bluuebunny/crossref_metadata_2025 huggingface dataset:
Aldol Reactions of Dioxanes Derived from Tartaric Acid. A Total Synthesis of (+)‐Nephrosteranic Acid.
Authors: Barros M. Teresa , Maycock Christopher D. , Ventura M. Rita
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Solid State Synthesis and Characterization of Tin‐Based Low‐Dimensional Materials
Authors: Salami Tolulope O. , Oliver Scott R. J.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Inorganic/Organic Nanocomposites Synthesized by the Homogeneous Precipitation Method
Authors: Yada Mitsunori , Kijima Tsuyoshi
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Simulations of Magnetic Dynamics in Iron—Cobalt Films
Authors: Yan Ming , Berezovsky J. , Crowell P. A. , Campbell C. E.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
FePt Magnetic Recording Media: Problems and Possibilities for Practical Use
Authors: Shibata Kazuyoshi
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Redistribution of Twin Martensitic Domains in Magnetic Shape Memory Ni2MnGa Alloys Caused by External Magnetic Field
Authors: Glavatska N.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Magnetic, Electrical and Structural Properties of Some Ternary and Quaternary Spinels with Chromium
Authors: Warczewski Jerzy , Krok‐Kowalski Jozef
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Metal Complexes with Hydrazones Derived from 6‐Amino‐5‐formyl‐1,3‐ dimethyluracil
Authors: Illan‐Cabeza Nuria A. , Moreno‐Carretero Miguel N. , Penas‐Chamorro Antonio L.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
The Way to a New Class of Catalysts — High‐Valent Transition‐Metal Complexes that Catalyze Reductions
Authors: Thiel Werner R.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Selective Oxidation of Hydrocarbons with Molecular Oxygen Catalyzed by Transition Metal Substituted Silicotungstates
Authors: Mizuno Noritaka , Hashimoto Masaki , Sumida Yasutaka , Nakagawa Yoshinao , Kamata Keigo
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Encapsulation of Atom into the C60 Cage
Authors: Kubozono Yoshihiro
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Endohedral Fullerenes: N@C60, N@C70, and P@C60
Authors: Pietzak B. , Weidinger A. , Dinse K.‐P. , Hirsch A.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Putting Nonmetals into Fullerenes
Authors: Saunders Martin , Cross R. James
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
P(R‐NCH2‐CH2)3N: Very Strong Non‐Ionic Bases Useful in Organic Synthesis
Authors: Verkade John G.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Tin Hydrides
Authors: Clark A. J.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Single‐Mode Microwave Synthesis in Organic Material Chemistry
Authors: Barlow Stephen , Marder Seth R.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Tandem Allylboration—Ring Closing Metathesis Reactions for the Preparation of Biologically Active Molecules
Authors: Ramachandran P. Veeraraghavan , Reddy M. Venkat Ram , Brown Herbert C.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Ligands and Protecting Groups: The t‐Butyl Advantage
Authors: Woltermann Christopher J.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Nonexponential Decay of Reactive Intermediates: New Challenges for Spectroscopic Observation, Kinetic Modeling and Mechanistic Interpretation
Authors: Carpenter Barry K.
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
A Novel Catalytic Technology for the Manufacture of CF3I
Authors: Nagasaki Noritaka
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Sourcing Organic Compounds Based on Natural Isotopic Variations Measured by High Precision Isotope Ratio Mass Spectrometry
Authors: Asche Sven , Michaud Anthony L. , Brenna J. Thomas
Published: July 2005

For Abstract see ChemInform Abstract in Full Text.
Von IGLU zu SINUS‐Grundschule
Authors: Demuth Reinhard
Published: July 2005

Die Forderung, „mehr in Bildung zu investieren”︁, ist inzwischen in aller Munde. Bevor man investiert, ist es erforderlich, eine Bestandsaufnahme vorzunehmen, um zu wissen „wo man steht”︁. Eine sinnvolle Investition setzt jedoch genauso eine genaue Zielbestimmung voraus auf das, „was man will”︁. Auf diese Ziele müssen die zu ergreifenden Maßnahmen ausgerichtet sein – auf diese Ausrichtung muss sich später eine Überprüfung der Wirksamkeit der ergriffenen Maßnahmen beziehen.
Transcriptome analysis of the murine forelimb and hindlimb autopod
Authors: Shou Siming , Scott Virginia , Reed Cheryl , Hitzemann Robert , Stadler H. Scott
Published: July 2005

To gain insight into the coordination of gene expression profiles during forelimb and hindlimb differentiation, a transcriptome analysis of mouse embryonic autopod tissues was performed using Affymetrix Murine Gene Chips (MOE‐430). Forty‐four transcripts with expression differences higher than 2‐fold (T test, P ≤0.05) were detected between forelimb and hindlimb tissues including 38 new transcripts such as Rdh10, Frzb, Tbx18, and Hip that exhibit differential limb expression. A comparison of gene expression profiles in the forelimb, hindlimb, and brain revealed 24 limb‐signature genes whose expression was significantly enriched in limb autopod versus brain tissue (fold change >2, P ≤ 0.05). Interestingly, the genes exhibiting enrichment in the developing autopod also segregated into significant fore‐ and hindlimb‐specific clusters (P ≤ 0.05) suggesting that by E 12.5, unique gene combinations are being used during the differentiation of each autopod type. Developmental Dynamics 234:74–89, 2005. © 2005 Wiley‐Liss, Inc.
Expression of mouse dchs1, fjx1, and fat‐j suggests conservation of the planar cell polarity pathway identified in drosophila
Authors: Rock Rebecca , Schrauth Sabrina , Gessler Manfred
Published: July 2005

