bluuebunny/crossref_metadata_2025_split huggingface dataset:
L,L‐Lactide and ε‐Caprolactone Block Copolymers by a ‘Poly(L,L‐lactide) Block First’ Route
Authors: Florczak Marcin , Libiszowski Jan , Mosnacek Jaroslav , Duda Andrzej , Penczek Stanislaw 
Published: June 2007

AbstractL,L‐lactide (LA) and ε‐caprolactone (CL) block copolymers have been prepared by initiating the poly(ε‐caprolactone) (PCL) block growth with living poly(L,L‐lactide) (PLA*). In the previous attempts to prepare block copolymers this way only random copolyesters were obtained because the PLA* + CL cross‐propagation rate was lower than that of the PLA–CL* + PLA transesterification. The present paper shows that application of Al‐alkoxide active centers that bear bulky diphenolate ligands results in efficient suppression of the transesterification. Thus, the corresponding well‐defined di‐ and triblock copolymers could be prepared.magnified image
Morphology Transition in Ultrathin Titania Films: From Pores to Lamellae
Authors: Cheng Ya‐Jun , Zhou Shaoying , Gutmann Jochen S. 
Published: June 2007

AbstractNanostructured TiO2 thin films were prepared using an amphiphilic PS‐b‐PEO block copolymer as a templating agent. A good–poor solvent pair‐induced pair phase separation process was coupled with sol–gel chemistry to control the morphology of the TiO2 film in a solution of 1,4‐dioxane, concentrated HCl, and titanium tetraisopropoxide (TTIP). By varying the block copolymer concentration from 0.25 to 4.0 wt.‐% while keeping the relative ratios among 1,4‐dioxane, conc. HCl, and TTIP constant, a morphology transition from pores to lamellae was observed. The photoluminescence (PL) properties of the film composed of different morphologies were studied, and the PL properties were found to be independent of the morphologies of the mesoporous films. The mechanism of the morphology evolution with respect to the copolymer concentration is further discussed.magnified image
NMR Reveals Non‐Distributed and Uniform Character of Network Chain Dynamics
Authors: Saalwächter Kay , Sommer Jens‐Uwe 
Published: June 2007

AbstractResults of different NMR investigations of elastomers are reviewed with respect to their significance for statistical models of rubber elasticity. In contrast to earlier work based on lineshape analysis and relaxometry, results of recent multiple‐quantum experiments indicate that the NMR‐detected dynamic chain order parameter, which reflects the conformational space of individual monomer units at which the signal is detected locally, is a rather narrowly distributed quantity. Constraints to the dynamics and the conformations of a network chain thus act uniformly and appear as a dynamic average over chains of different length and with different end‐to‐end separations. All our findings are in good agreement with large‐scale computer simulations. Anomalies on swelling such as chain desinterspersion at the early stages and the appearance of heterogeneities, are also discussed.magnified image
Towards Controlled Graft Polymerization of Poly[styrene‐co‐(maleic anhydride)] on Functionalized Silica Mediated by Oxoaminium Bromide Salt. Facile Synthetic Pathway Using Nitroxide Chemistry
Authors: Bonilla‐Cruz José , Lara‐Ceniceros Tania , Saldívar‐Guerra Enrique , Jiménez‐Regalado Enrique 
Published: June 2007

AbstractA TEMPO bromide salt is used to functionalize a silica surface with nitroxyl moieties. The functionalization reaction takes place in 48 h under mild conditions. In a second step, grafts of styrene‐maleic anhydride copolymer are grown from the functionalized silica surface by heating it in the presence of the monomers. FT‐IR and TGA analysis show that the silica was first functionalized with nitroxide moieties, and then that grafts of styrene‐maleic anhydride grew from the functionalized silica surface. A reaction mechanism is proposed in order to explain the findings. The results suggest that the oxoaminium salts are good candidates for the functionalization and grafting of surfaces that contain hydroxy groups and for the generation of hybrid materials with improved properties.magnified image
A Preparation Method for Well‐Defined Crystallites of Mgcl2‐Supported Ziegler‐Natta Catalysts and their Observation by AFM and SEM
Authors: Andoni Adelaida , Chadwick John C. , Niemantsverdriet Hans J. W. , Thüne Peter C. 
Published: June 2007

