bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mode‐matching analysis of a new omnidirectional circular rod antenna with double dielectric gratings for millimeter‐wave application
Authors: Jing Hengzhen , Xu Shanjia 
Published: May 2003

AbstractThe radiation characteristics of a new millimeter‐wave omnidirectional circular rod antenna with double dielectric gratings are analyzed using the rigorous mode‐matching method. The results indicate that under the condition of the same radiation intensity, the double‐grating antenna has relatively smaller dimensions than that of the single one. This characteristic is of essential and practical significance in the case where limitation of the system's size and weight is strictly required. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 132–134, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10994
Broadband circularly polarized inverted‐L patch antenna
Authors: Su Che‐Wei , Chang Fa‐Shian , Wong Kin‐Lu 
Published: May 2003

AbstractAn innovative design of a corner‐truncated inverted‐L patch antenna for achieving circular polarization (CP) operation over a wide bandwidth is presented. The antenna has a thick air‐layer substrate; however, it can be easily excited using a probe feed with a short probe pin. CP operation is obtained by selecting an optimal size of the truncated corners, and good impedance matching over a wide bandwidth is obtained by using a beveling technique on the vertical portion of the inverted‐L patch. For a prototype constructed for wireless local area network (WLAN) operation in the 2.4‐GHz band (2.4–2.484 GHz), the obtained CP bandwidth (3‐dB axial ratio) reaches about 7%, and the measured antenna gain is about 8.0 dBi across the CP bandwidth. Details of the antenna design and the experimental results are presented. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 134–136, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10995
Coupling between dissimilar rectangular dielectric waveguides
Authors: Cory H. , Skorka O. , Sharkansky M. 
Published: May 2003

AbstractThe coupling between two identically excited, dissimilar rectangular dielectric waveguides, whose axes are parallel, is studied as a function of frequency and of the geometrical and the electrical properties of the structure. It is found that, for a given permittivity ratio, the power transfer between the guides is maximal, but not complete, at some particular frequency. It is also found that, for a given frequency, the power transfer between the guides is complete for the appropriate combination of permittivity and size of the guides, thus the same propagation coefficient is achieved for both. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 136–139, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10996
Design of dual‐polarization stacked arrays for ISM band applications
Authors: See T. S. P. , Ning Chen Zhi 
Published: May 2003

AbstractIn this paper, a dual linearly polarized stacked array for ISM band base station applications is presented. The patches on the bottom layer are fed diagonally by a microstrip line. A superstrate layer is stacked above the bottom layer to increase the operating bandwidth. The design parameters are simulated and optimized for the satisfactory impedance and radiation characteristics, which are compared against measured results. The measurements show that the antenna satisfies the requirements for a base station antenna and is capable of having broad bandwidth for the VSWR ≤ 1.5 with stable radiation patterns, low front‐to‐back ratios, and side‐lobe levels in the planes of interest. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 142–147, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10998
A miniaturized side‐coupled 45° Schiffman phase shifter on Teflon substrate
Authors: Chai Dongkyu , Yim Munhyuk , Linh Mai , Yoon Giwan 
Published: May 2003

AbstractA novel side‐coupled 45° Schiffman phase shifter for 2.2‐GHz applications is presented with measurement results. The proposed phase shifter on a Teflon substrate is fabricated in a smaller area and more cost‐effective way, as compared to the conventional Schiffman phase shifter. In addition, the phase shifter seems very promising and useful, particularly for future 2.2‐GHz wireless applications and beyond. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 147–150, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10999
Improvement in second harmonics linearization technique for multichannel amplifiers
Authors: Males‐Ilic Natasa , Milovanovic Bratislav , Budimir Djuradj 
Published: May 2003

AbstractA linearization technique that uses the injection of the fundamental signal second harmonics together with the fundamental signals at the amplifier input has been improved in this paper by introducing phase correction of the fundamental signals according to the differences in phases of the second harmonics. As the result, the improvement in third‐order intermodulation power levels is approximately 40 dB for analog and 22 dB for digitally modulated signals for multichannel applications. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 150–153, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11000
Evanescent modes stored in cavity resonators with backward‐wave slabs
Authors: Tretyakov S. A. , Maslovski S. I. , Nefedov I. S. , Kärkkäinen M. K. 
Published: May 2003

