472 research outputs found
A study of transition metal K-edge x-ray absorption spectra of LaBO3 (B=Mn, Fe, Co, Ni), La2CuO4 and SrMnO3 using partial density of states
The transition metal K-edge x-ray absorption near edge structure (XANES)
studies have been carried on LaBO3 (B=Mn, Fe, Co, Ni), La2CuO4 and SrMnO3
compounds. The theoretical spectra have been calculated using transition metal
(TM) 4p density of states (DOS) obtained from full-potential LMTO density
functional theory. The exchange-correlation functional used in this calculation
is taken under local density approximation (LDA). The comparison of
experimental spectra with the calculated ones indicates that single-particle
transitions under LDA are sufficient to generate all the observed XANES
including those which have earlier been attributed to many-body shake-up
transitions and core-hole potentials. The present study reveals that all the
experimentally observed features are mainly due to distribution in TM 4p DOS
influenced by hybridization with other orbitals. Specifically, for LaMnO3, the
feature earlier attributed to shake-up process is seen to arise from
hybridization of Mn 4p with La 6p and O 2p orbitals; in La2CuO4 the features
attributed to core hole potential correspond to hybridization of Cu 4p with La
6p, La 5d and O 2p orbitals. To see the effect of inhomogeneous electronic
charge distribution and on-site Coulomb and exchange interaction (U) on the
XANES of these compounds generalized-gradient approximation and U corrections
are incorporated in the calculations. These corrections do not generate any new
features in the spectra but affect the detailed intensity and positions of some
of the features.Comment: 23 pages, 8 figures. To appear in J. Phys.: Condens. Matte
Magnetoresistance through a single molecule
The use of single molecules to design electronic devices is an extremely
challenging and fundamentally different approach to further downsizing
electronic circuits. Two-terminal molecular devices such as diodes were first
predicted [1] and, more recently, measured experimentally [2]. The addition of
a gate then enabled the study of molecular transistors [3-5]. In general terms,
in order to increase data processing capabilities, one may not only consider
the electron's charge but also its spin [6,7]. This concept has been pioneered
in giant magnetoresistance (GMR) junctions that consist of thin metallic films
[8,9]. Spin transport across molecules, i.e. Molecular Spintronics remains,
however, a challenging endeavor. As an important first step in this field, we
have performed an experimental and theoretical study on spin transport across a
molecular GMR junction consisting of two ferromagnetic electrodes bridged by a
single hydrogen phthalocyanine (H2Pc) molecule. We observe that even though
H2Pc in itself is nonmagnetic, incorporating it into a molecular junction can
enhance the magnetoresistance by one order of magnitude to 52%.Comment: To appear in Nature Nanotechnology. Present version is the first
submission to Nature Nanotechnology, from May 18th, 201
X-ray Raman scattering study of aligned polyfluorene
We present a non-resonant inelastic x-ray scattering study at the carbon
K-edge on aligned poly[9,9-bis(2-ethylhexyl)-fluorene-2,7-diyl] and show that
the x-ray Raman scattering technique can be used as a practical alternative to
x-ray absorption measurements. We demonstrate that this novel method can be
applied to studies on aligned -conjugated polymers complementing
diffraction and optical studies. Combining the experimental data and a very
recently proposed theoretical scheme we demonstrate a unique property of x-ray
Raman scattering by performing the symmetry decomposition on the density of
unoccupied electronic states into - and -type symmetry contributions.Comment: 19 pages, 8 figure
The Wooster Voice (Wooster, OH), 1949-12-08
Dr. T. Cuyler Young addresses the campus during the annual Wooster Day celebration. Dr. Delbert Lean will give his 40th annual reading of Charles Dickens\u27 Christmas Carol. Plans to build a darkroom for student publications are announced. Additionally, Wooster host the fall conference of the Ohio division of the National Student Association.https://openworks.wooster.edu/voice1941-1950/1204/thumbnail.jp
Soft solar X-rays and solar activity
Soft solar X-rays in the wavelength interval 8–12 Å were observed from OSO III. The totality of the observations that were made between 9 March, 1967, and 18 May, 1968, is summarized graphically and compared to the course of solar activity as observed at other wavelengths, with particular emphasis upon visible activity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43715/1/11207_2004_Article_BF00146064.pd
Impacts of changed litter inputs on soil CO2 efflux in three forest types in central south China
We have defined Neutrosophic Over-/Under-/Off-Set and Logic for the first time in 1995 and published in 2007. During 1995-2016 we presented them to various national and international conferences and seminars. These new notions are totally different from other sets/logics/probabilities.
We extended the neutrosophic set respectively to Neutrosophic Overset {when some neutrosophic component is > 1}, to Neutrosophic Underset {when some neutrosophic component is < 0}, and to Neutrosophic Offset {when some neutrosophic components are off the interval [0, 1], i.e. some neutrosophic component > 1 and other neutrosophic component < 0}.
