bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zinc Oxide Thin Films Grown by Aerosol Assisted CVD
Authors: Waugh Mathew R. , Hyett Geoffrey , Parkin Ivan P. 
Published: December 2008

AbstractZinc oxide (ZnO) thin films are deposited at 400–650 °C onto glass substrates by aerosol assisted (AA)CVD of a zinc acetate [Zn(C2H3O2)2] solution in methanol. The thin films show high transparency over the visible and infrared regions (80–95%) and a 001 (c‐axis) preferred orientation. The surface morphology and crystallographic orientation are dependent on the substrate temperature. The photocatalytic activity of the films is determined using the destruction of stearic acid (SA) by UV irradiation. The rate is monitored via infrared spectroscopy (IRS) and shows appreciable activity, close to that seen for anatase titania, in the films deposited at 650 °C. Water droplet contact angles on both ambient and UV‐irradiated ZnO surfaces are determined, and there is seen to be an increase in photoinduced hydrophillicity for all films, with a reduction in contact angle of around 50 °.
Formal Synthesis of Natural 1,3‐Polyol/α‐Pyrone Diastereoisomers
Authors: Sabitha Gowravaram , Gopal Peddabuddi , Yadav Jhillu S. 
Published: December 2008

AbstractA stereoselective formal synthesis of diastereoisomers of 1,3‐polyol/α‐pyrone antifungal natural products isolated from Ravensara anisata has been achieved involving epoxide opening and asymmetric allylation as key steps.
Limonoids from the Twigs and Leaves of Chukrasia tabularis
Authors: Zhang Chuan‐Rui , Yang Sheng‐Ping , Chen Xue‐Qin , Wu Yan , Zhen Xue‐Chu , Yue Jian‐Min 
Published: December 2008

AbstractSeven new limonoids, tabularisins J–P (1–7, resp.), together with eight known compounds, were isolated from the twigs and leaves of Chukrasia tabularis. Their structures were determined primarily by spectroscopic methods. The potassium channel blocking activities of some of these isolates were evaluated, and a few of them exerted significant activities on the delayed rectifier (IK) K+ current.
A New Synthesis of Ciliapterin and Dictyopterin. Ene Reactions of (Alkenylamino)‐nitroso‐pyrimidines
Authors: Zhang Fang‐Li , Vasella Andrea 
Published: December 2008

AbstractA comparison of the reactivity of (acylamino)‐nitroso‐pyrimidines 1 and the alkenylamino analogue 17 in intramolecular ene reactions showed the considerably lower reactivity of 17, leading to the pteridine 18. Pteridin‐7‐one 11 resulting from 1 (R1=OBn, R2=Me) was transformed into 4‐(benzyloxy)‐6‐[(E)‐prop‐1‐enyl]pteridin‐2‐amine (13) by O‐triflation, followed by reduction with LiBHEt3, while the 4‐MeO analogue 18 was prepared by spontaneous oxidation of the initial ene product of 17. The (alkenylamino)‐nitroso‐pyrimidine 17 was synthesized by substitution of the dimethoxy‐nitroso‐pyrimidine 16 with the allylamine 15. Ciliapterin (5) and dictyopterin (7) were synthesized from pteridine 18 by a Sharpless asymmetric dihydroxylation.
Functional PLGA Scaffolds for Chondrogenesis of Bone‐Marrow‐Derived Mesenchymal Stem Cells
Authors: Park Kwideok , Cho Kyoung‐Jin , Kim Jae‐Jin , Kim Ik‐Hwan , Han Dong Keun 
Published: December 2008

