A Compact Dual-Band MIMO Antenna for Sub-6 GHz 5G Terminals

In this paper, a dual-band multiple-input-multiple-output (MIMO) antenna is proposed for fifth-generation (5G) wireless communication terminals. The measured −10 dB impedance bandwidths of 380 MHz (3.34–3.72 GHz) and 560 MHz (4.57–5.13 GHz) can cover the 3.4–3.6 GHz and 4.8–5 GHz 5G bands. The single antenna element of this proposed MIMO is composed of an F-shaped feed strip and an inverted L-shaped radiation strip. A defected ground structure is employed to obtain a good isolation performance, whereby the measured isolation between the antenna elements is observed to be larger than 23 dB. The measured total radiation efficiencies at 3.5 GHz and 4.9 GHz are 76.65% and 71.93%, respectively. Besides, the calculated envelope correlation coefficients (ECC) are less than 0.00125 and 0.01164 at the low-frequency and high-frequency bands, respectively. Furthermore, the specific absorption ratio (SAR) analysis of the antenna verifies that it qualifies for 5G terminals

Multi-Layered Hydrogels for Biomedical Applications

Multi-layered hydrogels with organization of various functional layers have been the materials of choice for biomedical applications. This review summarized the recent progress of multi-layered hydrogels according to their preparation methods: layer-by-layer self-assembly technology, step-wise technique, photo-polymerization technique and sequential electrospinning technique. In addition, their morphology and biomedical applications were also introduced. At the end of this review, we discussed the current challenges to the development of multi-layered hydrogels and pointed out that 3D printing may provide a new platform for the design of multi-layered hydrogels and expand their applications in the biomedical field

The effect of layer thickness ratio on the drug release behavior of alternating layered composite prepared by layer-multiplying co-extrusion

Multi-layered drug delivery (MLDD) system has promising potential to achieve controlled release. However, existing technologies face difficulties in regulating the number of layers and layer-thickness ratio. In our previous works, layer-multiplying co-extrusion (LMCE) technology was applied to regulate the number of layers. Herein, we utilized layer-multiplying co-extrusion technology to modulate the layer-thickness ratio to expand the application of LMCE technology. Four-layered poly (ε-caprolactone)-metoprolol tartrate/poly (ε-caprolactone)-polyethylene oxide (PCL-MPT/PEO) composites were continuously prepared by LMCE technology, and the layer-thickness ratios for PCL-PEO layer and PCL-MPT layer were set to be 1:1, 2:1, and 3:1 just by controlling the screw conveying speed. The in vitro release test indicated that the rate of MPT release increased with decreasing the thickness of the PCL-MPT layer. Additionally, when PCL-MPT/PEO composite was sealed by epoxy resin to eliminate the edge effect, sustained release of MPT was achieved. The compression test confirmed the potential of PCL-MPT/PEO composites as bone scaffolds

Multiple Conformations of Phosphodiesterase-5: IMPLICATIONS FOR ENZYME FUNCTION AND DRUG DEVELOPMENT

Phosphodiesterase-5 (PDE5) is the target for sildenafil, vardenafil, and tadalafil, which are drugs for treatment of erectile dysfunction and pulmonary hypertension. We report here the crystal structures of a fully active catalytic domain of unliganded PDE5A1 and its complexes with sildenafil or icarisid II. These structures together with the PDE5A1-isobutyl-1-methylxanthine complex show that the H-loop ( residues 660-683) at the active site of PDE5A1 has four different conformations and migrates 7-35 angstrom upon inhibitor binding. In addition, the conformation of sildenafil reported herein differs significantly from those in the previous structures of chimerically hybridized or almost inactive PDE5. Mutagenesis and kinetic analyses confirm that the H-loop is particularly important for substrate recognition and that invariant Gly(659), which immediately precedes the H-loop, is critical for optimal substrate affinity and catalytic activity

A Low Profile Dual-Band High Gain Directional Antenna for Anti-Interference WLAN Station Applications

This paper presents a low-profile dual-band antenna with directional radiation characteristics for wireless local area network (WLAN) applications. The proposed directional antenna is composed of a coupling microstrip line, two F-shaped strips, two rectangular strips, and a defected ground plane. The measured impedance bandwidth of the proposed antenna is 180 MHz (2.33–2.51 GHz) and 830 MHz (5.09–5.92 GHz), which can cover Institute of Electrical and Electronic Engineers (IEEE) 802.11 a/b/g frequency bands. The dual-band antenna exhibits a desirable directional radiation patterns in the vertical and horizontal planes with the peak gain of 6.55 dBi in the lower frequency band and 8.1 dBi in the higher frequency band. The measured antenna efficiency is 70% at 2.4 GHz and 84.5% at 5.5 GHz. The proposed dual-band WLAN station antenna is designed on a FR4 substrate with overall dimensions of 69 mm × 50 mm × 1.6 mm

