bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reversible coordinative chain transfer polymerization of styrene by rare earth borohydrides, chlorides/dialkylmagnesium systems
Authors: Zinck Philippe , Valente Andreia , Bonnet Fanny , Violante Ana , Mortreux André , Visseaux Marc , Ilinca Simona , Duchateau Rob , Roussel Pascal 
Published: January 2010

AbstractThe ability of various rare earth borohydride and chloride complexes/n‐butylethylmagnesium systems to operate styrene chain transfer polymerization in mild conditions has been assessed. Thirteen precatalysts have been considered: the rare earth trisborohydrides Ln(BH4)3(THF)x (x = 3, Ln = Nd (1), La (2), Sm (3), x = 2, Ln = Y (4), Sc (5)), the rare earth chlorides LnCl3(THF)x (x = 3, Ln = Nd (6), La (7), Sm (8), Y (9), x = 2, Ln = Sc (10)), the mixed La(BH4)2Cl(THF)2.6 (11) and the half‐lanthanidocenes Cp*Ln(BH4)2(THF)2 (Ln = Nd (12), La (13)). Six systems were found to be active precatalysts for the polymerization of styrene. 1, 2, and 11 led to an efficient transmetalation of the growing polystyrene chain with the simultaneous occurrence of βH elimination, whereas 7, 12, and 13 led to catalyzed chain growth behavior. It is noteworthy that the catalyzed chain growth obtained with 12 and 13 occurs with significant stereoselectivity. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 802–814, 2010
Effect of oligonucleotide conformation on its facilitation efficiency on negatively charged micelle‐to‐vesicle transition
Authors: Guo Xia , Li Hua , Ran Xiangmei , Gong Zhiyun , Guo Rong 
Published: January 2010

AbstractIn our previous article, we reported for the first time that the oligonucleotides composed of one nucleotide species, for example, oligo d(A)n, oligo d(C)n, and oligo d(T)n, could facilitate negatively charged sodium dodecyl sulfate/dodecyl triethyl ammonium bromide mixed micelles to transform to vesicles. In this study, we will report the facilitation ability of self‐complementary hairpin‐structured oligonucleotides, oligo d(AnCTn) and oligo d(AT)nACT(AT)n (or oligo d(AT)nC(AT)n), on micelle‐to‐vesicle transition. It is found that the facilitation behavior of hairpin‐structured oligonucleotide is different from that of the oligonucleotide comprising one base species, and the facilitation efficiency of hairpin‐structured oligonucleotide is closely dependent on the sequence of bases A and T; oligo d(AnCTn) is more efficient than oligo d(AT)nACT(AT)n (or oligo d(AT)nC(AT)n). Moreover, oligo d(AnCTn) is more efficient than oligo d(A)n, oligo d(C)n, and oligo d(T)n. Since so far, there is very limited report about the facilitation effect of oligonucleotide and DNA on vesicle formation as well as the role of their conformation in their interaction with surfactant, this study should be expected to provide some helpful information for the application of DNA/amphiphile system. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 852–860, 2010
Synthesis and gas permeation properties of poly(diarylacetylene)s having substituted and twisted biphenyl moieties
Authors: Hu Yanming , Shimizu Toshiyuki , Hattori Kyohei , Shiotsuki Masashi , Sanda Fumio , Masuda Toshio 
Published: January 2010

AbstractDiarylacetylene monomers containing substituted biphenyl (1a–f) and anthryl (1g) groups were synthesized and then polymerized with TaCl5‐n‐Bu4Sn catalyst to produce the corresponding poly(diarylacetylene)s (2a–g). Polymers 2a–f were soluble in common organic solvents such as cyclohexane, toluene, and chloroform. According to thermogravimetric analysis, the onset temperatures of weight loss of the polymers were over 400 °C in air, indicating considerably high thermal stability. Free‐standing membranes 2a and 2c–e were prepared by the solution casting method. Desilylation of Si‐containing membrane 2c was carried out with trifluoroacetic acid to afford 3c. All the polymer membranes, especially those having twisted biphenyl groups, exhibited high gas permeability; for example, their oxygen permeability (PO2) values ranged from 130 to 1400 barrers. Membrane 2d having two chlorine atoms in the biphenyl group showed the highest gas permeability (PO2 = 1400 barrers) among the present polymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 861–868, 2010
Living cationic polymerization of isobutyl vinyl ether using a variety of metal oxides as heterogeneous catalysts: Robust, reusable, and environmentally benign initiating systems
Authors: Kanazawa Arihiro , Kanaoka Shokyoku , Aoshima Sadahito 
Published: January 2010

