bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of poly(aspartic acid) hydrogel and poly(aspartic acid)/gelatin complex for entrapment and pH‐sensitive release of protein drugs
Authors: Jiang H. L. , Zhu K. J. 
Published: December 2005

AbstractBiodegradable poly(aspartic acid) (PASP) hydrogel and PASP/gelatin complex were prepared to evaluate their potential application as pH‐sensitive matrices for controlled protein release. Entrapment of myoglobin (Mb) and its release were compared between the two types of carriers. It was found that incorporation of Mb into PASP hydrogel strongly depended on the medium pH and NaCl concentration, and was time‐consuming. However, complete entrapment of Mb into PASP/gelatin complex was found within pH ranged from 2.5 to 4.0, which was concomitant with the formation of PASP/gelatin complex. By adjusting Mb feed ratio, Mb entrapment in the complex can be up to 31.54% (by weight) with high loading efficiency (96.2%). Gradual release of Mb from PASP hydrogel was observed within pH 2.0–7.4, while Mb release from PASP/gelatin complex was negligible within pH 2.0–4.2 for 4 days. In addition, pulsatile Mb release can be achieved by combining polyanhydride with pH‐sensitive PASP/gelatin complex, while the device composed of polyanhydride and PASP hydrogel is mechanically unstable. PASP/gelatin complex formed by electrostatic interactions is superior to the single‐component PASP hydrogel synthesized by chemical cross‐linking as pH‐sensitive matrices for controlled protein release when entrapment of proteins and pH‐sensitivity of protein release are concerned. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
CiteSpace II: Detecting and visualizing emerging trends and transient patterns in scientific literature
Authors: Chen Chaomei 
Published: December 2005

AbstractThis article describes the latest development of a generic approach to detecting and visualizing emerging trends and transient patterns in scientific literature. The work makes substantial theoretical and methodological contributions to progressive knowledge domain visualization. A specialty is conceptualized and visualized as a time‐variant duality between two fundamental concepts in information science: research fronts and intellectual bases. A research front is defined as an emergent and transient grouping of concepts and underlying research issues. The intellectual base of a research front is its citation and co‐citation footprint in scientific literature—an evolving network of scientific publications cited by research‐front concepts. Kleinberg's (2002) burst‐detection algorithm is adapted to identify emergent research‐front concepts. Freeman's (1979) betweenness centrality metric is used to highlight potential pivotal points of paradigm shift over time. Two complementary visualization views are designed and implemented: cluster views and time‐zone views. The contributions of the approach are that (a) the nature of an intellectual base is algorithmically and temporally identified by emergent research‐front terms, (b) the value of a co‐citation cluster is explicitly interpreted in terms of research‐front concepts, and (c) visually prominent and algorithmically detected pivotal points substantially reduce the complexity of a visualized network. The modeling and visualization process is implemented in CiteSpace II, a Java application, and applied to the analysis of two research fields: mass extinction (1981–2004) and terrorism (1990–2003). Prominent trends and pivotal points in visualized networks were verified in collaboration with domain experts, who are the authors of pivotal‐point articles. Practical implications of the work are discussed. A number of challenges and opportunities for future studies are identified.
New stellar and substellar candidate members of the Coma Berenices open star cluster
Authors: Casewell S. L. , Jameson R. F. , Dobbie P. D. 
Published: December 2005

AbstractWe present the results of a survey of the open star cluster Melotte 111 in Coma Berenices, undertaken using the USNO‐B1.0 and 2MASS Point Source catalogues. On the basis of their astrometric and photometric properties, we have identified 60 new candidate members with masses in the range 1.007 < M < 0.269 M⊙. We estimate a membership probability for each by extracting control clusters from the proper motion vector diagram. All 60 are found to have greater than 60 per cent probability of being cluster members, which if they are confirmed as members, more than doubles the number of known cluster members. We also have I and Z photometry for 100 low mass candidate members of the cluster, 13 of which we suggest may be brown dwarfs. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A study of the young open cluster Collinder 359
Authors: Lodieu N. 
Published: December 2005

