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Results 201 - 250 of 1666
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Reva Igor - - 2012
Spontaneous and near-infrared∕infrared (NIR∕IR)-induced interconversions between two amino-hydroxy conformers of monomeric cytosine have been investigated for the compound isolated in a low-temperature argon matrix. Combined use of a laser source (which provides narrowband NIR radiation) and a broadband NIR/IR source of excitation light allowed a detailed investigation of mutual conversions ...
Miao Meng - - 2012
Using first-principles calculations we have studied the reactions of water over Ti adatoms on the (110) surface of rutile TiO(2). Our results provide fundamental insights into the microscopic mechanisms that drive this reaction at the atomic level and assess the possibility of using this system to activate the water dissociation ...
Dudowicz Jacek - - 2012
The lattice cluster theory for solutions of telechelic polymer chains, developed in paper I, is applied to determine the enthalpy Δh(p) and entropy Δs(p) of self-assembly of linear telechelics and to evaluate the Flory-Huggins (FH) interaction parameter χ governing the phase behavior of these systems. Particular focus is placed on ...
Napolitano José G - - 2012
Botanical dietary supplements and herbal remedies are widely used for health promotion and disease prevention. Due to the high chemical complexity of these natural products, it is essential to develop new analytical strategies to guarantee their quality and consistency. In particular, the precise characterization of multiple botanical markers remains a ...
Huang Jing - - 2012
We investigate the spin transport properties of iron-phthalocyanine (FePc) molecule sandwiched between two N-doped graphene nanoribbons (GNRs) based on the density functional theory and nonequilibrium Green's function methods. Our calculated results clearly reveal that the FePc molecular junction has high spin-filter efficiency as well as negative differential resistance (NDR). The ...
Dong Shang-Wen SW Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin 300052, - - 2012
To investigate the promoter region methylation status of retinoblastoma protein-interacting zinc finger gene 1 (RIZ1) in the human esophageal squamous cell carcinoma (ESCC) cell lines and tissues and verify the relationship between methylation of RIZ1 and oncogenesis, tumor progression and metastasis etc of ESCC. Methylation-specific polymerase chain reaction (MSP) was ...
Santosh Mogurampelly - - 2012
In an effort to design efficient platform for siRNA delivery, we combine all atom classical and quantum simulations to study the binding of small interfering RNA (siRNA) by pristine single wall carbon nanotube (SWCNT). Our results show that siRNA strongly binds to SWCNT surface via unzipping its base-pairs and the ...
Morriss-Andrews Alex - - 2012
Mechanisms of peptide aggregation on hydrophobic surfaces are explored using molecular dynamics simulations with a coarse-grained peptide representation. Systems of peptides are studied with varying degrees of backbone rigidity (a measure of β-sheet propensity) and degrees of attraction between their hydrophobic residues and the surface. Multiple pathways for aggregation are ...
Koyama Takehito - - 2012
Depolarized light scattering is widely used to probe the spatial correlation of optical anisotropy in crystals, liquid crystals, and viscoelastic materials under stress, and a powerful means to study a non-equilibrium pattern evolution process of such a system. To follow the temporal change in the diagonal and off-diagonal contributions of ...
Hartkamp Remco - - 2012
The transient-time correlation function (TTCF) method is used to calculate the nonlinear response of a homogeneous atomic fluid close to equilibrium. The TTCF response of the pressure tensor subjected to a time-independent planar mixed flow of shear and elongation is compared to directly averaged non-equilibrium molecular dynamics (NEMD) simulations. We ...
Silva Rui Almeida RA Department of Gastroenterology, Instituto Português de Oncologia do Porto Francisco Gentil, R. Doutor António Bernardino de Almeida 4200-072, Porto, Portugal. - - 2012
To describe a modified technique for placement of a tracheobronchial self-expanding plastic stent (SEPS) in patients with benign refractory hypopharyngeal strictures in order to improve dysphagia and allow stricture remodeling. A case series of four consecutive patients with complex hypopharyngeal strictures after combined therapy for laryngeal cancer, previously submitted to ...
Eilam Asaf - - 2012
We propose a method based on the electromagnetically induced transparency (EIT) phenomenon for the detection of molecules which exist as a small minority in the presence of a majority of absorbers. The EIT effect we employ effectively eliminates the absorption of the majority species in the spectral region where it ...
Alexander Andrew J - - 2012
A protocol has been developed for production of intense crystalloluminescence (XTL) from sodium chloride in aqueous solution by selective doping with transition metal salts (Ag(+), Cu(2+), and Dy(3+)). The method was used to record complete, fully dispersed deep UV-visible (200-650 nm) XTL spectra of sodium chloride for the first time. ...
