bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface Physiochemistry Affects Protein Adsorption to Stoichiometric and Silicate‐Substituted Microporous Hydroxyapatites
Authors: Guth Katharina , Campion Charlie , Buckland Tom , Hing Karin A. 
Published: April 2010

AbstractAn important factor in the bioactivity and success of a bone‐graft substitute is the nature of the adsorbed protein layer, which plays a vital role in orchestrating cell attachment and development through the presence of adhesion proteins such as fibronectin (Fn) and vitronectin (Vn). In this study, microporous hydroxyapatite (HA) and silicate‐substituted hydroxyapatite (SA) discs with matched porosity and surface morphology are developed to mimic the topography found in commercial bone‐graft substitutes in order to identify whether the introduction of microporosity and associated surface roughness eliminates the beneficial effect that silicate substitution has on protein adsorption. The introduction of microporosity does not abolish the relative enrichment of the protein layer that is adsorbed to the microporous SA discs, as opposed to HA, but appears to accelerate it. Fibronectin and Vn adsorption in a range of competitive environments at physiological temperatures confirm that the microporous SA discs have a greater affinity for Fn and Vn compared with HA, suggesting differences in the mechanisms behind the surface affinity to SA. Thus, development of a surface protein layer on SA and HA is likely to be dependent on the nature of the local protein environment and a combination of factors that are associated with the addition of silicate: the surface charge, the nature of the ionic species at the interface and the resultant hydrophilicity of the surface. Total protein adsorption is not found to be a good indicator of potential implant performance, particularly at early time points.
Field‐Structured Chemiresistors
Authors: Read Douglas H. , Martin James E. 
Published: April 2010

AbstractA significantly improved material is developed for application to chemiresistors, which are resistance‐based sensors for volatile organic compounds. This material is a polymer composite containing Au‐coated magnetic particles organized into electrically conducting pathways by magnetic fields. This improved material overcomes the various problems inherent to conventional carbon‐black chemiresistors, while achieving an unprecedented response magnitude. When exposed to chemical vapors, the polymer swells only slightly, yet this is amplified into large, reversible resistance changes, as much as (1 × 1011)% at a swelling of only 1.5%. These conductor–insulator transitions occur over such a narrow range of analyte vapor concentration that these devices can be described as chemical switches. The sensitivity and response range of these sensors can be tailored over a wide range by controlling the stress within the composite, including through the application of a magnetic field. Such tailorable sensors can be used to create sensor arrays that can accurately determine analyte concentration over a broad concentration range, or can be used to create logic circuits that signal a particular chemical environment.
Properties and Catalytic Activities of New Easily‐Made Amphiphilic Phosphanes for Aqueous Organometallic Catalysis
Authors: Ferreira Michel , Bricout Hervé , Azaroual Nathalie , Gaillard Cédric , Landy David , Tilloy Sébastien , Monflier Eric 
Published: April 2010

AbstractMono‐ and disulfonated amphiphilic versions of triphenylphosphane (PPh3) and cyclohexyl(phenyl)phosphane were easily synthesized from commercial reagents and sulfuric acid. The behaviour of these phosphanes in solution was investigated by surface tension, isothermal titration calorimetry, nuclear magnetic resonance and cryo‐transmission electron microscopy. Two different supramolecular assemblies were evidenced according to the degree of sulfonation. The monosulfonated phosphanes formed well organized micelle‐like aggregates while the disulfonated phosphanes formed heterogeneous and disorganized vesicle‐like assemblies. The efficiency of these amphiphilic phosphanes was evaluated in the aqueous biphasic, palladium‐catalyzed cleavage of allyl alkyl carbonates.
Longitudinal course of anxiety in children and adolescents with Williams syndrome
Authors: Woodruff‐Borden Janet , Kistler Doris J. , Henderson Danielle R. , Crawford Nicole A. , Mervis Carolyn B. 
Published: April 2010