AbstractA method for the preparation of well‐defined crystallites of MgCl2‐supported Ziegler‐Natta catalysts on Si wafers has been developed. This has been achieved by the spin‐coating of a MgCl2 solution onto a flat Si wafer, followed by controlled crystal growth to give well‐defined MgCl2 · nEtOH crystallites. The growth of the crystallites on the flat silica facilitates their characterization using electron and scanning probe microscopy. The relative proportions of 120° and 90° edge angles indicate the preference for the formation of a particular crystallite face for the MgCl2. Polyethylene has been identified to be formed on the lateral faces of the crystallite.magnified image
Neue Kapseltechnik für Diamantverbundwerkstoffe mittels PVD‐Verfahren
Authors: Tillmann W. , Gathen M. , Vogli E. , Ullrich C. 
Published: June 2007

AbstractFür die Bearbeitung mineralischer Materialien werden Diamantwerkzeuge bestehend aus diamantimprägnierten Segmenten, aufgelötet auf Stahlträgerkörpern eingesetzt. Diese Segmente werden häufig mittels Heißpressen hergestellt. Weitere Herstellungsverfahren sind druckloses Sintern von Grünkörpern teilweise kombiniert mit heißisostatischem Pressen und das heißisostatische Pressen gekapselter Pulvermischungen. Der Verdichtungseffekt des heißisostatischen Pressprozesses erfordert eine geringe Porosität der Sinterkörper erzielt durch die Verwendung ultra‐feiner Metallpulver oder den Einsatz gasdichter Metall‐ oder Glaskapseln. Der Lehrstuhl für Werkstofftechnologie verfolgt eine neuartige Herstellungsroute, bei der mittels PVD‐Verfahren eine Beschichtung auf den drucklos gesinterten Sinterkörpern abgeschieden wird. Diese dünne Schicht wirkt ähnlich einer Kapsel und garantiert die Druckübertragung während des anschließenden heißisostatischen Pressprozesses. Trotz des Einsatzes von Bronzepulvern mit Korngrößen bis zu 90 μm ist die Herstellung dichter diamantimprägnierter Verbundwerkstoffe möglich. Im Vergleich zu konventionellen Kapseltechniken liegt der Vorteil dieser neuen Prozessroute in dem Einsatz verhältnismäßig grober Metallpulver und der hohen geometrischen Flexibilität.
First case of X‐linked dystonia‐parkinsonism (“Lubag”) to demonstrate a response to bilateral pallidal stimulation
Authors: Evidente Virgilio Gerald H. , Lyons Mark K. , Wheeler Mark , Hillman Renee , Helepolelei Luann , Beynen Froukje , Nolte Dagmar , Müller Ulrich , Starr Philip A. 
Published: June 2007

Abstract“Lubag” or X‐linked dystonia‐parkinsonism (XDP) is a genetic syndrome afflicting Filipino men. Intracranial surgical procedures for Lubag have been unsuccessful. We report a 45‐year‐old Filipino male with genetically confirmed XDP who underwent bilateral pallidal deep brain stimulation (DBS) surgery. The patient started to exhibit improvement on initial programming, most notably of his severe jaw‐opening dystonia. At 1‐year follow‐up, his Burke‐Fahn‐Marsden dystonia score and motor Unified Parkinson's Disease Rating Scale score were improved by 71% and 62%, respectively, with the stimulators on compared to stimulators off state. Bilateral pallidal DBS may be a viable option for Lubag patients with medically refractory symptoms. © 2007 Movement Disorder Society
Variation of selective gray and white matter atrophy in Huntington's disease
Authors: Jech Robert , Klempíř Jiří , Vymazal Josef , Židovská Jana , Klempířová Olga , Růžička Evžen , Roth Jan 
Published: June 2007

