bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hybrid PSTD‐FDTD technique for scattering analysis
Authors: Li Qingliang , Chen Yinchao , Li C. K. 
Published: August 2002

AbstractThis paper employs a hybrid method that combines the pseudo‐spectral time‐domain (PSTD) algorithm and the finite‐difference–time‐domain (FDTD) method to analyze the scattering problems involving fine structures. In principle, the PSTD is applied in a direction with low‐density variation of structures but large computation volume, whereas the FDTD is used in other directions with high‐density variation and relatively small computation dimensions. In implementation of this hybrid algorithm, the pure scattered‐field formulation is utilized to introduce the incident wave, and a hybrid near‐to‐far‐zone field transform is developed for calculating the scattering width (SW) of the targets. The hybrid method is illustrated by analyzing two canonical scattering targets: a thin dielectric slab and a conductor‐backed dielectric slab. It is observed that the proposed algorithm is very accurate and efficient compared to the FDTD calculations for the same cases investigated. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 19–24, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10361
Extension of impedance matrix compression method with wavelet transform for 2‐D conducting and dielectric scattering objects due to oblique plane‐wave incidence
Authors: Yu Jin , Kishk Ahmed A. 
Published: August 2002

AbstractThe impedance matrix compression (IMC) technique is applied to analyze the square method–of‐moments (MoM) matrix arising from the surface integral equation for 2‐D conducting and dielectric objects with oblique plane‐wave incidence. The induced current components are processed separately by using wavelet basis functions. The comparison between cylinders with circular and square cross section is presented to show the effectiveness of IMC, which depends on the geometry of the object and the wavelet transform matrix. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 53–56, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10371
Simple equations for π‐phase‐modulated Talbot illuminator
Authors: Zhou Changhe , Xi Peng , Zhao Shuai , Liu Liren 
Published: August 2002

AbstractA π‐phase‐modulated Talbot illuminator means that there is a half‐period π phase modulation in the output array. We will show that, by using the rule of regularly rearranged neighboring‐phase difference, simple equations can be derived to describe the pure‐phase distributions and the pulse‐density increased phenomena in a π‐phase‐modulated Talbot illuminator. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 49–52, 2001.
A nonuniform transmission‐line approach for modeling bends on transmission lines
Authors: Chunfei Ye , Yim Tan Soon , Erping Lee 
Published: August 2002

AbstractA novel approach for modeling the discontinuities of transmission lines such as conductors with bends and varying size is proposed. The effect from the discontinuities is incorporated in the per‐unit‐length parameters of nonuniform transmission‐line equations. For canonical problems, our approach yields correct results. For a more general case, a comparison between our calculations and experimental data reported in the literature shows good general agreement. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 71–74, 2001.
An estimation of power transmission through a doubly clad optical fiber with an annular core
Authors: Choudhury P. K. , Lessard Roger A. 
Published: August 2002

AbstractAn estimation has been made of the distribution of power (over different modes) through the guiding region of an optical fiber with an annular core. The general expression for the power in the guiding region is derived under the use of a scalar field approximation, and the power pattern is plotted against the dimensionless core parameter for three lowest azimuthal model indexes. The analysis is rigorous in the sense that no approximation is used to determine the field functions. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 402–405, 2001.
Six‐finger Lange coupler on 3 mil GaAs substrate using multilayer MMIC technology
Authors: Bahl Inder J. 
Published: August 2002

AbstractThis paper presents the design and test data for six‐finger Lange couplers on a 3 mil GaAs substrate using the multilayer MMIC process. We achieved coupling of 3.3±0.5 dB, isolation greater than 20 dB, and return loss better than 15 dB over most of the 8–16 GHz frequency range. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 322–327, 2001.
Retinoid chemoprevention in patients at high risk for skin cancer*
Authors: DiGiovanna John J. 
Published: August 2002

