bluuebunny/crossref_metadata_2025 huggingface dataset:
SDSS data management and photometric quality assessment
Authors: Ivezić Ž. , Lupton R. H. , Schlegel D. , Boroski B. , Adelman‐McCarthy J. , Yanny B. , Kent S. , Stoughton C. , Finkbeiner D. , Padmanabhan N. , Rockosi C. M. , Gunn J. E. , Knapp G. R. , Strauss M. A. , Richards G. T. , Eisenstein D. , Nicinski T. , Kleinman S. J. , Krzesinski J. , Newman P. R. , Snedden S. , Thakar A. R. , Szalay A. , Munn J. A. , Smith J. A. , Tucker D. , Lee B. C.
Published: October 2004

We summarize the Sloan Digital Sky Survey data acquisition and processing steps, and describerunQA, a pipeline designed for automated data quality assessment. In particular, we show how the position of the stellar locus in color‐color diagrams can be used to estimate the accuracy of photometric zeropoint calibration to better than 0.01 mag in 0.03 deg2patches. Using this method, we estimate that typical photometric zeropoint calibration errors for SDSS imaging data are not larger than ∼0.01 mag in theg,r, andibands, 0.02 mag in thezband, and 0.03 mag in theuband (root‐mean‐scatter for zeropoint offsets). (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Automatic data reduction and archiving for STELLA
Authors: Weber M.
Published: October 2004

The data is collected at the observatory, each data product is registered and a queue is set up to transfer the highest priority observations first. Optionally, lossy compression (e.g. White 1994) can be used to boost transfer speeds for time critical observations. Once the data has been transferred, the reduction process is started at the control‐center in Potsdam. The type of reduction steps required can be specified by the user or a default pipeline setup can be used. The users can be notified about the status of their observations in any desired detail. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
nightskylive.net: The Night Sky Live project
Authors: Pérez‐Ramírez D. , Nemiroff R. J. , Rafert J. B.
Published: October 2004

The Night Sky Live project's main goal is to create a useful continuous record of the night sky. In its current implementation, it is essentially a passive observatory, designed to work autonomously. It sees from horizon to horizon and does not track the sky. A continuous camera mates a Fisheye lens to a CCD camera under the control of a laptop computer. These components are housed in a case similar in size to a large briefcase. This observatory is designed to be bolted to a rooftop and connected to power and Ethernet, and is programmed remotely over the Internet. In addition to information about weather and seeing conditions, there are many scientific objectives established by the Night Sky Live project. The data is considered public domain immediately upon recording. Currently, these cameras are allocated at major professional observatories all over the World. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Design of the Pan‐STARRS telescopes
Authors: Hodapp K. W. , Kaiser N. , Aussel H. , Burgett W. , Chambers K. C. , Chun M. , Dombeck T. , Douglas A. , Hafner D. , Heasley J. , Hoblitt J. , Hude C. , Isani S. , Jedicke R. , Jewitt D. , Laux U. , Luppino G. A. , Lupton R. , Maberry M. , Magnier E. , Mannery E. , Monet D. , Morgan J. , Onaka P. , Price P. , Ryan A. , Siegmund W. , Szapudi I. , Tonry J. , Wainscoat R. , Waterson M.
Published: October 2004

Pan‐STARRS, the Panoramic Survey Telescope and Rapid Response System, is a project by the Institute for Astronomy, University of Hawaii, to first develop a single wide field synoptic survey telescope (Pan‐STARRS‐1) followed by a system of four such telescopes. It is designed to accomplish many of the science goals envisioned by the Decadal Review for the Large Synoptic Survey Telescope (LSST). The primary mission of Pan‐STARRS is the detection of potentially hazardous asteroids (PHA), secondary science objectives are a (nearly) all‐sky survey, a medium‐deep survey, an ultra‐deep survey, and studies of transients and variable objects. This paper presents the current status of the telescope system design, with emphasis on the optics. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectroscopic orbits of potential interferometric binaries
Authors: Fekel F. C. , Tomkin J.
Published: October 2004

We are obtaining high‐resolution, red‐wavelength spectra at McDonald and Kitt Peak National Observatory to improve the orbits of known spectroscopic binaries that are potential targets for ground‐based optical interferometers. The combination of such observations will produce three‐dimensional orbits from which very accurate masses and orbital parallaxes can be obtained for double‐lined systems. This spectroscopic program will be expanded and placed on the menu of the 2 meter Automatic Spectroscopic Telescope of Tennessee State University once it commences routine operation. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Blazar variability studies with the 1.3 m Robotically Controlled Telescope and the automated 0.6 m Bell Observatory telescope
Authors: Carini M. T. , Barnaby D. , Mattox J. R. , Walters R. , Poteet C. , Wills W. , Gelderman R. , Davis D. , Everett M. , Guinan E. , Howell S. , McGruder C. H.
Published: October 2004

One of the key programs on the 1.3 m Robotically Controlled Telescope (RCT) located at Kitt Peak National Observatory and the 0.6 m telescope at the Bell Observatory operated by Western Kentucky University is a study of the variability of the class of Active Galactic Nuclei (AGN) known as Blazars. Blazars are highly variable on timescales of minutes to decades and this variability is seen across the electromagnetic spectrum. In addition, they display a featureless spectrum, thus continuum variability provides the only diagnostic of these objects. Variability provides information on the size of the emission region responsible for the observed variations and when observations are obtained at multiple wavelengths, it can be used to discriminate between emission models. However, traditional ground based observations are limited in a variety of ways. We will discuss how an automated facility, with time dedicated to this astrophysically interesting problem, can overcome many of these limitations, and we show results from the Bell Observatory as well as some of the first results of Blazar observations from the RCT. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Meteorological monitoring system of TÜBİTAK National Observatory
Authors: Koçak M. , Selam S. O. , Keskin V.
Published: October 2004