AbstractThe relationship between the extent of local gray/white matter atrophy, genetic load, and clinical impairment was studied in Huntington's disease (HD) by means of voxel‐based morphometry. T1‐weighted brain images from 33 patients (mean age 49.5, range 25–73 years) with HD duration of 1 to 15 years were analyzed by correlation of each voxel intensity with the number of CAG triplets and the UHDRS‐motor score (P < 0.001). The CAG number correlated inversely with gray matter intensity in the caudate nuclei and with white matter intensity in the both postcentral gyri and the right cerebellum. The UHDRS‐motor score correlated inversely with the atrophy of both caudates, right hippocampus, calcarine fissure, and with the white matter along the fourth and lateral ventricles. While atrophy of the caudate nucleus was related to a higher number of CAG triplets and higher UHDRS‐motor score, atrophy in other parts of the brain covaried with the two parameters differently: higher genetic load was associated with greater loss of cortical somatosensory projections and the worse UHDRS‐motor score was accompanied by increased atrophy of the internal capsule, lower brainstem, hippocampus, and visual cortex. According to our results, the genetic load in HD predicts partially the extent of selective gray/white brain matter atrophy, which is then reflected in the severity of motor impairment. © 2007 Movement Disorder Society
Dopa‐responsive pseudo‐orthostatic tremor in parkinsonism
Authors: Thomas Astrid , Bonanni Laura , Antonini Angelo , Barone Paolo , Onofrj Marco 
Published: June 2007

AbstractIn four patients an inabilitating standing tremor appeared years before that parkinsonian symptoms were evidenced. This tremor was refractory to gabapentin and dramatically responded to Levodopa administration. Its dominant frequency was 6.2 to 6.9 Hz with sporadic subharmonics at 8 to 18 Hz. Three patients were affected by different genetic mutations (Park 2, Park 6, mtDNA deletion) in one no genetic or metabolic alterations could be evidenced. All patients had dopamine transporter abnormalities. We suggest that the term “Pseudo‐Orthostatic Tremor” could be used to define this Dopa responsive, 6 to 7 Hz standing tremor. © 2007 Movement Disorder Society
Navier–Stokes equations in aperture domains: Global existence with bounded flux and time‐periodic solutions
Authors: Crispo Francesca , Maremonti Paolo 
Published: June 2007

AbstractWe consider the Navier–Stokes equations in an aperture domain of the three‐dimensional Euclidean space. We are interested in proving the existence of regular solutions corresponding to small initial data and flux through the aperture. The flux is assumed to be smooth and bounded on (0, +∞). As a consequence, we prove the existence of a time‐periodic solution corresponding to a time‐periodic flux through the aperture. Finally, we compare our solution with a solution belonging to a wider class, showing that, if such a solution does exist, then the two solutions coincide. Copyright © 2007 John Wiley & Sons, Ltd.
Role of dietary lignans in the reduction of breast cancer risk
Authors: Saarinen Niina M. , Wärri Anni , Airio Maarit , Smeds Annika , Mäkelä Sari 
Published: June 2007

AbstractLignans are a large group of fiber‐associated phenolic compounds widely distributed in edible plants. Some of the ingested plant lignans are converted by intestinal microbiota to enterolignans, enterodiol (END) and enterolactone (ENL), the latter of which has been thought to be the major biologically active lignan, and suggested to be associated with low risk of breast cancer. In line with this, administration of plant lignans which are further metabolized to ENL, or ENL as such, have been shown to inhibit or delay the growth of experimental mammary cancer. The mechanism of anticarcinogenic action of ENL is not yet fully understood, but there is intriguing evidence for ENL as a modulator of estrogen signaling. These findings have generated interest in the use of lignans as components of breast cancer risk reducing functional foods. Identification of target groups, who would benefit most, is of pivotal importance. Therefore, further identification and validation of relevant biomarkers, which can be used as indicators of lignan or ENL action and breast cancer risk reduction at different stages of the disease, are of importance.
Bioavailability of soy isoflavones in rats Part I: Application of accurate methodology for studying the effects of gender and source of isoflavones
Authors: Sepehr Estatira , Cooke Gerard , Robertson Patrick , Gilani G. Sarwar 
Published: June 2007

