bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of Focused Ion Beam Milling for Patterned Growth of Carbon Nanotubes
Authors: Chen Ying , Chen Ying , Chen Hua , Williams James S 
Published: April 2011

AbstractA new template technique has been developed to help patterned growth of carbon nanotubes (CNTs) on Si surface without predeposition of metal catalysts. Focused ion beam (FIB) milling was used to create trenches on Si wafer surface as the template and carbon nanotubes only nucleated and grew inside the trenches during a controlled pyrolysis of iron phthalocyanine at 1000oC. The selective growth in the trenches is due to its special surface morphology, crystalline structure and capillarity effect.
A Scheme for Blocking Non-Specific Antibody Binding on Single Wall Carbon Nanotubes
Authors: Teker Kasif 
Published: April 2011

AbstractCarbon nanotubes have many unique properties such as high surface area, hollow cavities, and excellent mechanical and electrical properties. Interfacing carbon nanotubes with biological systems could lead to significant applications in various disease diagnoses. Significant progress in interfacing carbon nanotubes with biological materials has been made in key areas such as aqueous solubility, chemical and biological functionalization for biocompatibility and specificity, and electronic sensing of proteins. Bioconjugated nanotubes combined with the sensitive nanotube-based electronic devices would enable sensitive biosensors toward medical diagnostic. Furthermore, recent findings of improved cell membrane permeability for carbon nanotubes would also expand medical applications to therapeutics using carbon nanotubes as carriers in gene delivery systems. One of the main issues in nanobio systems is the specificity, which requires biofunctionalization of nanomaterials for recognition of only one type of target biomolecule. This study presents an effective functionalization scheme for preventing non-specific antibody binding on nanotubes. Non-specific antibody binding on nanotubes was successfully prevented by co-adsorption of a bio-compatible polymer PEG and a surfactant (NaDDBS) on nanotubes. Optical studies through confocal microscopy revealed very minimal non-specific antibody binding on the PEG/NaDDBS-coated nanotubes (WCC < 0.05) compared to high degree of non-specific antibody binding on nanotubes without PEG pretreatment (WCC > 0.80), as determined by weighted co-localization coefficients (WCC). In addition to the confocal microscopy studies, electronic detection studies revealed that PEG/NaDDBS pretreated devices exhibited very little conductance change due to antibody adsorption compared to the devices without any PEG/NaDDBS pretreatment. These findings indicate that the PEG/NaDDBS pretreatment is a very effective functionalization scheme in preventing non-specific antibody binding on nanotubes.
Ion Conductance of Cylindrical Solid State Nanopores Used in Coulter Counting Experiments
Authors: Petrossian Leo , Wilk Seth J , Joshi Punarvasu , Goryll Michael , Posner Jonathan D , Goodnick Stephen M , Thornton Trevor J 
Published: April 2011

AbstractNanoscale apertures that provide a fluidic path between two reservoirs can be used for numerous applications. These applications include patch-clamp type measurements, Coulter counting and molecular studies. For Coulter counting of nanometer-sized analytes, we have developed a process capable of reproducibly fabricating cylindrical apertures in a silicon-on-insulator substrate with diameters less than 30 nm. The fabrication process utilizes electron beam lithography for the lithographic definition of the apertures enabling accurate control of final device dimensions. Measurements of the conductance of the pores as a function of KCl concentration reveal the presence of a surface conduction mechanism that dominates the conductance of the nanopore and leads to a deviation of the concentration dependence of the conductance from the case of bulk solution. From current traces recorded, the passage of individual particles through the pore can be concluded.
Micropatterned Biorecognition Surfaces on Nonbiofouling Polymer by Living Radical Photopolymerization for High Sensitivity Biosensing
Authors: Takai Madoka , Sibarani James , Ishihara Kazuhiko 
Published: April 2011

