bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Simple and Versatile Re‐Catalyzed Meyer–Schuster Rearrangement of Propargylic Alcohols to α,β‐Unsaturated Carbonyl Compounds
Authors: Stefanoni Massimo , Luparia Marco , Porta Alessio , Zanoni Giuseppe , Vidari Giovanni 
Published: March 2009

AbstractRhenium does the job! A readily available rhenium complex efficiently catalyzed the direct Meyer–Schuster‐like rearrangement of different alkyl‐ and aryl‐substituted propargylic secondary and tertiary alcohols to the corresponding α,β‐unsaturated compounds, which were produced with virtually complete E stereoselectivity. The reaction proceeded under neutral conditions and no racemization of potentially enolizable stereocenters was observed.magnified image
A Simple Catalyst for the Efficient Benzylation of Arenes by Using Alcohols, Ethers, Styrenes, Aldehydes, or Ketones
Authors: Prades Amparo , Corberán Rosa , Poyatos Macarena , Peris Eduardo 
Published: March 2009

AbstractOne catalyst fits all! One catalyst is active for a wide set of benzylating reactions (see scheme). A tandem process allows the use of aldehydes and ketones as benzylating agents.magnified imageThe compound [IrCp*(OTf)2(InBu)] (InBu=1,3‐di‐n‐butyl‐imidazolylidene) is an effective catalyst in the benzylation of arenes with different benzylating agents, such as alcohols, ethers and styrenes, representing an unprecedented highly versatile catalyst for this type of process. The same compound also catalyses a remarkable tandem process that allows the use of aldehydes and ketones as benzylating agents, through the base‐free hydrogenation of CO bonds with iPrOH and further use of the resulting primary or secondary alcohols as benzylating agents.
A Germanium(II) Cation with [1+1] Coordination
Authors: Schäfer Annemarie , Saak Wolfgang , Haase Detlev , Müller Thomas 
Published: March 2009

AbstractBreaking the molecular symmetryby protonation of germylene1is the key step in the synthesis of the germyliumylidene2, which is stabilized by an intramolecular interaction with a distant imido group.magnified image
Luminescent Heteropolynuclear Complexes of 3,5‐Dimethylpyrazolate [Pt2Au2M2(Me2pz)8] (M=Ag, Cu) Showing the Synergistic Effect of Three Transition Elements in the Excited State
Authors: Umakoshi Keisuke , Saito Keizo , Arikawa Yasuhiro , Onishi Masayoshi , Ishizaka Shoji , Kitamura Noboru , Nakao Yoshihide , Sakaki Shigeyoshi 
Published: March 2009

AbstractSwap the coins! The Pt2Au2, Pt2Au2Cu2, and Pt2Au2Ag2 complexes of 3,5‐dimethylpyrazolate exhibit yellow‐green, orange, and sky‐blue luminescence, respectively (see figure). The emission energies of Pt2Au2M2 complexes can be controlled by the change of the third coinage metal ions M. The Pt2Au2M2 complexes take the cis configuration with respect to the Au2M2 plane.magnified image
Dehnungsmessung an Kolonnenböden im laufenden Anlagenbetrieb zur Belastungsbestimmung
Authors: Staak D. , Repke J.‐U. , Wozny G. , Morillo A. 
Published: March 2009

AbstractEin auf Dehnungsmessstreifen basierendes Messverfahren wurde entwickelt und erfolgreich unter Betriebsbedingungen eingesetzt. Die Messung ermöglicht die Ermittlung der mechanischen Belastungen von Kolonneneinbauten während des laufenden Anlagenbetriebs. Bei dem Messverfahren werden die auf den Boden wirkenden Spannungen direkt gemessen. Die durchgeführten Versuche zeigen, dass im Gegensatz dazu indirekte Messverfahren wie eine Differenzdruckmessungen nur bedingt die tatsächliche Bodenbelastung wiedergeben können.
2‐Phenylquinolones as Inhibitors of the HIV‐1 Tat–TAR Interaction
Authors: Gatto Barbara , Tabarrini Oriana , Massari Serena , Giaretta Giulia , Sabatini Stefano , Del Vecchio Claudia , Parolin Cristina , Fravolini Arnaldo , Palumbo Manlio , Cecchetti Violetta 
Published: March 2009

AbstractNovel 2‐phenylquinolones aimed at the Tat–TAR complex were synthesized and tested. Derivatives characterized by precise modifications of the quinolone nucleus and to the side chain of the 2‐phenyl ring allowed a thorough structure–activity study, confirming 2‐phenylquinolone as a suitable scaffold for inhibition of the Tat–TAR interaction.magnified image
Cellular expression of midkine‐a and midkine‐b during retinal development and photoreceptor regeneration in zebrafish
Authors: Calinescu Anda‐Alexandra , Vihtelic Thomas S. , Hyde David R. , Hitchcock Peter F. 
Published: March 2009

