bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contrast‐enhanced MR angiography using time resolved interleaved projection sampling with three‐dimensional cartesian phase and slice encoding (TRIPPS)
Authors: Du Jiang 
Published: March 2009

AbstractUndersampled projection reconstruction (PR) techniques provide contrast enhanced MR angiography (CE‐MRA) with high temporal resolution, but sensitivity to eddy current, gradient error and off‐resonance effects. It is desirable to combine the time efficiency of undersampled PR acquisition with the robustness of Cartesian imaging. In this work we present a technique designed to do this termed time resolved projection sampling with three‐dimensional (3D) Cartesian phase and slice encoding (TRIPPS), where 3D Cartesian k‐space is partitioned into multiple half projections in the ky‐kz plane. The phase and slice encoding are performed along predefined center‐out radial trajectories. The whole set of half projections is interleaved into multiple groups of half projections, with each group sparsely but uniformly covering the ky‐kz space. A view sharing sliding window reconstruction algorithm is adapted to reconstruct the dynamic images. The feasibility of the TRIPPS technique for CE‐MRA was demonstrated on the renal, pulmonary, and intracranial vasculatures of healthy volunteers with a high temporal resolution of 2 s/frame. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Modification of rat detrusor muscle contraction by ascorbic acid and citric acid involving enhanced neurotransmitter release and Ca2+influx
Authors: Dasgupta Jaydip , Elliott Ruth A. , Tincello Douglas G. 
Published: March 2009

AbstractAimsConsumption of carbonated soft drinks is independently associated with the development of overactive bladder (OR 1.41, 95% Cl 1.02–1.95). We have shown previously that artificial sweeteners, present in carbonated soft drinks, enhanced detrusor muscle contraction. Other constituents of soft drinks are preservatives and antioxidants, we evaluated the effects of two of these, ascorbic acid and citric acid, on the contractile response of isolated rat bladder muscle strips.MethodsDetrusor muscle strips were suspended in a perfusion organ bath. We determined the effect of ascorbic acid and citric acid on the contractile responses to electrical field stimulation (EFS) in the absence and presence of atropine, carbachol, α, β methylene ATP, potassium and calcium.ResultsAscorbic acid and citric acid (10−7M to 10−3M) enhanced the contractile response to 10 Hz EFS compared to control (P < 0.01). The frequency and amplitude of spontaneous bladder contractions were enhanced in the presence of ascorbic acid and citric acid by 14%, 21%, 21%, and 11% respectively. Ascorbic acid 10−4M significantly increased the atropine resistant response to EFS 5 Hz by 37% (P < 0.01) and inhibited contraction in response to carbachol 10−4M by 24%, (P < 0.05). Both ascorbic acid 10−4M and citric acid 10−5M significantly enhanced maximum contractile responses to α, β methylene ATP, KCI and calcium compared to control.ConclusionsAscorbic acid and citric acid augmented bladder muscle contraction possibly by enhanced Ca2+influx. Presynaptic neurotransmitter release was enhanced by ascorbic acid. Carbonated beverages containing preservatives may aggravate symptoms of OAB. Neurourol. Urodyn. 28:542–548, 2009. © 2009 Wiley‐Liss, Inc.
Naturally compatible: Starch acetate/cellulosic fiber composites. I. Processing and properties
Authors: Nättinen Kalle , Hyvärinen Sari , Joffe Roberts , Wallström Lennart , Madsen Bo 
Published: March 2009

AbstractComposite compounds based on hemp and flax fibers in triethyl citrate plasticized starch acetate were prepared by melt processing. For better properties and processability, compounds with plasticizer contents in the range 20–35 wt% were screened. Composites were prepared with fiber contents up to 50 wt%. The composite mechanical properties were measured from injection molded test specimens. A Young's modulus of 8.3 GPa and stress at maximum load of 51 MPa were obtained with 40 wt% flax fiber in a plasticized starch acetate with 20 wt% triethyl citrate. Decreasing the plasticizer and increasing the fiber content, the tensile properties were consistently improved. An almost linear relation between fiber content and the tensile properties was found. The increase of the fiber content first improved the impact strength, but at higher fiber contents resulted in a reduction of impact strength. The quality of the produced materials was found to be good; the variation in properties between duplicated compounds was acceptable low, the variation in density and fiber content along a single tensile specimen was low, and finally, the porosity content was low even at high fiber content. The latter result was verified with scanning electron microscope images of fracture surfaces of the composites. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Production of poly(lactic acid)/organoclay nanocomposite scaffolds by microcompounding and polymer/particle leaching
Authors: Ozkoc Guralp , Kemaloglu Sebnem , Quaedflieg Martin 
Published: March 2009

