bluuebunny/crossref_metadata_2025_split huggingface dataset:
A rotating bed system bioreactor enables cultivation of primary osteoblasts on well‐characterized sponceram® regarding structural and flow properties
Authors: Suck Kirstin , Roeker Stefanie , Diederichs Solvig , Anton Fabienne , Sanz‐Herrera Jose A. , Ochoa Ignacio , Doblare Manuel , Scheper Thomas , van Griensven Martijn , Kasper Cornelia 
Published: January 2010

AbstractThe development of bone tissue engineering depends on the availability of suitable biomaterials, a well‐defined and controlled bioreactor system, and on the use of adequate cells. The biomaterial must fulfill chemical, biological, and mechanical requirements. Besides biocompatibility, the structural and flow characteristics of the biomaterial are of utmost importance for a successful dynamic cultivation of osteoblasts, since fluid percolation within the microstructure must be assured to supply to cells nutrients and waste removal. Therefore, the biomaterial must consist of a three‐dimensional structure, exhibit high porosity and present an interconnected porous network. Sponceram®, a ZrO2 based porous ceramic, is characterized in the presented work with regard to its microstructural design. Intrinsic permeability is obtained through a standard Darcy's experiment, while Young's modulus is derived from a two plates stress–strain test in the linear range. Furthermore, the material is applied for the dynamic cultivation of primary osteoblasts in a newly developed rotating bed bioreactor. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Theoretical Studies on the Intermolecular Interactions of Potentially Primordial Base‐Pair Analogues
Authors: Šponer Judit E. , Vázquez‐Mayagoitia Álvaro , Sumpter Bobby G. , Leszczynski Jerzy , Šponer Jiří , Otyepka Michal , Banáš Pavel , Fuentes‐Cabrera Miguel 
Published: January 2010

AbstractRecent experimental studies on the Watson–Crick type base pairing of triazine and aminopyrimidine derivatives suggest that acid/base properties of the constituent bases might be related to the duplex stabilities measured in solution. Herein we use high‐level quantum chemical calculations and molecular dynamics simulations to evaluate the base pairing and stacking interactions of seven selected base pairs, which are common in that they are stabilized by two NH⋅⋅⋅O hydrogen bonds separated by one NH⋅⋅⋅N hydrogen bond. We show that neither the base pairing nor the base stacking interaction energies correlate with the reported pKa data of the bases and the melting points of the duplexes. This suggests that the experimentally observed correlation between the melting point data of the duplexes and the pKa values of the constituent bases is not rooted in the intrinsic base pairing and stacking properties. The physical chemistry origin of the observed experimental correlation thus remains unexplained and requires further investigations. In addition, since our calculations are carried out with extrapolation to the complete basis set of atomic orbitals and with inclusion of higher electron correlation effects, they provide reference data for stacking and base pairing energies of non‐natural bases.
Iron‐ and Cobalt‐Catalyzed Asymmetric Hydrosilylation of Ketones and Enones with Bis(oxazolinylphenyl)amine Ligands
Authors: Inagaki Tomohiko , Phong Le Thanh , Furuta Akihiro , Ito Jun‐ichi , Nishiyama Hisao 
Published: January 2010

AbstractChiral bis(oxazolinylphenyl)amines proved to be efficient auxiliary ligands for iron and cobalt catalysts with high activity for asymmetric hydrosilylation of ketones and asymmetric conjugate hydrosilylation of enones.
Numerical simulation of thermal and mass transport during Czochralski crystal growth of sapphire
Authors: Lu Chung‐Wei , Chen Jyh‐Chen 
Published: January 2010

AbstractThe thermal and flow transport in an inductively heated Czochralski crystal growth furnace during a crystal growth process is investigated numerically. The temperature and flow fields inside the furnace, coupled with the heat generation in the iridium crucible induced by the electromagnetic field generated by the RF coil, are computed. The results indicate that for an RF coil fixed in position during the growth process, although the maximum value of the magnetic, temperature and velocity fields decrease, the convexity of the crystal‐melt interface increases for longer crystal growth lengths. The convexity of the crystal‐melt interface and the power consumption can be reduced by adjusting the relative position between the crucible and the induction coil during growth. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of reduction/oxidation treatment on blue photorefraction in In:Fe:Cu:LiNbO3 crystals
Authors: Luo Suhua , Wu Fengjiang , Wang Jian , Sun Xiudong 
Published: January 2010

