bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of polyelectrolyte complex microparticles for drug release
Authors: Agüero L. , García J. , Valdés O. , Fuentes G. , Zaldivar D. , Blanco M. D. , Katime I. 
Published: September 2012

AbstractFree radical copolymerization of acryloxyethyl–trimethylammonium chloride with 2–hydroxyethyl methacrylate using sodium persulfate as initiator was carried out at 60°C and of its electrostatic interaction with sodium alginate (NaAlg) allowed obtaining polymeric microparticles by complex coacervation. The solute transport in this swellable matrix was investigated to check the effect of cross‐linking and simulated physiological condition over release process. Cefazolin Sodium loaded microparticles were prepared by incorporation of drug directly in the reaction mixture and their ability of releasing resulted in more extensive in enzyme‐free simulated intestinal medium. The polymeric microparticles prepared in this study were characterized by scanning electron microscopy showing irregular spherical form and rough structure. Particles showed unimodal distribution and the size distribution ranged from 1.1 to 1.8 mm (n = 100). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis and Evaluation of Novel 4‐Substituted Styryl Quinazolines as Potential Antimicrobial Agents
Authors: Modh Rahul P. , Patel Amit C. , Mahajan Dharmesh H. , Pannecouque Christophe , De Clercq Erik , Chikhalia Kishor H. 
Published: September 2012

AbstractIn an attempt to afford possible antibacterial and anti‐human immunodeficiency virus (HIV) agents, a series of 22 novel styryl quinazoline‐based heterocyclic entities were designed and synthesized. Various substituted aryl urea and thiourea cores were incorporated at position 4 of quinazoline, followed by styrylation of position 2, aiming at an augmented biological potential. The synthesized compounds were well characterized through IR, 1H NMR, 13C NMR and elemental analyses. All compounds were screened for their in vitro anti‐HIV activity against the HIV‐1 (IIIB) and HIV‐2 (ROD) strains. The antibacterial activity was also evaluated against various pathogenic Gram‐positive and Gram‐negative bacterial strains.
A chemiluminescent metalloimmunoassay based on copper‐enhanced gold nanoparticles for quantification of human growth hormone
Authors: Hasanpour Foroozan , Khayamian Taghi , Ensafi Ali. A. , Rahmani Hamidreza , Rezaei Behzad 
Published: September 2012

ABSTRACTA chemiluminescence (CL) immunoassay was developed to determine human growth hormone (hGH) based on copper‐enhanced gold nanoparticles. In this method, gold nanoparticles were deposited on polystyrene wells for adsorption of human growth antibodies as well as catalyst for reducing of copper ions from the copper enhancer solution. The reduction of copper ions was prevented where the gold nanoparticles were covered by the antibody–antigen immunocomplex. The deposited copper on Au nanoparticles was then dissolved in HNO3 solution and quantified using the CL method. The CL intensity response was logarithmically dependent on the hGH concentrations over the range 0.2–50 ng/mL, with a detection limit (3σ) of 0.036 ng/mL. Copyright © 2012 John Wiley & Sons, Ltd.
Preparation Methods for Multi‐Walled Carbon Nanotube Supported Palladium Catalysts
Authors: Sairanen Emma , Karinen Reetta , Borghei Maryam , Kauppinen Esko I. , Lehtonen Juha 
Published: September 2012

AbstractAtomic layer deposition (ALD) in preparation of MWCNT‐supported Pd catalysts was compared to dry and wet impregnation. The prepared catalysts were characterized by various methods and cinnamaldehyde hydrogenation was used as a model reaction to test the activity of the prepared catalysts. The main factor affecting the properties of the catalyst was found to be the precursor medium used during catalyst preparation. ALD, with a gaseous precursor, led to the smallest metal particles with the highest dispersion, whereas impregnation methods using liquid precursors led to the largest particles with the lowest dispersion. The variation in the metal particle sizes of different catalysts was shown to affect the product distribution in the model reaction and the reaction mechanisms of the surface reactions.
Fluid Dynamics of Vibrofluidized Beds during the Transient Period of Water Evaporation and Drying of Solutions
Authors: Meili L. , Freire F. B. , do Carmo Ferreira M. , Freire J. T. 
Published: September 2012