AbstractPreparation of nonbiofouling surface and micropatterned biorecognition layer over nonbiofouling for highly sensitive microarray biosensors, was conducted by constructing biocompatible poly(2-methacryloyloxyethyl phosphorylcholine(MPC)) brushes on polymer substrates based on living radical polymerization using macrophotoiniferters comprised of 2-ethylhexyl methacrylate (EHMA) and 4-vinylbenzyl N,N-diethyldithiocarbamate (VBDC). Protein adsorption on these modified surfaces significantly reduces compared to on polymeric substrate and the micropatterning consisted of poly(MPC) brush and biorecognition layer can be easily done by applying photomask with high fidelity.
Viscoelastic property and hydration level variations of proteins multilayer adsorbed on liquid crystal phthalocyanine thin film
Authors: Paul Sharmistha , Basova Tamara , Ray Asim K. 
Published: April 2011

AbstractWell established quartz crystal microbalance with dissipation (QCM-D) monitoring technique has been applied here for investigation the adsorption kinetics of three different proteins (BSA, IgG, Lysozyme) on thin film of liquid crystal copper octakishexylthiophthalocyanine [(C6S)8PcCu] surface. Modification of phthalocyanine surface by protein coating can be useful for photo dynamic therapy or in biomedical devices purpose in order to increase biocompatibility. The adsorption kinetics on vertically oriented molecular stacks of phthalocyanines were different for three proteins. Lysozyme reached to saturation quickly compare to BSA and IgG. Changes in resonance frequency and dissipation for three overtones were fitted with the Voigt viscoelastic model to calculate the shear viscosity and shear elastic modulus for the adsorbed proteins. Sauerbrey equation was used to calculate approximate adsorbed mass directly from frequency change. Adsorbed mass calculated from Voigt model was different from Sauerbrey equation. Hydration level of adsorbed protein layer was calculated from the difference in mass based on above two methods which was increased with concentration from 10-80% for BSA and IgG whereas it decreased from 20-1% for Lysozyme. Variation of viscosity and shear elastic modulus with concentration is opposite for BSA, IgG than Lysozyme. Depending on the hydration levels, adsorbed BSA and IgG formed soft (viscoelastic) layer compare to rigid layer of Lysozyme on (C6S)8PcCu surface.
Electrical and Chemical Control of Surfaces for DNA Immobilization and Hybridization
Authors: Cabeca Ricardo , Prazeres D. M.F. , Chu V. , Conde J. P. 
Published: April 2011

AbstractWe present the design of two biointerfaces on a SiO2 substrate for single stranded DNA (ssDNA) immobilization using either covalent grafting or electrostatic adsorption. The influence of the type of biointerface on the rate of diffusion-limited hybridization reaction with complementary ssDNA from a solution is studied. Patterning of the biointerfacefunctionalization layers and the scaling down of the reaction volumes to µL range is demonstrated. The use of externally applied electric field pulses is shown to accelerate the hybridization reaction kinetics to the sub-ms time scale.
Bioengineering of bacterial magnetic particles and its application to estrogen receptor-ligand binding assay
Authors: Yoshino Tomoko , Kaji Chihiro , Matsunaga Tadashi 
Published: April 2011

AbstractMagnetic particles are used for various biomedical applications because they are easy to both handle and separate from biological samples. Nano-sized bacterial magnetic particles (BacMPs) that display the human estrogen receptor ligand binding domain (ERLBD) on their surfaces were successfully produced by the magnetotactic bacterium,Magnetospirillum magneticumAMB-1. A receptor assay for endocrine-disrupting chemicals using ERLBD-displaying BacMPs was developed. A BacMP membrane-specific protein, Mms16 or Mms13, was used as an anchor protein to localize the ERLBD on the surfaces of BacMPs. ERLBD-BacMP complexes were assayed for competitive binding of alkaline phosphatase-conjugated 17β-estradiol (ALP-E2). Inhibition curve of ALP-E2 to the powerful antagonist, tamoxifen was generated by measuring decreases in luminescence intensity that resulted from the enzymatic reaction of alkaline phosphatase. The overall simplicity of this receptor-binding assay results in a method that can be easily adapted to a high-throughput format.
Bioanalogous Recognition with Sol-Gel Thin Films and Nanoparticles in Harsh Environments
Authors: Lieberzeit Peter A. , Afzal Adeel , Mujahid Adnan , Dickert Franz 
Published: April 2011

