bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calixarene‐Derived Mono‐Iminophosphoranes: Highly Efficient Ligands for Palladium‐ and Nickel‐Catalysed Cross‐Coupling
Authors: Monnereau Laure , Sémeril David , Matt Dominique 
Published: May 2013

AbstractThe first mono‐iminophosphoranes based on a calix[4]arene skeleton have been synthesised and tested in the arylation of aryl bromides and aryl chlorides. Combining these ligands with [Pd(OAc)2] or [Ni(cod)2] resulted in highly active Suzuki–Miyaura and Kumada–Tamao–Corriu cross‐coupling catalysts, respectively. TOFs up to ca. 4×105 mol(ArBr)⋅mol(M)−1⋅h−1 were obtained in each case. The remarkable activities observed probably arise from the ligands’ ability to form complexes with cavity‐entrapped “MArX” moieties (endo‐complexes), their highly crowded metal environment favouring formation of mono‐ligated intermediates over that of less reactive bis‐ligated ones. Possible supramolecular interactions within the cavity involving the receptor wall and the aromatic substrate may also significantly influence the reaction rates, notably by increasing the proportion of endo‐complexes.
1,4‐Phenylene and 2,5‐Thienylene π‐Linkers in Charge‐Transfer Chromophores
Authors: Kulhánek Jiří , Bureš Filip , Opršal Jakub , Kuznik Wojciech , Mikysek Tomáš , Růžička Aleš 
Published: May 2013

AbstractFifteen model charge‐transfer chromophores with ferrocene donors, NO2 acceptors, and 1,4‐phenylene and 2,5‐thienylene π‐linkers were synthesized and their properties investigated by X‐ray analysis, electrochemistry, absorption spectra, and DFT calculations. Structure–property relationships were further evaluated to answer the question of suitability of the π‐linkers in the construction of chromophore backbone. Gradual replacement of 1,4‐phenylene with 2,5‐thienylene and π‐linker extension resulted in a lower HOMO–LUMO gap, a bathochromic shift of both charge‐transfer bands, and overall planarization of the molecule. Hence, thiophene, when incorporated into a chromophore backbone, is a more polarizable moiety that allows very efficient intramolecular charge transfer.
The convergent evolution of blue iris pigmentation in primates took distinct molecular paths
Authors: Meyer Wynn K. , Zhang Sidi , Hayakawa Sachiko , Imai Hiroo , Przeworski Molly 
Published: May 2013

ABSTRACTHow many distinct molecular paths lead to the same phenotype? One approach to this question has been to examine the genetic basis of convergent traits, which likely evolved repeatedly under a shared selective pressure. We investigated the convergent phenotype of blue iris pigmentation, which has arisen independently in four primate lineages: humans, blue‐eyed black lemurs, Japanese macaques, and spider monkeys. Characterizing the phenotype across these species, we found that the variation within the blue‐eyed subsets of each species occupies strongly overlapping regions of CIE L*a*b* color space. Yet whereas Japanese macaques and humans display continuous variation, the phenotypes of blue‐eyed black lemurs and their sister species (whose irises are brown) occupy more clustered subspaces. Variation in an enhancer of OCA2 is primarily responsible for the phenotypic difference between humans with blue and brown irises. In the orthologous region, we found no variant that distinguishes the two lemur species or associates with quantitative phenotypic variation in Japanese macaques. Given the high similarity between the blue iris phenotypes in these species and that in humans, this finding implies that evolution has used different molecular paths to reach the same end. Am J Phys Anthropol 151:398–407, 2013.© 2013 Wiley Periodicals, Inc.
CD8A gene polymorphisms predict severity factors in chronic rhinosinusitis
Authors: Alromaih Saud , Mfuna‐Endam Leandra , Bosse Yohan , Filali‐Mouhim Abdelali , Desrosiers Martin 
Published: May 2013

