bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lanthanide‐Doped LiLuF4 Upconversion Nanoprobes for the Detection of Disease Biomarkers
Authors: Huang Ping , Zheng Wei , Zhou Shanyong , Tu Datao , Chen Zhuo , Zhu Haomiao , Li Renfu , Ma En , Huang Mingdong , Chen Xueyuan 
Published: January 2014

AbstractLanthanide‐doped upconversion nanoparticles (UCNPs) have shown great promise in bioapplications. Exploring new host materials to realize efficient upconversion luminescence (UCL) output is a goal of general concern. Herein, we develop a unique strategy for the synthesis of novel LiLuF4:Ln3+ core/shell UCNPs with typically high absolute upconversion quantum yields of 5.0 % and 7.6 % for Er3+ and Tm3+, respectively. Based on our customized UCL biodetection system, we demonstrate for the first time the application of LiLuF4:Ln3+ core/shell UCNPs as sensitive UCL bioprobes for the detection of an important disease marker β subunit of human chorionic gonadotropin (β‐hCG) with a detection limit of 3.8 ng mL−1, which is comparable to the β‐hCG level in the serum of normal humans. Furthermore, we use these UCNPs in proof‐of‐concept computed tomography imaging and UCL imaging of cancer cells, thus revealing the great potential of LiLuF4:Ln3+ UCNPs as efficient nano‐bioprobes in disease diagnosis.
Distribution, structure and function of Nordic eelgrass (Zostera marina) ecosystems: implications for coastal management and conservation
Authors: Boström Christoffer , Baden Susanne , Bockelmann Anna‐Christina , Dromph Karsten , Fredriksen Stein , Gustafsson Camilla , Krause‐Jensen Dorte , Möller Tiia , Nielsen Søren Laurentius , Olesen Birgit , Olsen Jeanine , Pihl Leif , Rinde Eli 
Published: January 2014

ABSTRACTThis paper focuses on the marine foundation eelgrass species, Zostera marina, along a gradient from the northern Baltic Sea to the north‐east Atlantic. This vast region supports a minimum of 1480 km2 eelgrass (maximum >2100 km2), which corresponds to more than four times the previously quantified area of eelgrass in Western Europe.Eelgrass meadows in the low salinity Baltic Sea support the highest diversity (4–6 spp.) of angiosperms overall, but eelgrass productivity is low (<2 g dw m‐2 d‐1) and meadows are isolated and genetically impoverished. Higher salinity areas support monospecific meadows, with higher productivity (3–10 g dw m‐2 d‐1) and greater genetic connectivity. The salinity gradient further imposes functional differences in biodiversity and food webs, in particular a decline in number, but increase in biomass of mesograzers in the Baltic.Significant declines in eelgrass depth limits and areal cover are documented, particularly in regions experiencing high human pressure. The failure of eelgrass to re‐establish itself in affected areas, despite nutrient reductions and improved water quality, signals complex recovery trajectories and calls for much greater conservation effort to protect existing meadows.The knowledge base for Nordic eelgrass meadows is broad and sufficient to establish monitoring objectives across nine national borders. Nevertheless, ensuring awareness of their vulnerability remains challenging. Given the areal extent of Nordic eelgrass systems and the ecosystem services they provide, it is crucial to further develop incentives for protecting them.© 2014 The Authors. Aquatic Conservation: Marine and Freshwater Ecosystems published by John Wiley & Sons, Ltd.
A Synthetic Approach for Constructing the 3/6/6/5‐Fused Tetracyclic Skeleton of Tenuipesine A
Authors: Tian Jin‐Miao , Zhao Xiong , Tu Yong‐Qiang , Gong Wei , Zhang Fu‐Min , Zhang Shu‐Yu , Wang Shao‐Hua 
Published: January 2014

