bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Atomic‐Scale View of CO and H2 Oxidation on a Pt/Fe3O4 Model Catalyst
Authors: Bliem Roland , van der Hoeven Jessi , Zavodny Adam , Gamba Oscar , Pavelec Jiri , de Jongh Petra E. , Schmid Michael , Diebold Ulrike , Parkinson Gareth S. 
Published: September 2015

AbstractMetal–support interactions are frequently invoked to explain the enhanced catalytic activity of metal nanoparticles dispersed over reducible metal oxide supports, yet the atomic‐scale mechanisms are rarely known. In this report, scanning tunneling microscopy was used to study a Pt1‐6/Fe3O4 model catalyst exposed to CO, H2, O2, and mixtures thereof at 550 K. CO extracts lattice oxygen atoms at the cluster perimeter to form CO2, creating large holes in the metal oxide surface. H2 and O2 dissociate on the metal clusters and spill over onto the support. The former creates surface hydroxy groups, which react with the support, ultimately leading to the desorption of water, while oxygen atoms react with Fe from the bulk to create new Fe3O4(001) islands. The presence of the Pt is crucial because it catalyzes reactions that already occur on the bare iron oxide surface, but only at higher temperatures.
Organomediated Enantioselective 18F Fluorination for PET Applications
Authors: Buckingham Faye , Kirjavainen Anna K. , Forsback Sarita , Krzyczmonik Anna , Keller Thomas , Newington Ian M. , Glaser Matthias , Luthra Sajinder K. , Solin Olof , Gouverneur Véronique 
Published: September 2015

AbstractThe first organomediated asymmetric 18F fluorination has been accomplished using a chiral imidazolidinone and [18F]N‐fluorobenzenesulfonimide. The method provides access to enantioenriched 18F‐labeled α‐fluoroaldehydes (>90 % ee), which are versatile chiral 18F synthons for the synthesis of radiotracers. The utility of this process is demonstrated with the synthesis of the PET (positron emission tomography) tracer (2S,4S)‐4‐[18F]fluoroglutamic acid.
Manganese‐Catalyzed Direct Nucleophilic C(sp2)H Addition to Aldehydes and Nitriles
Authors: Zhou Bingwei , Hu Yuanyuan , Wang Congyang 
Published: September 2015

AbstractHerein, a manganese‐catalyzed nucleophilic addition of inert C(sp2)H bonds to aldehydes and nitriles is disclosed by virtue of a dual activation strategy. The reactions feature mild reaction conditions, excellent regio‐ and stereoselectivity, and a wide substrate scope, which includes both aromatic and olefinic CH bonds, as well as a large variety of aldehydes and nitriles. Moreover, mechanistic studies shed light on possible catalytic cycles.
Energy Migration Upconversion in Manganese(II)‐Doped Nanoparticles
Authors: Li Xiyan , Liu Xiaowang , Chevrier Daniel M. , Qin Xian , Xie Xiaoji , Song Shuyan , Zhang Hongjie , Zhang Peng , Liu Xiaogang 
Published: September 2015

AbstractWe report the synthesis and characterization of cubic NaGdF4:Yb/Tm@NaGdF4:Mn core–shell structures. By taking advantage of energy transfer through Yb→Tm→Gd→Mn in these core–shell nanoparticles, we have realized upconversion emission of Mn2+ at room temperature in lanthanide tetrafluoride based host lattices. The upconverted Mn2+emission, enabled by trapping the excitation energy through a Gd3+ lattice, was validated by the observation of a decreased lifetime from 941 to 532 μs in the emission of Gd3+ at 310 nm (6P7/2→8S7/2). This multiphoton upconversion process can be further enhanced under pulsed laser excitation at high power densities. Both experimental and theoretical studies provide evidence for Mn2+ doping in the lanthanide‐based host lattice arising from the formation of F− vacancies around Mn2+ ions to maintain charge neutrality in the shell layer.
Inhibition of Osteoarthritis by Adipose‐Derived Stromal Cells Overexpressing Fra‐1 in Mice
Authors: Schwabe Kay , Garcia Mireia , Ubieta Kenia , Hannemann Nicole , Herbort Bettina , Luther Julia , Noël Daniele , Jorgensen Christian , Casteilla Louis , David Jean‐Pierre , Stock Michael , Herrmann Martin , Schett Georg , Bozec Aline 
Published: September 2015

