bluuebunny/crossref_metadata_2025 huggingface dataset:
Nux vomica 30 prepared with and without succussion shows antialcoholic effect on toads and distinctive molecular association
Authors: Sukul NC , De A , Dutta R , Sukul A , Sinhababu SP
Published: September 2002

Adult toads, Bufo melanostictus, were administered Nux vomica (Nux v) 30 prepared with and without succussion on the tongue. The drug was mixed with sterile distilled water at the rate 0.05 ml/ml water and given orally 0.05 ml/individual. The control consisted of blank ethanol solution. Seeds of Strychnos nuxvomica were ground and extracted with 90% ethanol in the laboratory. Nux v 30 was prepared by successive dilution and succussion in 30 steps, Nux v 30 u was prepared by successive dilution only. Four hours after treatment, toads were given 25% ethanol i.p. at 8 g/kg body weight. The duration of ethanol induced sleep time was recorded for each toad. Both Nux v 30 and Nux v 30 u significantly reduced ethanol induced sleep time in toads as compared to their respective controls.

Electronic, infra red and nuclear magnetic resonance spectra of Nux v 30, Nux v 30 u and their diluent medium (90% ethanol) show marked differences from each other. These dilutions and ethanol 30 and ethanol 30 u show marked differences from each other with respect to spin-lattice relaxation time (T1) and chemical shift. The difference has been attributed to the variation in intra and inter-molecular association of ethanol and water.
Homeopathy in the USA
Authors: Thomas P
Published: September 2002

Homeopathy was introduced into the USA by Hans Burch Gram in 1825. It developed largely through immigration of German homeopaths. The first homeopathic medical college was established in Allentown, PA in 1835. The American institute of Homeopathy (AIH) was founded in 1844. The American Medical Association was founded in 1847 and pursued policies hostile to homeopathy from the outset. Eclectic medicine was widespread in nineteenth century medicine, one of the greatest homeopaths, JT Kent had originally been an eclectic. The International Hahnemannian Association split from the AIH in 1880. The Flexner Report of 1910 resulted in many homeopathic medical colleges being closed down. Homeopathy in the USA was in steep decline from the 1920s to the 1960s but has had a strong recovery since the 1970s.
Observational study of quality of life in patients with headache, receiving homeopathic treatment
Authors: Muscari-Tomaioli G , Allegri F , Miali E , Pomposelli R , Tubia P , Targhetta A , Castellini M , Bellavite P
Published: September 2002

This study describes the results obtained from a prospective observational research of homeopathic treatment for patients suffering from headache (migraine with- and without aura and tension-type headache). Fifty-three patients were asked to complete the SF-36 questionnaire at the beginning of the treatment and after 4–6 months. The homeopathic medicine and potency were not pre-defined, but were adapted to each single patient according to individualised homeopathic prescription. Most patients (73.6%) completed the study. There was heterogeneity in the answers (patients in very poor health as well as those with only slight disorders). Analysis of the data according to the concept of ‘intention-to-treat’ showed that after therapy, the mean and median scores of all life quality dimensions rose. More than 60% of the cases experienced an improvement in pain and the limitations caused by pain, as well as in limitations in social activities and health in general. All the differences between pre/post treatment were statistically highly significant, with the strongest results in the ‘bodily pain’ and ‘vitality’ parameters (P<0.0001).
Raman spectra of nano-structured carbon films synthesized using ammonia-containing feed gas
Authors: Choi Seungho , Park Kyung Ho , Lee Soonil , Koh Ken Ha
Published: September 2002

We examined the Raman spectra of nanostructured carbon films grown using the ammonia-containing feed gas at two excitation wavelengths, 514.5 and 1064 nm. The increase of the ammonia concentration in the feed gas resulted in two prominent changes: the complete morphology change (from nanoparticle dominance to nanotube dominance) and the degradation of the graphitic sheet quality. However, the Raman spectra preserved strong resemblance to those of graphite and glassy carbon and showed only systematic variation in the peak position, width, and the intensities. We noted that the ammonia-concentration-dependent broadening of D and G bands, the up-shift of D band, and the increase of the intensity ratio I(D)/I(G) of these films could be interpreted as the signature for the increase of disorder in the graphitic structure and/or the reduction of the graphitic crystallite size in accordance with the similar observation from other carbon-based films. We attributed the observed excitation-energy-dependent shift of the D-band position and the variation of I(D)/I(G) value to the resonance phenomena in Raman scattering. Moreover, we showed that the dispersion of the D band was in good quantitative agreement with the model proposed by Matthews et al. [Phys. Rev. B 59, R6585 (1999)].
Light-emitting diodes based on phosphorescent guest/polymeric host systems
Authors: Vaeth Kathleen M. , Tang C. W.
Published: September 2002

Fabrication of polymer light-emitting diodes based on emission from the phosphorescent molecule fac tris(2-phenylpyridine) iridium doped into a poly(vinyl carbazole) host are reported. Several spin-coating solvents were evaluated for deposition of the polymer layer; toluene and chlorobenzene were found to consistently produce device-quality films with sufficient incorporation of the dopant. For single-layered devices with Mg0.9Ag0.1 cathodes, the luminance efficiency at 20 mA/cm2 was measured to be 8.7 Cd/A for devices processed from chlorobenzene. This efficiency could be increased by over a factor of two with a trilayered device geometry consisting of the doped polymer layer, a hole-blocking layer, and electron transport layer. Further increases in efficiency, up to 30 Cd/A and 8.5% external quantum efficiency, were observed when a second dopant of 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole was added to the polymer emitter layer.
Analytical investigations of an electron–water molecule pseudopotential. II. Development of a new pair potential and molecular dynamics simulations
Authors: Turi László , Borgis Daniel
Published: September 2002

