bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of lung volume on MR signal intensity changes of the lung parenchyma
Authors: Bankier Alexander A. , O'Donnell Carl R. , Mai Vu M. , Storey Pippa , De Maertelaer Viviane , Edelman Robert R. , Chen Qun 
Published: November 2004

AbstractPurposeTo test the hypothesis that, in magnetic resonance (MR) imaging of healthy individuals, equal relative changes in lung volume cause equal relative changes in MR signal intensity of the lung parenchyma.Materials and MethodsIn two experimental runs, 10 volunteers underwent spirometrically monitored MR imaging of the lungs, with MR images acquired at 10 incremental lung volumes ranging from total lung capacity to 10% above residual volume. Average signal intensity, signal variability, and signal intensity integrals were calculated for each volunteer and for each lung volume. The effect of lung volume on signal intensity was quantified using linear regression analysis complemented by the runs test. Slopes and intercepts of regression lines were compared with an analysis of covariance. Slopes of the lines of best fit for lung volumes and signal intensities from the two runs were compared to the slope of the line of identity. Comparisons between the two runs were visualized using Bland and Altman plots.ResultsThe slopes of the 10 individual regression lines yielded no significant differences (F = 1.703, P = 0.101; F = 1.321, P = 0.239). The common slopes were –0.556 ± 0.027 (P = 0.0001) for the first and –0.597 ± 0.0031 (P = 0.0001) for the second experimental run. Both slopes displayed no significant nonlinearity (P = 0.419 and P = 0.067). There was a strong association between changes in lung volumes (rs = 0.991, P = 0.0001) and changes in signal intensity (rs = 0.889, P = 0.0001) in the two experimental runs. Lines of best fit for lung volume and signal intensities were not significantly different from the slope of the line of identity (P = 0.321 and P = 0.212, respectively).ConclusionEqual changes in lung volume cause equal changes in MR signal intensity of the lung parenchyma. This linear and reproducible phenomenon could be helpful in comparing pulmonary MR signal intensity between individuals. J. Magn. Reson. Imaging 2004;20:961–966. © 2004 Wiley‐Liss, Inc.
Comparative study of FAST gradient echo MRI sequences: Phantom study
Authors: Perrin Rosalind L. , Ivancevic Marko K. , Kozerke Sebastian , Vallee Jean‐Paul 
Published: November 2004

AbstractPurposeTo investigate a balanced steady state free precession sequence (b‐SSFP) under a large range of conditions and to compare its performance with other types of gradient echo sequences for dynamic imaging.Materials and MethodsBalanced turbo field echo (b‐TFE; Philips Medical Systems, Best, The Netherlands) was investigated in vitro at a range of T2/T1 along with T1‐contrast enhanced turbo field echo (T1‐TFE) and turbo field echo (TFE) so that a comparison could be made. Performance was quantified in terms of the initial slope of the signal‐to‐noise ratio (SNR) vs. 1/T1 curve (sensitivity) and the range of 1/T1 before signal saturation (contrast dynamic range [CDR]).ResultsThe b‐TFE sequence was found to best perform, in terms of an optimal CDR, with a 90° flip angle (FA), saturation preparation, and short inversion time. Using these parameters, the sensitivity was also higher than that of the TFE sequence and T1‐TFE sequence under their respective optimal conditions. For detection of small changes in contrast agent concentration (0.0–0.1 mM), b‐TFE was also found to be the sequence of choice, with optimized parameters as follows, 90° FA, shortest TR/TE, and no magnetization preparation. The smallest matrices gave the highest signal sensitivity for all three sequences.ConclusionThe CDR of b‐TFE was much narrower than that of T1‐TFE but could be widened under optimized conditions. The sensitivity of the b‐TFE technique was the highest of the three sequences under all conditions tested. J. Magn. Reson. Imaging 2004;20:1030–1038. © 2004 Wiley‐Liss, Inc.
Contribution of diffusion tensor imaging to delineation of gliomas and glioblastomas
Authors: Tropine A. , Vucurevic G. , Delani P. , Boor S. , Hopf N. , Bohl J. , Stoeter P. 
Published: November 2004

