bluuebunny/crossref_metadata_2025 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

Here, 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

Here, 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

Poly(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

A 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

Infantile 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

Objectives

Work 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.

Methods

Scores 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.

Results

Using 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.

Conclusions

Maternal 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

Einfacher 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.

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Laser‐Modulated Ordering of Gold Nanoparticles at the Air/Water Interface
Authors: Volinsky Roman , Jelinek Raz
Published: May 2009

Beam 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.

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Hydroaminierung eines Alkens, induziert durch niederenergetische Elektronen
Authors: Hamann Thorben , Böhler Esther , Swiderek Petra
Published: May 2009

Elektronen 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.

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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

InBr3 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.

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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

Sparsames 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.

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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

Supersize 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.

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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

Efficiency 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.

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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

A 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.

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Laser‐Modulated Ordering of Gold Nanoparticles at the Air/Water Interface
Authors: Volinsky Roman , Jelinek Raz
Published: May 2009

Beam 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.

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Taking Fingerprints of DNA Polymerases: Multiplex Enzyme Profiling on DNA Arrays
Authors: Kranaster Ramon , Marx Andreas
Published: May 2009

A 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.

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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

Experimental 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

The 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

Many 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

Polyaluminocarbosilane (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

Modification 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
Effect of ferrocene moieties on the copper‐based atom transfer radical polymerization of methyl methacrylate
Authors: Sunsin Atchariya , Wisutsri Nuttaporn , Suriyarak Sarisa , Teanchai Rattapon , Jindabot Sudarat , Chaicharoenwimolkul Laksamee , Somsook Ekasith
Published: May 2009

The atom transfer radical polymerization (ATRP) of methyl methacrylate catalyzed by copper–tripodal complexes with ferrocene moieties (CuX/TRENFcImine, where X is Br or Cl, and TRENFcImine is tris‐[2‐(ferrocenylmethyleneimino)ethyl]amine) was investigated to understand the effect of redox active moieties on the performance of ATRP catalysts. The CuBr/TRENFcImine system was highly active, with 82% conversion in 2 h. However, the polymerization became slower at higher molar ratios of monomer to catalyst. The polydispersity index was broad, and the initiation efficiency was relatively low. On the basis of the conformational analysis, the highly active and less controlled polymerization was probably caused by the electronic effect rather than the steric effect on the ferrocene moieties, which led to the higher and lower values in the activation and deactivation steps, respectively. The polydispersity index was improved by the addition of CuBr2, but this led to slower rates of polymerization. The effect of halide groups on ATRP caused a faster rate in the CuBr/TRENFcImine polymerization system than in the CuCl/TRENFcImine system. The higher molar ratio of monomer to catalyst had no significant effect on the CuCl/TRENFcImine system. Nonetheless, the trace of water in the CuCl2·2H2O system accelerated the rate of propagation, which led to a higher molecular weight. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Developing a visual taxonomy: Children's views on aesthetics
Authors: Large Andrew , Beheshti Jamshid , Tabatabaei Nahid , Nesset Valerie
Published: May 2009

This article explores the aesthetic design criteria that should be incorporated into the information visualization of a taxonomy intended for use by children. Seven elementary‐school students were each asked to represent their ideas in drawings for visualizing a taxonomy. Their drawings were analyzed according to six criteria—balance, equilibrium, symmetry, unity, rhythm, and economy—identified as aesthetic measures in previous research. The drawings revealed the presence of all six measures, and three—unity, equilibrium, and rhythm—were found to play an especially important role. It is therefore concluded that an aesthetic design for an information visualization for young users should incorporate all six measures.
Sound research, unimportant discoveries: Research, universities, and formal evaluation of research in Spain
Authors: Rodríguez‐Navarro Alonso
Published: May 2009

Nobel Prizes are an important indicator of research excellence for a country. Spain has not had a science Nobel Prize winner since 1906, although its gross domestic product (GDP) is high, research and development (R&D) investments, in monetary terms, are high, and conventional bibliometric parameters are fairly good. Spanish research produces many sound papers that are reasonably cited but does not produce top‐cited publications. This absence of top‐cited publications suggests that important achievements are scarce and, consequently, explains the absence of Nobel Prize awards. I argue that this negative research trend in Spain is caused by the extensive use of formal research evaluations based on the number of publications, impact factors, and journal rankings. These formal evaluations were introduced to establish a national salary bonus that mitigated the lack of research incentives in universities. When the process was started, the results were excellent but, currently, it has been kept too long and should be replaced by methods to determine the actual interest of the research. However, this replacement requires greater involvement of universities in stimulating research.
Signaling networks and transcription factors regulating mechanotransduction in bone
Authors: Papachristou Dionysios J. , Papachroni Katerina K. , Basdra Efthimia K. , Papavassiliou Athanasios G.
Published: May 2009