AbstractThere are limited and controversial reports about the effects of gender and source of isoflavones on their bioavailability. Moreover, several previous studies have not used appropriate methodology to determine the bioavailability of soy isoflavones, which requires comparing the area under the plasma concentration‐time curve after both oral and intravenous injection (IV) administration. Therefore, the present study was conducted to determine the bioavailability of isoflavones from different sources following both oral and IV administration in male and female rats. Three sources of isoflavones; NovasoyTM (a commercial supplement), a mixture of synthetic aglycones (daidzein, genistein and glycitein) and a mixture of synthetic glucosides (daidzin, genistin and glycitin) were tested. Following administration, blood samples were collected at several time points (0, 10, 30 min and 1, 2, 8, 24, 48 h post oral gavage and 0, 10, 30, 45 min and 1, 2, 3, 4, 8 h post‐IV dosing) and plasma isoflavones were measured by LC/MS. Bioavailability values for daidzein, genistein and glycitein were significantly (p <0.05) higher (up to sevenfold) in NovasoyTM and the glucoside forms of isoflavones compared with those of the aglycone forms. Moreover, significant (p <0.05) gender differences in the bioavailability of 7‐hydroxyl‐3‐(4′‐hydroxyphenyl)‐chroman (a metabolite of daidzein), glycitein and daidzein were observed for NovasoyTM, with higher values in male rats. In summary, the source of isoflavones and the sex of rats had significant effects on isoflavone bioavailability.
Simplified description of asymmetric right‐handed composite right/left‐handed coupler in microstrip chip technology
Authors: Wang Youzhen , Zhang Yewen , Liu Fuqiang , He Li , Li Hongqiang , Chen Hong , Caloz Christophe 
Published: June 2007

AbstractThe coupling frequency range of the asymmetric coupler composed of a conventional microstrip right‐handed (RH) transmission line and a composite right/left‐handed (CRLH) transmission line with lumped‐elements is investigated. It shows theoretically that the coupling frequency range can be explicitly determined by the given formulas. In the coupling frequency range, the effective permittivity and permeability of the CRLH transmission lines are both negative, at the same time the product of the average permittivity and the average permeability is negative, i.e., ϵL < 0, μL < 0, and $\bar{\varepsilon}$ · $\bar{\mu}$ < 0. Two types of RH‐CRLH couplers are designed, simulated, and measured. The coupling frequency range obtained from the simulated and the experimental results confirms the theoretical results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2063–2068, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22643
Compact printed semi‐elliptical monopole antenna for super‐wideband applications
Authors: Yan Xiao‐Rong , Zhong Shun‐Shi , Liang Xian‐Ling 
Published: June 2007

AbstractA compact semi‐elliptical patch antenna fed by a tapered coplanar waveguide is introduced for super‐wideband (SWB) applications. The simulated and experimental results demonstrate that the antenna possesses the desirable SWB characteristics, achieving a ratio bandwidth of 19.7:1 for VSWR ≤ 2, and exhibits a nearly omni‐directional radiation pattern, while its area is only about 0.15λl × 0.21λl, where λl is the wavelength of the lowest operating frequency. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2061–2063, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22644
A bandpass filter with harmonic suppression using SIR and zigzag coupling
Authors: Guan Fu‐Hong , Gu Jian‐Zhong , Sun Xiao‐Wei 
Published: June 2007

AbstractThis article presents a new compact, low‐insertion loss, wide stopband, and narrow‐band microstrip bandpass filter using a step‐impedance resonators. A compact filter operated at 2.13 GHz is designed. Experimental results show that the insertion loss of the filter is 1.08 dB and the upper stopband is extended over 8.5 GHz. The effect of varying the width and shape of the couple line to the performance of the filter has been studied. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2071–2074, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22647
Spiral patch with wideband and circular polarization for millimeter‐wave communication
Authors: He Wei , Jin Ronghong , Yang Junping G. G. 
Published: June 2007

AbstractIn this study, a spiral patch antenna operating millimeter‐wave band is proposed. Using this spiral structure, the patch antenna is designed for circular polarization and wideband operation at about 30.8–36.9 GHz for millimeter‐wave communication. Simulated and measured results for main parameters such as return loss, impedance bandwidth, radiation patterns, and gains are also discussed herein. The study shows that the modeling of such antennas, with simplicity in designing and feeding, can well meet millimeter‐wave wireless communication. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2068–2071, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22648
Simultaneous noise and input matched ultra wide band LNA design
Authors: Shim Yuna , Kim Chang‐Wan , Lee Sang‐Gug 
Published: June 2007

AbstractProposed a low noise amplifier (LNA) design technique that satisfies simultaneous noise and input matched condition over ultra wide band (UWB) frequency range. Simultaneously, noise‐ and input‐matched UWB LNA is implemented in 0.18 μm CMOS technology, and measurements show higher than 8 dB of input return loss, maximum gain of 10.5 dB, and noise figure of 3.9–6 dB over 2–4 GHz while dissipating 4 mA from a 1.8‐V supply. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2275–2279, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22650
Effects of varying the series capacitance in CSRR‐loaded metamaterial transmission lines
Authors: Vélez Adolfo , Bonache Jordi , Martín Ferran 
Published: June 2007

