A dual-polarized hybrid eight-antenna array operating in the 2.6-GHz band (2550-2650 MHz) for 5G communication multi-input multi-output (MIMO) operation in the smartphone is presented. The proposed ...hybrid antenna array elements are symmetrically placed along the long edges of the smartphone, and they are composed of two different four-antenna array types (C-shaped coupled-fed and L-shaped monopole slot) that exhibit orthogonal polarization. Therefore, coupling between the two antenna array types can be reduced, and the MIMO system performances are enhanced. A prototype of the proposed eight-antenna array is manufactured and measured. A good impedance matching (10 dB return loss or better), desirable cross-polarization discrimination (better than 15 dB), and an acceptable isolation (better than 12.5 dB) are obtained. Envelope correlation coefficient and channel capacity are also calculated to evaluate the MIMO performances of the proposed antenna array.
A tri-polarized 12-antenna array working in the 3.5-GHz band (3.4-3.6 GHz) for future 5G (the fifth generation mobile communication) multiple-input multiple-output (MIMO) operations in the smartphone ...is presented. In order to reduce the mutual couplings and simplify the design process, orthogonal polarization technique is utilized. By combining a quarter mode substrate integrated wave-guide antenna and two open-end slots, a compact 3-antenna tri-polarization block operating in the 3.5-GHz band is achieved within a small volume of <inline-formula> <tex-math notation="LaTeX">17\times 17\times6 </tex-math></inline-formula> mm 3 . Thanks to the orthogonal polarization features, the three antennas within the block are able to have good impedance matchings and low mutual couplings between antennas. By integrating four such tri-polarization blocks, a 12-antenna MIMO array is then designed for smartphone applications. It is also due to the tri-polarization feature, the proposed array could attain acceptable isolations and low correlations between antennas with only two additional decoupling structures. The proposed array is fabricated and tested, good antenna performances, such as return loss better than 10 dB, isolation higher than 12.5 dB, and antenna efficiencies higher than 50%, are obtained. The channel capacity of the 12-antenna array is calculated to be about 57 bps/Hz in a <inline-formula> <tex-math notation="LaTeX">12\times12 </tex-math></inline-formula> MIMO system with 20-dB signal-to-noise ratio, which indicates the proposed array using tri-polarization technique is a good choice for future 5G terminals.
Objective
To examine the use of platelet-rich plasma (PRP) for treatment of pilonidal disease (PD) and thus provide a reference for clinical application.
Methods
A systematic review of PubMed and the ...Cochrane Library was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We considered all studies that reported the use of PRP for treatment of PD. Extracted data included the first author’s name, year of publication, study type, number of included patients, inclusion and exclusion criteria, interventions, anesthesia, application of PRP (source, preparation, dose, and operation), antibiotics, follow-up time, therapeutic outcomes, and adverse events.
Results
In total, eight randomized controlled trials and one prospective cohort study involving 809 patients were included. PRP reduced pain, accelerated healing, and reduced adverse events. The application of combined minimally invasive surgery achieved better results. However, overfilling of the wound with PRP in minimally invasive surgeries was shown to potentially increase the risk of adverse events.
Conclusion
PRP can be used as an adjuvant treatment in PD surgery to improve the therapeutic effect and reduce adverse events. The optimal combination of PRP and various factors is an important direction of future research.
INPLASY registration number: INPLASY2023100070.
Aims and objectives
To investigate the interrelationships between workplace violence, thriving at work and turnover intention among Chinese nurses and to explore the action mechanism among these ...variables.
Background
Workplace violence is a dangerous occupational hazard globally, and it is pervasive in the health service industry. As a corollary, workplace violence may produce many negative outcomes among nursing staff. Consequently, it hinders nurses’ professional performance and reduces nursing quality.
Design
A cross‐sectional online survey was conducted.
Methods
A total of 1,024 nurses from 26 cities in China were recruited from February–May 2016. An anonymous questionnaire was used in this survey. Participants’ completed data were collected using a demographics form and a 26‐item questionnaire consisting of scales addressing workplace violence, thriving at work, job satisfaction, subjective well‐being and turnover intention. To evaluate multivariate relationships, some multiple linear hierarchical regression analyses were performed.
Results
Workplace violence significantly negatively influenced nurses’ job satisfaction and thriving at work, and significantly positively influenced nurses’ turnover intention. Job satisfaction significantly predicted thriving at work and turnover intention. Job satisfaction not only fully mediated the relationship between workplace violence and thriving at work, but also partially mediated the relationship between workplace violence and turnover intention. Subjective well‐being moderated the relationship between workplace violence and job satisfaction and the relationship between workplace violence and nurses’ turnover intention.
Conclusions
Adverse effects of workplace violence were demonstrated in this study. Decreases in job satisfaction were a vital mediating factor. The moderating effect of subjective well‐being was helpful in reducing the harm of workplace violence to nurses and in decreasing their turnover intention.
Relevance to clinical practice
Workplace violence and its negative impact on nursing work should not go unnoticed by nursing managers. Nurses’ subjective well‐being is critical in controlling and mitigating the adverse effects of workplace violence.
