Search

This paper first introduces the standard recipe for deriving quantity implicatures in the neo-Gricean framework. Then, it compares this pragmatic stance with the grammatical view that argues that scalar implicatures should be generated via an operator in syntax. After showing how the grammatical view can derive canonical scalar implicatures, motivations for this view are discussed which include embedded implicatures, obligatory scalar implicatures concerning the Hurford Constraint, and Free Choice inferences. This paper finally examines basic tenets of the grammatical view and points out three potential problems for this approach. [ABSTRACT FROM AUTHOR]

Electric dipoles and magnetic dipoles are the most fundamental particles in electromagnetic theory. Huygens and Janus sources, formed by the orthogonal combination of electric and magnetic dipoles, both show good directionality in the near field. Although the Huygens source has been widely used in antennas and metasurfaces, the applications of Janus source are heretofore limited. In this paper we report the physical construction of an active Janus source. Through full-wave simulations within the parallel plate waveguide (PPW) environment, we show that our source achieves the directional electromagnetic near-field and quasi-isotropic far-field requisite of the Janus source. Using this fact, we demonstrate that two active Janus and Huygens sources in close proximity (about 0.10 to 0.25 wavelengths) achieve a near 1000-fold reduced mutual coupling compared to electric dipole sources. Particularly, the simultaneous achievement of strong mutual coupling suppression and quasi-isotropic radiation make the Janus source an ideal candidate for consideration in future compact multi-input multi-output (MIMO) communication systems. The distinct near- and far-field directionalities of three fundamental dipoles (electric, Huygens and Janus) can be used to manipulate electromagnetic waves. The authors juxtapose the properties for these dipoles and propose a realistic active Janus source which suppresses mutual coupling by close to 1000-fold for two closely-spaced antennas. [ABSTRACT FROM AUTHOR]

Diabetic cystopathy (DCP) is a prevalent etiology of bladder dysfunction in individuals with longstanding diabetes, frequently leading to bladder interstitial fibrosis. Research investigating the initial pathological alterations of DCP is notably scarce. To comprehend the development of fibrosis and find effective biomarkers for its diagnosis, we prepared streptozotocin-induced long-term diabetic SD rats exhibiting a type 1 diabetes phenotype and bladder fibrosis in histology detection. After observing myofibroblast differentiation from rats' primary bladder fibroblasts with immunofluorescence, we isolated fibroblasts derived exosomes and performed exosomal miRNA sequencing. The co-differentially expressed miRNAs (DEMis) (miR-16-5p and let-7e-5p) were screened through a joint analysis of diabetic rats and long-term patients' plasma data (GES97123) downloaded from the GEO database. Then two co-DEMis were validated by quantitative PCR on exosomes derived from diabetic rats' plasma. Following with a series of analysis, including target mRNAs and transcription factors (TFs) prediction, hubgenes identification, protein–protein interaction (PPI) network construction and gene enrichment analysis, a miRNA-mediated genetic regulatory network consisting of two miRNAs, nine TFs, and thirty target mRNAs were identified in relation to fibrotic processes. Thus, circulating exosomal miR-16-5p and let-7e-5p are associated with bladder fibrosis of DCP, and the crucial genes in regulatory network might hold immense significance in studying the pathogenesis and molecular mechanisms of fibrosis, which deserves further exploration. [ABSTRACT FROM AUTHOR]

GPS-based maneuvering target localization and tracking is a crucial aspect of autonomous driving and is widely used in navigation, transportation, autonomous vehicles, and other fields.The classical tracking approach employs a Kalman filter with precise system parameters to estimate the state. However, it is difficult to model their uncertainty because of the complex motion of maneuvering targets and the unknown sensor characteristics. Furthermore, GPS data often involve unknown color noise, making it challenging to obtain accurate system parameters, which can degrade the performance of the classical methods. To address these issues, we present a state estimation method based on the Kalman filter that does not require predefined parameters but instead uses attention learning. We use a transformer encoder with a long short-term memory (LSTM) network to extract dynamic characteristics, and estimate the system model parameters online using the expectation maximization (EM) algorithm, based on the output of the attention learning module. Finally, the Kalman filter computes the dynamic state estimates using the parameters of the learned system, dynamics, and measurement characteristics. Based on GPS simulation data and the Geolife Beijing vehicle GPS trajectory dataset, the experimental results demonstrated that our method outperformed classical and pure model-free network estimation approaches in estimation accuracy, providing an effective solution for practical maneuvering-target tracking applications. [ABSTRACT FROM AUTHOR]

