• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.8
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• pp.880-886
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• 2007

We have proposed a new "hybrid" envelope elimination and restoration(EER) transmitter architecture using an efficiency optimized power amplifier(PA) and modified bias modulator. The efficiency of the PA at the average drain voltage is very important for the overall transmitter efficiency because the PA operates mostly at the average power region of the modulation signal. Accordingly, the efficiency of the PA has been optimized at the region. Besides, the bias modulator has been accompanied with the emitter follower for the minimization of memory effect. A saturation amplifier, class $F^{-1}$ is built using a 5-W PEP LDMOSFET for forward-link single-carrier wideband code-division multiple-access(WCDMA) at 1-GHz. For the interlock experiment, the bias modulator has been built with the efficiency of 64.16% and peak output voltage of 31.8 V. The transmitter with the proposed PA and bias modulator has been achieved an efficiency of 44.19%, an improvement of 8.11%. Besides, the output power is enhanced to 32.33 dBm due to the class F operation and the PAE is 38.28% with ACLRs of -35.9 dBc at 5-MHz offset. These results show that the proposed architecture is a very good candidate for the linear and efficient high power transmitter.

• ALGAE
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• v.28 no.1
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• pp.111-119
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• 2013

Marine microalgae are a promising source of organisms that can be cultured and targeted to isolate the broad spectrum of functional metabolites. In this study, two species of cyanobacteria, Chlorella ovalis Butcher and Nannchloropsis oculata Droop, one species of bacillariophyta, Phaeoductylum tricornutum Bohlin, and one species of Dinophyceae, Amphidinium carterae (Hulburt) were cultured and biomasses used to evaluate the proximate comical compositions. Among the determined proximate chemical compositions of the cultured marine microalgae, the highest content of crude proteins and lipids were exhibited in P. tricornutum and A. carterae, respectively. Solvent-solvent partition chromatography was subjected to fractionate each of the cultured species and separated n-hexane, chloroform, ethyl acetate, and aqueous fractions. Nitric oxide production inhibitory level (%) and cytotoxicity effect on lipo-polysaccharide-induced RAW 264.7 macrophages were performed to determine the anti-inflammatory activity. N. oculata hexane and chloroform fractions showed significantly the strongest anti-inflammatory activity at $6.25{\mu}g\;mL^{-1}$ concentration. The cancer cell growth inhibition (%) was determined on three different cell lines including HL-60 (a human promyelocytic leukemia cell line), A549 (a human lung carcinoma cell line), and B16F10 (a mouse melanoma cell line), respectively. Among the extracts, C. ovalis ethyl acetate and A. carterae chloroform fractions suppressed the growth of HL-60 cells significantly at 25 and $50{\mu}g\;mL^{-1}$ concentrations. Thus, the cultured marine microalgae solvent extracts may have potentiality to isolate pharmacologically active metabolites further using advance chromatographic steps. Hence, the cultured marine microalgae can be described as a good candidate for the future therapeutic uses.

• Journal of Pharmacopuncture
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• v.5 no.2
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• pp.120-136
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• 2002

