bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palladium‐ and Nickel‐Catalyzed Alkenylation of Enolates
Authors: Ankner Tobias , Cosner Casey C. , Helquist Paul 
Published: January 2013

AbstractTransition‐metal‐catalyzed alkenylation of enolates provides a direct method to synthesize broadly useful β,γ‐unsaturated carbonyl compounds from the corresponding carbonyl compound and alkenyl halides. Despite being reported in the early seventies, this reaction class saw little development for many years. In the past decade, however, efforts to develop this reaction further have increased considerably, and many research groups have reported efficient coupling protocols, including enantioselective versions. These reactions most commonly employ palladium catalysts, but there are also some important reports using nickel. There are many examples of this powerful transformation being used in the synthesis of complex natural products.
“Clickable” Vitamin B12 Derivative
Authors: Chromiński Mikołaj , Gryko Dorota 
Published: January 2013

AbstractA “clickable” vitamin B12 derivative possessing the azide functionality at the 5′‐position was synthesized by means of a two‐step procedure on the gram scale. The reaction of cobalamin with mesyl chloride (MsCl) afforded the 5′‐OMs derivative, which was subsequently transformed to the desired 5′‐azide, the structure of which was confirmed using X‐ray analysis. It proved to be reactive in the azide–alkyne 1,3‐dipolar cycloaddition reaction to give substituted triazoles in high yields. A study of the reaction conditions and the scope of the process are reported.
Three‐Dimensional MOF‐Type Architectures with Tetravalent Uranium Hexanuclear Motifs (U6O8)
Authors: Falaise Clément , Volkringer Christophe , Vigier Jean‐François , Henry Natacha , Beaurain Arnaud , Loiseau Thierry 
Published: January 2013

AbstractFour metal–organic frameworks (MOF) with tetravalent uranium have been solvothermally synthesized by treating UCl4 with rigid dicarboxylate linkers in N,N‐dimethylfomamide (DMF). The use of the ditopic ligands 4,4′‐biphenyldicarboxylate (1), 2,6‐naphthalenedicarboxylate (2), terephthalate (3), and fumarate (4) resulted in the formation of three‐dimensional networks based on the hexanuclear uranium‐centered motif [U6O4(OH)4(H2O)6]. This motif corresponds to an octahedral configuration of uranium nodes and is also known for thorium in crystalline solids. The atomic arrangement of this specific building unit with organic linkers is similar to that found in the zirconium‐based porous compounds of the UiO‐66/67 series. The structure of [U6O4(OH)4(H2O)6(L)6]⋅X (L=dicarboxylate ligand; X=DMF) shows the inorganic hexamers connected in a face‐centered cubic manner through the ditopic linkers to build up a three‐dimensional framework that delimits octahedral (from 5.4 Å for 4 up to 14.0 Å for 1) and tetrahedral cavities. The four compounds have been characterized by using single‐crystal X‐ray diffraction analysis (or powder diffraction analysis for 4). The tetravalent state of uranium has been examined by using XPS and solid‐state UV/Vis analyses. The measurement of the Brunauer–Emmett–Teller surface area indicated very low values (Langmuir <300 m2 g−1 for 1, <7 m2 g−1 for 2–4) and showed that the structures are quite unstable upon removal of the encapsulated DMF solvent.
Synthesis of Carbohydrate‐Functionalised Sequence‐Defined Oligo(amidoamine)s by Photochemical ThiolEne Coupling in a Continuous Flow Reactor
Authors: Wojcik Felix , O'Brien Alexander G. , Götze Sebastian , Seeberger Peter H. , Hartmann Laura 
Published: January 2013

