bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein‐Enabled Synthesis of Monodisperse Titania Nanoparticles On and Within Polyelectrolyte Matrices
Authors: Kharlampieva Eugenia , Slocik Joseph M. , Singamaneni Srikanth , Poulsen Nicole , Kröger Nils , Naik Rajesh R. , Tsukruk Vladimir V. 
Published: May 2009

AbstractHere, the results of a study of the mechanism of bio‐enabled surface‐mediated titania nanoparticle synthesis with assistance of polyelectrolyte surfaces are reported. By applying atomic force microscopy, surface force spectroscopy, circular dichroism, and in situ attenuated total reflection Fourier‐transform infrared spectroscopy, structural changes of rSilC‐silaffin upon its adsorption to polyelectrolyte surfaces prior to and during titania nanoparticle growth are revealed. It is demonstrated that the adhesion of rSilC‐silaffin onto polyelectrolyte surfaces results in its reorganization from a random‐coil conformation in solution into a mixed secondary structure with both random coil andβ‐sheet structures presented. Moreover, the protein forms a continuous molecularly thin layer with well‐defined monodisperse nanodomains of lateral dimensions below 20 nm. It is also shown that rSilC embedded inside the polylelectrolyte matrix preserves its titania formation activity. It is suggested that the surface‐mediated, bio‐enabled synthesis of nanostructured materials might be useful to develop general procedures for controlled growth of inorganic nanomaterials on reactive organic surfaces, which opens new perspectives in the design of tailored, in situ grown, hybrid inorganic–organic nanomaterials.
Porous Polymer Coatings: a Versatile Approach to Superhydrophobic Surfaces
Authors: Levkin Pavel A. , Svec Frantisek , Fréchet Jean M. J. 
Published: May 2009

AbstractHere, a facile and inexpensive approach to superhydrophobic polymer coatings is presented. The method involves the in situ polymerization of common monomers in the presence of a porogenic solvent to afford superhydrophobic surfaces with the desired combination of micro‐ and nanoscale roughness. The method is applicable to a variety of substrates and is not limited to small areas or flat surfaces. The polymerized material can be ground into a superhydrophobic powder, which, once applied to a surface, renders it superhydrophobic. The morphology of the porous polymer structure can be efficiently controlled by composition of the polymerization mixture, while surface chemistry can be adjusted by photografting. Morphology control is used to reduce the globule size of the porous architecture from micro down to nanoscale thereby affording a transparent material. The influence of both surface chemistry as well as the length scale of surface roughness on the superhydrophobicity is discussed.
Controlling Affinity Binding with Peptide‐Functionalized Poly(ethylene glycol) Hydrogels
Authors: Lin Chien‐Chi , Anseth Kristi S. 
Published: May 2009

AbstractPoly(ethylene glycol) (PEG) hydrogels functionalized with peptide moieties have been widely used in regenerative medicine applications. While many studies have suggested the importance of affinity binding within PEG hydrogels, the relationships between the structures of the peptide motifs and their binding to protein therapeutics remain largely unexplored, especially in the recently developed thiol‐acrylate photopolymerization systems. Herein, Förster resonance energy transfer (FRET) and thiol‐acrylate photopolymerizations are employed to investigate how the architectures of affinity peptides in crosslinked hydrogels affect their binding to diffusible proteins. The binding between diffusible streptavidin and biotinylated peptide immobilized to PEG hydrogel network was used as a model system to reveal the interplay between affinity binding and peptide sequences/architectures. In addition, peptides with different structures are designed to enhance affinity binding within PEG hydrogels and to provide tunable affinity‐based controlled delivery of basic fibroblast growth factor (bFGF). This study demonstrates the importance of affinity binding in controlling the availability of hydrogel‐encapsulated proteins and provides strategies for enhancing affinity binding of protein therapeutics to bound peptide moieties in thiol‐acrylate photopolymerized PEG hydrogels. The results presented herein should be useful to the design and fabrication of hydrogels that retain and exhibit sustained release of growth factors for promoting tissue regeneration.
Design of a high‐efficiency hydrofoil through the use of computational fluid dynamics and multiobjective optimization
Authors: Spogis N. , Nunhez J.R. 
Published: May 2009