This is no surprise since our real-world has numerous examples and applications of over-/under-/off-neutrosophic components
Prognostic Significance of Vitamin D Receptor Polymorphisms in Head and Neck Squamous Cell Carcinoma
BACKGROUND:In patients with advanced non-small-cell lung cancer, vitamin D receptor (VDR) polymorphisms and haplotypes are reported to be associated with survival. We hypothesized that a similar association would be observed in patients with head and neck squamous-cell carcinoma (HNSCC). METHODS:In a post-hoc analysis of our previous prospective cohort study, VDR polymorphisms including Cdx2 G/A (rs11568820), FokI C/T (rs10735810), BsmI A/G (rs1544410), ApaI G/T (rs7976091), and TaqI T/C (rs731236) were genotyped by sequencing in 204 consecutive patients with HNSCC who underwent tumor resection. Progression-free survival was compared between VDR polymorphisms using Kaplan-Meier survival curves with log-rank tests and Cox proportional hazard models adjusting for age, gender, smoking status, primary tumor sites, postoperative stages, existence of residual tumor, and postoperative treatment with chemotherapy or radiotherapy. RESULTS:During a median follow-up of 1,047 days, tumor progression and death occurred in 76 (37.3%) and 27 (13.2%) patients, respectively. The FokI T/T genotype was associated with poor progression-free survival: median survival for T/T was 265 days compared with 1,127 days for C/C or C/T (log-rank test: P = 0.0004; adjusted hazard ratio, 3.03; 95% confidence interval, 1.62 to 5.67; P = 0.001). In contrast, the other polymorphisms (Cdx2, BsmI, ApaI, TaqI) showed no significant association with progression-free survival. The A-T-G (Cdx2-FokI-ApaI) haplotype demonstrated a significant association with a higher progression rate (P = 0.02). CONCLUSION:These results suggest that VDR polymorphisms and haplotypes may be associated with prognosis in patients with HNSCC, although the sample size is not large enough to draw definitive conclusions
Control of mechanical pain hypersensitivity in mice through ligand-targeted photoablation of TrkB-positive sensory neurons
Mechanical allodynia is a major symptom of neuropathic pain whereby innocuous touch evokes severe pain. Here we identify a population of peripheral sensory neurons expressing TrkB that are both necessary and sufficient for producing pain from light touch after nerve injury in mice. Mice in which TrkB-Cre-expressing neurons are ablated are less sensitive to the lightest touch under basal conditions, and fail to develop mechanical allodynia in a model of neuropathic pain. Moreover, selective optogenetic activation of these neurons after nerve injury evokes marked nociceptive behavior. Using a phototherapeutic approach based upon BDNF, the ligand for TrkB, we perform molecule-guided laser ablation of these neurons and achieve long-term retraction of TrkB-positive neurons from the skin and pronounced reversal of mechanical allodynia across multiple types of neuropathic pain. Thus we identify the peripheral neurons which transmit pain from light touch and uncover a novel pharmacological strategy for its treatment
A Genetic Basis for Mechanosensory Traits in Humans
Hearing and touch are genetically related, and people with excellent hearing are more likely to have a fine sense of touch and vice versa
Microarray Analysis in the Archaeon Halobacterium salinarum Strain R1
Background: Phototrophy of the extremely halophilic archaeon Halobacterium salinarum was explored for decades. The research was mainly focused on the expression of bacteriorhodopsin and its functional properties. In contrast, less is known about genome wide transcriptional changes and their impact on the physiological adaptation to phototrophy. The tool of choice to record transcriptional profiles is the DNA microarray technique. However, the technique is still rarely used for transcriptome analysis in archaea. Methodology/Principal Findings: We developed a whole-genome DNA microarray based on our sequence data of the Hbt. salinarum strain R1 genome. The potential of our tool is exemplified by the comparison of cells growing under aerobic and phototrophic conditions, respectively. We processed the raw fluorescence data by several stringent filtering steps and a subsequent MAANOVA analysis. The study revealed a lot of transcriptional differences between the two cell states. We found that the transcriptional changes were relatively weak, though significant. Finally, the DNA microarray data were independently verified by a real-time PCR analysis. Conclusion/Significance: This is the first DNA microarray analysis of Hbt. salinarum cells that were actually grown under phototrophic conditions. By comparing the transcriptomics data with current knowledge we could show that our DNA microarray tool is well applicable for transcriptome analysis in the extremely halophilic archaeon Hbt. salinarum. The reliability of our tool is based on both the high-quality array of DNA probes and the stringent data handling including MAANOVA analysis. Among the regulated genes more than 50% had unknown functions. This underlines the fact that haloarchaeal phototrophy is still far away from being completely understood. Hence, the data recorded in this study will be subject to future systems biology analysis
- …