Stephens Susanna L - - 2012
Pure rotational spectra of the ground vibrational states of six isotopologues of OC⋅⋅⋅AgI have been measured by chirped-pulse Fourier transform microwave spectroscopy. The spectra are assigned to determine the rotational constant, B(0), centrifugal distortion constant, D(J), and nuclear quadrupole coupling constant of the iodine atom, χ(aa)(I). The complex is linear. ...
Calandra Pietro - - 2012
This work focuses on the dynamic phenomena emerging in self-assembled transient intermolecular networks formed when two different surfactants are mixed. In particular, the relaxation processes in liquid mixtures composed by bis(2-ethylhexyl)amine (BEEA) and octanoic acid (OA) in the whole composition range has been investigated by dielectric spectroscopy and Brillouin spectroscopy. ...
Ezzat Tarek T HPB and Liver Transplantation Surgery, Royal Free Hospital, University College London, London NW3 2PF, - - 2012
To investigate a dual labeling technique, which would enable real-time monitoring of transplanted embryonic stem cell (ESC) kinetics, as well as long-term tracking. Liver damage was induced in C57/BL6 male mice (n = 40) by acetaminophen (APAP) 300 mg/kg administered intraperitoneally. Green fluorescence protein (GFP) positive C57/BL6 mouse ESCs were ...
Thilagam A - - 2012
The non-Hermitian quantum dynamics of excitonic energy transfer in photosynthetic systems is investigated using a dissipative two-level dimer model. The approach is based on Green's function formalism which permits consideration of decoherence and intersite transfer processes on comparable terms. The results indicate a combination of coherent and incoherent behavior at ...
Kuo Ying-Ju - - 2012
Prostate cancer has seen a rapid rise in Taiwanese men. The current study was undertaken to evaluate trends of the disease diagnosed on prostate needle biopsy during a ten-year period at the Department of Pathology, Taipei Veterans General Hospital. The study included 8236 men who underwent a total of 9995 ...
Vilar Jose M G - - 2012
Many important processes at the microscale require far-from-equilibrium conditions to occur, as in the functioning of mesoscopic bioreactors, nanoscopic rotors, and nanoscale mass conveyors. Achieving such conditions, however, is typically based on energy inputs that strongly affect the thermal properties of the environment and the controllability of the system itself. ...
Swiatla-Wojcik Dorota - - 2012
Flexible models of the radical and water molecules including short-range interaction of hydrogen atoms have been employed in molecular dynamic simulation to understand mechanism of (●)OH hydration in aqueous systems of technological importance. A key role of H-bond connectivity patterns of water molecules has been identified. The behavior of (●)OH(aq) ...
Coccolini Federico - - 2012
The difference between stages I and III of gastric gastrointestinal stromal tumor depends principally on the number of mitosis. According with TNM classification, the presence in the tumor of high mitotic rate determines the upgrading. Many studies exposed different count techniques in evaluating the number of mitosis. An international standardized ...
Huntington Lee M J - - 2012
We have recently introduced a parameterized coupled-cluster singles and doubles model (pCCSD(α, β)) that consists of a bivariate parameterization of the CCSD equations and is inspired by the coupled electron pair approximations. In our previous work, it was demonstrated that the pCCSD(-1, 1) method is an improvement over CCSD for ...
Shao Zhuo - - 2012
The energy levels of CH(3)Cl(+)X̃(2)E showing strong spin-vibronic coupling effect (Jahn-Teller effect) have been measured up to 3500 cm(-1) above the ground vibrational state using one-photon zero-kinetic energy photoelectron and mass-analyzed threshold ionization spectroscopic method. Theoretical calculations have been also performed to calculate the spin-vibronic energy levels using a diabatic ...
Huggins David J - - 2012
Water is one of the simplest molecules in existence, but also one of the most important in biological and engineered systems. However, understanding the structure and dynamics of liquid water remains a major scientific challenge. Molecular dynamics simulations of liquid water were performed using the water models TIP3P-Ewald, TIP4P-2005, TIP5P-Ewald, ...
Wang Ying-Ping YP Department of Physiology, Shanghai Jiaotong University School of Medicine, Shanghai 200025, - - 2012
To assess the role of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels in regulating the excitability of vagal and spinal gut afferents. The mechanosensory response of mesenteric afferent activity was measured in an ex vivo murine jejunum preparation. HCN channel activity was recorded through voltage and current clamp in acutely dissociated ...
