bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of Triazole Gold(III) Complex as an Effective Catalyst for the Synthesis of E‐α‐Haloenones
Authors: Yang Yongchun , Hu Wenkang , Ye Xiaohan , Wang Dawei , Shi Xiaodong 
Published: July 2016

AbstractThe pyridyltriazole ligand was prepared and applied as a new ligand system for the coordination towards gold(III) cations. The resulting complex showed excellent stability and effective catalytic reactivity for the Meyer–Schuster rearrangement of propargyl alcohols and sequential allene halogenation, giving α‐haloenones with excellent yields and good E/Z selectivity. More importantly, by using this new gold(III) catalytic system, the challenging α‐chloroenone substrates were synthesized in good yields for the first time. This work also permits the avoidance of preparing of acetate derivatives as required in the case of Au(I) catalysts and validates that the triazole gold(III) complex is an effective new catalyst for alkyne activation.magnified image
A Mixed Ligand Approach for the Asymmetric Hydrogenation of 2‐Substituted Pyridinium Salts
Authors: Renom‐Carrasco Marc , Gajewski Piotr , Pignataro Luca , de Vries Johannes G. , Piarulli Umberto , Gennari Cesare , Lefort Laurent 
Published: July 2016

AbstractHerein we describe a new methodology for the asymmetric hydrogenation (AH) of 2‐substituted pyridinium salts. An iridium catalyst based on a mixture of a chiral monodentate phosphoramidite and an achiral phosphine was shown to hydrogenate N‐benzyl‐2‐arylpyiridinium bromides to the corresponding N‐benzyl‐2‐arylpiperidines with full conversion and good enantioselectivity. The mechanism of the reaction under optimized conditions was investigated via kinetic measurements and isotopic labeling experiments. Our study suggests that the hydrogenation starts with a 1,4‐hydride addition and that the enantiodiscriminating step involves the reduction of an iminium intermediate.magnified image
Phosphoramidite Ligands Based on Simple 1,2‐Diols: Synthesis, Use in Copper‐Catalyzed Asymmetric Additions, and Achirotopic Stereogenic Phosphorus Centres
Authors: Mistry Nisha , Fletcher Stephen P. 
Published: July 2016

AbstractPhosphoramidite ligands are widely used in catalysis and normally constructed from large C2‐symmetrical diols such as BINOL or TADDOL. We report here on new ligands based on a set of simple diols that had been previously overlooked. Ligands based on (S,S)‐trans‐cyclohexanediol and (R,R)‐(+)‐1,2‐diphenyl‐1,2‐ethanediol, in combination with both chiral and achiral amines, were tested in 3 different copper‐catalyzed asymmetric reactions and up to 89% ee was observed. A different ligand gave the best results in each reaction examined. Using meso‐cis‐cyclohexanediol and meso‐cis‐diphenyl‐1,2‐ethanediol with a chiral non‐racemic amine gave diastereomeric ligands bearing achirotopic stereogenic phosphorus atoms which were characterized with the assistance of X‐ray crystallography and variable temperature NMR studies. This work provides a new set of ligands that may be useful in some asymmetric reactions when phosphoramidites based on BINOL and TADDOL are ineffective. We also identify a novel stereochemical feature of phosphoramidites that may be useful in asymmetric catalysis and ligand design.magnified image
Spatial Price Transmission and Efficiency in the Urea Market
Authors: Hu Zhepeng , Brorsen B. Wade 
Published: July 2016

