Enhanced structural and magnetic ordering of FePt/Mn-oxide bilayers by ion-beam bombardment and annealing

This journal issue contain selected papers of APDSC'10Poster Session - A. Magnetic Recording Technologies: PA-7Structural and magnetic properties of FePt thin films were affected strongly by capped MnO x layers prepared by ion-beam bombardment and post-annealing. As-deposited FePt/MnO x bilayer exhibited a magnetically soft fcc phase, and it turned to an ordered fct FePt phase with large coercivity (∼8 kOe) after annealing at 550°C. Increasing the %O 2/Ar in capped MnO x layer during deposition resulted in smaller ordered FePt grains separated by grain boundaries of MnO x. We found that the superlattice (001) peak is broadened considerably with larger amount of MnO x incorporated into FePt, likely due to the hindered formation of hard phase. Our results indicate that FePt/MnO x films deposited with lower %O 2/Ar, the oxygen atoms may occupy the interstitial positions in the FePt lattice to induce a local strain thus enhancing the FePt ordering. Further increased %O 2/Ar in capped MnO x layer, the excess oxygen atoms act a diffusion barrier effectively to inhibit the FePt grain growth and ordering. © 2011 IEEE.published_or_final_versionThe Asia-Pacific Data Storage Conference (APDSC'10), Hualien, Taiwan, 27-29 October 2010. In IEEE Transactions On Magnetics, 2011, v. 47 n. 3, p. 501-50

Curcumin induces apoptosis through FAS and FADD, in caspase-3-dependent and -independent pathways in the N18 mouse-rat hybrid retina ganglion cells

[[abstract]]Curcumin, a naturally occurring yellow pigment isolated from turmeric, is a well known antioxidant with broad spectrum of anti-tumor activities against many human cancer cells. In this study, curcumin-induced cytotoxic effect of mouse-rat hybrid retina ganglion cells (N18) were investigated. For determining cell viability, the trypan blue exclusion and flow cytometric analysis were used. The curcumin-caused cell cycle arrest in N18 cells was examined by flow cytometry. Curcumin affect on the production of reactive oxygen species and Ca2+ and on the decrease of the level of mitochondria membrane potential (Delta Psi(m)) were also examined by flow cytometry. Curcumin-induced apoptosis was determined by DAPI staining and Western blotting was used for examining the apoptotic signaling proteins. Cell cycle analysis showed that G2/M phase arrest and sub-G1 occurs in N18 cells following 48 h exposure to curcumin. Curcumin also caused a marked increase in apoptosis, as characterized by DNA fragmentation (sub-G1 phase formation) and DAPI staining, and dysfunction of mitochondria, which was associated with the activation of caspase-8, -9 and -3. Curcumin also promoted the levels of Fas and FADD, Bax, cytochrome c release, but decreased the levels of Bcl-2 causing changes of Delta Psi(m). Curcumin also induced endoplasmic reticulum stress in N18 cells which was based on the changes of GADD153 and GRP78 and caused Ca2+ release. Curcumin induced apoptosis through the intrinsic pathway and caspase-3-dependent and -independent pathways in N18 cells

Involvement of Matrix Metalloproteinases on the Inhibition of Cells Invasion and Migration by Emodin in Human Neuroblastoma SH-SY5Y Cells

[[abstract]]Emodin (1,3,8-trihydroxy-6-methylanthaquinone), an active component present in the root and rhizome of Rheum palmatum L. (Polygonaceae) has anti-bacterial, anti-tumor, diuretic and vasorelaxant effects. However, its mechanism of action on the cell migration and invasion of human neuroblastoma cancer SH-SY5Y cells is not fully understood. In this study, firstly, the effects of emodin on the percentage of viable cells were examined by using MTT assay and it was found that emodin induced dose-and time-dependent inhibition in human neuroblastoma SH-SY5Y cells. Second, the effects of emodin on the migration and invasion of SH-SY5Y cells were examined by using wound assay and matrigel counting and the results showed that emodin suppressed the migration and invasion of SH-SY5Y cells. Third, we examined the effect of emodin on the levels of associated proteins by using Western blotting and the results indicated that emodin inhibited the levels of GRB2, RhoA, HIF-1 alpha, VEGF, FAK, iNOS, COX2, p-p38, p-c-jun, MMP2, MMP9 and MMP7 but promoted the levels of PKC, PI3K, MEKK3 and NF-kappa B p65 that led to the inhibition of migration and invasion of SH-SY5Y cells in vitro

Danthron Induced Apoptosis Through Mitochondria- and Caspase-3-Dependent Pathways in Human Brain Glioblastoma Multiforms GBM 8401 Cells