AbstractIn the retina of adult teleosts, stem cells are sustained in two specialized niches: the ciliary marginal zone (CMZ) and the microenvironment surrounding adult Müller glia. Recently, Müller glia were identified as the regenerative stem cells in the teleost retina. Secreted signaling molecules that regulate neuronal regeneration in the retina are largely unknown. In a microarray screen to discover such factors, we identified midkine‐b (mdkb). Midkine is a highly conserved heparin‐binding growth factor with numerous biological functions. The zebrafish genome encodes two distinct midkine genes: mdka and mdkb. Here we describe the cellular expression of mdka and mdkb during retinal development and the initial, proliferative phase of photoreceptor regeneration. The results show that in the embryonic and larval retina mdka and mdkb are expressed in stem cells, retinal progenitors, and neurons in distinct patterns that suggest different functions for the two molecules. Following the selective death of photoreceptors in the adult, mdka and mdkb are coexpressed in horizontal cells and proliferating Müller glia and their neurogenic progeny. These data reveal that Mdka and Mdkb are signaling factors present in the retinal stem cell niches in both embryonic and mature retinas, and that their cellular expression is actively modulated during retinal development and regeneration. J. Comp. Neurol. 514:1–10, 2009. © 2009 Wiley‐Liss, Inc.
Beyond early development: Xenopus as an emerging model for the study of regenerative mechanisms
Authors: Beck Caroline W. , Izpisúa Belmonte Juan Carlos , Christen Bea 
Published: March 2009

AbstractWhile Xenopus is a well‐known model system for early vertebrate development, in recent years, it has also emerged as a leading model for regeneration research. As an anuran amphibian, Xenopus laevis can regenerate the larval tail and limb by means of the formation of a proliferating blastema, the lens of the eye by transdifferentiation of nearby tissues, and also exhibits a partial regeneration of the postmetamorphic froglet forelimb. With the availability of inducible transgenic techniques for Xenopus, recent experiments are beginning to address the functional role of genes in the process of regeneration. The use of soluble inhibitors has also been very successful in this model. Using the more traditional advantages of Xenopus, others are providing important lineage data on the origin of the cells that make up the tissues of the regenerate. Finally, transcriptome analyses of regenerating tissues seek to identify the genes and cellular processes that enable successful regeneration. Developmental Dynamics 238:1226–1248, 2009. © 2009 Wiley‐Liss, Inc.
The IFN regulatory factor 7‐dependent type I IFN response is not essential for early resistance against murine cytomegalovirus infection
Authors: Steinberg Christian , Eisenächer Katharina , Gross Olaf , Reindl Wolfgang , Schmitz Frank , Ruland Jürgen , Krug Anne 
Published: March 2009

AbstractIFN regulatory factor 7 (IRF7) has been described as the master regulator of type I IFN responses and has been shown to be critical for innate antiviral immunity in vivo. In addition to type I IFN, NK cell responses are involved in the control of viral replication during acute viral infection. To investigate the role of IRF7 in the context of a viral infection that induces a strong NK cell response, the murine cytomegalovirus (MCMV) infection model was used. WT, IRF7‐deficient and IRF3/IRF7‐double deficient mice were infected with MCMV. The systemic IFN‐α response to MCMV was entirely dependent on IRF7, but independent of IRF3. However, peak IFN‐β production during MCMV infection was not affected by the lack of IRF7 or both IRF7 and IRF3. Despite the complete lack of IFN‐α production IRF7‐ and IRF3/IRF7‐deficient mice were surprisingly efficient in controlling MCMV replication and were only modestly more susceptible to MCMV infection than WT mice. NK cell cytotoxicity was unimpaired and NK cell IFN‐γ production was enhanced in IRF7‐deficient mice correlating with increased levels of bioactive IL‐12. Owing to these compensatory mechanisms IRF7‐dependent antiviral immune responses were not essential for resistance against acute MCMV infection in vivo.
Mouse Th17 cells: Current understanding of their generation and regulation
Authors: Dong Chen 
Published: March 2009

AbstractIL‐17‐expressing CD4+ T cells have been recently recognized as a new subset of Th cells, namely Th17 cells. Considerable progress has been made in understanding the developmental regulation of mouse Th17 cells. Here, I summarize this knowledge and discuss on the relationship of Th17 with regulatory and follicular Th cells.
Diseases that may benefit from manipulating the Th17 pathway
Authors: Miossec Pierre 
Published: March 2009

