bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Pressure Indicator for Continuous Flow PCR Chip Using Micro Molded PDMS Pillar Arrays
Authors: Zhao Yi , Zhang Xin 
Published: April 2011

ABSTRACTDNA amplification is one of the most routine experiments carried out in biological laboratories. Continuous flow PCR chip releases biologists from their laborious exercises. The use of such chip is, however, hindered by costly expense of the syringe pump, which is used to maintain a constant flow rate. In this paper, we demonstrate a novel pressure indicator which makes up an in-line flow sensor in a continuous flow PCR chip. The pressure of PCR channel is achieved from pattern change in fabricated microstructures, and converted to volume flow rate. A polymeric PCR chip with such pressure indicators is presented. With a much less expense as compared to its conventional peers, this indicator has a wide potential for the use in the laboratories which runs daily activities like sequencing or mutagenesis.
More Efficient Capture of Bacteria on Nanostructured Materials
Authors: Webster Thomas J. , Liu Jin X. , Banks Margaret K. 
Published: April 2011

ABSTRACTNanobiotechnology is a growing area of research, primarily due to the potentially numerous applications of new synthetic nanomaterials in engineering/science. Although various definitions have been given to the word “nanomaterials” by many different experts, the commonly accepted one refers nanomaterials as those materials which possess grains, particles, fibers, or other constituent components that have one dimension specifically less than 100 nm. In biological applications, most of the research to date has focused on the interactions between mammalian cells and synthetic nanophase surfaces for the creation of better tissue engineering materials. Although mammalian cells have shown a definite positive response to nanophase materials, the evidence for bacteria interactions with nanophase materials remains for the most part a mystery. For this reason, this study determined the capture of a model bacteria (Pseudomonas fluorescens) on nanophase compared to conventional grain size alumina. Results provided the first evidence of increased capture of Pseudomonas fluorescens on alumina with nanometer compared to conventional grain sizes. Although not measured at the atomic scale, similar chemistry, crystallinity, crystal phase, and porosity was observed between nanophase and conventional alumina. For this reason, a major material property difference between nanophase and conventional alumina was reduced grain size (and perhaps associated changes in charge density) which led to increased bacteria capture and the design of better environmental filters.
Nanoparticle-Decorated Surfaces for the Study of Cell-Protein-Substrate Interactions
Authors: Ballard Jake D. , Dell'Acqua-Bellavitis Ludovico M. , Bizios Rena , Siegel Richard W. 
Published: April 2011

ABSTRACTThe present study was motivated by the need for accurately-controlled and well-characterized novel biomaterial formulations for the study of cell-protein-material interactions. For this purpose, the current research has focused on the design, fabrication and characterization of model native oxide-coated silicon surfaces decorated with silica nanoparticles of select sizes, and has examined the adhesion of osteoblasts and fibroblasts on these nanoparticle-decorated surfaces. The results demonstrate the capability to deposit nanoparticles of select diameters and substrate surface coverage onto native silicon oxide-coated silicon, the firm attachment of these nanoparticles to the underlying native silicon oxide, and that nanoparticle size and coverage modulate adhesion of osteoblasts and fibroblasts to these substrates. The material formulations tested provide a well-controlled and well-characterized set of model substrates needed to study the effects of nanoscale features on the functions of cells that are critical to the clinical fate of implantable biomaterials.
Fabrication of Novel Porous Chitosan Matrices as Scaffolds for Bone Tissue Engineering
Authors: Jiang Tao , Pilane Cyril M. , Laurencin Cato T. 
Published: April 2011