[[abstract]]Danthron (1,8-dihydroxyanthraquinone), is one of component from Rheum palmatum L. (Polygonaceae), has been shown several biological activities but did not show to induce apoptosis in human brain tumor cells. The aim of this study is to investigate the mechanisms by danthron for the induction of apoptotic potential on human brain glioblastoma multiforms GBM 8401 cell line. Danthron showed a marked concentration- and time-dependent inhibition of GBM 8401 cell viability and induced apoptosis in a dose-and time-dependent manner. There was an attenuation of mitochondrial membrane potential (Delta I (m) ) with the alterations of Bcl-2/Bax protein ratio in GBM 8401 cells, indicating the participation of a mitochondria-related mechanism. Pretreatment of a caspase-8 inhibitor (Z-IETD-FMK), caspase-9 inhibitor (Z-LEHD-FMK) and caspase-3 inhibitor (Z-DEVE-FMK) significantly increased the viable of GBM 8401 cells implied that the participations of caspases. Western blotting analysis also showed the activation of initiator caspase-8 and caspase-9, and executor caspase-3 in GBM 8401 cells. Meanwhile, danthron also promoted the generation of reactive oxygen species (ROS) and cytosolic Ca2+ in GBM 8401 cells. Taken together, our data showed that danthron induced apoptosis in GBM 8401 cells through mitochondria-related and caspase-related pathways, and it may be further evaluated as a chemotherapeutic agent for human brain cancer

Gypenosides induced G0/G1 arrest via inhibition of cyclin e and induction of apoptosis via activation of caspases-3 and-9 in human lung cancer A-549 cells

[[abstract]]Gynostemma pentaphyllum Makino is known in Asia for its effect on the treatment of hepatitis and cardiovascular diseases. Gypenosides (Gyp) are the major components extracted from Gynostemma pentaphyllum Makino. However, the molecular mechanism underlying the Gyp-induced cell cycle arrest and apoptotic process is unclear. In this study, the chemopreventive role of Gyp in human lung cancer (A549) cells in vitro was evaluated by studying the regulation of the cell cycle and apoptosis. Gyp induced G0/G1 arrest and apoptosis in the human lung cancer A549 cells. Investigation of the cyclin-dependent protein kinase inhibitors by Western blotting showed that p16, p21, p27 and p53 proteins were increased with the increasing time of incubation with. Gyp in the A549 cells. This increase may be the major factor by which Gyp caused G0/G1 arrest in the examined cells. Flow cytometric assay and gel electrophoresis of DNA fragmentation also confirmed that Gyp induced apoptosis in the A549 cells. Our data demonstrated that Gyp-induced apoptotic cell death was accompanied by up-regulation of Bax, caspase-3 and caspase-9, but down-regulation of the Bcl-2 levels. Taken together, Gyp appears to exert its anticancer properties by inducing G0/G1-phase arrest and apoptosis via activation of caspase-3 in human lung A549 cancer cells

Curcumin-Induced DNA Damage and Inhibited DNA Repair Genes Expressions in Mouse-Rat Hybrid Retina Ganglion Cells (N18)

[[abstract]]Curcumin is reported to be a potent inhibitor of the initiation and promotion of many cancer cells. We investigated to examine whether or not curcumin induce DNA damage in mouse-rat hybrid retina ganglion cell line N18 cells. The Comet assay showed that incubation of N18 cells with 10, 25 and 30 mu M of curcumin led to a longer DNA migration smear (Comet tail). The DNA gel electrophoresis showed that 20 mu M of curcumin for 24 and 48 h treatment induced DNA damage and fragments in N18 cells. The real time PCR analysis showed that 20 mu M of curcumin for 48 h treatment decreased ATM, ATR, BRCA1, 14-3-3 sigma, DNA-PK and MGMT mRNA, and ATM and MGMT mRNA expression were inhibited in a time-dependent manner. Our results indicate that curcumin caused DNA damage and inhibited DNA repair genes which may be the factors for curcumin-inhibited cell growth

Solution-based growth of ZnO nanorods for light-emitting devices: Hydrothermal vs. electrodeposition

ZnO nanorods have been grown by two inexpensive, solution-based, low-temperature methods: hydrothermal growth and electrodeposition. Heterojunction n-ZnO nanorods/p-GaN light-emitting diodes have been studied for different nanorod growth methods and different preparation of the seed layer. We demonstrate that both the nanorod properties and the device performance are strongly dependent on the growth method and seed layer. All the devices exhibit light emission under both forward and reverse bias, and the emission spectra can be tuned by ZnO nanorod deposition conditions. Electrodeposition of rods or a seed layer results in yellow emission, while conventional hydrothermal growth results in violet emission. © The Author(s) 2010. This article is published with open access at Springerlink.com.published_or_final_versionSpringer Open Choice, 01 Dec 201

International Collaborative Partnership for the Study of Atrial Fibrillation (INTERAF): Rationale, Design, and Initial Descriptives.

published_or_final_versio

Scattering Theory and PT\mathcal{P}\mathcal{T}-Symmetry

We outline a global approach to scattering theory in one dimension that allows for the description of a large class of scattering systems and their $\mathcal{P}$-, $\mathcal{T}$-, and $\mathcal{P}\mathcal{T}$-symmetries. In particular, we review various relevant concepts such as Jost solutions, transfer and scattering matrices, reciprocity principle, unidirectional reflection and invisibility, and spectral singularities. We discuss in some detail the mathematical conditions that imply or forbid reciprocal transmission, reciprocal reflection, and the presence of spectral singularities and their time-reversal. We also derive generalized unitarity relations for time-reversal-invariant and $\mathcal{P}\mathcal{T}$-symmetric scattering systems, and explore the consequences of breaking them. The results reported here apply to the scattering systems defined by a real or complex local potential as well as those determined by energy-dependent potentials, nonlocal potentials, and general point interactions.Comment: Slightly expanded revised version, 38 page