bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of CaTiO3/TiO2 composite coating on titanium alloy for biomedical applications
Authors: Wei Daqing , Zhou Yu , Jia Dechang , Wang Yaming
Published: July 2007

Plasma electrochemical oxidation (PEO) was used to prepare TiO2‐based coating containing Ca and P on titanium alloy. After alkali‐ and then heat‐treatment at 800°C of the PEO coating, a CaTiO3/TiO2 composite (CTC) coating was obtained. The current results indicate that the apatite‐forming ability of the CTC coating is higher than that of the PEO coating. During the simulated body fluid (SBF) incubation, Ca of the CTC coating is released into the SBF. An ionic exchange between Ca2+ ions of the CTC coating and H3O+ ions of the SBF may take place during the SBF incubation. As a result, the abundant TiOH groups are formed on the surface of the CTC coating. The hydroxyl functionalized surface greatly enhances the nucleation and growth of apatite, leading to the high apatite‐forming ability of the CTC coating. The apatite induced by the CTC coating exhibits a porous and carbonated structure. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Prevalence of IgG autoantibody against F‐actin in patients suspected of having autoimmune or acute viral hepatitis
Authors: Jaskowski Troy D. , Konnick Eric Q. , Ashwood Edward R. , Litwin Christine M. , Hill Harry R.
Published: July 2007

Our objectives in this study were to compare results obtained by an enzyme immunoassay (EIA) for F‐actin antibody (FAA) immunoglobulin G (IgG) to those determined by an indirect fluorescent antibody (IFA) assay for smooth muscle antibody (SMA) IgG, and to determine the prevalence of FAA in patient sera having serologic evidence of acute viral hepatitis. Sera from 415 patients suspected of having autoimmune hepatitis (AIH), 208 patients suspected of having acute viral hepatitis A, B, or C, and 100 healthy blood donors (HBD) were included in the study. Only one of 100 HBD showed low levels (20–30 Units) of F‐actin IgG. In patients suspected of having AIH, the prevalence of FAA increased as SMA titers increased and all sera with SMA titers of ≥1:160 were FAA‐positive. In contrast, there were many sera with negative (<1:20) or low (1:20–1:40) SMA titers that contained moderate to high levels (>30 Units) of FAA; many exceeding 80 Units. Moreover, 51.4% of these sera were also positive for anti‐nuclear antibody (ANA), which is also utilized in diagnosing type 1 AIH. FAA was detected in 25% of viral hepatitis antibody–positive sera, with the majority (59.3%) containing low levels, and all were ANA‐negative. J. Clin. Lab. Anal. 21:249–253, 2007. © 2007 Wiley‐Liss, Inc.
Measurement of gp210 autoantibodies in sera of patients with primary biliary cirrhosis
Authors: Bauer Alicja , Habior Andrzej
Published: July 2007

Primary biliary cirrhosis (PBC) is an autoimmune liver disease with unknown etiology. Patients with PBC have antimitochondrial autoantibodies (AMA) and additionally 50% of them have antinuclear antibodies (ANA). A 15–amino acid fragment (DRKASPPSGLWSPAY) from the C‐terminal part of the nuclear envelope glycoprotein gp210 has been proposed as one of the antigenic targets for ANA. The aim of this work was to develop an immunoenzymatic assay for determination of gp210 autoantibodies using for its binding a synthetic pentadecapeptide derived from the gp210 amino acid sequence and to determine level of these autoantibodies in sera of patients with PBC and other autoimmune liver diseases from Poland. Polystyrene microtitration plates coated with the synthetic peptide were consecutively incubated with diluted sera, anti‐human immunoglobulin G (IgG) antibodies conjugated with horseradish peroxidase, and with tetramethylobenzidine. Optical density (OD) was read at 450 nm. The mean values of the intra‐ and interassay of variation coefficients of the test were 4.1 and 10.2%, respectively. Anti‐gp210 was detected in 44% of PBC patients and in 6% of patients with PSC. The results were negative for healthy blood donors and other controls. The specificity of the test was 99%, so the anti‐gp‐210 autoantibodies estimated on DRKASPPSGLWSPAY can be a reliable marker of PBC. J. Clin. Lab. Anal. 21:227–231, 2007. © 2007 Wiley‐Liss, Inc.
Evaluation of PorB variable region typing of Neisseria gonorrhoeae using PCR‐ELISA in samples collected from men who have sex with men
Authors: Ling A.E. , Bash M.C. , Lynn F. , Lister N.A. , Zhu P. , Garland S.M. , Fairley C.K. , Tabrizi S.N.
Published: July 2007

A polymerase chain reaction (PCR)‐based enzyme‐linked immunosorbent assay (ELISA) methodology was developed to characterize Neisseria gonorrhoeae porB gene variable regions (VR); the methodology was evaluated in comparison to porB VR typing by checkerboard hybridization. Clinical noncultured samples from 35 men who have sex with men (MSM), positive by nucleic amplification assays for N. gonorrhoeae, were typed using a panel of 40 oligonucleotide probes to porB VRs and compared to checkerboard hybridization. Complete concordance was observed between the two methods at PIB VRs 1, 3, and 7. At the more degenerate VRs 5 and 6, PCR ELISA resulted in obtaining more typeable VRs than checkerboard hybridization due to single nucleotide mismatches. By PCR ELISA, two predominant PIB porB types were identified in 58% of the samples and the remaining 16 samples had one of six other porB types. Both PCR ELISA and checkerboard hybridization methods of porB VR typing allowed characterization of N. gonorrhoeae from noncultured clinical samples including throat and rectal swabs and discriminated N. gonorrhoeae from N. meningitidis present in some of the samples. PCR ELISA is a rapid, relatively inexpensive and alternative molecular typing method for N. gonorrhoeae, suitable for use in conjunction with molecular diagnostic tests. J. Clin. Lab. Anal. 21:237–243, 2007. © 2007 Wiley‐Liss, Inc.
Activin receptor‐like kinase 1 inhibits human microvascular endothelial cell migration: Potential roles for JNK and ERK
Authors: David Laurent , Mallet Christine , Vailhé Bruno , Lamouille Samy , Feige Jean‐Jacques , Bailly Sabine
Published: July 2007

