bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visualizing an Ultra‐Weak Protein–Protein Interaction in Phosphorylation Signaling
Authors: Xing Qiong , Huang Peng , Yang Ju , Sun Jian‐Qiang , Gong Zhou , Dong Xu , Guo Da‐Chuan , Chen Shao‐Min , Yang Yu‐Hong , Wang Yan , Yang Ming‐Hui , Yi Ming , Ding Yi‐Ming , Liu Mai‐Li , Zhang Wei‐Ping , Tang Chun 
Published: August 2014

AbstractProteins interact with each other to fulfill their functions. The importance of weak protein–protein interactions has been increasingly recognized. However, owing to technical difficulties, ultra‐weak interactions remain to be characterized. Phosphorylation can take place via a KD≈25 mM interaction between two bacterial enzymes. Using paramagnetic NMR spectroscopy and with the introduction of a novel GdIII‐based probe, we determined the structure of the resulting complex to atomic resolution. The structure accounts for the mechanism of phosphoryl transfer between the two enzymes and demonstrates the physical basis for their ultra‐weak interaction. Further, molecular dynamics (MD) simulations suggest that the complex has a lifetime in the micro‐ to millisecond regimen. Hence such interaction is termed a fleeting interaction. From mathematical modeling, we propose that an ultra‐weak fleeting interaction enables rapid flux of phosphoryl signal, providing a high effective protein concentration.
Iridium‐Catalyzed Enantioselective Allyl–Allylsilane Cross‐Coupling
Authors: Hamilton James Y. , Hauser Nicole , Sarlah David , Carreira Erick M. 
Published: August 2014

AbstractAn enantioselective allyl–allylsilane cross‐coupling involving racemic branched allylic alcohols and allylsilanes is reported. An iridium‐(P,olefin) phosphoramidite complex enables the transformation with high regio‐ and stereoselectivity under operationally simple conditions. The utility of the coupling is demonstrated in a concise catalytic, enantioselective synthesis of a pyrethroid insecticide protrifenbute.
Size‐Dependent Thermochromism through Enhanced Electron–Phonon Coupling in 1 nm Quantum Dots
Authors: Tamaki Haruna , Watanabe Hiroto , Kamiyama Sachiko , Oaki Yuya , Imai Hiroaki 
Published: August 2014

Abstract1 nm CuO quantum dots (QDs) were produced in size‐controlled super‐micropores of a silica matrix. The reversible color change of the QDs from pale blue to deep green was clearly observed in a wide temperature range from 298 to 673 K. This particular thermochromism is ascribed to an enhanced bandgap shift depending on temperature with a strong electron–phonon coupling in the confined space of the 1 nm QDs.
Three‐Dimensional Characterization of Noble‐Metal Nanoparticles and their Assemblies by Electron Tomography
Authors: Bals Sara , Goris Bart , Liz‐Marzán Luis M. , Van Tendeloo Gustaaf 
Published: August 2014

AbstractNew developments in the field of nanomaterials drive the need for quantitative characterization techniques that yield information down to the atomic scale. In this Review, we focus on the three‐dimensional investigations of metal nanoparticles and their assemblies by electron tomography. This technique has become a versatile tool to understand the connection between the properties and structure or composition of nanomaterials. The different steps of an electron tomography experiment are discussed and we show how quantitative three‐dimensional information can be obtained even at the atomic scale.
Enhanced Separation of Potassium Ions by Spontaneous K+‐Induced Self‐Assembly of a Novel Metal–Organic Framework and Excess Specific Cation–π Interactions
Authors: Wu Wenyu , Kirillov Alexander M. , Yan Xuhuan , Zhou Panpan , Liu Weisheng , Tang Yu 
Published: August 2014

AbstractA novel metal–organic framework (MOF) was fabricated by spontaneous K+‐induced supramolecular self‐assembly with the embedded tripodal ligand units. When the 3D ligand was loaded onto Fe3O4@mSiO2 core‐shell nanoparticles, it could effectively separate K+ ions from a mixture of Na+, K+, Mg2+, and Ca2+ ions through nanoparticle‐assisted MOF crystallization into a Fe3O4@mSiO2@MOF hybrid material. Excess potassium ions could be extracted because of the specific cation–π interaction between K+ and the aromatic cavity of the MOF, leading to enhanced separation efficiency and suggesting a new application for MOFs.
Extensive Structural Rearrangements upon Reduction of 9H‐9‐Borafluorene
Authors: Hübner Alexander , Bolte Michael , Lerner Hans‐Wolfram , Wagner Matthias 
Published: August 2014

