bluuebunny/crossref_metadata_2025 huggingface dataset:
Overexpression of a constitutively active form of c‐src in skin epidermis increases sensitivity to tumor promotion by 12‐O‐tetradecanoylphorbol‐13‐acetate
Authors: Matsumoto Takashi , Jiang Jianghong , Kiguchi Kaoru , Carbajal Steve , Rho Okkyung , Gimenez‐Conti Irma , Beltrán Linda , DiGiovanni John
Published: August 2002

Transgenic mice were developed to study the role of c‐src in epithelial tumorigenesis through targeted expression of a constitutively active form of murine c‐src (src529). Src529 was targeted to the interfollicular epidermis with the human keratin 1 (HK1) promoter. The skin phenotype of these mice was characterized by exaggerated epidermal hyperplasia and hyperkeratosis within the first week after birth. The severity of this phenotype correlated with overall src kinase activity, both of which subsided with age. Treatment of adult HK1.src529 transgenic mice with the phorbol ester tumor promoter 12‐O‐tetradecanoylphorbol‐13‐acetate resulted in an increase in epidermal hyperplasia and labeling index significantly greater than that seen in nontransgenic littermates. In addition, HK1.src529 transgenic mice developed papillomas earlier and in significantly greater numbers compared with nontransgenic littermates in a standard initiation‐promotion experiment. The data support the hypothesis that activation of c‐src kinase plays a role in skin tumor promotion. © 2002 Wiley‐Liss, Inc.
Comparison of Ha‐ras mutational spectra of N‐methyldibenzo[c,g]carbazole and 7H‐dibenzo[c,g]carbazole–induced mouse skin tumors
Authors: Mitchell Kent R. , Warshawsky David
Published: August 2002

Carcinogenic N‐heterocyclic aromatic hydrocarbons are formed during the incomplete combustion of fossil fuels as well as cigarette smoke. N‐Methyldibenzo[c,g]carbazole (NMeDBC) and 7H‐dibenzo[c,g]carbazole (DBC) are members of this group. DBC induces mouse skin and liver tumors, whereas NMeDBC induces only mouse skin tumors. The objective of this study was to elucidate the mechanism of action of these compounds in skin by assessing the Ha‐ras mutational spectra induced by a two‐stage initiation‐promotion protocol. NMeDBC (200 nmol) or DBC (200 nmol) was applied to the back skin of 24 female Hsd:ICR(Br) mice (12 per group) once. 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) (2 μg) was then applied twice weekly for 28 wk. Tumors were screened for Ha‐ras mutations using enriched polymerase chain reaction and mutations defined by dideoxy sequencing. In DBC animals 58% produced papillomas, of which 71% had codon 61 mutations, 4% had codon 12 mutations, 4% had codon 13 mutations, and 21% had no Ha‐ras mutations. In NMeDBC animals 92% produced papillomas, of which 73% had codon 61 mutations and 27% had no Ha‐ras mutations. All of the codon 61 mutations, from both NMeDBC and DBC, were CAA→CTA transversions. The DBC‐induced tumors with the codon 12 mutation had a GGA→GAA transition, and the codon 13 mutation was a GGC→GTC transversion. These results suggest that NMeDBC is a more potent tumor inducer than DBC, but the resulting H‐ras mutations in each group were predominantly in codon 61, and, therefore, mutation induction in skin by each chemical appears to proceed by a similar mechanism. © 2001 Wiley‐Liss, Inc.
Assessing risky public investments with MUSTARD
Authors: Scannella Giuseppe , Beuthe Michel
Published: August 2002

This paper presents a practical implementation of multicriteria methodologies based on the UTA model by Jacquet‐Lagrèze and Siskos and Quasi‐UTA model by Beuthe and Scannella, which are specified with a non‐linear, but piecewise linear, additive utility function. In contrast with the general UTA model, the Quasi‐UTA specification structures the partial utilities as recursive exponential functions of only one curvature parameter. This allows for a reduction of the quantity of information necessary to build the utility function.

The software MUSTARD implements different variants of these models. Firstly, it offers the basic deterministic UTA model of disaggregation, but also its first programmed stochastic version. In both cases, the software proceeds stepwise and interactively helping the decision maker to formulate the problem and state preferences between projects; in the stochastic case, the decision maker is even helped to build the criteria distributions. The Quasi‐UTA specification can be introduced in this disaggregation model. Secondly, the software offers an aggregation model whereby the Quasi‐UTA partial utility functions are built separately through specific questioning processes. The questions relating to deterministic criteria are of the ‘direct rating type’, while those of the stochastic criteria are either of the ‘variable probability’ or the ‘variable outcome’ type. The criteria weights can be assessed by the ‘swing weight’ method or by a UTA‐II side‐program. As an example as well as a test of the Quasi‐UTA aggregation approach, the paper presents its application to a real problem of selecting road investment projects in Belgium. Several experts and civil servants were interviewed, and their individual utility functions derived. The projects are ranked according to their rate of return, which is computed on the basis of the projects certain equivalent money value. Copyright © 2002 John Wiley & Sons, Ltd.
Simple gradient system For capillary electrochromatography
Authors: Medina Juan Carlos , Alonso M. Carmen , Barcelo Damia , Lee Milton L.
Published: August 2002

