• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.204-209
• /
• 2004

SiC materials have been extensively studied for high temperature components in advanced energy system and advanced gas turbine. However, the brittle characteristics of SiC such as low fracture toughness and low strain-to fracture still impose a severe limitation on practical applications of SiC materials. For these reasons, $SiC_f/SiC$ composites can be considered as a promising for various structural materials, because of their good fracture toughness compared with monolithic SiC ceramics. But, high temperature and pressure lead to the degradation of the reinforcing fiber during the hot pressing. Therefore, reduction of sintering temperature and pressure is key requirements for the fabrication of $SiC_f/SiC$ composites by hot pressing method. In the present work, Monolithic LPS-SiC was fabricated by hot pressing method in Ar atmosphere at 1760 $^{\circ}C$, 1780 $^{\circ}C$, 1800 $^{\circ}C$ and 1820 $^{\circ}C$ under 20 MPa using $Al_2O_3-Y_2O_3$ system as sintering additives in order to low sintering temperature. The starting powder was high purity ${\beta}-SiC$ nano-powder with an average particle size of 30 nm. Monolithic LPS-SiC was evaluated in terms of sintering density, micro-structure, flexural strength, elastic modulus and so on. Sintered density, flexural strength and elastic modulus of fabricated LPS-SiC increased with increasing the sintering temperature. In the micro-structure of this specimen, it was found that grain of sintered body was grown from 30 nm to 200 nm.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.11
• /
• pp.1573-1582
• /
• 2015

This study was to investigate the effect of soyabean isoflavones (SIF) on onset of puberty, serum hormone concentration, and gene expression in hypothalamus, pituitary and ovary of female Bama miniature pigs. Fifty five, 35-days old pigs were randomly assigned into 5 treatment groups consisting of 11 pigs per treatment. Results showed that dietary supplementation of varying dosage (0, 250, 500, and 1,250 mg/kg) of SIF induced puberty delay of the pigs with the age of puberty of pigs fed basal diet supplemented with 1,250 mg/kg SIF was significantly higher (p<0.05) compared to control. Supplementation of SIF or estradiol valerate (EV) reduced (p<0.05) serum gonadotrophin releasing hormone and luteinizing hormone concentration, but increased follicle-stimulating hormone concentration in pigs at 4 months of age. The expression of KiSS-1 metastasis-suppressor (KISS1), steroidogenic acute regulatory protein (StAR) and 3-beta-hydroxysteroid dehydrogenase/delta-5-delta-4 isomerase ($3{\beta}-HSD$) was reduced (p<0.01) in SIF-supplemented groups. Expression of gonadotropin-releasing hormone receptor in the pituitary of miniature pigs was reduced (p<0.05) compared to the control when exposed to 250, 1,250 mg/kg SIF and EV. Pigs on 250 mg/kg SIF and EV also showed reduced (p<0.05) expression of cytochrome P450 19A1 compared to the control. Our results indicated that dietary supplementation of SIF induced puberty delay, which may be due to down-regulation of key genes that play vital roles in the synthesis of steroid hormones.

• Korean Journal of Microbiology
• /
• v.28 no.1
• /
• pp.13-18
• /
• 1990

A DNA sequence encoding the adr subtype preS2 region of hepatitis B virus envelope protein was fused to 5' end of lacZ gene yielding a plasmid pTSZ, in order to produce a preS2-$\beta$-galactosidase fusion protein. Serial deletions from 3' and 5' end of preS2 were constructed in plasmids, which were expressed and their antigenicities were examined with the monoclonal antibody H8. Deletions from amino and carboxy terminal to certain points did not affect the antigenicity, but the longer deletions destroyed the antigenicity. End points of deleted preS2 sequence were determined by DNA sequencing. As a result, each end of preS2 epitope was located in the region of amino acid residue 130-132 and 140-142, respectively. Residue 143 may be supplementary for antigenic epitope since the deletion from carboxy terminal to residue 143 revealed partial defect of antigenicity. In the interval of antigenic epitope the amino acid differences between adr and adw2 subtype occurred ar residue 130, 132, and 141. This result indicated that one or more of the three residues are responsible for the binding specificity of monoclonal antibody H8 to adr subtype preS2 fusion protein.

