bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectroellipsometric characterization of Au-Y2O3–stabilized ZrO2 nanocomposite films
Authors: Sirinakis George , Siddique Rezina , Dunn Kathleen A. , Efstathiadis Harry , Carpenter Michael A. , Kaloyeros Alain E. , Sun Lianchao
Published: December 2005

Nanocomposite thin films consisting of Au nanoparticles embedded in yttria-stabilized zirconia (YSZ) were synthesized at room temperature by radio frequency magnetron co-sputtering from YSZ and Au targets and subsequently annealed in an argon atmosphere. Au microstructure and particle size were characterized as a function of annealing temperature from 600 to 1000 °C by x-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Rutherford backscattering spectroscopy. Spectroscopic ellipsometry was also used to determine the optical constants of the resulting films. In particular, the refractive index of the nanocomposites was found to undergo an anomalous dispersion in the spectral region where the extinction coefficient achieves its maximum. Additionally, the incorporation of Au in the YSZ matrix was found to increase the refractive index in comparison to that of YSZ. At annealing temperatures higher than 800 °C, a good agreement was found between experimental findings and theoretical models using bulk dielectric functions for Au, as modified to account for a reduced mean free path for scattering than that for free electrons. However, for annealing temperatures below 800 °C, an additional offset was required for the optical constants of Au to obtain good agreement between theory and experiment. This behavior was attributed to a relatively high atomic Au concentration in the YSZ matrix.
Growth of superconducting and non-superconducting whiskers in the Bi-Sr-Ca-Cu-O (BSCCO) system
Authors: Badica P. , Togano K.
Published: December 2005

Growth of such non-superconducting whiskers [Sr2.24Ca0.4Al2Ox, (Ca0.8–0.85Sr0.15–0.1)2CuO3,CuO, or Bi2.44Sr2Ca1.3–2Cu6.9–9.95Al0.35–0.46Ox (Cu-rich whiskers)] formed during the growth of Bi-2212 superconducting whiskers from powder or glassy substrates, is discussed. These whiskers are likely to grow from the bottom end, and there is a tight relationship with the growth of the Bi-2212 whiskers. A general reaction-path model for the whisker growth in the BSCCO system, independent of the type of the catalytic impurity and substrate, is proposed. When whiskers are grown under magnetic fields, up to 10 T, changes in the whisker size, aspect ratio, and morphology are observed.
Compressive properties at elevated temperatures of porous aluminum processed by the spacer method
Authors: Hakamada Masataka , Nomura Tatsuho , Yamada Yasuo , Chino Yasumasa , Hosokawa Hiroyuki , Nakajima Takeshi , Chen Youqing , Kusuda Hiromu , Mabuchi Mamoru
Published: December 2005

Compressive properties at 573–773 K of porous aluminum produced by the spacer method were investigated and compared with those of bulk reference aluminum with the same chemical compositions. The stress exponent and activation energy for deformation at elevated temperatures in the porous aluminum were in agreement with those in the bulk reference aluminum. In addition, the plateau stress of the porous aluminum was comparable to the stress of the bulk reference aluminum upon compensation by the relative density. Therefore, it is conclusively demonstrated that the mechanism of deformation at elevated temperatures in the porous aluminum is the same as that in the bulk reference aluminum. This is likely due to the homogeneous microstructure in the porous aluminum produced by the spacer method.
One-dimensional β–Ga2O3 nanostructures on sapphire (0001): Low-temperature epitaxial nanowires and high-temperature nanorod bundles
Authors: Chang Ko-Wei , Wu Jih-Jen
Published: December 2005

Well-aligned Ga2O3 nanowires were formed on the sapphire (0001) substrates at temperatures of 650–450 °C using a single precursor of gallium acetylacetonate via a vapor-liquid-solid (VLS) method. Structural analyses reveal that the well-aligned Ga2O3 nanowires are expitaxially grown on the sapphire (0001) with Ga2O3/ sapphire orientational relationship [201]||[0001] and [211]||[1120]. In addition, formation of the flowerlike Ga2O3 nanorod bundles at a temperature of 750 °C via the vapor-solid (VS) mechanism was also demonstrated. Instead of being catalysts in the VLS method, the Au nanoparticles are proposed to play a role in sinking the Ga vapor for forming the nuclei of Ga2O3 nanorods in the VS method.
Silk apatite composites from electrospun fibers
Authors: Li Chunmei , Jin Hyoung-Joon , Botsaris Gregory D. , Kaplan David L.
Published: December 2005