Activin receptor‐like kinase 1 (ALK1) is an endothelial‐specific type I receptor of the TGFβ receptor family that is implicated in angiogenesis and in the pathogenesis of the vascular disease, hereditary hemorrhagic telangiectasia (HHT). In the absence of a specific ligand, ALK1 cellular functions have been mainly studied through the use of a constitutively active form of this receptor (ALK1ca) and are still debated. We previously reported that ALK1ca inhibits proliferation and migration of human endothelial cells suggesting that ALK1 plays an important role in the maturation phase of angiogenesis (Lamouille et al., 2002, Blood 100: 4495–4501). In the present work, we further analyzed the role of ALK1 in the migration of human dermal microvascular endothelial cell (HMVEC‐d) and observed that silencing endogenous ALK1 expression with siRNAs accelerates endothelial cell migration in the wound assay. Further, we demonstrate that ALK1‐induced inhibition of migration is Smad‐independent. Using a panel of kinase inhibitors, we found that HMVEC‐d wound closure was completely inhibited by a JNK inhibitor and to a lower degree by an ERK kinase inhibitor. Further, HMVEC‐d wounding induced activation of both JNK and ERK, and these were inhibited by ALK1ca expression. Taken together, these results support a significant role for ALK1 as a negative regulator of endothelial cell migration and suggest the implication of JNK and ERK as mediators of this effect. J. Cell. Physiol. 213: 484–489, 2007. © 2007 Wiley‐Liss, Inc.
TRAIL inhibits osteoclastic differentiation by counteracting RANKL‐dependent p27Kip1 accumulation in pre‐osteoclast precursors
Authors: Zauli Giorgio , Rimondi Erika , Stea Susanna , Baruffaldi Fabio , Stebel Marco , Zerbinati Carlotta , Corallini Federica , Secchiero Paola
Published: July 2007

Experimental evidences indicate that the TNF family member TNF‐related apoptosis inducing ligand (TRAIL) might be involved in modulating osteoclastic differentiation. The ability of recombinant soluble TRAIL to affect bone density in vivo was evaluated by using 4‐week‐old mice subcutaneously (s.c.) injected with TRAIL for 8 days. TRAIL injection induced a significant increase of tibia trabecular thickness and total bone mass in 4‐week‐old mice, accompanied by a significant decrease of TRAP serum levels, without modulation of osteocalcin and osteoprotegerin (OPG). Parallel experiments performed in vitro showed that inhibition of osteoclastic differentiation, induced by treatment of human peripheral blood osteoclast precursors with TRAIL, was associated to inhibition of receptor activator of nuclear factor kappa B ligand (RANKL)‐induced accumulation of p27Kip1. The potential role of p27Kip1 pathway in mediating the anti‐osteoclastic activity of TRAIL was further suggested by in vitro gene knock‐down experiments performed in osteoclast precursor cultures. Taken together, our data strongly suggest that recombinant TRAIL inhibits osteoclastogenesis by inducing the ubiquitin‐mediated degradation of p27Kip1. J. Cell. Physiol. 214:117–125, 2008. © 2007 Wiley‐Liss, Inc.
Adult mesenchymal stem cells for tissue engineering versus regenerative medicine
Authors: Caplan Arnold I.
Published: July 2007

Adult mesenchymal stem cells (MSCs) can be isolated from bone marrow or marrow aspirates and because they are culture‐dish adherent, they can be expanded in culture while maintaining their multipotency. The MSCs have been used in preclinical models for tissue engineering of bone, cartilage, muscle, marrow stroma, tendon, fat, and other connective tissues. These tissue‐engineered materials show considerable promise for use in rebuilding damaged or diseased mesenchymal tissues. Unanticipated is the realization that the MSCs secrete a large spectrum of bioactive molecules. These molecules are immunosuppressive, especially for T‐cells and, thus, allogeneic MSCs can be considered for therapeutic use. In this context, the secreted bioactive molecules provide a regenerative microenvironment for a variety of injured adult tissues to limit the area of damage and to mount a self‐regulated regenerative response. This regenerative microenvironment is referred to as trophic activity and, therefore, MSCs appear to be valuable mediators for tissue repair and regeneration. The natural titers of MSCs that are drawn to sites of tissue injury can be augmented by allogeneic MSCs delivered via the bloodstream. Indeed, human clinical trials are now under way to use allogeneic MSCs for treatment of myocardial infarcts, graft‐versus‐host disease, Crohn's Disease, cartilage and meniscus repair, stroke, and spinal cord injury. This review summarizes the biological basis for the in vivo functioning of MSCs through development and aging. J. Cell. Physiol. 213: 341–347, 2007. © 2007 Wiley‐Liss, Inc.
Molecular mechanisms of the antiproliferative effect of beraprost, a prostacyclin agonist, in murine vascular smooth muscle cells
Authors: Lin Heng , Lee Ja‐Ling , Hou Hsin‐Han , Chung Chih‐Peng , Hsu Sung‐Po , Juan Shu‐Hui
Published: July 2007

