bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD4+CD25lowGITR+ cells: A novel human CD4+ T‐cell population with regulatory activity
Authors: Bianchini Rodolfo , Bistoni Onelia , Alunno Alessia , Petrillo Maria Grazia , Ronchetti Simona , Sportoletti Paolo , Bocci Elena Bartoloni , Nocentini Giuseppe , Gerli Roberto , Riccardi Carlo 
Published: May 2011

AbstractTreg subsets play a role in sustaining peripheral tolerance, are characterized by markers such as forkhead winged‐helix transcription factor (FOXP3) and CD25, and produce suppressive cytokines, such as IL‐10 and TGF‐β. Glucocorticoid‐induced TNF receptor family‐related (GITR) protein has been suggested to regulate Treg activity in mice. The aim of our study was to investigate GITR expression in human CD4+ T lymphocytes and its possible role in Treg function. Results indicate that a subset of CD4+ T cells in the peripheral blood expresses GITR and low levels of CD25 (CD4+CD25lowGITR+). These cells show Treg features as they express FOXP3, IL‐10, TGF‐β and are anergic but, as opposed to natural Tregs, express low levels of CTLA‐4 and are CD127high. CD4+CD25lowGITR+ cells represent a low percentage of the CD4+ T‐cell population (0.32–1.74%) and are mostly memory cells. Functional experiments demonstrated that CD4+CD25lowGITR+ cells have relevant suppressive activity that depends on TGF‐β. Moreover, an anti‐GITR Ab inhibited their suppressive activity, as observed in CD4+CD25+ murine Tregs. Taken together, these data indicate that human CD4+CD25lowGITR+ cells represent a distinct Treg subpopulation.
Synovial fibroblasts promote immunoglobulin class switching by a mechanism involving BAFF
Authors: Alsaleh Ghada , François Antoine , Knapp Anne‐Marie , Schickel Jean‐Nicolas , Sibilia Jean , Pasquali Jean‐Louis , Gottenberg Jacques‐Eric , Wachsmann Dominique , Soulas‐Sprauel Pauline 
Published: May 2011

AbstractFibroblast‐like synoviocytes (FLSs) are important actors in rheumatoid arthritis (RA) pathogenesis. The autoimmune nature of RA is attributed to autoantibody production, which confers to B cells a predominant role in RA. Several arguments support an induction of class switch recombination (CSR) in RA synovium, causing – in conjunction with somatic hypermutation – the production of potentially pathogenic IgG. To determine whether RA FLSs can directly promote CSR and to analyze the role of external factors like TLR signals and BAFF (B cell activating factor) family cytokines in this FLS‐B cell crosstalk, we performed cocultures of blood B cells (from normal individuals or RA patients) with RA FLSs and analyzed CSR induction by quantification of AICDA (encoding activation‐induced cytidine deaminase, AID) and switch circular transcripts expression, and IgG secretion. RA FLSs – and to a lesser extent osteoarthritis or control FLSs – promoted CSR, and TLR3 stimulation potentialized it. In addition, induction of CSR by RA FLSs was totally dependent on cell–cell contact in basal conditions, and partially dependent in the case of TLR3 stimulation. Finally, we showed that the mechanism by which RA FLSs induce CSR is mostly BAFF‐dependent. Our results support the hypothesis that CSR can be induced outside the ectopic lymphoid structures in RA.
Synthesis, Coordination Properties and Application of New N,N‐Ligands Based on Bornyl and Binaphthylazepine Chiral Backbones in Palladium‐Catalyzed Allylic Substitution Reactions
Authors: Bottari Giovanni , Meduri Angelo , Drommi Dario , Brancatelli Giovanna , Faraone Felice 
Published: May 2011