ABSTRACTThree dimensional (3-D) scaffolds with appropriate mechanical properties play a significant role in scaffold-based tissue engineering. Chitosan, a natural polymer obtained from chitin, which forms a major component of crustacean exoskeleton, is a potential candidate for bone tissue engineering due to its excellent osteocompatibility and biodegradability. The aim of the present study is to develop 3-D porous chitosan scaffolds with mechanical properties in the range of trabecular bone as scaffolds for bone tissue engineering. Three dimensional scaffolds were prepared by sintering chitosan microspheres. Chitosan microspheres were prepared by ionotropic gelation of chitosan solution using sodium tripolyphosphate. It has been found that the microsphere size increased significantly with the increase of the concentration of chitosan solution. The microspheres were then sintered together using the synergetic effect of solvent and temperature. The compressive moduli of the 3-D sintered matrices were found to be in the mid range of trabecular bone. The osteocompatibility and osteoconductivity of the 3-D matrices were demonstrated by adhesion and proliferation of MC3T3-E1 osteoblast like cells on the matrices after 14 days in culture.
Room temperature conversion of X0.3V2O5· nH2O phase into X2V6O16· nH2O phase Influence of the nature of the cation X+
Authors: Durupthy Olivier , Es-salhi Saïd , Steunou Nathalie , Coradin Thibaud , Livage Jacques 
Published: April 2011

ABSTRACTVarious cations (Li+, Na+, K+, NH4+, Cs+, Mg2+, Ca2+, Ba2+) were introduced during the formation of a V2O5. nH2O gel. Cation intercalated Xy V2O5. nH2O (y = 0.3 for X = Li+, Na+, K+, NH4+ or y = 0.15 for Mg2+, Ca2+, Ba2+) were first obtained at room temperature but some of them evolve upon ageing into a new phase: XV3O8. nH2O for X = Na+, K+, NH4+ and Cs+ or XV6O16. nH2O for X = Mg2+, Ca2+, Ba2+. All the vanadium oxide phases were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared spectroscopy (IR); the supernatant solutions were analysed by 51V NMR spectroscopy. These vanadium oxide phases exhibit a layered structure with cations and water molecules intercalated within the interlayer space. The formation of the different phases depends mainly on the pH of the supernatant solution and on the nature of the cation.
The Effect of Terminal Ligands on the Dimensionality and Topology of Metal Dicarboxylate Coordination Structures
Authors: Pan Long , Ching Nancy , Huang Xiaoying , Lee Jeongyong , Li Jing , Yuen Tan , Lin C. L. , Zan Jason 
Published: April 2011

ABSTRACTSolvothermal/hydrothermal reactions of 4, 4′-biphenyldicarboxylic acid (H2bpdc) and cobalt (II) salt with pyridine derivative ligands such as 3-methylpyridine (3-pic), 4-methylpyridine (4-pic), as well as a longer terminal ligand 4-benzylpyridine (4-bzpy) generated four new extended structures: 1D zigzag polymer chain 1 crystallized in C2/c with a formula [Co(bpdc)(3-pic)2]·(3-pic); 1D helical chain compound 2 crystallized in P41 with a formula [Co(bpdc)(4-pic)2], 2D non-interpenetrating network 3 crystallized in P2221 with a formula [Co(bpdc)(4-pic)2]·(4-pic)0.5·H2O, and 2D non-interpenetrating network 4 crystallized in P2/c, formulated as [Co(bpdc)(bzpy)2]. Our studies show that terminal ligands play an important role in affecting the dimensionality and topology of the structures formed. Magnetic susceptibility and isothermal magnetization results revealed an antiferromagnetic ground state for 3 with a transition temperature T = 4.7 K, and paramagnetic behavior at high temperature range for 1 and 2.
The preparation of Ni nano particles by the chemically controlled polyol process
Authors: Yoon Seon-Mi , Choi Jae-Young , Lee Yong Kyun , Lee Eun Sung , Kim Seul Ki 
Published: April 2011

ABSTRACTThe chemically controlled polyol process, with TMAH and water as OH- donors in the nickel hydroxyglycolate intermediate phase, prepares the nickel nano particles. The water additive acts as the OH- donor and enhances the solubility of salt in polyol for efficient production and monodispersive particles. Water and TMAH, selected to decrease the contamination of alkali metal from inorganic base, as OH- donors control the intermediary solid phase as a reservoir for Ni2+ species. The particle is about 80 nm with a faceted shape when the reaction is controlled by a combination of TMAH and water,. The nucleating agent is powerful to decrease the particle size, but in this basic reaction condition, it is not effective enough to get a small size.
Preparation of NiNb2O6 Columbite Ceramics by a Reaction-Sintering Process
Authors: Liou Yi-Cheng , Shiue Chao-Yang 
Published: April 2011