BackgroundA genetic basis to chronic rhinosinusitis (CRS) is postulated, but remains elusive. We have recently identified low levels of circulating CD8 lymphocytes as a frequent finding in difficult‐to‐treat or refractory CRS. In major histocompatibility complex 1 class 1 (MHC1) deficiency, low circulating levels of CD8 lymphocytes secondary to mutations in the cluster of differentiation 8a (CD8A), tapasin 1 (TAP1), tapasin 2 (TAP2), or tapasin binding‐protein (TAPBP) genes lead to a clinical syndrome, which is associated with severe CRS. The objective of this work was to identify whether genetic factors associated with MHC1 deficiency are present in CRS.MethodsPrevious results from a genomewide association study of CRS were screened for polymorphisms in the CD8A, TAP1, TAP2, and TAPBP genes associated with MHC1 immunodeficiency syndrome. Significant polymorphisms were tested for associations with demographic factors characterizing severe CRS.ResultsPolymorphisms in the CD8A (rs3810831) and TAPBP (rs2282851) genes were significantly associated with CRS. Major allele homozygosity for CD8A (rs3810831) was associated with a higher frequency of affected relatives (p = 0.052), increased severity as characterized by age at diagnosis (p = 0.009), age at first surgery (p = 0.004), and number of surgeries (p = 0.008), whereas TAPBP (rs2282851) was associated increased risk for CRS (odds ratio [OR] = 2.48, p = 0.0076).ConclusionModified CD8A or TAPBP gene function may contribute to the development of refractory CRS via altered MHC1 function and reduction of circulating CD8 lymphocytes. Identification of markers in the CD8A or TAPBP genes via sequencing may offer a basis for genetic testing in CRS.
Effect of ZnCl2‐ and SiCl4‐doped TiCl4/MgCl2/THF catalysts for ethylene polymerization
Authors: Phiwkliang Wanna , Jongsomjit Bunjerd , Praserthdam Piyasan 
Published: May 2013

ABSTRACTIn this research, ethylene polymerization was carried out in the presence of different additives (ZnCl2, SiCl4, and the combined ZnCl2‐SiCl4) on TiCl4/MgCl2/THF catalytic system. The presence of ZnCl2‐SiCl4 mixtures showed higher activity in ethylene polymerization when compared with the catalytic activity in the presence of single Lewis acids, ZnCl2, or SiCl4. The modified catalyst with ZnCl2‐SiCl4 demonstrated the highest activity, which was more than three times the activity of the system without Lewis acid modification. The enhanced activity can be attributed to the reduction in the peak intensity of MgCl2/THF complexes with Lewis acid compounds as proven by XRD. This was reasonable because of some THF removal from the structure of MgCl2/THF by Lewis acid compounds. In addition to the effect of modification with additives on the partial elimination of THF, the catalytic activities could be increased due to the titanium atoms that have been locally concentrated on the surface as seen by energy dispersive X‐ray spectroscopy measurement. On the basis of the in situ electron spin resonance measurement, the mixed metal chlorides (ZnCl2‐SiCl4) addition could promote the amount of Ti3+after reduction with triethylaluminum. It revealed that the modification of TiCl4/MgCl2/THF catalytic system with mixed metal chlorides (ZnCl2‐SiCl4) is very useful for ethylene polymerization. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1588–1594, 2013
Einfaches Prüfverfahren zur Bewertung der Schubfestigkeit von Kreuzlagenholz/Brettsperrholz
Authors: Kreuzinger Heinrich , Sieder Mike 
Published: May 2013

AbstractIm Rahmen der Zustimmung im Einzelfall für die Verwendung eines eingeklebten Verbindungsmittels in kreuzweise verklebten Vollholz beim Projekt “Timber Tower” (Windkraftanlage mit Holzturm) wurde von den Autoren eine gutachterliche Stellungnahme zur Tragfähigkeit und zum Ermüdungsverhalten der Verbindung erarbeitet, welche tangierende Fragestellungen beinhaltete, wie zum Beispiel die Festigkeitswerte des Kreuzlagenholzes/Brettsperrholzes bei Beanspruchung als Schubfeld.Basic test method for valuation of shear strength of cross laminated timberIn the context of the approval in individual cases for application of glued in fasteners in cross laminated timber at the project “Timber Tower” (wind power station with timber tower) the authors have prepared an expertise for the load‐bearing capacity and the fatigue behavior of the connection. Thereby some additional questions arose, for example the strength value of the cross laminated timber in case of stress as a shear field.
Bewertung von bestehenden Brücken hinsichtlich Schiffsanprall
Authors: Kunz Claus 
Published: May 2013

