Fabrication of p-Type Nitrogen-Doped MgZnO by Depressing N-Related Donors

B. Yao,Z. P. Wei,Y. F. Li,D. Z. Shen,Y. M. Lu,Z. Z. Zhang,B. H. Li,C. J. Zheng,X. H. Wang,J. Y. Zhang,D. X. Zhao,X. W. Fan,Z. K. Tang 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

Wurtzite nitrogen-doped MgZnO (MgZnO:N) films were grown on c-plane sapphire by using plasma-assisted molecular beam epitaxy with radical NO as the oxygen source and nitrogen dopant. P-type conduction of MgZnO:N was obtained by decreasing the donor defects ((N2)O, VO, etc.) through annealing, revealing a hole concentration of 6.1 × 1017 cm−3 and a mobility of 6.42 cm2/Vs. Furthermore, as-grown p-type films with a hole concentration of 1 × 1017 cm−3 and a mobility of 3 cm2/Vs were obtained by decreasing the (N2)O double donor defect through control of the plasma conditions. ZnMgO:N/ZnO p-n junctions were obtained by using these p-type films. ode-like, rectifying I-V characteristics with a threshold voltage of about 5 V and a different reverse leakage current were observed at room temperature.

International Comparison of Enumeration-Based Quantification of DNA Copy-Concentration Using Flow Cytometric Counting and Digital Polymerase Chain Reaction

Yoo, Hee-Bong,Park, Sang-Ryoul,Dong, Lianhua,Wang, Jing,Sui, Zhiwei,Pavs&#x30c,ic&#x30c,, Jernej,Milavec, Mojca,Akgoz, Muslum,Moziog&#x306,lu, Erkan,Corbisier, Philippe,Janka, Ma&#x301,trai,Cosme, Bru American Chemical Society 2016 ANALYTICAL CHEMISTRY - Vol.88 No.24

<P>Enumeration-based determination of DNA copy-concentration was assessed through an international comparison among national metrology institutes (NMIs) and designated institutes (DIs). Enumeration-based quantification does not require a calibration standard thereby providing a route to 'absolute quantification', which offers the potential for reliable value assignments of DNA reference materials, and International System of Units (SI) traceability to copy number 1 through accurate counting. In this study, 2 enumeration based methods, flow cytometric (FCM) counting and the digital polymerase chain reaction (dPCR), were compared to quantify a solution of the pBR322 plasmid at a concentration of several thousand copies per microliter. In addition, 2 orthogonal chemical-analysis methods based on nucleotide quantification, isotope-dilution mass spectrometry (IDMS) and capillary electrophoresis (CE) were applied to quantify a more concentrated solution of the plasmid. Although 9 dPCR results from 8 laboratories showed some dispersion (relative standard deviation [RSD] = 11.8%), their means were closely aligned with those of the FCM-based counting method and the orthogonal chemical-analysis methods, corrected for gravimetric dilution factors. Using the means of dPCR results, the RSD of all 4 methods was 1.8%, which strongly supported the validity of the recent enumeration approaches. Despite a good overall agreement, the individual dPCR results were not sufficiently covered by the reported measurement uncertainties. These findings suggest that some laboratories may not have considered all factors contributing to the measurement uncertainty of dPCR, and further investigation of this possibility is warranted.</P>

Prohibitin 1 Regulates the H19-Igf2 Axis and Proliferation in Hepatocytes

Ramani, Komal,Mavila, Nirmala,Ko, Kwang Suk,Mato, Jose&#x301,M.,Lu, Shelly C. American Society for Biochemistry and Molecular Bi 2016 The Journal of biological chemistry Vol.291 No.46