ABSTRACTPreparation of NiNb2O6 columbite ceramics by a reaction-sintering process has been investigated. The mixture of raw materials was pressed and sintered into ceramics without any calcination stage involved. Columbite NiNb2O6 ceramics were obtained after being sintered at 1250–1450°C for 2 h and 4 h from mixture of Nb2O5 and 50%Ni(NO3)2-50%NiO (NN1). In pellets from mixture of Nb2O5 and NiO (NN2), columbite NiNb2O6 ceramics were obtained after being sintered at 1150–1350°C for 2 h and 4 h. A density of 4.47 g/cm3 was obtained in NN1 for 2 h sintering at 1400°C. For NN2, a higher density 5.62 g/cm3 (99.8% of the theoretical value) was obtained for 2 h sintering at 1300°C. The reaction-sintering process has proven to be a simple and effective method in preparing columbite NiNb2O6 ceramics. A higher density could be obtained at lower sintering temperature by using NiO instead of 50%Ni(NO3)2-50%NiO in the reaction with Nb2O5.
Effect of The Glass Composition on The Spontaneous Emission Probabilities of Tm3+ in TeO2-ZnO Glass
Authors: Özen Gönül , Kabalcı İdris , Collins John M , Chen Xuesheng , Forte Ottavio , Di Bartolo Baldassare 
Published: April 2011

ABSTRACTThis paper reports our findings for the effect of the glass composition on the local environment of the thulium ions in the glass structure and its spontaneous and stimulated emission probabilities in the infrared region at room temperature. Absorption measurements in the UV/VIS/NIR region were used to determine spontaneous emission probabilities for the 4f-4f transitions of the thulium ion. Six bands corresponding to the absorptions of the 1G2, 3F2, 3F3, 3F4, 3H5, 3H4 from the ground level were observed. Integrated absorption cross-section of each band except that of 3H5 level was found to vary with the glass composition. Luminescence spectra of the samples were measured upon 785nm using a diode laser. Two emission bands centered about 1500nm and 1800nm were observed.The effect of the glass composition on the Judd-Ofelt Parameters and therefore on the spontaneous emission probabilities for the metastable levels of thulium ions will be discussed in detail.
Evolution of ZnO nanowires, nanorods, and nanosheets with an oxygen-assisted carbothermal reduction process
Authors: Park Jae-Hwan , Choi Young-Jin , Park Jae-Gwan 
Published: April 2011

ABSTRACTA systematic hierarchical evolution of nanowires, nanorods, and nanosheets in ZnO, based on a oxygen-assisted carbothermal reduction process, was presented. Nanowires, nanorods, and nanosheets were synthesized in series with controlling oxygen partial pressure from 10-6 to 10-1. It was impossible to get ZnO nanowires with using Ar gas only and more than 1ppm of oxygen could successfully introduce the ZnO nanowires on the Si substrates at the downstream of the tube. The additional oxygen gas with Ar carrier gas could introduce not only the nanowires but also the combs and sheets. The details of nanocombs and nanosheets also were presented.
Influence of oxygen partial pressure on the quality of nanowires for energetic photon detection applications
Authors: Zhang Y. , Mao S. S. 
Published: April 2011

ABSTRACTZnO based semiconductors have emerged as promising materials for energetic photon detection. Aimed to improve photon detection efficiency, we have successfully grown ZnO nanowires based on vapor- liquid-solid approach. In this paper, we examine the influence of oxygen partial pressure on the quality ZnO nanowires. Optical properties of the nanowires grown under different oxygen environment were characterized, and we found that low oxygen partial pressure can result in large concentration of defect states, as reflected by increased visible emission and an elevated threshold for stimulated emission.
Influence of the Particle Morphology on the Micro-and Macromechanics of Nano-Reinforced Materials
Authors: Sarkissov Alexander , Meijer Han , Fischer Hartmut 
Published: April 2011

