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Michael K Yeung, Sophia L Sze, Jean Woo, Timothy Kwok, David H K Shum, Ruby Yu, Agnes S Chan
BACKGROUND: Some functional magnetic resonance imaging studies have reported altered activations in the frontal cortex during working memory (WM) performance in individuals with mild cognitive impairment (MCI), but the findings have been mixed. The objective of the present study was to utilize near-infrared spectroscopy (NIRS), an alternative imaging technique, to examine neural processing during WM performance in individuals with MCI. METHODS: Twenty-six older adults with MCI (7 males; mean age 69...
October 27, 2016: Dementia and Geriatric Cognitive Disorders
Luca Antonio Dimuccio, Nelson Rodrigues, Felice Larocca, João Pratas, Ana Margarida Amado, Luís A E Batista de Carvalho
This study examines the geochemical and mineralogical variations in the ferruginous mineralisations that crop out within Grotta della Monaca, which is considered to be the most striking and best known example of a prehistoric iron mine-cave from the southern Apennines (Calabria, Italy). Previous archaeological research identified three local and distinct ancient exploitation phases of these ferruginous mineralisations: (1) an Upper Palaeolithic phase; (2) a Late Neolithic phase; and (3) a post-Medieval phase...
October 17, 2016: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Daniele Rimini, Filippo Molinari, William Liboni, Marina Balbo, Roberta Darò, Erika Viotti, Isabel Fernandez
INTRODUCTION: Eye Movement Desensitization and Reprocessing (EMDR) is a psychotherapeutic treatment resolving emotional distress caused by traumatic events. With EMDR, information processing is facilitated by eye movements (EM) during the recall of a traumatic memory (RECALL). The aim of this study is to investigate the effects of ocular movements of EMDR on the hemodynamics of the prefrontal cortex (PFC). MATERIAL AND METHODS: Two groups were recruited: a trial group (wEM) received a complete EMDR treatment, whereas a control group (woEM) received a therapy without EM...
2016: PloS One
Prerak Gupta, Mimi Adhikary, Joseph Christakiran M, Manishekhar Kumar, Nandana Bhardwaj, Biman B Mandal
Composite biomaterials as artificial bone graft materials are pushing the present frontiers of bioengineering. In this study, a biomimetic, osteoconductive tricomposite scaffold made of hydroxyapatite (HA) embedded in non-mulberry Antheraea assama (A. assama) silk fibroin fibers and its fibroin solution is explored for osteogenic potential. Scaffolds were physico-chemically characterized for morphology, porosity, secondary structure conformation, water retention ability, biodegradability and mechanical property...
October 26, 2016: ACS Applied Materials & Interfaces
Soo Hyeon Lim, Eun-Young Ahn, Youmie Park
Gold nanoparticles were synthesized using a water extract of Artemisia capillaris (AC-AuNPs) under different extract concentrations, and their catalytic activity was evaluated in a 4-nitrophenol reduction reaction in the presence of sodium borohydride. The AC-AuNPs showed violet or wine colors with characteristic surface plasmon resonance bands at 534~543 nm that were dependent on the extract concentration. Spherical nanoparticles with an average size of 16.88 ± 5.47~29.93 ± 9.80 nm were observed by transmission electron microscopy...
December 2016: Nanoscale Research Letters
Doocheon Seo, Jaehong Oh, Changno Lee, Donghan Lee, Haejin Choi
Kompsat-3A, which was launched on 25 March 2015, is a sister spacecraft of the Kompsat-3 developed by the Korea Aerospace Research Institute (KARI). Kompsat-3A's AEISS-A (Advanced Electronic Image Scanning System-A) camera is similar to Kompsat-3's AEISS but it was designed to provide PAN (Panchromatic) resolution of 0.55 m, MS (multispectral) resolution of 2.20 m, and TIR (thermal infrared) at 5.5 m resolution. In this paper we present the geometric calibration and validation work of Kompsat-3A that was completed last year...
October 24, 2016: Sensors
David Salido-Monzú, Francisco J Meca-Meca, Ernesto Martín-Gorostiza, José L Lázaro-Galilea
A wide range of measuring applications rely on phase estimation on sinusoidal signals. These systems, where the estimation is mainly implemented in the digital domain, can generally benefit from the use of undersampling to reduce the digitizer and subsequent digital processing requirements. This may be crucial when the application characteristics necessarily imply a simple and inexpensive sensor. However, practical limitations related to the phase stability of the band-pass filter prior digitization establish restrictions to the reduction of noise bandwidth...
