bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of abnormal cytoskeletal structure on erythrocyte membrane mechanical properties
Authors: Waugh Richard E. 
Published: April 2005

AbstractMeasurements of the mechanical properties of the erythrocyte membrane provide a direct assessment of the proper function of its structural components. To assess the effects of alterations in molecular structure on membrane mechanical properties, measurements have been performed on cells from six individuals whose membranes contain inherited, biochemically characterized structural defects. Because the contribution of the memmbrane skeleton to the mechanical behavior of the membrane is most evident in shear deformation, mechanical experiments were performed to measure the material constants which characterize the response of the membrane to shear force resultants. The surface elastic shear modulus characterizes the elastic response of the membrane; the yield shear resultant is the maximum shear force resultant which the membrane can support elastically; and the plastic viscosity coefficient characterizes the rate of membrane deformation when the elastic limit has been exceeded.Generally, it was found that when the molecular defect is found to occur in a region of the skeleton which is stress‐supporting, the maximum elastic strength of the membrane is reduced. However, the magnitude of the reduction can be quite different for membranes having similar or even identical defects. In some cases the differences can be attributed to the removal of the most fragile cells of the population by the spleen, but other results indicate that the biochemical description of the defects may be incomplete. These results emphasize the need for further refinements both in the biochemical characterization of membrane skeleton structure and in the description and measurement of membrane mechanical properties.
Extension of filopodia by motor‐dependent actin assembly
Authors: Sheetz Michael P. , Wayne Denise B. , Pearlman Alan L. 
Published: April 2005

AbstractA variety of mechanisms have been proposed to explain the forward extension of cytoplasm in advancing cells and axonal growth cones, including actin polymerization and osmotic swelling. Based on our observations of the filopodia of cultured neuronal growth cones, we propose a mechanism involving motor‐induced extension and retraction. We observed that filopodia (actin‐based protrusions 0.2–0.5 μ in diameter) extend and retract from growth cone lamellae at the same rate. Further, force is generated at the tips of filopodia which is sufficient to produce compressive buckling of the proximal portion of the filopodium. From our analysis of these movements we suggest that a motor protein powers both the extension and retraction of filopodia. © 1992 Wiley‐Liss, Inc.
TX‐1877, a bifunctional hypoxic cell radiosensitizer, enhances anticancer host response: Immune cell migration and nitric oxide production
Authors: Oshikawa Tetsuya , Okamoto Masato , Ahmed Sharif U. , Furuichi Sachiko , Tano Tomoyuki , Sasai Akiko , Kan Shin , Kasai Soko , Uto Yoshihiro , Nagasawa Hideko , Hori Hitoshi , Sato Mitsunobu 
Published: April 2005

AbstractWe investigated in the current study the effect of TX‐1877, a bifunctional hypoxic cell radiosensitizer, in augmenting anticancer host response. In the syngeneic squamous cell carcinoma‐bearing mouse model, a single administration of TX‐1877 significantly inhibited the primary tumor growth as well as lung metastasis. TX‐1877 administration resulted in a significant infiltration of immune cells, such as CD4+T, CD8+T cells, macrophages and dendritic cells (DCs), and an increased expression of chemokines for cytotoxic T lymphocytes (CTLs), helper T‐cell 1 (Th1) cells, monocytes/macrophages and DCs, in tumor tissues. Nitric oxide (NO) production and the expression of inducible NO synthase (iNOS) and interferon‐γ, a major Th1 cytokine that plays a major role in anticancer immunity, were also enhanced. Furthermore, neutralization of NO by N‐monomethyl‐L‐arginine acetate resulted in a marked inhibition of the antitumor effect of TX‐1877. In tumor‐draining lymph nodes, MHC class I‐restricted CD8+ memory CTLs specific for inoculated cancer cells were induced by TX‐1877. In in vitro experiments, TX‐1877 induced chemokines and iNOS/NO in several types of culture cells. These findings strongly suggested that TX‐1877 induces migration of CD8+CTLs, CD4+Th1 cells, macrophage/monocytes and dendritic cells into the tumor site, and that this migration is mediated by chemokine induction. In addition, it was suggested that NO produced by several types of cells stimulated by TX‐1877 in the tumor sites plays a major role in the anticancer effect of TX‐1877. TX‐1877 was thus shown to be an effective immunopotentiator as well as a hypoxic cell radiosensitizer. © 2005 Wiley‐Liss, Inc.
COX‐2 inhibitors suppress integrin α5 expression in human lung carcinoma cells through activation of Erk: Involvement of Sp1 and AP‐1 sites
Authors: Han ShouWei , Roman Jesse 
Published: April 2005