Prostacyclin (PGI2) has been shown to inhibit proliferation in vascular smooth muscle cells. To clarify the underlying molecular mechanism, we investigated the vasoprotection of beraprost (a PGI2 agonist) both in vivo and in vitro. Beraprost eliminated increases in proliferation of rat aortic smooth muscle cells (RASMCs) by 12‐O‐tetradecanoylphorbol 13‐acetate, and enhanced the peroxisome proliferator‐activated receptor‐delta (PPARδ) and inducible nitric oxide synthetase (iNOS) expressions, which were associated with the antiproliferative action of beraprost according to inhibition experiments by [3H]thymidine incorporation. Additionally, elimination of iNOS activity by PPARδ antagonists suggested that iNOS is the downstream target of PPARδ. Furthermore, beraprost increased both consensus PPARδ‐responsive element (PPRE)‐driven luciferase activity and the binding activity of the PPARδ to the putative PPRE in the iNOS promoter; nevertheless, it was abolished by PPARδ antagonists. Deletion of PPRE (−1,349/−1,330) in the iNOS promoter region (−1,359/+2) strongly reduced promoter‐driven activity, representing a novel mechanism of iNOS induction by beraprost. Consistent with this, PPARδ and the concomitant iNOS induction by beraprost were also evident in vivo. Beraprost‐mediated protection in a murine model of balloon angioplasty was significantly attenuated by 13S‐HODE, a PPARδ antagonist. Taken together, the results suggest that the causal relationship between PPARδ and iNOS contributes to the vasoprotective action of beraprost in RASMCs. J. Cell. Physiol. 214: 434–441, 2008. © 2007 Wiley‐Liss, Inc.
Compensating for a bad start: catch‐up growth in juvenile lizards (Amphibolurus muricatus, agamidae)
Authors: Radder Rajkumar S. , Warner Daniel A. , Shine Richard
Published: July 2007

In most natural environments, food availability varies unpredictably through space and time, and growth rates of individual organisms respond accordingly. However, growth rates are not necessarily a simple function of current nutritional conditions: growth rates can be affected by earlier nutritional experience as well as current circumstances. Thus, even a brief period of dietary restriction early in life might influence growth rates later on: either reducing them (if early experience sets subsequent rates, as in the “silver spoon” effect) or increasing them (if underfed individuals can compensate by growing more rapidly to cancel out the early decrement). Alternatively, later growth may be unaffected by earlier rates of growth. We experimentally manipulated food supply (and thus, growth rates) of hatchling lizards (Amphibolurus muricatus) for 1 month post‐hatching, then maintained both high‐food and low‐food animals under identical nutritional conditions in outdoor enclosures for another 6 months. Low food abundance early in life significantly reduced juvenile growth, but these previously underfed animals exploited the subsequent (common garden) conditions to grow much faster than their larger (initially better‐fed) siblings. Thus, the two groups were indistinguishable in body size at 6 months of age. Intriguingly, the compensatory growth occurred in winter, a period that is generally unsuitable for rapid growth in ectotherms. J. Exp. Zool. 307A:500–508, 2007. © 2007 Wiley‐Liss, Inc.
Daily and annual variations of the hepatic Glucose 6‐phosphate dehydrogenase activity and seasonal changes in the body fats of the gilthead seabream Sparus aurata
Authors: Gómez‐Milán Encarnación , Lozano Maria José Sánchez‐Muros
Published: July 2007

In mammalians, Glucose 6‐phosphate dehydrogenase (G6PDH) is clearly related with the daily cycle lipogenesis/lipolysis and therefore with the photoperiod and activity. In fish the temporally changes on the activity of this enzyme have not been described. In this work, annual and diurnal activity of G6PDH was investigated in the liver of Sparus aurata in different seasonal conditions of temperature and photoperiod. During experiment the fish were kept in cages under natural temperature and photoperiod while consuming a commercial diet. The months studied were chosen to establish if there is any influence on the G6PDH activity, because of the change in temperature and photoperiod (equal photoperiod and different temperature, March and October; different photoperiod and equal temperature, May and November; and different photoperiod and temperature, June and January). To study the enzyme activity along the day, the livers of six fish were removed every 3 hr during 24 hr. Annual activity was determined as the average activity during 1 day. Also the annual changes on fat content in muscle and digestive system were studied. The Vmax (maximum velocity) showed seasonal changes in period and phase of the rhythms and for the Km (Michaelis–Menten constant) a period of 24 hr was found in all sampled months, except March, the phase time moves depending on the month. In addition, the annual variations in muscular fat and G6PDH‐specific activity seem to be more related to the reproductive stage than any other variable considered. J. Exp. Zool. 307A:516–526, 2007. © 2007 Wiley‐Liss, Inc.
Is the Friedman Method Applicable to Transformations with Temperature Dependent Reaction Heat?
Authors: Sbirrazzuoli Nicolas
Published: July 2007

In the case of chemical reactions with temperature dependent reaction heat, differences in the activation energy values are obtained using the Friedman (FR) and the advanced non‐linear (NLN) isoconversional methods. The FR method leads to systematic errors when the reaction heat significantly changes with the heating rate (from 7 to 16%), while the advanced NLN isoconversional method that uses integrated values is not subject to these systematic errors. An explanation of this is given. For long time predictions, the FR method can lead to inaccurate results.

