bluuebunny/crossref_metadata_2025_split huggingface dataset:
Facile way to disperse single‐walled carbon nanotubes using a noncovalent method and their reinforcing effect in poly(methyl methacrylate) composites
Authors: Liu Xiaoqing , Chan‐Park Mary B. 
Published: August 2009

AbstractIn this work, a noncovalent method was used to functionalize and thereby disperse single‐walled carbon nanotubes (SWCNTs) in dimethylformamide with poly[methyl methacrylate‐co‐(fluorescein O‐acrylate)] as a surfactant, and then the resultant poly(methyl methacrylate) (PMMA)‐based nanocomposites were fabricated via solution casting. The dispersion level of carbon nanotubes in the solvent was investigated by means of scanning electron microscopy and atomic force microscopy. The results showed that carbon nanotubes were well wrapped by the surfactant, and small carbon nanotube bundles several nanometers or less in diameter and several micrometers in length were obtained. Both scanning electron microscopy and transmission electron microscopy confirmed the uniform dispersion of SWCNTs in the PMMA matrix. The mechanical properties of the composites were determined with a universal tension tester. The PMMA composite containing 2 wt % SWCNTs showed improved tensile properties versus neat PMMA, showing 56 and 30% enhancements of the tensile modulus and tensile stress, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effects of superfine silk protein powders on mechanical properties of wet‐spun polyurethane fibers
Authors: Liu Hongtao , Xu Weilin , Liu Xiuying , Xu Jie , Li Wenbin , Liu Xin 
Published: August 2009

AbstractMechanical measurements were employed to investigate the effects of three types of superfine silk protein powder on tensile strength, elongation, and elasticity of wet‐spun Pellethane® 2363‐80AE polyurethane (PU) fiber. These superfine silk protein powders included undegummed silk (with both native silk fibroin and sericin, water insoluble), native silk fibroin (with native silk fibroin only, water insoluble), and regenerated silk fibroin (with regenerated silk fibroin only, water soluble) in powder form. Experimental data derived from the mechanical measurements illustrated that the miscibility between the PU and regenerated silk fibroin were superior to that between PU and the other two silk proteins. This may be attributed to the similar chemical structure and microphase separation of PU and regenerated silk fibroin with lower molecular weight than native silk fibroin. This preliminary work may provide some information for biomimetic processing of silk‐inspired PU biofibers, which combine elasticity of synthetic PU with biofunction of natural silk fibroin for special biomedical applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Electromagnetic properties and mechanical properties of Ni0.8Zn0.2Fe2O4/polyolefin elastomer composites for high‐frequency applications
Authors: Yang Haibo , Lin Ying , Zhu Jianfeng , Wang Fen 
Published: August 2009

AbstractA low‐loss flexible magnetic composite with Ni0.8Zn0.2Fe2O4 (NZO) ultrafine particles embedded in a thermoplastic polyolefin elastomer matrix was fabricated with extrusion technology. The electromagnetic and mechanical properties of the as‐prepared composites were investigated in detail. The results indicate that as the volume of the ceramic fillers increased, the permittivity, permeability, and dielectric and magnetic loss of the composite all increased. The cutoff frequencies of the composites were all above 1 GHz. Because of the low resistivity of NZO, the dielectric losses of the composites were big and decreased with frequency below 100 MHz. Good frequency stability of the permittivities and permeabilities and low dielectric and magnetic losses within the measurement range were observed. All of the composites showed very good flexibility. With increasing volume of the ceramic filler, the tensile strength and elongation decreased. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Cardanol‐based novolac resins as curing agents of epoxy resins
Authors: Campaner Pietro , D'Amico Daniele , Longo Luigia , Stifani Cristina , Tarzia Antonella 
Published: August 2009

AbstractTwo different novolac resins, named Nov‐I and Nov‐II, containing an amount of unreacted cardanol of 35 wt % and 20 wt %, respectively, were synthesized by the condensation reaction of cardanol and paraformaldehyde using oxalic acid as catalyst. Cardanol is the main constituent of cashew nut shell liquid, a renewable natural resource. The cardanol‐based novolacs were tested as curing agents of the diglycidyl ether of bisphenol A epoxy resin employing 2‐ethyl‐4‐methyl‐imidazole as catalyst and differential scanning calorimeter and thermogravimetric studies were performed to identify the final thermal properties of the cured resins. In addition, tensile tests were carried out to evaluate the mechanical properties of the epoxy resin cured with the novolacs, which showed to deserve consideration as effective epoxy curing agents. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Towards a model of implicit feedback for Web search
Authors: Fu Xin 
Published: August 2009

