bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constitutive activation of Bruton's tyrosine kinase induces the formation of autoreactive IgM plasma cells
Authors: Kersseboom Rogier , Kil Laurens , Flierman Roelof , van der Zee Marten , Dingjan Gemma M. , Middendorp Sabine , Maas Alex , Hendriks Rudi W. 
Published: July 2010

AbstractB‐cell receptor (BCR)‐mediated signals provide the basis for B‐cell differentiation in the BM and subsequently into follicular, marginal zone, or B‐1 B‐cell subsets. We have previously shown that B‐cell‐specific expression of the constitutive active E41K mutant of the BCR‐associated molecule Bruton's tyrosine kinase (Btk) leads to an almost complete deletion of immature B cells in the BM. Here, we report that low‐level expression of the E41K or E41K‐Y223F Btk mutants was associated with reduced follicular B‐cell numbers and significantly increased proportions of B‐1 cells in the spleen. Crosses with 3‐83μδ and VH81X BCR Tg mice showed that constitutive active Btk expression did not change follicular, marginal zone, or B‐1 B‐cell fate choice, but resulted in selective expansion or survival of B‐1 cells. Residual B cells were hyperresponsive and manifested sustained Ca2+ mobilization. They were spontaneously driven into germinal center‐independent plasma cell differentiation, as evidenced by increased numbers of IgM+ plasma cells in spleen and BM and significantly elevated serum IgM. Because anti‐nucleosome autoantibodies and glomerular IgM deposition were present, we conclude that constitutive Btk activation causes defective B‐cell tolerance, emphasizing that Btk signals are essential for appropriate regulation of B‐cell activation.
Developing T lymphocytes are uniquely sensitive to a lack of topoisomerase III alpha
Authors: Mönnich Maren , Hess Isabell , Wiest Waltraud , Bachrati Csanad , Hickson Ian D. , Schorpp Michael , Boehm Thomas 
Published: July 2010

AbstractAll organisms possess at least one type IA DNA topoisomerase. These topoisomerases function as part of a DNA structure‐specific “dissolvasome,” also known as the RTR complex, which has critical functions in faithful DNA replication, recombination, and chromosome segregation. In humans, the heteromeric RTR complex consists of RMI1, RMI2, the Bloom's syndrome gene product (BLM), and topoisomerase 3A (TOP3A) proteins. Here, we describe the identification and characterization of two deleterious mutations in the zebrafish top3a gene that reveal an unexpected tissue‐specific requirement of top3a function in developing thymocytes. Deficiency in top3a activates a p53‐dependent check‐point but does not affect VDJ recombination. Our results suggest that TOP3A could be a candidate gene involved in human primary immunodeficiency syndromes.
Convergent pathways of macrophage polarization: The role of B cells
Authors: Sica Antonio , Porta Chiara , Riboldi Elena , Locati Massimo 
Published: July 2010

AbstractThe construction of an inflammatory microenvironment provides the fuel for cancer development and progression. Hence, solid tumors promote infiltration of leukocyte populations, among which tumor‐associated macrophages (TAM) represent a paradigm for cancer‐promoting inflammation. TAM orchestrate various aspects of cancer, including diversion and skewing of adaptive responses, cell growth, angiogenesis, matrix deposition and remodelling, the construction of a metastatic niche and actual metastasis, response to hormones and chemotherapeutic agents. Several lines of evidence indicate that TAM show a remarkable degree of plasticity and functional heterogeneity, suggesting that during tumor progression macrophages undergo a phenotypic “switch”, eventually exhibiting the alternatively activated, “M2”, phenotype that is associated with immunosuppression, promotion of tumor angiogenesis and metastasis. Although recent studies have attempted to address the role of microenvironmental signals on TAM “reprogramming”, the interplay between innate and adaptive immunity is emerging as a crucial step of this event. In this issue of the European Journal of Immunology, a study demonstrates that B1 lymphocytes expressing IL‐10 play a key role in promoting a pro‐tumoral M2‐biased phenotype of macrophages. This article defines a new in vivo pathway of macrophage polarization and suggests that targeting B cells is a possible therapeutic intervention to reinstate anti‐cancer functions by TAM.
The Vibrational Spectra of the Cyanide Ligand Revisited: Double Bridging Cyanides
Authors: Kettle Sidney F. A. , Diana Eliano , Marchese Edoardo M. C. , Boccaleri Enrico , Croce Gianluca , Sheng Tianlu , Stanghellini Pier Luigi 
Published: July 2010