A new gradient system for CEC was designed and adapted to a home‐built CEC system. Chromatographic separations are initiated with a predetermined mobile phase composition and, after a desired time period, a syringe pump delivers pure organic solvent at a preset flow rate into a 2 mL vial used as the inlet buffer reservoir. Mixing is achieved by the use of a microstir bar in the buffer reservoir, which in turn is driven by an air‐actuated stir plate. In this way, a convex‐shaped gradient is generated, and the mobile phase is introduced into the separation column by electro‐osmotic flow. Use of this system significantly reduced analysis time while still retaining acceptable reproducibility. Nonaqueous CEC was used for isocratic and gradient separation (<3.5% RSD in retention times). Demonstrated applications include the analysis of triglycerides in different vegetable oil samples. This system is expected to be well suited for generating other types of gradients, such as pH and ionic strength gradients, in electroseparation techniques. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 351–360, 2001
Optimization and validation by SPE‐CGC‐MSD of the analysis of tributyltin in environmental samples
Authors: Nogueira J. M. F. , Teixeira P. , Florêncio M. H.
Published: August 2002

The optimization by SPE‐CGC‐MSD methodology of the analysis of tributyltin in environmental samples is presented. Fifteen assays with certified reference material for sediment matrices (54±15 ng/g), as well as with in‐house standards for aqueous matrices (50 ng), were performed using solid phase extraction for tributyltin speciation, which was shown to be easy, solventless, and fast. The solid phase extraction tube was preconditioned with ethyl acetate to remove possible impurities, conditioned with methanol, water, and HCl 5% and after tributyltin extraction, washed again with HCl 5% and water, and finally eluted with ethyl acetate. Subsequently the samples were derivatized with methyl magnesium bromide in a diethylether solution, concentrated, injected in the splitless mode, separated by capillary gas chromatography, and detected by mass spectrometry in the selected ion‐monitoring mode. The results obtained showed a value of 50±18 ng/g for tributyltin in the sediment matrices assays which, according to European Co‐operation for Accreditation of Laboratories guidance for interlaboratory comparisons, led to a deviation normalized lower than 0.2, showing that the SPE‐CGC‐MSD methodology is validated for TBT speciation in sediment samples, due to the high accuracy reached. For the in‐house standard aqueous matrices assays, a value of 44±21 ng gave recoveries higher than 85%, showing that this methodology is also validated, due to the substantial accuracy for tributyltin speciation in aqueous samples. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 48–53, 2001
Chiral selective separation of tocainide by capillary electrophoresis using various cyclodextrin derivatives
Authors: Juvancz Zoltán , Markides Karin E. , Jicsinszky László , Iványi Róbert
Published: August 2002

Chiral separation of tocainide, an antiarrythmic agent, was solved using the capillary electrophoresis method. Fifteen types of cyclodextrins were tried as chiral selective buffer additives, and baseline separation was achieved with five of them. The variables that were studied comprise, type and concentration of the chiral selectors, pH of the buffers, and the organic modifiers. The best resolution, an Rs value of 5.2, was achieved using 7.5 mM γ‐cyclodextrin phosphate at pH 6.8. Migration reversal of enantiomers was observed when changing the type of cyclodextrins. Not only the tocainide but also its by‐product were enantiomericaly separated. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 62–68, 2001
Separation of pyridazinone derivatives using pressurized gradient capillary electrochromatography
Authors: Jiang Zhengjin , Gao Ruyu , Zhou Yibo , Zhang Zhichao , Wang Qinsun , Yan Chao
Published: August 2002

A pressurized, gradient capillary electrochromatography (pCEC) instrument has been designed and built. This versatile instrument can be operated in three separation modes, namely, pCEC, micro high performance liquid chromatography (μHPLC) and capillary electrophoresis (CE). In pCEC mode, both an electric field and a pressure can be applied across a packed capillary column, allowing fine tuning of the selectivity without changing the composition of the mobile phase. This technique also facilitates the use of gradient elution, making it more powerful for separation of complex mixtures. The technique was evaluated and compared with μHPLC by separating a mixture of organic acids and neutral pyridazinone derivatives. Experiments in pCEC were carried out with a fused‐silica capillary column packed with 3‐μm octadecyl silica (ODS) particles. A separation with baseline resolution was achieved for ten pyridazinone derivatives at optimum conditions. Compared with the separation results by μHPLC method, pCEC is more powerful than μHPLC for the separation of both neutral and charged compounds. The influence of the supplementary pressure, the flow rate of pumps and applied voltage on the separation was also investigated. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 191–196, 2001
Estimating deferred taxation on dividends in business groups
Authors: Brioschi Francesco , Giudici Giancarlo , Paleari Stefano
Published: August 2002

In a group of companies corporate income taxation is levied on basic earnings and then on dividends paid to holding companies. The entity of this taxation depends on the tax regime, so that income may be taxed twice, first in the hands of the subsidiaries, then in the next years in the hands of holding companies. Therefore, consolidated profits may not be wholly paid to shareholders (who are the ultimate owners) and deferred taxes have to be computed in order to determine the true profitability of a group of companies. Using input–output theory, we developed a framework to estimate deferred taxation on dividends in business groups. Such relationships can be particularly useful when cross‐shareholdings exist to determine deferred liabilities under several accounting standards. Copyright © 2000 John Wiley & Sons, Ltd.
The tau A0 allele in Parkinson's disease
Authors: Golbe Lawrence I. , Lazzarini Alice M. , Spychala John R. , Johnson William G. , Stenroos Edward S. , Mark Margery H. , Sage Jacob I.
Published: August 2002