AbstractA computational fluid dynamics (CFD) model is proposed, based on ANSYS‐CFX tools coupled to optimization models inside the commercial optimization software modeFRONTIER in order to obtain an optimal design of a high‐efficiency impeller for solids suspension. The analysis of impeller shape performance was carried out using the shear‐stress transport (SST) turbulence model with streamline curvature correction. This turbulence model combined the advantages of the κ−ε and κ−ω models, ensuring a proper relation between turbulent stress and turbulent kinetic energy, allowing an accurate and robust prediction of the impeller blade flow separation. The multiple frames of reference and the frozen rotor frame change models were used for the rotor/stator interaction inside the mixing vessel. The optimization procedure used seven design variables, two nonlinear constraints and two objective functions. The objective functions chosen (among many other possible options) to evaluate the impeller performance were the maximum solid distribution throughout the vessel (homogeneous suspension) reflected by a low variance between local solid concentration and average solid concentration inside the vessel and the higher pumping effectiveness, which was defined as the quotient of the flow and power numbers. The first objective function searches for impeller configurations able to provide good solid suspension, since it aims to achieve homogeneous suspension. The second objective function aims to reduce power consumption for a high‐pumping capacity of the impeller. These criteria were considered enough to characterize the optimized impeller. Results indicated that the optimized impeller presented an increase of the pumping impeller capacity and homogeneous solid suspension with low‐power consumption, especially when compared with the PBT 45° impeller. © 2009 American Institute of Chemical Engineers AIChE J, 2009
A single‐center experience in 20 patients with infantile malignant osteopetrosis
Authors: Mazzolari Evelina , Forino Concetta , Razza Alessia , Porta Fulvio , Villa Anna , Notarangelo Luigi Daniele 
Published: May 2009

AbstractInfantile malignant osteopetrosis (IMO) includes various genetic disorders that affect osteoclast development and/or function. Genotype–phenotype correlation studies in IMO have been hampered by the rarity and heterogeneity of the disease and by the severity of the clinical course, which often leads to death early in life. We report on the clinical and molecular findings and treatment in 20 consecutive patients (11 males, nine females) with IMO, diagnosed at a single center in the period 1991–2008. Mean age at diagnosis was 3.9 months, and mean follow‐up was 66.75 months. Mutations in TCIRG1, OSTM1, ClCN7, and TNFRSF11A genes were detected in nine, three, one, and one patients, respectively. Six patients remain genetically undefined. OSTM1 and ClCN7 mutations were associated with poor neurologic outcome. Among nine patients with TCIRG1 defects, six presented with hypogammaglobulinemia, and one showed primary pulmonary hypertension. Fourteen patients received hematopoietic cell transplantation; of these, nine are alive and eight of them have evidence of osteoclast function. These data may provide a basis for informed decisions regarding the care of patients with IMO. Am. J. Hematol. 2009. © 2009 Wiley‐Liss, Inc.
Racial and ethnic disparities in low birth weight delivery associated with maternal occupational characteristics
Authors: Meyer John D. , Warren Nicholas , Reisine Susan 
Published: May 2009

AbstractObjectivesWork characteristics and maternal education have both been associated with low birth weight (LBW) delivery. We sought to examine the relative contribution of these two factors to LBW delivery and determine whether ethnic/racial differentials in educational attainment and work characteristics might play a role in well‐described disparities in LBW.MethodsScores for work substantive complexity (SC) derived from the O*NET were imputed to maternal occupation for Connecticut singleton births in 2000. Risks for LBW were estimated separately for black, Hispanic, and white mothers using logistic regression controlling for maternal covariates.ResultsUsing white mothers as a referent, working is associated with reduced LBW risk in black mothers compared to those not in work (OR 2.06 vs. 3.07). LBW in working black women was strongly associated with less that a high school education (OR 4.80, 95% CI 1.68–13.7), and with low work SC in blacks in those with a college education or greater (OR 4.48, 95% CI 1.24–16.2). Examination of work SC scores, controlling for age and educational level, showed lower values for blacks; increased work SC was seen in Hispanics after adjustment for lower educational attainment. A decrease in risk for LBW was seen in black mothers, compared with whites, as work SC increased. By contrast, college‐educated black mothers had a greater risk for LBW than those with high school or some college education.ConclusionsMaternal employment and work in a job with greater SC were associated with a reduced risk of LBW in black mothers. Improved LBW risk was also seen with employment in Hispanics. Low work SC in those with higher educational attainment was strongly associated with LBW in blacks, but not whites or Hispanics. Education/work mismatch may play a role in racial disparities in birth outcomes. Am. J. Ind. Med. 53:153–162 2010. © 2009 Wiley‐Liss, Inc.
Simplifying the Creation of Hollow Metallic Nanostructures: One‐Pot Synthesis of Hollow Palladium/Platinum Single‐Crystalline Nanocubes
Authors: Huang Xiaoqing , Zhang Huihui , Guo Changyou , Zhou Zhiyou , Zheng Nanfeng 
Published: May 2009