AbstractPatients who develop large numbers of skin cancers suffer increased morbidity and mortality. A high skin cancer risk can result from inherited disorders such as xeroderma pigmentosum (abnormal repair of UV‐induced DNA damage) or the nevoid basal cell carcinoma syndrome (tumor suppressor gene abnormality). The efficacy of systemic retinoid skin cancer chemoprevention was first demonstrated in these disorders. Since the mechanism of cancer prevention was not thought to involve correction of the underlying defect causing the disorder, individuals at high risk for new skin cancers from other causes may also benefit from this approach. With the success of organ transplantation, there is a growing population of transplant recipients living long, active lives who also have sustained chronic UV damage. This population is at high risk for developing aggressive squamous cell carcinomas. In this population, extensive skin involvement with human papilloma virus induced warts and actinic keratoses results in difficulty with diagnosis and monitoring for these dangerous malignancies. Patients who have received treatment with agents that cause DNA damage, such as X‐radiation, may also have a high skin cancer risk. Retinoid chemoprevention may also be of benefit in the management of selected patients with these iatrogenic conditions. This evolving therapeutic role has heightened the need for the development of new retinoids, with more efficacy and less toxicity, for cancer chemoprevention. Med. Pediatr. Oncol. 36:564–567, 2001. © 2001 Wiley‐Liss, Inc.
Epstein barr virus associated pediatric nasopharyngeal carcinoma: Its correlation with p53 and bcl‐2 expression
Authors: Preciado María Victoria , Chabay Paola A. , De Matteo Elena N. , Gismondi María Inés , Rey Guadalupe , Zubizarreta Pedro 
Published: August 2002

AbstractBackgroundPediatric nasopharyngeal carcinoma (NPC) is relatively rare. The Epstein Barr virus (EBV) association with the oncogenesis of NPC is well established. Apoptosis‐related proteins, p53 and bcl‐2, have also been described in adult NPC pathogenesis.ProcedureFrom 1988 to 1998, 16 patients with NPC were treated at R. Gutierrez Children's Hospital and the National J.P. Garrahan Pediatric Hospital. Their median age was 12 years (range 8–20), 2 females and 14 males. The presence of p53, bcl‐2 and latent membrane protein‐1 (LMP‐1) of EBV expression was studied by immunohistochemistry and Epstein Barr encoded RNAs (EBERs) by in situ hybridization in tissue sections from formalin‐fixed, paraffin‐embedded NPC biopsiesResultsEBV presence and LMP‐1 expression in epithelial tumor cells were detected in all the biopsies studied. p53 was expressed in 13/16 NPCs, but the frequency of positive malignant cells differed from case to case, ranging from less than 25 to 100% with heterogeneous staining intensity. Bcl‐2 positive staining in tumor epithelial cells was detected in 2/16; whereas 10/16 cases showed bcl‐2 positivity in infiltrating lymphocytes.ConclusionsAlthough our series is small, we conclude that the pathogenesis of pediatric NPC as a multistep process may well involve EBV infection. This leads to LMP‐1 expression and p53 overexpression in epithelial tumor cells, whereas bc‐2 seems unrelated to the development of this disorder. Med. Pediatr. Oncol. 2002;38:345–348. © 2002 Wiley‐Liss, Inc.
Modified, pulse field gradient‐enhanced inverse‐detected HOESY pulse sequence for reduction of t1 spectral artifacts
Authors: Alam Todd M. , Pedrotty Dawn M. , Boyle Timothy J. 
Published: August 2002

AbstractA modified pulse field gradient (PFG)‐enhanced inverse (1H)‐detected 2D heteronuclear Overhauser effect spectroscopy (HOESY) pulse sequence is demonstrated for the acquisition of 1H–7Li heteronuclear correlations. In practice, t1 noise artifacts were observed using the original PFG‐enhanced inverse‐detected HOESY pulse sequence, which degraded the ability to detect accurately weak heteronuclear Overhauser signals. Experimentally it is shown that a simple modification of the PFG‐enhanced inverse‐detected HOESY pulse sequence greatly reduces the t1 noise that may result from variations in magnetic susceptibility, and allows improved detection of weak 1H–7Li correlations. Copyright © 2002 John Wiley & Sons, Ltd.
1H{15N} GHMQC study of 5,7‐diphenyl‐1,2,4‐triazolo[1,5‐a]pyrimidine and 1H, 13C and 15N NMR coordination shifts in Au(III) chloride complexes of 1,2,4‐triazolo[1,5‐a]pyrimidines
Authors: Szłyk Edward , Pazderski Leszek , Łakomska Iwona , Kozerski Lech , Sitkowski Jerzy 
Published: August 2002