Mechanical stimulation has a critical role in the development and maintenance of the skeleton. This function requires the perception of extracellular stimuli as well as their conversion into intracellular biochemical responses. This process is called mechanotransduction and is mediated by a plethora of molecular events that regulate bone metabolism. Indeed, mechanoreceptors, such as integrins, G protein‐coupled receptors, receptor protein tyrosine kinases, and stretch‐activated Ca2+ channels, together with their downstream effectors coordinate the transmission of load‐induced signals to the nucleus and the expression of bone‐related genes. During the past decade, scientists have gained increasing insight into the molecular networks implicated in bone mechanotransduction. In the present paper, we consider the major signaling cascades and transcription factors that control bone and cartilage mechanobiology and discuss the influence of the mechanical microenvironment on the determination of skeletal morphology.
Liquid chromatography mass spectrometry for the determination of salvianolic acid B, a natural compound from the herb Danshen in rat plasma and application to pharmacokinetic study
Authors: Han De‐En , Gao Zi‐Dong , Zhao Di , Wang Lei , Li Na , Li Ting‐Ting , Wu Lei , Chen Xi‐Jing
Published: May 2009

A sensitive and specific liquid chromatographic–electrospray ionization mass spectrometric method was developed for quantification of salvianolic acid B in rat plasma with resveratrol as the internal standard. The analytes were separated on a reversed‐phase column with acetonitrile (40%) and water (60%) containing 0.75% formic acid as mobile phase at a flow rate of 1 mL/min. Liquid–liquid extraction was adopted for the sample preparation, and the analytes were determined using electrospray negative ionization mass spectrometry in the selective monitoring mode. The method was validated over the concentration range 0.1–40 µg/mL using 0.1 mL of plasma with coefficients of correlation >0.999. The intra‐ and inter‐day precisions of analysis were <10%, and accuracy ranged from 94 to 101%. This method was successfully applied to a pharmacokinetics of salvianolic acid B in rats. Copyright © 2009 John Wiley & Sons, Ltd.
Simple and rapid micro‐scale quantification of artemisinin in living Artemisia annua L. by improved gas chromatography with electron‐capture detection
Authors: Liu Shuoqian , Tian Na , Li Juan , Huang Jianan , Liu Zhonghua
Published: May 2009

Malaria threatens 300–500 million people and kills more than one million people annually. Artemisinin has been widely used as part of the artemisinin‐based combination therapies against malaria. However, its supply is seriously short due to very small amounts of production of artemisinin in Artemisia annua. Molecular biologic researches aimed at increasing the artemisinin yield in plant have received more and more attention and therefore corresponding quantification methods for artemisinin analysis are urgently needed. A variety of methods for determination of artemisinin have been developed but they cannot be applied when only very little plant material is available or the material should be kept live, which often occurs in molecular biologic researches. The present work developed a simple, fast and low toxic micro‐scale analysis procedure for determination of artemisinin in a single leaf or flower of living Artemisia annua using improved gas chromatography with electron‐capture detection. The recovery of >95% was achieved by vortex of a piece of fresh leaf in 1 mL ethyl acetate for 2 min at room temperature. This method provides a powerful tool for biosynthesis study of artemisnin, high‐throughput screening high‐yield clone in an early stage, or real‐time quality control of Artemisia annua crop. Copyright © 2009 John Wiley & Sons, Ltd.
Optimization and validation of an ion‐pair RP‐HPLC‐UV method for the determination of total free iodine in rabbit plasma: application to a pharmacokinetic study
Authors: Cui Lijun , Wen Jun , Zhou Tingting , Wang Shuowen , Fan Guorong
Published: May 2009