AbstractCommon wisdom has it that organoboranes are readily oxidized. Described herein is that also their reduction can result in remarkable chemistry. Treatment of dimeric 9H‐9‐borafluorene with Li metal in toluene yields two strikingly different classes of compounds. One part of the sample reacts in a way similar to B2H6, thus affording an aryl(hydro)borane cluster reminiscent of the [B3H8]− anion. The other part furnishes a dianionic boron‐doped graphene flake devoid of hydrogen substituents at the boron centers and featuring a central BB bond. A change in the solvent to THF allows an isolation of this dibenzo[g,p]chrysene analogue in good yields.
The effect of BMP‐2 and VEGF loading of gelatin‐pectin‐BCP scaffolds to enhance osteoblast proliferation
Authors: Amirian Jhaleh , Linh Nguyen Thuy Ba , Min Young Ki , Lee Byong‐Taek 
Published: August 2014

ABSTRACTA composite scaffold of gelatine (Gel)‐pectin (Pec)‐biphasic calcium phosphate (BCP) was successfully fabricated. Growth factors such as bone morphogenetic protein‐2 (BMP‐2) and vascular endothelial growth factor (VEGF) were loaded into the Gel‐Pec‐BCP hydrogel scaffolds by freeze‐drying. The surface morphology was investigated by scanning electron microscopy, and BCP dispersion in the hydrogel scaffolds was measured by energy dispersive and X‐ray diffraction spectroscopy. The results obtained from Fourier transform infrared spectroscopy and quantitative measurements showed successfully loading of BMP‐2 and VEGF into the Gel‐Pec‐BCP hydrogel scaffolds. In addition MC3T3‐E1 preosteoblasts were cultivated on the three types of scaffolds to investigate the effects of BMP‐2 and VEGF on cell viability and proliferation. The Gel‐Pec‐BCP scaffolds loaded with VEGF and BMP‐2 demonstrated more cell spreading and proliferation compared to those of the Gel‐Pec‐BCP scaffolds. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41241.
Synthesis, characterization, and mechanical properties of a novel terphenyl liquid crystalline epoxy resin
Authors: Harada Miyuki , Ando Junichiro , Yamaki Motohiro , Ochi Mitsukazu 
Published: August 2014

ABSTRACTA novel terphenyl liquid crystalline (LC) epoxy resin was synthesized and characterized by 1H‐NMR, Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), and polarizing optical microscopy. Depending on the curing temperature, the synthesized resin formed both smectic and nematic LC phases. A time‐temperature‐transformation diagram was constructed to optimize the curing process, which helped in the preparation of LC and isotropic system. The terphenyl epoxy resin obtained exhibited higher acid resistance than a comparable Schiff‐base epoxy resin, and also displayed excellent fracture toughness. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41296.
Alkyl pectin: Hydrophobic matrices for controlled drug release
Authors: Zheng Xue‐Fang , Lian Qi , Yang Hua , Zhu Hong 
Published: August 2014

ABSTRACTAlkyl pectin with various fatty acid (C4–C16) bromides increased its hydrophobic characteristic and made important changes in its structural features. Unmodified pectin exhibited a low degree of order (DO) and a weak tablet‐crushing strength. Pectin alkylated with a short chain length (C4) possessed similar properties but exhibited significant swelling. Alkylation with longer side chains (C8–C16) resulted in a higher DO and crushing strength but a lower swelling. The best mechanical characteristics and drug‐release properties were found for octanoyl pectin (OP; degree of substitution = 7.06–15.41%) tablets with 20% bovine serum albumin as a tracer. The high stability of these monolithic tablets appeared to be due to hydrophobic interactions between side chains, as shown by a more organized structure. IR spectroscopy and differential scanning calorimetry analyses of OP were consistent with a hydrophobic self‐assembling model. The drug dissolution kinetics showed longer release times for higher degrees of functionalization, that is, 35 h (for 10.88% substitution) and 80 h (for 15.41% substitution); this suggested OP excipients as interesting candidates for oral and subdermal pharmaceutical applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41302.
Ultra‐high enhancement in the toughness of polyethylene by exfoliated natural clay nanosheets
Authors: Cai Dongyu , Song Mo 
Published: August 2014