AbstractThe discovery of IL‐17 and of the Th17 pathway has been a step in the classification of human diseases. Th17 targeting appears rather straightforward in diseases associated with inflammation and matrix destruction, such as rheumatoid arthritis, psoriasis, and Crohn's disease. In other conditions where IL‐17 is expressed and Th17 activated, it is unclear whether this is a primary or secondary event, making the use of Th17 inhibitors less obvious.
IL‐17 and anti‐bacterial immunity: Protection versus tissue damage
Authors: Cooper Andrea M. 
Published: March 2009

AbstractIL‐17 can impact health in a variety of ways. It is protective for some pathogens but it is also associated with tissue damaging inflammation. By examining the role of IL‐17 in a variety of bacterial infections the mechanisms by which this cytokine mediates both protection and damage can be dissected. A key element in understanding the role of this cytokine is determining where and when it is acting. Dissecting its essential protective role from its immunopathologic role will allow for improved intervention in both acute and chronic disease.
Modulation of Th17 development and function by activation of the aryl hydrocarbon receptor – the role of endogenous ligands
Authors: Stockinger Brigitta , Veldhoen Marc , Hirota Keiji 
Published: March 2009

AbstractThe elucidation of the crucial differentiation factors for the new Th17 CD4 effector T‐cell subset spurred an explosive growth in research publications focused on these cells and led to rapid advances in knowledge concerning their regulation and functional activities. Here we discuss recent discoveries linking the development and functional potential of Th17 cells to a transcription factor that mediates the response to exogenous and endogenous environmental signals.
How B cells shape the immune response against Mycobacterium tuberculosis
Authors: Maglione Paul J. , Chan John 
Published: March 2009

AbstractExtensive work illustrating the importance of cellular immune mechanisms for protection against Mycobacterium tuberculosis has largely relegated B‐cell biology to an afterthought within the tuberculosis (TB) field. However, recent studies have illustrated that B lymphocytes, through a variety of interactions with the cellular immune response, play previously underappreciated roles in shaping host defense against non‐viral intracellular pathogens, including M. tuberculosis. Work in our laboratory has recently shown that, by considering these lymphocytes more broadly within their variety of interactions with cellular immunity, B cells have a significant impact on the outcome of airborne challenge with M. tuberculosis as well as the resultant inflammatory response. In this review, we advocate for a revised view of TB immunology in which roles of cellular and humoral immunity are not mutually exclusive. In the context of our current understanding of host defense against non‐viral intracellular infections, we review recent data supporting a more significant role of B cells during M. tuberculosis infection than previously thought.
New assay to detect low‐affinity interactions and characterization of leukocyte receptors for collagen including leukocyte‐associated Ig‐like receptor‐1 (LAIR‐1)
Authors: Jiang Lei , Barclay A. Neil 
Published: March 2009

AbstractLeukocyte activity is controlled by numerous interactions between membrane receptors and ligands on the cell surface. These interactions are of low affinity making detection difficult. We developed a sensitive assay that could readily detect extremely weak interactions such as that between CD200 and the activating receptor CD200RLa (Kd>500 μM) at the protein level. We used the new technology to screen for interactions of inhibitory receptors for collagens. We confirmed that both human and mouse leukocyte‐associated Ig‐like receptor‐1, and in addition the related inhibitory leukocyte Ig‐like receptor subfamily B member 4 (CD85K, Gp49B), bound collagen specifically, whereas other cell surface proteins gave no binding. The monomeric affinities of the interactions were then determined to allow comparison with other leukocyte interactions and indicate conditions when these interactions might lead to inhibitory signals.
CTLA‐4 co‐receptor impacts on the function of Treg and CD8+ T‐cell subsets
Authors: Rudd Christopher E. 
Published: March 2009

AbstractCTLA‐4 has potent regulatory effects on the threshold of T‐cell signalling and, in the process, guards against the development of hyper‐proliferation and autoimmunity. Despite this, the role of CTLA‐4 on specific T‐cell subsets has been unclear. Such studies could shed light on both the function of CTLA‐4, and on the contribution of the subsets to the disease phenotype of the Ctla4−/− mouse. Recently, a role for this co‐receptor in the function of Treg has been outlined and, in this issue of the European Journal of Immunology, the selective targeting of the T‐box transcription factor Eomes by CTLA‐4 in the regulation of CD8+ cytolytic T‐cell (CTL) effector function is shown. Together, these papers shed light on the role of CTLA‐4 in different T‐cell subsets.
Laser CVD of Nanodisperse Ge–Sn Alloys Obtained by Dielectric Breakdown of SnH4/GeH4 Mixtures
Authors: Křenek Tomáš , Bezdička Petr , Murafa Nataliya , Šubrt Jan , Pola Josef 
Published: March 2009