AbstractThe synthesis of new imine‐amine and diamine ligands, based on both the atropisomeric (Sa)‐ or (Ra)‐1,1′‐binaphthyl and (R)‐bornyl backbones, and incorporating an ethylenediamino spacer, are reported. In addition, analogue ligands in which one chiral arm is replaced by the achiral NMe2 group were synthesized. These N,N‐ligands when coordinated to a palladium metal centre form highly enantioselective catalysts for the asymmetric allylic alkylation of rac‐2‐acetoxy‐1,3‐diphenylpropene by dimethyl malonate. In one case, the synergic effect of the chirality elements in the palladium catalyst afforded the (S) substitution product with an enantiomeric excess (ee) of >99 %. Based on NMR studies of the active species in solution, a reliable explanation for the origin of the enantioselectivity of these palladium catalysts is also provided.
Polymers for Green C–C Couplings (Eur. J. Inorg. Chem. 15/2011)
Authors: Albéniz Ana C. , Carrera Nora 
Published: May 2011

AbstractThe cover picture shows how palladium‐catalyzed cross coupling reactions can be carried out in a clean and green way by attaching either the reagents (bottom) or the catalyst (upper right) to polymers, here represented as branches of a blooming tree. This is the topic of the Microreview by A. C. Albéniz and N. Carrera on p. 2347 ff, where examples of polymer‐supported palladium catalysts or polymer‐attached reagents (specially organotin derivatives in the Stille reaction) are discussed. The water in the background of the picture suggests that this solvent can also be used in couplings where the catalyst is supported on a polymeric scaffold.
Insight into the Mechanism of Quinoline Formation by the Chromium(0) Fischer Carbene Catalytic Transmetallation to Palladium and Rhodium: Application to the Synthesis of the Alkaloids of Ruta chalepensis
Authors: López‐Alberca María P. , Fernández Israel , Mancheño María J. , Gómez‐Gallego Mar , Casarrubios Luis , Sierra Miguel A. 
Published: May 2011

AbstractThe Pd‐ and Rh‐mediated cyclization of group 6 (2‐aminoethenyl)carbene complexes incorporating aryl iodides or boronates in their structures is reported. The process led to the formation of quinoline rings and has been applied to the synthesis of quinoline alkaloids 12 and 13 isolated from the roots of the perennial grass Ruta chalepensis. The computational (DFT) study of the cyclization processes revealed unusual features. Thus, for the Pd‐mediated cyclization of (2‐aminoethenyl)carbene complexes incorporating aryl iodides in their structures, the first step in the pathway to the quinolines is the Cr‐to‐Pd transmetallation reaction, leading to palladacarbenes instead of the expected oxidative addition to the aryl iodide. For RhI‐mediated cyclizations in (2‐aminoethenyl)carbene complexes incorporating aryl boronates, the sequence of events involves an initial Cr‐to‐Rh transmetallation followed by oxidative addition to the aryl–boron bond. The evolution of these intermediates to the final quinolines parallels the Pd‐catalyzed pathway.
Synthesis of Naturally Occurring Cyclohexene Rings Using Stereodirected Intramolecular Diels–Alder Reactions Through Asymmetric 1,3‐Dioxane Tethering (Eur. J. Org. Chem. 15/2011)
Authors: Abdelkafi Hajer , Evanno Laurent , Deville Alexandre , Dubost Lionel , Chiaroni Angèle , Nay Bastien 
Published: May 2011

AbstractThe cover picture shows a synthetic n‐puzzle, a game that challenges players to move tiles along unbending routes in order to establish a certain end configuration. Our templated 1,3,9‐decatrienoate precursors, advanced synthetic tiles, were designed on the basis of a chiral 1,3‐dioxane tether and paved the way for stereodirected intramolecular Diels–Alder reactions, leading to asymmetric cyclohexene rings. The 1,3‐dioxane tether was expected to rigidify the decatrienoate system for efficient stereocontrol, with the ester carbonyl group strongly favoring endo‐boat transitions states. Thanks to this method we succeeded in synthesizing valuable intermediates towards the total synthesis of the diterpene harringtonolide originating from the plum yew shown in the background and the fungal polyketide pyrrocidine A. Details of this work are described in the article by B. Nay et al. on p. 2789 ff.
Appealing to common humanity increases forgiveness but reduces collective action among victims of historical atrocities
Authors: Greenaway Katharine H. , Quinn Emerald A. , Louis Winnifred R. 
Published: May 2011