AbstractCationic polymerization of isobutyl vinyl ether (IBVE) was examined using a variety of metal oxides in conjunction with IBVE–HCl adduct as a cationogen in toluene at 0 °C. Iron oxides (α‐Fe2O3, γ‐Fe2O3, and Fe3O4) induced living polymerization in the presence of an added base, ethyl acetate or 1,4‐dioxane, to give polymers with very narrow molecular weight distributions (MWDs). Conversely, with other metal oxides such as Ga2O3, In2O3, ZnO, Co3O4, and Bi2O3, polymers with bimodal MWDs, including long‐lived species along with uncontrolled higher molecular weight portions, were produced in the presence of an added base. A small amount of nBu4NCl or 2,6‐di‐tert‐butylpyridine (DTBP) suppressed the uncontrolled portion to induce controlled reactions with Ga2O3, In2O3, and ZnO. The roles of these reagents are discussed in terms of the nature of the active sites of the catalyst surface and the polymerization mechanisms. In addition, the reusability of the catalyst, the effect of stirring before and during polymerization, and the estimation of the number of active sites are also described. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 916–926, 2010
Magnetic polyvinylamine nanoparticles by in situ precipitation reaction
Authors: Mohammadi Zahra , Wang Xiang , Berkland Cory 
Published: January 2010

AbstractMagnetic nanoparticles represent emerging tools in biomedical and pharmaceutical research. Because in most cases, the surfaces of these nanoparticles are hydrophobic, surface modifiers are usually applied to stabilize the colloidal suspension in an aqueous media. This investigation reports a simple technique for the preparation of MnFe2O4 synthesized within polyvinylamine (PVAm) nanoparticle reactors. Magnetite nanoparticles were previously synthesized using a similar scheme; however, substituting MnFe2O4 for Fe3O4 improved nanoparticle magnetization properties and further established the synthetic approach. PVAm nanoparticles exhibited more than 18% manganese ferrite loading by weight, a saturation magnetization of ∼ 40 emu/g of MnFe2O4, excellent colloidal stability, and reactive primary amines for possible drug conjugation or surface modification. Transmission electron micrographs revealed that the dispersions contained ∼ 50 nm PVAm nanoparticles incorporating manganese ferrite particles with a size less than ∼ 7 nm. This reaction scheme further justifies a unique synthetic methodology for magnetic nanoparticles offering potential use in contrast‐enhanced magnetic resonance imaging or drug delivery. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 991–996, 2010
Intrastrand foldamer crosslinking by reductive amination
Authors: Smaldone Ronald A. , Lin En‐chi , Moore Jeffrey S. 
Published: January 2010

AbstractA series of m‐phenylene ethynylene (mPE) foldamers were crosslinked in their helical conformation using a reductive amination‐based strategy. This was accomplished by placing aldehyde moieties in the backbone of the oligomer at specific residues, which allowed a diamine crosslinker to covalently link the helical loops together. Three different foldamers with crosslinks placed at different locations in the backbone were synthesized and characterized by mass spectrometry, 1H NMR, and gel permeation chromatography. The effect of the crosslinking on the stability of the folded state was evaluated through solvent denaturation studies. These studies show a reduction in the oligomer's ability to unfold of up to 30% relative to an unmodified mPE oligomer of the same length in solvents that promote unfolding. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 927–935, 2010
Synthesis of statistical and block copolymers containing adamantyl and norbornyl moieties by reversible addition‐fragmentation chain transfer polymerization
Authors: Lou Qin , Kishpaugh Matthew A. , Shipp Devon A. 
Published: January 2010

AbstractThe synthesis of statistical and block copolymers, consisting of monomers often used as resist materials in photolithography, using reversible addition‐fragmentation chain transfer (RAFT) polymerization is reported. Methacrylate and acrylate monomers with norbornyl and adamantyl moieties were polymerized using both dithioester and trithiocarbonate RAFT agents. Block copolymers containing such monomers were made with poly(methyl acrylate) and polystyrene macro‐RAFT agents. In addition to have the ability to control molecular weight, polydispersity, and allow block copolymer formation, the polymers made via RAFT polymerization required end‐group removal to avoid complications during the photolithography. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 943–951, 2010
Nucleation effect of cyclodextrin inclusion complexes on the crystallization of isotactic poly(1‐butene)
Authors: Li Chun , Isshiki Naoe , Saito Hiromu , Kohno Kazufumi , Toyota Akinori 
Published: January 2010