ABSTRACTThe full exfoliation of inorganic natural clay was engineered in a nonpolar polyethylene following a novel method without the involvement of any chemical modification to the surface of silicate layers. Tensile results showed that the toughening effect was dependent of strain rates, and the toughness of polyethylene was substantially improved by nearly five times with 0.5 wt % natural clay nanosheets at a strain rate of 0.15 s−1. Toughening mechanism was also discussed based on this new exfoliated system. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41314.
Postsacral Vertebral Morphology in Relation to Tail Length Among Primates and Other Mammals
Authors: Russo Gabrielle A. 
Published: August 2014

ABSTRACTTail reduction/loss independently evolved in a number of mammalian lineages, including hominoid primates. One prerequisite to appropriately contextualizing its occurrence and understanding its significance is the ability to track evolutionary changes in tail length throughout the fossil record. However, to date, the bony correlates of tail length variation among living taxa have not been comprehensively examined. This study quantifies postsacral vertebral morphology among living primates and other mammals known to differ in relative tail length (RTL). Linear and angular measurements with known biomechanical significance were collected on the first, mid‐, and transition proximal postsacral vertebrae, and their relationship with RTL was assessed using phylogenetic generalized least‐squares regression methods. Compared to shorter‐tailed primates, longer‐tailed primates possess a greater number of postsacral vertebral features associated with increased proximal tail flexibility (e.g., craniocaudally longer vertebral bodies), increased intervertebral body joint range of motion (e.g., more circularly shaped cranial articular surfaces), and increased leverage of tail musculature (e.g., longer spinous processes). These observations are corroborated by the comparative mammalian sample, which shows that distantly related short‐tailed (e.g.,Phascolarctos,Lynx) and long‐tailed (e.g.,Dendrolagus,Acinonyx) nonprimate mammals morphologically converge with short‐tailed (e.g.,Macaca tonkeana) and long‐tailed (e.g.,Macaca fascicularis) primates, respectively. Multivariate models demonstrate that the variables examined account for 70% (all mammals) to 94% (only primates) of the variance in RTL. Results of this study may be used to infer the tail lengths of extinct primates and other mammals, thereby improving our understanding about the evolution of tail reduction/loss. Anat Rec, 298:354–375, 2015. © 2014 Wiley Periodicals, Inc.
Immunologically Controlled Biofuel Cell as a Self‐Powered Biosensor for Antibiotic Residue Determination
Authors: Conzuelo Felipe , Vivekananthan Jeevanthi , Pöller Sascha , Pingarrón José M. , Schuhmann Wolfgang 
Published: August 2014

AbstractA biofuel cell consisting of a self‐powered sulfonamide immunosensor as biocathode and a cellobiose dehydrogenase (CDH)‐based bioanode was developed for the determination of sulfonamide antibiotics in milk. A graphite‐rod electrode was modified with protein G for the immobilization of selective capture antibodies. A direct competitive immunoassay with a horseradish‐peroxidase‐labeled analog of the antibiotic and the 2,2′‐azino‐bis(3‐ethyl benzothiazoline‐6‐sulfonic acid) diammonium salt‐mediated reduction of H2O2 allows quantification of antibiotic residues. CDH was co‐immobilized with a toluidine‐blue‐modified redox polymer on a graphite electrode for the biocatalytic oxidation of lactose in milk. An open‐circuit voltage of 676 mV and a maximal power density of 6.9 µW cm−2 were obtained. The power densities measured at 550 mV (vs. the anode) as a function of antibiotic concentration in milk samples allowed the construction of a calibration curve with a detection limit for sulfapyridine as low as 2.4 ng mL−1.
Evolution of an Adenine–Copper Cluster to a Highly Porous Cuboidal Framework: Solution‐Phase Ripening and Gas‐Adsorption Properties
Authors: Venkatesh V. , Pachfule Pradip , Banerjee Rahul , Verma Sandeep 
Published: August 2014