AbstractAppealing to common humanity is often suggested as a method of uniting victims and perpetrators of historical atrocities. In the present experiment (N = 109), we reveal that this strategy may actually work against victim groups' best interests. Appealing to common humanity (versus intergroup identity) increased forgiveness of perpetrators but independently also served to lower intentions to engage in collective action. Both effects were mediated but not moderated by reduced identification with the victim group. We, thus reveal an important feature of appeals to common humanity: That this strategy may reduce social change at the same time as helping to promote more positive intergroup attitudes. These novel findings extend research on the human identity to a new theoretically interesting and socially important domain. Copyright © 2011 John Wiley & Sons, Ltd.
Preparation and Application of Urea Electrochemical Sensor Based on Chitosan Molecularly Imprinted Films
Authors: Chen Yan‐Ping , Liu Bin , Lian Hui‐Ting , Sun Xiang‐Ying 
Published: May 2011

AbstractA novel urea electrochemical sensor was constructed based on chitosan molecularly imprinted films which were prepared by potentiostatic electrodeposition of chitosan in the presence of urea followed by eluting with 0.1 M KCl. Various techniques were carried out to investigate the formation of molecularly imprinted polymer (MIP) films and the performance of the sensor. According to our expectation, the urea MIP electrochemical sensor showed excellent selectivity to urea among the structural similarities and co‐existences, high linear sensitivity to urea in the range from 1.0×10−8 to 4.0×10−5 M with a detection limit of 5.0×10−9 M. Furthermore, the recovery ranged from 96.3 % to 103.3 % and therefore offered great potential for clinical diagnosis applications.
A DNA-based assay for toxic chemicals in wastewater
Authors: Foreman Amy L , Phillips Leo , Kanellis Vangelis G , Hammoudeh Daoud , Naumann Christoph , Wong Henri , Chisari Robert , Hibbert D. Brynn , Lee Garry S.H , Patra Ronald , Julli Moreno , Chapman John , Cooke A. Roger , dos Remedios Cristobal G 
Published: May 2011

Abstract
Chemical toxicants, particularly metal ions, are a major contaminant in global waterways. Live-organism bioassays used to monitor chemical toxicants commonly involve measurements of activity or survival of a freshwater cladoceran (Ceriodaphnia dubia) or light emitted by the marine bacterium Vibrio fischeri, used in the commercial Microtox® bioassay. Here we describe a novel molecule-based assay system employing DNA as the chemical biosensor. Metals bind to DNA, causing structural changes that expel a bound (intercalated) fluorescent reporter dye. Analyses of test data using 48 wastewater samples potentially contaminated by metal ions show that the DNA-dye assay results correlate with those from C. dubia and Microtox bioassays. All three assays exhibit additive, antagonistic, and synergistic responses that cannot be predicted by knowing individual metal concentrations. Analyses of metals in these samples imply the presence of chemical toxicants other than metal ions. The DNA-dye assay is robust, has a 12-month shelf life, and is only slightly affected by sample pH in the range 4 to 9. The assay is completed in a matter of minutes, and its portability makes it well suited as a screening assay for use in the field. We conclude that the DNA-dye test is a surrogate bioassay suitable for screening chemical toxicity. Environ. Toxicol. Chem. 2011; 30:1810–1818. © 2011 SETAC
Surface Fluorination of Poly(fluorenyl ether ketone) Ionomers as Proton Exchange Membranes for Fuel Cell Application
Authors: Hu H. , Xiao M. , Wang S. J. , Shen P. K. , Meng Y. Z. 
Published: May 2011