Human bone is a three-dimensional composite structure consisting of inorganic apatite crystals and organic collagen fibers. An attractive strategy for fabricating mimics of these types of composite biomaterials is to selectively grow apatite on polymers with control of structure, mechanical properties, and function. In the present study, silk/apatite composites were prepared by growing apatite on functionalized nanodiameter silk fibroin fibers prepared by electrospinning. The functionalized fibers were spun from an aqueous solution of silk/polyethylene oxide (PEO) (78/22 wt/wt) containing poly(L-aspartate) (poly-Asp), which was introduced as an analogue of noncollageous proteins normally found in bone. Silk fibroin associated with the acidic poly-Asp and acted as template for mineralization. Apatite mineral growth occurred preferentially along the longitudinal direction of the fibers, a feature that was not present in the absence of the combination of components at appropriate concentrations. Energy dispersive spectroscopy and x-ray diffraction confirmed that the mineral deposits were apatite. The results suggest that this approach can be used to form structures with potential utility for bone-related biomaterials based on the ability to control the interface wherein nucleation and crystal growth occur on the silk fibroin. With this level of inorganic–organic control, coupled with the unique mechanical properties, slow rates of biodegradation, and polymorphic features of this type of proteins, new opportunities emerge for utility of biomaterials.
Preparation and tribological properties of SiC/rice bran carbon composite ceramics
Authors: Zhou You , Hirao Kiyoshi , Yamaguchi Takeshi , Hokkirigawa Kazuo
Published: December 2005

Silicon carbide (SiC) ceramics have good wear resistance but poor friction properties under dry sliding conditions. To lower the friction of SiC, a novel porous carbon material called rice bran carbon (RBC) was added into SiC to make SiC/RBC composite ceramics. The SiC/RBC composites were prepared by mixing one of three kinds of RBC powders having different particle sizes and a fine SiC doped with Al4C3and B4C additives and sintering at 1600 °C for 5 min by a pulse electric current sintering (PECS) method. The mechanical and tribological properties of the SiC/RBC composites were evaluated and compared with those of monolithic SiC, monolithic RBC bulk material, and SiC/graphite composite. The SiC/RBC composites not only had superior fracture strength (3–4 times as high as that of the monolithic RBC material) but also showed low friction coefficients (around 0.25) and high wear resistance (at a level of 10−6mm3N−1m−1) when slid against a silicon carbide ceramic counterface during block-on-ring sliding tests under dry conditions. Compared with the conventional SiC/graphite composite, the SiC/RBC composites had higher mechanical strength, lower friction coefficients, and better wear resistance.
Achieving more intelligent cities
Authors: Komakech D.
Published: December 2005

Knowledge-based revision of the planning, design and maintenance of infrastructure and civil administration by tapping the efficiencies of emerging information tools (such as the digital communication network) and/or engineering technology is a pivotal step in achieving an intelligent city which would ensure an enhanced well-being of the city's inhabitants and visitors alike.
Advanced transport management in an intelligent city
Authors: McQueen B. , Chen K. , Shi Q. , Carlin G.
Published: December 2005

A significant proportion of the world's population live in metropolitan areas and the number is growing quickly. The success of the city has brought with it a series of needs, issues, problems and objectives that today's transport community must address if they are to be successfully resolved. Great progress has been made and the best is yet to come. Advanced technologies hold the promise of more intelligent cities, adapting to the needs of city dwellers. Smart telecommunications, sensors and information technology-based services can make the intelligent city of tomorrow an even better place in which to live and work. From a transport perspective these can significantly enhance service delivery, with minimum undesirable side-effects, if applied in a thoughtful and coherent manner. The intent of this paper is to explain the needs, issues, problems and objectives that advanced transport technologies might address, to provide a simple overview of technology applications and to describe a suggested approach for harnessing the power and benefits of advanced technology and conventional approaches with respect to metropolitan transport management. Lessons and approaches from the wider world of business and commerce are incorporated in the proposed approach, taking advantage of previous experience with similar applications.
Integration improves traffic management in York, UK
Authors: Capes D. , Hewitt R.
Published: December 2005