AbstractWe present the first deep, optical, wide‐field imaging survey of the young open cluster Collinder 359, complemented by near‐infrared follow‐up observations. This study is part of a large programme aimed at examining the dependence of the mass function on environment and time. We have surveyed 1.6 square degree in the cluster in the I and z filters with the CFH12K camera on the Canada‐France‐Hawaii 3.6m telescope down to completeness and detection limits in both filters of 22.0m and 24.0m, respectively. Based on their location in the optical (I‐z ,I ) colour‐magnitude diagram, we have extracted new cluster member candidates in Collinder 359 spanning 1.3‐0.04 M⊙, assuming an age of 100 Myr and a distance of 450 pc for the cluster.We have used the 2MASS database as well as our own near‐infrared photometry to confirm the membership of the optically‐selected cluster candidates. Additionally, we have obtained optical spectroscopy and employed chromospheric activity as a further criterion to assess the membership of candidates. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rotation and variability of young very low‐mass objects
Authors: Scholz A. , Jayawardhana R. , Eislöffel J. , Froebrich D. 
Published: December 2005

AbstractVariability studies are an important tool to investigate key properties of stars and brown dwarfs. From photometric monitoring we are able to obtain information about rotation and magnetic activity, which are expected to change in the mass range below 0.3 solar masses, since these fully convective objects cannot host a solar‐type dynamo. On the other hand, spectroscopic variability information can be used to obtain a detailed view on the accretion process in very young objects. In this paper, we report about our observational efforts to analyse the variability and rotational evolution of young brown dwarfs and very low‐mass stars. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Proper motion surveys in the infrared
Authors: Hambly N. C. , Deacon N. R. 
Published: December 2005

AbstractCurrent and future wide field surveys in infrared passbands present opportunities for ultra low‐mass stellar sample selection via proper motions, as well as or instead of purely photometric techniques. Furthermore, proper motion measurements yield additional clues as to candidate membership of cluster or field (kinematic) populations. In this paper we review some recent results and speculate as to the possibilities afforded by the next generation of wide‐field infrared surveys. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Close binary systems among very low‐mass stars and brown dwarfs
Authors: Jeffries R. D. , Maxted P. F. L. 
Published: December 2005

AbstractUsing Monte Carlo simulations and published radial velocity surveys we have constrained the frequency and separation (a ) distribution of very low‐mass star (VLM) and brown dwarf (BD) binary systems.We find that simple Gaussian extensions of the observed wide binary distribution, with a peak at 4AU and 0.6 < σ log(a /AU) < 1.0, correctly reproduce the observed number of close binary systems, implying a close (a < 2.6 AU) binary frequency of 17–30% and overall frequency of 32–45%. N‐body models of the dynamical decay of unstable protostellar multiple systems are excluded with high confidence because they do not produce enough close binary VLMs/BDs. The large number of close binaries and high overall binary frequency are also completely inconsistent with published smoothed particle hydrodynamical modelling and argue against a dynamical origin for VLMs/BDs. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ten new very low‐mass close binaries resolved in the visible
Authors: Law N. M. , Hodgkin S. T. , Mackay C. D. , Baldwin J. E. 
Published: December 2005

AbstractWe present preliminary results from the first part of the LuckyCam late M‐dwarf binarity survey. We survey a sample of 48 nearby (< 40 pc) and red (M5–M9) stars with the novel high angular resolution visible light imaging technique Lucky Imaging, in only 8 hours of 2.5m telescope time. We discover 10 new binaries; although the survey is sensitive to brown dwarf companions none are detected. The orbital radius distribution of the newly discovered binaries broadly matches that of previous detections by other groups, although we do discover one wide binary at ∼40 AU. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lithium depletion in the brown dwarf binary GJ 569Bab
Authors: Zapatero Osorio M. R. , Martín E. L. , Lane B. F. , Pavlenko Ya. , Bouy H. , Baraffe I. , Basri G. 
Published: December 2005

