bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Stereochemical Behaviour of Congested Ruthenium(II) Complexes Containing Asymmetric Thioether Ligands Based on Pyridine and Pyrimidine
Authors: Tresoldi Giuseppe , Lanza Santo , Di Pietro Santo , Drommi Dario 
Published: September 2008

AbstractThe asymmetric thioethers L [L = 2‐pyridylmethyl 2′‐pyrimidyl sulfide (pps) and 2‐(4‐methylpyrimidyl) 2′‐pyridylmethyl sulfide (mps)] reacted with cis‐[RuCl2(N,N‐L′)2] [L′ = di‐2‐pyridyl sulfide (dps); 2,2′‐bis(4‐methylpyridyl) sulfide (4mdps); 2,2′‐bis(5‐methylpyridyl) sulfide (5mdps)] to give the five‐membered‐ring chelate complexes [Ru(N,N‐L′)2(Npyridine,S‐L)]++ as the major products (92–95 %). Because the sulfur and ruthenium atoms are stereogenic centres, with (R) and (S) and Δ and Λ configurations, respectively, four isomers, including the enantiomers were obtained. At low temperature and in the methylene region of the 1H NMR spectra, two AB systems due to the enantiomer couples ΔS ΛR (a) and ΔR ΛS (b) were observed with abundances of 77–89 and 6–18 %, respectively. Furthermore, NMR spectroscopic investigations showed that the hybrid polydentate ligands L change their coordination mode. Thus, although a and b largely predominate, a mixture of species containing L and the Ru(N,N‐L′)2 unit in the ratio 1:1 are present. The four‐membered‐ring chelate complexes [Ru(N,N‐L′)2(Npyrimidine,S‐L)]++ (c), as minor species (abundance 1–8 %), are always observed, whereas the dinuclear species [{Ru(N,N‐L′)2}2(μ‐L)2]+4 (d, e) are observed when L′ = dps or 5mdps. In these cases, four AB systems are assigned to dinuclear species d and e containing two bridging L that act as Npyridine,S‐ or Npyridine,Npyrimidine‐donor ligands. The 1H NMR spectra are temperature dependent in that at low temperature the complexes undergo inversion of the chiral centre of the coordinated sulfur atom (a [rlhar2] b) and the dimer (d, e) and monomer (c) are in equilibrium; at higher temperatures the complexes undergo a structural dynamic rearrangement, which involves exchange between the coordinated and uncoordinated N atoms (b [rlhar2] c). One‐dimensional band‐shape analysis of the exchanging methylene and methyl proton signals showed that the energy barriers for inversion of the sulfur centre are in the 50–53 kJ mol–1 range, whereas those for the higher‐temperatures process are in the 62–68 kJ mol–1 range. The possible mechanisms of the processes are discussed. NMR spectroscopic findings suggest that inversion at the sulfur centre occurs without any bond rupture, whereas the exchange, at higher temperatures (b [rlhar2] c), is a dissociative process involving the breaking of a Ru–Npyridine bond.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthetic Studies Directed towards Agelasine Analogs – Synthesis, Tautomerism, and Alkylation of 2‐Substituted N‐Methoxy‐9‐methyl‐9H‐purin‐6‐amines
Authors: Roggen Heidi , Gundersen Lise‐Lotte 
Published: September 2008

AbstractN‐Methoxy‐9‐methyl‐9H‐purin‐6‐amines, carrying various substituents in the 2 positions, were synthesized by the N‐methylation of known 6‐chloropurines, followed by a displacement of the chlorine. Great variations in the amino/imino tautomer ratio among the compounds studied were observed. The tautomers were identified by NMR methods. Treatment of N‐methoxy‐9‐methyl‐9H‐purin‐6‐amines carrying alkyl, alkoxy, or amino substituents in the 2 position with benzyl bromide resulted in a mixture of N‐7‐ and N6‐benzylated compounds with the former as the major products. N‐Methoxy‐9‐methyl‐9H‐purin‐6‐amines with strongly electronegative substituents at C‐2 hardly reacted at all under the same set of reaction conditions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Ready Transformation of Partially Unprotected Thioglycosides into Glycosyl Fluorides Mediated by NIS/HF–Pyridine or Et3N·3HF
Authors: López J. Cristóbal , Bernal‐Albert Paloma , Uriel Clara , Gómez Ana M. 
Published: September 2008