An ion‐pair reverse‐phase high performance liquid chromatographic method with UV–vis detection has been developed for the determination of total free iodine in rabbit plasma after vaginal administration of povidone–iodine (PVP‐I). Sample preparation was done by protein precipitation with acetonitrile in 96‐well format and aspirin was used as the internal standard. The 100 µL sodium thiosulfate solution (5 g L−1) was added to 100 µL plasma sample before protein precipitation, to convert the total free iodine in plasma to iodide (I−). Separation was performed on a C18 column (200 × 4.6 mm i.d., 5 µm). The mobile phase consisting of a mixture of water phase (containing 10 mmol L−1 18‐crown‐6 ether, 5 mmol L−1 octylamine and 5 mmol L−1 sodium dihydrogen phosphate, pH adjusted to 6.0 with phosphoric acid) and acetonitrile in the ratio 70:30 (v/v) was delivered isocraticly at a flow rate of 1.0 mL min−1. The method was sensitive with a lower limit of quantification of 0.005 µg mL−1, with good linearity (r2 > 0.9990) over the linear range of 0.005–2 µg mL−1. All the validation data, such as linearity, accuracy and precision, were within the required limits. The method was successfully applied to study the pharmacokinetic of PVP–I in rabbits after vaginal administration. Copyright © 2009 John Wiley & Sons, Ltd.
Decomposition of 3′‐azido‐2′,3′‐dideoxythymidine 5′‐monophosphate (AZTMP) prodrugs in biological media studied by on‐line solid‐phase extraction coupled to liquid chromatography mass spectrometry
Authors: Lefebvre Isabelle , Beltran Thierry , Peyrottes Suzanne , Périgaud Christian
Published: May 2009

Using a column‐switching HPLC method previously described, we studied the behavior of some mononucleotide prodrugs (pronucleotides) of 3′‐azido‐2′,3′‐dideoxythymidine in various biological media. From UV data, this method allowed quantification of transient metabolites resulting from prodrug bioconversion. The kinetic data related to the successive steps were calculated according to pseudo‐first‐order kinetic models and optimized using mono‐ or poly‐exponential regressions. Various metabolites were identified by co‐injection with authentic samples and/or ESI‐MS coupling. The results led us to propose, for each considered pronucleotide, a global decomposition pathway ending in the selective delivery of the corresponding mononucleotide. Associated to the determination of other parameters (lipophilicity, aqueous solubility), the present study contributes to the search of suitable pharmacological properties for furtherin vivoevaluations. Copyright © 2009 John Wiley & Sons, Ltd.
Coupling of solid‐phase microextraction with micellar desorption and high performance liquid chromatography for the determination of pharmaceutical residues in environmental liquid samples
Authors: Padrón M. E. Torres , Ferrera Z. Sosa , Rodríguez J. J. Santana
Published: May 2009

A residue analytical method combining solid‐phase microextraction (SPME) with external micellar desorption (MD) and high‐performance liquid chromatography with diode array detector (HPLC‐DAD) has been developed and validated for the simultaneous determination of six pharmaceutical compounds, belonging to various therapeutic categories in water samples. Target compounds include antiinflamatory drugs (ibuprofen, ketoprofen and naproxen), an analgesic (phenazone), a lipid regulator (bezafibrate) and an antiepileptic (carbamazepine). A detailed study of the experimental conditions of extraction and desorption with different surfactants was performed in order to obtain the best results during instrumental analysis. Of the different fibers and surfactants investigated, 65 µm polydimethysiloxane‐divinilbenzene (PDMS‐DVB) fiber and polyoxyethylene 10 lauryl ether (POLE) and polyoxyethylene 6 lauryl ether (C12E6) as desorbing agents produced the optimal response to pharmaceutical residues. Recoveries obtained were generally higher than 80% and the variability of the method was below 16% for all compounds in both surfactants. Method detection limits were 0.05–12 ng mL−1 for POLE and 0.1–5 ng mL−1 for C12E6. The developed method was compared using external desorption with organic solvent and it was successfully applied to the determination of these pharmaceutical compounds in water samples from different origin. Solid‐phase microextraction with micellar desorption (SPME‐MD) represents a new approach for the extraction of different pharmaceutical compounds in natural waters because it combines shorter handling time, better efficiency, safety and more environmentally friendly process than the traditional methods. Copyright © 2009 John Wiley & Sons, Ltd.
Protein folding for finding active sites by the VMD tool and force field simulation
Authors: Sung Wen‐Tsai
Published: May 2009

This article employed VMD tool and force field simulation theorem for protein folding solution. This technique consists of two components: finished protein folding process and found out active sites for drug docking. The goal of protein folding simulation is to search the global energy minimum location with stability state, and the when the protein is finished the folding task, I can find out the active sites for pre‐process of ligand protein docking. This work succeeds in citing minimum energy to support this theme. The VMD is a molecular visualization program for displaying, animating, and analyzing large bimolecular systems using 3D graphics and built‐in scripting. In force field, I survey many force statistics methods, such as AMBER, MMFF, this work endeavored to predict the structures of the protein folding. Protein folding is a nonlinear dynamics chaos system; the VMD tool and force field simulation were used to attempt to find the optimal solution with low cost and accelerated folding by using. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 717–723, 2011
Assessment design: A step towards interoperability
Authors: Barchino Roberto , de Marcos Luis , Gutiérrez José María , Otón Salvador , Jiménez Lourdes , Gutiérrez José Antonio , Hilera José Ramón , Martínez José Javier
Published: May 2009

