bluuebunny/crossref_metadata_2025_split huggingface dataset:
The results of the expression array studies correlate and enhance the known genetic basis of gastric and colorectal cancer
Authors: Galamb Orsolya , Sipos Ferenc , Fischer Krisztina , Tulassay Zsolt , Molnar Bela 
Published: October 2005

AbstractGastric and colorectal cancers belong to the most frequent cancer types in the world today. This fact emphasizes the importance of identification of useful diagnostic and prognostic markers, in the earliest stage of the disease. The examination of gene expression profile in gastric and colorectal cancer may develop the bases of early diagnosis and of individual therapeutic strategies. In the microarray examinations done so far for these types of cancers, the expression of hundreds and thousands of genes were studied, however, both the sample collection and the results showed wide variations. The diversity of expression array methods and data analysis makes the comparison of microarray results difficult. Beside the exposition of the practical aspects of the chip technology, our aims are the systematization of data that are currently available in the international scientific literature and the description of the results in a comprehensive way. Microarray results show that the gene expression pattern, detected in gastric and colon cancers, highly depends on the histological type and heterogeneity of the sample, array type, and softwares, used for data analysis. Recent experiments point out not just the changes of the alterations of tumor suppression, apoptosis, cell‐cycle regulation, and signal transduction, but tumor cell metabolism and cell‐microenvironment interactions also. Results show connection to and make more complete the already known molecular background of gastric and colorectal cancers. Based on the accumulation of recent and further data, such kind of multifunctional diagnostic microarrays that can be suited for completing the conventional histological diagnostics and subtypization will certainly become available in the near future. © 2005 Wiley‐Liss, Inc.
Synthesis and Linear Optical Properties of Tris(catecholato)metal(III,IV) Complexes with Acceptor‐Substituted Ligands
Authors: Kriegisch Volker , Lambert Christoph 
Published: October 2005

AbstractThe synthesis of C3‐symmetric chromophores (2–4, 9, 10, 14) with acceptor‐substituted catecholato ligands and different central metal atoms (Si, Al, Ti) is described. These complexes might serve as octupolar chromophores with first‐order nonlinear optical properties. UV/Vis spectroscopic investigations show a red‐shift of the lowest‐energy charge‐transfer band on going from SiIV, AlIII to TiIV complexes, dependent on the increasing ionic character of the M–O bond. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A Convenient Synthetic Route for the Preparation of Nonsymmetric Metallo‐salphen Complexes
Authors: Kleij Arjan W. , Tooke Duncan M. , Spek Anthony L. , Reek Joost N. H. 
Published: October 2005

AbstractNew nonsymmetric metallo(II)‐salphen complexes 1–6 [salphen = N,N′‐bis(salicylidene)‐1,2‐diaminobenzene, M = Zn, Ni] have been prepared in high yield by a templated, one‐pot two‐step procedure starting from substituted ortho‐phenylenediamines, salicylaldehydes and metal acetates in MeOH under mild conditions. The procedure allows the introduction of functional groups in the bridging phenyl fragment, whereas the use of the substituted monoimine intermediates 7–10 results in complexes with two structurally different phenyl side groups with various functionalities (complexes 11–21) upon reaction with a second, different, salicylaldehyde reagent. A range of analytical tools confirmed the structures of these nonsymmetric salphen derivatives and the X‐ray molecular structure of one of these nonsymmetric ZnII‐salphen complexes (i. e., 4) is also reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Chemiluminescence of Electrochemically Oxidized 9‐(Phenylthiophosphoryloxymethylidene)‐10‐methylacridan Derivatives
Authors: Mirkhalaf Fakhradin , Wilson Robert 
Published: October 2005

AbstractThe electrochemistry and electrochemiluminescence (ECL) properties of acridan phosphate ester are reported. Electrochemical oxidation of 9‐(phenylthiophosphoryloxymethylidene)‐10‐methylacridan disodium salt (Compound 1) yields the corresponding acridinium ester. The latter undergoes a fast reaction with hydrogen peroxide forming an intermediate, which produces electronically excited 9‐methyl acridone and emits blue light after relaxation to the ground state. The electrochemical oxidation of this compound appears to occur in two one‐electron steps and light emission is observed for both steps. The chemiluminescence reaction could also be triggered by electrochemical oxidation of Compound 1 in the absence of H2O2 when the solution was saturated with O2. Mechanisms for these reactions based on ECL, voltammetry and in situ UV‐vis identification of the oxidation products are proposed. Due to the low electrode potential required to achieve ECL emission and the occurrence of light emission in the absence of hydrogen peroxide, this compound is proposed as a label for rapid and sensitive determination of biomolecules in automated analysis.
Evolution of the morphological innovations of feathers
Authors: Prum Richard O. 
Published: October 2005