AbstractThe vibrational behaviour of complexes of general formula [(ML5CN)2M′L′4] with either a cis or trans geometry has been studied. The ν(CN) modes have been assigned on the basis of both infrared and Raman intensities. The CN vibrators are but weakly coupled, particularly so in the cis arrangement. The spectroscopic analysis offers insights into the interpretation of the spectra of Prussian Blue species as cis and trans M–CN–M′–NC–M complexes may be regarded as building blocks of Prussian Blue. The structure of the complex [(CO)5MoCNNi(Bipy)2NCMo(CO)5] confirms the expected cis geometry of the metal core. The complex [Cp(dppe)FeNCRu(4‐EtPy)4CNFeCp(dppe)]3+[PF6–]3 was prepared by oxidising the reduced form (2+ cation) and its crystal structure was determined and compared with that of the starting complex. Analysis of the structural and spectroscopic data led to the conclusion that the two iron atoms in the oxidised form have different charges and that the vibrations of the two CN groups are essentially independent. DFT calculations indicate that although π‐bonding and antibonding occur, electrostatic effects (as described by the IVSE model) are probably more important.
pH‐Responsive Switching of the Near‐Infrared Absorption of the Water‐Soluble Bis(o‐diiminobenzosemiquinonato)platinum(II) Complex
Authors: Masuya Atsuko , Iki Nobuhiko , Kabuto Chizuko , Ohba Yasunori , Yamauchi Seigo , Hoshino Hitoshi 
Published: July 2010

AbstractThe electronic structure of a water‐soluble near‐infrared (NIR)‐absorbing complex was determined to be singlet diradical [PtII(LISQ)2]2– [(LISQ)2–· = o‐diiminosulfobenzosemiquinonate radical] by X‐ray diffraction and 1H NMR spectroscopy. Cyclic voltammetry (CV) showed redox reactions of [PtII(LISQ)2]2– to give [PtII(LISQ)(LIBQ)]– (E${1 \over 2}$1 = –0.26 V vs. Fc+/Fc) and [PtII(LISQ)(LPDI)]3– (E${1 \over 2}$2 = –1.46 V) [(LIBQ)– = o‐diiminosulfobenzoquinonate, (LPDI)3– = o‐phenylenediiminesulfonate]. The monoradical structure of the latter was confirmed by electron paramagnetic resonance (EPR) spectroscopy. Splitting of the reduction wave of [PtII(LISQ)(LIBQ)]– in CV and the weak EPR signal suggested the formation of a dimer. Because the rest potential of the solution exceeds Epa1 at pH 4.0, the decrease in the NIR absorption at pH < 4.0 can be attributed to the oxidation of [PtII(LISQ)2]2– followed by dimerization.
Synthesis and Reaction Chemistry of Heterodi‐ and Heterotrimetallic Transition‐Metal Complexes Based on 1‐(Diphenylphosphanyl)‐1′‐terpyridylferrocene
Authors: Hildebrandt Alexander , Wetzold Nora , Ecorchard Petra , Walfort Bernhard , Rüffer Tobias , Lang Heinrich 
Published: July 2010

