• Journal of Embryo Transfer
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• v.33 no.4
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• pp.305-311
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• 2018

Gonadotropin releasing hormone (GnRH) centrally plays a role in control of the hypothalamic-pituitary-gonadal axis-related hormone secretions in the reproductive neuroendocrine system. In addition, hormone receptors like luteinizing hormone receptor (LHR) are important element for hormones to take effect in target organ. However, ageing-dependent changes in terms of the distribution of GnRH neurons in the brain and LHR expression in the acyclic ovary have not been fully understood yet. Therefore, we comparatively investigated those ageing-dependent changes using young (1-5 months), middle (11-14 months) and old (21-27 months) aged female mice. Whereas a number of GnRH positive fibers and neurons with monopolar or bipolar morphology were abundantly observed in the brain of the young and middle aged mice, a few GnRH positive neurons with multiple dendrites were observed in the old aged mice. In addition, acyclic ovary without repeated development and degeneration of the follicles was shown in the old aged mice than others. LHR expression was localized in theca cells, granulosa cell, corpora lutea and atretic follicle in the ovaries from young and middle aged mice, in contrast, old aged mice had few positive LHR expression on the follicles due to acyclic ovary. However, the whole protein level of LHR was higher in the ovary of old aged mice than others. These results are expected to be used as an important basis on the relationship between GnRH and LHR in old aged animals as well as in further research for reproduction failure.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.233-240
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• 2021

For the production of neodymium-doped zinc sulfide thin films in various amounts, zinc sulfide and neodymium were simultaneously deposited using an RF magnetron sputtering equipment to form a thin films, and rapid thermal annealing was performed at 400℃ for 30 minutes as a post-treatment process. The structure, shape, and optical properties of ZnS thin films having various neodymium doping contents (0.35at.%, 1.31at.%, 1.82at.% and 1.90at.%) were studied. The X-ray diffraction pattern was grown to a (111) cubic structure in all thin films. The surface and structural morphology of the thin films due to the neodymium doping content was explained through SEM and AFM images. Only elements of Zn, S, and Nd that do not contain other impurities were identified through EDAX. The transmittance and band gap of the prepared thin films were confirmed using the UV-vis spectrum.

• Journal of Species Research
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• v.10 no.3
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• pp.227-236
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• 2021

To obtain unrecorded freshwater bacterial species in Korea, water and sediment samples were collected from streams, lakes, and wetland of the Han River watershed in 2020. Approximately 800 bacterial strains were isolated on R2A agar after aerobic or anaerobic incubation, and identified using 16S rRNA gene sequences. A total of 28 strains, with ≥98.7% 16S rRNA gene sequence similarity with validly published bacterial species but not reported in Korea, were determined to be unrecorded bacterial species in Korea. The unrecorded bacterial strains were phylogenetically diverse and belonged to four phyla, eight classes, 13 orders, 19 families, and 25 genera. The unreported species were assigned to Acetobacter, Alsobacter, Mesorhizobium, Prosthecomicrobium, and Microvirga of the class Alphaproteobacteria; Vogesella, Formosimonas, Aquincola, Massilia, Acidovorax, and Brachymonas of the class Betaproteobacteria; Pseudoxanthomonas, Thermomonas, Lysobacter, Enterobacter, Kosakonia, and Acinetobacter of the class Gammaproteobacteria; Sulfuricurvum of the class Epsilonproteobacteria; Mycolicibacterium, Agromyces, Phycicoccus, and Microbacterium of the class Actinobacteria; Paenibacillus of the class Bacilli; Clostridium of the class Clostridia; and Flavobacterium of the class Flavobacteriia. The details of the unreported species, including Gram reaction, colony and cell morphology, biochemical characteristics, and phylogenetic position are also provided in the description of the strains.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.2
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• pp.91-98
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• 2021

