bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Characterization of Pyrazolyl‐Functionalized Imidazolium‐Based Ionic Liquids and Hemilabile (Carbene)palladium(II) Complex Catalyzed Heck Reaction
Authors: Wang Ruihu , Zeng Zhuo , Twamley Brendan , Piekarski Melissa M. , Shreeve Jean'ne M. 
Published: November 2006

AbstractNeat reactions of 1‐(pyrazolylmethyl)imidazole with an excess of alkyl or polyfluoroalkyl halides at 100 °C followed by subsequent metathetical reactions with LiN(SO2CF3)2 or KPF6 at 25 °C gave rise to a series of monoquaternary salts 3a–3k. These salts can be also prepared through treatment of 1‐alkylimidazole with 1‐(chloromethyl)pyrazole hydrochloride in the presence of base, followed by anion exchange with LiN(SO2CF3)2 or KPF6. Their phase‐transition temperature, thermal stability, density and solubility in common solvents have been investigated. Most of the bis(trifluoromethanesulfon)amide salts are room‐temperature ionic liquids. The effect of anions and of alkyl substituents bonded to the imidazolium cation on the physicochemical properties was examined. Using 3‐butyl‐1‐(pyrazolylmethyl)imidazolium chloride (2d), the precursor of 3‐butyl‐1‐(pyrazolylmethyl)imidazolium bis(trifluoromethanesulfon)amide (3d), as a reactant, a hemilabile (N‐heterocyclic carbene)palladium(II) complex 4 was synthesized through a (carbene)silver(I) transfer reagent. It was characterized by single‐crystal X‐ray diffraction analysis. The catalytic activity and recyclability of 4 in 3d were preliminarily evaluated by consecutive Heck reactions using different substrates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Aziridines in Parallel‐ and Solid‐Phase Synthesis
Authors: Olsen Christian A. , Franzyk Henrik , Jaroszewski Jerzy W. 
Published: November 2006

AbstractAziridines are versatile and powerful building blocks in organic synthesis due to their high reactivity as well as stereo‐ and regioselectivity of their ring‐opening reactions with nucleophiles. Thus, aziridines possess potential as building blocks in the preparation of combinatorial libraries for biological high‐throughput screening. Although the development of strategies for parallel synthesis and solid‐phase chemistry utilizing aziridines is still in its infancy, the diverse applications described so far emphasize their utility. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
A new chronology for the age of Appalachian erosional surfaces determined by cosmogenic nuclides in cave sediments
Authors: Anthony Darlene M. , Granger Darryl E. 
Published: November 2006

AbstractThe relative chronology of landscape evolution across the unglaciated Appalachian plateaus of Kentucky and Tennessee is well documented. For more than a century, geomorphologists have carefully mapped and correlated upland erosional surfaces inset by wide‐valley straths and smaller terraces. Constraining the timing of river incision into the Appalachian uplands was difficult in the past due to unsuitable dating methods and poorly preserved surface materials. Today, burial dating using the differential decay of cosmogenic 26Al and 10Be in clastic cave sediments reveals more than five million years of landscape evolution preserved underground. Multilevel caves linked hydrologically to the incision history of the Cumberland River contain in situ sediments equivalent to fluvial deposits found scattered across the Eastern Highland Rim erosional surface. Cave sediments correlate with: (1) thick Lafayette‐type gravels on the Eastern Highland Rim deposited between c. 5·7 and c. 3·5 Ma; (2) initial incision of the Cumberland River into the Eastern Highland Rim after c. 3·5 Ma; (3) formation of the Parker strath between c. 3·5 Ma and c. 2·0 Ma; (4) incision into the Parker strath at c. 2 Ma; (5) formation of a major terrace between c. 2·0 Ma and c. 1·5 Ma; (6) shorter cycles of accelerated incision and base level stability beginning at c. 1·5 Ma; and (7) regional aggradation at c. 0·85 Ma. Initial incision into the Appalachian uplands is interpreted as a response to eustasy at 3·2–3·1 Ma. Incision of the Parker strath is interpreted as a response to eustasy at 2·5–2·4 Ma. A third incision event at c. 1·5 Ma corresponds with glacial reorganization of the Ohio River basin. Widespread aggradation of cave passages at c. 0·85 Ma is interpreted as the beginning of intense glacial–interglacial cycling associated with global climate change. Copyright © 2006 John Wiley & Sons, Ltd.
A computer program (WDTSRP) designed for computation of sand drift potential (DP) and plotting sand roses
Authors: Saqqa W. A. , Saqqa A. W. 
Published: November 2006

