bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Palladium(II)‐Catalyzed Cyclization via N‐Alkylation of an Allyl Alcohol with an Urethane and Its Application to the Synthesis of Natural Products
Authors: Yokoyama Hajime , Hirai Yoshiro 
Published: November 2008

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 of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Multifunctional Linkers for Combinatorial Solid‐Phase Synthesis
Authors: Jung Nicole , Wiehn Matthias , Braese Stefan 
Published: November 2008

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 of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Reductive Coupling of Unactivated Alkenes and Alkynes
Authors: Broene Richard D. 
Published: November 2008

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 of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Reductive Aldol, Michael, and Mannich Reactions
Authors: Nishiyama Hisao , Shiomi Takushi 
Published: November 2008

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 of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Reductive C—C Bond Formation After Epoxide Opening via Electron Transfer
Authors: Gansaeuer Andreas , Justicia Jose , Fan Chun‐An , Worgull Dennis , Piestert Frederik 
Published: November 2008

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 of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Nickel‐Catalyzed Reductive Couplings of Aldehydes and Alkynes
Authors: Montgomery John , Sormunen Grant J. 
Published: November 2008

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 of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Why Are Spin Wave Excitations All Important in Nanoscale Magnetism?
Authors: Baberschke Klaus 
Published: November 2008

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 of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Engineering of Squalene Cyclizing Enzymes
Authors: Abe Ikuro 
Published: November 2008

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 of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Structure and Biological Activity of Glycosphingolipids from Starfish and Feather Stars
Authors: Inagaki Masanori 
Published: November 2008

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 of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Reveal the Truth of Powder — From the Base to the Application
Authors: Sunada Hisakazu 
Published: November 2008

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 of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: The Local Structure of Molecular Reaction Intermediates at Surfaces
Authors: Woodruff D. P. 
Published: November 2008

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 of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Resolution and absolute configuration assignment of a natural racemic chromane from Peperomia obtusifolia (Piperaceae)
Authors: Batista João Marcos , López Silvia Noelí , Da Silva Mota Jonas , Vanzolini Kenia Lourenço , Cass Quezia Bezerra , Rinaldo Daniel , Vilegas Wagner , Da Silva Bolzani Vanderlan , Kato Massuo Jorge , Furlan Maysa 
Published: November 2008

AbstractThe resolution of the natural racemic chromane 3,4‐dihydro‐5‐hydroxy‐2,7‐dimethyl‐8‐(3″‐methyl‐2″‐butenyl)‐2‐(4′‐methyl‐1′,3′‐pentadienyl)‐2H‐1‐benzopyran‐6‐carboxylic acid (1) isolated from the leaves of Peperomia obtusifolia has been accomplished using stereoselective HPLC. The absolute configuration of the resolved enantiomers was determined by the analysis of optical rotations and CD spectra. The finding of a racemic mixture instead of an enantiomerically pure metabolite raises questions about the final steps in the biosynthesis of this class of natural products, suggesting that the intramolecular chromane ring formation step may not be enzymatically controlled at all in P. obtusifolia. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Enantioseparation of benzoxazolinone aminoalcohols and their aminoketone precursors, potential adrenergic ligands, by analytical and preparative liquid chromatography on amylose chiral stationary phases and characterization of the enantiomers
Authors: Lipka Emmanuelle , Vaccher Claude , Bonte Jean‐Paul 
Published: November 2008

AbstractTo obtain milligram amounts of the enantiomers of benzoxazolinone derivatives to be tested for binding to adrenergic sites, analytical HPLC methods using derivatized amylose chiral stationary phases were developed for the direct enantioseparation of benzoxazolinone aminoalcohols and their aminoketone precursors, derivatives with one or two chirals centers. The separations were made using normal phase methodology with a mobile phase of n‐hexane‐alcohol (ethanol, 1‐propanol, or 2‐propanol) in various proportions, and silica‐based amylose (tris‐3, 5‐dimethylphenylcarbamate) Chiralpak AD and (tris‐(S)‐1‐phenylethylcarbamate) Chiralpak AS columns. The effects of concentration of various aliphatic alcohols in the mobile phase were studied. The best separation was achieved on Chiralpak AS, so preparative HPLC was set up with this chiral stationary phase using a mobile phase consisting of n‐hexane‐alcohol using isocratic conditions and multiple repetitive injections. Physicochemicals properties of enantiomers were reported The effect of structural features of the solutes on discrimination between the enantiomers was examined. Limit of detection (LD) and limit of quantification (LQ) were determined using both ultra‐violet (UV) and evaporative light‐scattering detection (ELSD). Chirality, 2009. © 2008 Wiley‐Liss, Inc.
A validated enantiospecific method for determination and purity assay of clopridogrel
Authors: Nikolic Katarina , Ivković Branka , Bešović Željka , Marković Slavko , Agbaba Danica 
Published: November 2008