ABSTRACTUrea fertilizer is widely used in the United States, however, urea is not publicly traded and formula pricing is common. This article studies spatial transmission and efficiency of urea prices in the Arkansas River‐New Orleans urea markets and the New Orleans‐Middle East urea markets. A vector error correction model (VECM) and Baulch's (1997) parity bound model (PBM) are estimated. A threshold VECM is considered, but no threshold effects are found so threshold effects are not included in the final VECM. The estimated VECM shows that violations of spatial price equilibrium are corrected faster between Arkansas River‐New Orleans prices than New Orleans‐Middle East prices. The long term adjustments to deviations from spatial equilibrium in the New Orleans‐Middle East price relationship are made through adjustments in the New Orleans price. The PBM shows that New Orleans‐Middle East price spreads are greater than transportation costs about 23% of the time. [EconLit citations: C32, Q13, R32].
Tracing residential mobility during the Merovingian period: An isotopic analysis of human remains from the Upper Rhine Valley, Germany
Authors: Schuh Christine , Makarewicz Cheryl A. 
Published: July 2016

AbstractObjectivesWritten sources have provided information about the rise of Merovingian power and their territorial conquests after the disintegration of the Western Roman Empire, but the extent to which altered power relations in the newly annexed territories reshaped regional and local communities is poorly understood. The early medieval cemetery of Dirmstein, located in the Upper Rhine Valley, is one of the rare sites bearing archeological evidence of simultaneous use by an indigenous community and newcomers from outside the Merovingian core area, and it offers the opportunity to investigate residential mobility at the former Roman Rhine frontier during the Merovingian period.Materials and MethodsWe conducted strontium, oxygen, and carbon isotope analyses on human tooth enamel recovered from 25 sixth century inhumations at the Dirmstein cemetery to establish the presence of newcomers to the Upper Rhine region.ResultsThe low δ13C values exhibited by the Dirmstein individuals revealed ingestion of a C3 terrestrial based diet, with no detectable contribution of C4 plants, which indicates the absence of individuals from regions where a C4‐based diet was common. Human 87Sr/86Sr values well outside the local range of bioavailable strontium, in combination with low δ18O values, suggest a notable presence of newcomers from more eastern or high altitude regions.ConclusionsThe isotopic evidence indicates that residential mobility was important and new settlers, most likely from outside the Merovingian core area, contributed to the settlement of the northern Upper Rhine Valley during the sixth century AD.
Comparing primate crania: The importance of fossils
Authors: Fleagle John G. , Gilbert Christopher C. , Baden Andrea L. 
Published: July 2016

AbstractObjectivesExtant primate crania represent a small subset of primate crania that have existed. The main objective here is to examine how the inclusion of fossil crania changes our understanding of primate cranial diversity relative to analyses of extant primates. We hypothesize that fossil taxa will change the major axes of cranial shape, occupy new areas of morphospace, change the relative diversity of major primate clades, and fill in notable gaps separating major primate taxa/clades.Materials and MethodsEighteen 3D landmarks were collected on 157 extant and fossil crania representing 90 genera. Data were subjected to a Generalized Procrustes Analysis then principal components analysis. Relative diversity between clades was assessed using an F‐statistic.ResultsFossil taxa do not significantly alter major axes of cranial shape, but they do occupy unique areas of morphospace, change the relative diversity between clades, and fill in notable gaps in primate cranial evolution. Strepsirrhines remain significantly less diverse than anthropoids. Fossil hominins fill the gap in cranial morphospace between extant great apes and modern humans.DiscussionThe morphospace outlined by living primates largely includes that occupied by fossil taxa, suggesting that the cranial diversity of living primates generally encompasses the total diversity that has evolved in this Order. The evolution of the anthropoid cranium was a significant event allowing anthropoids to achieve significantly greater cranial diversity compared to strepsirrhines. Fossil taxa fill in notable gaps within and between clades, highlighting their transitional nature and eliminating the appearance of large morphological distances between extant taxa, particularly in the case of extant hominids.
123I‐2β‐carbomethoxy‐3β‐(4‐iodophenyl)‐N‐(3‐fluoropropyl) nortropane single photon emission computed tomography and 123I‐metaiodobenzylguanidine myocardial scintigraphy in differentiating dementia with lewy bodies from other dementias: A comparative study
Authors: Tiraboschi Pietro , Corso Angelo , Guerra Ugo Paolo , Nobili Flavio , Piccardo Arnoldo , Calcagni Maria Lucia , Volterrani Duccio , Cecchin Diego , Tettamanti Mauro , Antelmi Luigi , Vidale Simone , Sacco Leonardo , Merello Maria , Stefanini Stefano , Micheli Anna , Vai Paola , Capitanio Selene , Gabanelli Sara Vincenzina , Riva Riccardo , Pinto Patrizia , Biffi Ave Maria , Muscio Cristina ,   for the SCILLA Working Group
Published: July 2016