AbstractThe synthesis and directed evolution of a tetranuclear copper cluster, supported by 8‐mercapto‐N9‐propyladenine ligand, to a highly porous three‐dimensional cubic framework in the solid state is reported. The structure of this porous framework was unambiguously characterized by X‐ray crystallography. The framework contains about 62 % solvent‐accessible void; the presence of a free exocyclic amino group in the porous framework facilitates reversible adsorption of gas and solvent molecules. Oriented growth of framework in solution was also tracked by force and scanning electron microscopy studies, leading to identification of an intriguing ripening process, over a period of 30 days, which also revealed formation of cuboidal aggregates in solution. The elemental composition of these cuboidal aggregates was ascertained by EDAX analysis.
Halotriazolium Axle Functionalised [2]Rotaxanes for Anion Recognition: Investigating the Effects of Halogen‐Bond Donor and Preorganisation
Authors: Mercurio James M. , Knighton Richard C. , Cookson James , Beer Paul D. 
Published: August 2014

AbstractThe anion‐templated synthesis of three novel halogen‐bonding 5‐halo‐1,2,3‐triazolium axle containing [2]rotaxanes is described, and the effects of altering the nature of the halogen‐bond donor atom together with the degree of inter‐component preorganisation on the anion‐recognition properties of the interlocked host investigated. The ability of the bromotriazolium motif to direct the halide‐anion‐templated assembly of interpenetrated [2]pseudorotaxanes was studied initially; bromide was found to be the most effective template. As a consequence, bromide anion templation was used to synthesise the first bromotriazolium axle containing [2]rotaxane, the anion‐binding properties of which, determined by 1H NMR spectroscopic titration experiments, revealed enhanced bromide and iodide recognition relative to a hydrogen‐bonding protic triazolium rotaxane analogue. Two halogen‐bonding [2]rotaxanes with bromo‐ and iodotriazolium motifs integrated into shortened axles designed to increase inter‐component preorganisation were also synthesised. Anion 1H NMR spectroscopic titration experiments demonstrated that these rotaxanes were able to bind halide anions even more strongly, with the iodotriazolium axle integrated rotaxane capable of recognising halides in aqueous solvent media. Importantly, these observations suggest that a halogen‐bonding interlocked host binding domain, in combination with increased inter‐component preorganisation, are requisite design features for a potent anion receptor.
Synthesis of Soluble, Alkyne‐Substituted Trideca‐ and Hexadeca‐Starphenes
Authors: Rüdiger Elias C. , Porz Michael , Schaffroth Manuel , Rominger Frank , Bunz Uwe H. F. 
Published: August 2014

AbstractTwo literature‐known TIPS‐ethynyl‐dibromoacenes were prepared and employed to synthesize cyclotrimers by using Yamamoto coupling conditions. Two large, well‐soluble starphenes were isolated in good yields. Crystallographic characterization verifies the triangular shape and shows significant differences in crystal packing.
Dehydrative Cross‐Coupling Reactions of Allylic Alcohols with Olefins
Authors: Gumrukcu Yasemin , de Bruin Bas , Reek Joost N. H. 
Published: August 2014

AbstractThe direct dehydrative activation of allylic alcohols and subsequent cross‐coupling with alkenes by using palladium catalyst containing a phosphoramidite ligand is described. The activation of the allyl alcohol does not require stoichiometric additives, thus allowing clean, waste‐free reactions. The scope is demonstrated by application of the protocol to a series allylic alcohols and vinyl arenes, leading to variety of 1,4‐diene products. Based on kinetic studies, a mechanism is proposed that involves a palladium hydride species that activates the allyl alcohol to form the allyl intermediate.
One‐Year Outcomes Associated With Using Observation Services in Triaging Patients With Nonspecific Chest Pain
Authors: Abbass Ibrahim M. , Virani Salim S. , Michael Swint J. , Chan Wenyaw , Franzini Luisa 
Published: August 2014