A Quad-Port Dual-Band MIMO Antenna Array for 5G Smartphone Applications

A quad-port antenna array operating in 3.5 GHz band (3.4–3.6 GHz) and 5 GHz band (4.8–5 GHz) for fifth-generation (5G) smartphone applications is presented in this paper. The single antenna element consists of an L-shaped strip, a parasitic rectangle strip, and a modified Z-shaped strip. To reserve space for 2G/3G/4G antennas, the quad-port antenna array is printed along the two long frames of the smartphone. The evolution design and the analysis of the optimal parameters of a single antenna element are derived to investigate the principle of the antenna. The prototype of the presented antenna is tested and the measured results agree well with the simulation. The measured total efficiency is better than 70% and the isolation is larger than 16.5 dB

Cellular signaling pathways modulated by low-intensity extracorporeal shock wave therapy

Low-intensity extracorporeal shock wave therapy (Li-ESWT) is a form of energy transfer that is of lower intensity (<0.2mJ/mm2) relative to traditional Extracorporeal Shock Wave Lithotripsy (ESWL) used for management of urinary stones. At this intensity and at appropriate dosing energy transfer is thought to induce beneficial effects in human tissues. The proposed therapeutic mechanisms of action for Li-ESWT include neovascularization, tissue regeneration, and reduction of inflammation. These effects are thought to be mediated by enhanced expression of vascular endothelial growth factor, endothelial nitric oxide synthase, and proliferating cell nuclear antigen. Upregulation of chemoattractant factors and recruitment/activation of stem/progenitor cells may also play a role. Li-ESWT has been studied for management of musculoskeletal disease, ischemic cardiovascular disorders, Peyronie's Disease, and more recently erectile dysfunction (ED). The underlying mechanism of Li-ESWT for treatment of ED is incompletely understood. We summarize the current evidence basis by which Li-ESWT is thought to enhance penile hemodynamics with an intention of outlining the fundamental mechanisms by which this therapy may help manage ED

Soil-Microbial CNP Content and Ecological Stoichiometry Characteristics of Typical Broad-Leaved Tree Communities in Fanjing Mountain in Spring

This study aims to investigate the impact of diverse forest stand types and soil depths on soil ecological stoichiometry characteristics, shedding light on nutrient limitations and cycling patterns within the mid-subtropical forest ecosystem in southwest China during spring. The research focused on four representative forest stands situated in Fanjing Mountain: Castanopsis fargesii (C. fargesii), Cyclobalanopsis multiervis (C. multiervis), Cyclobalanopsis argyrotricha (C. argyrotricha), and Rhododendron argyrophyllum Franch (R. argyrophyllum). Sample plots were established in these forest types, and soil samples were collected from the 0–20 cm and 20–40 cm soil layers in March, spring of 2023. Various soil parameters, including pH, soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), soil microbial biomass carbon (MBC), soil microbial nitrogen (MBN), and soil microbial phosphorus (MBP) were measured, and their stoichiometric ratios were calculated. The findings of the study were as follows: (1) In the 0–20 cm soil layer, C. argyrotricha exhibited the highest soil organic carbon, followed by C. fargesii, C. multiervis, and R. argyrophyllum with the lowest content. No significant differences in soil organic carbon were observed among the four forests in the 20–40 cm soil layer. Additionally, C. argyrotricha displayed a significantly higher soil C:N ratio compared to other forest types in different soil layers. In the typical broad-leaved forest area of Fanjing Mountain, the TP was classified as deficient. (2) In the 0–20 cm soil layer, the MBC of C. fargesii surpassed C. multiervis, C. argyrotricha, and R. argyrophyllum by 26.59%, 42.92%, and 24.67%, respectively. There were no significant differences in soil MBC:MBP ratio and MBN:MBP ratio, regardless of forest species and soil depths. The low availability of soil nitrogen in different forest stand types in Fanjing Mountain strongly limits soil microorganism biomass. (3) The correlation between SOC, TN, TP, and their stoichiometric ratios varied across different soil layers. Therefore, in managing the Fanjing Mountain forest area, attention should be paid to supplementing N and P in the soil

A Compact Ultra-Thin 4 × 4 Multiple-Input Multiple-Output Antenna

This article reported a compact ultra-thin tightly arranged 4 × 4 multiple-input multiple-output (MIMO) antenna pair (AP) functioning in the fifth-generation (5G) n78 band (3.4–3.6 GHz) for the ultra-thin 5G mobile handset. Two APs were printed on the center of two sideboards. A T-shaped open-ended slot was utilized in the grounding plane to improve the port impedance matching and attenuate the reciprocal magnetic coupling. A minimized total volume of 145 × 75 × 5 mm3 was obtained, and the area of each radiating unit was only 8.5 × 4.2 mm2 (0.1λ0 × 0.05λ0, λ0 is the free-space wavelength at the frequency of 3.5 GHz). By placing two radiating elements in an exceeding closed (1 mm or 0.01167λ0) distance, the designed AP precisely resonated at 3.5 GHz, and an acceptable measured isolation performance superior to 17 dB was attained. A prototype of this presented APs system was printed and tested, and remarkable consistency was observed between the simulated and measured curves. Numerous indicators were computed to assess its MIMO performance, such as Envelope Correlation Efficiency (ECC), Diversity Gain (DG), Total Active Reflection Coefficient (TARC), and Multiplexing Efficiency (ME)