AbstractA new and accurate HPLC method using β‐cyclodextrin chemically bonded to spherical silica particles as chiral stationary phase (CSP) was developed and validated for determination ofS‐clopidogrel and its impuritiesR‐enantiomer andS‐acid as a hydrolytic product. The effects of acetonitrile and methanol content in the mobile phase and temperature on the resolution and retention of enantiomers were investigated. A satisfactory resolution ofS‐clopidogrel active form and its impurities was achieved on ChiraDex® column (5 μm, 4 × 250 mm) at a flow rate of 1.0 ml/min and 17°C using acetonitrile, methanol and 0.01 M potassium dihydrogen phosphate solution (15:5:80 v/v/v) as mobile phase. The detection wavelength was set at 220 nm. The method was validated in terms of accuracy, precision, linearity, and robustness. The limit of detection forR‐enantiomer andS‐acid were 0.75 and 0.09 μg/ml, respectively, injection volume being 20 μl. Finally, the molecular modeling of the inclusion complexes between the analytes and β‐cyclodextrin was performed to investigate the mechanism of the enantiorecognition and to study the quantitative structure–retention relationships. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Modeling River Stage‐Discharge Relationships Using Different Neural Network Computing Techniques
Authors: Kisi Özgür , Çobaner Murat 
Published: November 2008

AbstractOne of the most important problems in hydrology is the establishment of rating curves. The statistical tools that are commonly used for river stage‐discharge relationships are regression and curve fitting. However, these techniques are not adequate in view of the complexity of the problems involved. Three different neural network techniques, i. e., multi‐layer perceptron neural network with Levenberg‐Marquardt and quasi‐Newton algorithms and radial basis neural networks, are used for the development of river stage‐discharge relationships by constructing nonlinear relationships between stage and discharge. Daily stage and flow data from three stations, Yamula, Tuzkoy and Sogutluhan, on the Kizilirmak River in Turkey were used. Regression techniques are also applied to the same data. Different input combinations including the previous stages and discharges are used. The models' results are compared using three criteria, i. e., root mean square errors, mean absolute error and the determination coefficient. The results of the comparison reveal that the neural network techniques are much more suitable for setting up stage‐discharge relationships than the regression techniques. Among the neural network methods, the radial basis neural network is found to be slightly better than the others.
Analysis of Diffusion and Adsorption of Volatile Organic Compounds in Zeolites by a Single Pellet Moment Technique
Authors: Akosman Cevdet , Kalender Mehmet 
Published: November 2008

AbstractThe diffusion and adsorption of two common volatile organic compounds, i. e., methanol and benzene, in different zeolite pellets were studied experimentally by using the single pellet moment technique. The experiments were conducted in a one‐sided single pellet adsorption cell at different temperatures in the range between 303 and 343 K. The results showed that both volatile organic tracers were adsorbed reversibly onto all zeolite samples. The overall adsorption equilibrium constants of both volatile organic compounds decreased with increasing temperature. The adsorption of the tracers onto the zeolite samples were found to increase in the order of NaY > clinoptilolite > 4A. In the range between 303 and 343 K, the adsorption constants of benzene range from 10.51 to 5.52 for zeolite 4A, from 11.90 to 6.37 for clinoptilolite and from 20.32 to 9.82 for NaY. The adsorption constants of methanol range from 19.05 to 8.26 for zeolite 4A, from 38.40 to 9.12 for clinoptilolite and from 74.21 to 14.70 for NaY at temperatures between 303 and 333 K. The effective diffusivities for benzene varied from 2.20·10–6 to 13.01·10–6 m2/s, whereas for methanol, they varied from 9.80·10–6 to 15.60·10–6 m2/s at the temperatures studied.
Water Quality Modeling and Dissolved Oxygen Balance in Streams: A Point Source Streeter‐Phelps Application in the Case of the Harsit Stream
Authors: Nas S. Serkan , Nas Evin 
Published: November 2008