AbstractPurposeTo determine if the diffusion tensor imaging (DTI) parameters fractional anisotropy (FA) and mean diffusivity (MD) can differentiate between accompanying edema and tumor cell infiltration of white matter (WM) beyond the tumor edge as defined from conventional MRI in low‐ and high‐grade gliomas.Materials and MethodsWe examined 12 patients with high‐grade gliomas/glioblastomas and eight patients with low‐grade gliomas and compared them to 10 patients with meningiomas, in which no tumor infiltration is expected. The tumor was defined as the enhancing area in glioblastomas and meningiomas and as the area of increased T2‐signal in low‐grade gliomas. FA and MD were measured in the center of the tumor and in the adjacent WM. The contralateral WM and internal capsule were used as an internal standard.ResultsComparing the WM areas of increased T2‐signal adjacent to meningiomas and glioblastomas, we saw a trend (without significance) towards a reduction of FA, but not of MD, in glioblastomas. We found no changes of FA and MD in the WM adjacent to low‐grade gliomas (without T2‐signal increase) compared to the WM of the contralateral hemisphere. In meningiomas and high‐grade gliomas/glioblastomas, a narrow rim of significantly (P < 0.01) increased FA and decreased MD values around the enhancing tumor area was seen, whereas in low‐grade gliomas, such a rim could not be defined. There was no contribution of FA or MD to grading of gliomas.ConclusionIn glioblastomas, a reduction of FA in the edematous area surrounding the tumor may indicate tumor cell infiltration, but a reliable differentiation between infiltration and vasogenic edema is not yet possible on the basis of DTI. The additional finding of a narrow rim of increased FA and decreased MD at the edge of glioblastomas (as well as in meningiomas) may be caused by com‐pressed WM fibers and/or increased vascularity, but does not contribute to exclude peripheral cellular infiltration. J. Magn. Reson. Imaging 2004;20:905–912. © 2004 Wiley‐Liss, Inc.
Nerve conduction study in Sydenham's chorea
Authors: Cardoso Francisco , Dornas Leonardo , Cunningham Mauro , Oliveira José Teotonio 
Published: November 2004

AbstractSydenham's chorea (SC) is a late complication of group A β‐hemolytic streptococci infection presumably caused by an abnormal autoimmune reaction. Despite rare case reports of peripheral neuropathy associated with streptococcal infection, there is no investigation of peripheral nerve in SC. We performed nerve conduction studies in a cohort of patients with SC. The neurophysiology investigation comprised measurement of amplitude and sensory conduction velocity of median, ulnar, and sural nerves; amplitude and motor conduction velocity; and F‐wave latency of median, ulnar, fibular, and tibial nerves. Twenty‐six patients entered the study (12 females, 14 males; mean age 12.8 ± 3.6 years). Thirteen subjects had absent or decreased deep reflexes. All investigated neurophysiological parameters fell within the normal range for our population. We failed to find neurophysiological evidence of peripheral nerve involvement in patients with a history of SC. Our findings suggest that the possible autoimmune dysfunction in SC patients is not targeted against epitopes present in peripheral nerves. © 2004 Movement Disorder Society
Parallel scheduling problems in next generation wireless networks
Authors: Becchetti L. , Leonardi S. , Marchetti‐Spaccamela A. , Vitaletti A. , Diggavi S. , Muthukrishnan S. , Nandagopal T. 
Published: November 2004

AbstractNext‐generation 3G/4G wireless data networks allow multiple codes (or channels) to be allocated to a single user, where each code can support multiple data rates. Providing fine‐grained QoS to users in such networks poses the two‐dimensional challenge of assigning both power (rate) and codes to every user. This gives rise to a new class of parallel scheduling problems. We abstract general downlink scheduling problems suitable for proposed next‐generation wireless data systems. Our contribution includes a communication‐theoretic model for multirate wireless channels. In addition, while conventional focus has been on throughput maximization, we attempt to optimize the maximum response time of jobs, which is more suitable for streams of user requests. We present provable results on the algorithmic complexity of these scheduling problems. In particular, we are able to provide very simple, on‐line algorithms for approximating the optimal maximum response time. We also perform an experimental study with realistic data of channel conditions and user requests that strengthens our theoretical results. © 2004 Wiley Periodicals, Inc. NETWORKS, Vol. 45(1), 9–22 2005
Personality and biological markers of creativity
Authors: Reuter M. , Panksepp J. , Schnabel N. , Kellerhoff N. , Kempel P. , Hennig J. 
Published: November 2004

