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Hydrogen sulfide (H2S), an emerging gas transmitter, has been shown to be involved in multiple intracellular physiological and biochemical processes. In this study, the effects of hydrogen sulfide coupled with calcium on cadmium removal and resistance in Phanerochaete chrysosporium were examined. The results revealed that H2S enhanced the uptake of calcium by P. chrysosporium to resist cadmium stress. The removal and accumulation of cadmium by the mycelium was reduced by H2S and Ca2+ pretreatment. Moreover, oxidative damage and membrane integrity were alleviated by H2S and Ca2+. Corresponding antioxidative enzyme activities and glutathione were also found to positively respond to H2S and Ca2+, which played an important role in the resistance to cadmium-induced oxidative stress. The effects of hydroxylamine (HA; a hydrogen sulfide inhibitor) and ethylene glycol-bis-(2-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA; a calcium chelator) toward H2S and Ca2+ and their cross-interactions confirmed the positive roles and the potential crosstalk of H2S and Ca2+ in cadmium stress resistance. These findings imply that the protective effects of H2S in P. chrysosporium under cadmium stress may occur through a reduction in the accumulation of cadmium and promotion of the antioxidant system, and the H2S-regulated pathway may be associated with the intracellular calcium signaling system. Key points • Altered monoterpenoid tolerance mainly related to altered activity of efflux pumps. • Increased tolerance to geranic acid surprisingly caused by decreased export activity. • Reduction of export activity can be beneficial for biotechnological conversions.

Imidacloprid (IMI), a typic neonicotinoid insecticide, is widely used and persist in soils with long half-time causing serious threat to ecosystem and human health. It is urgent to develop suitable and effective methods to accelerate it degradation and alleviate its negative impacts in soil. In this study, the introduction of functional microbe white-rot fungus Phanerochaete chrysosporium to remediate IMI contaminated wetland soil was carried out. The remediation performance and the response of the soil microbial community were examined. The results showed that P. chrysosporium could improve the degradation of IMI in soil no matter the soil was sterilized or not. The bioaugmentation was especially observed in non-sterilized soil under the inoculation patterns of FE and SP with the maximum IMI degradation rate of 91% and 93% in 7 days, respectively. The invertase activity in soil was also enhanced with P. chrysosporium inoculation. Microbial community analysis revealed that P. chrysosporium inoculation could increase the diversity and richness of bacterial community, and stimulate some IMI degraders genera including Ochrobactrum, Leifsonia, Achromobacter, and Bacillus. Moreover, the xenobiotic degradation and metabolism pathway was generally enhanced with P. chrysosporium inoculation based on PICRUSt analysis. These obtained results demonstrated that the introduction of white-rot fungus is of great potentially enabling the remediation of neonicotinoids contaminated soil.

In this study, the propagation characteristics of electromagnetic waves in a parity-time (PT)-symmetrical 1D photonic crystal comprising dispersed silver layers are investigated. Based on the transmission matrix theory, the total reflection and transmission coefficients of the structure are obtained. It was found that, due to the PT-symmetrical structure, the reflections of the left and right incident waves are nonreciprocal. Numerical simulations indicated that the width of the band gap decreases with the increase in the gain and loss factor ρ in the PT medium, and the band gap ultimately disappears when ρ reaches a critical value, i. e., ρ P T ${\rho }_{PT}$ . With the increase in ρ > ρ P T $\rho { >}{\rho }_{PT}$ , anomalous transmittance and reflection occur within the original bang gap. As the gain and loss factor ρ continue to increase, the abnormal transmittance and reflectivity exhibit a trend of oscillatory decline, and perfect transmission can be achieved at larger values of ρ.

Human activity recognition has been growing for decades in a variety of technological disciplines. However, in the existing WiFi-based human activity recognition systems, there are the following problems: Firstly, in the processing of channel state information (CSI) data, mainly for the removal of noise in the superimposed signal, there is no effective removal of useless multipath signals; Secondly, the data segmentation algorithm based on the empirical threshold requires manual adjustment of the threshold in different environments, resulting in poor robustness and unstable segmentation; Thirdly, simple learning classification is applied without specific design for CSI data structure and sufficiently abstracting information features. In this paper, a device-free human activity recognition system with a temporal-frequency attention mechanism is proposed, which can be deployed on commercial WiFi devices to identify human’s daily activities. Firstly, the multipath signal affected by the channel change is extracted by using the difference of the propagation delay of different multipath, thereby eliminating the delay and invalid multipath signals that have undergone multiple reflections and refractions. Secondly, a neural network model based on attention mechanism is proposed, which assigns different weights to different characteristics and sequences by imitating the human brain to dedicate more attention to important information. Then, the long short-term memory (LSTM) model is used to learn the correlation features of different dimensions to realize human activity recognition. Finally, the system performance is evaluated in different environments, and the experimental results show that our syetem holds a better performance in both line-of-sight (LOS) and non-line-of-sight (NLOS) than the existing human activity recognition systems.