AbstractTwo chondrogenic factors, Dex and TGF‐β1, were incorporated into PLGA scaffolds and their chondrogenic potential was evaluated. The Dex‐loaded PLGA scaffold was grafted with AA and heparin, the heparin‐immobilized one was then reacted with TGF‐β1, yielding a PLGA/Dex‐TGF (PLGA/D/T) scaffold. The scaffolds were seeded with rabbit MSCs and cultured for 4 weeks. The results show that the scaffolds including chondrogenic factors strongly upregulated the expression of cartilage‐specific genes and clearly displayed type‐II collagen immunofluorescence. The functionalized PLGA scaffolds could provide an appropriate niche for chondrogenic differentiation of MSC without a constant medium supply of Dex and TGF‐β1.magnified image
The effect of heat treatment on the corrosion behaviour of 319 aluminium alloy
Authors: Panagopoulos C. N. , Georgiou E. P. , Giannakopoulos K. I. 
Published: December 2008

AbstractThe effect of various heat treatments on the corrosion behaviour of 319 T1 cast aluminium alloy was investigated. From this alloy, specimens were heat treated in T5, T6 and two steps solution heat treatment T6 conditions and afterwards were subjected to electrochemical corrosion in a 0.1 M NaCl solution (pH = 12). From the above treatments, T5 heat treatment did not improve the corrosion resistance of the as‐received alloy in contrast to T6 heat treatment which improved the corrosion resistance of the same alloy. However, two steps solutionizing T6 treatment showed the best corrosion resistance of the aluminium alloy.
Composite cerium oxide/titanium oxide thin films for corrosion protection of AZ91D magnesium alloy via sol–gel process
Authors: Fan J. M. , Li Q. , Kang W. , Zhang S. Y. , Chen B. 
Published: December 2008

AbstractAnti‐corrosive composite cerium oxide/titanium oxide (CeO2/TiO2) thin films were successfully prepared on an AZ91D magnesium alloy substrate by applying cerium oxide (CeO2) thin films as the inner layer with a sol–gel process. Composition and surface morphology of the thin films were analyzed using X‐ray diffraction (XRD) and scanning electron microscope (SEM). XRD showed that the composite films consisted of cerianite and anatase phases. The wettability of the thin films was evaluated by water contact angles measurements. Potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) tests were used to evaluate the corrosion behavior of the bare substrate and coated samples in 3.5 wt% sodium chloride solution (3.5 wt% NaCl). The results demonstrated that titanium oxide (TiO2) thin film mainly dominated the corrosion resistance of samples and the composite films with excellent hydrophilicity could significantly improve the corrosion resistance of AZ91D magnesium alloy.
Polymer‐Solvent Interactions in Solutions of Thermoresponsive Polymers Studied by NMR and IR Spectroscopy
Authors: Spěváček Jiří , Starovoytova Larisa , Hanyková Lenka , Kouřilová Hana 
Published: December 2008

AbstractSummary: NMR relaxation and diffusion coefficient measurements revealed that a portion of water molecules is bound in mesoglobules formed in poly(N‐isopropylmethacrylamide) (PIPMAm) and poly(vinyl methyl ether) (PVME) aqueous solutions above the LCST, with fast exchange between bound and free states (residence time ∼1 ms). Two types of bound water molecules were assigned to water bound inside mesoglobules and on their surface. For highly concentrated PVME/D2O solutions (c ≥ 20 wt%) a slow exchange was detected by NMR for bound water (residence time = 2.1 s). For PIPMAm aqueous solution IR spectra indicate a two‐steps character of the phase transition. For PIPMAm in D2O/ethanol (EtOH) mixtures the globular structures were observed by NMR at 298 K for certain compositions of the mixed solvent (cononsolvency effect). Virtually no EtOH is bound in these globular structures, in contrast to the temperature‐induced globular structures.
Swelling of Acrylic Interpenetrating Polymer Networks in Liquid Crystals
Authors: Boudraa Kamel , Bouchaour Tewfik , Maschke Ulrich 
Published: December 2008