The assessment in e‐learning systems is a basic element to successfully complete any formative action. In this article we present a generic, flexible, interoperable and reusable language for design assessments, and its implementation in the EDVI Learning Management System. This language is based on XML and we have used XML Schema technology. We also describe the language attributes required to set the assessment plan based on our practical experience in e‐learning courses. The main purpose of this language is to make the assessment design interoperable among systems in a simple and efficient way. An adequate implementation will also reduce the time required to configure assessment activities, simplifying and automating them. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 770–776, 2011
Computational models calibration: Experiences in environmental engineering studies
Authors: López P. A. , Martínez‐Solano F. J. , Fuertes V. S. , Iglesias P. L.
Published: May 2009

Mathematical models are a fundamental tool in the learning process of environmental engineering. These models need to be calibrated in order to be used by future engineers as a simulation tool for the represented problems. This paper deals with the concept of computational models calibration applied to higher environmental engineering studies. In this paper, we depict a methodology to calibrate water quality models, as an educational example that represents the environmental problem of dissolved oxygen in a stream. This methodology is based on defining two types of parameters involved in calibration. First, internal parameters appear in the equations from semi‐empirical estimations and can be found within some intervals. Genetic algorithms are proposed to estimate them. Second, experimental measurements enter into equations as external parameters. They affect the accuracy of the final solutions. Therefore, an uncertainty analysis has to be performed. Finally, a termination criterion for calibration has been proposed, based on the overlap between the confidence intervals of predicted and measured values. By developing this methodology, we provide awareness to our students of the importance of calibration of mathematical models so that they can apply them in their future simulation of environmental problems. Students identify the possible sources of uncertainty at each stage of the environmental model performance and apply them in this particular problem, Genetic Algorithm Techniques, as a computational tool to improve the accuracy of their model predictions. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 795–805, 2011
Microsphere‐Mediated Protein Delivery into Cells
Authors: Sanchez‐Martin Rosario M. , Alexander Lois , Muzerelle Mathilde , Cardenas‐Maestre Juan M. , Tsakiridis Anestis , Brickman Joshua M. , Bradley Mark
Published: May 2009

Delivering the goods: By coupling proteins to varyingly sized polymeric microspheres, it is possible to deliver them to cells in an easy and effective way. For this study a fluorescent protein (EGFP) and a functional enzyme (β‐galactosidase) were coupled to these particles. Evaluation of the cellular uptake after “beadfection” shows that the functionality and activity of these proteins were not adversely affected through coupling to the carrier system; this shows that their functional structure is retained.

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Structures of HIV TAR RNA–Ligand Complexes Reveal Higher Binding Stoichiometries
Authors: Ferner Jan , Suhartono Marcel , Breitung Sven , Jonker Hendrik R. A. , Hennig Mirko , Wöhnert Jens , Göbel Michael , Schwalbe Harald
Published: May 2009

Target TAR by NMR: Tripeptides containing arginines as terminal residues and non‐natural amino acids as central residues are good leads for drug design to target the HIV trans‐activation response element (TAR). The structural characterization of the RNA–ligand complex by NMR spectroscopy reveals two specific binding sites that are located at bulge residue U23 and around the pyrimidine‐stretch U40‐C41‐U42 directly adjacent to the bulge.

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Asymmetric Allylation of Methyl Ketones by Using Chiral Phenyl Carbinols
Authors: Tietze Lutz F. , Kinzel Tom , Wolfram Thomas
Published: May 2009

To methyl or to alkyl? High induced facial selectivities and excellent yields are obtained in the allylation of aliphatic methyl ketones by using a structurally simple phenylbenzyl auxiliary to give the corresponding homoallylic ethers (see scheme). The transferred auxiliary has a very good protecting quality and can easily be removed.