Andreussi Oliviero - - 2012
The solvation model proposed by Fattebert and Gygi [J. Comput. Chem. 23, 662 (2002)] and Scherlis et al. [J. Chem. Phys. 124, 074103 (2006)] is reformulated, overcoming some of the numerical limitations encountered and extending its range of applicability. We first recast the problem in terms of induced polarization charges ...
Iuchi Satoru - - 2012
A simple model electronic Hamiltonian to describe the potential energy surfaces of several low-lying d-d states of the [Fe(bpy)(3)](2+) complex is developed for use in molecular dynamics (MD) simulation studies. On the basis of a method proposed previously for first-row transition metal ions in aqueous solution, the model Hamiltonian is ...
Hao Xiao-Wen XW Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, 10050 Beijing, - - 2012
To investigate the expression and methylation status of the secreted frizzled-related protein 2 (SFRP2) in esophageal squamous cell carcinoma (ESCC) and explore its role in ESCC carcinogenesis. Seven ESCC cell lines (KYSE 30, KYSE150, KYSE410, KYSE510, EC109, EC9706 and TE-1) and one immortalized human esophageal epithelial cell line (Het-1A), 20 ...
Edmonds Christopher M - - 2012
We investigate unforced and forced translocation of a Rouse polymer (in the absence of hydrodynamic interactions) through a silicon nitride nanopore by three-dimensional Langevin dynamics simulations, as a function of pore dimensions and applied voltage. Our nanopore model consists of an atomistically detailed nanopore constructed using the crystal structure of ...
Tonge Nicola M - - 2012
We report the first spectroscopic study of a complex consisting of a rare earth atom in combination with ammonia. Using two-color resonance-enhanced multiphoton ionization (REMPI) spectroscopy, the lowest energy electronic transition of YbNH(3) has been found in the near-infrared. The spectrum arises from a spin-forbidden transition between the (1)A(1) ground ...
Shin Hyeondeok - - 2012
Path-integral Monte Carlo calculations have been performed to study (4)He adsorption on a single C(60) molecule. Helium corrugations on the fullerene molecular surface are incorporated with the (4)He-C(60) interaction described by the sum of all (4)He-C interatomic pair potentials. Radial density distributions show a layer-by-layer growth of (4)He with the ...
Frenette Catherine C California Pacific Medical Center, San Francisco, CA 94115, USA. - - 2012
Hepatocellular carcinoma (HCC) is a lethal disease in most patients, due to its aggressive course and a lack of effective systemic therapies for advanced disease. Surgical resection and liver transplantation remain the only curative options for a small subset of patients. Few patients with HCC are diagnosed early enough to ...
Friedrich R - - 2012
The effects of electronic states and air exposure on the spectroscopic properties of manganese phthalocyanine (MnPc) have been examined. The observed features of the Q-band in the absorption spectra can be explained by intrinsic electronic properties of MnPc, i.e., the formation of singly charged molecules by charge transfer excitations. However, ...
Kim Hyung Hun HH Department of Internal Medicine, Seoul Paik Hospital, Inje University College of Medicine, Seoul 100-032, South - - 2012
To investigate the expressions of leptin and peroxisome proliferator-activated receptor γ (PPARG) in relation to body mass index (BMI). We evaluated leptin and PPARG expression in 30 adenomas over 1 cm in size by immunohistochemical staining. In addition, clinicopathologic features including BMI were assessed. PPARG and leptin expression showed a ...
Dudowicz Jacek - - 2012
The lattice cluster theory (LCT) for the thermodynamics of a wide array of polymer systems has been developed by using an analogy to Mayer's virial expansions for non-ideal gases. However, the high-temperature expansion inherent to the LCT has heretofore precluded its application to systems exhibiting strong, specific "sticky" interactions. The ...
Dash L K - - 2012
We analyze how functionality could be obtained within single-molecule devices by using a combination of non-equilibrium Green's functions and ab initio calculations to study the inelastic transport properties of single-molecule junctions. First, we apply a full non-equilibrium Green's function technique to a model system with electron-vibration coupling. We show that ...
Birzniece I - - 2012
The diode laser induced B(1)(1)Π → X(1)Σ(+) fluorescence spectra of the KCs molecule were recorded by Fourier-transform spectrometer with resolution of 0.03 cm(-1). Buffer gas Ar was used to facilitate appearance of rotation relaxation lines in the spectra, thus enlarging the B(1)(1)Π dataset, allowing one to determine the Λ-splitting constants ...