AbstractSummary: The swelling properties of acrylate based polymer networks in anisotropic solvents (LCs) are examined. Two Interpenetrating Polymer Networks (IPNs) consisting of crosslinked poly(ethyl hexyl‐acrylate) (PolyEHA) and poly(n butyl‐acrylate) (PolyABu) are investigated. The samples are prepared by sequential UV‐curing of the monomers in the presence of a cross‐linking agent and a photo‐initiator. Microscopy observations are used to measure the diameter of the samples in the dry and swollen states and to deduce the kinetics of polymer‐solvent swelling for different systems. The theoretical calculations based on the Fick model are presented.
Stabilisation of the Secondary Structure of Chitosan Gels during the Preparation of Composites
Authors: Djelad A. , Morsli A. , Robitzer M. , Bengueddach A. , Di Renzo F. , Quignard F. 
Published: December 2008

AbstractSummary: Zeolite‐chitosan composites have been prepared by encapsulation of zeolites by a gelling solution of chitosan or by in‐situ synthesis of zeolites inside a chitosan gel. The preparation of the composite implies modifications of both components. Zeolites are dealuminated by the acid solution in which chitosan is dissolved and the morphology of the chitosan fibrils is stabilized by iniorganic species issued from the dealumination of the zeolites or from their synthesis medium. Zeolite‐bearing chitosan xerogels present surface area and porosity similar to the textural properties of chitosan aerogels.
A Sonogel/L‐Cystein and a SAM L‐Cystein Modified Electrodes for Detection of Dopamine
Authors: Bouhouti H. El , Rodriguez I. Naranjo , de Cisneros J.L. Hidalgo Hidalgo , Temsamani K. R. , Choukairi M. , Bouchta D. 
Published: December 2008

AbstractSummary: The Sonogel‐Carbon electrode is a special class of sol‐gel electrode that exhibits favourable mechanics and electric properties that can be used as electrochemical sensors. In this study, a Sonogel‐Carbon modified with L‐Cysteine was used to prepare a novel electrochemical sensor. The objective of this new electrode modification was to seek new electrochemical performances for thedetection of dopamine (DA). The influence of natural interferents such as Ascorbic Acid (AA) and Uric Acid (UA) was explored. The concentration of theses strong interferent was increased to a certain level in order to determine to what extends AA and UA may disturb the neurotransmitters electroanalysis. Our work showed that the modified electrode offers interesting analytical performances such as:(a) Fast and linear responses towards the neurotransmitter dopamine: The differential pulse voltammetry current peak was linear with the DA concentration in the range 2 · 10−7 M to 10−5 M with a detection limit of 4 · 10−8 M (S/N = 3).(b) Simultaneous detection and well‐resolved signals between the DA, AA and UA: The new sensor could sensitively and separately determine DA in the presence of 1000 and 900 times higher concentrations of AA and UA respectively.Optimization of parameters such as the amount of L‐cysteine in the Sonogel‐Carbon mixture, interference effect, perm‐selectivity and mechanical stability of the sensor are discussed. A comparison with a SAM L‐Cysteine/gold electrode was also made.On the other hand the new Sonogel modified electrode has been applied to the determination of dopamine in urine samples with satisfactory results.With good selectivity and sensitivity, the proposed sensor is a simple tool for the selective detection of DA, AA and UA in biological samples.
Influence of Supercritical Carbon Dioxide Extraction Temperature on the Crystalline Structure and the Morphology of Syndiotactic Polystyrene Aerogels
Authors: Daniel Christophe , Giudice Simona , Guerra Gaetano 
Published: December 2008

AbstractSummary: In this manuscript the influence of supercritical carbon dioxide extraction temperature on the morphology, the porosity, and the crystalline structure of syndiotactic polystyrene aerogels is investigated. Results show that depending on the extraction temperature, δ‐form, γ‐form, and β‐form high porosity aerogels characterized by a fibrillar morphology can be obtained.
1H and 13C NMR assignments for two new steroids from the coral Chromonephthea sp.
Authors: Geng Hua‐Wei , Liao Xiao‐Jian , Xu Shi‐Hai 
Published: December 2008

