bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methods to calculate sedimentation rates of floodplain soils in the middle region of the Elbe River
Authors: Krüger Frank , Schwartz René , Kunert Maritta , Friese Kurt 
Published: June 2006

AbstractThis study presents different methods to quantify the historic and recent sedimentation of floodplain soils along the Elbe River. These methods include the comparison of surface elevations, the quantification of sedimentation with the aid of anthropogenic and geogenic tracers, sediment trap studies, and the calculation of load balances. Selected results from sites at the lower section of the middle Elbe River are presented and verified. The results show that several methods are suitable. In future work it should be possible, depending on the available soil and sediment data, to calculate sedimentation in Elbe River floodplain and the loss of retention volume for larger areas.
Physical and mechanical properties of flexible polybenzoxazine resins: Effect of aliphatic diamine chain length
Authors: Allen Douglas J. , Ishida Hatsuo 
Published: June 2006

AbstractA series of linear aliphatic diamine‐based benzoxazine monomers has been polymerized into transparent, crosslinked specimens that are free of voids and have good mechanical integrity. The density of these polybenzoxazines is measured as a function of the amine chain length. Dynamic mechanical analysis of these linear aliphatic polybenzoxazines shows two, chain length dependent transitions. Properties, such as room temperature modulus, glass transition temperature, crosslink density, thermal degradation temperature, and char yield, of the polybenzoxazines are investigated as a function of the chain length. All these properties exhibit strong dependence on the chain length. These aliphatic amine‐based polybenzoxazines are found to be much more flexible than the bisphenol‐type polybenzoxazines. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2798–2809, 2006
Fabrication and characterization of a persimmon leaves (PL)/poly(acrylonitrile) (PAN) blend bio‐fiber
Authors: Li De‐Lan , Shen Qing , Ding Hong‐Gui , Gu Qing‐Feng , Wang Zhi‐Xin 
Published: June 2006

AbstractAdopting persimmon leaves, PL, as a biomaterial to blend with poly(acrylonitrile) (PAN) via the wet spinning method, a PL/PAN blend biofiber was fabricated. On the basis of mechanical measurements, X‐ray diffraction, and DSC characterization, it was found that this biofiber has acceptable mechanical properties for further applying to different cases. Results also showed that though the crystal structure, especially the crystal size, is changed indeed for blend fiber, it seems to be of less influence on the thermal properties, especially the crystallization temperature, Tc. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2810–2813, 2006
Poly(aspartic‐acid) derivatives as polymeric micelle drug delivery systems
Authors: Jiang Tong‐ying , Wang Zhong‐yan , Chen Chuang , Mo Feng‐kui , Xu Yan‐li , Tang Lin‐xi , Liang Ji‐jun 
Published: June 2006

AbstractA novel amphiphilic biodegradable graft copolymer based on poly(aspartic acid) (PASP) was prepared by coupling monomethoxy poly(ethylene glycol) as the hydrophilic segment with PASP‐g‐octadecyl (PASP‐g‐OD) as the hydrophobic backbone. The critical micelle concentration of the copolymer was obtained by measuring the conductivity and fluorescence spectroscopy. Polymeric micelles were prepared with the solvent evaporation method, and the size distribution and morphology of the polymeric micelles were characterized by dynamic light scattering and transmission electron microscopy. The ability of the PASP derivatives to solubilize hydrophobic drugs was investigated using methotrexate (MTX), oleanolic acid, and podophyllotoxin (PODO) as models. The results demonstrated that drug solubility depends on the copolymer concentration, copolymer composition, as well as the physicochemical property of the drug. A stability study performed with PODO loaded by polymeric micelle solution demonstrated that the micelle carrier could protect the drug from being destroyed in a pH 7.4 buffer solution; however, the micelle did not protect it in a pH 9.5 buffer solution. Pharmacokinetic studies were carried out by intravenous administration of MTX loaded by polymeric micelle solution and MTX solution. The results demonstrated that the polymeric micelle prolonged the drug permanence in blood circulation with a mean residence time of about 2.37 times and increased the systemic bioavailability with the area under the drug concentration–time curve by about 2.34 times. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2871–2878, 2006
Novel organosoluble poly(amide‐imide‐imide)s synthesized from new tetraimide‐dicarboxylic acid by condensation with 4,4′‐oxydiphthalic anhydride, 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene, trimellitic anhydride, and various aromatic diamines
Authors: Yang Chin‐Ping , Chen Ya‐Ping , Woo E. M. 
Published: June 2006

