• Title/Summary/Keyword: Hwe

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Evaluation of crystallinity and defect on (100) ZnTe/GaAs grown by hot wall epitaxy

  • Kim, Beong-Ju
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.12 no.6
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    • pp.299-303
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    • 2002
  • The relationship of crystallinity between defects distribution with (100) ZnTe/GaAs using HWE growth was investigated by four crystal rocking curve (FCRC) and transmission electron microscopy (TEM). The thickness dependence of crystal quality in ZnTe epilayer was evaluated. The FWHM value shows a strong dependence on ZnTe epilayer thickness. For the films thinner than 6 ${\mu}{\textrm}{m}$, the FWHM value decreases very steeply as the thickness increases. For the films thicker than 6 ${\mu}{\textrm}{m}$, it becomes an almost constant value. At the thickness of 12 $\mu\textrm{m}$ with the smallest value of 66 arcsec. which is the best value so far reported on ZnTe epilayers was obtained. Investigation into the nature and behavior of dislocations with film thickness in (100) ZnTe/(100)GaAs heterostructures grown by Hot Wall Epitaxy (HWE). This film defects range from interface to 0.7 ${\mu}{\textrm}{m}$ thickness was high density, due to the large lattice mismatch and thermal expansion coefficients. The thickness of 0.7~1.8 ${\mu}{\textrm}{m}$ was exists low defect density. In the thicker range than 1.8 ${\mu}{\textrm}{m}$ thickness was measured hardly defects.

Inbreeding Coefficients in Two Isolated Mongolian Populations - GENDISCAN Study

  • Sung, Joo-Hon;Lee, Mi-Kyeong;Seo, Jeong-Sun
    • Genomics & Informatics
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    • v.6 no.1
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    • pp.14-17
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    • 2008
  • GENDISCAN study (Gene Discovery for Complex traits in Asian population of Northeast area) was designed to incorporate methodologies which enhance the power to identify genetic variations underlying complex disorders. Use of population isolates as the target population is a unique feather of this study. However, population isolates may have hidden inbreeding structures which can affect the validity of the study. To understand how this issue may affect results of GENDISCAN, we estimated inbreeding coefficients in two study populations in Mongolia. We analyzed the status of Hardy-Weinberg Equilibrium (HWE), polymorphism information contents (PIC), heterozygosity, allelic diversity, and inbreeding coefficients, using 317 and 1,044 STR (short tandem repeat) markers in Orkhontuul and Dashbalbar populations. HWE assumptions were generally met in most markers (88.6% and 94.2% respectively), and single marker PIC ranged between 0.2 and 0.9. Inbreeding coefficients were estimated to be 0.0023 and 0.0021, which are small enough to assure that conventional genetic analysis would work without any specific modification. We concluded that the population isolates used in GENDISCAN study would not present significant inflation of type I errors from inbreeding effects in its gene discovery analysis.

Growth of ZnSe/ZnSe(bulk) Epilayer by HWE Method (HWE 방법에 의한 ZnSe/ZnSe(bulk) 박막 성장)

  • Shin, Yeong-Jin;Jeong, Tae-Soo;Shin, Hyun-Keel;Kim, Taek-Sung;Jeong, Cheol-Hoon;lee, Hoon;Shin, Yeong-Shin
    • Journal of the Korean Vacuum Society
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    • v.2 no.1
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    • pp.78-84
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    • 1993
  • Hot-Wall Epitaxy(HWE) 방법으로 ZnSe/ZnSe(bulk) 박막을 성장하였다. 이 때 사용되어진 ZnSe 기판은 승화법으로 증발부분의 온도를 $1160^{\circ}C$ 성장부분의 온도를 $1130^{\circ}C$로 하여 약 2주 동안 직경 20mm, 높이 18mm인 원추형의 ZnSe 단결정을 얻었다. 양질의 ZnSe 박막을 얻기 위한 조건은 증발부분의 온도는 $610^{\circ}C$, 기판의 온도는 49$0^{\circ}C$이었다. ZnSe(bulk) 기판위에 성장한 ZnSe 박막의 광발광에서는 강한 D-A pair emission과 Cu 불순물에 의한 녹색과 적색 발광이 관측되었고 SA 발광은 관측되지 않았다.

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Verification of Antimicrobial Activities of Various Pine Needle Extracts against Antibiotic Resistant Strains of Staphylococcus aureus (다양한 적송잎 추출물의 항생제 내성 황색포도상구균에 대한 항균활성 검증)

  • Kim, Nam-Young;Jang, Min-Kyung;Jeon, Myung-Je;Lee, Dong-Geun;Jang, Hye-Ji;Lee, Seung-Woo;Kim, Mi-Hyang;Kim, Sung-Gu;Lee, Sang-Hyeon
    • Journal of Life Science
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    • v.20 no.4
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    • pp.589-596
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    • 2010
  • We investigated antimicrobial activities of various pine (Pinus densiflora) needle extracts against antibiotic resistant strains of Staphylococcus aureus. Hot water extract showed the highest antimicrobial activity against normal and methicillin resistant Staphylococcus aureus (MRSA), however, it exhibited no antimicrobial activity against penicillin resistant S. aureus (PRSA). Hot water-hexane (HWH), hot water-ethanol (HWE), hexane, and ethanol extracts showed antimicrobial activity against S. aureus, PRSA and MRSA. Minimum inhibitory concentrations (MIC) of HWH, HWE, hexane, and ethanol extracts were 0.05, 0.05, 0.5 and 5 mg/ml, respectively, and HWH and HWE extracts showed the strongest antimicrobial activity among these extracts. Antimicrobial activities of pine needle extracts were stable after heating at $121^{\circ}C$ for 20 min. These results suggested that pine needle extracts can be used as an effective natural antimicrobial agent for food and medical industries.