Cajahuaringa Samuel - - 2012
We use molecular simulation to analyze liquid dynamics in the vicinity of the liquid-liquid phase transition (LLPT) recently discovered in the modified embedded-atom model for elemental gallium. For this purpose we analyze the diffusive behavior in terms of the mean-squared displacement and self-intermediate scattering functions for two systems obtained by ...
Chavalitdhamrong Disaya - - 2012
Endoscopic ultrasound (EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde cholangiopancreatography (ERCP). EUS-guided biliary drainage has become feasible due to the development of large channel curvilinear therapeutic echo-endoscopes and the use of real-time ...
Jaeger Heather M - - 2012
Multi-exciton generation (MEG), the creation of more than one electron-hole pair per photon absorbed, occurs for excitation energies greater than twice the bandgap (E(g)). Imperfections on the surface of quantum dots, in the form of atomic vacancies or incomplete surface passivation, lead to less than ideal efficiencies for MEG in ...
Groot Robert D - - 2012
Long-range hydrodynamics between colloidal particles or fibers is modelled by the fluid particle model. Two methods are considered to impose the fluid boundary conditions at colloidal surfaces. In the first method radial and transverse friction forces between particle and solvent are applied such that the correct friction and torque follows ...
Niu Kai - - 2012
The third-order polarization for coherent anti-Stokes Raman scattering (CARS) from a pure state is described by 48 terms in perturbation theory, but only 4 terms satisfy the rotating wave approximation. They are represented by Feynman dual time-line diagrams and four-wave mixing energy level diagrams. In time-resolved (tr) fs and fs/ps ...
Bruni F - - 2012
By combining neutron diffraction and Monte Carlo simulations, we have determined the microscopic structure of the hydration ions shell in aqueous solutions of MgCl(2) and CaCl(2), along with the radial distribution functions of the solvent. In particular the hydration shell of the cations, show cation specific symmetry, due to the ...
Kawata Isao - - 2012
A new method for analyzing and visualizing the molecular excited states, named "excited state paired interacting orbital (EPIO)," is proposed. The method is based both on the paired interacting orbital (PIO) proposed by Fujimoto and Fukui [J. Chem. Phys. 60, 572 (1974)] and the natural transition orbital (NTO) by Martin ...
Li Huashan - - 2012
Transition state analyses have been carried out within a density functional theory setting to explain and quantify the distinctly different ways in which hydrogen and methyl terminations serve to protect silicon surfaces from the earliest onset of oxidation. We find that oxidation occurs via direct dissociative adsorption, without any energy ...
Gong Yan Y Department of Gastroenterology and Hepatology, Chinese PLA General Hospital, Beijing 100853, - - 2012
To explore the potential risk factors related to gastrointestinal cancer in northern China. A total of 3314 cases of gastrointestinal cancer (esophageal, gastric, pancreatic and biliary) and 2223 controls (including healthy individuals, glioma and thyroid cancer) were analyzed by case-control study. Multivariable logistic regression analysis was applied to evaluate the ...
Raghunathan Shampa - - 2012
Explicitly time-dependent density functional theory (TDDFT) is a formally exact theory, which can treat very large systems. However, in practice it is used almost exclusively in the adiabatic approximation and with standard ground state functionals. Therefore, if combined with coherent control theory, it is not clear which control tasks can ...
Miura Tsuyoshi - - 2012
A fluorous organocatalyst promotes direct asymmetric aldol reactions of aromatic aldehydes with ketones in brine to afford the corresponding anti-aldol products in high yield with up to 96% ee. Fluorous organocatalyst can be readily recovered by solid phase extraction using fluorous silica gel and reused without purification.
Knippenberg S - - 2012
An earlier proposed approach to molecular response functions based on the intermediate state representation (ISR) of polarization propagator and algebraic-diagrammatic construction (ADC) approximations is for the first time employed for calculations of nonlinear response properties. The two-photon absorption (TPA) spectra are considered. The hierarchy of the first- and second-order ADC∕ISR ...
Köck Matthias M Alfred-Wegener-Institut für Polar- und Meeresforschung in der Helmholtz-Gemeinschaft, Am Handelshafen 12, D-27570 Bremerhaven, Germany. - - 2012
The structure elucidation of the palau'amine congener tetrabromostyloguanidine (1), which used interproton distances from ROESY spectra as restraints in a computational approach, the so-called fc-rDG/DDD method, led to a revision of the relative configuration of palau'amine (2) and its congeners in 2007. The recent total synthesis of (±)-palau'amine (2) subsequently ...
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