Objectives : The purpose of this study is to investigate Acute and Subacute Toxicity, and Anti-cancer Effect of H Herbal-acupuncture on mice and rats. Methods : Balb/c mice were injected intraperitoneally with H Herbal-acupuncture for $LD_{50}$ and acute toxicity test. Sprague-Dawley rats were experimented in the same way for subacute toxicity test. H Herbal-acupuncture was injected into abdomen of mice having S-180 cancer cell line. Result : 1. During the test, $LD_{50}$ could not be counted since there was no expired subjects. 2. In an acute toxicity test, the loss of motility and reflex action was observed, but weight increased in the treatment group, compared with those in the normal group (P<0.05). 3. In an acute toxicity test of serum biochemical values of mice, glucose increased in the treatment group II while total cholesterol was increased in the all treatment groups (P<0.05). 4. In a subacute toxicity test, a little loss of motility and reflex action was observed in the treatment group. Weight of mice in the treatment group decreased on the 28th day. 5. In a subacute toxicity test, liver weight was decreased but lung weight of mice increased in the all treatment groups (P<0.05). 6. As a result of measuring Complete Blood Count test (CBC) of rat, HCT was decreased in treatments even though it was not significant, compared with the normal group (P<0.05). 7. In a serum biochemical value test of subacute toxicity, total protein and albumin decreased in the all treatment groups. Creatinine, glucose, GOT increased in the treatment group I compared with the control group. Alkaline phos-phatase decreased in treatment II group, compared with the control group (P<0.05). 8. Median survival time that was measured in the rats treated with sarcoma-180 cancer cell Median decreased in the treatment group, compared with the control group (P<0.05). 9. Natural killer cell activity showed significant reduction at 100:1 and 10:1 E/T ratio while it increased at 50:1 E/T ratio. It is inferred that there was an error in the experiment (P<0.05). 10. In an interleukin-2 productivity test, even though it decreased in lung cancer, and increased in abdomen cancer, but it was only a small difference (P<0.005). 11. After injecting B16F10 cell into a capillary vessel of C57BL/6 mice and generating metastasized lung cancer, the lung was examined with the naked eye. It was not possible to see metastasized cancer in the all groups on the seventh day but the cancer was viewed on the fourteenth day. The number and volume of metastasized cancer in the treatment group enlarged in the treatment group, compared with the control group. Conclusion : According to the results, H herbal-acupuncture took no effects in cancer.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.651-661
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• 2021

Eruca sativa, called arugula, is a perennial plant in the Brassicaceae family, an edible plant commonly used in Italian cuisine. To study as a cosmetic material application E. sativa was extracted with 70% ethanol (ES). Then ES was fractionated using n-hexane, chloroform, ethyl acetate, n-butyl alcohol and water (EHex, EEA, ECHCl₃, EBuOH and EDW). EEA showed mushroom tyrosinase inhibitory activity. ES, EEA and EBuOH showed inhibition of tyrosinase activity. As a result, ES is expected to have skin whitening efficacy. ES was applied to 0.05, 0.1% the toner and emulsion formulation to test the stability. The anti-microbial activity of eight bacteria and fungi including Staphylococcus aureus and Propionibacterium acnes which cause dermatitis and acne was evaluated. EEA showed effects in all of microorganisms. The toner and emulsion containing ES with 0.05, 0.1% were passed in the challenge test. At -20, 4, 25, 55 ℃ and daylight, there was no significant change on pH, viscosity for 4 months. However, emulsions had phase separation phenomenon at 55 ℃, so the base formulation needs improvement. In addition, through the skin penetration test, EEA penetrated 0.058% in 6 hr, predicting the clinical efficacy. This means that E. sativa can contribute whitening agent and the synergistic effect of preservatives.

• Clinical and Experimental Pediatrics
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• v.45 no.4
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• pp.505-511
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• 2002

Purpose : Mean platelet volume(MPV) and platelet distribution width(PDW) are useful parameters in evaluating disorders of platelets. In cases with idiopathic thrombocytopenic purpura(ITP), they change as platelet count increases. In this study, we compared the values of MPV and PDW in ITP patients at diagnosis with those of normal children. We also studied whether the early changes in MPV may predict the clinical course. Methods : From December 1995 to May 2001, 71 patients with ITP were admitted to Ajou University Hospital. They were treated with IVIg 400 mg/kg for five days and MPV, PDW, platelet count were analysed. Normal control group(n=38) was compared. The study group was divided into acute and chronic forms, and also divided into group A, good early responders whose platelets increased more than $100,000/{\mu}L$ within 5 days and group B who did not. Results : Mean value of MPV at diagnosis in ITP patients was lower than the normal control group(P<0.05). In group A, MPV was abruptly increased on the first day after IVIg and then started to decrease. But in group B, MPV was steadily increased until the fourth day after IVIg. In the normal control group, there were inverse correlations between platelet count and MPV(r=-0.415, P<0.05), but in ITP patients, there were positive relationships between platelet count and MPV(r=0.646, P<0.05) at diagnosis. Conclusions : MPV at diagnosis of ITP was lower than the normal control. MPV and PDW could not predict the course of ITP patients, but MPV could distinguish good early responders. More research is needed to find out the reasons of decreased MPV at diagnosis of ITP.