October 24, 2016: Sensors
Joseph T Brice, Tao Liang, Paul L Raston, Anne B McCoy, Gary E Douberly
Sequential capture of OH and CO by superfluid helium droplets leads exclusively to the formation of the linear, entrance-channel complex, OH-CO. This species is characterized by infrared laser Stark and Zeeman spectroscopy via measurements of the fundamental OH stretching vibration. Experimental dipole moments are in disagreement with ab initio calculations at the equilibrium geometry, indicating large-amplitude motion on the ground state potential energy surface. Vibrational averaging along the hydroxyl bending coordinate recovers 80% of the observed deviation from the equilibrium dipole moment...
September 28, 2016: Journal of Chemical Physics
S Dalbouha, M L Senent, N Komiha, R Domínguez-Gómez
Various astrophysical relevant molecules obeying the empirical formula C2H3NO are characterized using explicitly correlated coupled cluster methods (CCSD(T)-F12). Rotational and rovibrational parameters are provided for four isomers: methyl isocyanate (CH3NCO), methyl cyanate (CH3OCN), methyl fulminate (CH3ONC), and acetonitrile N-oxide (CH3CNO). A CH3CON transition state is inspected. A variational procedure is employed to explore the far infrared region because some species present non-rigidity. Second order perturbation theory is used for the determination of anharmonic frequencies, rovibrational constants, and to predict Fermi resonances...
September 28, 2016: Journal of Chemical Physics
D Möncke, E I Kamitsos, D Palles, R Limbach, A Winterstein-Beckmann, T Honma, Z Yao, T Rouxel, L Wondraczek
A series of transition and post-transition metal ion (Mn, Cu, Zn, Pb, Bi) binary borate glasses was studied with special consideration of the cations impact on the borate structure, the cations cross-linking capacity, and more generally, structure-property correlations. Infrared (IR) and Raman spectroscopies were used for the structural characterization. These complementary techniques are sensitive to the short-range order as in the differentiation of tetrahedral and trigonal borate units or regarding the number of non-bridging oxygen ions per unit...
September 28, 2016: Journal of Chemical Physics
Joseph A Korn, Daniel P Tabor, Edwin L Sibert, Timothy S Zwier
An important initial step in the combustion of gasoline and diesel fuels is the abstraction of hydrogen from alkylbenzenes to form resonance-stabilized alkyl benzyl radicals. This work uses, for the first time, double resonance spectroscopy methods to explore the conformation-specific vibronic and infrared spectroscopy of the α-ethylbenzyl (αEtBz) and α-propylbenzyl (αPrBz) radicals. Local mode Hamiltonian modeling enables assignment of the alkyl CH stretch IR spectra, accounting for Fermi resonance that complicates aliphatic alkyl CH stretch IR spectroscopy...
September 28, 2016: Journal of Chemical Physics
John C Pearson, Shanshan Yu, Olivier Pirali
The vibrational spectrum of ammonia has received an enormous amount of attention due to its potential prevalence in hot exo-planet atmospheres and persistent challenges in assigning and modeling highly excited and often highly perturbed states. Effective Hamiltonian models face challenges due to strong coupling between the large amplitude inversion and the other small amplitude vibrations. To date, only the ground and ν2 positions could be modeled to experimental accuracy using effective Hamiltonians. Several previous attempts to analyze the 2ν2 and ν4 energy levels failed to model both the microwave and infrared transitions to experimental accuracy...
September 28, 2016: Journal of Chemical Physics
Sylvestre Twagirayezu, Gregory E Hall, Trevor J Sears
Sub-Doppler, saturation dip, spectra of lines in the v1 + v3, v1 + 2v4, and v3 + 2v4 bands of (14)NH3 have been measured by frequency comb-referenced diode laser absorption spectroscopy. The observed spectral line widths are dominated by transit time broadening and show resolved or partially-resolved hyperfine splittings that are primarily determined by the (14)N quadrupole coupling. Modeling of the observed line shapes based on the known hyperfine level structure of the ground state of the molecule shows that, in nearly all cases, the excited state level has hyperfine splittings similar to the same rotational level in the ground state...
October 14, 2016: Journal of Chemical Physics
Fengyan Wang, Kopin Liu
When a CHD3 molecule is pumped to the C-H stretching-excited state by absorbing a linearly polarized infrared (IR) photon via the R(0) branch of the v1 = 1←0 transition, the rotational angular momentum j of the prepared state jK=10 preferentially lies in a plane perpendicular to the IR polarization axis εIR. By way of contrast, when the Q(1) branch is used, the state of jK=1±1 is prepared with j aligned along the direction of εIR. Reported here is a detailed study of the title reaction by actively controlling the collision geometries under these two IR-excitation schemes at collision energy Ec = 8...