Parkinson's disease (PD) is primarily an α‐synucle‐ inopathy, rather than a tauopathy, but there is evidence for an indirect association of tau with the pathogenetic process in PD. We therefore assessed the frequency in PD of the tau A0 allele, a dinucleotide repeat marker that has been associated with a sporadic tauopathy, progressive supranuclear palsy (PSP). We found the A0 allele to comprise 79.2% of 758 alleles from PD patients and 71.2% of 264 control alleles (P = 0.008). We also performed a meta‐analysis of three previous reports, two of which failed to produce statistically significant results. Taken together, they also support a PD/A0 allelic association, even after correction for misdiagnosis of PSP as PD (P< 0.001). The A0/A0 genotype frequency in our patients (62.3%) did not differ significantly from that in controls (53.0%, P = 0.062), but the meta‐analysis, even after correction for misdiagnosis, showed a significant result, with P = 0.002. The frequency of A0 allele and the A0/A0 genotype were compatible with Hardy‐Weinberg equilibrium. The frequency of the A0 allele and the A0/A0 genotype in our patients with familial PD was not significantly greater than in those with sporadic PD. We conclude that the tau protein may play a small role in the pathogenesis of PD and that biochemical characterization of this role may suggest opportunities for PD prophylaxis. © 2001 Movement Disorder Society.
Auxiliary liver transplantation with portal arterialization in the rat: description of a new model
Authors: Aguirrezabalaga Javier , Arnal Francisco , Marini Milagros , Centeno Alberto , Fernandez‐Selles Carlos , Rey Ignacio , Gomez Manuel
Published: August 2002

In recent years, portal arterialization has been used in liver transplantation to increase the portal flow, as a solution for singular technical problems. We have developed a new auxiliary liver transplantation model in the rat with portal arterialization, so the native hepatic hilium remains untouched, consisting on a graft with a previous 70% hepatectomy. It is sited on the right renal bed, joining the infrahepatic inferior vena cava (IVC) of the graft with the recipient IVC. With an abdominal aortic graft, we connect the recipient aorta with the portal vein from the auxiliary liver. All the animals survived at the seventh day. No thrombosis was seen in any graft and an important rejection was observed in all the fields. We have developed a new experimental model of an auxiliary liver with portal arterialization, avoiding the utilisation of the native hepatic hilium, necessary for the possible recovering of the proper liver in the case of a reversible fulminant hepatitis. © 2002 Wiley‐Liss, Inc. MICROSURGERY 22:21–26, 2002 DOI 10.1002/micr.22003
L1 Decay estimates for dissipative wave equations
Authors: Milani Albert , Han Yang
Published: August 2002

Let u and v be, respectively, the solutions to the Cauchy problems for the dissipative wave equation

$$u_{tt}+u_t‐\Delta u=0$$\nopagenumbers\end
and the heat equation

$$v_t‐\Delta v=0$$\nopagenumbers\end

We show that, as $t\rightarrow+\infty$\nopagenumbers\end, the norms $\|\partial_t^k\,D_x^\alpha u(\,\cdot\,,t)\|_{L^1({\rm R}^n)}$\nopagenumbers\end and $\|\partial_t^k\,D_x^\alpha v(\,\cdot\,,t)\|_{L^1({\rm R}^n)}$\nopagenumbers\end decay to 0 with the same polynomial rate. This result, which is well known for decay rates in $L^p({\rm R}^n)$\nopagenumbers\end with $2\leq p\leq+\infty$\nopagenumbers\end, provides another illustration of the asymptotically parabolic nature of the hyperbolic equation (1). Copyright © 2001 John Wiley & Sons, Ltd.
Non‐linear singular integral equations on a finite interval
Authors: Junghanns P. , Semmler G. , Weber U. , Wegert E.
Published: August 2002

A class of nonlinear singular integral equations of Cauchy type on a finite interval is transformed to an equivalent class of (discontinuous) boundary value problems for holomorphic functions in the complex unit disk. Using recent results on the solvability of explicit Riemann–Hilbert problems, we prove the existence of solutions to the integral equation with bounded piecewise continuous nonlinearities. We discuss the influence of parameters and additional conditions and demonstrate the approach for a free boundary problem arising from seepage near a channel. Copyright © 2001 John Wiley & Sons, Ltd.
Asymptotic convergence of p‐Laplace equationswith constraint as p tends to 1
Authors: Shirakawa Ken
Published: August 2002

In this paper we treat the Euler–Lagrange equation of a functional including the p‐Laplacian for 1<p<2. The limiting equation as $p\searrow1$ corresponds to a steady state problem of a modified Stefan–Gibbs–Thomson problem. We investigate the structure of the limit set of all solutions as $p\searrow1$. Furthermore, we clarify the relationship between the limit set and the solution set of the limiting equation. Copyright © 2002 John Wiley & Sons, Ltd.
Optical code‐division switching network based on simultaneous capacity prime code
Authors: Lee Yang‐Han , Wu Rong‐Hou , Yu Fun
Published: August 2002

In this paper, a novel optical switch OCDSN (optical code‐division switching network) using the simultaneous capacity of the prime code is proposed. Selecting the prime code in accordance with transmission routing forms the basis of this three‐layer network architecture. This network code switching provides one‐to‐one, multicast, and broadcast characteristics. The optimal connection methods and modularized design are proposed. From mathematical analysis, we see that the optical nodes of the OCDSN are less complex than Omega's. And the optical nodes of the modularized P3 OCDSN are almost half in number as compared to the P5 OCDSNs under the same input port conditions. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 336–340, 2001.
Bandwidth enhancement for slotted waveguide spatial power combiners
Authors: Tan W. L. , Coetzee J. C.
Published: August 2002