AbstractA series of sulphonated poly(fluorenyl ether ketone) ionomers were successfully fluorinated by the means of direct surface fluorination. Polymer ionomer samples in two different states (membrane and powder) were treated with F2 gas which is diluted in N2 in a special reactor. X‐ray photoelectron spectroscopy (XPS) was used to examine the F/C ratios of the fluorinated materials. The results revealed that the fluorination only occurred on the membrane surface and the fluorination degree increased with increasing F2 concentration in N2. The membrane subjected to fluorination shows an obviously enhanced oxidative stability. The endurance in a Fenton's reagent of FSPFEK‐P‐28 is longer than 180 min which is two times longer than that of un‐fluorinated SPFEK. The PEM properties and single fuel cell performances were investigated by comparison of un‐ and fluorinated polymer ionomers. The fluorinated membranes demonstrated an enhanced hydrophobic surface property, increased proton conductivities and better single fuel cell performances. Surface fluorination provides a convenient and useful approach to prepare highly proton conductive membrane with long life‐time PEM fuel cell applications.
The Role of Reactive Reaction Intermediates in Two‐Step Heterogeneous Electrocatalytic Reactions: A Model Study
Authors: Fuhrmann J. , Zhao H. , Langmach H. , Seidel Y. E. , Jusys Z. , Behm R. J. 
Published: May 2011

AbstractThis paper summarises the result of previous experimental investigations of heterogeneous electrocatalytic reactions performed in flow cells which provide an environment with controlled parameters. Measurements of the oxygen reduction reaction in a flow cell with an electrode consisting of an array of Pt nanodisks on a glassy carbon substrate exhibited a decreasing fraction of the intermediate H2O2 in the overall reaction products with increasing density of the nanodisks. A similar result is true for the dependence on the catalyst loading in the case of a supported Pt/C catalyst thin‐film electrode, where the fraction of the intermediate decreases with increasing catalyst loading. Similar effects have been detected for the methanol oxidation.In order to give a possible explanation to the observed effect, we present a model of multistep heterogeneous electrocatalytic oxidation and reduction reactions based on an adsorption‐reaction‐desorption scheme using the Langmuir assumption and macroscopic transport equations. A continuum based model problem in a vertical cross‐section of a rectangular flow cell is proposed in order to explain basic principles of the experimental situation. It includes three model species A, B, C, which undergo adsorption and desorption at a catalyst surface, as well as adsorbate reactions from A to B to C. These surface reactions are coupled with diffusion and advection in the Hagen Poiseuille flow in the flow chamber of the cell. High velocity asymptotic theory and a finite volume numerical method are used to obtain approximate solutions to the model. Both approaches show a behaviour similar to the experimentally observed. Working in more general situations, the finite volume scheme was applied to a catalyst layer consisting of a number of small catalytically active areas corresponding to nanodisks. Good qualitative agreement with the experimental findings is established for this case as well.
Effects of rollover strategies and information stability on the performance measures in options markets: An examination of the KOSPI 200 index options market
Authors: Choi Youngsoo , Ok SoonChan 
Published: May 2011

AbstractOne of the most widely used option valuation models among practitioners is the ad hoc Black–Scholes (AHBS) model. The main contribution of this study is methodological. We carefully consider two rollover strategies (nearest‐to‐next strategy and next‐to‐next) used in the AHBS model to investigate their effect on pricing errors. We suggest a new rollover strategy, next‐to‐next strategy, and demonstrate that our rollover strategy produces more consistent estimates between in‐sample market and model option prices. Probably even more important is that our new rollover strategy makes more accurate out‐of‐sample forecasts for 1‐day or 1‐week ahead prices. Prior literature has documented some anomalies associated with the use of AHBS model, for example, an overfitting problem. A secondary contribution is that our new rollover strategy does not suffer from this overfitting critique. Third, this study uses the mean square error for out‐of‐sample pricing and price changes to determine how the options investors are influenced by moneyness. The results indicate that underpricing (or overpricing) by the AHBS model for the near‐the‐money category is more likely to be maintained for the next several trading days but that such a phenomenon is disappeared for the deep out‐of‐the‐money category. Finally, we suggest the ratio of the number of option contracts to differences in strike prices available for trading between the current day and the previous day(s) as a good categorizing factor for options, such as moneyness. © 2011 Wiley Periodicals, Inc. Jrl Fut Mark
Efficient synthesis of α‐aminophosphonates via one‐pot reactions of aldehydes, amines, and phosphates in ionic liquid
Authors: Hajinasiri Rahimeh , Hossaini Zinatossadat , Rostami‐Charati Faramarz 
Published: May 2011

