bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization and determination of chlorophacinone in plasma by ion chromatography coupled with ion trap electrospray ionization mass spectrometry
Authors: OuYang Xiao‐kun , Chen Xiao‐hong , Yan Yong‐qing , Jin Mi‐cong 
Published: November 2008

AbstractPlasmatic chlorophacinone is commonly measured with liquid chromatographic assay, which convenient but lacks sensitivity and selectivity and usually requires ion pair reagents to reduce the chromatographic tailed peak. In this paper, a novel method using eluent generator reagent‐free ion chromatography coupled with electrospray ionization ion trap mass spectrometric detection for the determination of chlorophacinone in plasma has been developed. After samples were extracted with 10% (v/v) methanol in acetonitrile and cleaned by solid‐phase extraction, chromatographic separation was performed on an IonPac® AS11 analytical column (250 × 4.0 mm) using 40.0 mmol/L KOH containing 10% (v/v) methanol as organic modifier. Quantification was performed by negative electrospray ionization in multiple reaction monitoring mode. The transition m/z 373 → 201 was for the quantification ion; the transitions m/z 373 → 172 and m/z 373 → 145, as well as the isotope ions m/z 375 and m/z 203, were for the qualitative ions. All the method parameters were validated. It was confirmed that this method can be used in clinical diagnosis and forensic toxicology. Copyright © 2008 John Wiley & Sons, Ltd.
Small‐Angle X‐Ray Scattering and Near‐Infrared Vibrational Spectroscopy of Water Confined in Aerosol‐OT Reverse Micelles
Authors: Balakrishnan Sangeetha , Javid Nadeem , Weingärtner Hermann , Winter Roland 
Published: November 2008

AbstractThe state of water confined in Aerosol‐OT–hydrocarbon–water reverse micelles with cyclohexane, n‐pentane, n‐octane, and n‐dodecane as apolar solvents is investigated by small‐angle X‐ray scattering and near‐infrared vibrational spectroscopy of the first overtone of the OH stretching mode of water. The experiments focus on water/AOT molecular ratios W0=2–20, where water is strongly affected by the confinement and surface–water interactions. The pair‐distance distribution functions derived from the small‐angle scattering patterns allows a detailed characterization of the topology of these systems, and they indicate deviations from monodisperse, spherical water pools for some of these hydrocarbon systems. In contrast to a common assumption, the pool size does not scale linearly with W0 in going from dry reverse micelles (W0→0) to essentially bulk‐like water (W0>20). The first overtone of the OH‐stretching vibration exhibits highly structured spectra, which reveal significant changes in the hydrogen bonding environment upon confinement. The spectra are rationalized by a core/shell model developed by Fayer and co‐workers. This model subdivides water into core water in the interior of the micelle and shell water close to the interface. Core water is modelled by the properties of bulk water, while the properties of shell water are taken to be those of water at W0=2. The model allows the representation of the spectra at any hydration level as a linear combination of the spectra of core and shell water. Different approaches are critically reviewed and discussed as well.
Current‐mode biquadratic filter using DO‐CCCDBAs
Authors: Siripruchyanun Montree , Jaikla Winai 
Published: November 2008

AbstractThis paper presents a current‐mode universal biquadratic filter performing three functions; low pass, high pass and band pass, based on dual‐output current‐controlled current differencing buffered amplifiers (DO‐CCCDBAs). The features of the circuit are that the quality factor and pole frequency can be tuned independently via the input bias currents; the circuit description is very simple, consisting of merely three DO‐CCCDBAs and two grounded capacitors. Without any external resistors that require component matching conditions and using only grounded elements, the proposed circuit is very appropriate to further develop into an integrated circuit. The PSPICE simulation results are depicted. The given results agree well with the theoretical anticipation. Copyright © 2008 John Wiley & Sons, Ltd.
Explicit design formulas for current‐mode leap‐frog OTA‐C filters and 300 MHz CMOS seventh‐order linear phase filter
Authors: Sun Yichuang , Zhu Xi , Moritz James 
Published: November 2008