AbstractAn efficient approach toward the 3/6/6/5‐fused tetracyclic skeleton of tenuipesine A has been accomplished. The strategy featured 1) a tandem Mitsunobu and 3,3‐rearrangement reaction yielding the key intermediate 7 with two adjacent all‐carbon quaternary centers with high d.r.; and 2) a tandem DBDMH‐mediated semipinacol rearrangement via a 1,2‐oxygen migration of an allylic hemiketal to construct the highly substituted tetrahydropyran ring.
Lipochitin Oligosaccharides Immobilized through Oximes in Glycan Microarrays Bind LysM Proteins
Authors: Maolanon Nicolai N. , Blaise Mickael , Sørensen Kasper K. , Thygesen Mikkel B. , Cló Emiliano , Sullivan John T. , Ronson Clive W. , Stougaard Jens , Blixt Ola , Jensen Knud J. 
Published: January 2014

AbstractGlycan microarrays have emerged as novel tools to study carbohydrate–protein interactions. Here we describe the preparation of a covalent microarray with lipochitin oligosaccharides and its use in studying proteins containing LysM domains. The glycan microarray was assembled from glycoconjugates that were synthesized by using recently developed bifunctional chemoselective aminooxy reagents without the need for transient carbohydrate protecting groups. We describe for the first time the preparation of a covalent microarray with lipochitin oligosaccharides and its use for studying proteins containing LysM domains. Lipochitin oligosaccharides (also referred to as Nod factors) were isolated from bacterial strains or chemoenzymatically synthesized. The glycan microarray also included peptidoglycan‐related compounds, as well as chitin oligosaccharides of different lengths. In total, 30 ligands were treated with the aminooxy linker molecule. The identity of the glycoconjugates was verified by mass spectrometry, and they were then immobilized on the array. The presence of the glycoconjugates on the array surface was confirmed by use of lectins and human sera (IgG binding). The functionality of our array was tested with a bacterial LysM domain‐containing protein, autolysin p60, which is known to act on the bacterial cell wall peptidoglycan. P60 showed specific binding to Nod factors and to chitin oligosaccharides. Increasing affinity was observed with increasing chitin oligomer length.
Solid‐Phase Synthesis and Biological Evaluation of N‐Dipeptido L‐Homoserine Lactones as Quorum Sensing Activators
Authors: Hansen Mette R. , Le Quement Sebastian T. , Jakobsen Tim H. , Skovstrup Søren , Taboureau Olivier , Tolker‐Nielsen Tim , Givskov Michael , Nielsen Thomas E. 
Published: January 2014

AbstractBacteria use small signaling molecules to communicate in a process termed “quorum sensing” (QS), which enables the coordination of survival strategies, such as production of virulence factors and biofilm formation. In Gram‐negative bacteria, these signaling molecules are a series of N‐acylated L‐homoserine lactones. With the goal of identifying non‐native compounds capable of modulating bacterial QS, a virtual library of N‐dipeptido L‐homoserine lactones was screened in silico with two different crystal structures of LasR. The 30 most promising hits were synthesized on HMBA‐functionalized PEGA resin and released through an efficient acid‐mediated cyclative release mechanism. Subsequent screening for modulation of QS in Pseudomonas aeruginosa and E. coli identified six moderately strong activators. A follow‐up library designed from the preliminary derived structure–activity relationships was synthesized and evaluated for their ability to activate the QS system in this bacterium. This resulted in the identification of another six QS activators (two with low micromolar activity) thus illuminating structural features required for QS modulation.
On One Leg: Trehalose Monoesters Activate Macrophages in a Mincle‐Dependent Manner
Authors: Stocker Bridget L. , Khan Ashna A. , Chee Stephanie H. , Kamena Faustin , Timmer Mattie S. M. 
Published: January 2014

AbstractThe C22 and C26 trehalose monoesters, each containing a single acyl chain, were synthesised in good overall yields and found to activate macrophages in a Mincle‐dependent manner. The activities of the monoesters paralleled those of their diester counterparts, and both mono‐ and diesters could activate the immune response in the absence of priming. This is the first time that trehalose monoesters have been found to activate macrophages, and these studies thus provide an important framework for the rational design of other Mincle agonists.
Impact of CMS coverage decision on access to transcatheter aortic valve replacement
Authors: O'Neill Brian P. , O'Neill William W. , Williams Donald , Cohen Mauricio G. , Heldman Alan W. , Macon Conrad , Martinez Claudia A. , Alfonso Carlos E. , Clark Pedro Martinez , Velasquez Omaida , Seo David , Clermont Pascal Goldschmidt , Moscucci Mauro 
Published: January 2014

