bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermochemistry of Organic and Heteroorganic Species. Part 19. Structural Aspects and Thermochemical Approach to Isomerization and Fragmentation of Negative Ions: Skeletal Rearrangements, Molecular Ion and Artifacts
Authors: Ponomarev Dmitry , Takhistov Viatcheslav 
Published: May 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Examination of granule layer cell count, cell density, and single‐pulse brdu incorporation in rat organotypic hippocampal slice cultures with respect to culture medium, septotemporal position, and time in vitro
Authors: Sadgrove Matthew P. , Laskowski Alexandra , Gray William P. 
Published: May 2006

AbstractAdult neurogenesis in the dentate gyrus is assuming an increasingly important role in supporting hippocampal‐dependent learning and the modulation of mood and anxiety. Moreover, injury to the developing postnatal dentate gyrus has profound effects on neurogenesis and hippocampal learning throughout life. Organotypic hippocampal slice cultures represent an attractive model for studying neurogenesis both in the early postnatal and adult hippocampus, as they retain much of their anatomical and functional circuitry in vitro. Ongoing neurogenesis has been recently demonstrated in organotypic hippocampal slice cultures. However, cell proliferation, one of the critical components of neurogenesis, has yet to be characterized in this culture system. We examined single‐pulse S‐phase bromo‐deoxyuridine (BrdU) labeling in the dentate granule layer with respect to the septotemporal position of origin of the slice culture, the medium the cultures were grown in, and the time the cultures were maintained in vitro up to 14 days, when they are believed to have matured to a near adult state. Using single 10‐μm sections through a culture as our reference volume, we report significant effects of septotemporal position on the number of granule layer cells and the number of cells in S‐phase, as estimated by short‐survival (2 hours) BrdU studies. We report a declining rate of BrdU incorporation, evidence of significant structural changes within the granule cell layer, and differences in cell death between culture media over the first 14 days in vitro. We report caution with the use of BrdU cell density and changes in cell number to indirectly estimate proliferation. J. Comp. Neurol. 497:397–415, 2006. © 2006 Wiley‐Liss, Inc.
DISC1 immunoreactivity at the light and ultrastructural level in the human neocortex
Authors: Kirkpatrick Brian , Xu Leyan , Cascella Nicola , Ozeki Yuji , Sawa Akira , Roberts Rosalinda C. 
Published: May 2006

AbstractDisrupted‐In‐Schizophrenia 1 (DISC1) is one of two genes that straddle the chromosome 1 breakpoint of a translocation associated with an increased risk of schizophrenia. DISC1 has been identified in the brain of various mammalian species, but no previous immunocytochemical studies have been conducted in human neocortex. We examined DISC1 immunoreactivity in frontal and parietal cortex (BA 4, 9, 39, and 46) in normal human brain. At the light microscopic level, immunolabeling was prominent in the neuropil, in multiple populations of cells, and in the white matter. At the ultrastructural level, staining was prominent in structures associated with synaptic function. Immunolabeled axon terminals comprised 8% of all terminals and formed both asymmetric and symmetric synapses. Labeled axon terminals formed synapses with labeled spines and dendrites; in some, only the postsynaptic density (PSD) of the postsynaptic structure was labeled. The most common configuration, however, was an unlabeled axon terminal forming an asymmetric synapse with a spine that had immunoreactivity deposited on the PSD and throughout the spine. The presence of DISC1 in multiple types of synapses suggests the involvement of DISC1 in corticocortical as well as thalamocortical connections. Staining was also present in ribosomes, parts of the chromatin, in dendritic shafts, and on some microtubules. Labeling was absent from the Golgi apparatus and multivesicular bodies, which are associated with protein excretion. These anatomical localization data suggest that DISC1 participates in synaptic activity and microtubule function, and are consistent with the limited data on its adult function. J. Comp. Neurol. 497:436–450, 2006. © 2006 Wiley‐Liss, Inc.
Embryogenesis of the serotonergic system in the earthworm Eisenia fetida (Annelida, Oligochaeta): Immunohistochemical and biochemical studies
Authors: Koza Anna , Wilhelm Márta , Hiripi László , Elekes Károly , Csoknya Mária 
Published: May 2006