AbstractEinfacher effizient: Eine Synthesestrategie wird vorgestellt, die einkristalline hohle Pd/Pt‐Nanowürfel liefert (rechts im Bild; links: Pd‐Nanowürfel). Verglichen mit ähnlich großen kompakten Pd/Pt‐Nanowürfeln haben die hohlen Pd/Pt‐Nanowürfel eine größere zugängliche Oberfläche und damit eine höhere Aktivität bei der elektrokatalytischen Ameisensäureoxidation.magnified image
Laser‐Modulated Ordering of Gold Nanoparticles at the Air/Water Interface
Authors: Volinsky Roman , Jelinek Raz 
Published: May 2009

AbstractBeam mich hoch, Scotty! Die Bestrahlung von Langmuir‐Monoschichten aus Goldnanopartikeln (NPs) und Elaidinsäure mit Laserlicht bewirkt eine drastische Reorganisation, die von der Laserenergie abhängt (siehe Bild, Maßstab=100 μm). Experimente bei mehreren Temperaturen sprechen dafür, dass ein durch den Laserstrahl ausgelöstes lokalisiertes Erhitzen der Oberfläche in einem sehr engen Temperaturbereich ein Ordnen der NPs bewirkt.magnified image
Hydroaminierung eines Alkens, induziert durch niederenergetische Elektronen
Authors: Hamann Thorben , Böhler Esther , Swiderek Petra 
Published: May 2009

AbstractElektronen als Katalysator‐Ersatz: Eine neue Strategie zur Steuerung chemischer Reaktionen durch niederenergetische Elektronenstrahlen nutzt die elektrostatische Anziehung nach sanfter Ionisation eines der Reaktionspartner. Als Testfall diente die Reaktion von C2H4 mit NH3 zu Aminoethan. Die Reaktion ähnelt einer Hydroaminierung – mit dem Unterschied, dass der Elektronenstrahl den in der organischen Synthese verwendeten Katalysator ersetzt.magnified image
Regio‐ and Stereoselective Generation of Alkenylindium Compounds from Indium Tribromide, Alkynes, and Ketene Silyl Acetals
Authors: Nishimoto Yoshihiro , Moritoh Ryosuke , Yasuda Makoto , Baba Akio 
Published: May 2009

AbstractInBr3 unterstützt die Addition von Ketensilylacetalen an monosubstituierte Alkine zu 2,2‐disubstituierten Alkenylindiumverbindungen mit hoher Regio‐ und Stereoselektivität (siehe Schema). Die Alkenylindiumderivate wurden anschließend in Gegenwart eines Palladiumkatalysators mit Iodbenzol gekuppelt.magnified image
Indoles from Simple Anilines and Alkynes: Palladium‐Catalyzed CH Activation Using Dioxygen as the Oxidant
Authors: Shi Zhuangzhi , Zhang Chun , Li Si , Pan Delin , Ding Shengtao , Cui Yuxin , Jiao Ning 
Published: May 2009

AbstractSparsames Pd: Im Schema ist ein palladiumkatalysierter Zugang zu Indolen mithilfe der Titelreaktion gezeigt. Als Oxidationsmittel diente bei diesem Katalysezyklus O2. Mit dieser Methode können sowohl N‐unsubstituierte als auch N‐alkylmonosubstituierte Aniline in die entsprechenden Indole überführt werden.magnified image
Efficient Replication Bypass of Size‐Expanded DNA Base Pairs in Bacterial Cells
Authors: Delaney James C. , Gao Jianmin , Liu Haibo , Shrivastav Nidhi , Essigmann John M. , Kool Eric T. 
Published: May 2009

AbstractSupersize me! Size‐expanded DNA bases (xDNA) are able to encode natural DNA sequences in replication. In vitro experiments with a DNA polymerase show nucleotide incorporation opposite the xDNA bases with correct pairing. In vivo experiments using E. coli show that two xDNA bases (xA and xC, see picture) encode the correct replication partners.magnified image
Simplifying the Creation of Hollow Metallic Nanostructures: One‐Pot Synthesis of Hollow Palladium/Platinum Single‐Crystalline Nanocubes
Authors: Huang Xiaoqing , Zhang Huihui , Guo Changyou , Zhou Zhiyou , Zheng Nanfeng 
Published: May 2009