AbstractIonic liquids such as 1,3‐dialkylimidazolium bromides make excellent solvents for synthesis of α‐aminophosphonates from aldehydes, amines, and phosphites. The ionic liquids are successfully regenerated and reused. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:625–629, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20724
Quantile regression analysis of body mass and wages
Authors: Johar Meliyanni , Katayama Hajime 
Published: May 2011

SUMMARYUsing the National Longitudinal Survey of Youth 1979, we explore the relationship between body mass and wages. We use quantile regression to provide a broad description of the relationship across the wage distribution. We also allow the relationship to vary by the degree of social skills involved in different jobs. Our results find that for female workers body mass and wages are negatively correlated at all points in their wage distribution. The strength of the relationship is larger at higher‐wage levels. For male workers, the relationship is relatively constant across wage distribution but heterogeneous across ethnic groups. When controlling for the endogeneity of body mass, we find that additional body mass has a negative causal impact on the wages of white females earning more than the median wages and of white males around the median wages. Among these workers, the wage penalties are larger for those employed in jobs that require extensive social skills. These findings may suggest that labor markets reward white workers for good physical shape differently, depending on the level of wages and the type of job a worker has. Copyright © 2011 John Wiley & Sons, Ltd.
ent‐Kaurane Diterpenes and Further Constituents from Wedelia trilobata
Authors: Qiang Yin , Du Dao‐Lin , Chen Yan‐Jun , Gao Kun 
Published: May 2011

AbstractTwo new ent‐kaurane diterpenes, wedelidins A (8) and B (9), together with eighteen other constituents, including the sesquiterpenoids 1 and 2, ent‐kaurane diterpenes 3–7, triterpenoids 10 and 11, steroids 12–14, and flavonoids 15–17 as well as benzene derivatives 18–20, were isolated from the aerial parts of Wedelia trilobata. The structures of wedelidins A (8) and B (9) were elucidated by extensive spectroscopic analyses (including UV, IR, NMR, and MS). Furthermore, the structures of compounds 2 and 3 were confirmed by X‐ray single‐crystal diffraction analyses.
Organic Reaction in Water: A Highly Efficient and Environmentally Friendly Synthesis of Spiro Compounds Catalyzed by L‐Proline
Authors: Dabiri Minoo , Noroozi Tisseh Zeinab , Nobahar Mohsen , Bazgir Ayoob 
Published: May 2011

AbstractWe have developed a clean, simple and efficient method for the synthesis of spiro compounds by three‐component reaction of isatins (=1H‐indole‐2,3‐diones) or acenaphthylene‐1,2‐dione, 1,3‐diphenyl‐1H‐pyrazoles‐5‐amines, and tetronic acid (=furan‐2,4‐(3H,5H)‐dione or 2‐hydroxy‐1,4‐naphthoquinone in the presence of a catalytic amount of L‐proline in aqueous media. The advantages of this procedure are mild reaction conditions, high yields of products, operational simplicity, and easy workup procedures employed.
A New Tetracyclic Diterpene from Jatropha curcas
Authors: Xu Jun‐Ju , Fan Jun‐Ting , Zeng Guang‐Zhi , Tan Ning‐Hua 
Published: May 2011