<P>Prohibitin 1 (PHB1) is a mitochondrial chaperone that regulates cell growth. Phb1 knock-out mice exhibit liver injury and hepatocellular carcinoma (HCC). Phb1 knock-out livers show induction of tumor growth-associated genes, H19 and insulin-like growth factor 2 (Igf2). These genes are controlled by the imprinting control region (ICR) containing CCCTC-binding transcription factor (CTCF)-binding sites. Because Phb1 knock-out mice exhibited induction of H19 and Igf2, we hypothesized that PHB1-mediated regulation of the H19-Igf2 axis might control cell proliferation in normal hepatocytes. H19 and Igf2 were induced (8-20-fold) in 3-week-old Phb1 knock-out livers, in Phb1 siRNA-treated AML12 hepatocytes (2-fold), and HCC cell lines when compared with control. Phb1 knockdown lowered CTCF protein in AML12 by approximate to 30% when compared with control. CTCF overexpression lowered basal H19 and Igf2 expression by 30% and suppressed Phb1 knockdown-mediated induction of these genes. CTCF and PHB1 co-immunoprecipitated and co-localized on the ICR element, and Phb1 knockdown lowered CTCF ICR binding activity. The results suggest that PHB1 and CTCF cooperation may control the H19-Igf2 axis. Human HCC tissues with high levels of H19 and IGF2 exhibited a 40-50% reduction in PHB1 and CTCF expression and their ICR binding activity. Silencing Phb1 or overexpressing H19 in the mouse HCC cell line, SAMe-D, induced cell growth. Blocking H19 induction prevented Phb1 knockdown-mediated growth, whereas H19 overexpression had the reverse effect. Interestingly H19 silencing induced PHB1 expression. Taken together, our results demonstrate that the H19-Igf2 axis is negatively regulated by CTCF-PHB1 cooperation and that H19 is involved in modulating the growth-suppressive effect of PHB1 in the liver.</P>

Choice of dispersants for the nano-apatite filler of polylactide-matrix composite biomaterial

C. Deng,J. Weng,Q.Y. Cheng,S.B. Zhou,X. Lu,J.X. Wan,S.X. Qu,B. Feng,X.H. Li 한국물리학회 2007 Current Applied Physics Vol.7 No.6

The aim of this study is to compare de-aggregative ability of common organic dispersants for the acicular nano-apatite crystallite withmain composition of calcium hydroxyapatite (HA) as a ller of composite containing polylactide (PLA) matrix. Firstly, the acicularnano-apatite powders with an average length of 70120 nm were synthesized based on traditional chemical co-precipitation andfreeze-drying techniques. Common organic dispersants including tetrahydrofuran, acetone, chloroform,N,N-dimethyl formamideiments showed that nano-apatite suspension dispersed by DMF and ethanol presented homogeneous and stable colloid after vigorly stir-red for 24 h and then kept still for same time, respectively. Results of particle measurements and viscosity measurement illuminated that alarge number of the nano-apatite particles with an average dimension of 297.86 nm and viscosity of 0.8872 cP in DMF suspension couldbe dispersed up to 91.28 nm by the DMF dispersant and the DMF dispersant could minimize agglomeration between the apatite ultra-furan, acetone and ethanol, when the nano-apatite/PLA composite biomaterials were prepared.

100KW DC Arc Plasma of CVD System for Low Cost Large Area Diamond Film Deposition

Lu, F.X.,Zhong, G.F.,Fu, Y.L.,Wang, J.J.,Tang, W.Z.,Li, G.H.,Lo, T.L.,Zhang, Y.G.,Zang, J.M.,Pan, C.H.,Tang, C.X.,Lu, Y.P. The Korean Ceramic Society 1996 The Korean journal of ceramics Vol.2 No.4

In the present paper, a new type of DC arc plasma torch is disclosed. The principles of the new magnetic and fluid dynamic controlled large orifice long discharge tunnel plasma torch is discussed. Two series of DC Plasma Jet diamond film deposition equipment have been developed. The 20kW Jet equipped with a $\Phi$70 mm orifice torch is capable of deposition diamond films at a growth rate as high as 40$\mu\textrm{m}$/h over a substrate area of $\Phi$65 mm. The 100kW high power Jet which is newly developed based on the experience of the low power model is equipped with a $\Phi$120 mm orifice torch, and is capable of depositing diamond films over a substrate area of $\Phi$110 mm at growth rate as high as 40 $\mu\textrm{m}$/h, and can be operated at gas recycling mode, which allows 95% of the gases be recycled. It is demonstrated that the new type DC plasma torch can be easily scaled up to even higher power Jet. It is estimated that even by the 100kW Jet, the cost for tool grade diamond films can be as low as less than $4/carat.

