bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular design and stabilization mechanism of acrylonitrile bipolymer
Authors: Ju Anqi , Guang Shanyi , Xu Hongyao 
Published: February 2013

AbstractIn order to replace terpolymer with bipolymer, a bifunctional comonomer 3‐aminocarbonyl‐3‐butenoic acid methyl ester (ABM) was synthesized for preparing poly(acrylonitrile‐co‐3‐aminocarbonyl‐3‐butenoic acid methyl ester) [P(AN‐co‐ABM)] bipolymers as carbon fiber precursor. The structure and stabilization of P(AN‐co‐ABM) bipolymers were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, and differential scanning calorimetry. The monomer reactivity ratios were calculated by the Fineman‐Ross and Kelen‐Tüdõs methods, and the results show that ABM displays higher reactivity than acrylonitrile. Two parameters Es = A1618cm‐1/A2244cm‐1 and SI = (I0 ‐ Is)/I0 were defined to evaluate the extent of stabilization, and the activation energy (Ea) of the stabilization reactions were calculated by Kissinger and Ozawa methods. The results show that the P(AN‐co‐ABM) bipolymers exhibit significantly improved stabilization performance when compared with polyacrylonitrile (PAN) homopolymer, such as lower cyclization temperature, lower Ea, and larger extent of stabilization under the same conditions. Simultaneously, the rheological analysis shows that P(AN‐co‐ABM) possesses better spinnability than PAN. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Readily Accessible Fluorescent Probes for Sensitive Biological Imaging of Hydrogen Peroxide
Authors: Daniel Kevin B. , Agrawal Arpita , Manchester Marianne , Cohen Seth M. 
Published: February 2013

AbstractHydrogen peroxide is a major component of oxygen metabolism in biological systems that, when present in high concentrations, can lead to oxidative stress in cells. Noninvasive molecular imaging of H2O2 using fluorogenic systems represents an effective way to detect and measure the accumulation of this metabolite. Herein, we detail the development of robust H2O2‐sensitive fluorescent probes using a boronic ester trigger appended to the fluorophore through a benzyl ether linkage. A major advantage of the probes presented here is their synthetic accessibility, with only one step needed to generate the probes on the gram scale. The sensitivity of the probes was evaluated in simulated physiological conditions, showing micromolar sensitivity to H2O2. The probes were tested in biological model systems, demonstrating effective imaging of unstimulated, endogenous H2O2 levels in RAW 264.7 cells and murine brain tissue.
Pharmacokinetics and Safety of Migalastat HCl and Effects on Agalsidase Activity in Healthy Volunteers
Authors: Johnson Franklin K. , Mudd Paul N. , Bragat Alexander , Adera Mathews , Boudes Pol 
Published: February 2013

AbstractMigalastat HCl is an investigational, oral treatment for Fabry disease, an X‐linked lysosomal storage disorder. Four Phase 1 studies were conducted to determine the pharmacokinetics, pharmacodynamics, safety, and tolerability of migalastat. Healthy volunteers (N = 124), 18–55 years old, received migalastat HCl single (25 mg–2000 mg) or twice‐daily doses (50 mg, 150 mg) for 7 days in a double‐blind, placebo‐controlled fashion. Migalastat pharmacokinetics were dose‐proportional (AUC∞ range: 1129–72 838 ng h/mL, Cmax range: 200.5–13 844 ng/mL, t1/2 3–4 hours). Steady state was achieved by Day 7. Up to 67% of the dose was excreted as unchanged drug in urine. Increased α‐Gal A activity was dose related. No abnormal cardiac effects, including prolonged QTc intervals, were observed. The pharmacokinetics of migalastat were well characterized in these Phase 1 studies conducted healthy volunteers. The 150 mg dose of migalastat HCl administered BID for 7 days was generally safe and well tolerated. A TQT study demonstrated lack of a positive signal at therapeutic and supra‐therapeutic doses. Increases in α‐Gal A enzyme activity for the 150 mg dose observed in healthy subjects suggested a successful proof of mechanism for further investigations.
Pharmacokinetic Studies in Healthy Subjects for the Development of an Extended‐Release Tablet Formulation of Guaifenesin: A 505(b)(2) New Drug Application Approval
Authors: Vilson Lineau , Owen Joel S. 
Published: February 2013