AbstractWind Data Tabulator and Sand Rose Plotter (WDTSRP) is an interactive developed computer program accessible for estimating sand transport potential by winds in barren sandy deserts. The Fryberger (1979) formula for determining sand drift potential (DP) was adopted to create and develop the computer program. WDTSRP is capable of working out weighting factors (WFs), frequency of wind speed occurrence (t), drift potential (DP), resultant drift potential (RDP) and directional variability of winds (DV) and of plotting sand roses. The developed computer program is built up of a simplified system driven by a group of options and dialogue boxes that allow users to input and handle data easily and systematically. Copyright © 2006 John Wiley & Sons, Ltd.
Physical‐scale modelling of jökulhlaups (glacial outburst floods) with contrasting hydrograph shapes
Authors: Rushmer E. Lucy 
Published: November 2006

AbstractJökulhlaups (glacial outburst floods) are hazards in many glaciated environments. Jökulhlaups generated by different trigger mechanisms have different hydrograph shapes. Field evidence indicates that jökulhlaups with different hydrograph shapes produce different impacts. However, little attention has been paid to understanding the controls on jökulhlaups with differing hydrograph shapes and their subsequent impacts. Historically, flume studies have been used to investigate fluvial processes under controlled laboratory conditions. Nevertheless, few flume studies have replicated scaled hydrographs, and none have attempted to model field jökulhlaups. This study documents the technical procedure by which field prototype jökulhlaups were replicated using physical‐scale modelling techniques: an ‘exponentially rising’ jökulhlaup characterized by a prolonged rising stage and a rapid falling stage, and a ‘linearly rising’ jökulhlaup characterized by a rapid rising stage and a prolonged falling stage. The parameters of water discharge, time, discharge acceleration and deceleration rate, sediment size and sediment discharge were scaled to a 1:20 ratio.Better‐sorted sediment, more uniform downstream sediment thickness and more gradual aggradation and deposition rates resulted from the prolonged rising stage of the exponentially rising hydrograph. More time was available during the prolonged rising stage of the exponentially rising hydrograph for bedload sheets to migrate, and for sand ripples to develop. Rapid rising stage deposition during the linearly rising hydrograph produced thick proximal deposits, limited bedload sheet migration, massive sand sheets and structureless and poorly sorted sediments. During the prolonged falling of the linearly rising hydrograph, sufficient time was available to support sand ripple development.The study highlights that jökulhlaup hydrograph shape is important for controlling rates of sediment acquisition, transport, deposition, erosion and bedform development. The outcomes of these experimental investigations indicate that modelling of high magnitude floods is feasible in a laboratory flume. This technical approach has proved very beneficial for developing a greater understanding of flood impacts and the processes that operate during jökulhlaups. Copyright © 2006 John Wiley & Sons, Ltd.
The (Epi)genetics of human synovial sarcoma
Authors: de Bruijn Diederik R. H. , Nap Jan‐Peter , van Kessel Ad Geurts 
Published: November 2006

AbstractHuman synovial sarcomas are aggressive soft tissue tumors with relatively high rates of recurrences and metastases. They display a variable response to common treatment protocols such as radiation and chemotherapy. For the development of novel diagnostic, prognostic, and therapeutic approaches, detailed information on the molecular mechanisms underlying the development of these tumors is of imperative importance. Fusion of the SS18 and (one of the) SSX genes is a molecular hallmark of human synovial sarcomas. The SS18 and SSX genes encode nuclear proteins that exhibit opposite transcription regulatory activities, likely through epigenetic mechanisms. The SS18 protein functions as a transcriptional coactivator and interacts directly with members of the epigenetic chromatin remodeling and modification machineries. In contrast, the SSX proteins function as transcriptional corepressors and are associated with several Polycomb group proteins. Since the domains involved in these apparently opposite transcription regulatory activities are retained in the SS18–SSX fusion proteins, we hypothesize that these fusion proteins function as “activator–repressors” of transcription. The implications of this model for human synovial sarcoma development and future treatment are discussed. © 2006 Wiley‐Liss, Inc.
Antitumor efficacy and local distribution of doxorubicin via intratumoral delivery from polymer millirods
Authors: Weinberg Brent D. , Ai Hua , Blanco Elvin , Anderson James M. , Gao Jinming 
Published: November 2006