AbstractOrganization of the serotonergic system and changes of the serotonin (5‐HT) content were studied during the embryogenesis of the earthworm Eisenia fetida, using immunocytochemistry and HPLC. A gradual emergence of 5‐HT immunoreactive (IR) cells and their axon projections in the several ganglia of the central (CNS) and peripheral nervous system are described in the context of a staged time‐scale of development. The first 5‐HT‐IR neurons appear in the subesophageal ganglion at an early embryonic stage (E2), followed by neurons in some rostrally located ventral ganglia. In the cerebral ganglion, 5‐HT‐IR cells can be detected only from stage E5. The number of labeled cells in each ganglion of the embryo increases until hatching, when it is still considerably lower than that observed in adults. This shows that the development of the 5‐HTergic system is far from complete by the end of embryogenesis. Organization of 5‐HT‐IR innervation of the body wall starts by stages E3 to E4. In the stomatogastric nervous system the first 5‐HT‐IR fibers can be detected by stage E5. By stage E9 5‐HT immunopositive neurons can be observed in both the stomatogastric ganglia and the enteric plexus. Both 5‐HT levels and the numbers of the labeled cells show a significant increase before hatching, which indicate a functional maturation of the 5‐HTergic system. Based on the early appearance of 5‐HT, we suppose that it may play a regulatory role in both the gangliogenesis and the maturation of peripheral functions necessary during postembryonic life. J. Comp. Neurol. 497:451–467, 2006. © 2006 Wiley‐Liss, Inc.
Estradiol increases α7 nicotinic receptor in serotonergic dorsal raphe and noradrenergic locus coeruleus neurons of macaques
Authors: Centeno Maria Luisa , Henderson Jessica A. , Pau K.‐Y. Francis , Bethea Cynthia L. 
Published: May 2006

AbstractAcetylcholine, acting on presynaptic nicotinic receptors (nAChRs), modulates the release of neurotransmitters in the brain. The rat dorsal raphe nucleus (DR) and the locus coeruleus (LC) receive cholinergic input and express the α7nAChR. In previous reports, we demonstrated that estradiol (E) administration stimulates DR serotonergic and LC noradrenergic function in the macaque. In addition, it has been reported that E induces the expression of the α7nAChR in rats. We questioned whether E increased the expression of the α7nAChR in the macaque DR and LC. We utilized double immunostaining to study the effect of a simulated preovulatory surge of E on the expression of the α7nAChR in the DR and the LC and to determine whether α7nAChR colocalizes with serotonin and tyrosine hydroxylase (TH) in macaques. There was no difference in the number of α7nAChR‐positive neurons between ovariectomized (OVX) controls and OVX animals treated with a silastic capsule containing E (Ecap). However, supplemental infusion of E for 5‐30 hours to Ecap animals (Ecap + inf) significantly increased the number of α7nAChR‐positive neurons in DR and LC. In addition, supplemental E infusion significantly increased the number of neurons in which α7nAChR colocalized with serotonin and TH. These results constitute an important antecedent for study of the effects of nicotine and ovarian steroid hormones in the physiological functions regulated by the DR and the LC in women. J. Comp. Neurol. 497:489–501, 2006. © 2006 Wiley‐Liss, Inc.
Characterization and Insulin‐Mimetic Potential of Oxidovanadium(IV) Complexes Derived from Monoesters and ‐carboxylates of 2,5‐Dipicolinic Acid
Authors: Gätjens Jessica , Meier Beate , Adachi Yusuke , Sakurai Hiromu , Rehder Dieter 
Published: May 2006

