Contaje de mitosis en imágenes histológicas mediante redes neuronales convolucionales

El diagnóstico último del cáncer se realiza por los patólogos mediante el análisis de imágenes histológicas. Uno de los marcadores más importantes en el pronóstico y detección temprana del mismo es el denominado grado de proliferación, que se estima mediante el contaje de figuras mitóticas en imágenes histológicas tintadas con hematoxilina y eosina. Los patólogos realizan este contaje de mitosis de manera manual. Este proceso es costoso y subjetivo, existiendo discrepancias entre los expertos. En los últimos años, el aumento de microscopios escáneres ha permitido la digitalización de las muestras histológicas y su posterior procesamiento. En este trabajo se presenta un método para el contaje automático de mitosis en imágenes histológicas. Este método comprende dos fases: 1) selección de regiones candidatas a mitosis basada en técnicas convencionales de procesamiento de imagen; 2) clasificación mediante Redes Neuronales Convolucionales y técnicas de Deep Learning. El método ha sido validado sobre una base de datos con 656 casos, y se ha obtenido una sensibilidad de 0.617 y un valor de F1 de 0.541 en consonancia con el estado del arte

Contaje de mitosis en imágenes histológicas mediante redes neuronales convolucionales

El diagnóstico último del cáncer se realiza por los patólogos mediante el análisis de imágenes histológicas. Uno de los marcadores más importantes en el pronóstico y detección temprana del mismo es el denominado grado de proliferación, que se estima mediante el contaje de figuras mitóticas en imágenes histológicas tintadas con hematoxilina y eosina. Los patólogos realizan este contaje de mitosis de manera manual. Este proceso es costoso y subjetivo, existiendo discrepancias entre los expertos. En los últimos años, el aumento de microscopios escáneres ha permitido la digitalización de las muestras histológicas y su posterior procesamiento. En este trabajo se presenta un método para el contaje automático de mitosis en imágenes histológicas. Este método comprende dos fases: 1) selección de regiones candidatas a mitosis basada en técnicas convencionales de procesamiento de imagen; 2) clasificación mediante Redes Neuronales Convolucionales y técnicas de Deep Learning. El método ha sido validado sobre una base de datos con 656 casos, y se ha obtenido una sensibilidad de 0.617 y un valor de F1 de 0.541 en consonancia con el estado del arte

Resonant elastic X-ray scattering of antiferromagnetic superstructures in EuPtSi3_{3}

We report resonant elastic X-ray scattering (REXS) of long-range magnetic order in EuPtSi$_{\text{3}}$, combining different scattering geometries with full linear polarization analysis to unambiguously identify magnetic scattering contributions. At low temperatures, EuPtSi$_{\text{3}}$ stabilizes type A antiferromagnetism featuring various long-wavelength modulations. For magnetic fields applied in the hard magnetic basal plane, well-defined regimes of cycloidal, conical, and fan-like superstructures may be distinguished that encompass a pocket of commensurate type A order without superstructure. For magnetic field applied along the easy axis, the phase diagram comprises the cycloidal and conical superstructures only. Highlighting the power of polarized REXS, our results reveal a combination of magnetic phases that suggest a highly unusual competition between antiferromagnetic exchange interactions with Dzyaloshinsky--Moriya spin--orbit coupling of similar strength

Contaje de mitosis en imágenes histológicas mediante redes neuronales convolucionales

