bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanocrystalline hydroxyapatite coatings from ultrasonated electrolyte: Preparation, characterization, and osteoblast responses
Authors: Narayanan R. , Kim So‐Young , Kwon Tae‐Yub , Kim Kyo‐Han 
Published: February 2008

AbstractAn electrochemical method of producing nanograined hydroxyapatite coatings on titanium surface is reported in this article. The electrolyte contained Ca(NO3)2 and NH4H2PO4 in the molar ratio of 1.67:1. The electrolyte had physiological pH and was ultrasonically agitated throughout the time of electrolysis. Coatings were deposited for 30 minutes at 10 and 15 mA/cm2 and contained monohydroxyapatite phase whose grain sizes were 18 and 25 nm, respectively. These sizes are comparable with the grain size of bone. Small globules of hydroxyapatite covered the coating surface completely. Cell viability and total protein assay studies were carried out using SaOS‐2 human osteoblast‐like cell line. Of the two, the coating produced at 10 mA/cm2 showed higher viability and protein activity and seems to be a promising material for osseointegration. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Patients' predilections regarding informed consent for hospital treatments
Authors: Upadhyay Shweta , Beck Andrew , Rishi Adeel , Amoateng‐Adjepong Yaw , Manthous Constantine A. 
Published: February 2008

AbstractBACKGROUNDRespect for patient autonomy is a core principle of American medicine. Informed consent is required for surgical procedures and blood transfusions but not for most medical treatments of hospitalized patients.HYPOTHESISIf given the option, patients want to give permission for common medical therapies during hospitalization.SUBJECTSParticipants in the study were patients admitted to the medical service of a 350‐bed community teaching hospital.METHODSA questionnaire comprising 4 scenarios of varying risk/benefit ratios was administered to all patients who agreed to participate.RESULTSA total of 634 patients were admitted to the medicine service between June and August 2006. Two hundred and ten patients (103 men, 107 women), with a mean age (± SE) of 63.3 ± 1.1 years, agreed to answer the questionnaire. Of these patients, 85% wished to participate in even trivial medical decision making (ie, potassium supplementation), 92% wished to participate in treatments with moderate risk (ie, diuretic for congestive heart failure). When a risk was initially posed as less than a 5% risk of brain hemorrhage and benefits of therapy were substantially higher (eg, thrombolysis for pulmonary embolus), 93% wanted to make the decision. If the risk of brain hemorrhage was 20% or greater, 95% wanted to make the decision. Younger patients (<65 years) were more likely to prefer requiring doctors to obtain their “permission no matter what” than were older patients (≥65 years), and older patients were more likely to waive consent across levels of risk.CONCLUSIONSMost acutely ill hospitalized medicine patients wished to participate in even the most mundane aspects of their medical decision making. Although it is not logistically feasible to obtain informed consent for every treatment of every hospitalized patient, clinicians should be aware of patients' predilections and might consider offering opportunities for patients to participate in clinical decision making, especially for therapies that carry substantial risk. Journal of Hospital Medicine 2008;3:6–11. © 2008 Society of Hospital Medicine.
Limb bones asymmetry and stress in medieval and recent populations of Central Europe
Authors: Kujanová M. , Bigoni L. , Velemínská J. , Velemínský P. 
Published: February 2008