AbstractPoly/oligo(amidoamine)s (PAAs) have recently been recognised for their potential as well‐defined scaffolds for multiple carbohydrate presentation and as multivalent ligands. Herein, we report two complimentary strategies for the preparation of such sequence‐defined carbohydrate‐functionalised PAAs that use photochemical thiolene coupling (TEC) as an alternative to the established azide–alkyne cycloaddition (“click”) reaction. In the first approach, PAAs that contained multiple olefins were synthesised on a solid support from a new building block and subsequent conjugation with unprotected thio‐carbohydrates. Alternatively, a pre‐functionalised building block was prepared by using TEC and assembled on a solid support to provide a carbohydrate‐functionalised PAA. Both methods rely on the use of a continuous flow photoreactor for the TEC reactions. This system is highly efficient, owing to its short path length, and requires no additional radical initiator. Performing the reactions at 254 nm in Teflon AF‐2400 tubing provides a highly efficient TEC procedure for carbohydrate conjugation, as demonstrated in the reactions of O‐allyl glycosides with thiols. This method allowed the complete functionalisation of all of the reactive sites on the PAA backbone in a single step, thereby obtaining a defined homogeneous sequence. Furthermore, reaction at 366 nm in FEP tubing in the flow reactor enabled the large‐scale synthesis of an fluorenylmethyloxycarbonyl (Fmoc)‐protected glycosylated building block, which was shown to be suitable for solid‐phase synthesis and will also allow heterogeneous sequence control of different carbohydrates along the oligomeric backbone. These developments enable the synthesis of sequence‐defined carbohydrate‐functionalised PAAs with potential biological applications.
Traceless Chelation‐Controlled Rhodium‐Catalyzed Intermolecular Alkene and Alkyne Hydroacylation
Authors: Hooper Joel F. , Young Rowan D. , Weller Andrew S. , Willis Michael C. 
Published: January 2013

AbstractA new functional‐group tolerant, rhodium‐catalyzed, sulfide‐reduction process is combined with rhodium‐catalyzed chelation‐controlled hydroacylation reactions to give a traceless hydroacylation protocol. Aryl‐ and alkenyl aldehydes can be combined with both alkenes, alkynes and allenes to give traceless products in high yields. A preliminary mechanistic proposal is also presented.
Retinorecipient areas in the diurnal murine rodent Arvicanthis niloticus: A disproportionally large superior colliculus
Authors: Gaillard Frédéric , Karten Harvey J. , Sauvé Yves 
Published: January 2013

AbstractThe Nile grass rat (Arvicanthis niloticus) has a high proportion of cone photoreceptors (∼30–40%) compared with that in the common laboratory mouse and rat (∼1–3%) and may prove a preferable murine model with which to study cone‐driven information processing in retina and primary visual centers. However, other than regions involved in circadian control, little is known about the retinorecipient structures in this rodent. We undertook a detailed analysis of the retinal projections as revealed after intravitreal injection of the anterograde tracer cholera toxin subunit B. Retinal efferents were evaluated in 45 subcortical structures. Contralateral projections were always dominant. Major contralateral inputs consisted of the suprachiasmatic nucleus, dorsolateral geniculate nucleus (dLGN), intergeniculate leaflet, ventral geniculate nucleus (magnocellular part), lateroposterior thalamic nucleus, all six pretectal nuclei, superficial layers of the superior colliculus (SC), and the main nuclei of the accessory optic system. Terminals from the contralateral eye were also localized in an unnamed field rostromedial to the dLGN as well as in the subgeniculate thalamic nucleus. Ipsilateral inputs were found mainly in the suprachiasmatic nucleus, dLGN, intergeniculate leaflet, internal sector of the magnocellular part of the ventral geniculate nucleus, olivary pretectal nucleus, and SC optic layer. Retinal afferents were not detected in the basal forebrain or the dorsal raphe nucleus. Morphometric measurements revealed that the superficial layers of the SC are disproportionately enlarged relative to other retinorecipient regions and brain size compared with rats and mice. We suggest that this reflects the selective projection of cone‐driven retinal ganglion cells to the SC. J. Comp. Neurol. 521:1699–1726, 2013. © 2012 Wiley Periodicals, Inc.
An Interference‐Free Glucose Biosensor Based on an Anionic Redox Polymer‐Mediated Enzymatic Oxidation of Glucose
Authors: Deng Huimin , Shen Wei , Gao Zhiqiang 
Published: January 2013