AbstractZur möglichen Bewertung von bestehenden Brücken hinsichtlich Schiffsanprall wurde eine Methode entwickelt, die Schiffsstoßlast für bestehende Brücken als restnutzungsdauerabhängige Einwirkung zu berechnen. Diese Methode, als restnutzungsdauerorientiertes Konzept bezeichnet, steht in Übereinstimmung mit DIN EN 1990, die ein zuverlässigkeitsbasiertes Bemessungskonzept beinhaltet. Das Konzept berücksichtigt die aktuellen Prinzipien der Instandhaltung und erlaubt die sichere und wirtschaftliche Bewertung bestehender Brücken hinsichtlich Schiffsstoß über die verbleibende Restnutzungsdauer. Grundlage der Stoßlastbestimmung ist die Verknüpfung eines Last‐ mit einem Kollisionsmodell, wie für die Bestimmung von Schiffsstoßlasten für neue Brücken. Die Berechnung der restnutzungsdauerabhängigen dynamischen Stoßlasten übernimmt dabei die Gesamtzuverlässigkeit, wie für die Nutzungsdauer neuer Brücken, jedoch übertragen auf die Restnutzungsdauer, weil ein Versagen in der Standzeit der Brücke nicht aufgetreten war. Mit diesen Stoßlasten, die mit zunehmender Standzeit der Brücke methodengemäß geringer ausfallen, lassen sich unwirtschaftliche nachträgliche Verstärkungen verhindern. Das Konzept wurde als BAW‐Merkblatt “Nachweis bestehender Brücken auf Schiffsanprall (MNaBS)” veröffentlicht.Evaluation of existing bridges concerning ship impactExisting bridges have sometimes to be evaluated considering ship impact. Using present codes for accidental actions would often lead to rehabilitation measures or to new structures which might not be efficient regarding the rareness of serious ship collision events to bridges. Therefore a method has been developed to determine ship collision forces as time‐dependent action for the remaining lifetime of an existing bridge. This method, called remaining life expectancy concept, is based on the design concept of DIN EN 1990 which is a reliability‐based design procedure. It considers the principles of the common maintenance strategies and allows the safe and economic verification of existing bridges considering their experienced lifetime. The contribution explains the probabilistic methodology of modern ship impact determination by combining a load model with a collision model as it is used for the design of new bridges. The adaption to remaining lifetime adapted dynamic impact forces is shown. The method has been published in 2010 as a guideline by Bundesanstalt für Wasserbau.
Experimental system for real‐time assessment of potential changes in protein conformation induced by electromagnetic fields
Authors: Beyer Christian , Christen Philipp , Jelesarov Ilian , Fröhlich Jürg 
Published: May 2013

AbstractA novel experimental system to distinguish between potential thermal and non‐thermal effects of electromagnetic fields (EMFs) on the conformational equilibrium and folding kinetics of proteins is presented. The system comprises an exposure chamber installed within the measurement compartment of a spectropolarimeter and allows real‐time observation of the circular dichroism (CD) signal of the protein during EMF exposure. An optical temperature probe monitors the temperature of the protein solution at the site of irradiation. The electromagnetic, thermal, and fluid‐dynamic behavior of the system is characterized by numerical and experimental means. The number of repeated EMF on/off cycles needed for achieving a certain detection limit is determined on the basis of the experimentally assessed precision of the CD measurements. The isolated thermosensor protein GrpE of the Hsp70 chaperone system of Eschericha coli serves as the test protein. Long‐term experiments show high thermal reproducibility as well as thermal stability of the experimental setup. Bioelectromagnetics. 34:419–428. © 2013 Wiley Periodicals, Inc.
Zum Tragverhalten von Rahmenknoten mit Stahlfaserbeton unter seismischer Belastung
Authors: Röhm Constanze , Novák Balthasar , Karusala Ramanjaneyulu , Sasmal Saptarshi 
Published: May 2013