AbstractThe influence of vibration number Γ, amplitude A, and frequency of vibration f on the fluid dynamic behavior of a vibrofluidized bed operating with inert particles in the transient period of water evaporation and drying of different solutions was evaluated. The solutions investigated were sewage sludge, skimmed milk, and calcium carbonate of three different solids contents. The impact of feed rate and vibration parameters on the dynamic behavior of variables such as pressure drop and inlet air velocity was determined. Based on the results it was verified that the operation at A = 0.015 m improved the bed dynamics and the gas‐particle contact in the wetted beds. As different dynamic behaviors may be obtained under the same Γ value, the values of A or f must be informed together with Γ for a complete characterization of vibration effects.
Monomer–Dimer Equilibrium for the 5′–5′ Stacking of Propeller‐Type Parallel‐Stranded G‐Quadruplexes: NMR Structural Study
Authors: Do Ngoc Quang , Phan Anh Tuân 
Published: September 2012

AbstractGuanine‐rich sequence motifs, which contain tracts of three consecutive guanines connected by single non‐guanine nucleotides, are abundant in the human genome and can form a robust G‐quadruplex structure with high stability. Herein, by using NMR spectroscopy, we investigate the equilibrium between monomeric and 5′–5′ stacked dimeric propeller‐type G‐quadruplexes that are formed by DNA sequences containing GGGT motifs. We show that the monomer–dimer equilibrium depends on a number of parameters, including the DNA concentration, DNA flanking sequences, the concentration and type of cations, and the temperature. We report on the high‐definition structure of a simple monomeric G‐quadruplex containing three single‐residue loops, which could serve as a reference for propeller‐type G‐quadruplex structures in solution.
Covalent Modification of Reduced Graphene Oxide by Means of Diazonium Chemistry and Use as a Drug‐Delivery System
Authors: Wei Guangcheng , Yan Miaomiao , Dong Renhao , Wang Dong , Zhou Xiangzhu , Chen Jingfei , Hao Jingcheng 
Published: September 2012

AbstractUnder acidic conditions, reduced graphene oxide (rGO) was functionalized with p‐aminobenzoic acid, which formed the diazonium ions through the diazotization with a wet‐chemical method. Surfactants or stabilizers were not applied during the diazotization. After the functionalized rGO was treated through mild sonication in aqueous solution, these functionalized rGO sheets were less than two layers, which was determined by atomic force microscopy (AFM) imaging. The water solubility of functionalized rGO after the introduction of polyethyleneimine (PEI) was improved significantly; it was followed by covalent binding of folic acid (FA) molecules to the functionalized rGO to allow us to specifically target CBRH7919 cancer cells by using FA as a receptor. The loading and release behaviors of elsinochrome A (EA) and doxorubicin (DOX) on the functionalized rGO sheets were investigated. The EA loading ratio onto rGO‐C6H4‐CO‐NH‐PEI‐NH‐CO‐FA (abbreviated rGO‐PEI‐FA, the weight ratio of drug loaded onto rGO‐PEI‐FA) was approximately 45.56 %, and that of DOX was approximately 28.62 %. It was interesting that the drug release from rGO‐PEI‐FA was pH‐ and salt‐dependent. The results of cytotoxicity (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) and flow cytometry (FCM) assays, as well as cell morphology observations) clearly showed that the concentration of rGO‐PEI‐FA as the drug‐delivery composite should be less than 12.5 mg L−1. The conjugation of DOX and rGO‐PEI‐FA can enhance the cancer‐cell apoptosis effectively and can also push the cancer cells to the vulnerable G2 phase of the cell cycle, which is most sensitive and susceptible to damage by drugs or radiation.
Cycloruthenated Complexes from Imine‐Based Heterocycles: Synthesis, Characterization, and Reactivity toward Alkynes
Authors: Cuesta Luciano , Soler Tatiana , Urriolabeitia Esteban P. 
Published: September 2012

