Monitoring the Evolution of Asynchrony between Mean Arterial Pressure and Mean Cerebral Blood Flow via Cross-Entropy Methods

Cerebrovascular control is carried out by multiple nonlinear mechanisms imposing a certain degree of coupling between mean arterial pressure (MAP) and mean cerebral blood flow (MCBF). We explored the ability of two nonlinear tools in the information domain, namely cross-approximate entropy (CApEn) and cross-sample entropy (CSampEn), to assess the degree of asynchrony between the spontaneous fluctuations of MAP and MCBF. CApEn and CSampEn were computed as a function of the translation time. The analysis was carried out in 23 subjects undergoing recordings at rest in supine position (REST) and during active standing (STAND), before and after surgical aortic valve replacement (SAVR). We found that at REST the degree of asynchrony raised, and the rate of increase in asynchrony with the translation time decreased after SAVR. These results are likely the consequence of the limited variability of MAP observed after surgery at REST, more than the consequence of a modified cerebrovascular control, given that the observed differences disappeared during STAND. CApEn and CSampEn can be utilized fruitfully in the context of the evaluation of cerebrovascular control via the noninvasive acquisition of the spontaneous MAP and MCBF variability.     

Homogeneous films by inverse pulsed laser deposition

Recently, we proposed an alternative arrangement to traditional on- or off-axis PLD geometries, termed inverse PLD (IPLD) that is capable of producing films of improved surface morphology. Two configurations of this new target-substrate arrangement were developed, namely static and co-rotating IPLD. In the static IPLD configuration, the substrate is stationary with respect to the ablated spot; while in the co-rotating IPLD configuration the substrate is fixed to the target surface and rotates simultaneously with the target, hence offering an appealingly simple approach to homogenize film properties.Here we report the growth of CN_x and Ti films, simultaneously deposited in the co-rotating and static IPLD arrangements. The homogeneity of the co-rotating films is described by a thickness inhomogeneity index, which allows for the comparison of films of different lateral dimension. A semi-analytical, semi-numerical model is proposed to derive the radial variation of the growth rate of co-rotating IPLD films from the lateral growth rate distributions measured along the symmetry axes of static IPLD films. The laterally averaged growth rate, LAGR is used to describe how the ambient pressure affects growth in the 0.5-50 Pa domain. As an example, the absolute error between the measured and calculated radial growth rate variation, obtained at 5 Pa, was less than 3%, while the LAGR of CN_x layers grown by co-rotating IPLD was predicted with 20% accuracy.     

First CNGS events detected by LVD

The CERN Neutrino to Gran Sasso (CNGS) project aims to produce a high energy, wide band ν_μ beam at CERN and send it toward the INFN Gran Sasso National Laboratory (LNGS), 732 km away. Its main goal is the observation of the ν_τ appearance, through neutrino flavour oscillation. The beam started its operation in August 2006 for about 12 days: a total amount of 7.6×10¹⁷ protons were delivered to the target. The LVD detector, installed in hall A of the LNGS and mainly dedicated to the study of supernova neutrinos, was fully operating during the whole CNGS running time. A total number of 569 events were detected in coincidence with the beam spill time. This is in good agreement with the expected number of events from Monte Carlo simulations. PACS 14.60.Pq; 29.27.Fh; 29.40.Mc; 95.55.Vj     

The Luttinger sum rule in the slave-particle theories

The usual mean field decoupling procedure applied to the slave-particle representations of the problems with strong local interaction produces a resonant band, but violates the Luttinger sum rule for the physical single-electron propagator. The number of occupied resonant states is small and equal to the deviation from the sum rule, shedding doubt on the overall results. It is therefore argued and illustrated on the example of the Emery model for the high-T _c superconductors that, through the consistent application of the mean field procedure to the Hamiltonian and the propagators, the sum rule is restored and the resonant band conserved. In addition to the resonant band, the electron spectrum contains large number of occupied states close to the bare site-energy of the site with strong repulsion. These results are also related here to the other similar decoupling problems, which also lead to the breakdown of the Luttinger sum rule.Received: 2 July 2003, Published online: 9 September 2003PACS: 71.10.Fd Lattice fermion models (Hubbard model, etc.) - 71.27.+a Strongly correlated electron systems; heavy fermions     

Biological significance of essential oil of Zataria multiflora boiss

The absolute from Zataria multiflora was explored for enzyme inhibition, insect repellent, and insecticidal activities. GC-MS of the absolute of fresh plant showed that thymol is the major constituent while carvacrol is the major constituent in the absolute of dried plant.     

