bluuebunny/crossref_metadata_2025_split huggingface dataset:
Knockdown of amyloid precursor protein normalizes cholinergic function in a cell line derived from the cerebral cortex of a trisomy 16 mouse: An animal model of down syndrome
Authors: Opazo Patricia , Saud Katherine , de Saint Pierre Michelle , Cárdenas Ana María , Allen David D. , Segura‐Aguilar Juan , Caviedes Raúl , Caviedes Pablo 
Published: August 2006

AbstractWe have generated immortal neuronal cell lines from normal and trisomy 16 (Ts16) mice, a model for Down syndrome (DS). Ts16 lines overexpress DS‐related genes (App, amyloid precursor protein; Sod1, Cu/Zn superoxide dismutase) and show altered cholinergic function (reduced choline uptake, ChAT expression and fractional choline release after stimulation). As previous evidence has related amyloid to cholinergic dysfunction, we reduced APP expression using specific mRNA antisense sequences in our neuronal cell line named CTb, derived from Ts16 cerebral cortex, compared to a cell line derived from a normal animal, named CNh. After transfection, Western blot studies showed APP expression knockdown in CTb cells of 36% (24 hr), 40.4% (48 hr), and 50.2% (72 hr) compared to CNh. Under these reduced APP levels, we studied 3H‐choline uptake in CTb and CNh cells. CTb, as reported previously, expressed reduced choline uptake compared to CNh cells (75%, 90%, and 69% reduction at 1, 2, and 5 min incubation, respectively). At 72 hr of APP knockdown, choline uptake levels were essentially similar in both cell types. Further, fractional release of 3H‐choline in response to glutamate, nicotine, and depolarization with KCl showed a progressive increase after APP knockdown, reaching values similar to those of CNh after 72 hr of transfection. The results suggest that APP overexpression in CTb cells contributes to impaired cholinergic function, and that gene knockdown in CTb cells is a relevant tool to study DS‐related dysfunction. © 2006 Wiley‐Liss, Inc.
Bcl2 enhances survival of newborn neurons in the normal and ischemic hippocampus
Authors: Sasaki Tsutomu , Kitagawa Kazuo , Yagita Yoshiki , Sugiura Shiro , Omura‐Matsuoka Emi , Tanaka Shigeru , Matsushita Kohji , Okano Hideyuki , Tsujimoto Yoshihide , Hori Masatsugu 
Published: August 2006

AbstractNeuronal progenitors in the adult hippocampus continually proliferate and differentiate to the neuronal lineage, and ischemic insult promotes hippocampal neurogenesis. However, newborn neurons show a progressive reduction in numbers during the initial few weeks, therefore, enhanced survival of newborn neurons seems to be essential for therapeutic strategy. Bcl‐2 is a crucial regulator of programmed cell death in CNS development and in apoptotic and necrotic cell death. Therefore, we tested whether Bcl‐2 overexpression enhances survival of newborn neurons in the adult mouse hippocampus under normal and ischemic conditions. Many newborn neurons in the hippocampal dentate gyrus undergo apoptosis. Human Bcl‐2 expression in NSE‐bcl‐2 transgenic mice began at the immature neuronal stage and remained constant in surviving mature neurons. Bcl‐2 significantly increased survival of newborn neurons under both conditions, but particularly after ischemia, with decreased cell death of newborn neurons in NSE‐bcl‐2 transgenic mice. We also clarified the effect by Bcl‐2 overexpression of enhanced survival of newborn neurons in primary hippocampal cultures with BrdU labeling. These findings suggest that Bcl‐2 plays a crucial role in adult hippocampal neurogenesis under normal and ischemic conditions. © 2006 Wiley‐Liss, Inc.
Age‐dependent modulation of hippocampal long‐term potentiation by antioxidant enzymes
Authors: Watson J.B. , Arnold M.M. , Ho Y.‐S. , O'Dell T.J. 
Published: August 2006

