bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper, Silver and Gold‐Based Catalysts for Carbene Addition or Insertion Reactions.
Authors: Diaz‐Requejo M. Mar , Perez Pedro J. 
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.
Phosphorylated Macrocycles: Structures, Complexing Properties, and Molecular Recognition
Authors: Finocchiaro P. , Failla S. , Consiglio G. 
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.
Resolution of Organic Racemates via Host—Guest Enantioselective Inclusion Complexation in Bile Acid Derivatives
Authors: Bortolini O. , Fantin G. , Fogagnolo M. , Maietti S. 
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.
Formation and Conversion of Peroxide Intermediates of the N‐Alkanes and Cycloalkanes Oxidation in a Liquid Phase
Authors: Perkel A. L. , Voronina S. G. , Buneeva E. I. 
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.
Interaction of Low‐Energy Ions and Hydrocarbon Radicals with Carbon Surfaces
Authors: Jacob W. , Hopf C. , Meier M. , Schwarz‐Selinger T. 
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.
Bioorganic Chemistry of Nyctinasty Using Functional Probes
Authors: Ueda Minoru , Fujii Tomohiko , Kato Eisuke , Sugimoto Takanori , Kato Nobuki 
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.
Elucidation of Residue‐Level Structure and Dynamics of Polypeptides via Isotope‐Edited Infrared Spectroscopy
Authors: Decatur Sean M. 
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.
Solid‐State NMR Studies of the Structure, Dynamics, and Assembly of β‐Sheet Membrane Peptides and α‐Helical Membrane Proteins with Antibiotic Activities
Authors: Hong Mei 
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.
Differential distribution of voltage‐gated calcium channels in dopaminergic neurons of the rat retina
Authors: Witkovsky Paul , Shen Changpeng , McRory John 
Published: May 2006

AbstractWe studied by immunocytochemistry and Western blots the identity and cellular distribution of voltage‐gated calcium channels within dopaminergic neurons of the rat retina. The aim was to associate particular calcium channel subtypes with known activities of the neuron (e.g., transmitter release from axon terminals). Five voltage‐gated calcium channels were identified: α1A, α1B, α1E, α1F, and α1H. All of these, except the α1B subtype, were found within dopaminergic perikarya. The α1B channels were concentrated at axon terminal rings, together with α1A calcium channels. In contrast, α1H calcium channels were most abundant in the dendrites, and α1F calcium channels were restricted to the perikaryon. The α1E calcium channel was present at such a low density that its cellular distribution beyond the perikaryon could not be determined. Our findings are consistent with the available pharmacological data indicating that α1A and α1B calcium channels control the major fraction of dopamine release in the rat retina. J. Comp. Neurol. 497:384–396, 2006. © 2006 Wiley‐Liss, Inc.
Generation and Growth Mechanism of Metal (Fe, Co, Ni) Nanotube Arrays
Authors: Cao Huaqiang , Wang Liduo , Qiu Yong , Wu Qingzhi , Wang Guozhi , Zhang Lei , Liu Xiangwen 
Published: May 2006

AbstractNanotubes composed of layered or nonlayered materials have been synthesized through various methods, among which template‐based electrodeposition technology provides a versatile technique for synthesizing one‐dimensional nanostructured materials. However, the growth mechanism of nanotubes using the template method is seldom clarified. Herein, we present the systematic preparation of metal nanotube arrays and put forward the growth mechanism, termed current‐directed tubular growth (CDTG), for template‐based electrodeposition. There are competitive growth rates for metal atoms entering the crystal lattice, that is, v∥ (growth rate parallel to current direction) and v⊥ (growth rate perpendicular to current direction). Metal nanotubes can be obtained at v∥≫v⊥, while nanowires can be obtained at v∥≈v⊥. The as‐synthesized metal (Fe, Co, Ni) nanotubes are constructed from nonlayered materials, which are of body‐centered cubic iron structure, hexagonal close packed cobalt structure, and face‐centered cubic nickel structure, respectively. The CDTG mechanism is expected to have applications in designing and synthesizing other metal nanotubes and even compound nanotubes via template‐based electrodeposition technology.
Study of the Formation and Thermal Decomposition of an Azo‐Bridged Tricyclic Ring System
Authors: Novák Zoltán , Vincze Zoltán , Czégény Zsuzsanna , Magyarfalvi Gábor , Smith David M. , Kotschy András 
Published: May 2006