ObjectiveTo determine whether overexpression of the activator protein 1 (AP‐1) transcription factor Fra‐1 in adipose‐derived stromal cells (ADSCs) is an effective treatment of collagenase‐induced osteoarthritis (OA).MethodsOA was induced by injection of collagenase into the knee joints of male C57BL/6 mice. ADSCs were isolated from the inguinal fat pads of 8‐week‐old wild‐type or Fra‐1–transgenic mice and injected into the knee joints of mice with collagenase‐induced OA 7 days after OA induction. Histologic analyses of cartilage destruction and chondrocyte cell death were performed. Adipogenic differentiation capacity was evaluated, gene expression was analyzed, and cytokine profiling was performed in stromal vascular fractions (SVFs) and ADSCs.ResultsOA‐related cartilage destruction and chondrocyte cell death were significantly reduced in mouse knee joints treated with ADSCs from Fra‐1–transgenic mice compared to mouse knee joints treated with ADSCs from wild‐type mice. This effect did not result from the higher number of adipogenic progenitors observed in SVFs from Fra‐1–transgenic compared to wild‐type mouse fat pads, since injection of wild‐type mouse ADSCs enriched for adipogenic progenitors did not show any additional chondroprotective effects compared to nonsorted ADSCs. However, Fra‐1–transgenic mouse ADSCs showed decreased adipogenic differentiation capacity. Moreover, Fra‐1 significantly inhibited proinflammatory interleukin‐6 and pentraxin 3 expression, while increasing the expression of extracellular matrix proteins, such as periostin and spondin 1. These findings suggest that Fra‐1 overexpression leads to an increased chondroprotective effect of ADSCs in OA.ConclusionADSCs overexpressing Fra‐1 effectively protect against OA. Our data indicate that genetic modifications of ADSCs, such as Fra‐1 overexpression, may improve their potential to protect articular cartilage against OA‐mediated damage.
Analyzing and optimizing pedestrian flow through a topological network based on M/G/C/C and network flow approaches
Authors: Khalid Ruzelan , Baten Md. Azizul , Nawawi Mohd. Kamal Mohd. , Ishak Nurhanis 
Published: September 2015

SummaryAn M/G/C/C state dependent queuing network measures the performance of a system whose service rate decreases with the increasing number of residing entities. However, the performance in terms of throughputs, levels of congestions, the expected number of entities, and the expected service time is typically analyzed based on a series of arrival rates without any further discussion on the optimal arrival rate. This paper derives the optimal arrival rates of corridors in a topological network using calculus and numerical analysis approaches. These optimal rates are then used as capacity parameters in the network's flow model to obtain the optimal arrival rates that maximize its total throughput. To ease the construction and performance evaluation of the network, we design and construct an M/G/C/C framework based on the Object‐Oriented Programming approach that integrates the lingo software as an optimization tool. The framework is then tested on virtual and real networks. This framework can be used to develop a more advanced traffic management tool for studying and managing traffic flow through a complex network. Copyright © 2015 John Wiley & Sons, Ltd.
Molecular modeling and multi‐spectroscopic approaches to study the interaction between antibacterial drug and human immunoglobulin G
Authors: Wang Qin , Min Suotian , Liu Zhifeng , Zhang Shengrui 
Published: September 2015

AbstractMechanistic and conformational studies on the interaction of sulfamethoxazole (SMX) with human immunoglobulin G (HIgG) were performed by molecular modeling and multi‐spectroscopic methods. The interaction mechanism was firstly predicted through molecular modeling that confirmed the interaction between SMX and HIgG. The binding parameters and thermodynamic parameters at different temperatures had been calculated according to the Stern−Volmer, Scatchard, Sips and Van ’t Hoff equations, respectively. Experimental results showed that the fluorescence intensity of HIgG was quenched by the gradual addition of SMX. The binding constants of SMX with HIgG decreased with the increase of temperature, which meant that the quenching mechanism was a static quenching. Meanwhile, the results also confirmed that there was one independent class of binding site on HIgG for SMX during their interaction. The thermodynamic parameters of the reaction, namely standard enthalpy ΔH0 and entropy ΔS0, had been calculated to be −14.69 kJ·mol−1 and 22.99 J·mol−1·K−1, respectively, which suggested that the electrostatic and hydrophobic interactions were the predominant intermolecular forces in stabilizing the SMX−HIgG complex. Furthermore, experimental results obtained from three‐dimensional fluorescence spectroscopy, UV−vis absorption spectroscopy and circular dichroism (CD) spectroscopy confirmed that the conformational structure of HIgG was altered in the presence of SMX. Copyright © 2015 John Wiley & Sons, Ltd.
Micro 3D cell culture systems for cellular behavior studies: Culture matrices, devices, substrates, and in‐situ sensing methods
Authors: Choi Jonghoon , Lee Eun Kyu , Choo Jaebum , Yuh Junhan , Hong Jong Wook 
Published: September 2015