AbstractThe leap‐frog (LF) configuration is an important structure in analogue filter design. Voltage‐mode LF OTA‐C filters have recently been studied in the literature; however, general explicit formulas do not exist for current‐mode LF OTA‐C filters and there is also need for current‐mode LF‐based OTA‐C structures for realization of arbitrary transmission zeros. Three current‐mode OTA‐C structures are presented, including the basic LF structure and LF filters with an input distributor or an output summer. They can realize all‐pole characteristics and functions with arbitrary transmission zeros. Explicit design formulas are derived directly from these structures for the synthesis of, respectively, all‐pole and arbitrary zero filter characteristics of up to the sixth order. The filter structures are regular and the design formulas are straightforward to use. As an illustrative example, a 300 MHz seventh‐order linear phase low‐pass filter with zeros is presented. The filter is implemented using a fully differential linear operational transconductance amplifier (OTA) based on a source degeneration topology. Simulations in a standard TSMC 0.18µm CMOS process with 2.5 V power supply have shown that the cutoff frequency of the filter ranges from 260 to 320 MHz, group delay ripple is about 4.5% over the whole tuning range, noise of the filter is 420nA/√Hz, dynamic range is 66 dB and power consumption is 200 mW. Copyright © 2008 John Wiley & Sons, Ltd.
Stochastic bitstream‐based CNN and its implementation on FPGA
Authors: Rák Ádám , Soós Balázs Gergely , Cserey György 
Published: November 2008

AbstractIn this paper, we present a new type of cellular nonlinear network (CNN) model and FPGA implementation of cellular nonlinear network universal machine. Our approach uses stochastic bitstreams as data carriers. With the help of stochastic data streams more complex nonlinear cell interactions can be realized than conventional CNN hardware implementations have. The accuracy as indexed by bit depth resolution can be improved at the expense of computation time without influencing hardware complexity. Our simulation results prove the universality and utility of the model. Our experimental results show that the proposed model can be implemented on an FPGA hardware. Copyright © 2008 John Wiley & Sons, Ltd.
Kinematics and dynamics of motion control based on acceleration control
Authors: Ohishi Kiyoshi , Ohba Yuzuru , Katsura Seiichiro 
Published: November 2008

AbstractThe first IEYuzuruernational Workshop on Advanced Motion Control held in 1990 pointed out the importance of physical interpretation of motion control. The software servoing technology is now common in machine tools, robotics, and mechatronics. It has been intensively developed for the numerical control (NC) machines. Recently, motion control in an unknown environment will be more and more important. Conventional motion control is not always suitable due to the lack of adaptive capability to the environment. A more sophisticated ability in motion control is necessary for compliant contact with the environment. Acceleration control is the key technology of motion control in an unknown environment. The acceleration control can make a motion system a zero control stiffness system without losing robustness. Furthermore, a realization of multi‐degree‐of‐freedom motion is necessary for future human assistance. Motion for human assistant will require various control stiffness corresponding to the task. The review paper focuses on the modal coordinate system to integrate various control stiffness in the virtual axes. A bilateral teleoperation is a good candidate to consider for the future human assistant motion and integration of decentralized systems. Thus, the paper reviews and discusses the bilateral teleoperation from the control stiffness and the modal control design points of view. © 2008 Wiley Periodicals, Inc. Electron Comm Jpn, 91(6): 12– 22, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10117
Metallocenium Salts of Nickel Bis(α‐thiophenedithiolate) [M(Cp*)2][Ni(α‐tpdt)2] (M = Fe, Mn, Cr) – Metamagnetism and Magnetic Frustration (Eur. J. Inorg. Chem. 34/2008)
Authors: Belo Dulce , Mendonça Joana , Santos Isabel C. , Pereira Laura Cristina Jesus , Almeida Manuel , Novoa Juan J. , Rovira Concepció , Veciana Jaume , Gama Vasco 
Published: November 2008

AbstractThe cover picture shows the multilayer spin arrangement in [Mn(Cp*)2][Ni(α‐tpdt)2] (α‐tpdt = 2,3‐thiophenedithiolate). The crystal structures of the salts [M(Cp*)2][Ni(α‐tpdt)2] (M = Fe, Mn and Cr) consist of alternating layers that are composed of arrangements of parallel mixed chains. The chains in neighboring layers are perpendicular. The arrangement between the chains and the magnetic anisotropy of the cations in case of the salt [Mn(Cp*)2][Ni(α‐tpdt)2] lead to a degenerate ground state and to a frustrated magnetic behavior, which can be associated with the absence of long‐range order between the ferromagnetic layers. Details are discussed in the article by M. Almeida, V. Gama et al. on p. 5327 ff.
The effect of foundation embedment on inelastic response of structures
Authors: Mahsuli Mojtaba , Ghannad M. Ali 
Published: November 2008

