bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of strength and deformation behavior of human cartilage for the definition of significant parameters
Authors: Grellmann W. , Berghaus A. , Haberland E.‐J. , Jamali Y. , Holweg K. , Reincke K. , Bierögel C. 
Published: April 2006

AbstractIn reconstructive surgery, an artificial supporting scaffold made from autogenous cartilage from the rib, the ear concha, or the nasal septum is used as a substitute for the destroyed endogenous tissue in the ear concha, the nose, the trachea, and in parts of the facial skeleton. For the successful use of polymer materials in reconstructive surgery, an exact knowledge of the material properties of the natural tissues is required. The applicability of conventional material test methods was examined with regard to the suitability of the test methodology. Materials properties are to be assessed for different specimen sizes and geometries. Human cartilage specimens from the septum, rib, and ear were subsected to the following test methods: (1) tension, (2) bending, (3) compression, and (4) micro‐hardness measuring. Specimen geometry was evaluated for each experimental method by taking into account the dimensions of samples used in plastics testing as well as the appropriate model of miniaturization. Elastic properties determined using test methods (1), (2), and (3) are Et‐sep = (7.2 ± 3.4) MPa, Ef‐rib = (8.8 ± 2.9) MPa, and Ec‐rib = (103 ± 30) MPa. The micro‐hardness values hpl fluctuate for septum from 1 to 4 N/mm2 and for the rib from 0.5 to 1.3 N/mm2. The experiments have shown that, beside the sex‐ and age‐specific values recorded, the standard values and their variation are particularly influenced by preparation technique and by the conditions of storage. As a result of these first investigations, characteristic values for strength and deformation were determined under quasistatic and dynamic load conditions. The aim of this study was not the determination of statistically firmed properties, but the examination of the applicability of mechanical test methods of the polymer testing for these materials. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Does seeding density affect in vitro mineral nodules formation in novel composite scaffolds?
Authors: Zhou Y.F. , Sae‐Lim V. , Chou A.M. , Hutmacher D.W. , Lim T.M. 
Published: April 2006

AbstractThis study investigated the human alveolar osteoblasts (AOs) proliferation and extracellular matrix formation at seeding density of 0.05, 0.1, 0.2, 0.4, and 0.8 million (M) per 3 × 4 × 4 mm3 on medical grade polycaprolactone‐tricalcium phosphate (mPCL‐TCP) scaffolds designed for bone regeneration. Over 80–90% of the initial seeded cells were retained in the scaffolds after 24 h. AOs bridged over pores at density of 0.2M/scaffold and below, but formed cell balls at density of 0.4M/scaffold and above. At seeding density of 0.2M and below, cell proliferation increased with time having DNA content peaked to 1600 ng/scaffold at day 21 and 28, respectively, whereas at 0.4 and 0.8M, the corresponding DNA content decreased to 1600 ng in 28 days. At day 7, higher alkaline phosphatase (ALP) activity and higher osteocalcin (OCN) secretion were detected at 0.2M/scaffold and below. After 28 days, multilayered cell‐sheet formation and collagen fibers were observed at all densities. ALP and OCN in matrix and mineral nodules were found mainly at the border of AOs‐scaffold construct. These findings demonstrated that the density of 0.2M and below per 3 × 4 × 4 mm3 scaffold resulted in better cell proliferation and extracellular matrix synthesis, potentially resulting in better mineralized tissue formation. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Half‐numerical evaluation of pseudopotential integrals
Authors: Flores‐Moreno Roberto , Alvarez‐Mendez Rodrigo J. , Vela Alberto , Köster Andreas M. 
Published: April 2006

AbstractA half‐numeric algorithm for the evaluation of effective core potential integrals over Cartesian Gaussian functions is described. Local and semilocal integrals are separated into two‐dimensional angular and one‐dimensional radial integrals. The angular integrals are evaluated analytically using a general approach that has no limitation for the l‐quantum number. The radial integrals are calculated by an adaptive one‐dimensional numerical quadrature. For the semilocal radial part a pretabulation scheme is used. This pretabulation simplifies the handling of radial integrals, makes their calculation much faster, and allows their easy reuse for different integrals within a given shell combination. The implementation of this new algorithm is described and its performance is analyzed. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1009–1019, 2006
Decreased bacterial clearance from the lungs of mice following primary respiratory syncytial virus infection
Authors: Stark James M. , Stark Marilyn A. , Colasurdo Giuseppe N. , LeVine Ann Marie 
Published: April 2006