AbstractTEA CO2 laser‐induced dielectric breakdown of an equimolar mixture of gaseous stannane and germane in Ar allows decomposition of both metal hydrides and chemical vapour deposition of the nanostructured Ge/Sn films. Analysis of the films by FTIR and Raman spectroscopy, X‐ray diffraction analysis and electron microscopy revealed nanoregions of crystalline Sn and Sn‐rich Ge/Sn alloys surrounded by an amorphous Ge/Sn phase. The crystalline Ge/Sn nanoalloys contain different amounts of Sn incorporated into the Ge lattice and undergo changes in composition at temperatures as low as 200 °C.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis and Characterization of a Series of New Luminescent NHC‐Coordinated AuI–AgI Tetra‐ and Polymetallic Complexes Containing Benzoate‐Bridged Ag2 Dimers
Authors: Ghosh Amit K. , Catalano Vincent J. 
Published: March 2009

AbstractThe reaction of [Au(CH3impy)2]PF6 (2), with substituted silver benzoate salts bearing different halide substituents produced a series of new mixed‐metal species having two different structural motifs. One structural motif contains discrete tetrametallic Ag2Au2 diamond cores, whereas the other motif contains the same tetrametallic diamond core interconnected by benzoate‐bridged silver dimers to form polymers. All the complexes are substitution‐inert and stable both in the solid state as well as in solution. We also report the synthesis of oxidative addition products of [Au(CH3impy)2]PF6, which were also obtained during our attempts to oxidize the above‐mentioned multimetallic assembly with bromine and iodine. Compounds 3–7 are intensely luminescent in frozen acetonitrile solution, but surprisingly no luminescence is observed at room temperature. All the complexes were completely characterized by 1H, 13C NMR, electronic absorption, emission spectroscopy, elemental analysis and X‐ray crystallography. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Organoplatinum(IV) Complexes with Amide Groups: Supramolecular Structure as a Function of Ligand Flexibility
Authors: Au Richard H. W. , Jennings Michael C. , Puddephatt Richard J. 
Published: March 2009

AbstractThe oxidative addition of the benzyl bromide derivative 4‐BrCH2C6H4(CH2)xC(=O)NH(CH2)y‐4‐C6H4‐tBu (A), x = y = 0; (B), x = 0, y = 1; (C), x = 1, y = 0; (D), x = y = 1, to the dimethylplatinum(II) complex [PtMe2(bu2bipy)] (1), bu2bipy = 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine, gave the corresponding amide‐substituted benzylplatinum(IV) complexes of the formula [PtBrMe2(4‐CH2C6H4(CH2)xC(=O)NH(CH2)y‐4‐C6H4‐tBu)(bu2bipy)], bu2bipy = 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine, 2–5. In the solid state, the complexes 2–5 undergo self‐assembly to give the supramolecular polymers 2–4 or the dimers 5. Intermolecular N–H···Br‐Pt hydrogen bonds are favored over the typical NH···O=C hydrogen bonds found in organic amides. The carbonyl group may be hydrogen‐bonded to solvent or not involved in hydrogen bonding. The structures are dependent on the size and flexibility of the amide‐substituted benzyl group. In solution, the complexes 3–5 exhibited an equilibrium between the neutral complexes and the bromo‐bridged, ionic binuclear complexes [(μ‐Br){PtBrMe2(4‐CH2C6H4(CH2)xC(=O)NH(CH2)y‐4‐C6H4‐tBu)(bu2bipy)}2]Br. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Calorimetric study of milk fat/rapeseed oil blends and their interesterification products
Authors: Aguedo Mario , Giet Jean‐Michel , Hanon Emilien , Lognay Georges , Wathelet Bernard , Destain Jacqueline , Brasseur Robert , Vandenbol Micheline , Danthine Sabine , Blecker Christophe , Wathelet Jean‐Paul 
Published: March 2009