AbstractSol-gel thin films and nanoparticles can be functionalized by imprinting strategies based on self-organization of the polymer precursors around a template compound. The resulting rugged layers are highly suitable for operating as sensor layers in harsh environments, such as engine oils. By adding e.g. dimethyl formamide or polyethylene glycol to titanate sols, the resulting layers show substantially increased sensitivity due to higher porosity and accessibility of the recognition sites. The same is true for nanoparticles, where the sensor effects are directly correlated to particle dimensions. Furthermore, also imprinted ZrO2 nanoparticles show very appreciable selectivity.
One-step separation of CD20+cells from whole blood using bacterial magnetic particles displaying protein G
Authors: Takahashi Masayuki , Yoshino Tomoko , Takeyama Haruko , Matsunaga Tadashi 
Published: April 2011

AbstractMagnetic separation of target cells from mixtures, such as peripheral blood and bone marrow, has considerable practical potential in research and medical applications. Among the current cell separation techniques, magnetic cell separation using immunomagnetic particles has been routinely applied and has proven rapidness and simplicity.Magnetospirillum magneticumAMB-1 synthesizes intracellular nano-sized bacterial magnetic particles (BacMPs) that are individually enveloped by a stable lipid bilayer membrane. BacMPs, which exhibit strong ferrimagnetism, can be collected easily with commercially available permanent magnets. In this study, a novel magnetic nanoparticle displaying protein G (protein G-BacMPs) was fabricated, and one-step cell separation for direct cell separation from whole blood was performed using the protein G-BacMPs. B lymphocytes (CD20+cells), which cover less than 0.3×10−2% of whole blood cells, were separated with 93% purity using protein G-BacMPs binding with anti-CD20 monoclonal antibodies. The results of this study demonstrate the utility of protein G-BacMPs and the magnetic cell separation approach based on protein G-BacMPs in numerous applications.
Synthesis and Characterization of Photocurable Polyionic Hydrogels
Authors: Desai Pooja N , Yang Hu 
Published: April 2011

AbstractIn this study we describe preparation of polyionic hydrogels based on PEGylated polyamidoamine (PAMAM) dendrimers. Polyethylene glycol (PEG) with varied chain length (MW=1500, 6000, or 12000) was first conjugated to the Starburst™ G3.0 PAMAM dendrimer to form stealth dendrimers. The free hydroxyl group of PEG was further converted to an acrylate group using acrolyl chloride and triethylamine. The conjugation was characterized with 1H-NMR. The loading degree of PEG on the dendrimer surface was estimated by using both the ninhydrin assay and 1H-NMR. Hydrogel formation was realized by subjecting dendrimer-PEG acrylate to UV exposure for a brief period of time at the presence of Eosin Y, triethanolamine and 1-vinyl-2-pyrrolidinone. PEGylated G3.0 PAMAM dendrimer served as cross-linking agent to form hydrogels because of its multiple functionalities. The surface charges conferred by terminal groups on the dendrimer surface made the hydrogel polyionic with controllable charge density. This new type of hydrogel has many favorable biological properties such as non toxicity and non immunogenecity and multifunctional ties for a variety of in vivo applications. Current studies have demonstrated feasibility of chemistry and hydrogel formation.
Micromachined Linear Brownian Motor: A Nanosystem Exploting Brownian Motion of Nanobeads for Uni-directional Transport
Authors: Altintas Ersin , Sarajlic Edin , Bohringer Karl F. , Fujita Hiroyuki 
Published: April 2011

AbstractNanosystems operating in liquid media may suffer from random thermal fluctuations. Some natural nanosystems, e.g. biomolecular motors, which survive in an environment where the energy required for bio-processes is comparable to thermal energy, exploit these random fluctuations to generate a controllable unidirectional movement. Inspired by the nature, a transportation system of nanobeads achieved by exploiting Brownian motion were proposed and realized. This decreases energy consumption and saves the energy compared to ordinal pure electric or magnetic drive. In this paper we present a linear Brownian motor with a 3-phase electrostatic rectification aimed for unidirectional transport of nanobeads in microfluidic channels. The transport of the beads is performed in 1 μm deep, 2 μm wide PDMS microchannels, which constrain three-dimensional random motion of nanobeads into 1D fluctuation, so-called tamed Brownian motion. We have experimentally traced the rectified motion of nanobeads and observed the shift in the beam distribution as a function of applied voltage. The detailed computational analysis on the importance of switching sequence on the speed performance of motor is performed and compared with the experimental results showing a good agreement.
Characterization of Materials for a Hydrogen-Based Economy by Cold Neutron Prompt Gamma-Ray Activation Analysis
Authors: Paul Rick , Cao Lei Raymond 
Published: April 2011

