• Horticultural Science & Technology
• /
• v.33 no.1
• /
• pp.31-38
• /
• 2015

This study was carried out to investigate the relationship between endogenous polyamines (PAs) and floral bud differentiation in chrysanthemum (Chrysanthemum morifolium). In this study, PA content (free, bound, and conjugated) in apical buds, leaves, and roots changed appreciably during floral bud differentiation. PAs accumulated during series of processes such as floral induction, differentiation of floret primordia, and crown formation in apical buds; changes in PAs in apical buds may have a relationship with those in leaves and roots. The levels of free PAs and conjugated PAs [putrescine (Put) and spermine (Spm)] in apical buds rapidly increased during the initiation stage of floral bud differentiation, while free and conjugated spermidine (Spd) reached their highest levels at the stage of floret primordium differentiation. In the free, conjugated, and bound PA fractions, the changes in Spm content were negligible compared to those of Put and Spd throughout the experiment. These findings indicate that PAs participate in regulating the process of flower bud differentiation in chrysanthemum.

• The Korean Journal of Food And Nutrition
• /
• v.17 no.4
• /
• pp.442-449
• /
• 2004

The purpose of this study was to examine the antioxidative activities and tissue cell of mouse liver added caffeine. The body weight of all experimental groups increased during experimental periods, but the body weight of caffeine-containing groups were lower than those of any other experimental groups. Superoxide dismutase and catalase activities tended to decrease significantly with caffeine-containing groups, but increased in control and ginseng-containing groups. Hydroperoxide contents were increase significantly with caffeine-containing groups. Lipid peroxidation levels decreased in ginseng-containing groups, but it increased significantly with caffeine-containing group. Protein contents were a tendency of similar between control and ginseng-containing groups, but it showed a increasing tendency in caffeine-containing groups. Microscopic observation of mouse liver cell were similar tissue in ginseng and caffeine-containing groups, but it showed somewhat more injuring only at the liver cell of anhydrous caffeine group, and became the suspicion in liver diseases. This results show that antioxidative activities are slightly higher in non-caffeine and ginseng-containing drinks than caffeine-cotaining drinks. From this standpoint, we suggest that too much drinking of caffeine-containing drinks for a long time is undesirable.

• Korean Journal of Environmental Biology
• /
• v.35 no.4
• /
• pp.515-520
• /
• 2017

Sexual dimorphism of the mouthpart, antenna and mandible of the Cyllorhynchites ursulus in South Korea was studied with linear measurements. The mouthpart and antenna measurements were conducted with a stereoscopic microscope using 122 specimens (72 males and 50 females). Microscopic observation of the mandible were conducted with a Field Emission Scanning Electron Microscope (FE-SEM) using 103 specimens (73 males and 30 females). Results showed that the size difference between males and females was significant in the size of the mouthpart and antenna. On the other hand, we could not detect sexual size dimorphism in the microstructure of the mandible. The bivariate plots made by the result of Principal Component Analysis (PCA) and Discriminant Analysis (DA) showed a size dimorphism in the size of the mouthpart and the antenna between males and females. Based on our study, sexual dimorphism in the mouthpart and antenna exists in C. ursulus from the South Korean population, and this difference seems to be related to the behavioral differences between males and females.

• Journal of Nutrition and Health
• /
• v.32 no.5
• /
• pp.519-525
• /
• 1999

The effects of Ganoderma Lucidum consumption (GL) on the liver function and lipid metabolic disorder induced by alcohol consuming were studied in rats using GL powder(1%, 2%, 4%) and 10% ethly alcohol. Thirty-five rats(Sprague-Dawley, male) were divided into five groups and fed experimental diets for seven weeks. The concentrations of serum cholesterol, HDL-cholesterol and triglyceride were the highest in the alcohol group, while the levels were apparently reduced by in groups fed GL. The atherogenic indices(AI) also tended to be higher in the alcohol group. Glutamic oxaloacetic transaminase(GOT) activities were significantly lower in body alcohol + 2% GL and alcohol + 4% GL groups, and glutamic pyruvic transaminase(GPT)activities lower only in the alcohol + 2% GL compared with the alcohol group. Alkaline phosphatase(ALP) activities were not significantly different among the groups. The elevated levels of liver cholesterol and triglyceride due to alcohol consumption, were apparently reduced by GL supplementation. On microscopic observation of liver tissues, fat droplets appeared extensively on the liver-lobule in the alcohol group, while fat droplets appeared only on the central vein in the alcohol + 1% GL group. However, in groups administered 2% and 4% GL, fat droplets appeared similar to the alcohol group. The concentrations of fecal bile acid were significantly increased in groups fed GL. These results indicate that GL exerted some beneficial effects on lipid metabolic disorder caused by long-term alcohol consumption. Thus, it seems that GL may be effective in preventing or curing some aspects of alcohol toxicity. More detailed studies are needed in order to determine proper dietary levels of GL for combating alcohol toxicity.

• Journal of the Korean institute of surface engineering
• /
• v.39 no.1
• /
• pp.13-17
• /
• 2006

The effects of an organic additive, naphthalene trisulfonic acid (NTSA), contained in the nickel sulfamate bath on the surface properties of the electrodeposited nickel layer were investigated through electrochemical technique, x-ray diffraction analysis, and microscopic observation. The addition of NTSA facilitated the oxidation process of electrodeposited nickel layer during anodic scan and also increased the hardness and internal stress of the nickel film as the applied current density became higher. It seems that NTSA modulated the deposit structure during electrodeposition and so induced higher distribution of (110) orientation with respect to (200). With the increase of the NTSA in the bath, nickel layer was formed in small grain size, which resulted in enhanced surface evenness and brightness.

• YAKHAK HOEJI
• /
• v.56 no.6
• /
• pp.382-389
• /
• 2012

Effects of citrate-capped silver nanoparticles (AgNPs) on the blood coagulation and platelet aggregation were investigated using whole blood, platelet rich plasma (PRP) and washed platelet obtained from SD male rats. To confirm the stability of AgNPs in the test, size distribution of the nanoparticles was measured in the vehicles including distilled water, serum, and platelet buffers. The average size of AgNPs was 20 nm in the vehicles, which means that the stability was maintained during the whole experimental period. When blood coagulation was monitored by using whole blood impedance aggregometer, coagulation was not observed at the concentration of 1, 10 and 50 ppm. Platelets in plasma or in buffer were not aggregated by AgNPs at the concentration of 1, 2 and 4 ppm, respectively. The test concentration of AgNPs could not be increased because the dark color of the nanoparticles impeded the transmission of light, which is an indicator of aggregation. Although the blood or platelets were pre-activated by collagen, thrombin, or ADP with sub-threshold level, aggregation was not observed at the test concentration. Microscopic observation also supported the result obtained by the aggregometer.

• Journal of the Korean Wood Science and Technology
• /
• v.47 no.1
• /
• pp.110-123
• /
• 2019

This work was conducted to examine the relationship between lignin content and the durability of larch (LAR) pellets. LAR sawdust was immersed in tap water (TW), sulfuric acid (AC) and sodium hydroxide (AK) solutions, and then the immersed sawdust was used for pellet fabrication. Klason lignin (KL) content of the immersed LAR, contents of soluble lignin (SL) and monomeric sugars liberated from the immersion of LAR, and durability of LAR pellets were measured. KL content decreased as the concentration of AC and AK solutions increased, but glucose content increased with increase in AC and AK concentration. Durability of wood pellets fabricated using non-immersed LAR sawdust was the highest, followed by those made using TW-, AK- and AC-immersed sawdust. LAR pellets became more durable as the concentration of KL and SL increased, but a significant positive correlation was found only between pellet durability and KL content. Through the fluorescent microscopic observation and SEM-EDX analysis, it was verified that lignin content of non-immersed LAR pellets was higher than that of AC- and AK-immersed LAR pellets. These results suggest that lignin might contribute to an increase in inter-particle bonding in wood pellets.