AbstractThe longitudinal course of anxiety disorders in 45 children and adolescents with Williams syndrome (WS) was examined. Children were ages 4–13 years at the initial assessment. To assess their child's DSM‐IV diagnoses, parents completed a structured diagnostic interview 3–9 times at intervals of at least 1 year. At the first assessment, 60% of the sample presented with at least one anxiety diagnosis; 82.2% received an anxiety diagnosis at some time during the study. Chronic, persistent anxiety within the period 5 years after their initial diagnosis was shown by 62.2% of those with an anxiety diagnosis (51.1% of the entire sample). The most common diagnoses were specific phobias and generalized anxiety disorder. Multilevel logistic regression models were estimated for the presence of any anxiety disorder, specific phobia, and specific phobia of loud noises. Developmental trajectories, expressed as the probability of a positive diagnosis, suggested that the odds of a positive diagnosis did not change with age. IQ was not significantly related to the presence of an anxiety disorder. However, there was a significant relation between executive functioning and anxiety such that the presence of an anxiety diagnosis was associated with increased scores on behavioral regulation, indicative of increased difficulty with inhibitory control of affect and behavior. These findings are discussed in terms of persistence of anxiety over time and the need to develop and test interventions to address the high levels of anxiety experienced by children and adolescents with WS. © 2010 Wiley‐Liss, Inc.
High prevalence of diabetes and pre‐diabetes in adults with Williams syndrome
Authors: Pober B.R. , Wang E. , Caprio S. , Petersen K.F. , Brandt C. , Stanley T. , Osborne L.R. , Dzuria J. , Gulanski B. 
Published: April 2010

AbstractA standard oral glucose tolerance test (OGTT) was administered to 28 adults with Williams syndrome (WS). Three quarters of the WS subjects showed abnormal glucose curves, meeting diagnostic criteria for either diabetes or the pre‐diabetic state of impaired glucose tolerance. Fasting mean glucose and median insulin levels did not differ significantly in the total WS cohort versus age–gender–BMI matched controls, though the glucose area under the curve was greater in the WS subjects. HbA1c levels were not as reliable as the OGTT in diagnosing the presence of diabetes. Given the high prevalence of impaired glucose regulation, adults with WS should be screened for diabetes, and when present should be treated in accordance with standard medical practice. Hemizygosity for a gene mapping to the Williams syndrome chromosome region (WSCR) is likely the major factor responsible for the high frequency of diabetes in WS. Syntaxin‐1A is a prime candidate gene based on its location in the WSCR, its role in insulin release, and the presence of abnormal glucose metabolism in mouse models with aberrantly expressed Stx‐1a. © 2010 Wiley‐Liss, Inc.
Introduction: Williams syndrome
Authors: Morris Colleen A. 
Published: April 2010

AbstractIn the nearly 50 years since the description of Williams syndrome by [Williams et al. (1961); Circulation 24:1311–1318], the focus of scientific inquiry has shifted from identification, definition, and description of the syndrome in small series to genotype–phenotype correlation, pathophysiologic investigation in both humans and in animal models, and therapeutic outcomes in large cohorts. Study of this rare syndrome has provided insight into the structure and function of the extracellular matrix, has contributed to understanding of genomic structure and rearrangement, and is beginning to elucidate genetic underpinnings of learning, language, and behavior. The results of current research not only recommend interventions that can be implemented now, but also identify areas requiring additional investigation, and suggest future therapeutic approaches. © 2010 Wiley‐Liss, Inc.
Initiating levodopa/carbidopa therapy with and without entacapone in early Parkinson disease: The STRIDE‐PD study
Authors: Stocchi Fabrizio , Rascol Olivier , Kieburtz Karl , Poewe Werner , Jankovic Joseph , Tolosa Eduardo , Barone Paulo , Lang Anthony E. , Olanow C. Warren 
Published: April 2010

AbstractObjectiveL‐dopa is the most widely used and most effective therapy for Parkinson disease (PD), but chronic treatment is associated with motor complications in the majority of patients. It has been hypothesized that providing more continuous delivery of L‐dopa to the brain would reduce the risk of motor complications, and that this might be accomplished by combining L‐dopa with entacapone, an inhibitor of catechol‐O‐methyltransferase, to extend its elimination half‐life.MethodsWe performed a prospective 134‐week double‐blind trial comparing the risk of developing dyskinesia in 747 PD patients randomized to initiate L‐dopa therapy with L‐dopa/carbidopa (LC) or L‐dopa/carbidopa/entacapone (LCE), administered 4× daily at 3.5‐hour intervals. The primary endpoint was time to onset of dyskinesia.ResultsIn comparison to LC, patients receiving LCE had a shorter time to onset of dyskinesia (hazard ratio, 1.29; p = 0.04) and increased frequency at week 134 (42% vs 32%; p = 0.02). These effects were more pronounced in patients receiving dopamine agonists at baseline. Time to wearing off and motor scores were not significantly different, but trended in favor of LCE treatment. Patients in the LCE group received greater L‐dopa dose equivalents than LC‐treated patients (p < 0.001).InterpretationInitiating L‐dopa therapy with LCE failed to delay the time of onset or reduce the frequency of dyskinesia compared to LC. In fact, LCE was associated with a shorter time to onset and increased frequency of dyskinesia compared to LC. These results may reflect that the treatment protocol employed did not provide continuous L‐dopa availability and the higher L‐dopa dose equivalents in the LCE group. ANN NEUROL 2010;68:18–27
Magnetically Separable Nanocatalysts: Bridges between Homogeneous and Heterogeneous Catalysis
Authors: Shylesh Sankaranarayanapillai , Schünemann Volker , Thiel Werner R. 
Published: April 2010