AbstractThe purpose of this study was to evaluate the antitumor efficacy and local drug distribution from doxorubicin‐containing poly(D,L‐lactide‐co‐glycolide) (PLGA) implants for intratumoral treatment of liver cancer in a rabbit model. Cylindrical polymer millirods (length 8 mm, diameter 1.5 mm) were produced using 65% PLGA, 21.5% NaCl, and 13.5% doxorubicin. These implants were placed in the center of VX2 liver tumors (n = 16, ˜8 mm in diameter) in rabbits. Tumors were removed 4 and 8 days after millirod implantation, and antitumor efficacy was assessed using tumor size measurements, tumor histology, and fluorescent measurement of drug distribution. The treated tumors were smaller than the untreated controls on both day 4 (0.17 ± 0.06 vs. 0.31 ± 0.08 cm2, p = 0.048) and day 8 (0.14 ± 0.04 vs. 1.8 ± 0.8 cm2, p = 0.025). Drug distribution profiles demonstrated high doxorubicin concentrations (>1000 μg/g) at the tumor core at both time points and drug penetration distances of 2.8 and 1.3 mm on day 4 and 8, respectively. Histological examination confirmed necrosis throughout the tumor tissue. Biodegradable polymer millirods successfully treated the primary tumor mass by providing high doxorubicin concentrations to the tumor tissue over an eight day period. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Microscopic analysis of subcutaneous reactions to endodontic sealer implants in rats
Authors: Batista Renata F.C. , Hidalgo Miriam M. , Hernandes Luzmarina , Consolaro Alberto , Velloso Tânia R.G. , Cuman Roberto K.N. , Caparroz‐Assef Silvana M. , Bersani‐Amado Ciomar A. 
Published: November 2006

AbstractThe reaction of subcutaneous tissues to Endofill®, Endomethasone®, Sealer 26®, and AH‐Plus® was investigated microscopically after implantation of in rats polyethylene cannulae, obturated with gutta‐percha cones and sealers, in rats. Empty polyethylene cannulae and cannulae filled with gutta‐percha cones alone were used as controls. The inflammatory reactions caused by the sealers were evaluated 7, 14, and 30 days after implantation using a descriptive, histopathological analysis. Inflammatory reactions at each implant site were gauged as either absent, discreet, moderate, or intense, and scores from 0 to 3 were attributed, respectively. Microscopic analysis revealed that Endomethasone showed the best biological behavior for all postimplant periods, followed by Sealer 26 and AH Plus, which produced an irritating effect only during the initial pos‐implant period. Endofill caused the severest irritation, producing an inflammatory reaction that ranged from moderate to intense over the entire experimental period. Reactions were more intense near those parts of the cannulae containing more sealer. These results reveal that the root canal sealers tested cause inflammation in rat, subcutaneous conjunctive tissue, the intensity of which may be related to the type and quantity of sealer used, and to postimplant period. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Synthesis of novel cholic acid functionalized branched oligo/poly(ε‐caprolactone)s for biomedical applications
Authors: Fu Hui‐Li , Yu Lan , Zhang Hua , Zhang Xian‐Zheng , Cheng Si‐Xue , Zhuo Ren‐Xi 
Published: November 2006

AbstractNovel cholic acid functionalized branched oligo/poly(ε‐caprolactone)s were synthesized through the ring‐opening polymerization of ε‐caprolactone initiated by cholic acid with hydroxyl groups. The molecular weight of the branched polymers can be adjusted by controlling the feed ratio of the initiator cholic acid to the monomer ε‐caprolactone. Comparing with linear homopolymer poly(ϵ‐caprolactone) (PCL), these branched oligo/poly(ε‐caprolactone)s show much faster hydrolytic degradation rates, implies that our approach provides a convenient and effective strategy to accelerate degradation of the biodegradable polymers with slow degradation rates such as PCL. The cell culture experiment indicates the incorporation of cholic acid moiety to the polymer chain can improve both cell adherence and proliferation obviously. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Effects of coumestrol on neonatal and adult mice osteoblasts activities
Authors: Sun Jui‐Sheng , Li Ya‐Ying , Liu Man‐Hai , Sheu Shiow‐Yunn 
Published: November 2006

