5,557 research outputs found

    Frequency-Reconfigurable Antenna using Metasurface

    Get PDF
    A frequency-reconfigurable antenna designed using metasurface (MS) to operate at around 5 GHz is proposed and studied. The frequency-reconfigurable metasurfaced (FRMS) antenna is composed of a simple circular patch antenna and a circular MS with the same diameter of 40 mm (0.67 λ) and implemented using planar technology. The MS is placed directly atop the patch antenna, making the FRMS antenna very compact and low profile with a thickness of only 3.048 mm (0.05 λ). The MS consists of rectangular-loop unit cells placed periodically in the vertical and horizontal directions. Simulation results show that the operating frequency of the antenna can be tuned by physically rotating the MS around the center with respect to the patch antenna. The MS placed atop the patch antenna behaves like a dielectric substrate and rotating the MS changes the equivalent relative permittivity of the substrate and hence the operating frequency of the FRMS antenna. Measured results show that the antenna has a tuning range from 4.76 to 5.51 GHz, a fractional tuning range of 14.6%, radiation efficiency and a realized peak gain of more than 80% and 5 dBi, respectively, across the tuning range. © 2013 IEEE.published_or_final_versio

    A novel base station antenna based on rectangular waveguide

    Full text link
    © 2016 IEICE. A novel base station antenna element is proposed. It consists of a surface of parallel strips to rotate the polarization direction and a segment of a rectangular waveguide. The surface is designed on a single-sided substrate, which has the same area as the aperture of the waveguide. In assembling, the non-copper side of the substrate is placed in direct contact with the aperture of the waveguide antenna. To achieve the polarization rotation, the parallel strips on the surface are rotated by 45° with respect to the walls of the waveguide antenna. By adding the surface, the linear polarization direction of the rectangular waveguide antenna is rotated by 45° to comply with the requirements of cellular industry. SMA connector with a conical probe is used as the coaxial-to-waveguide adaptor. Results have shown that the proposed antenna has a fractional impedance bandwidth of 35%, and a stable radiation pattern is also achieved

    ENHANCEMENT OF WOUND HEALING BY TOPICAL APPLICATION OF EPIDERMAL GROWTH FACTOR IN ANIMAL MODEL

    Get PDF
    Objective: Wound healing is a complex process of biological events involving re-epithelialization and granulation that are mainly mediated by several endogenously released growth factors such as epidermal growth factor. This work was undertaken to study the effects of various doses of locally applied recombinant human epidermal growth factor (rhEGF) on wound healing in rats. Methods: Recombinant human EGF consists of 53 amino acids. In vitro, rhEGF promoted its obvious cell growth and proliferation when added to cultured 3T3 cells using MTT assay. In the test groups, in vivo, wound sites were given daily with a solution containing 2, 5, 10, 50ug of EGF spray and 40ug of EGF ointment, respectively. Results: Current study presented evidence that a significant decreased healing time in wound was observed in all rhEGF groups when compared with the control, and reach to its maximal efficacy at 10ug/ml of rhEGF spray. The rate of wound closure was over 50% at initial 3 days of treatment. Treatment with rhEGF significantly decreased the length of time to over 50% healing by approximately 4-5 days, and that to 70% and 90% healing by approximately 3-4 days and 3 days, respectively. A stimulatory, dose-dependent effect of EGF on wound healing was observed with increased hEGF concentration. In toxicological group, higher doses of 100ug/ml of rhEGF spray was applied by local dorsal incision in rats. Moreover, a dose of single 200ug, single 300ug or 300ug within 24 hrs of subcutaneous and intramuscular rhEGF injection was given respectively. There were no significant adverse side effects. Conclusion: Current study recommended a proposal of clinical drug doses in wound at 2µg, 5 µg and 10 µg /ml of rhEGF spray, and 10 µg and even higher 40 µg rhEGF/g of ointment. The results indicated that prepared rhEGF by genetic engineering in current study is safe, and is emerging in clinical effective use in assisting wound healing time.                             Peer Review History: Received 8 January 2020;   Revised 12 February; Accepted 2 March, Available online 15 March 2020 Academic Editor: Dr. Ali Abdullah Al-yahawi, Al-Razi university, Department of Pharmacy, Yemen, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.5/10 Average Peer review marks at publication stage: 8.5/10 Reviewer(s) detail: Asmaa Ahmed Mohamed Ahmed Khalifa, Pharos University, Alexandria, Egypt, [email protected] Dr. Sabah Hussien El-Ghaiesh , Tanta University, Egypt, [email protected] Similar Articles: POTENTIAL OF SNAKEHEAD FISH (OPHIOCEPHALUS STRIATUS) IN ACCELERATING WOUND HEALIN

    A General Design Rule to Manipulate Photocarrier Transport Path in Solar Cells and Its Realization by the Plasmonic-Electrical Effect

