• Title/Summary/Keyword: Gan

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Characteristics of selective area growth of GaN/AlGaN double heterostructure grown by hydride vapor phase epitaxy on r-plane sapphire substrate (HVPE 방법에 의해 r-plane 사파이어 기판 위의 선택 성장된 GaN/AlGaN 이종 접합구조의 특성)

  • Hong, S.H.;Jeon, H.S.;Han, Y.H.;Kim, E.J.;Lee, A.R.;Kim, K.H.;Hwang, S.L.;Ha, H.;Ahn, H.S.;Yang, M.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.19 no.1
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    • pp.6-10
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    • 2009
  • In this paper, a selective area growth (SAG) of a GaN/AlGaN double heterostructure (DH) has been performed on r-plane sapphire substrate by using the mixed-source hydride vapor phase epitaxy (HVPE) with multi-sliding boat system. The SAG-GaN/AlGaN DH consists of GaN buffer layer, Te-doped AlGaN n-cladding layer, GaN active layer, Mg-doped AlGaN p-cladding layer, and Mg-doped GaN p-capping layer. The electroluminescence (EL) characteristics show an emission peak of wavelength, 439 nm with a full width at half maximum (FWHM) of approximately 0.64 eV at 20 mA. The I-V measurements show that the turn-on voltage of the SAG-GaN/AlGaN DH is 3.4 V at room temperature. We found that the mixed-source HVPE method with a multi-sliding boat system was one of promising growth methods for III-Nitride LEDs.

Study on 『BianZhengGiMun)』's medical characteristics - In view of ShangHan - (『변증기문(辨證奇聞)』의 의학적(醫學的) 특징(特徵)에 관(關)한 고찰(考察) -상한문(傷寒門)을 중심(中心)으로-)

  • Lee, Won-Suk;Park, Sun-Dong;Park, Won-Hwan;Kim, Jun-Ki;Kim, Jong-Dae
    • The Journal of Dong Guk Oriental Medicine
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    • v.6 no.2
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    • pp.33-85
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    • 1998
  • In order to find the characteristic medical methods of "BianZhengGiMun" by the author ChenShihTo, we have translated and analyzed the mentioned book. Upon analyses, the following facts were noted : 1) "BianZhengGiMun" is written and composed of case studies. Prescriptive methods described here differ rather from previously known methods, where as our nation's Oriental medicine practitioners refer and consider these methods as miraculous modern methodologies. 2) Book's content has much similarities to "ShangHanLun"'s original text. Moreover, the content is adjusted towards presenting methodologies not coverd in "ShangHanLun"'s text, together with adding more information to conserve "ShangHanLun"'s methods as well as to critique them. 3) Diagnostic methods mainly follow the ZangFuBianZheng(臟腑辨證)'s pattern, where it's recorded information and theories are valid. 4) "BianZhengGiMun"'s proscriptive methods usually follow BuYinShengJin(補陰生津)'s form, where they were appropriate for that period and circumstances. 5) In consideration of all of the above factors, ChenShihTo grasped ShangHan and WenBing(acute febrile disease due to exogenous factor) as WaiGanReBing(外感熱病)'s double sided characteristics, where this corresponds with the current belief. It is believed that this in turn would provide much practical value to the present time.

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Electrochemical Properties of Current Collector in the All-vanadium Redox Flow Battery (바나듐 레독스-흐름 전지에서 집전체의 전기화학적 특성)

  • Hwang, Gan-Jin;Oh, Yong-Hwan;Ryu, Cheol-Hwi;Choi, Ho-Sang
    • Korean Chemical Engineering Research
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    • v.52 no.2
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    • pp.182-186
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    • 2014
  • Two commercial carbon plates were evaluated as a current collector (bipolar plate) in the all vanadium redox-flow battery (V-RFB). The performance properties of V-RFB were test in the current density of $60mA/cm^2$. The electromotive forces (OCV at SOC 100%) of V-RFB using A and B current collector were 1.47 V and 1.54 V. The cell resistance of V-RFB using A current collector was $4.44{\sim}5.00{\Omega}{\cdot}cm^2$ and $3.28{\sim}3.75{\Omega}{\cdot}cm^2$ for charge and discharge, respectively. The cell resistance of V-RFB using B current collector was $4.19{\sim}4.42{\Omega}{\cdot}cm^2$ and $4.71{\sim}5.49{\Omega}{\cdot}cm^2$ for charge and discharge, respectively. The performance of V-RFB using each current collector was evaluated. The performance of V-RFB using A current collector was 93.1%, 76.8% and 71.4% for average current efficiency, average voltage efficiency and average energy efficiency, respectively. The performance of V-RFB using B current collector was 96.4%, 73.6% and 71.0% for average current efficiency, average voltage efficiency and average energy efficiency, respectively.