AbstractThe 1H{15N} NMR spectrum of 5,7‐diphenyl‐1,2,4‐triazolo[1,5‐a]‐pyrimidine (3) was measured by GHMQC, unambiguously assigned and compared with the spectra of 1,2,4‐triazolo[1,5‐a]pyrimidine (1) and 5,7‐dimethyl‐1,2,4‐triazolo[1,5‐a]pyrimidine (2). A series of Au(III) chloride complexes of general formula AuLCl3, where L = 1, 2, 3, was synthesized and studied by 1HH{15N} GHMQC and 1H{13C} GHMBC. Low‐frequency shifts of 72–74 ppm (15N) and 5–6 ppm (13C) were observed upon complexation by Au(III) ions for the coordination site N‐3 and adjacent C‐2, C‐3a atoms, respectively. The 13C signals of C‐5, C‐6, C‐7 and the 1H resonances of H‐2, H‐6 were shifted to higher frequency. Comparison with analogous Pd(II), Pt(II) and Pt(IV) complexes revealed that in the case of Au(III) coordination the 15N shifts were relatively smaller, whereas those for 13C and 1H were larger. Copyright © 2002 John Wiley & Sons, Ltd.
Solid‐state 1H → 19F/19F → 1H CP/MAS NMR study of poly(vinylidene fluoride)
Authors: Ando Shinji , Harris Robin K. , Reinsberg Stefan A. 
Published: August 2002

AbstractSolid‐state 1H → 19F and 19F → 1H cross‐polarization magic angle spinning (CP/MAS) NMR spectra have been investigated for a semicrystalline fluoropolymer, namely poly(vinylidene fluoride) (PVDF). The 1H → 19F CP/MAS spectra can be fitted by five Lorentzian functions, and the amorphous peaks were selectively observed by the DIVAM CP pulse sequences. Solid‐state spin‐lock experiments showed significant differences in T1ρF and T1ρH between the crystalline and amorphous domains, and the effective time constants, THF* and T1ρ*, which were estimated from the 1H → 19F CP curves, also clarify the difference in the strengths of dipolar interactions. Heteronuclear dipolar oscillation behaviour is observed in both standard CP and 1H → 19F inversion recovery CP (IRCP) experiments. The inverse 19F → 1H CP‐MAS and 1H → 19F CP‐drain MAS experiments gave complementary information to the standard 1H → 19F CP/MAS spectra in a manner reported in our previous papers for other fluoropolymers. The value of NF/NH (where N is a spin density) estimated from the CP‐drain curve is within experimental error equal to unity, which is consistent with the chemical structure. Copyright © 2001 John Wiley & Sons, Ltd.
Long‐range 19F–15N heteronuclear shift correlation: examination of J‐modulations associated with broad range accordion excitation
Authors: Russell David J. , Hadden Chad E. , Martin Gary E. , Krishnamurthy Krish 
Published: August 2002

AbstractThe first demonstrated example of 19F–15N long‐range heteronuclear shift correlation spectroscopy at natural abundance is reported. Because of the very large variation in the size of 2J(N,F) vs 3J(N,F) long‐range heteronuclear couplings, the utilization of one of the new accordion‐optimized long‐range heteronuclear shift correlations experiments is essential if all possible correlations are to be observed in a single experiment. A modified IMPEACH‐MBC pulse sequence was used in conjunction with an optimization range from 4 to 50 Hz to demonstrate the technique using a mixture of 2‐ and 3‐fluoropyridine, which had 2J(N,F) and 3J(N,F) long‐range couplings of −52 and 3.6 Hz, respectively. Because of the size of the 2J(N,F) long‐range coupling constant, a J‐modulation of the long‐range correlation response is observed in the spectrum resulting in a ‘doublet’ in F1 due to amplitude modulation. The size of the ‘doublet’ is shown to be a function of the parameter selection (t1max,Tmax,Tmin and spectral width in F1). This behavior is similar to F1 ‘skew’ associated with long‐range correlation responses in ACCORD‐HMBC spectra which has been analyzed in detail previously. Copyright © 2002 John Wiley & Sons, Ltd.
Inhibition of apoptosis in serum starved porcine embryonic fibroblasts
Authors: Lee Chang‐Kyu , Piedrahita Jorge A. 
Published: August 2002

