bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractThe 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

AbstractThis 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

AbstractNobel 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

AbstractMechanical 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

AbstractA 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

AbstractMalaria 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

AbstractAn 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

AbstractUsing 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

AbstractA 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

AbstractThis 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

AbstractThe 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

AbstractMathematical 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

AbstractDelivering 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.magnified image
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

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

AbstractTo 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.magnified imageNovel 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

AbstractEnzymatic 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).magnified imageThe 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

AbstractHave 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).magnified image
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

AbstractChemInform 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

AbstractChemInform 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

AbstractChemInform 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

AbstractChemInform 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.