ABSTRACTThis paper describes mechanical properties of polymer-clay nanocomposites with platelet and fibrous like nanoparticles evaluated on a of nano, meso and micro length scale. Platelet reinforced materials were found to display a mixed morphology consisting of intercalated and exfoliated regions. A better dispersion was obtained for fibrous clay nanocomposites where homogeneous distribution of single particles was achieved. The deformation behavior was investigated by in-situ XRD and SEM experiments during drawing; the macro-mechanical characteristics were extracted from tensile tests. The stiffness was found to increase in both platelet and fibrous clay nanocomposites. The presence of intercalated stacks in the latter resulted in a significant reduction in drawability, the better homogeneity of the fibrous clay systems allowed a reasonably high extensions.
Mechanical grafting and morphology characterization in immiscible polymer blends
Authors: Joshi Jayant , Lehman Richard L. , Nosker Thomas J. 
Published: April 2011

ABSTRACTBlends of PS/HDPE and PS/PP were investigated for synergism in flexural modulus with varying composition. The evolution of blend morphology was studied and related to the improvement in flexural modulus around the co-continuous composition. DSC studies were conducted to study crystallinity variations in the semi-crystalline component of the blend. We found that co-continuous morphologies help in developing strong mechanical bonds between the components. Crystallization is inhibited in the co-continuous region and is related to the spatial constraints during the solidification process.
Influence of Electrostatic Interactions on Chain Dynamics and Morphological Development in Perfluorosulfonate Ionomer Membranes
Authors: Page Kirt A. , Moore Robert B. 
Published: April 2011

ABSTRACTSeveral high temperature methods of processing Nafion® have been developed using various alkylammonium ion forms of the ionomer, and the choice of counterion has been shown to have a significant effect on the thermal and mechanical properties of this material. In particular, it has been shown that neutralization gives rises to two high-temperature mechanical relaxations as observed in dynamic mechanical analysis (DMA). While several studies in the literature have attempted to explain the molecular origins of these mechanical relaxations, the assignments were based primarily on limited DMA results and have at times been contradictory. The study presented here is a fundamental investigation into the molecular origins of the thermally induced morphological relaxations and dynamics of alkylammonium forms of Nafion® membranes as studied by variable temperature small-angle x-ray scattering (SAXS) and solid-state 19F NMR spectroscopy. The intensity of the small-angle ionomer peak at ca. q = 2 nm–1 was monitored as a function of temperature for each alkylammonium neutralized sample in unoriented and oriented states. In the case of the oriented samples, the degree of anisotropic scattering from the oriented ionomer morphology was quantified using the Hermann's orientation function and monitored as a function of temperature. Changes in intensity of the ionomer peak and the Hermann's parameter as a function of temperature were shown to correlate well with relaxations observed in DMA. Several variable temperature solid-state 19F NMR techniques (including spin diffusion, side-band analysis and T1ρ experiments) were used to investigate the dynamics of the Nafion® chains. Side band analysis indicated that the side-chain is more mobile than the main chain and that the mobility is greatly affected by the size of the counterion. Changes in side-band intensity as a function of temperature were shown to correlate well with DMA data. Results from T1ρ experiments show strong counterion dependence and suggest coupled main- and side-chain motions. A two-component relaxation process was also observed for the main-chain fluorines. The results of the NMR investigations, along with the SAXS data, have led to the development of a more detailed description of the dynamics of Nafion® and the molecular origins of the mechanical relaxations. With this information, the continuing goal to determine how the strength of the electrostatic interactions in perfluorosulfonate ionomers affects the chain dynamics and developing morphology may be realized for the purpose of controlling the morphology to create more efficient ionomeric membrane materials.
Middle Devonian palynomorphs from southern Moravia: an evidence of rapid change from terrestrial deltaic plain to carbonate platform conditions
Authors: Vavrdová Milada , Dašková Jiřina 
Published: April 2011