The dachsous (ds), fat (ft), and four‐jointed (fj) genes have been identified in Drosophila as part of a signaling pathway that regulates planar cell polarity (PCP). A homologous PCP signaling pathway has also been identified in vertebrates, but nothing is known thus far about the conservation of Ds/Ft/Fj signaling. Here we analyzed and compared for the first time the expression patterns of all ds, ft and fj homologs in the mouse. During embryogenesis, expression analysis was performed by RNA in situ hybridization and in adult organs by real time PCR. As in Drosophila, we detected a complementary expression of fjx1 and dchs1 in organs like kidney, lung, and intestine. The ubiquitous expression of ft in several tissues in Drosophila appears to be split into an epithelial expression of fat1/fat3 and a mesenchymal expression of fat‐j. These data are compatible with a conservation and subfunctionalization of the Drosophila Ds, Fj, and Fat signaling in higher vertebrates. Developmental Dynamics 234:747–755, 2005. © 2005 Wiley‐Liss, Inc.
Proneural factors and neurogenesis
Authors: Kiefer Julie C.
Published: July 2005

The role of proneural factors in specifying neuronal progenitors and in promoting neuronal differentiation is conserved from Drosophila to vertebrates. This primer discusses the basic functions of proneural factors in neurogenesis, mechanisms of proneural factor function, and models for how proneural factors generate neuronal subtypes. The primer also features a dialog about current topics and future directions in the field between two experts in neurogenesis: Andrew Jarman, Ph.D., and Jane Johnson, Ph.D. Developmental Dynamics 234:808–813, 2005. © 2005 Wiley‐Liss, Inc.
Abundance, Population Structure and Production of Scrobicularia plana and Abra tenuis (Bivalvia: Scrobicularidae) in a Mediterranean Brackish Lagoon, Lake Ichkeul, Tunisia
Authors: Casagranda Caterina , Boudouresque Charles François
Published: July 2005

Abundance, growth and production of the deposit‐feeding bivalves were studied in the Ichkeul wetland, northern Tunisia, from July 1993 – April 1994. Scrobicularia plana (Da Costa, 1778) occurred at annual mean densities (biomasses) of 299 ± 65 to 400 ± 100 individuals/m2 (22.54 ± 3.00 to 34.27 ± 3.96 g ash‐free dry mass (AFDM)/m2) depending on the study area. The annual mean density of Abra tenuis (Montagu, 1803) amounted to 640 ± 74 individuals/m2 during the whole study period, in contrast the biomass rose from 2.87 g AFDM/m2 in July to 10.29 g AFDM/m2 in April. Both species were largely dominated by age class I. Although not very successful, recruitment presented a two‐period pattern: the main period at the beginning of spring, and a secondary one in late summer/autumn. S. plana rarely exceeded 40 mm and lived for only 2 years, while most individuals of A. tenuis lived for only 15–18 months growing to a length of 12 mm. The annual bivalve deposit‐feeder production for the whole lagoon system (90 km2) was 8.24 g AFDM/m2 (5.26 g C/m2, 0.65 g N/m2). The annual P/$ \bar B $ ratio was about 0.4 and therefore in the same order of magnitude as estimates from other brackish coastal waters. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Factors Influencing the Seasonal Phenology and Composition of Zooplankton Communities in Mountain Temporary Pools
Authors: Tavernini Silvia , Mura Graziella , Rossetti Giampaolo
Published: July 2005

In 2001 nine temporary pools of the northern Apennines (Italy) were visited on 13 occasions during the ice‐free season (May to October). The aims of this research were to define the relationships between hydroperiod and other environmental variables and the zooplankton. In total, 49 zooplankton taxa were identified: 36 rotifers, 5 cladocerans, 6 copepods and 2 anostracans. Our results indicate that hydroperiod is a major determinant affecting zooplankton species richness. The highest number of taxa was found in the pond having the longest duration. Distinctive species assemblages were observed in different habitat types: pools with the shortest hydroperiod were characterised by organisms with brief life cycles (e.g. rotifers) and/or typical of temporary habitat (e.g. anostracans). Of the physical and chemical characteristics, pH and chlorophyll‐a appeared to have the largest influence on zooplankton distribution in the studied pools. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of controlled fibronectin surface orientation on subsequent Staphylococcus epidermidis adhesion
Authors: Jarvis R. A. , Bryers J. D.
Published: July 2005

Several bacterial species, including Staphylococcus aureus and Staphylococcus epidermidis (SE) are known to express cell receptors that bind specifically to surface immobilized or extracellular matrix ligands, such as the protein fibronectin (FN). Yet, few existing studies have examined the effect of protein surface orientation on bacterial adhesion. We report here a substratum modification protocol that allows for the specific orientation of FN molecules on a surface at known levels of surface coverage. Monoclonal antibodies (Mabs), specific to either the COOH‐terminus or NH3‐terminus of FN, are conjugated to biotin, then immobilized to streptavidin‐coated glass substrata. Specific orientation of the bound FN molecules is verified using the same Mabs in an ELISA. Bacterial adhesion of Staphylococcus epidermidis (SE) to FN bound by either its C‐terminus or its NH3‐terminus was quantified in batch static adhesion assays. Results indicate an increase in SE adhesion to FN‐coated surfaces when the FN is bound by its C‐terminus (NH3‐terminus free), indicating SE receptor‐specific adhesion to the FN NH3‐terminus. These studies demonstrate that antifibronectin monoclonal antibodies can be used to specifically bind and orient fibronectin on a surface. In addition, adhesion of SE to these model substrata can be controlled by the orientation of the protein. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Poloxamine hydrogels with a quaternary ammonium modification to improve cell attachment
Authors: Sosnik Alejandro , Sefton Michael V.
Published: July 2005

