bluuebunny/crossref_metadata_2025_split huggingface dataset:
Signatures of rapid climatic changes in organic matter records in the western Mediterranean Sea during the last glacial period
Authors: Baudin François , Combourieu-Nebout Nathalie , Zahn Rainer 
Published: February 2007

AbstractRecords of calcium carbonate, organic matter (organic carbon content, palynology) and planktonic foraminiferal oxygen isotopes from ODP Site 976, Alboran Sea, are used to reconstruct the evolution of continental climates and oceanic productivity in the westernmost Mediterranean over the past 50,000 years. The records mimic the Greenland ice core records in that they display the Heinrich events and the rapid Dansgaard/Oeschger-type stadial-interstadial oscillations. Warm interstadials correlate with an expansion of deciduous forests on the adjacent continents and enhanced river runoff and organic matter flux from terrestrial sources. In contrast, cold stadials are characterized by an expansion of semi-desert vegetation, reduced river runoff and limited terrestrial organic matter flux. The organic carbon record displays a longer-term cyclicity that correlates with the North Atlantic ’Bond’ cooling cycles. The records enable the documentation of rapid changes of continental climates in the western Mediterranean borderlands that caused changes in river runoff and in oceanic productivity that were driven by rapid fluctuations of the Atlantic inflow into the Mediterranean Sea. The combined terrestrial-marine patterns demonstrate the close linking of western Mediterranean climate with the climatic evolution in the North Atlantic region.
Determination of Protein Contacts by Chemical Cross‐Linking With EDC and Mass Spectrometry
Authors: Marekov Lyuben N. 
Published: February 2007

AbstractThis unit describes a method for analyzing protein complexes by chemically cross‐linking closely positioned amino acids. The cross‐linked products are isolated by SDS‐PAGE and the bands of interest are excised. Proteins in the excised gel piece are digested with trypsin and the resulting peptides recovered. Chemically bonded peptides are distinct from the multitude of unmodified single peptides by the presence of two carboxy‐terminal ends. The protocol also describes incorporation of 18O at the carboxy‐terminal ends and purification and preparation of the peptide mixture for mass spectroscopy.
Incorporation of Isotopically Enriched Amino Acids
Authors: Samuel‐Landtiser Mini , Zachariah Cherian , Williams Chris R. , Edison Arthur S. , Long Joanna R. 
Published: February 2007

AbstractThe incorporation of isotope labels into proteins is extremely useful for the application of nuclear magnetic resonance (NMR), X‐ray or neutron‐diffraction crystallography, and mass spectrometry (MS) methodologies to investigate the structure and dynamics of proteins. This unit presents methods for incorporating isotopic labels into proteins via expression in E. coli and baculovirus transfected Sf9 insect cells or through cell‐free means. The unit also presents methods for introducing isotopic labels by chemical means into synthetic peptides by solid phase peptide synthesis or into isolated proteins by chemical modification of labile protein groups.
Toxicology Testing in Drug Discovery and Development
Authors: Dorato Michael A. , Buckley Lorrene A. 
Published: February 2007

AbstractThe primary objective of toxicology studies in the drug discovery process is to evaluate the safety of potential drug candidates. This is accomplished using relevant animal models and validated procedures. The ultimate goal is to translate the animal responses into an understanding of the risk for human subjects. To this end the toxicologist must be aware of the international guidelines for safety evaluation as well as traditional and nontraditional toxicology models. As described in this unit, the typical toxicology profile consists of safety pharmacology, genetic toxicology, acute and subchronic toxicology, absorption, distribution, metabolism, and excretion (ADME) studies, reproductive and developmental toxicity, and an evaluation of carcinogenic potential.
Supported Planar Bilayers for Study of the Immunological Synapse
Authors: Dustin Michael L. , Starr Toby , Varma Rajat , Thomas V. Kaye 
Published: February 2007

AbstractSupported planar bilayers have been used in immunology research for over 25 years, including in the initial demonstrations of MHC‐peptide complex functional activity and adhesion molecule activity. More recent modifications of the method have been used to measure two‐dimensional affinities and to study the formation of the immunological synapse. This unit covers the incorporation of glycolipid‐anchored membrane proteins, 6‐histidine‐tagged soluble proteins, and monobiotinylated soluble proteins into supported planar bilayers. Reagents developed for the MHC‐peptide tetramer staining method (UNIT 17.3) can readily be adapted to presentation on planar bilayers. The unique advantage of this approach is that the proteins presented on the surface of the supported bilayer are laterally mobile. This provides a more physiological presentation of cell‐surface molecules and supports visualization of protein rearrangement on the bilayer by live cells.
Tissue Culture Assays Used to Analyze Invasion by Staphylococcus aureus
Authors: Cheung Ambrose L. , Bayles Kenneth W. 
Published: February 2007

