bluuebunny/crossref_metadata_2025_split huggingface dataset:
Motions of a cantilevered flexible plate in viscous channel flow driven by a constant pressure drop
Authors: Tetlow G. A. , Lucey A. D. 
Published: April 2009

AbstractAn improved approach for studying the stability of a cantilevered flexible plate positioned within two‐dimensional viscous channel flow is presented in the context of human upper‐airway dynamics. Previous work has used constant inlet velocity conditions. Here we model a constant pressure drop that may better reflect inspiratory effort. Positioning of the flexible plate within the channel can also be varied. The constant pressure drop is imposed for each time step by computing appropriate inlet velocities. The Navier–Stokes equations are solved using an explicit finite‐element method written specifically for the channel geometry within which the fully coupled plate moves. The motion of the plate, driven by the pressure‐field, is modelled using classical thin‐plate mechanics with the addition of the fluid shear‐stress‐induced tension term. The investigation focuses on low‐amplitude motions of the flexible plate (soft‐palate) that, when unstable, may be the precursors to snoring and airway blockage during sleep. We show that imposing constant inlet velocity conditions generates over‐predictions of energy transfer between flow and flexible plate during inhalation. Finally, we show that offsetting the flexible plate within the channel leads to a reduction in oscillation frequency and a significant change to its energy interaction with the fluid flow. Copyright © 2009 John Wiley & Sons, Ltd.
A scalable key pre‐distribution mechanism for large‐scale wireless sensor networks
Authors: Shen An‐Ni , Guo Song , Chien Hung Yu , Guo Minyi 
Published: April 2009

AbstractMany applications of wireless sensor network (WSN) require secure data communications, especially in a hostile environment. In order to protect the sensitive data and the sensor readings, secret keys should be used to encrypt the exchanged messages between communicating nodes. Traditional asymmetric key cryptosystems are infeasible in WSNs due to the extremely low capacity and constrained resources at each senor node. Recently proposed protocols are either vulnerable to the large‐scale node capture attacks or lack of performance scalability in terms of storage, communication and computation costs. To address these limitations, we study the key pre‐distribution schemes in this paper and propose a new one with all of the following properties which are particularly beneficial to the large‐scale resource‐constrained WSNs: (1) it completely defends against the node capture attacks, (2) it provides full connectivity of the network, and (3) it reduces the storage and communication overhead significantly compared with the other proposals. Copyright © 2009 John Wiley & Sons, Ltd.
Design and implementation of a DDS‐based multi‐carrier GMSK modulator
Authors: Kesoulis M. J. , Koukourlis C. S. , Lygouras J. N. , Soudris D. , Sahalos J. N. 
Published: April 2009

AbstractThe design and hardware implementation of a multi‐carrier Gaussian minimum shift keying (GMSK) modulator, based on a direct digital synthesizer, suitable for global system for mobile (GSM) base station applications is described. The synthesizer does not only generate the baseband GMSK signal, but also delivers it at a low IF. Special care has been taken in order to minimize the required memory of the synthesizer. The hardware implementation is mainly based on a field programmable gate array device (FPGA) and a D/A converter. The number of carriers depends on the size of the FPGA. Finally, the hardware implementation of a two‐carrier modulator is given. Copyright © 2009 John Wiley & Sons, Ltd.
Oxido Pincer Ligands – Exploring the Coordination Chemistry of Bis(hydroxymethyl)pyridine Ligands for the Late Transition Metals
Authors: Klein Axel , Elmas Said , Butsch Katharina 
Published: April 2009

AbstractCoordination of the 2,6‐bis(hydroxymethyl)pyridine‐based oxido pincer ligands RR′pydimH2 [R = R′ = H (pydimH2); R = R′ = Me (pydipH2); R = 2‐tolyl, R′ = Me (pydotH2)] towards late transition metals CoII, NiII, CuII, ZnII, PdII and PtII allows the formation of molecular species (complexes), which exhibit three main structural motifs in the solid state. The two main species are pentacoordinate [(RR′pydimH2)MCl2] and hexacoordinate [(RR′pydimH2)2M]X2, both of which are stable in solution and can be interconverted by changing the solvent polarity. The disproportionation equilibrium [(RR′pydimH2)MCl2] [rlhar2] [(RR′pydimH2)2M]2+ + [MCl4]2– was studied by optical spectroscopy. The chiral ligand pydotH2 allows the formation of chiral complexes. In the square‐planar complexes [(pydimH2)2MCl2] (M = PdII or PtII) the oxido donor functions of the ligands do not take part in the coordination.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A Series of CuI Complexes Containing 1,10‐Phenanthroline Derivative Ligands: Synthesis, Characterization, Photophysical, and Oxygen‐Sensing Properties
Authors: Shi Linfang , Li Bin 
Published: April 2009

