bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solvent‐free Liquid‐phase Oxidation of 1‐Hexene using Supported Gold Catalysts
Authors: Alshammari Hamed , Miedziak Peter J. , Bawaked Salem , Knight David W. , Hutchings Graham J. 
Published: August 2012

AbstractWe report the solvent‐free oxidation of 1‐hexene with air by using supported gold catalysts with a catalytic amount of tert‐butyl hydroperoxide (TBHP) as initiator. We confirm that gold supported on graphite is an effective catalyst for such oxidations and that graphite was the preferred support. Preparation of catalysts using modified sol‐immobilisation was found to be effective, particularly when the PVA stabiliser was removed by a solvent treatment prior to the reaction.
Hybrid Polyoxotungstates as Functional Comonomers in New Cross‐Linked Catalytic Polymers for Sustainable Oxidation with Hydrogen Peroxide
Authors: Carraro Mauro , Fiorani Giulia , Mognon Lorenzo , Caneva Francesca , Gardan Martino , Maccato Chiara , Bonchio Marcella 
Published: August 2012

AbstractAnchoring terminal octenyl tails on molecular polyoxotungstates yield polymerizable organic–inorganic monomers with formula [{CH2CH(CH2)6Si}xOySiWwOz]4−[x=2,w=11,y=1,z=39 (1);x=2,w=10,y=1,z=36 (2); andx=4,w=9,y=3,z=34 (3)]. These molecular hybrids can use aqueous hydrogen peroxide to catalyze the selective oxidation of organic sulfides in CH3CN. Copolymerization of1–3with methyl methacrylate and ethylene glycol dimethacrylate leads to porous materials with a homogeneous distribution of the functional monomers, as indicated by converging evidence from FTIR spectroscopy and electronic microscopy. The catalytic polymers activate hydrogen peroxide for oxygen transfer, as demonstrated by the quantitative and selective oxidation of methylp‐tolyl sulfide, which was screened as model substrate. The hybrid material containing monomer2was also tested inn‐octane to evaluate its potential for the oxidation and removal of dibenzothiophene, a well‐known gasoline contaminant.
Enantioselective Organocatalytic One‐Pot Amination/aza‐Michael/Aldol Condensation Reaction Sequence: Synthesis of 3‐Pyrrolines with a Quaternary Stereocenter
Authors: Desmarchelier Alaric , Coeffard Vincent , Moreau Xavier , Greck Christine 
Published: August 2012

AbstractPrimary amine‐catalyzed direct conversion of α,α‐disubstituted aldehydes into 3‐pyrrolines with a quaternary stereocenter is reported. The one‐pot enantioselective sequence is based on a α‐amination, an aza‐Michael addition of hydrazine, an aldol condensation dehydratation and proceeds with good yields and excellent levels of enantioselectivity. Synthetically attractive applications including the formation of aziridinopyrrolidine or epoxypyrrolidine derivatives with good yields and selectivities are also described.
MT1‐Selective Melatonin Receptor Ligands: Synthesis, Pharmacological Evaluation, and Molecular Dynamics Investigation of N‐{[(3‐O‐Substituted)anilino]alkyl}amides
Authors: Rivara Silvia , Pala Daniele , Lodola Alessio , Mor Marco , Lucini Valeria , Dugnani Silvana , Scaglione Francesco , Bedini Annalida , Lucarini Simone , Tarzia Giorgio , Spadoni Gilberto 
Published: August 2012

AbstractThe design of compounds selective for the MT1 melatonin receptor is still a challenging task owing to the limited knowledge of the structural features conferring selectivity for the MT1 subtype, and only few selective compounds have been reported so far. N‐(Anilinoalkyl)amides are a versatile class of melatonin receptor ligands that include nonselective MT1/MT2 agonists and MT2‐selective antagonists. We synthesized a new series of N‐(anilinoalkyl)amides bearing 3‐arylalkyloxy or 3‐alkyloxy substituents at the aniline ring, looking for new potent and MT1‐selective ligands. To evaluate the effect of substituent size and shape on binding affinity and intrinsic activity, both flexible and conformationally constrained derivatives were prepared. The phenylbutyloxy substituent gave the best result, providing the partial agonist 4 a, which was endowed with high MT1 binding affinity (pKi=8.93) and 78‐fold selectivity for the MT1 receptor. To investigate the molecular basis for agonist recognition, and to explain the role of the 3‐arylalkyloxy substituent, we built a homology model of the MT1 receptor based on the β2 adrenergic receptor crystal structure in its activated state. A binding mode for MT1 agonists is proposed, as well as a hypothesis regarding the receptor structural features responsible for MT1 selectivity of compounds with lipophilic arylalkyloxy substituents.
Asymmetric 4‐Aryl‐1,4‐dihydropyridines Potentiate Mutant Cystic Fibrosis Transmembrane Conductance Regulator (CFTR)
Authors: Giampieri Michele , Vanthuyne Nicolas , Nieddu Erika , Mazzei Marco T. , Anzaldi Maria , Pedemonte Nicoletta , Galietta Luis J. V. , Roussel Christian , Mazzei Mauro 
Published: August 2012

