Circularly Polarized Antenna with Reconfigurable Broadside and Conical Beams Facilitated by a Mode Switchable Feed Network

© 1963-2012 IEEE. A pattern-reconfigurable slot-augmented patch antenna is reported that radiates circularly polarized (CP) fields and is switchable between a broadside and a conical radiating mode. Two novel design strategies were adopted to realize these advantageous performance characteristics. First, a mode switchable feed network which includes a set of eight L-probes was developed that facilitates the proper excitation of either the patch's TM11 or TM21 mode and yields symmetric radiation patterns. Second, their operating bands were made to overlap by augmenting this patch with an annular slot. Consequently, the radiation pattern is easily switched between the broadside and the conical modes within the overlapping operational bandwidths. A prototype was fabricated and tested. The measured results are in good agreement with their simulated values, verifying the design concepts. The measured operating bandwidth, 7.8% from 2.45 to 2.65 GHz, was determined from the overlap of the impedance and axial ratio bandwidths for both modes. The measured realized gain values are stable for both radiating states within this operational bandwidth, the broadside (conical) peak value being 8.5 dBic (5.8 dBic). The CP pattern reconfigurability of this antenna with its favorable performance characteristics makes it an ideal candidate for many RFID and satellite communication applications

Pattern reconfigurable techniques for LP and CP antennas with the broadside and conical beams

© Institution of Engineering and Technology.All Rights Reserved. This paper presents two pattern reconfigurable techniques to realize linear (LP) and circular (CP) broadside and conical-beam switchable radiation patterns from a single antenna. First, a wideband monopolar patch and a L-probe fed patch were organically integrated together to achieve a wideband (2.25 to 2.85 GHz) broadside and conical-beam pattern reconfigurable system that radiates LP radiation. Radiation coverage and wireless channel capacity were improved significantly making the reported LP antenna a good candidate as a ceiling mounted antenna for indoor wireless communications. On the other hand, a circularly-polarized (CP) broadside and conical-beam reconfigurable antenna would be preferred for satellite communications. To realize it, we successfully excited both the TM11 and TM21 modes on a circular patch with an annular slot antenna. A reconfigurable feeding network was designed to provide the correct excitations for these two modes. CP switchable broadside and conical radiated beams were realized within the same overlapping frequency ranges from 2.45 to 2.65 GHz. Both the LP and CP antennas were fabricated and tested. Experimental results show good agreement with their simulated performance characteristics. Very good radiation performance was obtained

Physical Layer Security in Large-Scale Millimeter Wave Ad Hoc Networks

Wireless networks with directional antennas, like millimeter wave (mmWave) networks, have enhanced security. For a large scale mmWave ad hoc network in which eavesdroppers are randomly located, however, eavesdroppers can still intercept the confidential messages, since they may reside in the signal beam. This paper explores the potential of physical layer security in the mmWave ad hoc networks. Specifically, we characterize the impact of mmWave channel characteristics and large antenna arrays on the secrecy performance. We also characterize the impact of artificial noise in this networks. Our results reveal that in the low transmit power regime, the use of low mmWave frequency achieves better secrecy performance, when increasing transmit power, a transition from low mmWave frequency to high mmWave frequency is demanded for obtaining more secrecy rate. Eavesdroppers can intercept more information by using wide beam pattern. Furthermore, the use of artificial noise may be unable to enhance the secrecy rate for the case of low node density

The development and initial validation of the Chinese Significant Wish Fulfillment Scale

This paper reports the development and validation of the Chinese Significant Wish Fulfillment Scale (CSWFS), a new multidimensional scale for assessing the perceived importance and level of fulfillment of wishes of older adults. Three studies were involved. Study 1 developed a 26-item pool on wish fulfillment through in-depth interviews with 22 older adults. Study 2 reduced the pool to 23 items through validation with a new sample of 315 older adults and examined the internal reliability. Study 3 involved a confirmatory factor analysis (CFA) and examined the test-retest reliability and the convergent validity of the scale with the construct of regret. A five-factor structure model of 23 items was identified through exploratory factor analysis, which accounted for 51.67% of variance. As informed by the CFA in Study 3, a five-factor 22-item model was the best fit. Internal reliability and test-retest reliability was found to be good. Convergent validity was examined through correlation with the construct of future regret. The correlation, though statistically significant, was small. CSWFS demonstrates good psychometric properties, but the construct might be slightly different from that of future regrets. Probably, CSWFS addresses a construct that is under-explored but is of importance to older adults and especially to the Chinese community.published_or_final_versio

Wideband Pattern-Reconfigurable Antenna with Switchable Broadside and Conical Beams