AbstractFeathers are complex assemblages of multiple morphological innovations. Recent research on the development and evolution of feathers has produced new insights into the origin and diversification of the morphological innovations in feathers. In this article, I review and discuss the contribution of three different factors to the evolution of morphological innovations in feathers: feather tubularity, hierarchical morphological modularity, and the co‐option molecular signaling modules. The developing feather germ is a tube of epidermis with a central dermal pulp. The tubular organization of the feather germ and follicle produces multiple axes over which morphological differentiation can be organized. Feather complexity is organized into a hierarchy of morphological modules. These morphological modules evolved through the innovative differentiation along multiple different morphological axes created by the tubular feather germ. Concurrently, many of the morphological innovations of feathers evolved through the evolutionary co‐option of plesiomorphic molecular signaling modules. Gene co‐option also reveals a role for contingency in the evolution of hierarchical morphological innovations. J. Exp. Zool. (Mol. Dev. Evol.) 304B, 2005. © 2005 Wiley‐Liss, Inc.
Surface‐Initiated Atom Transfer Radical Polymerization on Poly(Vinylidene Fluoride) Membrane for Antibacterial Ability
Authors: Zhai Guangqun , Shi Zhi L. , Kang En T. , Neoh Koon G. 
Published: October 2005

AbstractSummary: Surface‐active microporous membranes were prepared from the poly(vinylidene fluoride)‐graft‐poly(2‐(2‐bromoisobutyryloxy)ethyl acrylate) copolymer (PVDF‐g‐PBIEA copolymer) by phase inversion in water. The PBIEA side chains could function as initiators for the atom transfer radical polymerization (ATRP) of 2‐(N,N‐dimethylamino)ethyl methacrylate on the membrane surfaces to give rise to the PVDF‐g‐PBIEA‐ar‐PDMAEMA membranes. N‐alkylation with hexyl bromide and nitromethane gave rise to the quanternized PVDF‐g‐PBIEA‐ar‐QPDMAEMA membranes with polycation chains chemically tethered on the membrane surface, including the pore surfaces. The changes in the surface morphology and the surface chemical composition were confirmed by scanning electron microscopy and X‐ray photoelectron spectroscopy. The scanning electron microscopy revealed that, in comparison to the pristine PVDF‐g‐PBIEA membranes, not only could the PVDF‐g‐PBIEA‐ar‐QPDMAEMA membranes remove the Gram‐negative bacterium Escherichia coli but also inhibited the bacterial reproduction on the membranes to a significant extent.PVDF‐g‐PBIEA and PVDF‐g‐PBIEA‐ar‐QPDMAEMA membranes after exposure to water‐borne E. coli suspension for 24 h.magnified imagePVDF‐g‐PBIEA and PVDF‐g‐PBIEA‐ar‐QPDMAEMA membranes after exposure to water‐borne E. coli suspension for 24 h.
Hydroxypropyl Chitosan Bearing β‐Cyclodextrin Cavities: Synthesis and Slow Release of its Inclusion Complex with a Model Hydrophobic Drug
Authors: Prabaharan Mani , Mano João F. 
Published: October 2005

AbstractSummary: Hydroxypropyl chitosan‐graft‐carboxymethyl β‐cyclodextrin (HPCH‐g‐CM β‐CD) was synthesized by grafting CM β‐CD onto HPCH using water soluble 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide (EDC) as the condensing agent. Due to the presence of hydrophobic β‐CD rings onto the HPCH backbone, this polymer can be used as a matrix for controlled drug release. The adsorption of a hydrophobic model drug, ketoprofen, by HPCH‐g‐CM β‐CD microparticles (using tripolyphosphate as an ionic crosslinking agent) fitted well in the Langmuir isotherm equation. The drug dissolution profile showed that HPCH‐g‐CM β‐CD microparticles provided a slower release of the entrapped ketoprofen than chitosan, and the release behavior was influenced by the pH value of the medium. These results suggest that β‐CD grafted with chitosan derivatives may become a potential biodegradable delivery system to control the release of hydrophobic drugs with pH‐responsive capability.The structure and drug release profiles of HPCH‐g‐CM β‐CD.magnified imageThe structure and drug release profiles of HPCH‐g‐CM β‐CD.
Novel Hydrogel Membrane Based on Copoly(hydroxyethyl methacrylate/p‐vinylbenzyl‐poly(ethylene oxide)) for Biomedical Applications: Properties and Drug Release Characteristics
Authors: Arıca M. Yakup , Bayramoǧlu Gülay , Arıca Betül , Yalçın Emine , Ito Koichi , Yagci Yusuf 
Published: October 2005