AbstractThe reaction of [Fe(η5‐C5H4PPh2)(η5‐C5H4terpy)] (5; terpy = 2,2′:6′,2″‐terpyridin‐4′‐yl) with diverse transition‐metal compounds including [PtCl2(Et2S)2], [Pd(cod)X2], [AuCl(tht)], [CuBr], [Mo(CO)4(nbd)], and [{RhCl(cod)}2] (X = Cl, Br; tht = tetrahydrothiophene; nbd = norbornadiene; cod = cyclooctadiene) to afford heterobi‐ and trimetallic complexes and a coordination polymer is reported. The following compounds were prepared: [Fe(η5‐C5H4PPh2{PtCl2(SEt2)})(η5‐C5H4terpy)] (7), trans‐[PtCl2{(Ph2P‐η5‐C5H4)(η5‐C5H4terpy)Fe}2] (9), [Fe(η5‐C5H4PPh2PdCl2)(η5‐C5H4terpy)] (12), [Fe{η5‐C5H4PPh2(Cl3Pd–)}(η5‐C5H4terpy{(dmso)2ClNi+})] (14), trans‐[PdX2{(Ph2P‐η5‐C5H4)(η5‐C5H4terpy)Fe}2] (16a, X = Cl;16b, X = Br), [Mo(CO)4{(η5‐C5H4PPh2)(η5‐C5H4terpy)Fe}2](17), [Fe{η5‐C5H4Ph2P(CuBr)}(η5‐C5H4terpy)]n (19), [Fe{η5‐C5H4Ph2P(AuCl)}(η5‐C5H4terpy)] (22), [Fe(η5‐C5H4Ph2P{Rh(cod)Cl})(η5‐C5H4terpy)] (23), [Ru({η5‐C5H4Ph2P(AuCl)}(η5‐C5H4terpy)Fe)2]Cl2 (25), and [Fe{η5‐C5H4PPh2(PdCl2)}{η5‐C5H4‐CH=CHC(O)(py)}] (26). The molecular structures of 5, 9, 12, 14, 16b, 22, and 26 in the solid state are reported. They show typical features of related phosphanylferrocenes and terpyridylferrocenes. Characteristic of 12 is a C–H activation as a result of the close distance of palladium to the terpyridyl moiety. Complexes 12, 26, and [PdCl2(dppf)] [dppf = 1,1′‐bis(diphenylphosphanyl)ferrocene], for comparison, were used in preliminary studies as catalysts in the carbon–carbon coupling of iodobenzene with tert‐butyl acrylate to give (E)‐tert‐butyl cinnamate. The conversion amounts to 80 % with a turnover number of 160 and turnover frequency of 48 h–1.
“Tail–Tail Dimerization” of Ferrocene Amino Acid Derivatives
Authors: Siebler Daniel , Förster Christoph , Heinze Katja 
Published: July 2010

AbstractAcid anhydrides of N‐protected 1′‐aminoferrocene‐1‐carboxylic acid (Fca) have been prepared and spectroscopically characterized (protection group Boc, Fmoc, Ac; 4a–4c). The structure of the Boc‐derivative 4a has been determined by single‐crystal X‐ray crystallography. An intramolecular N–H···O hydrogen bond involving the carbamate units results in a ring structure containing the two ferrocene units, the anhydride moiety, and the hydrogen bond. In the crystal, the individual molecules are connected by intermolecular N–H···O hydrogen bonds of the carbamate unit. Experimental and theoretical studies suggest that the ring motif is also a dominant species in solution. Electronic communication across the anhydride moiety is found to be very weak as judged from electrochemical, spectroscopic, and theoretical experiments.
Postprandial lipemic response to alpha‐linolenic acid rich oil, butter, and olive oil
Authors: Svensson Julia , Rosenquist Anna , Adlercreutz Patrick , Nilsson Åke , Ohlsson Lena 
Published: July 2010

AbstractPostprandial lipemia varies with composition of dietary fat due to partitioning of fatty acids between β‐oxidation, incorporation into TAG, and tissue lipids. Effects of alpha‐linolenic acid (ALA) are poorly characterized. Lipase‐catalyzed transesterification was used to produce a novel ALA‐oil (35% ALA) from rapeseed and linseed oil. We hypothesized a lower postprandial lipemic response with ALA‐oil than with olive oil and butter due to higher β‐oxidation of ALA. A randomized crossover study with 26 healthy men compared the effects on plasma lipids 7 h after a breakfast containing 35 g ALA‐rich oil, butter fat, or olive oil. The incremental area under curve for plasma TAG was lower with butter than with olive oil (34%, p<0.05) and ALA‐oil (25%, ns). After ALA‐oil percentage ALA increased, in TAG to a constant level of 7 mol% and in NEFA to 6% after 7 h. Since total NEFA increased with time the amount of exogenous ALA in NEFA also increased. Butter resulted in lower postprandial lipemia than the oils, the difference exceeding what is expected from the presence of short and medium chain fatty acids in butter. There was a considerable recirculation of ALA into the NEFA pool available for oxidation.Practical application: Enzymatic transesterification was used to produce a dietary oil rich in ALA. By randomizing the partitioning of ALA more evenly between the TAG molecules the risk of oxidation could be reduced. Analyses showed that the ALA‐oil was stable during storage for at least 3 months. Enzymatic transesterification could be used as an advantageous method to design an ALA rich dietary oil with new properties regarding fatty acid composition, susceptibility to oxidation, and effects on blood lipids.
Nucleophilicities and Nucleofugalities of Organic Carbonates
Authors: Streidl Nicolas , Branzan Ramona , Mayr Herbert 
Published: July 2010