Air Temperature And Leaf Growth of Several Woody Plants in Early Gruwing Season (수 종 목본식물의 생육초기 기온과 잎의 생장)

  • 민병미
    • The Korean Journal of Ecology
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    • v.17 no.1
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    • pp.49-58
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    • 1994
  • To investigate the relationship between leaf growth of several woody plants and ait tempera ture in early growing season (from April to June) in deciduous forests, I surveyed the changes of leaf area (LA), leaf weight (LW) and specific leaf area (SLA) of 19 specles, in two areas Namhansansung (NA) and Taegwallyong (TA) area in which that the latitudes are similer ($37^{\circ}28'N$ at NA and $37^{\circ}27'N$ an TA), but annual mean-temperatures were different ($11.8^{\circ}C\;in\;NA, \;6.3^{\circ}C$ in TA) for two years, 1991 and 1992. In the same species, the plants of NA began to grow 10-25 days earlier than those of TA, but the latter grew faster than the former. On 10 June the values of LA and LW per leaf were similar in the two areas but the maximum values of SLA were higher in NA. In the same plant, the values of LA and LW were constant year by year, except for PYIOLUS leveilleana, Quercus mongolica, Symplocos chznensis for. pilosa and S t y a r ubussiu. In N A , the leaves be gan to grow during the first ten days of April, and eariler in 1992 than in 1991, and daily mean temperature (DMT) of the former from 27 March to 6 April were higher than those of thc latter. But the LA increased faster in 1991 than in 1992. and DMT from 10 April to 16 April were higher in 1991 than in 1992.

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Design of Mobile Agent Management System based on OSGi (OSGi 기반 이동 에이전트 관리 시스템 설계)

  • Lee, Seung-Keun;Kim, In-Tae;Kim, Tae-Gan;Lee, Kyoung-Mo;Rim, Ki-Wook;Lee, Jung-Hyun
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.42 no.5
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    • pp.41-48
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    • 2005
  • OSGi(Open Service Gateway Initiative) offers a unique opportunity for pervasive computing as a potential framework for achieving interoperability between various sensors, home appliances, and networked devices. The OSGi framework supports a remote installation of a bundle, which is a unit that installs and deploys services. However, in order for the bundle in execution to migrate, a specific form of bundle such a mobile agent, is needed one which is able to move through a heterogeneous network. This paper proposes a method that can manage bundles like these dynamic agents, in order to ensure the mobility of entities in multiple OSGi framework environments. For our purposes, we have designed the mobile agent management system for managing the lifecycle and mobility of agents in the OSGi framework. The mobile agent management system we are proposing implements a bundle form which can perform in an OSGi framework as well as manage autonomous mobile services. As a result, mobility in a pervasive environment will be supported more efficiently.

A Study on the Development of men's Wear in Korea (남성복의 변화에 관한 연구)

  • 이순홍
    • Journal of the Korean Society of Costume
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    • v.29
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    • pp.5-22
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    • 1996
  • the present thesis aims to contribute to the further development of the men's wear indus-try in Korea which now confronts the need to adjust itself more actively to the conditions of the coming age of internationalization and free trade. To achieve this this thesis suggests the trade should provide for the changing domestic needs on theone hand and refine its wares as high value-added products in compe-tition with those from the advanced countries in fashion industry on the other, The history of the 'suit' the standard men's attire dates back to 1850 when the 'Ditto suit' was introduced composed of coat waist coat vest and trousers to remain virtually unchanged till the end of the nineteenth cen-tury and the modern men's wear originated in Britain. In Korea since the introduction of western clothes from 1876 custom-made suits had been dominant until 1944 while western clothes earned popular currency between 1945 and 1964 and ready-made suits began to spread with their advantages recognized in terms of practicality convenience and functionality The next phase from 1965 to 1985 witnessed the establishment of a number of ready-made brands although custom-made suits stayed in their height of prosperity until 1975. The turn-ing point for the men's wear industry came in 1975 when high-calss ready-made brands be-gan to turn up with the arrival of large companies in the market matching the change in consumers' life style. The men's wear market went through further diversification and specialization dur-ing the years between 1985. and 1990. Around the year 1990 however the expansion of the business suit industry came to slow down ac-companied by an oversupplied market. The fashion of pragmatism in the 1990s called for the growth of the casual wear department and as consumers' life style became more and more individualized conscious dressing in accord ance with T.P.O established itself as an important branch of culture, Such casual boom is likely to aid in promoting Korea's men's wear indus-try to peer with that of advanced countries. Consumers' fashion sense is now ahead of the trade's as well as being shortcycled highly individualized stylized and diversified. To meet consumers' demands under such circum-stances each company is required to develop its unique soft Know How based on accurate information and strategically specialized plan-ning. The trade should convert its hithero producer-oriented strategy to a new consumer oriented one and actively lead the needs and purchasin g pattern of consumers by providing an efficient and reasonable price policy with optimum supply of merchandise and also by presenting 'our' trend suited to our circum-stances.