AbstractA new monomer of tetraimide‐dicarboxylic acid (IV) was synthesized by starting from ring‐opening addition of 4,4′‐oxydiphthalic anhydride, trimellitic anhydride, and 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene at a 1:2:2 molar ratio in N‐methyl‐2‐pyrrolidone (NMP). From this new monomer, a series of novel organosoluble poly(amide‐imide‐imide)s with inherent viscosities of 0.7–0.96 dL/g were prepared by triphenyl phosphite activated polycondensation from the tetraimide‐diacid with various aromatic diamines. All synthesized polymers were readily soluble in a variety of organic solvents such as NMP and N,N‐dimethylacetamide, and most of them were soluble even in less polar m‐cresol and pyridine. These polymers afforded tough, transparent, and flexible films with tensile strengths ranging from 99 to 125 MPa, elongations at break from 12 to 19%, and initial moduli from 1.6 to 2.4 GPa. The thermal properties and stability were also good with glass‐transition temperatures of 236–276°C and thermogravimetric analysis 10 wt % loss temperatures of 504–559°C in nitrogen and 499–544°C in air. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2854–2864, 2006
Transetherification of melamine–formaldehyde resin methyl ethers and competing reaction of self‐condensation
Authors: Pavlyuchenko V. N. , Ivanchev S. S. , Rätzsch M. , Bucka H. , Primachenko O. N. , Leitner P. , Khaikin S. Ya. 
Published: June 2006

AbstractTransetherification of methyl ethers of melamine‐formaldehide resins (MER) with monophenyl ethers of ethylene glycol or propylene glycol (ROH) and competing reaction of self‐condensation are studied depending on MER composition (amounts of CH3O, CH2OH, and NH2 groups), ROH type, MER/ROH molar ratio, presence or absence of acid catalysts, and temperature. High rates of self‐condensation processes prevent a complete conversion of CH3O into RO‐groups. It turned out MER free of methylol groups were not able to be transetherified with high yields due to a premature gelation taking place prior to attaining 50% conversion of methoxy groups (∼4 mol/kg) even at low MER/ROH ratios. In contrast, transetherification of MER with methylol groups content up to 3 mol/kg affords the incorporation of RO‐groups into the resin up to 8 mol/kg owing to direct etherification of CH2OH groups. The following factors are responsible for the growth of etherified product yield: presence of methylol groups in MER in some amounts without deterioration of MER–ROH compatibilization; CH3O/ROH molar ratio no higher than 1; primary alcohols (ROH) is more preferable compared to secondary ones; thermal activation of the process is more efficient in comparison with acidic catalysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2977–2985, 2006
Mechanical and thermal properties of ABS and leather waste composites
Authors: Ramaraj B. 
Published: June 2006

AbstractTo determine the possibility of using leather waste as reinforcing filler in the thermoplastic polymer composite, acrylonitrile–butadiene–styrene (ABS) as the matrix and leather buffing powder as reinforcing filler were used to prepare a particulate reinforced composite to determine testing data for the physical, mechanical, and thermal properties of the composites, according to the filler loading in respect to thermoplastic polymer. The ABS and leather powder composites were prepared by the extrusion of ABS with 2.5, 5, 7.5, 10, 12.5, and 15 wt % of leather powder in corotating twin screw extruder. The extruded strands were cut into pellets and injection molded to make specimens. These specimens were tested for physicomechanical properties like tensile and flexural strengths, tensile and flexural modulus, Izod and charpy impact strength, abrasion resistance, Rockwell hardness, density, Heat deflection temperature (HDT) and Vicat softening point (VSP), water absorption, and thermal degradation analysis. The incorporation of leather waste powder does not affect the tensile, flexural strengths, Izod impact strength, abrasion resistance, Rockwell hardness, density, HDT and VSP values drastically. However, the tensile modulus, tensile elongation, and charpy impact strength values are reduced significantly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3062–3066, 2006
Formation of Freestanding Single‐Walled Carbon Nanotubes by Plasma‐Enhanced CVD
Authors: Kato T. , Hatakeyama R. 
Published: June 2006