AbstractMonitoring the degree of asymmetry in different parts of the human body can contribute to population studies, as it may be connected indirectly with the social structure, living conditions, and also with biomechanical stress affecting the person. Analysis of asymmetry may also assess preferential use of the right or left of the body during specific activities. This study is based on the measurements of bones of the upper and lower limbs of skeletons derived from the remarkable medieval cemeteries of Mikulčice‐Kostelisko (78 male, 132 female) and Prušánky (66 male, 69 female) (9th–12th centuries AD), and a series of skeletons representing a recent population from Bohemia (143 male, 157 female). The objective was to assess directional asymmetry (DA), fluctuating asymmetry (FA) and antisymmetry (AS) of the dimensions of the evaluated bones, and to use these data to compare the characteristics of the medieval and recent populations. DA was recorded in most dimensions. In the upper limb, the humerus exhibited the greatest expression of asymmetry, and, with the exception of the clavicle, DA was always more pronounced on the right side. Conversely, DA was less prevalent in the lower limb bones. It was more pronounced on the transverse, sagittal and circumferential dimensions of the diaphyses and epiphyses than on the length, and in most cases it was on the left side. The FA values were very low, and almost negligible in relation to the size. Nevertheless, FA was markedly more frequent on the lower than on the upper limb. In contrast to the medieval population, the recent population had higher FA and DA values. Thus, we propose that people from this medieval population were subjected to lower developmental stress than the recent sample. Copyright © 2008 John Wiley & Sons, Ltd.
Non‐Gaussian conductance noise in disordered electronic systems
Authors: Orlyanchik V. , Kozub V. I. , Ovadyahu Z. 
Published: February 2008

AbstractThe results of conductance‐noise experiments on disordered films of crystalline indium oxide in their glassy phase are discussed. The power‐spectrum of the noise has the usual 1/f form, and when measured under small bias, the noise is Gaussian even in samples as small as 2 mm. However at larger voltages V used in the conductance measurements the noise may acquire non‐Gaussian features with a non‐trivial dependence on V. Theoretical model relating this behavior to a non‐linear effect inherent to electronic transport in a hopping system is presented. It is concluded that the non‐Gaussian features can be observed whenever the systemis glassy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Longitudinal resistivity in the quantum Hall effect regime in a split‐gate Si MOSFET with variable electron density
Authors: Shlimak I. , Friedland K.‐J. , Kravchenko S. V. , Ginodman V. , Butenko A. , Klapwijk T. M. 
Published: February 2008

AbstractLongitudinal resistivity in the quantum Hall effect regime was measured in a Si MOSFET sample in which split‐gate allows to vary the electron density and filling factor in different parts of the sample. In case of equal gate voltages on both sides of the split, the resistance, measured across the split in zero and weak magnetic fields, is larger due to electron scattering by split‐induced potential barrier. However, in strong magnetic fields, the additional resistance disappears because the current flows mostly via the edge channels along the equipotential curves. In case of different gate voltages, the longitudinal resistance is different for opposite sides of the sample because the Hall voltage difference is added only to one side of the sample depending on the sign of the gradient of gate voltages and magnetic field direction. An increase of longitudinal resistance was observed when electrons across the split occupy Landau levels with opposite spin orientation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Kubo conductivity in the IQHE regime within Hartree‐Fock
Authors: Sohrmann Christoph , Römer Rudolf A. 
Published: February 2008

AbstractWe compute the Kubo conductivity for mesoscopic quantum Hall samples taking into account the Coulomb interaction at the level of a Hartree‐Fock approximation. We first explain how to compute the conductivity by rewriting the matrix elements of the position operator in terms of phase‐shifted wave functions. Next, varying both magnetic field B and charge density ne, we can show that the resulting conductivity data is very different from a non‐interacting approach. Regions around the quantum Hall plateaus at integer filling factors remain quantized and the range of these quantized regions agrees with estimates based on a breakdown of screening condition. However, in the transition regions of linear screening, we find no evidence for stripes in the conductivity, contrary to recent experiments (D. H. Cobden et al., Phys. Rev. Lett. 82, 4695 (1999), T. Machida et al., Phys. Rev. 63(4), 045318 (2001) [1, 2]). This, together with an argument given in [2], seems to suggest an effect beyond numerically tractable system sizes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Entanglement in disordered systems at criticality
Authors: Varga Imre , Méndez‐Bermúdez José Antonio 
Published: February 2008

AbstractEntanglement is a physical resource of a quantum system just like mass, charge or energy. Moreover it is an essential tool for many purposes of nowadays quantum information processing, e.g. quantum teleportation, quantum cryptography or quantum computation. In this work we investigate an extended system of N qubits. In our system a qubit is the absence or presence of an electron at a site of a tight‐binding system. Several measures of entanglement between a given qubit and the rest of the system and also the entanglement between two qubits and the rest of the system are calculated in a one‐electron picture in the presence of disorder. We invoke the power law band random matrix model which even in one dimension is able to produce multifractal states that fluctuate at all length scales. The concurrence, the tangle and the entanglement entropy all show interesting scaling properties. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Central moments in quantum chemistry
Authors: Small David W. , Head‐Gordon Martin 
Published: February 2008