AbstractThe kinetics of the reactions of the methyl carbonate ion with benzhydrylium ions in acetonitrile have been studied by UV/Vis spectrophotometry. Substitution of the resulting second‐order rate constants and the electrophilicity parameters E of the benzhydrylium ions into the linear free energy relationship log k = s(N + E) yielded the nucleophilicity parameters N25 = 16.03 and s25 = 0.64 for methyl carbonate in acetonitrile. The kinetics of the reverse reactions, i.e., of the solvolyses of ring‐substituted benzhydryl alkyl carbonates in different aqueous solvents were followed by conductimetry. The obtained first‐order rate constants and the known electrofugality parameters Ef of benzhydrylium ions were used to determine the nucleofugality parameters Nf and sf of the ROCO2– groups by using the linear free energy relationship log k = sf(Nf + Ef). The leaving group abilities of carbonates decrease by a factor of about 300 from PhOCO2– over MeOCO2– and iBuOCO2– to tBuOCO2– in various alcoholic and aqueous solvents. tert‐Butyl carbonates (tBocO‐R) are, thus, considerably more stable with respect to heterolytic cleavage of the O–R bond than other organic carbonates.
A Combined Experimental and Theoretical Study of Anion–π Interactions inN6‐ andN9‐Decyladenine Salts
Authors: Garcia‐Raso Angel , Albertí Francisca M. , Fiol Juan J. , Lagos Yolanda , Torres Marta , Molins Elies , Mata Ignasi , Estarellas Carolina , Frontera Antonio , Quiñonero David , Deyà Pere M. 
Published: July 2010

AbstractWe report the synthesis and X‐ray characterization of N9‐ and N6‐decyladenine hydrochloride salts. The latter exhibits interesting anion–π interactions, which are responsible for crystal packing. In contrast, the former does not present any anion–π interactions; the anion is stabilized by hydrogen‐bonding interactions. Finally, a theoretical study of the different binding modes observed in the solid state is useful to explain the experimental findings.
Functionalized Chiral Ionic Liquid Catalyzed Asymmetric SN1 α‐Alkylation of Ketones and Aldehydes
Authors: Zhang Long , Cui Lingyun , Li Xin , Li Jiuyuan , Luo Sanzhong , Cheng Jin‐Pei 
Published: July 2010

AbstractPyrrolidine‐derived functionalized chiral ionic liquids (FCILs) have been found to catalyze asymmetric SN1 α‐alkylations of ketones and aldehydes with up to 99 % yield, >99:1 dr and 87 % ee. The FCIL catalysts enable SN1 α‐alkylations of cyclic ketones, particularly of 3‐ and 4‐substituted cyclohexanones with excellent diastereoselectivity and good enantioselectivity, featuring unprecedented desymmetrization and kinetic resolution processes for these types of asymmetric reaction. Full details of this study as well as the proposed enamine transition‐state are presented.
Inductively Heated Oxides Inside Microreactors – Facile Oxidations under Flow Conditions
Authors: Wegner Jens , Ceylan Sascha , Friese Carsten , Kirschning Andreas 
Published: July 2010