A new electron–water molecule pseudopotential is developed and tested in the present paper. The formal development of the potential is based on our earlier quantum mechanical model calculations of the excess electronic states of the electron-water molecule system [Turi et al., J. Chem. Phys. 114, 7805 (2001)]. Although the new pseudopotential has a very simple analytical form containing only nine adjustable parameters, it reproduces the exact eigenvalue of the excess state and the electron density of the smooth pseudo-wave function in the static-exchange limit. Of the individual potential energy terms, one can extract the exact electrostatic, the local repulsion and, as the remaining part, the local exchange potentials. The polarization term is added to the potential a posteriori. The most important feature of the potential is that the repulsive core region of the potential is finite and relatively narrow. This property leads to the non-negligible penetration of the excess electron in the core. The attractive wells of the potential also appear significantly closer to the nuclei than in previous pseudopotentials. The new pseudopotential is tested in quantum molecular dynamics simulations of a ground-state excess electron in a water bath. Whereas the basic features of the equilibrium hydrated electron are similar to those predicted in earlier simulations, important quantitative details are significantly improved relative to available experimental data. In particular, the simulations reproduce the equilibrium ground state energy and the optical absorption spectrum quite well. The differences of the present pseudopotential from previous works are also manifested in the more diffuse ground-state electron distribution and the more compact solvation structure. Further structural and dynamical consequences of the application of the new pseudopotential are analyzed in detail.
Synthesis and characterization of size-controlled vanadium dioxide nanocrystals in a fused silica matrix
Authors: Lopez R. , Boatner L. A. , Haynes T. E. , Feldman L. C. , Haglund R. F.
Published: September 2002

Vanadium dioxide single-crystal precipitates with controlled particle sizes were produced in an amorphous, fused SiO2 host by the stoichiometric coimplantation of vanadium and oxygen ions and subsequent thermal processing. The effects of the vanadium dioxide nanocrystal size, nanocrystal morphology, and particle/host interactions on the VO2 semiconductor-to-metal phase transition were characterized. VO2 nanoparticles embedded in amorphous SiO2 exhibit a sharp phase transition with a hysteresis that is up to 50 °C in width—one of the largest values ever reported for this transition. The relative decrease in the optical transmission in the near-infrared region in going from the semiconducting to the metallic phase of VO2 ranges from 20% to 35%. Both the hysteresis width and the transition temperature are correlated with the size of the precipitates. Doping the embedded VO2 particles with ions such as titanium alters the characteristics of the phase transition, pointing the way to control the hysteresis behavior over a wide range of values and providing insight into the operative physical mechanisms.
Shear-induced structure in polymer blends with viscoelastic asymmetry
Authors: Hobbie E. K. , Jeon H. S. , Wang H. , Kim H. , Stout D. J. , Han C. C.
Published: September 2002

Light scattering and optical microscopy have been used to measure the morphology as a function of shear rate and composition in polymer blends with viscoelastic asymmetry in the melt components. The blends studied are immiscible mixtures of low-vinyl polybutadiene (PB) and high-vinyl polyisoprene (PI), where the vinyl content strongly influences the rheological properties of the melt. At the temperatures where the optical measurements described here were performed, the PI starts to exhibit an elastic response above a critical shear rate γ̇c, while the PB responds like a viscous fluid up to the highest shear rates of interest. The disparate rheology of the two fluids leads to a rich variety of domain patterns and orientations as the volume fraction of the more elastic component is varied.
A geminal model chemistry
Authors: Rassolov Vitaly A.
Published: September 2002

We modify the existing model of the antisymmetrized product of strongly orthogonal geminals to define a size consistent variational theory free from any adjustable parameters apart from the usual choice of a basis set. The new theory is only slightly more computationally expensive than Hartree–Fock, gives an exact solution for an ensemble of noninteracting singlet two electron systems, and is applicable to open- and closed-shell systems. We use it to calculate equilibrium geometries, vibrational frequencies, and dipole moments of diatomic molecules from G2/97 database. We find excellent agreement with experimental values for covalently bound molecules, and overstretched bonds of molecules formed by atoms with extreme electronegativity.
Vibrational spectroscopy of a harmonic oscillator system nonlinearly coupled to a heat bath
Authors: Kato Tsuyoshi , Tanimura Yoshitaka
Published: September 2002

Vibrational relaxation of a harmonic oscillator nonlinearly coupled to a heat bath is investigated by the Gaussian–Markovian quantum Fokker–Planck equation approach. The system–bath interaction is assumed to be linear in the bath coordinate, but linear plus square in the system coordinate modeling the elastic and inelastic relaxation mechanisms. Interplay of the two relaxation processes induced by the linear–linear and square–linear interactions in Raman or infrared spectra is discussed for various system–bath couplings, temperatures, and correlation times for the bath fluctuations. The one-quantum coherence state created through the interaction with the pump laser pulse relaxes through different pathways in accordance with the mechanisms of the system–bath interactions. Relations between the present theory, Redfield theory, and stochastic theory are also discussed.
Spectral shape of in situ mass spectra of sympathetically cooled molecular ions
Authors: Baba Takashi , Waki Izumi
Published: September 2002