AbstractIm Rahmen eines indisch‐deutschen Kooperationsprojekts wurde das Tragverhalten von außen liegenden Rahmenknoten aus Stahlfaserbeton (SFB) unter zyklischer Belastung untersucht. Das Potenzial von SFB sollte zum einen genutzt werden, um zu hohe Bewehrungsgrade im Knoten zu verhindern und damit die Ausführung zu vereinfachen. Zum andern sollte die Umschnürungswirkung der Fasern für die Tragfähigkeit, Energiedissipation und Knotenintegrität herangezogen werden und eine alternative Bewehrungsführung zur Verschiebung des plastischen Gelenks in den Balken entwickelt werden.Nach einer allgemeinen Einführung zum Knotentragverhalten und den Vorteilen der Verwendung von SFB werden einige der experimentellen Untersuchungen vorgestellt. Dabei wurde zunächst die Knotentragfähigkeit mit SFB untersucht, um darauf aufbauend den Knoten so auszulegen, dass ein Biegeversagen im Balken in einem bestimmten Abstand zum Stützenanschnitt erzielt wird. Die Versuchsergebnisse zeigen die günstige Auswirkung der Stahlfasern auf die Energiedissipation und die Knotenintegrität. Nachrechnungen der Versuche anhand numerischer Untersuchungen sowie einem Stabwerkmodell unter Ansatz der Restzugfestigkeit des Stahlfaserbetons zeigen eine gute Übereinstimmung im Hinblick auf Traglasten und Versagensmechanismen. Der Beitrag endet mit Empfehlungen zur Auslegung eines Rahmenknotens zur Verschiebung des plastischen Gelenks in den Balken.Behaviour of FRC beam column joints under seismic loadingThe present paper discusses the behaviour of fibre reinforced concrete (FRC) beam column joints under cyclic loading carried out as an Indian‐German collaborative research project. To avoid reinforcement congestion in the joint region without compromising performance, FRC is found to be extremely potential. Addition of steel fibres would lead to improved strength, energy dissipation capacity and integrity inside the joint. Moreover an alternate reinforcement detailing has been developed to move the plastic hinge in the beam region. First, the positive effects of using FRC are discussed followed by the experimental studies. Strength of beam column joints using FRC was experimentally evaluated to ensure that they are strong enough to produce a failure in the beam at a predetermined distance away from the column face. The test results showed the beneficial effect of FRC on energy dissipation and joint integrity. Further, the results obtained from both numerical and analytical studies in terms of strength and failure mechanism are in good aggreement with those obtained from the experimental studies. The paper concludes with recommendations to design the beam column joint and to shift the plastic hinge in the beam region.
Feasibility study of semi‐selective protein precipitation with salt‐tolerant copolymers for industrial purification of therapeutic antibodies
Authors: Capito Florian , Bauer Johann , Rapp Almut , Schröter Christian , Kolmar Harald , Stanislawski Bernd 
Published: May 2013

ABSTRACTWe present a feasibility study for an antibody capturing process from clarified cell culture fluid using semi‐selective protein precipitation with salt‐tolerant copolymers. Protein precipitation is mediated by hydrophobic and electrostatic interactions with the copolymer that can be customized for the respective target. Precipitation yield with different copolymers at ionic strength of 2–22.5 mS cm−1 and pH 5.0–pH 5.7 was evaluated using pure monoclonal antibody solutions. Optimized parameters were used to elucidate yield and purity of various antibodies precipitated at physiological conditions from cell culture fluid of CHO, NS0, and SP2/0 cell culture fluid. Precipitated protein was easily redissolved in small volume, enabling concentrating monoclonal antibodies (mAb) more than 40‐fold and up to 100‐fold, while residual polymer was removed to >98% using cationic polymer attached to silica flakes. mAb recovery of >90% and host cell protein clearance of >80% were achieved, not requiring any pre‐dilution of cell culture fluid. Precipitation showed no impact on mAb binding affinity when compared to non‐precipitated mAb. The obtained yield and purity were lower compared to a protein A based purification and loss of mAb was factor 1.5–3.0 higher. Yet, for high titer mAb purification processes being implemented in the future, precipitation is an attractive option due to its ease of scalability and cost‐effectiveness. Biotechnol. Bioeng. 2013;110: 2915–2927. © 2013 Wiley Periodicals, Inc.
Facile Fluorescence‐Based Detection of PAD4‐Mediated Citrullination
Authors: Wildeman Erin , Pires Marcos M. 
Published: May 2013

