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R Royle, Y Sentoku, R C Mancini, I Paraschiv, T Johzaki
Solid-density plasmas driven by intense x-ray free-electron laser (XFEL) radiation are seeded by sources of nonthermal photoelectrons and Auger electrons that ionize and heat the target via collisions. Simulation codes that are commonly used to model such plasmas, such as collisional-radiative (CR) codes, typically assume a Maxwellian distribution and thus instantaneous thermalization of the source electrons. In this study, we present a detailed description and initial applications of a collisional particle-in-cell code, picls, that has been extended with a self-consistent radiation transport model and Monte Carlo models for photoionization and KLL Auger ionization, enabling the fully kinetic simulation of XFEL-driven plasmas...
June 2017: Physical Review. E
Natalie J Miller, Candice D Church, Lichun Dong, David Crispin, Matthew P Fitzgibbon, Kristina Lachance, Lichen Jing, Michi Shinohara, Ioannis Gavvovidis, Gerald Willimsky, Martin McIntosh, Thomas Blankenstein, David M Koelle, Paul Nghiem
Tumor-infiltrating CD8(+) T cells are associated with improved survival of patients with Merkel cell carcinoma (MCC), an aggressive skin cancer causally linked to Merkel cell polyomavirus (MCPyV). However, CD8(+) T-cell infiltration is robust in only 4% to 18% of MCC tumors. We characterized the T-cell receptor (TCR) repertoire restricted to one prominent epitope of MCPyV (KLLEIAPNC, "KLL") and assessed whether TCR diversity, tumor infiltration, or T-cell avidity correlated with clinical outcome. HLA-A*02:01/KLL tetramer(+) CD8(+) T cells from MCC patient peripheral blood mononuclear cells (PBMC) and tumor-infiltrating lymphocytes (TIL) were isolated via flow cytometry...
February 2017: Cancer Immunology Research
Tamar Leshem, Peter M Letcher, Martha J Powell, Assaf Sukenik
Only a few chytrid fungi have been reported as parasites of dinoflagellates. Among these reports, chytrids are periodically observed growing on the dinoflagellate, Peridinium gatunense, in Lake Kinneret (Sea of Galilee), Israel. Because of the distinctive roles of parasitic chytrid fungi in decreasing phytoplankton populations and in transforming inedible algae into chytrid biomass which zooplankton grazers can eat, characterizing dinoflagellate parasites contributes to our understanding of the sustainability of this important water resource...
July 2016: Mycologia
Noritake Isomura, Masao Kamada, Takamasa Nonaka, Eiken Nakamura, Takumi Takano, Harue Sugiyama, Yasuji Kimoto
A unique analytical method is proposed for local structure analysis via extended X-ray absorption fine structure (EXAFS) spectroscopy. The measurement of electron energy distribution curves at various excitation photon energies using an electron energy analyzer is applied to determine a specific elemental Auger spectrum. To demonstrate the method, the N K-edge EXAFS spectra for a silicon nitride film were obtained via simultaneous measurement of the N KLL Auger and background spectra using dual-energy windows...
January 2016: Journal of Synchrotron Radiation
Carlos Alberto Martínez, Kshitij Khare, Mauricio A Elzo
In this paper, decision theory was used to derive Bayes and minimax decision rules to estimate allelic frequencies and to explore their admissibility. Decision rules with uniformly smallest risk usually do not exist and one approach to solve this problem is to use the Bayes principle and the minimax principle to find decision rules satisfying some general optimality criterion based on their risk functions. Two cases were considered, the simpler case of biallelic loci and the more complex case of multiallelic loci...
October 21, 2015: Journal of Theoretical Biology
Justyna Drzał-Grabiec, Justyna Rykała, Justyna Podgórska, Sławomir Snela
BACKGROUND: With age, the body posture undergoes involutional changes. It is not possible to determine accurately the beginning of these changes. They begin between 40 and 50 years of age, and their slow progress increases after 60 years of age. The aim of this study was to assess the body posture of women and men over 60 years of age. MATERIAL AND METHOD: Seventy people over 60 years old (35 women and 35 men) participated in the study. The control group consisted of 70 people (35 women and 35 men) between the age of 20 and 25...
September 2012: Ortopedia, Traumatologia, Rehabilitacja
Dahlang Tahir, Sven Tougaard
The electronic and optical properties of Cu, CuO and Cu(2)O were studied by x-ray photoelectron spectroscopy (XPS) and reflection electron energy-loss spectroscopy (REELS). We report detailed Cu 2p, Cu LVV, O 1s and O KLL spectra which are in good agreement with previous results. REELS spectra, recorded for primary energies in the range from 150 to 2000 eV, were corrected for multiple inelastically scattered electrons to determine the effective inelastic scattering cross section. The dielectric functions and optical properties were determined by comparing the experimental inelastic electron scattering cross section with a simulated cross section calculated within the semi-classical dielectric response model in which the only input is Im(-1/ε) by using the QUEELS-ε(k,ω)-REELS software package...