AbstractFive novel copper(I) complexes with the general formula [Cu(dpephos)(NN)]BF4 {dpephos = bis[2‐(diphenylphosphanyl)phenyl] ether, NN = 2‐phenyl‐1H‐imidazo[4,5‐f][1,10]phenanthroline (pip, 1), 1‐ethyl‐2‐phenyl‐1H‐imidazo[4,5‐f][1,10]phenanthroline (epip, 2), 2‐(naphthalen‐1‐yl)‐1H‐imidazo[4,5‐f][1,10]phenanthroline (nip, 3), 1‐ethyl‐2‐(naphthalen‐1‐yl)‐1H‐imidazo[4,5‐f][1,10]phenanthroline (enip, 4), 2‐(anthracen‐9‐yl)‐1‐ethyl‐1H‐imidazo[4,5‐f][1,10]phenanthroline (aeip, 5)} were rationally designed and synthesized, and these complexes were characterized by 1H NMR and IR spectroscopy and elemental analysis. X‐ray crystal‐structure analysis of 3 and 4 are also presented. Their photophysical properties at room temperature were examined by using a combination of cyclic voltammetry and electronic absorption spectroscopy. It was found that 1–4 display broad‐band emission in the solid state upon excitation at λ = 400 nm, and the emission maxima are located in the range 530–558 nm; the excited‐state lifetimes of these complexes are 8.24, 1.97, 6.99, and 2.43 μs, respectively. As a result, the emission intensity of complexes 1–4 is sensitive to oxygen concentration, and they display oxygen‐sensing properties after they are encapsulated into mesoporous silica MCM‐41 or SBA‐15.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Betaine Adducts of N‐Heterocyclic Carbenes: Synthesis, Properties, and Reactivity / Synthesis and Study of 5,5′‐Bibenzimidazolylidenes and Their Bimetallic Complexes / Synthesis and in vitro Efficacy Studies of Silver Carbene Complexes on Biosafety Level 3 Bacteria / Structure and Reactivity of Dinitrogen Rhodium Complexes Containing N‐Heterocyclic Carbene Ligands / SambVca: A Web Application for the Calculation of the Buried Volume of N‐Heterocyclic Carbene Ligands — (Eur. J. Inorg. Chem. 13/2009)
Authors: Delaude Lionel , Bielawski Christopher W. , Estes D. Mark , Cannon Carolyn L. , Leid Jeff G. , Youngs Wiley J. , Crudden Cathleen M. , Cavallo Luigi 
Published: April 2009

AbstractThe cover picture is a composite design depicting the variety in NHC complex chemistry. Like pieces in a puzzle, all details contribute to our growing knowledge of these compounds. The first puzzle piece in the bottom left corner represents the carbene precursors, essential in all synthesis design (C. W. Bielawski et al.; p. 1729 ff). The background reflects the importance of these complexes, here in the homogeneous catalytic chemistry of gaseous molecules (C. M. Crudden et al.; p. 1746 ff), while the diverse structural types are highlighted by the zwitterionic “crabenes” mid right (L. Delaude; p. 1681 ff). Related aspects such as the physical chemistry or biological relevance are not forgotten: the sketch of the buried volume of an NHC ligand symbolizes the former (L. Cavallo et al.; p. 1759 ff), and the antimicrobial activity of silver–NHC complexes against biosafety level 3 bacteria typifies the latter (W. J. Youngs et al.; p. 1739 ff). Mr. François Nicks is acknowledged for drawing the “crabene”. The editorial office thanks all authors for their excellent contributions to this cover picture puzzle. Finally, there are many gaps. EurJIC hopes that this issue will stimulate you to discover another fragment that will complete the picture.
Chemical Tools To Study the Proteasome
Authors: Verdoes Martijn , Florea Bogdan I. , van der Marel Gijsbert A. , Overkleeft Herman S. 
Published: April 2009