AbstractMicrofabricated systems equipped with 3D cell culture devices and in‐situ cellular biosensing tools can be a powerful bionanotechnology platform to investigate a variety of biomedical applications. Various construction substrates such as plastics, glass, and paper are used for microstructures. When selecting a construction substrate, a key consideration is a porous microenvironment that allows for spheroid growth and mimics the extracellular matrix (ECM) of cell aggregates. Various bio‐functionalized hydrogels are ideal candidates that mimic the natural ECM for 3D cell culture. When selecting an optimal and appropriate microfabrication method, both the intended use of the system and the characteristics and restrictions of the target cells should be carefully considered. For highly sensitive and near‐cell surface detection of excreted cellular compounds, SERS‐based microsystems capable of dual modal imaging have the potential to be powerful tools; however, the development of optical reporters and nanoprobes remains a key challenge. We expect that the microsystems capable of both 3D cell culture and cellular response monitoring would serve as excellent tools to provide fundamental cellular behavior information for various biomedical applications such as metastasis, wound healing, high throughput screening, tissue engineering, regenerative medicine, and drug discovery and development.
Quantitative determination of pravastatin and its metabolite 3α‐hydroxy pravastatin in plasma and urine of pregnant patients by LC‐MS/MS
Authors: Zhang Xing , Vernikovskaya Daria I. , Wang Xiaoming , Nanovskaya Tatiana N. , Costantine Maged , Hankins Gary D. V. , Ahmed Mahmoud S. 
Published: September 2015

AbstractThis report describes the development and validation of a chromatography/tandem mass spectrometry method for the quantitative determination of pravastatin and its metabolite (3α‐hydroxy pravastatin) in plasma and urine of pregnant patients under treatment with pravastatin, as part of a clinical trial. The method includes a one‐step sample preparation by liquid–liquid extraction. The extraction recovery of the analytes ranged between 93.8 and 99.5% in plasma. The lower limits of quantitation of the analytes in plasma samples were 0.106 ng/mL for pravastatin and 0.105 ng/mL for 3α‐hydroxy pravastatin, while in urine samples they were 19.7 ng/mL for pravastatin and 2.00 ng/mL for 3α‐hydroxy pravastatin. The relative deviation of this method was <10% for intra‐ and interday assays in plasma and urine samples, and the accuracy ranged between 97.2 and 106% in plasma, and between 98.2 and 105% in urine. The method described in this report was successfully utilized for determining the pharmacokinetics of pravastatin in pregnant patients enrolled in a pilot clinical trial for prevention of preeclampsia. Copyright © 2015 John Wiley & Sons, Ltd.
Ultrafast Photoinduced Charge Separation in Wide‐Band‐Capturing Self‐Assembled Supramolecular Bis(donor styryl)BODIPY–Fullerene Conjugates
Authors: Shao Shuai , Gobeze Habtom B. , Karr Paul A. , D'Souza Francis 
Published: September 2015

AbstractA new series of self‐assembled supramolecular donor–acceptor conjugates capable of wide‐band capture, and exhibiting photoinduced charge separation have been designed, synthesized and characterized using various techniques as artificial photosynthetic mimics. The donor host systems comprise of a 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) containing a crown ether entity at the meso‐position and two styryl entities on the pyrrole rings. The styryl end groups also carried additional donor (triphenylamine or phenothiazine) entities. The acceptor host system was a fulleropyrrolidine comprised of an ethylammonium cation. Owing to the presence of extended conjugation and multiple chromophore entities, the BODIPY host revealed absorbance and emission well into the near‐IR region covering the 300–850 nm spectral range. The donor–acceptor conjugates formed by crown ether–alkyl ammonium cation binding of the host–guest system was characterized by optical absorbance and emission, computational, and electrochemical techniques. Experimentally determined binding constants were in the range of 1–2×105 M−1. An energy‐level diagram to visualize different photochemical events was established using redox, computational, absorbance, and emission data. Spectral evidence for the occurrence of photoinduced charge separation in these conjugates was established from femtosecond transient absorption studies. The measured rates indicated ultrafast charge separation and relatively slow charge recombination revealing their usefulness in light‐energy harvesting and optoelectronic device applications. The bis(donor styryl)BODIPY‐derived conjugates populated their triplet excited states during charge recombination.
Proton Transverse Relaxation as a Sensitive Probe for Structure Determination in Solid Proteins
Authors: Rovó Petra , Grohe Kristof , Giller Karin , Becker Stefan , Linser Rasmus 
Published: September 2015

