bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collagen functionalized with unsaturated cyclic anhydrides—interactions in solution and solid state
Authors: Potorac S. , Popa M. , Picton L. , Dulong V. , Verestiuc L. , Cerf D. Le 
Published: June 2013

ABSTRACTMaleic anhydride (CMA) and itaconic anhydride modified collagen (CITA) were prepared as precursors for production of interpenetrated polymer networks (IPN). Calculated values for Huggins coefficient in aqueous diluted and semi‐diluted solutions of modified collagen indicated a slightly tendency of aggregation for itaconic anhydride‐modified collagen. In semi‐diluted solution collagen (Coll) and CMA present slightly differences in the thixotropic behavior, while CITA has a pronounced thixotropic behavior. Flow and oscillatory measurements revealed an elastic behavior of the collagen solutions, pure and modified with MA or ITA, as the storage modulus (G′) has always a superior value compared with the loss modulus (G″). The denaturation temperature (Td) of unmodified collagen increased from 34oC to 40oC for CMA and to 39oC for CITA respectively, by formation of covalent bonds that stabilize the triple helix. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 228–236, 2014.
Fast analysis of triterpenoids in Ganoderma lucidum spores by ultra‐performance liquid chromatography coupled with triple quadrupole mass spectrometry
Authors: Yan Zhou , Xia Bing , Qiu Ming Hua , Li Sheng Ding , Xu Hong Xi 
Published: June 2013

ABSTRACTA rapid and reliable method was established for simultaneous determination of main triterpenoids in Ganoderma lucidum spores using ultra‐high‐performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC‐TQ‐MS). The established method was validated in terms of linearity, sensitivity, precision, accuracy and stability, and was successfully applied to determine the contents of 10 main triterpenoids in different batches of G. lucidum spores. The analysis results showed that moderate levels of triterpenoids were found in G. lucidum spores. In addition, a MS full scan with a daughter ion scan experiment was performed to identify the potential derivatives of triterpenoids present in G. lucidum spores. As a result, a total of 22 triterpenoids from different G. lucidum spores were unequivocally or tentatively identified via comparisons with authentic standards and literatures. This method provides both qualitative and quantitative results without the need for repetitive UPLC‐MS analyses, thereby increasing efficiency and productivity, making it suitable for high‐throughput applications. Copyright © 2013 John Wiley & Sons, Ltd.
Fluorescent THF‐Based Fructose Analogue Exhibits Fructose‐Dependent Uptake
Authors: Tanasova Marina , Plutschack Matthew , Muroski Megan E. , Sturla Shana J. , Strouse Geoffrey F. , McQuade D. Tyler 
Published: June 2013

AbstractRecent publications suggest that high dietary fructose might play a significant role in cancer metabolism and can exacerbate a number of aspects of metabolic syndrome. Addressing the role that fructose plays in human health is a controversial question and requires a detailed understanding of many factors including the mechanism of fructose transport into healthy and diseased cells. Fructose transport into cells is thought to be largely mediated by the passive hexose transporters Glut2 and Glut5. To date, no probes that can be selectively transported by one of these enzymes but not by the other have been identified. The data presented here indicate that, in MCF‐7 cells, a 1‐amino‐2,5‐anhydro‐D‐mannitol‐based fluorescent NBDM probe is transported twice as efficiently as fructose and that this takes place with the aid of Glut5. Its Glut5 specificity and differential uptake in cancer cells and in normal cells suggest this NBDM probe as a potentially useful tool for cross‐cell‐line correlation of Glut5 transport activity.
Dual Activators of Protein Kinase R (PKR) and Protein Kinase R‐Like Kinase (PERK) Identify Common and Divergent Catalytic Targets
Authors: Bai Huijun , Chen Ting , Ming Jie , Sun Hong , Cao Peng , Fusco Dahlene N. , Chung Raymond T. , Chorev Michael , Jin Qi , Aktas Bertal H. 
Published: June 2013