AbstractTwo new steroids isolated from EtOH extracts of the South China Sea soft coral Chromonephthea sp. were identified. One‐dimensional (1D) and two‐dimensional (2D) NMR experiments including COSY, HSQC, HMBC and NOESY were used for the determination of their structure. Copyright © 2008 John Wiley & Sons, Ltd.
NMR spectroscopic characterization of inclusion complexes comprising cyclodextrins and gallated catechins in aqueous solution: cavity size dependency
Authors: Ishizu Takashi , Tsutsumi Hiroyuki , Yamamoto Hideji , Harano Kazunobu 
Published: December 2008

AbstractThe structure of inclusion complexes of γ‐cyclodextrin (γ‐CD), (–)‐gallocatechin gallate (GCg), and (–)‐epigallocatechin gallate (EGCg) in D2O was investigated using several NMR techniques. GCg formed a 1:1 inclusion complex with γ‐CD in which the A and C rings of GCg were inserted deep at the head of the A ring into the γ‐CD cavity from the wide secondary hydroxyl group side. In the 1:1 inclusion complex with GCg and γ‐CD, the GCg moiety maintained a conformation in which the B and B′ rings of GCg took both pseudoequatorial positions with respect to the C ring. The structure of the inclusion complex of GCg and γ‐CD obtained from NMR experiments supported well that determined from PM6 semiempirical SCF MO calculations. However, 1H NMR experiments suggested that EGCg did not form any inclusion complex with γ‐CD in D2O. The marked difference between GCg and EGCg in inclusion behavior toward γ‐CD may be explained in terms of the stabilization energy calculated with the PM6 method. Copyright © 2008 John Wiley & Sons, Ltd.
An adaptive resource reservation for vehicular mobile networks
Authors: Ben Hamida I. , Boukhatem L. 
Published: December 2008

AbstractThis paper presents the time‐based bandwidth reservation (TBR) algorithm, suitable for handoff management in cellular systems. TBR is based on real‐time measurements of mobile stations (position, velocity and acceleration). The scheme consists in sending reservation requests to the neighboring cells based on an extrapolation of the user's motion. The originality of our approach lies in dynamically adjusting the amount of time for which bandwidth has to be allocated and reserved in a cell. In addition, we propose an optimal channel requests arrangement (CRA) algorithm in order to improve the performance of TBR in terms of resource utilization. Finally, we propose VTBR, an adapted and extended version of TBR for better support of vehicular network specificities where service degradation or forced call termination may occur owing to frequent handoffs. Detailed simulation results for TBR and VTBR schemes and a comparison with the guard channel scheme are presented. The results show that TBR and VTBR can efficiently improve the flow dropping probability. Copyright © 2008 John Wiley & Sons, Ltd.
Modeling of materials with fading memory using neural networks
Authors: Oeser Markus , Freitag Steffen 
Published: December 2008

AbstractA neural network‐based concept for the solution of a fractional differential equation is presented in this paper. Fractional differential equations are used to model the behavior of rheological materials that exhibit special load (stress) history characteristics (e.g. fading memory). The new concept focuses on rheological materials that exhibit Newtonian‐like displacement behavior when undergoing (time varying) creep loads. For this purpose, a partial recurrent artificial neural network is developed. The network supersedes the storage of the entire load (stress) history in contrast to the exact solution of the fractional differential equation, where access to all previous load (stress) increments is required to determine the new displacement (strain) increment. The network is trained using data obtained from six different creep simulations. These creep simulations have been conducted by means of the exact solution of the fractional differential equation, which is also included in the paper. Furthermore, the network architecture as well as a complete set of network parameters is given. A validation of the network has been carried out and its outcome is discussed in the paper. To illustrate the particular way the network works, all relevant algorithms (e.g. scaling of the input data, data processing, transformation of the output signal, etc.) are provided to the reader in this paper. Copyright © 2008 John Wiley & Sons, Ltd.
The effect of cooking on the survivorship of jackrabbit skeletons (Lepus californicus) presented to desert scavengers of the eastern Great Basin, North America
Authors: Ugan Andrew 
Published: December 2008