AbstractSolid‐state nuclear magnetic resonance (NMR) spectroscopy has been successfully applied to elucidate the atomic‐resolution structures of insoluble proteins. The major bottleneck is the difficulty to obtain valuable long‐distance structural information. Here, we propose the use of distance restraints as long as 32 Å, obtained from the quantification of transverse proton relaxation induced by a methanethiosulfonate spin label (MTSL). Combined with dipolar proton–proton distance restraints, this method allows us to obtain protein structures with excellent precision from single spin‐labeled 1 mg protein samples using fast magic angle spinning.
Beryllepin, C6H6Be, and “Beryllium‐Inserted Benzenes,” C6H6Ben, n = 2–6: A Density Functional Computational Investigation
Authors: Tabares Annette A. , Waters Essene L. , Zoellner Robert W. 
Published: September 2015

ABSTRACTThe seven‐membered beryllium‐containing heterocycle beryllepin, C6H6Be, has been examined computationally at the B3LYP/6‐311++G** density functional level of theory. Beryllepin is best described as a planar singlet heterocyclic conjugated triene with marginal aromatic character containing a C–Be–C moiety forced to be nonlinear (∠C‐Be‐C = 146.25°) by the cyclic constraints of the seven‐membered ring. The molecule can be considered to be derived from a benzene‐like system in which a neutral beryllium atom has been inserted between two adjacent carbon atoms. The 11 other possible “beryllium‐inserted benzenes,” C6H6Ben, n = 2–6, have also been investigated. Only two of these heterocyclic systems, the eight‐membered 1,4‐diberyllocin and the nine‐membered 1,4,7‐triberyllonin, were found to be stable, singlet‐ground‐state systems, albeit with little aromatic character. Of the remaining nine beryllium‐inserted benzenes, with the exception of the 11‐membered ring containing five beryllium atoms and the 12‐membered ring containing six beryllium atoms, which were calculated to exist as a ground state pentet and septet, respectively, all were calculated to be ground state triplet systems.
Recent advances in optical fiber devices for microfluidics integration
Authors: Blue Robert , Uttamchandani Deepak 
Published: September 2015

This paper examines the recent emergence of miniaturized optical fiber based sensing and actuating devices that have been successfully integrated into fluidic microchannels that are part of microfluidic and lab‐on‐chip systems. Fluidic microsystems possess the advantages of reduced sample volumes, faster and more sensitive biological assays, multi‐sample and parallel analysis, and are seen as the de facto bioanalytical platform of the future. This paper considers the cases where the optical fiber is not merely used as a simple light guide delivering light across a microchannel, but where the fiber itself is engineered to create a new sensor or tool for use within the environment of the fluidic microchannel.
Detection and trapping of molecules can be achieved with optical fibers directly located within the fluidic microchannel.magnified imageDetection and trapping of molecules can be achieved with optical fibers directly located within the fluidic microchannel.
Beta oscillations in freely moving Parkinson's subjects are attenuated during deep brain stimulation
Authors: Quinn Emma J. , Blumenfeld Zack , Velisar Anca , Koop Mandy Miller , Shreve Lauren A. , Trager Megan H. , Hill Bruce C. , Kilbane Camilla , Henderson Jaimie M. , Brontë‐Stewart Helen 
Published: September 2015