AbstractThe β‐cyclodextrin (β‐CD) and γ‐cyclodextrin (γ‐CD) inclusion complexes (ICs) with four kinds of polyolefin were prepared. The crystallization behavior of isotactic poly(1‐butene) (iPB‐1) blended with these CDs and ICs was investigated by differential scanning calorimetry, polarized optical microscopy, and wide‐angle X‐ray diffraction. The iPB‐1 blended with the ICs was found to exhibit higher crystallization temperature (TC), smaller spherulites, and faster crystallization rate than neat iPB‐1. These results indicate that the ICs can act as nucleating agent on the crystallization of iPB‐1 and induce the accelerated crystallization. The guest molecules of ICs play an important role in the nucleation effect of ICs on the crystallization of iPB‐1. ICs with polyolefin having higher TC as guest molecules have higher nucleation effect than the one with polyolefin having lower TC as guest molecules. And, the CDs and ICs induce different crystal form of iPB‐1. The crystal of iPB‐1 blended with CDs is defective, whereas the crystal of iPB‐1 blended with ICs is more perfect. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 389–395, 2010
Dimensional stability of sparse network microstructures formed by photopolymerization‐induced phase separation
Authors: Guenthner Andrew J. , Hess David M. , Cash Jessica J. 
Published: January 2010

AbstractThe morphology of sparse filament networks formed during photopolymerization‐induced phase separation of mixtures of NOA81 (a UV‐curable thiol‐ene adhesive) in mixed cosolvents consisting of water, diglyme, and polyethers of varying molecular weight was investigated as a function of the molecular weight and relative amount of the polyethers used. During photopolymerization (50 mW/cm−2 of 365 nm radiation for 60 s) of solutions containing 5 wt % NOA81 and a total oligo‐ether or polyether to water ratio of 8:1 by weight, viscoelastic phase separation produced a sparse network of interconnected NOA81 filaments. During the subsequent evaporation and/or solidification of the solvents, the network compacted significantly via a collapse process that was curtailed by increasing both the weight fraction and molecular weight of the nonvolatile polyether. The influence of mass and momentum transport processes on the collapse of the phase‐separated network and the resultant final morphology was determined with the aid of dimensional analysis, leading to the identification of sedimentation and compaction driven by the motion of the interface as key factors. The networks exhibiting the least collapse combine a high level of interconnectivity and specific surface area with a low occupied volume fraction while being fabricated via a simple, template‐free process. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 396–410, 2010
Optical characterization of polycarbonate: Influence of additives on optical properties
Authors: Aden Mirko , Roesner Andreas , Olowinsky Alexander 
Published: January 2010

AbstractIn laser transmission welding of thermoplastics the optical properties of the joining parts determine the quality of the welding result. Especially, the scattering of laser radiation in the transparent welding part has an impact on weld seam properties. This scattering is caused by additives. For polycarbonate (PC) with different additives the transmittance, the reflectance and the collimated transmittance are measured with a UV‐VIS‐NIR spectrometer. From this data, the optical properties, such as scattering coefficient, absorption coefficient, and anisotropy factor are calculated. The calculations are made with the aid of the four‐flux model of radiation transport in the diffusive approximation. The results show that the additives have a significant influence on the scattering coefficient. For most additives under consideration the scattering is forward directed, which means that most of the radiation is transmitted into the absorbing welding part. However, the power density distribution of the transmitted radiation may differ significantly from PC without additives. So, the weld seam may also differ due to different additives. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 451–455, 2010
Nucleation of isotactic polypropylene crystallization by gold nanoparticles
Authors: Masirek Robert , Szkudlarek Ewelina , Piorkowska Ewa , Slouf Miroslav , Kratochvil Jaroslav , Baldrian Josef 
Published: January 2010