AbstractFreestanding individual single‐walled carbon nanotubes (SWNTs) are successfully produced using plasma‐enhanced (PE)CVD. The quantitative effects of plasmas on SWNT growth are also discussed on the basis of detailed plasma measurements and simple calculations. According to these quantitative results, it is found that the plasma sheath effectively plays the role of driving force in making individual SWNTs stand vertically on a substrate surface. This three‐dimensional alignment control of individual SWNTs based on plasma science and technology has huge potential to create a new type of architecture for future nanotube devices.
Developmental cell death during Xenopus metamorphosis involves BID cleavage and caspase 2 and 8 activation
Authors: Du Pasquier D. , Rincheval V. , Sinzelle L. , Chesneau A. , Ballagny C. , Sachs L.M. , Demeneix B. , Mazabraud A. 
Published: June 2006

AbstractElimination of tadpole organs during Xenopus metamorphosis is largely achieved through apoptosis, and recent evidence suggest involvement of the mitochondrial death route and bax‐initiated caspase‐3 and ‐9 deployment. However, events upstream of the activation of Bax are unknown. In other models, proteins of the BH3‐only group such as BID are known to assure this function. We show that Xenopus bid transcript levels increase at metamorphosis in larval cells destined to disappear. This increase correlates with an abrupt rise in Caspase‐2 and ‐8 mRNA levels and an enhanced activity of Caspase‐2 and ‐8. In BIDGFP transgenic animal's tail regression is accelerated. The cleavage of BIDGFP fusion protein during natural or T3‐induced metamorphosis was specifically inhibited by caspase‐8 inhibitors. Our results show that tail regression at metamorphosis implicates an apoptotic pathway inducible by T3 hormone in an organ autonomous manner and involving the cell death executioners BID and Caspases‐2 and ‐8. Developmental Dynamics 235:2083–2094, 2006. © 2006 Wiley‐Liss, Inc.
Chiral separation of cetirizine by capillary electrophoresis
Authors: Van Eeckhaut Ann , Michotte Yvette 
Published: June 2006

AbstractChiral separation of cetirizine, a second‐generation H1‐antagonist, was studied by CD‐mediated CE. Several parameters, including pH, CD type, buffer concentration, type of co‐ion, applied voltage and temperature, were investigated. The best conditions for chiral separation were obtained using a 75 mM triethanolamine‐phosphate buffer (pH 2.5) containing 0.4 mg/mL heptakis(2,3‐diacetyl‐6‐sulfato)‐β‐CD and 10% ACN. Online UV detection was performed at 214 nm, a voltage of 20 kV was applied and the capillary was temperature controlled at 25°C by liquid cooling. Hydrodynamic injection was performed for 1 s. The method was validated for the quantification of levocetirizine in tablets and for enantiomeric purity testing of the drug substance. Selectivity, linearity, LOD and LOQ, precision and accuracy were evaluated for both methods. The amount of levocetirizine dihydrochloride in the commercially available tablets was quantified and was found to be within the specification limits of the claimed amount (5 mg). The amount of distomer in levocetirizine drug substance was found to be 0.87 ± 0.09% w/w, which is in agreement with the certificate of analysis supplied by the company.
Simulation of flows with violent free surface motion and moving objects using unstructured grids
Authors: Löhner Rainald , Yang Chi , Oñate Eugenio 
Published: June 2006

AbstractA volume of fluid (VOF) technique has been developed and coupled with an incompressible Euler/Navier–Stokes solver operating on adaptive, unstructured grids to simulate the interactions of extreme waves and three‐dimensional structures. The present implementation follows the classic VOF implementation for the liquid–gas system, considering only the liquid phase. Extrapolation algorithms are used to obtain velocities and pressure in the gas region near the free surface. The VOF technique is validated against the classic dam‐break problem, as well as series of 2D sloshing experiments and results from SPH calculations. These and a series of other examples demonstrate that the ability of the present approach to simulate violent free surface flows with strong nonlinear behaviour. Copyright © 2006 John Wiley & Sons, Ltd.
Arsenic derivatives in hematologic malignancies: a role beyond acute promyelocytic leukemia?
Authors: Verstovsek Srdan , Giles Francis , Quintás‐Cardama Alfonso , Perez Nichole , Ravandi‐Kashani Farhad , Beran Miloslav , Freireich Emil , Kantarjian Hagop 
Published: June 2006

