Bone grafts have been predominated used to treat bone defects, delayed union or non-union, and spinal fusion in orthopaedic clinically for a period of time, despite the emergency of synthetic bone ...graft substitutes. Nevertheless, the integration of allogeneic grafts and synthetic substitutes with host bone was found jeopardized in long-term follow-up studies. Hence, the enhancement of osteointegration of these grafts and substitutes with host bone is considerably important. To address this problem, addition of various growth factors, such as bone morphogenetic proteins (BMPs), parathyroid hormone (PTH) and platelet rich plasma (PRP), into structural allografts and synthetic substitutes have been considered. Although clinical applications of these factors have exhibited good bone formation, their further application was limited due to high cost and potential adverse side effects. Alternatively, bioinorganic ions such as magnesium, strontium and zinc are considered as alternative of osteogenic biological factors. Hence, this paper aims to review the currently available bone grafts and bone substitutes as well as the biological and bio-inorganic factors for the treatments of bone defect.
Most common specific targets of relevant bioinorganic ions in their role of therapeutic agents revealed by current researches 273. Display omitted
•Autologous bone graft is the gold standard clinical material for bone regeneration in term of osteoconduction and osteoinduction. However, limited availability and donor site morbidity are concerned.•Bone allograft becomes to the second higher option for orthopaedic procedures due to the availability in various forms and large quantities. Unfortunately, reduced osteoinductivity may lead to inferior healing as compared with the use of autologous grafts.•Hence, synthetic bone substitutes and biological factors e.g. calcium phosphate (CaP) cements and ceramics, hydroxyapatite (HAp) and recombinant human bone morphological proteins (rhBMP-2 and rhBMP-7) are considered, either alone or combined, for bone tissue regeneration.
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•We built a random forest model on ozone using TROPOMI and HRRR data.•Our model had a cross-validated (CV) R2 of 0.84 for daily ground ozone concentrations.•Model predictions captured ...daily ozone distributions at 10 km spatial resolution.•TROPOMI column O3 data improved the characterization of high concentrations.
Estimating ground-level ozone concentrations is crucial to study the adverse health effects of ozone exposure and better understand the impacts of ground-level ozone on biodiversity and vegetation. However, few studies have attempted to use satellite retrieved ozone as an indicator given their low sensitivity in the boundary layer. Using the Troposphere Monitoring Instrument (TROPOMI)'s total ozone column together with the ozone profile information retrieved by the Ozone Monitoring Instrument (OMI), as TROPOMI ozone profile product has not been released, we developed a machine learning model to estimate daily maximum 8-hour average ground-level ozone concentration at 10 km spatial resolution in California. In addition to satellite parameters, we included meteorological fields from the High-Resolution Rapid Refresh (HRRR) system at 3 km resolution and land-use information as predictors. Our model achieved an overall 10-fold cross-validation (CV) R2 of 0.84 with root mean square error (RMSE) of 0.0059 ppm, indicating a good agreement between model predictions and observations. Model predictions showed that the suburb of Los Angeles Metropolitan area had the highest ozone levels, while the Bay Area and the Pacific coast had the lowest. High ozone levels are also seen in Southern California and along the east side of the Central Valley. TROPOMI data improved the estimate of extreme values when compared to a similar model without it. Our study demonstrates the feasibility and value of using TROPOMI data in the spatiotemporal characterization of ground-level ozone concentration.
Non-radiative bound states in the continuum (BICs) allow construction of resonant cavities with confined electromagnetic energy and high-quality (Q) factors. However, the sharp decay of the Q factor ...in the momentum space limits their usefulness for device applications. Here we demonstrate an approach to achieve sustainable ultrahigh Q factors by engineering Brillouin zone folding-induced BICs (BZF-BICs). All the guided modes are folded into the light cone through periodic perturbation that leads to the emergence of BZF-BICs possessing ultrahigh Q factors throughout the large, tunable momentum space. Unlike conventional BICs, BZF-BICs show perturbation-dependent dramatic enhancement of the Q factor in the entire momentum space and are robust against structural disorders. Our work provides a unique design path for BZF-BIC-based silicon metasurface cavities with extreme robustness against disorder while sustaining ultrahigh Q factors, offering potential applications in terahertz devices, nonlinear optics, quantum computing, and photonic integrated circuits.
•A novel mZVI/AC composite synthesized by BM for Cr(VI) removal was developed.•Cr(VI) was effectively removed under acid and anaerobic conditions.•The effects of AC on mZVI activity and Cr(VI) ...removal mechanism were explored.•Inactivated mZVI/AC can be rejuvenated by BM again with a small amount of AC.