AbstractWe define central moments of operators on finite‐dimensional vector spaces and study some of their basic aspects. Central moments may be viewed as generalizations of the dispersion of a Hermitian operator. We show how eigenvalues may be represented by central moments, and how central moments may be used to obtain Krylov subspace approximations for operators on inner product spaces. We show that central‐moments approximations are compatible with the concepts of size‐consistency in quantum chemistry, and we use this to suggest a foundation for central‐moments approximations in Coupled Cluster theory. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
L2‐absolute and input‐to‐state stabilities of equations with nonlinear causal mappings
Authors: Gil' M. I. 
Published: February 2008

AbstractNonlinear scalar equations with causal mappings are considered. These equations include differential, difference, differential‐delay, integro‐differential and other traditional equations. Estimates for the L2‐norms of solutions are established. These estimates give us explicit conditions for the absolute and input‐to‐state stabilities of the considered equations. The Aizerman‐type problem from the theory of absolute stability is also discussed.The suggested approach enables us to consider various classes of systems from the unified point of view. Copyright © 2008 John Wiley & Sons, Ltd.
The ‘lead vessel’: a vascular ultrasound feature of metastasis in the ovaries
Authors: Testa A. C. , Mancari R. , Di Legge A. , Mascilini F. , Salutari V. , Scambia G. , Ferrandina G. 
Published: February 2008

AbstractObjectiveTo investigate, in a series of metastatic and primary invasive ovarian lesions examined by color Doppler, the prevalence of a main peripheral vessel penetrating into the central part of the ovarian mass with a tree‐shaped morphology, defined as the ‘lead vessel’.MethodsThis was a retrospective study of 31 patients with histopathologically confirmed metastatic involvement of the ovary and 106 patients with confirmed primary invasive ovarian carcinoma, who had undergone standardized ultrasound examination, with established definitions of ultrasound characteristics. We retrieved sonographic images and videoclips, focusing on the detection of the lead vessel.ResultsThe presence of the lead vessel was detected in 11/31 (35.4%) metastatic ovarian tumors, and in only two (0.01%) cases of primary ovarian carcinoma (P = 0.0001). At color Doppler analysis, metastatic ovarian lesions were characterized by significantly lower pulsatility index (P = 0.0001) and resistance index (P = 0.0001) values, and significantly higher peak systolic velocity (P = 0.0002) and time‐averaged maximum velocity (P = 0.04) values, when compared with primary ovarian carcinomas. The lead vessel was detected in 11/21 (52%) solid metastatic lesions and in no cases of multilocular or multilocular‐solid lesions (P = 0.008).ConclusionThe lead vessel is a novel sonographic feature of vascular morphology in solid ovarian metastases. The more frequent observation of this feature in metastatic ovarian tumors compared with primary invasive ovarian carcinomas warrants further investigation in order to explore its potential role in the diagnosis of metastatic ovarian masses. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
An intercomparison of model and observed global precipitation climatologies
Authors: Hulme Mike 
Published: February 2008

Three independent observed precipitation climatologies are used to evaluate the performance of six different General Circulation Models (GCM) control runs. Two of the observed climatologies consist of mean monthly global fields (JAEGER and LEGATES), while the third is a new land‐only time series of monthly precipitation from 1951 to 1980 (CRU5180). The six models evaluated are from the GFDL, GISS, LLNL, OSU and UKMO.Comparisons are undertaken of hemispheric means and mean seasonal cycles, and of the spatial pattern of mean monthly precipitation. A distinction is made between landonly and land and ocean fields. Of the models examined here, observed monthly precipitation over both ocean and land areas is best simulated by the high resolution UKMO model (UKMO‐H) and least well by the OSU model. Of the low resolution models UKMO performs demonstrably better than GISS, GFDL and OSU, especially in its reproduction of hemispheric seasonal cycles.
VLF‐HF HEATING OF THE LOWER IONOSPHERE AND ELF WAVE GENERATION
Authors: Taranenko Y. N. , Inan U. S. , Bell T. F. 
Published: February 2008