AbstractOrganoclay reinforced poly(lactic acid) (PLA)/poly(vinyl alcohol) (PVA) blend based porous nanocomposite scaffolds are prepared by microcompounding/injection molding and subsequent polymer (PVA)/particle (NaCl) leaching method. The objective of the study is to investigate the effect of clay content on the properties of scaffolds for tissue engineering. It is revealed from X‐ray diffraction and TEM studies that incorporation of PVA to PLA matrix as a polymeric porogen enhance the state of dispersion of clay particles resulting in an exfoliated structure. The porosities of all the scaffolds are higher than 70% and the pores are well‐interconnected as observed by SEM. The addition of clay to the scaffolds improves the compressive modulus. Differential scanning calorimeter analysis shows that Tg of neat‐PLA is shifted to lower values when it is compounded with PVA. As a result, it is demonstrated that the method applied in this work can be a good candidate for production of polymeric scaffolds for tissue engineering applications. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
A comparative analysis of a modified picture frame test for characterization of woven fabrics
Authors: Milani A.S. , Nemes J.A. , Lebrun G. , Bureau M.N. 
Published: March 2009

AbstractAn experimental, finite‐element analysis framework is utilized to estimate the deformation state in a modified version of the picture frame test. During the analysis, the effect of fiber misalignment and the deformation heterogeneity in the tested fabric, a 2 × 2 PP/E‐Glass twill, is accounted for and a force prediction model is presented. Using an equivalent stress–strain normalization scheme, the comparison of the modified test with the conventional (original) picture frame and bias‐extension tests is also made, and results reveal similarities and differences that should receive attention in the identification of constitutive models of woven fabrics using these basic tests. Ideally, the trellising behavior should not change from one test to another but results show that in the presence of fiber misalignment, the modified picture frame test yields a behavior closer to that of the bias‐extension test, while the general form of the test's repeatability, measured by a signal‐to‐noise metric, remains similar to the original picture frame test. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Opening the white boxes: the licensing documentation of efficacy and safety of psychotropic medicines for children
Authors: Aagaard Lise , Thirstrup Steffen , Hansen Ebba Holme 
Published: March 2009

AbstractPurposeThe objective of the present study was to explore the available evidence in a regulatory agency on the safety and efficacy of two types of psychotropic medicine frequently prescribed to children and adolescents.MethodsWe analysed the documentation in registration files, renewal registration files, summaries of product characteristics and scientific assessment reports in the Danish Medicines Agency for two psychotropic medications prescribed for children: methylphenidate and citalopram to discover what data pertaining to the pediatric population are available to the regulatory agency.ResultsThe licensing of methylphenidate for treating attention‐deficit hyperactivity disorders (ADHD) in children from the age of six was based on a single‐dose crossover study and, a 2‐week double blind, parallel group clinical trial in 100 patients from ages 6 to 12 and published literature. Citalopram is not licensed for pediatric use in Denmark. Citalopram was being investigated in three ongoing clinical trials lasting 8–24 weeks in 423 patients aged 7–18 years. The registration files contained no data on the long‐term efficacy and safety of citalopram in pediatric use. Registration material also contained information on planned clinical trials with methylphenidate and citalopram among children/adolescents.ConclusionsEvidence on the efficacy and safety of methylphenidate and citalopram for pediatric use in the Danish Medicine Agency is limited and supports the need for further clinical trials. Medicine prescription for the pediatric population should be monitored in order to identify risks that were not identified at the time of licensing. The results of clinical trials already conducted should be made publicly available. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of microstructure on crazing onset in polyethylene under tension
Authors: Addiego Frédéric , Dahoun Abdesselam , G'Sell Christian , Hiver Jean‐Marie , Godard Olivier 
Published: March 2009