We formulated a model to reproduce the spectral shape of in situ mass spectra of sympathetically cooled molecular ions trapped in a linear radio-frequency-quadrupole. The molecular ions are sympathetically cooled by laser cooled ions. The mass spectrum is obtained by observing fluorescence emitted from the laser-cooled ions as we excite the resonant motion of the sympathetically cooled molecular ions in the trap. The model, which uses a pseudopotential and space-charge approach, reproduces the mass spectra of molecules. The model suggests that the variation of the space-charge density of the laser-cooled ions can produce in-trap kinetic excitation without the loss of the excited ions from the trap.
Microsecond carrier recombination times in InAs/AlAs quantum dots
Authors: Dawson P. , Ma Z. , Pierz K. , Göbel E. O.
Published: September 2002

We report the measurement of microsecond decay times of the photoluminescence from self-assembled InAs/AlAs quantum dots. The long decay times are attributed to recombination involving electrons and holes localized in spatially separated quantum dots. The spatial separation occurs during the relaxation process where electrons can scatter to adjacent quantum dots via the AlAs X states.
A comparison between transport and diffusion calculations using a finite element‐spherical harmonics radiation transport method
Authors: Aydin E. D. , de Oliveira C. R. E. , Goddard A. J. H.
Published: September 2002

Most researchers choose the diffusion approximation to the transport equation as the model to describe photon migration in biological tissues. However, the applicability of this approximation is limited and, in certain cases, invalid. In this paper we introduce a two‐dimensional, finite element‐spherical harmonics (FE‐ radiation transport method for the simulation of light propagation in tissue. The propagation of light is investigated first in a layered cylinder, which can be seen as a very simplistic approximation of a human head. Effects of the anisotropy factor g on the photon migration is then examined in homogeneous and heterogeneous media for different values of g and The influence of void‐like heterogeneities and channels in which absorption and scattering are very small compared with the surrounding medium on the transport of photons is also investigated. Significant differences between transport and diffusion calculations are shown to occur in all cases.
Monte Carlo investigation of the dosimetric properties of the new Model Pd‐1 source
Authors: Chan Gordon H. , Prestwich William V.
Published: September 2002

Recently,brachytherapy sources have been increasingly used for interstitial implants as an alternative tosources. The BrachySeed™Pd‐103 Model Pd‐1 seed is one of the latest in a series of new brachytherapy sources that have become available commercially. The dosimetric properties of the seed were investigated by Monte Carlo simulation, which was performed using the Integrated Tiger Series CYLTRAN code. Following the AAPM Task Group 43 formalism, the dose rate constant, radial dose function, and anisotropy parameters were determined. The dose rate constant, Λ, was calculated to beThis air kerma strength was derived from Monte Carlo simulation using the point extrapolation method. The radial dose function,was computed at distances from 0.15 to 10 cm. The anisotropy function,and anisotropy factor,were calculated at distances from 0.5 to 7 cm. The anisotropy constant,was determined to be 0.978, which is closer to unity than most otherseeds, indicating a high degree of uniformity in dose distribution. The dose rate constant and the radial dose function were also investigated by analytical modeling, which served as an independent evaluation of the Monte Carlo data, and found to be in good agreement with the Monte Carlo results.
A microRNA in a Multiple-Turnover RNAi Enzyme Complex
Authors: Hutvágner György , Zamore Phillip D.
Published: September 2002

In animals, the double-stranded RNA-specific endonuclease Dicer produces two classes of functionally distinct, tiny RNAs: microRNAs (miRNAs) and small interfering RNAs (siRNAs). miRNAs regulate mRNA translation, whereas siRNAs direct RNA destruction via the RNA interference (RNAi) pathway. Here we show that, in human cell extracts, the miRNA
let
-
7
naturally enters the RNAi pathway, which suggests that only the degree of complementarity between a miRNA and its RNA target determines its function. Human
let
-
7
is a component of a previously identified, miRNA-containing ribonucleoprotein particle, which we show is an RNAi enzyme complex. Each
let
-
7
–containing complex directs multiple rounds of RNA cleavage, which explains the remarkable efficiency of the RNAi pathway in human cells.
DIRECT GROWTH OF EPITAXIAL La0.67Ca0.33MnO3 - δ THIN FILMS
Authors: CAMPILLO G. , CASTRO L. F. , VIVAS P. , BACA E. , PRIETO P. , ARIAS D. , SANTAMARÍA J. , BERGER A. , BADER S. D.
Published: September 2002

La 0.67 Ca 0.33 MnO 3 - δ thin films were deposited using a high-pressure dc-sputtering process. Pure oxygen at a pressure of 3.8 mbar was used as sputtering gas. The films were grown on (001) LaAlO 3 and (001) SrTiO 3 substrates at heater temperature of 850° without any annealing treatment. The formation of highly a-axis-oriented films with sharp interface with substrate surface is demonstrated by X-ray diffraction, transmission electron microscope (TEM), and atomic force microscope (AFM) analysis. Electrical characterization revealed a metal–insulator transition at T MI = 276 K, and magnetic characterization showed good magnetic properties with a PM–FM transition at TC ≈ 262 K.
Electrodeposition of Antimony Telluride
Authors: Leimkühler Gisbert , Kerkamm Ingo , Reineke-Koch Rolf
Published: September 2002

