• Journal of Animal Reproduction and Biotechnology
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• v.39 no.2
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• pp.131-137
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• 2024

Background: Porcine embryonic development is widely utilized in the medical industry. However, the blastocyst development rate in vitro is lower compared to in vivo. To address this issue, various supplements are employed. Extracellular vesicles (EVs) play the role of communicators that carry many bioactive cargoes. Additionally, the contents of EVs can vary on the estrous cycle. Methods: We compared the effects of adding EVs derived from porcine uterine fluid (UF), categorized as non-EV (G1), EVs in estrus (G2) and EVs in diestrus (G3). After in vitro culture (IVC) was performed in three different groups, cleavage rate and blastocyst development rate were examined. In addition, glutathione (GSH) and reactive oxygen species (ROS) levels were measured 2 days after activation to assess oxidative stress. Results: Using NTA and cryo-TEM, we confirmed the presence of EVs with sizes ranging from 30 nm to 200 nm, that the particles were suitable for analysis for analysis. In IVC data, the highest cleavage rate was observed in G2, which was significantly different from G1 but not significantly different from the next highest, G3. Similarly, the highest blastocyst development rate was observed in G2, which was significantly different from G1 but not significantly different from the next highest, G3. Conclusions: These results indicate that estrus derived EVs contain biofactors beneficial for early blastocyst development, including GSH which protects the blastocyst from oxidative stress. Additionally, although diestrus-derived EVs are expected to have some effect on blastocyst development, it appeared to be less effective than estrus-derived EVs.

• Journal of Advanced Navigation Technology
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• v.28 no.4
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• pp.507-517
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• 2024

Analysis of air accident investigation data led experts from ICAO and IATA member countries to agree on the need for further improvements in flight safety and led to a comprehensive review of pilot training. As a result of this review, emphasis was placed on developing pilots' technical as well as non-technical competencies related to CRM. In 2013, ICAO recommended that contracting countries implement EBT to develop and strengthen pilots' competencies to improve flight safety. This study intend to find out how Korean airlines utilize EBT training programs and how they manage threats and errors when encountering abnormal situations to secure and promote safety, which is the original purpose of operations. We sought to derive ways to improve and develop non-technical core competencies.

• The Plant Pathology Journal
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• v.40 no.5
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• pp.486-497
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• 2024

Mosaic is the most common viral disease affecting fig plants. Although the Fig mosaic virus is the leading cause of mosaic disease, other viruses are also involved. High-throughput sequencing was used to assess viral infections in fig plants with mosaic. The genomic DNA and total RNAseq of mosaic-symptomatic fig leaves were sequenced using the Illumina platform. The analysis revealed the presence of fig badnavirus 1 (FBV-1), grapevine badnavirus 1 (GBV-1), citrus exocortis viroid (CEVd), and apple dimple fruit viroid (ADFVd). The FBV-1 and GBV-1 sequences were 7,140 bp and 7,239 bp long, respectively. The two genomes encode one open reading frame containing five major protein domains. The viroids, CEVd and ADFVd, were 397 bp and 305 bp long. Phylogenetic analyses revealed a close relationship between FBV-1 and Iranian isolates of the same species, while GBV-1 was closely related to Russian grapevine badnavirus isolates (Tem64, Blu17, KDH48, and Pal9). CEVd was closely related to other Iraqi isolates, while ADFVd was strongly related to a Spanish isolate. A registered endogenous pararetrovirus, caulimovirus-Fca1, with a size of 7,556 bp, was found in the RNA transcripts with a low expression level. This integrant was also detected in the genomes of the two lines 'Horaishi' (a female line) and 'Caprifig 6085' (a male line). Phylogenetic analyses revealed that caulimovirus-Fca1 was distinct from two other clades of different endogenous virus genera.

• Journal of Powder Materials
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• v.31 no.4
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• pp.324-328
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• 2024

This study analyzed the influence of ball size and process control agents on the refinement and dehydrogenation behavior of TiH₂ powder. Powders milled using ZrO₂ balls with diameters of 0.1 mm, 0.3 mm, and 0.3+0.5+1 mm exhibited a bimodal particle size distribution, of which the first mode had the smallest size of 0.23 ㎛ for the 0.3 mm balls. Using ethanol and/or stearic acid as process control agents was effective in particle refinement. Thermogravimetric analysis showed that dehydrogenation of the milled powder started at a relatively low temperature compared to the raw powder, which is interpreted to have resulted from a decrease in particle size and an increase in defects. The dehydrogenation kinetics of the TiH₂ powder were evaluated by the magnitude of peak shift with heating rates using thermogravimetric analysis. The activation energy of the dehydrogenation reaction, calculated from the slope of the Kissinger plot, was measured to be 228.6 kJ/mol for the raw powder and 194.5 kJ/mol for the milled powder. TEM analysis revealed that both the milled and dehydrogenated powders showed an angular shape with a size of about 200 nm.