AbstractMany successful pathogens have developed the ability to adhere to and invade animal tissues. Recent experimental evidence suggests that S. aureus, generally perceived as an extracellular pathogen, can also invade and, in some cases, multiply within host cells. As a proxy to infections in animal hosts, the study of S. aureus interactions with tissue culture cells has become an important research tool in many aspects of bacterial pathogenesis. In this unit, we describe two cell culture models, including bovine mammary epithelial cells and human umbilical vein endothelial cells, that investigators have used to study the interactions of S. aureus with host cells.
Laboratory Maintenance of Borrelia burgdorferi
Authors: Zückert Wolfram R. 
Published: February 2007

AbstractThis unit describes the propagation of Borrelia burgdorferi as well as other “cultivable” Borrelia species in Barbour‐Stoenner‐Kelly‐II (BSK‐II) medium. It supplies a detailed recipe for BSK‐II, as well as protocols for standard liquid culture, the generation of frozen Borrelia stocks, and the plating of B. burgdorferi cells in solid BSK‐II medium.
Rapid Full‐Length Cloning of Nonpolyadenylated RNA Virus Genomes
Authors: Beckett Randy , Miller W. Allen 
Published: February 2007

AbstractAccess to a full‐length infectious clone of a viral genome is a virtual necessity for research aimed at understanding virus replication and gene expression mechanisms. While construction of a full‐length clone may be straightforward, obtaining one that is infectious is by no means routine. Here the authors describe methods to maximize the likelihood of obtaining a full‐length infectious clone. These include protocols to (1) sequence the ends of nonpolyadenylated RNA genomes, (2) obtain a full‐length PCR product in a single reaction directly from viral RNA, and (3) efficiently clone the PCR product into a vector that allows in vitro transcription of viral RNA containing perfect or near‐perfect termini. Given the traditional difficulty of obtaining infectious clones of RNA genomes (especially of nonpolyadenylated RNA viruses), this unit should be valuable to all virologists working with nonpolyadenylated as well as polyadenylated viruses of plants and animals.
Cooxidation of ammonia and ethanol in supercritical water, part 1: Experimental results
Authors: Ploeger Jason M. , Mock Michael A. , Tester Jefferson W. 
Published: February 2007

AbstractThe cooxidative effect of ethanol on ammonia oxidation in supercritical water was studied for a range of temperatures (655–705°C), initial ammonia (1–3 mM), ethanol (0–1.0 mM), and oxygen concentrations (0.7–5.0 mM), corresponding to fuel equivalence ratios ranging from 0.9 to 2.2 for the complete combustion of both organic species. With a stoichiometric amount of oxygen available for complete oxidation, the addition of ethanol on an equivalent molar basis was found to increase ammonia conversion from 20 to 65% at initial concentrations of 1 mM for each reactant, T = 700°C, P = 246 bar, and τ = 2.5 s. Nitrous oxide was produced in much larger quantities for ammonia–ethanol cooxidation than for ammonia oxidation. Based on fractional yields of nitrogen product, this amounted to 40–75% for co‐oxidation with ethanol versus 4–13% without ethanol present. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Contiguous gene deletion involving L1CAM and AVPR2 causes X‐linked hydrocephalus with nephrogenic diabetes insipidus
Authors: Tegay David H. , Lane Andrew H. , Roohi Jasmin , Hatchwell Eli 
Published: February 2007

AbstractX‐linked hydrocephalus with aqueductal stenosis (HSAS) is caused by mutation or deletion of the L1 cell adhesion molecule gene (L1CAM) at Xq28. Central diabetes insipidus (CDI) can arise as a consequence of resultant hypothalamic dysfunction from hydrocephalus and must be distinguished from nephrogenic diabetes insipidus (NDI) by exogenous vasopressin response. Causes of NDI are heterogeneous and include mutation or deletion of the arginine vasopressin receptor 2 gene (AVPR2), which is located ∼29 kb telomeric to L1CAM. We identified a patient with both HSAS and NDI where DNA sequencing failure suggested the possibility of a contiguous gene deletion. A 32.7 kb deletion mapping from L1CAM intron1 to AVPR2 exon2 was confirmed. A 90 bp junctional insertion fragment sharing short direct repeat homology with flanking sequences was identified. To our knowledge this is the first reported case of an Xq28 microdeletion involving both L1CAM and AVPR2, defining a new contiguous gene syndrome comprised of HSAS and NDI. Contiguous gene deletion should be considered as a mechanism for all patients presenting with hydrocephalus and NDI. © 2007 Wiley‐Liss, Inc.
Interferon regulatory factor 6 (IRF6) and fibroblast growth factor receptor 1 (FGFR1) contribute to human tooth agenesis
Authors: Vieira Alexandre R. , Modesto Adriana , Meira Raquel , Barbosa Anna Renata Schneider , Lidral Andrew C. , Murray Jeffrey C. 
Published: February 2007