Based on clues taken from the design of antenna arrays, multibranching techniques are used to expand the frequency performance of slotted waveguide power amplifiers. Both simulated and measured results reveal that the use of a corporate feed network may improve the bandwidth of the linear slotted amplifier by up to 50%. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 285–287, 2002.
Design and optimization of a nonplanar multidipole array using genetic algorithms for mobile communications
Authors: Saha Misra I. , Raychowdhury A. , Mallik K. K. , Roy M. N.
Published: August 2002

This paper presents the application of a genetic algorithm (GA) to the design and optimization of a nonplanar dipole array in light of its application at a cell‐site antenna for mobile communication. Cell‐site antennas demand widely different radiation patterns depending upon the geographical location, terrain, and interference conditions of the cell site. The theoretical analysis for the radiation characteristics of the array is developed first, and subsequently, the GA is applied for obtaining the optimized parameters of the array to obtain the desired pattern as needed in different application areas of the cell site. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 301–304, 2002.
A simple approach including gate leakage for calculating the minimum noise figure of GaN HEMTs
Authors: Oxley C. H.
Published: August 2002

The article presents a simple noise equation for the first time, including a contribution from the gate leakage, which accurately predicts the experimentally observed relatively flat minimum noise figure NFmin for a GaN HEMT with frequency, published by Lu et al. [1] © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 113–115, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10245
Time‐delay characteristics of in‐room UHF radio propagation channels
Authors: Zhang Y. P. , Wang F.
Published: August 2002

This Letter presents the measured time‐delay characteristics of UHF radio propagation channels in room environments. The measurements used the swept‐frequency technique with a different calibration method. The measured frequency bands include 2.4 GHz, 1.8 GHz, and 900 MHz. The particular interest is devoted to 2.4 GHz; the other two frequency bands were selected for comparison purpose. A simple channel model is derived from the measurement results. The in‐room wideband propagation model is believed to be useful for BER simulation, modem scheme evaluation, and system design. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 115–119, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10248
Long‐wavelength EDFA gain enhancement through 1550‐nm‐band lasing
Authors: Sun Junqiang
Published: August 2002

Gain enhancement and bandwidth broadening in a long‐wavelength band (L band) EDFA are demonstrated by incorporating an erbium‐doped fiber laser. Utilizing the strong 1550 nm lasing signal used as a secondary pump source, considerable improvements in gain and its bandwidth are achieved. The enhancement of the L‐band gain characteristics is strongly influenced by a secondary pump signal wavelength and its optical power. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 240–242, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10286
A shorted patch antenna with an l‐shaped ground plane for internal mobile handset antennas
Authors: Hsiao Fu‐Ren , Wong Kin‐Lu
Published: August 2002

This letter presents a novel shorted patch antenna for applications as internal mobile handset antennas. Instead of a conventional simple ground plane, the proposed antenna uses an L‐shaped ground plane, which effectively decreases the antenna's backward radiation and enhances the antenna gain. A prototype of the proposed antenna suitable for operating in the UMTS (1920–2170 MHz) band has been constructed, and experimental results are presented. The constructed prototype occupies a small volume of 30 × 17 × 7 mm3, which makes it suitable to be employed as an internal mobile handset antenna, and shows a peak antenna gain of about 3.5 dBi, with gain variations less than 1.2 dBi for frequencies within the UMTS band. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 314–316, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10305
Hybrid fiber radio systems for pico‐cell communications
Authors: Kim Ajung , Ju Young Hoon , Kim Young Soo , Nahm Sang Min
Published: August 2002

We built a test‐bed of a hybrid fiber radio (HFR) system for 60 GHz millimeter‐wave wireless communication. Transmission at 155 Mbps over 24 km of an optical link with a tolerable BER less than 10−6 was achieved over the pico‐radio cell with a radius of 2.6 m, which confirms the feasibility of 60 GHz HFR systems. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 328–330, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10311
Effect of pitch angle on modal propagation characteristics of an annular circular dielectric waveguide having helical windings on the inner and outer boundaries as claddings
Authors: Srivastava S. K. , Pandey P. C. , Singh U. N. , Ojha S. P.
Published: August 2002

Using a fairly rigorous analysis, a general characteristic equation for an annular step‐index fiber with helical windings on the core‐cladding boundaries was derived. We present the modal dispersion characteristics for some lower‐order modes of this dielectric waveguide. We also use the variation of helix pitch angles of the windings and discuss their effect on the dispersion curves of the proposed waveguide. An important property, the presence of band gap, was found for some particular combinations of pitch angles. This may be attributed to the periodicity of the helical structure. We can say that pitch angle acts as a controlling factor for the propagation modes. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 338–344, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10315
Improved perturbation analysis for a new omnidirectional periodic dielectric rod leaky‐wave antenna for millimeter‐wave application
Authors: Xu Shanjia , Lin Kaihui
Published: August 2002