AbstractChemical genetics has evolved into a powerful tool for studying gene function in normal and pathobiology. PKR and PERK, two eukaryotic translation initiation factor 2 alpha (eIF2α) kinases, play critical roles in the maintenance of cellular hemostasis, metabolic stability, and anti‐viral defenses. Both kinases interact with and phosphorylate additional substrates including tumor suppressor p53 and nuclear protein 90. Loss of function of both kinases has been studied by reverse genetics and with recently identified inhibitors. In contrast, no activating probes for studying the catalytic activity of these kinases are available. We identified 3‐(2,3‐dihydrobenzo[b][1,4]dioxin‐6‐yl)‐5,7‐dihydroxy‐4H‐chromen‐4‐one (DHBDC) as a specific dual activator of PKR and PERK by screening a chemical library of 20 000 small molecules in a dual luciferase surrogate eIF2α phosphorylation assay. We present here extensive biological characterization and a preliminary structure–activity relationship of DHBDC, which phosphorylates eIF2α by activating PKR and PERK but no other eIF2α kinases. These agents also activate downstream effectors of eIF2α phosphorylation by inducing CEBP homologue protein, suppressing cyclin D1 expression, and inhibiting cancer cell proliferation, all in a manner dependent on PKR and PERK. Consistent with the role of eIF2α phosphorylation in viral infection, DHBDC inhibits the proliferation of human hepatitis C virus. Finally, DHBDC induces the phosphorylation of IκBα and activates the NF‐κB pathway. Surprisingly, activation of the NF‐κB pathway is dependent on PERK but independent of PKR activity. These data indicate that DHBDC is an invaluable probe for elucidating the role of PKR and PERK in normal and pathobiology.
Radial artery spasm associated with transradial cardiovascular procedures: Results from the RAS registry
Authors: Goldsmit Alejandro , Kiemeneij Ferdinand , Gilchrist Ian C , Kantor Pablo , Kedev Sasko , Kwan Tak , Dharma Surya , Valdivieso Leon , Wenstemberg Bernard , Patel Tejas 
Published: June 2013

ObjectivesTo report the incidence and predictors of moderate/severe radial artery spasm (RAS) in patients undergoing cardiovascular percutaneous procedures through a transradial approach (TRA) in centers with TRA expertise.BackgroundData regarding the actual rate of clinically meaningful RAS are limited due to difference in study designs and operator expertise.MethodsThe RAS registry, an international (14 centers from Argentina, Chile, India, Indonesia, Macedonia, The Netherlands and United States of America) registry that included 1,868 patients undergoing TRA cardiovascular procedures (63.5% diagnostic and 56.5% therapeutic).All selected centers used TRA as default strategy in the cardiac catheterization laboratory. Throughout 2012, each center included all consecutive TRA cases (during a 2‐month period) into a dedicated database covering clinical characteristics as well as procedural topics related to TRA patterns and RAS occurrence.ResultsThe incidence of moderate/severe RAS was 2.7%. Only 0.7% of patients required crossover (8 to transfemoral and 5 to contralateral TRA). Patients with moderately/severe spasm were more frequently females, had a history of dyslipidemia, received more often a 7F sheath and more puncture attempts than patients without spasm. By multivariate analysis, the need for more than one attempt and the use of a 7 F sheath were independent predictors of the development of moderate/severe RAS.ConclusionsThe incidence of moderate/severe RAS is low in centers with a default TRA. Its development appears to be strongly related to the numbers of puncture attempts and the use of large sheaths. © 2013 Wiley Periodicals, Inc.
MF Interactions and Heterobimetallics: Furthering the Understanding of Heterobimetallic Stabilization
Authors: Buchanan William D. , Ruhlandt‐Senge Karin 
Published: June 2013

AbstractHeterobimetallic complexes containing alkali, alkaline‐earth, and divalent europium metals utilizing the perfluoro‐tert‐butoxide (PFTB) ligand following the general formula, [AM(PFTB)3(co‐ligand)x] (A=Na, K; M=Mg, Sr, Ba, Eu; co‐ligand=THF, toluene), have been isolated. These compounds sublime at low temperatures with low residual weight indicating their potential as metal–organic chemical‐vapor deposition (MOCVD) precursors. The complexes have unique molecular architectures that are strongly influenced by MF interactions, as was verified in the solid state by using X‐ray crystallography. The significance of these interactions were further reinforced by bond‐valence sums analysis and 19F VT‐NMR spectroscopy, in which rotational energies of 18.75 and 19.08 kcal mol−1 were measured.
Towards Dynamic Control of Wettability by Using Functionalized Altitudinal Molecular Motors on Solid Surfaces
Authors: London Gábor , Chen Kuang‐Yen , Carroll Gregory T. , Feringa Ben L. 
Published: June 2013

