bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rhodium Nanoparticle Encapsulated in a Porous Carbon Shell as an Active Heterogeneous Catalyst for Aromatic Hydrogenation
Authors: Harada Takashi , Ikeda Shigeru , Ng Yun Hau , Sakata Takao , Mori Hirotaro , Torimoto Tsukasa , Matsumura Michio 
Published: July 2008

AbstractRhodium (Rh) nanoparticle (core)–carbon (shell) powder was prepared by double‐layer coating of a silica layer and a mesoporous silica/carbon layer on an Rh nanoparticle followed by chemical etching with aqueous hydrofluoric acid to remove siliceous components. The use of various techniques for characterization of the structure showed that the powder thus‐obtained had a rattle‐like structure: Rh nanoparticles were encapsulated in the hollow carbon‐shell having well‐developed porosity. The porous wall structure of the lateral carbon shell provides channels and hydrophobic void spaces that allow efficient penetration and absorption of organic species present in aqueous media. This offers a microenvironment with a high concentration of organic substrates inside the shell. Moreover, the surfaces of medial Rh nanoparticles were free from any ligands, i.e., the active surface site(s) was exposed to induce organic transformations. These unique properties, which cannot be achieved by conventional Rh nanoparticles stabilized with organic agents, led to excellent catalytic activity for hydrogenation of various aromatic and heterocyclic rings in water.
Transparent Thin Films of Multiwalled Carbon Nanotubes Self‐Assembled on Polyamide 11 Nanofibers
Authors: Havel Mickael , Behler Kristopher , Korneva Guzeliya , Gogotsi Yury 
Published: July 2008

AbstractElectrospun polyamide 11 (PA11) nanofiber films are used as a guide for the deposition of two‐dimensional networks of multi‐walled carbon nanotubes (MWNTs). This method allows for the manufacturing of transparent and electrically conductive thin films. It is demonstrated that the sheet resistance (Rs) and transmittance (T) decrease, as the films become thicker due to longer electrospinning times or larger fibers. The transmittance could be improved by fusing (melting) the fibers at moderate temperatures or impregnating the film with a resin, showing that light scattering rather than absorption by the MWNTs or the polymer was responsible for a low transmittance. As the number of MWNT deposition cycles increases, the Rs decreases with a constant transmittance. A fused 100 nm film obtained after 10 min of electrospinning of the 2 wt % PA11 solution shows Rs = 154 kΩ sq−1 and T = 83% after ten MWNT deposition cycles. A 95% transmittance was achieved after removing the polymer fibers by heating the glass plate in air (Rs = 440 kΩ sq−1 after five MWNT deposition cycles).
Tin Dioxide Microspheres as a Promising Material for Phosphopeptide Enrichment Prior to Liquid Chromatography‐(Tandem) Mass Spectrometry Analysis
Authors: Sturm Martin , Leitner Alexander , Smått Jan‐Henrik , Lindén Mika , Lindner Wolfgang 
Published: July 2008

AbstractFunctional materials are frequently used to identify and characterize proteins and their modifications in complex biological samples throughout the analytical workflow. Protein phosphorylation is a highly important post‐translational modification that is being examined with the help of diverse materials that exhibit affinity towards the phosphate group of phosphoamino acids. Titanium dioxide and zirconium dioxide particles are increasingly used to enrich phosphopeptides from proteolytic digests of protein mixtures, although specificity and recovery still leave room for improvement. Here, we present tin dioxide (SnO2, stannia) microspheres as a new type of metal oxide material for phosphopeptide enrichment. The microspheres are produced by a nanocasting process, starting from silica particles as a template, which allows the tuning of material properties such as particle diameter and porosity of the microspheres in a straightforward manner. For the first time, we are able to show that tin dioxide can be used to enrich phosphopeptides from mixtures such as enzymatic digests of proteins, followed by analysis by liquid chromatography‐mass spectrometry (LC‐MS). For optimization of the enrichment protocol, we use synthetic phosphorylated and nonphosphorylated peptides, and test different solvent compositions for loading and washing steps to enhance the selectivity of the material without compromising phosphopeptide recovery. Furthermore, the selectivity and phosphopeptide binding properties of tin dioxide are compared to the established metal oxide materials, titanium dioxide and zirconium dioxide, using mixtures of model proteins. Even without the use of additional additives such as α‐hydroxy acids, which have been used to enhance the specificity of TiO2‐based enrichment, we show that a comparably good performance can be achieved for the SnO2 spheres.
Identification of chromosome abnormalities in subtelomeric regions by microarray analysis: A study of 5,380 cases
Authors: Shao Lina , Shaw Chad A. , Lu Xin‐Yan , Sahoo Trilochan , Bacino Carlos A. , Lalani Seema R. , Stankiewicz Pawel , Yatsenko Svetlana A. , Li Yinfeng , Neill Sarah , Pursley Amber N. , Chinault A. Craig , Patel Ankita , Beaudet Arthur L. , Lupski James R. , Cheung Sau W. 
Published: July 2008