AbstractInductively heated iron oxides mixed with solid oxidants like CrO2 and NiO2 efficiently oxidize organic substrates under flow conditions in fixed‐bed reactors.
Metal‐Catalyzed Cycloisomerization and Tandem Oxycyclization/Hydroxylation of Alkynols: Synthesis of Nonfused, Spiranic and Fused Oxabicyclic β‐Lactams
Authors: Alcaide Benito , Almendros Pedro , Martínez del Campo Teresa , Carrascosa Rocío 
Published: July 2010

Abstract2‐Azetidinone‐tethered alkynols, readily prepared from the corresponding aldehydes or ketones, were used as starting materials for the oxycyclization reaction catalyzed by precious metals. AgOAc exclusively affords dihydrofurans, methylenetetrahydrofurans, or methylenetetrahydro‐2H‐pyrans through specific 5‐endo, 5‐exo, or 6‐exo pathways, respectively. Interestingly, in the presence of a catalytic amount of PtII or AuIII salts, cyclization reactions occurred preferentially through a tandem oxycyclization/hydroxylation of alkynols to afford a variety of nonfused, spiranic and fused oxabicyclic β‐lactams in moderate to high yields. Besides, it has been observed that the tandem gold‐catalyzed cycloetherification/hydroxylation of a methoxymethyl alkynyl ether can be accomplished.
Elimination Procedure as a Novel and Promising Mathematical Approach in Voltammetric Methods
Authors: Serrano Nuria , Klosova Katerina , Trnkova Libuse 
Published: July 2010

AbstractIn the contribution, it has been demonstrated that Elimination Voltammetry with Linear Scan (EVLS) introduces an enhancement of the linear sweep and/or cyclic voltammetric results, and provides information about the type of the currents involved in the considered process. An extension of EVLS has been developed for any combination of scan rates (integers) for six elimination functions that are capable of conserving or eliminating of some voltammetric current components. Simple procedure to obtain the necessary coefficients from the chosen scan rates has been reported. In addition, the calculation and discussion of the relative error of elimination function (REEF) have been presented. The verification of the presented calculations has been done by studying different ratios of scan rates for reduction and oxidation processes of Cd(II) at a hanging mercury drop electrode (HMDE).
Stripping Voltammetric Determination of Methylmercury in the Presence of Inorganic Mercury
Authors: Korolczuk Mieczyslaw , Stepniowska Anna 
Published: July 2010

AbstractA procedure for methylmercury determination in the presence of a large excess of Hg(II) is described. In this procedure to increase the selectivity of methylmercury determination a gold film electrode coated with Nafion and complexation of Hg(II) by DTPA were examined. Gold film was covered with Nafion film using a pneumatic nebulizer from an AAS apparatus. Electrochemical regeneration of a gold film electrode coated with Nafion film was proposed. At optimized conditions the calibration graph for methylmercury in the presence of 2.5×10−5 mol L−1 Hg(II) was linear in the range from 1×10−8 to 5×10−7 mol L−1 for the deposition time of 300 s.
The Impact of Intermetallic Compounds CuxZn in the Determination of Free Zn2+ Concentration with AGNES
Authors: Chito Diana , Galceran Josep , Companys Encarnació 
Published: July 2010

AbstractIntermetallic compounds can interfere the determination of free Zn with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping). The “trajectory” (plot of the retrieved currents in front of the deposition times) diverges from the “reference current” (i.e. that unaffected by the interference) at a critical time and eventually reaches steady state. Most experimental AGNES results are interpreted with a thermodynamic model, while others require kinetic considerations. We identify safe conditions for AGNES measurements and show that free Zn can be determined with the simplest implementation provided that total Cu concentration is less than 45 times that of free Zn.
Voltammetric Determination of Genotoxic Nitro Derivatives of Fluorene and 9‐Fluorenone Using a Mercury Meniscus Modified Silver Solid Amalgam Electrode
Authors: Vyskočil Vlastimil , Navrátil Tomáš , Polášková Petra , Barek Jiří 
Published: July 2010