AbstractTumor cell expression of COX‐2 has been implicated in the progression of murine and human lung cancer. Inhibition of COX‐2 by nonsteroidal antiinflammatory drugs reduces the risk of cancer development in humans and suppresses tumor growth in animal models. However, the underlying mechanisms for this beneficial effect are not fully understood. Here we explore the potential link between the anticancer effects of COX‐2 inhibitors and the expression of the integrin α5β1. Expression of this integrin in carcinoma cells is associated with invasiveness and malignant progression. This, together with our studies showing that fibronectin, the ligand of α5β1, stimulates the growth of human lung carcinoma cells, and that this effect is mediated through α5β1‐dependent signals, has prompted us to examine the effects of COX‐2 inhibitors on α5β1 expression in human non small cell lung carcinoma (NSCLC) cells. We found that the selective COX‐2 inhibitors NS398 and Nimesulide decreased mRNA expression and protein production of the integrin α5 subunit. This effect was associated with inhibition of NSCLC cell adhesion to fibronectin. The COX‐2 inhibitors triggered the phosphorylation of extracellular signal‐regulated kinase (Erk) in a time‐dependent manner, and the inhibitor of Mek‐1/Erk PD98095 prevented their inhibitory effects on integrin α5 expression. Transient transfection assays showed that the COX‐2 inhibitors affected integrin α5 gene transcription by acting between −92 to −41 bp of the human integrin α5 gene promoter. Gel mobility shift assays showed that the COX‐2 inhibitors increased Sp1 DNA binding, but decreased that of AP‐1. These effects were accompanied by an increase in Sp1 protein and a decrease in c‐Jun protein expression, as well as inhibition of SAPK/JNK phosphorylation. The Sp1 inhibitor, Mithramycin A, also blocked the inhibitory effect of the COX‐2 inhibitors on α5 expression and promoter activity. Overall, these findings suggest that COX‐2 inhibitors suppress α5β1 integrin expression in NSCLC through effects on integrin α5 gene transcription mediated by Erk activation, increased Sp1, decreased AP‐1 DNA binding and inactivation of SAPK/JNK signals. Our observations unveil a new mechanism of action against NSCLC for COX‐2 inhibitors that relates to regulation of integrin α5 gene expression and, consequently, recognition of extracellular matrices (i.e., fibronectin) by tumor cells. © 2005 Wiley‐Liss, Inc.
Viral infections in the acquired immunodeficiency syndrome
Authors: Miller Sara E. , Howell David N. 
Published: April 2005

AbstractThe following communication is a tripartite synopsis of the role of viral infection in the acquired immunodeficiency syndrome (AIDS). The first section describes the impact of viral opportunistic infection in AIDS; for each virus, clinical presentation and diagnosis, laboratory diagnostic approaches (with emphasis on electron microscopy), and therapeutic interventions attempted to date are discussed. The second segment explores current theories on the pathogenesis of AIDS, and describes diagnostic and therapeutic approaches to the syndrome itself. The final section catalogues ultrastructural anomalies in the cells of AIDS patients, many of which have been mistakenly identified as etiologic agents.
Early apoptotic and late necrotic components associated with altered Ca2+ homeostasis in a peptide‐delivery model of polyglutamine‐induced neuronal death
Authors: Suzuki Mari , Koike Tatsuro 
Published: April 2005

