• v.25 no.6
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• pp.476-482
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• 2012

Asian dust particles are known to have sizes ranging from a few nanometers up to about a few micrometers. The environmental and health effects depend on the size of the dust particles. The smaller, the farther they are transported, and the deeper they penetrate into the human respiratory system. Sedimentation field-flow fractionation (SdFFF) provides separation of nano to microparticles using a combination of centrifugal force and parabolic laminar flow in a channel. In this study, the steric mode of SdFFF (Sd/StFFF) was tested for size-based separation and characterization of Asian dust particles. Various SdFFF experimental parameters including flow rate, stop-flow time and field strength of the centrifugal field were optimized for the size analysis of Asian dust. The Sd/StFFF calibration curve showed a good linearity with $R^2$ value of 0.9983, and results showed an excellent capability of Sd/StFFF for a size-based separation of micron-sized particles.The optical microscopy (OM) was also used to study the size and the shape of the dust particles. The size distributions of the samples collected during a thick dust period were shifted towards larger sizes than those of the samples collected during thin dust periods. It was also observed that size distribution of the sample collected during dry period shifts further towards larger sizes than that of the samples collected during raining period, suggesting the sizes of the dust particle decrease during raining periods as the components adsorbed on the surface of the dust particles were removed by the rain water. Results show Sd/StFFFis a useful tool for size characterization of environmental particles such as the Asian dust.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.2
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• pp.121-131
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• 2014

Due to the high UV light scattering effect of Zinc oxide (ZnO), it is frequently used in sunscreen skincare products. Recently ZnO coated with silica has been used in cosmetics to improve UV protection, texture, decreased photocatalytic activity, dispersibility and stability of the skin care product. In this study, we developed a ZnO composite powder coated with silica for the future application to skincare products to block UV rays that could cause photoaging. To improve consumer's satisfaction rating, we used ZnO microparticles which are widely used in the cosmetics industry. The silica was coated using hydrothermal method with sodium silicate and acid hydrolysis. UV protection of the composite powder was analyzed by UV-Vis and in-vitro test and the advantages for practical use of this powder as a skincare product were determined.

• Polymer(Korea)
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• v.31 no.2
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• pp.168-176
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• 2007

The sub-micron particles of poly ($\gamma-glutamic$ acid) (PGA) containing lysozyme have been prepared using supercritical antisolvent (SAS) precipitation process at various experimental conditions such as pressure, temperature, inner diameter of nozzle, and concentration. As overall results of the application of SAS process to this system, the smaller size powder has been produced as (i) increasing pressure, (ii) decreasing temperature, (iii) decreasing the inner diameter of nozzle, and (iv) decreasing the concentration of PGA and lysozyme. It is found by means of FT-IR analysis that during SAS process, the composition has changed from the original composition of PGA : lysozyme=50 : 50 into PGA : lysozyme=33 : 67 at final product powder. It means that PGA has higher solubility for the mixed solvent of carbon dioxide and dimethyl sulfoxide (DMSO). Due to such difference of solubility, this particle forms the core-shell structure of which the core consists mainly of lysozyme. It is also found that the residual DMSO amount of $7.8\times10^{-3}wt%$ exists inside the powder.

• Food Engineering Progress
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• v.13 no.4
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• pp.269-274
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• 2009

The main objective of this study was to establish optimum condition of wet grinding process for manufacturing microparticulated seaweed calcium. Process parameters such as concentration of forming agent, rotor speed, bead size, feed rate, and grinding time were adapted during wet-grinding of seaweed calcium. The particle size range of the raw seaweed calcium was 10-20 $\mu$m. The calcium particles were reduced to under 1 $\mu$m as nano scale after grinding. Gum arabic was suitable for forming agent and 5%(w/v) concentration was the most effective in grinding efficiency. A wet-grinding process operated at 4,000 rpm rotor speed, 0,4 mm bead size, and 0.4 L/hr feeding rate, respectively, produced less than 600 mm(>>90%)-sized particles. In batch systems, 8 cycles of grinding showed higher efficiency, but 20 min of grinding time in continuous processing was more efficient to reduce particle size than the batch processing. Based on the result, the optimum conditions of the wet grinding process were established: operation time of 20 minutes, rotor speed of 4,000 rpm, bead size of 0.4 mm, feed rate of 40 mL/min and 30% mixing ration with water. The size of the resulting ultra fine calcium particles ranged between 40 and 660 mm.

• Journal of the Korean Wood Science and Technology
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• v.49 no.3
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• pp.213-225
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• 2021

In this paper, we investigated the carbonization characteristics of lignin hydrochar prepared by hydrothermal carbonization and established a model for predicting the carbonization degree using near-infrared spectroscopy and partial least squares regression. The carbon content of the hydrothermally carbonized lignin at the temperature of 200 ℃ was higher by approximately 3 wt% than that of the untreated sample, and the carbon content tended to gradually increase as the heating time increased. Hydrothermal carbonization made lignin more carbon-intensive and more homogeneous by eliminating the microparticles. The discriminant and predictive models using near-infrared spectroscopy and partial least squares regression approppriately determined whether hydrothermal carbonization has been applied and predicted the carbon content of hydrothermal carbonized lignin with high accuracy. In this study, we confirmed that we can quickly and nondestructively predict the carbonization characteristics of lignin hydrochar manufactured by hydrothermal carbonization using a partial least squares regression model combined with near-infrared spectroscopy.

• Applied Chemistry for Engineering
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• v.34 no.1
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• pp.23-29
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• 2023

Microfluidic reactors have been made to achieve significant development for the generation of new functional materials to apply in a variety of fields. Over the last decade, microfluidic reactors have attracted attention as a user-friendly approach that is enabled to control physicochemical parameters such as size, shape, composition, and surface property. Here, we develop a centrifugal microfluidic reactor that can control the flow of fluid based on centrifugal force and generate multifunctional particles of various sizes and compositions. A centrifugal microfluidic reactor is fabricated by combining microneedles, micro- centrifuge tubes, and conical tubes, which are easily obtained in the laboratory. Depending on the experimental control param- eters, including centrifuge rotation speed, alginate concentration, calcium ion concentration, and distance from the needle to the calcium aqueous solution, this strategy not only enables the generation of size-controlled microparticles in a simple and reproducible manner but also achieves scalable production without the use of complicated skills or advanced equipment. Therefore, we believe that this simple strategy could serve as an on-demand platform for a wide range of industrial and academic applications, particularly for the development of advanced smart materials with new functionalities in biomedical engineering.