AbstractAn instrument for cold neutron prompt gamma-ray activation analysis (PGAA) at the NIST Center for Neutron Research (NCNR) has proven useful for the chemical characterization of hydrogen storage materials and other materials of importance to a hydrogen-based economy. The detection limit for hydrogen is less than 10 mg/kg for most materials. Potential hydrogen storage materials that have been characterized by PGAA include single-wall carbon nanotubes with and without boron doping, porous carbons, lithium magnesium imides, and ternary hydrides of various elements. The capability to allow in situ hydrogenation and characterization of materials is currently under development. PGAA has also been used to characterize materials used in hydrogen fuel cells, including solid proton conductors, polymer membrane, and proton exchange membranes. Future upgrades to the instrument will improve detection limits and functionality of the instrument.
Ab Initio Alloying of Mg for Hydrogen Storage
Authors: Kecik Deniz , Aydinol Mehmet Kadri 
Published: April 2011

AbstractA candidate hydrogen storing material should have high storage capacity and fast dehydrogenation kinetics. On this basis, magnesium hydride (MgH2) is an outstanding compound with 7.6 wt% storage capacity, despite its slow dehydriding kinetics and high desorption temperature. Therefore in this study, formation energies of alloyed bulk MgH2, adsorption energies on alloyed magnesium (Mg) and MgH2 surface structures were calculated by total energy pseudopotential methods. Also, the effect of substitutionally placed dopants to the dissociation of hydrogen molecule (H2) at the surface of Mg was investigated via Molecular Dynamics (MD). The results show that 31 out of 32 selected dopants decreased the formation energy of bulk MgH2, within a range of ˜37 kJ/mol-H2 where only Sr did not display any such effect. The most favorable elements in this respect are; P, K, Tl, Si, Sn, Ag and Pb. Moreover, surface adsorption energy values display that all elements are adsorbed substitutionally on the clean (0001) surface of Mg where adsorption on MgH2 (001) surface is possible only for alloying elements other than Zn, Au, In, Ag, Li, Tl, Cd, Na and K. Finally, results of MD simulations point out that the elements giving rise to the dissociation of hydrogen molecule came out to be Ti, V, Cr, Mn, Fe, Co, Ni, Zr, Nb, Mo, Ru, Rh ve Hf.
Effect of Pore Size on Dehydrogenation Temperature of Carbon Cryogel-Ammoniaborane Nanocomposites
Authors: Sepehri Saghar , Batalla Garcia Betzaida , Cao Guozhong 
Published: April 2011

AbstractThis study reports the effects of pore size of porous carbon scaffold on the dehydrogenation of ammoniaborane in the coherent carbon- ammoniaborane nanocomposites. Porous carbon scaffold is obtained from resorcinol formaldehyde derived carbon cryogels. The nanocomposites are made by simple soaking porous carbon scaffold in ammonia borane solution. Nitrogen sorption analysis and differential scanning calorimetry are used to investigate the structure and dehydrogenation of the nanocomposites. The results reveal that dehydrogenation temperature decreases in nanocomposites as compared to neat ammonia borane, and is lower in nanocomoposites with smaller pore sizes. These findings can be used to tune the dehydrogenation temperature to meet specific hydrogen storage applications. Also, dehydrogenation kinetics of nanocomposites is enhanced as compared to neat ammonia borane.
Anode Composites Based on NiO and Apatite-Type Lanthanum Silicate for Intermediate Temperature Solid Oxide Fuel Cells
Authors: Kharlamova Tamara , Pavlova Svetlana , Sadykov Vladislav , Krieger Tamara , Alikina Galina , Frade Jorge , Argirusis Christos 
Published: April 2011

