bluuebunny/crossref_metadata_2025_split huggingface dataset:
An architecture for amplify‐and‐forward cooperative systems with real modulations
Authors: Krikidis Ioannis 
Published: July 2009

AbstractThis paper proposes a simple architecture for half‐duplex cooperative systems which use amplify‐and‐forward (AF) as a relay strategy and one‐dimensional modulations for source messages. The proposed solution uses the two orthogonal channels of quadrature modulation in order to allow a node to behave simultaneously as a source and a relay. We demonstrate that the new scheme has a similar performance to the conventional orthogonal amplify‐and‐forward protocol without suffering from bandwidth loss, and avoids error propagation problems of previously reported AF superposition schemes. The proposed technique is suitable for applications with low spectral efficiencies and practical adaptive systems where real modulations are implemented based on a quadrature modulation core. Copyright © 2009 John Wiley & Sons, Ltd.
3D‐QSAR studies of cytotoxic heterocyclic quinones using calculated reduction potential
Authors: Lee Yoonji , Kim Seoeun , Rhee Hee‐Kyung , Doh Kyung‐Eun , Park Junhee , Lee Chong‐Ock , Choi Sun , Choo Hea‐Young Park 
Published: July 2009

AbstractMost quinones with 2–4 fused aromatic rings exhibit cytostatic activity via DNA intercalation that causes enzyme blockade and reading errors during the replication process. The redox activity of quinones plays a role in the DNA cleavage mediated by oxygen or sulfur radicals. To develop novel anticancer agents based on nitrogen‐containing heterocyclic quinones, pharmacophore models of representative molecules with high activity were generated using Genetic Algorithm with Linear Assignment of Hypermolecular Alignment of Database (GALAHAD). A series of compounds were aligned to the selected pharmacophore model and the 3D‐quantitative structure activity relationships (QSAR) were analyzed using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA), resulting in q2 values of 0.734 and r2 of 0.951, and q2 of 0.803 and r2 of 0.917, respectively, in each study. In addition, the potentials for the one‐electron reduction of quinones were calculated from LUMO energies using the semi‐empirical Austin Model 1 (AM1) method. These also showed a good correlation (r2 of 0.816) with the cytotoxic activities of the quinones. Drug Dev Res 2009. © 2009 Wiley‐Liss, Inc.
Effect of CJX2, an amlodipine derivative, combined with verapamil on P‐glycoprotein efflux function in vitro
Authors: Ji Bian‐Sheng , Li Ming , He Ling 
Published: July 2009

AbstractIn an effort to inhibit P‐glycoprotein (P‐gp) efflux function with greater activity and less side effects, the combined effect of CJX2 and verapamil (Ver) was evaluated isobolographically in fixed ratio combinations of 1:1, 1:2, 1:4, 1:8, and 1:10 in doxorubicin‐resistant human myelogenous leukemia (K562/DOX ) cells and rat brain microvessel endothelial cells (RBMEC). The results displayed that mixtures of both drugs at the fixed ratios of 1:1, 1:2, 1:4, 1:8, and 1:10 exerted synergistic interactions, indicating that when the two blockers that bind P‐gp on separate membrane sites were combined, each contributes to the overall interaction with P‐gp, leading to the greater effect than that seen by either agent alone. Drug Dev Res, 2009. © 2009 Wiley‐Liss, Inc.
Increased numbers of thymic and peripheral CD4+ CD25+Foxp3+ cells in the absence of CD5 signaling
Authors: Ordoñez‐Rueda Diana , Lozano Francisco , Sarukhan Adelaida , Raman Chander , Garcia‐Zepeda Eduardo A. , Soldevila Gloria 
Published: July 2009

AbstractIt has been suggested that high affinity/avidity interactions are required for the thymic selection of Treg. Here, we investigated the role of CD5, a negative regulator of TCR signaling, in the selection and function of “naturally occurring” CD4+CD25+ Treg (nTreg). Analysis of CD5−/− mice showed a significant increase in the percentage and absolute numbers of CD4+ CD25+Foxp3+ thymocytes and peripheral T lymphocytes, compared with BALB/c mice. Thymi from CD5−/− mice showed reduced cellularity due to increased apoptosis, which preferentially affected naïve T cells. To characterize nTreg selection at the molecular level we investigated the phosphorylation of Erk, c‐Cbl, PI3K and Akt. CD5−/− nTreg showed increased basal levels of p‐Erk compared with wild‐type nTreg. Interestingly, in response to CD3 plus CD28 costimulation, CD5−/− naïve T cells but not CD5−/− nTreg showed lower levels of p‐Akt. Finally, CD5−/− nTreg were thymus‐derived and fully functional. We conclude that the enrichment of nTreg observed in the absence of CD5 signaling is due to de novo generation of nTreg and selective reduction of CD4+CD25− naïve thymocytes. Furthermore, we provide new evidence supporting a potential role of CD5 in thymocyte survival, through a mechanism that may involve the phosphorylation of Akt.
Synergistic OX40 and CD30 signals sustain CD8+ T cells during antigenic challenge
Authors: Bekiaris Vasileios , Gaspal Fabrina , Kim Mi‐Yeon , Withers David R. , Sweet Clive , Anderson Graham , Lane Peter J. L. 
Published: July 2009