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Optically Active Methacrylic Copolymers Bearing Side‐Chain Bisazoaromatic and Bulky Achiral Moieties
Authors: Angiolini Luigi , Benelli Tiziana , Giorgini Loris , Mauriello Francesco , Salatelli Elisabetta
Published: July 2007

The synthesis of two novel series of optically active methacrylic copolymers that contain a side‐chain chiral moiety linked to a photochromic bisazoaromatic chromophore has been carried out by radical copolymerization of the monomer (S)‐3‐methacryloyloxy‐1‐[4′‐phenylazo‐(4‐azobenzene)]pyrrolidine with highly sterically hindered monomers such as tert‐butyl methacrylate or triphenylmethyl methacrylate with the aim to investigate the effect on the optical activity of the resulting derivatives. The copolymeric products have been fully characterized and their spectroscopic and thermal properties compared to those of the related optically active homopolymer and the copolymers with methyl methacrylate, previously reported.

The optical activity displayed by the polymers is discussed in terms of extent of chiral conformations assumed by the macromolecules as a consequence of the insertion of co‐monomers capable of affecting the dipole‐dipole interactions that occur in these derivatives between the side‐chain bisazoaromatic chromophores disposed according to a mutual chiral arrangement.

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Extremely Color‐Stable Blue Light‐Emitting Polymers Based on Alternating 2,7‐Fluorene‐co‐3,9‐carbazole Copolymer
Authors: Liu Ransheng , Xiong Yan , Zeng Wenjin , Wu Zhonglian , Du Bin , Yang Wei , Sun Mingliang , Cao Yong
Published: July 2007

Novel alternating 2,7‐fluorene‐co‐3,9‐carbazole copolymer(3,9‐PFCz) was synthesized by Suzuki polycondensation between 3‐bromo‐9‐(2‐iodo‐9,9‐dioctyl‐9H‐fluoren‐7‐yl)‐9H‐carbazole and 2,7‐bis(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)‐9,9‐dioctylfluorene. Cyclic voltammetry studies showed a higher HOMO level (−5.23 eV) than the polyfluorene homopolymer(PFO). The glass transition temperature of the copolymer (110 °C) was much higher than that of the PFO (67 °C). After the copolymer had been annealed at 200 °C for 2 h, the PL spectra showed almost no change and no aggregation‐ or oxidation‐related undesirable long‐wavelength emission has been observed. The light‐emitting diode in configuration of ITO/PEDOT/EML/CsF/Al showed a maximum external quantum efficiency of 1.54% with a luminance of 435 cd · m−2 and the maximum brightness of 2 630 cd · m−2 with CIE coordinate (0.17, 0.14) was achieved at 8.4 V. The device prepared in configuration of ITO/PEDOT/PVK/polymer/Ba/Al exhibits an efficient, stable blue emission; it has a turn‐on voltage of 6 V and maximum external quantum efficiency of 1.1%. The EL emission remains stable at high current density and after thermal treatment at 150 °C for 30 min. Extremely color‐stable blue emission from alternating poly[(2,7‐fluorene)‐co‐(3,9‐carbazole)] copolymer makes it a promising candidate for flat‐panel display applications.

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On Hardy–Steklov and geometric Steklov operators
Authors: Burenkov V. , Jain P. , Tararykova T.
Published: July 2007

A new (non‐Muckenhoupt type) weight characterization for the boundedness of the general Hardy–Steklov operator is obtained in the case 1 < p ≤ q < ∞. The estimates obtained for the norm of the Hardy–Steklov operator allow the limiting procedure and as a result the boundedness of the corresponding geometric Steklov operator is investigated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Annihilating polynomials for quadratic forms and Stirling numbers of the second kind
Authors: De Wannemacker Stefan
Published: July 2007

We present a set of generators of the full annihilator ideal for the Witt ring of an arbitrary field of characteristic unequal to two satisfying a non‐vanishing condition on the powers of the fundamental ideal in the torsion part of the Witt ring. This settles a conjecture of Ongenae and Van Geel. This result could only be proved by first obtaining a new lower bound on the 2‐adic valuation of Stirling numbers of the second kind. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gateaux differentiability in Orlicz–Lorentz spaces and applications
Authors: Levis Fabian E. , Cuenya Hector H.
Published: July 2007

Let Λw,ϕ be the Orlicz–Lorentz space. We study Gateaux differentiability of the functional ψw,ϕ (f) = $ \int _{0} ^{\infty} $ ϕ (f *)w and of the Luxemburg norm. More precisely, we obtain the one‐sided Gateaux derivatives in both cases and we characterize those points where the Gateaux derivative of the norm exists. We give a characterization of best ψw,ϕ ‐approximants from convex closed subsets and we establish a relation between best ψw,ϕ ‐approximants and best approximants from a convex set. A characterization of best constant ψw,ϕ ‐approximants and the algorithm to construct the best constant for maximum and minimum ψw,ϕ ‐pproximants are given. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electro‐Copolymerization of Layer‐by‐Layer Deposited Polythiophene and Polycarbazole Precursor Ultrathin Films
Authors: Waenkaew Paralee , Taranekar Prasad , Phanichphant Sukon , Advincula Rigoberto C.
Published: July 2007

The synthesis, layer‐by‐layer deposition, and electro‐copolymerization of precursor polyelectrolyte multilayer ultrathin films with thiophene and carbazole electroactive groups are described. The interest is in observing an electrochemical cross‐linking approach towards a highly ordered ultrathin film that contains two types of monomers to result in possible layer‐limited homo‐ and copolymerization. A uniform linear growth with alternate deposition of the polyelectrolytes is observed. The multilayer films were then electrochemically polymerized anodically by cyclic voltammetry (CV), which results in copolymerization between two different electroactive groups. Cross‐linking of the layers was verified by CV and spectroelectrochemistry data with very good linear electro‐copolymerizability.