AbstractRecovery and reuse of expensive catalysts after catalytic reactions are important factors for sustainable process management. The aim of this Review is to highlight the progress in the formation and catalytic applications of magnetic nanoparticles and magnetic nanocomposites. Directed functionalization of the surfaces of nanosized magnetic materials is an elegant way to bridge the gap between heterogeneous and homogeneous catalysis. The introduction of magnetic nanoparticles in a variety of solid matrices allows the combination of well‐known procedures for catalyst heterogenization with techniques for magnetic separation.
Effect of the Photoperiod and Administration of Melatonin on the Pars Tuberalis of Viscacha (Lagostomus maximus maximus): An Ultrastructural Study
Authors: Romera Edith Perez , Mohamed Fabian , Fogal Teresa , Dominguez Susana , Piezzi Ramón , Scardapane Luis 
Published: April 2010

AbstractThe pituitary pars tuberalis (PT) is a glandular zone exhibiting well‐defined structural characteristics. Morphologically, it is formed by specific secretory cells, folliculostellate cells, and migratory cells coming from the pars distalis. The purpose of this work was to investigate differences in specific cellular characteristics in the PT of viscachas captured in summer (long photoperiod) and winter (short photoperiod), as well as the effects of chronic melatonin administration in viscachas captured in summer and kept under long photoperiod. In summer, the PT‐specific cells exhibited cell‐like characteristics with an important secretory activity and a moderate amount of glycogen. In winter, the PT‐specific granulated cells showed ultrastructural variations with signs of a reduced synthesis activity. Also, PT showed a high amount of glycogen and a great number of cells in degeneration. After melatonin administration, the ultrastructural characteristics were similar to those observed in winter, but the amount of glycogen was higher. These results suggest possible functional implications as a result of morphological differences between long and short photoperiods, and are in agreement with the variations of the pituitary‐gonadal axis, probably in response to the natural photoperiod changes through the pineal melatonin. The ultrastructural differences observed in PT, after melatonin administration, were similar to those observed in the short photoperiod, thus supporting the hypothesis that these cytological changes are induced by melatonin. Anat Rec, 293:871–878, 2010. © 2010 Wiley‐Liss, Inc.
Synthesis and Characterization of Novel Gold(III) Complexes of Asymmetrically Aryl‐Substituted 1,2‐Dithiolene Ligands Featuring Potential‐Controlled Spectroscopic Properties
Authors: Ambrosio Lucia , Aragoni M. Carla , Arca Massimiliano , Devillanova Francesco A. , Hursthouse Michael B. , Huth Susanne L. , Isaia Francesco , Lippolis Vito , Mancini Annalisa , Pintus Anna 
Published: April 2010

AbstractThe tetrabutylammonium (TBA+) salts of square‐planar monoanionic gold complexes of the unsymmetrically substituted Ar,H‐edt2− 1,2‐dithiolene ligands (Ar,H‐edt2−=arylethylene‐1,2‐dithiolato; Ar=phenyl (1−), 2‐naphthyl (2−), and 1‐pyrenyl (3−)) were synthesized and characterized by spectroscopic and electrochemical methods and the corresponding neutral species (1, 2, and 3, respectively) were obtained in CH2Cl2 solution at room temperature by diiodine oxidation. The single‐crystal X‐ray diffraction structural data collected for (TBA+)(2−), supported by DFT theoretical calculations, are consistent with the ene‐1,2‐dithiolate form of the ligand and the AuIII oxidation state. All complexes feature intense near‐IR absorptions (at about 1.5 μm) in their neutral states and Vis‐emitting properties in the 400–550 nm range, the energy of which is controlled by the charge of the complex in the case of the 3−/3 couple. The spectroscopic and electrochemical features of 1x− and 2x− (x=0, 1), both in their cis and trans conformations, were investigated by means of DFT and time‐dependent (TD) DFT calculations.
The Chemistry of CH Bond Activation on Diamond
Authors: Zhong Yu Lin , Loh Kian Ping 
Published: April 2010