AbstractWe report the synthesis of altitudinal molecular motors that contain functional groups in their rotor part. In an approach to achieve dynamic control over the properties of solid surfaces, a hydrophobic perfluorobutyl chain and a relatively hydrophilic cyano group were introduced to the rotor part of the motors. Molecular motors were attached to quartz surfaces by using interfacial 1,3‐dipolar cycloadditions. To test the effect of the functional groups on the rotary motion, photochemical and thermal isomerization studies of the motors were performed both in solution and when attached to the surface. We found that the substituents have no significant effect on the thermal and photochemical processes, and the functionalized motors preserved their rotary function both in solution and on a quartz surface. Preliminary results on the influence of the functional groups on surface wettability are also described.
Peripheral Arylation of Subporphyrazines
Authors: Higashino Tomohiro , Rodríguez‐Morgade M. Salomé , Osuka Atsuhiro , Torres Tomás 
Published: June 2013

AbstractPeripherally hexaarylated subporphyrazines (SubPzs) have been prepared through a Pd‐catalyzed, CuTC‐mediated coupling of a hexaethylsulfanylated subporphyrazine with arylboronic acids. The introduced aryl substituents strongly influence the electronic properties of the subporphyrazine through effective conjugative interaction. Aryl rings endowed with π‐electron‐donating groups at the para positions produce a remarkable perturbation of the electron density of the SubPz macrocycle. This is reflected through significant redshifts of the SubPz CT and Q‐bands, together with increase of the molar absorptivity of the former, with respect to those exhibited by the hexaphenyl‐SubPz 2 a. Moreover, the trend in the first SubPz reduction potentials correlates with the Hammett constants (σp) corresponding to the para substituents of the aryl. The domed, extended SubPz π‐system self‐assembles in the solid state to form a dimeric capsule that houses a solvent molecule.
Synthesis and Radiopharmacological Characterisation of a Fluorine‐18‐Labelled Azadipeptide Nitrile as a Potential PET Tracer for in vivo Imaging of Cysteine Cathepsins
Authors: Löser Reik , Bergmann Ralf , Frizler Maxim , Mosch Birgit , Dombrowski Lilli , Kuchar Manuela , Steinbach Jörg , Gütschow Michael , Pietzsch Jens 
Published: June 2013

AbstractA fluorinated cathepsin inhibitor based on the azadipeptide nitrile chemotype was prepared and selected for positron emission tomography (PET) tracer development owing to its high affinity for the oncologically relevant cathepsins L, S, K and B. Labelling with fluorine‐18 was accomplished in an efficient and reliable two‐step, one‐pot radiosynthesis by using 2‐[18F]fluoroethylnosylate as a prosthetic agent. The pharmacokinetic properties of the resulting radiotracer compound were studied in vitro, ex vivo and in vivo in normal rats by radiometabolite analysis and small‐animal positron emission tomography. These investigations revealed rapid conjugate formation of the tracer with glutathione in the blood, which is associated with slow blood clearance. The potential of the developed 18F‐labelled probe to image tumour‐associated cathepsin activity was investigated by dynamic small‐animal PET imaging in nude mice bearing tumours derived from the human NCI‐H292 lung carcinoma cell line. Computational analysis of the obtained image data indicated the time‐dependent accumulation of the radiotracer in the tumours. The expression of the target enzymes in the tumours was confirmed by immunohistochemistry with specific antibodies. This indicates that azadipeptide nitriles have the potential to target thiol‐dependent cathepsins in vivo despite their disadvantageous pharmacokinetics.
Design of a Highly Selective and Potent Class of Non‐planar Estrogen Receptor β Agonists
Authors: Sundén Henrik , Ma Jian‐Nong , Hansen Lars K. , Gustavsson Anna‐Lena , Burstein Ethan S. , Olsson Roger 
Published: June 2013

AbstractSelective activation of the estrogen receptor β (ERβ) could be a safe approach to hormone replacement therapy for both women and men, in contrast to the estrogens currently used for women which activate both ERβ and ERα, occasionally causing severe side effects. The selective ERβ agonist AC‐131 has shown efficacy in animal models of Parkinson’s disease and neuropathic pain. With the use of AC‐131 as template, herein we report the discovery, synthesis, and structure–activity relationship (SAR) study of a new class of dihydrobenzofurans as potent and selective ERβ agonists. The SAR was established by enantioselective synthesis, molecular modeling, and whole‐cell‐based functional assays. The most potent diastereomer, cis‐10‐SR, was shown to have an EC50 value of <1 nM, potency 100‐fold higher than that of AC‐131. Even more interestingly, compound trans‐10‐SS exhibited 1000‐fold ERβ/ERα selectivity while still maintaining good potency (∼10 nM). In addition, trans‐10‐SS showed only partial agonist activity (30–60 % Eff.) toward ERα at 10 μM. This unprecedented selectivity could be rationalized by molecular modeling. Compound trans‐10‐SS appears to be the first molecule to take advantage of both conservative amino acid differences found in the α‐ and β‐faces of the binding cavities of ERα and ERβ.
Engineering‐aided treatment of chest deformities to improve the process of breathing
Authors: Gzik‐Zroska Bożena , Wolański Wojciech , Gzik Marek 
Published: June 2013