• Journal of Veterinary Science
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• v.25 no.5
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• pp.67.1-67.8
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• 2024

Importance: Carbapenem-resistant Enterobacteriaceae are emerging as a global public health risk. Therefore, assessing the prevalence of carbapenem-resistant Escherichia coli (CRE) in both humans and animals is important. Objective: We aimed to ascertain the occurrence and characteristics of CRE isolated from companion animals, dogs and cats. Methods: E. coli strains were tested for antimicrobial susceptibility using the broth microdilution technique. Antimicrobial resistance genes were detected by polymerase chain reaction and sequencing analysis. The molecular characteristics of CRE were determined using multi-locus sequence typing, replicon typing, and pulsed-field gel electrophoresis (PFGE). Results: In total, 13 CRE isolates (0.13%) were identified from dogs possessing bla_NDM-5 along with β-lactamase genes, mostly blaCMY-2 (92.2%) and blaTEM-1 (53.8%). The commonly observed mutations were S83L and D87N in gyrA, S80I in parC, and S458A in parE. CRE carried non-beta-lactam resistance genes, with the majority being tet(B) (100%), sul (84.6%), and aac(3)-II (53.8%). Nine different PFGE patterns (P1-P9), IncX3-type plasmids (69.2%), and ST410 (84.6%) were predominantly detected. Conclusions and Relevance: This investigation provides significant insight into the prevalence and molecular characteristics of bla_NDM-5-carrying E. coli in dogs. The co-existence of bla_NDM-5 and other antimicrobial resistance genes in E. coli potentially poses severe health hazards to humans.

• Macromolecular Research
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• v.12 no.6
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• pp.553-558
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• 2004

An ultrafiltration membrane (polyethersulfone, PM 10) was surface-modified by treating it with low-tem­perature plasmas of oxygen, acrylic acid (AA), acetylene, diaminocyolohexane (DACH), and hexamethyldisiloxane (HMDSO). The effects that these modifications have on the filtration efficiency of a membrane in waste water treat­ment were investigated. The oxygen, AA, and DACH plasma-treated membranes became more hydrophilic. The water contact angles ranged from < $10^{\circ}\;to\;55^{\circ}$ depending on the type of plasma and the treatment conditions. The oxygen plasma-treated membranes displayed a higher initial flux $(312-429\%),$ but lower rejection $(6-91\%),$ than did an untreated membrane. The AA plasma-treated membranes displayed lower or higher initial flux $(42-156\%),$ depending upon the treatment conditions, but higher rejection $(224-295\%)$ in all cases. The DACH plasma-treated membranes displayed lower initial flux. All of them, especially the AA plasma-treated membrane, displayed improved fouling resistance with either a slower or no flux decline. Acetylene and HMDSO plasma-treated membranes became more hydrophobic and displayed both lower initial flux and lower fouling resistance.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.678-687
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• 2014

The catalytic performance of silicon carbide supported nickel catalysts modified with or without second metal (Co, Cu and Zn) for the methanation of CO has been investigated in a fixed-bed reactor using a feed consisting of 25% CO and 75% $H_2$ without any diluent gas. It has been found that the introduction of Co species can clearly improve the catalytic activity of Ni/SiC catalyst, whereas the addition of Cu or Zn can result in a significant decrease in the catalytic activity. The characterizations by means of XRD, TEM, XPS, CO-TPD and $H_2$-TPR indicate that the addition of Co could decrease the particle size of active metal, increase active sites on the surface of methanation catalyst, improve the chemisorption of CO and enhance the reducibility of methanation catalysts. Additionally, the special interaction between Co species and Ni species is likely favorable for the dissociation of adsorbed CO on the surface of catalyst, and this may also contribute to the high activity of 5Co-Ni/SiC catalyst for CO methanation reaction. For 5Cu-Ni/SiC catalyst and 5Zn-Ni/SiC catalyst, Cu and Zn species could cover partial nickel particles and decrease the chemisorption amount of CO. These could be responsible for the low methanation activity. In addition, a 150h stability test under 2 MPa and $300^{\circ}C$ showed that 5Co-Ni/SiC catalyst was very stable for CO methanation reaction.