EFFECT OF ADDITIVE ON THE HEAT RELEASE RATE AND EMISSIONS OF HCCI COMBUSTION ENGINES FUELED WITH RON90 FUELS

X.-C. LU,L.-B. JI,W. CHEN,Z. HUANG 한국자동차공학회 2007 International journal of automotive technology Vol.8 No.1

The effect of the di-tertiary butyl peroxide (DTBP) additive on the heat release rate and emissions of a homogeneous charge compression ignition (HCCI) engine fueled with high Research Octane Number (RON) fuels were investigated. The experiments were performed using 0%, 1%, 2%, 3%, and 4% (by volume) DTBP-RON90 blends. The RON90 Fuel was obtained by blending 90% iso-octane with 10% n-heptane. The experimental results show that the operation range was remarkably expanded to lower temperature and lower engine load with the DTBP additive in RON90 fuel. The first ignition phase of HCCI combustion was observed at 850 K and ended at 950 K while the hot ignition occurred at 1125 K for all fuels at different engine working conditions. The chemical reaction scale time decreases with the DTBP addition. As a result, the ignition timing advances, the combustion duration shortens, and heat release rates were increased at overall engine loads. Meanwhile, the unburned hydrocarbon (UHC) and CO emissions decrease sharply with the DTBP addition while the NOx emissions maintain at a lower level.

EFFECT OF ADDITIVE ON THE HEAT RELEASE RATE AND EMISSIONS OF HCCI COMBUSTION ENGINES FUELED WITH RON90 FUELS

Lu, X.C.,Ji, L.B.,Chen, W.,Huang, Z. The Korean Society of Automotive Engineers 2007 International journal of automotive technology Vol.8 No.1

The effect of the di-tertiary butyl peroxide (DTBP) additive on the heat release rate and emissions of a homogeneous charge compression ignition (HCCI) engine fueled with high Research Octane Number (RON) fuels were investigated. The experiments were performed using 0%, 1%, 2%, 3%, and 4% (by volume) DTBP-RON90 blends. The RON90 Fuel was obtained by blending 90% iso-octane with 10% n-heptane. The experimental results show that the operation range was remarkably expanded to lower temperature and lower engine load with the DTBP additive in RON90 fuel. The first ignition phase of HCCI combustion was observed at 850 K and ended at 950 K while the hot ignition occurred at 1125 K for all fuels at different engine working conditions. The chemical reaction scale time decreases with the DTBP addition. As a result, the ignition timing advances, the combustion duration shortens, and heat release rates were increased at overall engine loads. Meanwhile, the unburned hydrocarbon (UHC) and CO emissions decrease sharply with the DTBP addition while the NOx emissions maintain at a lower level.

Functional Characterization of Mammary Gland of Holstein Cows under Humid Tropical Summer Climates

Lu, C.H.,Chang, C.J.,Lee, P.N.,Wu, C.P.,Chen, M.T.,Zhao, X. Asian Australasian Association of Animal Productio 2003 Animal Bioscience Vol.16 No.7

Physiological parameters were measured on six primiparous, non-pregnant Holstein cows prior to peak lactation over a 3-month summer season in southwestern Taiwan. The objectives were to characterize heat stress-induced change in functionality of mammary gland under natural climates of tropical summer and to establish physiological indices applicable to this environment in referring to this change. Environmental and physiological readings, milk and blood samples were taken at 15:00 h biweekly for totally five time points during the study. Climate readings showed that the afternoon humidex value reached the highest (53.5) around mid summer. Rectal temperature of cows taken simultaneously varied between $38.26^{\circ}C$ and $40.02^{\circ}C$ in parallel to humidex. Milk production declined drastically from 29.2 to 22.2 kg/d the first month entering summer but leveled up at end of the summer season suggesting effects exerted by heat stress rather than stages of lactation. Lactose content decreased linearly (p<0.05) with times in summer, from 4.69 to 4.38%. On the other hand, activity of N-acetylglucosaminidase (NAGase) in milk increased linearly to over two folds (p<0.05) during the same intervals. Elevations of fractional constituent of BSA in whey protein and serum cortisol level were also noticed in the course. Measurement of arteriovenous concentration (A-V) difference across the mammary gland demonstrated net uptake of glucose and net release of urea throughout the study period. The amount of urea released from mammary gland increased (p<0.05) progressively from 1.54 to 7.76 mg/dl during summer. It is concluded that gradual regression of mammary gland occurred along the humid tropical summer season. This regression is likely initiated through elevation of body temperature, which is irreversible above certain point. The increased release of urea from mammary gland during heat stress suggests its potential role as an early indicator of suboptimal mammary function.