AbstractAs shown by N. Engheta, electromagnetic fields in two adjacent slabs bounded by two metal walls can satisfy the boundary conditions, even if the distance between the two walls is much smaller than the wavelength. This is possible if one of the slabs has a negative permeability. Here we show that these subwavelength “resonators” resonate only if the permeability of at least one of the slabs is frequency dependent. Thus, there is no advantage of using these structures as frequency‐selective devices. However, we have found that these systems can, in principle, be used as memory devices for evanescent fields, because the boundary conditions are identically satisfied for all plane evanescent waves inside the cavity. The physical meaning and practical limitations for possible realizations are discussed. The analysis is supported by FDTD simulations. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 153–157, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11001
Numerical calculation of leakage‐loss in W‐tunneling optical fibers
Authors: Minning Ji 
Published: May 2003

AbstractA new numerical method based on point‐matching is presented to calculate leakage loss of fundamental mode in W‐tunneling optical fibers. Calculation stability is tested. The relationship between leakage loss and optical fiber parameter is shown by numerical calculation. Numerical and experimental results are compared and they agree well with each other. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 157–161, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11002
Design of a folded waveguide traveling‐wave tube
Authors: Han Seong‐Tae , Kim Jung‐II , Park Gun‐Sik 
Published: May 2003

AbstractA method to synthesize the parameters of a folded waveguide traveling‐wave tube (FWTWT) is derived. For the device designed using this method, cold characteristics such as phase velocity and interaction impedance of virtual TM wave, as well as the growth rate, show reasonable agreement with those obtained by HFSS and MAGIC3D particle‐in‐cell (PIC) simulation, respectively. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 161–165, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11003
Efficacy of antibodies against Escherichia coli expressed chimeric recombinant protein encompassing multiple epitopes of zona pellucida glycoproteins to inhibit in vitro human sperm–egg binding
Authors: Sivapurapu Neela , Upadhyay Abhishek , Hasegawa Akiko , Koyama Koji , Gupta Satish K. 
Published: May 2003

AbstractTo minimize ovarian dysfunction subsequent to immunization with zona pellucida (ZP) glycoproteins, synthetic peptides encompassing the antigenic B cell epitopes as immunogens have been proposed. In this study, attempts have been made to clone and express a recombinant chimeric protein encompassing the epitopes corresponding to bonnet monkey (Macaca radiata) ZP glycoprotein‐1 (bmZP1, amino acid residues 132–147), ZP glycoprotein‐2 (bmZP2, amino acid residues 86–113), and ZP glycoprotein‐3 (bmZP3, amino acid residues 324–347). The above chimeric recombinant protein (r‐bmZP123) was expressed as a polyhistidine fusion protein in Escherichia coli. Immunoblot with murine monoclonal antibody, MA‐813, generated against recombinant bmZP1 revealed a major band of approximately 10 kDa. The r‐bmZP123 was purified on nickel‐nitrilotriacetic acid resin under denaturing conditions. The female rabbits immunized with purified r‐bmZP123 conjugated to diphtheria toxoid (DT) generated antibodies that reacted with r‐bmZP123 and DT in an ELISA. In addition, the immune sera also reacted with E. coli expressed recombinant bmZP1, bmZP2, and bmZP3. In an indirect immunofluorescence assay, the antibodies against r‐bmZP123 recognized native ZP of bonnet monkey as well as human. The immune sera also inhibited, in vitro, the binding of human spermatozoa to the human zona in the hemizona assay (HZA). These studies, for the first time, demonstrate the feasibility of assembling multiple epitopes of different ZP glycoproteins as a recombinant protein that elicit antibodies which are reactive with native zona and also inhibit, in vitro, human sperm–oocyte binding. Mol. Reprod. Dev. 65: 309–317, 2003. © 2003 Wiley‐Liss, Inc.
Cold‐induced calcium elevation triggers DNA fragmentation in immature pig oocytes
Authors: Mattioli Mauro , Barboni Barbara , Luisa Gioia , Loi Pasqualino 
Published: May 2003

