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The effects of B2O3 on the sinter ability and microwave dielectric properties of Ca[(Li1/3Nb2/3) 0.92Zr0.08?δ?0.05TiO2 (CLNZ?0.05TiO 2) ceramics were investigated. B2O3 doping can effectively reduce sintering temperature by 150∼200 °C. The temperature coefficient of resonator frequency τfincreased with an increase of B2O3 content and sintering temperature. When B 2O3 of 2.5 wt % were added, the optimum microwave dielectric properties: εr =34.2, Qf =15680GHz and τf = ? 4.7×10?6/°C were obtained at the sintering temperature of 950 oC. ©(2012) Trans Tech Publications, Switzerland.


Crystal structure and microwave dielectric properties of ( Ca1- xPrx) [(LiNb2/3)0.95Zr 0.15]3+ω (0.0?


Xiong G.,Xianning College
Solid State Phenomena | Year: 2012

Crystal structure and microwave dielectric properties of Ca[(Li 1/3Nb2/3) 0.95Zr0.05]O 3?ωxTiO2(0x0.1) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x=0.02∼0.1. With an increasing of Ti4± content, the Qf value decreased due to a decrease of the degree of B-site 1:2 ordering. However, the τf value increased from-14.7ppm /oC to -6.9ppm/oC. When x=0.04, the optimum microwave dielectric properties: εr=31.1, Qf =21640GHz and τf =?8.8 ppm/oC. © (2012) Trans Tech Publications, Switzerland.


Liu C.,The University of Oklahoma Health Sciences Center | Liu C.,Xianning College | Liang B.,The University of Oklahoma Health Sciences Center | Wang Q.,The University of Oklahoma Health Sciences Center | And 2 more authors.
Journal of Biological Chemistry | Year: 2010

Accumulating evidence suggests that AMP-activated protein kinase (AMPK) activation exerts anti-apoptotic effects in multiple types of cells. However, the underlying mechanisms remain poorly defined. The aim of the present study was to determine how AMPK suppresses apoptosis in endothelial cells exposed to hypoxia and glucose deprivation (OGD). AMPK activity, NF-κB activation, and endothelial cell apoptosis were assayed in cultured endothelial cells and mouse common carotid artery with or without OGD treatment. OGD markedly activated AMPK as early as 30 min, and AMPK activity reached maximal at 2 h of OGD. Endothelial apoptosis was not detected until 2 h of OGD but became markedly elevated at 6 h of OGD treatment. Furthermore, AMPK inhibition by Compound C or overexpression of dominant negativeAMPK(AMPK-DN) exacerbated, whereas AMPK activation by pharmacologic (aminoimidazole carboxamide ribonucleotide (AICAR)) or genetic means (overexpression of constitutively active AMPK) suppressed endothelial cell apoptosis caused by OGD. Concomitantly, AMPK activation increased the expression of both Bcl-2 and Survivin, two potent anti-apoptotic proteins. Furthermore, AMPK activation significantly enhanced IκBα kinase activation, NF-κB nuclear translocation, and DNA binding activity of NF-κB. Consistently, selective inhibition of NF-κB, which abolished OGD-enhanced expression of Bcl-2 and Survivin, accentuated endothelial apoptosis caused by OGD. Finally, we found that genetic deletion of the AMPKα1, but not AMPKα2, suppressed OGD-enhanced NF-κB activation, the expression of Bcl-2 and Survivin, and endothelial apoptosis. Overall, our results suggest that AMPKα1, but not AMPKα2 activation, promotes cell survival by increasing NF-κB-mediated expression of anti-apoptotic proteins (Bcl-2 and Survivin) and intracellular ATP contents. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc.


The effects of ZnO-B2O3-Na2O(ZBN) glass on the sinterability and microwave dielectric properties of Ca[(Li1/3Nb2/3)0.8Sn0.2]O3−δ−0.1TiO2 (CLNS−0.1TiO2) ceramics were investigated . ZBN glass doping can effectively reduce sintering temperatue by 100~150oC. The temperature coefficient of resonator frequency τf increased with an increase of ZBN glass content and sintering temperatue. When ZBN glass of 3wt% were added, the optimum microwave dielectric properties: εr =28.8,Qf =10960GHz and τf = − 7.5×10−6/oC were obtained at the sintering temperature of 1050oC. © (2011) Trans Tech Publications, Switzerland.


Crystal structure and microwave dielectric properties of Ca[(Li1/3Nb2/3) 0.92Zr0.08]O3−δ−xTiO2(0≤x≤0.2) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x=0.0~0.1. With an increasing of Ti4+ content, the Qf value decreased due to a decrease of the degree of B-site 1:2 ordering. However, the τf value firstly increased from-14.2ppm /ºC to -6.6ppm/ºC, and then moved to the negative direction. When x=0.05, the optimum microwave dielectric properties: εr=32.8, Qf =19460GHz and τf =−8.3 ppm/ºC. © (2011) Trans Tech Publications, Switzerland.