AbstractJatrophodione A (1), a new diterpene with four rings, together with nine known compounds, caniojane (2), jatropholone A (3), jatropholone B (4), jatrogrossidione (5), 2‐epijatrogrossidione (6), heudelotinone (7), gossweilone (8), (3α)‐3‐hydroxy‐ent‐pimara‐8(14),15‐dien‐12‐one (9), and 12‐hydroxy‐13‐methylpodocarpa‐8,11,13‐trien‐3‐one (10), was isolated from the aerial parts of Jatropha curcas. Compounds 5, 6, 9, and 10 were found for the first time in this plant. Their structures were established by spectroscopic analysis, including 2D‐NMR spectroscopic techniques. Cytotoxicities of compounds 1, 2, 7, 8, and 9 were tested on the three cancer cell lines A549, Hela, and SMMC‐7721. Results showed that 7 exhibited cytotoxicity against SMMC‐7721 with an IC50 value of 21.68 μM, whereas 7 and 8 were active against A549 with the IC50 values of 16.04 and 20.47 μM, and against Hela with the IC50 values of 10.67 and 22.83 μM, respectively.
Novel Cyanoglucosides from the Leaves of Hydrangea macrophylla
Authors: Wang Zhi‐Bin , Gao Hui‐Yuan , Yang Chun‐Juan , Sun Zhi , Wu Li‐Jun 
Published: May 2011

AbstractFour non‐cyanogenic cyanoglucosides including hydranitrilosides A1, A2, B1, and B2 (1–4, resp.), together with a new phenolic glucoside, 3‐hydroxy‐4‐methoxybenzoic acid 3‐O‐β‐D‐glucopyranoside (5), were isolated from the leaves of Hydrangea macrophylla. Their structures were determined on the basis of chemical and spectral evidence.
Convergent Domino Knoevenagel Hetero‐DielsAlder and Domino Oxidation Hetero‐DielsAlder Reactions Encountered in an Unexpected Formation of Novel 5‐Aryl‐1H‐pyrano[2,3‐d]pyrimidine‐2,4(3H,5H)‐diones and 5‐Aryl‐2,3‐dihydro‐2‐thioxo‐1H‐pyrano[2,3‐d]pyrimidin‐4(5H)‐ones
Authors: Zidar Nace , Kikelj Danijel 
Published: May 2011

AbstractConvergent domino Knoevenagel hetero‐DielsAlder and domino oxidation hetero‐DielsAlder reactions, in which both diene and dienophile are formed under the same reaction conditions in situ, are described for the first time, and their application is demonstrated by a one‐pot synthesis of novel 5‐aryl‐1H‐pyrano[2,3‐d]pyrimidine‐2,4(3H,5H)‐diones and 5‐aryl‐2,3‐dihydro‐2‐thioxo‐1H‐pyrano[2,3‐d]pyrimidin‐4(5H)‐ones.
Synthesis of Allyl Aryl Sulfone Derivatives from BaylisHillman Acetates in Water
Authors: Karnakar Konkala , Shankar Jilla , Narayana Murthy Sabbavarapu , Nageswar Yadavalli Venkata Durga 
Published: May 2011

AbstractVarious phenyl and p‐tolyl allyl sulfone derivatives were prepared stereoselectively by reacting BaylisHillman acetates with sodium 4‐R‐benzenesulfinate (R=H, Me) in H2O. The reaction was very efficient in providing the corresponding sulfone derivatives in good to excellent yields (Table).
An Efficient Stereoselective Total Synthesis of Synargentolide A and Its Epimer
Authors: Das Biswanath , Balasubramanyam Penagaluri , Veeranjaneyulu Boyapati , Chinna Reddy Gandolla 
Published: May 2011

AbstractThe stereoselective total synthesis of a naturally occurring α‐pyrone (=2H‐pyran‐2‐one) derivative, synargentolide A (1), and of its epimer 2 (with the originally proposed structure of synargentolide A) was efficiently accomplished involving D‐tartaric acid as the starting material and an olefin cross‐metathesis reaction as the key step.