AbstractIn order to study the effects of human processing decisions on consumption and destruction of small animal skeletons by scavengers, twenty‐six blacktailed jackrabbits were dry roasted or boiled and their skeletons presented to scavengers at various locations throughout the Sevier Desert of Utah. Skeletons of all samples were quickly and substantially destroyed, with roasted animals surviving at one‐half to one‐third the rate of their boiled counterparts. Survivorship of elements was unrelated to skeletal density in either case, but rather to the amount of adhering tissue, marrow, and fat. Axial elements tended to be preferentially destroyed, particularly in the case of roasting. These effects echo ethnographic and ethnoarchaeological observations on the relationship between cooking, length of site occupation, and small animal survivorship and carry clear implications for how we use the relative frequencies of large and small animals to interpret prehistoric subsistence. Copyright © 2008 John Wiley & Sons, Ltd.
Phenolysis of diaryl thiolcarbonates and thionocarbonates
Authors: Castro Enrique A. , Cepeda Marjorie , Pavez Paulina , Santos José G. 
Published: December 2008

AbstractThe phenolysis of phenyl S‐4‐nitrophenyl thiolcarbonate (1), 4‐chlorophenyl S‐4‐nitrophenyl thiolcarbonate (2), phenyl 4‐nitrophenyl thionocarbonate (3), 3‐chlorophenyl 4‐nitrophenyl thionocarbonate (4) and 3‐methoxyphenyl 4‐nitrophenyl thionocarbonate (5) are studied kinetically in 44 wt% ethanol–water, at 25.0 °C, ionic strength 0.2 M. The Brønsted plots (log kN vs. pKa of phenols) for the reactions of 1 and 2 are linear and those of 3, 4 and 5 are curved. The Brønsted slopes for 1 and 2 are 0.64 and 0.60, respectively, which suggest a concerted mechanism for these reactions. The curved Brønsted plots for the reactions of 3, 4 and 5 show slope values of 1.0, 1.1 and 1.1, respectively, at low pKa, and 0.39, 0.28 and 0.34, respectively, at high pKa. The shape and slope values of these Brønsted plots are in accordance with a stepwise mechanism. The reactivity towards phenoxides of the thiocarbonates increases with the increase in the Hammett σ value for the substituents in the non‐leaving group. The fact that the phenolysis of 3 is stepwise, whereas that of phenyl 4‐nitrophenyl carbonate is concerted can be attributed to the destabilization of the intermediate T−. A similar argument explains the stepwise phenolysis of 3, in contrast to the concerted phenolysis of 1, where there is an additional destabilization of T− caused by the change of the leaving group, from 4‐nitrophenoxide in 3 to 4‐nitrobenzenethiolate in 1. Thiolcarbonates 1 and 2 in 44 wt% ethanol–water are less reactive towards phenoxide anions (ca. 100‐fold) than their corresponding oxycarbonates in water. Copyright © 2008 John Wiley & Sons, Ltd.
Fullerene–ferrocene dyad linked by rigid bilinkage: synthesis, photophysical properties and application as copper ion sensor
Authors: Kumar Anish , Menon Shobhana K. 
Published: December 2008

AbstractA novel fullerene–ferrocene based donor–bridge–acceptor dyad was synthesized and characterized by elemental analysis, FT‐IR, 1H NMR, 13C NMR and FAB‐MS. The dyad with a bilinker comprising of azomethine and ester group was studied for its photo physical properties using absorption spectra and steady‐state fluorescence spectra as a function of dielectric constant of the medium. Fluorescence spectra of the dyad studied with excitation at 449 nm showed a weak emission at 742 nm, which got weaker on increasing the dielectric constant of the medium, indicating efficient electron transfer from ferrocene to fullerene. By designing a bilinked structure between the two redox moieties, we obtained a chelating structure which was found to coordinate copper ion efficiently and hence found application as a metal ion sensor. Copyright © 2008 John Wiley & Sons, Ltd.
Single Chain Epidermal Growth Factor Receptor Antibody Conjugated Nanoparticles for in vivo Tumor Targeting and Imaging
Authors: Yang Lily , Mao Hui , Wang Y. Andrew , Cao Zehong , Peng Xianghong , Wang Xiaoxia , Duan Hongwei , Ni Chunchun , Yuan Qingan , Adams Gregory , Smith Mark Q. , Wood William C. , Gao Xiaohu , Nie Shuming 
Published: December 2008