AbstractSome of the genetic mutations that cause cystic fibrosis (CF) impair the gating of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl− ion channel. This defect can be corrected with pharmacological tools (potentiators) that belong to various chemical families, including the 1,4‐dihydropyridines (DHPs). A small set of asymmetric 4‐aryl‐DHPs was synthesized, and each racemic couple was tested in a functional assay carried out on cells expressing the G1349D, ΔF508, and G551D mutants. The most active racemates were subjected to chiral separation by HPLC, and the pure enantiomers were tested to evaluate any gains in activity. Although three enantiomers demonstrated high potency (Kd values less than 0.09, 0.1, and 0.5 μM in G1349D, ΔF508, and G551D, respectively), in general, the screening of pure enantiomers did not produce a great diversity in potency values. It is probable that the degree of DHP asymmetry considered in our analysis is still insufficient with respect to that allowed in a putative DHP binding site in CFTR, so that the site could equally accommodate both enantiomers.
Photocatalytic and Photoelectrochemical Water Oxidation over Metal‐Doped Monoclinic BiVO4 Photoanodes
Authors: Parmar Kanak Pal Singh , Kang Hyun Joon , Bist Amita , Dua Piyush , Jang Jum Suk , Lee Jae Sung 
Published: August 2012

AbstractThe visible‐light‐induced water oxidation ability of metal‐ion‐doped BiVO4 was investigated and of 12 metal ion dopants tested, only W and Mo dramatically enhanced the water photo‐oxidation activity of bare BiVO4; Mo had the highest improvement by a factor of about six. Thus, BiVO4 and W‐ or Mo‐doped (2 atom %) BiVO4 photoanodes about 1 μm thick were fabricated onto transparent conducting substrate by a metal–organic decomposition/spin‐coating method. Under simulated one sun (air mass 1.5G, 100 mW cm−2) and at 1.23 V versus a reversible hydrogen electrode, the highest photocurrent density (JPH) of about 2.38 mA cm−2 was achieved for Mo doping followed by W doping (JPH≈1.98 mA cm−2), whereas undoped BiVO4 gave a JPH value of about 0.42 mA cm−2. The photoelectrochemical water oxidation activity of W‐ and Mo‐doped BiVO4 photoanodes corresponded to the incident photon to current conversion efficiency of about 35 and 40 % respectively. Electrochemical impedance spectroscopy and Mott–Schottky analysis indicated a positive flat band shift of about 30 mV, a carrier concentration 1.6–2 times higher, and a charge‐transfer resistance reduced by 3–4‐fold for W‐ or Mo‐doped BiVO4 relative to undoped BiVO4. Electronic structure calculations revealed that both W and Mo were shallow donors and Mo doping generated superior conductivity to W doping. The photo‐oxidation activity of water on BiVO4 photoanodes (undoped<W doped<Mo doped) was in accordance with the results from electrochemical impedance spectroscopy, Mott–Schottky analysis, and theoretical electronic structural calculations. Thus, Mo or W doping enhanced the photocatalytic and photoelectrochemical water oxidation activity of monoclinic BiVO4 by drastically reducing its charge‐transfer resistance and thereby minimizing photoexcited electron–hole pair recombination.
Acid‐Catalyzed Dehydration of Fructose into 5‐Hydroxymethylfurfural by Cellulose‐Derived Amorphous Carbon
Authors: Qi Xinhua , Guo Haixin , Li Luyang , Smith Richard L. 
Published: August 2012