AbstractSubtelomeric imbalances are a significant cause of congenital disorders. Screening for these abnormalities has traditionally utilized GTG‐banding analysis, fluorescence in situ hybridization (FISH) assays, and multiplex ligation‐dependent probe amplification. Microarray‐based comparative genomic hybridization (array‐CGH) is a relatively new technology that can identify microscopic and submicroscopic chromosomal imbalances. It has been proposed that an array with extended coverage at subtelomeric regions could characterize subtelomeric aberrations more efficiently in a single experiment. The targeted arrays for chromosome microarray analysis (CMA), developed by Baylor College of Medicine, have on average 12 BAC/PAC clones covering 10 Mb of each of the 41 subtelomeric regions. We screened 5,380 consecutive clinical patients using CMA. The most common reasons for referral included developmental delay (DD), and/or mental retardation (MR), dysmorphic features (DF), multiple congenital anomalies (MCA), seizure disorders (SD), and autistic, or other behavioral abnormalities. We found pathogenic rearrangements at subtelomeric regions in 236 patients (4.4%). Among these patients, 103 had a deletion, 58 had a duplication, 44 had an unbalanced translocation, and 31 had a complex rearrangement. The detection rates varied among patients with a normal karyotype analysis (2.98%), with an abnormal karyotype analysis (43.4%), and with an unavailable or no karyotype analysis (3.16%). Six patients out of 278 with a prior normal subtelomere‐FISH analysis showed an abnormality including an interstitial deletion, two terminal deletions, two interstitial duplications, and a terminal duplication. In conclusion, genomic imbalances at subtelomeric regions contribute significantly to congenital disorders. Targeted array‐CGH with extended coverage (up to 10 Mb) of subtelomeric regions will enhance the detection of subtelomeric imbalances, especially for submicroscopic imbalances. © 2008 Wiley‐Liss, Inc.
Non‐random error in genotype calling procedures: Implications for family‐based and case–control genome‐wide association studies
Authors: Anney Richard J.L. , Kenny Elaine , O'Dushlaine Colm T. , Lasky‐Su Jessica , Franke Barbara , Morris Derek W. , Neale Benjamin M. , Asherson Philip , Faraone Stephen V. , Gill Michael 
Published: July 2008

AbstractThe considerable data‐handling requirements for genome wide association studies (GWAS) prohibit individual calling of genotypes and create a reliance on sophisticated “genotype‐calling algorithms.” Despite their obvious utility, the current genotyping platforms and calling‐algorithms used are not without their limitations. Specifically, some genotypes are not called due to the ambiguity of the data. Any bias in the missing data could create spurious results. Using data from the Genetic Analysis Information Network (GAIN) we observed that missing genotypes are not randomly distributed throughout the homozygous and heterozygous groups. Using simulation, we examined whether the level and type of missingness observed might influence deviation from the null‐hypothesis under common case–control and family‐based statistical approaches. Under a case–control model, where missingness is present in a case group but not the controls, we observed bias giving rise to genome‐wide significant type‐I error for missingness as low as 3%. The family‐based association simulations show close to nominal type‐I error at 4% genotype missingness. These findings have important implications to study design, quality‐control procedures and reporting of findings in GWAS. © 2008 Wiley‐Liss, Inc.
Biarylphosphanliganden in der palladiumkatalysierten Aminierung
Authors: Surry David S. , Buchwald Stephen L. 
Published: July 2008

AbstractIn den vergangenen 12 Jahren erfuhr die palladiumkatalysierte Aminierung von Arylhalogeniden eine rasche Entwicklung, die durch die Einführung neuer Ligandenklassen vorangetrieben wurde. Biarylphosphane liefern in diesem Zusammenhang besonders reaktive Katalysatoren. Dieser Aufsatz behandelt Anwendungen solcher Katalysatoren zur C‐N‐Kreuzkupplung in der Synthese von Heterocyclen und Pharmazeutika, in den Materialwissenschaften und in der Naturstoffsynthese.
Effect of coagulation bath temperature on formation mechanism of poly(vinylidene fluoride) membrane
Authors: Wang Xuyun , Zhang Lin , Sun Dahai , An Quanfu , Chen Huanlin 
Published: July 2008