AbstractPhenotypic characteristics expressed in syndromes give clues to the factors involved in the cause of isolated forms of the same defects. We investigated two genes responsible for craniofacial syndromes,FGFR1andIRF6, in a collection of families with isolated tooth agenesis. Cheek swab samples were obtained for DNA analysis from 116 case/parent trios. Probands had at least one developmentally missing tooth, excluding third molars. In addition, we studied 89 cases and 50 controls from Ohio to replicate any positive findings. Genotyping was performed by kinetic polymerase chain‐reaction or TaqMan assays. Linkage disequilibrium analysis and transmission distortion of the marker alleles were performed. The same variants in theIRF6gene that are associated with isolated orofacial clefts are also associated with human tooth agenesis (rs861019,P = 0.058; rs17015215—V274I,P = 0.0006; rs7802,P = 0.004). Mutations inIRF6cause Van der Woude and popliteal pterygium syndromes. The craniofacial phenotypic characteristics of these syndromes include oral clefts and preferential tooth agenesis of incisors and premolars, besides pits on the lower lips. Also it appears that preferential premolar agenesis is associated withFGFR1(P = 0.014) andIRF6(P = 0.002) markers. There were statistically significant data suggesting thatIRF6interacts not only withMSX1(P = 0.001), but also withTGFA(P = 0.03). © 2007 Wiley‐Liss, Inc.
Traumatic injuries and imperialism: The effects of Egyptian colonial strategies at Tombos in upper Nubia
Authors: Buzon Michele R. , Richman Rebecca 
Published: February 2007

AbstractAs circumstances of conquest change, leaders of empires must adapt their colonial strategies in order to be successful. One example of such modification in approach is the shift from Middle Kingdom to New Kingdom Egyptian colonial activities in Nubia. During the Middle Kingdom (2050–1650 BC) Egypt used aggressive military campaigns to subdue the strong Nubian polity at Kerma, resulting in the construction of fortresses and many victory stelae. In the subsequent New Kingdom period (1550–1050 BC) during which the Egyptian administration succeeded in occupying nearly all of Nubia, changes were necessary in conquest strategies. Diplomacy and cooperation may have replaced military action as mechanisms of control. This article investigates changes in imperial policy through the examination of traumatic injuries in human skeletal remains. Patterns of injuries in a sample from the site of Tombos, an Egyptian colonial cemetery in Nubia dating to the New Kingdom period, are compared with data on the patterns of injuries from Kerma, a cemetery dating to the Middle Kingdom period, published by Judd (2004). Analysis indicates a decrease in the level of traumatic injuries from Kerma to Tombos supporting the idea that through time the Egyptian administration modified their colonial strategy toward more nonviolent means. This article presents data on differences in the patterns of injury at Tombos and Kerma and explores possible explanations for this variation. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.
Definitionen von Grundbegriffen mit Bezug zu Polymerreaktionen und zu funktionellen polymeren Materialien
Authors: Jonas Ulrich , Theato Patrick 
Published: February 2007

AbstractHier werden die Ausdrücke definiert, die im Bereich von Polymerreaktionen und funktionellen Polymeren am geläufigsten sind. Dabei wurden nur Begriffe aufgenommen, die für Polymersysteme spezifisch sind. Die Zusammenstellung ist in drei Abschnitte unterteilt: Im ersten werden die Begriffe definiert, die sich auf Polymerreaktionen beziehen. Die Namen spezifischer chemischer Reaktionen wurden nicht aufgenommen, auch nicht in Fällen, in denen die Reaktionen wichtig für das Gebiet der Polymerreaktionen sind. Im zweiten Abschnitt werden Begriffe zu polymeren Reaktanten und reaktiven polymeren Materialien definiert, und im dritten Begriffe, die funktionelle polymere Materialien beschreiben.
Poly(m‐xylene adipamide)–kaolinite and poly(m‐xylene adipamide)–montmorillonite nanocomposites
Authors: Ammala Anne , Hill Anita J. , Lawrence Kelly A. , Tran Thuy 
Published: February 2007