AbstractGJ 569Bab is the first brown dwarf binary for which the mass of each component has been derived by solving the astrometric and spectroscopic orbit of the pair, i.e., independently of any theoretical assumption. This allows us to test the predictions of the various evolutionary models available in the literature. Particularly interesting are the predictions of lithium depletion for the mass (0.08–0.05M⊙) and likely age (300–800 Myr) of the substellar components. High‐resolution optical spectra of GJ 569B (the pair is not resolved) obtained with HIRES at the Keck telescope show that there has been significant lithium depletion in both components. We will compare these results to state‐of‐the‐art theoretical calculations. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The low‐mass companion of GQ Lup
Authors: Guenther E. W. , Neuhäuser R. , Wuchterl G. , Mugrauer M. , Bedalov A. , Hauschildt P. H. 
Published: December 2005

AbstractUsing NACO on the VLT in the imaging mode we have detected an object at a distance of only 0.7 arcsec from GQ Lup. The object turns out to be co‐moving. We have taken two K‐band spectra with a resolution of λ /Δλ = 700. In here, we analyze the spectra in detail. We show that the shape of spectrum is not spoiled by differences in the Strehl ratio in the blue and in the red part, as well as differential refraction. We reanalyze the spectra and derive the spectral type of the companion using classical methods. We find that the object has a spectral type between M9V and L4V, which corresponds to a T eff between 1600 and 2500 K. Using GAIA‐dusty models, we find that the spectral type derivation is robust against different log(g )‐values. The T eff derived from the models is again in the range between 1800 and 2400 K. While the models reproduce nicely the general shape of the spectrum, the 12CO lines in the spectrum have about half the depth as those in the model. We speculate that this difference might be caused by veiling, like in other objects of similar age, and spectral class. We also find that the absolute brightness of the companion matches that of other low‐mass free‐floating objects of similar age and spectral type. A comparison with the objects in USco observed by Mohanty et al. (2004b) shows that the companion of GQ Lup has a lower mass than any of these, as it is of later spectral type, and younger. The same is as true, for the companion of AB Pic. To have a first estimate of the mass of the object we compare the derived T eff and luminosity with those calculated from evolutionary tracks. We also point out that future instruments, like NAHUAL, will finally allow us to derive the masses of such objects more precisely. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Status of the physics of substellar objects project
Authors: Jones H. R. A. , Viti S. , Tennyson J. , Barber B. , Harris G. , Pickering J. C. , Blackwell‐Whitehead R. , Champion J.‐P. , Allard F. , Hauschildt P. H. , Jorgensen U. G. , Ehrenfreund P. , Stachowska E. , Ludwig H.‐G. , MartÍn E. L. , Pavlenko Ya. , Lyubchik Yu. , Kurucz R. L. 
Published: December 2005

AbstractA full understanding of the properties of substellar objects is one of the major challenges facing astrophysics. Since their discovery in 1995, hundreds of brown dwarfs and extrasolar planets have been discovered. While these discoveries have enabled important comparisons with theory, observational progress has been much more rapid than the theoretical understanding of cool atmospheres. The reliable determination of mass, abundances, gravities and temperatures is not yet possible. The key problem is that substellar objects emit their observable radiation in the infrared region of the spectrum where our knowledge of atomic, molecular and line broadening data is poor. Here we report on the status of our PoSSO (Physics of SubStellar Objects) project. In order to understand brown dwarfs and extrasolar planets increasing more like those in our solar system, we are studying a wide range of processes. Here we give an update on the project and sketch an outline of atoms, molecules and processes requiring study. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Young Jupiters are faint: new models of the early evolution of giant planets
Authors: Fortney J. J. , Marley M. S. , Hubickyj O. , Bodenheimer P. , Lissauer J. J. 
Published: December 2005