AbstractFluo‐4 loaded immature oocytes were cooled from 30°C to various lower temperatures between 20 and 10°C and changes in intracellular calcium (Ca2+) levels were measured. Pig oocytes cooled to 14°C exhibited a clear biphasic Ca2+ rise. Lower temperatures produced similar responses, while higher temperatures did not exert any effect. The Ca2+ response appeared to rely on ryanodine dependent stores as removal of extracellular Ca2+ and intracytoplasmic injection of heparin did not modify cold‐induced Ca2+ elevation, while procaine or ruthenium red virtually eliminated the response. Confocal analysis of subcellular Ca2+ distribution during cooling revealed that the ion rises sharply within the nucleus. As Ca2+ imbalance may activate nuclear endonucleases, DNA integrity of cooled pig oocytes was evaluated by TUNEL and comet assays. Most cooled oocytes showed clear signs of DNA fragmentation. Oocytes injected with 1,2‐bis(2‐aminophenoxy)ethane‐N,N,N′,N′‐tetracetic acid tetrapotassium salt (BAPTA), a Ca2+ chelator, maintained their DNA integrity thus confirming that intracellular Ca2+ is involved in triggering DNA fragmentation. The protective effect exerted by ruthenium red and/or procaine further confirmed this hypothesis. These data show that a moderate and transient cooling is sufficient to cause an intracellular Ca2+ rise that leads to DNA damage. The addition of inhibitors of ryanodine dependent Ca2+ stores may represent a valuable protective treatment to reduce chilling injuries. Mol. Reprod. Dev. 65: 289–297, 2003. © 2003 Wiley‐Liss, Inc.
Asynchronous cytoplast and karyoplast transplantation reveals that the cytoplasm determines the developmental fate of the nucleus in mouse oocytes
Authors: Cheng Yong , Fan Heng‐Yu , Wen Duan‐Cheng , Tong Chao , Zhu Zi‐Yu , Lei Lei , Sun Qing‐Yuan , Chen Da‐Yuan 
Published: May 2003

AbstractThe relationship between nucleus and cytoplasm can be well revealed by nuclear transplantation. Here, we have investigated the behavior changes of the reconstructed oocytes after transferring the karyoplasts from mouse GV, MI, and MII oocytes into the cytoplasts at the different developmental stages. When the GV cytoplast was used as recipient and MI or MII karyoplast was used as donor (MI‐GV pair and MII‐GV pair), the reconstructed pairs extruded a polar body after electrofusion and culture. Both the cytoplasm and the polar body had a metaphase spindle in the MI‐GV pair, while only a clutch of condensed chromatin was observed in the cytoplasm and polar body of the MII‐GV pair. When the MI cytoplast was used as recipient and GV or MII karyoplast was used as donor (GV‐MI pair and MII‐MI pair), the reconstructed pairs also extruded a polar body. Each had one spindle and a group of metaphase chromosomes in the cytoplasm and polar body, respectively. When the MII cytoplast was used as recipient and GV or MI karyoplast was used as donor (GV‐MII pair and MI‐MII pair), the reconstructed pairs were activated, became parthenogenetic embryos and even developed to hatching blastocysts after electrofusion. The result from immunoblotting showed that MAP kinase activity was high in the MI and MII cytoplasts, while not detected in GV cytoplast. The results demonstrate that the cytoplasmic environment determines the behavior of asynchronous donors. Mol. Reprod. Dev. 65: 278–282, 2003. © 2003 Wiley‐Liss, Inc.
Meiotic state of bovine oocytes is regulated by interactions between cAMP, cumulus, and granulosa
Authors: Aktas Huseyin , Leibfried‐Rutledge M. Lorainne , First Neal L. 
Published: May 2003

AbstractBovine oocytes are arrested at the prophase of first meiotic cell cycle. Meiosis resumes in oocytes of pre‐ovulatory follicles upon LH surge. However, oocytes from secondary follicles spontaneously resume meiosis in the absence of hormones if removed from the follicle and cultured in vitro. The nature of meiotic arrestor in bovine follicles is poorly understood. In this study we investigated the role of cell–cell interactions between granulosa and cumulus cells and the oocyte in mediating maintenance of meiotic arrest by cAMP. We sorted oocytes as granulosa–cumulus oocyte complexes (GCOC) if surrounded with cumulus cells attached to a large granulosa investment or cumulus oocytes complexes (COC) if surrounded with cumulus cells only and investigated the role cAMP in maintenance of meiotic arrest in these oocytes under various conditions. In hormone‐ and serum‐free medium both GCOC and COC enclosed oocytes resumed meiosis. When [cAMP]i was elevated with addition of invasive adenylate cyclase (iAC) GCOC enclosed oocytes were maintained in the prophase with intact germinal vesicle (GV) while COC enclosed oocytes underwent GV breakdown (GVBD). iAC elevated [cAMP]i in both types of oocytes to the same level. If oocytes were liberated from the cumulus and granulosa cells, they re‐initiated meiosis in serum and hormone free medium, but remained in the GV stage if iAC was added to the medium. Untreated GCOC and COC enclosed oocytes extruded first polar body at the same frequency in hormone‐supplemented media. GCOC and COC enclosed oocytes but not denuded oocytes (DO) cultured without somatic cells acquired developmental competence if cultured in hormone‐containing medium. It is concluded that maintenance of meiotic arrest is regulated by the interplay of [cAMP]i, and cumulus and granulosa cells. Mol. Reprod. Dev. 65: 336–343, 2003. © 2003 Wiley‐Liss, Inc.
Cloning and expression of cynomolgus monkey and baboon zona pellucida proteins
Authors: Harris Jeffrey D. , Piersen Colleen E. 
Published: May 2003