The aim of the present study was to test (i) Eysenck's theory that psychoticism (P) should be related to creativity, (ii) whether testosterone (T), due to its association with P claimed in the literature, can be identified as a biological marker of creativity, and (iii) whether the SEEK dimension of the Affective Neuroscience Personality Scales (ANPS) was also related to creativity and to testosterone due to its relationship to Sensation Seeking. In a sample of N = 48 male and female subjects, test scores on figural, verbal, and numeric creativity were compared between high and low P‐scorers as well as between high and low SEEK‐scorers. Effects were controlled for fluid intelligence as measured by Cattell's CFT‐3 and crystallized intelligence as assessed by the Structure‐of‐Intelligence‐Test (Intelligenz‐Struktur‐Test, I‐S‐T 2000 R). Neither a main effect of P or T nor an interaction effect P×T on creativity could be obtained. Instead, SEEK was related to all components of creativity and explained more than 15% of the variance of total creativity. Moreover, significant differences in SEEK could be explained by differences in T, independently of gender. Furthermore, 39% of the variance of SEEK could be explained by the two uncorrelated indicators testosterone and creativity. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis, characterization, and water sorption properties of new aromatic polyamides containing benzimidazole and ethylene oxide moieties
Authors: Ayala Vanesa , Maya Eva M. , García Jose M. , De La Campa Jose G. , Lozano Angel E. , De Abajo Javier 
Published: November 2004

AbstractNew polyamides, containing a benzimidazole side group and ethylene oxide moieties in the structural repeat unit, were synthesized by low‐temperature polycondensation. The aim of this design was to obtain polyamides that were more soluble in common organic solvents and hence had better processability than benzimidazole polyamides while maintaining the water sorption properties characteristic of the latter. The results showed that the number of ether linkages of the repeat unit played an important role in the glass‐transition temperature and in the water sorption properties, the polyamides with one or two ethylene oxide units being more hydrophilic than benzimidazole polyamides. However, the length of the ethylene oxide chain played a minor role in the solubility because the second member of the series, with two ether linkages (i.e., one ethylene oxide unit), reached the same level of solubility as those polyamides with more ethylene oxide moieties. No crystallinity was observed by X‐ray and calorimetric measurements for the new polymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 112–121, 2005
Characterization of the denaturation of human α‐lactalbumin in urea by molecular dynamics simulations
Authors: Smith Lorna J. , Jones Rachel M. , van Gunsteren Wilfred F. 
Published: November 2004

AbstractMolecular dynamics (MD) simulations were used to characterize the non‐cooperative denaturation of the molten globule A‐state of human α‐lactalbumin by urea. A solvent of explicit urea and water molecules was used, corresponding to a urea concentration of approximately 6M. Three simulations were performed at temperatures of 293K, 360K and 400K, with lengths of 2 ns, 8 ns and 8 ns respectively. The results of the simulations were compared with experimental data from NMR studies of human α‐lactalbumin and related peptides. During the simulations, hydrogen bonds were formed from the protein to both urea and water molecules as intra‐protein hydrogen bonds were lost. Urea was shown to compete efficiently with water as both a hydrogen bond donor and acceptor. Radial distribution functions of water and urea around hydrophobic side chain atoms showed a significant increase in urea molecules in the solvation shell as the side chains became exposed during denaturation. A considerable portion of the native‐like secondary structure persisted throughout the simulations. However, in the simulations at 360K and 400K, there were substantial changes in the packing of aromatic and other hydrophobic side chains in the protein, and many native contacts were lost. The results suggest that during the non‐cooperative denaturation of the molten globule, secondary structure elements are stabilized by non‐specific, non‐native interactions. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Extent of protein–protein interactions and quasi‐equivalence in viral capsids
Authors: Shepherd Craig M. , Reddy Vijay S. 
Published: November 2004

AbstractViral capsids are composed of multiple copies of one or a few gene products that self‐assemble on their own or in the presence of the viral genome and/or auxiliary proteins into closed shells (capsids). We have analyzed 75 high‐resolution virus capsid structures by calculating the average fraction of the solvent‐accessible surface area of the coat protein subunits buried in the viral capsids. This fraction ranges from 0 to 1 and represents a normalized protein–protein interaction (PPI) index and is a measure of the extent of protein–protein interactions. The PPI indices were used to compare the extent of association of subunits among different capsids. We further examined the variation of the PPI indices as a function of the molecular weight of the coat protein subunit and the capsid diameter. Our results suggest that the PPI indices in T=1 and pseudo‐T=3 capsids vary linearly with the molecular weight of the subunit and capsid size. This is in contrast to quasi‐equivalent capsids with T≥3, where the extent of protein–protein interactions is relatively independent of the subunit and capsid sizes. The striking outcome of this analysis is the distinctive clustering of the “T=2” capsids, which are distinguished by higher subunit molecular weights and a much lower degree of protein–protein interactions. Furthermore, the calculated residual (Rsym) of the fraction buried surface areas of the structurally unique subunits in capsids with T>1 was used to calculate the quasi‐equivalence of different subunit environments. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Topological determinants of protein unfolding rates
Authors: Jung Jaewoon , Lee Jooyoung , Moon Hie‐Tae 
Published: November 2004

