• Journal of the Korean Electrochemical Society
• /
• v.20 no.1
• /
• pp.7-12
• /
• 2017

Using a precursor of $LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$ as a starting material, a surface-modified cathode material was obtained by coating with KCl, where the added KCl reduces residual Li compounds such as $Li_2CO_3$ and LiOH, on the surface. The resulting electrochemical properties were investigated. The amounts of $Li_2CO_3$ and LiOH decreased from 8,464 ppm to 1,639 ppm and from 8,088 ppm to 6,287 ppm, respectively, with 1 wt% KCl added $LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$ that had been calcined at $800^{\circ}C$. X-ray diffraction results revealed that 1 wt% of KCl added $LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$ did not affect the parent structure but enhanced the development of hexagonal crystallites. Additionally, the charge transfer resistance ($R_{ct}$) decreased dramatically from $225{\Omega}$ to $99{\Omega}$, and the discharge capacity increased to 182.73mAh/g. Using atomic force microscopy, we observed that the surface area decreased by half because of the exothermic heat released by the Li residues. The reduced surface area protects the cathode material from reacting with the electrolyte and hinders the development of a solid electrolyte interphase (SEI) film on the surface of the oxide particles. Finally, we found that the introduction of KCl into $LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$ is a very effective method of enhancing the electrochemical properties of this active material by reducing the residual Li. To the best of our knowledge, this report is the first to demonstrate this phenomenon.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.37 no.2
• /
• pp.185-197
• /
• 1992

Differences in the amount and chemical characteristics of the epicuticular waxes on rice leaves were studied for the active tillering and heading stages of rice varieties differing widely in gross leaf-surface property and genetics. The amount of waxes on surfaces of rice leaf-blades was determined by extraction with chloroform and chemical composition of the waxes was characterized by thin layer chromatography, gas liquid chromatography and infrared spectrophotometry. The amount of waxes varied by variety and significantly with growth stage. The amount at the heading stage was 1.7 to 3.6 mg/g fresh weight of leaves, which was two to three times as much as that at the tillering stage of 0.8 to 1.8 mg/g fresh weight. The waxes consisted of seven chemical classes, namely diols, fatty acids, fatty alcohols, fatty aldehydes, fatty esters, saturated and unsaturated hydrocarbons. Diols and unsaturated hydrocarbons were identified as new chemical classes of the rice epicuticular waxes. The polar constituents such as dials, fatty acids and fatty alcohols and the non-polars such as fatty aldehydes, fatty esters, and saturated and unsaturated hydrocarbons were identified at the heading stage, but at the tillering stage only the non-polar compounds were identified. In the carbon numbers (C) of the chemical classes, diols were composed entirely of C30 and acids were mainly of C30 and C31. In alcohols, primary alcohols were composed of C13 and C32, and the secondary alcohols were of C14, C16 and / or C30 regardless of the rice varieties. The acid portion of fatty esters, mainly composed of C22 and C23, showed low cabon numbers compared with the aldehydes. The alcohol portion of them showed a wide distribution in carbon numbers from C13 to C26 depending on the rice varieties. Hydrocarbons had odd carbon numbers, consisting mainly of C29 and C31.

• Korean Chemical Engineering Research
• /
• v.43 no.2
• /
• pp.206-214
• /
• 2005

