bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Novel Bifunctional Michael Acceptors
Authors: Mediavilla Urbaneja Laura , Krause Norbert 
Published: October 2004

AbstractThe 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

AbstractWe 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

AbstractA 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

Abstract8‐(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

AbstractNovel 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

AbstractIn 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

AbstractThe 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

AbstractPolymeric 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

AbstractThe 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

AbstractSix 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

AbstractEnterovirus 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

AbstractThe 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

AbstractA 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

AbstractMonitoring 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

AbstractSerotyping 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

AbstractWe 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

AbstractThe 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.