Synthesis of polycrystalline

Sb

2

Te

3

via electrodeposition was carried out for the first time. The influence of pH, temperature, deposition potential, and bath composition was investigated. The thin films were characterized by means of X-ray diffraction, energy-dispersive X-ray analysis, and scanning electron microscopy. Gradual shifts from the

Sb

2

Te

3

lattice structure to the Sb lattice structure were observed. © 2002 The Electrochemical Society. All rights reserved.
SB 242784, a Selective Inhibitor of the Osteoclastic V-H
+
-ATPase, Inhibits Arterial Calcification in the Rat
Authors: Price Paul A. , June Helen H. , Buckley Jessica R. , Williamson Matthew K.
Published: September 2002

The present experiments were carried out to further test the hypothesis that arterial calcification is linked to bone resorption by determining whether the selective inhibition of bone resorption with SB 242784, a specific inhibitor of the osteoclastic V-H
+
-ATPase, will inhibit arterial calcification. Treatment for 96 hours with toxic doses of vitamin D caused widespread calcification in the aorta and in the femoral, mesenteric, hepatic, renal, and carotid arteries, and treatment with SB 242784 completely prevented the vitamin D-induced calcification of each of these arteries at a dose of 40 mg/kg per day and significantly reduced calcification at a dose of 10 mg/kg per day. Treatment with vitamin D also caused extensive calcification in the lungs, tracheal cartilage, and kidneys, and treatment with SB 242784 prevented or reduced calcification at each of these sites. Measurement of serum levels of cross-linked N-telopeptides, a specific measure of bone resorption activity, showed that treatment with vitamin D alone produced the expected 2.4-fold increase in bone resorption activity and that concurrent treatment with the 40-mg dose of SB 242784 reduced bone resorption activity to below control levels. With the inclusion of the present results, there are now three types of bone resorption inhibitors (each with an entirely different mode of action on the osteoclast) that share the ability to potently inhibit arterial calcification in the rat, the V-H
+
-ATPase inhibitor SB 242784, the cytokine osteoprotegerin, and the amino bisphosphonates alendronate and ibandronate.
Protease-Activated Receptor-1–Mediated DNA Synthesis in Cardiac Fibroblast Is via Epidermal Growth Factor Receptor Transactivation
Authors: Sabri Abdelkarim , Short Jacob , Guo Jianfen , Steinberg Susan F.
Published: September 2002

Proteases elaborated by inflammatory cells in the heart would be expected to drive cardiac fibroblasts to proliferate, but protease-activated receptor (PAR) function in cardiac fibroblasts has never been considered. This study demonstrates that PAR-1 is the only known PAR family member functionally expressed by cardiac fibroblasts and that PAR-1 activation by thrombin leads to increased DNA synthesis in cardiac fibroblasts. The increase in DNA synthesis induced by PAR-1 substantially exceeds the effects of other G protein–coupled receptor agonists in this cell type. PAR-1 stimulates phosphoinositide hydrolysis and mobilizes intracellular calcium via pertussis toxin (PTX)-sensitive and PTX-insensitive pathways. Activation of PAR-1 leads to an increase in Src, Fyn, and epidermal growth factor receptor (EGFR) phosphorylation, with EGFR receptor transactivation by Src family kinases the major mechanism for PAR-1–dependent activation of extracellular signal–regulated kinase, p38-mitogen-activated protein kinase, and protein kinase B. Activation of PAR-1 also leads to an increase in DNA synthesis. PAR-1 signaling is highly contextual in nature, inasmuch as PAR-1 activates extracellular signal–regulated kinase and only weakly stimulates protein kinase B via a pathway that does not involve EGFR transactivation in cardiomyocytes. PAR-1 responses in cardiac fibroblasts and cardiomyocytes are predicted to contribute importantly to remodeling during cardiac injury and/or inflammation.
Estimation of the spatial distribution of fluid permeability from surface and tomographic GPR data and core, with a 2‐D example from the Ferron Sandstone, Utah
Authors: Hammon William S. , Zeng Xiaoxian , Corbeanu Rucsandra M. , McMechan George A.
Published: September 2002

Reservoir analogs provide detailed information that is applicable to fluid transport simulations but that cannot be obtained directly from reservoirs because of inaccessibility. The Ferron Sandstone of east‐central Utah is an analog for fluviodeltaic reservoirs; its excellent outcrop exposures are ideal for detailed study. Ground‐penetrating radar (GPR) data were collected in and between two cored boreholes and are used to build a 2‐D fluid permeability model in four steps. First, an anisotropic GPR propagation velocity model is obtained from traveltime tomography between two boreholes and between each borehole and the earth's surface. Second, the geometry of the sedimentological features is imaged by prestack Kirchhoff depth migration of constant‐offset GPR data acquired along a line between the two holes at the earth's surface. Third, a background permeability is assigned to each layer by interpolating the geometrical average of the measured permeabilities in each sedimentological element. Finally, the spatial distribution of flow baffles and barriers is estimated by calibrating the instantaneous amplitude and frequency of the surface GPR data associated with the mudstone layers in the boreholes via cluster analysis. The result is an integrated model that contains GPR velocity, lithology, and fluid permeability distributions. Low GPR velocities correspond to mudstones with low permeability. The main mudstone layers (potential barriers and/or baffles to fluid flow) do not appear to be continuous between the boreholes, which means that interpretations based on borehole data alone would overestimate element continuity and thereby underestimate effective permeability.
Integrating surface georadar and crosshole radar tomography: A validation experiment in braided stream deposits
Authors: Tronicke Jens , Dietrich Peter , Wahlig Uwe , Appel Erwin
Published: September 2002