AbstractOxidative stress has long been associated with normal aging and age‐related neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD). However, it is now evident that reactive oxygen species (ROS) such as superoxide (O) and hydrogen peroxide (H2O2) also play pivotal roles in normal cell signaling. The focus of the present study was to examine the effects of the antioxidant enzymes CuZnSOD (SOD1) and catalase, which produce and remove H2O2, respectively, on long‐term potentiation (LTP) forms of synaptic plasticity during aging. Consistent wth previous studies, LTP, when induced in vitro in CA1 of the hippocampus with a high‐frequency stimulation protocol, is significantly reduced in slices from older mice (22–26 months) relative to younger mice (2–4 months). Neither knockout of the endogenous catalase gene (Cat KO) nor acute enzymatic treatment with SOD1 altered LTP in slices from adult mice. Conversely, enzymatic applications of SOD1 inhibited LTP in slices from older mice. A much different set of results emerges with exogenous applications of catalase to hippocampal slices. Catalase significantly inhibited LTP in slices from adult mice but reversed age‐related LTP deficits in slices from older mice. Measurements of H2O2 showed that exogenous treatments with catalase lowered H2O2 in synapse‐enriched synaptoneurosome (SN) fractions prepared from adult mice. Notably, SNs from both Cat KO and old mice were deficient in removing extracellular challenges of H2O2. Overall, the results suggest that dynamic alterations in extracellular H2O2 metabolism affect synaptic plasticity in the hippocampus during aging. © 2006 Wiley‐Liss, Inc.
Study of the influence of some organics as thiourea derivatives and butindiol in steel pickling baths
Authors: Fernández Díaz L. M. , Bendick O. , Ostwald C. , Appel T. 
Published: August 2006

AbstractThe corrosion inhibition effect of the following organic additives: 2‐butin‐1,4‐diol (BD), N,N′‐dimethylthiourea (DMTU), N,N′‐diethylthiourea (DETU) and N,N′‐diisopropylthiourea (DITU), in steel pickling baths (sulphuric acid solutions) was studied by means of weight loss and electrochemical measurements like open circuit potential (OCP), polarization curves and impedance spectroscopy (EIS). A significant decrease in the corrosion rate was observed in presence of the investigated compounds depending on the nature and the concentration of the additives. The weight loss experiments show an inhibitory efficiency that reaches values beyond 98 %. The protective effect increases with the enlargement of the lateral chain size in the case of the thioureas. The electrochemical experiments show also a protective effect of the organic additives against corrosion. Their adsorptive behaviour is found to follow the Langmuir model.
Poly(amine‐amide‐imide)s Bearing Pendent N‐Carbazolylphenyl Moieties: Synthesis and Electrochromic Properties
Authors: Liou Guey‐Sheng , Chen Hwei‐Wen , Yen Hung‐Ju 
Published: August 2006

AbstractSummary: A series of novel poly(amine‐amide‐imide)s with pendent N‐carbazolylphenyl units that have inherent viscosities of 0.45–0.66 dL · g−1 are prepared from various aromatic bis(trimellitimide)s and the new carbazole‐based aromatic diamine, 4,4′‐diamino‐4″‐N‐carbazolyltriphenylamine, by direct polycondensation. All the polymers are readily soluble in polar organic solvents. Flexible, amorphous, and deep reddish films of poly(amine‐amide‐imide)s can be obtained by solution casting, and have useful levels of thermal stability associated with high glass transition temperatures (307–343 °C), 10% weight‐loss temperatures in excess of 500 °C, and char yields at 800 °C in nitrogen higher than 65%. These polymers exhibit a maximum UV‐vis absorption at 300 nm with a fluorescence emission maxima around 449–454 nm in N‐methyl‐2‐pyrrolidinone solution. The hole‐transporting and electrochromic properties are examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the poly(amine‐amide‐imide) films cast onto an indium tin oxide‐coated glass substrate exhibit a reversible oxidation at 0.84 V and irreversible oxidation redox couples at 1.27 V versus Ag/AgCl in acetonitrile solution, and reveal good stability of electrochromic characteristics, with a color change from yellowish to green at applied potentials ranging from 0.00 to 0.95 V.Structure and properties of PAI‐2M (bottom left: cyclic voltammetry; bottom right: potential‐step absorptometry).imageStructure and properties of PAI‐2M (bottom left: cyclic voltammetry; bottom right: potential‐step absorptometry).
Multicyclic Polyethers Derived from Tetra(bromomethyl)methane and Flexible Diphenols
Authors: Kricheldorf Hans R. , Schellenberg Johann , Schwarz Gert 
Published: August 2006