AbstractMilk fat (MF) and rapeseed oil (RO) blends were analyzed by differential scanning calorimetry (DSC). It was shown that peak and onset temperatures can be used to determine the percentage of each fat in the blend and that the relative enthalpy of one peak assigned to low‐melting triacylglycerols (TAG) can also be used to determine the percentage of RO in the blend. A linear relation was also established between MF content of the blend and its dropping point (DP), indicating that DP can be linearly related with the above DSC data. A blend of MF/RO 70 : 30 (wt/wt) was then chosen as a model system for enzymatic interesterification (EIE). The applicability of DSC analyses to EIE products was checked and a correct correlation could be established between DSC values and the interesterification degree and DP. Among the data from the DSC profiles, the peak associated with low‐melting TAG was the best indicator of the reaction course. In the same way, a high‐melting MF stearin fraction was interesterified with RO. In that case, onset temperatures and peak “a” were better reaction indicators than for the interesterified MF/RO blend. We therefore suggest that values from DSC endotherms could be used to monitor EIE of fat blends.
Furo[3,4‐b]benzodioxin Cycloadditions – A One‐Pot Synthesis of Functionalized Bis‐Adducts
Authors: Bozzo Consol , Mur Núria , Constans Pere , Pujol Maria Dolors 
Published: March 2009

AbstractFuro[3,4‐b]benzodioxin 1 was found to undergo a doubleDiels–Alder reaction with several dienophiles. The diene reacts directly with the suitable dienophile to give the mono‐adduct intermediate that unexpectedly leads to a second cycloaddition at the internal, electron‐rich, oxabicyclic C4a–C10a double bond. The resulting bis‐adducts were formed under relatively mild conditions with dienophiles ranging from maleic anhydride and dimethyl acetylenedicarboxylate to the extremely reactive arynes. With this methodology of two uninterrupted sequential cycloaddition reactions, interesting formation of stable bis‐adducts was observed. The dienophile behavior of 1,4‐benzodioxin is described for the first time in this work.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Rhodium‐Catalyzed Tandem Transformations with Organoboron Reagents: Sequential Multiple C–C Bond Formations
Authors: Youn So Won 
Published: March 2009

AbstractTandem transformations represent one of the most efficient methods for the synthesis of complex molecules from readily available starting materials, as evidenced by the intense research activity and the plethora of literature published in this area. This review highlights recent developments of rhodium(I)‐catalyzed tandem transformations with organoboron compounds involving the formation of multiple carbon–carbon bonds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Tandem Staudinger–Aza‐Wittig Templated Reaction: De Novo Synthesis of Sugar–Ureido Cryptands
Authors: Porwanski Stanislaw , Marsura Alain 
Published: March 2009

AbstractA templated Staudinger–aza‐Wittig tandem reaction selectively affords in one step a monocellobiosyl[bis(ureido)]diazacrown cryptand and a bis(cellobiosyl)tetraureido[bis(diazacrown)] cryptand. Formation of each type of cryptand was under control by Na+ or Cs+ template effect. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A New Chromium(III) Microelectrode Based on Self‐Assembled Diethylenetriamminepentaacetic Acid‐Poly(fuchsin basic) Modified Electrode
Authors: Li Jianping , Le Shangwang , Li Qiuyan , Zhang Xuehong 
Published: March 2009

AbstractA new selective, sensitive, and rapid response microelectrode for microamount chromium(III) determination was developed. For the electrode preparation, fuchsin basic was electropolymerized onto a carbon microdisk electrode, and then diethylenetriamminepentaacetic acid (DTPA) was self‐assembled on the electrode surface by the reaction between DTPA and poly(fuchsin basic). The determination conditions were optimized. The electrode showed a linear response to Cr3+ ions in the concentration range of 1.0×10−6−1.0×10−4 M and exhibits a super‐Nernstian slope of 32.5±0.4 mV per decade. The detection limit is 3.6×10−7 M. The response time of the electrode is less than 10 s, and it can be used for at least 2 months with limited considerable divergences in its potentials. The proposed electrode was applied for monitoring the chromium ion level in wastewater of chromate industries.
Electrochemical Oxidation of Berberine and of Its Oxidation Products at a Glassy Carbon Electrode
Authors: Diculescu Victor C. , Enache Teodor Adrian , Oliveira Paulo J. , Oliveira‐Brett Ana Maria 
Published: March 2009

AbstractThe electrochemical behavior of berberine, an isoquinoline plant alkaloid with a wide spectrum of physiological effects, was studied at a glassy carbon electrode using cyclic, differential pulse and square‐wave voltammetry. The oxidation of berberine is a quasireversible, diffusion‐controlled process and occurred in a cascade mechanism with the formation of several oxidation products. The diffusion coefficient of berberine was calculated from cyclic voltammetry studies to beD=1.69×10−6cm2s−1. The oxidation process of berberine is also pH dependent and the number of electrons and protons transferred was determined using differential pulse voltammetry. The formation of several oxidation products that adsorbed at the glassy carbon electrode surface was observed and their electrochemical behavior characterized. A mechanism for the oxidation of berberine at a glassy carbon electrode was proposed.