We have used a combination of surface ground‐penetrating radar (GPR) profiling, crosshole radar tomography, and natural gamma‐ray logging to characterize a gravelly braided stream deposit. In a gravel pit, we conducted a survey using 300‐MHz surface GPR, 250‐MHz crosshole radar, and densely sampled gamma‐ray logging at single‐borehole locations. After excavation, we validated the geophysical results by comparison with the sedimentological and hydrogeological information obtained from the corresponding outcrop wall. We found the visual lithofacies boundaries agreed very well with the images provided by applied geophysical techniques. Our results illustrate how GPR reflector images are improved using tomographic velocity information. In addition, the structural interpretation of tomographic velocity fields is guided by the GPR reflector images in combination with natural gamma‐ray logging results.

Groundwater flow and transport modeling was also performed on different subsurface models. The hydrogeological response of parameter distributions derived from a digitized outcrop image are compared with the response of a parameter field derived from the combined geophysical data and with the response of a simple block interpolation between the boreholes. Comparison of cumulative particle arrival times (breakthrough curves) indicates that the characterization of an appropriate real aquifer would benefit from incorporating high‐resolution geophysical data into the analysis.
Computation of linear elastic properties from microtomographic images: Methodology and agreement between theory and experiment
Authors: Arns Christoph H. , Knackstedt Mark A. , Pinczewski W. Val , Garboczi Edward J.
Published: September 2002

Elastic property‐porosity relationships are derived directly from microtomographic images. This is illustrated for a suite of four samples of Fontainebleau sandstone with porosities ranging from 7.5% to 22%. A finite‐element method is used to derive the elastic properties of digitized images. By estimating and minimizing several sources of numerical error, very accurate predictions of properties are derived in excellent agreement with experimental measurements over a wide range of the porosity. We consider the elastic properties of the digitized images under dry, water‐saturated, and oil‐saturated conditions. The observed change in the elastic properties due to fluid substitution is in excellent agreement with the exact Gassmann's equations. This shows both the accuracy and the feasibility of combining microtomographic images with elastic calculations to accurately predict petrophysical properties of individual rock morphologies. We compare the numerical predictions to various empirical, effective medium and rigorous approximations used to relate the elastic properties of rocks to porosity under different saturation conditions.
Wavefield separation using densely deployed three‐component single‐sensor groups in land surface‐seismic recordings
Authors: Robertsson Johan O. A. , Curtis Andrew
Published: September 2002

Surface seismic data are usually acquired by placing receivers on the earth's free surface. This is exactly the surface at which all up‐coming wave energy is reflecting and converting into down‐going energy, so the wavefield recorded is the sum of up‐coming, down‐going reflected, and down‐going converted waves. In order to anaylze up‐coming (from the reservoir) energy only (e.g., for “true” amplitude analysis), it is necessary to separate and remove all down‐going waves from the recorded data.

We present a new approach for wavefield separation of land surface‐seismic data based on receiver groups with densely deployed single‐sensor recordings. By converting vertical spatial derivatives to horizontal derivatives using the free‐surface condition, the methodology only requires locally dense measurements of the wavefield at the free surface to calculate all spatial derivatives of the wavefield. These can in turn be used to compute divergence (giving P‐wave potential) and curl (giving S‐wave potential) of the wavefield at the free surface. The effects of the free surface are removed through an up/down separation step using the elastodynamic representation theorem. This results in infinite spatial‐filter expressions that are appropriate for homogeneous media. The filter for P‐waves depends on both P‐ and S‐velocity at the receivers, whereas the S‐wave filters only depend on the S‐velocity. These velocities can be estimated using the techniques in the companion paper by Curtis and Robertsson in this issue.

Spatially compact filters are chosen to approximate the analytical filter expressions. The filters are designed so that they can be applied within a densely deployed, spatially limited group of three‐component (3C) receivers. By assuming that the earth is locally homogeneous (no significant variations within the near‐surface region of the group), wavefield separation can be carried out also in areas with significant statics variations over the survey area. In particular, the simplest approximate expression for P‐waves consists of two terms. The first term corresponds to divergence in the presence of the free surface scaled by a material constant. The second term is a time derivative of the recorded vertical component scaled by a material constant. Hence, the first term is a correction that is added to the “traditional” P‐interpretation—the second term—which improves accuracy for incidence angles other than normal incidence.