The oxide film coated on the surface of zero-valent iron (ZVI) greatly limits the reducibility of ZVI. Application of iron-based materials especially microscale or nanoscale for water treatment can be more effective when modified with activated carbon (AC). In the study, the removal efficiency of Cr(VI) was significantly enhanced by mZVI/AC composite synthesized by ball milling (BM) under acidic and anaerobic conditions, and reached 94.01% within 120 min. And BM promoted effective contact or collision between mZVI and AC, which was a necessary condition for strengthening Cr(VI) removal by mZVI/AC. By detecting pH changes and the dissolution of total iron during batch experiments, it was shown that AC enhanced the corrosion of mZVI, accompanied by consumption of H+. Tafel scans further confirmed that the corrosion of mZVI was promoted when coupled with AC. Compared with mZVI, AC enhanced the adsorption-reduction ability, and also enhanced the homogeneous reduction reaction (the role of the secondary reducing agent Fe2+) in the process of Cr(VI) removal by mZVI/AC. Based on X-ray photoelectron spectroscopy (XPS), valence analysis of chromium and 1,10-phenanthroline shielding experiments, the Cr(VI) removal mechanism by mZVI/AC was also unraveled. Furthermore, the reusability of mZVI/AC was limited by the accumulation of (hydr)oxide on its surface and the loss of surface AC, but can be easily rejuvenated by BM again with a small amount of AC. In conclusion, mZVI/AC composite synthesized by BM are a promising green material to remove Cr(VI) from wastewater.
Wireless sensor networks (WSNs) is a multi-hop wireless network composed of a group of static or mobile sensor nodes in the form of self-organization. Uneven distribution of nodes often leads to the ...problem of over coverage and incomplete coverage of monitoring areas. To solve this problem, this paper establishes a network coverage optimization model and proposes a coverage optimization method based on an improved hybrid strategy weed algorithm (LRDE_IWO). The improvement of the weed algorithm includes three steps. Firstly, the standard deviation of normal distribution based on the tangent function is used as the seed's new step size in the seed diffusion stage to balance the ability of the global search and local search of weed algorithm. Secondly, to avoid the problem of premature convergence, a disturbance mechanism combining enhanced Levy flight and the adaptive random walk strategy is proposed in the process of seed breeding. Finally, in competition of invasive weed stage, the differential evolution strategy is introduced to optimize the competition operation process and speed up convergence. The improved weed algorithm is applied to coverage optimization of WSNs. The simulation results show that the coverage rate of LRDE_IWO is increased by about 1% to 6% compared with the original invade weed algorithm (IWO) and the differential evolution invasive weed optimization algorithm (DE_IWO), and the coverage rate of the LRDE_IWO algorithm is increased by 4.10%, 2.73% and 1.19%, respectively, compared with the antlion optimization algorithm (ALO), the fruit fly optimization algorithm (FOA) and the gauss mutation weed algorithm (IIWO). The results prove the superiority and validity of the improved weed algorithm for coverage optimization of wireless sensor networks.
The wireless physical-layer identification (WPLI) techniques utilize the unique features of the physical waveforms of wireless signals to identify and classify authorized devices. As the inherent ...physical-layer features are difficult to forge, WPLI is deemed as a promising technique for wireless security solutions. However, as of today, it still remains unclear whether the existing WPLI techniques can be applied under real-world requirements and constraints. In this paper, through both theoretical modeling and experiment validation, the reliability and the differentiability of the WPLI techniques are rigorously evaluated, especially under the constraints of the state-of-the-art wireless devices, real operation environments, as well as wireless protocols and regulations. In particular, a theoretical model is first established to systematically describe the complete procedure of the WPLI. More importantly, the proposed model is then implemented to thoroughly characterize the various WPLI techniques that utilize the spectrum features coming from the nonlinear RF front-end, under the influences from different transmitters, receivers, and wireless channels. Subsequently, the limitations of the existing WPLI techniques are revealed and evaluated in details using both the developed theoretical model and the in-lab experiments. The real-world requirements and constraints are characterized along each step in WPLI, including: 1) the signal processing at the transmitter (device to be identified); 2) the various physical-layer features that originate from circuits, antenna, and environments; 3) the signal propagation in various wireless channels; 4) the signal reception and processing at the receiver (the identifier); and 5) the fingerprint extraction and classification at the receiver.
