Triple band-notched UWB antenna using meandered ground stubs

In this paper, three pairs of meandered ground stubs are used to create a triple band-notched characteristic for a compact planar-monopole antenna used in the ultrawide band (UWB). The three band notches include the IEEE 802.16 (WiMax) band (3.3-3.6 GHz), the lower wireless area network (WLAN) band (5.15-5.35 GHz) and the higher WLAN band (5.725-5.825 GHz). The center frequencies and bandwidths of the notches can be adjusted using the dimensions of the meandered ground stubs. Prototype of the proposed antenna is designed and fabricated. The band-notched characteristics, return loss, radiation patterns, peak gains and efficiencies of the antenna are studied using both computer simulation and measurements. ©2010 IEEE.published_or_final_versionThe 2010 Loughborough Antennas and Propagation Conference (LAPC 2010), Loughborough, U.K., 8-9 November 2010. In Proceedings of LAPC, 2010, p. 341-34

Effects of ground-plane size on planar UWB monopole antenna

Planar monopole antennas have found widespread applications in wireless communication systems. Their advantages of compact size, omnidirectional radiation pattern and wide impedance bandwidth make them good candidates for the designs of ultra-wideband (UWB) antennas. This paper investigates the effects of the dimensions of the rectangular ground-plane on the return loss and efficiency of an elliptical planar monopole antenna for UWB applications. Computer simulation and measurement are carried out on a group of nine antennas with different rectangular ground plane sizes. The simulated and measured results on return loss agree well. However, the simulated and measured efficiencies do not agree well in the lower UWB band. The measured efficiency shows that the efficiency is affected more by the width rather than by the length of the ground plane while the length of the ground plane affects the lower cutoff frequency. © 2010 IEEE.published_or_final_versionThe 2010 IEEE Region 10 International Conference (TENCON 2010), Fukuoka, Japan, 21-24 November 2010. In TENCON (IEEE Region 10 Conference) Proceedings, 2010, p. 422-42

An antenna for UWB and Bluetooth standards with band-notched characteristic

This paper presents the design and results of a small size, integrated Bluetooth and Ultrawideband (UWB) planar monopole antenna with a band-notched characteristic in the WLAN band. The antenna consists of a dual-ring radiator as the primary radiation element for the Bluetooth and UWB bands and a complementary split-ring resonator (CSRR) to produce a notched characteristic at the center frequency of 5.5GHz. The return loss, voltage-standing-wave ratio (VSWR), radiation pattern and peak gain of the antenna are studied by computer simulation and verified by measurements which agree well with the simulation results. © 2009 IEEE.published_or_final_versionThe 2009 IEEE International Conference on Ultra-Wideband (ICUWB 2009), Vancouver, BC., 9-11 September 2009. In Proceedings of ICUWB, 2009, p. 170-17

Band-notched characteristic using meandered ground stubs for compact UWB antennas

In this paper, a pair of meandered ground stubs is used to design a single band-notched characteristic in a compact planar-monopole antenna for ultrawide band (UWB) applications. The single-band notch covers the wireless area network (WLAN) band from 5.15 GHz to 5.825 GHz. The center-notch frequency and notch bandwidth can be adjusted using the dimensions of the meandered ground stubs. Prototype of the proposed antenna is designed, fabricated and studied. The band-notched characteristics, return loss, radiation patterns, peak gains and efficiencies of the antenna are studied using both computer simulation and measurements. © 2010 IEEE.published_or_final_versionThe 2010 IEEE International Conference on Ultra-Wideband (ICUWB), Nanjing, China, 20-23 September 2010. In Proceedings of ICUWB2010, 2010, v. 1, p. 147-15

Modeling of cable for measurements of small monopole antennas

Coaxial cable is often used for measurements of antennas inside anechoic chambers. In the measurement of a monopole antenna with a small ground-plane, the finite-sized ground causes the current to flow back from the radiator to the outer surface of the coaxial cable. This results in secondary radiation which introduces errors to the measured radiation pattern. To reduce the unwanted secondary radiation, the coaxial cable can be covered with EMI suppressant tubing materials. However, this introduces errors to the measured efficiency. In this paper, the models of the coaxial cable with and without suppressant tubing are developed and used for computer simulation. The cable effects on the measured results of a small monopole ultrawide band (UWB) antenna are studied by using the antenna measurement equipment Satimo StarLab and the EM simulation tool CST. The results show great agreements between the simulated and measured results. © 2011 IEEE.published_or_final_versio

Topological analysis of the vasculature of angiopoietin-expressing tumours through scale-space tracing

This work describes the topological analysis of the vasculature of tumours. The analysis is performed with a scale-space technique, which traces the centrelines of vessels as topological ridges of the image intensities and then obtains a series of measurements, which are used to compare the vasculatures. Besides the measurements directly associated with the centrelines, the scales obtained allow the estimation of width andthusareacoveredwithvessels. Tumours of SW1222 human colorectal carcinoma xenografts were observed when growing in dorsal skin-fold window chambers in mice. Three variants of the tumours expressing either endogenous levels of angiopoietins (WT) or over-expressing either angiopoietin-1 (Ang-1) or angiopoietin-2 (Ang-2) were assessed with/without vascular targeted therapy. The scale-space technique was able to discriminate between the vasculatures of the three different tumour types prior to treatment. Results also suggested that over-expression of Ang-2 was associated with susceptibility of the tumour vasculature to the vascular disrupting agent, combretastatin A4 phosphate (CA4P). Substantiation of this finding would point to the potential of tumour Ang-2 expression as a predictive bio-marker for response to CA4P