AbstractGuaifenesin is an expectorant used to improve mucociliary clearance (MCC) and relieve chest congestion from upper respiratory tract infections. Immediate‐release (IR) guaifenesin requires dosing every 4 hours to maintain efficacy because of the drug's short half‐life. Extended‐release (ER) guaifenesin has been developed to prolong efficacy and reduce dosing frequency. As part of the 505(b)(2) new drug application (NDA), the pharmacokinetics (PK) of an ER bi‐layer tablet formulation of guaifenesin (Mucinex®) and bioequivalence to an over‐the‐counter (OTC) monograph IR formulation were evaluated in healthy subjects. In one study, subjects received 1,200 mg ER guaifenesin every 12 hours or 400 mg IR guaifenesin every 4 hours for 6 days. Steady‐state exposures were equivalent between the two products, as demonstrated by AUC and Cmax. In another study, subjects received a single dose of 600 mg (fasted) or 1,200 mg (fasted or fed) ER bi‐layer tablet formulations. AUC and Cmax were equivalent between both states for the 1,200 mg ER dose. However, Tmax of 1,200 mg ER guaifenesin was later in the fed than the fasted state. ER guaifenesin is bioequivalent to corresponding OTC monograph doses of IR guaifenesin. ER guaifenesin offers a convenient 12‐hour dosing alternative to 4‐hour dosing of IR guaifenesin.
A Simple Method for Fabricating Patterned Curvilinear Microstructures in Poly(dimethylsiloxane) by Selective Wetting
Authors: Ke Xi , Tang Jilin 
Published: February 2013

AbstractThe fabrication of patterned microstructures in poly(dimethylsiloxane) (PDMS) is a prerequisite for soft lithography. Herein, curvilinear surface relief microstructures in PDMS are fabricated through a simple three‐stage approach combining microcontact printing (μCP), selective surface wetting/dewetting and replica molding (REM). First, using an original PDMS stamp (first‐generation stamp) with linear relief features, a chemical pattern on gold substrate is generated by μCP using hexadecanethiol (HDT) as an ink. Then, by a dip‐coating process, an ordered polyethylene glycol (PEG) polymer‐dot array forms on the HDT‐patterned gold substrate. Finally, based on a REM process, the PEG‐dot array on gold substrate is used to fabricate a second‐generation PDMS stamp with microcavity array, and the second‐generation PDMS stamp is used to generate third‐generation PDMS stamp with microbump array. These fabricated new‐generation stamps are utilized in μCP and in micromolding in capillaries (MIMIC), allowing the generation of surface micropatterns which cannot be obtained using the original PDMS stamp. The method will be useful in producing new‐generation PDMS stamps, especially for those who want to use soft lithography in their studies but have no access to the microfabrication facilities.
Ranking Solvent Interactions and Dielectric Constants with [Pt(mesBIAN)(tda)]: A Cautionary Tale for Polarity Determinations in Ionic Liquids
Authors: Baker Gary A. , Rachford Aaron A. , Castellano Felix N. , Baker Sheila N. 
Published: February 2013

AbstractThe solvatochromic properties of [Pt(mesBIAN)(tda)] are studied in traditional molecular solvents and ionic liquids and duly compared along established empirical solvent parameter scales. The charge‐transfer absorption band of [Pt(mesBIAN)(tda)] is determined to be primarily dependent upon solvent acidity and dipolarity. Notably, ionic liquids do not obey the same well‐behaved trend as molecular solvents, highlighting the complexity and domain (nano)segregation inherent to ionic liquids.
The effect of surface topography on cell shape and early ERK1/2 signaling in macrophages; linkage with FAK and Src
Authors: Ghrebi Salem , Hamilton Douglas W. , Douglas Waterfield J. , Brunette Donald M. 
Published: February 2013

AbstractImplant surface topography can modulate macrophage behavior during wound healing by the production of proinflammatory cytokines. This study investigated the activation of FAK, Src, and ERK1/2 signaling intermediates of the proinflammatory ERK1/2 pathway in RAW 264.7 macrophages in response to polished (P), coarse‐grit‐blasted (B), acid etched (E), and grit‐blasted and etched (SLA) surface topographies. In addition, the effects of these topographies on cell spreading, vinculin organization, and viability were determined. Macrophages on the SLA surface changed from predominantly well‐spread cells to ones with a more spherical morphology over time. In contrast, macrophages on the P surface changed from being predominantly spherical cells to well spread. The morphological changes were associated with changes in the distribution of vinculin. The overall patterns of the pFAK, pSrc, pERK1/2 levels as well as pERK1/2 nuclear translocation associated with cell shape with greater activation being seen with a more spread morphology. These results suggest that surface topography differentially activates signaling pathways that affect cell function and raise the possibility that topographies can be designed to optimize desired cell responses. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Complete mitochondrial genome of the aluminum‐tolerant fungusRhodotorula taiwanensisRS1 and comparative analysis ofBasidiomycotamitochondrial genomes
Authors: Zhao Xue Qiang , Aizawa Tomoko , Schneider Jessica , Wang Chao , Shen Ren Fang , Sunairi Michio 
Published: February 2013