A custom meteorological monitoring system was constructed to reliably monitor the meteorological parameters of the site of TÜBİTAK National Observatory (TÜBİTAK: The Scientific and Technical Research Council of Turkey). The site is located on a mountain top known as Bakįrlįtepe about 50 km west of the Antalya City at a height of 2547 m. The system has software (C‐based data acquisition/archiving structure and PHP based WEB monitoring support) and micro‐controller based control electronics, fiber based custom designed encoder sensors (for wind speed and direction) and transmission lines using fiberoptic to RS232 transcievers. The constructed system can be used in any robotic telescope project for data monitoring and alert system creation. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A 2‐m robotic telescope project
Authors: Geyl R. , Gashut H.
Published: October 2004

This paper reports a recently started project for a 2‐m diameter robotic telescope dedicated to astronomy and education. After a brief recall of SAGAM‐REOSC background in this domain, the project will be presented with more details on the telescope optics, mount and control system, the dome, the coating chamber and the weather station. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐performance liquid chromatographic method for simultaneous determination of sophoridine and matrine in rat plasma
Authors: Li Yumin , Min Guangtao , Xue Qunji , Chen Liren , Liu Weimin , Chen Hao
Published: October 2004

A high‐performance liquid chromatographic (HPLC) method is described for the simultaneous determination of sophoridine and matrine in rat plasma. Sophoridine and matrine in the resulting supernatant of the plasma deproteinized with acetonitrile containing an internal standard (acetanilide) were directly determined by reversed‐phase HPLC and ultraviolet detection. The result of limits of quantitation for matrine and sophoridine were 200 and 350 ng/mL in plasma, respectively, and recovery of both analytes was greater than 98%. The assay was linear from 250 to 4000 ng/mL for matrine and from 500 to 8000 ng/mL for sophoridine. Variation over the range of the standard curve was less than 15%. The method was used to determine the concentration–time proﬁles of matrine and sophoridine in the plasma following oral administration of Kexieling tablets, which is one of the preparations of Kudouzi at a dose equivalent to 30 and 60 mg/kg of matrine and sophoridine, respectively. Copyright © 2004 John Wiley & Sons, Ltd.
Imaging the Selective Binding of Synapsin to Anionic Membrane Domains
Authors: Murray Jill , Cuccia Louis , Ianoul Anatoli , Cheetham James J. , Johnston Linda J.
Published: October 2004

Synapsins are membrane‐associated proteins that cover the surface of synaptic vesicles and are responsible for maintaining a pool of neurotransmitter‐loaded vesicles for use during neuronal activity. We have used atomic force microscopy (AFM) to study the interaction of synapsin I with negatively charged lipid domains in phase‐separated supported lipid bilayers prepared from mixtures of phosphatidylcholines (PCs) and phosphatidylserines (PSs). The results indicate a mixture of electrostatic binding to anionic PS‐rich domains as well as some nonspecific binding to the PC phase. Interestingly, both protein binding and scanning with synapsin‐coated AFM tips can be used to visualize charged lipid domains that cannot be detected by topography alone.
Identification and Biosynthesis of an Aggregation Pheromone of the Storage Mite Chortoglyphus arcuatus
Authors: Schulz Stefan , Fuhlendorff Jens , Steidle Johannes L. M. , Collatz Jana , Franz Jörg‐Thomas
Published: October 2004

In an effort to identify new pheromones from mites, the headspace of undisturbed colonies of the storage mite Chortoglyphus arcuatus was analyzed by GC‐MS by use of a closed‐loop stripping apparatus (CLSA) or solid‐phase microextraction (SPME). The major compound emitted from the mites is (4R,6R,8R)‐4,6,8‐trimethyldecan‐2‐one (4R,6R,8R‐8). The structure was elucidated by analysis of the mass spectrum, synthesis of authentic samples, and gas chromatography on a chiral phase. Bioassays show that this compound, for which we propose the trivial name chortolure, is an aggregation pheromone for both sexes of this species. Several related compounds are released in smaller amounts by the mites. The alarm pheromones of these mites, neral and geranial, can only be found in total extracts of the mites, in which 8 occurs only in minute amounts. The method of sampling is therefore crucial for pheromone identification. Feeding experiments with deuterated propionate showed that chortolure is a polyketide, formed by successive addition of four propionate units to an acetate starter.
Synthesis and Degradation of Nucleobases and Nucleic Acids by Formamide in the Presence of Montmorillonites
Authors: Saladino Raffaele , Crestini Claudia , Ciambecchini Umberto , Ciciriello Fabiana , Costanzo Giovanna , Di Mauro Ernesto
Published: October 2004

We describe the role of formamide, a product of the hydrolysis of hydrogen cyanide, as precursor of several components of nucleic acids under prebiotic conditions. When formamide is heated in the presence of montmorillonites, the efficient one‐pot synthesis of purine, adenine, cytosine, and uracil is obtained. Along with these nucleobases, several components of the inosine pathway are obtained: 5‐aminoimidazole‐4‐carboxamide, 5‐formamidoimidazole‐4‐carboxamide and hypoxanthine. This almost complete catalogue of nucleic acid precursors is accompanied by N9‐formylpurine, which, containing a masked glycosidic bond in its formyl moiety, is a plausible precursor of purine acyclonucleosides. In addition, montmorillonites differentially affect the rate of degradation of nucleobases when embedded in 2′‐deoxyoligonucleotides; namely, montmorillonites protect adenine and guanine from the degradative action of formamide, while thymine degradation is enhanced. The oligonucleotide backbone reactivity to formamide is also affected; this shows that the interaction with montmorillonites modifies the rate of abstraction of the Hα and Hβ protons on the sugar moieties.
NMR Backbone Assignment of a Protein Kinase Catalytic Domain by a Combination of Several Approaches: Application to the Catalytic Subunit of cAMP‐Dependent Protein Kinase
Authors: Langer Thomas , Vogtherr Martin , Elshorst Bettina , Betz Marco , Schieborr Ulrich , Saxena Krishna , Schwalbe Harald
Published: October 2004