AbstractSummary: Soluble multicyclic polyethers have been prepared by the polycondensation of tetra(bromomethyl)methane with various diphenols. The influence of the diphenol on the competition between cyclization and chain growth (yielding insoluble gels) is studied for feed ratios of 2/1 (a2/b4 monomer) and high conversions. With 4‐tert‐butylcatechol or 2,2′‐dihydroxy‐1,1′‐binaphthyl, mainly monomeric spiro‐cycles are formed. Soluble multicycles free of end‐groups are only obtained from α,ω‐bis(3‐hydroxyphenoxy) alkanes. The structure of the reaction products has been characterized by 1H NMR spectroscopy and MALDI‐TOF mass spectrometry. As characteristic properties of the compact multicyclic structure, low solution viscosities in combination with high polydispersities are found. DSC measurements prove an amorphous character with glass‐transition temperatures in the range of 45–85 °C.Formation of soluble multicyclic oligoethers.imageFormation of soluble multicyclic oligoethers.
Kinetics and Mechanistic Investigation of Hydrotalcite‐Catalyzed Melt Synthesis of Poly(ethylene terephthalate)
Authors: El‐Toufaili Faissal‐Ali , Feix Gunter , Reichert Karl‐Heinz 
Published: August 2006

AbstractSummary: Hydrotalcite‐catalyzed polycondensation of BHET was studied by thermogravimetry to elucidate the kinetics. The reaction was found to follow second‐order kinetics with respect to hydroxyl end groups. The overall activation energy of the polycondensation was found to decrease with increasing catalyst concentration before it leveled out to the value of 93 kJ · mol−1 at high catalyst concentration. This is a result of the uncatalyzed reaction that takes place parallel to the catalyzed one. The activation energy of the uncatalyzed path was found to be 156 kJ · mol−1. IR spectroscopy and XRD showed that the monomer intercalates between the layers of hydrotalcite at the beginning of the reaction enabling the complexation of oxygen‐containing functional groups with the hydroxide groups of the catalyst. Based on these findings a polycondensation mechanism is proposed. One end group of the monomer is activated in the form of alkoxide that counterbalances the positive charge of the hydrotalcite layer. This alkoxide group attacks an ester carbonyl group fixed close to it, generating a new ester bond and a glycoxide species. The role of hydrotalcite is to activate the reactants, rendering the attacking hydroxyl group more nucleophilic and the ester carbonyl group more electrophilic, and at the same time fixing the reactant together in a favorable geometry.Intercalation of BHET in the gallery of HT layers in a twisted alkoxide form.magnified imageIntercalation of BHET in the gallery of HT layers in a twisted alkoxide form.
A three‐dimensional transmission line with coplanar waveguide features
Authors: Farcich Nick J. , Asbeck P.M. 
Published: August 2006

AbstractA new type of coplanar‐like transmission line is presented based on using the available third dimension to extend the surface area of the center conductor and ground planes. A prototype 3D coplanar line was fabricated using polydimethylsiloxane as the substrate material. Experimental and full‐wave electromagnetic simulation results confirm the structure's viability as a low loss, reduced phase velocity microwave waveguide that also has good dispersion characteristics. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2189–2192, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21881
An SRR based microwave absorber
Authors: Bilotti Filiberto , Nucci Luca , Vegni Lucio 
Published: August 2006

AbstractIn this letter, the authors present the design of a resonant microwave absorber made by a proper array of split ring resonators (SRRs). The physical mechanism behind the operation of the proposed component is based on the SRR resonance, arising when the structure is excited by a properly polarized impinging wave. A resistive sheet, located nearby the resonating SRRs, absorbs the electromagnetic energy of the incoming field, without destroying the resonance condition of the SRRs. The two relevant features of the proposed absorber are its electrical thickness, which is very small compared with the operating wavelength, and the lack of a metallic backing, which represent a common part of conventional absorber layouts. The full‐wave simulations presented in the paper confirm the effectiveness of the proposed absorber for microwave applications. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2171–2175, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21891
Fibre Bragg grating interrogation based on high‐birefringence fibre loop mirror for strain temperature discrimination
Authors: Frazão O. , Marques L. M. , Baptista J. M. 
Published: August 2006