AbstractThe mechanisms by which polyglutamine expansion causes common features of neuronal death remain unclear. Here we describe an approach for delivering polyglutamine expansions directly into cultured sympathetic neurons. Glutamine (Q) residues (n = 10, 22, 30) were conjugated with a peptide possessing translocation properties across plasma membranes (PDP) and a nuclear localization signal (NLS). These peptides were rapidly incorporated into sympathetic neurons and showed neurotoxicity in a length‐ and dose‐dependent manner. A robust induction of c‐jun and cyclin D1 occurred following treatment with PDP‐Q22‐NLS. Enhanced c‐Jun phosphorylation showed c‐Jun N‐terminal kinase (JNK) activation. Coincidentally, TrkA tyrosine phosphorylation was decreased in association with loss of phospho‐Akt, the downstream target of PI‐3 kinase. Despite such proapoptotic signals, neither release of cytochrome c from mitochondria nor caspase‐3/7 activation was detected. TdT‐mediated dUTP nick‐end labeling‐positive nuclear condensation, but no fragmentation, occurred. At 24 hr of treatment, cytoplasmic Ca2+ levels began to become elevated, and the cellular level of ATP was decreased. Cytoplasmic Ca2+ responses to KCl depolarization displayed a delayed recovery, providing evidence for lack of Ca2+ homeostasis. The neurons became committed to death at about 36 hr when mitochondrial Ca2+ uptake declined concurrently with loss of mitochondrial membrane potential. Collectively, these results show that, despite induction of early apoptotic signals, nonapoptotic neuronal cell death occurred via perturbed Ca2+ homeostasis and suggest that mitochondrial permeability transition may play important roles in this model of neuronal death. © 2005 Wiley‐Liss, Inc.
Dual‐band LTCC chip antenna design using stacked meander patch for mobile handsets
Authors: Kim Young Do , Kim Ho‐Yong , Lee Hong Min 
Published: April 2005

AbstractThis paper presents design simulation, implementation, and measurement of a miniaturized GPS/K‐PCS dual‐band LTCC chip antenna for mobile communication handsets. The dimensions of the LTCC chip antenna is 9 × 15 × 1.2 mm. The meander‐type radiating patch for dual‐band operation is realized by using via holes with 0.3‐mm height to connect upper‐ and lower‐layer antennas. The lower meander‐type antenna is to be tuned to the lower frequency (GPS) band. The upper meander antenna has a via‐hole connection for the higher frequency (K‐PCS) band. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 271–273, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20793
A wideband circularly polarized microstrip patch antenna for 5–6‐GHz wireless LAN applications
Authors: Yang G. , Ali M. , Dougal R. 
Published: April 2005

AbstractA wideband slotted circularly polarized (CP) patch antenna is introduced for 5–6‐GHz WLAN applications. A small 14.6 × 14.6 mm square patch on Duroid 5880 substrate can provide a return‐loss bandwidth of 11% and an axial‐ratio bandwidth of 8% with a single feed. A possible reconfigurable design achievable using PIN diode or MEMS switches capable of left‐hand or right‐hand circular polarization is also introduced. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 279–285, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20796
23‐GHz low‐noise amplifier using parallel feedback in 0.18‐μm CMOS
Authors: Frank B. M. , Hossain M. M. , Antar Y. M. M. 
Published: April 2005

AbstractA three‐stage low‐noise amplifier (LNA) fabricated in a standard 0.18‐μm CMOS process (fT= 45 GHz) with a maximum gain of 18 dB at 23.2 GHz and a 5.8‐dB noise figure is presented. Parallel feedback between the gate and drain is used in all three stages. This configuration also provides much better linearity than other LNAs presented by resonating out the effect ofCgd. The amplifier has an output‐referred 3rd‐order intercept of 10 dBm, and a 3‐dB bandwidth of approximately 1 GHz. This paper demonstrates that parallel feedback is a viable technique for the design of 20+‐GHz CMOS LNAs. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 309–312, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20806
Implicit nonstaggered finite‐difference time‐domain method
Authors: Wang Shumin , Lee Robert , Teixeira Fernando L. 
Published: April 2005

AbstractA new, unconditionally stable, implicit nonstaggered finite‐difference time‐domain (INS‐FDTD) method is introduced. This method is more efficient than the (unconditionally stable) finite‐element time‐domain (FETD) method with brick elements because the number of nonzero elements in the system matrix is reduced. A numerical‐dispersion analysis is provided as well. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 317–319, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20809
Modal analysis of dielectric optical waveguides based on Chebyshev polynomials
Authors: Huang Chia‐Chien , Huang Chia‐Chih 
Published: April 2005

