5,292 research outputs found

    A Novel Dual-Polarized Planar Antenna

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    © 2018 IEEE. A wideband dual-polarized antenna with a novel planar configuration is presented for base station applications. Two groups of simple dipoles are fed by two microstrip feed networks to achieve ±45° polarizations. A novel feeding technique that leads to a planar configuration is described. Measured results show that excellent matching and stable radiation performances are achieved over a wide band

    Wideband Planarized Dual-Linearly-Polarized Dipole Antenna and Its Integration for Dual-Circularly-Polarized Radiation

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    © 2002-2011 IEEE. A planarized dual-linearly-polarized (dual-LP) antenna and an integrated dual-circularly-polarized (dual-CP) antenna are proposed in this letter. For the dual-LP antenna, two groups of dipoles are fed by two balun-included feed networks to achieve ±45° polarizations. The feed networks and the radiators are printed on two sides of a substrate, forming a fully planar structure. Taking advantage of its planar configuration, the dual-LP antenna is further integrated with a wideband coupler to realize dual-CP radiation. The coupler is bent and squeezed into the space between the radiators and the reflector, leading to a compact structure. Both the dual-LP antenna and the dual-CP antenna have very stable radiation performances across a wide operating band >66%

    Study on relationship between microsatellite polymorphism and producing ability on litter size trait of Hu sheep in China

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    Four microsatellite loci (OarAE101, BM1329, BM143 and OarHH55) linked to FecB gene on chromosome 6 and one microsatellite locus (OarHH55) on chromosome 4 were selected to study their correlation with litter size of Hu sheep breed. The results showed that the average polymorphism information content (PIC), heterozygosity (He) and effective allele number (Ne) were 0.7214, 0.7558 and 4.4094, respectively, and all 5 microsatellite loci reached high polymorphism (PIC > 0.5), and the five microsatellite loci can be used for genetic diversity evaluation in Hu sheep breed. The result of variance analysis showed that there were extreme significant differences among the different genotypes for the producing ability of litter size in OarAE101 locus and BM143 locus (P < 0.01), and OarHH35 locus (0.01 < P < 0.05). However, there was no significant difference among the different genotypes for the producing ability of litter size in BM1329 and OarHH55 loci (P > 0.05). Choosing by combining producing ability and special gene (gene type) will play an great role in improving selecting accuracy and breeding progress, and it is a wonderful and new analyzed thought in repeatable characters with low heritability which is affected by measuring frequencies. And this study will have an important role in MAS (marker-assistant selection) and molecular breeding in Hu sheep in future.Keywords: Hu sheep, microsatellite markers, litter size trait, producing ability of ewe

    A Dual Layered Loop Array Antenna for Base Stations with Enhanced Cross-Polarization Discrimination

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    © 1963-2012 IEEE. This paper presents a novel dual-loop array antenna targeted at current and future base station applications. The antenna has four rectangular loops and four trapezoidal loops printed on the front and back sides, respectively, of a substrate placed above a flat square reflector. All eight loop radiators are excited simultaneously with properly designed feed networks to achieve its ±45° polarization states. The trapezoidal loops act like folded (electric) dipoles; the rectangular loops act primarily as magnetic dipoles. The combination of these two loop arrays leads to a type of magnetoelectric loop antenna that has stable directivity patterns with high cross-polarization discrimination (XPD) values across a 45.5% operational fractional bandwidth from 1.7 to 2.7 GHz. A fabricated and measured prototype confirms the simulation results and demonstrates that the half-power beamwidths in the horizontal plane vary between 63° and 70°, the XPD values are >20 dB in the boresight direction, and are >10 dB within the entire cellular coverage angular range:-60 θ 60°

    Extracellular signal-regulated kinase 1/2 plays a pro-life role in experimental brain stem death via MAPK signal-interacting kinase at rostral ventrolateral medulla

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    <p>Abstract</p> <p>Background</p> <p>As the origin of a life-and-death signal detected from systemic arterial pressure, which sequentially increases (pro-life) and decreases (pro-death) to reflect progressive dysfunction of central cardiovascular regulation during the advancement towards brain stem death in critically ill patients, the rostral ventrolateral medulla (RVLM) is a suitable neural substrate for mechanistic delineation of this fatal phenomenon. The present study assessed the hypothesis that extracellular signal-regulated kinase 1/2 (ERK1/2), a member of the mitogen-activated protein kinases (MAPKs) that is important for cell survival and is activated specifically by MAPK kinase 1/2 (MEK1/2), plays a pro-life role in RVLM during brain stem death. We further delineated the participation of MAPK signal-interacting kinase (MNK), a novel substrate of ERK in this process.</p> <p>Methods</p> <p>An experimental model of brain stem death that employed microinjection of the organophosphate insecticide mevinphos (Mev; 10 nmol) bilaterally into RVLM of Sprague-Dawley rats was used, in conjunction with cardiovascular, pharmacological and biochemical evaluations.</p> <p>Results</p> <p>Results from ELISA showed that whereas the total ERK1/2 was not affected, augmented phosphorylation of ERK1/2 at Thr202 and Tyr204 in RVLM occurred preferentially during the pro-life phase of experimental brain stem death. Furthermore, pretreatment by microinjection into the bilateral RVLM of a specific ERK2 inhibitor, ERK activation inhibitor peptide II (1 nmol); a specific MEK1/2 inhibitor, U0126 (5 pmol); or a specific MNK1/2 inhibitor, CGP57380 (5 pmol) exacerbated the hypotension and blunted the augmented life-and-death signals exhibited during the pro-life phase. Those pretreatments also blocked the upregulated nitric oxide synthase I (NOS I)/protein kinase G (PKG) signaling, the pro-life cascade that sustains central cardiovascular regulatory functions during experimental brain stem death.</p> <p>Conclusions</p> <p>Our results demonstrated that activation of MEK1/2, ERK1/2 and MNK1/2 in RVLM plays a preferential pro-life role by sustaining the central cardiovascular regulatory machinery during brain stem death via upregulation of NOS I/PKG signaling cascade in RVLM.</p

