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61.
62.
J.R. Grandusky J.A. Smart M.C. Mendrick L.J. Schowalter K.X. Chen E.F. Schubert 《Journal of Crystal Growth》2009,311(10):2864-2866
Recently it has been discovered that when growing AlxGa1−xN on low-defect-density bulk AlN substrates pseudomorphic layers can be achieved with a thickness far exceeding the critical thickness as given by the Matthews and Blakeslee model. For instance, the critical thickness of an AlxGa1−xN layer (with x=0.6) is about 40 nm thick. However we have been able to grow layers with this composition that are pseudomorphic with a thickness exceeding the critical thickness by more than an order of magnitude. This work defines the limits of pseudomorphic growth on low defect density, bulk AlN substrates to obtain low defect density, high-power UV LEDs. 相似文献
63.
LL Handley R Azcón Ruiz Lozano JM CM Scrimgeour 《Rapid communications in mass spectrometry : RCM》1999,13(13):1320-1324
It has long been evident that plant (15)N chiefly reflects the processes which fractionate (15)N/(14)N rather than the (15)N of plant N source(s). It has emerged recently that one of the most important fractionating processes contributing to the whole plant (15)N is the presence/absence, type or species of mycorrhiza, especially when interacting with nutrient deficiency. Ecto- and ericoid mycorrhizas are frequently associated with (15)N-depleted foliar (15)N, commonly as low as -12 per thousand. As shown by the present study, plants having no mycorrhiza, or those infected with various species of arbuscular mycorrhiza (AM)-forming fungi, interact with varying concentrations of soil nitrogen [N] and moisture to enrich plant (15)N by as much as 3.5 per thousand. Hence the lack of a mycorrhiza, or variation in the species of AM-forming fungal associations, can account for about 25% of the usually reported variations of foliar (15)N found in field situations and do so by (15)N enrichment rather than depletion. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
64.
65.
B Anuradha CM Santosh V Hari Sai Priya G Suman Latha KJR Murthy Valluri Vijaya Lakshmi 《Journal of immune based therapies and vaccines》2007,5(1):8-7
Background
Mycobacterium bovis BCG vaccine has displayed inconsistent efficacy in different trials conducted in various geographical regions. Nevertheless, it significantly reduces the risk of severe childhood tuberculosis and continues to be used to prevent tuberculosis in many countries. Many studies revealed that efficacy of vaccine wanes with age. Most of the studies were based on in vivo and in vitro responses to tuberculin. With the advent of newer tests such as in vitro interferon-γ assays and identification of potent immunogenic mycobacterial proteins there is a need to corroborate the observations. This study aims at ascertaining the need for a booster at a later age as indicated by in vitro release of IFN-γ while evaluating Ag85A as an antigen. 相似文献66.
Babajan Banaganapalli Chaitanya Mulakayala Gowsia D Naveen Mulakayala Madhusudana Pulaganti Noor Ahmad Shaik Anuradha CM Raja Mohan Rao Jumana Yousuf Al-Aama Suresh Kumar Chitta 《Applied biochemistry and biotechnology》2013,171(7):1639-1657
Resveratrol (RVS) is a naturally occurring antioxidant, able to display an array of biological activities. In the present investigation, a new derivative of RVS, RVS(a), was synthesized, and its biological activity was determined on U937 cells. It was observed that RVS(a) showed pronounced activity on U937 cells than RVS. RVS(a) is able to induce apoptosis in tumor cell lines through subsequent DNA fragmentation. From the EMSA results, it was evident that RVS(a) was able to suppress the activity of NFkB by interfering its DNA binding ability. Furthermore, the molecular interaction analysis (docking and dynamics) stated that RVS(a) has strong association with the IkB-alpha site of NFkB compared with RVS; this binding nature of RVS(a) might be prevent the NFkB binding ability with DNA. The present findings represent the potential activity of propynyl RVS on U937 cells and signifying it as a one of putative chemotherapeutic drugs against cancer. 相似文献
67.
68.
Heiko Dartsch Christian Tessarek Timo Aschenbrenner Stephan Figge Carsten Kruse Marco Schowalter Andreas Rosenauer Detlef Hommel 《Journal of Crystal Growth》2011,320(1):108-112
Thermodynamic analyses of halide vapor phase epitaxy (HVPE) for the growth of ZnO were conducted to investigate the effects of growth conditions against growth rates. The partial pressures of gaseous species in equilibrium with ZnO and the resultant driving force for ZnO deposition are calculated with respect to temperatures, input H2 pressures and input VI/II ratios. It has been revealed that the driving force is weakly dependent on the temperature and is still positive even at 1200 °C, while it greatly decreases at higher temperatures in the presence of H2. The driving force is also significantly influenced when the VI/II ratio is below 1000. The experimental growth rates substantially agree with the dispositions of the driving force expected from the thermodynamic analyses. 相似文献
69.
Yang Y Lowry M Schowalter CM Fakayode SO Escobedo JO Xu X Zhang H Jensen TJ Fronczek FR Warner IM Strongin RM 《Journal of the American Chemical Society》2006,128(43):14081-14092
The synthesis of new benzo[a]- and [b]xanthene dye frameworks is described. A unique benzo[a]xanthene, seminaphtho[a]fluorone (SNAFR-1), is studied in a variety of media. The optimization of solution parameters and excitation wavelengths allows SNAFR-1 to display red, green, and blue emission bands of approximately equal intensities and also to produce white light. Ratiometric red (anion) and green (neutral) emissions are observed upon varying solution pH. A pH-independent violet-blue emission band is due to the addition of nucleophiles to the benzylic carbon of SNAFR-1. 相似文献