Heterogeneously-catalyzed oxidation of aqueous phase trichloroethylene (TCE) over supported metal oxides has been conducted to establish an approach to eliminate ppm levels of organic compounds in water. A continuous flow reactor system was designed to effect predominant reaction parameters in determining catalytic activity of the catalysts for wet TCE decomposition as a model reaction. 5 wt.% $CoO_x/TiO_2$ catalyst exhibited a transient period in activity vs. on-stream time behavior, suggesting that the surface structure of the $CoO_x$ might be altered with on-stream hours; regardless, it is probable to be the most promising catalyst. Not only could the bare support be inactive for the wet decomposition reaction at $36^{\circ}C$, but no TCE removal also occurred by the process of adsorption on $TiO_2$ surface. The catalytic activity was independent of all particle sizes used, thereby representing no mass transfer limitation in intraparticle diffusion. Very low TCE conversion appeared for $TiO_2$-supported $NiO_x$ and $CrO_x$ catalysts. Wet oxidation performance of supported Cu and Fe catalysts, obtained through an incipient wetness and ion exchange technique, was dependent primarily on the kinds of the metal oxides, in addition to the acidic solid supports and the preparation routes. 5 wt.% $FeO_x/TiO_2$ catalyst gave no activity in the oxidation reaction at $36^{\circ}C$, while 1.2 wt.% Fe-MFI was active for the wet decomposition depending on time on-stream. The noticeable difference in activity of the both catalysts suggests that the Fe oxidation states involved to catalytic redox cycle during the course of reaction play a significant role in catalyzing the wet decomposition as well as in maintaining the time on-stream activity. Based on the results of different $CoO_x$ loadings and reaction temperatures for the decomposition reaction at $36^{\circ}C$ with $CoO_x/TiO_2$, the catalyst possessed an optimal $CoO_x$ amount at which higher reaction temperatures facilitated the catalytic TCE conversion. Small amounts of the active ingredient could be dissolved by acidic leaching but such a process gave no appreciable activity loss of the $CoO_x$ catalyst.

• Journal of Life Science
• /
• v.28 no.11
• /
• pp.1339-1346
• /
• 2018

In Korea, edible mushrooms are produced largely on commercial artificial media, so the annual production of spent mushroom substrate (SMS), as a by-product of the mushroom industry, is estimated at over 200 million tons. This SMS is assumed to contain abundant fungal mycelia and pre-fruiting bodies, as well as various nutritive and bioactive compounds that are presently discarded. This study examined the physico-chemical, nutritional, and enzymatic characteristics of uninoculated sterilized medium (USM) and SMS of shiitake mushrooms with the aim of developing a high-value added product from SMS. The contents of crude protein, crude lipid, and ash were higher after the third SMS harvest ($SMS-A-3^{rd}$) than in USM or $SMS-A-1^{st}$. The contents of Ca, Mg, and P in $SMS-A-3^{rd}$ were 2.95, 2.35, and 2.1-fold higher compared than in USM. No As or Cd was detected in USM or SMS. The pH, Brix, and acidity were 4.6, 20.0, and 1.4, respectively in $SMS-A-3^{rd}$, but 5.6, 6.0, and 0.0, respectively, in USM. These results suggest a highly active production of soluble components and organic acids in $SMS-A-3^{rd}$. The distinct color differences noted for USM, $SMS-A-1^{st}$, and $SMS-A-3^{rd}$ could be used as a mycelial growth indicator. Enzyme activity assays using the APIZYM system showed that SMS is a potent source of hydrolysis-related enzymes, especially esterase (C4) and ${\beta}$-glucuronidase. Our results suggested that the SMS of shiitake has a high potential for use in environmental, agricultural, and stock-breeding industries, for example, as active ingredients for sewage treatment, waste-polymer degradation, and feed additives.

• Journal of Life Science
• /
• v.33 no.2
• /
• pp.169-175
• /
• 2023

As a protective defensive mechanism against ultraviolet (UV) light exposure in skin tissue, melanocytes produce the pigment melanin. Tyrosinase plays a key role in melanin production in melanocytes. However, the overproduction of melanin can lead to lesions, such as freckles and dark spots. Thus, it is clinically important to find a modulating molecule to control melanogenesis by regulating tyrosinase expression and/or activity. It is known that catechin, a plant flavonoid, can reduce melano- genesis through the downregulation of tyrosinase expression. Here, we tested whether catechin derivatives isolated from the stem bark of Ulmus parvifolia have an effect on melanin production by regulating tyrosinase in mouse melanoma cells and in vitro mushroom tyrosinase. The catechin derivatives used in this study included C5A, C7A, C7G, and C7X. Treatments using these catechin derivatives reduced melanin production in mouse melanoma B16F10 cells in which melanogenesis was stimulated by α-MSH. Notably, the anti-melanogenic effects of catechin derivatives were similar to those of kojic acid, a well-known anti-melanogenic molecule. Both C5A and C7A directly inhibited the activity of tyrosinase isolated from mushrooms in vitro. Furthermore, our in silico computational simulation showed that these two compounds were expected to bind to the active site of tyrosinase, which is similar to kojic acid. In addition, all four catechin derivatives reduced tyrosinase protein expression. In summary, our results showed that catechin derivatives can reduce melanogenesis by regulating tyrosinase activity or expression. Thus, this study suggests that catechin derivatives isolated from U. parvifolia can be novel modulators of melanin production.