AbstractThe Harsit Stream flowing into the Black Sea is an important watershed in the northeastern part of Turkey. The monthly averages of dissolved oxygen, carbonaceous biochemical oxygen demand, temperature, pH, total suspended solids, total phosphorus and total nitrogen were obtained for the water samples taken from the Tekke, Akcakale and Haciemin sites of the Harsit Stream. Water quality parameters were analyzed and evaluated according to the WHO standards and the Turkish Water Pollution Control Regulation. Initially, the variations in the dissolved oxygen profile were determined from dissolved oxygen, temperature and carbonaceous biochemical oxygen demand measurements by using the point source Streeter‐Phelps equation. Critical dissolved oxygen deficit values were calculated for the monthly average from January–December 2005, which are below the limit value (4 mg L–1) excluding April (7.26 mg L–1) and May (5.98 mg L–1) in the Harsit Stream, resulting in it having second class water quality in terms of dissolved oxygen concentration, temperature, pH and biochemical oxygen demand. It is also seen that the minimum dissolved oxygen limit value (8 mg L–1), which is a desired quantity for drinking water, is under the limit value for all months in the case of the water mixture. In particular, during the summer months, the consumption speed of oxygen is greater than the production speed of oxygen with increasing temperature and decreasing discharge, and negative values (anoxia) of dissolved oxygen sag are seen. These situations call for significant precautions and treatment criteria.
Removal and Recovery of Molybdenum from Aqueous Solutions by Adsorption onto Surfactant‐Modified Coir Pith, a Lignocellulosic Polymer
Authors: Namasivayam Chinnaiya , Sureshkumar Molagoundanpalayam Venkatachalam 
Published: November 2008

AbstractCoconut coir pith, a lignocellulosic polymer, is an unwanted by‐product of the coir fiber industry. The pith was used as a biosorbent for the removal of Molybdenum(VI) after modification with a cationic surfactant, hexadecyltrimethylammonium bromide. The optimum pH for maximum adsorption of Mo(VI) was found to be 3.0. Langmuir, Freundlich and Dubinin Radushkevich isotherms were used to model the adsorption equilibrium data and the system was seen to follow all three isotherms. The Langmuir adsorption capacity of the biosorbent was found to be 57.5 mg g–1. Kinetic studies showed that the adsorption generally obeyed a second‐order kinetic model. Desorption studies showed that the recovery of Mo(VI) from the spent adsorbent was feasible. The effect of foreign anions on the adsorption of Mo(VI) was also examined.
Polarized MT1‐MMP‐CD44 interaction and CD44 cleavage during cell retraction reveal an essential role for MT1‐MMP in CD44‐mediated invasion
Authors: Marrero‐Diaz Raquel , Bravo‐Cordero Jose J. , Megías Diego , García Maria A. , Bartolomé Ruben A. , Teixido Joaquin , Montoya María C. 
Published: November 2008

AbstractThe adhesion molecule CD44 and the membrane‐type matrix metalloproteinase MT1‐MMP act coordinately in tumor cells to promote cell invasion through a yet unclear mechanism. We are interested in studying the interplay between CD44 and MT1‐MMP in carcinoma cells embedded in HA containing three‐dimensional collagen I matrices (3D HA‐Col I) by time‐lapse confocal microscopy imaging. Here we report the in vivo interaction between CD44 and MT1‐MMP, revealed by fluorescence resonance energy transfer (FRET) microscopy. MT1‐MMP interacts with CD44 preferentially at the trailing edge of the invading tumor cells during rear retraction and on membrane fragments released during the invasion process. A fluorescent biosensor designed to monitor the proteolytic processing of CD44 by live cell imaging demonstrates that cleavage of the CD44 extracellular domain is enriched in the retracting rear ends of invasive tumor cells. Invasion assays showed that MT1‐MMP mediates CD44‐dependent tumor‐cell invasion, whereas CD44 is not essential for MT1‐MMP‐mediated invasion of 3D HA‐Col I matrices. Together, our results support a role for MT1‐MMP in cell retraction during CD44‐mediated cell invasion. Cell. Motil. Cytoskelton 2008. © 2008 Wiley‐Liss, Inc.
Landweber scheme for compact operator equation in Hilbert space and its applications
Authors: Qu Gangrong , Jiang Ming 
Published: November 2008

AbstractWe study the Landweber scheme for linear compact operator equation in infinite Hilbert spaces. Using the singular value decomposition for compact operators, we obtain a formula for the Landweber scheme after n iterations and iterative truncated error and consequently establish its convergence conditions. Our results extend known results on convergence conditions. As applications, we apply the Landweber scheme to the X‐ray tomography and extrapolation of band‐limited functions, and establish accelerated strategies for each application. Copyright © 2008 John Wiley & Sons, Ltd.
A method for fast simulation of multiple catastrophic faults in analogue circuits
Authors: Tadeusiewicz Michał , Hałgas Stanisław 
Published: November 2008

AbstractThe paper offers an efficient method for simulation of multiple catastrophic faults in linear AC circuits. The faulty elements are either open circuits or short circuits. The method exploits the well‐known Householder formula in matrix theory to find the node voltages deviations due to the perturbations of some circuit elements. The main achievement of the paper is a systematic method for performing the simulation of all combinations of the multiple catastrophic faults. The method includes two new procedures enabling us to find very efficiently the node impedance matrix of the nominal circuit and inverses of some matrices corresponding to different fault combinations. The procedures are the crucial point of this approach and make it very efficient. Consequently, the amount of the computing power needed to carry out all the simulations is significantly reduced. Numerical examples illustrating the proposed approach are provided. Copyright © 2008 John Wiley & Sons, Ltd.
Mouse hematopoietic stem cell identification and analysis
Authors: Challen Grant A. , Boles Nathan , Lin Kuan‐Yin K. , Goodell Margaret A. 
Published: November 2008