    Suppression of Cross-Band Scattering in Multiband Antenna Arrays

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    © 1963-2012 IEEE. This paper presents a novel method of suppressing cross-band scattering in dual-band dual-polarized antenna arrays. The method involves introducing chokes into low-band (LB) elements to suppress high-band (HB) scattering currents. The experimental results show that by inserting LB-pass HB-stop chokes into LB radiators, suppression of induced HB currents on the LB elements is achieved. This greatly reduces the pattern distortion of the HB array caused by the presence of LB elements. The array considered is configured as two columns of HB antennas operating from 1.71 to 2.28 GHz interleaved with a single column of LB antennas operating from 0.82 to 1.0 GHz. The realized array with choked LB element has stable and symmetrical radiation in both HB and LB

    Differential hepatic features presenting in Wilson disease-associated cirrhosis and hepatitis B-associated cirrhosis

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    © The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved. BACKGROUND Cirrhosis is a chronic late stage liver disease associated with hepatitis viruses, alcoholism, and metabolic disorders, such as Wilson disease (WD). There are no clear markers or clinical features that define cirrhosis originating from these disparate origins. We hypothesized that cirrhosis is not one disease and cirrhosis of different etiology may have differential clinical hepatic features. AIM To delineate the liver features between WD-associated cirrhosis and hepatitis Bassociated cirrhosis in the Chinese population. METHODS In this observational study, we reviewed the medical data of consecutive inpatients who had WD-associated cirrhosis or hepatitis B-associated cirrhosis from January 2010 to August 2018, and excluded patients who had carcinoma, severe heart or pulmonary diseases, or other liver diseases. According to the etiology of cirrhosis, patients were divided into two groups: WD-associated cirrhosis group (60 patients) and hepatitis B-associated cirrhosis group (56 patients). The liver fibrosis degree, liver function indices, and portal hypertension features of these patients were compared between the two groups. RESULTS No inter-group differences were observed in the diagnostic liver fibrosis markers, however, clinical features clearly defined the origin of cirrhosis. WD-associated cirrhosis patients (16-29 years) had lower levels of alanine transaminase, aspartate transaminase, and bilirubin, lower prothrombin time, lower incidence of hepatic encephalopathy, and lower portal vein diameter (P < 0.05), compared to cirrhosis resulting from hepatitis B in older patients (45-62 years). Importantly, they had decreased risks of progression from Child-Pugh grade A to B (odds ratio = 0.046, 95% confidence interval: 0.006-0.387, P = 0.005) and of ascites (odds ratio = 0.08, 95% confidence interval: 0.01-0.48, P = 0.005). Conversely, WDassociated cirrhosis patients had a higher risk of splenomegaly (odds ratio = 4.15, 95% confidence interval: 1.38-12.45, P = 0.011). CONCLUSION WD-associated cirrhosis presents a higher risk of splenomegaly associated with leukopenia and thrombocytopenia, although revealing milder liver dysfunction and portal hypertension symptoms, which recommends WD patients to be monitored for associated complications

    Synthesis of Polycyclic Aromatic Hydrocarbons by Phenyl Addition-Dehydrocyclization: The Third Way.

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    Polycyclic aromatic hydrocarbons (PAHs) represent the link between resonance-stabilized free radicals and carbonaceous nanoparticles generated in incomplete combustion processes and in circumstellar envelopes of carbon rich asymptotic giant branch (AGB) stars. Although these PAHs resemble building blocks of complex carbonaceous nanostructures, their fundamental formation mechanisms have remained elusive. By exploring these reaction mechanisms of the phenyl radical with biphenyl/naphthalene theoretically and experimentally, we provide compelling evidence on a novel phenyl-addition/dehydrocyclization (PAC) pathway leading to prototype PAHs: triphenylene and fluoranthene. PAC operates efficiently at high temperatures leading through rapid molecular mass growth processes to complex aromatic structures, which are difficult to synthesize by traditional pathways such as hydrogen-abstraction/acetylene-addition. The elucidation of the fundamental reactions leading to PAHs is necessary to facilitate an understanding of the origin and evolution of the molecular universe and of carbon in our galaxy

    Characterization of a hybrid powdered activated carbon-dynamic membrane bioreactor (PAC-DMBR) process with high flux by gravity flow: Operational performance and sludge properties

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    © 2016 Elsevier Ltd Three PAC-DMBRs were developed for wastewater treatment under different PAC dosages with biomass concentrations averaged at 2.5, 3.5 and 5.0 g/L. The DMBRs could be continuously operated at 40–100 L/m2 h, while higher fluxes were obtained within the PAC-DMBRs with hydraulic retention times varying in 4–10 h. A dose of 1 g/L PAC brought about obvious improvement in the sludge particle size distribution, settling, flocculating and dewatering properties due to the formation of biological PAC, and the sludge properties were further improved at a higher PAC dose (3 g/L). The addition of PAC notably shortened the DM formation time after air backwashing and enhanced pollutant removal. Moreover, under a long solid retention time (approximately 150 d), the concentrations of both soluble and bound extracellular polymeric substances (EPS) decreased substantially because of the adsorption and biodegradation effects of the biological PAC. No obvious impact on biomass activity was observed with PAC addition
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