Protein phosphorylation is one of the most important mechanisms used for intracellular regulation in eukaryotic cells. Currently, one of the best‐characterized protein kinases is the catalytic subunit of cAMP‐dependent protein kinase or protein kinase A (PKA). PKA has the typical bilobular structure of kinases, with the active site consisting of a cleft between the two structural lobes. For full kinase activity, the catalytic subunit has to be phosphorylated. The catalytic subunit of PKA has two main phosphorylation sites: Thr197 and Ser338. Binding of ATP or inhibitors to the ATP site induces large structural changes. Here we describe the partial backbone assignment of the PKA catalytic domain by NMR spectroscopy, which represents the first NMR assignment of any protein kinase catalytic domain. Backbone resonance assignment for the 42 kDa protein was accomplished by an approach employing 1) triply (2H,13C,15N) labeled protein and classical NMR assignment experiments, 2) back‐calculation of chemical shifts from known X‐ray structures, 3) use of paramagnetic adenosine derivatives as spin‐labels, and 4) selective amino acid labeling. Interpretation of chemical‐shift perturbations allowed mapping of the interaction surface with the protein kinase inhibitor H7. Furthermore, structural conformational changes were observed by comparison of backbone amide shifts obtained by 2D 1H,15N TROSY of an inactive Thr197Ala mutant with the wild‐type enzyme.
Some Novel Binuclear Group 13 Metal Tin Hydrides Formed in Ar Matrices Following the Codeposition of the Metal Vapor with SnH4
Authors: Gaertner Benjamin , Himmel Hans‐Jörg , Macrae Victoria A. , Pardoe Jennifer A. J. , Randall Paul G. , Downs Anthony J.
Published: October 2004

IR measurements show that co‐condensation of Al or Ga atoms (M) with SnH4in a solid Ar matrix at about 12 K results mainly in the spontaneous insertion of the metal into an SnH bond to form the MIIhydride HMSnH3. Simultaneously the Ga2dimer also reacts with SnH4, possibly to form anido‐type cluster Ga2(μ‐H)4Sn, with a metal‐deficient cubane‐like structure. All of these products are photolabile. Irradiation with visible light causes HMSnH3to tautomerize to the novel dihydrido‐bridged species H2M(μ‐H)2Sn, which decomposes in turn under broad‐band UV‐visible light (λ=200–800 nm); some H2Al(μ‐H)2Sn is formed even on deposition. The data collected from experiments with SnH4and SnD4and different reagent concentrations, together with the results of quantum chemical calculations, are used to interpret the results and elucidate the structures and bonding of the new species.
Use of Different Unsaturated Dicarboxylates Toward the Design of New 3D and 2D Networks of Copper(II)
Authors: Mukherjee Partha Sarathi , Ghoshal Debajyoti , Zangrando Ennio , Mallah Talal , Chaudhuri Nirmalendu Ray
Published: October 2004

Two new polymeric complexes of copper(II), [Cu(L1)(μ‐fum)(μ‐H2O)]n (1) (fum = fumarate dianion; L1 = N,N′‐dimethylethane‐1,2‐diamine) and [Cu(L2)(μ‐tp)]n (2) [tp = terephthalate dianion; L2 = N‐(2‐aminoethyl)‐3‐amino‐1‐propanol], have been synthesized. The molecular structures are determined by X‐ray crystallography. Complex 1 is a fumarato‐bridged zig‐zag 1D chain of CuII−L1, which is extended to a 3D coordination polymer through bridging water molecules. Complex 2 is a chain of CuII in which the terephthalate anions bridge in alternate bis(bidentate) and bis(monodentate) fashions. The coexistence of such types of bridging modes of terephthalate ions in a single molecule is unprecedented. The chelating terephthalate ion is linked to an equatorial and an axial site of consecutive metal ions, while the other terephthalate ion is axially linked to CuII centers. Both the complexes are characterized by variable‐temperature susceptibility measurements at room temperature down to 4 K. Fitting of the magnetic data reveals the existence of weak antiferromagnetic interactions through the bridging dicarboxylate pathways. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Coordination Chemistry of Large Diphosphanes − Directional Properties of a Calix[4]arene Proximally Substituted by Two −OCH2PPh2 Podand Arms
Authors: Kuhn Pierre , Jeunesse Catherine , Sémeril David , Matt Dominique , Lutz Pierre , Welter Richard
Published: October 2004

The proximally‐functionalised calixarene 5,11,17,23‐tetra‐tert‐butyl‐25,26‐bis(diphenylphosphanylmethoxy)‐27,28‐dihydroxycalix[4]arene (1), a large diphosphane in which the PIII centres are separated by 10 bonds, behaves as a chelating ligand towards NiX2 moieties (X = Cl, Br). As shown by three X‐ray studies carried out on complexes of the type [NiX2·1], the diphosphane is able to accommodate either tetrahedral or strongly distorted tetrahedral coordination geometries, but not a square planar one. In all structures, the ligand positions the nickel atom away from the calixarene axis. In the presence of methylaluminoxane (MAO), [NiCl2·1] effectively catalyses the oligomerisation of ethylene, affording C4−C12 oligomers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Lipase‐catalyzed acidolysis and phospholipase D‐catalyzed transphosphatidylation of phosphocholine
Authors: Wongsakul Sirirung , Bornscheuer Uwe T. , H‐Kittikun Aran
Published: October 2004