AbstractEffects of coagulation bath temperature on the membrane formation mechanism and the morphologies of the formed membranes were studied. The binodal and spinodal lines in the phase diagrams of water/DMAc/Poly(vinylidene fluoride) (PVDF) were calculated based on the thermodynamics equations of membrane formation, and the gel phase boundaries of the systems at 25°C and 60°C were determined via cloud point measurement. The obtained ternary phase diagrams of water/DMAc/PVDF contain three regions: the one‐phase region, the liquid–liquid two‐phase region, and the gel region. In the phase diagrams, the liquid–liquid demixing line (binodal) is located inside the gelation line. At low temperature, there exists a wide region between gelation line and binodal line. Gelation could occur in the absence of liquid–liquid demixing, and becomes the dominant membrane formation mechanism. At high temperatures (60°C), however, the gelation line approaches the binodal line, which results in a much smaller gelation zone. The kinetics of the solvent out‐flux and water influx were enhanced, liquid–liquid demixing is the dominant mechanism. The membrane formation mechanisms at different temperature were confirmed by the light transmission measurements during membrane forming process and the morphologies of the membranes examined by SEM imaging. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.
Studies on thermoplastic polyurethanes based on new diphenylethane‐derivative diols. III. The effect of molecular weight and structure of soft segment on some properties of segmented polyurethanes
Authors: Rogulska Magdalena , Kultys Anna , Pikus Stanisław 
Published: July 2008

AbstractTwo series of poly(ether urethane)s and one series of poly(ester urethane)s were synthesized, containing, respectively, poly(oxytetramethylene) diol (PTMO) of Mn = 1000 and 2000 and poly(ε‐caprolactone) diol of Mn = 2000 as soft segments. In each series the same hard segment, i.e., 4,4′‐(ethane‐1,2‐diyl)bis(benzenethiohexanol)/hexane‐1,6‐diyl diisocyanate, with different content (∼ 14–72 wt %) was used. The polymers were prepared by a one‐step melt polymerization in the presence of dibutyltin dilaurate as a catalyst, at the molar ratio of NCO/OH = 1 (in the case of the polymers from PTMO of Mn = 1000 also at 1.05). For all polymers structures (by FTIR and X‐ray diffraction analysis) and physicochemical, thermal (by differential scanning calorimetry and thermogravimetric analysis), and tensile properties as well as Shore A/D hardness were determined. The resulting polymers were thermoplastic materials with partially crystalline structures (except the polymer with the highest content of PTMO of Mn = 2000). It was found that the poly(ether urethane)s showed lower crystallinity, glass‐transition temperature (Tg), and hardness as well as better thermal stability than the poly(ester urethane)s. Poly(ether urethane)s also exhibited higher tensile strength (up to 23.5 MPa vs. 20.3 MPa) and elongation at break (up to ∼ 1950% vs. 1200%) in comparison with the corresponding poly(ester urethane)s. Among the poly(ether urethane)s an increase in soft‐segment length was accompanied by an increase in thermal stability, tensile strength, and elongation at break, as well as a decrease in Tg, crystallinity, and hardness. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Mechanical properties and antibacterial activity of peroxide‐cured silicone rubber foams
Authors: Park Eun‐Soo 
Published: July 2008

AbstractSilicone rubber (SR) foams were prepared by the peroxide curing of a silicone compound with 2,4‐dichlorobenzoyl peroxide (DCBP), di‐t‐butyl peroxide (DTBP), or 2,5‐dimethyl‐2,5‐di(t‐butylperoxy) hexane (DBPH) in the presence of 2,2′‐azobisisobutyronitrile (AIBN) as a blowing agent. The cells were formed in the foam as a result of nitrogen produced by the decomposition of AIBN during the foaming process. The cell size, hardness, and tensile properties of the SR foams were examined as a function of the peroxide concentration. When the peroxide concentration increased, the hardness and tensile strength of the SR foams increased, whereas the cell size and elongation at break decreased. The antibacterial activity of the prepared foams was also evaluated via their effects on Staphylococcus aureus and Escherichia coli. The peroxide‐cured SR foams had antibacterial activity because a toxic residue was generated by the peroxide decomposition. The foam prepared by the AIBN/DCBP system showed more antibacterial activity than the AIBN/DBPH and AIBN/DTBP ones. However, after postcuring at 250°C for 2 h, the antibacterial activity of the SR foams significantly decreased. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Fluorene‐ring‐containing diamine and resultant soluble thermally stable polyamides
Authors: Ghaemy M. , Barghamadi M. 
Published: July 2008