AbstractWe propose an accurate and efficient numerical method to compute the modal characteristics of dielectric optical waveguides. The present method represents electric and/or magnetic fields by Chebyshev polynomials based on a multidomain spectral collocation scheme. Compared with analytical solutions and the published results using rigorous numerical methods, our results show excellent agreement. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 328–331, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20813
Experimental validation of OSNR enhancement utilizing hybrid Raman/Erbium fiber amplifiers
Authors: Ahmad A. , Mas Izyani M. A. , Zamzuri A. K. , Adikan F. R. M. , Sheih S‐J. , Mahdi M. A. 
Published: April 2005

AbstractThe impact of employing a hybrid Raman/Erbium‐doped fiber amplifier (EDFA) in a transmission system is demonstrated by considering the optical signal‐to‐noise ratio (OSNR) performance. The gain flatness of hybrid Raman/EDFA is maintained below 1.2 dB from 1530 to 1565 nm through careful design of both amplifiers. The enhancement of OSNR is measured at around 5 dB, compared to the conventional EDFA approach with a 28‐dB span loss. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 333–335, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20815
Construction of refractive‐index profiles of graded‐index planar waveguides from effective indexes measured with different mode types and external refractive indexes
Authors: Wei J. , Xu X.‐F. , Kang Z.‐H. , Jiang Y. , Ding Y. , Gao J.‐Y. 
Published: April 2005

AbstractA method is presented whereby the refractive‐index profile (RIP) can be reconstructed from sets of effective indexes measured with different mode types and external refractive indexes. Single‐mode waveguide RIP characterization can be easily realized using an index‐matching liquid at a single wavelength. This method is described and demonstrated via numerical examples and experimental results. The method has the advantages of convenient operation and accurate results for the characterization of graded‐index planar waveguides that support both mode types and contain known modal birefringence. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 342–345, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20818
Probe‐fed center‐slotted suspended plate antennas with resistive and capacitive loadings
Authors: Chen Zhi Ning , Ng Jin Hau 
Published: April 2005

AbstractThis paper presents the probe‐fed center‐slotted suspended plate antennas (CS‐SPAs) with capacitive and resistive loading. The impedance and radiation characteristics of the proposed antennas, such as impedance bandwidth, gain, radiation patterns, and cross‐pol radiation levels are investigated. The simulated results are validated by the measurements and compared with three other CS‐SPAs fed by a single probe, short‐circuited, and open‐circuited loading, respectively. This study demonstrates an enhancement of impedance bandwidth and a decrease in gain with resistive loading, as compared to the CS‐SPA with a shorting pin. The gains of CS‐SPAs with plate‐capacitor loading generally increase, with the same impedance bandwidth as that of the CS‐SPA with a shorting pin. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 355–360, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20822
Relationship between biochemical biomarkers and pre‐copulatory behaviour and mortality in Gammarus pulex following pulse‐exposure to lambda‐cyhalothrin
Authors: Heckmann Lars‐Henrik , Friberg Nikolai , Ravn Helle W 
Published: April 2005

AbstractThe impact of the pyrethroid lambda‐cyhalothrin was studied in an in‐stream mesocosm placed in a natural riffle of a Danish stream. Twice during summer 2002, the natural macroinvertebrate community was exposed in situ to a 30‐min pulse of lambda‐cyhalothrin. During exposure, nets caught macroinvertebrates in drift. Exposed and unexposed individuals of the amphipod Gammarus pulex (L) were transferred to aquaria in the laboratory and monitored for biochemical changes (ie biomarkers), pre‐copulatory behaviour and mortality. Biochemical biomarkers were identified by screening extracts of exposed and unexposed G pulex using high‐performance planar chromatography (HPPC). Biochemical biomarkers were detected 3 h after pulse‐exposure, and one biomarker was persistent up to 7 days after exposure. Pre‐copulatory behaviour (ie pair formation) was significantly impaired up to 5 days after exposure, and had not fully recovered at the end of the observation period. EC10(0.5 h) and EC50(0.5 h) values for pre‐copulatory behaviour were 0.04 and 0.20 µg litre−1, respectively. Mortality was significant at 0.35 µg litre−1 with an LC50(0.5 h) of 5.69 µg litre−1. There was a significant relationship between two biomarkers and mortality. The study demonstrated that pulse‐exposure at expected environmental concentrations can reduce local populations of G pulex, resulting in severe impact on populations with limited possibilities of re‐colonisation. Copyright © 2005 Society of Chemical Industry
Possible ferromagnetic interactions between IS Co3+ ions in Nb doped cobaltites
Authors: Troyanchuk I. O. , Karpinsky D. V. , Szymczak R. 
Published: April 2005