AbstractPrior to acquiring a memory phenotype, antigen‐activated CD8+ T cells need to expand and then undergo a contraction phase. Utilizing two different antigenic stimuli, we provide evidence that the tumor necrosis factor receptors OX40 and CD30 integrate synergistic signals during the expansion phase to help maintain CD8+ effectors. Thus, double deficiency in OX40 and CD30 leads to CD8+ cell loss during expansion after immunization either with OVA or with murine CMV. Following their contraction, OX40‐ and CD30‐deficient CD8+ T cells persist normally in CMV‐infected mice. In contrast, persistence after OVA challenge is dependent on OX40 and CD30. Collectively, our data define the important role of both OX40 and CD30 during CD8+ T‐cell activation, and show that long‐term CD8 persistence after contraction is regulated not only by stimulatory receptors but also by the nature of the antigen or how the antigen is presented.
Aluminum Complexes with Bidentate N,N‐Dialkylaniline–arylamido Ligands: Synthesis, Structures, and Catalytic Properties for Efficient Ring‐Opening Polymerization of ϵ‐Caprolactone
Authors: Gao Aihong , Mu Ying , Zhang Jingshun , Yao Wei 
Published: July 2009

AbstractA number of Al complexes bearing bidentate N,N‐dialkylaniline–arylamido ligands, ortho‐(ArNCH2)C6H4NR2AlMe2 (R = Me, Ar = 2,6‐iPr2C6H3, 3a; 2,6‐Et2C6H3, 3b; 2,6‐Me2C6H3, 3c; 4‐MeC6H4, 3d; Ph, 3e; and R = Et, Ar = 2,6‐iPr2C6H3, 3f; 2,6‐Me2C6H3, 3g; Ph, 3h), have been synthesized from the reaction of the corresponding free ligands, ortho‐(ArNHCH2)C6H4NR2 (R = Me, Ar = 2,6‐iPr2C6H3, 2a; 2,6‐Et2C6H3, 2b; 2,6‐Me2C6H3, 2c; 4‐MeC6H4, 2d; Ph, 2e; and R = Et, Ar = 2,6‐iPr2C6H3, 2f; 2,6‐Me2C6H3, 2g; Ph, 2h), with AlMe3 (1 equiv.). All complexes were characterized by 1H and 13C NMR spectroscopy and elemental analysis. Single‐crystal X‐ray diffraction analysis of complexes 3c and 3e revealed that these Al complexes have a distorted tetrahedral geometry around the metal center. All complexes were found to be efficient catalysts for the ring‐opening polymerization of ϵ‐caprolactone (CL) in the presence of benzyl alcohol, and complexes 3a–h catalyze the polymerization of CL in a living fashion. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Calixarene‐Based Fluorescent Molecular Sensors for Toxic Metals
Authors: Leray Isabelle , Valeur Bernard 
Published: July 2009

AbstractThere is an increasing interest in the early detection of toxic metals in the environment. In this context, fluorescence is a very attractive detection method because of its intrinsic sensitivity, its response time and the possibility of imaging via fluorescence microscopy. Of the various complexing units available for the detection of toxic metal ions (chelators, open‐chain structures, crown‐ethers, cryptands), calixarenes offer distinct advantages in term of selectivity and the easy incorporation of a fluorophore into the structure. In this microreview, after recalling the main classes offluorescent molecular sensors based on cation‐induced changes in excited‐state processes (photoinduced electron‐ or charge‐transfer, excimer formation, energy transfer), we present various calixarene‐based sensors designed for the detection of caesium, mercury, lead and cadmium.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Ligation of Substituted Pyridines to Metallosalphen Complexes – Crystallographic Characterization of an Unexpected Four‐Component Supramolecular Assembly Comprising a Sterically Demanding Ligand
Authors: Escudero‐Adán Eduardo C. , Benet‐Buchholz Jordi , Kleij Arjan W. 
Published: July 2009