• Journal of Embryo Transfer
• /
• v.26 no.1
• /
• pp.71-78
• /
• 2011

This study was undertaken to find out the effect of cholesterol and serum albumin on sperm ability and lipid peroxidation levels period to the liquid storage of miniature pig sperm. Ejaculated semen from miniature pigs was collected by gloved-hand method into a pre-warmed ($37^{\circ}C$) thermos bottle, and extended with Modena solution {with and without BSA, methyl-beta-cyclodextrin (-cholesterol) and cholesterol loaded cyclodextrin (+cholesterol)}. Each semen was assessed for viability (SYBR-14/PI staining) and acrosome intactness, intensity and capacitation status by chlorotetracycline (CTC) staining at 1, 3, 5, 7 and 10 days of storage. At for the effects of cholesterol and serum albumin on lipid peroxidation, semen were incubated with $H_2O_2$ ($10\;{\mu}M$), and lipid peroxidation level were measured by flow cytometry using the lipid peroxidation reporter probe $C_{11}-BODIPY^{581/591}$. The result, lipid peroxidation level in sperm added with cholesterol were lower in $10\;{\mu}M$ $H_2O_2$ compared to the added sperm with serum albumin. Also, added cholesterol to sperm had significant (p<0.05) higher viability when storage for 7 and 10 days and lower when 10 days of storage percentage of acrosome-reacted sperm (AR pattern) in acrosome state as say result compared to other treated groups. In conclusion, role of cholesterol during lipid storage in miniature pig spermatozoa was protected boar spermatozoa from lipid peroxidation prior to lipid storage. Addition serum albumin during lipid storage in sperm may be induce sperm membrane damage by lipid peroxidation. Therefore, addition of cholesterol to miniature pig sperm will be lead to extension of liquid storage periods.

• Journal of Life Science
• /
• v.33 no.3
• /
• pp.234-241
• /
• 2023

At present, many countries around the world are legalizing cannabis and its products, and research on various treatments using cannabis is being actively conducted. However, the cannabis plant contains other compounds whose biological effects have not yet been established. We investigated the effect of cannabidiol (CBD) on hair growth in human dermal papilla cells (HDPCs). 2,2'-Azino-bis (3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays were performed to determine the antioxidant activity of CBD. The HDPCs viability of CBD was examined via water-soluble tetrazolium salt (WST-1) assay. The expression of hair-loss-related markers in HDPCs by CBD treatment was analyzed by real-time PCR and western blotting. The DPPH, ABTS radical scavenging activity assay showed that CBD had superior antioxidant activities. In HDPCs, CBD increased cellular proliferation at concentrations without cytotoxicity. It also increased the expressions of fibroblast growth factor 1 (FGF1), fibroblast growth factor 7 (FGF7), vascular endothelial growth factor (VEGF), and insulin-like growth factor (IGF). These results correlated with a decrease in the expression of inhibition-related factors, such as androgen receptor (AR) and transforming growth factor beta 1 (TGF-B1). Moreover, CBD resulted in a significant increase in the phosphorylation of AKT and extracellular signal-regulated kinase (ERK). Therefore, it is suggested that CBD may be a potential remedy for the treatment of alopecia.

• Journal of the Korean Applied Science and Technology
• /
• v.13 no.1
• /
• pp.21-29
• /
• 1996

Levels of total, neutral and polar lipids from the seeds of eight species of the Cucurbitaceae f Cucurbita moschata, Lufa cylindrica, Citrullus vulgari, Cucumis melo var. makuwa, Cucumis satvus, Lag leucantha. Trichosanthes kirilowii and Momordica charantia, were determinded, and their fatty compositions were also analyzed by gas-liquid chromatography. The results were summarized as foll. Lipid contents of the seeds range from 21.9 to 50.7%, which contained 98% up of neutral lipi the fatty acid compositon of ottal lipids from the seeds of Cucurbita moschata, Lufa cylindrica, Ci vulgari, Cucumis melo var. makuwa, Cucumis sativus and Lagenaria leucantha, linoleic acid is the mos dominant component(56.8${\sim}$84.0%) followed by oleic acid(5.7${\sim}$22.2%) and palmitic acid(6.1${\sim}$1) with a trace amount of ${\alpha}-linolenic$ acid(below 0.6%). On the contrary, the seed oils of Tricho kirilowii and Momordica charantia are characterized by presence of considerable amounts of con trienoic acid such as punicic acid($_{9c.11t.13c-}C_{18:3}$) and ${\alpha}-eleostearic$ acid($_{9c.11t.13c-}C_{18:3}$). For example total lipids of T. kirilowii seeds were mainly composed of linoleic acid(40.5%) and punicic acid(3) in the fatty acid composition, while those of M. charantia seeds predominantly comprised ${\alpha}-eleos$ acid as a main component(66.9%), accompanied by oleic acid(11.7%) and linoleic acid(10.4%). oil ${\beta}-eleostearic$ acid($_{9t.11t.13c-}C_{18:3}$) was checked as a trace. Fatty acid profiles of neutral lipids close resemblance to those of total lipids in all the seed oils, but are different from those of polar In particular, conjugate trienoic acids including punicic acid and ${\alpha}-eleostearic$ acid which are oc as the most abundant component in both neutral lipids of T. kirilowii and M. charantia seed oils, ar ent in a extremely small amount in both polar lipids. The fatty acid distribution in the polar lipid the samples except for T. kirilowii and M. charantia seed oils, showed a tendency of consid increased level of saturated fatty acids(25.0${\sim}$29.4%) compared with that in the neutral lipids(9.9%). The results obtained in this experiment suggest us that the seed oils of the Cucurbitaceae