Xu S.,Huazhong University of Science and Technology | Liang J.,Huazhong University of Science and Technology | Yi L.,Xianning College
Journal of the Optical Society of America B: Optical Physics | Year: 2010

An analytical solitary wave solution to the generalized nonlinear Schrödinger equation (NLSE) with varying coefficients in Bessel optical lattices is obtained based on the self-similar method. Our results indicate that a new family of Bessel (BSL) self-similar spatial solitons can be formed in the Kerr nonlinear media in the confined cylindrical symmetric geometry in sizes. These soliton profiles are rather stable, independent of propagation distance. © 2009 Optical Society of America.


Gui Y.,East China Normal University | Gui Y.,Xianning College | Li W.,East China Normal University
Nonlinearity | Year: 2010

The well-known self-affine Sierpinski carpets, first studied by McMullen and Bedford independently, are constructed geometrically by repeating a single action according to a given pattern. In this paper, we extend them by randomly choosing a pattern from a set of patterns with different scales in each step of their construction process. The Hausdorff and box dimensions of the resulting limit sets are determined explicitly and the sufficient conditions for the corresponding Hausdorff measures to be positive finite are also obtained. © 2010 IOP Publishing Ltd and London Mathematical Society.


Ding J.-G.,Xianning College
Journal of Clinical Rehabilitative Tissue Engineering Research | Year: 2010

BACKGROUND: Mesencephalon-derived neural stem cells (NSCs) differentiate into dopaminergic neurons in hypoxia and transgenic condition with body culture morphology and function of adequate maturity of dopamine neurons. Mesencephalon-derived NSCs become ideal seed cells for the treatment of Parkinson's disease with the rapid development of stem cell transplantation in the past few years. OBJECTIVE: To review research progress of mesencephalon-derived NSCs ransgene for treating Parkinson's disease. METHODS: PubMed database was retrieved in computer (1992-01/2006-12), with the key words of "Neural Stem Cell(NSC), Mesencephalic Neural Stem Cell (M-NSC), Neural Stem ell Transplant, Parkinson's Disease (PD)". Simultaneously, China Journal Full-Text Database (2003-01/2008-12) was retrieved with the same key words. RESULTS AND CONCLUSION: The NSCs and in the basic research of M-NSCs and M-NSCs transplantation in the treatment of PD-related documents were selected. A total of 83 documents were collected. Following reading titles and abstracts, 14 studies with irrelative objectives and contents, 16 studies with repetitive contents and 53 articles of Meta analysis were excluded. Totally 47 literatures were included. The main pathologic changes of Parkinson's disease are a dopaminergic neuron degeneration of necrosis in the brain substantia nigra. Using genetically modified neural stem cells in treatment of Parkinson's disease is the most recognized as the most promising treatment. In the hypoxia conditions, transgenic culture of brain-derived neural stem cells can be ffectively induced to differentiate into dopaminergic neurons, provide xperimental basis for in vitro sufficient amount of dopamine neuron transplantation in the treatment of PD. Basic research of neural stem cells have achieved certain results, but clinical and experimental study of neural stem cell transplantation in the treatment of PD is still stuck in the laboratory stage. Mesencephalic neural stem cell biological haracteristics, isolation, proliferation and differentiation are subject to further study. In addition, biological safety problems using mesencephalic neural stem cells in the human body gradually attracted the attention of the people. In vitro neural stem cells of many assages would occur, and will bring certain side effects, and tumorigenicity remains in further exploration.


Hu W.-P.,University of California at Irvine | Hu W.-P.,Xianning College | Li J.-D.,University of California at Irvine | Colwell C.S.,University of California at Los Angeles | Zhou Q.-Y.,University of California at Irvine
Sleep | Year: 2011

Objective: Vasoactive intestinal polypeptide (VIP) has been implicated in sleep regulation as a promoter of rapid eye movement (REM) sleep. Previous work has shown that the amount of time spent in REM sleep is increased by intracerebroventricular administration of VIP, and reduced by treatment with VIP antagonists or antibodies against VIP. A variety of evidence suggests that VIP is critical for normal expression of circadian rhythmicity of diverse physiological and behavioral parameters. In the present study, we investigated the role of this peptide in sleep regulation using VIP-deficient (VIP-/-) mice. Methods: EEG/EMG sleep-wake patterns were recorded in VIP-/- mice and their wild-type littermate controls under normal light-dark (LD), constant darkness (DD) and sleep deprivation conditions. Results: VIP-/- mice exhibited reduced REM sleep time over the 24-h cycle while total daily amounts of NREM sleep and wakefulness were not altered significantly. The reduced REM sleep time in VIP-/- mice occurred entirely during the day due to a reduction in the duration, but not the frequency, of REM sleep bouts. In response to sleep deprivation, compensatory rebounds in NREM sleep and REM sleep were also attenuated in VIP-/- mice. Finally, the loss of VIP altered the temporal distribution of sleep in that the VIP -/- mice exhibited smaller amplitude rhythms in total sleep, NREM sleep, and REM sleep under both LD and DD. Conclusions: These results indicate that VIP regulates the duration of REM sleep, sleep homeostatic mechanisms as well as the temporal patterning of sleep.

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