The objective of this study was to establish a selection process for high quality sperm in bovine semen using sperm separation by magnetic activation (MACS). For this, semen from 21 Nellore bulls was collected using an artificial vagina. To guarantee the presence of pathologies in the ejaculate, animals previously declassified in four consecutive spermiogram were used. Semen was analyzed in five statuses: (1) fresh semen (fresh); (2) density gradient centrifugation (DGC), percoll column; (3) non-apoptotic fraction after separation by MACS (MAC); (4) apoptotic fraction from the separation (MACPOOR); and (5) MAC followed by DGC (MACDGC). Using a computerized analysis system (CASA), motility was measured. The sperm morphology was evaluated by phase contrast, and the supravital test was completed with eosin/nigrosin staining. For DGC, 20 × 10⁶ cells were used in a gradient of 90% and 45% percoll. MACS used 10 × 10⁶ cells with 20 μL of nanoparticles attached to annexin V, and filtered through the MiniMACS magnetic separation column. Membrane integrity was assessed with SYBR-14/IP and mitochondrial potential with JC-1 by flow cytometry. Processing sperm by MACDGC, was more effective in obtaining samples with high quality sperm, verified by the total of abnormalities in the samples: 35.04 ± 2.29%, 21.50 ± 1.47%, 17.30 ± 1.10%, 30.68 ± 1.94% and 10.50 ± 1.46%, respectively for fresh, DGC, MAC, MACPOOR, and MACDGC. The subpopulation of non-apoptotic sperm had a high number of live cells (82.65%), membrane integrity (56.60%) and mitochondrial potential (83.98%) (p < 0.05). These findings suggest that this nanotechnological method, that uses nanoparticles, is efficient in the production of high-quality semen samples for assisted reproduction procedures in cattle.

• Microbiology and Biotechnology Letters
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• v.49 no.4
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• pp.587-593
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• 2021

Infertility is a key issue affecting mood and behavior in men. Microorganisms are one of the primary etiological agents that may be associated with infertility. The objective of the present study was to identify bacterial causative agents from the semen of infertile subjects and determine the effect of bacterial infection on sperm quality, as well as determine the susceptibility of these bacteria to drugs. Forty semen samples from 30 infertile patients and 10 fertile individuals were collected. The pH, volume, motility, and concentration of semen were analyzed. The samples were processed and identified by biochemical testing using API identification kits. The antibiotic susceptibility pattern was determined using the disc diffusion method. Abnormal sperm quality was observed. The mean age of the individual and their sperm morphology, concentration, progressive motility, pH level, and pus cell content were 31.9 years, 2.7%, 10.4 million/ml, 27.3%, 8.3, and 5.7, respectively. Among the tested samples, oligoasthenozoospermia was found to show the highest occurrence, at 27/30 samples, followed by teratozoospermia, at 25/30 samples, and asthenozoospermia, at 22/30 samples. Of the tested infertile patients' sperm, 19, 6, and 5 isolates were identified as Escherichia coli, Klebsiella pneumonia, and Staphylococcus epidermidis, respectively. The results also revealed multi-drug resistance in the bacteria. Compared to that shown by the other tested antibiotics, amikacin showed higher activity against all isolated bacteria. However, the bacteria exhibited maximum resistance against gentamicin, cefotaxime, levofloxacin, and ampicillin. In conclusion, leukocytospermia and bacterial infections are possibly responsible for sperm abnormalities. Multi-drug resistant bacteria were detected. Gentamicin, cefotaxime, levofloxacin and ampicillin were shown the highest resistance, while amikacin was the most effective antimicrobial agent against the isolated bacteria.

• Korean Journal of Materials Research
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• v.31 no.11
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• pp.619-625
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• 2021

Cu₂ZnSn(S,Se)₄ (CZTSSe) based thin-film solar cells have attracted growing attention because of their earth-abundant and non-toxic elements. However, because of their large open-circuit voltage (V_oc)-deficit, CZTSSe solar cells exhibit poor device performance compared to well-established Cu(In,Ga)(S,Se)₂ (CIGS) and CdTe based solar cells. One of the main causes of this large V_oc-deficit is poor absorber properties for example, high band tailing properties, defects, secondary phases, carrier recombination, etc. In particular, the fabrication of absorbers using physical methods results in poor surface morphology, such as pin-holes and voids. To overcome this problem and form large and homogeneous CZTSSe grains, CZTSSe based absorber layers are prepared by a sputtering technique with different RTA conditions. The temperature is varied from 510 ℃ to 540 ℃ during the rapid thermal annealing (RTA) process. Further, CZTSSe thin films are examined with X-ray diffraction, X-ray fluorescence, Raman spectroscopy, IPCE, Energy dispersive spectroscopy and Scanning electron microscopy techniques. The present work shows that Cu-based secondary phase formation can be suppressed in the CZTSSe absorber layer at an optimum RTA condition.