AbstractThis research investigated several important issues in using implicit feedback techniques to assist searchers with difficulties in formulating effective search strategies. It focused on examining the relationship between types of behavioral evidence that can be captured from Web searches and searchers' interests. A carefully crafted observation study was conducted to capture, examine, and elucidate the analytical processes and work practices of human analysts when they simulated the role of an implicit feedback system by trying to infer searchers' interests from behavioral traces. Findings provided rare insight into the complexities and nuances in using behavioral evidence for implicit feedback and led to the proposal of an implicit feedback model for Web search that bridged previous studies on behavioral evidence and implicit feedback measures. A new level of analysis termed an analytical lens emerged from the data and provides a road map for future research on this topic.
MYST family histone acetyltransferases take center stage in stem cells and development
Authors: Voss Anne K. , Thomas Tim 
Published: August 2009

AbstractAcetylation of histones is an essential element regulating chromatin structure and transcription. MYST (Moz, Ybf2/Sas3, Sas2, Tip60) proteins form the largest family of histone acetyltransferases and are present in all eukaryotes. Surprisingly, until recently this protein family was poorly studied. However, in the last few years there has been a substantial increase in interest in the MYST proteins and a number of key studies have shown that these chromatin modifiers are required for a diverse range of cellular processes, both in health and disease. Translocations affecting MYST histone acetyltransferases can lead to leukemia and solid tumors. Some members of the MYST family are required for the development and self‐renewal of stem cell populations; other members are essential for the prevention of inappropriate heterochromatin spreading and for the maintenance of adequate levels of gene expression. In this review we discuss the function of MYST proteins in vivo.
Assessing the limitations to terpenoid indole alkaloid biosynthesis in Catharanthus roseus hairy root cultures through gene expression profiling and precursor feeding
Authors: Goklany Sheba , Loring Ralph H. , Glick James , Lee‐Parsons Carolyn W. T. 
Published: August 2009

AbstractThe production of pharmaceutically important terpenoid indole alkaloids (TIAs) from Catharanthus roseus is partly regulated at the transcriptional level. In this study, limitations in TIA biosynthesis from C. roseus hairy root cultures were assessed through gene expression profiling and precursor feeding. The transcript levels of key TIA pathway genes (G10h, Tdc, Str, and Sgd) and metabolite levels associated with the TIA pathway (tryptamine, loganin, secologanin, strictosidine, ajmalicine, serpentine, and tabersonine) were monitored using quantitative RT‐PCR and HPLC, respectively. In cultures elicited with methyl jasmonate (250 μM MeJA on day 21), G10h, Tdc, Str, and Sgd expression increased by 9.1, 3.1, 6.7, and 8.3‐fold, respectively, after 24 h. Up‐regulation of gene expression was followed by a 160, 440, and 420% increase in strictosidine, ajmalicine, and tabersonine levels, respectively, after 5 days. Precursors loganin, tryptamine, or their combination were fed to noninduced and MeJA‐induced cultures to complement the above studies. TIA production was not significantly enhanced in either noninduced or MeJA‐induced cultures with precursor feeding. In noninduced cells, steps downstream of loganin and tryptamine were limiting (SLS, STR, or SGD) because either loganin or tryptamine accumulated in the cells with precursor feeding. These bottlenecks were partly overcome in MeJA‐induced cultures as the expression of Str and Sgd genes and TIA production increased. However, secologanin accumulated in MeJA‐induced cultures with precursor feeding, suggesting that STR was likely limiting under MeJA‐induced conditions. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Major Groove Derivatization of an Unnatural Base Pair
Authors: Seo Young Jun , Romesberg Floyd E. 
Published: August 2009

