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.
Liquid–liquid phase separation (LLPS) facilitates the formation of condensed biological assemblies with well-delineated physical boundaries, but without lipid membrane barriers. LLPS is increasingly ...recognized as a common mechanism for cells to organize and maintain different cellular compartments in addition to classical membrane-delimited organelles. Membraneless condensates have many distinct features that are not present in membrane-delimited organelles and that are likely indispensable for the viability and function of living cells. Malformation of membraneless condensates is increasingly linked to human diseases. In this review, we summarize commonly used methods to investigate various forms of LLPS occurring both in 3D aqueous solution and on 2D membrane bilayers, such as LLPS condensates arising from intrinsically disordered proteins or structured modular protein domains. We then discuss, in the context of comparisons with membrane-delimited organelles, the potential functional implications of membraneless condensate formation in cells. We close by highlighting some challenges in the field devoted to studying LLPS-mediated membraneless condensate formation.
Getting tougher in the ultracold Zhang, Peng; Zhang, Zhe-Feng
Science (American Association for the Advancement of Science),
12/2022, Letnik:
378, Številka:
6623
Journal Article
Recenzirano
Certain alloys show exceptional toughness in a liquid helium environment
The disastrous accident of the
Titanic
in 1912 occurred when the British ocean liner struck an iceberg and sank. Insufficient ...fracture resistance of the ship’s steel at low temperature ensured the ship’s demise (
1
). Thereafter, selection of materials with excellent cryogenic toughness became an important prerequisite for low-temperature, load-bearing applications. Despite progress in the understanding of fracture mechanics, most metallic materials show reduced toughness with decreasing temperatures (
2
), especially in the realm of the temperature of liquid helium (−269°C; 4.15 K). Thus, searching for tough alloys in cryogenic temperatures has remained a challenge. On page 978 of this issue, Liu
et al.
(
3
) report that certain alloys containing the metals chromium (Cr), cobalt (Co), and nickel (Ni) show exceptional fracture toughness at 20 K and attribute this property to a sequence of deformation mechanisms. These metal mixtures could potentially be used for applications in especially low temperatures, such as deep-space exploration (
4
).
All‐polymer solar cells (all‐PSCs) have received attention in recent years for their desirable properties in power conversion efficiency and long‐term operational stability. However, it is still a ...big challenge to acquire an “ideal” vertical‐phase distribution of polymer/polymer blends due to the non‐ideal molecular conformations and mixing behaviors. Herein, a ternary‐assisted sequential solution deposition (SSD) strategy is adopted to regulate the vertical compositional profile of all‐PSCs. A favorable acceptor(donor)‐enriched phase near the cathode(anode) can be obtained by a ternary‐assisted SSD strategy. With such a compositional profile, the exciton yield and carrier density can be enhanced by the vertical component gradient. Remarkably, the non‐geminate recombination is suppressed with an improved exciton diffusion length (15.36 nm) that delivers an outstanding power conversion efficiency over 16% of the ternary PM6/PY‐IT:PDI‐2T SSD devices. This work demonstrates the success of ternary‐assisted SSD strategy in reorganizing the vertical‐phase distribution, which provides a feasible route for a potential ternary device construction toward efficient all‐polymer photovoltaics.
A vertical compositional gradient within the active layer with a donor‐enriched active‐anode interface and an acceptor‐enriched active‐cathode interface can be achieved by sequential solution deposition treatment in PM6/PY‐IT:PDI‐2T device. As a result, charge transfer properties and exciton diffusion length are promoted with suppressed non‐geminate recombination to deliver an outstanding power conversion efficiency of 16% in the all‐polymer solar cells, which are verified with transient absorption, time‐resolved photoluminescence, and capacitance‐voltage measurements.