ObjectiveTo compare the diagnostic value of striatal 123I‐2β‐carbomethoxy‐3β‐(4‐iodophenyl)‐N‐(3‐fluoropropyl) nortropane (123I‐FP‐CIT) single photon emission computed tomography (SPECT) and 123I‐metaiodobenzylguanidine (123I‐MIBG) myocardial scintigraphy in differentiating dementia with Lewy bodies (DLB) from other dementia types.MethodsThis prospective longitudinal study included 30 patients with a clinical diagnosis of DLB and 29 patients with non‐DLB dementia (Alzheimer disease, n = 16; behavioral variant frontotemporal dementia, n = 13). All patients underwent 123I‐FP‐CIT SPECT and 123I‐MIBG myocardial scintigraphy within a few weeks of clinical diagnosis. All diagnoses at each center were agreed upon by the local clinician and an independent expert, both unaware of imaging data, and re‐evaluated after 12 months. Each image was visually classified as either normal or abnormal by 3 independent nuclear physicians blinded to patients' clinical data.ResultsOverall, sensitivity and specificity to DLB were respectively 93% and 100% for 123I‐MIBG myocardial scintigraphy, and 90% and 76% for 123I‐FP‐CIT SPECT. Lower specificity of striatal compared to myocardial imaging was due to decreased 123I‐FP‐CIT uptake in 7 non‐DLB subjects (3 with concomitant parkinsonism) who had normal 123I‐MIBG myocardial uptake. Notably, in our non‐DLB group, myocardial imaging gave no false‐positive readings even in those subjects (n = 7) with concurrent medical illnesses (diabetes and/or heart disease) supposed to potentially interfere with 123I‐MIBG uptake.Interpretation123I‐FP‐CIT SPECT and 123I‐MIBG myocardial scintigraphy have similar sensitivity for detecting DLB, but the latter appears to be more specific for excluding non‐DLB dementias, especially when parkinsonism is the only “core feature” exhibited by the patient. Our data also indicate that the potential confounding effects of diabetes and heart disease on 123I‐MIBG myocardial scintigraphy results might have been overestimated. Ann Neurol 2016;80:368–378
Isolierung, Strukturaufklärung und (Bio‐)Synthese von Haprolid, einem zellspezifisch zytotoxischen myxobakteriellen Makrolidnaturstoff
Authors: Steinmetz Heinrich , Li Jun , Fu Chengzhang , Zaburannyi Nestor , Kunze Birgitte , Harmrolfs Kirsten , Schmitt Viktoria , Herrmann Jennifer , Reichenbach Hans , Höfle Gerhard , Kalesse Markus , Müller Rolf 
Published: July 2016

AbstractMyxobakterien sind gut etablierte Quellen diverser hoch bioaktiver Naturstoffe. Das hier beschriebene Haprolid ist ein neuartiges Makrolacton, das aus vier modifizierten Aminosäuren und einem Polyketidfragment aufgebaut ist und aus Byssovorax‐cruenta‐Har1‐Kulturen isoliert wurde. Da sich die vollständige Bestimmung der stereochemischen Konfiguration als anspruchsvoll erwies, wurde eine bioinformatische Analyse der Biosynthesegene zur Vorhersage der Konfiguration der einzelnen Zentren angewendet. Eine detaillierte Analyse der für die Haprolidsynthese zuständigen Biosyntheseproteine ergab ein hybrides System aus Polyketidsynthase und Nichtribosomaler Peptidsynthetase und ermöglichte die bioinformatische Konfigurationsanalyse der einzelnen Stereozentren. Durch nachfolgende Totalsynthese von Haprolid konnten alle getroffenen Vorhersagen bestätigt werden. Haprolid zeigte eine zytotoxische Aktivität gegen bestimmte Zelllinien im nanomolaren Bereich, auf andere Zellen hatte es aber überraschenderweise kaum Einfluss.
Silver Complexes of Dihalogen Molecules
Authors: Malinowski Przemysław J. , Himmel Daniel , Krossing Ingo 
Published: July 2016