AbstractThe monomethyl ester 2MeOdipicH (1) of 2,5‐dipicolinic acid, characterized as its magnesium salt [Mg(H2O)6](2MeOdipic)2, was converted, via the diesters 2MeO‐5ROdipic and the copper complexes [Cu(5ROdipic)2], to the ligands 5ROdipicH (R = iPr 2a, (S)‐2‐Bu 2b). The proligands 2MeO‐5ROdipic (with R = diisopropyl‐D‐galactose 2c, myo‐inositol‐orthoformate 2d) and 2MeO‐5R′NHdipic (where R′ represents the ethyl‐protected L‐amino acid residues Gly 3a, Ala 3b, Val 3c and Phe 3d) were obtained from 2‐MeO‐5Cldipic and the amino acid ethyl esters. Reaction of 2 and3 with VOSO4 afforded the complexes [VO(H2O)(5ROdipic)2](4a–d) and [VO(H2O)(5R′NHdipic)2], 5a–d, respectively. [Mg(H2O)6](2MeOdipic)2·4H2O, 2b, 3a and 4a·0.5H2O were characterized by single‐crystal X‐ray diffraction analysis. Selected type 4 and 5 complexes were submitted to in vitro tests (fibroblasts, SV 3T3 mice fibroblasts) for their uptake kinetics and insulin‐mimetic behavior. The compounds were comparable to insulin in their ability to stimulate cellular glucose uptake and metabolism. In vitro tests with rat adipocytes showed that the complexes also mimic the ability of insulin to inhibit lipolysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis and Electrochemical Properties of Tetrasubstituted Tetraphenylethenes
Authors: Schreivogel Alina , Maurer Jörg , Winter Rainer , Baro Angelika , Laschat Sabine 
Published: May 2006

AbstractTetrakis(4‐acetoxyphenyl and 4‐benzoyloxyphenyl)ethenes 1f and 1g were obtained by acylation of tetrakis(4‐hydroxyphenyl)ethene 1b. Ullmann etherification of 4,4′‐dihydroxybenzophenone 2b and subsequent McMurry coupling yielded tetrakis(phenoxyphenyl)ethene 1i. The tetrakis(acetamidophenyl)ethene 1h was prepared in three steps from tetraphenylethene 1c by nitration, Raney‐Ni reduction and subsequent acetylation. Alternatively, trifluoroacetamide 1j, 2‐methylhexanamide 1k and 2,4‐dimethylbenzamide 1l, with less tendency to form 2D hydrogen bonding networks and thus increased solubility as compared to 1h, were prepared by acylation of 4,4′‐diaminobenzophenone 2a and subsequent McMurry coupling. Compounds 1f–l were investigated by cyclic voltammetry. While the phenyl ether derivative 1i displays single‐electron processes during oxidation, a two‐electron process was discovered for trifluoroacetamide 1j as was also supposed for the esters 1f and 1g. In addition, comproportionation constants were shown to be dependent on the solvent. In situ IR spectroelectrochemistry provided evidence for quinoidal type substructures in the dioxidized forms of tetraphenylethenes 1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Metabolites from the Endophytic Fungus Nodulisporium sp. from Juniperus cedre
Authors: Dai Jingqiu , Krohn Karsten , Flörke Ulrich , Draeger Siegfried , Schulz Barbara , Kiss‐Szikszai Attila , Antus Sándor , Kurtán Tibor , van Ree Teunis 
Published: May 2006