AbstractEstrogen replacement therapy has been shown to reduce postmenopausal osteoporosis. In the present study, we examined the effects of the phytoestrogen coumestrol on neonatal and adult osteoblasts metabolism. Two different sources of osteoblast cells (neonatal mice calvaria and adult mice long bone) cultures were used in this study. The effects of coumestrol on the cellular activities were analyzed by the mitochondrial tetrazolium (MTT) assay, secretion of alkaline phosphatase (ALP), intracellular calcium content (Ca), and the gene expression of bone matrix protein, estrogen receptors (ER‐α, ER‐β), and osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL). The results showed that the proliferation of neonatal mice osteoblast cells was enhanced by treatment of coumestrol. In the presence of 10−9M coumestrol, the osteoblast proliferation attained 139.5% of the control and that the coumestrol can increase the intracellular calcium contents. Type I collagen gene expression was upregulated 167% at the 1st day's culture; ALP gene expression was upregulated 360% at the 7th day's culture; while the osteocalcin gene expression was upregulated 222% at the 14th day's culture. When adult mice osteoblasts were cultured in the presence of 10−9M coumestrol, the osteoblasts population increased significantly earlier and attained its maximal effect at the 21st day's culture with 207.4% of control group. The content of ER‐β and osteoprotegerin secretion by neonatal mice control cells gradually increased during osteoblasts differentiation, whereas the ER‐α and OPGL content were decreased in this study. The cellular responses to the estradiol and counmestrol were quite different in the osteoblasts derived from different age. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Bioactive glass as precursor of designed‐architecture scaffolds for tissue engineering
Authors: Padilla S. , Sánchez‐Salcedo S. , Vallet‐Regí M. 
Published: November 2006

AbstractIn this work, the conditions to obtain concentrated and fluid suspensions from a bioactive glass (55‐SiO2; 41‐CaO; 4‐P2O5; mol %) were investigated. The influence of the heat treatment of the glass on the specific surface area, solubility, bioactivity, and finally on their dispersion characteristics was studied. Zeta potential and viscosity measurements were carried out, and based on the obtained results, the best dispersant was selected. The optimum concentration of dispersant, maximum content of solid and time of mixing were also investigated. Slurries containing 50 vol % could be obtained calcining the glass at 1100°C and using Darvan 811 (sodium polyacrylate) as dispersant. Scaffolds with designed architecture were prepared from these suspensions combining the gelcasting method and the stereolithography technique. A polymeric negative (replica of the desired structure) was previously obtained by stereolithography. The slurry was cast into the molds and then polymerized (gelcasting method). The negative was eliminated by heat treatment. After sintering at 1300°C, scaffolds with interconnected porosity and three‐dimensional channels of 400–470 μm and macropores of 1.4 μm were obtained. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Novel transparent nano‐ to micro‐heterogeneous substrates for in‐situ cell migration study
Authors: Tsai Irene Y. , Green J. Angelo , Kimura Masahiro , Jacobson Bruce , Russell Thomas P. 
Published: November 2006

AbstractTransparent substrates having heterogeneities ranging from nanometer to micrometer lateral length scale were fabricated to study cell migration. The surfaces were generated using thin films of block copolymers and homopolymer blends on ultra smooth transparent polyethylene terephthalate films. Results show that the lateral size scale of the surface heterogeneities affects fibroblast (NIH‐3T3) adhesion, spreading and motility. More specifically, fibroblasts migrate faster on micron‐sized than on nanometer‐sized heterogeneities. Cell movements and morphology on the micron patterned surfaces resemble cells cultured in a 3D environment. These surfaces, therefore, can potentially be utilized as models to study cell behavior in physiologically relevant conditions which can add to our fundamental understanding of cell‐substrate interactions and facilitate development of surfaces for medical devices. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Contrasting effects of collagen and bFGF‐2 on neural cell function in degradable synthetic PEG hydrogels
Authors: Mahoney Melissa J. , Anseth Kristi S. 
Published: November 2006