AbstractThe influence of microstructure on dilatation onset is analyzed in polyethylene (PE) under tension. Tests are performed by means of a video‐controlled testing system that gives access to true stress σ33—true strain ε33 curve and records volume strain εv during stretching. The results indicate that the strain ε (and the corresponding stress σ) from which viscoplastic dilatation begins depends on microstructural properties of PE. At microscopic scale, materials having a low ε are characterized by inhomogeneous deformation mechanisms leading to pronounced crazing phenomena in amorphous layers. On the contrary, materials having a high ε involve homogeneous deformation mechanisms that limit crazing. These observations are discussed on the basis of crystallinity and tie molecules density. A simple model predicting ε is developed from these microstructural aspects. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
The path to 25% silicon solar cell efficiency: History of silicon cell evolution
Authors: Green Martin A. 
Published: March 2009

AbstractThe first silicon solar cell was reported in 1941 and had less than 1% energy conversion efficiency compared to the 25% efficiency milestone reported in this paper. Standardisation of past measurements shows there has been a 57% improvement between confirmed results in 1983 and the present result. The features of the cell structure responsible for the most recent performance increase are described and the history of crystalline and multicrystalline silicon cell efficiency evolution is documented. Copyright © 2009 John Wiley & Sons, Ltd.
2‐D DIGE analysis of Senegalese sole (Solea senegalensis) testis proteome in wild‐caught and hormone‐treated F1 fish
Authors: Forné Ignasi , Agulleiro María J. , Asensio Esther , Abián Joaquín , Cerdà Joan 
Published: March 2009

AbstractIn the farmed flatfish Senegalese sole, F1 males reared in captivity often show lower sperm production and fertilization capacity than wild‐caught males. To gain insights into the molecular mechanisms that may be altered in the F1 testis, we used 2‐D DIGE to compare the protein profiling of the testis of wild‐caught males at the spermiation stage with that of F1 males showing different stages of germ cell development after hormone treatment in vivo. The abundance of 58 out of 1014 protein spots was found to differ significantly between the groups. De novo identification of these proteins by MS/MS revealed that proteins implicated in oxidoreductase activity, protein catabolism, formation of the zona pellucida receptor, cytoskeleton organization, and lipid binding and metabolism, were regulated in the F1 testes as germ cell development progressed. However, distinct isoforms or PTMs of some of these proteins, as well as of proteins involved in iron and glucose metabolism and ATP production, were expressed at lower levels in the testes of F1 males than in wild fish regardless of the hormone treatment. These results contribute to identifying proteins associated with spermatogenesis not previously described in teleosts, and suggest potential mechanisms that may be involved in the poor reproductive performance of Senegalese sole F1 males.
The two‐phase partitioning system – a powerful technique to purify integral membrane proteins of Corynebacterium glutamicum for quantitative shotgun analysis
Authors: Fränzel Benjamin , Fischer Frank , Trötschel Christian , Poetsch Ansgar , Wolters Dirk 
Published: March 2009

AbstractWe established a single consecutive strategy which assigned the most comprehensive number of integral membrane proteins from Gram‐positive bacteria to date. For this purpose, we adapted a biphasic partitioning system for the biotechnologically intensively used Corynebacterium glutamicum and proved for the first time that such a system is well suited for quantitative comparison. 297 integral membrane proteins were identified by our integrated approach, which depletes stringently cytosolic proteins. In combination with our previously developed SIMPLE strategy, our data comprise 61% (374 integral membrane proteins) of the entire membrane proteome, which aims towards an almost comprehensive coverage. Wild type and a production strain of C. glutamicum were compared by 15N metabolic labelling and quantitation was obtained by spectral counting and peak areas. Both quantification strategies display a consistent trend in up or downregulation of proteins. Nevertheless, spectral counting often provides results indicating a much stronger regulation compared to ProRata values. Either spectral counting seems to exaggerate protein regulation or ProRata tends to attenuate the information about the regulation level. We highlight some of the biologically relevant candidates, which prove that our approach helps to give a deeper quantitative insight towards the understanding of transport and other membrane associated processes, important for strain development of C. glutamicum.
Ethylene polymerization behavior of Cr(III)‐containing montmorillonite: Influence of chromium compounds
Authors: Yamamoto Kazuhiro , Ishihama Yoshiyuki , Isobe Eiji , Sugano Toshihiko 
Published: March 2009