El diagnóstico último del cáncer se realiza por los patólogos mediante el análisis de imágenes histológicas. Uno de los marcadores más importantes en el pronóstico y detección temprana del mismo es el denominado grado de proliferación, que se estima mediante el contaje de figuras mitóticas en imágenes histológicas tintadas con hematoxilina y eosina. Los patólogos realizan este contaje de mitosis de manera manual. Este proceso es costoso y subjetivo, existiendo discrepancias entre los expertos. En los últimos años, el aumento de microscopios escáneres ha permitido la digitalización de las muestras histológicas y su posterior procesamiento. En este trabajo se presenta un método para el contaje automático de mitosis en imágenes histológicas. Este método comprende dos fases: 1) selección de regiones candidatas a mitosis basada en técnicas convencionales de procesamiento de imagen; 2) clasificación mediante Redes Neuronales Convolucionales y técnicas de Deep Learning. El método ha sido validado sobre una base de datos con 656 casos, y se ha obtenido una sensibilidad de 0.617 y un valor de F1 de 0.541 en consonancia con el estado del arte

Observation of giant circular dichroism induced by electronic chirality

Chiral phases of matter, characterized by a definite handedness, abound in nature, ranging from the crystal structure of quartz to spiraling spin states in helical magnets. In $1T$-TiSe$_2$ a source of chirality has been proposed that stands apart from these classical examples as it arises from combined electronic charge and quantum orbital fluctuations. This may allow its chirality to be accessed and manipulated without imposing either structural or magnetic handedness. However, direct bulk evidence that broken inversion symmetry and chirality are intrinsic to TiSe$_2$ remains elusive. Here, employing resonant elastic scattering of x-rays, we reveal the presence of giant circular dichroism up to $\sim$ 40$\%$ at forbidden Bragg peaks that emerge at the charge and orbital ordering transition. The dichroism varies dramatically with incident energy and azimuthal angle. Comparison to calculated scattering intensities unambiguously traces its origin to bulk chiral electronic order in ${\mathrm{TiSe}}_2$ and establishes resonant elastic x-ray scattering as a sensitive probe to electronic chirality.Comment: 6 pages, 4 figure

Synthesis and structure determination via ultra-fast electron diffraction of the new microporous zeolitic germanosilicate ITQ-62