AbstractIn this research, a parametric study is carried out on the effect of soil–structure interaction on the ductility and strength demand of buildings with embedded foundation. Both kinematic interaction (KI) and inertial interaction effects are considered. The sub‐structure method is used in which the structure is modeled by a simplified single degree of freedom system with idealized bilinear behavior. Besides, the soil sub‐structure is considered as a homogeneous half‐space and is modeled by a discrete model based on the concept of cone models. The foundation is modeled as a rigid cylinder embedded in the soil with different embedment ratios. The soil–structure system is then analyzed subjected to a suit of 24 selected accelerograms recorded on alluvium deposits. An extensive parametric study is performed for a wide range of the introduced non‐dimensional key parameters, which control the problem. It is concluded that foundation embedment may increase the structural demands for slender buildings especially for the case of relatively soft soils. However, the increase in ductility demands may not be significant for shallow foundations with embedment depth to radius of foundation ratios up to one. Comparing the results with and without inclusion of KI reveals that the rocking input motion due to KI plays the main role in this phenomenon. Copyright © 2008 John Wiley & Sons, Ltd.
Weak imposition of boundary conditions for the Navier–Stokes equations by a penalty method
Authors: Caglar Atife , Liakos Anastasios 
Published: November 2008

AbstractWe prove convergence of the finite element method for the Navier–Stokes equations in which the no‐slip condition and no‐penetration condition on the flow boundary are imposed via a penalty method. This approach has been previously studied for the Stokes problem by Liakos (Weak imposition of boundary conditions in the Stokes problem. Ph.D. Thesis, University of Pittsburgh, 1999). Since, in most realistic applications, inertial effects dominate, it is crucial to extend the validity of the method to the nonlinear Navier–Stokes case. This report includes the analysis of this extension, as well as numerical results validating their analytical counterparts. Specifically, we show that optimal order of convergence can be achieved if the computational boundary follows the real flow boundary exactly. Copyright © 2008 John Wiley & Sons, Ltd.
A meshless numerical wave tank for simulation of nonlinear irregular waves in shallow water
Authors: Xiao Long‐Fei , Yang Jian‐Min , Peng Tao , Li Jun 
Published: November 2008

AbstractTime domain simulation of the interaction between offshore structures and irregular waves in shallow water becomes a focus due to significant increase of liquefied natural gas (LNG) terminals. To obtain the time series of irregular waves in shallow water, a numerical wave tank is developed by using the meshless method for simulation of 2D nonlinear irregular waves propagating from deep water to shallow water. Using the fundamental solution of Laplace equation as the radial basis function (RBF) and locating the source points outside the computational domain, the problem of water wave propagation is solved by collocation of boundary points. In order to improve the computation stability, both the incident wave elevation and velocity potential are applied to the wave generation. A sponge damping layer combined with the Sommerfeld radiation condition is used on the radiation boundary. The present model is applied to simulate the propagation of regular and irregular waves. The numerical results are validated by analytical solutions and experimental data and good agreements are observed. Copyright © 2008 John Wiley & Sons, Ltd.
Early Cretaceous exhumation of high‐pressure metamorphic rocks of the Sistan Suture Zone, eastern Iran
Authors: Rad G. R. Fotoohi , Droop G. T. R. , Burgess R. 
Published: November 2008

AbstractThe Sistan Suture Zone (SSZ) of eastern Iran is part of the Neo‐Tethyan orogenic system and formed by convergence of the Central Iranian and Afghan microcontinents. ArAr ages of ca. 125 Ma have been obtained from white micas and amphibole from variably overprinted high‐pressure metabasites within the Ratuk Complex of the SSZ. The metabasites, which occur as fault‐bounded lenses within a subduction mélange, document peak‐metamorphic conditions in eclogite or blueschist facies followed by near‐isothermal decompression resulting in an epidote–amphibolite‐facies overprint.40Ar/39Ar step heating experiments were performed on a phengite + paragonite mixture from an eclogite, phengites from two amphibolites, and paragonite from a blueschist; ‘best‐fit’ ages from these micas are, respectively, 122.8 ± 2.2, 124 ± 13, 116 ± 19 and 139 ± 19 Ma (2σ error). Barroisite from an amphibolite yielded an age of 124 ± 10 Ma. The ages are interpreted as cooling ages that record the post‐epidote–amphibolite stage in the exhumation of the rocks.Our results imply that both the high‐pressure metamorphism and the epidote–amphibolite‐facies overprint occurred prior to 125 Ma. Subduction of oceanic lithosphere along the eastern margin of the Sistan Ocean had therefore begun by Barremian (Early Cretaceous) times. Copyright © 2008 John Wiley & Sons, Ltd.
Prospective cohort study of lifetime physical activity and breast cancer survival
Authors: Friedenreich Christine M. , Gregory Jacqueline , Kopciuk Karen A. , Mackey John R. , Courneya Kerry S. 
Published: November 2008