AbstractComposite materials based on NiO and doped apatite-type lanthanum silicates (ATLS) that are new class of solid electrolytes were studied as anode materials for intermediate temperature solid oxide fuel cells (IT SOFC), with possibility to use both H2 and CH4 as a fuel being payed attention to. For cermets preparation different methods of Ni addition such as incipient wetness impregnation, modified Pechini methods or mechanical mixing were used. The composite materials were characterized by XRD, BET, TPO and methane steam reforming reaction. Doping with complex oxides possessing a high mobility of the lattice oxygen and partial Ni substitution by the mixed conductor were applied to improve anode stability to coking.
Design and Characterization of Nanocomposites Based on Complex Perovskites and Doped Ceria as Advanced Materials for Solid Oxide Fuel Cell Cathodes and Membranes
Authors: Sadykov Vladislav , Kharlamova Tamara , Batuev Lubsan , Mezentseva Nathalia , Alikina Galina , Muzykantov Vitalii , Krieger Tamara , Pavlova Svetlana , Zaikovskii Vladimir , Ishchenko Arcady , Zarubina Valeria , Rogov Vladimir , Bobrenok Oleg , Uvarov Nikolai , Kilner John , Druce John , Smirnova Alevtina 
Published: April 2011

AbstractLa0.8Sr0.2Fe0.6Ni0.4O3-x - Ce0.9Gd0.1O2-x and La0.8Sr0.2Fe0.8Co0.2O3-x - Ce0.9Gd0.1O2-x nanocomposites were synthesized via ultrasonic dispersion of nanocrystalline powders of perovskite and fluorite oxides in acetone with addition of a surfactant, followed by drying and sintering at temperatures up to 1200°C. The evolution of the structure of samples with sintering temperature was studied by XRD and TEM with EDX and compared with the data on conductivity, oxygen isotope exchange, O2 TPD, H2 and CH4 TPR. Preliminary testing of button-size cells with cathodes supported on thin YSZ layer covering Ni/YSZ cermet demonstrated a high and stable performance of LSNF–GDC composite promising for the practical application.
Modeling Particle Size Effects on Phase Stability and Transition Pathways in Nanosized Olivine Cathode Particles
Authors: Tang Ming , Huang Hsiao-Ying , Meethong Nonglak , Kao Yu-Hua , Carter W. Craig , Chiang Yet-Ming 
Published: April 2011

AbstractRecent experiments show that nanosized olivine LiFePO4 has different phase transition and solubility behavior than that of larger cathode particles. The possibility of metastable or globally stable amorphous phase in nanosized LiFePO4 particles during delithiation is considered in a diffuse-interface model. At a small enough particle size, a lithiated crystalline phase can undergo amorphization upon charging instead of transforming directly to the delithiated crystalline phase at nanoscale particle sizes.
Experimental Limits of Light Capture in Thin Film Silicon Devices
Authors: Poruba Ales , Klapetek Petr , Holovsky Jakub , Purkrt Adam , Vanecek Milan 
Published: April 2011

AbstractNew approach for the determination of the angular distribution of the scattered light at nano-rough surfaces/interfaces from AFM (Atomic Force Microscopy) data is presented. Calculation comes from modeling the electromagnetic field in the tight vicinity of the nano-rough surface by complex solution of Maxwell's equations and subsequent near field to far field transform. This method is demonstrated for four types of transparent conductive oxides (with rough free surfaces) deposited on glass substrates. As a result we have the amount and angular distribution of the scattered light „observed” in both transmission and reflection. Moreover calculation can be done for real sample dimensions (to compare the results with the measurement of the angular distribution function using LED laser) or for a semi-infinite sample which suppresses the interference effects and thus such distribution functions can be used as an input parameter for our 3-dimensional optical model CELL for thin film silicon solar cell modeling.In the second part of this contribution we describe our experiment of thin film silicon solar cell characterization by Light Beam Induced Current (LBIC). This measurement done for laboratory solar cell structures reveals the light scattering and light trapping properties of the multilayer stack on a glass substrate. We suggest the test structure for the direct back reflector quality comparison and thus also for its optimization.