• Journal of Ginseng Research
• /
• v.26 no.3
• /
• pp.111-131
• /
• 2002

Korean ginseng (Panax ginseng C.A. Meyer) received a great deal of attention from the Orient and West as a tonic agent, health food and/or alternative herbal therapeutic agent. However, controversy with respect to scientific evidence on pharmacological effects especially, evaluation of clinical efficacy and the methodological approach still remains to be solved. Author reviewed those articles published since 1980 when pharmacodynamic studies on ginseng have intensively started. Special concern was paid on metabolic disorders including diabetes mellitus, circulatory disorders, malignant tumor, sexual dysfunction, and physical and mental performance to give clear information to those who are interested in pharmacological study of ginseng and to promote its clinical use. With respect to chronic diseases such as diabetes mellitus, atherosclerosis, high blood pressure, malignant disorders, and sexual disorders, it seems that ginseng plays preventive and restorative role rather than therapeutics. Particularly, ginseng plays a significant role in ameliorating subjective symptoms and preventing quality of life from deteriorating by long term exposure of chemical therapeutic agents. Also it seems that the potency of ginseng is mild, therefore it could be more effective when used concomitantly with conventional therapy. Clinical studies on the tonic effect of ginseng on work performance demonstrated that physical and mental dysfunction induced by various stresses are improved by increasing adaptability of physical condition. However, the results obtained from clinical studies cannot be mentioned in the indication, which are variable upon the scientist who performed those studies. In this respect, standardized ginseng product and providing planning of the systematic clinical research in double-blind randomized controlled trials are needed to assess the real efficacy for proposing ginseng indication. Pharmacological mode of action of ginseng has not yet been fully elucidated. Pharmacodynamic and pharmacokinetic researches reveal that the role of ginseng not seem to be confined to a given single organ. It has been known that ginseng plays a beneficial role in such general organs as central nervous, endocrine, metabolic, immune systems, which means ginseng improves general physical and mental conditons. Such multivalent effect of ginseng can be attributed to the main active component of ginseng,ginsenosides or non-saponin compounds which are also recently suggested to be another active ingredients. As is generally the similar case with other herbal medicines, effects of ginseng cannot be attributed as a given single compound or group of components. Diversified ingredients play synergistic or antagonistic role each other and act in harmonized manner. A few cases of adverse effect in clinical uses are reported, however, it is not observed when standardized ginseng products are used and recommended dose was administered. Unfavorable interaction with other drugs has also been suggested, which the information on the products and administered dosage are not available. However, efficacy, safety, interaction or contraindication with other medicines has to be more intensively investigated in order to promote clinical application of ginseng. For example, daily recommended doses per day are not agreement as 1-2g in the West and 3-6 g in the Orient. Duration of administration also seems variable according to the purpose. Two to three months are generally recommended to feel the benefit but time- and dose-dependent effects of ginseng still need to be solved from now on. Furthermore, the effect of ginsenosides transformed by the intestinal microflora, and differential effect associated with ginsenosides content and its composition also should be clinically evaluated in the future. In conclusion, the more wide-spread use of ginseng as a herbal medicine or nutraceutical supplement warrants the more rigorous investigations to assess its effacy and safety. In addition, a careful quality control of ginseng preparations should be done to ensure an acceptable standardization of commercial products.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.26 no.1
• /
• pp.1-24
• /
• 2013