AbstractThe transformation of partially unprotected phenyl 1‐thioglycosides into glycosyl fluorides can be conveniently carried out by treatment with NIS in the presence of HF–pyridine. Other sources of halonium ions such as NBS, IDCP, have also been employed. The combination NIS/Et3N·3HF, where triethylamine–tris(hydrogen fluoride) (Et3N·3HF) replaces HF–pyridine, can also effect this transformation when acid‐sensitive substituents are present. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
In Vivo Electrochemical Detection of Nitroglycerin‐Derived Nitric Oxide in Tumor‐Bearing Mice
Authors: Griveau Sophie , Seguin Johanne , Scherman Daniel , Chabot Guy G. , Bedioui Fethi 
Published: September 2008

AbstractThe ability of an inserted electrode to detect in vivo NO in tumor was achieved by using a chemically modified Pt/Ir electrode as NO‐sensor and nitroglycerin NTG as NO donor. Enzymatically induced release of NO from NTG was tracked in the tumor, upon intra peritoneal injection of NTG. This approach allowed in vivo monitoring of the bioavailability of NO and could be applied to the in vivo study of candidate anticancer drugs acting on the NO pathways.
Multilayer Assembly of Hemoglobin and Colloidal Gold Nanoparticles on Multiwall Carbon Nanotubes/Chitosan Composite for Detecting Hydrogen Peroxide
Authors: Chen Shihong , Yuan Ruo , Chai Yaqin , Yin Bing , Xu Yang 
Published: September 2008

AbstractChitosan (CS) was chosen for dispersing multi‐wall carbon nanotubes (MWNTs) to form a stable CS‐MWNTs composite, which was first coated on the surface of a glassy carbon electrode to provide a containing amino groups interface for assembling colloidal gold nanoparticles (GNPs), followed by the adsorption of hemoglobin (Hb). Repeating the assembly step of GNPs and Hb resulted in {Hb/GNPs}n multilayers. The assembly of GNPs onto CS‐MWNTs composites was confirmed by transmission electron microscopy. The consecutive growth of {Hb/GNPs}n multilayers was confirmed by cyclic voltammetry and UV‐vis absorption spectroscopy. The resulting system brings a new platform for electrochemical devices by using the synergistic action of the electrocatalytic activity of GNPs and MWNTs. The resulting biosensor displays an excellent electrocatalytic activity and rapid response for hydrogen peroxide. The linear range for the determination of H2O2 was from 5.0×10−7 to 2.0×10−3 M with a detection limit of 2.1×10−7 M at 3σ and a Michaelis–Menten constant KMapp value of 0.19 mM.
Gas Diffusion Electrodes for Use in an Amperometric Enzyme Biosensor
Authors: Hämmerle Martin , Achmann Sabine , Moos Ralf 
Published: September 2008

AbstractThe preparation of gas diffusion electrodes and their use in an amperometric enzyme biosensor for the direct detection of a gaseous analyte is described. The gas diffusion electrodes are prepared by covering a PTFE membrane (thickness 250 μm, pore size 2 μm, porosity 35%) with gold, platinum, or a graphite/PTFE mixture. Gold and platinum are deposited by e‐beam sputtering, whereas the graphite/PTFE layer is prepared by vacuum filtration of a respective aqueous suspension. These gas diffusion electrodes are exemplarily implemented as working electrodes in an amperometric biosensor for gaseous formaldehyde containing NAD‐dependent formaldehyde dehydrogenase from P. putida [EC. 1.2.1.46] as enzyme and 1,2‐naphthoquinone‐4‐sulfonic acid as electrochemical mediator. The resulting sensors are compared with regard to background current, signal noise, linear range, sensitivity, and detection limit. In this respect, sensors with gold or graphite/PTFE covered membranes outclass ones with platinum for this particular analyte and sensor configuration.
Electroanalytical Responses of Arsenic Oxide, Methanol, and Oxygen at the Ruthenium Oxide–Hexachloroiridate with Platinum Hybrid Film
Authors: Umasankar Yogeswaran , Chen Shen‐Ming , Li Sheh‐Hung 
Published: September 2008