AbstractIn:Fe:Cu:LiNbO3 crystals with reduced/oxidized treatments were prepared by the Czochralski method. The defect structure was analyzed by the UV‐Visible absorption spectra. The blue photorefractive properties, such as the refractive index change, response time, recording sensitivity, dynamic range as well as two‐wave coupling gain coefficient, were also investigated at 488 nm wavelength using the two‐wave coupling experiment. Comparing the as‐grown and oxidized In:Fe:Cu:LiNbO3 crystals, the reduced sample has the highest recording sensitivity and largest dynamic range. Meanwhile, the high diffraction efficiency is still maintained. Experimental results definitely show that reduction treatment is an effective method to improve the blue photorefractive performance of In:Fe:Cu:LiNbO3 crystals. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rapid synthesis of dendrite‐ and platelet‐like α‐Fe2O3 via a hydrothermal oxidation route
Authors: Liang Jun , Li Li , Song Weiming , Fang Junzhuo , Luo Min , Li Yanping 
Published: January 2010

AbstractDendrite and platelet‐like α‐Fe2O3 microcrystals were synthesized by the oxidation reaction of K4Fe(CN)6and NaClO3 through a simple hydrothermal method. The structures and morphologies of the as‐prepared samples were characterized in detail by X‐ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The experiment results show that NaOH played an important role in controlling the morphology of the final products. The possible mechanism was discussed to elucidate the formation of different morphologies of the α‐Fe2O3 microstructures. Besides, the magnetic property of the dendrite α‐Fe2O3 microstructure was characterized by a vibrating sample magnetometer (VSM). (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of forced solution flow on lysozyme crystal growth
Authors: Yu Yong , Liu Yuhong , Wang Xuan , Oberthür D. , Dierks K. , Betzel C. 
Published: January 2010

AbstractIn order to study quantitatively the effects of forced solution on crystal growth, we designed a new set of experimental equipment, in particular, a microchannel mixer was used as crystallization container so that the consumption of protein samples was much reduced and thus an exact syringe pump could be used for precise control of the flow rates. Since the mixer's section was designed to be rectangular, the solution velocity in its center was steady and constant, and thus repeatable experiments were facilitated. Experimental results showed that the effects of forced solution on protein crystal growth were different under different levels of supersaturation, and new results were obtained for cases of high supersaturation. When the supersaturation is σ = 2.3, with increasing flow rates the growth rates of the lysozyme crystal's (110) face hardly change when the flow rates are lower than 1300 μm/s, and decrease quickly afterwards. When the flow rate reaches 2000 μm/s, the crystal nearly ceases to grow. When the supersaturation is σ = 2.7, with increasing flow rates the (110) face growth rates increase at the beginning then reach the maximum values at 1700 μm/s – 1900 μm/s and decrease afterwards, approaching zero or so when the flow rate reaches 12000 μm/s. The higher the supersaturation, the larger the flow rate at which the crystal ceases to grow. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and crystallographic characterization of crystalline modifications of 3,4:9,10‐perylenetetracarboxylic dianhydride at room temperature
Authors: Levin A. A. , Leisegang T. , Forker R. , Koch M. , Meyer D. C. , Fritz T. 
Published: January 2010