© 2017 IEEE. A wideband, pattern-reconfigurable antenna is reported that is, for example, a good candidate for ceiling-mounted indoor wireless systems. Switchable linearly polarized broadside and conical radiation patterns are achieved by systematically integrating a wideband low-profile monopolar patch antenna with a wideband L-probe fed patch antenna. The monopolar patch acts as the ground for the L-probe fed patch, which is fed with a coaxial cable that replaces one shorting via of the monopolar patch to avoid deterioration of the conical-beam pattern. A simple switching feed network facilitates the pattern reconfigurability. A prototype was fabricated and tested. The measured results confirm the predicted wideband radiation performance. The operational impedance bandwidth, i.e., S 11 ≤-10 dB, is obtained as the overlap of the bands associated with both pattern modalities. It is wide, from 2.25 to 2.85 GHz (23.5%). Switchable broadside and conical radiation patterns are observed across this entire operating bandwidth. The peak measured gain was 8.2 dBi for the broadside mode and 6.9 dBi for the conical mode. The overall profile of this antenna is 0.13λ 0 at its lowest operating frequency

ZNF750 is a lineage-specific tumour suppressor in squamous cell carcinoma.

ZNF750 controls epithelial homeostasis by regulating epidermal-differentiation genes, a role underscored by its pathogenic mutations in esophageal squamous cell cancers (SCCs). However, the precise role of ZNF750 in SCC cell biology remains unclear. In this study, we report that ZNF750 is exclusively deleted, mutated and underexpressed in human SCCs, and low ZNF750 expression is associated with poor survival. Restoration of wildtype, but not mutant ZNF750 protein uniquely inhibited the malignant phenotypes of SCC cells both in vitro and in vivo. Notably, ZNF750 promoted the expression of a long non-coding RNA (TINCR), which mediated both cancer-inhibition and differentiation-induction effects of ZNF750. In addition, ZNF750 potently suppressed cell migration by directly inhibiting the transactivation of LAMC2. Together, our findings characterize ZNF750 as a crucial SCC-specific suppressor and uncover its novel anticancer-associated functions

The mediating role of individual-level social capital among worries, mental health and subjective well-being among adults in Hong Kong during the COVID-19 pandemic

The COVID-19 pandemic has substantially induced worries and affected individual mental health and subjective well-being. Nonetheless, a high level of social capital could potentially protect individuals who suffer from mental health problems and thus promote their subjective well-being, especially under the social distancing policies during the pandemic. To this end, based on a random sample of 1053 Hong Kong adults, structural equation modeling was applied to study the path relationships between the worries of COVID-19, social capital, mental health problems, and subjective well-being. The study found that worries during the pandemic were associated with mental health and subjective well-being, through social capital as a mediator. Moreover, social capital exhibited a stronger influence on mental health and subjective well-being in the economically inactive group than in the economically active group. This study highlights the important role of social capital during the COVID-19 pandemic. While Hong Kong’s COVID-19 response has primarily focused on disease prevention, it must be noted that social services and mutual-help activities are also crucial for people to withstand the crisis

Locally applied Simvastatin improves fracture healing in mice

<p>Abstract</p> <p>Background</p> <p>HMG-CoA reductase inhibitors, statins, are widely prescribed to lower cholesterol. High doses of orally administered simvastatin has previously been shown to improve fracture healing in a mouse femur fracture model. In this study, simvastatin was administered either subcutaneously or directly to the fracture area, with the goal of stimulating fracture repair at acceptable doses.</p> <p>Methods</p> <p>Femur fractures were produced in 70 mature male Balb-C mice and stabilized with marrow-nailing. Three experiments were performed. Firstly, 20 mice received subcutaneous injections of either simvastatin (20 mg) or vehicle. Secondly, 30 mice were divided into three groups of 10 mice receiving continuous subcutaneous delivery of the vehicle substance, the vehicle with 5 mg or with 10 mg of simvastatin per kg bodyweight per day. Finally, in 20 mice, a silicone tube was led from an osmotic mini-pump to the fracture area. In this way, 10 mice received an approximate local dose of simvastatin of 0.1 mg per kg per day for the duration of the experiment and 10 mice received the vehicle compound. All treatments lasted until the end of the experiment. Bilateral femurs were harvested 14 days post-operative. Biomechanical tests were performed by way of three-point bending. Data was analysed with ANOVA, Scheffé's post-hoc test and Student's unpaired t-test.</p> <p>Results</p> <p>With daily simvastatin injections, no effects could be demonstrated for any of the parameters examined. Continuous systemic delivery resulted in a 160% larger force at failure. Continuous local delivery of simvastatin resulted in a 170% larger force at failure as well as a twofold larger energy uptake.</p> <p>Conclusion</p> <p>This study found a dramatic positive effect on biomechanical parameters of fracture healing by simvastatin treatment directly applied to the fracture area.</p