AbstractThe perfluorohexane‐soluble and donor‐free silver compound Ag(A) (A=Al(ORF)4; RF=C(CF3)3) prepared using a facile novel route has unprecedented capabilities to form unusual and weakly bound complexes. Here, we report on the three dihalogen–silver complexes Ag(Cl2)A, Ag(Br2)A, and Ag(I2)A derived from the soluble silver compound Ag(A) (characterized by single‐crystal/powder XRD, Raman spectra, and quantum‐mechanical calculations).
Catalytic Carbocation Generation Enabled by the Mesolytic Cleavage of Alkoxyamine Radical Cations
Authors: Zhu Qilei , Gentry Emily C. , Knowles Robert R. 
Published: July 2016

AbstractA new catalytic method is described to access carbocation intermediates via the mesolytic cleavage of alkoxyamine radical cations. In this process, electron transfer between an excited state oxidant and a TEMPO‐derived alkoxyamine substrate gives rise to a radical cation with a remarkably weak C−O bond. Spontaneous scission results in the formation of the stable nitroxyl radical TEMPO. as well as a reactive carbocation intermediate that can be intercepted by a wide range of nucleophiles. Notably, this process occurs under neutral conditions and at comparatively mild potentials, enabling catalytic cation generation in the presence of both acid sensitive and easily oxidized nucleophilic partners.
Pristinol, a Sesquiterpene Alcohol with an Unusual Skeleton from Streptomyces pristinaespiralis
Authors: Klapschinski Tim A. , Rabe Patrick , Dickschat Jeroen S. 
Published: July 2016

AbstractA terpene cyclase from Streptomyces pristinaespiralis was characterized as the synthase for (+)‐(2S,3S,9R)‐pristinol. The structure of this sesquiterpene alcohol, which has a new carbon skeleton, was established by NMR spectroscopy and single‐wavelength anomalous‐dispersion X‐ray crystallography. Extensive isotopic labelling experiments were performed to distinguish between various possible cyclization mechanisms of the terpene cyclase and to decipher the EI‐MS fragmentation mechanism for pristinol.
Dielectric and conducting behavior of pyrene functionalized PANI/P(VDF‐co‐HFP) blend
Authors: Singh Veer Pal , Ramani Ramasubbu , Singh Ajit Shankar , Mishra Preeti , Pal Vijay , Saraiya Amit 
Published: July 2016

ABSTRACTHerein, we present the dielectric and electrical conductivity properties of the partially miscible polymer blend prepared using pyrene functionalized polyaniline (pf‐PANI) and poly(vinylidene fluoride‐co‐hexafluoro propylene) (PVDF‐co‐HFP). The blend mostly retains the fluorescent nature of pf‐PANI as well as can be moldable and possesses good damping property. The dielectric properties have been investigated as a function of temperature at three different frequencies and the plausible origin of polarization responsible for dielectric behavior in this blend has been identified. The experimental results of dielectric measurements are compared with theoretical models and discussed. The surface morphology of the samples has been examined with a scanning electron microscope. The electrical conductivity has also been studied as a function of temperature and explained in terms of hopping of charge carriers/interconnected networks. The combined dielectric and conductivity results together with scanning electron microscope micrographs, reveal that there is hindrance to achieve percolation threshold even after pf‐PANI addition of 57 vol % and subsequent thermal treatment. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 44077.
Vinyl ether‐based polyacetal polyols with various main‐chain structures and polyurethane elastomers prepared therefrom: Synthesis, structure, and functional properties
Authors: Iinuma Atsushi , Hashimoto Tamotsu , Urushisaki Michio , Sakaguchi Toshikazu 
Published: July 2016