AbstractNovel cycloruthenated complexes 2 a–c, 4 a–c, and 6 a, b based on heteroaromatic cores have been synthesized by reaction of a series of heterocycle‐based imines with [{RuCl(η6‐p‐cymene)}2(μCl)2] and Cu(OAc)2. This approach has proved efficient for the cyclometalation of thiophene, benzothiophene, furan, benzofuran, pyrrole, and indole derivatives. In addition, even a double cyclometalation process over the same heterocyclic ring is possible, yielding unprecedented bimetallic complexes. These ruthenacycles react with 3‐hexyne through an unexpected pathway, which involves the coupling of the original imino heterocycle and acetylene followed by dearomatization to afford fused hetero‐hydropyridyl ligands bonded to the {Ru(p‐cymene)} organometallic moiety (i.e., 7 a–c and 8 a–c). These complexes represent, as far as we know, the first examples of this type of compound within the context of cyclometalation, and an exhaustive analysis of their structure was carried out in solution and solid state. Furthermore, these unique species react with CuCl2, which promotes the rearomatization and the release of highly valuable aromatic fused bis‐heterocycles (i.e., 9 a–c, 10 a–c, 11 a, and 12 a/12 a′), providing a novel and appealing synthetic route to this extraordinary family of molecules.
Metal‐Free Arylation of Oxygen Nucleophiles with Diaryliodonium Salts
Authors: Jalalian Nazli , Petersen Tue B. , Olofsson Berit 
Published: September 2012

AbstractPhenols and carboxylic acids are efficiently arylated with diaryliodonium salts. The reaction conditions are mild, metal free, and avoid the use of halogenated solvents, additives, and excess reagents. The products are obtained in good‐to‐excellent yields after short reaction times. Steric hindrance is very well tolerated, both in the nucleophile and diaryliodonium salt. The scope includes ortho‐ and halo‐substituted products, which are difficult to obtain by metal‐catalyzed protocols. Many functional groups are tolerated, including carbonyl groups, heteroatoms, and alkenes. Unsymmetric salts can be chemoselectively utilized to obtain products with hitherto unreported levels of steric congestion. The arylation has been extended to sulfonic acids, which can be converted to sulfonate esters by two different approaches. With recent advances in efficient synthetic procedures for diaryliodonium salts the reagents are now inexpensive and readily available. The iodoarene byproduct formed from the iodonium reagent can be recovered quantitatively and used to regenerate the diaryliodonium salt, which improves the atom economy.
Energy Propagation Through a Protometabolism Leading to the Local Emergence of Singular Stationary Concentration Profiles
Authors: Emond Matthieu , Le Saux Thomas , Allemand Jean‐Francois , Pelupessy Philippe , Plasson Raphaël , Jullien Ludovic 
Published: September 2012

AbstractLiving systems rely on chains of energy transfer from an energy source to maintain their metabolism. This task requires functionally identified components and organizations. However, propagation of a sustained energy flux through a cascade of reaction cycles has never been reproduced at a steady state in a simple chemical system. By using energy patterning and a diffusing hub reactant, we achieved the transfer of energy through an abiotic protometabolism. Patterned illumination was applied to a liquid solution of a reversible photoacid. It resulted in the local onset of a proton pump, which subsequently drove an extended reaction–diffusion cycle that involved pH‐sensitive reactants. Thus, light has been used for locally setting out of chemical equilibrium a reaction involving “blind” reactants. The spontaneous onset of an energy‐transfer chain notably drives the local generation of singular dissipative chemical structures; continuous matter fluxes are dynamically maintained at boundaries between spatially and chemically segregated zones, in the absence of any membrane or predetermined material structure.
Synthesis and Biological Evaluation of a Library of Glycoporphyrin Compounds
Authors: Daly Robin , Vaz Gisela , Davies Anthony M. , Senge Mathias O. , Scanlan Eoin M. 
Published: September 2012

