bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low Endogenous G-Protein-Coupled Receptor Kinase 2 Sensitizes the Immature Brain to Hypoxia–Ischemia-Induced Gray and White Matter Damage
Authors: Nijboer Cora H. A. , Kavelaars Annemieke , Vroon Anne , Groenendaal Floris , van Bel Frank , Heijnen Cobi J. 
Published: March 2008

Hypoxic–ischemic brain injury is regulated in part by neurotransmitter and chemokine signaling via G-protein-coupled receptors (GPCRs). GPCR-kinase 2 (GRK2) protects these receptors against overstimulation by inducing desensitization. Neonatal hypoxic–ischemic brain damage is preceded by a reduction in cerebral GRK2 expression. We determined the functional importance of GRK2 in hypoxic–ischemic brain damage.Nine-day-old wild-type and GRK2+/−mice with a ∼50% reduction in GRK2 protein were exposed to unilateral carotid artery occlusion and hypoxia. In GRK2+/−animals, gray and white matter damage was aggravated at 3 weeks after hypoxia–ischemia. In addition, cerebral neutrophil infiltration was increased in GRK2+/−animals. Neutrophil depletion reduced brain damage, but neuronal loss was still more pronounced in GRK2+/−animals. Onset of neuronal loss was advanced in GRK2+/−animals regardless of neutrophil depletion. White matter injury was advanced in GRK2+/−animals and was not affected by neutrophil depletion. Activation/infiltration of microglia/macrophages was stronger in GRK2+/−brains but only occurred 24 h after hypoxia–ischemia and is therefore not the primary cause of increased damage. During hypoxia, cerebral blood flow was reduced to the same extent in both genotypes.In vitro, GRK2+/−hippocampal slices and cerebellar granular neurons were more sensitive to glutamate-induced death.We propose the novel concept that the kinase GRK2 regulates onset and magnitude of hypoxic–ischemic brain damage. Increased gray and white matter damage in GRK2+/−animals was not dependent on infiltrating neutrophils and occurred before microglia/macrophage activation was detected. Collectively, our data suggest that cerebral GRK2 has an important endogenous neuroprotective role in ischemic cerebral damage.
Comparison of Drug Adherence Rates Among Patients with Seven Different Medical Conditions
Authors: Briesacher Becky A. , Andrade Susan E. , Fouayzi Hassan , Chan K. Arnold 
Published: March 2008

Study Objective. To compare drug adherence rates among patients with gout, hypercholesterolemia, hypertension, hypothyroidism, osteoporosis, seizure disorders, and type 2 diabetes mellitus by using a standardized approach.Design. Longitudinal studyData Source. Health care claims data from 2001–2004.Patients. A total of 706,032 adults aged 18 years or older with at least one of the seven medical conditions and with incident use of drug therapy for that condition.Measurements and Main Results. Drug adherence was measured as the sum of the days' supply of drug therapy over the first year observed. Covariates were age, sex, geographic residence, type of health plan, and a comorbidity score calculated by using the Hierarchical Condition Categories risk adjuster. Bivariate statistics and stratification analyses were used to assess unadjusted means and frequency distributions. Sample sizes ranged from 4984 subjects for seizure disorders to 457,395 for hypertension. During the first year of drug therapy, 72.3% of individuals with hypertension achieved adherence rates of 80% or better compared with 68.4%, 65.4%, 60.8%, 54.6%, 51.2%, or 36.8% for those with hypothyroidism, type 2 diabetes, seizure disorders, hypercholesterolemia, osteoporosis, or gout, respectively. Age younger than 60 years was associated with lower adherence across all diseases except seizure disorders. Comorbidity burden and adherence varied by disease. As comorbidity increased, adherence among subjects with osteoporosis decreased, whereas adherence among those with hypertension, hypercholesterolemia, or gout increased. Add‐on drug therapies and previous experience with taking drugs for the condition increased adherence among subjects with hypertension, type 2 diabetes, hypothyroidism, or seizure disorders but not the other conditions.Conclusion. This uniform comparison of drug adherence revealed modest variation across six of seven diseases, with the outlier condition being gout.
Modeling polycyclic aromatic hydrocarbon bioaccumulation and metabolism in time-variable early life-stage exposures
Authors: Mathew Rooni , McGrath Joy A , Toro Dominic M. Di 
Published: March 2008