AbstractThe post‐translational modifications of histone proteins are highly diverse and dynamic processes. It is becoming increasingly evident that modifying histone proteins can have a direct influence on both cellular homeostasis and disease states. Protein arginine deiminase 4 (PAD4) is an enzyme that converts peptidyl‐arginine to citrulline. The overexpression of PAD4 has been found in numerous types of human cancer and autoimmune diseases. We report a new, facile, fluorescence‐based assay for the detection of PAD4 activity that exploits the substrate specificity of trypsin to monitor the citrullination reaction carried out by PAD4 based on the fact that, upon citrullination, the positively charged arginine side chain is converted to the neutral citrulline. We show that the assay can be performed rapidly with readily available reagents and that it responds accordingly to a known PAD4 inhibitor.
ChemInform Abstract: CaTMg2 and CaTCd2 (T: Rh, Pd, Pt) with YPd2Si‐Type Structure.
Authors: Johnscher Michael , Kersting Marcel , Matar Samir F. , Poettgen Rainer 
Published: May 2013

AbstractThe title compounds are prepared from mixtures of the elements by high‐frequency melting in Nb ampules or through reactions in muffle furnaces.
ChemInform Abstract: Structural Characterization and Physical Properties of the New Transition Metal Oxyselenide La2O2ZnSe2.
Authors: Tuxworth Andrew J. , McCabe Emma E. , Free David G. , Clark Stewart J. , Evans John S. O. 
Published: May 2013

AbstractThe title compound is prepared from a mixture of La2O3, Se, and Zn using Al powder as an oxygen getter (alumina crucibles in an evacuated silica tube, 1100 °C, 12 h).
ChemInform Abstract: New Fluoride Carbonates: Centrosymmetric KPb2(CO3)2F and Noncentrosymmetric K2.70Pb5.15(CO3)5F3.
Authors: Tran T. Thao , Halasyamani P. Shiv 
Published: May 2013

AbstractK2.70Pb5.15(CO3)5F3 (I) and KPb2(CO3)2F (II) are solvothermally synthesized from mixtures of Pb(OAc)2, KF, MeOH, and trifluoroacetic acid (autoclave, 180 °C, 24 h, 70% yield for (I)) and by solid state reaction of KF, PbCO3 and PbF2 (alumina boat, flowing CO2, 250—270 °C, 2—3 d).
ChemInform Abstract: Asymmetric Synthesis of New Chiral 1,2‐ and 1,3‐Diols.
Authors: Yildiz Tuelay , Yusufoglu Ayse 
Published: May 2013

AbstractSeven chiral 1,2‐diols and six chiral 1,3‐diols are prepared by the asymmetric reduction of the corresponding 1,2‐ and 1,3‐diketones.
ChemInform Abstract: SOCl2/β‐Cyclodextrin: A New and Efficient Catalytic System for Beckmann Rearrangement and Dehydration of Aldoximes under Aqueous Conditions.
Authors: Patil Dipak , Dalal Dipak 
Published: May 2013

AbstractThe system SOCl2/β‐cyclodextrin can be used for the Beckmann rearrangement of ketoximes as well as for the dehydration of aldoximes under aqueous conditions.
ChemInform Abstract: Iodine‐Catalyzed Tandem Synthesis of Terminal Acetals and Glycol Mono Esters from Olefins.
Authors: Kumar Macharla Arun , Swamy Peraka , Naresh Mameda , Reddy Marri Mahender , Rohitha Chozhiyath Nappunni , Prabhakar Sripadi , Sarma Akella Venkata Subrahmanya , Kumar Joseph Richard Prem , Narender Nama 
Published: May 2013

AbstractA new metal‐free synthesis of terminal acetals and glycol mono esters from olefins is developed.
ChemInform Abstract: A Functional‐Group‐Tolerant Catalytic trans Hydrogenation of Alkynes
Authors: Radkowski Karin , Sundararaju Basker , Fuerstner Alois 
Published: May 2013

AbstractThis is the first practical and truly functional‐group‐tolerant procedure for the catalytic semihydrogenation of alkynes to E‐alkenes.
ChemInform Abstract: Benzimidazole‐Based Palladium—N‐Heterocyclic Carbene: A Useful Catalyst for C—C Cross‐Coupling Reaction at Ambient Condition.
Authors: Gupta Sumanta , Basu Basudeb , Das Sajal 
Published: May 2013