May 2, 2012: Journal of Physics. Condensed Matter: An Institute of Physics Journal
M Meyer, P Radcliffe, T Tschentscher, J T Costello, A L Cavalieri, I Grguras, A R Maier, R Kienberger, J Bozek, C Bostedt, S Schorb, R Coffee, M Messerschmidt, C Roedig, E Sistrunk, L F Di Mauro, G Doumy, K Ueda, S Wada, S Düsterer, A K Kazansky, N M Kabachnik
Two-color (x-ray+infrared) electron spectroscopy is used for investigating laser-assisted KLL Auger decay following 1s photoionization of atomic Ne with few-femtosecond x-ray pulses from the Linac Coherent Light Source. In an angle-resolved experiment, the overall width of the laser-modified Auger-electron spectrum and its structure change significantly as a function of the emission angle. The spectra are characterized by a strong intensity variation of the sidebands revealing a gross structure. This variation is caused, as predicted by theory, by the interference of electrons emitted at different times within the duration of one optical cycle of the infrared dressing laser, which almost coincides with the lifetime of the Ne 1s vacancy...
February 10, 2012: Physical Review Letters
S Diplas, O M Løvvik
The electronic structure of Ni-X (X = B, S, P) alloys was studied using x-ray photoelectron spectroscopy, x-ray induced Auger electron spectroscopy and density functional theory. The spectroscopic data in the form of the Ni 2p shake-up satellite and the Ni 2p LMM, P 2p KLL and S 2p KLL Auger parameters combined with density of states (DOS) and charge difference plots suggest an overall charge transfer from the Ni sites towards the alloying addition sites. However, this is masked, with intra-atomic charge redistribution leading to an increased occupancy of the Ni 3d states in the alloys...
June 17, 2009: Journal of Physics. Condensed Matter: An Institute of Physics Journal
I H Suzuki, Y Kono, A Ikeda, T Ouchi, K Ueda, O Takahashi, I Higuchi, Y Tamenori, S Nagaoka
Spectator resonant KL(23)L(23) Auger electron spectra have been measured in the Si 1s photoexcitation region of Si(CH(3))(4) using monochromatized undulator radiation combined with a hemispherical electron spectrometer. The broad peak with high intensity in a total ion yield spectrum, coming mainly from excitation of a 1s electron into the 6t(2) vacant orbital, induces a spectator Auger decay in which the excited electron remains in its excited orbital. The component on the higher energy side of this peak through 1s excitation into a Rydberg orbital produces resonant Auger decays in which the excited Rydberg electron moves into a slightly higher Rydberg orbital, or is partly shaken up to a significantly higher Rydberg orbital...
February 28, 2011: Journal of Chemical Physics
Shinjiro Hayakawa, Aya Tanaka, Takeshi Hirokawa
The averaged attenuation length of emitted electrons with the conversion electron yield (CEY) method was evaluated for Ni films with the x-rays below and above the Ni K absorption edge. The evaluated attenuation length was 13.1 nm with the x-rays below the Ni K absorption edge, and it became 24.0 nm with the contribution of Ni KLL Auger electrons that had the attenuation length of 78.1 nm. The probing depth of the CEY measurements are determined both the penetration depth of x-rays and the attenuation length of emitted electrons, and the modification of the probing depth was investigated with the grazing incidence condition...
2010: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Beata Lesiak, Josef Zemek, Jana Houdkova, Alexander Kromka, Adam Józwik
The X-ray excited Auger electron spectroscopy (XAES), X-ray photoelectron spectroscopy (XPS) and elastic peak electron spectroscopy (EPES) methods were applied in investigating samples of nanocrystalline diamond and highly oriented pyrolytic graphite of various C sp(2)/sp(3) ratios, crystallinity conditions and grain sizes. The composition at the surface was estimated from the XPS. The C sp(2)/sp(3) ratio was evaluated from the width of the XAES first derivative C KLL spectra and from fitting of XPS C 1s spectra into components...
2010: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Mineharu Suzuki, Nobuaki Urushihara, Noriaki Sanada, Dennis F Paul, Scott Bryan, John S Hammond
Cross-sections of GaAs/AlAs thin films prepared by cleavage of MBE-grown superlattices have been analyzed with Auger electron spectroscopy with a spatial resolution of 6 nm. Elemental distributions of Ga, Al, and As were clearly distinguished in line analysis as well as in two dimensional mapping for 50, 20, and 10 nm thin film structures. We have found an oscillation of Al KLL peak position between the two values while the peak positions of Ga LMM and As LMM remain constant. The origin of the Al KLL peak shift is a primary electron beam induced reduction of oxidized Al atoms formed during specimen preparation...