AbstractHerein a novel strategy for the construction of an amperometric biosensor for highly sensitive and selective determination of glucose is described. The biosensor is made of a biocomposite membrane of glucose oxidase (GOx) and an Os(bpy)2 (bpy=2,2′‐bipyridine)‐based anionic redox polymer (Os‐RP) mediator. The biosensor is fabricated through the co‐immobilization of GOx and the Os‐RP on the surface of a glassy carbon electrode by a simple one‐step chemical crosslinking process. The crosslinked Os‐RP/GOx composite membrane shows excellent catalytic activity toward the oxidation of glucose. Under optimal experimental conditions, a linear correlation between the oxidation current of glucose in amperometry at 0.25 V (vs. Ag/AgCl) and glucose concentration up to 10 mM with a sensitivity of 16.5 μA mM−1 cm−2 and a response time <5 s. Due to the presence of anionic sulfonic acid groups in the backbone of the redox polymer, the biosensor exhibits excellent selectivity to glucose in the presence of ascorbic acid and uric acid. The low hydrophobicity of the composite membrane also effectively retards the transport of molecular oxygen within the membrane.
Synthesis of Nanovoid Bi2WO6 2D Ordered Arrays as Photoanodes for Photoelectrochemical Water Splitting
Authors: Zhang Liwu , Bahnemann Detlef 
Published: January 2013

AbstractHerein we report a facile and economic method to prepare nanovoid Bi2WO6 2D ordered arrays employing a simple self‐assembly procedure. The electrochemical properties and performance of the 2D nanoarray as a photoanode for water splitting are investigated and compared with a conventional photoanode of similar thickness. The 2D array photoanode shows a much higher photocurrent density and photon‐to‐H2 conversion efficiency even with a small content of the Bi2WO6 material. The enhancement is further studied and explained on the basis of the superiority of light scattering and photogenerated hole diffusion within the 2D array structure. This work provides a facile method to improve the efficiency of solar energy conversion systems by minimizing the charge‐carrier diffusion length and reducing the light reflection, as well as reducing the amount of the semiconductor material (often costly and/or rare) present in the photoanode.
Assessment of a novel flow cytometry technique of one‐step intracellular staining: Example of FOXP3 in clinical samples
Authors: Demaret Julie , Saison Julien , Venet Fabienne , Malcus Christophe , Poitevin‐Later Francoise , Lepape Alain , Ferry Tristan , Monneret Guillaume 
Published: January 2013

AbstractBackground:By measuring multiple parameters on a single‐cell basis, flow cytometry is a potent tool to dissect the phenotypes and functions of cell subsets. However, because this technique may be time‐consuming, particularly for intracellular staining, it could be problematic for its use in daily routine or in large cohorts. Recently, a novel reagent has been developed to perform intracellular staining in one step. The objective of our study was thus to assess this new method in comparison with the reference technique by focusing on FOXP3 staining in clinical samples.Methods:Peripheral blood was collected from 15 HIV‐1‐infected patients, 5 critically ill patients, and 5 healthy volunteers and stained using the two different methods. Different subsets of FOXP3 positive cells were investigated by flow cytometry.Results:When comparing results obtained with the two techniques, no statistical differences between the percentages of CD4+FOXP3+, CD4+CD25+FOXP3+, and CD4+CD25+CD127−FOXP3+ cells were observed. Besides, a strong correlation between percentages of CD4+FOXP3+CD25+CD127− lymphocytes measured with both techniques was found in patients (r: 0.843, P < 0.001, intra‐class correlation coefficient: 0.820, P < 0.001). Importantly, flow cytometry stainings obtained with the one‐step method were very robust with an excellent intra‐assay precision, a better discriminative power and correct stability and reproducibility of the staining even after blood storage.Conclusions:With a strong correlation between the percentages of FOXP3+ Tregs when compared with the reference method, a better staining quality, a shorter realization time and no need of isotype control, this one step procedure may represent an important improvement for a daily routine use of intracellular staining. © 2012 International Clinical Cytometry Society
Intra‐ and interlaboratory variability of paroxysmal nocturnal hemoglobinuria testing by flow cytometry following the 2012 Practical Guidelines for high‐sensitivity paroxysmal nocturnal hemoglobinuria testing
Authors: Marinov Iuri , Kohoutová Martina , Tkáčová Vlasta , Lysák Daniel , Holubová Monika , Stehlíková Olga , Železníková Tatiana , Žontar Darja , Illingworth Andrea 
Published: January 2013