Two approaches on enzymatic phospholipid modification were studied: (1) transphosphatidylation of the 1,2‐dilauroyl‐sn‐glycero‐3‐phosphocholine (DLPC) and ethanolamine in biphasic and anhydrous organic solvent systems by phospholipase D (PLD) and (2) incorporation of oleic acid into the sn1‐position of DLPC in organic solvents with different immobilized lipases at controlled water activity. First, DLPC was chemically synthesized from glycerophosphocholine and lauric acid. Next, PLD‐catalyzed head group exchange of DLPC with ethanolamine was studied using an enzyme from Streptomyces antibioticus expressed recombinantly in E. coli. A comparison of the free PLD with the biocatalyst activated by a salt‐activation technique using KCl showed that the salt‐activated enzyme (PLD‐KCl) was 10–12 folds more active based on the amount of protein used. Thus, DLPC was quantitatively converted to 1,2‐dilauroyl‐sn‐glycero‐3‐phosphoethanolamine in an anhydrous solvent system within 12 h at 60 °C. For the acidolysis of DLPC with oleic acid, among the four lipases studied (CAL‐B, Lipozyme TL IM, Lipozyme RM IM and lipase D immobilized on Accurel EP‐100), Lipozyme TL IM showed the highest activity and incorporation of oleic acid. A quantitative incorporation was achieved at 40 °C using a 8‐fold molar excess of oleic acid in n‐hexane at a water activity of 0.11.
Recent Advances inCinchonaAlkaloid Chemistry
Authors: Hoffmann H. Martin R. , Frackenpohl Jens
Published: October 2004

Quinine has been among the best known alkaloids for over 300 years, thanks to its antimalarial activity. In the last two decades,Cinchonaalkaloids have emerged as powerful chiral auxiliaries, resulting in some well known landmark developments in asymmetric synthesis, but more recently these alkaloidsthemselveshave been shown to undergo some remarkable transformations and skeletal shifts that are rapidly widening perspectives in the chemistry ofCinchonabases, embracing both basic and applied science. The alkaloids enter into a series of fundamental transformations that have given rise to the industrial manufacture of a host of new enantiopure materials showing promise for asymmetric syntheses and combinatorial chemistry. Stereochemical diversity, well developed conformational minima not encountered in conventional organic substrates, hydrophilic pockets and stereoelectronics contribute subtle mechanistic features and structural complexity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
β‐Lactam‐Containing Cyclopeptide Analogs
Authors: Maier Thomas C. , Podlech Joachim
Published: October 2004

Cyclic peptide analogs containing a β‐lactam moiety were prepared. Reacting Fmoc‐protected amino acid‐derived diazo ketones 1, 2 with benzylidene‐protected amino esters 3, 4 in a photochemically induced Staudinger‐type reaction, trans‐substituted β‐lactams 5a/b and 6a/b were formed in 35−70% yield (dr 60:40−70:30). N‐Terminal chain elongation to the respective acyclic precursors 14, 17a/b and 19a/b was achieved using conventional peptide synthesis (i.e. the pentafluorophenyl ester protocol). After saponification, activation as pentafluorophenyl esters and subsequent cleavage of the N‐terminal Boc‐protecting group, the pre‐strained (3R,4S)‐configured isomers could be cyclized without the need for high dilution or prolonged reaction times. Contrary to this, the (3S,4R)‐configured isomers did not cyclize but gave polymeric material. The conformational stability of the cyclic peptidomimetics 16, 20, and 21 which were obtained in high yield, was elucidated by means of NMR spectroscopy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Donor‐Substituted Heptaazaphenalene as a Nonlinear Optically Active Molecule with Multiple Charge‐Transfer Transitions
Authors: Traber Boris , Oeser Thomas , Gleiter Rolf , Goebel Mark , Wortmann Rüdiger
Published: October 2004

The synthesis of a novel nonlinear optical (NLO) chromophore with threefold symmetry − 2,5,8‐tris(diethylamino)‐1,3,4,6,7,9,9b‐heptaazaphenalene (4) − is reported. Compound 4 was synthesized from 2,5,8‐trichloro‐1,3,4,6,7,9,9b‐heptaazaphenalene (3) through a nucleophilic aromatic substitution, its structural assignment was confirmed by X‐ray investigations, and its second‐order polarisability (β) was determined by hyper Rayleigh scattering (HRS). Compound 4 shows a very high absorbance coefficient in the UV and a remarkably large β value despite its short‐wavelength absorption. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of (ϵ‐13C‐,ϵ‐15N)‐Enriched L‐Lysine − Establishing Schemes for the Preparation of All Possible 13C and 15N Isotopomers of L‐Lysine, L‐Ornithine, and L‐Proline
Authors: Siebum Arjan H. G. , Tsang Robert K. F. , Steen Rob van der , Raap Jan , Lugtenburg Johan
Published: October 2004

In this paper we describe a simple synthetic strategy that, with the right rational adaptation, gives direct access to any 13C/15N isotopomer of L‐glutamate, L‐ornithine, L‐proline, L‐lysine, and L‐α amino adipic acid. This strategy also allows access to nonproteinogenic amino acids like L‐citrulline in high yields and optical purity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis and Rearrangement of N‐Organyloxy β‐Lactams Derived from a (4+2)/(3+2) Sequential Cycloaddition Reaction Involving Enol Ethers and Nitro Alkenes
Authors: van Berkom Leon W. A. , Kuster George J. T. , de Gelder René , Scheeren Hans W.
Published: October 2004