AbstractHere we show preliminary calculations of the cooling and contraction of a 2 MJ planet. These calculations, which are being extended to 1–10 MJ, differ from other published “cooling tracks” in that they include a core accretion‐gas capture formation scenario, the leading theory for the formation of gas giant planets.We find that the initial post‐accretionary intrinsic luminosity of the planet is ∼3 times less than previously published models which use arbitrary initial conditions. These differences last a few tens of millions of years. Young giant planets are intrinsically fainter than has been previously appreciated. We also discuss how uncertainties in atmospheric chemistry and the duration of the formation time of giant planets lead to challenges in deriving planetary physical properties from comparison with tabulated model values. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Alginate‐PLL microencapsulation: Effect on the differentiation of embryonic stem cells into hepatocytes
Authors: Maguire Tim , Novik Eric , Schloss Rene , Yarmush Martin 
Published: December 2005

AbstractThe emergence of hepatocyte based clinical and pharmaceutical technologies, has been limited by the absence of a stable hepatocyte cell source. Embryonic stem cells may represent a potential solution to this cell source limitation problem since they are highly proliferative, renewable, and pluripotent. Although many investigators have described techniques to effectively differentiate stem cells into a variety of mature cell lineages, their practicality is limited by: (1) low yields of fully differentiated cells, (2) absence of large scale processing considerations, and (3) ineffective downstream enrichment protocols. Thus, a differentiation platform that may be modified to induce and sustain differentiated cell function and scaled to increase differentiated cell yield would improve current stem cell differentiation strategies. Microencapsulation provides a vehicle for the discrete control of key cell culture parameters such as the diffusion of growth factors, metabolites, and wastes. In addition, both cell seeding density and bead composition may be manipulated. In order to assess the feasibility of directing stem cell differentiation via microenvironment regulation, we have developed a murine embryonic stem cell (ES) alginate poly‐l‐lysine microencapsulation hepatocyte differentiation system. Our results indicate that the alginate microenvironment maintains cell viability, is conducive to ES cell differentiation, and maintains differentiated cellular function. This system may ultimately assist in developing scalable stem cell differentiation strategies. © 2005 Wiley Periodicals, Inc.
Directed Evolution ofBacillus subtilisLipase A by Use of Enantiomeric Phosphonate Inhibitors: Crystal Structures and Phage Display Selection
Authors: Dröge Melloney J. , Boersma Ykelien L. , van Pouderoyen Gertie , Vrenken Titia E. , Rüggeberg Carsten J. , Reetz Manfred T. , Dijkstra Bauke W. , Quax Wim J. 
Published: December 2005

AbstractPhage display can be used as a protein‐engineering tool for the selection of proteins with desirable binding properties from a library of mutants. Here we describe the application of this method for the directed evolution ofBacillus subtilislipase A, an enzyme that has important properties for the preparation of the pharmaceutically relevant chiral compound 1,2‐O‐isopropylidene‐sn‐glycerol (IPG). PCR mutagenesis with spiked oligonucleotides was employed for saturation mutagenesis of a stretch of amino acids near the active site. After expression of these mutants on bacteriophages, dual selection with (S)‐(+)‐ and (R)‐(−)‐IPG stereoisomers covalently coupled to enantiomeric phosphonate suicide inhibitors (SIRAN Sc and Rc inhibitors, respectively) was used for the isolation of variants with inverted enantioselectivity. The mutants were further characterised by determination of their Michaelis–Menten parameters. The 3D structures of the Sc and Rc inhibitor–lipase complexes were determined and provided structural insight into the mechanism of enantioselectivity of the enzyme. In conclusion, we have used phage display as a fast and reproducible method for the selection ofBacilluslipase A mutant enzymes with inverted enantioselectivity.
Paclitaxel‐eluting stents for the treatment of chronic total coronary occlusions: A strategy of extensive lesion coverage with drug‐eluting stents
Authors: Werner Gerald S. , Schwarz Gero , Prochnau Dirk , Fritzenwanger Michael , Krack Andreas , Betge Stefan , Figulla Hans R. 
Published: December 2005