AbstractFor proteins that fold by two‐state kinetics, the folding and unfolding processes are believed to be closely related to their native structures. In particular, folding and unfolding rates are influenced by the native structures of proteins. Thus, we focus on finding important topological quantities from a protein structure that determine its unfolding rate. After constructing graphs from protein native structures, we investigate the relationships between unfolding rates and various topological quantities of the graphs. First, we find that the correlation between the unfolding rate and the contact order is not as prominent as in the case of the folding rate and the contact order. Next, we investigate the correlation between the unfolding rate and the clustering coefficient of the graph of a protein native structure, and observe no correlation between them. Finally, we find that a newly introduced quantity,the impact of edge removal per residue, has a good overall correlation with protein unfolding rates. The impact of edge removal is defined as the ratio of the change of the average path length to the edge removal probability. From these facts, we conclude that the protein unfolding process is closely related to the protein native structure. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Remarkable influence of heat treatment on the structural and superconducting properties of (Y1–xSmx)(SrBa)Cu3O6+z
Authors: Nafidi Ab. , Bellioua M. , El kaaouachi A. , Nafidi Ah. , Rukang Li , Greaves C. 
Published: November 2004

AbstractWe report here on the preparation, effect of heat treatments, X‐ray diffraction and AC magnetic susceptibility measurements in the high Tc superconductor (Y1–xSmx)(SrBa)Cu3O6+z (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8 and 1). Each sample was subject to two types of heat treatment: oxygen annealing [O] and argon annealing followed by oxygen annealing [AO]. When x increases from 0 to 1; in the samples [O] the orthorhombicity ε = b – a/b + a decreases from 9.35 × 10–3 to 0.38 × 10–3 indicating a structural phase transition from orthorhombic to tetragonal; and Tc decreases from 83 K to 79 K. While in the samples [AO], ε decreases by half from 10.14 × 10–3 to 5.72 × 10–3 with an orthorhombic symmetry. This was accompanied by an increase in Tc from 81.5 K to 85 K. For each x, the [AO] heat treatment increases ε(for 0 ≤ x ≤ 1) and Tc (for x ≥ 0.4). We observed a remarkable correlation between δTc(x) = Tc[AO] – Tc[O] and δε(x) = ε[AO] – ε[O]. A combination of several factors such as change in the Cu(1)‐apical oxygen distance, increase in phase purity, in hole density and chain oxygen ordering for the [AO] samples may quali‐ tatively account for the observed data. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Heats of formation of binary semiconductors
Authors: Kumar V. , Sastry B. S. R. 
Published: November 2004

AbstractHeats of formation of tetrahedrally coordinated II–VI and III–V groups of binary semiconductors have been calculated using plasmon energy data. Two simple relations between plasmon energy and heats of formation have been proposed. One is based on spectroscopic model of Phillips and Van Vechten and other is based on the best‐fit data of heats of formation. The calculated values of heats of formation from both the equations are compared with the experimental values and the values reported by earlier workers. A fairly good agreement has been obtained between them. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Suppressive effect of inducible nitric oxide synthase (iNOS) expression by the methanol extract of Actinodaphne lancifolia
Authors: Kim Youngleem , Min Hye‐Young , Park Hyen‐Joo , Lee Eun‐Jin , Park Eun‐Jung , Hwang Hye‐Jin , Jin Changbae , Lee Yong Sup , Lee Sang Kook 
Published: November 2004

AbstractNitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) has played a crucial role in various pathophysiological processes including inﬂammation and carcinogenesis. Therefore, the inhibitors of NO synthesis or iNOS gene expression have been considered as potential anti‐inﬂammatory and cancer chemopreventive agents. In our continuous search for iNOS inhibitors from natural products we have evaluated indigenous Korean plant extracts using an assay for inhibition of nitric oxide formation on lipopolysaccharide (LPS)‐activated mouse macrophage RAW 264.7 cells. As a result, the methanolic stem extract of Actinodaphne lancifolia showed an inhibitory activity of NO production in a dose‐dependent manner (IC50 = 2.5 µg/ml). Additional study demonstrated that the extract of Actinodaphne lancifolia signiﬁcantly suppressed the iNOS protein and gene expression in a dose‐dependent manner. These results suggest that Actinodaphne lancifolia could be a potential candidate for developing an iNOS inhibitor from natural products. Further elucidation of active principles for development of new cancer chemopreventive and/or anti‐inﬂammatory agents could be warranted. Copyright © 2004 John Wiley & Sons, Ltd.
A promising peptide antibiotic from Terfezia claveryi aqueous extract against Staphylococcus aureus in vitro
Authors: Janakat S. , Al‐Fakhiri S. , Sallal A.‐K. 
Published: November 2004

AbstractThe antimicrobial activity of aqueous and methanolic extracts, as well as partially puriﬁed proteins extracted from Terfezia claveryi aqueous extract were investigated against Staphylococcus aureus in vitro. A 5% aqueous extract inhibited the growth of S. aureus by 66.4%, while a methanolic extract was ineffective.Partial protein puriﬁcation of the aqueous extract using ammonium sulphate precipitation revealed that antimicrobial activity was within the third fraction. This fraction was then subjected to gel ﬁltration using Sephadex G‐100. Two peaks were obtained. Peak one possessed higher antimicrobial activity. This peak was then subjected to ion exchange chromatography using DEAE Sephadex. Only peak 4 from the six peaks obtained showed a slight antimicrobial activity.Antimicrobial activities of the aqueous extract and the fractions that showed antimicrobial activity were compared with reference antibiotics. Copyright © 2004 John Wiley & Sons, Ltd.
Evaluation of the antiherpetic activity of standardized extracts of Achyrocline satureioides
Authors: Bettega J. M. R. , Teixeira H. , Bassani V. L. , Barardi C. R. M. , Simões C. M. O. 
Published: November 2004

AbstractTraditionally, Achyrocline satureioides or ‘marcela’ has been used in South America for the treatment of several disorders. For the present study, three spray‐dried extracts (N1, N2 and N3) were used, all of them prepared with 50% of an hydroethanolic extract rich in ﬂavonoid compounds and 50% of blends of different adjuvants. The cytotoxic concentration which causes destruction in 50% monolayer cells (CC50) was 62.5 µg/ml for the three extracts. The antiviral activity was evaluated by using two different strains of herpes simplex virus (HSV‐1) and the best results were obtained with KOS strain and N2 extract. Studies concerning the mechanism of the antiherpetic activity demonstrated that N2 extracts showed no virucidal effect or activity on cellular receptors. HSV‐1 DNA synthesis was not inhibited. The antiherpetic activity occurred between the second and ninth hour of the virus replication cycle, probably indicating a perturbation on late stages of this cycle. Copyright © 2004 John Wiley & Sons, Ltd.
“Between Worlds,” or an Imagined Reminiscence by Oskar Morgenstern about Equilibrium and Mathematics in the 1920s
Authors: Leonard Robert 
Published: November 2004

“Iwas born in 1902 in Görlitz, a small provincial town in Germany, and raised in Vienna, the great city of the multinational Austro-Hungarian empire. On my father's side, my family goes back to about 1530 in Saxony, my Lutheran forebears having been farmers, church wardens, judges, and businessmen. My mother was a natural daughter of Frederick III of Germany …”Yet another account of myself, for yet another encyclopaedia. Italian, this time. Once again, I put pen to paper and collapse the events of fifty years ago to a few familiar milestones. Now what shall I tell these Italians?“I finished the Gymnasium and took my Dr. Rer. Pol. at the University of Vienna in 1925. Awarded a Rockefeller Memorial Fellowship, I spent the next three years in England, the United States, France and Italy. Returning to Vienna, I soon became Docent, later Professor, at the University, and Director of the Austrian Institute for Business Cycle Research …”And then there will be the doctoral thesis,Wirtschaftsprognose, the other Institute, Princeton, and so on. It is remarkable really, the rehearsed inevitability of it all … So often have I gone through exercises of this kind that there are times when I even begin to believe them myself.