The leakage characteristics of a new millimeter wave omnidirectional periodic circular dielectric rod leaky‐wave antenna are analyzed by an improved perturbation method. The electromagnetic fields are described in terms of a radial transmission‐line network, which brings considerable physical insight into the overall behavior of the leaky‐wave antenna. The analysis yields expression for the leakage constant in a closed form so that the design procedure of the antenna becomes very convenient. It was found that the circular dielectric shell layer greatly affects the leaky characteristics of the antenna. The results obtained by the present analysis are compared with the exact solution based on the mode‐matching method. It is justified that the improved perturbation procedure yields as accurate results as the rigorous method, with extreme simplicity of the analysis and calculations. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 344–346, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10316
Analysis of the effects of walls on indoor wave propagation using the FDTD method
Authors: Ji Zhong , Sarkar Tapan K. , Li Binhong
Published: August 2002

The ray‐tracing technique does not take into account the effects of the inner structure of walls for indoor propagation prediction. A numerical approach to consider this problem using the FDTD method is presented. Numerical results of the path loss calculated by the FDTD method are compared to those obtained by the ray‐tracing technique. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 19–21, 2001.
Broadband patch antenna for E‐band applications
Authors: Vera‐Isasa M. , Pedreira G. , De Lorenzo M. E. , Santalla V.
Published: August 2002

A broadband microstrip patch antenna fed by slot coupling is described. The operation frequencies are in the E‐band, and the required bandwidth is about 2 GHz. Results obtained from an antenna design to operate from 40.5 to 42.5 GHz are presented. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 40–42, 2001.
Wavelength‐tuning analysis of erbium‐doped fiber‐ring laser
Authors: Abd‐Rahman M. Kamil , Selvakennedy S. , Poopalan P. , Ahmad Harith
Published: August 2002

An erbium‐doped fiber‐ring laser (EDFL) with more than 50 nm of continuous wavelength tuning was achieved and analyzed through a numerical approach. An angle‐tuned Fabry–Perot etalon was incorporated in the laser cavity as the wavelength‐selective element. The numerical values are in close agreement with the experimental results. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 213–215, 2001.
Refractive‐index profile of fiber optics
Authors: Hindy Moataza A.
Published: August 2002

An optimized approach for obtaining the complex refractive‐index profile of graded‐index fiber optics is presented. The measured optical reflections from the sample are used to minimize the norm of the difference between measured and calculated data. An iterative technique based on a one‐dimensional search in the descent direction is applied for obtaining a new estimate of the refractive‐index profile. Numerical experiments are used to apply the gradient technique in solving optical inverse problems. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 252–256, 2001.
Performance enhancement of the base‐station antennas of mobile communications via the application of resistive plates
Authors: Chou Hsi‐Tseng , Su Po‐Lin
Published: August 2002

The wide intersector coverage overlap and sidelobes of antenna radiation in mobile communications result in irregular handover and unwanted interference. This paper employs techniques based on the application of resistive plates to reduce the interference and enhance the performance by guiding the power to where strong signals are required. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 267–270, 2001.
Efficient evaluation of the half‐space Green's function for fast‐multipole scattering models
Authors: Liu Zhijun , Carin Lawrence
Published: August 2002

There has recently been significant interest in the method‐of‐moments (MoM) and fast multipole method (FMM) for the analysis of scattering from targets in the presence of a lossy dielectric half space (soil). It is desirable to make the analysis of scattering from such a target consistent with use of the free‐space Green's function, to exploit previously developed free‐space scattering models, and for compatibility with the FMM. In this paper, we present a new and simple formulation for Green's‐function evaluation, which is shown to yield efficient and highly accurate scattering results. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 388–392, 2001.
A compact 90° hybrid for MMIC applications
Authors: Avitabile G. , Chellini B.
Published: August 2002

A monolithic 20 GHz 90° hybrid is introduced. The hybrid design is based on a lumped‐component approach that makes use of planar coupled inductors. The hybrid model and design technique are discussed. Experiments validating the structure are reported. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 392–394, 2001.
A modified expression for determining the wall thickness of monolithic half‐wave radomes
Authors: Sunil S. , Venu K. S. , Vaitheeswaran S. M. , Raveendranath U.
Published: August 2002

A comparison of the wall thickness for a monolithic half‐wave radome at different incidence angles is made by considering the loss tangent of the material used. It is seen that, for large incidence angles and for moderately low‐loss radome materials, the computed wall thickness is different from the values obtained by neglecting the loss tangent of the material. The above context seems to be important, particularly for variable thickness radomes for aerospace applications where the thickness from nose to base varies with the angle of incidence and angle of polarization so as to achieve the optimum design of the radome. An expression for computing the wall thickness is given which is valid for both moderately lossy and very low‐loss radome materials. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 350–352, 2001.
A novel corner reflector antenna
Authors: Joseph V. P. , Mathew K. T.
Published: August 2002

A new type of corner reflector (CR) antenna with a rectangular dielectric feed is presented. The radiation characteristics of the wideband CR were studied and compared with a standard corner reflector antenna. It is observed that this novel CR antenna has a wide bandwidth and better performance. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 403–404, 2001.
Invariant face recognition
Authors: Alamand M. S. , Al‐Samman A. F.
Published: August 2002