Four‐arm poly(ethylene oxide) and poly(propylene oxide) (PEO‐PPO) block copolymer (poloxamine, Tetronic 1107™) hydrogels were modified with positively charged groups with the aim of overcoming the low cell adhesion properties of these PEO‐rich systems. Different matrices containing poloxamine‐methacrylate (6–12%) and a quaternary ammonium methacrylate ([2‐(methacryloyloxy)ethyl]‐trimethylammonium chloride [MAETAC], 0–0.48M) were produced by a photo‐initiated free radical copolymerization. A sharp increase in water content for MAETAC‐containing gels was seen during the first 2 days of incubation in distilled water; some of the gels showed water uptakes as high as 12 times the initial wet weight. In phosphate‐buffered saline (PBS), this effect was less pronounced because of the decrease in the osmotic gradient. In addition, a gradual increase of both the storage and the loss modulus of the gels resulted from increasing the MAETAC content [e.g., G′ values increased from 13,500 Pa for 12% poloxamine‐methacrylate gels without MAETAC to 151,000 Pa for 0.48M MAETAC contents (at 1 Hz, 100 Pa of oscillatory stress)]. Although on pure poloxamine‐methacrylate gels HepG2 and HUVEC cells attached poorly, on MAETAC‐containing specimens a well‐spread morphology and confluent monolayers were obtained, at least after preincubation in serum containing medium. Although not having all the cell compatibility of collagen, these fully synthetic quaternary ammonium‐modified PEO‐rich gels may have some utility in tissue‐engineering applications where stiff gels and cell attachment after gelation are desired. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Better osteoblast adhesion on nanoparticulate selenium— A promising orthopedic implant material
Authors: Perla Venu , Webster Thomas J.
Published: July 2005

Apart from problems such as poor osseointegration, stress shielding, and wear debris‐associated bone cell death, a major concern of metallic orthopedic implants is that they slowly corrode under in vivo environments. It is possible that continuous tissue exposure to metallic corrosion products limits orthopedic implant efficacy; this is especially true for patients receiving implants due to bone cancer. To date, there is no metallic orthopedic implant available in the market that specifically deals with the prevention and/or recurring cancer that may happen in these patients. The objective of this study was to deal with these problems in an integrated way by introducing a new biomaterial to the orthopedic community with anticancer chemistry: selenium (Se). In this study, six types of Se compacts were tested for bone cell (osteoblast) adhesion under in vitro conditions. Two types of cylindrical compacts were made with conventional Se metal particles in the micron (6.539 ± 1.364‐μm diameter) and submicron (0.963 ± 0.139‐μm diameter) range. These two types of compacts were chemically etched with different concentrations of NaOH to create two additional types of Se particles in each category: conventional size particles with nanosurface roughness and nanometer particles (0.204‐ to 0.264‐μm diameter). Results showed for the first time, enhanced osteoblast adhesion on particulate surfaces of the compacts made from conventional Se compared with reference nonparticulate wrought titanium sheets. More importantly, this study provided the first evidence that osteoblast density was further increased on the surfaces of the Se compacts with nanometer particles. These initial findings indicate that there may be a promising future for nanoparticulate Se as an anticancer biocompatible orthopedic material. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Utilization of spent petrochemical sulfuric acid in the production of wet‐process phosphoric acid
Authors: Chojnacki Andrzej , Chojnacka Katarzyna , Górecki Henryk
Published: July 2005

The possibility of the application of spent sulfuric acid from the petrochemical industry in wet‐process phosphoric acid technology was investigated. The effect of organic impurities in sulfuric acid from benzol acidic refining on the solubility of calcium sulfate hydrates is discussed. Solubility isotherms and regression equations for CaSO4–H3PO4–H2SO4–H2O (pure and containing impurities) systems are presented. Phase transition temperatures between dihydrate and hemihydrate calcium sulfate were determined. The difference between pure and polluted sulfuric acid systems observed is negligible over the range of typical wet‐process phosphoric acid technology parameters. It is concluded that the application of spent sulfuric acid from benzol acidic refining does not have a negative influence on the crystallization process of dihydrate calcium sulfate and therefore can be applied in wet‐process phosphoric acid technology. Copyright © 2005 Society of Chemical Industry
Removal characteristics of some priority organic pollutants from water in a fixed bed fly ash column
Authors: Sarkar Mitali , Acharya Pradip Kumar , Bhattacharya Bhaskar
Published: July 2005

The efficiency of a coal fly ash (generated from a thermal power plant) adsorption column for the removal of some priority organic pollutants, viz phenol, o‐hydroxyphenol, m‐hydroxyphenol and 4‐nitrophenol from aqueous solution has been studied. The column performance was evaluated from the concept of the formation of a primary adsorption zone and the breakthrough curve. The extent of solute removal obtained from breakthrough curve during column operation was compared with that obtained from the isotherm parameters for batch operation. The loaded solutes in the column were successfully eluted with acetone, achieving 98% recovery. In order to determine the practical applicability of the column operation the process was repeated a number of times and the variation of column capacity with number of operation cycles was evaluated. Even after six successive cycles, the column was found to retain almost 80% capacity. Copyright © 2005 Society of Chemical Industry
Microbial O‐demethylation of sinesetin and antimutagenic activity of the metabolite
Authors: Okuno Yoshiharu , Miyazawa Mitsuo
Published: July 2005