• Bulletin of the Korean Chemical Society
• /
• v.10 no.2
• /
• pp.172-177
• /
• 1989

Stereoselective solvolyses of optically active activated esters in the aggregate system of optically active polymeric surfactants containing imidazole and benzene moieties were performed. The catalyst polymers employed were copolymers of N-methacryloyl-L-histidine methyl ester (MHis) with N,N-dimethyl-N-hexadecyl-N-[10-(p-methacryloylo xyphenoxycarbonyl)-decyl]ammonium bromide(DEMAB). In the solvolyses of N-carbobenzoxy-D- and L-phenylalanine p-nitrophenyl esters (D-NBP and L-NBP) by polymeric catalysts, copoly(MHis-DEMAB) exhibited not only increased catalytic activity but also enhanced enantioselectivity as the mole ${\%}$ of surfactant monomers in the copolymers increased. The polymeric catalysts showed noticeable enantioselective solvolyses toward D- and L-NBP of the substrates employed. As the reaction temperature was lowered for the solvolyses of D- and L-NBP with the catalyst polymer containing 3.5 mole ${\%}$ of MHis, the increased reaction rate and enhanced enantioselectivity were observed. The coaggregative systems of the polymer and monomeric surfactants were also investigated. In the case of coaggregate system consisted of 70 mole ${\%}$ of cetyldimethylethylammonium bromide with polymeric catalyst showed maximum enantioselective catalysis, viz., $k_{cat}(L)/k_{cat}(D)$ = 2.85. The catalyst polymers in the sonicated solvolytic solutions were confirmed to form large aggregate structure by electron microscopic observation.

• Journal of Applied Biological Chemistry
• /
• v.64 no.1
• /
• pp.1-4
• /
• 2021

Ambient air pollution, in particular, particulate matter (PM) pollution imposes serious health concerns such as hospitalization and premature deaths, worldwide. While commercial breathing masks are in use for protection against this hazardous issue, yet their efficiency in filtering PM was not up to the par, besides several other discomforts such as poor breathability due to reduced air flow, sweat production etc. In this study, commercial face mask coated with β-glucan, a high molecular weight polymer is tested for its efficacy in filtering PM. Quantification of PM before and after filtration and microscopic observation (using scanning electron microscopy (SEM)) of the fabric used in filtering the dust pollutants (generated from wood chips and cigarette) showed that β-glucan coated fabric were significantly efficient in capturing PM (size of 10 and 2.5 ㎛ in diameter) than that of the untreated control fabric, wherein the former had filtration efficacy with fold increase of 11.6 and 2.6 towards capturing PM2.5 and PM10 respectively than the latter. Thus, β-glucan coated fabric was found to be effective in filtering PM.

• Mycobiology
• /
• v.51 no.3
• /
• pp.186-194
• /
• 2023

In July 2021, wilting symptoms were observed in adult and seedling hemp (Cannabis sativa L. cv. Cherry Blossom) plants grown in a greenhouse. As the disease progressed, yellowing and wilting symptoms on the leaves developed, resulting in whole plant death. In seedling plants, typical damping-off symptoms were observed. To identify the pathogen, the roots of diseased plants were sampled, surface sterilized, and cultured on potato dextrose agar (PDA) media. From the culture, 4 different fungal isolates were recovered and purely cultured. Each fungal isolate showed distinct growth shapes and color development on malt extract agar, oatmeal agar, sabouraud dextrose agar, and PDA media. Microscopic observation and molecular identification using ribosomal DNA internal transcribed spacer sequencing identified them as 3 Fusarium spp. and 1 Thielaviopsis paradoxa. Additional sequencing of elongation factor 1-alpha and b-tubulin regions of 3 Fusarium spp. revealed that 2 of them are Fusarium solani, and the other one is Fusarium proliferatum. To examine which isolate can act as a causal agent of wilt disease of hemp, each isolate was tested for their pathogenicity. In the pathogenicity test, F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3, but not T. paradoxa AMCF4, were able to cause wilting disease in hemp seedlings. Therefore, we report that F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3 as causal agents of Fusarium wilt of hemp plants. To our knowledge, this is the first report of the wilt disease of C. sativa L. caused by Fusarium spp. in Korea.