AbstractSeven new metabolites, 3‐hydroxy‐1‐(2,6‐dihydroxyphenyl)butan‐1‐one (1), 1‐(2‐hydroxy‐6‐methoxyphenyl)butan‐1‐one (3), 2,3‐dihydro‐5‐methoxy‐2‐methylchromen‐4‐one (6), the dimeric naphthalenes nodulisporin A (9) and B (10), and the first naturally occurring dimeric indanone, nodulisporin C (12), as well as (4E,6E)‐2,4,6‐trimethylocta‐4,6‐dien‐3‐one (13) were isolated together with ten known compounds (2, 4, 5, 7, 8, 11, 14–17) from the culture extract of the endophytic fungus Nodulisporium sp. from Juniperus cedre from Gomera Island. The structure of dictafolin‐A, previously erroneously assigned as structure 6, is not identical with 2,3‐dihydro‐5‐methoxy‐2‐methylchromen‐4‐one, isolated in this investigation. The structures of new compounds were determined by spectroscopic methods (mainly extensive 1D and 2D NMR experiments and mass spectral measurements) and X‐ray single crystal analysis. All but one of the thirteen tested compounds exhibit herbicidal, antifungal and/or antibacterial activities. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Attitudes and beliefs in a marching band: stereotyping and accentuation in a favorable intergroup context
Authors: Rothbart Myron , Lewis Tiffany Li 
Published: May 2006

AbstractInter‐group perception was examined in a context characterized by positive interdependence and extensive contact across group boundaries. The attitudes and beliefs of the woodwind, brass, and percussion sections of a university marching band were examined using measures of ingroup favoritism, outgroup homogeneity, and 12 scales assessing adult temperament. Although there was no evidence of ingroup favoritism or outgroup homogeneity, and few actual temperament differences across groups, stereotypic expectations based on temperament characteristics were strong. For each target group, strength of stereotype was accentuated by ingroup judges and, most strongly, by outgroup judges. Accentuation of differences between groups occurred when the expectation, and not the reality, of group differences were present. Correlations between contact measures and individual measures of perceived ingroup–outgroup differences were generally low, but suggested that degree of contact correlated positively, rather than negatively, with the magnitude of perceived differences between groups. Copyright © 2006 John Wiley & Sons, Ltd.
Fabrication and Properties of Conducting Polypyrrole/SWNT‐PABS Composite Films and Nanotubes
Authors: Wanekaya Adam K. , Lei Yu , Bekyarova Elena , Chen Wilfred , Haddon Robert , Mulchandani Ashok , Myung Nosang V. 
Published: May 2006

AbstractWe report the electropolymerization and characterization of polypyrrole films doped with poly(m‐aminobenzene sulfonic acid (PABS) functionalized single‐walled nanotubes (SWNT) (PPy/SWNT‐PABS). The negatively charged water‐soluble SWNT‐PABS served as anionic dopant during the electropolymerization to synthesize PPy/SWNT‐PABS composite films. The synthetic, morphological and electrical properties of PPy/SWNT‐PABS films and chloride doped polypyrrole (PPy/Cl) films were compared. Characterization was performed by cyclic voltammetry, atomic force microscopy (AFM), scanning electron microscopy (SEM) and Raman spectroscopy. SEM and AFM images revealed that the incorporation of SWNT‐PABS significantly altered the morphology of the PPy. Cyclic voltammetry showed improved electrochemical properties of PPy/SWNT‐PABS films as compared to PPy/Cl films. Raman Spectroscopy confirmed the presence of SWNT‐PABS within composite films. Field effect transistor (FET) and electrical characterization studies show that the incorporation of the SWNT‐PABS increased the electronic performance of PPy/SWNT‐PABS films when compared to PPy/Cl films. Finally, we fabricated PPy/SWNT‐PABS nanotubes which may lead to potential applications to sensors and other electronic devices.
Electrode Modified with Langmuir–Blodgett (LB) Film of Calixarenes for Preconcentration and Stripping Analysis of Hg(II)
Authors: Dong Huimin , Lin Lin , Zheng Hao , Zhao Guoxin , Ye Baoxian 
Published: May 2006