AbstractThe complete mitochondrial genome ofRhodotorula taiwanensisRS1, an aluminum‐tolerantBasidiomycotafungus, was determined and compared with the known mitochondrial genomes of 12Basidiomycotaspecies. The mitochondrial genome ofR. taiwanensisRS1 is a circularDNAmolecule of 40,392 bp and encodes the typical 15 mitochondrial proteins, 23tRNAs, and small and largerRNAs as well as 10 intronic open reading frames. These genes are apparently transcribed in two directions and do not show syntenies in gene order with other investigatedBasidiomycotaspecies. The average G+C content (41%) of the mitochondrial genome ofR. taiwanensisRS1 is the highest among theBasidiomycotaspecies. Two introns were detected in the sequence of theatp9gene ofR. taiwanensisRS1, but not in that of otherBasidiomycotaspecies.Rhodotorula taiwanensisis the first species of the genusRhodotorulawhose full mitochondrial genome has been sequenced; and the data presented here supply valuable information for understanding the evolution of fungal mitochondrial genomes and researching the mechanism of aluminum tolerance in microorganisms.
Comments on Peierls‐distorted Indium Chains in In4Se3–x
Authors: Osters Oliver , Blazek Gustavo , Nilges Tom 
Published: February 2013

AbstractNominal In4Se3–x with x = 0.65, derived from the prototype compound In4Se3, is a good thermoelectric material achieving a Z value of 1.48 at 705 K. This value is close to state of the art thermoelectric materials. In literature this special behavior is explained by a Peierls‐distortion or Charge Density Wave within the compound caused by the selenium deficit. While extensive thermoelectric studies for different compositions are reported in literature, a solid proof of the existence of selenium deficit samples is still missing. In this work we report about the synthesis, phase analyses, and temperature dependent single crystal determinations of In4Se3–x samples in order to clarify these structural features.
Understorey structure and refuges from predators influence habitat use by a small ungulate, the Indian chevrotain (Moschiolaindica) in Western Ghats, India
Authors: Sridhara Sachin , Edgaonkar Advait , Kumar Ajith 
Published: February 2013

AbstractThe availability of refuges from predators and high quality food are thought to determine habitat use in small ungulates. We tested this hypothesis on habitat use by the Indian chevrotain in a tropical rainforest in the Western Ghats, using pellet‐groups to infer habitat use. Between December 2009 and April 2010, we sampled 204 grids of 50 m × 50 m with four spatial replicates in each, using occupancy framework. We quantified refuges such as fallen logs and boulders, understorey complexity, and noted the presence of fruiting trees in the grid. Detection probability, p, of pellet‐groups was estimated at 0.61. The naive estimate of occupancy was 0.52, which increased to 0.73 when p was accounted for. Out of eight candidate models compared using AICC, the one with the number of refuges and understorey complexity was the best model. Both covariates had non‐zero positive slopes. Fruiting trees occurred very infrequently and did not influence habitat use, perhaps because the chevrotain fed more on buds, shoots and young leaves during the dry period covered by this study. The strong influence of understorey complexity on habitat use was perhaps also due to the abundance of these food items. These results highlight the need to control human use that adversely impacts the availability of refuges and understorey complexity such as removal of fallen logs and rattans. This study also demonstrates the application of the occupancy approach in the study of small and elusive ungulates.
Measurement of Palladium Crust Thickness on Catalysts by Optical Microscopy and Image Analysis
Authors: Sorbier Loïc , Gay Anne-Sophie , Fécant Antoine , Moreaud Maxime , Brodusch Nicolas 
Published: February 2013