For incident wave power densities of 10−6 – 10−2 W/m2 (at 30 km altitude), VLF heating of the D‐region (< 90 km) is found to be 2–10 times more effective (depending on power) than HF heating, resulting in comparable perturbations of subionospheric VLF probe waves in spite of up to 103 times larger power density utilized in HF heating and at least as efficient in ELF wave generation. In view of generally larger (100×100 km) areas of the ionosphere illuminated by VLF transmitters, ELF wave generation by modulated VLF heating is estimated to produce ELF power levels of ∼100 mW, comparable with or larger than those produced in typical HF heating experiments. ELF wave generation in a typical midlatitude ambient ionosphere occurs primarily via the modulation of Pedersen current whereas in a typical auroral ionosphere Hall current is dominant for pump wave frequencies up to ∼6 MHz. For 10–30 MHz and power densities > 10−4 W/m2, Pedersen current modulation is again dominant, potentially providing up to 2–15 times higher ELF dipole moment than those found in recent experiments using 3–5 MHz heaters.
Nitrosyl sulfuric acid and stratospheric aerosols
Authors: Burley Joel D. , Johnston H. S. 
Published: February 2008

From information found in the atmospheric and chemical literature, we propose that nitrosyl sulfuric acid (NSA), NOHSO4, may play an important role in stratospheric chemistry. In one study, NSA was observed as a slurry of crystals in about a third of the aerosol particles collected between 15 and 20 km. From the chemical literature, we find that NSA is formed from several reactions between NOy species (averaging +3 oxidation state) and sulfuric acid, if the acid is above 70 wt % at room temperature and above 60 % at stratospheric temperatures. NSA is a non‐volatile ionic solid (NO+HSO4−), melting at 346 K and boiling with decomposition at 633 K. Over time, it could accumulate as a solution in the liquid aerosol, and upon reaching solubility saturation (about 3 % under lower stratospheric conditions) precipitate out as solid crystals, which permits further accumulation. At room temperature, HCl gas reacts with NSA, either the solid or in sulfuric acid solution, to form gaseous nitrosyl chloride, ClNO, which is rapidly photolyzed in the atmosphere to form nitric oxide and atomic chlorine. The overall catalytic cycle for this process can be written in a number of ways, depending upon the NOy species responsible for NSA formation; with NSA production from HONO, the cycle isThe net reaction is thermodynamically favorable for at least three modes of NSA formation. If the reaction probability of forming NSA per collision of NO with a sulfuric acid aerosol is 10−3, 1% of the sulfuric acid would be converted to NSA within 1 day at 20 km altitude. If NSA in the sulfate aerosols is 1% of the sulfuric acid and if the second order rate constant for (HCl + NOHSO4 = H2SO4 + ClNO) in sulfuric acid solution is greater than 10−18 cm3 molec.−1 s−1 under conditions at 20 km altitude, the rate of HCl + NSA is faster than the rate of HO + HCl. In this case, this heterogeneous catalysis is expected to affect the balance of NOy, Cly, and ozone in the lower stratosphere.
Compressional to shear wave velocity ratio of granular rocks: Role of rough grain contacts
Authors: Palciauskas Victor V. 
Published: February 2008

Experimental data indicate that although the compressional vp and shear vs wave velocities of unsaturated, monomineralic granular sedimentary rocks vary with grain mineralogy, degree of compaction (porosity), and confining pressure, their ratio vp/vs is to various degrees insensitive to these factors. A rough contact model for the elastic properties of a granular aggregate is presented which is consistent with these observations. The relevant assumptions of the model are: (1) the medium is a random aggregate of monomineralic, elastically isotropic, equal size grains, and (2) the intergrain contacts are rough and their elastic properties are described by the results of Yoshioka and Scholz [1989].The model predicts that vp/vs, the bulk to shear frame modulus ratio
, and the Poisson's ratio,
, of the aggregate are independent of porosity and confining pressure, and only weakly dependent on mineral Poisson's ratio. As the mineral Poisson's ratio varies between 0.08 and 0.40, vp/vs and
are essentially constant at 1.55 and 1.07 respectively, and the Poisson's ratio,
, varies between 0.141 and 0.144. These values are in good agreement with experimental data on dry, monomineralic granular rocks.
Incorporating landscape heterogeneity in land surface albedo models
Authors: Rowe Clinton M. 
Published: February 2008