ABSTRACTNovel acid degradable polyacetal polyols and polyacetal polyurethanes able to controlled acid degradation were developed. Polyacetal polyols with various main‐chain structures were synthesized by polyaddition of various vinyl ethers with a hydroxyl group [4‐hydroxy butyl vinyl ether (CH2CHOCH2CH2CH2CH2OH), 2‐hydroxy ethyl vinyl ether (CH2CHOCH2CH2OH), diethylene glycol monovinyl ether (CH2CHOCH2CH2OCH2CH2OH), and cyclohexanedimethanol monovinyl ether (CH2CHOCH2C6H10CH2OH)] with p‐toluenesulfonic acid monohydrate (TSAM) as a catalyst in the presence of the corresponding diols [1,4‐butandiol (HOCH2CH2CH2CH2OH), ethylene glycol (HOCH2CH2OH), diethylene glycol (HOCH2CH2OCH2CH2OH), and 1,4‐cyclohexanedimethanol (HOCH2C6H10CH2OH)], respectively. Polyacetal polyurethanes were prepared by a two‐step polymerization, using the synthesized polyacetal polyols, 4,4′‐diphenylmethane diisocyanate (MDI), and 1,4‐butandiol (BD) as a chain extender. Depending on the main‐chain structures, these polyurethanes had different glass transition temperature (from −44 to 19 °C) and properties such as hydrophobic or hydrophilic. Polyurethanes containing the hydrophilic main‐chain exhibited the thermoresponsiveness and had the certain volume phase transition temperature (VPTT). The polyacetal polyurethanes were flexible elastomers around room temperature (∼25  °C) and thermally stable (Td ≥ 310 °C) and additionally exhibited smooth degradation with a treatment of aqueous acid in THF at room temperature to give the corresponding raw material diols. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44088.
Why Cannibal? Representation and Defense in the Meiwes “German Cannibal” Case
Authors: Zaman Bashiran , Soldz Stephen 
Published: July 2016

AbstractWe examined the construction of media reporting on the Meiwes “cannibal” case where two consensual adults gratified fantasies resulting in the death, dismemberment and partial consumption of one. We found the media imposed a traditional but ill‐fitting predator–prey frame, contributing to omissions relating to sexuality and death, the utilization of cultural “Othering” and the presence of the defenses of intellectualization and humor; thus distracting us against anxiety from our own mortality. This study suggests the relationship between the British media and public in crime reporting is not passive but reciprocal: the media creates but also responds to public fantasies/desires.
Development of a Simple Adjustable Zinc Acid/Base Hybrid Catalyst for C−C and C−O Bond‐Forming and C−C Bond‐Cleavage Reactions
Authors: Yamashita Yasuhiro , Minami Kodai , Saito Yuki , Kobayashi Shū 
Published: July 2016

AbstractA newly designed zinc Lewis acid/base hybrid catalyst was developed. By adjusting the Lewis acidity of the zinc center, aldol‐type additions of 2‐picolylamine Schiff base to aldehydes proceeded smoothly to afford syn‐aldol adduct equivalents, trans‐N,O‐acetal adducts, in high yields with high selectivities. NMR experiments, including microchanneled cell for synthesis monitoring (MICCS) NMR analysis, revealed that anti‐aldol adducts were formed at the initial stage of the reactions under kinetic control, but the final products were the trans‐(syn)‐N,O‐acetal adducts that were produced through a retro‐aldol process under thermodynamic control. In the whole reaction process, the zinc catalyst played three important roles: i) promotion of the aldol process (C−C bond formation), ii) cyclization process to the N,O‐acetal product (C−O bond formation), and iii) retro‐aldol process from the anti‐aldol adduct to the syn‐aldol adduct (C−C bond cleavage and C−C bond formation).
Urban development with financially sustainable rail service
Authors: Wang David Z. W. , Lo Hong K. 
Published: July 2016