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Molecular Dynamics Simulations of Helium Permeation in Polyimides with a Bulky Dianhydride and a Fluorinated Diamine
Authors: Neyertz Sylvie
Published: July 2007

Fully‐atomistic molecular dynamics (MD) simulations have been carried out to model helium transport through four different glassy polyimides. While the polymer matrices had been pre‐validated, specific parameters and combination rules were used here in order to describe helium‐helium and helium‐polymer interactions. Gas permeabilities are in very good agreement with experimental evidence. Two ways to decrease chain cohesion and improve gas transport were considered – the replacement of an ODPA by a bulky BCDA dianhydride, and the substitution of a site on an ODA diamine by a CF3. The fluorinated polyimide appears to be the most promising material with more heterogeneity in the void‐space distribution, the highest model permeability and fewer constraints from an experimental point of view.

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Microarray analysis reveals that leptin induces autocrine/paracrine cascades to promote survival and proliferation of colon epithelial cells in an Apc genotype‐dependent fashion
Authors: Fenton Jenifer I. , Lavigne Jackie A. , Perkins Susan N. , Liu Huaitian , Chandramouli Gadisetti V.R. , Shih Joanna H. , Hord Norman G. , Hursting Stephen D.
Published: July 2007

The imbalance in systemic mediators of inflammation, such as leptin, is thought to be involved in obesity‐associated cancers. In addition, systemic endocrine signals can influence the local autocrine/paracrine factors produced within this microenvironment to influence epithelial cell fate. We previously demonstrated that leptin preferentially promotes the survival and proliferation of colon epithelial cells possessing an Apc mutation (IMCE) but not model normal cells (YAMC). Therefore, the purpose of this study was to identify leptin‐induced functional gene family changes which characterize the response of colon epithelial cells possessing an Apc mutation but not normal cells. Consistent with our knowledge of colon carcinogenesis, genes regulating the Wnt/β‐catenin‐mediated pathway including Mdm2, Pik3r1, and Rb1 were upregulated by leptin. Importantly, leptin induced IGF‐mediated pathway gene expression changes and their protein products in IMCE cells. In the IMCE cells IGFBP‐6, IGF‐1, and Crim1 expression was upregulated, while IGFBP‐2, IGFBP‐3, IGFBP‐4, IGFBP‐5, and Nov expression was downregulated by leptin treatment. These data establish a biologically plausible mechanistic link between the elevated levels of growth factors and the increased risk of colon cancer associated with obesity. © 2007 Wiley‐Liss, Inc.
Transcriptome analysis of serous ovarian cancers identifies differentially expressed chromosome 3 genes
Authors: Birch Ashley H. , Quinn Michael C.J. , Filali‐Mouhim Ali , Provencher Diane M. , Mes‐Masson Anne‐Marie , Tonin Patricia N.
Published: July 2007

Cytogenetic, molecular genetic and functional analyses have implicated chromosome 3 genes in epithelial ovarian cancers (EOC). To further characterize their contribution to EOC, the Affymetrix U133A GeneChip® was used to perform transcriptome analyses of chromosome 3 genes in primary cultures of normal ovarian surface epithelial (NOSE) cells (n = 14), malignant serous epithelial ovarian tumors (TOV) (n = 17), and four EOC cell lines (TOV‐81D, TOV‐112D, TOV‐21G, and OV‐90). A two‐way comparative analysis of 735 known genes and expressed sequences identified 278 differentially expressed genes, where 43 genes were differentially expressed in at least 50% of the TOV samples. Three genes, RIS1 (at 3p21.31), GBE1 (at 3p12.2), and HEG1 (at 3q21.2), were similarly underexpressed in all TOV samples. Deregulation of the expression of these genes was not associated with loss of heterozygosity (LOH) of the genetic loci harboring them. LOH analysis of the RIS1, GBE1, and HEG1 loci was observed at frequencies of 14.3%, 13.7%, and 9.2%, respectively, in a series of 66 malignant TOV samples of the serous subtype. Reduced expression levels of RIS1, GBE1, and HEG1 were observed only in the tumorigenic EOC cell lines (TOV‐21G, TOV‐112D, and OV‐90) and did not correlate with LOH. These results combined suggest that RIS1, GBE1, and HEG1, unlike classical tumor suppressor genes, are not likely to be primary targets of inactivation. This study provides a comprehensive analysis of chromosome 3 gene expression in NOSE and in EOC samples and identifies chromosome 3 gene candidates for further study. © 2007 Wiley‐Liss, Inc.
Hypermethylation status of APC inversely correlates with the presence of submucosal invasion in laterally spreading colorectal tumors
Authors: Hashimoto Kazuo , Shimizu Yoshihisa , Suehiro Yutaka , Okayama Naoko , Hashimoto Shinichi , Okada Toshiyuki , Hiura Mikako , Ueno Koji , Hazama Shoichi , Higaki Shingo , Hamanaka Yuichiro , Oka Masaaki , Sakaida Isao , Hinoda Yuji
Published: July 2007

Little is known about epigenetic alterations in laterally spreading colorectal tumors (LSTs). The goal of the present study was to elucidate the epigenetic background of LSTs and compare the methylation status of DNA CpG islands (CGIs) with clinicopathologic features. Methylation of MINT1, MINT2, MINT31, p16, O6‐methylguanine‐DNA methyltransferase (MGMT), adenomatous polyposis coli (APC), and human MutL homologue 1 (hMLH1) in 42 LSTs was assessed by methylation‐specific polymerase chain reaction (MSP) and compared with clinicopathologic parameters. The frequency of hypermethylation was 12.5% (4/32) for MINT1, 40.0% (16/40) for MINT2, 25.0% (10/40) for MINT31, 25.7% (9/35) for p16, 7.7% (3/39) for hMLH1, 26.5% (9/34) for MGMT, and 35.9% (14/39) for APC. APC methylation was inversely associated with submucosal invasion (P = 0.034), which was not found in any of 14 LST cases with APC methylation, whereas submucosal invasion was present in 8 of 25 (32.0%) cases without APC methylation. These data suggest that hypermethylation of APC could be a predictive marker for the absence of submucosal invasion of LSTs. © 2007 Wiley‐Liss, Inc.
BRCA1 and acetyl‐CoA carboxylase: The metabolic syndrome of breast cancer
Authors: Brunet Joan , Vazquez‐Martin Alejandro , Colomer Ramon , Graña‐Suarez Begoña , Martin‐Castillo Begoña , Menendez Javier A.
Published: July 2007