The synthesis of N‐organyloxy β‐lactams 2 by treatment of nitroso acetals 1 with a base is discussed. Based on the formation of a by‐product, a mechanism for the rearrangement to N‐organyloxy β‐lactams is proposed. This mechanism is supported by trapping of the intermediate acyl nitro compound 8 with dimethylamine. Furthermore, it was discovered that upon more forcing basic conditions these N‐organyloxy β‐lactams can rearrange further to 3‐organyloxy β‐lactams. By using a series of structurally diverse N‐organyloxy β‐lactams the generality of this novel rearrangement is demonstrated. A mechanism for the conversion of N‐organyloxy β‐lactams to 3‐organyloxy β‐lactams is proposed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
3(5)‐(2‐Hydroxyphenyl)‐5(3)‐styrylpyrazoles: Synthesis and Diels−Alder Transformations
Authors: Silva Vera L. M. , Silva Artur M. S. , Pinto Diana C. G. A. , Cavaleiro José A. S. , Elguero José
Published: October 2004

Reactions between cinnamoyl(2‐hydroxybenzoyl)methanes and hydrazine hydrate in acetic acid gave 3‐(2‐hydroxyphenyl)‐5‐styrylpyrazoles, while the corresponding reactions with phenylhydrazine yielded 5‐(2‐hydroxyphenyl)‐1‐phenyl‐3‐styrylpyrazoles as the major products and 3‐(2‐hydroxyphenyl)‐1‐phenyl‐5‐styrylpyrazoles as by‐products. The reaction mechanism of this transformation is discussed. The first cycloaddition reactions between ortho‐benzoquinodimethane and either 3‐(2‐hydroxyphenyl)‐5‐styrylpyrazoles or 5‐(2‐hydroxyphenyl)‐1‐phenyl‐3‐styrylpyrazoles afforded 5‐[2‐(3‐aryl‐1,2,3,4‐tetrahydronaphthyl)]‐3‐(2‐hydroxyphenyl)pyrazoles or 3‐[2‐(3‐aryl‐1,2,3,4‐tetrahydronaphthyl)]‐1‐phenyl‐5‐(2‐hydroxyphenyl)pyrazoles, respectively. These cycloadducts were converted into the corresponding naphthylpyrazoles by oxidation with DDQ in dry 1,4‐dioxane. The structures of all new derivatives have been established by NMR spectroscopy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of Novel Bifunctional Michael Acceptors
Authors: Mediavilla Urbaneja Laura , Krause Norbert
Published: October 2004

The conjugated dienones 1a, 1c−e, and 1g were synthesized by aldol reaction of cyclohex‐2‐enones 3 with aldehydes or ketones and subsequent elimination. Whereas the acetone adducts could be converted into the desired products 1a/g by treatment with CeCl3·7H2O/NaI, the dienones 1c−e were obtained by Appel bromination and dehydrobromination with triethylamine. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Facile Synthesis of Optically Active β‐Amino‐β‐arylethylphosphonates by Mitsunobu Reaction
Authors: Xu Chengfu , Yuan Chengye
Published: October 2004

We describe a convenient and simple synthesis of optically active β‐amino‐β‐arylethylphosphonates based on Mitsunobu reactions of chiral β‐aryl‐β‐hydroxyethylphosphonates, prepared in turn by Candida rugosa lipase catalyzed kinetic resolution of the corresponding racemates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of Methylene‐ and Methine‐Bridged Oligopyridines
Authors: Dyker Gerald , Muth Oliver
Published: October 2004

A variety of methylene‐ and methine‐bridged oligopyridines are conveniently accessible through stepwise nucleophilic aromatic substitution with fluoro‐substituted pyridines. The yields achieved are regularly above 90%. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Regio‐ and Stereoselective Stevens Rearrangement of Benzyltetrahydroprotoberberinium Salts
Authors: Valpuesta Maria , Diaz Amelia , Suau Rafael , Torres Gregorio
Published: October 2004

8‐(Arylmethyl)berbines are conveniently obtained through a Stevens rearrangement of the corresponding N‐arylmethylberbinium salts with sodium methylsulfinylmethylide in DMSO. This procedure has provided two new nonnatural 8‐benzylcanadines stereoselectively, without competition from the Hofmann elimination. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Metal 4‐Alkylidene‐4H‐pyridin‐1‐ides and 2H‐Imidazol‐4‐ones from Novel HighlyN‐(Pyridin‐4‐yl)methyl‐Substituted Azomethines
Authors: Hampe Diana , Günther Wolfgang , Görls Helmar , Anders Ernst
Published: October 2004

Novel azomethines3synthesized from 4‐(aminomethyl)pyridine (1) and various ketones2exhibit a higher acidity of the Cα‐protons compared with other 4‐alkylpyridines like 4‐benzylpyridine or 4‐(tosylmethyl)pyridine. Therefore, they can easily be metalated to give a variety of specific anions3(−), which deserve interest for further synthetic applications. Important properties of compounds3and their lithiated derivatives4(lithium 4H‐pyridin‐1‐ides, synthesized by deprotonation of the α‐CH2group in3) can be controlled by the carbonyl reactant2. These carbanions3(−)are remarkable intermediates regarding their NMR properties. Comparing the NMR spectra of the lithium 4H‐pyridin‐1‐ides4with their parent azomethines3reveal very distinct changes in the chemical shifts from which important structural and electronic properties of the carbanions can be deduced. The observation ofE/Zisomers in the case of3cand their mutual conversion at higher temperature inspire DFT calculations on the B3LYP/6‐311++G(d,p) level of theory to get insight into the energetic demand of such isomerization processes. Moreover, calculations on the same level of theory were carried out on the model azomethine anion5and different monomeric lithium coordination isomers6a−d. Experimentally, two selected examples will exemplify the reactivity of 4H‐pyridin‐1‐ide anions towards heterocumulenes. The 2‐(pyridin‐4‐yl)acetate7obtained from the reaction of4ewith carbon dioxide appears to be a CO2storage molecule as it easily releases CO2under protolysis conditions comparable with the vitamin B6reaction mode. Interesting five‐membered heterocycles were isolated after reaction of4with isocyanates followed by hydrolysis and oxidation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Conformational Analysis of Axially Substituted 4,4′‐Bi‐1,3‐dioxanyls
Authors: Brandl Trixi , Hoffmann Reinhard W.
Published: October 2004