AbstractIn this work, we present a fiber Bragg grating interrogation based on high‐birefringence fiber loop mirror for strain–temperature discrimination. Due to spectral response of the optical filters it is possible to determine the variation of the wavelength and the optical power of the Bragg grating sensor when subject to strain or temperature. Maximum errors of ±0.4°C and ±12 με are reported over 80°C and 2000 με measurement ranges. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2326–2328, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21894
Performance analysis of bidirectional hybrid WDM/SCM‐PON link based on reflective semiconductor optical amplifier
Authors: Kim Tae‐Young , Kang Jeung‐Mo , Han Sang‐Kook 
Published: August 2006

AbstractThe effect of noise on the transmission performance of an RSOA‐utilized bidirectional hybrid WDM/SCM‐PON link is experimentally analyzed. The link used in experiment allows 33‐km bidirectional transmission with 622‐Mbps NRZ signal for downstream and 20‐Mbps SCM signal at 1.5‐GHz RF carrier for upstream. In the link, the RSOA is used as a remodulator in optical network unit (ONU), which plays an important role in the overall noise characteristic of the link. Experimental results show that by properly controlling the gain of the RSOA, the effect of backreflection and backscattering noise can be reduced. Experimental results also suggest that both the uplink and the downlink signals should be modulated to reduce the effect of noise. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2301–2309, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21896
Electromagnetic energy in absorptive and dispersive medium based on the assembly of atomic oscillators
Authors: Cao Haibo , Cui Tie Jun 
Published: August 2006

AbstractOn the basis of the idealized structure of an atomic medium described by an assembly of independent oscillators, expressions for the stored electric and magnetic energy densities in absorptive and dispersive medium are derived. Such formulas are also valid for a left‐handed medium (LHM), where the permittivity and permeability are simultaneously less than zero within a frequency band. These formulas are completely equivalent to those derived from a general definition of electromagnetic energy density using the classical electromagnetics. It has been shown that the stored energy densities, no matter in a right‐handed medium or in a left‐handed medium, are always positive. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2288–2291, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21899
Study of a CPW‐fed circular slot antenna for UWB communications
Authors: Consoli Fabrizio , Maimone Fabio , Barbarino Sebastiano 
Published: August 2006

AbstractA numerical and experimental study of a circular‐slot antenna, fed by a coplanar waveguide with a rectangular stub, is proposed in this paper for ultra‐wideband communications. The antenna impedance bandwidth, phase linearity, gain and radiation patterns are presented, together with the time‐domain impulse response. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2272–2277, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21900
Performance comparison between uniformly and nonuniformly spaced adaptive antennas with respect to tolerance to pointing errors
Authors: Al‐Ka'bi Amin , Bialkowski Marek E. , Homer John 
Published: August 2006

AbstractThe paper presents theoretical and experimental investigations into performances of narrowband uniformly and nonuniformly spaced adaptive linear dipole array antennas that are subjected to pointing errors. The analysis focuses on the array's output Signal to Interference plus Noise Ratio. The presence of mutual coupling between the array elements is taken into account. It is shown that the array's tolerance to pointing errors can be enhanced by controlling the interelement spacing. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2233–2237, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21904
Compact ultra‐wideband planar tapered slot antenna for use in a microwave imaging system
Authors: Abbosh A. M. , Kan H. K. , Bialkowski M. E. 
Published: August 2006

AbstractThe design of an ultra‐wideband planar tapered slot antenna for use in a circular cylindrical microwave imaging system is presented. The antenna was designed assuming high dielectric substrate material Rogers RT6010LM to achieve its compact size. The developed antenna element (50 × 50 mm2) features a 10‐dB return loss bandwidth from 2.75 GHz to more than 11 GHz. The gain of the antenna is between 3.5 and 9.4 dBi over the 3–10 GHz band. The experimental tests showed that the manufactured antenna element supports transmission of narrow pulses with negligible distortions, as required in the microwave imaging system. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2212–2216, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21906
Reactive loaded microstrip leaky wave antenna for low cost beam steering applications
Authors: Augustin Gijo , Shynu S. V. , Mohanan P. , Aanandan C. K. , Vasudevan K. 
Published: August 2006