AbstractAn unnatural base pair that is replicated and transcribed with good efficiency would lay the foundation for the long term goal of creating a semisynthetic organism, but also would have immediate in vitro applications, such as the enzymatic synthesis of site‐specifically modified DNA and/or RNA. One of the most promising of the unnatural base pairs that we have identified is formed between d5SICS and dMMO2. The ortho substituents of these nucleotides are included to facilitate unnatural base pair extension, presumably by forming a hydrogen‐bond with the polymerase, but the synthesis of the unnatural base pair still requires optimization. Recently, we have shown that meta and/or para substituents within the dMMO2 scaffold can facilitate unnatural base pair synthesis, although the mechanism remains unclear. To explore this issue, we synthesized and evaluated several dMMO2 derivatives with meta‐chlorine, ‐bromine, ‐iodine, ‐methyl, or ‐propinyl substituents. Complete characterization of unnatural base pair and mispair synthesis and extension reveal that the modifications have large effects only on the efficiency of unnatural base pair synthesis and that the effects likely result from a combination of changes in steric interactions, polarity, and polarizability. The results also suggest that functionalized versions of the propinyl moiety of d5PrM should serve as suitable linkers to site‐specifically incorporate other chemical functionalities into DNA. Similar modifications of d5SICS should allow labeling of DNA with two different functionalities, and the previously demonstrated efficient transcription of the unnatural base pair suggests that derivatives might similarly enable site‐specific labeling of RNA.
A new angiographic method to assess coronary flow reserve—Validation in humans
Authors: Rittger Harald , Kuper Asher , Breithardt Ole‐Alexander , Kuon Eberhardt , Schmidt Martin , Sinha Anil‐Martin , Blüm Barbara , Jakob Axel , Brachmann Johannes 
Published: August 2009

AbstractBackground: Coronary flow reserve (CFR) is defined as the ratio between coronary artery flow during maximal hyperemia and rest. It is considered as a marker for the integrity of the epicardial coronary circulation and the microcirculation. CFR measurement typically requires the introduction of a guide wire into a diseased coronary artery. We tested a new algorithm, which allows to estimate CFR by analysis of coronary angiograms without the need for direct intracoronary measurements. Methods: Twenty seven patients (10 female, mean age 64 ± 11 years) underwent diagnostic cardiac catheterization for the evaluation of chest pain. A Doppler wire was introduced into the diseased coronary artery and CFRdoppler was calculated by the flow velocity ratio between rest and maximal hyperemia, induced by intravenous administration of 140 μg of adenosine per kg bodyweight. This was compared to the angiographically determined CFR (CFRangio) under the same conditions (rest and induced maximal hyperemia) by densitometry. CFRangio was based on the creation of two time density curves representing the disappearance of contrast over time. CFRangio was the resulting ratio between the density values during hyperemia and rest. Results: An excellent correlation was found between CFRdoppler and CFRangio: CFRangio = 1 × CFRdoppler (r = 0.87; P < 0.0001). The average absolute difference between both indeces was 0.36 ± 0.31. Conclusion: Measurement of CFRangio by densitometry is feasible and provides results, which are comparable to Doppler‐derived intracoronary flow velocity measurements. © 2009 Wiley‐Liss, Inc.
First trans‐axillary implantation of Edwards Sapien valve to treat an incompetent aortic bioprosthesis
Authors: Sharp Andrew S.P. , Michev Iassen , Colombo Antonio 
Published: August 2009

AbstractThere exist case reports of using transcatheter aortic valves to treat dysfunctional surgically implanted aortic bioprosthesis. There are also case series reported of transaxillary implantation of the CoreValve device to treat Aortic Stenosis. In this article, we report the successful implantation an Edwards Sapien 23mm transcatheter aortic valve through the left axillary artery, in a patient with a functioning LIMA graft in order to treat a severely regurgitant Freestyle 23mm aortic bioprosthesis. © 2009 Wiley‐Liss, Inc.
Clinical and angiographic outcomes with an everolimus‐eluting stent in large coronary arteries: The SPIRIT III 4.0 mm registry
Authors: Gordon Paul C. , Applegate Robert J. , Hermiller James B. , Weinsier Steven B. , Doostzadeh Julie , Cao Sherry , Sudhir Krishnankutty , Lansky Alexandra J. , Stone Gregg W. 
Published: August 2009