A planar millimeter-wave 2-D beam-scanning multibeam array antenna fed by compact 16-way beam-forming network (BFN) in multilayered substrate integrated waveguide (SIW) technology is addressed. The ...BFN is formed by connecting two stacks of sub-BFNs, the E-plane sub-BFN and the H-plane sub-BFN. The H-plane sub-BFN is realized by a traditional H-plane <inline-formula> <tex-math notation="LaTeX">4 \times 4 </tex-math></inline-formula> Butler matrix (BM). The key point of this design is to propose an E-plane <inline-formula> <tex-math notation="LaTeX">4 \times 4 </tex-math></inline-formula> BM which realizes a planar E-plane sub-BFN. These two sets of sub-BFNs can joint directly without resorting to any connectors or connecting networks to form such a compact 16-way BFN with a reduced area of merely <inline-formula> <tex-math notation="LaTeX">3\lambda \times 12\lambda </tex-math></inline-formula>. After that, to be compatible with the proposed BFN, a ladder-type <inline-formula> <tex-math notation="LaTeX">4 \times 4 </tex-math></inline-formula> slot antenna array is employed, which is comprised of four linear <inline-formula> <tex-math notation="LaTeX">1 \times 4 </tex-math></inline-formula> slot antenna arrays. Different from traditional array, the four subarrays are distributed in separate layers for the purpose of jointing to the BFN more conveniently. Transition network are also required to connect the BFN with the antenna array. Finally, a compact 2-D scanning multibeam array antenna based on the planar SIW BFN are fabricated and measured, which would be an attractive candidate for 5G application.
This letter presents a compact dual-layer 4 × 8 Butler matrix (BM) with sidelobe level (SLL) suppression in substrate-integrated waveguide (SIW) technology. Addressing the excessive crossovers in the ...classic 4 × 8 BM, a novel dual-layer configuration is proposed here. Such a configuration can help reduce the required crossovers from original five sets to merely one set. Therefore, the 4 × 8 BM can be significantly simplified to achieve better compactness. Based on this configuration, a SIW dual-layer 4 × 8 BM is designed with a dimension of 6.1 λ × 4.1 λ. To evaluate its SLL suppression effect, a multibeam array fed by the proposed BM is designed, simulated, and measured.
An eight-port antenna array designed for future 5G 2.6 GHz band (2550–2650 MHz) for multi-input multi-output (MIMO) in the smartphone applications is presented. In order to enhance the port isolation ...and reduce correlation between antennas, square loop radiating strip with orthogonal polarisation is employed. The proposed antenna array is composed of four pairs of uniform antenna elements that are symmetrically placed at the four corners of the main board, and each antenna pair includes a communal square loop and two independently coupled feeding strips. By exciting the square loop from the two feeding strips, respectively, two orthogonally polarised waves are generated. Thus, four horizontally polarised and four vertically polarised antennas are achieved in total. Due to this feature, coupling between antenna pairs is reduced and the MIMO performances are enhanced. A prototype of the proposed antenna array was fabricated, and the experimental results show good impedance matching and acceptable isolation measured across the bands of interest. The MIMO performances such as envelope correlation coefficient, mean effective gain, multiplexing efficiency and channel capacity are also calculated. Besides, simulations of the antenna shifted to 3.5 GHz are also performed. The consistent performances indicate that the proposed structure has good scalability and is promising for future 5G smartphone applications.
This letter presents a multibeam antenna array fed by a substrate integrated waveguide 8 × 8 dual-layer Butler matrix within the band from 28 to 31 GHz. The dual-layer structure is adopted aiming to ...achieve miniature, so that the size of the structure is reduced by more than 50% compared with similar single-layer design. The utilization of dual-layer structure also decreases the complexity of the whole Butler matrix. A 2 × 8 slot antenna array is used as the radiating portion to obtain high gains and relatively low side lobe levels. The proposed multibeam antenna array is fabricated and tested to verify the performances.
Light olefins are key components of modern chemical industry and are feedstocks for the production of many commodity chemicals widely used in our daily life. It would be of great economic ...significance to convert light alkanes, produced during the refining of crude oil or extracted during the processing of natural gas selectively to value-added products, such as light alkenes, aromatic hydrocarbons, etc., through catalytic dehydrogenation. Among various catalysts developed, Ga-modified ZSM-5-based catalysts exhibit superior catalytic performance and stability in dehydrogenation of light alkanes. In this mini review, we summarize the progress on synthesis and application of Ga-modified ZSM-5 as catalysts in dehydrogenation of light alkanes to olefins, and the dehydroaromatization to aromatics in the past two decades, as well as the discussions on in-situ formation and evolution of reactive Ga species as catalytic centers and the reaction mechanisms.
Sieb. et Zucc. is part of the genus
of the family
. Ripening and dry fruits (
) are recognized as an essential herb medicine in the traditional Chinese medicine (TCM) and have been widely used for ...over 2000 years. This review provides a comprehensive summary of
(CF), including the botany, phytochemistry, traditional use, and current pharmacological activities. According to the basic theory of TCM, CF usually participates in various Chinese medicinal formulae to exert the essential roles in replenishing liver and kidney, arresting seminal emission and sweat. Based on modern pharmacological studies, about 90 compounds have been isolated and identified from CF. In vivo and in vitro experimental studies indicate that CF exhibits extensive pharmacological activities including hypoglycemic, antioxidant, anti-inflammatory, anticancer, neuroprotective, hepatoprotective, and nephroprotective activities. However, only about 18% of chemical constituents in CF were tested. It means the potential pharmacological activities and clinical values of CF need to be further investigated.
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