October 14, 2016: Journal of Chemical Physics
Daria Galimberti, Alberto Milani, Lorenzo Maschio, Chiara Castiglioni
Density functional theory calculations with periodic boundary conditions are exploited to study the infrared spectrum of crystalline polyethylene. Spectral changes lead by the intermolecular packing in the orthorhombic three-dimensional crystal are discussed by means of a careful comparison with calculations carried out for an isolated polymer chain in the all-trans conformation, described as an ideal one-dimensional crystal. The results are analyzed in the framework of the "oligomer approach" through the modelling of the IR spectrum of n-alkanes of different lengths...
October 14, 2016: Journal of Chemical Physics
Yi-Ying Wang, Chao-Yu Chung, Yuan-Pern Lee
Criegee intermediates are carbonyl oxides that play critical roles in the ozonolysis of alkenes in the atmosphere. So far, the infrared spectra of only the simplest Criegee intermediates CH2OO and CH3CHOO are reported. We report the transient infrared spectrum of the next member (CH3)2COO, produced from ultraviolet irradiation of a mixture of (CH3)2CI2 + O2 in a flow reactor and detected with a step-scan Fourier-transform spectrometer. The four observed bands near 1424, 1368, 1040, and 887.4 cm(-1) provide definitive identification of (CH3)2COO...
October 21, 2016: Journal of Chemical Physics
Joel D Leger, Clyde Varner, Igor V Rubtsov
Fifth-order multidimensional infrared spectroscopy with heterodyned detection was carried out in the three-beam dual-frequency configuration. Numerous 5th-order cross peaks were detected for the 4-azidobutyrate-N-hydroxysuccinimide ester compound in solution involving several vibrational modes ranging in frequency from 1045 to 2100 cm(-1). Cross peaks involving overtones (2X/Z) and combination bands (XY/Z) among the tags, modes X and Y excited by the first two mid-IR laser pulses, and the reporter, modes Z excited by the third laser pulse, were acquired and the factors affecting the amplitude of 5th-order cross peaks are discussed...
October 21, 2016: Journal of Chemical Physics
Rajib Biswas, William Carpenter, Gregory A Voth, Andrei Tokmakoff
Infrared (IR) spectroscopy of the water O-H stretch has been widely used to probe both the local hydrogen-bonding structure and dynamics of aqueous systems. Although of significant interest, the IR spectroscopy of excess protons in water remains difficult to assign as a result of extensive and strong intermolecular interactions in hydrated proton complexes. As an alternate approach, we develop a mixed quantum-classical model for the vibrational spectroscopy of the excess proton in isotopically dilute water that draws on frozen proton-water clusters taken from reactive molecular dynamics trajectories of the latest generation multi-state empirical valence bond proton model (MS-EVB 3...
October 21, 2016: Journal of Chemical Physics
Lei Liu, Cui-E Hu, Mei Tang, Xiang-Rong Chen, Ling-Cang Cai
The low-lying isomers of cationic water cluster (H2O)6(+) have been globally explored by using particle swarm optimization algorithm in conjunction with quantum chemical calculations. Compared with previous results, our searching method covers a wide range of structural isomers of (H2O)6(+) and therefore turns out to be more effective. With these local minima, geometry optimization and vibrational analysis are performed for the most interesting clusters at second-order Møller-Plesset (MP2)/aug-cc-pVDZ level, and their energies are further refined at MP2/aug-cc-pVTZ and coupled-cluster theory with single, double, and perturbative triple excitations/aug-cc-pVDZ level...
October 21, 2016: Journal of Chemical Physics
Ching-Yin Chou, Yuan-Pern Lee
The addition reactions of chlorine atom with isobutene (i-C4H8) in solid para-hydrogen (p-H2) were investigated with infrared (IR) absorption spectra. When a p-H2 matrix containing Cl2 and isobutene was irradiated with ultraviolet light at 365 nm, intense lines in a set at 534.5, 1001.0, 1212.9, 1366.0, 2961.6, and 2934.7 cm(-1), and several weaker others due to the 1-chloro-2-methyl-2-propyl radical, (⋅)C(CH3)2CH2Cl, and those in a second set including intense ones at 642.7, 799.2, 1098.2, 1371.8, and 3027...
October 7, 2016: Journal of Chemical Physics
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