AbstractPartial clones for the three cynomolgus monkey (Macaca fasicularis) zona pellucida genes (cmZPA, cmZPB, and cmZPC) have previously been isolated. These partial clones contained the sequences for the C‐terminal portion of each rcmZP protein. To obtain full‐length clones for each cmZP, a fresh cynomolgus monkey ovarian cDNA library was constructed. PCR methodology was employed to speed the isolation of full‐length clones for each cmZP cDNA. The 3′ primers were designed based on sequence information from the previously identified clones; the 5′ primers were designed using the human ZP sequences. The PCR technique yielded full‐length clones of cmZPA and cmZPC, but not of cmZPB. Therefore, a genomic clone of cmZPB was isolated and the sequence determined. The exon/intron structure is nearly identical to the human ZPB exon/intron structure. New PCR primers were designed based on the cynomolgus monkey ZPB genomic sequence, and a full‐length cmZPB cDNA was obtained. The same primers that were used to generate the cmZPB were also used to generate a baboon (Papio cynocephalus) ZPB (bZPB) cDNA. As was done previously for the human zona pellucida (hZP) cDNAs, the cmZP, and bZPB cDNAs were transferred to shuttle vectors for transfection into Chinese Hamster Ovary (CHO) cells. Stable cell lines for producing each ZP protein were isolated. Each cell line secreted the desired recombinant zona pellucida (rZP) protein into the culture medium, and each protein was purified using an established protocol. In terms of size and purity, the purified recombinant cmZP (rcmZP) and rbZPB proteins resemble the rhZP proteins. Mol. Reprod. Dev. 65: 237–244, 2003. © 2003 Wiley‐Liss, Inc.
Cell cycle dependent expression of Plk1 in synchronized porcine fetal fibroblasts
Authors: Anger Martin , Kues Wilfried A. , Klima Jiri , Mielenz Manfred , Kubelka Michal , Motlik Jan , Esner Milan , Dvorak Petr , Carnwath Joseph W. , Niemann Heiner 
Published: May 2003

AbstractEnzymes of the Polo‐like kinase (Plk) family are active in the pathways controlling mitosis in several species. We have cloned cDNA fragments of the porcine homologues of Plk1, Plk2, and Plk3 employing fetal fibroblasts as source. All three partial cDNAs showed high sequence homology with their mouse and human counterparts and contained the Polo box, a domain characteristic for all Polo kinases. The expression levels of Plk1 mRNA at various points of the cell cycle in synchronized porcine fetal fibroblasts were analyzed by both RT‐PCR and the ribonuclease protection assay. Plk1 mRNA was barely detectable in G0 and G1, increased during S phase and peaked after the G2/M transition. A monoclonal antibody was generated against an in vitro expressed porcine Plk1‐protein fragment and used to detect changes in Plk1 expression at the protein level. Plk1 protein was first detected by immunoblotting at the beginning of S phase and was highest after the G2/M transition. In summary, the Plk1 expression pattern in the pig is similar to that reported for other species. The absence of Plk1 mRNA and protein appears to be a good marker for G0/G1 and thus for the selection of donor cells for nuclear transfer based somatic cloning. Mol. Reprod. Dev. 65: 245–253, 2003. © 2003 Wiley‐Liss, Inc.
Spermatid nuclear and sperm periaxonemal anomalies in the mouse Ube2b null mutant
Authors: Escalier Denise , Bai Xi‐Yuan , Silvius Derek , Xu Pin‐Xian , Xu Xin 
Published: May 2003