AbstractSummary: The aim of this study was to synthesize and characterize a novel biocompatible polymeric membrane system and demonstrate its potential use in various biomedical applications. Synthetic hydrogels based on poly(hydroxyethyl methacrylate), poly(HEMA), have been widely studied and used in biomedical fields. A novel copolymer hydrogel was prepared in the membrane form using 2‐hydroxyethyl methacrylate monomer (HEMA) and a macromonomer p‐vinylbenzyl‐poly(ethylene oxide) (V‐PEO) via photoinitiated polymerization. A series of poly(HEMA/V‐PEO) copolymer membranes with different compositions was prepared. The membranes were characterized using infrared, thermal and SEM analysis. The thermal stabilities of the copolymer membranes were found to be lowered by an increase in the ratio of macromonomer (V‐PEO) in the membrane structure. Because of the incorporation of PEO segments, the copolymers exhibited significantly higher hydrophilic surface properties than pure poly(HEMA), as demonstrated by contact angle measurements. Equilibrium swelling studies were conducted to investigate the swelling behavior of the membranes. The equilibrium water uptake was reached in about 4 h. Moreover, the blood protein adsorption and platelet adhesion were significantly reduced on the surface of the PEO containing copolymer membranes compared to control pure poly(HEMA). Drug release experiments were performed in a continuous release system using model drug (vancomycin) loaded copoly(HEMA/V‐PEO) membranes. A specific poly(HEMA/V‐PEO) membrane formulation possessing the highest PEO content (with a HEMA:V‐PEO (mmol:mmol) feed ratio of 112:1 and loaded with 40 mg antibiotic/g polymer) released about 81% of the total loaded drug in 24 h at pH 7.4. This membrane composition provided the best results and can be considered as a potential candidate for a transdermal antibiotic carrier and various biomedical and biotechnological applications.DSC measurements of membranes.magnified imageDSC measurements of membranes.
Microspheres Made of Poly(ε‐caprolactone)‐Based Amphiphilic Copolymers: Potential in Sustained Delivery of Proteins
Authors: Quaglia Fabiana , Ostacolo Luisanna , Nese Giuseppe , De Rosa Giuseppe , La Rotonda Maria Immacolata , Palumbo Rosario , Maglio Giovanni 
Published: October 2005

AbstractSummary: Microspheres of amphiphilic multi‐block poly(ester‐ether)s (PEE)s and poly(ester‐ether‐amide)s (PEEA)s based on poly(ε‐caprolactone) (PCL) were investigated as delivery systems for proteins. The interest was mainly focused on the effect of their molecular structure and composition on the overall properties of the microspheres, encapsulating bovine serum albumin (BSA) as a model protein. PEEs and PEEAs were prepared using a α,ω‐dihydroxy‐terminated PCL macromer ($\overline M _{\rm n}$ = 2.0 kDa) as a hydrophobic component. Hydrophilic oxyethylene sequences were generated using poly(ethylene oxide)s (PEO)s of different molecular mass ($\overline M _{\rm n}$ = 300–600 Da) in the case of PEEs, or 4,7,10‐trioxa‐1,13‐tridecanediamine (Trioxy) and PEO150 ($\overline M _{\rm n}$ = 150 Da) in the case of PEEAs. The copolymers showed a decrease of Tm and crystallinity values as compared with PCL. Within each class of copolymers, the bulk hydrophilicity increased with increasing the number of oxyethylene groups in the chain repeat unit. PEEAs were more hydrophilic than PEEs with a similar number of oxyethylene groups. Discrete spherical particles were prepared by both PEEs and PEEAs and their BSA encapsulation efficiency related to copolymer properties. Interestingly, the insertion of short hydrophilic segments is enough to significantly affect protein distribution inside microspheres and its release profiles, as compared to PCL microspheres. Different degradation rates and mechanisms were observed for copolymer microspheres, mainly depending on the distribution of oxyethylene units along the chain. The results highlight that a fine control over the structural parameters of amphiphilic PCL‐based multi‐block copolymers is a key factor for their application in the field of protein delivery.Release profiles of BSA from microspheres in 0.01 M phosphate buffer and CLSM images of BSA‐loaded microspheres.magnified imageRelease profiles of BSA from microspheres in 0.01 M phosphate buffer and CLSM images of BSA‐loaded microspheres.
Thermodynamic Differences Between Deuterated and Protonated Polystyrenes Evaluated Using Reversed Phase Liquid Chromatography
Authors: Kayillo Sindy , Shalliker R. Andrew , Dennis Gary R. 
Published: October 2005

