1,330 research outputs found

    A reconfigurable beam-scanning partially reflective surface (PRS) antenna

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    © 2015 EurAAP. A novel reconfigurable partially reflective surface (PRS) antenna is presented in this paper. The beam scanning ability is realized by employing a reconfigurable PRS structure and a phased array as the source. The design achieves a beam switching between -15°, 0°, to 15° with respect to the broadside direction from 5.5 GHz to 5.7 GHz with the realized gains over 12 dBi. Good agreement between the simulated and measured results is achieved

    Low-profile and wide-beamwidth dual-polarized distributed microstrip antenna

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    © 2013 IEEE. A low-profile and wide-beamwidth dual-polarized distributed microstrip antenna is presented in this paper. Four isolated micro patches are proposed as the radiation components and are excited by a compact differential-fed network. The micro patches in two diagonals determine the operating frequency bands of the two polarizations, respectively. By increasing the distances between the micro patches, the beamwidth in E plane can be broadened. Shorting poles between the patches and the ground plane are used to achieve good impedance matching. Compact dual-polarized differential-fed networks are also studied and compared with achieve the best antenna performance. To validate the proposed method, a wide-beamwith dual-polarized distributed microstrip antenna, whose dual polarizations operate at 2 and 2.2 GHz, respectively, is manufactured and measured. The external dimensions of the antenna is 70mm × 10 mm (0.49λ × 0.07λ ). The experimental results agree well with the simulated ones. The 3dB beamwidths in E planes reach 116° and 115°, and the gains are 5.15 and 5.5 dB for two polarizations, respectively. Meanwhile, the cross polarizations are less than -26.2 and -27.8 dB. In addition, the impedance bandwidths of 9.2% and 9.9% for VSWR leq 2 are achieved, and the port isolation is greater than 25.4 dB in the bands

    A wideband polarization reconfigurable antenna for WLAN applications

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    © 2016 European Association of Antennas and Propagation. This paper proposes a wideband polarization reconfigurable antenna design for WLAN applications. It consists of a shorted annular patch (SAP) antenna as the source, a partially reflective surface (PRS) structure to enhance the gain, and a reconfigurable Wilkinson power divider as the feed network. The antenna can electronically alter its polarization between linear polarization (LP), left-hand circular polarization (LHCP), and right-hand circular polarization (RHCP),achieving an overlapped 10dB impedance bandwidth and 3 dB axial-ratio bandwidth of 4.68-5.33 GHz (13%), thus outperforming most of the reported polarization reconfigurable antennas in terms of the frequency bandwidth

    Recent changes of water discharge and sediment load in the Yellow River basin, China

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    The Yellow River basin contributes approximately 6% of the sediment load from all river systems globally, and the annual runoff directly supports 12% of the Chinese population. As a result, describing and understanding recent variations of water discharge and sediment load under global change scenarios are of considerable importance. The present study considers the annual hydrologic series of the water discharge and sediment load of the Yellow River basin obtained from 15 gauging stations (10 mainstream, 5 tributaries). The Mann-Kendall test method was adopted to detect both gradual and abrupt change of hydrological series since the 1950s. With the exception of the area draining to the Upper Tangnaihai station, results indicate that both water discharge and sediment load have decreased significantly (p<0.05). The declining trend is greater with distance downstream, and drainage area has a significant positive effect on the rate of decline. It is suggested that the abrupt change of the water discharge from the late 1980s to the early 1990s arose from human extraction, and that the abrupt change in sediment load was linked to disturbance from reservoir construction.Geography, PhysicalGeosciences, MultidisciplinarySCI(E)43ARTICLE4541-5613

    A systematic analysis of host factors reveals a Med23-interferon-λ regulatory axis against herpes simplex virus type 1 replication

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    Herpes simplex virus type 1 (HSV-1) is a neurotropic virus causing vesicular oral or genital skin lesions, meningitis and other diseases particularly harmful in immunocompromised individuals. To comprehensively investigate the complex interaction between HSV-1 and its host we combined two genome-scale screens for host factors (HFs) involved in virus replication. A yeast two-hybrid screen for protein interactions and a RNA interference (RNAi) screen with a druggable genome small interfering RNA (siRNA) library confirmed existing and identified novel HFs which functionally influence HSV-1 infection. Bioinformatic analyses found the 358 HFs were enriched for several pathways and multi-protein complexes. Of particular interest was the identification of Med23 as a strongly anti-viral component of the largely pro-viral Mediator complex, which links specific transcription factors to RNA polymerase II. The anti-viral effect of Med23 on HSV-1 replication was confirmed in gain-of-function gene overexpression experiments, and this inhibitory effect was specific to HSV-1, as a range of other viruses including Vaccinia virus and Semliki Forest virus were unaffected by Med23 depletion. We found Med23 significantly upregulated expression of the type III interferon family (IFN-λ) at the mRNA and protein level by directly interacting with the transcription factor IRF7. The synergistic effect of Med23 and IRF7 on IFN-λ induction suggests this is the major transcription factor for IFN-λ expression. Genotypic analysis of patients suffering recurrent orofacial HSV-1 outbreaks, previously shown to be deficient in IFN-λ secretion, found a significant correlation with a single nucleotide polymorphism in the IFN-λ3 (IL28b) promoter strongly linked to Hepatitis C disease and treatment outcome. This paper describes a link between Med23 and IFN-λ, provides evidence for the crucial role of IFN-λ in HSV-1 immune control, and highlights the power of integrative genome-scale approaches to identify HFs critical for disease progression and outcome