[EN] Here, we present the synthesis and structure determination of the new zeolite ITQ-62. Its structure was determined via ultra-fast electron diffraction tomography and refined using powder XRD data of the calcined material. This new zeolite contains a tridirectional channel system of highly distorted 8-rings, as well as a monodirectional 12-ring channel system.The authors gratefully acknowledge financial support from the Spanish Government (MAT2015-71842-P and MAT2015-71261-R MINECO/FEDER and Severo Ochoa SEV-2016-0683). The authors thank ALBA Light Source for beam allocation at the beamline MSPD, and specially thank the Electron Microscopy Service of the Universitat Politecnica de Valencia. Finally, the authors thank Dr Alejandro Vidal and Dr Teresa Blasco for helping in the NMR data discussion.Bieseki, L.; Simancas Coloma, R.; Jorda Moret, JL.; Bereciartua-Pérez, PJ.; Cantin Sanz, A.; Simancas-Coloma, J.; Pergher, SB.... (2018). Synthesis and structure determination via ultra-fast electron diffraction of the new microporous zeolitic germanosilicate ITQ-62. Chemical Communications. 54(17):2122-2125. https://doi.org/10.1039/c7cc09240gS212221255417Barrer, R. M., & Denny, P. J. (1961). 201. Hydrothermal chemistry of the silicates. Part IX. Nitrogenous aluminosilicates. Journal of the Chemical Society (Resumed), 971. doi:10.1039/jr9610000971Kerr, G. T. (1966). Chemistry of Crystalline Aluminosilicates. II. The Synthesis and Properties of Zeolite ZK-4. Inorganic Chemistry, 5(9), 1537-1539. doi:10.1021/ic50043a015Burton, A. W., & Zones, S. I. (2007). Organic Molecules in Zeolite Synthesis: Their Preparation and Structure-Directing Effects. Introduction to Zeolite Science and Practice, 137-179. doi:10.1016/s0167-2991(07)80793-2Zones, S. I., Nakagawa, Y., Lee, G. S., Chen, C. Y., & Yuen, L. T. (1998). Searching for new high silica zeolites through a synergy of organic templates and novel inorganic conditions. Microporous and Mesoporous Materials, 21(4-6), 199-211. doi:10.1016/s1387-1811(98)00011-0Burton, A. W., Zones, S. I., & Elomari, S. (2005). The chemistry of phase selectivity in the synthesis of high-silica zeolites. Current Opinion in Colloid & Interface Science, 10(5-6), 211-219. doi:10.1016/j.cocis.2005.08.005Moliner, M., Rey, F., & Corma, A. (2013). Towards the Rational Design of Efficient Organic Structure-Directing Agents for Zeolite Synthesis. Angewandte Chemie International Edition, 52(52), 13880-13889. doi:10.1002/anie.201304713Park, G. T., Jo, D., Ahn, N. H., Cho, J., & Hong, S. B. (2017). Synthesis and Structural Characterization of a CHA-type AlPO4 Molecular Sieve with Penta-Coordinated Framework Aluminum Atoms. Inorganic Chemistry, 56(14), 8504-8512. doi:10.1021/acs.inorgchem.7b01194Dorset, D. L., Strohmaier, K. G., Kliewer, C. E., Corma, A., Díaz-Cabañas, M. J., Rey, F., & Gilmore, C. J. (2008). Crystal Structure of ITQ-26, a 3D Framework with Extra-Large Pores. Chemistry of Materials, 20(16), 5325-5331. doi:10.1021/cm801126tDorset, D. L., Kennedy, G. J., Strohmaier, K. G., Diaz-Cabañas, M. J., Rey, F., & Corma, A. (2006). P-Derived Organic Cations as Structure-Directing Agents:  Synthesis of a High-Silica Zeolite (ITQ-27) with a Two-Dimensional 12-Ring Channel System. Journal of the American Chemical Society, 128(27), 8862-8867. doi:10.1021/ja061206oJo, D., Ryu, T., Park, G. T., Kim, P. S., Kim, C. H., Nam, I.-S., & Hong, S. B. (2016). Synthesis of High-Silica LTA and UFI Zeolites and NH3–SCR Performance of Their Copper-Exchanged Form. ACS Catalysis, 6(4), 2443-2447. doi:10.1021/acscatal.6b00489Miller, M. A., Moscoso, J. G., Koster, S. C., Gatter, M. G., & Lewis, G. J. (2007). Synthesis and characterization of the 12-ring zeolites UZM-4 (BPH) and UZM-22 (MEI) via the charge density mismatch approach in the Choline-Li2O-SrO-Al2O3-SiO2 system. Studies in Surface Science and Catalysis, 347-354. doi:10.1016/s0167-2991(07)80859-7Simancas, R., Jordá, J. L., Rey, F., Corma, A., Cantín, A., Peral, I., & Popescu, C. (2014). A New Microporous Zeolitic Silicoborate (ITQ-52) with Interconnected Small and Medium