AbstractA new type of current sensor, Langmuir–Blodgett (LB) film of calixarene on the surface of glassy carbon electrode (GCE) was prepared for determination of mercury by anodic stripping voltammetry (ASV). An anodic stripping peak was obtained at 0.15 V (vs. SCE) by scanning the potential from −0.6 to +0.6 V. Compared with a bare GCE, the LB film coated electrode greatly improves the sensitivity of measuring mercury ion. The fabricated electrode in a 0.1 M H2SO4+0.01 M HCl solution shows a linear voltammetric response in the range of 0.07–40 μg L−1 and detection limit of 0.04 μg L−1 (ca. 2×10−10 M). The high sensitivity, selectivity, and stability of this LB film modified electrode demonstrates its practical application for a simple, rapid and economical determination of Hg2+ in a water sample.
Determination of cytokinins in coconut (Cocos nucifera L.) water using capillary zone electrophoresis‐tandem mass spectrometry
Authors: Ge Liya , Yong Jean Wan Hong , Tan Swee Ngin , Ong Eng Shi 
Published: May 2006

AbstractThe applicability of CZE in combination with MS and MS/MS methods for the simultaneous separation and determination of 12 cytokinins was investigated for the first time. Cytokinins were first completely separated by CZE within less than 20 min using a volatile buffer and then detected directly by MS or MS/MS. Satisfactory separation of the 12 cytokinin standards was achieved using a 25 mM ammonium formate/formic acid buffer (pH 3.4) and 3% ACN v/v with a separation voltage of 25 kV. On the basis of the resolution of the neighboring peaks, the various parameters for CZE‐MS optimization, such as buffer pH value, concentration of buffer and organic modifier, applied voltage and sheath liquid, were evaluated systematically. MS/MS with multiple reaction monitoring detection was carried out to obtain sufficient selectivity and sensitivity. The combination of on‐line sample stacking and CZE‐MS/MS achieved a detection limit in the range of 0.05–0.18 μM for the 12 cytokinins at an S/N of 3. The optimized CZE‐MS/MS method was simple, rapid, low cost, robust and highly selective. Furthermore, the developed method was successfully applied to screen for endogenous cytokinins in purified coconut water extract sample. Nine cytokinins were detected and quantified in coconut water after SPE.
Separation of CD34+ cells from human peripheral blood through polyurethane foaming membranes
Authors: Higuchi Akon , Iizuka Ayumi , Gomei Yumiko , Miyazaki Toyohiko , Sakurai Masaru , Matsuoka Yuki , Natori Shizue Hayashi 
Published: May 2006

AbstractCell separation from peripheral blood was investigated using polyurethane (PU) foaming membranes and PU membranes (pore size, 5 or 12 μm) at different blood permeation speeds. Permeation ratio of hematopoietic stem cells (CD34+ cells) through the PU membranes was the lowest among the blood cells at any blood permeation speed. This is thought to be because CD34+ cells are more adhesive than red blood cells (RBCs), platelets, T cells, and B cells. Primitive hematopoietic stem and progenitor cells tend to adhere to the surface of mature blood cells, because of the high expression of cell‐adhesion molecules on the surface of the cells. Human serum albumin solution was exposed to PU‐COOH membranes to detach adhered cells from the surface of the membranes, allowing isolation of CD34+ cells and reduction of RBCs in the permeate solution. Most purified CD34+ cells (high recovery ratio of CD34+ cells divided by recovery ratio of RBCs) were obtained in the recovery process using PU‐COOH membranes (pore size, 5.2 μm) at a permeation speed of 0.3–1 mL/min. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Novel alginate–acrylic polymers as a platform for drug delivery
Authors: Laurienzo Paola , Malinconico Mario , Mattia Giuditta , Russo Roberto , Rotonda M.I. La , Quaglia Fabiana , Capitani Donatella , Mannina Luisa 
Published: May 2006

AbstractThe aim of the present work was to develop a family of novel materials based on a combination of sodium alginate and acrylic polymers and to evaluate their potential in drug delivery applications. In the presence of sodium alginate, acrylic chains with acidic as well as basic moieties were polymerized to create an interpolymer complex based on electrostatic interactions that are able to modulate the release rate of low molecular weight drugs. The synthesized materials were used to prepare hydrophilic matrices for drug delivery and tested for their adhesion properties to glass, used as a model substrate for mucoadhesion. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Mechanical properties of porous, electrosprayed calcium phosphate coatings
Authors: Leeuwenburgh S.C.G. , Wolke J.G.C. , Lommen L. , Pooters T. , Schoonman J. , Jansen J.A. 
Published: May 2006