Abstract
Recent laboratory investigations into the bioaccumulation and toxicity of polycyclic aromatic hydrocarbons (PAH) have focused on low-level, time-variable exposures to early life-stage fish. Polycyclic aromatic hydrocarbon body-burden residues reported in these studies were lower than critical body-burden residues predicted by the target lipid model (TLM). To understand this discrepancy, a time-variable uptake and depuration model of PAH bioaccumulation was developed. Kinetic constants were fit using measured exposure and tissue concentrations. The resulting lipid-water partition coefficients (KLW) were uncorrelated with the octanol-water partition coefficient (Kow)—a qualitatively unrealistic finding considering that numerous studies have reported a positive correlation between the two. Because PAHs are known to be metabolized, the comparison of KLW with Kow suggests that metabolism may be occurring in early life-stage fish. Therefore, the uptake and depuration model was modified to include metabolism while assuming linearity of KLW with Kow. Calculated metabolism rates were positively correlated with Kow—a finding qualitatively similar to those of other studies. The present study provides a reasonable explanation for the discrepancy between the TLM predictions and the measured toxic effect levels. Given the time-variable exposure concentrations, the maximum measured body burdens used to relate to toxic effects may be underestimated. In addition, the maximum body burden of parent PAH plus metabolites may be a better measure in relating tissue concentrations to toxic effects. Incorporating these refinements in relating body burdens to toxic effects may result in a better comparison between TLM predictions and measured effect levels.
Quantitative structure-activity relationships for kinetic parameters of polycyclic aromatic hydrocarbon biotransformation
Authors: Dimitriou-Christidis Petros , Autenrieth Robin L , Abraham Michael H 
Published: March 2008

Abstract
Quantitative structure-activity relationships (QSARs) were developed for three Monod-type parameters—qmax, KS, and qmax/KS—that express the kinetics of polycyclic aromatic hydrocarbon (PAH) biotransformation by Sphingomonas paucimobilis strain EPA505. The training sets contained high-quality experimental values of the kinetic parameters for 20 unsubstituted and methylated PAHs as well as values of 41 meaningful molecular descriptors. A genetic function approximation algorithm was used to develop the QSARs. Statistical evaluation of the developed QSARs showed that the relationships are statistically significant and satisfy the assumptions of linear-regression analysis. The Organization for Economic Cooperation and Development principles for (Q)SAR validation were followed to evaluate the developed QSARs, which showed that the QSARs are valid. The QSARs contain spatial, spatial and electronic, topological, and thermodynamic molecular descriptors. Whereas spatial descriptors were essential in explaining biotransformation kinetics, electronic descriptors were not. Mechanistic interpretation of the QSARs resulted in evidence that is consistent with the hypothesis of membrane transport as being the rate-limiting process in PAH biotransformation by strain EPA505. The present study demonstrates the value of QSAR not only as a predictive tool but also as a framework for understanding the mechanisms governing biodegradation at the molecular level.
Impact of the lasr wavelength and fluence on the ablation rate of aluminium
Authors: Stafe Mihai , Vladoiu Ionut , Popescu Ion 
Published: March 2008

Abstract
The dependence of the ablation rate of aluminium on the fluence of nanosecond laser pulses with wavelengths of 532 nm and respectively 1064 nm is investigated in atmospheric air. The fluence of the pulses is varied by changing the diameter of the irradiated area at the target surface, and the wavelength is varied by using the fundamental and the second harmonic of a Q-switched Nd-YAG laser system. The results indicate an approximately logarithmic increase of the ablation rate with the fluence for ablation rates smaller than ∼6 μm/pulse at 532 nm, and 0.3 μm/pulse at 1064 nm wavelength. The significantly smaller ablation rate at 1064 nm is due to the small optical absorptivity, the strong oxidation of the aluminium target, and to the strong attenuation of the pulses into the plasma plume at this wavelength. A jump of the ablation rate is observed at the fluence threshold value, which is ∼50 J/cm2 for the second harmonic, and ∼15 J/cm2 for the fundamental pulses. Further increasing the fluence leads to a steep increase of the ablation rate at both wavelengths, the increase of the ablation rate being approximately exponential in the case of visible pulses. The jump of the ablation rate at the threshold fluence value is due to the transition from a normal vaporization regime to a phase explosion regime, and to the change of the dimensionality of the hydrodynamics of the plasma-plume.
New results in the use of a “reverse engineering” method in cosmologies with scalar field
Authors: Vulcanov Dumitru 
Published: March 2008