AbstractElectrochemically active ruthenium oxide (RuOx⋅nH2O), ruthenium oxide/hexachloroiridate (RuOx⋅nH2O/IrCl62−), and ruthenium oxide/hexachloroiridate/platinum (RuOx⋅nH2O/IrCl62−/Pt) hybrid films have been prepared from the mixture of Ru3+, IrCl62−, and PtCl62− ions in an acidic aqueous solution. The repetitive cyclic voltammetry (CV) has been used for the film preparation process. The electrochemical properties and the growth mechanism of the above mentioned different kinds of hybrid films have been investigated using CV and electrochemical quartz crystal microbalance. The morphological and quantitative analyses have been carried out using scanning electron microscopy, atomic force microscopy and energy dispersive X‐ray. Among these above mentioned films, RuOx⋅nH2O/IrCl62−/Pt hybrid film exhibits promising electrocatalytic activity towards the oxidation of arsenic oxide, methanol and reduction of oxygen. Further, detailed study of electrocatalysis using rotating ring disk electrodes and amperometric methods have been carried out for arsenic oxide oxidation and oxygen reduction reactions at the hybrid films. From the results, the sensitivity of RuOx⋅nH2O/IrCl62−/Pt hybrid film has been calculated for arsenic oxide as 0.7 mA mM−1; and for oxygen as 1.8 mA mM−1.
Thiol‐Functionalized Silica Thin Film Modified Electrode in Determination of Mercury Ions in Natural Water
Authors: Cesarino Ivana , Cavalheiro Éder Tadeu Gomes 
Published: September 2008

AbstractThe use of a thin thiol‐functionalized silica film modified glassy carbon electrode in the determination of Hg(II) ions in a natural water sample is described. A typical measurement involves two successive steps: a glassy carbon electrode coated with a thin mesoporous silica film containing 10% of mercaptopropyl groups, according to the MPTMS/TEOS ratio in the starting sol‐gel, was first immersed into the accumulation medium for 15 min, then removed, and finally transferred into a detection solution containing KCl 1.0 mol L−1 where detection was performed by anodic stripping voltammetry. In this medium the previously accumulated Hg2+ species complexed by the thiol groups in an open circuit preconcentration step is then directly reduced at −0.6 V during 60 s prior to be quantified by a differential pulse anodic scan from −0.6 to 0.3 V (vs. Ag/AgCl). A stripping peak appeared at about −0.01 V, which is directly proportional to the quantity of the analyte previously accumulated into the film. The best results were obtained under the following conditions: 100 mV pulse amplitude and 10 mV s−1 scan rate in 1.0 mol L−1 KCl solution pH 2.0. Using such parameters a linear dynamic range from 1.00 to 10.0×10−8 mol L−1 Hg(II) was observed with a limit of detection of 4.3 nmol L−1 for an accumulation time of 15 min. Hg(II) spiked in a natural water sample was determined between 97.0 and 101.4% mean recovery at 10−8 mol L−1 level. The results indicate that this electrode is sensitive and selective for the Hg(II)determination.
Analysis and prediction of faunal distributions from video and multi‐beam sonar data using Markov models
Authors: Foster Scott D. , Bravington Mark V. , Williams Alan , Althaus Franziska , Laslett Geoff M. , Kloser Rudy J. 
Published: September 2008

AbstractWe present a statistical framework for analysing video transect data from the marine environment. Variables observed in the video data, especially those describing marine fauna, are related to physical variables derived from coarser scale acoustic data that has much greater spatial coverage. The observations from the video data are multivariate, and their distribution is factorised conditionally into univariate distributions. We accommodate the auto‐correlation in each conditional univariate distribution using a reversible Markov model, where the transition probabilities vary with the physical explanatory variables and the conditioning observed variables. Predictions for a random variable's stationary distribution, marginal to other observed variables, are made using a suitably weighted average. An average prediction and an approximation to its variance are given for large spatial areas. This is an important application for resource management in the deep ocean where spatially based management approaches are commonly used, and where the cost of collecting fine‐scale data is high. We demonstrate the method using data from the east coast of Tasmania, Australia. Copyright © 2008 John Wiley & Sons, Ltd.
On the simulation of a time‐dependent cavity flow of an Oldroyd‐B fluid
Authors: Pan Tsorng‐Whay , Hao Jian , Glowinski Roland 
Published: September 2008

AbstractIn this article we present a finite element method for simulating the time‐dependent flow of an Oldroyd‐B fluid in a lid‐driven cavity, which is a stringent test problem at high Weissenberg number. The key considerations for developing the methodology are the preservation of the positive definiteness of the conformation tensor via the log‐conformation representation and additional diffusion, from second‐order upwind scheme, to smooth the high‐frequency modes. The combination of the log‐conformation representation, finite element method, and an operator‐splitting Lie's scheme, gives us a robust and easy‐to‐implement scheme. We have obtained convergent results when simulating time‐dependent cavity flows. Copyright © 2008 John Wiley & Sons, Ltd.
Functional soft palate reconstruction: A comprehensive surgical approach
Authors: Seikaly Hadi , Rieger Jana , Zalmanowitz Jana , Tang Judith Lam , Alkahtani Khalid , Ansari Khalid , O'Connell Daniel , Moysa Gerald , Harris Jeffrey 
Published: September 2008