ObjectivesTo assess the impact of the Centers for Medicare and Medicaid Services (CMS) national coverage determination (NCD) on access for patients with aortic stenosis (AS) with transcatheter aortic valve replacement (TAVR) in a tertiary care center.BackgroundTAVR has given hope to patients with AS who are deemed inoperable. The effects of the NCD on access to patients with AS has not been evaluated.Materials and MethodsA total of 94 inoperable AS patients were evaluated and treated from December 2011 through June of 2012 with TAVR. Patients who underwent transfemoral (TF) vs. non‐TF access were compared. The CMS NCD was released on May 1, 2012 and on July 1, 2012, the nontransfemoral access program was put on hold due to lack of reimbursement.ResultsPatients in the TF (n = 33) and non‐TF access (n = 61) groups were similar in age (85.2 ± 6.3 vs. 84.8 ± 6.6 P = 0.74) and STS mortality (9.38 ± 5.33 vs. 7.91 ± 3.69, P = 0.074). The iliofemoral arteries were larger diameter in the TF group (7.72 ± 1.49 vs. 6.21 ± 1.78, P < 0.001) and males (7.39 ± 1.81 vs. 6.1 ± 1.61 P < 0.001). More women underwent valve implantation via non‐TF access (73 vs. 23%, P = 0.03). After the NCD, 21 patients who previously qualified for non‐TF TAVR would not be reimbursed by CMS. Four died soon after.ConclusionsAfter the NCD, the proportion of inoperable patients with severe AS that can be treated with TAVR was greatly reduced due the lack of reimbursement for TAVR via non‐TF access. This effect is particularly pronounced in women. © 2014 Wiley Periodicals, Inc.
The Properties of Individual Carbon Residuals and Their Influence on The Deactivation of Ni–CaO–ZrO2 Catalysts in CH4 Dry Reforming
Authors: Wang Changzhen , Sun Nannan , Zhao Ning , Wei Wei , Zhang Jun , Zhao Tiejun , Sun Yuhan , Sun Chenggong , Liu Hao , Snape Colin E. 
Published: January 2014

AbstractNi–CaO–ZrO2 catalysts with different properties were prepared and tested for CO2 reforming of methane. The catalysts were characterized by means of transmission electron microscopy, thermogravimetric analysis, Raman spectroscopy, X‐ray photoelectron spectroscopy, and X‐ray diffraction to reveal their distinct properties and carbon deposition behaviors in the reforming reaction. It was found that the catalyst prepared by a coprecipitation method and ageing by heating to reflux exhibited a nanocrystalline structure with strong metal–support interaction, which was responsible for both high activity and stability, but it also exhibited the highest carbon formation rate among the tested catalysts. This result suggests that catalyst deactivation might not necessarily correlate with the amount of formed carbon, and the individual properties of carbon residuals could play a more decisive role. Carbon residuals on different catalysts were identified as amorphous carbon, encapsulating carbon, whisker carbon, and graphite, which had different influence on the deactivation. On the surface of the most active and stable catalyst, the carbon species mainly consisted of amorphous and whisker carbon, suggesting that the formation of such carbon species does not necessarily lead to catalyst deactivation. In contrast, the deactivation was found to be closely related to the formation of encapsulating carbon and graphite, which could coat the catalyst surface. The accumulation of different carbon residuals was proven to follow a formation–diffusion/elimination scenario, which was significantly influenced by the Ni particle size and Ni–ZrO2 interactions.
Ring‐Opening Polymerization and Copolymerization of Propylene Oxide Catalyzed by N‐Heterocyclic Carbenes
Authors: Lindner Ronald , Lejkowski Michael L. , Lavy Séverine , Deglmann Peter , Wiss Kerstin T. , Zarbakhsh Sirus , Meyer Lars , Limbach Michael 
Published: January 2014