AbstractMagnetic and electrotransport properties studies have been performed for La1–xSrxCo1–x/2Nbx/2O3 solid solutions containing cobalt ions in three valence electronic state. It was shown that these solid solutions are spin glasses with temperature of magnetic moment freezing (Tf) of about 25 K. The ferromagnetic component is the most pronounced in the sample with x = 0.15. This result can be explained by a model according to which Co ions near to Sr ones are in intermediate spin state and the Co3+–O–Co3+ superexchange interactions are ferromagnetic due to local dynamic orbital correlations. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical study on the reaction mechanism and thermodynamics of tin oxidation by oxygen species and chlorine species
Authors: Li Lai‐Cai , Deng Ping , Zhu Yuan‐Qiang , Zha Dong , Tian An‐Min , Xu Ming‐Hou , Wong Ning‐Bew 
Published: April 2005

AbstractIn this work ab initio molecular orbital methods were employed to study the coal combustion reaction mechanisms of tin oxidized by different oxidants, including HOCl, HCl, ClO, ClO2, NO3, CO2, and O2. Eleven reaction pathways were identified. The results show that Sn can react with HCl, ClOO, CO2, O2, and NO3 to form SnO and SnCl. SnO can be oxidized into SnCl by HOCl and HCl. SnCl can be further oxidized into a soluble compound, SnCl2. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Theoretical and experimental luminescence quantum yields of coordination compounds of trivalent europium
Authors: Faustino Wagner M. , Junior Severino A. , Thompson Larry C. , De Sá Gilberto F. , Malta Oscar L. , Simas Alfredo M. 
Published: April 2005

AbstractAn appraisal of a semiempirical methodology recently introduced by us for the theoretical calculation of luminescence quantum yields is presented. Six coordination compounds of Eu3+ were considered, possessing either benzoylacetonate or benzoyltrifluoroacetonate, together with either water, 2,2′‐bipyridine, or 1,10‐phenanthroline as ligands. Their geometries were calculated using the SMLC/AM1 method. The ligand–Eu3+ energy transfer rates were calculated in terms of a model of intramolecular energy transfer processes in lanthanide coordination compounds developed earlier by our group. The luminescence quantum yields of the complexes were calculated by solving numerically a system of rate equations for each compound, and by comparing them with the quantum yields determined spectroscopically. Finally, we show that the theoretical quantum yields correlate linearly with the experimental yields, within their error bars. Such linear correlation indicates that the theoretical approach can be useful for the a priori design of highly luminescent lanthanide coordination compounds. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Spatial distributions of desorbing products in basic catalytic processes and surface nano‐structures
Authors: Matsushima Tatsuo , Rzeznicka Izabela , Ma Yunsheng 
Published: April 2005

AbstractReviews of recent progress in angle‐resolved measurements of desorbing surface reaction products are discussed. The angular and velocity distributions of desorbing products deliver information about the reaction site as well as the reaction mechanism when the products are repulsively desorbed. These distribution measurements can yield symmetry and orientation information of the reaction site for associative processes whereas, in dissociative desorption, the collimation of fragment desorption is related to the orientation of the intermediate species immediately before dissociation. These different collimations provide information on desorption steps whenever any step becomes rate determining. © 2005 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 5: 81–93; 2005: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20036
Genetic counseling for a family with two distinct anomalies: A case report of a neural tube defect and 5p‐ syndrome in a fetus
Authors: Begleiter Michael L. , Rogers Jill Cellars 
Published: April 2005

AbstractA couple presented for genetic counseling because of an elevated maternal serum alpha fetoprotein. Ultrasound examination revealed the presence of a neural tube defect. The couple declined an amniocentesis, but chose serial ultrasound evaluations instead. Ultrasounds eventually identified microcephaly, but the couple continued to decline amniocentesis. After the child's birth, the diagnosis of 5p‐ syndrome was made. The couple's decision not to have an amniocentesis allowed the family their right to autonomy; however, prenatal chromosome analysis would have provided this couple with a great deal more prognostic information. We discuss the conflict between a counselor's duty to respect a client's freedom vs. duty to care for a client's welfare. We address issues of nondirective counseling and the need for more studies looking at the decision‐making process in prenatal diagnosis.