AbstractA new fluorene‐ring‐containing diamine, N′‐[7‐(acetyl‐4‐aminoanilino)‐9,9‐dioctylflouren‐2‐yl]‐N′‐4‐aminophenyl)acetamide, was prepared through the reaction of 2,7‐dibromo‐9,9‐dioctylfluorene with 4‐aminoacetanilide in the presence of 10 mol % CuI, 20 mol % N,N′‐dimethyl ethylene diamine as a catalyst, and K2CO3 as a base. A series of novel polyamides were prepared by the direct polycondensation of the new diamine with various commercially available aliphatic and aromatic dicarboxylic acids. The novel diamine and the obtained polyamides were characterized with conventional methods (Fourier transform infrared and NMR spectroscopy) and elemental analysis. All the synthesized polyamides showed good solubility in various solvents such as dimethyl sulfoxide, N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide, hexamethylene phosphoramide, and pyridine and exhibited inherent viscosities in the range of 0.44–0.55 dL/g. According to the differential scanning calorimetry analysis, the glass‐transition temperatures of the polyamides were in the range of 85–196°C. Thermogravimetric analysis of the polyamides indicated a 10% weight loss in the temperature range of 344–417°C in an N2 atmosphere. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polyvalency: A promising strategy for drug design
Authors: Vance David , Shah Mrinal , Joshi Amit , Kane Ravi S. 
Published: July 2008

AbstractThe simultaneous binding of multiple ligands on one entity to multiple receptors on another can result in an affinity that is significantly greater than that for the binding of a single ligand to a single receptor. This concept of “polyvalency” can be used to design molecules that are potent inhibitors of toxins and pathogens. We describe the design of potent polyvalent inhibitors that neutralize anthrax toxin in vivo as well as our attempts to elucidate the relationship between inhibitor structure and activity. We also highlight promising future avenues for research in polyvalent drug design. Biotechnol. Bioeng. 2008;101: 429–434. © 2008 Wiley Periodicals, Inc.
Intrachain Electron and Energy Transfer in Conjugated Organometallic Oligomers and Polymers
Authors: Aly Shawkat Mohammed , Ho Cheuk‐Lam , Fortin Daniel , Wong Wai‐Yeung , Abd‐El‐Aziz Alaa S. , Harvey Pierre D. 
Published: July 2008

AbstractThe synthesis of polymers of the type (‐Cz‐CC‐PtL2‐CC‐Cz‐X‐)n along with the corresponding model compounds (Ph‐PtL′2‐CC‐Cz)2‐X‐, where Cz=3,3′‐carbazole, X=nothing, Cz, or F (2,2′‐fluorene), L=PBu3, and L′=PEt3 are reported. The electronic spectra (absorption, excitation, emission, and ns‐transient spectra) and the photophysics of these species in 2‐methyltetrahyrofuran (2MeTHF) at 298 and 77 K are presented. Evidence for singlet electron and triplet energy transfer from the Cz chromophore to the F moiety are provided and discussed in detail. The rate for electron transfer is very fast (>4×1011 s−1), whereas that for triplet–triplet energy transfer is much slower (≈103 s−1). This work represents a very rare example of studies that address electronic communication in the backbone of a conjugated organometallic polymer.
T‐Shaped Platinum Boryl Complexes: Synthesis and Structure
Authors: Braunschweig Holger , Radacki Krzysztof , Uttinger Katharina 
Published: July 2008

AbstractA series of cationic T‐shaped 14‐electron boryl complexes of the type trans‐[(Cy3P)2Pt{B(X)X′}]+ (X=Br; X′=ortho‐tolyl, tBu, NMe2, piperidyl, Br; XX′=(NMe2)2, catecholato) were synthesized by halide abstraction from trans‐[(Cy3P)2Pt(Br){B(X)X′}] (Cy=cyclohexyl) with Na[BArf4] (Arf=3,5‐(CF3)2C6H3), K[B(C6F5)4], or Na[BPh4]. X‐ray diffraction studies were performed on all compounds, revealing a subtle correlation between the trans‐influence of the boryl moiety and the PtH and PtC separations. However, no notable agostic CH interaction with the platinum center was detected. trans‐[(Cy3P)2Pt(BCat)]+ (Cat=catecholato), the complex with the shortest PtH and PtC distances, was treated with Lewis bases (L), forming compounds of the type trans‐[(Cy3P)2Pt(L)(BCat)]+, thus proving a decisive influence of the degree of trans‐influence exerted by the boryl ligands on the chemical reactivity of the title complexes. Another point that was investigated and clarified is the different behavior of trans‐[(Cy3P)2Pt(Br){B(Br)Mes}] (Mes=mesityl) towards K[B(C6F5)4] with formation of the borylene species trans‐[(Cy3P)2Pt(Br)(BMes)]+.
Tunneling Splittings in the S0 and S1 States of the Benzoic Acid Dimer Determined by High‐Resolution UV Spectroscopy
Authors: Kalkman Ivo , Vu Chau , Schmitt Michael , Meerts W. Leo 
Published: July 2008