BackgroundSutherland et al. recently published the Practical Guidelines for high‐sensitivity detection of paroxysmal nocturnal hemoglobinuria (PNH) clones by flow cytometry (FCM), containing concise protocols for PNH testing.MethodsUsing this approach, we studied the intra‐ and interlaboratory variability observed in a multicenter study in which fresh blood samples containing three clinically relevant PNH clone sizes within the granulocytic, monocytic, and red blood cell (RBC) populations were shipped to each participating center.ResultsCoefficients of variation (CVs) for precision/reproducibility analysis ranged from 0.01%/0.02% to 0.48%/0.45% (big clone), from 0.69%/1.52% to 4.24%/5.80% (small‐intermediate clone), from 1.47%/3.91% to 15.01% /17.83% (minor clone) for PNH white blood cells (WBCs) and from 0.24%/0.48% to 1.76%/1.83% (big clone), from 0.80%/1.14% to 2.39%/4.45% (small‐intermediate clone), from 1.09%/3.36% to 10.54%/10.23% (minor clone) for PNH RBCs, respectively. Linear regression analysis showed excellent performance correlation between centers (r > 0.99), Wilcoxon rank test revealed no statistically significant differences for PNH granulocytes, monocytes, and RBCs (P > 0.05%), Bland–Altman analysis demonstrated good performance agreement for all target PNH clones (mean bias ranging from −1.47 to 0.71).ConclusionOur results demonstrate very good intra‐ and interlaboratory performance characteristics for both precision and reproducibility analyses and excellent correlation and agreement between centers for all target PNH clone sizes. Our data confirm the reliability and robustness of the recently published Practical Guidelines approach for high sensitivity PNH testing by flow cytometry and suggest that such an approach represents an excellent basis for standardization of PNH testing by flow cytometry. © 2013 International Clinical Cytometry Society
Spin Crossover in Polymeric Materials Using Schiff Base Functionalized Triazole Ligands
Authors: Scott Hayley S. , Ross Tamsyn M. , Moubaraki Boujemaa , Murray Keith S. , Neville Suzanne M. 
Published: January 2013

AbstractFunctionalized 1,2,4‐(R)‐triazole‐based Schiff base (R‐N=CH‐R′) ligands have been incorporated into spin crossover 1D materials of the general formula [Fe(Xtrz)3](A)2·2H2O (A = BF4, ClO4, Br, NO3; Xtrz = triazole liands). The ligand N‐salicylidene 4‐amino‐1,2,4‐triazole (Hsaltrz) and the novel ligand N‐cinimalidene 4‐amino‐1,2,4‐triazole (Hcintrz) were targeted to assess the implication of incorporating various aromatic functional groups on the spin crossover properties of this well‐known family of one‐dimensional materials. Magnetic susceptibility measurements on the polycrystalline powdered materials [Fe(Hsaltrz)3](A)2·2H2O [A = BF4 (1), ClO4 (2), Br (3)] and [Fe(Hcintrz)3](A)2·1.5(H2O) [A = BF4 (4), ClO4 (5), Br (6)] revealed spin transitions over the range T${1 \over 2}$ = 100–225 K. The spin crossover properties of the dehydrated materials were also investigated [1–6(dh)]. In attempts to prepare single crystals of these materials a dinuclear {[Fe2(Hsaltrz)5(NCS)4]·2MeOH (7)} and a trinuclear {[Fe3(Hsaltrz)6(H2O)2(EtOH)4](ClO4)6·2(EtOH) (8)} complex were obtained; these materials remain high spin over all temperatures and display weak antiferromagnetic exchange coupling. The structure of the novel ligand Hcintrz (9) is reported.
Synthesis of Functionalized Hexadentate Iminopyridine FeII Complexes – Toward Anion‐Dependent Spin Switching in Polar Media
Authors: McDaniel Ashley M. , Klug Christina M. , Shores Matthew P. 
Published: January 2013