Pores. Journal of the American Chemical Society, 136(9), 3342-3345. doi:10.1021/ja411915cSimancas, R., Dari, D., Velamazan, N., Navarro, M. T., Cantin, A., Jorda, J. L., … Rey, F. (2010). Modular Organic Structure-Directing Agents for the Synthesis of Zeolites. Science, 330(6008), 1219-1222. doi:10.1126/science.1196240Martinez-Franco, R., Moliner, M., Yun, Y., Sun, J., Wan, W., Zou, X., & Corma, A. (2013). Synthesis of an extra-large molecular sieve using proton sponges as organic structure-directing agents. Proceedings of the National Academy of Sciences, 110(10), 3749-3754. doi:10.1073/pnas.1220733110Choi, M., Na, K., Kim, J., Sakamoto, Y., Terasaki, O., & Ryoo, R. (2009). Stable single-unit-cell nanosheets of zeolite MFI as active and long-lived catalysts. Nature, 461(7261), 246-249. doi:10.1038/nature08288Zones, S. I., & Davis, M. E. (1996). Zeolite materials: recent discoveries and future prospects. Current Opinion in Solid State and Materials Science, 1(1), 107-117. doi:10.1016/s1359-0286(96)80018-0Bellussi, G., Carati, A., & Millini, R. (2010). Industrial Potential of Zeolites. Zeolites and Catalysis, 449-491. doi:10.1002/9783527630295.ch16Zones, S. I. (2011). Translating new materials discoveries in zeolite research to commercial manufacture. Microporous and Mesoporous Materials, 144(1-3), 1-8. doi:10.1016/j.micromeso.2011.03.039Olsbye, U., Svelle, S., Bjørgen, M., Beato, P., Janssens, T. V. W., Joensen, F., … Lillerud, K. P. (2012). Conversion of Methanol to Hydrocarbons: How Zeolite Cavity and Pore Size Controls Product Selectivity. Angewandte Chemie International Edition, 51(24), 5810-5831. doi:10.1002/anie.201103657Korhonen, S. T., Fickel, D. W., Lobo, R. F., Weckhuysen, B. M., & Beale, A. M. (2011). Isolated Cu2+ions: active sites for selective catalytic reduction of NO. Chem. Commun., 47(2), 800-802. doi:10.1039/c0cc04218hMoliner, M., Franch, C., Palomares, E., Grill, M., & Corma, A. (2012). Cu–SSZ-39, an active and hydrothermally stable catalyst for the selective catalytic reduction of NOx. Chemical Communications, 48(66), 8264. doi:10.1039/c2cc33992gBereciartua, P. J., Cantín, Á., Corma, A., Jordá, J. L., Palomino, M., Rey, F., … Casty, G. L. (2017). Control of zeolite framework flexibility and pore topology for separation of ethane and ethylene. Science, 358(6366), 1068-1071. doi:10.1126/science.aao0092Dodin, M., Paillaud, J.-L., Lorgouilloux, Y., Caullet, P., Elkaïm, E., & Bats, N. (2010). A Zeolitic Material with a Three-Dimensional Pore System Formed by Straight 12- and 10-Ring Channels Synthesized with an Imidazolium Derivative as Structure-Directing Agent. Journal of the American Chemical Society, 132(30), 10221-10223. doi:10.1021/ja103648kPaillaud, J.-L. (2004). Extra-Large-Pore Zeolites with Two-Dimensional Channels Formed by 14 and 12 Rings. Science, 304(5673), 990-992. doi:10.1126/science.1098242Lorgouilloux, Y., Dodin, M., Paillaud, J.-L., Caullet, P., Michelin, L., Josien, L., … Bats, N. (2009). IM-16: A new microporous germanosilicate with a novel framework topology containing d4r and mtw composite building units. Journal of Solid State Chemistry, 182(3), 622-629. doi:10.1016/j.jssc.2008.12.002Earl, D. J., Burton, A. W., Rea, T., Ong, K., Deem, M. W., Hwang, S.-J., & Zones, S. I. (2008). Synthesis and Monte Carlo Structure Determination of SSZ-77: A New Zeolite Topology. The Journal of Physical Chemistry C, 112(24), 9099-9105. doi:10.1021/jp7116856Tang, L., Shi, L., Bonneau, C., Sun, J., Yue, H., Ojuva, A., … Zou, X. (2008). A zeolite family with chiral and achiral structures built from the same building layer. Nature Materials, 7(5), 381-385. doi:10.1038/nmat2169Corma, A., Navarro, M. T., Rey, F., Rius, J., & Valencia, S. (2001). Pure Polymorph C of Zeolite Beta Synthesized by Using Framework Isomorphous Substitution as a Structure-Directing Mechanism. Angewandte Chemie International Edition, 40(12), 2277-2280. doi:10.1002/1521-3773(20010618)40:123.0.co;2-oYun, Y., Hernández, M., Wan, W., Zou, X., Jordá, J. L., Cantín, A., … Corma, A. (2015). The first zeolite with a tri-directional