    Get PDF
    It is well known that transport paths of photocarriers (electrons and holes) before collected by electrodes strongly affect bulk recombination and thus electrical properties of solar cells, including open-circuit voltage and fill factor. For boosting device performance, a general design rule, tailored to arbitrary electron to hole mobility ratio, is proposed to decide the transport paths of photocarriers. Due to a unique ability to localize and concentrate light, plasmonics is explored to manipulate photocarrier transport through spatially redistributing light absorption at the active layer of devices. Without changing the active materials, we conceive a plasmonic-electrical concept, which tunes electrical properties of solar cells via the plasmon-modified optical field distribution, to realize the design rule. Incorporating spectrally and spatially configurable metallic nanostructures, thin-film solar cells are theoretically modelled and experimentally fabricated to validate the design rule and verify the plasmonic-tunable electrical properties. The general design rule, together with the plasmonic-electrical effect, contributes to the evolution of emerging photovoltaics.published_or_final_versio

    Impact factors for curved continuous CFST truss girder bridges

    Full text link
    © 13th International Conference on Shock and Impact Loads on Structures, SILOS 2019. All Rights Reserved. A finite element model for curved continuous concrete-filled steel tubular (CFST) composite truss girder bridges has been built, and a new iterative process has been proposed for the analysis of the vehicle-bridge coupled system. The vibration modes and impact factors of the curved continuous CFST composite truss girder bridge have been obtained. The effects of parameters on the impact factors, such as the vehicle speed and deck unevenness, have been studied. The results show that the impact factor of the bridge is much larger than the value calculated from the current design code. The resonant critical vehicle speed and the resonant critical loading position are varied for different girder spans. The vehicle speed limit cannot effectively reduce the dynamic impact, and the bridge deck roughness excitation has an amplification effect on the impact factor causing by resonance. The results in this study are useful for design consideration and maintenance of CFST composite truss girder bridges

    Polarization-Rotated Waveguide Antennas for Base-Station Applications

    Full text link
    © 2017 IEEE. A novel base-station antenna element is proposed. It consists of an artificial surface composed of parallel strips rotating in the polarization direction and a segment of a rectangular waveguide. The surface is designed on a single-sided substrate, which has the same area as the aperture of the waveguide. To achieve the polarization rotation, the parallel strips on the surface are rotated by 45° with respect to the orientation of the waveguide antenna. By adding the surface, the linear polarization direction of the rectangular waveguide antenna rotates by 45° to comply with the requirements of the cellular industry. To verify the simulation results, the proposed antenna was fabricated and measured. Results show that the antenna has an operating bandwidth from 698-960 MHz, where a stable radiation pattern is achieved

    视觉分散和视听分散对接受结肠镜检病人焦虑和接受性的影响

    Get PDF
    2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Long term survivors with metastatic pancreatic adenocarcinoma treated with gemcitabine: a retrospective analysis

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Metastatic pancreatic adenocarcinoma has a short median overall survival (OS) of 5–6 months. However, a subgroup of patients survives more than 1 year. We analyzed the survival outcomes of this subgroup and evaluated clinical and pathological factors that might affect survival durations.</p> <p>Methods</p> <p>We identified 20 patients with metastatic or recurrent pancreatic adenocarcinoma who received single-agent gemcitabine and had an OS longer than 1 year. Baseline data available after the diagnosis of metastatic or recurrent disease was categorized as: 1) <it>clinical/demographic data </it>(age, gender, ECOG PS, number and location of metastatic sites); 2) <it>Laboratory data </it>(Hematocrit, hemoglobin, glucose, LDH, renal and liver function and CA19-9); 3) <it>Pathologic data </it>(margins, nodal status and grade); 4) <it>Outcomes data </it>(OS, Time to Treatment Failure (TTF), and 2 year-OS). The lowest CA19-9 levels during treatment with gemcitabine were also recorded. We performed a univariate analysis with OS as the outcome variable.</p> <p>Results</p> <p>Baseline logarithm of CA19-9 and total bilirubin had a significant impact on OS (HR = 1.32 and 1.31, respectively). Median OS and TTF on gemcitabine were 26.9 (95% CI = 18 to 32) and 11.5 (95% CI = 9.0 to 14.3) months, respectively. Two-year OS was 56.4%, with 7 patients alive at the time of analysis.</p> <p>Conclusion</p> <p>A subgroup of patients with metastatic pancreatic cancer has prolonged survival after treatment with gemcitabine. Only bilirubin and CA 19-9 levels were predictive of longer survival in this population. Further analysis of potential prognostic and predictive markers of response to treatment and survival are needed.</p

    A Self-Reference False Memory Effect in the DRM Paradigm: Evidence from Eastern and Western Samples

    Get PDF
    It is well established that processing information in relation to oneself (i.e., selfreferencing) leads to better memory for that information than processing that same information in relation to others (i.e., other-referencing). However, it is unknown whether self-referencing also leads to more false memories than other-referencing. In the current two experiments with European and East Asian samples, we presented participants the Deese-Roediger/McDermott (DRM) lists together with their own name or other people’s name (i.e., “Trump” in Experiment 1 and “Li Ming” in Experiment 2). We found consistent results across the two experiments; that is, in the self-reference condition, participants had higher true and false memory rates compared to those in the other-reference condition. Moreover, we found that selfreferencing did not exhibit superior mnemonic advantage in terms of net accuracy compared to other-referencing and neutral conditions. These findings are discussed in terms of theoretical frameworks such as spreading activation theories and the fuzzytrace theory. We propose that our results reflect the adaptive nature of memory in the sense that cognitive processes that increase mnemonic efficiency may also increase susceptibility to associative false memories
    corecore