AbstractWe report the syntheses and characterizations of low‐spin FeII complexes of hexadentate ligands poised for anion‐triggered spin‐state switching in polar solutions: [Fe(L5‐OH)](BF4)2 (1) and [Fe(L5‐ONHtBu)](BF4)2 (3), in which L5‐OH and L5‐ONHtBu are tripodal iminopyridine ligands that contain methanolic or tert‐butylamide functional groups, respectively, bound meta to the pyridyl N donor atom. Solid‐state evidence for strong hydrogen bonding between Cl– anions and all three amide functional groups in [Fe(L5‐ONHtBu)]2+ is provided by the crystal structure of {[Fe(L5‐ONHtBu)]⊂Cl}2[FeCl4] (2). In ambient‐temperature acetonitrile solutions of 1 and 3, chloride ion titrations produce marked changes in the 1H NMR spectra, including large downfield shifts for the amide NH and hydroxy OH resonances, which indicates strong anion binding events. Interestingly, for amide‐containing 3, we observe small changes in magnetic susceptibility as (nBu4N)Cl is added, which suggests that spin‐state control by anion–cation interactions may be accessible for related compounds with weaker ligand fields.
Catalytic Hydrolysis of Adenosine Triphosphate (ATP) by Antitumoral ϵ‐Keggin Core Compound, [H2MoV12O28(OH)12(MoVIO3)4]6–, at pH 5 and 7.5
Authors: Ishikawa Eri , Yamase Toshihiro 
Published: January 2013

AbstractThe hydrolysis of adenosine triphosphate (ATP) [to adenosine diphosphate (ADP) and phosphate] at 40 °C by [Me3NH]6[H2MoV12O28(OH)12(MoVIO3)4]·2H2O (PM‐17) as an important candidate for antitumor chemotherapy is investigated with the help of 31P NMR spectroscopy, electrospray ionization mass spectrometry (ESI‐MS), and isothermal titration calorimetry (ITC). The ATP hydrolysis at pH 5 and 7.5 proceeds catalytically to yield ADP, HnPO4(3–n)–, adenosine monophosphate (AMP), and [(PO4)2Mo5O15]6–. AMP and [(PO4)2Mo5O15]6– result from the secondary step of the ATP hydrolysis: the former was produced by the hydrolysis of ADP (with the liberation of phosphate), and the latter by the condensation among phosphates and monomolybdates (derived from the partial release of the MoVIO3 moieties from the PM‐17 anion). The enhancement of the ATP hydrolysis in the presence of K+ is discussed in terms of the electrostatic interaction of K+ at the Pγ phosphate in the negatively charged ATP 5′‐triphosphates, which accompanies the coordination of PM‐17 anions with a resultant conformational constraint of this phosphate. Values of thermodynamic parameters for the interaction between ATP and PM‐17 at pH 7.5 suggest the K+‐mediated assembly of PM‐17 anions at the 5′‐triphosphate chain (matrix effect), which leads to a decrease in the ATP hydrolysis owing to the depressed activation of the Pγ–O–Pβ linkage.
Dimerized Spin‐Crossover Iron(II) Complexes as Supramolecular Anion Capsules
Authors: Shiga Takuya , Oshiro Emiko , Nakayama Naoko , Mitsumoto Kiyotaka , Newton Graham N. , Nishikawa Hiroyuki , Oshio Hiroki 
Published: January 2013