AbstractBackground.Dysfunction of the soft palate is devastating to the patient's quality of life, resulting in unintelligible speech and poor swallowing. Reconstruction of the soft palate is complex because the dynamic fibromuscular structure cannot be duplicated. The efficacy of soft palate reconstruction has therefore been called into question. The purpose of this article is: (1) to describe our comprehensive surgical paradigm for soft palate reconstruction, (2) to provide details of the surgical techniques used, and (3) to report on patient functional outcomes.Methods.Fifty‐two patients spanning 3 different size‐based categories of soft palate reconstruction were included in the final analysis. Using videofluoroscopic studies of swallowing, the presence of nasopharyngeal reflux and any instance of aspiration of a bolus into the airway was noted. In addition, a simple diet survey was completed, and the use of a g‐tube was noted.Results.The results revealed that our protocol for soft palate reconstruction provided the majority of our patients with separation of the oropharynx and nasopharynx, while maintaining nasal patency. Restoration of swallowing function was timely, with 91% of the patients returning to an oral diet at the early postoperative visit and only 14% of patients demonstrating mild nasopharyngeal reflux.Conclusion.We have developed a comprehensive reconstructive protocol that provides patients with separation of the oropharynx and nasopharynx, while maintaining nasal patency. Restoration of function is timely, with reestablishment of normal intelligibility and resonance of speech as well as safe and efficient swallowing function. © 2008 Wiley Periodicals, Inc. Head Neck, 2008
Validation and assessment of voice‐related quality of life in Indian patients undergoing total laryngectomy and primary tracheoesophageal puncture
Authors: Deshpande Mandar S. , Kakade Anagha C. , Chaukar Devendra A. , Gore Vinod T. , Pai Prathamesh S. , Chaturvedi Pankaj , D'Cruz Anil K. 
Published: September 2008

AbstractBackground.Voice‐related quality of life (V‐RQOL) has never been studied in Indian patients. This study was planned to validate and assess V‐RQOL in patients using tracheoesophageal puncture (TEP).Methods.A cross‐sectional study was undertaken to validate V‐RQOL questionnaire by testing reliability, validity, and responsiveness. V‐RQOL was assessed in patients undergoing total laryngectomy with primary TEP.Results.One hundred thirty‐two patients filled 188 questionnaires. Analysis was carried out on 122 patients. Reliability and validity of questionnaire were tested by Cronbach's alpha (.84–.91) and item‐scale correlation (.67–.86). Median V‐RQOL‐Total score was 76.2 indicating excellent V‐RQOL. Higher scores were observed in patients less than 50 years (82.5 vs 72.5,p= .08). There was no effect of time interval between laryngectomy and assessment of questionnaire on the V‐RQOL scores.Conclusion.V‐RQOL questionnaire can be used reliably to assess V‐RQOL, which is found to be excellent in Indian patients undergoing TEP. © 2008 Wiley Periodicals, Inc. Head Neck, 2009
Can the office environment stimulate a manager's creativity?
Authors: Ceylan Canan , Dul Jan , Aytac Serpil 
Published: September 2008

AbstractThis article explores whether the manager's physical office work environment can stimulate the manager's creativity. A total of 60 managers from a large manufacturing company participated in the study. They rated the creativity potential and physical elements of office environments shown in 25 photographs. The results indicate that offices differ in terms of creativity potential. Compared to offices with low creativity potential, offices with high creativity potential have lower complexity, more plants, bright lighting conditions, windows, cooler colors, and a computer facility. The results suggest that a good interior design of manager's office environment could stimulate a manager's creativity and could therefore contribute to an organization's innovation. © 2008 Wiley Periodicals, Inc.
Knowledge transfer barriers between research and development and marketing groups within Taiwanese small‐ and medium‐sized enterprise high‐technology new product development teams
Authors: Huang Chung‐Ming , Chang Han‐Chao , Henderson Steven 
Published: September 2008