Abstract1‐Amino‐2‐methyl‐1,3‐pentadienes were treated with dimethyl 1,2,4,5‐tetrazine‐3,6‐dicarboxylate to give diazatricyclo[2.2.2.0]octenes and dimethyl 4‐methylpyridazine‐3,6‐dicarboxylate, the product distribution being largely dependent on the nature of the amino substituent. Under similar conditions the analogous 1‐morpholino‐1,3‐butadiene afforded dimethyl pyridazine‐3,6‐dicarboxylate as the major product. The tricyclic products underwent selective thermal decomposition to give dimethyl 4‐methylpyridazine‐3,6‐dicarboxylate in excellent yield. The proposed mechanism of the formation as well as of the decomposition was supported by quantum chemical calculations and experimental evidence. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Prenylated Stilbenes and Their Novel Biogenetic Derivatives from Artocarpus chama
Authors: Wang Yong‐Hong , Hou Ai‐Jun , Chen Dao‐Feng , Weiller Markus , Wendel Albrecht , Staples Richard J. 
Published: May 2006

AbstractTwo new prenylated stilbenes, artochamins F (1) and G (2), and their four novel derivatives, artochamins H–K (3–6), were isolated from the stems of Artocarpus chama. Their structures were elucidated mainly by NMR spectroscopy and mass spectrometry. The structure of 3 was confirmed by X‐ray crystallographic analysis. The origin of 3–6 could be assumed biogenetically from 2. The cytotoxicity of these compounds against HepG2 cells was evaluated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Voltammetric Determination of Uric Acid with a Glassy Carbon Electrode Coated by Paste of Multiwalled Carbon Nanotubes and Ionic Liquid
Authors: Yan Quanping , Zhao Faqiong , Li Guangzu , Zeng Baizhao 
Published: May 2006

AbstractThe voltammetric behavior of uric acid (UA) has been studied at a multiwalled carbon nanotube‐ionic liquid (i.e., 1‐butyl‐3‐methylimidazolium hexafluorophosphate, BMIMPF6) paste coated glassy carbon electrode (MWNTs‐BMIMPF6/GC). It is found that UA can effectively accumulate at this electrode and cause a sensitive anodic peak at about 0.49 V (vs. SCE) in pH 4.0 phosphate buffer solutions. Experimental parameters influencing the response of the electrode, such as solution pH and accumulation time, are optimized for uric acid determination. Under the optimum conditions, the anodic peak current is linear to UA concentration in the range of 1.0×10−8 M to 1.0×10−6 M and 2.0×10−6 M to 2.0×10−5 M. The detection limit is 5.0×10−9 M for 180 s accumulation on open circuit. The electrode can be regenerated by successively cycling in a blank solution for about 3 min and exhibits good reproducibility. A 1.0×10−6 M UA solution is measured for eight times using the same electrode regenerated after every determination, and the relative standard deviation (RSD) of the peak current is 3.2%. As for different electrodes fabricated by the same way the RSD (i.e., the electrode to electrode deviation) is 4.2%(n=9). This method has been applied to the determination of UA in human urine samples, and the recoveries are 99%–100.6%. In addition, comparison is made between MWNTs‐BMIMPF6/GC and MWNTs/GC. Results show that the MWNTs‐BMIMPF6/GC exhibits higher sensitivity, selectivity and ratio of peak current to background current.
Electrochemical Properties of an Osmium(II) Copolymer Film and Its Electrocatalytic Ability Towards the Oxidation of Ascorbic Acid in Acidic and Neutral pH
Authors: Foster Kevin , McCormac Timothy 
Published: May 2006