AbstractA novel fixed frequency beam scanning microstrip leaky wave antenna is reported. The beam scanning at fixed frequency is achieved by reactive loading. Simulation and measured results shows frequency scanability of 80° as well as fixed frequency beam steering of 68° over the −10 dB impedance band of 4.56–5.06 GHz © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2299–2301, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21912
Compact LTCC bandpass filter design with controllable transmission zeros in the stopband
Authors: Deng Jianhua , Wang Bing‐Zhong , Gan Tiguo 
Published: August 2006

AbstractMethod of designing a modified Chebyshev bandpass filter with controllable transmission zeros in the stopband is described. A novel compact structure of this kind of filter with a transmission zero located at higher stopband for low temperature co‐fired ceramic implementation is proposed. The filter has promising potential applications in miniaturized wireless communication systems. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2261–2264, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21916
Growth and studies of optical properties of double‐doped In:Fe:LiTaO3 crystal
Authors: Ma Decai , Wang Biao , Fang Shuangquan , Zhang Tao , Wang Rui , Wei Yuan 
Published: August 2006

AbstractIn:Fe:LiTaO3 crystals were grown in an air atmosphere using the Czochralski method. The photorefractive properties were measured by the two‐wave coupling experiments, and light‐induced scattering was used to characterize the optical damage. It was found that the photorefractive response speed of In:Fe:LiTaO3 was about four times faster than that of Fe:LiTaO3, and the resistance ability to optical damage was drastically improved. The increase in damage resistance and faster response speed could be attributed to the Fe3+ losing their electron acceptor properties and, therefore, an increase in photoconductivity. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2227–2230, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21919
Wide band dumbbell‐shaped patch antenna
Authors: Jacob K. Francis , Suma M. N. , Joseph Manoj , Mohanan P. 
Published: August 2006

AbstractThe design and radiation characteristics of a wide band dumbbell‐shaped patch excited by planar strip monopole with truncated ground plane is proposed in this letter. The antenna can be easily modified for dual band operation by adjusting the location of the patch over the planar monopole. The antenna offers a bandwidth of 35 and 9% at 3.2 and 5.3 GHz bands, respectively. The overall area of the antenna including the 50 Ω line feed is only 65 × 65 mm2. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2295–2296, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21926
Simplified hand model including the user's forearm for the study of internal GSM/DCS mobile phone antenna
Authors: Wu Chih‐Hsien , Wong Kin‐Lu , Lin Chun‐I , Su Chih‐Ming , Yeh Shih‐Huang , Tang Chia‐Lun 
Published: August 2006

AbstractA simplified hand model for the study of internal mobile phone antenna for analyzing its impedance and radiation characteristics with the presence of the user's hand is proposed. The antenna in this study is a compact internal antenna having two separate resonant strips capable of generating two wide bandwidths for GSM and DCS operations. For the simplified hand model, it is a one‐layer hand model including the user's forearm with a relative permittivity of 35 and a conductivity of 0.5 S/m. With this simplified hand model, efficient and reliable simulation study of the mobile phone antenna with the user's hand can be obtained. Detailed effects of the user's hand on the impedance and radiation characteristics of the internal mobile phone antenna are analyzed in this study. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2202–2205, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21935
Novel trapezoidal planar dual‐mode bandpass filter using one single patch resonator
Authors: Xiao Jian‐kang , Li Ying 
Published: August 2006

AbstractMicrostrip bandpass filters are widely used in a variety of microwave systems, particularly in transmitter and receiver sections etc. to select a desired band of frequencies. However, common bandpass filters have deficiencies such as several resonators coupling, coupling gaps, only one attenuation pole in frequency responses, and so on. This paper proposes a triangular dual‐mode bandpass filter and two types of trapezoidal dual‐mode bandpass filters using one single patch resonators with corner cuts or crossed slots. It shows degenerate dual‐mode with corner cuts and unequaled crossed slots can improve the performances of filter greatly. The proposed filters have outstanding virtues such as novel and simple structures as they have one single patch without coupling gaps, small volume, easy integration and miniaturization, and so on. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2142–2145, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21939