AbstractSelective hydrogenation is an important process in petrochemistry to purify feedstock for polymer synthesis. For this process, catalysts containing metallic palladium deposited with an eggshell distribution on porous alumina are usually employed. For this kind of catalyst, the activity is known to be in close relation with the thickness of the palladium crust. As palladium oxide is brown and alumina is white, the palladium distribution in a catalyst bead before the reduction step can be characterized by optical microscopy. We propose an original and automatic procedure of optical image analysis to obtain a fast and robust method to measure the mean crust thickness of a catalyst batch and the corresponding standard deviation. The approach is validated by two different methods. First, we compared the crust thickness with those obtained by electron probe microanalysis. Then, catalytic tests of four samples with varying palladium crust thicknesses were performed and confirmed the expected correlation between activity and crust thickness measured by optical microscopy coupled with image analysis.
High-Frequency QPOs and Overstable Oscillations of Black-Hole Accretion Disks
Authors: Lai Dong , Fu Wen , Tsang David , Horak Jiri , Yu Cong 
Published: February 2013

AbstractThe physical origin of high-frequency QPOs (HFQPOs) in black-hole X-ray binaries remains an enigma despite many years of detailed observational studies. Although there exists a number of models for HFQPOs, many of these are simply “notions” or “concepts” without actual calculation derived from fluid or disk physics. Future progress requires a combination of numerical simulations and semi-analytic studies to extract physical insights. We review recent works on global oscillation modes in black-hole accretion disks, and explain how, with the help of general relativistic effects, the energy stored in the disk differential rotation can be pumped into global spiral density modes in the disk, making these modes grow to large amplitudes under certain conditions (“corotational instability”). These modes are robust in the presence of disk magnetic fields and turbulence. The computed oscillation mode frequencies are largely consistent with the observed values for HFQPOs in BH X-ray binaries. The approximate 2:3 frequency ratio is also expected from this model. The connection of HFQPOs with other disk properties (such as production of episodic jets) is also discussed.
Instrumental Selection Effect on the Bimodal T90 Distribution of Gamma-Ray Bursts
Authors: Qin Y. , Liang E. W. , Virgili F. J. , Zhang B. 
Published: February 2013

AbstractThe durations (T90) of 315 GRBs detected with Fermi/GBM (8-1000 keV) by 2011 September are calculated using the Bayesian Block method. We compare the T90 distributions between this sample and that observed with previous/current GRB missions. We show that T90 is energy-band dependent and the observed bimodal T90 distribution would be due to the instrumental selection effect.
White dwarf accretion and type Ia supernovae
Authors: Han Z. , Chen X. 
Published: February 2013

AbstractType Ia supernovae (SNe Ia) are believed to be thermonuclear explosions of carbon-oxygen white dwarfs at a mass close to the Chandrasekhar limit. However, a white dwarf at birth has a significantly lower mass and needs to accrete mass to grow to the limit for the explosion. Various progenitor models have been proposed and those models play an important role in our understanding of SNe Ia and cosmology.
Accretion Disks of Bounce-Back CVs
Authors: Tovmassian Gagik , Zharikov Sergey 
Published: February 2013

AbstractWe explore conditions and structure of accretion disks in the short-period Cataclysmic Variables, which have evolved beyond the period minimum. We show that the accretion disk in a system with extreme mass ratio grows in the size reaching 2:1 resonance radius and are relatively cool. They also become largely optically thin in the continuum, contributing to the total flux less than the stellar components of the system. In contrast, the viscosity and the temperature in spiral arms formed at the outer edge of the disk are higher and their contribution in continuum plays an increasingly important role. We model such disks and generate light curves which successfully simulate the observed double-humped light curves in the quiescence.
Center Black Hole Mass Determinations for Fermi Blazars
Authors: Fan J. H. , Liu Y. , Yang J. H. , Yuan Y. H. , Li Y. , Zhang Q. F. 
Published: February 2013

AbstractIn this paper, we estimated the black hole mass for some blazars with available variability time scales by assuming that the γ-ray emissions are from a distance of 200Rg from the center. The results show that the central black hole masses are in the range of log (M/M⊙) = 6.45 to 8.30.
Time Lag in Sgr A* Intra-Day Variability between the light curves at 90 and 102 GHz
Authors: Miyazaki Atsushi , Tsuboi Masato , Tsutsumi Takahiro 
Published: February 2013