AbstractThe importance of arsenic trioxide (As2O3) has been underscored over the last decade due to its efficacy against acute promyelocytic leukemia (APL), a disease in which this agent has been associated with complete hematologic and molecular remission rates of 87% and 83%, respectively. The different molecular mechanisms of action of As2O3 suggest its applicability in hematologic malignancies other than APL. However, responses obtained thus far have consisted of improvements in signs and symptoms without the elimination of a given disease. Toxicities derived from As2O3 are significant but manageable and reversible. However, the risk/benefit ratio of As2O3 in hematologic malignancies other than APL is still unclear. The development of new generations of orally bioavailable inorganic, as well as new organic, arsenic compounds with improved toxicity profiles may bolster the therapeutic application of arsenic derivatives in hematologic malignancies such as leukemia, multiple myeloma and myelodysplastic syndromes. Copyright © 2006 John Wiley & Sons, Ltd.
Can the semiempirical PM3 scheme describe iron‐containing bioinorganic molecules?
Authors: McNamara Jonathan P. , Sundararajan Mahesh , Hillier Ian H. , Ge Jun , Campbell Andrew , Morgado Claudio 
Published: June 2006

AbstractA set of iron parameters for use in the semiempirical PM3 method have been developed to allow the structure and redox properties of the active sites of iron‐containing proteins to be accurately modeled, focussing on iron–sulfur, iron–heme, and iron‐only hydrogenases. Data computed at the B3LYP/6‐31G* level for a training set of 60 representative complexes have been employed. A gradient‐based optimization algorithm has been used, and important modifications of the core repulsion function have been highlighted. The derived parameters lead in general to good predictions of the structure and energetics of molecules both within and outside the training set, and overcome the extensive deficiencies of a B3LYP/STO‐3G model. Particularly encouraging is the success of the parameters in describing [4Fe‐4S] cubanes. The derived parameter set provides a starting point should greater accuracy for a more restricted range of compounds be required. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1307–1323, 2006
MRI, volumetry, 1H spectroscopy, and cerebropetal blood flowmetry in childhood idiopathic anatomic megalencephaly
Authors: Koudijs Suzanne M. , van der Grond Jeroen , Hoogendoorn Mechteld L.C. , Hulshoff Pol Hilleke E. , Schnack Hugo G. , Witkamp Theo D. , Gooskens Rob H.J.M. , van Nieuwenhuizen Onno , Braun Kees P.J. 
Published: June 2006

AbstractPurposeTo evaluate cerebral abnormalities in childhood idiopathic anatomic megalencephaly (MC) by means of different magnetic resonance (MR) modalities.Materials and MethodsMRI, volumetry, spectroscopy, and cerebropetal blood flowmetry were performed in six children with idiopathic anatomic MC, and seven volunteers.ResultsMRI revealed an increased ventricular system in five of six patients. A thalamic hamartoma was found in one patient and a Chiari I malformation was found in two. Volumetric analysis showed a disproportional increase of ventricular volume but normal subarachnoid cerebrospinal fluid (CSF) volume. Supratentorial volume was disproportionally increased compared to cerebellar volume. Intracranial volume correlated significantly with skull circumference. MR spectroscopy (MRS) N‐acetyl aspartate/choline (NAA/Cho) peak ratios in WM were significantly higher in patients than in controls. Choline/creatine (Cho/Cr) peak ratios in WM were significantly lower in patients. Cortical gray matter (GM) MRS ratios were unaltered. Cerebropetal flow was increased in MC, possibly related to increased brain volume.ConclusionThis study reveals associated developmental anomalies for idiopathic anatomic MC. A relative ventriculomegaly was found, which should not be misinterpreted as true hydrocephalus. In contrast to metabolic MC, MRS showed no severe disturbances. Total intracranial volume is correlated to skull circumference and cerebropetal blood flow. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
High‐resolution, time‐resolved MRA provides superior definition of lower‐extremity arterial segments compared to 2D time‐of‐flight imaging
Authors: Thornton F.J. , Du J. , Suleiman S.A. , Dieter R. , Tefera G. , Pillai K.R. , Korosec F.R. , Mistretta C.A. , Grist T.M. 
Published: June 2006