Density functional theory calculations at PBE38/6-311+G** level by involving the polarizable continuum model in solvent dichloromethane were employed to explore the geometries, electronic excitations and associated properties of the donor–acceptor-donor (D–A–D) di-triphenylaniline-modified thiophenes of 4,4′-(thiophene-2,5-diyl)bis(N,N-diphenylaniline) (TPA–Th–TPA), 4,4′-([2,2′-bithiophene]-5,5′-diyl)bis(N,N-diphenylaniline) (TPA–ThTh–TPA) and 4,4′-(thieno[3,2-b]thiophene-2,5-diyl)bis(N,N-diphenylaniline) (TPA–TT–TPA). The spectral properties were investigated with the time-dependent density functional theory at the same theoretical level, involving 37.5% of the Hartree–Fock exchange energies and 50% of the local and non-local contributions, respectively, for the rest of the energies. It was found that the most stable TPA–Th–TPA has no symmetry (C1 point group) in the 1A electronic state, while the most stable structures for both TPA–ThTh–TPA and TPA–TT–TPA have C2 symmetry in the 1A state. Their vertical absorption spectra were examined with the twenty lowest excitations, while the emission spectra were equivalently simulated by the vertical transition (from S1 to S0) of the structure of the S1 state. Both the theoretical absorption and emission spectra agree very well with the experiments in terms of absolute wavelengths and their sequence for different compounds. For the absorption with the maximum wavelength and strength, the theoretical wavelengths reproduced the experiments with deviations of only 4.4, 0.6 and 7.3 nm for TPA–Th–TPA, TPA–ThTh–TPA and TPA–TT–TPA, respectively. While the emission peaks have slightly larger deviations by 44.5, 90.5 and 53.3 nm. Detailed features for the next intense peak, as well as their peak shoulders, were explored. For the electronic properties associated with the S0 → S1 transition, the hole-electron, frontier orbital and natural transition orbital analyses supported charge transfer characteristics. The inter-segment charge transfer analyses provided the magnitude of inter-segment charge transfer of TPA–Th–TPA, TPA–ThTh–TPA and TPA–TT–TPA by 67.1, 60.6 and 66.4%, respectively, within which the transfer from donors to acceptor(s) is dominant. In addition to the largest π conjugation of the ThTh group that leads to the largest redshift of the spectra and charge redistribution, TPA–ThTh–TPA has the largest vertical electron affinity energy, electronegativity and global electrophilicity with 2.01, 3.68 and 4.05 eV, respectively. All the molecules have electrostatic potentials in their S0 and S1 states by approximately 54% in the negative potential region, supplied mainly by the lone pair electrons of the S and N atoms as well as the π electrons of the C atoms. This leads to the compounds being more susceptible to electrophilic reactions. Similar atomic natural charge distributions for the different compounds in their S0 and S1 states were found, with the S atom(s) having the most positive charge (~ 0.42 e) and the N atoms having the most negative charge (~ − 0.51 e). Small changes in the atomic charge were found in the excitations, indicating that the charge transfer does not significantly change the atomic charge distributions. [ABSTRACT FROM AUTHOR]

Graphene, a honeycomb lattice of carbon material with single‐atom‐layer structure, demonstrates extraordinary mechanical, thermal, chemical and electronic properties. Thus, it has sparked tremendous interests in various fields, such as energy storage and conversion devices, field‐effect transistors (FET), chemical sensors and biosensors. In this review, we will first focus on the synthesis method of graphene and the fabrication strategy of graphene‐based materials. Subsequently, the construction of graphene‐based biosensors are introduced, in which three kinds of biosensors are discussed in details, including the FET, electrochemical biosensors and electrochemiluminescence (ECL) biosensors. The performances of the state‐of‐the‐art biosensors on the detection of biomolecules are also displayed. Finally, we also highlight some critical challenges remain to be solved and the development in this field for further research. [ABSTRACT FROM AUTHOR]

