528 research outputs found

    STAT3, tumor microenvironment, and microvessel density in diffuse large B cell lymphomas

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    Constitutively activated STAT3 is correlated with more advanced clinical stage and overall poor survival of diffuse large B-cell lymphoma (DLBCL). The aim of this study was to evaluate STAT3 and Ki67 tumor cell expression, inflammatory cell infiltration, microvascular density in DLBCL bioptic specimens. RNA-scope showed that activated B cell (ABC) tissue samples contained a significant higher number of STAT3+ cells as compared to germinal center B (GCB) tissue samples. Immunohistochemical analysis showed a significant increased levels of CD3, CD8, CD68, CD163, CD34, and Ki67 positive cells in ABC patients. A positive correlation between STAT3 and CD3, CD8, CD68, and CD163 was evidenced in ABC group. In ABC group, we found also a positive correlation between CD8 and CD34 and a positive correlation between Ki67 and, CD68, and CD163. These data indicate that in ABC—as compared to GCB-DLBCL, a higher STAT3 expression is associated with a higher CD163+ TAM and CD8+ cell infiltration which induces a strong angiogenic response

    PB2064 USE OF RNASCOPE TECHNOLOGY TO DETERMINE STAT-3 EXPRESSION IN HUMAN DIFFUSE LARGE B-CELL LYMPHOMA

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    Diffuse large B-cell lymphoma (DLBCL) is the most common and one of the most heterogeneous lymphomas. Therefore, it is critical to further stratify cases of DLBCL into biologically similar and clinically meaningful subgroups, which will not only guide prognostic assessment and facilitate therapeutic decisions, but also stimulate further research to understand the pathogenesis and develop potential novel treatments. Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that exerts important biological functions related to cell proliferation, differentiation, survival, angiogenesis and immune response

    Symmetry lowering of pentacene molecular states interacting with a Cu surface

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    Pentacene adsorbed on the Cu(119) vicinal surface forms long-range ordered chain structures. Photoemission spectroscopy measurements and ab initio density functional theory simulations provide consistent evidences that pentacene molecular orbitals mix with the copper bands, giving rise to interaction states localized at the interface. Angular-resolved and polarization dependent photoemission spectroscopy shows that most of the pentacene derived intensity is strongly dichroic. The symmetry of the molecular states of the free pentacene molecules is reduced upon adsorption on Cu(119), as a consequence of the molecule-metal interaction. Theoretical results show a redistribution of the charge density in \u3c0 molecular states close to the Fermi level, consistent with the photoemission intensities (density of states) and polarization dependence (orbital symmetry)

    Discontinuous Transition from a Real Bound State to Virtual Bound State in a Mixed-Valence State of SmS

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    Golden SmS is a paramagnetic, mixed-valence system with a pseudogap. With increasing pressure across a critical pressure Pc, the system undergoes a discontinuous transition into a metallic, anti-ferromagnetically ordered state. By using a combination of thermodynamic, transport, and magnetic measurements, we show that the pseudogap results from the formation of a local bound state with spin singlet. We further argue that the transition Pc is regarded as a transition from an insulating electron-hole gas to a Kondo metal, i.e., from a spatially bound state to a Kondo virtually bound state between 4f and conduction electrons.Comment: 5 pages, 5 figure

    Laser-based angle-resolved photoemission spectroscopy with micrometer spatial resolution and detection of three-dimensional spin vector

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    We have developed a state-of-the-art apparatus for laser-based spin- and angle-resolved photoemission spectroscopy with micrometer spatial resolution (micro-SARPES). This equipment is achieved through the combination of a high-resolution photoelectron spectrometer, a 6-eV laser with high photon flux that is focused down to a few micrometers, a high-precision sample stage control system, and a double very-low-energy-electron-diffraction spin detector. The setup achieves an energy resolution of 1.5 (5.5) meV without (with) the spin detection mode, compatible with a spatial resolution better than 10 micrometers. This enables us to probe both spatially-resolved electronic structures and vector information of spin polarization in three dimensions. The performance of micro-SARPES apparatus is demonstrated by presenting ARPES and SARPES results from topological insulators and Au photolithography patterns on a Si (001) substrate.Comment: 18 pages, 5 figure

    Valence band electronic structure of V2O3: identification of V and O bands

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    We present a comprehensive study of the photon energy dependence of the valence band photoemission yield in the prototype Mott-Hubbard oxide V2O3. The analysis of our experimental results, covering an extended photon energy range (20-6000 eV) and combined with GW calculations, allow us to identify the nature of the orbitals contributing to the total spectral weight at different binding energies, and in particular to locate the V 4s at about 8 eV binding energy. From this comparative analysis we can conclude that the intensity of the quasiparticle photoemission peak, observed close to the Fermi level in the paramagnetic metallic phase upon increasing photon energy, does not have a significant correlation with the intensity variation of the O 2p and V 3d yield, thus confirming that bulk sensitivity is an essential requirement for the detection of this coherent low energy excitation

    Molecular charge distribution and dispersion of electronic states in the contact layer between pentacene and Cu(119) and beyond

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    The interaction of pentacene molecules in contact with the Cu(119) stepped surface has been directly imaged by scanning tunneling microscopy and analyzed by angle resolved photoemission spectroscopy. Interacting molecules, which are in contact with copper, generate dispersive electronic states associated with a perturbed electron charge density distribution of the molecular orbitals. In contrast, the electron charge density of molecules of the pentacene on top of the first layer, which is not in direct contact with the Cu surface, shows an intramolecular structure very similar to that of the free molecule. Our results indicate that the delocalization of the molecular states in the pentacene/Cu system is confined to the very first molecular layer at the interface

    Cortical depth dependent functional responses in humans at 7T: improved specificity with 3D GRASE

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    Ultra high fields (7T and above) allow functional imaging with high contrast-to-noise ratios and improved spatial resolution. This, along with improved hardware and imaging techniques, allow investigating columnar and laminar functional responses. Using gradient-echo (GE) (T2* weighted) based sequences, layer specific responses have been recorded from human (and animal) primary visual areas. However, their increased sensitivity to large surface veins potentially clouds detecting and interpreting layer specific responses. Conversely, spin-echo (SE) (T2 weighted) sequences are less sensitive to large veins and have been used to map cortical columns in humans. T2 weighted 3D GRASE with inner volume selection provides high isotropic resolution over extended volumes, overcoming some of the many technical limitations of conventional 2D SE-EPI, whereby making layer specific investigations feasible. Further, the demonstration of columnar level specificity with 3D GRASE, despite contributions from both stimulated echoes and conventional T2 contrast, has made it an attractive alternative over 2D SE-EPI. Here, we assess the spatial specificity of cortical depth dependent 3D GRASE functional responses in human V1 and hMT by comparing it to GE responses. In doing so we demonstrate that 3D GRASE is less sensitive to contributions from large veins in superficial layers, while showing increased specificity (functional tuning) throughout the cortex compared to GE
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