City of York Council has been at the forefront of developments in the UK's Urban Traffic Management and Control (UTMC) programme, which aims to exploit the latest developments in communications and information technology to improve traffic management in cities. A major focus of the programme is the employment of a common database to enable the sharing of data between information sources and applications. In York the common database is the heart of the system, not only used for data storage but for the implementation of control algorithms and data processing. The York approach provides an improved service to council officers responsible for network management, for other council officers and members, and for the public at large. The York UTMC system is fully integrated with other council information technology systems and assists in meeting wider e-government targets. The impact of this on the design is significant and raises issues not normally encountered in traditional traffic management systems, particularly in the areas of security and audit, while offering savings through the shared communications infrastructure. A comparison is made between the approach being taken in the UK and similar systems overseas.
Managing a city's transportation network—a case study
Authors: Welsh P.
Published: December 2005

As pressures on the transportation network continue to increase, the Traffic Management Act 2004 places a duty on the network manager to monitor and manage the network in normal and abnormal conditions. Birmingham City Council, UK, is creating the services to address these needs by implementing an urban traffic management and control system. The system will be open-ended, with an emphasis on helping public transport. The Birmingham system will become part of a larger countywide system, so that in the event of an emergency, the county's transportation network can be managed from any location, to support the emergency services and controlling delay on the network. A key element of the service will be the relationship of the seven West Midlands county metropolitan authorities with the Highways Agency and the eventual development of automated and shared strategies.
Recommending a Minimum English Proficiency Standard for Entry-Level Nursing
Authors: O’Neill Thomas R. , Tannenbaum Richard J. , Tiffen Jennifer
Published: December 2005

When nurses who are educated internationally immigrate to the United States, they are expected to have English language proficiency in order to function as a competent nurse. The purpose of this research was to provide sufficient information to the National Council of State Boards of Nursing (NCSBN) to make a defensible recommended passing standard for English proficiency. This standard was based upon the Test of English as a Foreign Language (TOEFL™). A large panel of nurses and nurse regulators (N = 25) was convened to determine how much English proficiency is required to be minimally competent as an entry-level nurse. Two standard setting procedures, the Simulated Minimally Competent Candidate (SMCC) procedure and the Examinee Paper Selection Method, were combined to produce recommendations for each panelist. In conjunction with collateral information, these recommendations were reviewed by the NCSBN Examination Committee, which decided upon an NCSBN recommended standard, a TOEFL score of 220. Because the adoption of this standard rests entirely with the individual state, NCSBN has little more to do with implementing the standard, other than answering questions and providing documentation about the standard.
Cross-Cultural Equivalence and Psychometric Properties of the Portuguese Version of the Depressive Cognition Scale
Authors: Sousa Valmi D. , Zauszniewski Jaclene A. , Mendes Isabel A. C. , Zanetti Maria L.
Published: December 2005

There is a great need for researchers to have access to reliable and valid research instruments in their own language to measure a concept of interest or concern. Therefore, the purpose of this study was to determine semantic equivalency and psychometric properties of the Depressive Cognition Scale (DCS) in a Brazilian sample of diabetics. Back-translation and field testing methodology was used to determine the DCS semantic equivalency and psychometric properties. A convenience sample of 40 bilingual Brazilian adults was used to conduct the field testing of the scale. The findings suggested that the translation of the DCS was adequate and initial estimates of internal consistency and construct validity were adequate for both the DCS and its Portuguese version. Psychometric testing of the Portuguese language version of the DCS in this small sample appears to have sufficient reliability and validity for use in examining depressive cognitions in Brazilian adults. Further psychometric testing of the Portuguese version of the DCS in a larger Portuguese-speaking sample with diabetes is recommended.
Band‐Edge Photoluminescence Recovery from Zinc‐Blende CdSe Nanocrystals Synthesized at Room Temperature
Authors: Li R. , Lee J. , Kang D. , Luo Z. , Aindow M. , Papadimitrakopoulos F.
Published: December 2005

Low‐cost, large‐scale production of highly photoluminescent semiconductor nanocrystals (NCs) is desirable for a variety of applications. In this paper we report the realization of highly photoluminescent zinc‐blende CdSe nanocrystals from room‐temperature water‐phase synthesis, followed by low‐temperature (80 ± 5 °C) chemical etching in a solution of 3‐amino‐1‐propanol/H2O (v/v = 10/1). X‐ray diffraction (XRD) and transmission electron microscopy (TEM) data indicate that these CdSe NCs exhibit a cubic, zinc‐blende crystal structure. After etching, these CdSe nanocrystals show strong band‐edge photoluminescence (with quantum efficiency as high as 50 %) and lack of deep‐trap emissions. A high‐resolution TEM investigation suggests that this etching not only removes surface irregularities, but also attacks grain boundaries. Moreover, the size distribution reduces upon progressive etching to allow photoluminescence full‐width‐at‐half‐maximum (FWHM) values as low as 30 nm.
Hydrolysis of olive oil using lipase bonded to modified carbon membrane
Authors: Sachan S. , Sachdeva S. , Pugazhenthi G. , Kumar Anil
Published: December 2005