AbstractCopolymerization of an osmium(II) functionalized pyrrole moiety, osmium‐bis‐N,N'‐(2,2′‐bipyridyl)‐N‐(pyridine‐4‐ylmethyl‐(8‐pyrrole‐1yl–octyl)‐amine)chloride (I) with 3‐methylthiophene was carried out. The resulting conducting polymer film exhibited a clear redox couple associated with the Os3+/2+ response and the familiar conducting polymer backbone signature. The effect of film thickness upon the redox properties of the copolymer was investigated in organic electrolyte solutions. Scanning electron micrographs (SEM) along with energy dispersive X‐ray (EDX) spectra of the copolymerized films were undertaken, both after formation and redox cycling in neutral buffer solution. These clearly show that electrolyte is incorporated into the polymer film upon redox cycling through the Os3+/2+ redox system. The Os3+/2+ response associated with the copolymer was seen to be significantly altered in the presence of ascorbic acid both in acidic and neutral pH buffer solutions. This pointed to an electrocatalytic reaction between the ascorbic acid and the Os3+ form of the copolymer. Under acidic conditions the copolymer film exhibited a sensitivity of 1.76 (±0.05) μA/mM with a limit of detection (LOD) of 1.45 μM for ascorbic acid. Under neutral pH conditions the copolymer exhibited a sensitivity of 19.26 (±1.05) μA/mM with a limit of detection (LOD) of 1.28 μM for ascorbic acid.
Integrated Bienzyme Chip for Ethanol Monitoring
Authors: Gonzalo‐Ruiz Javier , Alonso‐Lomillo M. Asunción , Escudé‐Pujol Roger , Muñoz F. Javier 
Published: May 2006

AbstractAn ethanol chip biosensors based on bienzymatic system has been developed. Horse radish peroxidase and alcohol oxidase have been co‐immobilized into a polypyrrole matrix, as well as the mediator, onto the integrated working electrode. Variables that affect to the chronoamperometric response of ethanol have been optimized through the experimental design methodology. Under these conditions, the slopes of several calibrations curves show a reproducibility, repeatability and limit of detection of 6.09% (n=5), 9.03% (n=5) and 2.98±0.38 mmol dm−3 (α=β=0.05, n=3), respectively. Finally, the biosensors based on platinum chips were applied to the determination of ethanol in white wine samples, obtaining successful results.
Capillary electrophoresis‐mass spectrometry characterisation of secondary metabolites from the antihyperglycaemic plant Genista tenera
Authors: Edwards Emma L. , Rodrigues João A. , Ferreira Joana , Goodall David M. , Rauter Amélia P. , Justino Jorge , Thomas‐Oates Jane 
Published: May 2006

AbstractGenista tenera is endemic to the Portuguese island of Madeira, where an infusion of the aerial parts of the plant is used in folk medicine as an antidiabetic agent. Consequently the medicinal properties of the secondary metabolites of this plant have been the subject of an ongoing study. A recently reported LC‐MS method using a 100 min separation allowed identification of five flavonoid components in an extract of the aerial parts of this plant. In order to obtain additional information on the range and complexity of the plant's secondary metabolite components a CE‐MS method has been developed and applied for the analysis of an extract of G. tenera. Twenty‐six different components are distinguished in an analysis time of only 10 min. Results demonstrate that CE‐MS/MS rapidly generates data complementary to those obtainable by LC‐MS/MS and is particularly suited to the analysis of plant metabolites where concentration is not limiting.
Comprehensive two‐dimensional separation in coupling of reversed‐phase chromatography with capillary isoelectric focusing followed by MALDI‐MS identification using on‐target digestion for intact protein analysis
Authors: Yu Wenjia , Li Yan , Deng Chunhui , Zhang Xiangmin 
Published: May 2006

AbstractA coupling of capillary RP LC as the first dimension with CIEF as the second dimension followed by MALDI‐MS identification was demonstrated. Based on 2‐D separation system developed by our group (Electrophoresis 2003, 24, 3289–3295), this paper focused on incorporating tryptic digestion into the top‐down proteomics methodology, retaining the benefits of the top‐down method. Hydrophobic layer of packing‐material C18 coated with SE‐30 on the MALDI‐target surface was used to permit the CIEF fractions to be easily concentrated and free of ampholytes using on‐target washing. Following the removal of ampholytes, on‐target tryptic digestion was performed to generate PMF for protein identification. Using the proteome analytical strategy, we could obtain not only intact protein pI value but also PMF for accurate protein identification. The feasibility of the strategy was first tested with a mixture of model proteins with different pIs and molecular masses. Proteome of rat liver tissue extracts was further analyzed using the system for verification. The results have shown that the system is effective for complex proteomic analysis.
Efficient and highly reproducible capillary electrophoresis–mass spectrometry of peptides using Polybrene‐poly(vinyl sulfonate)‐coated capillaries
Authors: Catai Jonatan R. , Toraño Javier Sastre , de Jong Gerhardus J. , Somsen Govert W. 
Published: May 2006