AbstractVoltammetric behavior of selected genotoxic nitro compounds (2‐nitrofluorene, 2,7‐dinitrofluorene, 2‐nitro‐9‐fluorenone and 2,7‐dinitro‐9‐fluorenone) has been investigated using direct current voltammetry (DCV), differential pulse voltammetry (DPV) and adsorptive stripping differential pulse voltammetry (AdSDPV) at a mercury meniscus modified silver solid amalgam electrode (m‐AgSAE). The optimum conditions have been found for their determination in a 1 : 1 mixture of methanol and aqueous Britton–Robinson buffer solution, with the limits of quantification, (LOQ), 2, 0.3, 0.5, and 0.5 μmol L−1 (DCV at m‐AgSAE) and 0.2, 0.2, 0.4, and 0.2 μmol L−1 (DPV at m‐AgSAE) for 2‐nitrofluorene, 2,7‐dinitrofluorene, 2‐nitro‐9‐fluorenone, and 2,7‐dinitro‐9‐fluorenone, respectively. An attempt at increasing the sensitivity using AdSDPV at m‐AgSAE was successful only for 2‐nitrofluorene (LOQ=2 nmol L−1). Practical applicability of the newly developed methods was verified on direct determination of the studied compounds in drinking and river waters with LOQs ~ 10−7 mol L−1 for all the studied compounds.
Elimination Voltammetry of Miniaturized Mercury Drop Electrodes
Authors: Trnkova Libuse , Novotny Ladislav , Serrano Nuria , Klosova Katerina , Polaskova Petra 
Published: July 2010

AbstractElimination voltammetry with linear scan (EVLS) in connection with renewed mini‐ drop mercury electrodes provides valuable information about the character and kinetics of processes at electrode/electrolyte interfaces. Based on the experiment related to the hydrogen evolution, it is presented that the EVLS is more sensitive than other voltammetric methods. Using miniaturized mercury electrodes, the EVLS is capable of detecting the effect of spherical diffusion associated with both the scan rates and the size of an electrode drop.
Capillary sieving electrophoresis and micellar electrokinetic capillary chromatography produce highly correlated separation of tryptic digests
Authors: Dickerson Jane A. , Dovichi Norman J. 
Published: July 2010

AbstractWe perform 2‐D capillary electrophoresis on fluorescently labeled proteins and peptides. Capillary sieving electrophoresis (CSE) was performed in the first dimension and MEKC was performed in the second. A cellular homogenate was labeled with the fluorogenic reagent FQ and separated using the system. This homogenate generated a pair of ridges; the first had essentially constant migration time in the CSE dimension, while the second had essentially constant migration time in the MEKC dimension. In addition, a few spots were scattered through the electropherogram. The same homogenate was digested using trypsin, and then labeled and subjected to the 2‐D separation. In this case, the two ridges observed from the original 2‐D separation disappeared and were replaced by a set of spots that fell along the diagonal. Those spots were identified using a local‐maximum algorithm and each was fit using a 2‐D Gaussian surface by an unsupervised nonlinear least squares regression algorithm. The migration times of the tryptic digest components were highly correlated (r=0.862). When the slowest migrating components were eliminated from the analysis, the correlation coefficient improved to r=0.956.
Different ways to compute temperature return levels in the climate change context
Authors: Parey Sylvie , Hoang Thi Thu Huong , Dacunha‐Castelle Didier 
Published: July 2010

AbstractThe climate change context has raised new problems in the computation of temperature return levels (RLs) in using the statistical extreme value theory. This arises since it is not yet possible to accept the hypothesis that the series of maxima or of high level values are stationary, without at least verifying the assumption. Thus, in this paper, different approaches are tested and compared to derive high order RLs in the nonstationary context. These RLs are computed by extrapolating identified trends, and a bootstrap method is used to estimate confidence intervals. The identification of trends can be made either in the parameters of the extreme value distributions or in the mean and variance of the whole series. Then, a methodology is proposed to test if the trends in extremes can be explained by the trends in mean and variance of the whole dataset. If this is the case, the future extremes can be derived from the stationary extremes of the centered and normalized variable and the changes in mean and variance of the whole dataset. The RL can then be estimated as nonstationary or as stationary for fixed future periods. The work is done for both extreme value methods: block maxima and peak over threshold, and will be illustrated with the example of a long observation time series for daily maximum temperature in France. Copyright © 2010 John Wiley & Sons, Ltd.