Abstract
The method of “reverse engineering” for designing potentials in cosmologies with “quintessence” scalar field is systematically used for several types of cosmologies (through the time behavior of the scale factor). The general recipe is introduced and then applied when matter other than the scalar field is present, and for tachyonic scalar fields. The possibility of using this method for prescribing initial data in numerical simulations in cosmology is investigated.
Exact and approximate statistical approaches for the exergy of blackbody radiation
Authors: Badescu Viorel 
Published: March 2008

Abstract
There is a long term debate in literature about the exergy of blackbody radiation (BBR). Most authors contributing to this dispute used classical thermodynamics arguments. The objective of this paper is to propose a statistical thermodynamics approach. This gives new perspectives to previous results. Four simple statistical microscopic models are used to derive BBR exergy. They consist of combinations of quantum and classical descriptions of the state occupation number and entropy, respectively. In all four cases the BBR exergy (or exergy flux density) is given by the internal energy (or energy flux density) times an efficiency-like factor containing the environment temperature and the blackbody radiation temperature. One shows that Petela-Landsberg-Press efficiency is the “exact” result while the Jeter (Carnot) efficiency corresponds to the classical approximation. Other two (new) approximate efficiency-like factors are also reported.
Determination of thin film refractive index and thickness by means of film phase thickness
Authors: Nenkov Milen , Pencheva Tamara 
Published: March 2008

Abstract
A new approach for determination of refractive index dispersion n(λ) (the real part of the complex refractive index) and thickness d of thin films of negligible absorption and weak dispersion is proposed. The calculation procedure is based on determination of the phase thickness of the film in the spectral region of measured transmittance data. All points of measured spectra are included in the calculations. Barium titanate thin films are investigated in the spectral region 0.38–0.78 μm and their n(λ) and d are calculated. The approach is validated using Swanepoel’s method and it is found to be applicable for relatively thin films when measured transmittance spectra have one minimum and one maximum only.
Ultraviolet detectors based on ZnO films by thermal oxidation of Zn metallic films
Authors: Zheng Xue , Li Qing 
Published: March 2008

Abstract
Metallic Zn films were deposited on glass substrates by electron-beam evaporation. ZnO films were synthesized by thermal oxidation of Zn metallic films in air. At the annealing temperature of 550 °C, ZnO nanowires appeared on the surface, which mainly result from the decrease of oxidation rate. A ZnO ultraviolet photodetector was fabricated based on a metal-semiconductor-metal planar structure. The detector showed a large UV photoresponse with an increase of two orders of magnitude. It is concluded that promising UV detectors can be obtained on ZnO films by thermal oxidation of Zn metallic films. The ways of performing spectral response measurements for polycrystalline ZnO films are also discussed.
Stochastic quantization method for spinning particles in a gravitational plane wave field
Authors: Lehtihet Zehoua , Chetouani Lyazid 
Published: March 2008

Abstract
The exact and analytic Green functions for spinning relativistic particles in interaction with a gravitational plane wave field are obtained within the Stochastic Quantization Method of Parisi and Wu. We have separated the classical calculations from those related to the quantum fluctuations. The problem has been solved by using a perturbative treatment via the Langevin equation relying on phase and configuration spaces formulation.
Coherent control for the spherical symmetric box potential in short and intensive XUV laser fields
Authors: Barna Imre , Dombi Péter 
Published: March 2008