AbstractFive different isotopologues of the benzoic acid dimer and a vibronic band located 57 cm−1 above the electronic origin, which is assigned to the out‐of‐plane butterfly motion, are studied by rotationally resolved UV spectroscopy. From these measurements a ground‐state structure with C2h symmetry is deduced, whereas the symmetry is lowered to Cs in the S1 state. The increase in the center‐of‐mass distance between the two monomers that is found on electronic excitation indicates a decrease in hydrogen‐bond strength. The tunneling splittings in the S0 and S1 states are 1385.2±0.7 and 271.2±0.7 MHz, respectively, corresponding to an increase in barrier height by 7.2 % on electronic excitation.
Numerical models and ductile ultimate deformation response of post‐tensioned self‐centering moment connections
Authors: Kim Hyung‐Joon , Christopoulos Constantin 
Published: July 2008

AbstractNew steel moment‐resisting connections that incorporate post‐tensioning elements to provide a self‐centering capacity and devices to dissipate seismic input energy have recently been proposed and experimentally validated. Experimental studies have confirmed that these connections are capable of undergoing large lateral deformations with negligible residual drifts. To facilitate their implementation, accurate modeling of the behavior of systems incorporating post‐tensioned connections must be readily available to designers and researchers. A number of simplified models have been suggested in the literature by researchers trying to capture experimental results at the beam–column connections and thereby to predict the global response of structures incorporating such connections. To provide a clear set of guidelines for the modeling of post‐tensioned steel frames, for practicing engineers as well as researchers, in this paper three types of numerical models of increasing complexity are presented: (i) a sectional analysis procedure, (ii) a lumped plasticity spring frame leveled approach and (iii) a non‐linear solid finite element analysis to predict the response at ultimate deformation levels. The analytical results obtained from the numerical models predict well the structural behavior of these connections when compared with available experimental data. Even at the ultimate deformation level, analytical results are in good agreement with test results. Furthermore, detailing requirements are proposed to assure that flexural hinges form in the beams in order to improve the cyclic response of steel self‐centering connections when drifts exceeding the design drifts are imposed to the system. Experimental and analytical studies demonstrate that steel post‐tensioned self‐centering connections incorporating the proposed detailing in the beams develop an increased deformation capacity and thereby exhibit a ductile response while avoiding a sudden loss of their strength and stiffness. Copyright © 2008 John Wiley & Sons, Ltd.
NFIB rearrangement in superficial, retroperitoneal, and colonic lipomas with aberrations involving chromosome band 9p22
Authors: Italiano Antoine , Ebran Nathalie , Attias Rita , Chevallier Anne , Monticelli Isabelle , Mainguené Claire , Benchimol Daniel , Pedeutour Florence 
Published: July 2008

AbstractLipomas are frequently characterized by rearrangements resulting in the fusion of the HMGA2 gene (12q14.3) with a variety of partners. Chromosome band 9p22 rearrangements occur in about 1% of lipomas. We report here the molecular cytogenetic analysis of five cases of lipoma with a 9p22 aberration, including the first cytogenetic analysis of a colonic lipoma. Three out of the five cases showed a rearrangement of NFIB at 9p22.3. The NFIB rearrangement involved a fusion with HMGA2 in two cases. We have identified an in‐frame fusion of the first three exons of HMGA2 with exon 6 of MSRB3 (12q14.3) and exons 8 and 9 of NFIB by using 3′RACE‐PCR in a case of superficial lipoma. In a case of retroperitoneal lipoma we found a fusion of HMGA2 with NFIB by fluorescence in situ hybridization analysis. The colonic lipoma was characterized by a t(9;16;19)(p22;q21;q13) with a rearrangement of NFIB and no rearrangement of HMGA2. NFIB belongs to the nuclear factor I transcription family. It has been previously shown to be fused with HMGA2 in one case of lipoma and to be a recurrent partner of HMGA2 in pleormorphic adenoma of salivary glands. We here demonstrate that NFIB can also be rearranged independently from HMGA2, indicating a potentially important role in lipoma pathobiology. Our findings suggest that the rearrangement of NFIB might be associated with deep‐seated lipomas, such as retroperitoneal or gastro‐intestinal lipomas. © 2008 Wiley‐Liss, Inc.