AbstractEpidermal growth factor receptor (EGFR) targeted nanoparticle are developed by conjugating a single‐chain anti‐EGFR antibody (ScFvEGFR) to surface functionalized quantum dots (QDs) or magnetic iron oxide (IO) nanoparticles. The results show that ScFvEGFR can be successfully conjugated to the nanoparticles, resulting in compact ScFvEGFR nanoparticles that specifically bind to and are internalized by EGFR‐expressing cancer cells, thereby producing a fluorescent signal or magnetic resonance imaging (MRI) contrast. In vivo tumor targeting and uptake of the nanoparticles in human cancer cells is demonstrated after systemic delivery of ScFvEGFR‐QDs or ScFvEGFR‐IO nanoparticles into an orthotopic pancreatic cancer model. Therefore, ScFvEGFR nanoparticles have potential to be used as a molecular‐targeted in vivo tumor imaging agent. Efficient internalization of ScFvEGFR nanoparticles into tumor cells after systemic delivery suggests that the EGFR‐targeted nanoparticles can also be used for the targeted delivery of therapeutic agents.
Direct Magnetic Patterning due to the Generation of Ferromagnetism by Selective Ion Irradiation of Paramagnetic FeAl Alloys
Authors: Menéndez Enric , Liedke Maciej Oskar , Fassbender Jürgen , Gemming Thomas , Weber Anja , Heyderman Laura J. , Rao K. V. , Deevi Seetharama C. , Suriñach Santiago , Baró Maria Dolors , Sort Jordi , Nogués Josep 
Published: December 2008

AbstractSub‐100‐nm magnetic dots embedded in a non‐magnetic matrix are controllably generated by selective ion irradiation of paramagnetic Fe60Al40 (atomic %) alloys, taking advantage of the disorder‐induced magnetism in this material. The process is demonstrated by sequential focused ion beam irradiation and by in‐parallel broad‐beam ion irradiation through lithographed masks. Due to the low fluences used, this method results in practically no alteration of the surface roughness. The dots exhibit a range of magnetic properties depending on the size and shape of the structures, with the smallest dots (<100 nm) having square hysteresis loops with coercivities in excess of µ0HC = 50 mT. Importantly, the patterning can be fully removed by annealing. The combination of properties induced by the direct magnetic patterning is appealing for a wide range of applications, such as patterned media, magnetic separators, or sensors.
Cancer‐Cell‐Phenotype‐Dependent Differential Intracellular Trafficking of Unconjugated Quantum Dots
Authors: Barua Sutapa , Rege Kaushal 
Published: December 2008

AbstractA diverse array of nanoparticles, including quantum dots (QDs), metals, polymers, liposomes, and dendrimers, are being investigated as therapeutics and imaging agents in cancer diseases. However, the role of the cancer‐cell phenotype on the uptake and intracellular fate of nanoparticles in cancer cells remains poorly understood. Reported here is that differences in cancer‐cell phenotypes can lead to significant differences in intracellular sorting, trafficking, and localization of nanoparticles. Unconjugated anionic QDs demonstrate dramatically different intracellular profiles in three closely related human‐prostate‐cancer cells used in the investigation: PC3, PC3‐flu, and PC3‐PSMA. QDs demonstrate punctated intracellular localization throughout the cytoplasm in PC3 cells. In contrast, the nanoparticles localize mainly at a single juxtanuclear location (“dot‐of‐dots”) inside the perinuclear recycling compartment in PC3‐PSMA cells, where they co‐localize with transferrin and the prostate‐specific membrane antigen. The results indicate that nanoparticle sorting and transport is influenced by changes in cancer‐cell phenotype and can have significant implications in the design and engineering of nanoscale drug delivery and imaging systems for advanced tumors.