A noninterpenetrating supported carbon membrane was prepared using a resole‐type phenol‐formaldehyde resin as precursor. Amine groups were created on the carbon membrane through nitration using NOx and used to immobilize lipase enzyme by reacting with glutaraldehyde. To maintain high enzyme activity, surface carboxylic groups were modified and the immobilized enzyme on the membrane thus obtained was active even after 3 months of usage. The performance of the biphasic membrane reactor is studied in terms of amount of free fatty acid produced per unit time based on the volume of aqueous phase and the effect of operating variables (pH of aqueous phase solution, solvent used for olive oil, olive oil concentration, and aqueous phase circulation rate) were evaluated. Experiments show that the activity of lipase increases 1.42‐fold upon immobilization. The maximum reaction rate was 3.6‐fold higher, and the base case rate was 1.4‐fold higher than the values reported in the literature for a similar enzyme membrane reactor but with a different membrane. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Trisomy 16p: A longitudinal profile and photo essay
Authors: Sommer Annemarie , Pastore Matthew , Wenger Gail
Published: December 2005

As more cases of complete or partial trisomy 16p are described, a clinical picture of these patients is emerging. A specific phenotype appears to be most consistent if the band 16p13.1–16p13.3 is present in triplicate. The hallmarks of this syndrome are microcephaly, a specific facial appearance with round facies, micrognathia, and small protruding auricles, and psychomotor as well as growth retardation. We report on a patient with partial trisomy 16p due to a maternally‐inherited balanced translocation between chromosomes 2q and 16p and describe the change in phenotype over 21 years, as well as the level of development achieved. © 2005 Wiley‐Liss, Inc.
Regional, social, and evolutionary perspectives on treponemal infection in the Southeastern United States
Authors: Hutchinson Dale L. , Richman Rebecca
Published: December 2005

The origin and geographic distribution of syphilis, a form of treponemal infection, have long been regarded as among the most important medical riddles of prehistoric and historic disease evolution. In this study, we expand on previous discussions of the origin, evolution, and relationship of treponemal infections as they occur in the prehistoric southeastern United States. Individuals from 25 skeletal series (n = 2,410 individuals) were examined for cranial and dental lesions characteristic of treponemal infection. They lived between the Archaic period (8000–1000 BC) and protohistoric period (AD 1500–1600), and in physiographic zones from the coast to the mountains of Alabama, Florida, North Carolina, and Tennessee. Radial cranial scars were found for 47 individuals, but none of the four cases of dental lesions could be attributed to congenital syphilis. Differences in frequency of cranial lesions by region were minimal, with the least number of cases found for the mountains, but the frequency of positive cases tended to increase through time. It is suggested that increasing population density and changing behaviors, rather than novel strains of the treponemal pathogen, are responsible for the chronological increase in the frequency of positive cases. Am J Phys Anthropol, 2006. © 2005 Wiley‐Liss, Inc.
Histological identification of syphilis in pre‐Columbian England
Authors: von Hunnius Tanya E. , Roberts Charlotte A. , Boylston Anthea , Saunders Shelley R.
Published: December 2005

Microscopic analyses served to complement the macroscopic identification of venereal syphilis in two of four pre‐Columbian skeletons from the site Hull Magistrates Court in England. Diagnosis was based on parameters presented by Schultz ([1994] Origin of Syphilis in Europe, Toulon: Centre Archaeologique du Var, p. 63–67; [2001] Yrbk. Phys. Anthropol. 44:106–147; [2003] Identification of Pathological Conditions in Human Remains, New York: Academic Press, p. 73–109), which characterized venereal syphilis at a histological level. Observation of the microarchitecture of these samples allowed a more comprehensive approach to identification of the disease (processes). In most samples, Polsters and Grenzstreifen (or remnants of such structures) could be identified, suggesting the presence of a chronic, inflammatory disease such as venereal syphilis. Sinous lacunae were also observed in all histological samples, pointing to lytic activity (osteitis). The combination of both proliferative and destructive processes is pathognomonic for syphilis, and histological analyses provided a more accurate diagnosis of this infectious disease in these four individuals. As a result, the histological evidence suggests that venereal syphilis was present in England prior to 1492. This secondary form of evidence supports the macroscopic identification of the disease, and shows the power of a multimethodological approach to paleopathological diagnoses. Am J Phys Anthropol, 2006. © 2005 Wiley‐Liss, Inc.
Functional Liquid‐Crystalline Assemblies: Self‐Organized Soft Materials
Authors: Kato Takashi , Mizoshita Norihiro , Kishimoto Kenji
Published: December 2005