AbstractNucleation of isotactic polypropylene (iPP) crystallization by gold (Au) nanoparticles was studied. Regardless of their size, 4.3, 8.8, 28.3, and 84.5 nm, all particles were able to nucleate spherulites when deposited on the iPP surface. However, when added and melt‐mixed with iPP, only the smallest particles affected significantly the iPP bulk crystallization. Au nanoparticles larger than 4.3 nm, at the concentration of 0.001 wt %, did not influence the crystallization of iPP. Contrary to this, 0.001 and 0.005 wt % of Au nanoparticles having the size of 4.3 nm increased crystallization temperature of the iPP by 7–8 °C and decreased markedly the sizes of polycrystalline aggregates. Aggregation of Au nanoparticles in the polymer matrix was evidenced by electron microscopy and contributed to their decreased effectiveness in the nucleation of iPP crystallization. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 469–478, 2010
The Best of pss
Authors: Stutzmann Martin 
Published: January 2010

AbstractContrary to the overall trend in the worldwide economy, 2009 actually has turned out a good year for the physica status solidi journal series. With more than 10.000 published pages, pss (a), pss (b), pss (c), and pss (RRL) continue to be major players on the stage of journals covering the entire broad spectrum of solid state physics. While more and more highly specialized journals appear on the market, the broad scope of physica status solidi constitutes an opportunity and a challenge at the same time: An opportunity for those who from time to time look across the borders of their own field of specialization and become interested in and are inspired by seemingly unrelated results of colleagues in other fields. A challenge, because the organization of a high quality peer review process for a broad range of topics requires a much larger base of knowledgeable referees and puts a higher demand on the Editorial Boards and the editorial staff. Although we at physica status solidi are certainly not perfect, I am confident that we have done a pretty good job here again in 2009.This is reflected by the continuously increasing Impact Factor of the ISI‐listed pss journals (see figure), as well as by the large number of accesses and downloads on the internet. We are particularly proud of the fact that the first official Impact Factor of the youngest member in the pss family, the Rapid Research Letters, is higher than 2. This is definitely a good start and motivates us to further develop the unique profile of pss (RRL) as the fastest peer‐reviewed journal in solid state physics.To give you an idea of the broad range of topics covered by the various journals of the pss series, below please find a list [1–16] of highly cited, respectively downloaded, or otherwise outstanding articles published in 2008/2009. They reflect the many scientific facets of modern solid state physics: solar cells, carbon‐based materials, spin physics and magnetism, nanotechnology, electronic devices, solid state theory, ferroelectricity, auxetic materials, photocatalysis, organic/inorganic hybrid systems, etc., etc. This ‘Best of pss’ collection can also be reached through the materials science portal of Wiley‐VCH materialsviews.com, and all articles are freely accessible until June. If you have a couple of minutes or – even better – an hour, just browse through this list and enjoy!My best personal wishes and thanks go to all our contributors, readers, referees, my fellow Editors, and the dedicated staff of the Editorial Office in Berlin. May 2010 be a good year for all of you!
Multifaceted activity of HIV Vpr/Vpx proteins: the current view of their virological functions
Authors: Fujita Mikako , Otsuka Masami , Nomaguchi Masako , Adachi Akio 
Published: January 2010

AbstractPrimate immunodeficiency viruses encode viral proteins that are uniquely auxiliary to their growth in host cells. Of these accessory proteins, those designated Vpr and Vpx are least well understood with respect to their functions in the viral replication cycle. Moreover, their assigned roles based on the results in published studies remain controversial. This review summarises current knowledge on human immunodeficiency virus (HIV) Vpr/Vpx proteins, and discusses their functional activities during the viral life cycle in macrophages and T lymphocytes, the two major target cells of HIV infection. Copyright © 2010 John Wiley & Sons, Ltd.
Escape of herpesviruses from the nucleus
Authors: Lee Chung‐Pei , Chen Mei‐Ru 
Published: January 2010