Abstract
Coherent control calculations are presented for a spherically symmetric box potential for non-resonant two photon transition probabilities. With the help of a genetic algorithm (GA), the population of the excited states are maximized and minimized. The external driving field is a superposition of three intensive extreme ultraviolet (XUV) linearly polarized laser pulses with different frequencies in the femtosecond duration range. We solved the quantum mechanical problem within the dipole approximation. Our investigation clearly shows that the dynamics of the electron current has a strong correlation with the optimized and neutralizing pulse shape.
Superconducting state parameters of La100-C
GaC binary metallic glasses
Authors: Vora Aditya 
Published: March 2008

Abstract
The theoretical investigations of the superconducting state parameters (SSP) viz. electron-phonon coupling strength λ, Coulomb pseudopotential μ*, transition temperature T
C, isotope effect exponent α and effective interaction strength N
O
V of six binary La100-C
GaC (C = 16, 20, 22, 24, 26 and 28 at. %) metallic glasses have been reported using Ashcroft’s empty core (EMC) model potential for the first time. Five local field correction functions proposed by Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are used in the present investigation to study the screening influence on the aforesaid properties. It is observed that the electron-phonon coupling strength λ and the transition temperature T
C are quite sensitive to the selection of the local field correction functions, whereas the Coulomb pseudopotential μ*, isotope effect exponent α and effective interaction strength N
O
V show weak dependences on the local field correction functions. The T
C obtained from H-local field correction function are found in qualitative agreement with available experimental data and show almost linear nature with the concentration (C) of ‘Ga’ element. A linear T
C equation is proposed by fitting the present outcomes for H-local field correction function, which is in conformity with other results for the experimental data. Also, the present results are found to be in qualitative agreement with other such earlier reported data, which confirms the superconducting phase in the metallic glasses.
The uncertainty relation expressed by means of a new entropic function
Authors: Majerník Vladimir 
Published: March 2008

Abstract
In this article we use a new entropic function, derived from an f-divergence between two probability distributions, for the construction of an alternative entropic uncertainty relation. After a brief review of some existing f-divergences, a new f-divergence and the corresponding entropic function, derived from it, is introduced and its useful characteristics are presented. This entropic function is then applied to construct an alternative uncertainty relation of two non-commuting observables in quantum physics. An explicit expression for such an uncertainty relation is found for the case of two observables which are the x- and z-components of the angular momentum of the spin-1/2 system.
Entanglement conditions for four-mode states via the uncertainty relations in conjunction with partial transposition
Authors: Song Lijun , Wang Xiaoguang , Yan Dong , Li Yongda 
Published: March 2008

Abstract
From the Heisenberg uncertainty relation in conjunction with partial transposition, we derive a class of inequalities for detecting entanglements in four-mode states. The sufficient conditions for bipartite entangled states are presented. We also discuss the generalization of the entanglement conditions via the Schrödinger-Robertson indeterminacy relation, which are in general stronger than those based on the Heisenberg uncertainty relation.
Superconducting state parameters of binary metallic glasses
Authors: Vora Aditya 
Published: March 2008

Abstract
Ashcroft’s empty core (EMC) model potential is used to study the superconducting state parameters (SSPs) viz. electron-phonon coupling strength λ, Coulomb pseudopotential μ*, transition temperature T
C, isotope effect exponent αand effective interaction strength N
O
V of some binary metallic glasses based on the superconducting (S), conditional superconducting (S’) and non-superconducting (NS) elements of the periodic table. Five local field correction functions proposed by Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are used for the first time with EMC potential in the present investigation to study the screening influence on the aforesaid properties. The T
C obtained from the H-local field correction function are in excellent agreement with available theoretical or experimental data. In the present computation, the use of the pseudo-alloy-atom model (PAA) was proposed and found successful. Present work results are in qualitative agreement with such earlier reported experimental values which confirm the superconducting phase in all metallic glasses. A strong dependency of the SSPs of the metallic glasses on the valence ‘Z’ is identified.
Particle tunneling and scattering in a three-dimensional potential with a barrier
Authors: Olkhovsky Vladislav , Petrillo Vittoria , Jakiel Jacek , Kantor Wiesław 
Published: March 2008

Abstract
The particle tunneling through a 3-D rectangular potential barrier has been studied. The simplest model for multiple internal reflections has been assumed. The explicit expression for all the transmission and reflection probability amplitudes have been derived, as well as the tunneling and reflection phase times.
Simple signal path technique for matching circuit in packaged semiconductor diode laser
Authors: Han J. 
Published: March 2008