AbstractThis article reports on efforts to explore barriers to the transfer of knowledge from provider to seeker and the role of knowledge management strategies during the new product development (NPD) period. The study used the cultural‐historical activity theory (CHAT) framework from Hasan and Gould (2001) to examine the cross‐functional knowledge creation process and details surrounding the concept of stickiness (Szulanski, 1996). Strategies we observed can be categorized as being classical or processual oriented (Whittington, 1993). We describe how NPD teams can reduce barriers by aligning strategies in the four knowledge‐creation steps: socialization, externalization, combination, and internalization. This CHAT framework was verified on the basis of samples from 107 Taiwanese NPD teams. Results show that the barriers differed among stages within the NPD period. During the transfer process, the processual strategy reduced barriers to knowledge transfer during the planning, developing, and commercialization stages of the NPD period. In contrast, the classical strategy was shown only to have a positive effect during the marketing stage. Survey results also showed that the highly formalized communication model and periodic meetings advocated by Song and colleagues (Song, Sabrina, & Zhao, 1996; Song, van der Bji, & Weggeman, 2005) and Ingelgard, Roth, Shani, and Styhre (2002) were gradually replaced by bounded transfer and a less formalized approach. These preliminary results suggest that if team leaders can use classical and processual strategies in real time, the barriers to the transfer of knowledge from provider to seeker in the four steps of the NPD period can be effectively reduced. © 2008 Wiley Periodicals, Inc.
Temporally weighted average curve number method for daily runoff simulation
Authors: Kim Nam Won , Lee Jeongwoo 
Published: September 2008

AbstractThe modified Soil Conservation Service curve number (CN) method is widely used in long‐term continuous models to predict daily surface runoff. However, it has been shown that this method gives poor results in reproducing peak flows in high rainfall periods. This is because there is an inaccuracy stemming from the model algorithm as it adjusts the daily runoff curve number as a function of soil moisture content at the end of the previous day. This paper proposes an alternative daily based curve number technique that can provide better prediction of daily runoff during the high flow season. The proposed method uses the temporally weighted average curve number (TWA‐CN) to estimate daily surface runoff, while considering the effect of rainfall during a given day as well as the antecedent soil moisture condition. To test the applicability of the TWA‐CN method, it was incorporated with the long‐term, continuous simulation watershed models SWAT and SWAT‐G. Simulations were conducted for the Miho River watershed located in the middle of South Korea. The graphical displays and statistics of the determination coefficient (R2) and the Nash–Sutcliffe model efficiency (NSE) of the observed and simulated daily runoff indicated that the modified SWAT with the TWA‐CN method may provide better runoff prediction (R2 = 0·837, NSE = 0·833) than the original SWAT (R2 = 0·815, NSE = 0·824). Likewise, the determination coefficient (R2 = 0·816) and the Nash–Sutcliffe efficiency (NSE = 0·834) for the modified SWAT‐G are also higher than the original version (R2 = 0·782, NSE = 0·825). It is expected that the improved capability in predicting surface runoff using the suggested CN estimate method will provide a sound contribution to the accurate simulations of water yield. Copyright © 2008 John Wiley & Sons, Ltd.
Notch1 is a frequent mutational target in chemically induced lymphoma in mouse
Authors: Karlsson Anneli , Ungerbäck Jonas , Rasmussen Anna , French John E. , Söderkvist Peter 
Published: September 2008

AbstractActivating Notch1 mutations have been reported in human T‐lineage acute lymphoblastic leukemia (T‐ALL) and lymphomas from genetically modified mice. We report that Notch1 is a prevalent and major mutational target in chemically induced mouse lymphoma. The regions of the gene that are frequently mutated are the heterodimerization domain and the N‐terminal ligand‐binding region, important for protein stability, and the polypeptide rich in proline, glutamate, serine and threonine (PEST) domains, which is critical for protein degradation. Another gene, CDC4, is also involved in Notch1 degradation and shows frequent mutations. Mutations in the heterodimerization and the ligand‐binding regions may cause ligand‐independent signaling, whereas mutations preventing protein degradation result in accumulation of intracellular Notch1. We analyzed 103 chemical‐induced mouse lymphomas for mutations in the Notch1 gene using single strand conformation analysis (SSCA) and DNA sequencing. Genetic alterations resulting in premature truncation of Notch1 were identified in 28 tumors, whereas 8 revealed alterations in the heterodimerization and 16 harbored deletions in the ligand‐binding region. Dideoxycytidine‐induced lymphomas displayed the highest frequency of Notch1 mutations (49%), whereas in butadiene‐ and phenolphthalein‐induced tumors showed lower frequencies (26 and 10%, respectively). In total, 26 novel and 3 previously reported mutations were detected. This report shows that Notch1 is a prevalent and major mutational target for 2′,3′‐dideoxycytidine and butadiene‐induced lymphoma. © 2008 Wiley‐Liss, Inc.