Objectives: The object of this study was to observe the protective effect of Gamijipaesan aqueous extracts(GJS), which has been traditionally used in Korean medicine in obstetrics & gynecological fields as anti-infectious and anti-inflammatory agents, against mastitis induced by Staphylococcus aureus infection in a rat model through antibacterial, antiinflammatory, immunomodulatory, and anti-oxidant effects. Methods: Antibacterial activities of GJS against S. aureus were detected using standard agar microdilution methods, with the effects on the bacterial invasion and intracellular killing of individual test materials in human mammary gland carcinoma cell(MCF-7) and murine macrophages(Raw 264.7) at MIC1/2, MIC and MIC2 concentration levels. In addition, the effects on the cell viability, nitric oxide(NO), tumor necrosis factor(TNF)-${\alpha}$ and interleukin (IL)-6 productions of LPS activated Raw 264.7 cells. The changes on the mammary tissue viable bacterial numbers, myeloperoxidae(MPO), inducible nitric oxide synthetase(iNOS), TNF-${\alpha}$ and IL-6 contents were observed in the S. aureus in vivo intramammary infectious rat model. The anti-bacterial and anti-inflammatory effects were compared with ciprofloxacin and piroxicam, respectively in the present study. Results: MIC of GJS and ciprofloxacin against S. aureus were detected as $0.860{\pm}0.428$ (0.391-1.563) mg/ml and $0.371{\pm}0.262$(0.098-0.782) ${\mu}g/ml$, respectively. In addition, GJS and ciprofloxacin were also showed marked dosage-dependent inhibition of the both bacterial invasion and intracellular killing assays using MCF-7 and Raw 264.7 cells at MIC1/2, MIC and $MIC{\times}2$ concentrations, respectively. $ED_{50}$ against LPS-induced cell viabilities and NO, TNF-${\alpha}$ and IL-6 releases of GJS were detected as 0.72, 0.04, 0.08 and 0.11 mg/ml, and as 19.04, 4.18, 5.37 and 4.27 ${\mu}g/ml$ in piroxicam, respectively. 250 and 500 mg/kg of GJS also inhibit the intramammary bacterial growth, MPO, iNOS, TNF-${\alpha}$ and IL-6 contents in S. aureus in vivo intramammary infected rats, respectively. GJS 500 mg/kg showed quite similar antibacterial and anti-infectious effects as compared with ciprofloxacin 40 mg/kg and also showed similar anti-inflammatory effects as piroxicam 10 mg/kg, in S. aureus in vivo intramammary infectious models. Conclusions: The results obtained in this study suggest that over 250 mg/kg of GJS showed favorable anti-infectious effects against S. aureus infection in a rat model through their antibacterial, anti-inflammatory, immunomodulatory and anti-oxidant effects and therefore expected that GJS can be used as alternative therapies, having both anti-inflammatory and anti-infectious activities. However, more detail mechanism studies should be conducted in future with the efficacy tests of individual herbal composition of GJS and the screening of the biological active compounds in individual herbs. In the present study, GJS 500 mg/kg showed quite similar anti-infectious effects were detected as compared with ciprofloxacin 40 mg/kg treated rats, and also GJS shows quite similar anti-inflammatory effects as compared with piroxicam 10 mg/kg in S. aureus in vivo intramammary infectious rats, but ciprofloxacin did not showed any anti-inflammatory effects, and piroxicam did not showed anti-infectious effects in this study.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.30 no.2
• /
• pp.49-70
• /
• 2017

Objectives: The present study is to observe the skin-regeneration, anti-wrinkle, whitening and skin moisturizing effects of Cheongsangbangpung-tang (CSBPT) with cytotoxicity. Methods: In the present study, cytotoxicity of CSBPT lyophilized aqueous extracts (yield=18.71%) was experimented against human normal fibroblast cells and B16F10 murine melanoma cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide (MTT) assay, and skin regeneration and anti-wrinkle effects were also showed through the assay of collagen type I synthesis by an enzyme immunoassay (EIA) kit as comparing with transforming growth factor (TGF)-${\beta}1$, hyaluronidase, collagenase and matrix metalloproteinase (MMP)-1 inhibitory assays as comparing with oleanolic acid (OA), and elastase inhibitory effects as comparing with phosphoramidon disodium salt (PP). In addition, whitening effects of CSBPT were observed by tyrosinase inhibitory assay and melanin formation test in B16/F10 melanoma cells as comparing with arbutin, and skin moisturizing effects were measured through mouse skin water contents test, respectively. Results: No CSBPT treatment related cytotoxic effects were demonstrated against human normal fibroblast cells and B16/F10 murine melanoma cells. CSBPT concentration-dependent increased collagen type I synthesis at human normal fibroblast cells. It also effectively suspreessed hyaluronidase, collagenase, elastase and MMP-1 activities, which were enzymes that related to declining of ECM and formation of wrinkle. CSBPT supressed B16/F10 melanoma cells's melanin productions with tyrosinase activity, which was an enzyme connected with melanin formation, and dose-dependent and significant increases of skin water contents were detected in CSBPT treated mouse skin as compared with vehicle control skins. Conclusions: CSBPT showed favorable and enough skin regeneration, anti-wrinkle, whitening and skin moisturizing effects at least in a condition of this experiment. However, more detail mechanism and in vivo skin protective efficacy studies should be conducted in future with the screening of the biological active compounds in individual herbs of Cheongsangbangpung-tang.