Biotransformation of sinesetin by Aspergillus niger afforded 4′‐hydroxy‐5,6,7,3′‐tetramethoxyflavone on the basis of its spectroscopic data including IR, heteronuclear multiple quantum coherence (HMQC) and heteronuclear multiple bond connectivity (HMBC) analysis. Sinesetin and the metabolite showed antimutagenic activity against chemical mutagens 4‐dimethyl‐3H‐imidazo[4,5‐f]quinolin‐2‐amine (MeIQ) and 3‐amino‐14‐dimethyl‐5H‐pyrido[4,3‐b]indole (Trp‐P‐1) in the umu test using Salmonella typhimurium TA1535/pSK1002. Copyright © 2005 Society of Chemical Industry
Strong Fibers and Films of Microbial Polyesters
Authors: Iwata Tadahisa
Published: July 2005

Summary: Poly[(R)‐3‐hydroxybutyrate] (P(3HB)) and its copolymers are accumulated by a wide variety of microorganisms as intracellular carbon and energy material, and are extensively studied as biodegradable and biocompatible thermoplastics. However, these microbial polyesters have not been recognized as practical because of their stiffness and brittleness. Recently, by new drawing techniques, we succeeded in obtaining strong fibers and films from microbial polyesters, produced by both wild‐type and recombinant bacteria. The improvement in mechanical properties of the fibers and films is due not only to the orientation of molecular chains, but also to the generation of a zigzag conformation and network structure, formed by fibrillar and lamellar crystals. The structure of strong fibers with a tensile strength over 1.0 GPa was analyzed by micro‐beam X‐ray diffraction with synchrotron radiation. The strong fibers and films were completely degraded in natural, river freshwater or by extracellular polyhydroxybutyrate depolymerases. In this feature article, the processing, mechanical properties, highly ordered structure and biodegradability of strong fibers and films produced from microbial polyesters are presented.

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Characterization of Carbon Monoxide Centered Triads in Poly[ethylene‐co‐(butyl acrylate)‐co‐(13C‐carbon monoxide)] by Isotopic Labeling and Two‐Dimensional NMR
Authors: Al‐Amri Abdullah , Monwar Masud , McCord Elizabeth F. , Buback Michael , Latz Henning , Rinaldi Peter L.
Published: July 2005

Summary: Poly[ethylene‐co‐(butyl acrylate)‐co‐(carbon monoxide)] (polyEBC) samples, prepared from 13C‐labeled carbon monoxide, were characterized using two dimensional (2D) pulsed field gradient (PFG) 750 MHz NMR spectroscopy. To elucidate the complex mixture of structures present in this terpolymer, 2D 1H/13C‐heteronuclear multiple bond correlation (HMBC) experiments were conducted by selectively exciting the enhanced peaks resulting from 13C‐labeling. High resolution 2D NMR combined with 13C‐labeling of the polymer greatly simplifies the 2D NMR spectra, selectively enhances the weak peaks from low occurrence C‐centered triad structures and aids in their resonance assignments.

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On the Interpretation of X‐Ray Diffraction Powder Patterns in Terms of the Nanostructure of Cellulose I Fibres
Authors: Garvey Christopher J. , Parker Ian H. , Simon George P.
Published: July 2005

Summary: The average lateral dimensions of cellulose microfibrils in paper sheets can be determined from the width of X‐ray Bragg peaks at half the maximum height. The method assumes it is the finite size of the crystallite which is the main contributor to peak broadening in the directions orthogonal to the long axis of the crystallite. This assumption is examined in the context of samples from different botanical sources, of varying crystallinity and cellulose content and the various instrumental sources of broadening X‐ray powder patterns. Excellent fits to the data from paper samples can be obtained by using five Voigt functions to the powder diffraction patterns, for the 101, $10\bar 1$, 021, 002 and 040 reflections. Of these reflections, the 020 is the clearest, and the best able to determine the lateral dimension of the crystallite. Results indicate that the size of microfibrils is dependent on the botanical source of the fibres.

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The Rapid Chain Extension of Anthracene‐Functional Polyesters by the Diels‐Alder Reaction with Bismaleimides
Authors: Kriegel Robert M. , Saliba Katie L. , Jones Genay , Schiraldi David A. , Collard David M.
Published: July 2005

Summary: The chain extension of anthracene end‐capped oligoesters by reaction with bismaleimides constitutes a rapid route to high molecular weight polyesters. Polytransesterification of bis(2‐hydroxyethyl) terephthalate in the presence of a small amount of 2‐hydroxyethyl 2‐anthracenecarboxylate provides low molecular weight anthracene‐terminated macromers with anthracene end group functionality (fAN) of 1.66–1.85. These are subject to rapid chain extension with di(4‐maleimidophenyl)methane by Diels‐Alder cycloadditions resulting in consumption of the anthracene and maleimide end groups to generate polymers with $\overline M _{\rm n}$ > 2.0 × 104 g · mol−1. Thus, generation of the polymeric structure is achieved rapidly by addition reactions rather than sluggish transesterification reactions in which a condensate must be removed from the viscous polymer melt.

Chain extension of low‐molecular weight 2‐anthracenecarboxylate terminated oligoesters.