AbstractVirus respiratory infections often precede bacterial pneumonia in healthy individuals. In order to determine the potential role of respiratory syncytial virus (RSV) in bacterial secondary infections, a mouse sequential pulmonary infection model was developed. Mice were exposed to RSV then challenged with Streptococcus pneumoniae (StPn). Exposure of BALB/c mice to 106–107 plaque forming units (pfu) of virus of RSV significantly decreased StPn clearance 1–7 days following RSV exposure. This finding was not restricted to StPn alone: exposure to RSV followed by Staphylococcus aureus (SA) or Pseudomonas aeruginosa(PA) resulted in similar decreases in bacterial clearance. Both bronchoalveolar lavage (BAL) cell counts and pulmonary histopathology demonstrated that RSV‐StPn exposed mice had increased lung cellular inflammation compared to mice receiving StPn or RSV alone. The effect of RSV infection on bacterial clearance was dependent on the mouse genetic background: C57BL/6J mice (relatively resistant to RSV infection) demonstrated a modest change in StPn clearance following RSV exposure, whereas FVBN/J mice (similar to the BALB/cJ mice in RSV susceptibility) demonstrated a similar degree of RSV‐associated decrease in StPn clearance 7 days following RSV exposure. Neutrophils from the RSV‐StPn sequentially exposed BALB/cJ mice were functionally altered‐produced greater levels of peroxide production but less myeloperoxidase (MPO) compared to mice receiving StPn alone. These data demonstrate that RSV infection decreases bacterial clearance, potentially predisposing to secondary bacterial pneumonia despite increased lung cellular inflammation, and suggest that functional changes occur in the recruited neutrophils that may contribute to the decreased bacterial clearance. J. Med. Virol. 78:829–838, 2006. © 2006 Wiley‐Liss, Inc.
Comparison of seven meteorological indices for drought monitoring in Iran
Authors: Morid Saeid , Smakhtin Vladimir , Moghaddasi Mahnosh 
Published: April 2006

AbstractDrought monitoring is an essential component of drought risk management. It is normally performed using various drought indices that are effectively continuous functions of rainfall and other hydrometeorological variables. A number of drought indices have been introduced and applied in different countries to date. This paper compares the performance of seven indices for drought monitoring in the Tehran province of Iran. The indices used include deciles index (DI), percent of normal (PN), standard precipitation index (SPI), China‐Z index (CZI), modified CZI (MCZI), Z‐Score and effective drought index (EDI). The comparison of indices is based on drought cases and classes that were detected in the province over the 32 years of data, as well as over the latest 1998–2001 drought spell. The results show that SPI, CZI and Z‐Score perform similarly with regard to drought identification and respond slowly to drought onset. DI appears to be very responsive to rainfall events of a particular year, but it has inconsistent spatial and temporal variation. The SPI and EDI were found to be able to detect the onset of drought, its spatial and temporal variation consistently, and it may be recommended for operational drought monitoring in the Province. However, the EDI was found to be more responsive to the emerging drought and performed better. Copyright © 2006 Royal Meteorological Society
A meta‐analysis of the neurocognitive sequelae of treatment for childhood acute lymphocytic leukemia
Authors: Campbell Laura K. , Scaduto Mary , Sharp William , Dufton Lynette , Van Slyke Deborah , Whitlock James A. , Compas Bruce 
Published: April 2006