Abstract3,4:9,10‐Perylenetetracarboxylic dianhydride (PTCDA) powder obtained from Sigma‐Aldrich was purified by three cycles of temperature gradient sublimation in an evacuated quartz glass tube providing variable conditions. By means of X‐ray diffraction (XRD) analysis, a crystallographic characterization of the powders obtained during the sublimation process and selected single crystals was carried out evidencing the presence of a major α‐ and a minor β‐PTCDA component in all samples. Lattice parameters of high precision were obtained for α‐PTCDA (a = 3.73283(4) Å, b = 12.0328(6) Å, c = 17.3998(4) Å, β = 98.689(2)°, V = 772.57(4) Å3 and d102 = 3.219(3) Å) by whole‐X‐ray‐powder‐pattern‐fitting of the experimental XRD pattern using the Le Bail approach. Employing a (001) KCl wafer as substrate for the material purification results in formation of single phase α‐PTCDA accompanied by a decrease in the size of the crystallites which is attributed to the presumed lower temperature of the KCl wafers. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization and solventless growth of salicylic acid macro‐crystals involving a nitrogen gas flow
Authors: Menaa B. , Takahashi M. , Tokuda Y. , Yoko T. 
Published: January 2010

AbstractWe report an original solventless thermal crystallisation method to grow large needle‐like salicylic acid (SA) crystals of 10‐12 mm in length. The method is based on the utilization of nitrogen gaz flow on salicylic acid powder during heating just below melting point temperature for 24 h. Salicylic acid provides one of the best examples of a pharmaceutical substance used for cosmetics whose physical and chemical properties indicate hydrogen‐bond formation between the hydroxyl group and an adjacent oxygen atom of the same molecule. The structure of the crystals is confirmed by single crystal X‐ray diffraction; it is monoclinic, a = 4.93(2) Å, b = 11.23(5) Å, c = 11.56(6) Å, β = 90.77(4)° with the space group P 21/c. The macrocrystals formation using this method is new and represents an interesting finding for a wide range of applications to be developed in the fields of biotechnology and photonics (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural, optical and photoconductive properties of electron beam evaporated CdSxSe1‐x films
Authors: Sivaramamoorthy K. , Asath Bahadur S. , Kottaisamy M. , Murali K. R. 
Published: January 2010

AbstractCdSxSe1‐x films were deposited by the electron beam evaporation technique on glass substrates at different temperatures in the range 30 – 300 °C using the laboratory synthesized powders of different composition. The films exhibited hexagonal structure and the lattice parameters shifted from CdSe to CdS side as the composition changed from CdSe to CdS side. The bandgap of the films increased from 1.68 to 2.41 eV as the concentration of CdS increased. The root‐mean‐roughness (RMS) values are 3.4, 2.6, 1.2 and 0.6 nm as the composition of the films shifted towards CdS side. The conductivity varies from 30 Ωcm‐1 to 480 Ωcm‐1 as the ‘x’ value increases from 0 to 1. The films exhibited photosensitivity. The PL spectrum shifts towards lower energies with decreasing x, due to the decrease of the fundamental gap with Se composition. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthetic Studies Directed Towards Various Homologues of Natural Sesquiterpene‐Coumarin Ethers: The Domino Approach
Authors: Corbu Andrei , Castro Juan M. , Aquino Maurizio , Gandara Zoila , Retailleau Pascal , Arseniyadis Siméon 
Published: January 2010

AbstractA domino‐based strategy was used to construct analogues containing the basic skeleton of the monocyclic sesquiterpene‐coumarin ethers galbanic acid (1) and secodrial (3), through conversion of the domino adduct 19 into 10 and 11, chosen as representative targets. 1H NMR patterns, corroborated by X‐ray crystallographic analysis for two of the four possible diastereomeric arrangements of the six‐membered B‐ring common to various A‐seco terpenes, have been determined. The observed trends help in the design of substituent combinations that provide a tool for diastereomeric recognition, depending on the cis/trans arrangement of the adjacent methyl groups and the adopted conformations.
Development of a capillary gel electrophoresis method for monitoring disulfide isomer heterogeneity in IgG2 antibodies
Authors: Lacher Nathan A. , Wang Qian , Roberts Rachel K. , Holovics Heidi J. , Aykent Serdar , Schlittler Michael R. , Thompson Melissa R. , Demarest Charles W. 
Published: January 2010