In this paper, we investigate human face recognition for facial images involving a high degree of in‐plane and out‐of‐plane 3‐D distortions such as rotation. In the proposed technique, we investigate the problem of invariant face recognition by considering four different classes of images. A small subset of images is used for every class to create a composite image, which represents each class. The proposed technique is implemented by using the fringe‐adjusted filter‐based joint transform correlator (JTC) technique due to its superior performance over alternate JTCs and the feasibility of its implementation in the optical domain. Furthermore, the utilization of the synthetic discriminant function to generate the composite image for enhancing the correlation output is also investigated. Computer simulation results are presented to show the validity of the proposed technique. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 418–423, 2001.
Absence of activating mutations in ras and gsp oncogenes in a cohort of nine patients with sporadic pediatric thyroid tumors
Authors: Pauws Erwin , Tummers Rob F.H.M. , Ris‐Stalpers Carrie , de Vijlder Jan J.M. , Voûte Tom
Published: August 2002

Background

Characterization of the genetic background of pediatric thyroid carcinomas could aid in distinguishing between differently staged tumors with respect to treatment and prognosis. Two known genetic factors associated with thyroid carcinoma, the proto‐oncogenes gsp and ras were investigated.

Procedure

DNA was extracted from paraffin sections from both tumor and normal thyroid tissue of nine patients (ages 9–16 years). Of these patients, eight were diagnosed with papillary carcinoma and one with follicular adenoma. The coding exons of gsp and the three known ras genes (H, K, and N‐ras) were screened for mutations using SSCP‐analysis.

Results

There were no mutations present in the ras and gsp proto‐oncogenes hot spots, however, LOH of H‐ras (chromosome location 11p15.5) was found in tumor tissue from one patient and a homozygous mutation in exon 12 of gsp causing a Pro→Ser conversion was present in the thyroid tumor tissue from another patient. Two silent polymorphisms were detected, H‐ras exon1, 86T→C and gsp exon 5, 81T→C.

Conclusions

Our results indicate that the ras/gsp mutations found are probably late events in the tumorigenesis representing general oncogenic stress. In conclusion, it seems that ras/gsp activation is not a factor in the mechanism causing sporadic thyroid carcinoma in children. Med. Pediatr. Oncol. 36:630–634, 2001. © 2001 Wiley‐Liss, Inc.
1H and 13C spectral assignment of o‐chloroformyl substituted 1,4‐dihydropyridine derivatives
Authors: Suárez Margarita , Martín Nazario , Martínez Roberto , Verdecia Yamila , Molero Dolores , Alba Livan , Seoane Carlos , Ochoa Estael
Published: August 2002

The 1H and 13C NMR spectroscopic data for alkyl 4‐aryl‐6‐chloro‐5‐formyl‐2‐methyl‐1,4‐dihydopyridine‐3‐carboxylates were fully assigned by combination of one‐ and two‐dimensional experiments (DEPT, HMBC, HMQC, COSY, NOE). Copyright © 2002 John Wiley & Sons, Ltd.
PGSE‐WATERGATE, a new tool for NMR diffusion‐based studies of ligand–macromolecule binding
Authors: Price William S. , Elwinger Fredrik , Vigouroux Cécile , Stilbs Peter
Published: August 2002

A new pulsed gradient spin‐echo NMR diffusion sequence, PGSE‐WATERGATE, which is based on the extremely efficient WATERGATE solvent suppression sequence, is presented. The sequence is simple to set up and particularly suited to measuring the diffusion coefficients of small ligands in aqueous solution such as is commonly required in pharmaceutical and combinatorial applications. It also affords the possibility of measuring the diffusion of exchangeable resonances, which is often impossible in conjunction with other suppression schemes. Further, a trivial modification of the sequence affords the possibility of multiple solvent suppression, thereby increasing its suitability to LC–NMR applications. The utility of the sequence is demonstrated on the salicylate–bovine serum albumin system. The dissociation constant, Kd, and the number of binding sites were found to be 0.030 M and 33, respectively. Importantly, the extremely high degree of suppression provided by the new sequence allowed the salicylate diffusion coefficients to be measured over a very wide concentration range sufficient to show that the salicylate–bovine serum albumin system is not well described by a simple two‐site model. Previous studies in the literature have been based on data from a smaller concentration range, for which this model gives an apparently good fit. Copyright © 2002 John Wiley & Sons, Ltd.
Two new acylated flavonoid glycosides from Morina nepalensis var. alba Hand.‐Mazz.
Authors: Teng Rongwei , Xie Hongyang , Li Hai Zhou , Liu Xikui , Wang Dezu , Yang Chongren
Published: August 2002

From the whole plant of Morina nepalensis var. alba Hand.‐Mazz., two new acylated flavonoid glycosides (1 and 2), together with four known flavonoid glycosides (3–6), were isolated. Their structures were determined to be quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L‐arabinopyranosyl‐(1→6)‐β‐D‐galactopyranoside (monepalin A, 1), quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L‐arabinopyranosyl‐(1→6)‐β‐D‐glucopyranoside (monepalin B, 2), quercetin 3‐O‐α‐L‐arabinopyranosyl‐(1→6)‐β‐D‐galactopyranoside (rumarin, 3), quercetin 3‐O‐β‐D‐galactopyranoside (4), quercetin 3‐O‐β‐D‐glucopyranoside (5) and apigenin 4′‐O‐β‐D‐glucopyranoside (6). Their structures were determined on the basis of chemical and spectroscopic evidence. Complete assignments of the 1H and 13C NMR spectra of all compounds were achieved from the 2D NMR spectra, including H–H COSY, HMQC, HMBC and 2D HMQC‐TOCSY spectra. Copyright © 2002 John Wiley & Sons, Ltd.
Towards the automatic analysis of 1H NMR spectra: Part 2. Accurate integrals and stoichiometry
Authors: Griffiths Lee
Published: August 2002