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Regular Endurance Exercise Decreases Blood Pressure via Enhancement of Angiogenesis and VEGF Expression in Spontaneously Hypertensive Rats (규칙적인 지구성운동이 고혈압쥐 골격근의 혈관생성과 VEGF 발현의 증가를 통한 혈압감소에 미치는 효과)

  • Li, Wei;Park, Hee-Geun;Lee, Young-Ran;Jang, Hak-Young;Choo, Sung-Ho;Lee, Young-Hwa;Gan, Li;Jun, Jong-Kui;Lee, Wang-Lok;Lee, Sang-Ki
    • Journal of Life Science
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    • v.22 no.5
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    • pp.665-670
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    • 2012
  • This study investigated the effect of endurance exercises on blood pressure, angiogenesis, and the vascular endothelial growth factor (VEGF) expression in the skeletal muscle of spontaneously hypertensive rats (SHR). Five week old SHRs and Wistar-Kyoto rats (WKY) were randomly divided into 3 groups: Wistar-Kyoto rats (WKY, n=9), SHR control (SHR-C, n=9), and SHR endurance exercise training (SHR-E, n=9). Endurance exercise training was performed on a treadmill (12-20 m/min, 0% grade, 60 min/day, 5 days/week, 16 weeks). Systolic blood pressure was monitored with the tail-cuff method. The expression of VEGF protein and capillary density were identified using western blotting and H&E staining in the soleus muscle, respectively. Systolic blood pressure was reduced by endurance exercise in SHR ($p$ <0.05). The capillary density of skeletal muscles in SHR-C was lower than in WKY ($p$ <0.05), but it was recovered by endurance exercise training (SHR-E) compared to SHR-C ($p$ <0.05), and VEGF protein was also increased by endurance exercise training compared to SHR-C ($p$ <0.05). These data suggest that the enhancement of capillary density via an increase of VEGF expression in skeletal muscles by endurance exercise training could be an important factor to inhibit blood pressure elevation in SHR.

Expression of ER, PR, C-erbB-2 and Ki-67 in Endometrial Carcinoma and their Relationships with the Clinicopathological Features

  • Yu, Cui-Ge;Jiang, Xiang-Yang;Li, Bin;Gan, Lu;Huang, Jian-Feng
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6789-6794
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    • 2015
  • Background: To analyze the expression of estrogen receptors (ER), progesterone receptors (PR), C-erbB-2 and Ki-67 in endometrial carcinoma (EC) and their relationships with the clinicopathological features. Materials and Methods: Sixty-seven EC samples, 53 normal endometrial samples and 53 atypical hyperplasia endometrial samples were all selected in Shaanxi Provincial People's Hospital from Jun., 2012 to Jun., 2014. The expression of ER, PR, C-erbB-2 and Ki-67 in EC tissue, normal endometrial tissue and atypical hyperplasia endometrial tissue was respectively detected using immunohistochemical SP method. The relationships between the expression of ER, PR, C-erbB-2 and Ki-67 and the patients' clinicopathological features as well as their correlations in EC tissue were also analyzed. Results: The positive expression rates of ER and PR in EC tissue were 44.8% and 41.8%, respectively, dramatically lower than in atypical hyperplasia endometrial tissue and normal endometrial tissue (P<0.01). The positive expression rates of C-erbB-2 and Ki-67 in EC tissue were 80.6% and 64.2%, respectively, significantly higher than in atypical hyperplasia endometrial tissue and normal endometrial tissue (P<0.01). In EC tissue, the expression of ER and PR was closely associated with the differentiated degrees and depth of myometrial invasion (P<0.05), while that of C-erbB-2 and Ki-67 with the clinical staging, differentiated degrees, depth of myometrial invasion and presence or absence of lymph node metastasis (P<0.05). Spearman correlation analysis further displayed that the expression of ER was positively correlated with PR (r=0.393, P=0.001), but negatively with C-erbB-2 and Ki-67 (r=-0.469, P=0.000; r=-0.329, P=0.007); The expression of PR was negatively correlated with C-erbB-2 and Ki-67 (r=-0.273, P=0.025; r=-0.251, P=0.041), but that of C-erbB-2 positively with Ki-67 (r=0.342, P=0.005). Conclusions: Abnormal expression of ER, PR, C-erbB2 and Ki-67 might play an important role in endometrial malignant transformation and cell differentiation, so their joint detection is likely to be a comprehensive combination of immune factors, which is of great importance for EC prognosis.