AbstractObjective: This study evaluates the safety and efficacy of the XIENCE V® 4.0 mm stent for the treatment of de novo native coronary artery lesions. Background: In the SPIRIT III trial, the XIENCE V® everolimus‐eluting stent (EES), compared with the TAXUS EXPRESS2 paclitaxel‐eluting stent (PES) in 2.5–3.75 mm diameter coronary arteries, resulted in reduced angiographic late loss (LL), noninferior rates of target vessel failure (TVF), and fewer major adverse cardiac events (MACE). Methods: The SPIRIT III 4.0 mm registry was a concurrent arm of the SPIRIT III trial consisting of 69 nonrandomized patients with lesions ≤28 mm in length and reference vessel diameter 3.75–4.25 mm treated with a 4.0 mm EES. The primary endpoint was 8‐month in‐segment LL compared with the randomized PES arm. Results: In‐segment LL was 0.17 ± 0.38 mm in the 4.0 mm EES registry compared with 0.28 ± 0.48 mm in the PES arm (P < 0.0001 for noninferiority). The 1‐year rates of ischemia‐driven TVF (cardiac death, myocardial infarction [MI], or target vessel revascularization) and MACE (cardiac death, MI, or target lesion revascularization [TLR]) were numerically, but not statistically, lower in the 4.0 mm EES patients compared with the randomized PES patients (5.9 vs. 11.3%, P = 0.27 and 5.9 vs. 10.3%, P = 0.36, respectively). There was no difference in 8‐month LL or 1‐year TVF or MACE between the 4.0 mm EES and randomized EES patients. Conclusions: In large coronary arteries, the 4.0 mm EES results in low rates of LL at 8 months and adverse clinical events at 1 year. © 2009 Wiley‐Liss, Inc.
Diagnosis and therapy for pulmonary arteriovenous fistula in patients with presumed patent foramen ovale
Authors: Alqoofi Faisal , Tyrrell Benjamin , Feldman Ted 
Published: August 2009

AbstractAn increasing number of patients are being referred for PFO closure for prevention of recurrent paradoxical embolism. Diagnosis is usually made using hand agitated echo bubble contrast with transthoracic or transesophageal echo. It is inevitable that some of these patients will have pulmonary arteriovenous fistulae (PAVF), either with or without associated PFO, which may be the sole cause of paradoxical embolism, or remain after PFO closure as a source of continued embolization. Intravenous contrast echo for the diagnosis of PFO is both insensitive and nonspecific. We describe a method to diagnose and localize PAVF during a catheterization procedure using intracardiac echo in conjunction with selective injection of bubble contrast into the pulmonary arteries. This allows for the rapid and accurate diagnosis of PAVF when a PFO is not found and for the exclusion of associated PAVF when PFO exists. © 2009 Wiley‐Liss, Inc.
Acute mesenteric ischemia
Authors: Cortese Bernardo , Limbruno Ugo 
Published: August 2009

AbstractIntroduction: Management of acute mesenteric ischemia is still a matter of concern for physicians. This disorder has been associated to an increased mortality mainly because of a late diagnosis and controversial treatment options. Methods and Results: we describe the case of a multidisciplinary approach to a cardiogenic thrombotic occlusion of superior mesenteric artery resulting in acute mesenteric ischemia. After rapid diagnosis with Duplex scan, we brought the patient to our catheterization laboratory and managed it with the common tools used for primary percutaneous coronary intervention. Among the specific issues of this case report, we observed some of the common complications of the acute myocardial infarction managed in the catheterization laboratory and treated them with the same tools used in the “myocardial area.” Conclusions: we showed how an “interventional cardiologist's” approach to acute mesenteric ischemia was effective in restoring superior mesenteric artery patency and in aborting a mesenteric infarction.© 2009 Wiley‐Liss, Inc.
X‐ray Absorption Spectroscopy of an Fe‐Promoted Rh/TiO2 Catalyst for Synthesis of Ethanol from Synthesis Gas
Authors: Gogate Makarand R. , Davis Robert J. 
Published: August 2009

AbstractX‐ray absorption near‐edge structure (XANES) and extended X‐ray absorption fine structure (EXAFS) have been used to elucidate the structural features of a 2 % Rh–2.5 % Fe/TiO2 catalyst for syngas conversion to ethanol. The results from Rh K‐edge and Fe K‐edge spectroscopy on a fresh catalyst exposed to air indicated that both Rh and Fe were present as highly dispersed oxides on the titania, and that both adopted a +3 formal oxidation state. For the catalyst reduced in H2 at 573 K, the Rh K‐edge EXAFS revealed RhRh interactions (coordination number N=6.1, RhRh distance rRhRh=2.67 Å) and a second feature arising from either RhTi or RhO coordination. The metal particles contained on an average about 20 atoms, which is consistent with a particle size of 1 nm. A shift in the Rh K‐edge XANES by −2 eV indicated that the reduced Rh particles were electron rich compared to bulk Rh metal. Although Rh was reduced completely to the metal by H2, the iron oxide promoter was reduced primarily from FeIII to FeII oxide. The results from X‐ray absorption spectroscopy at both the Fe and Rh K‐edges were unchanged by exposure of the reduced catalyst to syngas (H2+CO) at 543 K. A structural model for this ethanol synthesis catalyst is proposed.
Chemistry of Ethylene Glycol on a Rh(100) Single‐Crystal Surface
Authors: Jansen Maarten M. M. , Nieuwenhuys Ben E. , Niemantsverdriet Hans 
Published: August 2009