Antitumor and immunomodulatory effects of a hot water extract of Phellinus baumii using Sarcoma-180 in the mouse (Pheflinus baumii 자실체 추출물의 Sarcoma-180 에 대한 항암 및 면역효과)

  • Ha, Hyo-Cheol;Kim, Hyun-Pyo;Sim, Ji Young;Chang, Yun-Hee;Kim, Hyun Su
    • Journal of Mushroom
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    • v.2 no.4
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    • pp.169-174
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    • 2004
  • A hot water extract(HWE-P4) was separated from the fruit bodies of PMO-P4, and its antitumor and immunomodulatory activities against sarcoma-180 in ICR mice were investigated. The internal transcribed spacer(ITS) regions from PMO-P4 were amplified using polymerase chain reaction(PCR) and sequenced. The results revealed that PMO-P4 was belong to the Phellinus baumii. When oral administration at the dose of 160mg/kg/day in the mice until the end of the experiment with 2 week's pre-feeding of the HWE-P4, the survival rate of the mice was 152% for 50days after the inoculation of sarcoma-180 and the suppression rate of the tumor growth was 35.3%(p<0.05) for 28 days after inoculation of sarcoma-180. The HWE-P4 increased 71.4% of the CD4/CD8 ratio and 5-fold of the expression of CD25(IL-2 receptor chain) compared with the control. From these results, the antitumor activity of HWE-P4 is exerted through its immunomodulating activity on the host's immune system.

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The Antioxidants Activities of Hot-Water Extracts of Wa-song (Orostachys japonicus A. Berger) on Edible oil and Fat (식용유지에 대한 와송 열수추출물의 항산화효과)

  • Shin, Jung-Hye;Lee, Soo-Jung;Cha, Ji-Young;Seo, Jong-Kwon;Cheon, Eun-Woo;Sung, Nak-Ju
    • Korean journal of food and cookery science
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    • v.24 no.6
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    • pp.748-756
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    • 2008
  • This study was conducted to investigate the antioxidant activity of hot water extracts of wa-song (Orostachys japonicus A. Berger) dried using hot air (HWE) and frozen (FWE). Varying levels (0.1, 0.5 and 1.0 g/100 g) of HWE and FWE were added to soybean oil and lard. Chromaticity, anisidine value, acid value, peroxide value (POV) and thiobarbituric acid (TBA) value in oils were measured periodically during their storage for 28 days at $60^{\circ}C$. The chromaticity of edible oils showed a general increas with prolonged storage as well increasing levels of extracts. The anisidine value was not significantly increased during storage for 14 days, but was significantly increased after storage for 21 days in soybean oil and lard. The anisidine value of HWE on soybean oil was $12.60{\pm}0.92{\sim}13.82{\pm}0.68$ after storage for 28 days its value was lower than that of the control and buthylated hydroxy anisol (BHT). The antioxidant activity of HWE was found to be more effective than that of FWE. The acid value of HWE was significantly increased during storage from 14 to 21 days in soybean oil and from 7 to 14 days in lard. The antioxidant activity of FWE was particulary effective at the primary stage of the reaction system of lard storage. POV was highly increased during the storage periods between 7 and 14 days in soybean oil. The antioxidant activity in all the samples tested did not significantly increase after storage for 14 days, except when 0.1 g/ 100 g of FWE added to lard. TBA values of all the samples were lower than that of control and 0.02% BHT during their storage. The antioxidant activities of wa-song within the reaction system of oils were more effective in soybean oil than in lard.

Analysis of the Contents and Physiological Activities of Calystegia japonica Leaf Extracts (메꽃(Calystegia japonica) 잎 추출물의 함유성분과 생리활성에 관한 연구)

  • Choi, Bok-Dong;Jeon, Ho-Sung;Lee, Yang-Suk;Joo, Eun-Young;Kim, Nam-Woo
    • Korean Journal of Food Science and Technology
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    • v.42 no.2
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    • pp.250-255
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    • 2010
  • This study examined the physiological activities as well as the total polyphenol and flavonoid content of water extract (WE), ethanol extract (EE) and hot water extract of Calystegia japonica leaves under high pressure (HWE). The xanthine oxidase inhibitory rate of EE was the highest with a value of 98.89% at a concentration of 1.0 mg/mL, whereas the rate of WE and HWE was over 90% at a concentration of 0.3 mg/mL. The superoxide dismutase (SOD)-like activity of HWE was the highest at 18.88%. The nitrite scavenging abilities were 64.59-66.46% at conditions of pH 1.2 and 1.0 mg/mL, and 52.78-55.89% at pH 3.0. The electron donating ability of EE was the highest with a value of 84.80% at a concentration of 0.1 mg/mL. All extracts showed the highest degree of electron donating at the concentration of 0.1 mg/ mL, and this effect decreased as the extract concentration increased. The EE had the highest content of total polyphenol compound (173.89 mg/g) and flavonoid compounds (40.68 mg/g).