AbstractTwo clay compounds, montmorillonite (Cloisite 30B) and kaolinite, were dispersed in a poly(m‐xylene adipamide) resin at loading levels of 2 wt % clay. The samples were melt‐compounded and extruded. The extruded samples were injection‐molded into preforms and then blow‐molded into multilayer bottles. Rheology, calorimetry, electron microscopy, and gas‐transport measurements were performed. Both clays were nucleating agents, giving crystallite sizes that did not cause haze. Kaolinite was more difficult to exfoliate than montmorillonite, and under similar processing conditions, kaolinite resulted in a higher degree of crystallinity. Both nanocomposites exhibited improved gas‐barrier properties over the neat resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1377–1381, 2007
Atom‐transfer radical polymerization of acrylonitrile under microwave irradiation
Authors: Hou Chen , Guo Zhenliang , Liu Junshen , Ying Liang , Geng Dongdong 
Published: February 2007

AbstractA single‐pot atom‐transfer radical polymerization under microwave irradiation was first used to successfully synthesize polyacrylonitrile. This was achieved with FeBr2/isophthalic acid as the catalyst and 2‐bromopropionitrile as the initiator. With the same experimental conditions, the apparent rate constant under microwave irradiation was higher than that under conventional heating. An FeBr2/isophthalic acid ratio of 1:2 not only gave the best control of molecular weight and its distribution but also provided a rather rapid reaction rate. The polymers obtained were end‐functionalized by bromine atoms, and they were used as macroinitiators to proceed the chain extension polymerization. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1382–1385, 2007
Viscoelastic sol–gel state of the chitosan and alginate solution mixture
Authors: Shon Sung Ok , Ji Byung Chul , Han Young A , Park Dong‐Joon , Kim Ik Su , Choi Jin Hyun 
Published: February 2007

AbstractThe rheological behavior of chitosan/alginate solutions was investigated in relation to gelation and polyelectrolyte complex (PEC) formation. Before mixing, the chitosan and the alginate solutions were both homogeneous fluids. However, heterogeneity developed after mixing, accompanied by a serious increase of viscosity. To determine the sol–gel state of the solutions, the viscoelastic variables, such as the dynamic storage modulus (G′) and loss modulus (G″), the loss tangent, and the viscoelastic exponents for G′ and G″, were obtained. Depending on the concentration, the chitosan/alginate solutions revealed unexpected rheological behavior. At a polymer concentration of 1.0 wt %, the chitosan/alginate solution was in a viscoelastic gel state, whereas, at higher concentrations, viscoelastic sol properties were dominant. A viscoelastic gel state for the chitosan/alginate solution was induced based on the weak formation of fiber‐shaped precipitates of a PEC at a low polymer concentration. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1408–1414, 2007
“Smart” membrane materials: Preparation and characterization of PVDF‐g‐PNIPAAm graft copolymer
Authors: Wang Wenyu , Chen Li 
Published: February 2007

AbstractIn this research, a smart membrane material of graft copolymer of poly(vinylidene fluoride) with poly(N‐isopropylacrylamide) (PVDF‐g‐PNIPAAm) was synthesized by atom transfer radical polymerization (ATRP) using poly(vinylidene fluoride) (PVDF) as a macroinitiator and direct initiation of the secondary fluorinated site PVDF facilitates grafting the N‐isopropylacrylamide comonomer. The copolymers were characterized by Fourier transform infrared (FTIR), 1H NMR, gel‐permeation chromatography (GPC), and X‐ray photoelectron spectroscopy (XPS). The temperature‐sensitive membrane was prepared from the PVDF‐g‐PNIPAAm graft copolymers by the phase inversion method. The effects of temperature on the flux of pure water of membrane was investigated. The results showed that alkyl fluorides were successfully applied as ATRP initiators in the synthetic condition and the flux of pure water through the PVDF‐g‐PNIPAAm membrane depended on the temperature change. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1482–1486, 2007
Rheological and electrical properties of Egyptian bentonite as a drilling mud
Authors: Mostafa Bassem A. , Assaad Faiz F. , Attia Mosaad 
Published: February 2007