The proposed methodology is tested on synthetic data. By comparing “traditional” P‐sections to those obtained using the new methodology, we demonstrate that a significant improvement in amplitudes and phases of arrivals is obtained using the new methodology. By using the simplest possible filter which only involves first‐order derivatives in time and space, we obtained sufficiently accurate results up to incidence angles of around 30° away from normal incidence.
Traveltime and amplitude calculations using the damped wave solution
Authors: Shin Changsoo , Min Dong‐Joo , Marfurt Kurt J. , Lim Harry Y. , Yang Dongwoo , Cha Youngho , Ko Seungwon , Yoon Kwangjin , Ha Taeyoung , Hong Soonduk
Published: September 2002

Because of its computational efficiency, prestack Kirchhoff depth migration remains the method of choice for all but the most complicated geological depth structures. Further improvement in computational speed and amplitude estimation will allow us to use such technology more routinely and generate better images. To this end, we developed a new, accurate, and economical algorithm to calculate first‐arrival traveltimes and amplitudes for an arbitrarily complex earth model. Our method is based on numerical solutions of the wave equation obtained by using well‐established finite‐difference or finite‐element modeling algorithms in the Laplace domain, where a damping term is naturally incorporated in the wave equation. We show that solving the strongly damped wave equation is equivalent to solving the eikonal and transport equations simultaneously at a fixed reference frequency, which properly accounts for caustics and other problems encountered in ray theory. Using our algorithm, we can easily calculate first‐arrival traveltimes for given models. We present numerical examples for 2‐D acoustic models having irregular topography and complex geological structure using a finite‐element modeling code.
Partial VP1/2A gene sequence based molecular epidemiology of wild type 1 poliovirus isolates from some parts of India
Authors: ANAND R. , GHOSH D. , BHUPATIRAJU A. V. , BROOR S. , PASHA S. T. , KHARE S. , KUMAR M. , DUTTA K. K. , RAI A.
Published: September 2002

Genomic variability within the sequences of VP1/2A junction among polioviruses from across the globe has revealed the existence of several endemic genotypes and their epidemiological inter-relationships; but such data on Indian isolates are scanty. The present work was intended to ascertain the persistence and transmission pattern of different genotypes of wild type 1 polioviruses circulating in India. Forty-eight wild type 1 poliovirus isolates obtained from different parts of India during 1996–8 were subjected to RT–PCR and nucleotide sequencing using M13 tailed primers. A 293 base pair region was amplified and sequenced for genetic variation study. Considering the 15% divergence of the sequences from Sabin 1, the isolates from six different states of India confirmed a single dominant genotype 4. Phylogenetic analysis revealed the circulation and active inter-state transmission of many genetically distinct strains of wild poliovirus type 1 belonging to genotype 4. This warrants the need for insisting on more efficient surveillance mechanisms so as to assess the impact of an extensive pulse polio immunization programme in India.
The epidemiology of glycopeptide-resistant enterococci on a haematology unit – analysis by pulsed-field gel electrophoresis
Authors: BRADLEY S. J. , KAUFMANN M. E. , HAPPY C. , GHORI S. , WILSON A. L. T. , SCOTT G. M.
Published: September 2002

As part of an interventional study to determine glycopeptide-resistant enterococci (GRE) acquisition on a three-ward haematology unit, rectal swabs were taken weekly from 293 patients recruited to the study between June 1995 and December 1996. The GRE isolates obtained from the first positive rectal swab from 120 colonized patients, the isolates from 7 patients with clinical infection and 43 isolates obtained from the ward environment were compared by pulsed-field gel electrophoresis (PFGE). Sixty-three of 120 patients were colonized by one of strains A-H, while 49 were colonized by unique strains. The first 18 weeks were associated with the highest prevalence of GRE by rectal swab, with a single strain A responsible for 52% of acquisitions on ward 2, 22% on ward 3 and 36% on ward 4. Other smaller ward associated clusters were evident. Environmental sampling of ward 2 during this time showed that all but 2 of 30 isolates were indistinguishable from strain A. As the GRE prevalence fell, rectal swab and environmental isolates became more heterogeneous, and strain A disappeared after week 55. GRE prevalence rose again in the final 15 weeks of the study, and a new predominant strain B emerged on ward 2 responsible for 50% of new acquisitions. In the seven patients with clinical infection with GRE, the clinical isolates were compared with the contemporaneous rectal swab isolate, and were found to be the same in only two cases. An analysis of five long-term carriers colonized for a median of 19 weeks (range 11–34) showed colonization with at least two and in one case six distinct strains, raising the question of how many strains may be colonizing a patient at any one time, and suggesting that multiple colonies should be analysed. These data suggest that cross-infection was an important factor in the spread of GRE when the colonization rate was high.
Evaluation of hepatitis C surveillance in Poland in 1998
Authors: MAZUREK J. , HUTIN Y. , McNUTT L.-A. , MORSE D. L.
Published: September 2002

The aim was to evaluate hepatitis C surveillance in Poland during 1998. Hepatitis C reports were obtained from epidemiology offices. Public health staff were interviewed to collect information on surveillance operations. To estimate the proportion of acute cases among the total reported, a study was conducted in the Warsaw district to validate case reports. A total of 1661 (97.2%) hepatitis C cases were studied. Hepatitis C surveillance was timely and acceptable to the user, but did not provide a number of information elements required to differentiate acute from chronic cases of infection. Of the 268 case reports available in the Warsaw district, only 15 (5.6%) met the acute hepatitis C case definition. It is concluded that hepatitis C surveillance in Poland cannot provide useful incidence estimates and information regarding risk factors for acute infection. A strict case definition and a modified case form with specific questions for HCV transmission routes should be applied.
Drug resistances in salmonella isolates from animal foods, Italy 1998–2000
Authors: MAMMINA C. , CANNOVA L. , MASSA S. , GOFFREDO E. , NASTASI A.
Published: September 2002