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Chain extension of low‐molecular weight 2‐anthracenecarboxylate terminated oligoesters.
Synthesis and Optical Properties of Poly[2‐{N‐Methyl‐N‐(4‐(4‐ethynylphenylazo)phenyl)amino}ethyl butyrate]
Authors: Yin Shouchun , Xu Hongyao , Fang Min , Shi Wenfang , Gao Yachen , Song Yinlin
Published: July 2005

Summary: The high‐molecular‐weight functional polyacetylene that contain a para‐aminoazobenzene chromophore, poly[2‐{N‐Methyl‐N‐(4‐(4‐ethynylphenylazo)phenyl)amino}ethyl butyrate] [poly(EAPAB)], was synthesized in moderate yield and characterized by FT‐IR, 1H NMR, UV‐vis, TGA, and GPC. The nonlinear optical and optical limiting properties were performed with 8 ns pulse width at 532 nm wavelength. The results show that the introduction of the flexible amino group effectively improved the solubility of polymer [poly(EAPAB)] in common organic solvent, such as CHCl3, THF, and dioxane, while poly(4‐ethynylazobenzene) [poly(4EAB)] without the flexible amino group shows poor solubility in common organic solvent. Simultaneously, poly(EAPAB) still shows good thermal stability, large third‐order nonlinear optical property, and novel optical limiting property owing to the functionalization of the para‐aminoazobenzene chromophore.

Polymerization of EAPAB by Rh(nbd)Cl2‐Et3N to poly(EAPAB).

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Polymerization of EAPAB by Rh(nbd)Cl2‐Et3N to poly(EAPAB).
Macrocyclic and Acyclic Bis(2,5‐diphenyl‐1,3,4‐oxadiazole)s with Electron‐Transporting and Hole‐Blocking Ability in Organic Electroluminescent Devices
Authors: Ono Katsuhiko , Ezaka Seiichi , Higashibata Akinori , Hosokawa Ryohei , Ohkita Masakazu , Saito Katsuhiro , Suto Michitaka , Tomura Masaaki , Matsushita Yosuke , Naka Shigeki , Okada Hiroyuki , Onnagawa Hiroyoshi
Published: July 2005

Summary: Two types of bis(2,5‐diphenyl‐1,3,4‐oxadiazole)s, macrocyclic and acyclic, were prepared and evaluated as electron‐transporting and hole‐blocking materials in phosphorescent EL devices. Maximum efficiencies of ηext = 10.4% at J = 0.11 mA · cm−2 for the macrocycle and ηext = 14.1% at J = 3.01 mA · cm−2 for the acycle were observed. X‐ray crystallographic analysis and DSC measurements revealed a strong intermolecular interaction between the macrocycles and weaker intermolecular interactions between the acycles. The EL characteristics depend on the intermolecular interactions.

The two types of bis(2,5‐diphenyl‐1,3,4‐oxadiazole)s used in the study.

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The two types of bis(2,5‐diphenyl‐1,3,4‐oxadiazole)s used in the study.
Complexation Behavior of Cu2+ in the Presence of Iminodiacetic Acid and Poly(ethyleneimine)
Authors: Moreno‐Villoslada Ignacio , González Felipe , Jofré Marlen , Chandía Patricio , Hess Susan , Rivas Bernabé L.
Published: July 2005

Summary: Multicomponent aqueous systems containing Cu2+ as metal ion, iminodiacetic acid (IDAA) as a low‐molecular‐weight chelating molecule, and branched poly(ethyleneimine) (BPEI) as a polychelatogen are analyzed at different pH by UV‐Vis spectroscopy and diafiltration. It was found that at pH 4, saturation of BPEI with Cu2+ takes place at a Cu2+:BPEI ratio of 1:5.7, probably indicating a stoichiometry for the complex of 1:4. At the same conditions the Cu2+‐IDAA complex has a stoichiometry of 1:1. The ability of BPEI to bind the metal ion is higher than that of IDAA in mixtures of both chelating molecules. Lowering the pH between 2 and 3.5, protonation of BPEI allows increasing the amounts of Cu2+‐IDAA complex so that Cu2+ is transferred from the polychelatogen to IDAA. Good correlations are found comparing the results obtained by diafiltration and by UV‐Vis spectroscopy. Moreover, diafiltration results indicate that in the absence of Cu2+, IDAA interacts with BPEI with apparent dissociation constants of 2.88 at pH 2.7 and 0.96 at pH 4. These interactions may be responsible for the appearance of an apparent dissociation constant of 3.60 for the interactions between BPEI and the Cu2+‐IDAA complex at pH 4.

The binding of Cu2+ to branched poly(ethyleneimine) and iminodiacetic acid in water.

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The binding of Cu2+ to branched poly(ethyleneimine) and iminodiacetic acid in water.
Sorption of Hydrophobic Organic Compounds by Aqueous Latexes
Authors: Tauer Klaus , Nozari Samira , Ali A. M. Imroz , Kozempel Steffen
Published: July 2005

Summary: Optical absorption measurements are used for the first time to investigate the uptake of pure organic solvents or solutions by latex particles. Sorption into glassy polymer particles is a two‐stage process with distinctly different characteristic times, which reflects that an initial softening of the outer particle layer facilitates further uptake. The sorption of solutions containing highly water‐insoluble compounds allows the preparation of composite nanoparticles, which are hardly accessible by other routes.

Photograph of the neat 100 nm latex (right) particles and the particles after dying by sorption with the hydrophobic pigment Sudan IV (left).