• The Korean Journal of Food And Nutrition
• /
• v.28 no.3
• /
• pp.369-375
• /
• 2015

This study was performed to investigate the physiological activities of Ginkgo biloba sarcotesta extracts before and after heat treatment. G. biloba sarcotesta was heated at $130^{\circ}C$ for 2 h and extracted with water, 70% ethanol and 80% methanol. ABTS and DPPH radical scavenging activities increased after heating in the water (14.95 mg AAE/g and 7.36 mg TE/g) and ethanol extracts (12.20 mg AAE/g and 6.23 mg TE/g). ${\alpha}$-Glucosidase inhibitory activity decreased after heating in all but the water extract. Angiotensin converting enzyme I inhibitory activities decreased after heating in all extracts. Nitric oxide production inhibitory activity increased from 12.40~44.55% of the raw sample to 40.76~72.39% of the heated sample at a concentration of $200{\mu}g/mL$. Lipid accumulation inhibitory activities were similar before and after heat treatment. The highest antiproliferative effects on MCF-7 human breast cancer cell lines were observed in 80% methanol extract in the heated sample. Cell viability at concentrations of 25, 50, 100, and $200{\mu}g/mL$ measured 34.88, 17.58, 8.44 and 10.48%, respectively. From the results, the antioxidant and antiproliferative activities of G. biloba sarcotesta extracts increased with heat treatment, and research on the identification of the structure for the active compounds are needed in further studies.

• Tuberculosis and Respiratory Diseases
• /
• v.44 no.5
• /
• pp.1063-1071
• /
• 1997

Backgroung : The efficacy of oral corticosteroids in the treatment of chronic asthma is undisputed, but their long-term use is associated with adverse side-effects, including supression of the hypothalamic-pituitary adrenal axis function, osteoporosis, weight gain, hypertension and impaired glucose tolerance. The introduction of inhaled corticosteroids in the early 1970's represented a significant therapeutic advance in the management of asthma, since these compounds combined high topical potency with low systemic activity. Fluticasone propionate is a new topically active synthetic glucocorticosteroid that combinds a high degree of efficacy with negligible systemic bioavailability. This study was perfomed to determine the effect of inhaled fluticasone propionate on the adreocortical supression in patients with bronchial asthma or chronic obstructive pulmonary disease. Method : The adrenocortical function was assessed by measurement of plasma cortisol concentration at 8 o'clock in morning and free cortisol in 24 hour urine collection at interval. Absolutely, no steroid was taken during pretreatment period of 10days. There after each subject inhaled fluticasone aerosol, in daily doses of 500 or 1000micrograms for 12days. The dose was delivered by metered dose inhaler(MDI). Results : The serum cortisol and 24hour urinary free cortisol were not decreased during the treatment period in patients with inhaled fluticasone propionate in daily doses of 500 micrograms. In contrast, serum cortisol was significantly decreased on 9th and 12th day(p less than 0.05). And, 24hour urinary free cortisol was also significantly decreased on 3rd and 12th day of treatement period(p less than 0.05) in patients with inhaled fluticasone in daily doses of 1000 micrograms. Conclusion : These results suggested that endogenous cortisol secretion was not supressed after short-term inhalation of fluticasone in daily dose of 500 micrograms, but in daily dose of 1000 micrograms, the endogenous cortisol secretion was supressed.