Development of the 3.7 GHz LHCD System on HL-2A

B. Lu,M. Huang,H. Zeng,X. Y. Bai,X. H. Mao,Z. H. Lu,J. Liang,Z. H. Kang,M. W. Wang,K. Feng,H. Wang,C. Wang,J. Q. Wang,S. Wei,T. Yao,Y. N. Bu,J. Feng,G. Y. Cheng,S. D. Song,D. H. Xia,J. Rao 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.8

A 2 MW-3.7 GHz lower hybrid current drive (LHCD) system is under development for physicsexperiments on the HL-2A device. The RF Power is generated by four TH2103A klystron amplifiersand propagates in the TE10 mode through WR284 waveguides. The transmission lines with a lengthof 20 m to 30 m are pressurized with 2 bars of nitrogen to decrease the possibility of arcing. Thelauncher, based on the passive-active multi-junction (PAM) concept, has been developed and iscurrently being realized. It was designed for a power spectrum peaked at Nk = 2.75 with goodcoupling properties over a wide range of plasma parameters. The four klystrons are fed by ahigh-voltage power supply (HVPS) based on the pulse step modulation (PSM) concept with a fastswitch-off time of less than ten μs. This system is expected to be in operation within 1 years and willexplore many international thermonuclear experimental reactor (ITER) related LH experiments inthe following years.

Genome-wide association study in a Chinese population identifies a susceptibility locus for type 2 diabetes at 7q32 near <i>PAX4</i>

Ma, R. C. W.,Hu, C.,Tam, C. H.,Zhang, R.,Kwan, P.,Leung, T. F.,Thomas, G. N.,Go, M. J.,Hara, K.,Sim, X.,Ho, J. S. K.,Wang, C.,Li, H.,Lu, L.,Wang, Y.,Li, J. W.,Wang, Y.,Lam, V. K. L.,Wang, J.,Yu, W.,Ki Springer-Verlag 2013 Diabetologia Vol.56 No.6

<P><B>Aims/hypothesis</B></P><P>Most genetic variants identified for type 2 diabetes have been discovered in European populations. We performed genome-wide association studies (GWAS) in a Chinese population with the aim of identifying novel variants for type 2 diabetes in Asians.</P><P><B>Methods</B></P><P>We performed a meta-analysis of three GWAS comprising 684 patients with type 2 diabetes and 955 controls of Southern Han Chinese descent. We followed up the top signals in two independent Southern Han Chinese cohorts (totalling 10,383 cases and 6,974 controls), and performed in silico replication in multiple populations.</P><P><B>Results</B></P><P>We identified <I>CDKN2A/B</I> and four novel type 2 diabetes association signals with <I>p</I> < 1 × 10<SUP>−5</SUP> from the meta-analysis. Thirteen variants within these four loci were followed up in two independent Chinese cohorts, and rs10229583 at 7q32 was found to be associated with type 2 diabetes in a combined analysis of 11,067 cases and 7,929 controls (<I>p</I><SUB>meta</SUB> = 2.6 × 10<SUP>−8</SUP>; OR [95% CI] 1.18 [1.11, 1.25]). In silico replication revealed consistent associations across multiethnic groups, including five East Asian populations (<I>p</I><SUB>meta</SUB> = 2.3 × 10<SUP>−10</SUP>) and a population of European descent (<I>p</I> = 8.6 × 10<SUP>−3</SUP>). The rs10229583 risk variant was associated with elevated fasting plasma glucose, impaired beta cell function in controls, and an earlier age at diagnosis for the cases. The novel variant lies within an islet-selective cluster of open regulatory elements. There was significant heterogeneity of effect between Han Chinese and individuals of European descent, Malaysians and Indians.</P><P><B>Conclusions/interpretation</B></P><P>Our study identifies rs10229583 near <I>PAX4</I> as a novel locus for type 2 diabetes in Chinese and other populations and provides new insights into the pathogenesis of type 2 diabetes.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1007/s00125-013-2874-4) contains peer-reviewed but unedited supplementary material, which is available to authorised users.</P>