    Structural, thermal and dissolution properties of MgO- and CaO-containing borophosphate glasses: effect of Fe2O3 addition

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    This paper investigated manufacture of high-durability phosphate glass fibres for biomedical applications. Five different borophosphate glass formulations in the systems of 45P2O5–5B2O3–5Na2O–(29 − x)CaO–16MgO–(x)Fe2O3 and 45P2O5–5B2O3–5Na2O–24CaO–(21 − x)MgO–(x)Fe2O3 where x = 5, 8 and 11 mol% were produced via melt quenching. The compositions and amorphous nature of the glasses were confirmed by ICP-MS and XRD, respectively. FTIR results indicated depolymerisation of the phosphate chains with a decrease in Q2 units with increasing Fe2O3 content. DSC analyses showed an increase in Tg by ~5 °C with an increment of 3 mol% in Fe2O3 content. The thermal properties were also used to calculate processing window (i.e. Tc,ons—Tg) and another parameter, Kgl, to determine the suitability for fibre drawing directly from melt, which equals (Tc,ons—Tg)/(Tl—Tc,ons). The degradation study conducted in PBS solution at 37 °C showed a decrease of 25–47% in degradation rate with increasing Fe2O3 content. This confirmed that the chemical durability of the glasses had increased, which was suggested to be due to Fe2O3 addition. Furthermore, the density measured via Archimedes method revealed a linear increase with increasing Fe2O3 content

    Chromosome 2p14 Is Linked to Susceptibility to Leprosy

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    BACKGROUND: A genetic component to the etiology of leprosy is well recognized but the mechanism of inheritance and the genes involved are yet to be fully established. METHODOLOGY: A genome-wide single nucleotide polymorphism (SNP) based linkage analysis was carried out using 23 pedigrees, each with 3 to 7 family members affected by leprosy. Multipoint parametric and non-parametric linkage analyses were performed using MERLIN 1.1.1. PRINCIPAL FINDINGS: Genome-wide significant evidence for linkage was identified on chromosome 2p14 with a heterogeneity logarithm of odds (HLOD) score of 3.51 (rs1106577) under a recessive model of inheritance, while suggestive evidence was identified on chr.4q22 (HLOD 2.92, rs1349350, dominant model), chr. 8q24 (HLOD 2.74, rs1618523, recessive model) and chr.16q24 (HLOD 1.93, rs276990 dominant model). Our study also provided moderate evidence for a linkage locus on chromosome 6q24-26 by non-parametric linkage analysis (rs6570858, LOD 1.54, p = 0.004), overlapping a previously reported linkage region on chromosome 6q25-26. CONCLUSION: A genome-wide linkage analysis has identified a new linkage locus on chromosome 2p14 for leprosy in Pedigrees from China

    Caregiver awareness of reproductive health issues for women with intellectual disabilities

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    <p>Abstract</p> <p>Background</p> <p>Limited attention has been paid to the issue of reproductive health as it affects women with intellectual disabilities, despite reproductive health being a vital issue in public health policy for women in the general population. This paper describes caregiver awareness of reproductive health issues relative to women with intellectual disabilities who are being cared for in welfare institutions in Taiwan.</p> <p>Methods</p> <p>The study employed a cross-sectional, questionnaire-based study which recruited 1,152 caregivers (response rate = 71.87%) from 32 registered disability welfare institutions in Taiwan. We classified their understanding/awareness of reproductive health issues into four domains: menstrual (1) and menopause (2) issues, sex education (3), and reproductive health services (4). Each domain had five associated yes/no questions and the total score for the four domains was out of a maximum of 20. Data were analyzed using SPSS 15.0 software.</p> <p>Results</p> <p>We found that most of the caregivers were familiar with matters concerning sex education, menopause, and reproductive health services, but they lacked adequate understanding of issues associated with menstruation in women with ID. Many aspects of reproductive health such as "menstrual pain", "age at menarche", "masturbation", "diet during perimenopause", and "publicly available reproductive health services" were issues in which caregivers lacked adequate knowledge and required further instruction. Logistic regression analysis revealed that female caregivers with a university degree, and those who had experience assisting with reproductive health care were more inclined to have higher reproductive health awareness scores than their counterparts.</p> <p>Conclusions</p> <p>This study highlights that service providers should offer appropriate reproductive health education to institutional caregivers, and that more attention be focused on the personal experiences and concerns of intellectually disabled women in future research.</p

    Downregulation of RKIP Is Associated with Poor Outcome and Malignant Progression in Gliomas

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    Malignant gliomas are highly infiltrative and invasive tumors, which precludes the few treatment options available. Therefore, there is an urgent need to elucidate the molecular mechanisms underlying gliomas aggressive phenotype and poor prognosis. The Raf Kinase Inhibitory protein (RKIP), besides regulating important intracellular signaling cascades, was described to be associated with progression, metastasis and prognosis in several human neoplasms. Its role in the prognosis and tumourigenesis of gliomas remains unclear
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