AbstractThe nuclear envelope of eukaryotic cells is composed of double lipid‐bilayer membranes, the membrane‐connected nuclear pore complexes and an underlying nuclear lamina network. The nuclear pore complexes serve as gates for regulating the transport of macromolecules between cytoplasm and nucleus. The nuclear lamina not only provides an intact meshwork for maintaining the nuclear stiffness but also presents a natural barrier against most DNA viruses. Herpesviruses are large DNA viruses associated with multiple human and animal diseases. The complex herpesviral virion contains more than 30 viral proteins. After viral DNA replication, the newly synthesised genome is packaged into the pre‐assembled intranuclear capsid. The nucleocapsid must then transverse through the nuclear envelope to the cytoplasm for the subsequent maturation process. Information regarding how nucleocapsid breaches the rigid nuclear lamina barrier and accesses the inner nuclear membrane for primary envelopment has emerged recently. From the point of view of both viral components and nuclear structure, this review summarises recent advances in the complicated protein–protein interactions and the phosphorylation regulations involved in the nuclear egress of herpesviral nucleocapsids. Copyright © 2010 John Wiley & Sons, Ltd.
Weight of a link in a shortest path tree and the Dedekind Eta function
Authors: Van Mieghem Piet 
Published: January 2010

AbstractThe weight of a randomly chosen link in the shortest path tree on the complete graph with exponential i.i.d. link weights is studied. The corresponding exact probability generating function and the asymptotic law are derived. As a remarkable coincidence, this asymptotic law is precisely the same as the distribution of the cost of one “job” in the random assignment problem. We also show that the asymptotic (scaled) maximum interattachment time to that shortest path tree, which is a uniform recursive tree, equals the square of the Dedekind Eta function, a central function in modular forms, elliptic functions, and the theory of partitions. © 2010 Wiley Periodicals, Inc. Random Struct. Alg., 2010
Multi‐ink pattern generation by dip‐pen nanolithography®
Authors: Jang Jae‐Won , Smetana Alexander , Stiles Paul 
Published: January 2010

AbstractMultiplexed patterns of hydrogels and phospholipids with fluorescent dyes are accomplished by dip‐pen nanolithography® (DPN®). For example, four different dye‐labeled hydrogel dot arrays are DPN® patterned within 50×50 µm2 area, and two different dye‐doped phospholipids dots and letters with less than 1 µm line‐width are also DPN® patterned. We demonstrate that multi‐ink patterns with precise alignment are able to be printed by DPN® within a micron‐scale. Moreover, this multi‐ink DPN® patterning methodology can be extended to delicate bio‐materials printing in a subcellular scale with accurate positioning control. SCANNING 32: 24–29, 2010. © 2010 Wiley Periodicals, Inc.
Cord entanglement and perinatal outcome in monoamniotic twin pregnancies
Authors: Dias T. , Mahsud‐Dornan S. , Bhide A. , Papageorghiou A. T. , Thilaganathan B. 
Published: January 2010

AbstractObjectivesTo assess the prevalence of cord entanglement and perinatal outcome in a large series of monoamniotic twin pregnancies and to review the recent literature on similar published large series.MethodsProspective observational study of all prenatally detected cases of monoamniotic twin pregnancies during an 8‐year period in a tertiary fetal medicine unit. A Medline database review for publications since 2000 containing five or more cases of monoamniotic pregnancies that showed data on cord entanglement and perinatal outcome was also undertaken.ResultsA total of 32 monoamniotic pregnancies were diagnosed during the study period, including three conjoined twins, seven pregnancies with twin reversed arterial perfusion (TRAP) syndrome, three surgical pregnancy interruptions for discordant fetal abnormality and one miscarriage before 16 weeks' gestation. The remaining 18 monoamniotic pregnancies were included in the study analysis. All monoamniotic pregnancies were complicated with antenatal cord entanglement diagnosed by B‐mode and color Doppler ultrasound. There were 34 live births and a double intrauterine death diagnosed at 19 + 2 weeks' gestation. There were two late neonatal deaths, one from congenital complete heart block and the other after surgery for transposition of the great arteries. The overall perinatal loss rate was 11.1% after 16 weeks and 5.9% after 20 weeks' gestation. The cumulative rates of cord entanglement and perinatal mortality in the reviewed literature were 74% and 21%, respectively.ConclusionsUmbilical cord entanglement is present in all monoamniotic twins when it is systematically evaluated by ultrasound and color Doppler. Perinatal mortality in monoamniotic twins is mainly a consequence of conjoined twins, TRAP, discordant anomaly and spontaneous miscarriage before 20 weeks' gestation. Expectantly managed monoamniotic twins after 20 weeks have a very good prognosis despite the finding of cord entanglement. The practice of elective very preterm delivery or other interventions to prevent cord accidents in monoamniotic twins should be re‐evaluated. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.