AbstractA CGE method for monitoring the disulfide isomer distribution characteristic of IgG2 MAbs is presented. Disulfide heterogeneity of MAbs has been studied using various chromatographic and electrophoretic methods. Although CGE operates using a different selectivity mechanism from that of sorption chromatographic techniques, similar trends are present in the data, which allow the CGE method to be used as a complementary method for studying disulfide isomer distribution. This article focuses on the optimization of a capillary‐based gel electrophoresis method that can be used to support antibody development including bioprocess optimization, antibody characterization, release, and formulation stability assessment.
Rapid and direct determination of glyphosate, glufosinate, and aminophosphonic acid by online preconcentration CE with contactless conductivity detection
Authors: See Hong Heng , Hauser Peter C. , Ibrahim Wan Aini Wan , Sanagi Mohd Marsin 
Published: January 2010

AbstractRapid and direct online preconcentration followed by CE with capacitively coupled contactless conductivity detection (CE‐C4D) is evaluated as a new approach for the determination of glyphosate, glufosinate (GLUF), and aminophosphonic acid (AMPA) in drinking water. Two online preconcentration techniques, namely large volume sample stacking without polarity switching and field‐enhanced sample injection, coupled with CE‐C4D were successfully developed and optimized. Under optimized conditions, LODs in the range of 0.01–0.1 μM (1.7–11.1 μg/L) and sensitivity enhancements of 48‐ to 53‐fold were achieved with the large volume sample stacking‐CE‐C4D method. By performing the field‐enhanced sample injection‐CE‐C4D procedure, excellent LODs down to 0.0005–0.02 μM (0.1–2.2 μg/L) as well as sensitivity enhancements of up to 245‐ to 1002‐fold were obtained. Both techniques showed satisfactory reproducibility with RSDs of peak height of better than 10%. The newly established approaches were successfully applied to the analysis of glyphosate, glufosinate, and aminophosphonic acid in spiked tap drinking water.
Nanoparticle‐based capillary electroseparation of proteins in polymer capillaries under physiological conditions
Authors: Nilsson Christian , Harwigsson Ian , Becker Kristian , Kutter Jörg P. , Birnbaum Staffan , Nilsson Staffan 
Published: January 2010

AbstractTotally porous lipid‐based liquid crystalline nanoparticles were used as pseudostationary phase for capillary electroseparation with LIF detection of proteins at physiological conditions using unmodified cyclic olefin copolymer capillaries (Topas®, 6.7 cm effective length). In the absence of nanoparticles, i.e. in CE mode, the protein samples adsorbed completely to the capillary walls and could not be recovered. In contrast, nanoparticle‐based capillary electroseparation resolved green fluorescent protein from several of its impurities within 1 min. Furthermore, a mixture of native green fluorescent protein and two of its single‐amino‐acid‐substituted variants was separated within 2.5 min with efficiencies of 400 000 plates/m. The nanoparticles prevent adsorption by introducing a large interacting surface and by obstructing the attachment of the protein to the capillary wall. A one‐step procedure based on self‐assembly of lipids was used to prepare the nanoparticles, which benefit from their biocompatibility and suspension stability at high concentrations. An aqueous tricine buffer at pH 7.5 containing lipid‐based nanoparticles (2% w/w) was used as electrolyte, enabling separation at protein friendly conditions. The developed capillary‐based method facilitates future electrochromatography of proteins on polymer‐based microchips under physiological conditions and enables the initial optimization of separation conditions in parallel to the chip development.
A novel Escherichia coli‐derived mutation detected with the Big Blue® cII mutant selectable assay
Authors: Ward Tonya L. , Prtenjaca Anita , Hill Kathleen A. 
Published: January 2010