AbstractEfficiency simplified: A synthetic strategy has been developed to prepare single‐crystalline hollow Pd/Pt nanocubes (right, see picture; left: nanocubes). Compared to the solid Pd/Pt nanocubes of similar sizes, the hollow Pd/Pt nanocubes increase accessible surface area and therefore improve electrocatalytic activity in formic acid oxidation.magnified image
Low‐Temperature Atomic Layer Deposition of Copper Metal Thin Films: Self‐Limiting Surface Reaction of Copper Dimethylamino‐2‐propoxide with Diethylzinc
Authors: Lee Byoung H. , Hwang Jae K. , Nam Jae W. , Lee Song U. , Kim Jun T. , Koo Sang‐M. , Baunemann A. , Fischer Roland A. , Sung Myung M. 
Published: May 2009

AbstractA uniform, conformal, pure copper metal thin film was grown at very low substrate temperatures (100–120 °C) on Si(100) substrates by atomic layer deposition involving the ligand exchange of [Cu(OCHMeCH2NMe2)2] with Et2Zn (see scheme). Patterned copper thin films of Cu nanotubes (diameter 150 nm, length 12 μm) were fabricated.magnified image
Laser‐Modulated Ordering of Gold Nanoparticles at the Air/Water Interface
Authors: Volinsky Roman , Jelinek Raz 
Published: May 2009

AbstractBeam me up, Scotty! Laser irradiation of Langmuir monolayers of gold nanoparticles (NPs) and elaidic acid led to dramatic reorganization that was dependent on the laser power (see picture, scale bar=100 μm). Variable‐temperature experiments indicate that localized surface heating in an extremely small temperature range, induced by the laser beam, causes ordering of the NPs.magnified image
Taking Fingerprints of DNA Polymerases: Multiplex Enzyme Profiling on DNA Arrays
Authors: Kranaster Ramon , Marx Andreas 
Published: May 2009

AbstractA novel screening approach based on an oligonucleotide‐addressing enzyme assay enables multiplexed simultaneous profiling of DNA polymerases in nanoliter volumes in terms of their different properties. This approach was used to identify enzymes with altered properties out of a library of protein mutants.magnified image
Effect of the geometry on the performance of the Maxblend™ impeller with viscous Newtonian fluids
Authors: Guntzburger Yoann , Fradette Louis , Farhat Maya , Héniche Mourad , Tanguy Philippe A. , Takenaka Katsuhide 
Published: May 2009

AbstractExperimental and numerical investigations have been carried out to assess the effect of the vessel geometry (number of baffles) and the shape of the Maxblend impeller (configuration of the bottom paddle and angle of the upper grid) with viscous Newtonian fluids in the laminar and lower turbulent mixing regimes. Two parameters have been explored namely the power consumption of the impeller and the mixing time. Videos of the discoloration process have also been taken to get access to the mixing patterns. A nominal 50‐l vessel has been used in the experiments. The number of baffles has been varied from 1 to 4, and the bottom paddle has been modified by making openings to allow flow passage. Finally, the effect of using a straight grid in the upper part of the Maxblend has been studied under the same conditions. It is shown that the number of baffles does not have a significant effect on the power consumption, the mixing evolution, and the mixing time regardless of the flow regime. Making openings in the bottom paddle allows for the destruction of the segregated zones at the bottom of the tank at the expense of a very slight increase in power consumption and mixing time. Finally, the power and mixing time are both increased with a straight grid Maxblend. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Transformation behaviors of excluded pyrite during O2/CO2 combustion of pulverized coal
Authors: Sheng Changdong , Lin Jun , Li Yi , Wang Chao 
Published: May 2009