AbstractThe adsorption and decomposition of ethylene glycol on Rh(100) have been studied with temperature‐programmed reaction spectroscopy and reflection absorption infrared spectroscopy. Ethylene glycol adsorbs onto the surface via the hydroxyl groups. At 150 K, both hydroxyl bonds are broken, forming an ethylenedioxy intermediate. At high coverage, a portion of the ethylene glycol molecules dehydrogenate only one hydroxyl bond, forming a monodentate species. These intermediates decompose further, with complete dehydrogenation and simultaneous CC bond breaking occurring at around 290 K. Hydrogen and carbon monoxide are formed, which desorb at 290 and 500 K, respectively.
Measurement of wheat germ agglutinin binding with a fluorescence microscope
Authors: Model Michael A. , Reese Jennifer L. , Fraizer Gail C. 
Published: August 2009

AbstractSignal intensity in fluorescence microscopy is often measured relative to arbitrary standards. We propose a calibration method based on a solution of the same fluorophore, whose binding to cells needs to be quantified. The method utilizes the low sensitivity of intensity to the object distance in wide‐field imaging of uniform materials. Liquid layers of slowly varying depth were prepared by immersing a spherical lens into a drop of a fluorophore placed on a slide. Flatfield‐corrected images of the contact and surrounding areas showed linear dependence of the gray level on the depth of fluorescent liquid. This allowed conversion of the measured intensity into the number of molecules per unit area. The method was applied to different cell types stained by WGA‐Alexa 488 and WGA‐TRITC. Consistent results were obtained by comparing microscopy with flow cytometry, comparing imaging through different objectives and comparing different WGA conjugates. Reproducibility of calibration was within 97% when low magnification was used. Fluorescence of free and bound WGA was found to be different, however, and therefore precise measurement of the number of cell‐bound molecules was problematic in this particular system. We conclude that the method achieves reliable measurement of cellular staining in the units of soluble fluorophore. For probes whose fluorescent properties are unaffected by binding, quantification of staining in true molecular units should be possible. © 2009 International Society for Advancement of Cytometry
Psychobiology of purging disorder: Reduction in circulating leptin levels in purging disorder in comparison with controls
Authors: Jimerson David C. , Wolfe Barbara E. , Carroll Devon P. , Keel Pamela K. 
Published: August 2009

AbstractObjective:Purging disorder (PD), a recently recognized eating disorder syndrome, is differentiated from bulimia nervosa (BN) based on the absence of objectively large binge episodes. BN has been associated with low serum leptin levels. This study examined whether PD is also characterized by low serum leptin.Method:Participants included women with PD (n = 20) or BN (n = 37), and non‐eating disorder controls (n = 33). Blood samples for measurement of leptin and total ghrelin were obtained after overnight fast.Results:In comparison with control values, leptin levels were significantly decreased in PD (p < .01), as well as in BN (p < .02). Plasma ghrelin levels did not differ significantly across groups.Discussion:These results provide the first evidence that PD is associated with alteration in a neurobiological pathway influencing eating patterns and body weight. Further research is needed to assess whether low leptin levels in PD and BN are associated with restrained eating and weight suppression. © 2009 by Wiley Periodicals, Inc. (Int J Eat Disord 2010;)
Lanthanum Phosphite Microspheres: Hydrothermal Synthesis, Ab Initio Structure Determination, Morphology and Photoluminescence of La(HO)(HPO3)
Authors: Xiong Ding‐Bang , Zhao Yu‐Feng , Gulay Lubomir D. , Zhao Jing‐Tai 
Published: September 2009

AbstractLanthanum phosphite microspheres with diameters of 80–100 μm were obtained under hydrothermal conditions by using lanthanum oxalate as precursor. The surfaces of these spherules consist of well‐orientated submicron‐sized rods with typical diameters of 300 nm and lengths of 6 μm. The possible mechanism of formation of this morphology was suggested. The product is a new phase, and its crystal structure was determined by ab initio methods from high‐resolution conventional X‐ray powder diffraction analysis. Chains consisting of face‐sharing LaO9 polyhedra were observed; these chains form three‐dimensional compact frameworks by sharing vertexes in the ab plane and edges along the c axis. The sample doped with Ce3+ showed an intensive broad emission band with a maximum around 364 nm under UV excitation.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)