In contrast to the simple 4,4′‐bi‐1,3‐dioxanyl derivative 6, which has no conformational preference at the inter‐ring bond, the derivatives 9 and 10, which have two strategically placed axial methyl groups, show conformational preferences exceeding 95 %. This is related to the conformational preference found in one of the substructures of the natural product prymnesin. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Cover Picture: Recent Advances in Cinchona Alkaloid Chemistry (Eur. J. Org. Chem. 21/2004)
Authors: Hoffmann H. Martin R. , Frackenpohl Jens
Published: October 2004

The cover picture shows the pair of quinidine and quinine, two pseudo‐enantiomeric alkaloids from the bark of the Cinchona tree which is cultivated in tropical parts of Africa. A view over African medicinal trees in Kirstenbosch Botanical Gardens, situated on the eastern slopes of Table Mountain (Cape Town, South Africa; picture taken by I. Schmelzer), is used as a backdrop. Also shown are selected new products of novel key transformations which are discussed in the Microreview by H. M. R. Hoffmann and J. Frackenpohl on p. 4293 ff. These alkaloids are a valuable resource for the discovery and invention of new chemistry, embracing both basic and applied science.
Fibroblast adhesion to micro‐ and nano‐heterogeneous topography using diblock copolymers and homopolymers
Authors: Tsai Irene Y. , Kimura Masahiro , Stockton Rebecca , Green J. Angelo , Puig Ricardo , Jacobson Bruce , Russell Thomas P.
Published: October 2004

Polymeric substrates of different surface chemistry and length scales were found to have profound influence on cell adhesion. The adhesion of fibroblasts on surfaces of oxidized polystyrene (PS), on surfaces modified with random copolymers of PS and poly(methyl methacrylate) [P(S‐r‐MMA)] with topographic features, and chemically patterned surfaces that varied in lateral length scales from nanometers to microns were studied. Surfaces with heterogeneous topographies were generated from thin film mixtures of a block copolymer, PS‐b‐MMA, with homopolymers of PS and PMMA. The two homopolymers macroscopically phase separated and, with the addition of diblock copolymer, the size scales of the phases decreased to nanometer dimensions. Cell spreading area analysis showed that a thin film of oxidized PS surface promoted adhesion whereas a thin film of P(S‐r‐MMA) surface did not. Fibroblast adhesion was examined on surfaces in which the lateral length scale varied from 60 nm to 6 μm. It was found that, as the lateral length scale between the oxidized PS surfaces decreased, cell spreading area and degree of actin stress fiber formation increased. In addition, scanning electron microscopy was used to evaluate the location of filopodia and lamellipodia. It was found that most of the filopodia and lamellipodia interacted with the oxidized PS surfaces. This can be attributed to both chemical and topographic surface interactions that prevent cells from interacting with the P(S‐r‐MMA) at the base of the topographic features. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 462–469, 2004
Prediction of physicochemical properties of organic molecules using van der Waals surface electrostatic potentials
Authors: Kim Chan Kyung , Lee Kyung A , Hyun Kwan Hoon , Park Heung Jin , Kwack In Young , Kim Chang Kon , Lee Hai Whang , Lee Bon‐Su
Published: October 2004

The generalized interaction properties function (GIPF) methodology developed by Politzer and coworkers, which calculated molecular surface electrostatic potential (MSESP) on a density envelope surface, was modified by calculating the MSESP on a much simpler van der Waals (vdW) surface of a molecule. In this work, vdW molecular surfaces were obtained from the fully optimized structures confirmed by frequency calculations at B3LYP/6‐31G(d) level of theory. Multiple linear regressions for normal boiling point, heats of vaporization, heats of sublimation, heats of fusion, liquid density, and solid density were performed using GIPF variables from vdW model surface. Results from our model are compared with those from Politzer and coworkers. The surface‐dependent β (and γ) values are dependent on the surface models but the surface‐independent α and regression coefficients (r) are constant when vdW surface and density surface with 0.001 a.u. contour value are compared. This interesting phenomenon is explained by linear dependencies of GIPF variables. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 2073–2079, 2004
Change in hepatitis C virus genotype in injecting drug users
Authors: Aitken Campbell , McCaw Rhonda , Jardine Darren , Bowden Scott , Higgs Peter , Nguyen Oanh , Crofts Nick , Hellard Margaret
Published: October 2004

Six major genotypes of the hepatitis C virus (HCV) have been described; it is assumed to be uncommon for genotypes to change in chronically infected individuals. Venous blood samples obtained from Vietnamese‐Australian injecting drug users who participated in successive studies conducted in Melbourne, Australia, were genotyped using the Bayer line probe assay and genotype confirmed by sequencing whenever possible. Three changes of HCV genotype were observed, and one infection in an individual not exposed previously. The rate of change of genotype was 3 in 11.4 person‐years (py), or 26.4 per 100 py (95% CI: 8.5, 81.6). Traditionally‐calculated HCV incidence was 1 in 4.3 py, or 23.3 per 100 py (95% CI: 3.3, 165.1). These data imply that HCV genotype change in injecting drug users occurs at least as frequently as infections in naïve individuals, and that traditionally‐calculated HCV incidence rates represent a minority of actual HCV transmission among practicing injecting drug users. J. Med. Virol. 74:543–545, 2004. © 2004 Wiley‐Liss, Inc.
Human endothelial cell activation and apoptosis induced by enterovirus 71 infection
Authors: Liang Chun‐Ching , Sun Mu‐Jie , Lei Huan‐Yao , Chen Shun‐Hua , Yu Chun‐Keung , Liu Ching‐Chuan , Wang Jen‐Reng , Yeh Trai‐Ming
Published: October 2004