Air quality plays a vital role in people's health, and air quality forecasting can assist in decision making for government planning and sustainable development. In contrast, it is challenging to multi-step forecast accurately due to its complex and nonlinear caused by both temporal and spatial dimensions. Deep models, with their ability to model strong nonlinearities, have become the primary methods for air quality forecasting. However, because of the lack of mechanism-based analysis, uninterpretability forecasting makes decisions risky, especially when the government makes decisions. This paper proposes an interpretable variational Bayesian deep learning model with information self-screening for PM2.5 forecasting. Firstly, based on factors related to PM2.5 concentration, e.g., temperature, humidity, wind speed, spatial distribution, etc., an interpretable multivariate data screening structure for PM2.5 forecasting was established to catch as much helpful information as possible. Secondly, the self-screening layer was implanted in the deep learning network to optimize the selection of input variables. Further, following implantation of the screening layer, a variational Bayesian gated recurrent unit (GRU) network was constructed to overcome the complex distribution of PM2.5 and achieve accurate multi-step forecasting. The high accuracy of the proposed method is verified by PM2.5 data in Beijing, China, which provides an effective way, with multiple factors for PM2.5 forecasting determined using deep learning technology. [ABSTRACT FROM AUTHOR]

The environment and development are major issues of general concern. After much suffering from the harm of environmental pollution, human beings began to pay attention to environmental protection and started to carry out pollutant prediction research. A large number of air pollutant predictions have tried to predict pollutants by revealing their evolution patterns, emphasizing the fitting analysis of time series but ignoring the spatial transmission effect of adjacent areas, leading to low prediction accuracy. To solve this problem, we propose a time series prediction network with the self-optimization ability of a spatio-temporal graph neural network (BGGRU) to mine the changing pattern of the time series and the spatial propagation effect. The proposed network includes spatial and temporal modules. The spatial module uses a graph sampling and aggregation network (GraphSAGE) in order to extract the spatial information of the data. The temporal module uses a Bayesian graph gated recurrent unit (BGraphGRU), which applies a graph network to the gated recurrent unit (GRU) so as to fit the data's temporal information. In addition, this study used Bayesian optimization to solve the problem of the model's inaccuracy caused by inappropriate hyperparameters of the model. The high accuracy of the proposed method was verified by the actual PM2.5 data of Beijing, China, which provided an effective method for predicting the PM2.5 concentration. [ABSTRACT FROM AUTHOR]

Under the traditional hybrid modulation strategy, the output powers of the hybrid cascaded H-bridge inverter are not balanced between the cascaded units. With a hybrid cascaded H-bridge 13-level inverter with a DC side voltage ratio of 1:1:1:3 (referred to as III-inverter in the paper) as the research object, a hybrid modulation power equalization strategy based on carrier rotation is proposed. Under the control of which, the output voltage of inverters is formed by superposition of multiple basic voltage waveforms. Firstly, the hybrid modulation strategy is adopted to modulate the inverter so that the high- and low-voltage units, respectively, operate in the low-frequency and high-frequency states. Then, the pulse sequence within the 3/2 output voltage cycle is made to circulate among all the cascaded units by carrier rotation. Finally, the output voltage of each cascaded units is made to contain all the basic voltage waveforms, thus implementing the output power balance between all the cascaded units. Based on simulation and experiment, the effectiveness of the strategy is verified, and it is shown that under the control of this power balance modulation strategy, the output voltage waveform quality of the inverter is high, there is no current backflow, and the output power can be balanced within 3/2 cycles. [ABSTRACT FROM AUTHOR]

Compared with mechanism-based modeling methods, data-driven modeling based on big data has become a popular research field in recent years because of its applicability. However, it is not always better to have more data when building a forecasting model in practical areas. Due to the noise and conflict, redundancy, and inconsistency of big time-series data, the forecasting accuracy may reduce on the contrary. This paper proposes a deep network by selecting and understanding data to improve performance. Firstly, a data self-screening layer (DSSL) with a maximal information distance coefficient (MIDC) is designed to filter input data with high correlation and low redundancy; then, a variational Bayesian gated recurrent unit (VBGRU) is used to improve the anti-noise ability and robustness of the model. Beijing's air quality and meteorological data are conducted in a verification experiment of 24 h PM2.5 concentration forecasting, proving that the proposed model is superior to other models in accuracy. [ABSTRACT FROM AUTHOR]