• Journal of Hydrogen and New Energy
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• v.16 no.3
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• pp.238-243
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• 2005

Mg and Mg-based alloys are most important hydrogen storage materials. It is a lightweight and low-cost materials with high hydrogen storage capacity. However, the formation of hydride at high temperature, the deterioration effect, the hydriding and dehydriding kinetics are bad factor for application. In this study, Mg and Ni have been produced by hydrogen induced mechanical alloying(HIMA) process. The raw materials, Mg(purity 99.9%) chip and Ni(purity 99.95%) chip was prepared by using a planetary ball mill apparatus(FRITSCH pulverisette 5). The balls to chips mass ratio(BCR) are 30:1. The hydrogen pressure induced 2.0MPa and milling times were 12, 24, 48, 72, 96 hours with a rotating speed of 200rpm. X-ray diffraction(XRD) analysis was made to characterize the crystallite size and misfit strain. The crystallite size measured by laser particle size analysis(PSA). Microstructure changes were investigated by scanning electron microscopy(SEM) and the transmission electron microscopy(TEM). The hydrogen storage properties were evaluated by using an Sivert's type automatic pressure-composition-therm(PCT) apparatus.

• Macromolecular Research
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• v.17 no.10
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• pp.776-784
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• 2009

N,N-dimethyldodecylamine (tertiary amine)-modified MMT (DDA-MMT) was prepared as an organically modified layered silicate (OLS), after which styrene-butadiene rubber (SBR) nanocomposites reinforced with the OLS were manufactured via the latex method. The layer distance of the OLS and the morphology of the nanocomposites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). By increasing the amount of N,N-dimethyldodecylamine (DDA) up to 2.5 g, the maximum values of torque, tensile strength and wear resistance of the SBR nanocomposites were increased due to the increased dispersion of the silicate layers in the rubber matrix and the increased crosslinking of the SBR nanocomposites by DDA itself. When SBR nanocomposites were manufactured by using the ternary filler system (carbon black/silica/OLS) to improve their dynamic properties as a tire tread compound, the tan $\delta$(at $0^{\circ}C$ and $60^{\circ}C$) property of the compounds was improved by using metal stearates instead of stearic acid. The mechanical properties and wear resistance were increased by direct substitution of calcium stearate for stearic acid because the filler-rubber interaction was increased by the strong ionic effect between the calcium cation and silicates with anionic surface. However, as the amount of calcium stearate was further increased above 0.5 phr, the mechanical properties and wear resistance were degraded due to the lubrication effect of the excessive amount of calcium stearate. Consequently, the SBR/organoclay nanocomposites that used carbon black, silica, and organoclay as their ternary filler system showed excellent dynamic properties, mechanical properties and wear resistance as a tire tread compound for passenger cars when 0.5 phr of calcium stearate was substituted for the conventionally used stearic acid.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.403-408
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• 2012

In this study, the homogenous Pd nanoparticles (Pd NPs) were first prepared with bayberry tannin (BT) as the stabilizers. Subsequently, the obtained bayberry tannin-stabilized Pd nanoparticles (BT-Pd) were immobilized onto ${\gamma}-Al_2O_3$ to prepare heterogeneous ${\gamma}-Al_2O_3$-BT-Pd catalysts. Fourier Transformation Infrared Spectrum (FTIR) and X-ray Photoelectron Spectroscopy (XPS) analyses confirmed that the Pd NPs were well stabilized by the phenolic hydroxyl groups of BT. Transmission Electron Microscopy (TEM) observation indicated that the diameter of the Pd NPs can be effectively controlled in the range of 4.2-16.0 nm by varying the amount of BT. It is found that the ${\gamma}-Al_2O_3$-BT-Pd catalysts exhibit highly activity for various olefin hydrogenations. For example, the initial TOF (turnover frequency) of the ${\gamma}-Al_2O_3$-BT-Pd in the allyl alcohol hydrogenation is as high as $12804 mol{\cdot}mol^{-1}{\cdot}h^{-1}$. Furthermore, the ${\gamma}-Al_2O_3$-BT-Pd can be reused 5 times without significant loss of activity, exhibiting a superior reusability as compared with conventionally prepared ${\gamma}-Al_2O_3$-Pd catalysts.