Breast cancer‐associated mutations affecting the highly‐conserved C‐terminal BRCT domains of the tumor suppressor gene breast cancer susceptibility gene 1 (BRCA1) fully disrupt the ability of BRCA1 to interact with acetyl coenzyme A carboxylase alpha (ACCA), the rate‐limiting enzyme catalyzing de novo fatty acid biogenesis. Specifically, BRCA1 interacts solely with the phosphorylated (inactive) form of ACCA (P‐ACCA), and the formation of the BRCA1/P‐ACCA complex interferes with ACCA activity by preventing P‐ACCA dephosphorylation. One of the hallmarks of aggressive cancer cells is a high rate of energy‐consuming anabolic processes driving the synthesis of lipids, proteins, and DNA (all of which are regulated by the energy status of the cell). The ability of BRCA1 to stabilize the phosphorylated/inactive form of ACCA strongly suggests that the tumor suppressive function of BRCA1 closely depends on its ability to mimic a cellular‐low‐energy status, which is known to block tumor cell anabolism and suppress the malignant phenotype. Interestingly, physical exercise and lack of obesity in adolescence have been associated with significantly delayed breast cancer onset for Ashkenazi Jewish women carrying BRCA1 gene mutations. Further clinical work may explore a chemopreventative role of “low‐energy‐mimickers” deactivating the ACCA‐driven “lipogenic phenotype” in women with inherited mutations in BRCA1. This goal might be obtained with current therapeutic approaches useful in treating the metabolic syndrome and associated disorders in humans (e.g., type 2 diabetes and obesity), including metformin, thiazolidinediones (TZDs), calorie deprivation, and exercise. Alternatively, new forthcoming ACCA inhibitors may be relevant in the management of BRCA1‐dependent breast cancer susceptibility and development. © 2007 Wiley‐Liss, Inc.
N‐way MMIC redundant switch
Authors: Bahl Inder J. , Griffin Edward L. , Willems David A.
Published: July 2007

A novel approach to provide redundancy in an N‐way MESFET switch has been invented and realized with monolithic microwave integrated circuit technology. This switch circuit uses series and shunt FETs configured in a manner to prevent failure of the switch even if several FETs fail. For example, a SPDT redundant switch is capable of providing 1.3‐dB insertion loss and return loss and isolation better than 20 and 35 dB, respectively, over dc to 12 GHz, even if 25% of the FETs fail in each arm.
Compact, broadband double‐slot waveguide radiator
Authors: Kisliuk M. , Axelrod A. , Maoz J.
Published: July 2007

A compact, broadband double‐slot waveguide antenna is presented. The present design is an improvement of another double‐slot waveguide radiator proposed earlier by the authors. The antenna is characterized by high efficiency and moderate (less than 2.5:1) VSWR in more than 38% frequency band.
Light amplification using backward Raman pumping
Authors: Wu Jingshown , Kao Ming‐Seng
Published: July 2007

Analytical expressions for backward Raman amplification using pulse pumping are presented. We find that pulse pumping results in higher amplification gain than CW pumping and there exists an optimum pumping length at which maximum gain occurs. The results can be extended to CW pumping.
A phase‐noise‐compensating transmission method for phase‐modulated coherent optical systems
Authors: Betti S. , Curti F. , De Marchis G. , Iannone E.
Published: July 2007

A new method capable of overcoming the limitations in coherent optical systems that occur when the optical source has a nonnegligible linewidth is proposed. The transmission of a reference signal derived from a common source allows the use of high‐power laser sources which are required in long‐haul optical systems.
Solutions of some transmission lines
Authors: Lin Weigan , Changhua Wan
Published: July 2007

Solutions of the unscreened slab line, the triangular slab line, the square slab line, and the hexagonal slab line are obtained by means of conformal mapping and the continuity of electric potential. Both the method and the results are new. All the solutions are believed to be virtually exact for all ranges of the ratio of the dimensions.
A periodic nonlinear analysis technique for microwave mixers
Authors: Smith I. , Richardson J. R. , Miles R. E.
Published: July 2007

A general, iterative method is described for obtaining voltage and current waveforms in a periodically driven nonlinear active circuit. This allows local oscillator modulation of the parameters of device models to be studied. The technique is applicable to both diode and FET circuit models, since it can accommodate multiple nonlinearities.
Application of method of lines to solve problems in the cylindrical coordinates
Authors: Xu Yansheng
Published: July 2007

In this article the method of lines is extended to solve the electromagnetic problems in cylindrical coordinates. It is shown that this method is both simple and effective in treating the calculation of cylindrical microstrips, striplines, and other related problems.
All‐optical logic gates using colloids
Authors: Chowdhury A. H. , Ackerson B. J. , Wood F. , Karim M. A. , Awwal A. A. S.
Published: July 2007