AbstractIn nuclear transplantation, serum starvation is a general method to synchronize donor cells at the quiescent stage (G0) of the cell cycle. However, serum starvation during culture of mammalian cells may induce cell death, especially through apoptosis, thus contributing to the low efficiency of nuclear transplantation. This study was performed to characterize apoptosis during serum starvation and to determine the effects of apoptosis inhibitors such as a protease inhibitor [α2‐macroglobulin (MAC)] and antioxidants [N‐acetylcysteine (NAC), glutathione (GSH)] on serum starved porcine embryonic fibroblasts (PEF). PEF, collected from day 25–30 porcine fetuses, were cultured for 5 days in media containing 0.5% FBS to induce quiescence. Serum starved PEF showed typical morphology of apoptotic cells and stained for DNA fragmentation by TUNEL assay (26.7%). All apoptosis inhibitors tested in this study significantly (P < 0.05) reduced apoptosis of serum starved PEF, with antioxidants having better results (MAC: 7.4% vs. NAC: 1.0%, and GSH: 0.8%). Equally and importantly, the treatment with apoptosis inhibitors did not change the proportion of G0/G1 stage cells. Therefore, the addition of MAC and antioxidants during serum starvation of PEF reduces apoptosis of quiescent fibroblasts and may contribute to increasing the efficiency of nuclear transplantation by improving the quality of donor nuclei. Mol. Reprod. Dev. 62: 106‐112, 2002. © 2002 Wiley‐Liss, Inc.
Pyruvate utilization by mouse oocytes is influenced by meiotic status and the cumulus oophorus
Authors: Downs Stephen M. , Humpherson Peter G. , Leese Henry J. 
Published: August 2002

AbstractIn this study, the effects of meiotic status on the energy substrate dynamics of mouse oocyte‐cumulus cell complexes (OCCs) and denuded oocytes (DOs) have been examined. In the first series of experiments, OCCs from PMSG‐primed, immature mice were cultured in minimum essential medium in 8‐μl microdrops under a variety of conditions, and the medium and oocytes were sampled for pyruvate and glucose concentration and for meiotic status. Oocytes in control medium underwent germinal vesicle breakdown within 3 hr and the OCCs displayed a time‐dependent increase in pyruvate consumption, but the glucose concentration changed very little. Treatment with IBMX or dbcAMP, which maintained complete meiotic arrest, suppressed pyruvate consumption, but slightly more glucose was consumed than in controls. Hypoxanthine (HX) allowed up to 10% of the oocytes to resume maturation, and pyruvate and glucose consumption resembled that of control OCCs. FSH added to HX‐containing medium stimulated significant glucose consumption and pyruvate production. In general, a reciprocal relationship was observed between glucose and pyruvate consumption. When the energy substrate dynamics were compared with meiotic status of the oocytes, pyruvate consumption was associated with the maturation process. Although HX maintained oocytes in the germinal vesicle stage, the meiotic arrest was “leaky,” allowing increased pyruvate consumption. Additional experiments showed that DOs at either the prophase I or metaphase II stages consumed less pyruvate than oocytes actively engaged in meiotic maturation. DOs oxidized significantly more pyruvate than OCCs, and glycolytic metabolism of glucose lowered the oxidation rate in OCCs. Furthermore, while 5–6.2 times more pyruvate was consumed by OCCs than by DOs in the absence of glucose, oxidation did not mediate the meiosis‐inducing effect of pyruvate, since less of this substrate was oxidized by OCCs than by DOs. We conclude that meiotically active oocytes have a greater requirement for pyruvate than prophase I‐ or metaphase II‐arrested oocytes and that meiotic status can influence the metabolism not only of oocytes, but also of the OCCs. Mol. Reprod. Dev. 62: 113‐123, 2002. © 2002 Wiley‐Liss, Inc.
Cdc25C expression in meiotically competent and incompetent goat oocytes
Authors: Gall Laurence , Ruffini Sylvie , Le Bourhis Daniel , Boulesteix Claire 
Published: August 2002

AbstractChange in Cdc25C expression and localization during maturation and meiotic competence acquisition was investigated in goat oocytes. Western blot analysis revealed that Cdc25C is constitutively expressed throughout meiosis in competent goat oocytes, with changes in its phosphorylation level. Cdc25C was detected at 55 and 70 kDa, representing the nonphosphorylated form and the hyperphosphorylated active form, respectively. During the G2‐M transition at meiosis resumption, Cdc25C was hyperphosphorylated as evidenced by a clear shift from 55 to 70 kDa. Okadaic acid which induced premature meiosis resumption associated with MPF activation also involved a premature shift from 55 to 70 kDa in goat competent oocytes. After artificial activation of goat oocytes, Cdc25C returned to its 55 kDa form. By indirect immunofluorescence, Cdc25C was found essentially localized in the nucleus at the germinal vesicle stage, suggesting that Cdc25C functions within the nucleus to regulate MPF activation. Concomitantly with germinal vesicle breakdown, Cdc25C was redistributed throughout the cytoplasm. The amount of Cdc25C, very low in incompetent oocytes, increased with meiosis competence acquisition. On the other hand, during oocyte growth while the expression of Cdc25C increased, its phosphorylation level increased concomitantly as well as its nuclear translocation. These results suggest that meiosis resumption needs a sufficient amount of Cdc25C which must be completely phosphorylated and nuclear and that the amount of Cdc25C may be a limiting factor for meiotic competence acquisition. We could consider that Cdc25C nuclear translocation and phosphorylation, during oocyte growth, prepare the oocytes in advance for the G2‐M phase transition occurring during meiosis resumption. Mol. Reprod. Dev. 62: 4‐12, 2002. © 2002 Wiley‐Liss, Inc.
Ran binding protein RanBP1 in zebrafish embryonic development*
Authors: Mangos Steve , Vanderbeld Barbara , Krawetz Roman , Sudol Krzysztof , Kelly Gregory M. 
Published: August 2002