AbstractWe performed the observation of the flux densities of Sgr A* at 90 and 102 GHz on 6 April 2005 using the Nobeyama Millimeter Array in order to detect the time lag between these frequencies. We constructed light curves covering a few hour with 1 min bin, and the Intra-Day Variability, which had a rising phase and intensity peak, of Sgr A* is clearly seen at both frequencies. We calculated the z-transformed discrete correlation function between the light curves of Sgr A* at 90 and 102 GHz. The derived time lag of the flares at these frequencies was approximately zero, contrary to our expectations based on the previously reported time lag at lower frequencies. If the radio flares of Sgr A* are explained by the expanding plasma model, the light curve at 90 GHz would be delayed with respect to the one at 102 GHz. However, we could not find such a delay with statistical significance in our data.
On the accretion onto the white dwarfs in symbiotic binaries: A test with the Thomson scattering process
Authors: Sekeráš Matej , Skopal Augustin 
Published: February 2013

AbstractWe tested the origin of the nebular radiation in the symbiotic star AG Dra, during different levels of its activity. We modeled the broad wings of the OVI 1032, 1038 Å resonance lines and HeII 1640 Å line by the Thomson scattering process, and determined the electron-scattering optical depth, τe, of the symbiotic nebula. The increase of τe during active phases results from an increase in the accretion rate onto the white dwarf.
The evolution of inner disk radius with orbital phase in Circinus X-1
Authors: Wang Yanan , Ding Guoqiang , Huang Chunping 
Published: February 2013

AbstractUsing RXTE observations, we investigate the evolution of inner disk radius (Rin) of Cir X-1 during two cycles and find obvious orbital modulation. We argue that the modulation is attributed to its high orbital eccentricity. The disk luminosity is inversely with the inner disk temperature (kTin), which is ascribed to the slow increase of kTin and, however, the rapid decrease of Rin during the passage for the neutron star to depart from the companion star.
Radiation Properties of GeV Narrow Line Seyfert 1 Galaxies
Authors: Zhang Jin , Sun X. N. , Zhang S. N. , Liang E. W. 
Published: February 2013

AbstractThe broadband SEDs of four gamma-ray NLS1s are compiled and explained with the leptonic model. It is found that their characteristics and fitting parameters of the observed SEDs are more like FSRQs than BL Lacs.
The Radius Estimation of Double Pulsar PSR J0737-3039A
Authors: Zhao H. H. , Song L. M. 
Published: February 2013

AbstractWe investigate the radius of the recycled pulsar in double pulsar PSR J0737-3039. In the standard accretion spin-up model, the recycled pulsar spin up continues until arriving at a minimum spin period, or so-called “equilibrium period”, which is related to stellar magnetic field, accretion rate, mass and radius. If present spin period is much longer than that at birth, the spin-down age can give the realistic true age estimation for normal pulsar J0737-3039B. Base on the above conditions, we estimate the radius of millisecond pulsar (MSP) J0737-3039A by assuming its true age is same as the spin-down age of its companion J0737-3039B. We obtained that the radius of J0737-3039A ranges approximately from 5 to 27 km.
The correlations between optical variability and physical parameters of quasars in SDSS Stripe 82
Authors: Zuo Wenwen , Wu Xue-Bing , Liu Yi-Qing , Jiao Cheng-Liang 
Published: February 2013

AbstractWe investigate the optical variability of 7658 quasars from SDSS Stripe 82. Taking advantage of a larger sample and relatively more data points for each quasar, we estimate variability amplitudes and divide the sample into small bins of redshift, rest-frame wavelength, black hole mass, Eddington ratio, and bolometric luminosity, respectively, to investigate the relationships between variability and these parameters. An anti-correlation between variability and rest-frame wavelength is found. The variability amplitude of radio-quiet quasars shows almost no cosmological evolution, but that of radio-loud ones may weakly anti-correlate with redshift. In addition, variability increases as either luminosity or Eddington ratio decreases. However, the relationship between variability and black hole mass is uncertain; it is negative when the influence of Eddington ratio is excluded, but positive when the influence of luminosity is excluded. The intrinsic distribution of variability amplitudes for radio-loud and radio-quiet quasars are different. Both radio-loud and radio-quiet quasars exhibit a bluer-when-brighter chromatism. Assuming that quasar variability is caused by variations of accretion rate, the Shakura–Sunyaev disk model can reproduce the tendencies of observed correlations between variability and rest-frame wavelength, luminosity as well as Eddington ratio, supporting that changes of accretion rate play an important role in producing the observed optical variability. However, the predicted positive correlation between variability and black hole mass seems to be inconsistent with the observed negative correlation between them in small bins of Eddington ratio, which suggests that other physical mechanisms may still need to be considered in modifying the simple accretion disk model.