AbstractMontmorillonite was treated with Cr(NO3)3, Cr(acetate)3, and Cr(acac)3 to give three catalyst precursors, Cr‐MMT‐1, Cr‐MMT‐2, and Cr‐MMT‐3, respectively. Application of these catalysts to the ethylene polymerization reaction revealed Cr‐MMT‐1 to be much more reactive than the other two while the molecular weight distributions of the polymers were practically the same. Elemental analysis, XRD, and TEM measurements suggested that chromium occupied the interlayer section in Cr‐MMT‐1 and mostly the outer surface region for the other two catalysts. Aluminosilicate‐supported Cr catalysts exhibited reactivity similar to that of Cr‐MMT‐2 and Cr‐MMT‐3. However, more of the low‐molecular‐weight polymer was formed. These data suggested that there is a relationship between the sites of the Cr ions and catalytic reactivity, and between supporting solid identity and molecular weight distribution of the polymer. The use of n‐Bu2Mg and Et2Zn in the place of Et3Al led to lower activity but gave polymers of narrower molecular weight distribution, with more of the high‐molecular‐weight material. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2272–2280, 2009
Heterogeneous polymerization with polyaspartate macromonomer having vinyl pendant groups. II. Control of particle diameter and diameter distribution in dispersion copolymerization
Authors: Tomita Keisuke , Ono Tsutomu 
Published: March 2009

AbstractTo control particle diameter and particle diameter distribution in dispersion copolymerization of styrene and sodium polyaspartate macromonomer containing vinylbenzyl pendant groups, effects of some polymerization parameters, water contents, initiator concentration, styrene monomer concentration, reaction temperature, and type of initiator on the particle diameter and the diameter distribution were investigated. Variation of the water contents from 20 to 80 vol % controls the resultant particle diameter from 0.066 to 0.47 μm. The diameter increased with increasing initiator concentration. This tendency is similar to dispersion polymerization system using a nonpolymerizable stabilizer. Particle diameter distribution broadened with increasing styrene monomer concentration. This trend was attributed to the increase of a period of particle formation. This result indicated that the period of particle formation affected the resultant particle diameter distribution. Particle diameter distribution was successfully improved (CV = 9.1 from 23.6%) by shortening of decomposition time of initiator. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2281–2288, 2009
Alternatively linking fullerene and conjugated polymers
Authors: Hiorns Roger C. , Iratçabal Pierre , Bégué Didier , Khoukh Abdel , De Bettignies Rémi , Leroy Jocelyne , Firon Muriel , Sentein Carole , Martinez Hervé , Preud'homme Hugues , Dagron‐Lartigau Christine 
Published: March 2009

AbstractThe stereo‐electronic control over bisadditions of conjugated polymers to fullerene (C60) is explored in the formation of alternating copolymers. The chemistry, resulting configuration, and properties of poly(3‐hexylthiophene)‐alt‐C60 copolymers prepared by either classic pyrrolidine ring formation or an atom transfer radical addition are compared. Both routes result in controlled additions of polymers to C60. Extensive macromolecular modeling through PM6 methods indicate that there is no conjugation between P3HT and C60 in the systems studied. This along with 2D‐NMR, AFM, and photovoltaic characterizations of the materials indicate the importance of the structure of the modified C60 and the nature of the linking group between C60 and P3HT segments in determining the morphology of the copolymers in the solid state. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2304–2317, 2009
High Tg and high organosolubility of novel unsymmetric polyimides
Authors: Chern Yaw‐Terng , Tsai Jeng‐Yu , Wang Jane‐Jen 
Published: March 2009

AbstractA series of new polyimides (PIs) containing di‐tert‐butyl side groups were synthesized via a polycondensation of 1‐(4‐aminophenoxy)‐4‐(4‐amino‐2‐methylphenyl)‐2,6‐di‐tert‐butylbenzene (3) with various aromatic tetracarboxylic dianhydrides. The novel unsymmetric PIs exhibited a low dielectric constants (2.78–3.02), low moisture absorption (0.53–1.35%), excellent solubility, and high glass transition temperature (308–450 °C). The PI derived from the new diamine and the very rigid naphthalene‐1,4,5,8‐tetracarboxylic dianhydride (NTDA) was soluble in N‐methyl‐2‐pyrrolidone, chloroform, m‐cresol, and cyclohexanone. The unsymmetric di‐tert‐butyl pendent groups significantly enhance the rotational barrier of the polymer chains; thus these PIs had high Tgs. The 1H NMR spectrum of the diamine 3 revealed that the protons of 4‐aminophenoxy moiety are not chemical shift equivalent. This is because the steric hindrance of the bulky di‐tert‐butyl groups prevents the benzene ring of 4‐aminophenoxy moiety from rotating freely. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2443–2452, 2009
Micro‐FT‐IR study of stretching a single filament: Polymorphic transition in nylon 6
Authors: Na Bing , Lv Ruihua , Tian Nana , Xu Wenfei , Li Zhujun , Fu Qiang 
Published: March 2009