AbstractCarbonaceous solid (CS) catalysts with SO3H, COOH, and phenolic OH groups were prepared by incomplete hydrothermal carbonization of cellulose followed by either sulfonation with H2SO4 to give carbonaceous sulfonated solid (CSS) material or by both chemical activation with KOH and sulfonation to give activated carbonaceous sulfonated solid (a‐CSS) material. The obtained carbon products (CS, CSS, and a‐CSS) were amorphous; the CSS material had a small surface area (<0.5 m2 g−1) and a high SO3H group concentration (0.953 mmol g−1), whereas the a‐CSS material had a large surface area (514 m2 g−1) and a low SO3H group concentration (0.172 mmol g−1). The prepared materials were evaluated as catalysts for the dehydration of fructose to 5‐hydroxymethylfurfural (5‐HMF) in the ionic liquid 1‐butyl‐3‐methylimidazolium chloride ([BMIM][Cl]). Remarkably high 5‐HMF yields (83 %) could be obtained efficiently (80 °C and 10 min reaction time). CSS and a‐CSS catalysts had similar catalytic activities and efficiencies for the conversion of fructose to 5‐HMF in [BMIM][Cl]; this could be explained by the trade‐off between SO3H group concentration (high for CSS) and surface area (high for a‐CSS). The cellulose‐derived catalysts and ionic liquid exhibited constant activity for five successive recycles, and thus, the methods developed provide a renewable strategy for biomass conversion.
Hand preference for pointing and language development in toddlers
Authors: Vauclair Jacques , Cochet Hélène 
Published: August 2012

AbstractThe aim of this study was to investigate the relationship between hand preference for communicative gestures and language during development. Hand preference for pointing gestures and level of language were assessed in 46 toddlers between 12 and 30 months of age. Results showed a right‐hand preference for pointing and the use of a developmental quotient (DQ) for language revealed a significant correlation between the degree of hand preference and DQ for language in children with a quotient above 100. Thus, these children were more right‐handed for pointing gestures as DQ increased. These results highlight the close association between the development of hand preference for pointing and the speed of language development, suggesting a new direction for studies of language–gesture links in toddlers. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 757–765, 2013.
Variations in maternal care associated with differences in female rat reproductive behavior in a group‐mating environment
Authors: Prior Karen M. , Meaney Michael J. , Cameron Nicole M. 
Published: August 2012

AbstractMaternal care influences the development of sexual behavior in pair mating rats, under laboratory conditions. This study examined the effect of variations in maternal care in a group‐mating condition. Groups of two low and two high licking/grooming (LG) female offspring mated with two males in a large pacing chamber for 36 hr. Sexual behaviors were scored for the first 15 vaginal–cervical stimulations (VCS) and the entire 36 hr. Low LG females spent more time mating, required more time to receive an intromission after entering the male compartment. They also received more ejaculations compared to high LG females during the first 15 VCS. This difference disappeared as mating continued. Males were more responsive to high than low females. No pregnancy rate difference was seen between the two female phenotypes, demonstrating that variation in maternal care received results in two mating strategies that are both reproductively successful under group‐mating conditions. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 838–848, 2013.
GAL4 enhancer traps that can be used to drive gene expression in developing Drosophila spermatocytes
Authors: Bunt Stephanie M. , Monk Adrian C. , Siddall Nicole A. , Johnston Neisha L. , Hime Gary R. 
Published: August 2012

AbstractThe Drosophila testis has proven to be a valuable model organ for investigation of germline stem cell (GSC) maintenance and differentiation as well as elucidation of the genetic programs that regulate differentiation of daughter spermatogonia. Development of germ cell specific GAL4 driver transgenes has facilitated investigation of gene function in GSCs and spermatogonia but specific GAL4 tools are not available for analysis of postmitotic spermatogonial differentiation into spermatocytes. We have screened publically available pGT1 strains, a GAL4‐encoding gene trap collection, to identify lines that can drive gene expression in late spermatogonia and early spermatocytes. While we were unable to identify any germline‐specific drivers, we did identify an insertion in the chiffon locus, which drove expression specifically in early spermatocytes within the germline along with the somatic cyst cells of the testis. genesis 50:914–920, 2012. © 2012 Wiley Periodicals, Inc.
Strain‐specific hyperkyphosis and megaesophagus in Add1 null mice
Authors: Robledo Raymond F. , Seburn Kevin L. , Nicholson Anthony , Peters Luanne L. 
Published: August 2012

AbstractThe three adducin proteins (α, β, and γ) share extensive sequence, structural, and functional homology. Heterodimers of α‐ and β‐adducin are vital components of the red cell membrane skeleton, which is required to maintain red cell elasticity and structural integrity. In addition to anemia, targeted deletion of the α‐adducin gene (Add1) reveals unexpected, strain‐dependentnon‐erythroid phenotypes. On an inbred 129 genetic background, Add1 null mice show abnormal inward curvature of the cervicothoracic spine with complete penetrance. More surprisingly, a subset of 129‐Add1 null mice develop severe megaesophagus, while examination of peripheral nerves reveals a reduced number of axons in 129‐Add1 null mice at four months of age. These unforeseen phenotypes, described here, reveal new functions for adducin and provide new models of mammalian disease. genesis 50:882–891, 2012. © 2012 Wiley Periodicals, Inc.
The decline and fall of the IGF‐I receptor
Authors: Baserga Renato 
Published: August 2012