2010: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Kentaro Fujii, Akinari Yokoya, Naoya Shikazono
PURPOSE: To reveal the reaction process in DNA by Auger electrons using the observed single strand breaks (SSB) and base lesions induced by monochromatic ultrasoft X-rays in dry plasmid DNA film. Desorbed ions from DNA and 2-deoxy-D-ribose thin films were also measured to ascertain the decomposition site in DNA. MATERIALS AND METHODS: Dry plasmid DNA (pUC18) films were irradiated with synchrotron monochromatic ultrasoft X-rays (USX). Two photon energies, 270, and 560 eV, were chosen for the irradiation experiments...
December 2008: International Journal of Radiation Biology
Spas D Stoychev, Alexander I Kuleff, Francesco Tarantelli, Lorenz S Cederbaum
The accessible relaxation channels of the electronic states of Ne(++)-Ne and Ne(3+)-Ne populated by KLL Auger decay are studied. In particular, we address the "direct" and "exchange" interatomic Coulombic decays (ICDs) and the electron-transfer-mediated decay following the population of one-site states Ne(++)(2s(-2))-Ne and Ne(++)(2s(-1)2p(-1) (1)P)-Ne. Radiative charge transfer of the low lying Ne(++)(2p(-2))-Ne states, three-electron ICD process from the Ne(++)(2s(-2))-Ne states, as well as charge transfer at the points of curve crossing of the lowest in energy Ne(3+)(2p(-3))-Ne states are also discussed...
August 21, 2008: Journal of Chemical Physics
Guy Guiffo-Soh, Belén Hernandez, Yves-Marie Coïc, Fatima-Zohra Boukhalfa-Heniche, Mahmoud Ghomi
Aqueous solution secondary structures of minimalist LK-peptides, with the generic sequence defined as KLL(KLLL)nKLLK, have been analyzed by means of circular dichroism (CD) and Raman scattering techniques. Our discussion in the present paper is mainly focused on four synthetic peptides (from 5 to 19 amino acids), KLLLK, KLLKLLLKLLK, KLLKLLLKLLLKLLK, and KLLKLLLKLLLKLLLKLLK, corresponding to the repeat unit, and to the peptide chains with the values of n = 1-3, respectively. CD and Raman spectra were analyzed in order to study both structural features of the peptide chains and their capability to form aggregates...
November 1, 2007: Journal of Physical Chemistry. B
M Lampimäki, K Lahtonen, M Hirsimäki, M Valden
Surface oxidation of Cu(100) in O(2) has been investigated in situ by x-ray photoelectron spectroscopy, x-ray induced Auger electron spectroscopy (XAES), and scanning tunneling microscopy (STM) as a function of surface temperature (T(S)=303-423 K) and O(2) pressure (p(O(2) )=3.7 x 10(-2)-213 mbars). Morphology of the oxide on the surface and in the near surface layers is characterized by utilizing STM and the inelastic electron background of the XAES O KLL signal. Analysis of the peak shape of the XAES Cu LMM facilitates the quantification of Cu, Cu(2)O, and CuO surface concentrations...
January 21, 2007: Journal of Chemical Physics
Tsutomu Sonoda, Akira Watazu, Kiyotaka Katou, Tadashi Asahina
Deposition of Ti/N compositionally gradient film onto Ti-6Al-4V alloy substrates was carried out by reactive DC sputtering, not only to improve the blood compatibility of the alloy but also to relax the stress concentrated at the interface between the film and the alloy substrate. The compositional gradient was realized by varying continuously the nitrogen content in Ar-N2 sputter gas during deposition. In Auger electron spectroscopy (AES) analysis, Auger spectra were acquired in the N(E) mode using the beam brightness modulation (BBM) method to overcome the problem of the peak overlap of the principal Auger nitrogen transition peak (N-KLL) with one of titanium peaks (Ti-LMM)...
August 2006: Microscopy and Microanalysis
A J González Martínez, J R Crespo López-Urrutia, J Braun, G Brenner, H Bruhns, A Lapierre, V Mironov, R Soria Orts, H Tawara, M Trinczek, J Ullrich, J H Scofield
We present experimental data on the state-selective quantum interference between different pathways of photorecombination, namely, radiative and dielectronic recombination, in the KLL resonances of highly charged mercury ions. The interference, observed for well resolved electronic states in the Heidelberg electron beam ion trap, manifests itself in the asymmetry of line shapes, characterized by "Fano factors," which have been determined with unprecedented precision, as well as their excitation energies, for several strong dielectronic resonances...
May 27, 2005: Physical Review Letters
András Berkó, Anett Magony, János Szökõ
The properties of Mo ultrathin films deposited on a TiO2(110) surface were investigated by scanning tunneling microscopy (STM) and spectroscopy (STS), as well as by Auger electron spectroscopy (AES). The substrate exhibited mainly large (1 x 1) terraces decorated by additional [001] rows (missing or added 1D structures) of reduced TiO(x) phases. Only a few percent of the surface exhibited a cross-linked (1 x 2) arrangement. The deposition of Mo layers at room temperature with a rate of approximately 0.4 monolayer/ min resulted in nanoclusters of 1-2 nm with a low-profile shape (2D-like)...
May 10, 2005: Langmuir: the ACS Journal of Surfaces and Colloids
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