X-Ray Repair Cross-Complementing Group 1(XRCC1) Genetic Polymorphisms and Thyroid Carcinoma Risk: a Meta-Analysis

  • Qian, Ke;Liu, Kui-Jie;Xu, Feng;Chen, Xian-Yu;Chen, Gan-Nong;Yi, Wen-Jun;Zhou, En-Xiang;Tang, Zhong-Hua
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.6385-6390
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    • 2012
  • A number of studies have been conducted to explore the association of XRCC1 polymorphisms with thyroid cancer risk, but the results have been inconsistent. Thus we performed the present meta-analysis to clarify this issue based on all of the evidence available to date. Relevant studies were retrieved by searching PubMed and statistical analysis conducted using Stata software. Nine studies were included in this meta-analysis (1,620 cases and 3,557 controls). There were 6 studies (932 cases and 2,270 controls) of the Arg194Trp polymorphism, 7 studies (1432 cases and 3356 controls) of the Arg280His polymorphism and 9 studies (1,620 cases and 3,557 controls) for the Arg399Gln polymorphism. No association of XRCC1 Arg194Trp, Arg280His and Arg399Gln polymorphism with thyroid cancer risk was observed in the overall analysis. However, subgroup analysis revealed: 1) an elevated risk in aa vs AA analysis (OR=2.03, 95%CI= 1.24-3.31) and recessive genetic model analysis (OR=1.93, 95%CI= 1.20-3.08) in the larger sample size trials for XRCC1 Arg194Trp polymorphism; 2) a decreased thyroid cancer risk on subgroup analysis based on ethnicity in Aa vs AA analysis (OR=0.84, 95%CI= 0.72-0.98) and in a dominant genetic model (OR=0.84, 95%CI= 0.72-0.97) in Caucasian populations for the XRCC1 Arg399Gln polymorphism; 3) a decreased thyroid cancer risk on subgroup analysis based on design type in Aa vs AA analysis (OR=0.72, 95% CI= 0.54-0.97) among the PCC trials for the Arg399Gln polymorphism. Our results suggest that the XRCC1 Arg399Gln polymorphism may be associated with decreased thyroid cancer risk among Caucasians and XRCC1 Arg194Trp may be associated with a tendency for increased thyroid cancer risk in the two larger sample size trials.

Sensitivity of Plasmodium falciparum to Antimalarial Drugs in Hainan Island, China

  • Wang, Shan-Qing;Wang, Guang-Ze;Li, Yu-Chun;Meng, Feng;Lin, Shi-Gan;Zhu, Zhen-Hu;Sun, Ding-Wei;He, Chang-Hua;Hu, Xi-Min;Du, Jian-Wei
    • Parasites, Hosts and Diseases
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    • v.53 no.1
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    • pp.35-41
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    • 2015
  • Pyronaridine and artesunate have been shown to be effective in falciparum malaria treatment. However, pyronaridine is rarely used in Hainan Island clinically, and artesunate is not widely used as a therapeutic agent. Instead, conventional antimalarial drugs, chloroquine and piperaquine, are used, explaining the emergence of chloroquine-resistant Plasmodium falciparum. In this article, we investigated the sensitivity of P. falciparum to antimalarial drugs used in Hainan Island for rational drug therapy. We performed in vivo (28 days) and in vitro tests to determine the sensitivity of P. falciparum to antimalarial drugs. Total 46 patients with falciparum malaria were treated with dihydroartemisinin/piperaquine phosphate (DUO-COTECXIN) and followed up for 28 day. The cure rate was 97.8%. The mean fever clearance time ($22.5{\pm}10.6hr$) and the mean parasite clearance time ($27.3{\pm}12.2hr$) showed no statistical significance with different genders, ages, temperatures, or parasite density (P>0.05). The resistance rates of chloroquine, piperaquine, pyronarididine, and artesunate detected in vitro were 71.9%, 40.6%, 12.5%, and 0%, respectively (P<0.0001). The resistance intensities decreased as follows: chloroquine>piperaquine>pyronarididine>artesunate. The inhibitory dose 50 ($IC_{50}$) was $3.77{\times}10^{-6}mol/L$, $2.09{\times}10^{-6}mol/L$, $0.09{\times}10^{-6}mol/L$, and $0.05{\times}10^{-6}mol/L$, and the mean concentrations for complete inhibition (CIMC) of schizont formation were $5.60{\times}10^{-6}mol/L$, $9.26{\times}10^{-6}mol/L$, $0.55{\times}10^{-6}mol/L$, and $0.07{\times}10^{-6}mol/L$, respectively. Dihydroartemisinin showed a strong therapeutic effect against falciparum malaria with a low toxicity.