Subwavelength confinement of light with plasmonics is promising for nanophotonics and optoelectronics. However, it is nontrivial to obtain narrow plasmonic resonances due to the intrinsically high ...optical losses and radiative damping in metallic structures. In this review, a thorough summary of the recent research progress on achieving high‐quality (high‐Q) factor plasmonic resonances is provided, emphasizing the fundamentals and six resonant mode types, including surface lattice resonances, multipolar resonances, plasmonic Fano resonances, plasmon‐induced transparency, guided‐mode resonances, and Tamm plasmon resonances. The applications of high‐Q plasmonic resonances in spectrally selective thermal emission, sensing, single‐photon emission, filtering, and band‐edge lasing are also discussed.
In this review article, the recent research progress on achieving high‐quality (high‐Q) factor plasmonic resonances is thoroughly summarized. Six channels for achieving high‐Q in nanophotonic designs are introduced in detail: surface lattice resonances, multipolar resonances, plasmonic Fano resonances, plasmon‐induced transparency, guided‐mode resonances, and Tamm plasmon resonances. Also, applications of the high‐Q plasmonic resonances are discussed.
A bound state in the continuum (BIC) is a nonradiating state of light embedded in the continuum of propagating modes providing drastic enhancement of the electromagnetic field and its localization at ...micro–nanoscale. However, access to such modes in the far‐field requires symmetry breaking. Here, it is demonstrated that a nanometric dielectric or semiconductor layer, 1000 times thinner than the resonant wavelength (λ/1000), induces a dynamically controllable quasi‐bound state in the continuum (QBIC) with ultrahigh quality factor in a symmetric metallic metasurface at terahertz frequencies. Photoexcitation of nanostrips of germanium activates ultrafast switching of a QBIC resonance with 200% transmission intensity modulation and complete recovery within 7 ps on a low‐loss flexible substrate. The nanostrips also form microchannels that provide an opportunity for BIC‐based refractive index sensing. An optimization model is presented for (switchable) QBIC resonances of metamaterial arrays of planar symmetric resonators modified with any (active) dielectric for inverse metamaterial design that can serve as an enabling platform for active micro–nanophotonic devices.
A simple strategy for introducing and engineering narrow and active resonances in metamaterials is demonstrated. A nanoscale‐thick semiconducting strip breaks the structure's symmetry, providing access to a quasi‐bound state in the continuum (quasi‐BIC) that can be modulated with light. Inverse design of such resonances and their potential for ultrafast terahertz switchable filters and sensors are demonstrated.
•Nd self-ion implantation produces a smooth and hydrophobic surface on rare-earth WE43 Mg alloy.•The implanted layer is composed of mainly Nd2O3 and MgO.•Degradation is significantly retarded in ...simulated body fluids and cell culture medium.•The Nd-implanted WE43 alloy exhibits remarkably enhanced cell adhesion and biocompatibility.
Without introducing extraneous elements, a small amount of Nd is introduced into rare-earth WE43 magnesium alloy by ion implantation. The surface composition, morphology, polarization, and electrochemical properties, as well as weight loss, pH, and leached ion concentrations after immersion, are systematically evaluated to determine the corrosion behavior. The cell adhesion and viability are also determined to evaluate the biological response in vitro. A relatively smooth and hydrophobic surface layer composed of mainly Nd2O3 and MgO is produced and degradation of WE43 is significantly retarded. Furthermore, significantly enhanced cell adhesion and excellent biocompatibility are observed after Nd self-ion implantation.
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•A machine learning method was adopted to predict compression property of braided-textile tubes.•The method has high accuracy in predicting the energy absorbing properties.•The method ...can guide the design of composite tubes with good energy absorption.
Braided-textile composites have been applied in various engineering fields and used for high-efficiency energy absorbers to meet different loading requirements. However, it’s difficult to accurately forecast the mechanical properties of these braided-textile composites based on theoretical method, which is a big obstacle to the precise design of the energy-absorbing structure. In this research, carbon fiber reinforced composite (CFRC) tubular structures were fabricated by two-dimensional braided textiles, and 160 groups of orthogonal axial compression experiments were carried out.
Axial compression behaviors of CFRC tubular structures, including peak force, mean crushing force, energy absorption, specific energy absorption, elastic modulus and other relevant parameters, were tested and collected in a database. The feed forward back propagation (FFBP) algorithm based on artificial neural network (ANN), as an algorithm with high convergence accuracy in machine learning (ML), was adapted to build a prediction model to forecast the overall axial compression properties of those CFRC tubular structures uncollected in the database. By a series of error analyses, the ML method was proven to have high accuracy in predicting the relevant mechanical properties within the range of orthogonal design groups. Although the relative error of marginal sample data (especially single-layer tubes) is large, the mean absolute error (MAE) of training set and test set is only about 5% and 10%, respectively. Our work demonstrates the potential of machine learning methods in predicting the overall mechanical properties and guiding the design of composite materials.
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