AbstractMechanical properties of calcium phosphate coatings (CaP), deposited using the electrostatic spray deposition (ESD) technique, have been characterized using a range of analytical techniques, including tensile testing (ASTM C633), fatigue testing (ASTM E855), and scratch testing using blunt and sharp scratch styli. Moreover, a simple explantation procedure was successfully introduced using ESD‐coated, threaded dental implants to characterize the mechanical performance of CaP coatings qualitatively under conditions that mimic clinical situations as close as possible. Generally, all analysis techniques revealed that ESD coatings need to be crystallized in order to ensure interfacial adhesion to the substrate and sufficient mechanical strength of the superficial reticular structure. Crystalline carbonated hydroxyapatite coatings (CHA, heat‐treated at 700°C) were resistant to fatigue as well as to plastic ploughing deformation by means of various scratch styli, and the fragile surface structure of ESD coatings was maintained to a large extent after unscrewing CHA‐coated dental implants from femoral condyles of goat cadavers. From these experiments, it was concluded that interfacial adhesion of crystalline CHA ESD coatings to the titanium substrate was sufficient, but that mechanical strength of the superficial architecture of ESD coatings need to be optimized for applications where high shear and compressive stresses are imposed onto the rather fragile coating surface of reticular ESD morphologies. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Folic acid‐PEG conjugated superparamagnetic nanoparticles for targeted cellular uptake and detection by MRI
Authors: Sun Conroy , Sze Raymond , Zhang Miqin 
Published: May 2006

AbstractWe report the development and in vitro study of a nanoconjugate serving as a targeted magnetic resonance imaging (MRI) contrast enhancement agent for detection of cancer cells overexpressing the folate receptor. The nanoconjugate was synthesized by coating superparamagnetic iron oxide nanoparticles with covalently bound bifunctional poly(ethylene glycol) (PEG), followed by conjugation with folic acid (FA). The specificity of the nanoconjugate targeting cancerous cells was demonstrated by comparative intracellular uptake of the nanoconjugate and PEG‐/dextran‐coated nanoparticles by human adenocarcinoma HeLa cells. Preferential targeting to cancerous cells was studied by comparing the uptake of the nanoconjugate by HeLa cells and by non‐FR expressing osteosarcoma MG‐63 cells. Uptake of the nanoconjugate by HeLa cells after 4 h incubation was found to be a 12‐fold higher than that of PEG‐ or dextran‐coated nanoparticles as quantified by inductively coupled plasma spectroscopy. A significant negative contrast enhancement was observed with magnetic resonance (MR) phantom imaging for HeLa cells over MG‐63 cells, when both were cultured with the nanoconjugate. Specificity of the nanoconjugate for folate receptors was also verified with a competitive inhibition assay, in which HeLa cells were incubated with both NP–PEG–FA and free FA. The bifunctional PEG used has amide linkages within the PEG chains that can form interchain hydrogen bonding, leading to improved stability of the PEG coating. Self‐assembled PEG can be controlled at the molecular level and are suitable for nanoscale coatings. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Trade liberalisation and trade performance in the Dominican Republic
Authors: U Santos‐Paulino Amelia 
Published: May 2006

AbstractDuring the 1990s the Dominican Republic managed its transition to a more open trade regime by eliminating non‐tariff barriers, simplifying the tariff structure and reducting the rates of duties. Using this information the study examines trade liberalisation's impact on the Dominican Republic's trade dynamics. It finds that import and export growth increased as a result of liberalisation, even though exports' response is somewhat higher. Moreover, the paper estimates a one percentage point improvement in the trade balance to GDP ratio following liberalisation. Copyright © 2006 John Wiley & Sons, Ltd.