AbstractTransgenic mouse mutation detection systems allow investigation of the origins and mechanisms of mutation associated with exogenous and endogenous mutagen exposures in individual tissues and cell types. In the past, selection assays for transgenic mutants have been contaminated with nonmurine‐derived mutations and assay validation is critical to ensure murine in vivo origins of mutations. This is critical in studies of spontaneous mutations and extrapolation to endogenous mammalian genes. Herein, we provide one measure of the contribution of Escherichia coli (E. coli)‐derived mutations to the Big Blue® cII transgene mutant selection assay. We report the first direct evidence of an E. coli‐derived cII mutation identified among mutations recovered in the cII selective assay. An E. coli transposable 5 (Tn5) element IS50R inverted repeat (1,534 bp) was identified at base pair 414 in the cII transgene and the insertion generated a 9 bp target site duplication typical of this type of transposition. The bacterial transposition occurred only once in the assay of 25 × 106 plaque forming units and sequencing of 1,177 cII mutants. The observed frequency of this type of mutation is 4 × 10−8 in retrieved λ phage and 8.5 × 10−4 in harvested cII mutants and thus a very rare occurrence in typical analyses of spontaneous in vivo mutations. Given that the frequency of transposition is equal to, or an order of magnitude higher, than the frequency of point mutations in E. coli, this article provides excellent validation for the murine origins of mutations detected using the cII mutant selection assay. Environ. Mol. Mutagen. 2010. © 2010 Wiley‐Liss, Inc.
The generation of wear‐resistant antimicrobial stainless steel surfaces by active screen plasma alloying with N and nanocrystalline Ag
Authors: Dong Yangchun , Li Xiaoying , Sammons Rachel , Dong Hanshan 
Published: January 2010

AbstractHospital‐acquired infections (HAIs), a large proportion of which are derived from contact transmission, represent a massive global challenge. In this study a novel active screen plasma (ASP) alloying technology has been developed to generate highly durable antimicrobial surfaces by combining a wear‐resistant S‐phase with nanocrystalline silver for medical grade stainless steel. The phase constituent, microstructure, composition and surface roughness of the alloyed surfaces were fully characterized, and the surface hardness, wear resistance and antimicrobial efficiency of the treated surfaces were evaluated. Experimental results showed that the surface hardness and sliding wear resistance of medical grade 316LVM stainless steel can be effectively improved by the ASP alloying treatment; furthermore, the Ag alloyed S‐phase can achieve 93% reduction in Escherichia coli (E. coli) after 6 h contact time. Therefore, the novel ASP alloying treatment can not only improve wear resistance but also confer antibacterial activity to stainless steel surfaces. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res PartB: Appl Biomater, 2010
In vitro antibacterial efficacy of tetracycline hydrochloride adsorbed onto Bio‐Oss® bone graft
Authors: Dashti A. , Ready D. , Salih V. , Knowles J. C. , Barralet J. E. , Wilson M. , Donos N. , Nazhat S. N. 
Published: January 2010

AbstractLocal delivery of antibiotics may provide the advantage of reducing the potential side effects associated with their systemic administration. This study assessed, in vitro, the antimicrobial efficacy of tetracycline hydrochloride (TCH) adsorbed onto Bio‐Oss® bone grafts against a range of pathogenic bacteria. Various levels of TCH were adsorbed onto Bio‐Oss® granules by immersing in TCH aqueous solutions of different initial concentrations for 48 h at room temperature. TCH release was assessed in phosphate buffered saline at 37°C, and its antimicrobial efficacy, up to 96 h, was tested against two Gram‐negative bacteria associated with periodontal diseases: Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans, and Porphyromonas gingivalis, and one Gram‐positive bacterium associated with soft‐tissue and bone infections: Staphylococcus aureus. The range of TCH concentrations studied was also assessed for cytotoxicity against osteoblast‐like human osteosarcoma cell lines. The amount of TCH adsorbed and released from Bio‐Oss® was concentration dependent. All TCH adsorbed Bio‐Oss® resulted in a reduction of A. actinomycetemcomitans, P. gingivalis, and S. aureus and higher concentrations were generally more effective in reducing or eliminating bacterial growth. The proliferation of HOS cells was not substantially reduced except for the maximum concentration of TCH. In addition to its osteoconductive role, TCH adsorbed Bio‐Oss® could also be functional in negating systemically antibiotic prophylactic treatment in the prevention of implant or biomaterial related infections. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010