SummaryThe positive correlation between urban population density and transit service patronage is well recognized, as was ascertained via statistical approaches in previous studies. In this study, we seek to derive some prescriptive results of the relationship between urban population density and the financial sustainability of rail transit service via analytical approaches. We consider an idealized metropolitan region with a central business district at its center, whose population is distributed according to a certain density saturation gradient pattern. Trips generated from the region to the central business district are served either by the rail service supplemented with feeder buses or by autos. Travelers choose one of the two modes to minimize the travel cost. The traffic congestion effects on highway system for auto users will be considered by assuming flow‐dependent travel time delay. The crowding costs of transit services will also be taken into account. The spatial equilibrium travel pattern with modal choices will be modeled by applying a differential equation approach. Then, we study the sensitivity of urban development density on the financial sustainability of the rail service by examining the supply and demand patterns. Through the analysis, the result sheds light on the threshold urban density required, below which the service cannot be sustained financially. The results also provide guidelines for planning urban development with financially sustainable rail services. Copyright © 2016 John Wiley & Sons, Ltd.
Maitake Pro4X has anti‐cancer activity and prevents oncogenesis in BALBc mice
Authors: Roldan‐Deamicis Agustina , Alonso Eliana , Brie Belén , Braico Diego Aguilera , Balogh Gabriela Andrea 
Published: July 2016

AbstractThe understanding of the molecular mechanisms of the immune tolerance induced by the tumoral microenvironment is fundamental to prevent cancer development or to treat cancer patients using immunotherapy. Actually, there are investigations about “addressed‐drugs” against cancer cells without affecting normal cells. It could be ideal to find selective and specific compounds that only recognize and destroy tumor cells without damaging the host normal cells. For thousands of years, mushrooms have been used for medicinal purposes because of their curative properties. D‐Fraction, an extract of Maitake (from the edible Grifola frondosa mushroom), rich in β‐glucans, exert notable effects in the immune system. Until now, some published articles suggest that Maitake D‐Fraction could have anti‐tumoral activity, prevent oncogenesis and metastasis in some tumor types. However, there are no clear data about Maitake D‐Fraction action on breast cancer prevention and its exact molecular mechanisms are not yet elucidated. The experiments were performed employing 25 female BALBc mice that were treated with and without Maitake D‐Fraction Pro4X or Maitake Standard for 15 days by daily intraperitoneal injection. After treatment period, all mice were implanted with murine tumor cells LM3 to induce mammary tumorigenesis. Animals were checked weekly and killed after 46 days of LM3 transplant; percentage of cancer prevention, rate of tumor growing, and overall survival were determined. Under dissection, the internal organs were evaluated histologically and genetically by RT‐PCR. We found that 5 mg/kg per day of Maitake D‐Fraction Pro4X, administered dairy during 15 days to BALBc mice was able to block more than 60% breast cancer development. However, Maitake Standard prevents oncogenesis in 26% to respect control. In this work, we found that Maitake D‐Fraction Pro4X, administered to BALBc mice, prevents breast carcinogenesis, block tumor invasiveness, reduce angiogenesis, and increase overall survival.
Coronary bifurcations in clinical practice: Tell me what we can do better
Authors: Collet Carlos , Serruys Patrick W. 
Published: July 2016

Key Points

In bifurcation lesion, a precise evaluation of lesion severity and disease extension requires the use of bifurcation (three branches) quantitative coronary angiography.
The use of Intravascular imaging to guide PCI in bifurcation has shown to reduce clinical events.
Selection and duration of the dual antiplatelet therapy after bifurcation lesion PCI require further investigation.