• The Korea Journal of Herbology
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• v.29 no.4
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• pp.61-67
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• 2014

Objectives : To present a differential standard of Armeniacae Semen and Persicae Semen that are easily confused. Methods : It was planed a differential standard form through outer appearance of the original plant, outer appearance in the form of each medicines and the appearance of the interior form through a microscope for each samples. Using an standard compound amygdalin, each samples have been analyzed by HPLC and TLC. Results : It was possible to distinguish the orignal plant between Armeniacae Semen and Persicae Semen through its leaf shape and calyx type. In Outer appearance in the form of each medicines, there was no difference pre-existing method(measuring length and width). In vascular pattern of the surface, however, there was a clear difference that Armeniacae Semen was developed more reticulated branches than Persicae Semen. In appearance through a microscope, it has not been possible to find a clear difference in the per original plant. However, there was a clear difference between Armeniacae Semen(1 layer) and Persicae Semen(3 layer) in inner albubemen cell. In TLC analysis, there was no difference in the pattern between samples. But in HPLC analysis, Armeniacae Semen showed amygdalin content higher on average. Conclusions : It will be possible to find various differences in the outer appearance of the original plant, the outer appearance in the form of each medicines, the appearance of the interior form through a microscope and physical and chemical research component.

• The Korea Journal of Herbology
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• v.32 no.4
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• pp.47-52
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• 2017

Objective : Phellinus spp. mushroom is an object of interest because it has excellent anticancer effect. Owing to the similalarities in the morphology, Phellinus linteus and Phellinus baumii are often used as same Sang Hwang Mushroom in the Korean market.. The quality control for mushrooms is needed because there are many differences in the efficacy according to cultivation method and cultivation area. Therefore, a reliable authentication method of these herbal medicine is necessary to compare and measure the amount of beta-glucan which is known to have a hypoglycemic effect, from the mushrooms collected in various regions Methods : 7 samples of medicinal mushrooms supplying phellinus spp. were collected in Korea, China and Cambodia. We investigated the hardness, colors, extract ratio, ${\alpha}-amylase$ and ${\alpha}-glucosidase$ inhibitory activities, glucose transporter 4 (GLUT-4) expressions of water extracts from Phellinus spp and also MTT assay were examined for cell toxicity. Results : The results revealed that Phellinus spp.water Ext.inhibited ${\alpha}-glucosidase$ activity. glucose transporter 4 (GLUT-4), the key insulin signaling pathway transcription factor, was remarkably increased by the Phellinus baumii water extract Conclusions : These results suggest that The more yellowish the mushroom is, the lower the hardness, the more the content of ${\beta}-glucan$ is proportional. Because the more ${\beta}-glucan$, the greater the effect of hypoglycemia. compared to the hypoglycemic effect, Phellinus Baumii grown at hanging on selves for 7 month in the green house is the best.

• Journal of Adhesion and Interface
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• v.23 no.2
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• pp.39-43
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• 2022

In optoelectronic devices including displays and solar cells that convert electricity into light or light into electricity, it is important to control optical behavior of light to improve device efficiency. Specifically, the control of internal emitting light in the OLEDs can induce more light to go out, improving luminous efficiency. In addition, the control of optical behavior of incident light in solar cells can increase optical path in the light absorption layer, increasing power-conversion efficiency. In this study, we generated wrinkles as a physical structure to control optical behavior of light and independently controlled their wavelength and height by changing stress relaxation time. To explore the effect of wavelength and height on optical behavior, we conducted UV/Vis spectroscopy analysis of wrinkles with various heights at a constant wavelength or various wavelengths at a comparable height, figuring out a wrinkle with high aspect ratio has more dispersive light and less straight light. It indicates that high aspect ratio is required to change the optical behavior and increase the optical path.

• Elastomers and Composites
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• v.58 no.1
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• pp.32-43
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• 2023

The worldwide use of polyurethane foam products generates large amounts of waste, which in turn has detrimental effects on the surroundings. Hence, finding an economical and environmentally friendly way to dispose of or recycle foam waste is an utmost priority for researchers to overcome this problem. In that sense, the glycolysis of waste flexible polyurethane foam (WFPF) from automotive seat cushions using different industrial-grade glycols and potassium hydroxide as a catalyst to produce recovered polyol was investigated. The effect of different molecular weight polyols, catalyst concentration, and material ratio (PU foam: Glycols) on the reaction conversion and viscosity of the recovered polyols was determined. The obtained recovered polyols are obtained as single or split-phase reaction products. Besides, the foaming characteristics and physical properties such as cell morphology, thermal stability, and compressive stress-strain nature of the regenerated flexible foams based on the recovered polyols were discussed. It was observed that the regenerated flexible foams displayed good seating comfort properties as a function of hardness, sag factor, and hysteresis loss compared to the reference virgin foam. With the growing demand for a sustainable and circular economy, a global valorization of glycolysis products from polyurethane scraps can be realized by transforming them into profitable substances.