A reliable and low‐cost solution‐processing procedure to synthesize a highly adhesive flexible metal antenna with low resistivity for radio‐frequency identification device (RFID) tags on paper ...substrates via inkjet printing combined with surface modification and electroless deposition (ELD) is demonstrated in this paper. Through the surface modification of colloidal solution of hydrolyzed stannous chloride and chitosan solution, the paper‐based substrate is able to reduce the penetration rate of ink and further increase the adsorption amount of silver ions, which could create a catalytic activating layer to catalyze the subsequent ELD of a conductive deposited metal antenna. The resulting metal antenna for RFID tags presents good adhesive strength and low resistivity of 2.58 × 10−8 Ω·m after 40 min of ELD, and maintains a reliable reading range of RFID tags even after over 1000 times of bending and mechanical stress. Consequently, the developed technology proposed allows for cheap, efficient, and massive production of metal antenna for paper‐based RFID tags with excellent mechanical and electrical properties. Furthermore, this process is especially advantageous for the fabrication of next‐generation flexible electronic devices based on paper substrates.
A novel and efficient solution‐processing procedure combined with inkjet printing, surface modification, and electroless deposition is proposed for the fabrication of an outstanding flexible radio‐frequency identification device (RFID) tag metal antenna on a paper‐based substrate without high temperature or sophisticated manufacturing equipment. This method is a low‐cost and portable fabrication route for RFID antennas, which is promising for large‐scale commercial manufacturing.
In experimental research a scientific conclusion is always drawn from the statistical testing of hypothesis, in which an acceptable cutoff of probability, such as 0.05 or 0.01, is used for ...decision-making. However, the probability of committing false statistical inferences would considerably increase when more than one hypothesis is simultaneously tested (namely the multiple comparisons), which therefore requires proper adjustment. Although the adjustment for multiple comparisons is proposed to be mandatory in some journals, it still remains difficult to select a proper method suitable for the various experimental properties and study purposes, especially for researchers without good background in statistics. In the present paper, we provide a brief review on mathematical framework, general concepts and common methods of adjustment for multiple comparisons, which is expected to facilitate the understanding and selection of adjustment methods.
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.
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.
Recent advances in organic photodetectors (OPDs) have enabled high detectivity, high quantum efficiency, and fast response, due to their broad spectral response, easy processing, compatibility with ...flexible devices, and cooling‐free operations. The advantages of combining ultrathin and self‐powered OPDs are rarely explored, as technological limitations and lack of knowledge on the underlying mechanisms may lead to low light absorption efficiency and carrier recombination issues. Here, a modification layer‐assisted approach is developed to construct ultrathin self‐powered OPDs with enhanced sensitivity and ultrafast response time performance due to efficient exciton dissociation, energy transfer, and charge extraction processes. Specifically, this strategy enables a reduced exciton binding energy (42.4 meV) for efficient dissociation, as well as an increased dielectric constant of the photosensitive layer that shields undesirable lattice binding effects of photogenerated excitons. As a result, a remarkable device responsivity (0.45 A W−1), improved response detectivity (1.25 × 1012 Jones), and enhanced energy transfer efficiency (78.7%) are observed in the modified ultrathin organic photodetector. These findings illustrate a clear correlation between the exciton dissociation process, photogenerated exciton yields, and energy transfer channels, providing essential insight into the design of efficient ultrathin organic photodetectors.
An ultrathin (≈10 nm) self‐powered organic photodetector with high performance is constructed using the modification layer‐assisted strategy. The exciton binding energy reduction is achieved by shielding undesirable lattice binding effects, and it is revealed that efficient exciton dissociation and Föster energy transfer processes are key factors to achieve optimized performance of the self‐powered photodetector.
In vivo fluorescence imaging in the second near-infrared window (NIR-II) has been considered as a promising technique for visualizing mammals. However, the definition of the NIR-II region and the ...mechanism accounting for the excellent performance still need to be perfected. Herein, we simulate the photon propagation in the NIR region (to 2340 nm), confirm the positive contribution of moderate light absorption by water in intravital imaging and perfect the NIR-II window as 900-1880 nm, where 1400-1500 and 1700-1880 nm are defined as NIR-IIx and NIR-IIc regions, respectively. Moreover, 2080-2340 nm is newly proposed as the third near-infrared (NIR-III) window, which is believed to provide the best imaging quality. The wide-field fluorescence microscopy in the brain is performed around the NIR-IIx region, with excellent optical sectioning strength and the largest imaging depth of intravital NIR-II fluorescence microscopy to date. We also propose 1400 nm long-pass detection in off-peak NIR-II imaging whose performance exceeds that of NIR-IIb imaging, using bright fluorophores with short emission wavelength.
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