AbstractThe polymorphic transition (γ → α conversion) in a single nylon 6 filament under stretching has been explored for the first time by using micro‐FT‐IR spectroscopy. The content of γ‐form deceases with straining while the amount of α‐form gradually increases, suggesting γ → α conversion. A two‐step mechanism, that is, melting and recrystallization, seems pertinent for the γ → α conversion considering that the γ‐form shows somewhat reversible and the α‐form keeps nearly intact upon unloading. Moreover, stress‐induced γ → α conversion at large strain can be well correlated with the molecular orientation in the amorphous phase and thus a serial arrangement between the γ crystals and amorphous phase along the stretching direction is proposed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 898–902, 2009
Characterization of poly(vinylidene fluoride)/Na+‐MMT composites: An investigation into the β‐crystalline nucleation effect of Na+‐MMT
Authors: Wu Tongfei , Xie Tingxiu , Yang Guisheng 
Published: March 2009

AbstractPoly(vinylidene fluoride)(PVDF)/Na+‐MMT composites have been successfully prepared utilizing sodium montmorillonite (Na+‐MMT) via N,N‐dimethylformamide (DMF) solution mixing. The dispersion of Na+‐MMT layers in composites were investigated by transmission electron microscopy (TEM) and X‐ray diffraction (XRD). The effect of adding Na+‐MMT on crystallization behavior of PVDF was specifically studied. The β‐crystalline nucleation effect of Na+‐MMT was investigated and confirmed by differential scanning calorimetry (DSC), XRD, and Fourier transform infrared (FTIR) results. The interaction between PVDF and the surface of Na+‐MMT layers in DMF solution was confirmed by UV‐Vis absorbency. The effect of adding Na+‐MMT on rheological and electrical properties of PVDF/Na+‐MMT composites were also determined. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 903–911, 2009
Physio‐Chemical Modifications of Polystyrene and Poly(propylene) Surfaces by Electron Beam‐Generated Plasmas Produced in Argon
Authors: Lock Evgeniya H. , Walton Scott G. , Fernsler Richard F. 
Published: March 2009

AbstractPulsed, electron beam generated plasmas produced in argon were used to modify the surfaces of polystyrene and poly(propylene). The influence of plasma parameters including duty factor, plasma period and exposure time on the surface chemistry, energy and morphology was investigated. In these plasmas, the energy of ions striking the surfaces was modest (≤ 5 eV) and comparable to the bond strength of most polymers. Despite the lack of reactive species in the background, a substantial modification in the chemical composition of the polymer surface occurred, leading to a significant increase in surface energy. These changes occurred without a significant increase in surface roughness, or loss of material due to etching. Indeed, the surface morphology of polystyrene was practically unchanged, whereas the surface of poly(propylene) became smoother with plasma exposure. Based on theoretical estimations, the ions play major role in the modification of polymers.magnified image
Thermal Initiation of Non‐Electric Detonators
Authors: Zucker Jonathan M. , Dickson Peter , Sanders V. Eric 
Published: March 2009

AbstractCookoff – the concept of heating explosives to ignition – is a useful tool for determining issues that may be related to safely using and storing explosives, and as such, cookoff experiments have been performed on many different materials. All explosive systems require a means of initiation, which is usually a detonator: a device that often contains a sensitive, primary explosive and a more powerful, secondary explosive. Even if the cookoff behaviors of all the individual explosives in an explosive system are known, the behavior of the combined system may be quite different. In this experiment, the cookoff behavior of non‐electric detonators is investigated. It was determined that there was no distinguishable difference between initiating detonators properly or heating them at a rate greater than 10 °C min−1. Heating detonators at rates less than 10 °C min−1 diminished their output.