AbstractUbe2b (yeast Ubc2b/Rad6 homolog) null mice were described previously. Ube2b encodes the murine ubiquitin conjugating enzyme mHR6B. Ube2b−/− mice were shown to present male infertility and their sperm head shape anomalies suggested that Ube2b may be involved in the replacement of nuclear proteins during spermatid chromatin condensation. Apoptosis of spermatocytes suggested additional targets of Ube2b during spermatogenesis. Consistently, we found Ube2b transcription in both meiotic and postmeiotic stages by in situ hybridization. Immuno‐electron microscopy revealed that transition proteins 1 and 2, protamines 1 and 2, and actin appear normally distributed during morphogenesis of Ube2b−/− spermatid heads. Surprisingly, electron microscopy revealed a particular sperm flagellum phenotype characterized by an abnormal distribution of periaxonemal structures. Flagellar anomalies of Ube2b null mice were previously described in infertile men indicating a possible genetic pathway for flagellar periaxonemal assembly in human. Mol. Reprod. Dev. 65: 298–308, 2003. © 2003 Wiley‐Liss, Inc.
Prolin‐rich tyrosine kinase 2 (PYK2) expression and localization in mouse testis
Authors: Chieffi Paolo , Barchi Marco , Di Agostino Silvia , Rossi Pellegrino , Tramontano Donatella , Geremia Raffaele 
Published: May 2003

AbstractProlin‐rich kinase 2 (PYK2) is a nonreceptor tyrosine kinase related to the focal adhesion kinase (FAK) p125FAK. PYK2 is rapidly phosphorylated on tyrosine residues in response to various stimuli, such as tumor necrosis factor‐α (TNF‐α), changes in osmolarity, elevation in intracellular calcium concentration, angiotensin, and UV irradiation. PYK2 has ligand sequences for Src homology 2 and 3 (SH‐2 and SH‐3), and has binding sites for paxillin and p130cas. Activation of PYK2 leads to modulation of ion channel function, phosphorylation of tyrosine residues, and activation of the MAP kinase signaling pathways. Immunocytochemistry shows that PYK2 is present in mouse germinal and Sertoli cells (ser). Northern blot and immunoprecipitation analysis demonstrate that, among germinal cells, PYK2 is more abundant in spermatocytes (spc) and spermatids (spt); in addition, immunofluorescence analysis clearly shows that the diffuse cytoplasmic localization of PYK2 changes in a specific cellular compartment in spt and spermatozoa. Mol. Reprod. Dev. 65: 330–335, 2003. © 2003 Wiley‐Liss, Inc.
Localization of glutamate cysteine ligase subunit mRNA within the rat ovary and relationship to follicular apoptosis
Authors: Luderer Ulrike , Diaz Dolores , Faustman Elaine M. , Kavanagh Terrance J. 
Published: May 2003

AbstractOvarian levels of the antioxidant tripeptide glutathione (GSH) increase following gonadotropin administration, suggesting that GSH synthesis in the ovary may be associated with follicular growth. In situ hybridization with 35S‐labeled riboprobes was used to localize ovarian mRNA expression of the catalytic and modulatory subunits of glutamate cysteine ligase (Gclc and Gclm), the rate‐limiting enzyme in GSH synthesis, during each stage of the rat estrous cycle. Gclm was highly expressed in the granulosa cells and oocytes of healthy, growing follicles, not in atretic follicles. Gclc was also highly expressed in follicles; however, unlike Gclm, Gclc was also expressed in corpora lutea and interstitial cells. In a subsequent experiment, the hypothesis that GSH synthesis occurs in healthy, but not in apoptotic, follicles was tested. Terminal deoxynucleotidyl transferase‐mediated dUTP nick end labeling (TUNEL) was used to detect apoptotic cells in the ovaries, and in situ hybridization for Gclm and Gclc was performed in adjacent sections of the same ovaries. TUNEL staining was found to be significantly associated with absence of Gclm hybridization in granulosa cells and oocytes and with lack of strong Gclc hybridization in granulosa cells. These results suggest that follicular apoptosis may be associated with down‐regulation of Gclm and Gclc transcription in granulosa cells and oocytes. Mol. Reprod. Dev. 65: 254–261, 2003. © 2003 Wiley‐Liss, Inc.