AbstractHerein, we demonstrate the application of adducts of various N‐heterocyclic carbenes (NHCs) with CO2 (i.e., NHC–CO2) as precatalysts in the ring‐opening homopolymerization of propylene oxide (PO) onto diethylene glycol as a chain starter to give well‐defined polyether diols. The influence of various NHCs on the structure of the polymers and the mechanism of this reaction were investigated both experimentally and through DFT calculations. With this methodology, copolymers of PO and the monomers ε‐caprolactone and (S,S)‐lactide are accessible.
Expanding the Chemical Diversity in Artificial Imine Reductases Based on the Biotin–Streptavidin Technology
Authors: Quinto Tommaso , Schwizer Fabian , Zimbron Jeremy M. , Morina Albert , Köhler Valentin , Ward Thomas R. 
Published: January 2014

AbstractWe report on the optimization of an artificial imine reductase based on the biotin‐streptavidin technology. With the aim of rapidly generating chemical diversity, a novel strategy for the formation and evaluation of biotinylated complexes is disclosed. Tethering the biotin‐anchor to the Cp* moiety leaves three free coordination sites on a d6 metal for the introduction of chemical diversity by coordination of a variety of ligands. To test the concept, 34 bidentate ligands were screened and a selection of the 6 best was tested in the presence of 21 streptavidin (Sav) isoforms for the asymmetric imine reduction by the resulting three legged piano stool complexes. Enantiopure α‐amino amides were identified as promising bidentate ligands: up to 63 % ee and 190 turnovers were obtained in the formation of 1‐phenyl‐1,2,3,4‐tetrahydroisoquinoline with [IrCp*biotin(L‐ThrNH2)Cl]⊂SavWT as a catalyst.
Hydroxyl Group‐Assisted Palladium‐Catalyzed Lactonization of Homoallylic Alcohols
Authors: Huang Liangbin , Wang Qian , Wu Wanqing , Jiang Huanfeng 
Published: January 2014

AbstractA convenient and highly efficient synthesis of α‐methylene‐γ‐lactones through the palladium(II)‐catalyzed lactonization of homoallylic alcohols with alkynamides has been reported. The hydroxyl group in the terminal olefins cooperates with the amide in alkynamides to promote the cyclization by suppressing the β‐H elimination. This process provides a route to construct naturally occurring biologically multifunctional α‐methylene‐γ‐lactones.
Gold‐Catalyzed Cyclization of Diynes: Controlling the Mode of 5‐endo versus 6‐endo Cyclization—An Experimental and Theoretical Study by Utilizing Diethynylthiophenes
Authors: Hansmann Max M. , Tšupova Svetlana , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K. 
Published: January 2014

AbstractHerein, a dual‐gold catalyzed cyclization of 3,4‐diethynylthiophenes generating pentaleno[c]thiophenes through gold–vinylidenes and CH bond activation is disclosed. Various new heteroaromatic compounds—substrate classes unexplored to date—exhibiting three five‐membered annulated ring systems could be synthesized in moderate to high yields. By comparison of the solid‐state structures of the corresponding gold–acetylides, it could be demonstrated that the cyclization mode (5‐endo versus 6‐endo) is controlled by the electronic and not steric nature of the diyne backbone. Depending on different backbones, we calculated thermodynamic stabilities and full potential‐energy surfaces giving insight into the crucial dual‐activation cyclization step. In the case of the 3,4‐thiophene backbone, in which the initial cyclization is rate and selectivity determining, two energetically distinct transition states could be localized explaining the observed 5‐endo cyclization mode by classical transition‐state theory. In the case of vinyl and 2,3‐thiophene backbones, the theoretical analysis of the cyclization mode in the bifurcated cyclization area demonstrated that classical transition‐state theory is no longer valid to explain the high experimentally observed selectivity. Herein, for the first time, the influence of the backbone and the aromatic stabilization effect of the 6‐endo product in the crucial cyclization step could be visualized and quantified by calculating and comparing the full potential‐energy surfaces.
A Janus‐Headed Lewis Superacid: Simple Access to, and First Application of Me3Si‐F‐Al(ORF)3
Authors: Rohde Michael , Müller Lutz O. , Himmel Daniel , Scherer Harald , Krossing Ingo 
Published: January 2014