Adult hippocampal neuroplasticity triggers susceptibility to recurrent depression

Depression is a highly prevalent and recurrent neuropsychiatric disorder associated with alterations in emotional and cognitive domains. Neuroplastic phenomena are increasingly considered central to the etiopathogenesis of and recovery from depression. Nevertheless, a high number of remitted patients experience recurrent episodes of depression, remaining unclear how previous episodes impact on behavior and neuroplasticity and/or whether modulation of neuroplasticity is important to prevent recurrent depression. Through re-exposure to an unpredictable chronic mild stress protocol in rats, we observed the re-appearance of emotional and cognitive deficits. Furthermore, treatment with the antidepressants fluoxetine and imipramine was effective to promote sustained reversion of a depressive-like phenotype; however, their differential impact on adult hippocampal neuroplasticity triggered a distinct response to stress re-exposure: while imipramine re-established hippocampal neurogenesis and neuronal dendritic arborization contributing to resilience to recurrent depressive-like behavior, stress re-exposure in fluoxetine-treated animals resulted in an overproduction of adult-born neurons along with neuronal atrophy of granule neurons, accounting for an increased susceptibility to recurrent behavioral changes typical of depression. Strikingly, cell proliferation arrest compromised the behavior resilience induced by imipramine and buffered the susceptibility to recurrent behavioral changes promoted by fluoxetine. This study shows that previous exposure to a depressive-like episode impacts on the behavioral and neuroanatomical changes triggered by subsequent re-exposure to similar experimental conditions and reveals that the proper control of adult hippocampal neuroplasticity triggered by antidepressants is essential to counteract recurrent depressive-like episodes.FCT (IF/01079/2014). This article has been developed under the scope of the project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the FCT, under the scope of the project POCI-01-0145-FEDER-007038info:eu-repo/semantics/publishedVersio

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Tumor necrosis factor alpha drugs in rheumatoid arthritis: systematic review and metaanalysis of efficacy and safety

Es reproducción del documento publicado en http://dx.doi.org/10.1186/1471-2474-9-52Background: To analyse available evidence on the efficacy and safety of anti-TNF alpha drugs (infliximab, etanercept and adalimumab) for treating rheumatoid arthritis (RA). Methods: We searched systematically for randomised controlled clinical trials on treatment of RA with anti-TNF alpha drugs, followed by a systematic review with metaanalysis. Trials were searched from MEDLINE, EMBASE and Cochrane Library databases. The American College of Rheumatology (ACR) efficacy response criteria were used. Safety parameters provided by the trials were also assessed. Positive and undesired effects were estimated using combined relative risks (RR), number needed to treat (NNT) and number needed to harm (NNH). Heterogeneity was evaluated by Cochrane's Q and I-2 statistics. Results: Thirteen trials (7087 patients) met the inclusion criteria. The combined RR to achieve a therapeutic response to treatment with recommended doses of any anti-TNF alpha drug was 1.81 (95% CI 1.43 - 2.29) with a NNT of 5 (5 - 6) for ACR20. NNT for ACR50 [5 (5 - 6)] and ACR70 [7 (7 - 9)] were similar. Overall therapeutic effects were also similar regardless of the specific anti-TNF alpha drug used and when higher than recommended doses were administered. However, lower than recommended doses elicited low ACR70 responses (NNT 15). Comparison of anti-TNF alpha drugs plus methotrexate (MTX) with MTX alone in patients with insufficient prior responses to MTX showed NNT values of 3 for ACR20, 4 for ACR50 and 8 for ACR70. Comparison of anti-TNF alpha drugs with placebo showed a similar pattern. Comparisons of anti-TNF alpha drugs plus MTX with MTX alone in patients with no previous resistance to MTX showed somewhat lower effects. Etanercept and adalimumab administered as monotherapy showed effects similar to those of MTX. Side effects were more common among patients receiving anti-TNF alpha drugs than controls (overall combined NNH 27). Patients receiving infliximab were more likely to drop out because of side effects (NNH 24) and to suffer severe side effects (NNH 31), infections (NNH 10) and infusion reactions (NNH 9). Patients receiving adalimumab were also more likely to drop out because of side effects (NNH 47) and to suffer injection site reactions (NNH 22). Patients receiving etanercept were less likely to drop out because of side effects (NNH for control versus etanercept 26) but more likely to experience injection site reactions (NNH 5). Conclusion: Anti-TNF alpha drugs are effective in RA patients, with apparently similar results irrespective of the drug administered. Doses other than those recommended are also beneficial. The main factor influencing therapeutic efficacy is the prior response to DMARD treatment. The effect of treatment with etanercept or adalimumab does not differ from that obtained with MTX. The published safety profile for etanercept is superior but the fact that no patients are treated with higher than recommended doses requires explanation