AbstractThe binding properties of various Zn(salphen) complexes with a range of substituted pyridine ligands has been studied in detail using NMR and UV/Vis spectroscopy, X‐ray diffraction analysis and molecular modelling studies. The combined results clearly demonstrate that subtle differences in the ortho‐substitution pattern on the pyridine ring have a dramatic effect on the strength of the Zn–Npyr interaction. In the case of a double ortho‐substitution, the pyridine donor is unable to bind to the Zn(salphen) complex as a result of the rigid geometry around the Zn ion and the steric repulsion that results upon ligation. The steric requirements of the pyridine ligand infers a preferred positioning of its pendant groups as to minimize repulsive interactions with the salphen ligand. The crystallization of two separate Zn(salphen) complexes in the presence of 2,6‐dimethylpyridine has furnished two remarkable 4‐component supramolecular structures in which the Zn ion is associated with a water ligand that in turn is surrounded by two pyridine H‐bond acceptors; a result that relates to the inability of this pyridine ligand to directly interact with the Zn metal centre. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Separation of reaction mixture after ethanolysis of rapeseed oil
Authors: Černoch Michal , Skopal František , Hájek Martin 
Published: July 2009

AbstractVarious effects on the separation of a raw reaction mixture after the ethanolysis of rapeseed oil were investigated. Water addition, initial temperature of separation, centrifugation, ionic compound addition and time effects affecting the concentrations of potassium and free glycerol and the yield of the ester phase were revealed. Centrifugation has the most positive effect. Finally, a correlation between the concentrations of potassium and free glycerol was found.
One‐Step Synthesis of Tröger's Base Hybrids Containing at Least One Halogen Atom
Authors: Faroughi Masoud , Zhu Kai‐Xian , Jensen Paul , Craig Donald C. , Try Andrew C. 
Published: July 2009

AbstractThe one‐step synthesis of a series of hybrid dibenzo Tröger's base analogues bearing at least one halogen atom is described. The strategy involves a reaction between two different anilines and affords hybrid compounds in yields as high as 46 %, together with the symmetric Tröger's base products. This straightforward approach requires only one chromatographic step and has the potential to replace multi‐step approaches to hybrid Tröger's base compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of (±) Wine Lactone and Its Analogues by a Diels–Alder Approach
Authors: O'Connor Patrick D. , Kim U Bin , Brimble Margaret A. 
Published: July 2009

AbstractA novel route to (±)‐wine lactone (1) by a cis‐selective kinetically controlled intramolecular Diels–Alder (IMDA) cycloaddition of the linear triene 2 is reported. The triene precursor was synthesised by TBAF‐catalysed coupling of an acyl fluoride with an silyl enol ether. Four butadienyl but‐3‐enoates were prepared and cyclised under mild conditions to give a series of wine lactone analogues. The diastereoselectivity of the IMDA cycloadditions was determined by NMR spectroscopy and GC‐MS, whereby the formation of the natural cis‐configured wine lactone (1) was established. The diastereomeric IMDA transition states were optimised by using density functional theory at the B3LYP/6‐31+G(d) level, and the Boltzmann populations of the electronic energies were found to correlate well with the experimentally observed diastereoselectivity.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A Novel Synthesis of Ferrocenylpyridazines
Authors: Klimova Elena I. , López Eduardo A. Vázquez , Alamo Marcos Flores , Klimova Tatiana , Martínez García Marcos 
Published: July 2009

AbstractThe reaction of 3‐[acyl(ethoxycarbonyl)]methylidene‐, 3‐diethoxycarbonylmethylidene‐, and 3‐diacylmethylidene‐1,2‐diferrocenylcyclopropenes with hydrazine at 80–85 °C afforded 3,4,5,6‐tetrasubstituted 5‐acyl(‐ethoxycarbonyl)pyridazines (3a–f) in 65–70 % yield. The structures of the obtained ferrocenylpyridazines were determined by IR and 1H and 13C NMR spectroscopy and mass spectrometry. The structures of 5‐ethoxycarbonyl‐ and 5‐acetyl‐3‐ferrocenyl‐4‐ferrocenylmethyl‐6‐methylpyridazines (3a, 3d) were confirmed by the data from X‐ray diffraction analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Photochromic Oxazines with Extended Conjugation
Authors: Petersen Michael Åxman , Deniz Erhan , Nielsen Mogens Brøndsted , Sortino Salvatore , Raymo Françisco M. 
Published: July 2009