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Novel chiral auxiliaries for the stereoselective allylation of aliphatic methyl ketones with allyltrimethylsilane and their use in the synthesis of homoallylic ethers are described. In a multicomponent domino process catalyzed by trifluoromethanesulfonic acid, the allyl moiety and the auxiliary are transferred onto the substrate to yield tertiary homoallylic ethers. The most useful auxiliary for a general application turned out to be the trimethylsilyl ether of phenyl benzyl carbinol with an induced diastereoselectivity of 90:10 using ethyl methyl ketone and 94:6 using isopropyl methyl ketone as substrates. The transferred substituted benzyl moiety has good protecting properties in subsequent transformations and can easily be removed under reductive conditions to provide the corresponding homoallylic alcohol. The origin of the high selectivity could be elucidated by identifying the relevant transition states using quantum‐chemical calculations. An excellent agreement between calculated and experimentally observed selectivities was obtained assuming an oxocarbenium ion as intermediate.
Use of an Osmium Complex as a Universal Luminescent Probe for Enzymatic Reactions
Authors: Virel Ana , Sanchez‐Lopez Jose , Saa Laura , García Ana Carla , Pavlov Valeri
Published: May 2009

Enzymatic modulation of fluorescence: The oxidised form of the OsIII complex is fluorescent in aqueous solution, whereas the reduced OsII form shows no significant fluorescence. This universal approach can be easily adapted to follow any enzymatic reaction to yield oxidising or reducing products capable of interacting with the reduced or oxidised form of the osmium complex, respectively (see figure).

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The water‐soluble bis(bipyridine)chloro(4‐picolinic acid) osmium complex, [OsIII(bpy)2Cl(PyCOOH)]2+ (bpy=2,2’‐bipyridine, Py=pyridine), is fluorescent in aqueous solution, whereas the reduced form of the complex, [OsII(bpy)2Cl(PyCOOH)]+, shows no significant fluorescence under the same conditions. Such reversible redox control of the fluorescence of the complex can be easily adapted to follow any enzymatic reaction to yield oxidising or reducing products that are capable of interacting with [OsIII(bpy)2Cl(PyCOOH)]2+ or [OsII(bpy)2Cl(PyCOOH)]+. Based on the redox reaction between products of biocatalytic reactions and the osmium complex, we have designed a simple bioanalytical assay for the detection of nerve gases, α‐ketoglutarate, hydrogen peroxide and glucose.
Controlled Synthesis of Large‐Area and Patterned Electrochemically Reduced Graphene Oxide Films
Authors: Zhou Ming , Wang Yuling , Zhai Yueming , Zhai Junfeng , Ren Wen , Wang Fuan , Dong Shaojun
Published: May 2009

Have you seen the film? Coupling a spray‐coating technique with a facile, low‐cost, efficient and environmentally friendly electrochemical method may realize the controllable synthesis of large‐area and patterned electrochemically reduced graphene oxide films on various conductive and insulating substrates with thicknesses ranging from a single monolayer to several microns (see figure).

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ChemInform Abstract: Low Temperature Structural Phase Transition of Ba3NaIr2O9.
Authors: zur Loye Hans‐Conrad , Kim Seung‐Joo , Macquart Rene , Smith Mark D. , Lee Yongjae , Vogt Tom
Published: May 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Syntheses and Crystal Structures of New Vanadium(IV) Oxyphosphates M(VO)2(PO4)2 with M: Co, Ni.
Authors: Kaoua S. , Gravereau P. , Chaminade J. P. , Pechev S. , Krimi S. , El Jazouli A.
Published: May 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: New Open‐Framework in the Uranyl Vanadates A3(UO2)7(VO4)5O (A: Li, Ag) with Intergrowth Structure Between A(UO2)4(VO4)3 and A2(UO2)3(VO4)2O.
Authors: Obbade S. , Renard C. , Abraham F.
Published: May 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Sonochemical Synthesis of Highly Luminescent Zinc Oxide Nanoparticles Doped with Magnesium(II).
Authors: Xiong Huan‐Ming , Shchukin Dmitry G. , Moehwald Helmuth , Xu Yang , Xia Yang‐Yao
Published: May 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Direct Observation of a Pressure‐Induced Metal‐to‐Semiconductor Transition in Lithium.
Authors: Matsuoka Takahiro , Shimizu Katsuya
Published: May 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: RERhZn (RE: Y, Sm, Gd—Lu) Compounds with TiNiSi Type Structure—Synthesis and Magnetic Properties.
Authors: Hermes Wilfried , Poettgen Rainer
Published: May 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Magnetic Properties and Magnetic Structure of Cu3IIMo2VIO9.
Authors: Vilminot Serge , Andre Gilles , Kurmoo Mohamedally
Published: May 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.