AbstractBackgroundImpaired neurocognitive functioning is one increasingly recognized long‐term consequence of childhood ALL treatment. However, research findings have been inconsistent regarding the domains affected and the degree to which they are compromised.ProcedureA comprehensive meta‐analytic review of the long‐term neurocognitive effects of childhood ALL was conducted. Studies were included if they were published in English, reported original quantitative data on the post‐treatment neurocognitive functioning of childhood ALL patients in first remission and control groups, and used neurocognitive measures with adequate psychometric properties and published normative data.ResultsData from 28 empirical studies yielding 13 effect sizes across nine domains were extracted and analyzed. All effects were negative (g = −0.34 to −0.71), demonstrating that ALL survivors consistently experienced significant deficits in intellectual functioning, academic achievement, and specific neurocognitive abilities compared to control groups. The role of potential moderators, including treatment with cranial irradiation, age at time of diagnosis, and time since treatment ended, was examined. However, no effects emerged as clearly and consistently moderated by these variables.ConclusionsThe results from this meta‐analysis suggest that declines in both global and specific areas of areas of neurocognitive functioning occur as a result of contemporary ALL treatment. Such deficits have significant implications for survivors' academic achievement and overall quality of life. Neurocognitive assessment plays a critical role in determining what remedial or specialized instruction is needed in childhood ALL survivors and should be included as a standard part of long‐term follow‐up care. Pediatr Blood Cancer 2007;49:65–73. © 2006 Wiley‐Liss, Inc.
Allogeneic bone marrow transplantation with reduced intensity conditioning for chronic granulomatous disease complicated by invasive Aspergillus infection
Authors: Sastry Jairam , Kakakios Alyson , Tugwell Heidi , Shaw Peter J. 
Published: April 2006

AbstractChronic granulomatous disease (CGD) is a rare disorder characterized by recurrent infections, often resulting in impaired quality of life and death. Allogeneic BMT provides a definitive cure for CGD, but carries a significant risk of mortality and morbidity. The risk is higher for those who have invasive fungal infection prior to transplant. Reduced intensity conditioning (RIC) is associated with less toxicity from the conditioning agents and may provide an alternative option for all non‐malignant diseases. We report a case of successful allogeneic BMT after RIC for a case of X‐linked CGD complicated by severe invasive aspergillosis (IA). Pediatr Blood Cancer 2006;47:327–329. © 2006 Wiley‐Liss, Inc.
Assessment of health‐related quality of life of adolescent cancer patients using the Minneapolis‐Manchester Quality of Life Adolescent Questionnaire
Authors: Wu Eric , Robison Leslie L. , Jenney Meriel E.M. , Rockwood Todd H. , Feusner James , Friedman Debra , Kane Robert L. , Bhatia Smita 
Published: April 2006

AbstractBackgroundImproved survival after childhood cancer has shifted the focus to health‐related quality of life (HRQL)—an understudied problem, especially among adolescents.ProcedureWe assessed HRQL among adolescents utilizing a validated self‐report tool, the Minneapolis‐Manchester Quality of Life (MMQL) Adolescent Form, consisting of 46 items comprising seven domains: physical, cognitive, psychological and social functioning, body image, intimate relations, and outlook on life, and computed an overall QoL score. The MMQL Adolescent Form was administered to 226 adolescent survivors of childhood cancer a median of 7.8 years from diagnosis (off therapy—median age: 16.2 years), 136 adolescent cancer patients undergoing therapy (on therapy—median age: 16.4 years), and 134 healthy adolescents (controls—median age: 15.5 years). Primary diagnoses included leukemia (46%), lymphoma (26%), brain tumors (5%), and other solid tumors (23%).ResultsCompared to healthy controls, on‐therapy patients were at increased risk for reporting poor overall QoL [Odds Ratio (OR) = 3.3, P = 0.002)] and poor physical functioning (OR = 11.8, P < 0.001). Off‐therapy survivors did not differ significantly from healthy controls for overall QoL (OR = 1.6, P = 0.5) or any HRQL domains. Female patients, both on‐ and off‐therapy, were more likely to report poorer overall QoL, physical, psychological and cognitive functioning as well as poorer body image when compared with male patients.ConclusionsWhile adolescent cancer patients undergoing active therapy report poor physical functioning, there is no evidence of long‐term QoL sequelae. Pediatr Blood Cancer 2007;48:678–686. © 2006 Wiley‐Liss, Inc.
Sorption and swelling of semicrystalline polymers in supercritical CO2
Authors: Bonavoglia Barbara , Storti Giuseppe , Morbidelli Massimo , Rajendran Arvind , Mazzotti Marco 
Published: April 2006