We investigated the distribution of serotypes and patterns of drug resistance of 206 strains of salmonella isolated in southern Italy in the years 1998–2000 from raw food of animal origin, faeces of food animals and animal feed. To improve knowledge of mobile genetic elements carrying the resistance genes, some molecular features were also investigated within isolates resistant to three or more antibiotics. A high proportion of isolates, 52.2% and 37.7%, respectively, belonging to both Typhimurium and other serotypes of animal origin, proved to be multidrug resistant. The DT104 complex specific multidrug pattern of resistance was quite infrequent among isolates other than Typhimurium, but resistances to nalidixic acid and kanamycin were more frequent within these last ones (36.9% vs. 11.4% and 56.5% vs. 2.2%, respectively). Class I integrons were detected in isolates of Typhimurium and seven different serotypes. The relevance of food animal environment as a drug resistance reservoir and animal food as a potential resistance gene vehicle between the farm and human ecological niches is confirmed by our findings.
Brain somatic representation of phantom and intact limb: a fMRI study case report
Authors: Condés‐Lara Miguel , Barrios Fernando A. , Romo Juan Romero , Rojas Rafael , Salgado Perla , Sánchez‐Cortazar Julian
Published: September 2002

Reports on phantom limb patients concerning neuronal reorganization using non‐invasive methods have focused mainly on the cortical regions and suggest the presence of pain as the cause of this reorganization. The phantom limb, however, includes other somatic and motor sensations other than pain. Here we describe the results of non‐painful stimulation in cortical and subcortical lateralization and reorganization and also examine the involvement of subcortical structures in phantom limb telescoping perception. We describe an enlarged contralateral cortical representation of the stump, a cortical and thalamic bilateral representation of the remaining leg, and a neuronal correlate of a telescoping perception of the phantom limb. The missing leg produces an enlarged cortical representation due to abnormal information and the remaining leg has a bilateral SII representation, which could be related to new, compensatory functions. The telescoping perception of a phantom limb by the stimulation of misallocation points was correlated with lenticular nuclei, thalamic and cingulate gyrus activation.

We therefore propose that the reorganization concept of a phantom limb, applied mainly to the cortex, must extend to the thalamic and the somatosensory and motor systems (pathways and relay nuclei).
Perceived future in chronic pain: the relationship between outlook on future and empirically derived psychological patient profiles
Authors: Hellström Christina , Jansson Bengt , Carlsson Sven G.
Published: September 2002

Perceived (subjective) future has been found to be a significant factor in explaining the relationship between pain and pain‐related distress. The present study is based on the assumption that chronic pain patients with the three psychological profiles introduced by Turk and Rudy in 1988 could also be found in a sample of chronic pain patients and if so, these profiles have different perspectives on the future. The Multidimensional Pain Inventory (MPI) and The Future Scale were used to collect data from 569 patients with heterogenous non‐malignant chronic pain. A cluster analysis was conducted, where the resulting clusters closely resembled the profiles labelled by Turk and Rudy as ‘dysfunctional’, ‘interpersonally distressed’ and ‘adaptive coper’. The results indicated that patients with adaptive coper profile have a more positive perception, while those with an interpersonally distressed profile have a more negative perception of the future. With an increased duration of pain, the proportion of the adaptive coper category decreased linearly, while an opposite trend was noted for the interpersonally distressed category. These results may better enable profiled psychological interventions in clinical pain treatment, e.g. by providing patients with therapies focused on positive future orientation, resulting in increased motivation for health‐seeking behaviour and better abilities to cope with pain.
Post stroke shoulder pain: more common than previously realized
Authors: Gamble Giles E. , Barberan Elisa , Bowsher David , Tyrrell Pippa J. , Jones Anthony K.P.
Published: September 2002

Stroke is a common disease often requiring rehabilitation, which may be prolonged by shoulder pain. The true incidence of post stroke shoulder pain has not been fully evaluated. In order to establish this, we undertook a prospective study of 123 consecutive patients with a diagnosis of acute stroke during a 6‐month period. Patients were assessed by interview, full rheumatological and neurological examination, 14 days post stroke, for a history of shoulder pain according to predetermined criteria. In addition, Barthel Index, HAD score and pain scores were also recorded. Twenty‐five percent of patients developed shoulder pain within 2 weeks of their stroke. There was a statistically significant association with ipsilateral sensory impairment (p<0.005), abnormal rheumatological examination (p<0.001) and depression score (p<0.005).