AbstractPurposeTo evaluate a novel time‐resolved contrast‐enhanced (CE) projection reconstruction (PR) magnetic resonance angiography (MRA) method for identifying potential bypass graft target vessels in patients with Class II–IV peripheral vascular disease.Materials and methodsTwenty patients (M:F = 15:5, mean age = 58 years, range = 48–83 years), were recruited from routine MRA referrals. All imaging was performed on a 1.5 T MRI system with fast gradients (Signa LX; GE Healthcare, Waukesha, WI). Images were acquired with a novel technique that combined undersampled PR with a time‐resolved acquisition to yield an MRA method with high temporal and spatial resolution. The method is called PR hyper time‐resolved imaging of contrast kinetics (PR‐hyperTRICKS). Quantitative and qualitative analyses were used to compare two‐dimensional (2D) time‐of‐flight (TOF) and PR‐hyperTRICKS in 13 arterial segments per lower extremity. Statistical analysis was performed with the Wilcoxon signed‐rank test.ResultsFifteen percent (77/517) of the vessels were scored as missing or nondiagnostic with 2D TOF, but were scored as diagnostic with PR‐hyperTRICKS. Image quality was superior with PR‐hyperTRICKS vs. 2D TOF (on a four‐point scale, mean rank = 3.3 ± 1.2 vs. 2.9 ± 1.2, P < 0.0001). PR‐hyperTRICKS produced images with high contrast‐to‐noise ratios (CNR) and high spatial and temporal resolution. 2D TOF images were of inferior quality due to moderate spatial resolution, inferior CNR, greater flow‐related artifacts, and absence of temporal resolution.ConclusionPR‐hyperTRICKS provides superior preoperative assessment of lower limb ischemia compared to 2D TOF. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Delivery and assessment of endovascular stents to repair aortic coarctation using MR and X‐ray imaging
Authors: Saeed Maythem , Henk Christine B. , Weber Oliver , Martin Alastair , Wilson Mark , Shunk Kendrick , Saloner David , Higgins Charles B. 
Published: June 2006

AbstractPurposeTo investigate the utility of MR and X‐ray imaging for characterizing aortic coarctation and flow, and guiding the endovascular catheter to place a stent to repair the coarctation.Materials and MethodsThe descending aorta in eight dogs was looped with elastic band and tightened distal to the subclavian artery. Balanced fast field echo (bFFE) and velocity‐encoded cine (VEC) MRI sequences were used for device tracking and measuring aortic flow. A T1‐weighted fast‐field echo sequence (T1‐FFE) was used to visualize the coarctation and roadmap the aorta. Nitinol stents were guided by a nitinol guidewire and placed under MR guidance.ResultsAortic coarctation was visible on MR and X‐ray imaging. The procedure success rate was 88%. VEC MRI measured the changes in aortic flow (baseline = 1.3 ± 0.2, coarctation = 0.2 ± 0.02, and stent placement = 0.8 ± 0.1 liters/minute). A significant reduction in iliac blood pressure was measured after coarctation, but it was reversed by stent placement. The stent lumen was visible on X‐ray fluoroscopy, but not on MRI.ConclusionStent deployment to repair aortic coarctation is feasible under MR guidance. The combined use of MR and X‐ray imaging is effective for anatomic and functional evaluation of aortic coarctation dilation, which may be crucial for optimal therapy. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Accelerated volumetric MRI with a SENSE/GRAPPA combination
Authors: Blaimer Martin , Breuer Felix A. , Seiberlich Nicole , Mueller Matthias F. , Heidemann Robin M. , Jellus Vladimir , Wiggins Graham , Wald Lawrence L. , Griswold Mark A. , Jakob Peter M. 
Published: June 2006

AbstractPurposeTo combine the specific advantages of the generalized autocalibrating partially parallel acquisitions (GRAPPA) technique and sensitivity encoding (SENSE) with two‐dimensional (2D) undersampling.Materials and MethodsBy splitting the 2D reconstruction process into multiple one‐dimensional (1D) reconstructions, the normal 1D GRAPPA method can be used for image reconstruction. Due to this data‐handling process, a GRAPPA reconstruction is performed along the phase‐encoding (PE) direction and effectively a SENSE reconstruction is performed along the partition‐encoding (PAE) direction.ResultsIn vivo experiments demonstrate the successful implementation of the SENSE/GRAPPA combination. Experimental results with up to 9.6‐fold acceleration using a prototype 32‐channel receiver head coil array are presented.ConclusionThe proposed SENSE/GRAPPA combination for 3D imaging allows the GRAPPA method to be applied in combination with 2D undersampling. Because the SENSE/GRAPPA combination is not based on knowledge of spatial coil sensitivities, it should be the method of choice whenever it is difficult to extract the sensitivity information. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.