AbstractWe synthesized four compounds with indole and benzooxazine fragments fused in their molecular skeleton and differing in the substituent in the para position, relative to the oxygen atom, of their phenoxy chromophore. This particular substituent extends the conjugation of the phenoxy chromophore and shifts its absorption bathochromically by up to 60 nm, relative to a parent compound with a 4‐nitrophenoxy group. The 1,3‐oxazine ring of all compounds opens upon addition of base to generate a hemiaminal incorporating a phenolate chromophore. Once again, the substituents on this fragment shift its absorption bathochromically by up to 60 nm, relative to the parent compound. Upon laser excitation at a wavelength within the absorption range of the phenoxy chromophore, the 1,3‐oxazine ring of the compound incorporating a 4‐nitrophenyl substituent opens in less than 6 ns to generate a zwitterionic isomer with a quantum yield of 0.11 in acetonitrile. Under these conditions, the photogenerated isomer has a lifetime of 29 ns and reverts spontaneously to the original species with first‐order kinetics. Furthermore, this photochromic system tolerates hundreds of switching cycles with no sign of degradation even in the presence of molecular oxygen. However, the excitation dynamics of the other three compounds, incorporating a 4‐nitrobiphenyl, 4‐nitrostyryl or 4‐nitrophenylethynyl substituent, are dominated by intersystem crossing. Consistently, the corresponding transient spectra reveal predominantly triplet–triplet absorptions. Thus, our studies demonstrate that the excitation wavelength and color of this class of photochromic compounds can be regulated by extending the conjugation of their phenoxy fragment with negligible influence on the photochromic performance only if the structural modification does not encourage intersystem crossing. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Efficient Rhodium‐Catalyzed Conjugate Addition of Arylboronic Acids to Unsaturated Furano Esters for the Highly Stereoselective Synthesis of Four Natural Trisubstituted Furanolignans
Authors: Mondière Aurélie , Pousse Guillaume , Bouyssi Didier , Balme Geneviève 
Published: July 2009

AbstractFour natural lignans, (±)‐dihydrosesamin (1a), (±)‐lariciresinol methyl ether (1b), (±)‐sanshodiol methyl ether (1c) and (±)‐acuminatin methyl ether (1d), were prepared stereoselectively in five steps from a 4‐(arylmethylene)‐2‐methoxytetrahydrofuran derivative obtained by a MCR reaction. The key step of this synthesis is the microwave‐assisted stereoselective addition of a boronic acid (Hayashi–Miyaura reaction) to a 4‐ethoxycarbonyldihydrofuran, generating three contiguous stereogenic centers with an excellent diastereoselectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Why some women can feel more, and others less, attractive after exposure to attractive targets: The role of social comparison orientation
Authors: Bosch A. Zwenneke , Buunk Abraham P. , Siero Frans W. , Park Justin H. 
Published: July 2009

AbstractAs the tendency to compare oneself with others may be associated with the tendency to focus on similarities, we hypothesized that individual differences in social comparison orientation (SCO) may moderate the consequences of upward and downward comparisons. In Study 1, high comparers were found to focus more on similarities than low comparers, suggesting that high comparers are more likely to assimilate in general. In Study 2, SCO was found to be positively associated with mood following exposure to an attractive target, and negatively associated with mood following exposure to a less attractive target. In Studies 2 and 3, SCO was found to be positively associated with self‐evaluations of attractiveness following exposure to an attractive target and negatively associated with self‐evaluations of attractiveness following exposure to a less attractive target. These results indicate that research on the consequences of social comparison must attend to individual differences in SCO. Copyright © 2009 John Wiley & Sons, Ltd.
Tubulin polymerization‐promoting protein (TPPP/p25) is critical for oligodendrocyte differentiation
Authors: Lehotzky Attila , Lau Pierre , Tőkési Natália , Muja Naser , Hudson Lynn D. , Ovádi Judit 
Published: July 2009