AbstractTwo dimerized iron(II) complexes, [{Fe(L)(HL)2}{Fe(HL)3}](PF6)(BF4)2·5CH3CN·4H2O (1) and [{Fe(L)(HL)2}{Fe(HL)3}](PF6)(FeCl4)2 (2) {HL = 3‐(2‐pyridyl)‐5‐[4‐(diphenylamino)phenyl]‐1H‐pyrazole}, supported by triphenylamine‐derivatized bidentate ligands and encapsulating hexafluorophosphate ions were synthesized. The complex iron ions have octahedral coordination geometries in which they interact with six nitrogen atoms from three bidentate ligands. Both compounds have capsule‐like dimerized supramolecular structures, in which the arrangements of the bulky ligands of two discrete mononuclear complexes create a central cavity in which a single hexafluorophosphate ion is captured. The bidentate ligands interact with the anionic guest molecules through the hydrogen atoms of the ligand pyrazole moieties. Cryomagnetic studies reveal that both compounds show spin‐crossover behavior. Complex 1 showed quasi‐reversible spin‐crossover around 200–300 K, hindered by desolvation effects, whereas 2 showed reversible gradual spin‐crossover behavior. The electronic states of the iron ions resulting from the spin‐crossover were confirmed by X‐ray structure analyses and Mössbauer spectra.
Influence of harvest year and cultivar on wax composition of olive oils
Authors: Giuffrè Angelo Maria 
Published: January 2013

AbstractOlive oils extracted from Italian cultivars grown in the Region of Calabria, Southern Italy were analyzed for their wax ester composition, for three successive harvest years. Three autochthonous cultivars from Calabria: Cassanese, Ottobratica, and Sinopolese and seven allochtonous cultivars: Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino, and Picholine were considered. This work demonstrates the presence of significant differences (ANOVA) for the different wax ester compounds present in these olive oils, taking into consideration the cultivar and the harvest year. The studied olive oils present a good wax ester composition according to both EU and IOC regulations. The cultivar Ottobratica showed the highest wax ester content, whereas Itrana presented the lowest content.Practical applications: Wax esters are naturally present on the drupe cuticle and are transferred into olive oil by means of mechanical extraction and especially by solvent extraction on an industrial scale. They are a legal parameter contained in the European Union regulation and in the International Olive Oil Council regulation. Wax esters are a quality indicator for olive oil evaluation, especially to detect a fraudulent admixture of pomace olive oil in labeled extra virgin olive oil or in labeled monocultivar extra virgin olive oil. The adaptability of allochthonous cultivars in a different geographical area is also demonstrated.
Machine‐to‐machine communications via airliners
Authors: Plass Simon , Berioli Matteo , Hermenier Romain , Liva Gianluigi , Munari Andrea 
Published: January 2013

ABSTRACTWithin this article, a new concept for machine‐to‐machine communications infrastructure via airliners is presented. The main principles and resulting challenges are described, together with a first study on possible coverage within Europe and North America using airliners that endorses the concept's feasibility. Accurate insights are drawn by taking into account all commercial flights during 24 h on the basis of real global flight data. We strengthen the proposed solution by investigating system dimension aspects in a proof‐of‐principle manner as well as by discussing medium access policies and coding strategies capable of achieving performance improvements over alternative architectures. The goal of the article is to stimulate further research activities and ideas in this area. Copyright © 2013 John Wiley & Sons, Ltd.
Mirabegron use in the treatment of overactive bladder symptoms
Authors: Digesu G Alessandro , Gore Michelle , Khullar Vik 
Published: January 2013

AbstractBeta‐3 adrenoreceptors have been proposed as a target in the treatment of OAB due to their role in the mediation of bladder smooth muscle relaxation. Mirabegron is an oral medication that selectively targets beta‐3 adrenoreceptors and has been shown to reduce rhythmic abnormal detrusor contractions in animal models. In this Drug profile the authors present the clinical data relating to its efficacy and adverse effects and discuss its potential place in the treatment of OAB. Copyright © 2013 John Wiley & Sons, Ltd.