AbstractThe equilibrium sorption and swelling behavior of four different polymers—poly(methyl methacrylate), poly(tetrafluoroethylene), poly(vinylidene fluoride), and the random copolymer tetrafluoroethylene–perfluoromethylvinylether–in supercritical CO2—are studied at different temperatures (from 40 to 80 °C) and pressures (up to 200 bar). Swelling is measured by visualization, and sorption through a gravimetric technique. From these data, the behavior of amorphous and semicrystalline polymers can be compared, particularly in terms of partial molar volume of CO2 in the polymer matrix. Both poly(methyl methacrylate) and the copolymer of tetrafluoroethylene exhibit a behavior typical of rubbery systems. On the contrary, polymers with a considerable degree of crystallinity, such as poly(tetrafluoroethylene) and poly (vinylidene fluoride), show larger values of partial molar volume. These can be related to the limited mobility of the polymer chains in a semicrystalline matrix, which causes the structure to “freeze” during the sorption process into a nonequilibrium state that can differ significantly from the actual thermodynamic equilibrium. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1531–1546, 2006
The effect of base bleed on vortex shedding and base pressure in compressible flow
Authors: Motallebi F. , Norbury J. F. 
Published: April 2006

Experiments have been carried out to investigate the phenomenon of vortex shedding from the blunt trailing edge of an aerodynamic body in transonic and supersonic flow. The effect of a discharge of bleed air from a slot in the trailing edge has been included and the relationship between the vortex formation and base pressure has been considered.In transonic flow a small amount of bleed air was found to produce a rearward shift in the point of origin of the vortices with a consequent substantial increase in base pressure. The effect was less marked in supersonic flow. At higher rates of bleed two different regimes of vortex shedding were identified and increase in bleed rate caused a reduction in base pressure. For bleed rates giving near-maximum base pressure no vortex shedding occurred.
Evolution and breakdown of a vortex street in two dimensions
Authors: Aref Hassan , Siggia Eric D. 
Published: April 2006

The initial-value problem defined by two parallel vortex sheets of opposite sign is studied. Strictly two-dimensional, incompressible, nearly inviscid dynamics is assumed throughout. The roll-up of the sheets into a vortex street is simulated numerically using 4096 point vortices. Much longer runs than in previous work are performed, and it is found that only for a finite range of values of the ratio,h/λ, of sheet separation to perturbation wavelength, does a long-lived vortex street emerge. Forh/λ [gsim ] 0·6 a pairing transition within each row intervenes. Forh/λ [lsim ] 0·3 we find oscillatory modes.Using up to 16384 point vortices, we also study the breakdown of the metastable street to a two-dimensional, turbulent shear flow. The vortex blobs that made up the street may merge with others of the same sign after the breakdown, but otherwise persist throughout the turbulent regime. Neither their disintegration nor amalgamation with vortices of opposite sign was observed. Using dimensional arguments we derive the relevant scaling theory, and show that it applies to a flow started from two random vortex sheets. The resulting turbulence is not self-similar. For the turbulent flow that follows from the breakdown of a regular vortex street two length scales with different power-law growth in time appear to be necessary. The important differences in the asymptotic structure of flows initialized from random and regular sheets leads us to question the idea of universality. The influence of the symmetry of the initial perturbation on the subsequent development is also considered.
Experiments on the flow and acoustic properties of a moderate-Reynolds-number supersonic jet
Authors: Troutt T. R. , Mclaughlin D. K. 
Published: April 2006