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Photograph of the neat 100 nm latex (right) particles and the particles after dying by sorption with the hydrophobic pigment Sudan IV (left).
Effect of Turbulent Flow on Coil‐Globule Transition of λ‐DNA
Authors: Lim Sung Taek , Choi Hyoung Jin , Chan Chi‐Keung
Published: July 2005

Summary: The addition of spermidine (SPD) into turbulent flow as a condensing agent showed the abrupt change of turbulent drag reducing (DR) efficiency of λ‐DNA in turbulent flow for the first time. The resultant asymptote DR efficiency explains the origin of those changes, which can be conclusively verified via the electrophoresis experiment. Despite the different fluid conditions, with and without condensing agent, all λ‐DNA molecules possessed the same half‐cut dimension, implying that the discrete change of DNA conformation can dramatically alter the flow characteristics.

Coil‐globule transition of DNA by spermidine.

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Coil‐globule transition of DNA by spermidine.
Applications of accelerator mass spectrometry for pharmacological and toxicological research
Authors: Brown Karen , Tompkins Elaine M. , White Ian N.H.
Published: July 2005

The technique of accelerator mass spectrometry (AMS), known for radiocarbon dating of archeological specimens, has revolutionized high‐sensitivity isotope detection in pharmacology and toxicology by allowing the direct determination of the amount of isotope in a sample rather than measuring its decay. It can quantify many isotopes, including 26Al, 14C, 41Ca, and 3H with detection down to attomole (10−18) amounts. Pharmacokinetic data in humans have been achieved with ultra‐low levels of radiolabel. One of the most exciting biomedical applications of AMS with 14C‐labeled potential carcinogens is the detection of modified proteins or DNA in tissues. The relationship between low‐level exposure and covalent binding of genotoxic chemicals has been compared in rodents and humans. Such compounds include heterocyclic amines, benzene, and tamoxifen. Other applications range from measuring the absorption of 26Al to monitoring 41Ca turnover in bone. In epoxy‐embedded tissue sections, high‐resolution imaging of 14C label in cells is possible. The uses of AMS are becoming more widespread with the availability of instrumentation dedicated to the analysis of biomedical samples. © 2005 Wiley Periodicals, Inc.
A study of glycoproteins in human serum and plasma reference standards (HUPO) using multilectin affinity chromatography coupled with RPLC‐MS/MS
Authors: Yang Ziping , Hancock William S. , Chew Tori Richmond , Bonilla Leo
Published: July 2005

The glycoproteome is a major subproteome present in human plasma. In this study, we isolated and characterized approximately 150 glycoproteins from the human plasma and serum samples provided by HUPO using a multilectin affinity column. The corresponding tryptic digest was separated by RP‐HPLC coupled to an IT mass spectrometer (3‐D LCQ). Also in this study, a new system, namely an Ettan MDLC system coupled to a linear ITLTQ, was compared with the previous LCQ platform and gave a greater number of protein identifications, as well as better quality. When we compared the composition of the glycoproteomes for the plasma and serum samples there was a close correlation between the samples, except for the absence of fibrinogen from the identified‐protein list in the latter sample, which was presumably as a result of the clotting process. In addition, the analysis of the samples from three ethnic specimens, Caucasian American, Asian American, and African American, were very similar but showed a higher angiotensinogen plasma level and a lower histidine‐rich glycoprotein level in Caucasian American samples, and a lower vitronectin level in African American blood samples.
Differences among techniques for high‐abundant protein depletion
Authors: Zolotarjova Nina , Martosella James , Nicol Gordon , Bailey Jerome , Boyes Barry E. , Barrett William C.
Published: July 2005

The need to identify protein or peptide biomarkers via readily available biological samples like serum, plasma, or cerebrospinal fluid is often hindered by a few particular proteins present at relatively high concentrations. The ability to remove these proteins specifically, reproducibly, and with high selectivity is increasingly important in proteomic studies, and success in this procedure is leading to an ever‐increasing list of lower abundant proteins being identified in these biological fluids. The current work addresses some of the potential problems in depleting proteins in typical biomarker studies, including nonspecific binding during depletion procedures and whether low molecular weight (LMW) species bind to the column in a so‐called “sponge” effect caused by the ability of albumin or other high‐abundant proteins to bind peptides or protein fragments. LC‐MS/MS methods were applied to the comparative analysis of an IgG‐based immunodepletion method and a Cibacron blue (CB)‐dye‐based method, for specificity of removing targeted proteins (binding fraction), as well as for assessing efficiency of target removal. This analysis was extended to examine the effects of repeated use of materials (cycles of binding and elution), in order to assess potential for carryover of one sample to the next. Capacity studies and efficiency of protein removal from the serum samples were followed for the IgG‐based system using both immunochemical assays (ELISA) as well as LC‐MS/MS methods. Additionally, the IgG‐based system was further characterized for the removal of LMW polypeptides by nonspecific binding. We conclude that the IgG‐based system provided effective removal of targeted proteins, with minimal carryover, high longevity, and minimal nonspecific binding. Significant differences are noted between the depletion techniques employed, and this should be considered based on the expectations set during experimental design.
Synthesis of well‐defined aromatic polyesters by chain‐growth polycondensation under suppression of transesterification
Authors: Iwashita Ken‐ichi , Yokoyama Akihiro , Yokozawa Tsutomu
Published: July 2005