AbstractUpon reaction of gaseous Me3SiF with the in situ prepared Lewis acid Al(ORF)3, the stable ion‐like silylium compound Me3Si‐F‐Al(ORF)3 1 forms. The Janus‐headed 1 is a readily available smart Lewis acid that differentiates between hard and soft nucleophiles, but also polymerizes isobutene effectively. Thus, in reactions of 1 with soft nucleophiles (Nu), such as phosphanes, the silylium side interacts in an orbital‐controlled manner, with formation of [Me3SiNu]+ and the weakly coordinating [FAl(ORF)3]– or [(FRO)3Al‐F‐Al(ORF)3]– anions. If exchanged for hard nucleophiles, such as primary alcohols, the aluminum side reacts in a charge‐controlled manner, with release of FSiMe3 gas and formation of the adduct R(H)OAl(ORF)3. Compound 1 very effectively initiates polymerization of 8 to 21 mL of liquid C4H8 in 50 mL of CH2Cl2 already at temperatures between −57 and −30 °C with initiator loads as low as 10 mg in a few seconds with 100 % yield but broad polydispersities.
A General Strategy for the Catalytic, Highly Enantio‐ and Diastereoselective Synthesis of Indolizidine‐Based Alkaloids
Authors: Abels Falko , Lindemann Chris , Schneider Christoph 
Published: January 2014

AbstractSixteen indolizidine‐based alkaloids (IBAs) that were isolated as poison constituents of the skin of frogs were synthesized in a highly flexible and stereoselective manner. As a key step, a three‐component, organocatalytic, highly enantio‐ and diastereoselective vinylogous Mukaiyama–Mannich reaction was employed furnishing optically highly enriched butyrolactams as central intermediates on a multigram scale. The attached six‐membered ring was constructed through cyclization of the pendant enoate moiety onto the pyrrolidine ring. The absolute configuration of the bridgehead chiral center and the adjacent 8‐position was established in the initial vinylogous Mannich reaction, whereas the 3‐ and 5‐substituents were introduced through organometallic addition at a late stage of the synthesis with full stereochemical control from the substrate. With this strategy, simple as well as even more complex alkaloids were accessible in good overall yields as single stereoisomers. These syntheses also served to establish the absolute and relative configuration of those IBAs that had never been synthesized before.
ChemInform Abstract: New Orthorhombic Derivative of CaCu5‐Type Structure: RNi4Si Compounds (R: Y, La, Ce, Sm, Gd—Ho), Crystal Structure and Some Magnetic Properties.
Authors: Morozkin A. V. , Knotko A. V. , Yapaskurt V. O. , Yuan Fang , Mozharivskyj Y. , Nirmala R. 
Published: January 2014

AbstractThe title compounds are prepared by arc melting of stoichiometric mixtures of the elements followed by annealing (argon, 1070 K, 200 h; quenching).
ChemInform Abstract: Cu3V2O8 Hollow Spheres in Photocatalysis and Primary Lithium Batteries.
Authors: Zhang Shaoyan , Sun Yan , Li Chunsheng , Ci Lijie 
Published: January 2014

AbstractCu3V2O8 hollow spheres are prepared from aqueous suspensions of colloidal carbon spheres as template, CuSO4, and NH4VO3 (room temp., 3 h, followed by heat treatment at 500 °C in air for 2 h).
ChemInform Abstract: Rapid Spontaneous Alloying Between Pd Nanocubes and Ag Nanoparticles in Aqueous Solution at Ambient Temperature.
Authors: Tsuji Masaharu , Shiraishi Chihiro , Hattori Masashi , Yajima Atsuhiko , Mitarai Masahito , Uto Keiko , Takemura Koichi , Nakashima Yukinori 
Published: January 2014

AbstractSpontaneous alloying between equal amounts of Pd nanocubes and Ag nanoparticles is observed in liquid phase.
ChemInform Abstract: Organocatalytic Enantioselective Michael Addition of Silyl Malonate to α,β‐Unsaturated Enones: One‐Pot Synthesis of Chiral δ‐Keto Esters.
Authors: Lee Ji Yeon , Kim Dae Young 
Published: January 2014