SUMMARYIn this paper, the application of new visualization technologies in correction of funnel chest is presented. Often, such defects cause problems with breathing, and therefore, to improve the cardiorespiratory efficiency, a correction is required. The virtual model of chest was formulated to determine the strains and stresses after correction of deformation with using the stabilizing plate. From biomechanical point of view, the knowledge of the load‐affecting stabilizer is necessary to select optimal parameters of the plate. The force‐affecting plate that was used in the correction of chest deformation by Nuss method was determined on the basis of finite element model of funnel chest. The main aim of this work was to select the optimal thickness of plate. Calculations were conducted for three alternative constraints. Copyright © 2013 John Wiley & Sons, Ltd.
Harnessing Light with Photonic Nanowires: Fundamentals and Applications to Quantum Optics
Authors: Claudon Julien , Gregersen Niels , Lalanne Philippe , Gérard Jean‐Michel 
Published: June 2013

AbstractThe efficient feeding of spontaneous emission (SE) into a controlled optical mode lies at the heart of a new generation of advanced optoelectronic devices, such as low‐threshold microlasers and bright sources of quantum light. In the solid state, single‐mode emission was first demonstrated by using the Purcell effect that arises in a resonant microcavity. Recently, the need to relax the constraints inherent to such a narrow‐band approach has motivated large effort to develop structures ensuring broadband and efficient SE control. This minireview deals with fiber‐like photonic nanowires, a class of high‐index waveguides that features key assets in this context. Combining theoretical predictions and experimental results, the paper details the SE dynamics in such tiny wires. In addition, it shows how the far‐field emission of a single wire can be tailored through proper engineering of the two wire ends. As an application in the field of quantum optics, we review the realization of an ultrabright single‐photon source. This first device was based on a self‐assembled quantum dot embedded in a wire antenna realized with a top‐down fabrication process. Considering recent advances in the direct growth of tapered photonic wires, we also propose a bottom‐up fabrication route to realize a complete device. In particular, this proposal ensures the optimal 3D positioning of a single emitter inside the antenna. Finally, future research and application prospects are also reviewed.
Characterization of Thermally Stable Brønsted Acid Sites on Alumina‐Supported Niobium Oxide after Calcination at High Temperatures
Authors: Kitano Tomoyuki , Shishido Tetsuya , Teramura Kentaro , Tanaka Tsunehiro 
Published: June 2013

AbstractThermally stable Brønsted acid sites were generated on alumina‐supported niobium oxide (Nb2O5/Al2O3) by calcination at high temperatures, such as 1123 K. The results of structural characterization by using Fourier‐transform infrared (FTIR) spectroscopy, TEM, scanning transmission electron microscopy (STEM), and energy‐dispersive X‐ray (EDX) analysis indicated that the Nb2O5 monolayer domains were highly dispersed over alumina at low Nb2O5 loadings, such as 5 wt %, and no Brønsted acid sites were presents. The coverage of Nb2O5 monolayer domains over Al2O3 increased with increasing Nb2O5 loading and almost‐full coverage was obtained at a loading of 16 wt %. A sharp increase in the number of hydroxy groups, which acted as Brønsted acid sites, was observed at this loading level. The relationship between the acidic properties and the structure of the material suggested that the bridging hydroxy groups (NbO(H)Nb), which were formed at the boundaries between the domains of the Nb2O5 monolayer, acted as thermally stable Brønsted acid sites.
Lithium‐Functionalized Metal–Organic Frameworks that Show >10 wt % H2 Uptake at Ambient Temperature
Authors: Han Sang Soo , Jung Dong Hyun , Choi Seung‐Hoon , Heo Jiyoung 
Published: June 2013