An all‐optical technique is used to realize three logic operations, AND, X‐OR, and NOT. The logic inputs are represented by laser beams that are made to cross in a sample of polymer microspheres at predetermined angles.
Inelastic scattering of gaussian beams by active molecules embedded in a sphere
Authors: Wang Zhi‐Liang , Lin Wei‐Gan
Published: July 2007

When an electromagnetic wave is incident on a dielectric body filled with active molecules, there also will be inelastically scattered waves in addition to elastically scattered waves. In this paper, making use of the expansion of vector spherical wave functions of Gaussian beams and the method of dyadic Green's functions, we analyze the problem of inelastic scattering of Gaussian laser beams by active molecules embedded in a two‐layer concentric sphere and we also give some numerical results for the first time.
On spot sizes of 1.3 ‐1.55‐μm InGaAsP/InP semiconductor laser diodes
Authors: Ghafoori‐Shiraz H.
Published: July 2007

The spot sizes for the fundamental TE modes of InGaAsP / InP laser diodes in directions parallel and perpendicular to the junction plane have been investigated based on the effective refractive index approach. The analytical results are in good agreement with the reported measured values in the literature. The results can be used to calculate the coupling efficiency between laser diodes and single‐mode fibers.
Scattering parameters of a step discontinuity in a suspended microstrip line
Authors: Picon Odile , Achkar Joseph , Hanna Victor Fouad , Citerne Jacques
Published: July 2007

The dominant and first nine higher‐order modes in a suspended micro‐strip lines are accurately described from a thorough spectral‐domain approach. Then coupling coefficients between eigenmodes at a step width discontinuity to be used in the generalized scattering matrix formulation are directly computed in the spectral domain. Scattering parameters of the dominant mode in the Ka band are presented.
Analysis of transmission structure with periodically loaded elliptical (oval) bars between parallel ground planes
Authors: Rao K. V. Seshagiri , Bhartia Prakash
Published: July 2007

The even and odd mode impedances are determined for the case of a structure consisting of elliptic bars located symmetrically between two infinite parallel plates with a periodic spacing along the width of the parallel plates using conformal transformation. Different compression ratios of the elliptic configuration of the center conductor are considered along with special cases like horizontal strip, circular bar, and vertical strip. The coupling between two adjacent conductors has been determined as a function of the dimensions of the center conductor for different spacings between the conductors. The results of the present analysis are compared with some of those special cases available in the literature.
Mode coupling in on‐fiber devices
Authors: Shankar P. Mohana
Published: July 2007

On‐fiber devices are fabricated by removing the cladding over a short length of the multimode fiber and replacing it with an active medium like electrooptic or magnetooptic material. When a field is applied, the index of this modified cladding goes up, leading to a redistribution of modal amplitudes, which may or may not be accompanied by optical power loss due to radiation modes. Significant optical power loss occurs when the induced index change is large while modal redistribution of amplitudes takes place with negligible power loss when the index change is very small. This modal redistribution has been investigated and expressions for the amplitude coupling coefficient related the modal amplitudes before and after the application of the field are derived. These coupling coefficients have been evaluated as a function of the induced index change in the cladding. The results indicate that this modal redistribution may be used as a sensing mechanism.
Analysis of self‐admittance of a longitudinal shunt slot radiating into a parallel plate region
Authors: Forooraghi Keyvan
Published: July 2007

A single longitudinal shunt slot in a rectangular waveguide radiating into a parallel plate region is analyzed. An expression for the magnetic field in the parallel plate region is obtained by developing a Green's function for this region. The slot admittance is computed. The subsequent formulation involves derivation of an integral equation which is solved by the method of moments. Good agreement with measurements has been established.
Microwave photoconductors
Authors: McGinn V. P. , Grimes D. M.
Published: July 2007

An optically controlled microwave attenuator is described. The bulk semiconductor properties of cadmium selenide are demonstrated effectively at Ku band frequencies. The device is configured monolithically with a low capacitance resistive channel. Electrical resonance is achieved with symmetric inductance loops which bridge the channel ends.
Local field in a bent step‐index slab waveguide
Authors: Cheng Y. H. , Lin Weigan
Published: July 2007

The local field, field shift, and perturbation correction to the propagation constant in a bent slab waveguide with symmetric step‐index profile are investigated by using local field theory. Simple analytical expressions are given to describe the local fields in the bent slab waveguide for TE and TM modes. An implicit equation is given for the shift of the field maximum of the TE0 fundamental mode.
A theoretical and experimental investigation on millimeter‐wave quantum well oscillators
Authors: Rydberg Anders , Grönqvist Hans , Kollberg Erik
Published: July 2007

The operation and FM noise of millimeter‐wave quantum well (QW) oscillators in a harmonic mode (relaxation oscillations) and a fundamental mode using post and cap waveguide mount structures are investigated. Harmonics up to the ninth harmonic was detected. State of the art results for QW oscillators registered were 84 μW (at 77 K physical temperature) and 60 μW at 90 GHz and 1 μW at 176 GHz (at 300 K physical temperature, respectively).
Folded radial‐line filters
Authors: Baños‐Polglase J. D. , Rebollar J. M.
Published: July 2007

In this article a new structure is proposed to substitute radial‐line filters, particularly for low rejection‐frequency applications, where the cross section of these filters becomes inconveniently large. A very accurate method based on modal analysis and the GSM concept of generalized two‐port discontinuity is applied to calculate the frequency response of both radial‐line and folded radial‐line filters. Agreement with data available for standard radial‐line filters is excellent. A detailed study of the influence of the different geometrical parameters on the response of folded radial‐line filters is also included.
Vector fourier transform analysis of dielectric‐covered slot in the broad wall of a waveguide
Authors: Rexberg Leonard
Published: July 2007