AbstractThe flow properties of Egyptian bentonite as a drilling mud were studied using anionic polyacrylamide as an additive (MW 1,000,000 g/mol). The rheological properties (plastic viscosity, yield point, thixotropy) of bentonite–polyacrylamide mud were investigated at different concentrations (5–20 mg/L). It was found that, as polyacrylamide concentration increases, rheological properties increase after 24‐h aging time and up to 40°C. By increasing temperature, rheological properties become nearly constant. Electrical properties (electrophoretic mobility and zeta potential) of Na bentonite/PAM mud were measured using zeta meter. The results showed that zeta potential of Egyptian bentonite/PAM mud increased at low PAM concentrations up to 10 mg/L. At high polyacrylamide concentrations, these properties decreased. To investigate the relation between rheological and electrical properties, potential energy profiles were constructed. Potential energy profile at 10 mg/L polyacrylamide–clay showed a high repulsion potential energy between clay surfaces, i.e., suspension stability attained. The most reliable clay suspension to meet the desired properties could be reached using 6% clay suspension concentration, 10 mg/L polyacrylamide, and temperature 40°C up to 24‐h aging time. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1496–1503, 2007
Synthesis and characteristics of imprinted 17‐β‐estradiol microparticle and nanoparticle with TFMAA as functional monomer
Authors: Zhu Qiujin , Tang Jian , Dai Jun , Gu Xiaohong , Chen Shangwei 
Published: February 2007

AbstractSubmicron‐scaled molecularly imprinted polymer (MIP) particles for 17‐β‐estradiol were prepared by precipitation polymerization method using 2‐(trifluoromethyl) acrylic acid as functional monomer and trimethylolpropane trimethacrylate as cross‐linker in acetonitrile. The obtained submicron‐scaled MIP particles were subsequently packed into stainless steel columns and the chromatographic characteristics of the MIP stationary phase were investigated. Interestingly, it was found that tandem MIP columns of 17‐β‐estradiol‐based MIP with two different ratios of the template could achieve almost complete separation of isomers (17‐α‐estradiol and 17‐β‐estradiol) with a good separation factor (2.45). Morphological characteristics and adsorption kinetics of the submicron‐scaled MIP particles, effect of flow‐rate, injection amount, and column temperature on separation were also investigated in detail. Results indicated that the submicron‐scaled MIP particles had both good selectivity and high affinity to the template molecule 17‐β‐estradiol. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1551–1558, 2007
Effects of water on the preparation, morphology, and properties of polyimide/silica nanocomposite films prepared by sol–gel process
Authors: Jiang Lizhong , Wang Wencai , Wei Xiaowei , Wu Dezhen , Jin Riguang 
Published: February 2007

AbstractPolyimide/silica (PI/SiO2) nanocomposite films with 10 wt % of silica content were prepared by sol–gel process under the conditions with and without additional water. The presence of additional water has great effect on the silica particle size and thus on the properties of the prepared PI/SiO2 films. The results indicated that with additional water, the silica particles formed before the imidization of poly(amic acid) (PAA) and aggregated with the increasing of temperature and degree of the proceeding imidization process. For the nonaqueous process, the hydrolysis condensation reaction of tetraethoxysilane (TEOS) did not occur until the imidization of PAA took place, and no silica particles were found in the unimidized PAA films. The hydrolysis–condensation reaction of TEOS was initiated simultaneously by the trace water released from the imidization reaction, the self‐catalysis mechanism of the approach provide a means of achieving uniformly dispersed silica particles formed in the PI matrix with particle size in the range of 30–70 nm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1579–1586, 2007
Preparation and solid‐state polyamidation of hexamethylenediammonium adipate: The effect of sodium 5‐sulfoisophthalic acid
Authors: Vouyiouka S. N. , Koumantarakis G. E. , Papaspyrides C. D. 
Published: February 2007

AbstractThe effect of sodium 5‐sulfoisophthalic acid (NaSIPA) on the solid‐state polymerization of hexamethylenediammonium adipate was studied. In particular, different polyamide salt grades, such as a model salt of hexamethylenediamine and NaSIPA and a polyamide 6,6 salt containing NaSIPA, were prepared through alternative procedures based on the solution–precipitation technique. Furthermore, selected salt grades were solid‐state‐polymerized in a thermogravimetric analysis chamber under static and flowing nitrogen. Critical reaction parameters, such as the reaction temperature, surrounding gas, and presence of NaSIPA, were investigated to determine the rate‐controlling mechanism of the process. More specifically, NaSIPA significantly influenced solid‐state polyamidation by reducing the reaction rate and changing the prevailing mechanism. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1609–1619, 2007