AbstractThe surface of hydrogen‐terminated diamond resembles a solid hydrocarbon substrate. Interestingly, the CH bonds on the diamond surface are not as unreactive as that of saturated hydrocarbon molecules owing to its unique surface electronic properties. The invention of CH bond activation and CC coupling reactions on the diamond surface allows chemists to develop powerful chemical transistors, biosensors, and photovoltaic cells on the diamond platform.
Über die elektrolytische Bestimmung des Nickels in Nitratlösung und seine Trennung vom Kupfer
Authors: Thiel A. 
Published: April 2010

AbstractZusammenfassung der Resultate1 . Nickel lädt sich aus einer von salpetriger Säure befreiten, ammoniakalischen Nitratlösung bei genügendem Ammoniakgehalte quantitativ abscheiden.2. Platinanoden werden hierbei) sobald sie nicht mehr von einer schützenden Nickeloxydhaut bedeckt sind, stark angegriffen.3. Die dadurch bedingten Fehler der Analysenmethode lassen sich durch Verwendung passivierter, gerader Eisendrahte als Anoden praktisch beseitigen.4. Die Endreaktion auf Nickel mit Schwefelammonium ist in stark ammoniakalischer Lösung unzuverlässig. Münster, Chemisches Institut der Universität)
Bücherschau
Authors: Lottermoser  , Meyer Julius 
Published: April 2010

AbstractAhrens' Sammlung chemischer und chemisch‐technischer Vorträge, Bd. XII, 4. bis 6. Heft: Neuere Färbetheorien. Von Dr. Karl Schwalbe. Verlag von F. Enke, Stuttgart. 1908.Kurzes Lehrbuch der organischen Chemie. Von William A. Noyes. Uebersetzt von Walter Ostwald. XXIV und 722 S. Verlag der Akademischen Verlagsgesellschaft m. b. H., Leipzig. 1907.Fortschritte der Elektrotechnik. Vierteljährliche Berichte über die neueren Erscheinungen auf dem Gesamtgebiete der angewandten Elektrizitätslehre, mit Einschluss des elektrischen Nachrichten‐ und Signalwesens. Im Auftrage und mit Unterstützung des Elektrotechnischen Vereins, sowie mit Unterstützung hervorragender elektrotechnischer Firmen, unter Mitwirkung von Borns, Breisig, Giebe, Grünbaum, Hartenheim, Nösselt, Schneider, Sprenger und Stade herausgegeben von Dr. Karl Strecker. 21. Jahrgang, das Jahr 1907, Heft 3. Verlag von Julius Springer, Berlin 1908. Preis 10 Mk.
Liquid chromatography tandem mass spectrometry method for the quantification of Sarpogrelate, a selective 5‐HT2Areceptor antagonist, in plasma: application to a pre‐clinical pharmacokinetic study
Authors: Nirogi Ramakrishna , Kandikere Vishwottam , Mudigonda Koteshwara , Ajjala Devender , Suraneni Ramakrishna , Thoddi Parthasarathi 
Published: April 2010

AbstractA simple LC‐MS/MS method was developed and validated for the estimation of sarpogrelate in 50 µL of rat plasma. The analyte and internal standard (IS) were extracted from rat plasma by acetonitrile precipitation and they were separated on a reversed‐phase C8column with gradient program. The MS acquisition was performed with multiple reaction monitoring mode usingm/z430.2 tom/z135.0 for analyte andm/z448.2 tom/z285.3 for IS. The calibration curves were linear over the range of 1–1000 ng/mL with the correlation coefficient greater than 0.999. With dilution integrity up to 20‐fold, the upper limit of quantification was extendable up to 15,000 ng/mL. The method was successfully applied to the analysis of rat plasma samples after single dose oral administration of sarpogrelate at 5 mg/kg to rats for the determination of its pharmacokinetics. Following oral administration the maximum mean concentration in plasma (Cmax, 11514 ng/mL) was achieved at 0.25 h (Tmax) and the area under curve (AUC0–24) was 11051 ± 3315 ng h/mL. The half‐life (t1/2) and clearance (Cl) were 2.9 ± 1.1 h and 490 ± 171 mL/h/kg, respectively. We believe that development of a method in rodent plasma would facilitate the ease of adaptability of sarpogrelate in human plasma. Copyright © 2010 John Wiley & Sons, Ltd.
Sesquiterpene Synthases Cop4 and Cop6 from Coprinus cinereus: Catalytic Promiscuity and Cyclization of Farnesyl Pyrophosphate Geometric Isomers
Authors: Lopez‐Gallego Fernando , Agger Sean A. , Abate‐Pella Daniel , Distefano Mark D. , Schmidt‐Dannert Claudia 
Published: April 2010