We conclude that post stroke shoulder pain is more common than previously realized and in addition to abnormal shoulder joint examination may also be associated with upper limb sensory impairment. Thorough neurological examination is required to detect sensory loss and hence establish patients at risk. This is probably best done by a structured proforma.
Relationship between mechanical sensitivity and postamputation pain: a prospective study
Authors: Nikolajsen Lone , Ilkjær Susanne , Jensen Troels S.
Published: September 2002

Limb amputation is followed by stump and phantom pain in a large proportion of amputees and postamputation pain may be associated with signs of hyperexcitability such as hyperalgesia to mechanical stimulation. The present study examined the possible relationship between mechanical pain threshold of the limb and early (after 1 week) and late (after 6 months) phantom pain. Thirty‐five patients scheduled for amputation of the lower limb were examined before, 1 week and 6 months after amputation. On all three examination days pressure–pain thresholds were measured and compared with the simultaneous recording of ongoing pain intensity assessed on a visual analogue scale (VAS). There was a weak but significant inverse relationship between preamputation thresholds and early stump and phantom pain. There was no relationship between preamputation thresholds and late stump and phantom pain. One week after amputation there was a significant and inverse relationship between mechanical thresholds and phantom pain but no relationship was found after 6 months. The findings suggest that although tenderness of the limb before and after amputation is related to early stump and phantom pain, the relationship is weak. Neuronal sensitization peripherally or centrally may play a role in the development of phantom pain.
Effects of human placental extract on chemical and thermal nociception in mice
Authors: Gurgel Luilma A. , Santos Flávia A. , Rao Vietla S.N.
Published: September 2002

Several reports indicate that pregnancy and parturition are associated with elevated maternal pain thresholds to noxious stimuli. The objective of this study was to examine whether the human placental extract, a clinically used preparation, can inhibit experimental nociception. Nociception was assessed in mice using acetic acid‐induced writhing and hot‐plate tests. The human placental extract (200 and 400 mg/kg, i.p.) elicited dose‐related antinociception in the acetic acid‐induced writhing test. Furthermore, it (200 mg/kg, i.p.) potentiated the morphine‐induced antinociception (1.25 mg/kg, s.c.). In the hot‐plate test, the human placental extract (100, 200 and 400 mg/kg, i.p.) per se, displayed no significant antinociception but potentiated the duration of morphine (10 mg/kg, s.c.) analgesia. The potentiation by the extract of the morphine‐induced antinociception in both acetic acid and hot‐plate tests was, however, found to be naloxone sensitive. Mice treated with the extract (400 mg/kg, i.p.) neither manifested any overt behavioural change in the open‐field test nor demonstrated significant influence on pentobarbital sleeping time, suggesting that it has no central depressant or sedative activity. The data provide evidence to show that the human placental extract has a peripheral analgesic property possibly mediated by an opioid mechanism.
Driving and intrathecal morphine administration
Authors: Van den Bosch G. , De Doncker  , Vercruysse P. , Maeyaert J. , Vissers K. , Neels H.
Published: September 2002

Since Belgian law recently set a limit to morphine concentration detectable in blood and urine while driving a vehicle, questions arose about the implications for the medical use of opiates. We determined morphine concentrations in whole blood and urine by gas chromatography–mass spectrometry in 15 patients on continuous intrathecal morphine administration. Effects on blood and urine concentration after water intake and the correlation with the intrathecal morphine daily dose were also evaluated. Our results confirm that, in all patients examined, the legally determined maximum blood morphine concentration of 20 ng/ml was never exceeded. Even patients on high intrathecal morphine dose schedules did never reach the maximum legal blood concentration. However, morphine concentration in urine reached levels which exceeded by far the legally determined maximum concentration of 300 ng/ml. Although legal actions against driving under the influence of morphine can only be taken after a positive urine and a subsequent positive blood sample, drivers on intrathecal opiates must be aware of the possibility of a positive roadside drug test.
Differential time courses of skin blood flow and hyperalgesia in the human sunburn reaction following ultraviolet irradiation of the skin
Authors: Benrath Justus , Gillardon Frank , Zimmermann Manfred
Published: September 2002

The response of skin to ultraviolet (UV) irradiation is an inflammation with pronounced vasodilation and hyperalgesia. Volunteers underwent UV irradiation of patches of forearm skin 3 cm in diameter. The intensity of the UV irradiation (290–320 nm) ranged between 133 mJ/cm2and 400 mJ/cm2. Changes in skin blood flow were measured with laser Doppler technique at 3, 6, 9, 12, 24, 30, 36, 48, 60, 72, 96 and 216 h post UV irradiation. The alteration in pain threshold was measured for heat with a Peltier thermode and for pressure with a metal stylus. The effect of repeated topical pre‐treatment 4 days prior to UV irradiation with 1.5 g of 0.04% capsaicin containing ointment was also investigated.

UV irradiation resulted in a dose‐dependent increase of skin blood flow for more than 96 h post‐irradiation. There were two peaks of blood flow at 12 h and 36 h. Topical application of capsaicin prior to UV irradiation attenuated blood flow from 30 h to 45 h post UV irradiation. Enhanced blood flow was also present 5 mm outside the irradiated area (flare reaction). The control level of heat pain threshold was 44.5±0.7 C in normal skin. Heat pain thresholds were lowered by up to 7.761.2C in UV‐irradiated areas in a dose‐dependent fashion. The control level of pressure pain threshold was 15.260.3N. Pressure pain thresholds were lowered by up to 6 N in irradiated areas. Maximal hyperalgesia coincided with the second peak of skin blood flow between 30 h and 60 h post UV irradiation. The effects of topical application of capsaicin suggests an involvement of neuropeptide mechanisms in the late phase of the human sunburn reaction.