AbstractA library of glycosylated porphyrins (glycoporphyrins) was prepared and the compounds were evaluated for their photodynamic therapy (PDT) activity against the oesophageal squamous‐cell carcinoma cell line OE21 in vitro. A synthetic methodology was developed to allow incorporation of biologically active carbohydrates, including the histo‐blood‐group antigen trisaccharide LewisX, onto the porphyrin backbone. The effect of the carbohydrate group and substitution pattern on the PDT activity, cell uptake and subcellular localisation of the glycoporphyrin compounds is reported.
Multicomponent Assembly of Macrocycles and Polymers by Coordination of Pyridyl Ligands to 1,4‐Bis(benzodioxaborole)benzene
Authors: Icli Burcak , Solari Euro , Kilbas Benan , Scopelliti Rosario , Severin Kay 
Published: September 2012

AbstractMulticomponent reactions between 1,4‐benzenediboronic acid, catechol, and different pyridyl ligands are reported. The condensation of 1,4‐benzenediboronic acid with catechol gives 1,4‐bis(benzodioxaborole)benzene. Upon crystallization, the ester aggregates with the N‐donor ligands through dative BN bonds. Depending on the nature of the pyridyl ligand, molecularly defined macrocycles or polymeric structures are obtained. 1D polymers are formed with 4,4‐bipyridine and 1,2‐di(4‐pyridyl)ethylene, whereas a 2D network is obtained with the tetradentate ligand tetra(4‐pyridylphenyl)ethylene. These results highlight the utility of dative BN bonds in structural supramolecular chemistry and crystal engineering.
Spiky Mesoporous Anatase Titania Beads: A Metastable Ammonium Titanate‐Mediated Synthesis
Authors: Chen Dehong , Huang Fuzhi , Cao Lu , Cheng Yi‐Bing , Caruso Rachel A. 
Published: September 2012

AbstractA complex titania nanostructure of monodisperse spiky mesoporous anatase beads composed of anatase nanocrystals with diameters of less than 15 nm in the core and much larger hollow‐cone shaped spikes on the surface was fabricated using a facile solvothermal process in the presence of ammonia. This proceeded through a controllable phase transformation from an amorphous titania to a metastable amorphous titania/ammonium titanate core‐shell structure then finally to anatase titania. The size of the spiky anatase nanostructures can be increased from approximately 55×100 nm to 160×410 nm (square edge×length) by increasing the ammonia concentration used in the solvothermal treatment step from 2.2 to 17.4 wt. %. Such hollow‐cone shaped nanostructures, as revealed by HRTEM characterization, are single crystals elongated along the c axis of the tetragonal anatase titania. The resultant spiky titania beads have high surface areas of up to 112 m2g−1 and pore diameters and pore volumes that vary depending on the ammonia concentration and solvothermal treatment time. The morphological evolution and crystallization process of the spiky titania beads was investigated using SEM and XRD techniques. A metastable amorphous titania/ammonium titanate core‐shell structure evolved from the smooth amorphous precursor beads producing a “fluffy” titanate intermediate, on further heating the final spiky mesoporous titania beads were clearly observed. This titanate‐phase‐mediated approach allows control over the size of the nanocrystals in the core of the bead, as well as the anatase spikes on the surface, and thereby, tuning of the surface area and porosity of the resultant products. The spiky mesoporous titania beads have been used to prepare working electrodes for dye‐sensitized solar cells achieving a solar to electric power conversion efficiency of 10.30 %, indicating their potential for application in the photovoltaic field. Such complex titania nanostructures would have a number of other possible applications, such as photocatalysis, lithium ion batteries, and catalysis.
ChemInform Abstract: Synthesis, Structure, and Properties of the New Mixed‐Valent Dodecahalogenotrimetallate In4Ti3Br12 and Its Relation to Compounds A3Ti2X9 (A: K, In; X: Cl, Br).
Authors: Schroeder Melanie , Hartwig Sabina , Kraemer Karl W. , Decurtins Silvio , Hillebrecht Harald 
Published: September 2012

AbstractBlack single crystals of the new title compound are prepared by reaction of InBr3 with Ti (silica ampule, 450 °C, 5 d).
ChemInform Abstract: Thermoelectric Properties of Type‐VIII Clathrate Ba8Ga16Sn30 Doped with Cu.
Authors: Saiga Y. , Du B. , Deng S. K. , Kajisa K. , Takabatake T. 
Published: September 2012