AbstractThe potential of capillaries noncovalently coated with a bilayer of oppositely charged polymers for the analysis of peptides by CE‐MS was investigated. Bilayer coatings were produced by subsequently rinsing fused‐silica capillaries with a solution of Polybrene (PB) and poly(vinyl sulfonate) (PVS). The PB‐PVS coating showed to be fully compatible with MS detection causing no ionization suppression or background signals. The bilayer coating provided a considerable EOF at low pH, thereby facilitating the fast separation of peptides using a BGE of formic acid (pH 2.5). Under optimized CE–MS conditions, for enkephalin peptides high separation efficiencies were obtained with plate numbers in the range of 300 000–500 000. It is demonstrated that both the cancellation of the hydrodynamic capillary flow induced by the nebulizer gas and a sufficiently high‐data acquisition rate are crucial for achieving these efficiencies. The overall performance of the CE‐MS system using PB‐PVS‐coated capillaries was evaluated by the analysis of a tryptic digest of cytochrome c. The system provided an efficient separation of the peptide mixture, which could be effectively monitored by MS/MS detection allowing identification of at least 13 peptides within a time interval of 1.5 min. In addition, the PB‐PVS coating proved to be very consistent yielding stable CE‐MS patterns with highly favorable migration time reproducibilities (RSDs < 1% over a 3‐day period).
Increased osteoblast adhesion on nanograined hydroxyapatite and partially stabilized zirconia composites
Authors: Evis Zafer , Sato Michiko , Webster Thomas J. 
Published: May 2006

AbstractTo improve the mechanical properties of hydroxyapatite (HA, Ca10(PO4)6(OH)2) for orthopedic applications, numerous investigators have proposed combining HA with high strength materials, specifically zirconia. Despite the fact that, compared to pure HA, it is now well‐established that zirconia and HA composites have improved mechanical properties, the cytocompatibility properties of this composite remain largely uninvestigated. For these reasons, the objective of the present in vitro study was to synthesize HA and partially stabilized zirconia composites for osteoblast (bone‐forming cell) adhesion assays. Various sintering temperatures and amounts of zirconia in HA composites were used in order to ascertain their influence on osteoblast adhesion. Results demonstrated increased interactions between HA and partially stabilized zirconia, when either higher sintering temperatures (between 900 and 1300°C for 1 h) or higher zirconia contents (between 10 and 40 wt %) were used during material synthesis. More importantly, greater osteoblast adhesion was measured on HA–zirconia composites sintered either at lower temperatures (specifically, 900°C) or with lower amounts of zirconia added to HA composites (specifically, 10 wt %). Results further indicated that when sintered at lower temperatures the composites possessed smaller nanometer grain sizes with increased surface roughness and a more stable HA phase. For these reasons, this study suggests that to optimize osteoblast adhesion on HA and partially stabilized zirconia composites for orthopedic applications, low sintering temperatures and low amounts of zirconia should be used. This suggests that a delicate balance must be reached between increasing mechanical properties of HA without decreasing osteoblast cytocompatibility properties through zirconia addition. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
In vitro and in vivo testing of bioabsorbable antibiotic containing bone filler for osteomyelitis treatment
Authors: Koort Jyri K. , Suokas Esa , Veiranto Minna , Mäkinen Tatu J. , Jalava Jari , Törmälä Pertti , Aro Hannu T. 
Published: May 2006