AbstractProteolysis, or the processing and degradation of proteins, has emerged as one of the most widely studied processes in biology today. Long viewed as a dead end process, of importance only for the removal of obsolete peptides and proteins, proteolytic events are now associated with numerous biological events. The main proteolytic pathway in the eukaryotic cytoplasm and nucleus, responsible for the degradation of 80–90 % of all cellular proteins is known as the Ubiquitin Proteasome System (UPS). Proteasomes are the central proteases in this tightly controlled ATP‐ and ubiquitin‐dependent proteolytic pathway. Proteasomes are multicatalytic, compartmentalized proteinase complexes. Their substrates include abnormal and damaged proteins, cell‐cycle regulators, oncogens and tumor suppressors. Furthermore, proteasomal degradation is imperative for the generation of MHC class I antigenic peptides. The recent approval of a proteasome inhibitor as a cancer drug has boosted proteasome research. This microreview highlights the recent advances in the development of chemical tools to study proteasome activity.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Design and Synthesis of Novel Phenothiazinium Photosensitiser Derivatives
Authors: New Olivia M. , Dolphin David 
Published: April 2009

AbstractA high‐yielding approach towards N‐(2‐aminoethyl)‐Azure B has been established and extended towards the preparation of a functionalized peptide‐dye synthetic precursor; Boc‐protected 3‐(alkylamino)phenothiazin‐5‐ium TFA. This has been utilized in a series of reactions with various amines towards nine novel 3,7‐disubstituted phenothiazin‐5‐ium derivatives. Cleavage of the Boc group in the 3,7‐disubstituted salts allowed a further seven novel dyes to be prepared and these have been utilized in a practical methodology designed for the synthesis of 13 novel phenothiazine‐peptide conjugates. These peptide‐photosensitizer vectors consist of a covalent attachment of a tethered dye to various protected amino acid moieties including the cell‐penetrating peptide (CPP) octa‐arginine and exhibit intense absorption maxima in the 623–650 nm regions of the visible spectrum. The main goal of the studies is the design of cell‐compatible photosensitisers that may be employed in photodynamic therapy.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Novel Conversions of Furandiols and Spiroacetal Enol Ethers into Cyclopentenones: Implications of the Isomerization Mechanism of 2‐Furylcarbinols into Cyclopentenones
Authors: Yin Biao‐Lin , Wu Yu‐Lin , Lai Jin‐Qiang 
Published: April 2009

AbstractTwo acid‐catalyzed conversions of furandiols 8 and its dehydration spiroacetalized products 9 into oxabicyclic cyclopentenones 10 in good to excellent yields are reported. To disclose the mechanism of these conversions, the fact that H2O catalyzes the conversion of 9 into 10 is presented and intermediates 9k and 20i have been structurally verified. In addition, two other related conversions of spiroacetal enol ethers 11 and 14 derived from 8 into cyclopentenones are presented, for which an intramolecular aldol reaction is the key step. On the basis of these results, we propose that these conversions occur through an aldol condensation step instead of electrocyclization of the 4π‐electron system, which was previously reported.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Optimization of the Electrochemical RNA‐Aptamer Based Biosensor for Theophylline by Using a Methylene Blue Redox Label
Authors: Ferapontova Elena E. , Gothelf Kurt V. 
Published: April 2009

AbstractThe electrochemical biosensor for theophylline detection in serum based on the RNA molecular beacon approach and methylene blue (MB) as a redox label has been developed. The RNA aptamer for theophylline was immobilized at gold electrodes in its open unfolded state through the alkanethiol linker at its 5′ end, and the MB redox label was attached to the 3′ end of the aptamer. Conformational folding of the aptamer upon theophylline binding increased the electrochemical response from the MB redox probe, then placed closer to the electrode surface. The signal was calibrated versus theophylline concentration within the 2 to 100 μM range, which allows practical determinations of theophylline within therapeutically important 20–100 μM range. The performance of the RNA‐aptamer based biosensor was not inhibited in serum, which was consistent with the absence of detrimental effects of adsorption of serum proteins within the operational potential window of the MB‐labeled biosensor.
Quantitative proteomics investigation of pancreatic intraepithelial neoplasia
Authors: Pan Sheng , Chen Ru , Reimel Beth Ann , Crispin David A. , Mirzaei Hamid , Cooke Kelly , Coleman Joshua F. , Lane Zhaoli , Bronner Mary P. , Goodlett David R. , McIntosh Martin W. , Traverso William , Aebersold Ruedi , Brentnall Teresa A. 
Published: April 2009