AbstractFew studies have examined the association between physical activity and disease outcomes in breast cancer survivors. Here, we report the association between lifetime total physical activity performed prior to diagnosis and disease outcomes in a population‐based sample of breast cancer survivors. A cohort of 1,231 women diagnosed with breast cancer between 1995 and 1997 was followed for a minimum of 8.3 years for any cancer progressions, recurrences and new primaries; and a minimum of 10.3 years for deaths. All treatment and follow‐up care received was abstracted from medical records. Data on physical activity including type (occupational, household, recreational) and dose (frequency, intensity and duration) performed during the entire lifetime until diagnosis were examined in Cox proportional hazards models as well as with cumulative incidence curves. An average of 126 MET‐hr/week were reported for total physical activity (of which 13.9, 46.9 and 65.3 MET‐hr/week were, respectively, for recreational, occupational and household activity). A decreased risk of breast cancer death and all deaths was observed among women in the highest versus the lowest quartiles of recreational activity (MET‐hr/week/year) (HR = 0.54, 95% CI = 0.36–0.79). Both moderate (0.56, 95% CI = 0.38–0.82) and vigorous intensity recreational activity (0.74, 95% CI = 0.56–0.98) decreased the risk of breast cancer death. Moderate intensity recreational activity decreased the risk of a recurrence, progression or new primary cancer (0.66, 95% CI = 0.48–0.91). No other association with breast cancer survival was observed for other types of physical activity. Prediagnosis recreational activity conferred a benefit for survival after breast cancer. Moderate intensity recreational activity was particularly protective. © 2008 Wiley‐Liss, Inc.
Concurrent release of admixed antimicrobials and salicylic acid from salicylate‐based poly(anhydride‐esters)
Authors: Johnson Michelle L. , Uhrich Kathryn E. 
Published: November 2008

AbstractA polymer blend consisting of antimicrobials (chlorhexidine, clindamycin, and minocycline) physically admixed at 10% by weight into a salicylic acid‐based poly (anhydride‐ester) (SA‐based PAE) was developed as an adjunct treatment for periodontal disease. The SA‐based PAE/antimicrobial blends were characterized by multiple methods, including contact angle measurements and differential scanning calorimetry. Static contact angle measurements showed no significant differences in hydrophobicity between the polymer and antimicrobial matrix surfaces. Notable decreases in the polymer glass transition temperature (Tg) and the antimicrobials' melting points (Tm) were observed indicating that the antimicrobials act as plasticizers within the polymer matrix. In vitro drug release of salicylic acid from the polymer matrix and for each physically admixed antimicrobial was concurrently monitored by high pressure liquid chromatography during the course of polymer degradation and erosion. Although the polymer/antimicrobial blends were immiscible, the initial 24 h of drug release correlated to the erosion profiles. The SA‐based PAE/antimicrobial blends are being investigated as an improvement on current localized drug therapies used to treat periodontal disease. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
FIAT inhibition increases osteoblast activity by modulating Atf4‐dependent functions
Authors: Yu Vionnie W.C. , El‐Hoss Jad , St‐Arnaud René 
Published: November 2008