AbstractBackgroundInvestigations into the effect of deep brain stimulation (DBS) on subthalamic (STN) beta (13‐30 Hz) oscillations have been performed in the perioperative period with the subject tethered to equipment. Using an embedded sensing neurostimulator, this study investigated whether beta power was similar in different resting postures and during forward walking in freely moving subjects with Parkinson's disease (PD) and whether STN DBS attenuated beta power in a voltage‐dependent manner.MethodsSubthalamic local field potentials were recorded from the DBS lead, using a sensing neurostimulator (Activa® PC+S, Medtronic, Inc., Food and Drug Administration– Investigational Device Exemption (IDE)‐, institutional review board–approved) from 15 PD subjects (30 STNs) off medication during lying, sitting, and standing, during forward walking, and during randomized periods of 140 Hz DBS at 0 V, 1 V, and 2.5/3 V. Continuous video, limb angular velocity, and forearm electromyography recordings were synchronized with neural recordings. Data were parsed to avoid any movement or electrical artifact during resting states.ResultsBeta power was similar during lying, sitting, and standing (P = 0.077, n = 28) and during forward walking compared with the averaged resting state (P = 0.466, n = 24), although akinetic rigid PD subjects tended to exhibit decreased beta power when walking. Deep brain stimulation at 3 V and at 1 V attenuated beta power compared with 0 V (P < 0.003, n = 14), and this was voltage dependent (P < 0.001).ConclusionsBeta power was conserved during resting and forward walking states and was attenuated in a voltage‐dependent manner during 140‐Hz DBS. Phenotype may be an important consideration if this is used for closed‐loop DBS. © 2015 International Parkinson and Movement Disorder Society
Body image and quality of life of breast cancer patients: influence of timing and stage of breast reconstruction
Authors: Teo Irene , Reece Gregory P. , Christie Israel C. , Guindani Michele , Markey Mia K. , Heinberg Leslie J. , Crosby Melissa A. , Fingeret Michelle Cororve 
Published: September 2015

AbstractObjectiveThe process of cancer‐related breast reconstruction is typically multi‐staged and can take months to years to complete, yet few studies have examined patient psychosocial well‐being during the reconstruction process. We investigated the effects of reconstruction timing and reconstruction stage on body image and quality of life at specific time points during the breast reconstruction process.MethodsIn this cross‐sectional study, 216 patients were grouped into four reconstructive stages: pre‐reconstruction, completed stage 1, completed stage 2, and final stages. Multiple regression analyses examined the roles of reconstruction timing (immediate vs delayed reconstruction) and reconstruction stage as well as their interaction in predicting body image and quality of life, controlling for patient age, BMI, type of reconstruction, chemotherapy, radiation therapy, and major complication(s).ResultsA difference in pattern of body image was observed across the reconstructive stages, with those receiving delayed reconstruction showing significant decrease in body image dissatisfaction compared with those with immediate reconstruction. At pre‐reconstruction, patients awaiting delayed reconstruction reported significantly lower social well‐being compared with those awaiting immediate reconstruction. Reconstruction stage predicted emotional well‐being, with higher emotional well‐being observed in those who had commenced reconstruction.ConclusionsTiming and stage of reconstruction are important to consider when examining psychosocial outcomes of breast cancer patients undergoing reconstruction. Those waiting to initiate delayed reconstruction appear at particular risk for body image, emotional, and social distress. Our findings have implications for delivery of psychosocial treatment to maximize body image and quality of life of patients undergoing cancer‐related breast reconstruction.Copyright © 2015 John Wiley & Sons, Ltd.
Oxidative stress by inorganic nanoparticles
Authors: Tee Jie Kai , Ong Choon Nam , Bay Boon Huat , Ho Han Kiat , Leong David Tai 
Published: September 2015

Metallic and metallic oxide nanoparticles (NPs) have been increasingly used for various bio‐applications owing to their unique physiochemical properties in terms of conductivity, optical sensitivity, and reactivity. With the extensive usage of NPs, increased human exposure may cause oxidative stress and lead to undesirable health consequences. To date, various endogenous and exogenous sources of oxidants contributing to oxidative stress have been widely reported. Oxidative stress is generally defined as an imbalance between the production of oxidants and the activity of antioxidants, but it is often misrepresented as a single type of cellular stress. At the biological level, NPs can initiate oxidative stress directly or indirectly through various mechanisms, leading to profound effects ranging from the molecular to the disease level. Such effects of oxidative stress have been implicated owing to their small size and high biopersistence. On the other hand, cellular antioxidants help to counteract oxidative stress and protect the cells from further damage. While oxidative stress is commonly known to exert negative biological effects, measured and intentional use of NPs to induce oxidative stress may provide desirable effects to either stimulate cell growth or promote cell death. Hence, NP‐induced oxidative stress can be viewed from a wide paradigm. Because oxidative stress is comprised of a wide array of factors, it is also important to use appropriate assays and methods to detect different pro‐oxidant and antioxidant species at molecular and disease levels. WIREs Nanomed Nanobiotechnol 2016, 8:414–438. doi: 10.1002/wnan.1374This article is categorized under:

Therapeutic Approaches and Drug Discovery > Emerging Technologies
Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials