Two particle correlations: a probe of the LHC QCD medium

The properties of $\gamma$--jet pairs emitted in heavy-ion collisions provide an accurate mean to perform a tomographic measurement of the medium created in the collision through the study of the medium modified jet properties. The idea is to measure the distribution of hadrons emitted on the opposite side of the %oppositely by tagging the direct photon. The feasibility of such measurements is studied by applying the approach on the simulation data, we have demonstrated that this method allows us to measure, with a good approximation, both the jet fragmentation and the back-to-back azimuthal alignment of the direct photon and the jet. Comparing these two observables measured in pp collisions with the ones measured in AA collisions reveals the modifications induced by the medium on the jet structure and consequently allows us to infer the medium properties. In this contribution, we discuss a first attempt of such measurements applied to real proton-proton data from the ALICE experiment.Comment: 4 pages, 4 figures, Proceedings for Hot Quark 2010 Conferenc

Lattice dynamics and electron-phonon coupling in Sr2RuO4

The lattice dynamics in Sr$_2$RuO$_4$ has been studied by inelastic neutron scattering combined with shell-model calculations. The in-plane bond-stretching modes in Sr$_2$RuO$_4$ exhibit a normal dispersion in contrast to all electronically doped perovskites studied so far. Evidence for strong electron phonon coupling is found for c-polarized phonons suggesting a close connection with the anomalous c-axis charge transport in Sr$_2$RuO$_4$.Comment: 11 pages, 8 figures 2 table

Subjective pain perception mediated by alpha rhythms

Suppression of spontaneous alpha oscillatory activities, interpreted as cortical excitability, was observed in response to both transient and tonic painful stimuli. The changes of alpha rhythms induced by pain could be modulated by painful sensory inputs, experimental tasks, and top-down cognitive regulations such as attention. The temporal and spatial characteristics, as well as neural functions of pain induced alpha responses, depend much on how these factors contribute to the observed alpha event-related desynchronization/synchronization (ERD/ERS). How sensory-, task-, and cognitive-related changes of alpha oscillatory activities interact in pain perception process is reviewed in the current study, and the following conclusions are made: (1) the functional inhibition hypothesis that has been proposed in auditory and visual modalities could be applied also in pain modality; (2) the neural functions of pain induced alpha ERD/ERS were highly dependent on the cortical regions where it is observed, e.g., somatosensory cortex alpha ERD/ERS in pain perception for painful stimulus processing; (3) the attention modulation of pain perception, i.e., influences on the sensory and affective dimensions of pain experience, could be mediated by changes of alpha rhythms. Finally, we propose a model regarding the determinants of pain related alpha oscillatory activity, i.e., sensory-discriminative, affective-motivational, and cognitive-modulative aspects of pain experience, would affect and determine pain related alpha oscillatory activities in an integrated way within the distributed alpha system. Copyright © 2015 Elsevier B.V. All rights reserved.postprin

Inhibition Effects of Scorpion Venom Extracts (Buthus matensii karsch) on the Growth of Human Breast Cancer MCF-7 cells

Background: To observe the inhibition effects of the Buthus matensii Karsch (BmK) scorpion venom extracts on the growth of human breastcancer MCF-7 cells, and to explore its mechanisms.Methods: Two common tumor cells (SMMC7721, MCF-7) were examined for the one which wasmore sensitivity to scorpion venom by MTT method. Cell cycle was determined by flow cytometry. Immunocytochemistry was applied to detect apoptosis-related protein Caspase-3 and Bcl-2 levels, while the expression of cell cycle-related protein Cyclin D1 was shown byWestern blotting.Results: Our data indicated that MCF-7 was the more sensitive cell line to scorpion venom. The extracts of scorpion venom could inhibit the growth and proliferation of MCF-7 cells. Furthermore, the extract of scorpion venom induced apoptosis through Caspase-3 up-regulation while Bcl-2 down-regulation in MCF-7 cells. In addition, the extracts of scorpion venom blocked the cells from G0/G1 phase to S phase and decreased cell cycle-related protein Cyclin D1 level after drug intervention compared with the negative control group.Conclusions: These results showed that the BmK scorpion venom extracts could inhibit the growth of MCF-7 cells by inducing apoptosis and blocking cell cycle in G0/G1 phase. The BmK scorpion venom extracts will be very valuable for the treatment of breast cancer.Key words: Apoptosis, Buthus matensii Karsch, cell cycle, MCF-7, scorpion venomAbbreviations: SVE: Scorpion venom extracts ; FBS: Fetal bovine serum; MTT: 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide;BmK ; Buthus matensii Karsch; PBS: Phosphate buffered saline; PI: Propidium iodide; FCM: Flow cytometry; SDS-PAGE: Sodium dodecylsulfate polyacrylamide gel electrophoresis; DAB: Diaminobenzidine; B-NHL: B-cell non-Hodgkin's tumors; DED: Death effector domain ; PTP:Permeability transition pores ; CKIs: Cyclin-dependent kinases inhabitors; pRB: Retinoblastoma tumor suppressor protein ; CDK: Cyclin-dependent kinase

Deformation behavior and mechanical properties of polycrystalline and single crystal alumina during nanoindentation

The nanoscale pop-in phenomena in polycrystalline alpha-Al2O3 and single crystal alpha-Al2O3(0001) were comparatively investigated by nanoindentation with Berkovich indenters. It was found that different radii and loading rates have significant effects on the pop-ins formation, stress distributions and dislocation nucleations. Using the Hertzian contact theory and energetic model approach, the pop-in observations and resolved shear stress analysis are consistent with the explanation that the first pop-in corresponds to the nucleation of homogeneous dislocations when the theoretical shear strenghth is exceeded

Nanoscale elastic-plastic deformation and stress distributions on the C plane of sapphire single crystal during nanoindentation

The nanoscale elastic-plastic characteristics of the C plane of sapphire single crystal were studied by ultra-low nanoindentation loads with a Berkovich indenter within the indentation depth less than 60 nm. The smaller the loading rate is, the greater the corresponding critical pop-in loads and the width of pop-in extension become. It is shown that hardness obviously exhibits the indentation size effect (ISE), which is 46.7 plus or equal to 15 GPa at the ISE region and is equal to 27.5 plus or equal to 2 GPa at the non-ISE region. The indentation modulus of the C plane decreases with increasing the indentation depth and equals 420.6 plus or equal to 20 GPa at the steady-state when the indentation depth exceeds 60nm. Based on the Schmidt law, Hertzian contact theory and crystallography, the possibilities of activation of primary slip systems indented on the C surface and the distributions of critical resolve shear stresses on the slip plane were analyzed