Enterovirus 71 (EV71), a neurotropic virus, its infection is transmitted mainly by the oral–fecal route. However, it is unclear how EV71 is disseminated/spread from initial replication sites to the central nervous system. Since endothelial cells form the interface between blood and tissues throughout the body, it is likely that EV71 can infect and then exit endothelial cells to establish infection. In this study, human endothelial cells were examined for susceptibility to EV71 infection using human microvascular endothelial cell line (HMEC‐1 cell). Immunofluorescence assay confirmed EV71 infection of HMEC‐1. Viable viruses were cultured from both the culture supernatant and the cell lysate. Live but not UV‐inactivated EV71 induced HMEC‐1 to secrete IL‐6, macrophage migration inhibition factor, and macrophage chemo‐attractant protein 1, and to express toll‐like receptor 4. In addition, EV71 decreased the viability and increased the apoptosis of HMEC‐1 cells after 36–48 hr of infection. These results demonstrate that EV71 is able to infect, activate, and induce apoptosis of endothelial cells, which may play a role in the pathogenesis of EV71 infection. J. Med. Virol. 74:597–603, 2004. © 2004 Wiley‐Liss, Inc.
Improved diagnosis on a daily basis of enterovirus meningitis using a one‐step real‐time RT‐PCR assay
Authors: Archimbaud Christine , Mirand Audrey , Chambon Martine , Regagnon Christel , Bailly Jean‐Luc , Peigue‐Lafeuille Hélène , Henquell Cécile
Published: October 2004

The detection of the enterovirus genome in cerebrospinal fluid (CSF) by PCR techniques has proved to be more sensitive than traditional cell culture for the diagnosis of enterovirus meningitis. However, PCR assays are time consuming and labor intensive, particularly if separate hybridization steps are used to confirm the specificity of positive findings. The aim of this study was to develop a one‐step real‐time RT‐PCR assay with LightCycler (LC) technology that was sensitive, rapid, and easy to perform in routine practice. The enterovirus detection limit was determined by testing 10‐fold limiting dilution series of cell culture stocks with the echovirus 25 (E‐25) prototype strain and with the third European Union Quality Control Concerted Action (EU‐QCCA) enterovirus proficiency panel. A total of 100 CSF specimens were investigated in a comparative study. With the E‐25 strain, the detection limit of the real‐time assay was 286 TCID50/ml (50% tissue culture infective dose). When samples of the EU‐QCCA panel were tested, our assay gave identical results (detection limit down to 3.6 TCID50/ml) to those of the reference laboratory, which used one‐step RT‐PCR assay. When CSF specimens were tested, there was a correlation between the real‐time assay and the conventional in‐house assay in 96 of 100 CSFs tested. This one‐step real‐time assay allows rapid enterovirus detection in CSF since results are obtained in 3 hr as against 36 hr with the “in‐house” RT‐PCR assay. This new assay is now being used in routine practice, and allows diagnosis on a daily basis. J. Med. Virol. 74:604–611, 2004. © 2004 Wiley‐Liss, Inc.
Sensitive and specific detection of strains of Japanese encephalitis virus using a one‐step TaqMan RT‐PCR technique
Authors: Huang Jau‐Ling , Lin Hui‐Tsu , Wang Yu‐Ming , Weng Ming‐Hui , Ji Da‐Der , Kuo Ming‐Der , Liu Huan‐Wun , Lin Chang‐Shen
Published: October 2004

A rapid, sensitive, and accurate laboratory diagnostic test is needed for distinguishing Japanese encephalitis virus (JEV) from other diseases featuring similar clinical symptoms and also for preventing potential outbreaks. In this study, a TaqMan reverse transcription (RT)‐polymerase chain reaction (PCR) assay was developed for rapid detection and quantification of the viral RNA of various JEV strains. A consensus JEV NS3 region was chosen to design the primers and the TaqMan probe. The JEV TaqMan assay used the EZ‐rTtH RT‐PCR system featuring advantages such as a one‐step, high‐temperature RT reaction modality and preventing carry‐over contamination. The sensitivity of the JEV TaqMan assay for detecting in vitro‐transcribed JEV NS3 RNA was estimated to be one to five copies of RNA per reaction. For cultured JE virions, less than 40 plaque forming unit (PFU)/ml of virus load (corresponding to 0.07 PFU/test) could be detected. In addition, the JEV TaqMan assay could detect all seven strains of JEV tested, but provided negative results for nine other flaviviruses and encephalitis viruses tested. The JEV TaqMan assay demonstrated greater sensitivity and specificity than traditional RT‐PCR methods as has been previously reported. The application of the JEV TaqMan assay herein has been shown to the sensitive detection of the JEV from both mosquito pools and also JEV‐spiking human blood. The assay should be of use in diagnostic laboratory conduct and could be used to replace or complement time‐consuming viral‐culture methods, thus achieving more rapid, sensitive, and highly specific identification of JEV infection. J. Med. Virol. 74:589–596, 2004. © 2004 Wiley‐Liss, Inc.
Quantitation of Epstein–Barr virus mRNA using reverse transcription and real‐time PCR
Authors: Weinberger Birgit , Plentz Annelie , Weinberger Klaus M. , Hahn Joachim , Holler Ernst , Jilg Wolfgang
Published: October 2004