In the 21st century, soft materials will become more important as functional materials because of their dynamic nature. Although soft materials are not as highly durable as hard materials, such as metals, ceramics, and engineering plastics, they can respond well to stimuli and the environment. The introduction of order into soft materials induces new dynamic functions. Liquid crystals are ordered soft materials consisting of self‐organized molecules and can potentially be used as new functional materials for electron, ion, or molecular transporting, sensory, catalytic, optical, and bio‐active materials. For this functionalization, unconventional materials design is required. Herein, we describe new approaches to the functionalization of liquid crystals and show how the design of liquid crystals formed by supramolecular assembly and nano‐segregation leads to the formation of a variety of new self‐organized functional materials.
Investigation of adsorption–desorption dynamism of bovine serum albumin on crosslinked N,N′‐diethylaminoethyl dextran microbeads: Solution phase
Authors: Can Hatice Kaplan , Güner Ali
Published: December 2005

New hydrogel microspheres based on crosslinked dextran containing N,N′‐diethylaminoethyl (DEAE) groups with different chemical structures have been used in adsorption–desorption studies. Bovine serum albumin (BSA) is frequently used in biophysical and biochemical studies. BSA has a well‐known primary structure that has been associated with binding of many different categories of small molecules. Both adsorption kinetics and equilibrium isotherms for the adsorption of BSA on crosslinked DEAE dextran have been determined experimentally. These were only slightly dependent on the initial concentration of BSA but were considerably affected by the pH of the medium. The results fitted the Freundlich–Langmuir isotherm model for pH 6.9. The adsorption capacity factor and the adsorption equilibrium constant were obtained and mathematical modeling of adsorption, adsorption rate constants, and maximum adsorption were determined. Swelling kinetics of crosslinked DEAE dextran and optimum ionic strength, pH, and mass of hydrogel were also investigated. Desorption studies were finally determined under optimum medium conditions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Magnetic properties of polystyrene‐b‐poly(2‐hydroxylethyl methacrylate)/metal hybrids
Authors: Wang Yanmei , Zhu Ruping , He Weidong
Published: December 2005

Hybrids, which were composed of the amphiphilic diblock copolymer polystyrene‐b‐poly(2‐hydroxylethyl methacrylate) (PSt‐b‐PHEMA) and nickel, cobalt, or a nickel–cobalt alloy, were characterized with infrared absorption spectroscopy and ultraviolet–visible (UV–vis) absorption spectroscopy. UV–vis spectroscopy analysis showed that a redshift happened after the PSt‐b‐PHEMA/metal‐ion complexes were reduced by KBH4. The PSt‐b‐PHEMA/nickel–cobalt alloy hybrids had the biggest redshift [difference of the UV‐vis absorption wavelength between (PSt‐b‐PHEMA)/metal ion complex and (PSt‐b‐PHEMA)/metal hybrids (Δλm = 19.9 nm)]. In comparison with the PSt‐b‐PHEMA/nickel hybrids (Δλm = 3.5 nm) and PSt‐b‐PHEMA/cobalt hybrids (Δλm = 9.0 nm). The magnetic properties of PSt‐b‐PHEMA/metal were studied with vibrating sample magnetometry. The results of magnetic hysteresis loop studies showed that the obtained PSt‐b‐PHEMA/metal hybrids could be categorized as ferromagnetic materials. The results showed that the magnetic susceptibility decreased with increasing temperature in the range of 150–400 K and increased with increasing temperature above 400 K. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
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

Biodegradable 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

This 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

We 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

We 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

Variability 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

Current 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

Using 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

We 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

GJ 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

Using 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

A 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

Here 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

The 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

Phage 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

The 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

Objective: 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

Percutaneous 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.