Middle Devonian palynomorphs from southern Moravia: an evidence of rapid change from terrestrial deltaic plain to carbonate platform conditions
Dispersed fossil miospores and acritarchs have been recovered from the subsurface pelites in the Uhřice-1 borehole, southern Moravia. Spores of ferns, sphenopsids and lycopods with rare marine microplankton (acritarchs and chitinozoans) cysts indicate a predominantly continental environment with a limited marine influence. Dispersed miospores with cysts of unicellular marine microplankton confirm the Middle Devonian, most probably early Givetian (AD lem) age of marine transgression in southern Moravia. Thermal alteration of palynomorphs shows average values, with TAI ranging from 2+ to 3+, corresponding to 60-70 °C.
Stratigraphy and tectonics of a tectonic window in the Magura Nappe (Świątkowa Wielka, Polish Outer Carpathians)
Authors: Oszczypko-Clowes Marta , Oszczypko Nestor 
Published: April 2011

Stratigraphy and tectonics of a tectonic window in the Magura Nappe (Świątkowa Wielka, Polish Outer Carpathians)The Świątkowa Wielka Tectonic Window belongs to the Grybów Nappe of the Fore-Magura Group of units. This tectonic window is located in the marginal part of the Magura Nappe and is composed of Oligocene — Sub-Grybów Beds as well as the Grybów Marl Formation. These beds have been correlated with the Oligocene deposits of other tectonic windows of the Grybów Nappe in Poland. Our research reveals that the Krosno beds' shally facies, which occur at the western termination of the Świątkowa Wielka Tectonic Window, belong to the Dukla succession. On the basis of calcareous nannoplankton analysis, the Grybów Marl Formation as well as the Krosno Beds belong to the NP23-NP24, and NP24 Zones, respectively. The structure of the Świątkowa Wielka Tectonic Window reveals a multistage evolution of the Magura Nappe overthrust onto their foreland.
Effect of Fear-Avoidance Beliefs of Physical Activities on a Model That Predicts Risk-Adjusted Functional Status Outcomes in Patients Treated for a Lumbar Spine Dysfunction
Authors: Hart Dennis L. , Werneke Mark W. , Deutscher Daniel , George Steven Z. , Stratford Paul W. 
Published: April 2011

Study Design Retrospective analysis of a prospective, longitudinal cohort study of 30 858 patients being treated for a lumbar spine dysfunction in outpatient physical therapy. Objectives To determine effect of adding a single-item screening variable classifying patients with elevated versus not-elevated scores of fear-avoidance beliefs of physical activities at intake, on a model predicting risk-adjusted functional status (FS) outcomes. Background Outcomes must be risk-adjusted before making meaningful interpretations. Elevated fear-avoidance beliefs scores have been predictive of poor outcomes. But the importance of elevated fear-avoidance scores in a multivariable model predicting FS outcomes needs further study. Methods Using retrospective analyses, predictive ability (R 2 ) of multivariable linear regression models of discharge FS with and without classification by elevated versus not-elevated fear-avoidance scores were compared, while controlling for intake FS, age, symptom acuity, surgical history, gender, number of comorbidities, and payer. Percent variance controlled and beta coefficients (95% confidence intervals) of each variable in both models were compared. A split-half design was used for model cross-validation. Predictive ratios (predicted FS, divided by actual discharge FS) were assessed. Results Adding fear-avoidance beliefs classification to the discharge FS model improved (P<.001) model predictive ability but only slightly (R 2 without, and with, fear-avoidance classification, 0.2997 and 0.3010, respectively). Variables impacted models similarly (95% confidence intervals not different). Fear-avoidance classification added 0.2% data variance control to the existing model. Cross-validation was supported. Predictive ratios were 1.09 and 1.10, without and with fear-avoidance, respectively. Conclusion Although screening for elevated fear-avoidance beliefs of physical activities significantly improves the FS outcomes predictive model, the amount of additional meaningful interpretation of FS outcomes was minimal. Exploration of other clinically relevant variables designed to improve outcomes prediction is warranted. Tlevel of Evidence Prognosis, level 2c. J Orthop Sports Phys Ther 2011;41(5):336–345, Epub 6 April 2011. doi:10.2519/jospt.2011.3534