A method was developed for the extraction of accurate NMR integrals, even where partially convoluted with other solute or solvent resonances, and then automatically allocating these to multiplets. The method yields an overall error of 7%, an assessment which includes a statistical distribution of overlapping and touching multiplets. A method was also developed to convert these multiplet integrals automatically from arbitrary units into protons, the overall error remaining at 7%. Copyright © 2001 John Wiley & Sons, Ltd.
1H and 13C chemical shifts for tetracycle‐fused acridine analogues of amsacrine
Authors: Robin M. , Galy J. P. , Faure R.
Published: August 2002

The 1H and 13C NMR resonances for 18 tetracyclic acridines 9‐substituted on the acridine ring with Cl, NH2 and AMS [N‐(4‐amino‐3‐methoxyphenyl)1methanesulfonamide] groups were completely and unequivocally assigned by the concerted application of gs‐HMQC and gs‐HMBC experiments. For NH2 and AMS substituents, the potential amino–imino tautomerism is completely shifted towards the imino tautomer. Copyright © 2001 John Wiley & Sons, Ltd.
Investigation of formation of superoxide anion radical in DMSO by ESR: Part 1. Influence of Fe2+ and Cu2+
Authors: Qiao Xiangli , Chen Shiming , Tan Li , Zheng Hu , Ding Yadi , Ping Zhenghua
Published: August 2002

The superoxide anion radical O2−. can be produced by reactions between dissolved oxygen, DMSO and NaOH. The analysis of DMSO of chemical purity grade showed that there are some ionic impurities such as Fe, Cu and Zn. A systematic study, by electron spin resonance, of the variation of the intensity of the O2−. radical as a function of the ion contents in DMSO showed that the amount of superoxide anion radical produced depends on the Fe2+ and Cu2+ contents in DMSO, but is independent of Zn2+ content. The presence of both Fe2+ and Cu2+ in a certain concentration range greatly favors radical formation. The mechanism of O2−. generation in the presence of Fe2+ and Cu2+in DMSO is discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Complete assignment of the 1H and 13C NMR spectra of resveratrol derivatives
Authors: Koh Dongsoo , Park Kwan Ha , Jung Jihyun , Yang Heejung , Mok K.Hun , Lim Yoongho
Published: August 2002

The complete 1H and 13C chemical shift assignments of six derivatives of resveratrol [(E)‐5‐[2‐(4‐hydroxyphenyl)ethenyl]‐1,3‐benzenediol] that possess leukotriene D4 receptor antagonistic activities are described. Two‐dimensional COSY, HMQC, HMBC and NOESY experiments, along with molecular modeling calculations, were employed to distinguish unambiguously between different configurations of the stilbene moiety. Copyright © 2001 John Wiley & Sons, Ltd.
Assignment of the 13C and 15N NMR spectra of the antitumour antibiotic streptonigrin
Authors: Anderberg Pia I. , Luck Ian J. , Harding Margaret M.
Published: August 2002

The assignments of the two pyridyl nitrogens and two amino nitrogens in the antitumour antibiotic streptonigrin, and all carbon resonances, were determined by 15N (HSQC, HMBC) and 13C (HSQC, HMBC) NMR techniques. These data provide useful probes for determination of the site(s) of metal complexation in the drug, which are important in the mechanism of antitumour activity. Copyright © 2002 John Wiley & Sons, Ltd.
DNA topoisomerase II is essential for preimplantation mouse development
Authors: St. Pierre Jason , Wright David J. , Rowe Thomas C. , Wright Shirley J.
Published: August 2002

Topoisomerase II (topo II) is an essential enzyme that alters DNA topology. This activity is important for a variety of chromosome functions including DNA replication, transcription, recombination, and chromosome condensation and segregation. Previously we localized topo II in mouse gametes and preimplantation embryos using isoform‐specific antibodies demonstrating the presence of the enzyme in oocytes and embryos, but not sperm. To probe functions of topo II during preimplantation development, we treated mouse zygotes with 100 nM teniposide, and assessed embryo morphology and DNA replication. Teniposide blocked cleavage in 69% embryos; the remainder cleaved once but had abnormal nuclei. Teniposide‐treated embryos were devoid of topo II immunofluorescence. Teniposide also prevented DNA replication, implicating topo II in this process. Embryos treated with a 2 hr pulse of teniposide recovered and developed to the blastocyst stage, indicating 100 nM teniposide did not induce apoptosis. To more specifically analyze topo IIα function, we treated zygotes with topo IIα‐targeted antisense oligodeoxynucleotides. Most zygotes arrested at the 2‐cell stage while controls developed into blastocysts indicating topo IIα is essential for preimplantation development. The absence of topo IIα, but not β immunofluorescence in antisense‐treated embryos confirms the specificity and impact of the treatment. In addition, topo IIα is newly synthesized at the 2‐cell stage. These results establish an essential function for topo II in mouse preimplantation embryonic development. Mol. Reprod. Dev. 61: 347–357, 2002. © 2002 Wiley‐Liss, Inc.
Androgen receptor and follicle‐stimulating hormone receptor in the pig ovary during the follicular phase of the estrous cycle*
Authors: Cárdenas H. , Pope W.F.
Published: August 2002