AbstractSingle p‐ and n‐type crystals of the title clathrate are grown from Ga flux and Sn flux, respectively.
ChemInform Abstract: Syntheses, Structures, and Spectroscopic Properties of Plutonium and Americium Phosphites and the Redetermination of the Ionic Radii of Pu(III) and Am(III).
Authors: Cross Justin N. , Villa Eric M. , Wang Shuao , Diwu Juan , Polinski Matthew J. , Albrecht‐Schmitt Thomas E. 
Published: September 2012

AbstractPu2[(HPO3)3(H2O)] (I) and Am2[(HPO3)3(H2O)] (II) are hydrothermally synthesized from aqueous mixtures containing PuCl3 or AmCl3, H3PO3, and Na2CO3 (autoclave, 200 °C, 2 h).
ChemInform Abstract: Technetium Tetrachloride Revisited: A Precursor to Lower‐Valent Binary Technetium Chlorides.
Authors: Johnstone Erik V. , Poineau Frederic , Forster Paul M. , Ma Longzou , Hartmann Thomas , Cornelius Andrew , Antonio Daniel , Sattelberger Alfred P. , Czerwinski Kenneth R. 
Published: September 2012

AbstractTcCl4 is synthesized from technetium metal and excess chlorine in sealed Pyrex ampules (450 °C, 14 h, 69% yield).
ChemInform Abstract: Study of the Lanthanide‐Catalyzed, Aqueous, Asymmetric Mukaiyama Aldol Reaction.
Authors: Mei Yujiang , Averill Derek J. , Allen Matthew J. 
Published: September 2012

AbstractThe synthesis of chiral syn‐ligand ACE is improved by using CH2Cl2 as solvent instead of MeCN applied in an initial report, resulting in an increase of the syn:anti ratio from 4:1 to 16:1.
ChemInform Abstract: New Neutral Reaction System with Crown Ether—KCl Complexes in Aqueous Solution.
Authors: Shirakawa Seiji , Wang Lijia , Kasai Atsuyuki , Maruoka Keiji 
Published: September 2012

AbstractA catalytic amount of lipophilic 18‐crown‐6 ether BBC in a biphasic H2O/toluene KCl solution is successfully applied for several conjugate addition reactions.
ChemInform Abstract: CuII‐Catalyzed Asymmetric Hydrosilylation of Diaryl‐ and Aryl Heteroaryl Ketones: Application in the Enantioselective Synthesis of Orphenadrine and Neobenodine.
Authors: Sui Yao‐Zong , Zhang Xi‐Chang , Wu Jun‐Wen , Li Shijun , Zhou Ji‐Ning , Li Min , Fang Wenjun , Chan Albert S. C. , Wu Jing 
Published: September 2012

AbstractEnantioselective reduction of a wide range of diaryl ketones and aryl hetaryl ketones to the corresponding secondary alcohols is efficiently achieved using PMHS in the presence of a Cu—bis(pyridylphosphine) catalyst.
ChemInform Abstract: Iridium‐Catalyzed Reaction of Enones with Alcohols Affording 1,3‐Diketones.
Authors: Obora Yasushi , Nakamura Kazuhiro , Hatanaka Shintaro 
Published: September 2012

AbstractAn atom‐economical synthesis of 1,3‐diketones (III) and (V) by the reaction of enones (I) and (IV) with benzylic alcohols (II) in the presence of an Ir‐catalyst is described.
ChemInform Abstract: Update: An Efficient Synthesis of Poly(ethylene glycol)‐Supported Iron(II) Porphyrin Using a Click Reaction and Its Application for the Catalytic Olefination of Aldehydes.
Authors: Chinnusamy Tamilselvi , Rodionov Valantin , Kuehn Fritz E. , Reiser Oliver 
Published: September 2012

AbstractPolyethylene glycol‐immobilized iron(II) porphyrin is an efficient catalyst for the selective olefination of aldehydes with ethyl diazoacetate in the presence of triphenylphosphine.
ChemInform Abstract: Tetrabutylammonium Iodide Catalyzed Synthesis of Allylic Ester with tert‐Butyl Hydroperoxide as an Oxidant.
Authors: Shi Erbo , Shao Ying , Chen Shulin , Hu Huayou , Liu Zhaojun , Zhang Jie , Wan Xiaobing 
Published: September 2012