AbstractHematopoietic stem cells (HSCs) remain by far the most well‐characterized adult stem cell population both in terms of markers for purification and assays to assess functional potential. However, despite over 40 years of research, working with HSCs in the mouse remains difficult because of the relative abundance (or lack thereof) of these cells in the bone marrow. The frequency of HSCs in bone marrow is about 0.01% of total nucleated cells and ∼5,000 can be isolated from an individual mouse depending on the age, sex, and strain of mice as well as purification scheme utilized. This prohibits the study of processes in HSCs, which require large amounts of starting material. Adding to the challenge is the continual reporting of new markers for HSC purification, which makes it difficult for the uninitiated in the field to know which purification strategies yield the highest proportion of long‐term, multilineage HSCs. This report will review different hematopoietic stem and progenitor purification strategies and compare flow cytometry profiles for HSC sorting and analysis on different instruments. We will also discuss methods for rapid flow cytometric analysis of peripheral blood cell types, and novel strategies for working with rare cell populations such as HSCs in the analysis of cell cycle status by BrdU, Ki‐67, and Pyronin Y staining. The purpose of this review is to provide insight into some of the recent experimental and technical advances in mouse hematopoietic stem cell biology. © 2008 International Society for Advancement of Cytometry
Endogenous clock gene expression in the suprachiasmatic nuclei of previsual newborn rabbits is entrained by nursing
Authors: Caldelas Ivette , González Belén , Montúfar‐Chaveznava Rodrigo , Hudson Robyn 
Published: November 2008

AbstractThe rabbit is particularly suitable for investigating the development of mammalian circadian function. Blind at birth, the pups are only visited by the mother to be nursed once every 24 h for about 3 min and so can be studied largely without maternal interference. They anticipate the mother's visit with increased behavioral arousal and with a rise in body temperature, both of which represent endogenous circadian rhythms. We now report that in newborn pups the suprachiasmatic nuclei of the hypothalamus (SCN; the main circadian pacemaker in mammals) show endogenous 24‐h rhythmicity in the expression of the clock genes Per1, Per2, and Bmal1. Pups nursed from postnatal days 1 to 7 and fasted to day 9 showed the same rhythms of clock gene expression as normally nursed controls. We also report that these rhythms are entrained by nursing. Pups killed on postnatal days 3–4 showed the same rhythms in gene expression as pups in the previous experiment, whereas littermates subsequently nursed from postnatal days 4 to 7 with nursing delayed 6 h showed a corresponding shift in the diurnal pattern of clock gene expression. Consistent with this, two groups of pups implanted with telemetric thermal sensors and nursed 6 h apart had daily patterns in body temperature synchronized with the two different nursing times. We conclude that the expression of clock genes associated with the newborn rabbit's circadian system is entrained by nonphotic cues accompanying nursing, the exact nature of which now needs to be clarified. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2009
Genetic signature for human risk assessment: Lessons from trichloroethylene
Authors: Shiao Yih‐Horng 
Published: November 2008

AbstractTrichloroethylene (TCE), an organic solvent commonly used for metal degreasing and as a chemical additive, is a significant environmental contaminant that poses health concerns in humans. The US Environmental Protection Agency (EPA) is currently revising the 2001 TCE human risk assessment draft. The next draft is expected to be ready in 2008. TCE metabolites are detectable in humans and carry varying potencies for induction of cancers in animals. Genomic mechanisms have been explored in animals and humans to link TCE to carcinogenesis. DNA analysis provides an opportunity for detection of unique genetic alterations representing a signature of TCE exposure. These alterations can arise from genotoxic and nongenotoxic pathways at multiple points throughout tumorigenesis. Although fixation of alterations may require several stages of selection and modification, the spectra can be specific to TCE. Only a fraction of these alterations eventually lead to tumor formation and some contribute to tumor progression. Genetic events in two major TCE target organs are reviewed, including the VHL gene in kidney, and the Ras gene and genome‐wide hypomethylation in liver. Attempts to identify a genetic signature of TCE exposure are challenged by inconsistent findings, lack of evidence of promutagenic lesions, biological relevance of specific genomic changes, and likelihood of coexposures. For human risk assessment, genome‐wide screening is useful and is possible with the development of new DNA‐sequencing technologies. Genetic screening for preneoplastic and tumor tissues from high‐risk population is proposed to exclude the noise of passenger mutations and genetic polymorphisms. Environ. Mol. Mutagen., 2009. Published 2008 Wiley‐Liss, Inc.