For the synthesis of aromatic polyesters with defined molecular weights and narrow molecular weight distributions (MWDs), we investigated the chain‐growth polycondensation of active amide derivatives of 4‐hydroxybenzoic acid, 1a and 1b, having an octyl or 4,7‐dioxaoctyl side chain, respectively. To suppress the transesterification of the polymer backbone with the monomer, the polymerization of 1 was carried out in tetrahydrofuran (THF) at −30 °C in the presence of initiator 2 and Et3SiH/CsF/18‐crown‐6, which generated a hydride ion as a base in situ. The number‐average molecular weight (Mn) of poly1a was controlled, and narrow MWDs were maintained, until the [1a]0/[2]0 feed ratio was 14.3 (Mn ≤ 3500), whereas that of poly1b was controlled until the feed ratio was 30 (Mn ≤ 7250). The difference stemmed from the higher solubility of poly1b in THF. This chain‐growth polycondensation was applied to the synthesis of a diblock copolyester of 1a and 1b of a defined architecture. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4109–4117, 2005
Determination of thermodynamic properties of macroporous glycidyl methacrylate‐based copolymers by inverse gas chromatography
Authors: Nastasović A. B. , Onjia A. E. , Milonjić S. K. , Jovanović S. M.
Published: July 2005

Macroporous crosslinked poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) (PGME) was synthesized by suspension copolymerization and modified by ring‐opening reaction of the pendant epoxy groups with ethylene diamine (EDA). Inverse gas chromatography (IGC) at infinite dilution was applied to determine the thermodynamic interactions of PGME and modified copolymer, PGME‐en. The specific surface areas of the initial and modified copolymer samples were determined by the BET method, from low‐temperature nitrogen adsorption isotherms. The specific retention volumes, V, of 10 organic compounds of different chemical nature and polarity (nonpolar, donor, or acceptor) were determined in the temperature range 333–413 K. The weight fraction activity coefficients of test sorbates,
$\Omega_1^\infty$, and Flory–Huggins interaction parameters, $\chi_{12}^\infty$, were calculated and discussed in terms of interactions of sorbates with PGME and PGME‐en. Also, the partial molar free energy, $\Delta G_1^S$, partial molar heat of mixing, $\Delta H_1^\infty$, sorption molar free energy, ΔG, sorption enthalpy ΔH, and sorption entropy, ΔS, were calculated. Glass transitions in PGME and PGME‐en, determined from IGC data, were observed in the temperature range 373–393 K and 363–373 K, respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2524–2533, 2005
Effect of increasing the microwave density in both continuous and pulsed wave mode on the growth of monocrystalline diamond films
Authors: Tallaire A. , Achard J. , Silva F. , Gicquel A.
Published: July 2005

Diamond synthetic single crystals exhibiting a high and reliable quality would find many applications in different areas such as optics, mechanics, or electronic devices. In this study, thick high quality homoepitaxial diamond films were grown on synthetic substrates using Micro‐Wave Plasma Assisted Chemical Vapour Deposition. The effect of increasing the density of the hydrogen methane discharge was investigated since it is believed to allow higher deposition rates by enhancing the production of precursor species. In continuous wave mode, it was actually observed that increasing the microwave density in the plasma from 65 to 125 W/cm3 leaded to an increase of diamond growth rates from 3 to 8.5 µm/h and from 11 to 19 µm/h when 4% and 7% of CH4 was added to the gas phase respectively. However, when such a high microwave power density is injected, overheating of the reactor walls, windows and wave‐guides occurs leading to problematic cooling‐down and higher contamination of the diamond film. In particular higher silicon incorporation was found by photoluminescence spectroscopy that probably originates from an enhanced etching of the quartz windows. Thanks to the use of a pulsed discharge with a peak power of 190 W/cm3 the deposition of diamond at rates close to 22 µm/h became possible while limiting this problem of overheating. The use of such pulsed discharges is thus considered to be a very promising method for the growth of high quality diamond single‐crystals at high deposition rates. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature dependence of hole drift mobility in high‐purity single‐crystal CVD diamond
Authors: Isberg Jan , Lindblom Adam , Tajani Antonella , Twitchen Daniel
Published: July 2005

Hole transport properties in high‐purity single crystal CVD diamond samples were studied using the time of flight technique with optical excitation of the carriers. The measurements were taken at different temperatures in the interval 80–470 K. By varying the intensity of the optical excitation over several orders of magnitude, measurements at different carrier concentrations have been performed. In this way, measurements have been made both in the space charge limited and non space charge limited regimes, with consistent results. The temperature dependence of the low‐field hole drift mobility shows a Tα dependence with α ≈ –1.5, below 350 K. This indicates that acoustic phonon scattering is the dominant scattering mechanism and a very low concentration of ionized impurities in this material. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strain mapping around dislocations in diamond and cBN
Authors: Willems B. , Nistor L. C. , Ghica C. , Van Tendeloo G.
Published: July 2005

Strain fields around dislocations in diamond and cBN have been quantitatively characterized at a sub nanometer scale. The combination of experimental high resolution electron microscopy (HREM) and image analysis using the geometric phase method provides an accurate determination of the local deformations and strain. The results of the strain analysis of the 60° perfect dislocation in diamond and cBN are discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of the f → d transition of heavy lanthanide and actinide ions in crystals using the simple model
Authors: Duan Chang‐Kui , Xia Shangda , Reid Michael F. , Ruan Gang
Published: July 2005

In this paper we extend the original simple model for f → d transition proposed by Duan and co‐workers [Phys. Rev. B 66, 155108 (2002); J. Solid State Chem. 171, 299 (2003)] to the more general cases applicable to heavy lanthanides and actinides. The model is successfully applied to the interpretation of low‐temperature f–d excitation spectra of Er3+ doped in crystals LiYF4 and CaF2. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surface and interface magnetism of V/W systems
Authors: Bakir A. M. , Hamad B. A. , Khalifeh J. M.
Published: July 2005