A nonreciprocal transmission structure is designed using a one-dimension multilayer medium, which consists of two asymmetric structure filled with the electric–gyrotropic dispersive media. The total transmission coefficients have been deduced using the transfer matrix method. Numerical results further provided evidence for the occurrence of the nonreciprocal surface electromagnetic waves. These states are affected by the thickness of layers, incident angles, and the externally applied magnetic fields. Given that the electric–gyrotropic media are inherently dispersive, our investigations will contribute to the practical application of nonreciprocal structures.

A one-dimensional nonreciprocal structure comprising two asymmetric multilayers filled with magneto-optical dispersive media and a defect layer is designed. The nonreciprocal optical Tamm states (O...

In low-power SAR ADCs, the energy consumed by capacitor DAC is the main source of the SAR ADC. In order to reduce the energy consumption, this paper proposes an energy-efficient and high area-efficient DAC switching scheme. By introducing dummy capacitor switching for the last two bits’ generation and a new third voltage reference Vq equal to a quarter of the voltage reference Vref, the proposed DAC switching scheme reduces the switching energy by 97.97%. Moreover, the DAC area of the proposed scheme is only 12.5% of the conventional SAR ADC architecture, which achieves a good area efficiency.

The human activity recognition system has been researched in various technical fields for decades. Nowadays, as WiFi is widely used in homes, using WiFi devices for human activity recognition has become a better choice. In recent years, more and more researchers have begun to use channel state information (CSI) to realize human activity recognition. The CSI features with fine-grained information can show the impact of human activity on the channel. But in the existing CSI-based human activity recognition system, there is an issue. Due to the high proportion of error and noise in the phase information in CSI, the information in CSI is not fully utilized during the processing of CSI data. In this paper, we propose a method for extracting phase information in CSI, so that we can completely extract the effective information in CSI as the input feature of the classifier. Then, we use k-means for feature extraction of main feature data. Finally, we use support vector machines (SVM) to learn features and conduct activity recognition. We evaluated the system performance, and the experimental results show that our system has good performance.

In this study, a one-way electromagnetic waveguide consisting of magneto-optical (MO) and parity-time (PT)-symmetric materials was constructed. Due to the composite boundary conditions, this waveguide simultaneously has two unidirectional dispersive curves and two different unidirectional mechanisms. One unidirectional mechanism is breaking the time-reversal symmetry of MO materials, and the other unidirectional mechanism is asymmetric complex eigenvalues in the local PT symmetrical configuration. The designed structure provides an effective approach to control the directions of electromagnetic waves.

Wi-Fi-based human activity recognition is playing a critical role in wireless sensing. However, the existing through-wall human activity recognition method does not fully analyze the influence of the wall on the signal, which results in poor robustness of the Wi-Fi indoor human activity recognition system. In order to solve this problem, this paper proposes a Wi-Fi based activity recognition algorithm under through-the-wall scenarios. First, the distribution of Wi-Fi signals in the presence of wall barriers is analyzed according to the Wi-Fi signal model. Then, according to the distribution characteristics of different Wi-Fi signals, the principal component analysis (PCA) algorithm is used to reconstruct the signal to complete the de-nosing processing of the Wi-Fi signal. Finally, feature extraction and feature classification in the time-frequency domain is performed to complete the human activity recognition. It is worth mentioning that in terms of feature extraction, we innovatively use the empirical mode decomposition (EMD) algorithm to extract the difference in time series of similar actions. Experimental results show that the system achieves an average accuracy of 95.82 percent in through-the-wall scenarios.

The surface plasmon resonance and strong coupling of three layers of metal-coated nanorods are studied in this paper. Numerical results show that an incident electromagnetic wave with a particular frequency can be guided through localized surface plasma resonances to different-sized cavities, realizing excellent absorbance of electromagnetic waves. The refractive index of the surrounding medium also influences the resonant frequency dramatically. Different metal shell thicknesses and materials can be used to effectively adjust the formant frequency. These unique properties of multi-mode resonance and excellent absorbance of electromagnetic waves in a multi-nanorod system have prospective applications in the fields of plasmon resonant sensors, resonators.

In this study, in order to achieve the nonreciprocal propagation properties of electromagnetic waves, a ternary asymmetrical magneto-optical multilayer structure with a defect layer is constructed. It was found that, due to the defect layer, three pair nonreciprocal dispersive curves in three band gaps are formed for forward and backward incident waves. With the increasing thickness of defect layer, the nonreciprocal transmission peaks appear red-shift, and nonreciprocity decrease with enlargement of the space between two transmission peaks. Numerical simulations further indicated that the unidirectional propagation is due to the nonreciprocal resonant modes formed in the magneto-optical material layer of the ternary asymmetrical structure. These nonreciprocal properties are affected by the incident angle and the asymmetric gyrotropic electromagnetic parameters.