AbstractThe title NHC‐catalyst appears to be efficient for Suzuki cross‐coupling reactions of a wide range of substrates including heteroaromatic systems, for multi Suzuki cross‐coupling reactions, and for C‐C cross‐coupling reactions between acid chlorides and arylboronic acid.
ChemInform Abstract: Synthesis of Enantioenriched Azo Compounds: Organocatalytic Michael Addition of Formaldehyde N‐tert‐Butyl Hydrazone to Nitroalkenes.
Authors: Monge David , Daza Silvia , Bernal Pablo , Fernandez Rosario , Lassaletta Jose M. 
Published: May 2013

AbstractThe asymmetric Michael addition of hydrazone (I) to nitroalkenes (II) leads to diazenes (III), which are readily converted into tautomeric hydrazones (IV) under the action of TFA.
ChemInform Abstract: Stereodivergence in Amine‐Catalyzed Regioselective [4 + 2] Cycloadditions of β‐Substituted Cyclic Enones and Polyconjugated Malononitriles.
Authors: Feng Xin , Zhou Zhi , Zhou Rong , Zhou Qing‐Qing , Dong Lin , Chen Ying‐Chun 
Published: May 2013

AbstractThis method gives either endo‐ or exo‐products depending on the used organocatalyst.
ChemInform Abstract: Copper‐Catalyzed Aliphatic C—H Amination with an Amidine Moiety.
Authors: Chen Hui , Sanjaya Stephen , Wang Yi‐Feng , Chiba Shunsuke 
Published: May 2013

AbstractA new method for the amination of aliphatic C—H bonds of N‐alkylamidines in the presence of PhI(OAc)2 and K3PO4 is described that utilizes Cu(OAc)2 as the catalyst.
ChemInform Abstract: Hypervalent Iodine Mediated para‐Selective Fluorination of Anilines.
Authors: Tian Tian , Zhong Wen‐He , Meng Shuai , Meng Xiang‐Bao , Li Zhong‐Jun 
Published: May 2013

AbstractA new, straightforward, regioselective, and metal‐free method for the synthesis of para‐fluorinated anilides is developed by using readily available reagents.
ChemInform Abstract: Synthesis, Characterization, and Reactivity of N‐Acyl Chloroformamidines: Useful Building Blocks for the Construction of N‐Acyl Substituted 1,1‐Diaminoethylenes, Amidines, Ureas, and Thioureas.
Authors: Wang Yang , Chi Yue , Zhao Fei , Zhang Wen‐Xiong , Xi Zhenfeng 
Published: May 2013

AbstractCarbodiimides react with carboxylic acid chlorides to give the title compounds in excellent yields.
ChemInform Abstract: Rhodium(III) and Hexabromobenzene — A Catalyst System for the Cross‐Dehydrogenative Coupling of Simple Arenes and Heterocycles wit Arenes Bearing Directing Groups.
Authors: Wencel‐Delord Joanna , Nimphius Corinna , Wang Honggen , Glorius Frank 
Published: May 2013

AbstractThe potential of the new Rh(III)‐catalyzed dehydrogenative cross‐coupling reaction is also demonstrated on the synthesis of the key intermediate (XII) of the fungicide molecule bixafen.
ChemInform Abstract: A Unique Cascade Reaction Between 3‐Arylprop‐2‐inylcarboxylates and Benzaldehydes Leading to the Formation of Morita—Baylis—Hillman Adducts.
Authors: Karpaviciene Ieva , Cikotiene Inga 
Published: May 2013

AbstractThe title reaction results in the formation of Morita—Baylis—Hillman adducts which are difficult or not available via a traditional MBH reaction.
ChemInform Abstract: Expedient Synthesis of Functionalized Triarylmethanols Through Tandem Formation of Geminal C—C and C—O Bonds.
Authors: Tian Yu , Sui Yi , Gu Yonghong , Tian Shi‐Kai 
Published: May 2013

AbstractTwo synthetically useful, atom‐efficient approaches to triarylmethanols are described.