Contact value relations and density functional theory for the electrical double layer

The recently developed contact-corrected density functional theory is applied to an electric double layer containing a valence and size symmetric electrolyte. The restricted primitive model is used to describe the electrolyte, and a non-polarisable, smooth, planar, uniformly charged hard surface is used to model the electrode. Comparison with Monte Carlo simulation results for this system shows that the theory satisfies the first contact value relation in line with the premise of the approach. Additionally, the theory is found to satisfy the semi-empirical second contact value relation quite closely. This is a welcome result, since no reference is made to this second relation nor is the relation used in the theoretical development. The second contact relation is closely related to the anomalous positive temperature derivative of the double layer capacitance at low temperature, low ion concentration, and low electrode charge, and indeed, the contact-corrected density functional theory predicts this effect.     

Dielectric and thermal effects on the optical properties of natural dyes: a case study on solvated cyanin

The optical properties of the flavylium state of the cyanin dye are simulated numerically by combining Car-Parrinello molecular dynamics and linear-response time-dependent density functional theory calculations. The spectrum of the dye calculated in the gas phase is characterized by two peaks in the yellow and in the blue (green and violet), using a GGA-PBE (hybrid-B3LYP) DFT functional, which would bring about a greenish (bright orange) color incompatible with the dark purple hue observed in nature. Describing the effect of the water solvent through a polarizable continuum model does not modify qualitatively the resulting picture. An explicit simulation of both solvent and thermal effects using ab initio molecular dynamics results instead in a spectrum that is compatible with the observed coloration. This result is analyzed in terms of the spectroscopic effects of the molecular distortions induced by thermal fluctuations.     

High‐refractive‐index and high‐barrier‐capable epoxy‐phenoxy‐based barrier film for organic electronics

A barrier film is a fundamental component of the fast growing organic electronic device industry that is necessary to sustain long‐term stability. The barrier film prevents the permeation of environmental moisture and oxygen into the organic electronic device. Superior barrier property is the most crucial characteristic of a barrier film, in addition to a high refractive index. A high‐refractive‐index barrier film has the potential to reduce the refractive‐index mismatch between a device and a protective film, consequently, reducing the energy costs by increasing the light output. In this work, six epoxy and phenoxy resin composite compositions are synthesized separately, each with a different cross‐linker. POL‐TE1/PET and POL‐HD1/PET films show enhanced refractive indexes of 1.726 (at 750 nm) and 1.721 (at 500 nm), allowing only 71.7% and 70.4% permeation, respectively, compared to those of POL/PET, while exhibiting more than 80% transparency and excellent properties. The films are fabricated using a straightforward process, from a solution, at low temperature and under atmospheric conditions, using an applicator and bar coating.     

Acceleration of decomposition of CL-20 explosive under nanoconfinement

Journal of Thermal Analysis and Calorimetry - The thermal properties of CL-20 explosive in the bulk and confined in controlled pore glass matrices to nanoscale dimensions were studied using dynamic...     

Thiophene based europium β-diketonate complexes: effect of the ligand structure on the emission quantum yield

The synthesis and the molecular and photophysical characterization, together with solid state and solution structure analysis, of a series of europium complexes based on β-diketonate ligands are reported. The Eu(III) complex emission, specifically its photoluminescence quantum yield (PL-QY), can be tuned by changing ligands which finely modifies the environment of the metal ion. Steady-state and time-resolved emission spectroscopy and overall PL-QY measurements are reported and related to geometrical features observed in crystal structures of some selected compounds. Moreover, paramagnetic NMR, based on the analogous complexes with other lanthanides, are use to demonstrate that there is a significant structural reorganization upon dissolution, which justifies the observed differences in the emission properties between solid and solution states. The energy of the triplet levels of the ligands and the occurrence of nonradiative deactivation processes clearly account for the luminescence efficiencies of the complexes in the series.