AbstractPatients with pancreatic cancer are usually diagnosed at late stages, when the disease is incurable. Pancreatic intraepithelial neoplasia (PanIN) 3 is believed to be the immediate precursor lesion of pancreatic adenocarcinoma, and would be an ideal stage to diagnose patients, when intervention and cure are possible and patients are curable. In this study, we used quantitative proteomics to identify dysregulated proteins in PanIN 3 lesions. Altogether, over 200 dysregulated proteins were identified in the PanIN 3 tissues, with a minimum of a 1.75‐fold change compared with the proteins in normal pancreas. These dysregulated PanIN 3 proteins play roles in cell motility, the inflammatory response, the blood clotting cascade, the cell cycle and its regulation, and protein degradation. Further network analysis of the proteins identified c‐MYC as an important regulatory protein in PanIN 3 lesions. Finally, three of the overexpressed proteins, laminin beta‐1, galectin‐1, and actinin‐4 were validated by immunohistochemistry analysis. All three of these proteins were overexpressed in the stroma or ductal epithelial cells of advanced PanIN lesions as well as in pancreatic cancer tissue. Our findings suggest that these three proteins may be useful as biomarkers for advanced PanIN and pancreatic cancer if further validated. The dysregulated proteins identified in this study may assist in the selection of candidates for future development of biomarkers for detecting early and curable pancreatic neoplasia.
Deduction and application of filtration and cleaning indices for aerosol filtration operations using nonwoven fabrics as filters
Authors: Sánchez Javier R. , Rodríguez J.M. , Alvaro A. , Estévez A.M. 
Published: April 2009

AbstractThe characteristics and properties of fabrics used to make filters, as well as the operation conditions, affect filtration and filter cleaning performance. Accordingly, it is appropriate to group, as done here, such characteristics in dimensionless numbers in order to compare different fabrics used in the filtration of gases in a simple way.In this sense, the authors have previously proposed certain parameters generically termed filtration indices and here these were deduced using dimensional analysis. What we have named cleaning efficiency index is also considered to evaluate the efficiency of a cleaning system.These parameters, and others widely discussed in the literature, were applied to the experimental results obtained by the authors in the filtration of fly ash aerosols with different nonwoven fabrics. Additionally, certain experimental results of other authors are used.The results show that the filtration and cleaning indices may be useful for the comparison of fabrics required for specific applications. © 2009 American Institute of Chemical Engineers Environ Prog, 2010
A new model of phase shifter for its efficient integration in interior point optimal power flow
Authors: Jiang Quanyuan , Huang Zhiguang , Guo Chuangxin , Chiang Hsiao‐Dong 
Published: April 2009

AbstractWhen phase shifters are used as control devices in optimal power flow (OPF), the symmetry of the admittance matrix is destroyed; this introduces some difficulties in the implementation of interior point OPF. This paper presents an efficient approach to handle phase shifters in an interior point OPF algorithm. First, a new power/current injection model of phase shifters is proposed. Then, a detailed explanation of how to integrate this model into the existing interior point OPF code is presented. This integration of phase shifters only requires minor modifications to the existing interior point OPF code by updating Jacobian/Hessian matrices of objective and constraints in each iterate. The distinguished features of the proposed approach are: (i) box constraints are used instead of implicit constraints; (ii) no additional buses are introduced, so the dimensions of Jacobian and Hessian matrices remain the same; and (iii) the admittance matrix is constant, and remains symmetric. Numerical studies on several power systems up to 2383 buses indicate that the proposed approach is simple and efficient. Copyright © 2009 John Wiley & Sons, Ltd.
Fluid dynamic numerical simulation coupled with heat transfer and reaction in the tubular reactor of industrial cracking furnaces
Authors: Li Chufu , Qiu Tong , Chen Bingzhen , Tian Liang , Song Bangyong , Li Jichun 
Published: April 2009