AbstractWe have used grand canonical Monte Carlo simulations with a first‐principles‐based force field to show that metal–organic frameworks (MOFs) with Li functional groups (i.e. CLi bonds) allow for exceptional H2 uptake at ambient temperature. For example, at 298 K and 100 bar, IRMOF‐1‐4Li shows a total H2 uptake of 5.54 wt % and MOF‐200‐27Li exhibits a total H2 uptake of 10.30 wt %, which are much higher than the corresponding values with pristine MOFs. Li‐functionalized MOF‐200 (MOF‐200‐27Li) shows 11.84 wt % H2 binding at 243 K and 100 bar. These hydrogen‐storage capacities exceed the 2015 DOE target of 5.5 wt % H2. Moreover, the incorporation of Li functional groups into MOFs provides more benefits, such as higher delivery amount, for H2 uptake than previously reported Li‐doped MOFs.
Thermal Activation of Ammonia by Transition‐Metal Hydroxide Cations
Authors: Kretschmer Robert , Schlangen Maria , Schwarz Helmut 
Published: June 2013

AbstractWith the exception of [Cu(OH)]+, the thermal reactions of the first‐row transition‐metal hydroxide cations, [Sc(OH)]+–[Zn(OH)]+, with ammonia have been studied by means of gas‐phase experiments and by computational methods for the whole series. The primary reaction channels involve NH bond activation, forming [M(NH2)]+ concomitantly with the elimination of water, and adduct formation, leading to [M(OH)(NH3)]+. Furthermore, [Ti(OH)]+ and [V(OH)]+ react with ammonia under dehydrogenation conditions, leading to [M,O,N,H2]+ (M=Ti, V), and for [Ni(OH)]+ ligand exchange is observed. Computations of the main reaction channels have been performed for the [M(OH)]+/NH3 couples (M=Sc–Zn) to uncover the underlying reaction mechanism and periodic trends across the first row. For NH bond activation, σ‐bond metathesis was found to be the underlying mechanism.
Assembly of Tin Oxide/Graphene Nanosheets into 3D Hierarchical Frameworks for High‐Performance Lithium Storage
Authors: Huang Yanshan , Wu Dongqing , Han Sheng , Li Shuang , Xiao Li , Zhang Fan , Feng Xinliang 
Published: June 2013

Abstract3D hierarchical tin oxide/graphene frameworks (SnO2/GFs) were built up by the in situ synthesis of 2D SnO2/graphene nanosheets followed by hydrothermal assembly. These SnO2/GFs exhibited a 3D hierarchical porous architecture with mesopores (≈3 nm), macropores (3–6 μm), and a large surface area (244 m2 g−1), which not only effectively prevented the agglomeration of SnO2 nanoparticles, but also facilitated fast ion and electron transport in 3D pathways. As a consequence, the SnO2/GFs exhibited a high capacity of 830 mAh g−1 for up to 70 charge–discharge cycles at 100 mA g−1. Even at a high current density of 500 mA g−1, a reversible capacity of 621 mAh g−1 could be maintained for SnO2/GFs with excellent cycling stability. Such performance is superior to that of previously reported SnO2/graphene and other SnO2/carbon composites with similar weight contents of SnO2.
Mesoporous TiN Microspheres with Hierarchical Chambers and Enhanced Visible Light‐Driven Hydrogen Evolution
Authors: Li Guisheng , Zhang Peng , Bian Zhenfeng , Zhu Jian , Wu Ling , Li Hexing 
Published: June 2013

AbstractMesoporous titanium nitride (TiN) microspheres with tunable chamber structures were synthesized through NH3 nitridation of organotitania obtained via solvothermal alcoholysis. Owing to high content of organic species in organotitania, which stabilized the original structure and also promoted the nitridation at low temperature, TiN duplicated the solid, yolk–shell, and hollow chambers of organotitania in NH3 nitridation and also formed the mesoporous structure after removing organic species. During visible light‐induced photocatalytic water splitting, the yolk–shell TiN demonstrated a higher H2 evolution efficiency than the solid, hollow, and crushed TiN; the yolk–shell TiN obtained through N2 nitridation; and other semiconductor photocatalysts reported so far without the aid of noble metals. This could be attributed mainly to the narrow energy band gap for absorbing visible light, high surface area, and excellent electrical conductivity, which facilitated light harvesting, reactant adsorption, and photoelectron–hole separation to suppress their recombination. Moreover, it could be easily recycled and thus used repetitively.