AbstractThe article was addressed to the transformation of excluded pyrite during O2/CO2 combustion of pulverized coal. Raw pyrite mineral was added to a pulverized coal sample, which was density fractionated to remove the excluded minerals, to simulate the excluded pyrite present in coal. The mixed sample was burned in a drop tube furnace in O2/CO2 and O2/N2 conditions to generate the residue ash, which was characterized by Mössbauer spectroscopic and size analyses. It was found that, in comparison with O2/N2 combustion at the same oxygen concentration, slightly less iron glass silicate was formed from excluded pyrite and silicates although the transformation of pyrite to oxides was slowed in O2/CO2 combustion, different from the behaviors of included pyrite in pulverized coal those were observed in previous study. Additionally, less fragmentation of excluded pyrite particles was also observed in O2/CO2 combustion. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Formation of highly oriented biodegradable polybutylene succinate adipate nanocomposites: Effects of cation structures on morphology, free volume, and properties
Authors: Dean Katherine M. , Pas Steven J. , Yu Long , Ammala Anne , Hill Anita J. , Wu Dong Yang 
Published: May 2009

AbstractMany biodegradable polymer materials have not been found to be suitable replacements for more traditional non‐biodegradable polymers owing to their insufficient gas and vapor barrier properties. The use of a series of novel organically modified synthetic fluorohectorites (FHTs) has been explored to produce biodegradable polybutylene succinate adipate (PBSA)‐clay nanocomposites with improved barrier. Highly oriented nanoclay structures (clearly showing a tortuous path required to reduce gas and vapor transmission) were observed using transmission electron microscopy (TEM), resulting in a significant reduction in oxygen permeability (up to a 53% decrease). In particular, these oriented structures were observed in the FHTs modified with di poly(oxyethylene) alkyl methyl ammonium and the longer chain dimethyl dialkyl ammonium. Orientation and dispersion were found to be a result of chemical functionality, chain length, and unique aspect ratios of these FHTs. It was concluded that this reduction in permeability was predominantly due to the tortuous path created by oriented platelets and not from any nucleating effects the platelets may have had. Interestingly, the FHTs were shown to disrupt crystallinity and no change in free volume (as measured using positron annihilation life‐time spectroscopy) was observed. The excellent clay dispersion and orientation also led to significant increases in other properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Method for preparing polyaluminocarbosilane
Authors: He Guomei , Chen Jiangxi , Chen Lifu , Xia Haiping , Zhang Litong 
Published: May 2009

AbstractPolyaluminocarbosilane (PACS) was synthesized directly by the one‐pot reaction of polydimethylsilane (PDMS) with aluminum acetylacetonate [Al(acac)3] in an autoclave. In this closed system, all the aluminum in Al(acac)3 was converted into PACS. Therefore, the content of aluminum could be readily controlled quantitatively. On the basis of Fourier transform infrared, 1H‐NMR, 13C‐NMR, 29Si‐NMR, and 27Al magic‐angle spinning NMR analysis, the reaction mechanism was proposed as follows: PDMS dissociated during pyrolysis to generate silicon free radicals, and then they reacted with Al(acac)3 to yield PACS containing (SiO)nAl groups (n = 4, 5, or 6). Meanwhile, these reactions resulted in the cleavage of OC and/or OC bonds in Al(acac)3. Some of the free‐radical fragments generated by this cleavage continued to react with the silicon free radicals and were incorporated into the structural units of PACS; the rest of them may have been converted into small oxygen‐containing compounds, which were removed in the subsequent processing after the reactions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Blending of low‐density polyethylene with vanillin for improved barrier and aroma‐releasing properties in food packaging
Authors: Jagadish R. S. , Raj Baldev , Asha M. R. 
Published: May 2009

AbstractModification of low‐density polyethylene (LDPE) with vanillin to obtain flavored packaging film with improved gas barrier and flavor‐releasing properties has been studied. The modification of LDPE with vanillin was monitored by Fourier transform infrared spectroscopy, wherein the appearance of new peaks at 1704.7, 1673.6, and 1597.2 cm−1 indicates the incorporation of vanillin into LDPE matrix. Films of uniform thickness were obtained by the extrusion of modified LDPE. Modified LDPE was found to have significantly higher gas barrier properties and grease resistance. Sensory quality of food products viz, doodhpeda (milk‐based solid soft sweet), biscuit, and skimmed milk powder packed in LDPE‐vanillin film showed that the doodhpeda sample had clearly perceptible vanilla aroma, whereas biscuit had marginal aroma and skimmed milk powder did not have noticeable aroma. When viewed in the light of imparting desirable vanilla aroma, results of the study indicated that LDPE‐vanillin film has better prospects as a packaging material for solid sweets with considerable fat content when stored under ambient conditions. The release of vanilla aroma was further confirmed by gas chromatography–mass spectrometery analysis. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009