AbstractThis review examines the effect of targeting the insulin‐like growth factor 1 receptor (IGF‐IR) in human cancers. The results are disappointing. The causes for the failure are discussed, as well as the possible use of the IGF‐IR as a secondary target. J. Cell. Physiol. 228: 675–679, 2013. © 2012 Wiley Periodicals, Inc.
Summer tree roost selection by Rafinesque's big‐eared bat
Authors: Clement Matthew J. , Castleberry Steven B. 
Published: August 2012

AbstractRoost requirements of most North American forest bats are well‐documented, but questions remain regarding the ultimate mechanisms underlying roost selection. Hypotheses regarding roost selection include provision of a stable microclimate, space for large colonies, protection from predators, and proximity to foraging habitat, among others. Although several hypotheses have been proposed, specific mechanisms likely vary by species and geographic region. Rafinesque's big‐eared bat (Corynorhinus rafinesquii) commonly roosts in trees with large basal hollows in the Coastal Plain of the southeastern United States. Our objective was to weigh evidence for hypotheses regarding selection of diurnal summer roosts by Rafinesque's big‐eared bat at 8 study sites across the Coastal Plain of Georgia, USA. We used transect searches and radiotelemetry to locate roosts and measured 22 characteristics of trees, tree cavities, and surrounding vegetation at all occupied roosts and for randomly selected unoccupied trees. We evaluated 10 hypotheses using single‐season occupancy models and used Akaike's information criterion to select the most parsimonious models. We located 170 tree roosts containing approximately 870 bats for our analysis. The best supported model predicted bat presence from cavity size, interior wall texture, and number of entrances. Because large cavities allow bats to fly and smooth walls impede attacks by terrestrial predators, our results are consistent with the hypothesis that bats select roosts that allow them to evade predators. However, data on predation rates are needed for a conclusive determination. Because trees suitable as roosts for Rafinesque's big‐eared bat are rare in the landscape, protection of suitable forested wetland habitat is essential to provide current and long‐term roost tree availability. © 2012 The Wildlife Society.
SESAM‐free mode‐locked semiconductor disk laser
Authors: Kornaszewski L. , Maker G. , Malcolm G.P.A. , Butkus M. , Rafailov E.U. , Hamilton C.J. 
Published: August 2012

AbstractExperimental demonstration of semiconductor saturable absorber‐free mode‐locked optically pumped semiconductor disk laser is presented. The origin of pulsed operation is attributed to the intensity dependent Kerr lens effect arising in the semiconductor gain medium. Achieved results represent a novel method to mode‐lock this type of laser opening new application opportunities. The laser worked stably in both hard and soft aperture configurations. No semiconductor saturable absorber was used in the laser cavity and the operation was self‐starting. The laser was mode‐locked at 210 MHz repetition rate with 1.5 W average output power and 930 fs pulse width at 985 nm. A record high 6.8 kW peak power was achieved. Measured data is presented along with a discussion of the Kerr lens effect in the cavity.
Tunable pH‐Sensitive Poly(β‐amino ester)s Synthesized from Primary Amines and Diacrylates for Intracellular Drug Delivery
Authors: Song Wantong , Tang Zhaohui , Li Mingqiang , Lv Shixian , Yu Haiyang , Ma Lili , Zhuang Xiuli , Huang Yubin , Chen Xuesi 
Published: August 2012

AbstractThe pH sensitivity of a series of PbAEs synthesized from primary amines and diacrylates is studied. By changing alkyl groups of the amine monomers, the pKb can be tuned across a broad range (from 3.5 to 7.2). Micelles formed from a PEG‐PbAE block copolymer retain the pH sensitivity of PbAE and can stably load hydrophobic molecules under neutral pH, while quickly dissociate and release their cargoes at pH ≈ 6.0. When the chemotherapy drug DOX is loaded, the micelles show efficient cell proliferation inhibition to HeLa cells and fast intracellular release. Thus, the primary‐amine‐based PbAEs are shown to be promising in the construction of intracellular targeting drug delivery systems. magnified image
Polyfluorene Nanoparticles Coated with Folate‐Functionalized Triblock Copolymer: Effective Agents for Targeted Cell Imaging
Authors: Liu Li , Patra Abhijit , Scherf Ullrich , Kissel Thomas 
Published: August 2012