Follicle‐stimulating hormone (FSH) is an important regulator of follicular development. Some effects of FSH on ovarian follicles might be enhanced by androgens. The main objectives of the present study were to examine expression of the androgen receptor (AR) and FSH receptor (FSHR) in late developing follicles in pigs. Ovaries were collected from gilts on days 13, 15, 17, and 19 of the estrous cycle (day 0 = first day of estrus, n = 4 gilts/day), a period coincident with the follicular phase. One ovary was processed for immunohistochemistry (IHC) of AR. Samples of surface wall from the largest follicles (4–5 per gilt) were dissected from the other ovary, pooled and processed for determination of AR and FSHR mRNAs using reverse transcription‐polymerase chain reaction (RT‐PCR). Intense AR immunostaining was present in nuclei of granulosa cells of preantral and antral follicles. AR immunoreactivity was also present in the nuclei of oocytes. Weak staining for AR was observed in cells of the theca interna, ovarian surface epithelium, and in most cells of the ovarian stroma. Relative amounts of immunoreactive AR in granulosa cells of late developing follicles, or small antral follicles (< 2 mm), did not differ between days 13, 15, 17, and 19. However, amounts of AR in granulosa cells of small antral follicles was greater (P < 0.05) than in the largest follicles present in the same ovary. The relative amounts of AR mRNA in tissue from the largest follicles on days 13, 15, 17, and 19 did not differ; however, amounts of FSHR mRNA in the same follicles were not different between days 13, 15, and 17, but decreased (P < 0.05) by day 19. Results indicate that during the follicular phase in gilts, the AR protein is mainly present in granulosa cells. Relative amounts of AR protein in granulosa cells and mRNA in walls of late developing follicles did not significantly change from day 13 to 19; however, amounts of FSHR mRNA decreased in preovulatory follicles by day 19 of the estrous cycle. Mol. Reprod. Dev. 62: 92‐98, 2002. © 2002 Wiley‐Liss, Inc.
Localization of an activin/activin receptor system in the porcine ovary
Authors: Van den Hurk R. , van de Pavert S.A.
Published: August 2002

The aim of this study was to locate a possible activin/activin receptor system within porcine ovaries containing functional corpora lutea. In situ hybridization was used to assess the gene expression of βA‐ and βB‐activin subunits, and immunohistochemical studies were done to detect activin‐A protein and activin receptor type II. mRNA expression of the βA‐ and βB‐activin subunits was found in the granulosa from the unilaminar follicle stage onward, in the developing thecal layer of multilaminar and small antral follicles, in the theca interna of mid‐sized antral follicles, in corpora lutea, and in the ovarian surface epithelium. Immunoreactive activin A protein could be detected at the same ovarian sites, but in thecal tissue of small antral follicles only. This protein was also demonstrated at the peripheral zone of oocytes from multilaminar and antral follicles. A positive immunoreaction for activin receptor was found in granulosa cells from multilaminar and older follicles and in oocytes from the earliest stages of follicular development onward. In late multilaminar follicles and in antral follicles, the oolemma was stained. Except for small antral follicles, a positive activin receptor immunoreaction was absent in the follicular theca. Activin receptor immunoreaction was furthermore present in corpora lutea and in the ovarian surface epithelium. It is concluded that, within porcine ovaries containing functional corpora lutea, an activin/activin receptor system is present in all intact follicles, the corpora lutea and the surface epithelium. Within follicles, granulosa and theca cells are the main sites of activin synthesis, while oocytes and granulosa cells are the main activin binding sites. Mol. Reprod. Dev. 60: 463–471, 2001. © 2001 Wiley‐Liss, Inc.
Bovine oocytes treated prior to in vitro maturation with a combination of butyrolactone I and roscovitine at low doses maintain a normal developmental capacity
Authors: Ponderato Nunzia , Lagutina Irina , Crotti Gabriella , Turini Paola , Galli Cesare , Lazzari Giovanna
Published: August 2002

Butyrolactone I (BL‐I) and Roscovitine (ROS), two specific and potent inhibitors of M‐phase promoting factor (MPF) kinase activity, were used to block germinal vesicle breakdown (GVBD) of cattle oocytes. A concentration 6.25 μM BL‐I and 12.5 μM ROS blocked over 93.3 ± 2.5% of oocytes in germinal vesicle (GV) stage during a 24‐hr culture period. Following a second 24‐hr culture step in maturation medium (IVM) almost all (91.5 ± 3.0%) inhibited oocytes resumed meiosis and reached the metaphase II (MII) stage. The MII kinetics was different for inhibited and control oocytes. Fifty percent MII was reached at 13–14 hr in BL‐I + ROS treated oocytes, compared to 18 hr in control oocytes. Therefore, control oocytes were fertilised (IVF) after 22 hr IVM and inhibited oocytes after 16 or 22 hr IVM. After IVF, percentage of grade 1 freezable embryos on day 7 (D + 7) as well as percentage of blastocyst formation on D + 8 in the group of BL‐I + ROS treated oocytes fertilised after 16 hr IVM were higher (P < 0.05) compared with the other experimental group fertilised after 22 hr IVM but not different in comparison with the control. Survival to freezing and thawing of grade 1 embryos frozen on D + 7 was employed as viability criteria and was similar in all groups. Thus, the presence of BL‐I + ROS in the prematuration medium of bovine oocytes determines a reversible meiotic block, without compromising their subsequent developmental competence. Mol. Reprod. Dev. 60: 579–585, 2001. © 2001 Wiley‐Liss, Inc.