AbstractThe use of local antibiotics from a biodegradable implant is appealing concept for treatment of chronic osteomyelitis. Our aim was to develop a new drug delivery system based on controlled ciprofloxacin release from poly(D/L‐lactide). Cylindrical composite pellets (1.0 × 0.9 mm) were manufactured from bioabsorbable poly(D/L‐lactide) matrix and ciprofloxacin (7.4 wt %). In vitro studies were carried out to delineate the release profile of the antibiotic and to verify its antimicrobial activity by means of MIC testing. A long‐term study in rabbits was performed to validate the release of ciprofloxacin from the composite in vivo. Therapeutic level of ciprofloxacin (>2 μg/mL) was maintained between 60 and 300 days and the concentration remained below the potentially detrimental level of 20 μg/mL in vitro. The released ciprofloxacin had retained its antimicrobial properties against common pathogens. In an exploratory long‐term in vivo study with three rabbits, ciprofloxacin could not be detected from the serum after moderate filling (160 mg) of the tibia (follow‐up 168 days), whereas after high dosing (a total dose of 1000 mg in both tibias) ciprofloxacin was found temporarily at low serum concentrations (14–34 ng/mL) during the follow‐up of 300 days. The bone concentrations of ciprofloxacin could be measured in all samples at 168 and 300 days. The tested copolylactide matrix seems to be a promising option in selection of resorbable carriers for sustained release of antibiotics, but the composite needs modifications to promote ciprofloxacin release during the first 60 days of implantation. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
In vitroflexural properties of hydroxyapatite and self‐reinforced poly(L‐lactic acid)
Authors: Wright‐Charlesworth Debra D. , King Julia A. , Miller Darinda M. , Lim Cho Hui 
Published: May 2006

AbstractPoly(L‐lactic acid) (PLLA) has been used for fracture fixation devices, but its use is limited because of its poor biocompatibility and mechanical properties. The effects of extrusion, incorporation of hydroxyapatite (HA) and self‐reinforced composites (SRCs) on the resultant mechanical properties of PLLA were examined. Samples were conditioned for up to 52 weeks in PBS at 37°C. Extrusion did not adversely affect the mechanical properties of PLLA. Afterin vitroconditioning, a slight but significant reduction in the strain to failure and modulus was seen. HA (10–40%) by weight was evenly distributed into PLLA using an intermeshing twin‐screw extruder. As ceramic content increased, the initial modulus increased but flexural strength decreased. After immersion, the modulus of all HA‐PLLA blends was lower than PLLA. HA particles did not form a strong bond with the PLLA, which promoted easier degradation of the HA‐PLLA matrix. SRCs showed a higher modulus and strength when compared to all materials except the modulus of 30 and 40% HA‐PLLA composites before immersion. Water preferentially attacked the matrix of the composite, leading to more fiber pullout, but the fiber orientation maintained the advantages in strength and modulus up to 24 weeksin vitro. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Comparing money and labour payment in contingent valuation: the case of forest fire prevention in Vietnamese context
Authors: Hung Le Trong , Loomis John B. , Thinh Vu Tien 
Published: May 2006

AbstractThe contingent valuation method for valuing public goods is a relatively new method in Vietnam. In developed countries, payments are often requested in money, but the form of payment should be more flexible in developing countries that do not have extensive cash economies. Drawing on historical precedent in Vietnam, payment in working days was also used and accepted by the local people; payment in money was less acceptable for the firebreak establishment and maintenance programme. The household mean willingness to pay for the firebreak establishment and maintenance programme was five days a year. The contingent valuation method was found workable at least for a forest fire prevention programme in the Vietnamese context. The lessons learned from this study should be of interest to researchers and policy makers considering applying the contingent valuation method in newly emerging market economies. Copyright © 2006 John Wiley & Sons, Ltd.
Social security in developing countries: MYTH or necessity? Evidence from India
Authors: Justino Patricia 
Published: May 2006

AbstractThis paper discusses the importance of social security policies in developing economies, using empirical evidence from India. The paper discusses the viability of implementing systems of social protection in developing countries and provides an empirical analysis of the effects of socio‐economic security policies on Indian's economic performance between 1973 and 1999, using a two‐stage least square model adapted to data from a panel of 14 Indian states. The results show that policies that strengthen the social and economic security of the Indian population have been an important endogenous variable to both the reduction of poverty and the increase in economic growth in India. Copyright © 2006 John Wiley & Sons, Ltd.JEL codes: C33, H50, I38, O10, O40, O53