An experimental investigation of the flow and acoustic properties of a moderate-Reynolds-number (Re = 70000), Mach number M = 2·1, axisymmetric jet has been performed. These measurements extended the experimental studies conducted previously in this laboratory to a higher-Reynolds-number regime where the flow and acoustic processes are considerably more complex. In fact, mean-flow and acoustic properties of this jet were determined to be closely comparable to published properties of high-Reynolds-number jets.The major results of the flow-field measurements demonstrate that the jet shear annulus is unstable over a broad frequency range. The initial growth rates and wavelengths of these instabilities as measured by a hot wire were found to be in reasonable agreement with linear stability theory predictions. Also, in agreement with subsonic-jet results, the potential core of the jet was found to be most responsive to excitation at frequencies near a Strouhal number of S = 0·3. The overall development of organized disturbances around S = 0·2 seems to agree in general with calculations performed using the instability theory originally developed by Morris and Tam.The acoustic near field was characterized in terms of sound-pressure level and directivity for both natural and excited (pure-tone) jets. In addition, propagation direction and azimuthal character of dominant spectral components were also measured. It was determined that the large-scale flow disturbances radiate noise in a directional pattern centred about 30° from the jet axis. The noise from these disturbances appears from simple ray tracing to be generated primarily near the region of the jet where the coherent fluctuations saturate in amplitude and begin to decay. It was also determined that the large-scale components of the near-field sound are made up predominately of axisymmetric (n = 0) and helical (n = ±1) modes. The dominant noise-generation mechanism appears to be a combination of Mach-wave generation and a process associated with the saturation and disintegration of the large-scale instability. Finally, the further development of a noise-generation model of the instability type appears to hold considerable promise.
Sedimentation in a dilute polydisperse system of interacting spheres. Part 1. General theory
Authors: Batchelor G. K. 
Published: April 2006

Small rigid spherical partials are settling under gravity through Newtonian fluid, and the volume fraction of the particles (ϕ) is small although sufficiently large for the effects of interactions between pairs of particles to be significant. Two neighbouring particles interact both hydrodynamically (with low-Reynolds-number flow about each particle) and through the exertion of a mutual force of molecular or electrical origin which is mainly repulsive; and they also diffuse relatively to each other by Brownian motion. The dispersion contains several species of particle which differ in radius and density.The purpose of the paper is to derive formulae for the mean velocity of the particles of each species correct to order ϕ, that is, with allowance for the effect of pair interactions. The method devised for the calculation of the mean velocity in a monodisperse system (Batchelor 1972) is first generalized to give the mean additional velocity of a particle of species i due to the presence of a particle of species j in terms of the pair mobility functions and the probability distribution pii(r) for the relative position of an i and a j particle. The second step is to determine pij(r) from a differential equation of Fokker-Planck type representing the effects of relative motion of the two particles due to gravity, the interparticle force, and Brownian diffusion. The solution of this equation is investigated for a range of special conditions, including large values of the Péclet number (negligible effect of Brownian motion); small values of the Ptclet number; and extreme values of the ratio of the radii of the two spheres. There are found to be three different limits for pij(r) corresponding to different ways of approaching the state of equal sphere radii, equal sphere densities, and zero Brownian relative diffusivity.Consideration of the effect of relative diffusion on the pair-distribution function shows the existence of an effective interactive force between the two particles and consequently a contribution to the mean velocity of the particles of each species. The direct contributions to the mean velocity of particles of one species due to Brownian diffusion and to the interparticle force are non-zero whenever the pair-distribution function is non-isotropic, that is, at all except large values of the Péclet number.The forms taken by the expression for the mean velocity of the particles of one species in the various cases listed above are examined. Numerical values will be presented in Part 2.
Subharmonics and vortex merging in mixing layers
Authors: Ho Chih-Ming , Huang Lein-Saing 
Published: April 2006

In the present study, it is shown that the spreading rate of a mixing layer can be greatly manipulated at very low forcing level if the mixing layer is perturbed near a subharmonic of the most-amplified frequency. The subharmonic forcing technique is able to make several vortices merge simultaneously and hence increases the spreading rate dramatically. A new mechanism, ‘collective interaction’, was found which can bypass the sequential stages of vortex merging and make a large number of vortices (ten or more) coalesce.A deeper physical insight into the evolution of the coherent structures is revealed through the investigation of a forced mixing layer. The stability and the forcing function play important roles in determining the initial formation of the vortices. The subharmonic starts to amplify at the location where the phase speed of the subharmonic matches that of the fundamental. The position where vortices are seen to align vertically coincides with the position where the measured subharmonic reaches its peak. This location is defined as the merging location, and it can be determined from the feedback equation (Ho & Nosseir 1981).The spreading rate and the velocity profiles of the forced mixing layer are distinctly different from the unforced case. The data show that the initial condition has a longlasting effect on the development of the mixing layer.