extra-large 14-ring pore system derived using a phosphonium-based organic molecule. Chemical Communications, 51(36), 7602-7605. doi:10.1039/c4cc10317cJiang, J., Yun, Y., Zou, X., Jorda, J. L., & Corma, A. (2015). ITQ-54: a multi-dimensional extra-large pore zeolite with 20 × 14 × 12-ring channels. Chemical Science, 6(1), 480-485. doi:10.1039/c4sc02577fHernández-Rodríguez, M., Jordá, J. L., Rey, F., & Corma, A. (2012). Synthesis and Structure Determination of a New Microporous Zeolite with Large Cavities Connected by Small Pores. Journal of the American Chemical Society, 134(32), 13232-13235. doi:10.1021/ja306013kJiang, J., Jorda, J. L., Diaz-Cabanas, M. J., Yu, J., & Corma, A. (2010). The Synthesis of an Extra-Large-Pore Zeolite with Double Three-Ring Building Units and a Low Framework Density. Angewandte Chemie International Edition, 49(29), 4986-4988. doi:10.1002/anie.201001506Blasco, T., Corma, A., Díaz-Cabañas, M. J., Rey, F., Vidal-Moya, J. A., & Zicovich-Wilson, C. M. (2002). Preferential Location of Ge in the Double Four-Membered Ring Units of ITQ-7 Zeolite. The Journal of Physical Chemistry B, 106(10), 2634-2642. doi:10.1021/jp013302bMoliner, M., Willhammar, T., Wan, W., González, J., Rey, F., Jorda, J. L., … Corma, A. (2012). Synthesis Design and Structure of a Multipore Zeolite with Interconnected 12- and 10-MR Channels. Journal of the American Chemical Society, 134(14), 6473-6478. doi:10.1021/ja301082nCorma, A., Diaz-Cabanas, M. J., Jorda, J. L., Rey, F., Sastre, G., & Strohmaier, K. G. (2008). A Zeolitic Structure (ITQ-34) with Connected 9- and 10-Ring Channels Obtained with Phosphonium Cations as Structure Directing Agents. Journal of the American Chemical Society, 130(49), 16482-16483. doi:10.1021/ja806903cCorma, A., Díaz-Cabañas, M. J., Jordá, J. L., Martínez, C., & Moliner, M. (2006). High-throughput synthesis and catalytic properties of a molecular sieve with 18- and 10-member rings. Nature, 443(7113), 842-845. doi:10.1038/nature05238Sun, J., Bonneau, C., Cantín, Á., Corma, A., Díaz-Cabañas, M. J., Moliner, M., … Zou, X. (2009). The ITQ-37 mesoporous chiral zeolite. Nature, 458(7242), 1154-1157. doi:10.1038/nature07957Corma, A., Rey, F., Valencia, S., Jordá, J. L., & Rius, J. (2003). A zeolite with interconnected 8-, 10- and 12-ring pores and its unique catalytic selectivity. Nature Materials, 2(7), 493-497. doi:10.1038/nmat921Werner, P. E., Eriksson, L., & Westdahl, M. (1985). TREOR, a semi-exhaustive trial-and-error powder indexing program for all symmetries. Journal of Applied Crystallography, 18(5), 367-370. doi:10.1107/s0021889885010512Simancas, J., Simancas, R., Bereciartua, P. J., Jorda, J. L., Rey, F., Corma, A., … Mugnaioli, E. (2016). Ultrafast Electron Diffraction Tomography for Structure Determination of the New Zeolite ITQ-58. Journal of the American Chemical Society, 138(32), 10116-10119. doi:10.1021/jacs.6b06394Kolb, U., Mugnaioli, E., & Gorelik, T. E. (2011). Automated electron diffraction tomography - a new tool for nano crystal structure analysis. Crystal Research and Technology, 46(6), 542-554. doi:10.1002/crat.201100036Grosse-Kunstleve, R. W., McCusker, L. B., & Baerlocher, C. (1999). Zeolite structure determination from powder diffraction data: applications of theFOCUSmethod. Journal of Applied Crystallography, 32(3), 536-542. doi:10.1107/s0021889899003453R. Bialek , KRIBER. Crystallographic computation program , ETH Zurich Institut fur Kristallographie , Zurich, Switzerland , 1991Ch. Baerlocher , A.Hepp and W. M.Meier , DLS-76. Distance least squares refinement program , ETH Zurich Institut fur Kristallographie , Zurich, Switzerland , 1977Fauth, F., Peral, I., Popescu, C., & Knapp, M. (2013). The new Material Science Powder Diffraction beamline at ALBA Synchrotron. Powder Diffraction, 28(S2), S360-S370. doi:10.1017/s0885715613000900Peral, I., McKinlay, J., Knapp, M., & Ferrer, S. (2011). Design and construction of multicrystal analyser detectors using Rowland circles: application to MAD26 at ALBA. Journal of Synchrotron Radiation, 18(6), 842-850. doi:10.1107/s090904951103152