AbstractTPPP/p25, a recently identified tubulin polymerization‐promoting protein (TPPP), is expressed mainly in myelinating oligodendrocytes of the CNS. Here, we show that TPPP/p25 is strongly upregulated during the differentiation of primary oligodendrocyte cells as well as the CG‐4 cell line. The microRNA expression profile of CG‐4 cells before and after induction of differentiation was established and revealed differential regulation of a limited subset of microRNAs. miR‐206, a microRNA predicted to target TPPP/p25, was not detected in oligodendrocytes. Overexpression of miR‐206 led to downregulation of TPPP/p25 resulting in inhibition of differentiation. Transfection of siRNAs against TPPP/p25 also inhibited cell differentiation and promoted cell proliferation, providing evidence for an important role of TPPP/p25 during oligodendrogenesis. These results support an essential role for TPPP/p25 in oligodendrocyte differentiation likely via rearrangement of the microtubule system during the process elongation prior to the onset of myelination. © 2009 Wiley‐Liss, Inc.
Different astroglia permissivity controls the migration of olfactory bulb interneuron precursors
Authors: García‐Marqués Jorge , De Carlos Juan A. , Greer Charles A. , López‐Mascaraque Laura 
Published: July 2009

AbstractThe rostral migratory stream (RMS) is a well defined migratory pathway for precursors of olfactory bulb (OB) interneurons. Throughout the RMS an intense astroglial matrix surrounds the migratory cells. However, it is not clear to what extent the astroglial matrix participates in migration. Here, we have analyzed the migratory behavior of neuroblasts cultured on monolayers of astrocytes isolated from areas that are permissive (RMS and OB) and nonpermissive (cortex and adjacent cortical areas) to migration. Our results demonstrate robust neuroblast migration when RMS‐explants are cultured on OB or RMS‐astrocytes, in contrast to their behavior on astroglia derived from nonpermissive areas. These differences, mediated by astrocyte‐derived nonsoluble factors, are related to the overexpression of extracellular matrix and cell adhesion molecules, as revealed by real‐time qRT‐PCR. Our results show that astroglia heterogeneity could play a significant role in migration within the RMS and in cell detachment in the OB. © 2009 Wiley‐Liss, Inc.
The —308 (G/A) single nucleotide polymorphism in the TNF‐α gene and the risk of major depression in the elderly
Authors: Cerri Anna Paola , Arosio Beatrice , Viazzoli Chiara , Confalonieri Roberto , Vergani Carlo , Annoni Giorgio 
Published: July 2009

AbstractObjectiveThe immune system (IS) plays a key role in the mechanisms underlying major depression (MD) and pro‐inflammatory cytokines seem to be particularly involved in the pathogenesis of the disease. There is growing evidence of a relationship between commonly studied single nucleotide polymorphisms (SNPs) in cytokine genes and an increased risk of MD.The aim of our study was to investigate the association between the −308(G/A) SNP in the tumour necrosis factor‐α (TNF‐α) gene and late‐life MD in elderly people without dementia.MethodsBlood samples were obtained from 50 subjects enrolled at the Geriatric Department of the San Gerardo Hospital in Monza, Italy, after screening with the geriatric depression scale (GDS ≥ 15) and mini‐mental state evaluation (MMSE ≥ 24). The −308 (G/A) SNP was genotyped by SSP‐PCR amplification. Two hundred and forty age‐matched healthy volunteers were taken as the control group.ResultsGenotype and allele distributions in patients with MD were significantly different from those of the controls. In subjects affected by MD we found a higher percentage of the GG genotype (84 vs. 68,3%; p = 0.007) and thus of the G allele (92 vs. 81,9%; p = 0.05).The GG genotype was associated with a greater risk of developing the disease (OR 2.433, CI 1.09–5.43).ConclusionsOur study suggests that the −308 (G/A) polymorphism in the TNF‐α gene could play a role in determining susceptibility to MD. An activation of the TNF‐α system could contribute to the development of MD in the elderly. Copyright © 2009 John Wiley & Sons, Ltd.
Strength of shoulder during one‐handed pushing in constrained conditions
Authors: Gielo‐Perczak Krystyna 
Published: July 2009

AbstractThis study hypothesizes that, by isolating the influences of contact surface friction, back foot support, and forward‐leaning body posture during pushing, the magnitude of recorded strength will be a closer estimate of physical capabilities of the shoulder. The shoulder strength of twelve participants during one‐handed pushing in constrained conditions in the coronal (frontal) plane, in a range from 5 to 30 degrees, was correlated with the anthropometric measures and two anatomical parameters of the shoulder joint. The data indicated that the acceptable loads at the handle for all the participants were lower than the recommended standards. Right arm length had the highest correlation coefficient with shoulder strength among anthropometric data, and the radius of the humerus bone among anatomical parameters. The findings from this study of one‐handed pushing will be used to help modify existing physical strength standards in an effort to reduce the high frequency of recorded shoulder injuries. © 2009 Wiley Periodicals, Inc.