Monitoring of Epstein–Barr virus (EBV) infection and reactivation in immunocompromized patients (e.g., after organ or bone‐marrow transplantation) is based mainly on serological assays and detection of viral DNA. For further characterization of virus reactivation and monitoring of viral transcription we established real‐time RT‐PCR assays using TaqMan technology to sensitively quantify viral transcripts expressed at different times of the lytic cycle: for BZLF1, an immediate early transactivator initiating the transition from latency to lytic replication, for the DNA‐polymerase BALF5 and for the major viral glycoprotein gp350/220 (BLLF1). RNA‐isolation was optimized to eliminate contaminating DNA. Preparations were shown to be virtually DNA‐free for up to 106 copies of RNA. With our PCR systems, it is possible to detect 10 copies of DNA or 100 copies of RNA per reaction as shown with serial dilutions of DNA‐plasmids or in vitro transcribed RNA, respectively. This corresponds to a detection limit of 8 × 102 copies/106 peripheral blood mononuclear cells (PBMCs). Evaluation of this system showed that even in healthy carriers borderline levels of BLLF1 mRNA were sometimes detectable. In patients with acute infectious mononucleosis (IM) viral transcripts were regularly found in varying concentrations. Extremely high levels of all three mRNA species could be seen in a patient after bone‐marrow transplantation monitored during an episode of lymphoproliferation which regressed during treatment with acyclovir and transfusion of donor T‐cells. This sensitive and reproducible method to detect and quantify different transcripts of EBV can be used to closely monitor reactivation of EBV, e.g., in immunocompromized patients. J. Med. Virol. 74:612–618, 2004. © 2004 Wiley‐Liss, Inc.
Evidence of rotavirus AU32 like G9 strains from nontypeable fecal specimens of Indian children hospitalized during 1993–1994
Authors: Awachat Pinki S. , Kelkar Shobhana D.
Published: October 2004

Serotyping of 432 rotavirus positive fecal specimens collected from hospitalized children during 1990–1997 was carried out at National Institute of Virology (NIV), Pune, India, using monoclonal antibodies (MAbs) directed against VP7 determinant of serotypes G1–G4, G6, G8, and G10. However, significant number of specimens, that is, 47.92% remained nontypeable. The aim of the present study was to culture adapt the nontypeable specimens and to characterize them further. Since the fecal specimens were not tested by MAb to G9 serotype, which has emerged as an important serotype infecting humans recently, presence of G9 serotype was expected in nontypeable specimens. Therefore, we selected specimens from those children, who showed higher neutralizing antibody (NAb) titer in their convalescent serum samples to G9 serotype than their mothers. Out of six isolates having long electropherotype, five isolates showed subgroup II, and one showed subgroup I, II. The isolates were confirmed as G9 by MAb based ELISA, neutralization assay, and PCR. The G9 specific nested PCR products of four isolates showed 96–99% identities to AU32 G9 strain reported from Japan. P type of four isolates was determined as P8. Besides isolates, four additional nontypeable fecal specimens were confirmed as G9 by MAb based ELISA. Thus, 10 (28.57%) out of 35 nontypeable specimens were identified as rotavirus serotype G9. The results indicate that serotype G9 may represent significant proportion of specimens, which were previously nontypeable. J. Med. Virol. 74:656–661, 2004. © 2004 Wiley‐Liss, Inc.
Current and voltage excitations for the eddy current model
Authors: Hiptmair R. , Sterz O.
Published: October 2004

We present a systematic study of how to take into account external excitation in the eddy current model. Emphasis is put on mathematically sound variational formulations and on lumped parameter excitation through prescribed currents and voltages. We distinguish between local excitation at known contacts, known generator current distributions and non‐local variants that rely on topological concepts. The latter case entails the violation of Faraday's law at so‐called cuts and prevents us from reconstructing a meaningful electric field. Copyright © 2004 John Wiley & Sons, Ltd.
Late Neolithic vegetation history at the pile‐dwelling site of Palù di Livenza (northeastern Italy
Authors: Pini Roberta
Published: October 2004

The Late Neolithic pile‐dwelling of Palù di Livenza yielded archaeological remains typical of the Square Mouth Pottery and Lagozza Cultures. A palynological investigation reveals important changes in the vegetation due to anthropogenic pressure. Between ca. 6590 and 5960 cal. yr BP, dense oak wood forests with deciduous Quercus, Fagus and Corylus extended around the mire, with no signs of human impact. The establishment of the pile‐dwelling, dated to ca. 5960 cal. yr BP, led to a strong reduction of forests, reclamation of wetlands, and expansion of herbaceous communities, with cultivated species, infestant weeds, nitrophilous and ruderal herbs, pastures and meadows. According to AMS dates and previous archaeological chronologies, the pile‐dwelling persisted for about 700 years (from ca. 5960 to 5260 cal. yr BP). The history of the pile‐dwelling after ca. 5260 cal. yr BP cannot be reconstructed because of recent contamination of the top part of the section. Rarefaction analysis was applied to estimate changes of palynological richness through time: the highest E(Tn) (between 56 and 69 taxa) are contemporaneous with the local development of the pile‐dwelling. The comparison of pollen data with archaeobotanical evidence indicates that Fragaria vesca, Malus sylvestris, Papaver somniferum and Physalis alkekengi were gathered at some distance from the site and that Linum usitatissimum is strongly under‐represented in pollen samples. Crop cultivation can be estimated for a radius of several hundred metres around the mire. Palù di Livenza is significant in the context of Neolithic archaeobotany of northern Italy and neighbouring countries. Copyright © 2004 John Wiley & Sons, Ltd.