Hidden Charge Order in an Iron Oxide Square-Lattice Compound

Since the discovery of charge disproportionation in the FeO2 square-lattice compound Sr3Fe2O7 by Mössbauer spectroscopy more than fifty years ago, the spatial ordering pattern of the disproportionated charges has remained “hidden” to conventional diffraction probes, despite numerous x-ray and neutron scattering studies. We have used neutron Larmor diffraction and Fe K-edge resonant x-ray scattering to demonstrate checkerboard charge order in the FeO2 planes that vanishes at a sharp second-order phase transition upon heating above 332 K. Stacking disorder of the checkerboard pattern due to frustrated interlayer interactions broadens the corresponding superstructure reflections and greatly reduces their amplitude, thus explaining the difficulty of detecting them by conventional probes. We discuss the implications of these findings for research on “hidden order” in other materials

Electronic structure and lattice dynamics of 1T-VSe2_2: origin of the 3D-CDW

In order to characterize in detail the charge density wave (CDW) transition of 1$T$-VSe$_2$, its electronic structure and lattice dynamics are comprehensively studied by means of x-ray diffraction, angle resolved photoemission (ARPES), diffuse and inelastic x-ray scattering (IXS), and state-of-the-art first principles density functional theory calculations. Resonant elastic x-ray scattering (REXS) does not show any resonant enhancement at either V or Se K-edges, indicating that the CDW peak describes a purely structural modulation of the electronic ordering. ARPES identifies (i) a pseudogap at T$>$T$_{CDW}$, which leads to a depletion of the density of states in the $ML-M'L'$ plane at T$<$T$_{CDW}$, and (ii) anomalies in the electronic dispersion reflecting a sizable impact of phonons on it. A diffuse scattering precursor, characteristic of soft phonons, is observed at room temperature (RT) and leads to the full collapse of the low-energy phonon ($\omega_1$) with propagation vector (0.25 0 -0.3) r.l.u. We show that the frequency and linewidth of this mode are anisotropic in momentum space, reflecting the momentum dependence of the electron-phonon interaction (EPI), hence demonstrating that the origin of the CDW is, to a much larger extent, due to the momentum dependence EPI with a small contribution from nesting. The pressure dependence of the $\omega_1$ soft mode remains nearly constant up to 13 GPa at RT, with only a modest softening before the transition to the high-pressure monoclinic $C2/m$ phase. The wide set of experimental data are well captured by our state-of-the art first-principles anharmonic calculations with the inclusion of van der Waals (vdW) corrections in the exchange-correlation functional. The description of the electronics and dynamics of VSe$_2$ reported here adds important pieces of information to the understanding of the electronic modulations of TMDs