AbstractA one‐pot enantioselective synthesis of δ‐keto esters via an organocatalytic domino sequence of conjugate addition reaction/desilylation/decarboxylation of silyl malonate (II) to enones is given.
ChemInform Abstract: Highly Chemo‐ and Regioselective Reaction of Hydroxybenzenes in Acidic Ionic Liquid.
Authors: Guo Hui , Zhuang Yu Wei , Cao Jian , Zhang Guo Bao 
Published: January 2014

AbstractThe reaction of hydroxybenzenes with α,β‐unsaturated compounds in acidic ionic liquid leads to a series of oxa‐Michael adducts or Friedel—Crafts alkylated products.
ChemInform Abstract: Efficient Synthesis of Heterocyclic Neurotensin Receptor Ligands by Microwave‐Assisted Aminocarbonylation.
Authors: Lang Christopher , Gmeiner Peter 
Published: January 2014

AbstractConversion of functionalized aryl bromides (I) to the corresponding amides (V) including the potent neurotensin NTS1 receptor SR142948A (IVd) is developed using aminocarbonylation with Mo(CO)6 as the CO source.
ChemInform Abstract: Palladium‐Catalyzed Alkyne Insertion/Reduction Route to Trisubstituted Olefins.
Authors: Fruchey Erin R. , Monks Brendan M. , Patterson Andrea M. , Cook Silas P. 
Published: January 2014

AbstractA new route to trisubstituted olefins through a palladium‐catalyzed alkyne insertion/reduction reaction with unactivated alkyl iodides is reported.
ChemInform Abstract: Synthesis of Substituted Nitroolefins: A Copper Catalyzed Nitrodecarboxylation of Unsaturated Carboxylic Acids.
Authors: Rokade Balaji V. , Prabhu Kandikere Ramaiah 
Published: January 2014

AbstractA novel, mild and convenient method for the nitrodecarboxylation of cinnamic acids using tBu‐O‐NO as nitrating source is developed.
ChemInform Abstract: Phenylated Benzotetraphenes (Dibenzanthracenes) by Nickel‐Catalyzed Diphenylacetylene Cycloadditions to Linear [3]Phenylenes.
Authors: Gu Zhenhua , Vollhardt K. Peter C. 
Published: January 2014

AbstractThe cycloaddition of diphenylacetylene to linear phenylenes proceeds via initial formation of phenanthrene derivatives (III).
ChemInform Abstract: Palladium‐Catalyzed Heteroallylation of Unactivated Alkenes — Synthesis of Citalopram (XII).
Authors: Hewitt Joanne F. M. , Williams Lewis , Aggarwal Pooja , Smith Craig D. , France David J. 
Published: January 2014

AbstractThe presented method affords a wide range of biologically relevant heterocyclic compounds.
ChemInform Abstract: Synthesis of Dihydrobenzofurans with Quaternary Carbon Center under Mild and Neutral Conditions.
Authors: Takeda Norihiko , Ueda Masafumi , Kagehira Syunsuke , Komei Hiroyuki , Tohnai Norimitsu , Miyata Mikiji , Naito Takeaki , Miyata Okiko 
Published: January 2014

AbstractA new method is developed for the construction of dihydrobenzofurans from O‐aryloxime ethers bearing an α‐cyano group via a sequential regioselective isomerization/[3,3]‐sigmatropic rearrangement/cyclization reaction without any catalysts.
ChemInform Abstract: Synthesis of Indoles with a Polyfluorinated Benzene Ring.
Authors: Politanskaya Larisa V. , Chuikov Igor P. , Shteingarts Vitalij D. 
Published: January 2014

AbstractPolyfluorinated 2‐iodoanilines are found to undergo a sequential Sonogashira coupling followed by KOH‐promoted cyclization of the 2‐alkynylaniline intermediates to yield 2‐substituted indoles.
ChemInform Abstract: Aerobic Ru‐Catalyzed Direct C2‐Olefination of N‐Heteroarenes with Alkenes Directed by a Removable N‐Dimethylcarbamoyl Group.
Authors: Zhang Luo‐Qiang , Yang Shiping , Huang Xiaolei , You Jingsong , Song Feijie 
Published: January 2014

AbstractSelective C2‐olefination of indoles (I) and (IV), pyrrole (X), and carbazole (XIII) is efficiently accomplished using oxygen as the terminal oxidant.