AbstractAn ultra‐bright fluorescence probe comprising conjugated polymer nanoparticles is developed for biological imaging. Highly blue fluorescent polyfluorene nanoparticles (PF‐NPs) stabilized by sodium dodecylsulfate with an average diameter of 100 nm are prepared by a miniemulsion technique. A folate‐conjugated cationic triblock copolymer is employed to coat negatively charged PF‐NPs via electrostatic interaction for specific cell imaging of folate receptor over‐expressing cancer cells. The coated PF‐NPs show a similar size and morphology to the pristine PF‐NPs, while the fluorescence intensity is enhanced. Such surface‐functionalized PF‐NPs are demonstrated to be suitable probes for efficient cell imaging of folate receptor over‐expressing KB cells by CLSM and flow cytometry. magnified image
Thermo‐Switchable Antibacterial Activity
Authors: Mattheis Claudia , Zhang Yi , Agarwal Seema 
Published: August 2012

AbstractA copolymer system of 2‐aminoethyl methacrylate and N‐isopropylacrylamide comprises novel properties: changes in conformation and hydrophilicity upon heating influence the antibacterial activity and result in a switchable biocidal effect. The copolymers are characterized via NMR, MALDI‐ToF MS, phase transition behavior, and antibacterial tests with E. coli or B. subtilis. MIC and MBC are determined using standard dilution methods, temperature‐dependence via incubation at different temperatures and cytotoxicity by MTT tests. The copolymers exhibit lower MIC in globule than coil conformation, crosslinking on cotton results in non‐leaching materials with better antibacterial activity above than below the phase‐transition point. magnified image
Functionalized Nanoporous Thin Films From Blends of Block Copolymers and Homopolymers Interacting via Hydrogen Bonding
Authors: Gamys Cé Guinto , Vlad Alexandru , Bertrand Olivier , Gohy Jean‐François 
Published: August 2012

AbstractBlends of poly(acrylic acid)‐block‐polystyrene (PAA‐b‐PS) copolymers and poly(ethylene oxide) (PEO) homopolymers in which PAA and PEO interact via hydrogen bonds were used as precursors of nanoporous PS thin films with cavities decorated by PAA blocks. The presence of free carboxylic acid groups inside the pores was evidenced by fluorescence spectroscopy after reacting them with a diazomethane functionalized fluorescent dye. These nanoporous thin films were then used as templates for the preparation of dense arrays of silica nanodots.
New Polymer Materials for Steel/Polymer/Steel Laminates in Automotive Applications
Authors: Avril Florence , Rahmé Roland , Doux Marjolaine , Verchere Didier , Sage Daniel , Cassagnau Philippe 
Published: August 2012

AbstractThe present works aims to develop multi‐materials such as steel/polymer/steel hybrid system for weight savings in automotive industries. This laminate must be compatible with processing on the industrial line (steel/polymer lamination under 200 °C) and the structure must be flow‐resistant during the paint process curing (200 °C for 30 min). Consequently, a yield stress polymer system based on compatibilized PA11/copolymer of ethylene and octene blends has been developed. The yield stress property (for T > 200 °C) depends on the phase concentration and compatibilization strategy. It is observed that an annealing process (heating treatment for 1 h at 200 °C), simulating the painting process, provides a strong benefit for the polymer/steel properties after aging under humidity conditions. magnified image
Design and Synthesis of Poly(butyl acrylate) Networks through RAFT Polymerization with Crosslinking for Controlled‐Release Applications
Authors: Huang Jianmin , Wang Wen‐Jun , Li Bo‐Geng , Zhu Shiping 
Published: August 2012

AbstractAn effective approach is presented for designing and tailoring diffusion‐controlled systems for targeted release rate profiles. The diffusion‐controlled system consists of PBA networks with precisely controlled crosslink densities via RAFT copolymerization of BA with ethylene glycol dimethacrylate, which gives a desired diffusivity. One‐dimensional releases in the crosslinked PBA matrix (CPM) slabs are evaluated with a hydrophobic dye. Fick's second law is used to model the transient mass transfers in the CPMs with a mixed Newton‐Tikhonov regularization method for determination of their diffusion coefficients. A two‐layer CPM (CPM‐2) with controlled crosslink densities is constructed. The dye release results from the CPM‐2 agreed well with theoretical predictions. magnified image