The extensive use of neonicotinoid pesticides in the past two decades caused serious impacts on many kinds of living beings. Therefore, it has been strongly suggested to detoxify and eliminate neonicotinoids’ residual levels in environment. Here, the degradation and detoxification of thiamethoxam (THX) by white-rot fungus Phanerochaete chrysosporium was conducted. Results shown that P. chrysosporium can tolerate THX and degraded 49% of THX after incubation for 15 days, and then 98% for 25 days at the initial concentration of 10 mg/L, which indicates the excellent degradation ability of this fungus to THX. Based on the by-products identified, THX underwent dechlorination, nitrate reduction, and C–N cleavage between the 2-chlorothiazole ring and oxadiazine. (Z)-N-(3-methyl-1,3,5-oxadiazinan-4-ylidene)nitramide and 3-methyl-1,3,5-oxadiazinan-4-imine were identified as the main metabolites. The impacts of THX and its corresponding degradation intermediates on the growth of E. coil and Microcystis aeruginosa as well as the germination of rape and cabbage demonstrated that P. chrysosporium effectively degrades THX into metabolites and reduces its biotoxicity. The present work demonstrates that P. chrysosporium can be effectively used for degradation and detoxification of THX.

The traditional high-salinity organic wastewater treatment process is cumbersome and costly, and involves an independent process for removing pollutants and salinity. A flow-through coupled system of electro-Fenton and electrosorption processes was designed in this work. The simultaneous purification and desalination of high concentration wastewater were effectively achieved through the cooperation of various electrochemical reactions, which avoids the complex processes of desalination and dilution in advance when treating high-salinity organic wastewater, and the removal performance was improved. The influence of key parameters, including voltage, initial pH, plate spacing, H2O2 concentration, and flow rate, were systematically investigated. The findings show that actual wastewater passing through the coupled system promptly turns to clean water with significantly decreased COD, TN, and salinity, with removal efficiencies reaching 96.5%, 98.2%, and 46.2%, respectively, under the optimal conditions (voltage intensity 1.5 V, initial pH 4, plate spacing 1 cm, flow rate 40 mL/min, H2O2 concentration 50 mM). The reaction mechanism study suggested that both the Fenton reaction, direct electron transfer, and indirect oxidation by active chlorine contributed to the removal of COD and TN, while the decrease in salinity mainly occurred in the process of electrosorption. Moreover, the regeneration of the ACF and the operational stability of the coupled system were good after five cycles. The economic analysis indicated that the cost of the flow-through coupled system was only $1.18/m3, which has important benefits.

The electromagnetic scattering characteristics of multilayered arrays of silver nanorods are investigated. Based on the scattering cross section of the multilayered structure, the near-field distributions of the two-layered and three-layered models are investigated by numerical simulations. It is found that the surface plasmons can be excited by incident electromagnetic waves with specific frequencies, and enhanced by the cavities formed by nanorods. The numerical results further show that surface plasmons resonant modes are affected by the sizes, number and positions of cavities. The unique and diverse resonant modes of SPs in the cavities can achieve electromagnetic wave focus and energy convergence, which has potential applications in many areas.

Based on classical EM field theory, the distributions of energy density and energy flow velocity in the 2-D cylinder cloak have been calculated. Due to the variable and special electromagnetic (EM) parameters, theoretical results indicate that the EM fields, EM energy density and EM energy flow are non-uniform in the cloak shell. The numerical simulations show that there is superluminal phenomena of the velocity of energy flow in the cloak shell, whether the EM field transmit along x -direction or along y -direction.

Objective: To investigate the expression and correlation of transforming growth factor-β1 (TGF-β1) and fibroblast growth factor receptor 4 (FGFR4) in human hepatocellular carcinoma (HCC) and the relationship with clinicopathological features and prognosis. Materials and methods: The expression of TGF-β1 and FGFR4 in 126 HCC samples was detected immunohistochemically. Combined with clinical postoperative follow-up data, the expression of TGF-β1 and FGFR4 in HCC and the relationship with the prognosis of patients were analyzed by statistically. Results: The positive expression rate of TGF-β1 was 84.1% (106/126) in tumors, and that in peritumoral liver tissues was 64.3% (81/126); the positive expression rate of FGFR4 in tumors was 74.6% (94/126) and that in peritumoral liver tissues was 57.1% (72/126). The expression of TGF-β1 and FGFR4 in the carcinoma tissues was significantly higher than that in peritumoral liver tissues (p < 0.05). Intratumoral TGF-β1 and FGFR4 expression was associated with TNM stage (p < 0.05). TGF-β1 and FGFR4 expression levels didn't significantly correlate with other clinicopathological parameters, including age, sex, tumor size, serum AFP level, tumor differentiation, lymph node metastasis, etc. (p > 0.05). TGF-β1 expression was positively correlated with FGFR4 expression (r = 0.595, p < 0.05). Patients with positive FGFR4 or TGF-β1 expression had shorter overall survival compared with negative expression (p < 0.05). Conclusions: The expression of TGF-β1 and FGFR4 could make synergy on the occurrence and progression of HCC, and may be used as prognosis indicators for HCC patients.