AbstractA new, simple, and efficient method to prepare a wide range of allylic esters is reported.
ChemInform Abstract: Pd‐Nanoparticle (PdNP)‐Catalyzed Negishi Coupling of Acid Chlorides Using Zinc Reagents.
Authors: Yu Lei , Ren Lingfeng , Chen Tian , Yi Rong , Wu Yulan , Guo Rong 
Published: September 2012

AbstractThis is the first example for the synthesis of ketones through Negishi cross‐coupling catalyzed by Pd nanoparticles which are generated in situ from palladium(II) acetate and tetrabutylammonium bromide.
ChemInform Abstract: Gold(I)‐Catalyzed Intermolecular [2 + 2] Cycloadditions Between Allenamides and Alkenes.
Authors: Faustino Helio , Bernal Paloma , Castedo Luis , Lopez Fernando , Mascarenas Jose L. 
Published: September 2012

AbstractThe cycloaddition of allenamide (I) to alkenes represents a simple and practical access to highly substituted cyclobutane derivatives and proceeds with high regioselectivity.
ChemInform Abstract: Aerobic Oxidative Dehydrogenation of Benzyl Alcohols to Benzaldehydes by Using a Cyclometalated Ruthenium Catalyst.
Authors: Taketoshi Ayako , Beh Xin Ning , Kuwabara Junpei , Koizumi Take‐aki , Kanbara Takaki 
Published: September 2012

AbstractA Ru(III)‐complex bearing a phenylpyridine ligand is found to be an efficient catalyst for the aerobic oxidative dehydrogenation of benzyl alcohols to afford the corresponding aldehydes.
ChemInform Abstract: A Comparative Study of Different Metal Acetylacetonates Covalently Anchored onto Amine Functionalized Silica: A Study of the Oxidation of Aldehydes and Alcohols to Corresponding Acids in Water.
Authors: Sodhi Ravinderpal Kour , Paul Satya , Clark J. H. 
Published: September 2012

AbstractSiO2‐Co(acac)2 catalyzes the oxidation of aldehydes (V) under air atmosphere without using any additional oxidant.
ChemInform Abstract: Enantioselective Synthesis of α‐Stereogenic γ‐Keto Esters via Formal Umpolung.
Authors: Prakash G. K. Surya , Wang Fang , Zhang Zhe , Ni Chuanfa , Haiges Ralf , Olah George A. 
Published: September 2012

AbstractThe derivative (X) can smoothly be converted into the tetrahydroquinoline (XI).
ChemInform Abstract: Synthesis of Arylidenepyruvic Amide Derivatives via Ugi‐Four Component Condensation.
Authors: Soleymanifard Bita , Heravi Majid M. , Shiri Morteza , Zolfigol Mohammad Ali , Rafiee Mohammad , Kruger Hendrik G. , Naicker Tricia , Rasekhmanesh Farzaneh 
Published: September 2012

AbstractA simple protocol allows for the synthesis of the title compounds (V) by Ugi‐four component reaction of arylidenepyruvic acids, amines, aldehydes, and isocyanides.
ChemInform Abstract: Nucleophilic Substitution of the Acetoxy Group in 3‐Methylbenzoylaminomethyl Acetate.
Authors: Labanauskas L. , Mazeikaite R. , Striela R. , Gedrimaite O. , Urbelis G. , Zilinskas A. 
Published: September 2012

AbstractThe acetoxy group in title compound (I) can be substituted by selected N‐ and S‐nucleophiles following a SN2 mechanism.
ChemInform Abstract: Rh‐Catalyzed [5 + 1] and [4 + 1] Cycloaddition Reactions of 1,4‐Enyne Esters with CO: A Shortcut to Functionalized Resorcinols and Cyclopentenones.
Authors: Fukuyama Takahide , Ohta Yuko , Brancour Celia , Miyagawa Kazusa , Ryu Ilhyong , Dhimane Anne‐Lise , Fensterbank Louis , Malacria Max 
Published: September 2012

AbstractThe novel title reactions are presented from readily available 1,4‐enyne esters.