AbstractImprovement in frequency bandwidth of a packaged diode laser is investigated by the circuit impedance matching. To overcome the structural limitation of the electronic package for high frequencies, employing conventional lumped element impedance matching technique in conjunction with the manipulation of signal path of the package connections showed significant enhancement for 3-dB bandwidth to more than 6 GHz.
Functional brain imaging by multi-wavelength time-resolved near infrared spectroscopy
Authors: Torricelli A. , Contini D. , Pifferi A. , Spinelli L. , Cubeddu R. 
Published: March 2008

AbstractWe present a description of evolution of time-resolved systems developed at the Department of Physics, Politecnico di Milano for tissue oximetry and functional brain imaging. From a single source and 4-channel set-up we have upgraded to a potentially 18-sources and 64-channel device. An example of sensitivity of the latest set-up is reported for a motor task experiment. A short discussion on the next generation time-resolved instrumentation for functional studies is also presented.
Monte Carlo simulation of light propagation in adult brain: influence of tissue blood content and indocyanine green
Authors: Niederer P. , Mudra R. , Keller E. 
Published: March 2008

AbstractNear-infrared spectroscopy (NIRS), applied to a human head, is a noninvasive method in neurointensive care to monitor cerebral hemodynamics and oxygenation. The method is particularly powerful when it is applied in combination with indocyanine green (ICG) as a tracer substance. In order to assess contributions to the measured optical density (OD) which are due to extracerebral circulation and disturb the clinically significant intracerebral signals, we simulated the light propagation in an anatomically representative model of the adult head derived from MRI measurements with the aid of Monte Carlo methods. Since the measured OD signal depends largely on the relative blood content in various transilluminated tissues, we weighted the calculated densities of the photon distribution under baseline conditions within the tissues with the changes and aberrations of the relative blood volumes which we expect to prevail under physiological conditions. Furthermore, the influence of the IGC dye as a tracer substance was assessed. We conclude that up to about different 70% of the measured OD signal may have its origin in the tissues of interest under optimal conditions, which is mainly due to the extrapolated high relative blood content of brain tissue along with the influence of ICG.
Bricks and pseudo MV-algebras are equivalent
Authors: Subrahmanyam N. 
Published: March 2008

Abstract
We will show that the bricks (of Bosbach) and the pseudo MV-algebras are each term equivalent to the class of semigroups with a pair of unary operations ^ and ˘ satisfying the equations: (âa)^b = b = b(aă)˘ and a($$
\hat b
$$
a)˘ = (bă)^b and also show that a brick is an interval [0, u] of the positive cone of a unital lattice ordered group. We further extend the notion of implications to a pseudo MV-algebra and study the algebra of such implications.
Groups with few conjugacy classes of non-normal subgroups
Authors: Falco Maria , Giovanni Francesco , Musella Carmela 
Published: March 2008

Abstract
The structure of groups with finitely many non-normal subgroups is well known. In this paper, groups are investigated with finitely many conjugacy classes of non-normal subgroups with a given property. In particular, it is proved that a locally soluble group with finitely many non-trivial conjugacy classes of non-abelian subgroups has finite commutator subgroup. This result generalizes a theorem by Romalis and Sesekin on groups in which every non-abelian subgroup is normal.
Oscillation of fourth order nonlinear neutral difference equations I
Authors: Tripathy A. 
Published: March 2008

Abstract
Oscillatory and asymptotic behaviour of solutions of a class of nonlinear fourth order neutral difference equations of the form $$
\Delta ^2 (r(n)\Delta ^2 (y(n) + p(n)y(n - m))) + q(n)G(y(n - k)) = 0
$$ and $$
(NH) \Delta ^2 (r(n)\Delta ^2 (y(n) + p(n)y(n - m))) + q(n)G(y(n - k)) = f(n)
$$ are studied under the assumption $$
\sum\limits_{n = 0}^\infty {\tfrac{n}
{{r(n)}} = \infty }
$$, for various ranges of p(n). Sufficient conditions are obtained for the existence of bounded positive solutions of (NH).