AbstractIn this work, the effects of varying the series capacitance in metamaterial transmission lines consisting on a microstrip line loaded with complementary split rings resonators (CSRRs) and series capacitors are analyzed in detail. It is found that by varying the series capacitance, the transmission characteristics of the line can be tailored. Specifically, the typical transmission zero present below the left handed band, as well as the limits of this band, are modified. It is even possible to balance the line by properly tuning the structure. These results are interpreted to the light of the equivalent circuit model of the unit cell. Comparison between experiment and theory supports the interpretation of the results. This work opens the door to the design of reconfigurable microwave components based on complementary split rings resonator‐loaded lines. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2245–2248, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22651
Broad band behavioral modeling of on‐chip RF inductors and transformers
Authors: Bhattacharya Rajarshi , Bhattacharyya T. K. , Dutta Asudeb 
Published: June 2007

AbstractThe broad band behavioral models of on‐chip inductors and transformers are extracted from sampled frequency response data. A linearized least square based model parameter extraction algorithm is used to obtain ‘s’‐domain rational function model. Model order is optimized to strike a balance between modeling error and time required for transient simulation of circuits consisting of on‐chip inductors and/or transformers. A new cost function is proposed to improve optimal model order selection. Particle swarm optimization (PSO) is applied to maximize the nonconvex fitness function, associated with model order optimization. A modification of PSO algorithm is proposed to speed up optimal model order selection. While modeling on‐chip inductors and transformers, the proposed modeling technique extracts highly accurate, yet reduced order models, which are valid over a wide band width and are compatible with SPICE‐like simulators. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2212–2216, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22653
Design of Yagi‐like printed antennas for WLAN applications
Authors: Ávila‐Navarro E. , Carrasco J. A. , Reig C. 
Published: June 2007

AbstractA directive broadband printed Yagi‐like antenna design is presented. We have focused on the 2.45 GHz WLAN band, at which some designs have been carried out. For the design and the modelling processes, we made use of FDTD based in‐house developed algorithms. Some selected prototypes have then been fabricated onto a low‐cost printed circuit board dielectric substrate and tested successfully. Bandwidths higher than 10% and moderate to high (>7 dBi) gains can be obtained this way. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2174–2178, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22655
A half‐moon antenna with tilt angles for wideband applications
Authors: Jung Chang Won , Kim Yongjin 
Published: June 2007

AbstractA half‐moon antenna is presented for wideband communication system. The proposed antenna radiates linear polarized wave omnidirectionally in wide frequency band from 1.5 GHz to more than 5 GHz (>∼110%). The frequency bands of the proposed antenna are investigated from the variable current path lengths by tilting angles. The overall radiation gain of the proposed antenna is 2–3 dBi. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2171–2174, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22656
High frequency RFID smart table antenna
Authors: Cai Ailian , Qing Xian Ming , Chen Zhi Ning 
Published: June 2007

AbstractIn this paper, loop antenna is investigated for high frequency (HF) radio frequency identification (RFID) smart table application. The antenna is optimized by making a compromise between the coverage and detection range. The performance test shows that the antenna is capable of detecting 90 plastic plates in a specific area (500 × 500 mm2) and achieving a detection rate of 100% when it was installed below a wood/plastic table. The proposed antenna has been successfully implemented in an HF RFID smart table prototype for a restaurant to count food plates and bill customers automatically. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2074–2076, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22662
Determining transmission zeroes of the general Chebyshev filter
Authors: Chu Qing‐Xin , Tu Zhi‐Hong 
Published: June 2007

AbstractDetermining transmission zeroes is the important precondition in the synthesis of the cross‐coupled filter. A novel method to determine the general Chebyshev filter degree and transmission zeroes at the same time is proposed, according to the extreme characteristic of the general Chebyshev function and the relationship between the filter degree and the number of transmission zeros. On the condition of given filter specifications, the least filter degree and the optimum positions of transmission zeroes are realized. Several application examples illustrate the procedure and the validity of the proposed method. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2270–2275, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22663