The dielectric properties of vegetation reflect the coupling between the electromagnetic and physical properties of the material. Understanding dielectric behavior is essential for remote sensing ...applications. The traditional approach of measuring broadleaf permittivity involves exerting pressure on stacked leaves, which not only requires a complicated system to measure the pressure but also introduces a degree of uncertainty by changing the internal leaf microstructure. We propose a measurement technique that avoids the aforementioned shortcomings by using a vacuum packaging machine to remove the air from a sample bag, which is the first contribution of this paper. The proposed technique is validated against corn, cotton, and soybean leaf permittivity measurements. The second contribution of this paper involves how temperature is treated when modeling permittivity. The Debye-Cole dual-dispersion model, which is influential in vegetation remote sensing applications, is almost exclusively applied at 22 °C. However, it is assumed that this model can be extrapolated to other temperatures. Our analysis indicates that this model may overestimate permittivity at 28 °C, with mean relative errors (MREs) of up to 22% and 37% for relative permittivity and dielectric loss. Thus, we adopt the structure of the model due to its soundness and modify the model parameters. Overall, we used four different methods, among which the optimal method reduced the MRE by no more than -2.5%.
A microwave thermal therapy was proposed based on the strategy of microwave sensitizers and the susceptibility of the tumor tissue for enhancing thermal antitumor therapy.
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Although ...surgical resection and chemotherapy were widely applied in tumor therapy, the dysfunction of normal cells resulted in the side effects (such as anorexia, nausea). MW thermal therapy is a non-invasive anticancer strategy under the help of MW sensitizer, with the safety and higher efficacy. Zirconium metal-organic framework nanocubes (ZrMOF NCs) modified with polyethylene glycol, were prepared via one pot method and carbodiimide technique, resulting in their large specific surface area and porosity. Our results showed that non-ion-loaded ZrMOF NCs in 0.9% NaCl solution exhibited better heating effect, higher than that in pure water, due to the robust collision among the ions under MW irradiation. The in vivo experiments confirmed that ZrMOF-PEG NCs+MW group exhibited the higher temperature in the tumor region than that of only MW treatment, suggesting a better MW thermal therapeutic anticancer efficacy. This work provides a new preparation strategy of biosafety nanomaterial as MW sensitizer for enhancing MW thermal anticancer therapy.
Silica nanorattles （SNs） with zinc oxide （ZnO） combination nanoparticles are reported to inhibit methicillin-resistant Staphylococcus aureus （MRSA） for the first time. SNs loaded with ZnO ...nanoparticles, which can produce free radicals, can cause severe damage to bacteria. ZnO nanoparticles not only provide free radicals in the combined nanostructures, which can inhibit the growth of bacteria, but also form nanorough surfaces with an irregular distribution of spikes on the SNs, which can enhance their adhesion to bacteria. Nanorough silica shell surfaces maintain the high activity and stability of small-sized ZnO nanoparticles and gather ZnO nanoparticles together to enhance production, which improves the effi- ciency of free radicals against the cytomembranes of bacterial cells. The enhanced adhesion of ZnO@SN nanoparticles to MRSA cells shortens the effective touching distance between free radicals and MRSA, which also improves antibacterial activity. As we expected, the ZnO@SN nanoparticles exhibit a better antibacterial effect than free ZnO nanoparticles against MRSA in vitro and in vivo. We also demonstrate that SNs loaded with ZnO nanoparticles can accelerate wound healing in MRSA skin inflam- mation models. This method of multilevel functionalization will be potentially applicable to the antibac- terial field.
The genetic diversity in the naked carp (
Gymnocypris przewalskii
) of China is threatened by climate change, human activities, as well as natural factors, eliciting conservation concerns. To explore ...the genetic aspects of
G. przewalskii
, the genetic diversity, genetic structure, population differentiation, and historical demography of 566 representative individuals from seven geographically distinct ranges of Qinghai Lake were evaluated by mitochondrial DNA cytochrome oxidase subunit I (
COI
) and D-loop sequences. Estimates of genetic parameters showed that the seven populations of
G. przewalskii
had high levels of haplotype diversity (0.50243–0.94620) and low levels of nucleotide diversity (0.00079–0.00624). Haplotype genealogy indicated there was no obvious phylogenetic pattern between haplotypes. Both markers denoted the absence of population genetic structure the genetic differentiation coefficient F-statistics (Fst) < 0 and the presence of high genetic flow (
COI: 0.
9731–1.0441; D-loop: 0.9480–1.0398). The mismatch between the distribution and neutrality tests supported the evidence of population expansion, which occurred during the late middle Pleistocene
COI
: 0.36–0.108 MYA (Million Years Ago); D-loop: 0.497–0.165 MYA. Furthermore, this work illustrated two simple, reliable, and inexpensive molecular markers for analysis of genetic diversity, while the sensitivity of the mitochondrial D-loop region as a reflection of genetic diversity in
G. przewalskii
is higher than that of the
COI
gene.