AbstractThe ATF4 transcription factor is a key regulator of osteoblast differentiation that controls osteocalcin gene transcription and type I collagen protein synthesis. We have characterized factor‐inhibiting ATF4‐mediated transcription (FIAT), a leucine zipper protein that dimerizes with ATF4 to form inactive dimers that cannot bind DNA. Overexpression of FIAT in osteoblasts of transgenic mice inhibited osteocalcin gene transcription and reduced osteoblastic activity, leading to osteopenia (Yu et al. [2005] J Cell Biol 169:591–601). We therefore hypothesized that inhibition of FIAT would enhance ATF4 activity, leading to increased osteocalcin transcription, type I collagen synthesis, and mineralization. We used small interfering RNAs (siRNA) to knockdown FIAT in pools of MC3T3‐E1 cells stably transfected with 1.3 kb of the mouse osteocalcin gene promoter driving expression of luciferase. Stable expression of the FIAT siRNA sequence inhibited FIAT expression without significantly affecting the level of total or Ribosomal S6 Kinase‐2‐phosphorylated ATF4 protein. Occupancy of the osteocalcin proximal promoter by ATF4 was increased and transcription of the osteocalcin‐promoter‐dependent luciferase reporter showed earlier onset and increased levels. Similarly, endogenous osteocalcin gene expression was enhanced in primary osteoblasts transfected with the FIAT siRNA. FIAT knockdown cells also displayed higher expression of bone sialoprotein, increased type I collagen protein synthesis, and enhanced mineralization. These data suggest that inhibition of FIAT expression increases ATF4 activity and confirm the important role of FIAT in osteoblast function. J. Cell. Biochem. 106: 186–192, 2009. © 2008 Wiley‐Liss, Inc.
Investigation of multiphase hydrogenation in a catalyst‐trap microreactor
Authors: McGovern S. , Harish G. , Pai C.S. , Mansfield W. , Taylor J.A. , Pau S. , Besser R.S. 
Published: November 2008

AbstractBACKGROUND: Multiphase hydrogenation plays a critical role in the pharmaceutical industry. A significant portion of the reaction steps in a typical fine chemical synthesis are catalytic hydrogenations, generally limited by resistances to mass and heat transport. To this end, the small‐scale and large surface‐to‐volume ratios of microreactor technology would greatly benefit chemical processing in the pharmaceutical and other industries. A silicon microreactor has been developed to investigate mass transfer in a catalytic hydrogenation reaction. The reactor design is such that solid catalyst is suspended in the reaction channel by an arrangement of catalyst traps. The design supports the use of commercial catalyst and allows control of pressure drop across the bed by engineering the packing density.RESULTS: This paper discusses the design and operation of the reactor in the context of the liquid‐phase hydrogenation of o‐nitroanisole to o‐anisidine. A two‐phase ‘flow map’ is generated across a range of conditions depicting three flow regimes, termed gas‐dominated, liquid‐dominated, and transitional, all with distinctly different mass transfer behavior. Conversion is measured across the flow map and then reconciled against the mass transfer characteristics of the prevailing flow regime. The highest conversion is achieved in the transitional flow regime, where competition between phases induces the most favorable gas–liquid mass transfer.CONCLUSION: The results are used to associate a mass transfer coefficient with each flow regime to quantify differences in performance. This reactor architecture may be useful for catalyst evaluation through rapid screening, or in large numbers as an alternative to macro‐scale production reactors. Copyright © 2008 Society of Chemical Industry
An investigation of the 125I‐radioiodination of colchicine for medical purposes
Authors: El‐Azony K. M. , El‐Mohty A. A. , Killa H. M. , Seddik U. , Khater S. I. 
Published: November 2008

AbstractA procedure for radioiodination of colchicine with iodine‐125 is carried out via an electrophilic substitution reaction. The reaction parameters studied were colchicine concentration, pH of the reaction mixture, reaction time, temperature, different oxidizing agents and different organic media to optimize the conditions for the labeling of colchicine and to obtain a high radiochemical yield of the 125I‐colchicine (125I‐Col). Using 3.7 MBq of Na125I, 1.25 mM of colchicine as substrate, 1.1 mM of chloramine‐T (CAT) as oxidizing agent in ethanol at 60°C for 5 min, a maximum radiochemical yield of 125I‐Col (60%) was obtained. The specific activity of 125I‐Col obtained was 44.4 MBq/0.5 mmol, and the labeled compound was not completely separated and purified from Col by means of high‐pressure liquid chromatography (HPLC), so the uncertainty in the purity may affect the distribution and clearance routes due to the expected competition between 125I‐Col and Col. The biological distribution in normal mice indicates the suitability of radioiodinated colchicine for imaging of muscles. Copyright © 2008 John Wiley & Sons, Ltd.