AbstractThe thermal cracking furnace is the heart of the ethylene production process in a petrochemical plant. This paper presents a comprehensive mathematical model containing equations for mass, momentum and heat transfer combined with Kumar molecular kinetic model to describe dynamic behaviors of fluid flow, heat transfer and reaction in the tubular reactor of thermal cracking furnaces. The ‘flow‐reaction’ decomposition strategy is adopted to solve the complex model for implementing the fluid dynamic simulation coupled with heat transfer and reaction in the tubular reactor by a conventional procedure. The proposed mathematical model and the decomposition algorithm are successfully applied to the fluid dynamic simulation in the tubular reactor of a millisecond industrial cracking furnace. The results of dynamic simulation reveal the various transient behaviors of fluid flow, temperature change and species content variation in the tubular reactor under the step disturbance of inlet feedrate. Finally, the performance of the decomposition algorithm is also investigated. Copyright © 2009 John Wiley & Sons, Ltd.
Breast cancer risk is not increased in individuals with TWIST1 mutation confirmed Saethre–Chotzen syndrome: An Australian multicenter study
Authors: James Paul A. , Culling Bronwyn , Mullan Glenda , Jenkins Mark , Elakis George , Turner Anne M. , Mowat David M. , Wilson Meredith , Anderson Peter , Savarirayan Ravi , Cliffe Simon T. , Caramins Melody , Buckley Michael F. , Tucker Kathy , Roscioli Tony 
Published: April 2009

AbstractSaethre‐Chotzen syndrome (SCS) is a rare autosomal dominant syndrome involving craniosynostosis, craniofacial abnormalities, and syndactyly. A recent Scandinavian study reported an increased risk of breast cancer in individuals with a clinical diagnosis of SCS. Because of the potential importance of this finding, we organized a multicenter study enrolling people with TWIST1 mutation confirmed SCS to determine if an increased risk of cancer is present. This study did not identify any cases of breast or ovarian cancer in a cohort of equivalent power to that reported previously. These results provide clinical reassurance that at present there is no evidence for breast cancer screening above standard practice for individuals with SCS. © 2009 Wiley‐Liss, Inc.
Classification of the abrasiveness of soil and rock
Authors: Thuro Kurosch , Käsling Heiko 
Published: April 2009

AbstractThe abrasiveness of soil and rock is a determining factor for tool wear in all processes of rock excavation above and below ground, for example drilling, cutting and excavating. Although this is highly cost‐relevant, no classification scheme has yet been produced, with which soil and rock can be classified according to their abrasiveness and wearing effect. Comparative investigations using three methods of determining abrasiveness were used to produce a proposal for the classification of rock material. Although further series of investigations still have to be performed, a classification scheme has been produced, which is already in practical use and could be of use in future projects.
Predicting the performance of earth pressure shields in loose rock
Authors: Maidl Ulrich , Wingmann Jörg 
Published: April 2009

AbstractThe prediction of the performance of EPBM drives is an essential tool for design and estimating. Realistic forecasting is only possible on the basis of the specific data for the project including all loadings, local conditions and interactions. The present article discusses the processes and their parameters typical for this method of tunnelling, defines the crucial soil mechanics parameters and recommended areas of application and makes recommendations for the estimation of the performance of earth pressure shields based on key performance indicators and the evaluation of data from a multitude of projects.
TBM modification for challenging rock conditions – a progress report of the Niagara Tunnel Project (NTP)
Authors: Gschnitzer Ernst , Goliasch Robert 
Published: April 2009

AbstractThe Niagara Tunnel Project (NTP) is a 10.2 km long bored pressure tunnel that will run under the City of Niagara Falls from the Upper Niagara River to the Sir Adam Beck Power Station. The completed project will enhance the capacity of the Sir Adam Beck Power Station by adding 500 m3/of water per second through the new diversion tunnel. The paper describes the project in which the world's largest hard rock TBM at 14.4 m in diameter is being used to excavate the tunnel. Features of the project include the use of a complex logistic system that allows different work steps simultaneously and describes the site installation for intake as well as for the outlet structures. The paper will also discuss the optimization of the TBM system as the tunnel advances through the varying geology consisting of various horizontal banked shale layers.In order to meet the aggressive construction schedule as requested by the client, the contractor decided to assembly all mayor equipment including the TBM without a workshop assembly. The tunnel boring operation began in September 2006. After a start‐up and commissioning period of four months, the production increased steadily through the various rock formations of the Niagara Escarpment into the Queenston Shale. Tunnelling through the Queenston shale proved to be far more difficult than expected with key block failures up to 20 t and over break exceeding 4 m in numerous occasions. The paper describes the design and construction methods to handle these extreme conditions with a big diameter open type TBM. Completion of the project is foreseen for 2012.