In this work, we investigate the magnetic properties of the V/W system, in the (001), (011), and (111) crystallographic orientations with and without relaxation at T = 0 K. Calculations of the magnetic moments are carried out using the real‐space tight‐binding method with a Hubbard Hamiltonian within the Hartree–Fock approximation. The coordination number, the type of the neighboring atoms, and the change of the vertical and horizontal distances between V atoms in the considered system are found to play a role in determining its magnetic properties. The magnetization is found to decrease when V is allowed to relax. The W interfacial layers acquired a sizeable induced magnetic moment. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pressure dependence of the optical and vibrational properties of hexagonal and cubic CdS films grown on GaAs
Authors: Choi I. H. , Yu P. Y.
Published: July 2005

The pressure dependence of the excitonic photoluminescence and Raman scattering in both hexagonal and cubic CdS films grown on GaAs substrates is reported. We found that the pressure coefficients of the cubic CdS films are equal to those of the hexagonal films within experimental uncertainties. The main difference between their optical and vibrational properties seems to lie in their exciton energies, the hexagonal phase having a slightly higher energy than the cubic phase. Strong enhancement in multi‐longitudinal optical (LO) phonon scattering has been observed by “pressure‐tuning” the exciton energy to resonate with the excitation laser line. As a result we have been able to determine the pressure coefficients of the higher order LO phonons in CdS for modes as high as 5LO. We found that the pressure coefficients of these higher order LO modes when normalized by the phonon frequency exhibit a systematic decrease with the order of the mode. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sein oder nicht sein? – Workout‐Scoring als Konzept zur Optimierung von Rückflussquoten
Authors: Rieder Markus J.
Published: July 2005

Kredit‐Scoring hat sich als Methode zur Differenzierung von Schuldnern bei der Kreditvergabe mit großem Erfolg durchgesetzt. Neben der Entscheidung über die Gewährung von Krediten ist es auch üblich geworden, ein Scoring zum Kredit‐Monitoring und als Instrument zur Frühwarnung zu installieren (Stichwort: “Verhaltens‐Scoring”). Darüber hinaus gibt es Ansätze, im Mahnverfahren scoring‐ähnliche Methoden zu verwenden.
Role of hydrophobic interactions in the fusion activity of influenza and sendai viruses towards model membranes
Authors: Ramalho-Santos João , Negrão Ricardo , de Lima Maria da Conceição Pedroso
Published: July 2005

We have studied the role of hydrophobic interactions in the fusion activity of two lipid enveloped viruses, influenza and Sendai. Using the fluorescent probe ANS (1-aminonaphtalene-8-sulfonate) we have shown that low-pH-dependent influenza virus activation involves a marked increase in the viral envelope hydrophobicity. The effect of dehydrating agents on the fusion activity of both viruses towards model lipid membranes was studied using a fluorescence dequenching assay. Dehydrating agents such as dimethylsulfoxide and dimethylsulfone greatly enhanced the initial rate of the fusion process, the effect of dimethylsulfone doubling that of dimethylsulfoxide. The effect of poly(ethylene glycol) on the fusion process was found to be dependent on the polymer concentration and molecular weight. In general, similar observations were made for both viruses. These results stress the importance of dehydration and hydrophobic interactions in the fusion activity of influenza and Sendai viruses, and show that these factors may be generally involved in membrane fusion events mediated by many other lipid enveloped viruses.
A role for tyrosine kinase activation in interleukin-1β induced nitric oxide production in the insulin producing cell line RINm-5F
Authors: Welsh Nils
Published: July 2005

The aim of this investigation was to study the putative role of protein phosphorylation in interleukin-1β (IL-1β) induced signal transduction in insulin producing cells. For this purpose, insulin producing RINm-5F cells were exposed to IL-1β for 7 hours with or without different agonists and antagonists to protein kinases and phosphatases and the production of nitrite was subsequently determined. It has been shown earlier that IL-1β will stimulate the production of nitrite in such cells. It was found that EDTA, TPA and staurosporine did not affect IL-1β induced nitrite production. However, the tyrosine kinase antagonist tyrphostin inhibited, whereas sodium orthovanadate, okadaic acid and cyclosporin A, all inhibitors of protein phosphatases, potentiated IL-1β induced nitrite release to the medium. The tyrosine kinase antagonist genistein potentiated at a low concentration and inhibited at a high concentration the IL-1β effect. It is concluded that protein phosphorylation events, mediated either by protein kinases or phosphatases on both tyrosine and serine/threonine residues, may mediate or antagonize IL-1 induced signal transduction in insulin producing cells.
A case of fatal ephedra intake associated with lipofuscin accumulation, caspase activation and cleavage of myofibrillary proteins
Authors: Chen‐Scarabelli Carol , Hughes Siân E. , Landon Giorgio , Rowley Peter , Allebban Zuhair , Lawson Noel , Saravolatz Louis , Gardin Julius , Latchman David , Scarabelli Tiziano M.
Published: July 2005

Ephedra, a herb reported to suppress appetite and stimulate the sympathetic nervous system as well as cardiac performance, has recently been related to several adverse events, including seizure, stroke, hypertension, myocardial infarction, and sudden death. Here, we describe the case of a 45‐year‐old woman who died of cardiovascular collapse while taking ephedra. Tissue analysis revealed non‐specific degenerative alterations in the myocardium (lipofuscin accumulation, basophilic degeneration and vacuolation of myocytes, as well as myofibrillary loss), associated with myocyte apoptosis, caspase activation, and extensive cleavage of miofibrillary proteins α‐actin, α‐actinin, and cardiac troponin T. Healthcare professionals are therefore urged to warn their patients about the risk of serious adverse effects, which may follow ephedra intake.