AbstractSummary: Deuterated compounds are generally considered to possess very similar properties to their protonated analogues. Reversed phase liquid chromatography (RPLC) was used to measure thermodynamic interactions between deuterated and protonated n‐butyl polystyrenes and a C18 stationary phase. Significant differences in enthalpies and entropies of interaction were observed for deuterated and protonated n‐butyl polystyrenes. This is very important because many techniques, such as small‐angle neutron scattering and neutron reflectivity, assume that the interaction of these molecules are identical.Structure of n‐butyl polystyrenes.magnified imageStructure of n‐butyl polystyrenes.
Novel Titanium Catalysts Bearing an [O, N, S] Tridentate Ligand for Ethylene Homo‐ and Copolymerization
Authors: Wang Cong , Sun Xiu‐Li , Guo Yang‐Hui , Gao Yuan , Liu Bo , Ma Zhi , Xia Wei , Shi Li‐Ping , Tang Yong 
Published: October 2005

AbstractSummary: By a sidearm approach, a series of titanium complexes bearing an [O, N, S] tridentate ligand have been synthesized and proven to be highly active for ethylene polymerization. The complexes also show excellent ability to copolymerize ethylene with hex‐1‐ene and norbornene. The effects of the different sidearms on the catalytic behavior of the complexes were studied in detail.The copolymerization of ethylene with hex‐1‐ene using titanium complexes bearing [O, N, S] tridentate ligands as catalysts.imageThe copolymerization of ethylene with hex‐1‐ene using titanium complexes bearing [O, N, S] tridentate ligands as catalysts.
Gelation Studies, 4
Authors: Richter Sven , Matzker Rolf , Schröter Klaus 
Published: October 2005

AbstractSummary:In a recent paper [S. Richter et al.,Macromol. Rapid Commun.2004,25, 1504] the sol‐gel transition of two thermoreversible gelling mixtures made of xanthan gum and locust bean gum has been studied by using time‐resolved dynamic light scattering (DLS) and low‐amplitude oscillatory shear rheology, and is indicated by the presence of the typical power‐law behaviors in the time‐intensity correlation functiong2(t) − 1 ∝ t−µand in the oscillatory shear experimentG′(ω) ∝ G″(ω) ∝ ωn. A significant and reproducible difference of 7 K for the estimated gelation temperatures was found again, with the higher one always determined by rheology. We now present a logical explanation together with new results obtained on this system that may also be of importance for other ones. The incipient infinite percolated cluster that is formed during the gelation process is more pronounced, and is detectable earlier by rheology than by DLS for this present system.Double‐logarithmic plot of the time‐intensity correlation functionsg2(t) − 1 versus the delay timetand at a scattering angle ofθ = 90° and at several temperatures of the mixture.imageDouble‐logarithmic plot of the time‐intensity correlation functionsg2(t) − 1 versus the delay timetand at a scattering angle ofθ = 90° and at several temperatures of the mixture.
Effect of Organic Modification on the Compatibilization Efficiency of Clay in an Immiscible Polymer Blend
Authors: Sinha Ray Suprakas , Bousmina Mosto 
Published: October 2005

AbstractSummary: This communication describes the effect of organic modifier miscibility with the matrices, and the effect of the initial interlayer spacing of the organoclay, on the overall morphology and properties of an immiscible polycarbonate/poly(methyl methacrylate) blend. By varying the organic‐modifier‐specific interactions with the blend matrices at the same time as changing the initial interlayer spacing of the organoclay, different levels of compatibilization were revealed. The evidence for the interfacial compatibilization of the organoclay was assessed by scanning electron microscopy observations and was supported by differential scanning calorimetry analyses. The effect on the level of clay exfoliation was also examined.Differential scanning calorimetry scans of virgin, montmorillonite, and various organically modified montmorillonite‐compatibilized 40PC/60PMMA blendsimageDifferential scanning calorimetry scans of virgin, montmorillonite, and various organically modified montmorillonite‐compatibilized 40PC/60PMMA blends
Hydrogen exchange mass spectrometry for the analysis of protein dynamics
Authors: Wales Thomas E. , Engen John R. 
Published: October 2005