AbstractInjectable biodegradable cell carriers provide a potential means to improve transplanted cell viability in the nervous system by providing physical protection from compaction, shear forces, and the acute inflammatory response that occurs following transplantation into the host brain environment. Synthetic polyethylene glycol (PEG) hydrogels are ideal candidates for this purpose, as the degradation profile and mechanical properties of the gel can be controlled. Here we introduce biological components into the synthetic gel with the goal of improving neural cell function in the inert PEG environment. In this study, it was found that (1) bFGF‐2 is a survival/mitogenic factor for neural precursor cells in degradable hydrogel cultures, (2) collagen has no measurable effect on cell survival, metabolic activity, or proliferation, and (3) co‐application of collagen and bFGF‐2 to hydrogel cultures targets cell survival and metabolic activity, an effect that is different than either applied individually. Because collagen and bFGF‐2 support the survival and growth of neural cells and other cell types, the co‐encapsulation approach and functional characterization described in this study can be extended to the development of an array of tissue engineering applications. These findings suggest the importance of understanding and developing strategies to control the chemical microenvironment surrounding cells in three‐dimensional biomaterials. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Chemical profile of adhesive/caries‐affected dentin interfaces using Raman microspectroscopy
Authors: Wang Yong , Spencer Paulette , Walker Mary P. 
Published: November 2006

AbstractIn clinical practice, dentists must frequently bond adhesives to caries‐affected dentin substrates, but the bond that characteristically forms with these substrates does not provide the durability necessary for long‐term clinical function. The purpose of this study was to characterize and compare the interfacial chemistry of adhesive with caries‐affected and noncarious dentin using micro‐Raman spectroscopy. The results indicated that the differences in the Raman spectra between noncarious and caries‐affected dentin could not be accounted for by simple decreased mineralization. Both the structure of collagen and mineral in the caries‐affected dentin has been altered by the caries process. The differences in structure and composition not only interfered with acid‐etching process but also subsequent resin monomer penetration. It was shown that the interface between the adhesive and caries‐affected dentin was wider and more complicated than that of the adhesive and noncarious dentin. As a result of adhesive phase separation, a structurally integrated hybrid layer did not form at the interface with either caries‐affected or noncarious dentin. Using chemical imaging techniques, this study provides the direct evidence of adhesive phase separation at the interface with caries‐affected dentin. Although our group previously reported adhesive phase separation at the interface with noncarious dentin, the chemistry of caries‐affected dentin leads to greater variability and a more highly irregular composition along the length and breadth of the interface. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Distinctin improves the efficacies of glycopeptides and betalactams against staphylococcal biofilm in an experimental model of central venous catheter infection
Authors: Giacometti Andrea , Cirioni Oscar , Ghiselli Roberto , Orlando Fiorenza , Silvestri Carmela , Renzone Giovanni , Testa Irma , Mocchegiani Federico , Vittoria Agnese Della , Saba Vittorio , Scaloni Andrea , Scalise Giorgio 
Published: November 2006

AbstractThe ability of microorganisms to adhere to medical implants is a problem of high visibility and has been focused in numerous investigations. To assess the efficacy of distinctin and conventional antibiotics in the treatment of central venous catheter in vitro and in vivo studies were performed. The in vitro susceptibility assay was performed against S. aureus biofilms developed on 96‐well polystyrene tissue culture plates. Efficacy studies were performed in a rat model of CVC infection. Twenty‐four hours after implantation, the catheters were filled with distinctin. Thirty minutes later, rats were challenged via the CVC with S. aureus. Administration of antibiotics into the CVC at a concentration equal to the MBC for adherent cells, or at 1024 μg/mL began 24 h later. The killing activities of all antibiotics against adherent bacteria were at least four‐ to eightfold lower than against freely growing cells. When antibiotics were used in distinctin pretreated wells, they showed a significant increase of activity. The in vivo studies showed that when CVCs were pretreated with distinctin biofilm bacterial load was further decreased to 101 CFU/mL and bacteremia was not detected. Distinctin displays potential as an adjunctive agent to antibiotics in the treatment of CVC‐related infections. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2007