The importance of incorporating landscape heterogeneity into climate models has been recognized by a number of researchers. However, attempts to relax the assumption of uniform, homogeneous and complete vegetation cover have generally been limited to modeling each component of the landscape (e.g., trees, grasses, shrubs) as a homogeneous unit and then combining the results for each type, weighted by the percentage of ground area it covers (i.e., an area‐weighted average is computed).The purpose of this paper is to demonstrate that substantial errors in the representation of vegetation‐atmosphere interactions can arise from the assumption of landscape homogeneity. Even when weighted averages are employed as a first attempt to consider landscape heterogeneity, the underlying assumption of homogeneity of the vegetation patches can lean to significant errors. To demonstrate an example of how this can occur, vegetation canopy albedo derived from weighted averages is compared to that computed with explicit consideration of canopy heterogeneity.
Introduction to special section on laboratory research for planetary atmospheres
Authors: Fox Kenneth 
Published: February 2008

The Third International Conference on Laboratory Research for Planetary Atmospheres (3rd ICLRPA) was held in Palo Alto, California, on November 3, 1991, preceding the 23rd Annual Meeting of the Division for Planetary Sciences of the American Astronomical Society (DPS/AAS). These conferences continue to highlight important progress in laboratory studies with an emphasis on their relationships to models and theories of planetary atmospheres, and importantly, with a focus on those needs for data most critical both to the analyses of ground‐based and spacecraft measurements, and to the planning of new missions. This special section of the Journal of Geophysical Research‐Planets (JGR‐Planets) includes several invited and contributed papers originally presented at the 3rd ICLRPA.I. de Pater and D. Mitchell (University of California, Berkeley) discussed radio observations of planetary atmospheres and solid surfaces, and explained the role of laboratory data in the analysis of these astronomical observations. They also noted the absence of certain relevant laboratory results needed to further develop our understanding of physical properties of planets. D.C. Reuter and J.M. Sirota (NASA Goddard Space Flight Center, Greenbelt, Maryland) discussed the utility of a spectroscopic system consisting of tunable diode lasers at wavelengths out to 28 microns; a liquid helium‐4 cooled, back‐illuminated, bounded impurity‐band (BIBIB) detector; and a 100‐m White cell to measure infrared transitions in molecules of planetary interest at very high spectral resolution and detectivity. B. Bezard (Observatory of Paris, Meudon, France) considered molecular spectra for Titan to be measured from the Infrared Space Observatory and the Cassini mission over a great range of wavelengths, from the infrared to the submillimeter, with high spectral resolution. He discussed the detectability of certain hydrocarbons and nitriles, and the corresponding need for spectroscopic measurements in the laboratory. H.A. Weaver (Space Telescope Science Institute, Baltimore, Maryland) reviewed the physical and chemical nature of cometary comae, and the connection of molecules and atoms therein with the composition of cometary nuclei. P.J. Gierasch (Cornell University, Ithaca, New York) reviewed the dynamics and thermal structure of the atmospheres of the outer planets, summarizing important measurements that are feasible with remote‐sensing spectroscopic techniques. He discussed precise observations of temperatures, velocities, and abundances to determine seasonal variations in global stratospheric circulations, winds, wave phenomena, and global oscillations. W.T. Huntress (NASA Headquarters, Washington, D.C.) introduced a program for state‐of‐the‐art, integrated systems of laboratory instruments designed for planetary applications. He noted that the establishment of these Centers for Laboratory Planetary Science Studies would facilitate, for all qualified experimentalists, the complex analytical studies needed to support planetary space missions.