• Mycobiology
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• v.40 no.2
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• pp.117-123
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• 2012

Nuruk contributes to the unique characteristics of Korean alcoholic beverages. In this study, the effects of nuruk extracts (NE) on anti-oxidant characters, melanogenesis, and anti-photoaging activity were investigated. NEs were obtained from the 70% ethanol extracts of six types of nuruk, which have been used in brewing of fermented alcohol beverages in Korea. First, various antioxidant characteristics were identified in terms of 2,2'-azino-bis(3-ethylbenzthiozoline-6-sulphonic acid) (ABTS) radical scavenging activity, superoxide dismutase (SOD) expression, and inhibition of xanthine oxidase activity. NE#4 exhibited potent ABTS radical scavenging activity ($IC_{50}$ = 19.51 ${\mu}g$/mL). Compared with NE#4, relatively lower levels of activity were observed for NE#3 and NE#6, with $IC_{50}$ values of 90.99 and 76.88 ${\mu}g$/mL, respectively. According to results of western blot analysis for determination of SOD expression in $H_2O_2$-treated HepG2 cells, NE#5 and NE#6 induced a dramatic increase in the expression ratio of SOD, compared to the group treated with $H_2O_2$ only. Activity of xanthine oxidase, which converts xanthine into uric acid, generating superoxide ions, was inhibited by NE#4 and NE#6 in a dose-dependent manner. NE#4 induced significant inhibition of mushroom tyrosinase activity. A reduction in cellular melanin contents of 80% was observed in B16F1 melanocytes treated with NE#5 and NE#6; these effects were similar to those of arbutin at 100 ${\mu}M$. In addition, gelatin zymography and reverse transcription-PCR analysis were performed for assessment of anti-photoaging activity of Nuruk. Treatment with NE#6 resulted in dramatically inhibited activities of matrix metalloproteinase (MMP)-2/-9, suppressed expression of MMP-1, and increased expression of type-1 procollagen. Results of gelatin zymography for NE#4 and NE#5 were similar, to a slightly lesser degree. These results suggest the potential of NE#4 and NE#6 as natural ingredients for use in functional foods and cosmetics.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.4
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• pp.550-555
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• 2013

Extrinsic skin aging is characterized by the loss of skin tone and resilience, irregular pigmentation, and deep wrinkles. The aim of this study was to investigate the effects of Ehwa Makgeolli containing oriental herbs (Glycyrrhiza uralensis Fisch., Lycium chinense MILL., Morus alba L., and Saururus chinensis Baill) on skin whitening and wrinkling in human skin cells. We prepared Makgeolli extracts (HEE) with 70% ethanol. HEE significantly inhibited in vitro mushroom tyrosinase activity and reduced the cellular and secreted melanin content of mouse melanoma melanocytes (B16F1 cells). HEE down-regulated the protein expression of tyrosinase related protein (TRP)-1/-2, a key player in melanogenesis. Treatment with HEE in human keratinoctyes (HaCaT cells) inhibited the proteolytic activities of matrix metalloproteinase (MMP)-2/-9 in a dose-dependent manner and dramatically reduced the expression of MMP-2/-9. In addition, HEE attenuated lipopolysaccharide (LPS)-induced nitric oxide production in murine macrophages (RAW264.7 cells). These results indicate that HEE may be a great cosmeceutical ingredient for its whitening, anti-wrinkle, and anti-inflammatory effects.