AbstractSesquiterpene synthases catalyze with different catalytic fidelity the cyclization of farnesyl pyrophosphate (FPP) into hundreds of known compounds with diverse structures and stereochemistries. Two sesquiterpene synthases, Cop4 and Cop6, were previously isolated from Coprinus cinereus as part of a fungal genome survey. This study investigates the reaction mechanism and catalytic fidelity of the two enzymes. Cyclization of all‐trans‐FPP ((E,E)‐FPP) was compared to the cyclization of the cis–trans isomer of FPP ((Z,E)‐FPP) as a surrogate for the secondary cisoid neryl cation intermediate generated by sesquiterpene synthases, which are capable of isomerizing the C2C3 π bond of all‐trans‐FPP. Cop6 is a “high‐fidelity” α‐cuprenene synthase that retains its fidelity under various conditions tested. Cop4 is a catalytically promiscuous enzyme that cyclizes (E,E)‐FPP into multiple products, including (−)‐germacrene D and cubebol. Changing the pH of the reaction drastically alters the fidelity of Cop4 and makes it a highly selective enzyme. Cyclization of (Z,E)‐FPP by Cop4 and Cop6 yields products that are very different from those obtained with (E,E)‐FPP. Conversion of (E,E)‐FPP proceeds via a (6R)‐β‐bisabolyl carbocation in the case of Cop6 and an (E,E)‐germacradienyl carbocation in the case of Cop4. However, (Z,E)‐FPP is cyclized via a (6S)‐β‐bisabolene carbocation by both enzymes. Structural modeling suggests that differences in the active site and the loop that covers the active site of the two enzymes might explain their different catalytic fidelities.
Cloning, Expression and Purification of Cindoxin, an Unusual Fmn‐Containing Cytochrome P450 Redox Partner
Authors: Hawkes David B. , Slessor Kate E. , Bernhardt Paul V. , De Voss James J. 
Published: April 2010

AbstractCytochromes P450 (P450s) belong to a superfamily of haemoproteins that catalyse a remarkable variety of oxidative transformations. P450 catalysis generally requires that cognate redox proteins transfer electrons, derived ultimately from NAD(P)H, to the P450 for oxygen activation. P450cin (CYP176A1) is a bacterial P450 that is postulated to allow Citrobacter braakii to live on cineole as its sole carbon source by initiating cineole biodegradation. Here we report the cloning, expression, purification and characterisation of one of its postulated redox partners, cindoxin (Cdx), which has strong similarity to the FMN domain of cytochrome P450 reductase. Cindoxin reductase (CdR), which displays strong similarity to NADPH‐dependent ferredoxin reductases, was unable to be expressed in a functional form. Mass spectrometric and HPLC analyses confirmed that the flavin cofactor of cindoxin was FMN. Redox potentiometric titrations were performed with cindoxin within the range 6<pH<8; this enabled the quinone/semiquinone (E1) and semiquinone/hydroquinone (E2) redox potentials to be determined. Our results show that cindoxin might be somewhat different to other flavodoxins that interact with P450s, in which generally only one couple is important. Both redox states of cindoxin could be catalytically relevant. A catalytically active system was reconstituted in vitro with E. coli flavodoxin reductase (Fpr) acting as the terminal redox partner in the absence of CdR. Our results show that Cdx and Fpr support regio‐ and stereoselective P450cin‐catalysed cineole oxidation to (1R)‐6β‐hydroxycineole with turnover rates up to 1500 min−1. This system is tightly coupled with 80 % of NADPH reducing equivalents funnelled into substrate oxidation.
Design of a Pipe/Ring Type of Sparger for a Bubble Column Reactor
Authors: Kulkarni A. V. 
Published: April 2010

AbstractThe sparger is an important accessory of bubble column reactors which governs the performance of the reactor. Specifically the sparger design becomes more important when the aspect ratio of the bubble column is low. The maldistribution and design of the sparger are of major concern and both these aspects are described in detail in the present work. Various methods for reducing maldistribution have been discussed and a simple method for its reduction is presented experimentally. Further a step‐wise design procedure for a pipe/ring type of sparger for bubble columns is presented together with a work example.