The resonant length versus offset of a dielectric‐covered narrow square ended slot is studied. The slot, located in the broad wall of a rectangular waveguide, is excited by a single mode. The external field is matched to the internal field by the Galerkin method concept. Corrections due to finite wall thickness are also included.
Single stage branchline couplers reappraised
Authors: Fusco V. F. , Kerlin J. B. D.
Published: July 2007

At present the preferred single stage branchline coupler is the conventional quarter wavelength branchline device. This paper illustrates that the quarter wavelength branchline coupler is a special case of a more general form that allows an infinite range of single stage branchline couplers to be developed for any degree of coupling and for any chosen center frequency. We term these couplers fractional wavelength branchline couplers. It is shown that the characteristics of the fractional wavelength branchline coupler are dependent on the design constraints imposed. The design can be constrained either by choice of branch lengths or by selection of line characteristic impedance. For comparison theoretical and experimental results for bandwidth, coupling, and isolation are shown for an example operating at 10 GHz.
A numerically efficient technique for the method of moments solution of electromagnetic problem associated with planar periodic structures
Authors: Chan C. H.
Published: July 2007

A numerically efficient summation technique, using the FFT algorithm, for the calculation of the impedance matrix in the method of moment solution to electromagnetic problems associated with planar periodic structures is presented. Comparisons between the CPU times for the conventional brute‐force summation and the present technique are given.
Analysis of beam divergence in InGaAsP/InP semiconductor laser diodes
Authors: Ghafoori‐Shiraz H.
Published: July 2007

The beam divergence angles for the fundamental TE mode both in the directions parallel and perpendicular to the junction plane of InGaAsP/InP semiconductor laser diodes emitting at 1.3 and 1.55 μm have been investigated. The analysis is based on the effective‐index method and the results can be used to design laser diodes (LDs) with minimum beam divergence which will improve the coupling efficiency between LDs and single‐mode fibers.
On the directivity of conical horn antennas
Authors: Hansen R. C.
Published: July 2007

The formula for directivity of conical horns has been recreated. Computer calculated curves are given that differ slightly from those of Gray and Schelkunoff, circa 1940, that are often reproduced in books.
Signal and noise in a coherent optical communication system using raman amplifier
Authors: Kao Ming‐Seng , Wu Jingshown
Published: July 2007

We present analytical expressions for the signal and the amplified spontaneous emission (ASE) noise in a coherent optical system using Raman amplification. The results show that the signal spectrum is unaffected by the amplifier and the ASE noise can be thought of as additive white Gaussian noise within the signal bandwidth.
Generation of microwave signals from a laser diode coupled to an external cavity
Authors: Arora Krishna , Arora Rajendra K.
Published: July 2007

This article describes a technique by which a laser diode coupled with an external cavity is used in an interferometric system resulting in a direct envelope modulation of the optical carrier. The laser output is fed to a Mach‐Zehnder interferometer in which the time delay associated with the path imbalance is adjusted to half the time period Tm of the modulating sawtooth current. The two signals are heterodyned to simulate an envelope modulated optical signal.
Binary phase only joint transform correlator
Authors: Yu Francis T. S. , Nagata Toshio
Published: July 2007

A joint transform hybrid optical correlator as applied to binary phase only filtering for pattern recognition is proposed. The interference fringes of the joint Fourier transformation, due to the reference and the input targets, are captured by a CCD camera feeding into a microcomputer for binarization. A binarized phase only filter, in principle, can be written onto a spatial light modulator (SLM). By simple coherent illumination of SLM, correlation operation of the reference and the input targets can be obtained. A computer simulation for the target embedded in an additive Gaussian noise is provided.
Lumped element hybrid networks for GaAs MMICs
Authors: Fusco V. F. , O'Caireallain S. B. D.
Published: July 2007

The use of lumped elements in microwave monolithic circuits (MMICs) is an essential feature allowing substantial reduction of GaAs substrate and reduced area cost when compared with conventional distributed microwave designs. The development of low loss passive circuit elements is therefore critical for the realisation of space conservative and efficient monolithic circuits.

This paper discusses the properties of a series of lumped element designs that exhibit the same functional behaviour as the distributed quarter‐wavelength quadrature branchline coupler and presents a set of closed equations for their design.
Inelastic multiple scattering by active molecules embedded in randomly distributed spherical scatterers
Authors: Wang Zhi‐Liang , Lin Wei‐Gan
Published: July 2007

According to the model of equivalent dipoles for active molecules, the analysis of inelastic EM scattering by active molecules embedded in a sphere is given by the method of dyadic Green's functions at first and then, based on the theory of elastic multiple scattering by randomly distributed spherical scatterers which we have developed recently, a new theory for analysis of inelastic multiple scattering by active molecules embedded in randomly distributed spherical scatterers also is developed.
A method of generating a linear frequency sweep in the microwave band
Authors: Hua Li
Published: July 2007

This article describes a method for generating a linear frequency sweep of more than 300 MHz in the band of 0.5 to 2.5 GHz using a phase‐locked loop and a design of microwave voltage‐controlled oscillator using a short‐circuited transmission line and a varactor diode as the tuned circuit. The result of linearity measurements on the system is presented.
First‐order eigenmode analysis of symmetrical five‐port microstrip ring coupler
Authors: Yeo S. P. , Yeo T. S. , Ng K. M.
Published: July 2007

Explicit formulas to predict the characteristics of a symmetrical five‐port microstrip ring coupler are obtained from a first‐order eigenmode analysis. Tests on a prototype coupler over the 2—4‐GHz bandwidth indicate that the agreement between theory and experiment is reasonably good.