AbstractHydrogen exchange coupled to mass spectrometry (MS) has become a valuable analytical tool for the study of protein dynamics. By combining information about protein dynamics with more classical functional data, a more thorough understanding of protein function can be obtained. In many cases, protein dynamics are directly related to specific protein functions such as conformational changes during enzyme activation or protein movements during binding. The method is made possible because labile backbone hydrogens in a protein will exchange with deuterium atoms when the protein is placed in a D2O solution. The subsequent increase in protein mass over time is measured with high‐resolution MS. The location of the deuterium incorporation is determined by monitoring deuterium incorporation in peptic fragments that are produced after the labeling reaction. In this review, we will summarize the general principles of the method, discuss the latest variations on the experimental protocol that probe different types of protein movements, and review other recent work and improvements in the field. © 2005 Wiley Periodicals, Inc.
Synthesis of isoelectronic polyazomethine and poly(arylene vinylene) by a palladium‐catalyzed Suzuki coupling method
Authors: Grigoras Mircea , Antonoaia Nicoleta Cristina 
Published: October 2005

AbstractTwo fully conjugated copolymers containing 2,7‐(9,9‐dioctyl) fluorene and 3,6‐(N‐hexyl‐9H‐carbazole) disubstituted rings and arylene vinylene or azomethine units in the main chain were synthesized through a palladium‐catalyzed Suzuki coupling method of 2,7‐bis(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)‐9,9‐dioctyl fluorene with 1,4‐bis(6‐bromo‐N‐hexyl‐9H‐carbazole‐3‐yl vinyl) benzene or N,N‐bis(6‐bromo‐N‐hexyl‐9H‐carbazole‐3‐yl methylidene) 1,4‐phenylenediamine. Bisbromine arylene vinylene and arylenazomethine monomers were synthesized by condensation of 3‐formyl‐N‐hexyl‐6‐bromo carbazole with tetraethyl‐p‐xylylene diphosphonate or 1,4‐phenylenediamine. Copolymers were characterized by FTIR, 1H‐NMR, DSC, UV‐visible and photoluminescence methods. Copyright © 2005 Society of Chemical Industry
In situ compatibilization of polystyrene/polyolefin elastomer blends by the Friedel–Crafts alkylation reaction
Authors: Guo Zhenghong , Tong Lifang , Fang Zhengping 
Published: October 2005

AbstractBlends of polystyrene (PS) with polyolefin elastomer (POE) were prepared by a reactive extrusion method. In order to increase the compatibility of the two blending components, a Lewis acid catalyst, aluminium chloride (AlCl3), was adopted to initiate the Friedel–Crafts alkylation reaction. Fourier‐transform infrared (FTIR) spectra of the PS/POE/AlCl3 blends extracted with butanone verified the graft structure between the PS and POE. Because the in situ generated PS‐graft‐POE copolymers acted as compatibilizers, the mechanical properties of PS/POE blends were greatly improved. For example, after compatibilization, the Charpy impact strength of an 80/20 (wt%) PS/POE blend was increased from 6.29 to 8.50 kJ m−2. Scanning electron microscopy (SEM) showed that the size of the droplets decreased from 9–10 µm to less than 2 µm with the addition of AlCl3. Gel permeation chromatography (GPC) showed competition between the grafting reaction and the degradation of blending components in the presence of AlCl3. Copyright © 2005 Society of Chemical Industry
Macromolecular design via reversible addition–fragmentation chain transfer (RAFT)/xanthates (MADIX) polymerization
Authors: Perrier Sébastien , Takolpuckdee Pittaya 
Published: October 2005

AbstractAmong the living radical polymerization techniques, reversible addition–fragmentation chain transfer (RAFT) and macromolecular design via the interchange of xanthates (MADIX) polymerizations appear to be the most versatile processes in terms of the reaction conditions, the variety of monomers for which polymerization can be controlled, tolerance to functionalities, and the range of polymeric architectures that can be produced. This review highlights the progress made in RAFT/MADIX polymerization since the first report in 1998. It addresses, in turn, the mechanism and kinetics of the process, examines the various components of the system, including the synthesis paths of the thiocarbonyl‐thio compounds used as chain‐transfer agents, and the conditions of polymerization, and gives an account of the wide range of monomers that have been successfully polymerized to date, as well as the various polymeric architectures that have been produced. In the last section, this review describes the future challenges that the process will face and shows its opening to a wider scientific community as a synthetic tool for the production of functional macromolecules and materials. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43:5347–5393, 2005