• Journal of Pharmacopuncture
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• v.6 no.1
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• pp.76-94
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• 2003

Objectives : The purpose of this study was to investigate Acute$\cdot$Subacute Toxicity and Anti-cancer Effect of K-Herbal-acupuncture in mice and rats. Methods : Balb/c mice were injected intraperitoneally with K-herbal-acupuncture for $LD_{50}$ and acute toxicity test. Sprague-Dawley rats were injected intraperitoneally with K-herbal-acupuncture for subacute toxicity test. K-Herbal-acupuncture was injected on abdomen of mice with S-180 cancer cell line. Result : 1. $LD_{50}$ of K-Herbal-acupuncture was limited $4{\times}10^{-3}$ml/kg~$2{\times}10^{-3}$ml/kg by the test. 2. In acute toxicity test, all of mice were down to the moving reflex, but the weight of mice was increased in treatment group, compared with the normal group. (P<0.05) 3. In acute toxicity test of serum biochemical values of mice, glucose was increased in treatment II group, total cholesterol was increased both treatments.(P<0.05) 4. In subacute toxicity test, the clinical signs of toxication was down to the moving reflex, but it is not severe like acute toxicity test, and observed weight loss at the treatments. 5. In subacute toxicity test, liver weight was decreased compared with the normal group. (P<0.05) 6. In subacute toxicity test of complete blood count test (CBC) of rat, HCT was decreased in treatments, compared with the normal group.(P<0.05) 7. In subacute toxicity test of serum biochemical values of rat, uric acid and triglyceride were decreased, and glucose was increased in treatment groups compared with the control group. (P<0.05) 8. Median survival time was increased about $45\%$ in treatment groups compared with the control group.(P<0.05) 9. Natural killer cell activity was increased in B16F10 lung cancer model, but it was not in sarcoma-180 abdomen cancer. 10. In interleukin-2 productivity test, treatment groups didn't show significant change in lung cancer and abdomen cancer, compared with the normal group.(P<0.005) 11. In making an examination of metastatic cancer with the naked eye, melanoma metastasized in the Lung of C57BL/6 mice. The treated group showed more Melanoma than the control in the numbers and volume. Conclusion : According to the result, K-herbal-acupuncture need further study to know the function and effect in cancer.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.3
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• pp.233-240
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• 2010

Derivatives of a novel natural compunds, melanostatin (PLG-$NH_2$) were prepared by solid phase synthesis[1,2] and assayed to evaluate their melanogensis inhibitory activity. Also, a small library (natural compound-XLG-$NH_2$, natural compound-X LG-OH) was prepared with same method for increasing synthetic yield and cost-reduction. PLG-$NH_2$ (Proline-Leucine-Glycine-$NH_2$) was well-known tripeptide as its $\alpha$-MSH release-inhibiting activity and tyrosinase inhibitory activity[3-5]. In order to choose best candidate for peptide derivatization, various natural compounds were screened by their tyrosinase inhibitory activity. As a result, caffeic acid and coumaric acid were selected. Most of these derivatives showed better activities than the parent natural compound, melanostatin.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.2
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• pp.143-149
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• 2009

Several hydroxycinnamic acid derivatives, p-coumaric acid, ferulic acid, N,N'-dicoumaroylputrescine (DCP), N-p-coumaroyl-N'-feruloyl-putrescine (CFP), and N,N'-diferuloylputrescine (DFP) were isolated and purified from corn bran. To develop the skin whitening agent, we investigated the effects of hydroxycinnamic acid derivatives from corn bran, on melanogenesis. CFP and DFP inhibited melanin synthesis in a dose dependent manner up to 44.7 ${\pm}$ 6.0 %, and 58.5 ${\pm}$ 3.1 % at a concentration of 50 ${\mu}g/mL$, respectively. The intracellular tyrosinase activity decreased about 42.5 ${\pm}$ 14.6 %, and 9.0 ${\pm}$ 4.4 % at a concentration of 50 ${\mu}g/mL$ of CFP and DFP, respectively. Our results suggest that inhibitory effects of hydroxycinnamic acid derivatives on melanogenesis are due to the inhibition of the intracellular tyrosinase activity. These results indicate that these hydroxycinnamic acid derivatives from corn bran may be potential natural skin whitening agents.