AbstractRan, which functions in nucleocytoplasmic transport and mitosis, binds to and is regulated in part by RanBP1. We have identified a zebrafish RanBP1 cDNA and report that it encodes for a polypeptide of 233 amino acids with considerable similarity to human and Xenopus RanBP1, despite the fact that it is 10% longer due to an extension at its carboxy terminus. RanBP1 mRNA is present as a maternal transcript and is expressed ubiquitously throughout the developing embryo. At the protein level, RanBP1 is present at all embryonic stages. Surprisingly, the ectopic overexpression of the protein had no obvious effect on embryogenesis. Attempts were also made to down‐regulate RanBP1 activity by RNA interference. Injecting double‐stranded RNA augmented both the mortality rate and the frequency of induced defects. Specific defects accompanied by changes in RanBP1 expression were not seen, leading us to propose that RNAi is not a reliable method for deregulating the activity of constitutively expressed genes, like RanBP1, in zebrafish. Mol. Reprod. Dev. 59:235–248, 2001. © 2001 Wiley‐Liss, Inc.
Comparison of gene transcription in cloned bovine embryos produced by different nuclear transfer techniques
Authors: Daniels R. , Hall V.J. , French A.J. , Korfiatis N.A. , Trounson A.O. 
Published: August 2002

AbstractThe efficiency of animal production using cloning technology is still relatively low and research to determine a more efficient nuclear transfer procedure is ongoing. One approach which may be informative in assessing the viability of nuclear transfer embryos is the analysis of embryonic gene expression. Using RT‐PCR techniques we have previously detected the aberrant expression of FGF4, FGFr2 and IL6 in a significant proportion of bovine granulosa cell‐derived nuclear transfer embryos, which correlated with a limited developmental potential in vivo. In order to analyse the effect of different donor cell nuclei on embryonic gene expression we have now analysed the expression of these genes in nuclear transfer embryos reconstructed with fetal epithelial cell nuclei. In addition, we have compared the expression of these genes in bovine nuclear transfer embryos produced by cell fusion or direct injection with variations in the timing of oocyte activation. In all nuclear transfer embryos analysed, FGFr2 and IL6 transcripts were detected at a similar rate to that in IVF embryos. However, the absence of FGF4 transcripts was again evident in a large proportion of nuclear transfer embryos and most significantly in those embryos whose development was activated almost immediately following the transfer of the donor nucleus. The results demonstrate the effects that different donor cell lines and different nuclear transfer procedures may have on the expression of developmentally important genes in nuclear transfer embryos. Mol. Reprod. Dev. 60: 281–288, 2001. © 2001 Wiley‐Liss, Inc.
Continuously moving table data acquisition method for long FOV contrast‐enhanced MRA and whole‐body MRI
Authors: Kruger David G. , Riederer Stephen J. , Grimm Roger C. , Rossman Phillip J. 
Published: August 2002

AbstractA method is presented in which an extended longitudinal field of view (FOV), as required for whole‐body MRI or MRA peripheral runoff studies, is acquired in one seamless image. Previous methods typically either acquired 3D data at multiple static “stations” which covered the extended FOV or as a series of 2D axial sections. The method presented here maintains the benefits of 3D acquisition while removing the discrete nature of the multistation method by continuous acquisition of MR data as the patient table moves through the desired FOV. Although the technique acquires data only from a homogeneous central volume of the magnet at any point in time, by spatially registering all data it is possible to extend the FOV well beyond this volume. The method is demonstrated experimentally with phantoms, in vivo angiographic animal studies, and in vivo human studies. Magn Reson Med 47:224–231, 2002. © 2002 Wiley‐Liss, Inc.