AbstractBackgroundObservation services are provided in greatly variant settings. The aim of this study was to reexamine the effectiveness of observation services compared to inpatient units for patients with nonspecific chest pain.HypothesisPatients admitted to observation units have similar outcomes to patients admitted to inpatient wards.MethodsWe conducted a claim‐based retrospective study for 7549 patients who were admitted to observation and inpatient units. Both models of care were evaluated using the 1‐year costs related to chest pain/cardiovascular diseases, and primary and secondary outcomes. Primary outcome was a composite of myocardial infarction, congestive heart failure, stroke, or cardiac arrest, whereas secondary outcomes included revascularization procedures, emergency room revisits, and hospitalization due to cardiovascular diseases.ResultsTwo‐thirds (65.7%, n = 4962) of patients in the sample had observation services, and 34.3% (n = 2587) were admitted to inpatient care. Of the inpatient group, 4.9% experienced a total of 167 primary outcomes, whereas 14.1% experienced a total of 571 secondary outcomes. In comparison, 3.8% of the observation group experienced 238 primary outcomes, and 10.3% experienced 737 secondary outcomes. After adjusting for baseline characteristics using Cox proportional hazard and quantile regression models, no differences between the 2 groups were detected in the 1‐year costs of cardiovascular services and primary or secondary outcomes. Patients who had observation services were 79% (95% confidence interval: 1.24‐2.58) more likely to have revascularization procedures compared to those admitted to inpatient care.ConclusionsPatients who had observation services had similar outcomes and 1‐year costs compared to patients admitted to inpatient wards.
Functionalization of Cantilever Tips with Nucleotides by the Phosphoramidite Method
Authors: David Ralf , Erdmann Matthias , Fornof Ann R. , Gaub Hermann E. 
Published: August 2014

AbstractIn atomic force microscopy (AFM) a sharp cantilever tip is used to scan surfaces at the atomic level. One further application is force spectroscopy, in which force–distance curves between binding partners located on the cantilever and substrate surface are determined. This requires specifically immobilized molecules. Herein we describe the covalent binding of single adenosine and thymidine nucleotides on an amino‐PEGylated cantilever tip by the phosphoramidite method. Force–distance curves between these cantilever tips and gold surfaces were recorded. The rupture forces of the coordination bond between the primary amine of adenosine and the undercoordinated gold atoms were determined to be 145 pN, which is in agreement with previously published data. The force–distance curves of thymidine‐functionalized tips did not show rupture events, because this nucleotide does not possess a primary amine function. Nucleotide‐functionalized tips could aid in the understanding of binding mechanisms of nucleotide binding molecules such as polymerases immobilized on surfaces or membranes.
Impact of complex blast waves on the human head: a computational study
Authors: Tan Long Bin , Chew Fatt Siong , Tse Kwong Ming , Chye Tan Vincent Beng , Lee Heow Pueh 
Published: August 2014

SUMMARYHead injuries due to complex blasts are not well examined because of limited published articles on the subject. Previous studies have analyzed head injuries due to impact from a single planar blast wave. Complex or concomitant blasts refer to impacts usually caused by more than a single blast source, whereby the blast waves may impact the head simultaneously or consecutively, depending on the locations and distances of the blast sources from the subject, their blast intensities, the sequence of detonations, as well as the effect of blast wave reflections from rigid walls. It is expected that such scenarios will result in more serious head injuries as compared to impact from a single blast wave due to the larger effective duration of the blast.In this paper, the utilization of a head–helmet model for blast impact analyses in AbaqusTM (Dassault Systemes, Singapore) is demonstrated. The model is validated against studies published in the literature. Results show that the skull is capable of transmitting the blast impact to cause high intracranial pressures (ICPs). In addition, the pressure wave from a frontal blast may enter through the sides of the helmet and wrap around the head to result in a second impact at the rear. This study recommended better protection at the sides and rear of the helmet through the use of foam pads so as to reduce wave entry into the helmet. The consecutive frontal blasts scenario resulted in higher ICPs compared with impact from a single frontal blast. This implied that blast impingement from an immediate subsequent pressure wave would increase severity of brain injury. For the unhelmeted head case, a peak ICP of 330 kPa is registered at the parietal lobe which exceeds the 235 kPa threshold for serious head injuries. The concurrent front and side blasts scenario yielded lower ICPs and skull stresses than the consecutive frontal blasts case. It is also revealed that the additional side blast would only significantly affect ICPs at the temporal and parietal lobes when compared with results from the single frontal blast case.By analyzing the pressure wave flow surrounding the head and correlating them with the consequential evolution of ICP and skull stress, the paper provides insights into the interaction mechanics between the concomitant blast waves and the biological head model. Copyright © 2014 John Wiley & Sons, Ltd.