• Korean Journal of Medicinal Crop Science
• /
• v.2 no.3
• /
• pp.198-204
• /
• 1994

This study was carried out to investigate the auxin(IAA, IBA, NAA) treatment and the effect of shading rate in Asarum sieboldii. The results obtained were summerized as follows: By the soaking treatment of auxins to the cutted rhizome enhanced root growth and plant weight. By the increment of shading rate, plant growth was much better compare to the control. Leaf fallen times appeared about 20 days more earlier at plain area then the alpain area. Root yield was much higher by the treatment of shading then the conventional cultivation so it seem to be the useful for large scale cultivations of A. sieboldii.

• Korean Journal of Medicinal Crop Science
• /
• v.2 no.3
• /
• pp.181-186
• /
• 1994

Vegetative node and rhizome of Ligusticum chuanxiong Hort. were planted in spring and autumn and harvested after one and two years to determine the appropriate harvesting time which produced a high yield. Plant height, leaf number and branch number per plant were increased in order of rhizome planted in spring and harvested after two year(RST), rhizome planted in autumn and harvested after one year(RAO), vegetative node planted in autumn and harvested after one year(VNAO), and vegetative node planted in spring and harvested after one year(VNSO). Leaf area index and dry leaf weight in VNSO were highest on August 16, but dry weights of stem and rhizome was increased until harvesting time. The appropriate harvesting time was October 17, in RST, November 9 in RAO and VNAO, and November 13 in VNSO. Yield in autumn planting was more increased than that in spring planting and also that in RST was 443kg per 10a and increased by 2.8 times compared to RAO. However the yield in the rhizome planting was more increased by 17 percent than the vegetative node planting, the latter planting was inexpensive and economic for purchasing seed materials.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.6
• /
• pp.671-680
• /
• 2017

This study was conducted to examine the effects and potential mechanisms of action of black soybean extracts and fermented black soybean extracts by Lactobacillus rhamnosus GG (LGG) and Bifidobacterium animals subsp. lactis BB-12 (BB-12) on proliferation of human follicle dermal papilla cells (HFDPC). We examined changes in pH, total polyphenol, sugar, and reducing sugar contents according to fermentation period of black soybean extracts. Assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was performed to determine cell toxicity levels of the four black soybean extracts [black soybean water extract (BWE), black soybean ethanol extract (BEE), fermented BWE (F-BEW), and fermented BEE (F-BEE)]. Changes in mRNA expression levels of hair growth promoting factors and hair growth inhibiting factors by the four black soybean extracts were measured by real-time PCR. In addition, phosphorylation levels of mitogen-activated protein kinase family proteins were measured by western blot analysis. As a result, fermentation of black soybeans significantly reduced pH, total polyphenols, and sugar/reducing sugar contents. All four black soybean extracts showed no cellular toxicity in HFDPC. In fact, BEE significantly enhanced cell viability of HFDPC at $100{\mu}g/mL$ compared to control. BWE, BEE, and BWE-F significantly increased mRNA expression of vascular endothelial growth factor, and all four extracts increased mRNA expression of fibroblast growth factor. However, mRNA expression levels of apoptosis-related genes were not affected by black soybean extracts in HFDPC. Furthermore, BWE, BEE, and BWE-F significantly increased phosphorylation levels of extracellular signal-regulated kinase compared to control. Taken together, we demonstrated that black soybean extracts enhanced proliferation of human follicle dermal papilla cells partially via activation of hair growth promoting factors, although no particular significant effects on proliferation were observed by fermentation of black soybeans.