AbstractThe recanalization of a chronic total coronary occlusion (CTO) is hampered by a high rate of lesion recurrence. The goal of the present study is to assess the effect of paclitaxel‐eluting stents in CTOs in a strategy of extensive stent coverage and the optional use of additional bare metal stents (BMSs). In 82 consecutive patients, a CTO (duration > 2 weeks) was successfully recanalized with implantation of one or more Taxus stents. These patients underwent a repeat angiography after 5.0 ± 1.5 months and were assessed by quantitative angiography. The patients were compared with 82 clinically and lesion‐matched patients from a consecutive series of 148 patients with CTOs treated by BMS in the preceding time period. In 21 of the 82 patients, additional lesions in the target artery not directly related to the original occlusion site were treated with BMSs (hybrid approach). The history of diabetes, extent of coronary artery disease, clinical symptoms, and angiographic features were similar in the Taxus and BMS group. Periprocedural adverse events were 3.3% with Taxus and 3.3% with BMS, but 12 months MACE was significantly lower in the group with exclusive use of Taxus (13.3% vs. 56.7%; P < 0.001), mainly due to a lower target lesion revascularization of 10.0% as compared to 53.4% (P < 0.001). There was only one late reocclusion with Taxus (1.7%) as compared to 21.7% with BMS (P < 0.05). However, in the hybrid group, the MACE rate was considerably higher, with 33.3%. Our data of a 80% reduction of target vessel failure as compared to BMS, with a lower risk of late reocclusions without increased acute adverse events, demonstrate the benefit of paclitaxel‐eluting stents in CTOs. However, diffuse atherosclerosis in CTOs should be covered completely by the drug‐eluting stents. © 2005 Wiley‐Liss, Inc.
Evaluation of the AMPLATZER vascular plug for embolization of peripheral vascular malformations associated with congenital heart disease
Authors: Hill S.L. , Hijazi Z.M. , Hellenbrand W.E. , Cheatham J.P. 
Published: December 2005

AbstractObjective: The purpose of this study is to evaluate the recently FDA‐approved AMPLATZER® Vascular Plug in the embolization of vascular lesions associated with congenital heart disease (CHD). Background: Fistulas and arteriovenous malformations have been occluded using various devices. The AMPLATZER Vascular Plug is a self‐expandable, cylindrical device, used for embolization in the peripheral vasculature. Methods: A total of 84 vessels in 52 patients with CHD from 11 centers were occluded with 89 AMPLATZER Vascular Plugs, delivered through a coronary guide catheter in various vascular sites, including collaterals, pulmonary arterio‐venous and coronary artery fistulas, transhepatic tracts, central shunts, patent ductus arteriosus (PDA), and excluded hepatic vein. Complete vessel occlusion was demonstrated within 10 min in 94% of patients. Results: There was no device embolization, vascular disruption, or procedure‐related complication. One vascular plug implanted in a large type C PDA required surgical removal followed by PDA ligation, after 5 weeks from successful implant because of significant residual flow through the device. Conclusions: The AMPLATZER Vascular Plug is an effective transcatheter occlusion device in the embolization of a wide variety of vascular lesions associated with CHD. Based on our early experience, caution should be used when considering the Vascular Plug as a closure device for large PDA. © 2005 Wiley‐Liss, Inc.
Techniques for percutaneous closure of prosthetic paravalvular leaks
Authors: Pate Gordon E. , Thompson Christopher R. , Munt Bradley I. , Webb John G. 
Published: December 2005

AbstractPercutaneous transcatheter closure techniques are now routinely applied in the management of atrial and ventricular septal defects, patent ductus arteriosus, and other pathological cardiac and vascular communications. Recently, these same techniques have been applied to paravalvular defects. Reports are few; success variable and techniques vary widely. We review the current considerations and techniques of percutaneous transcatheter closure of paravalvular leaks. © 2005 Wiley‐Liss, Inc.