ZrMOF@CdTe nanoparticles (NPs) with high fluorescence were synthesized by hydrothermal method. The morphology, particle size distribution, compositions, fluorescence properties and stability of the ...synthesized ZrMOF@CdTe were analyzed via the characterization by TEM, ICP-AES and fluorescence spectrophotometry, and the effects of the reaction time and pH value on the fluorescent property of ZrMOF@CdTe NPs were discussed. The results show that ZrMOFs could maintain its morphology and structure well during the process of loading CdTe quantum dots. With the increase of the loading reaction time, the red-shifted emission peaks of ZrMOF@CdTe NPs appear, and their fluorescence gradually changes from green to red color. With the increase of the pH value and temperature of the hydrothermal reaction, the fluorescence of ZrMOF@CdTe NPs was also consistent with the red-shifted change. The fluorescent property of ZrMOF@CdTe NPs could be remained for more than 3 months. Therefore, ZrMOF@CdTe NPs synthesized by the hydrothermal method have the characteristics of simple operation, adjustable fluorescent color and high stability, and the potential application in the fields of biological detection and sensing is expected.
A substrate integrated waveguide (SIW) based spoof surface plasmon polariton (SSPP) is proposed for the design of bandpass filter (BPF). The left and right edge cutoff frequencies of the passband can ...be easily adjusted by changing the parameters of SIW and ring slot embedded into the SIW. Then, four half-wavelength circular slots are added on two sides of the SSPP located at the center of the circuit to introduce a high-selectivity notch band. In order to make the notch band switchable, four full-wavelength circular slots and four PIN diodes are applied instead of the four half-wavelength circular slots. As the PIN diodes are under the ON state, the notch band will be generated within the passband of BPF. On the contrary, as the PIN diodes are under the OFF state, the notch band will disappear. To validate the design idea, two BPF examples are fabricated and measured, whose simulation and measurement results are both in reasonably good agreement.
Abstract
Avoiding overheating of the supply air inside the fire-rated duct of pressurisation system is crucial for the escape and rescue of the building occupants during the development of a fire. ...The simulation scenarios are established concerning three cross-sectional dimensions of ducts and four inner air velocities. Based on the performance criteria of insulation specified in the international standard of ISO 834-1, the temperature fields of supply air inside different fire-rated ducts and corresponding safety are analysed based on the assumption that the exterior of fire-rated ducts is in a consistent state of being subjected to fire.
Developing functional nanoagents for achieving the combination of microwave dynamic therapy (MDT) and microwave thermal therapy (MTT) is highly desirable due to the advantages of improving the ...therapeutic effect on tumors and minimizing the side effects. Metal–organic frameworks (MOFs), as emerging porous materials, exhibit many intriguing properties for application in biomedicine. Herein, new-style flexible Mn-doped zirconium metal–organic framework (Mn-ZrMOF) nanocubes (NCs) with the average size of about 60 nm were prepared easily by a one-pot hydrothermal method. Due to the strong inelastic collision of ions confined in a large number of micropores, the Mn-ZrMOF NCs were demonstrated to be an effective microwave-sensitive agent with a high thermal conversion efficiency up to 28.7%, which is the highest one of the recently reported microwave-sensitive agents. This is the first report of determining the microwave thermal conversion efficiency, which can be used to evaluate, compare, and predict the microwave sensitivity of different microwave-sensitive agents. More importantly, such Mn-ZrMOF NCs generate abundant reactive oxygen species (ROS) of hydroxyl radicals under microwave irradiation. As such, the Mn-ZrMOF NCs efficiently suppress the tumor cell growth in vivo and in vitro under mild microwave irradiation for the synergic effect of MTT and MDT. This work paves the way for developing nanoagents that are responsive to microwave irradiation, producing ROS and improving thermal effects to realize the noninvasive MTT and MDT treatment in clinics.
Bright CdSe quantum dots (QDs)/polycaprolactone (PCL) nanocomposite fluorescent films were fabricated by electronspinning. By using chloroform and N,N-dimethylformamide as electronspinning solvent, ...the oil-soluble CdSe QDs were uniformly distributed in PCL fibers, and were directly employed as optical probe without any modification processing. The fluorescences of CdSe QDs/PCL nanocomposite films were quickly quenched when the films were contacted with H2O2, solution. In the presence of glucose oxidase (GOD), the fluorescence intensities of these fluorescent films exhibit a liner change with the concentrations of glucose. The H2O2-sensitive electrospun QDs nanocomposite films are highly uniform and repeatable, demonstrating the potential to fabricate stable, sensitive and recyclable fluorescent biosensor for the detection different H2O2-generating oxidases and their substrates.
Synthetic aperture radar (SAR) imagery is significantly deteriorated by the random phase noises which are generated by the frequency jitter of the transmit signal and atmospheric turbulence. In this ...paper, we recast the SAR imaging problem via the phase-corrupted data as for a special case of quadratic compressed sensing (QCS). Although the quadratic measurement model has potential to mitigate the effects of the phase noises, it also leads to a nonconvex and quartic optimization problem. In order to overcome these challenges and increase reconstruction robustness to the phase noises, we proposed a QCS-based SAR imaging algorithm by greedy local search to exploit the spatial sparsity of scatterers. Our proposed imaging algorithm can not only avoid the process of precise random phase noise estimation but also acquire a sparse representation of the SAR target with high accuracy from the phase-corrupted data. Experiments are conducted by the synthetic scene and the moving and stationary target recognition Sandia laboratories implementation of cylinders (MSTAR SLICY) target. Simulation results are provided to demonstrate the effectiveness and robustness of our proposed SAR imaging algorithm.
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