For real-time evaluation of the cell behavior and function under in vivo-like 3D environment, the 3D functionalized scaffolds simultaneously integrate the function of 3D cell culture, and electrochemical sensing is a convincing candidate. Herein, Fe3O4 nanoparticles as the nanozyme (peroxide oxidase mimics) were modified on graphene foam scaffold to construct a 3D integrated platform. The platform displayed a wide linear range of 100 nM to 20 μM and a high sensitivity of 53.2 nA μM−1 toward detection of hydrogen peroxide (H2O2) under the working potential of + 0.6 V (vs. Ag/AgCl). The obtained 3D scaffold also displayed satisfactory selectivity toward the possible interferents that appeared in the cell culture environment. Furthermore, the cells still maintained high cell viability (almost 100%) after their growth and proliferation on the scaffold for 7 days. With the superior performance on cell culture and electrochemical monitoring, the functions on the 3D culture of MCF-7 or HeLa cells and in situ monitoring of cell-released H2O2 was easily achieved on this 3D platform, which show its great application prospects on further cancer-related disease diagnosis or drug screening. A nanozyme-based three-dimensional graphene scaffold was successfully constructed for cell culture and identification of cancer cells through in situ electrochemical monitoring of the cell-released H2O2. [ABSTRACT FROM AUTHOR]

• A combined optical and mechanical analysis of nanograting structures fabricated by tip-based nano down-milling is implemented. • Grating height is considered to be an important factor affecting the concentration of incident power onto either of two propagating orders. • The plastic deformation process of the grating formation is explained by FE analysis. • Nanograting structures with the optimal height and geometric consistency are obtained by controlling the milling trajectory. Structural coloration of metal surfaces based on the diffraction mechanism of blazed gratings has considerable value for use in anti-counterfeiting and information encryption applications. When the grating period is comparable to the wavelength of the incident light, the diffraction process will generate only two propagating orders, comprising the 0th order and the −1st order, resulting in lower dispersion. Improvement of the diffraction efficiency of the −1st order spectrum, which has a light splitting ability, is essential to improve the colouring quality of the diffraction structure. Such improvement of efficiency is closely related to the geometric features of the structure, but the relationship is insufficiently clear at present. The novelty of the approach in this paper lies in its use of a combination of optical and mechanical analyses of nano grating structures fabricated by tip-based nanoscale down-milling with the aim of establishing a connection between the diffraction characteristics of the structure and its processing formation. First, profiles of the nanograting structures are generated numerically by taking both the trajectory shape and the cutting edge radius into account. Using the finite-difference time-domain method, a diffraction model is then established to simulate the far-field spectral distributions of the generated profiles. It is concluded from these analyses that the grating height is an important factor that affects the −1st order diffraction efficiency. When the grating height is in the range of 155–185 nm with a grating period of 400 nm, the diffraction efficiency can reach up to 75 %–90 %, depending on the conditions of incidence. Then, with the aim of controlling the grating height, the nanograting structure fabrication processes are investigated under different revolving trajectory conditions by finite element analysis. The results show that the grating structures are formed mainly by extrusion caused by the moving tip, which results in the grating heights being affected by the undeformed chip thickness in each cycle and by the plastic deformation of the material. Under the optimal down-milling trajectory condition, nanograting structures with the expected height and good geometric consistency are obtained. [Display omitted] [ABSTRACT FROM AUTHOR]

Piezoelectric technology is widely used in the field of precision drives. However, when piezoelectric actuators are employed at high voltages and high frequencies, their hysteresis can greatly affect the accuracy of such systems. The Bouc-Wen model has typically been used by researchers to characterise the hysteresis of piezoelectric materials. Besides, to extract the parameters of this model from experimental data, particle swarm optimization (PSO) is often employed. However, the majority of such studies only considers hysteresis as a function of the electric field strength and not as a function of actuation frequency. In addition, most of such existing reports have focused on longitudinal type piezo actuators. In this context, the research presented here complements this body of knowledge by demonstrating the application of the PSO algorithm for determining the parameters of the Bouc-Wen model when hysteresis depends not only on the electric field but also on the rate of the driving signal and when applied on a shear-type piezoelectric actuator. The obtained experimental data showed that with the increase of electric field strength, both the piezoelectric coefficient and hysteresis value increased significantly, and that with the increase of frequency, the piezoelectric coefficient decreased, while the hysteresis value changed slightly. The variations of the Bouc-Wen model parameters with the electric field and frequency were identified and then used to predict the shear motion trajectory of the piezoelectric stack. It was found that in the identified range of electric field and frequency, the predicted error rate of the hysteresis loop amplitude was less than 16.5% with a minimum value of 0.1%, and the error rate of the hysteresis loop width was less than 14.5% with a minimum value of 2.7%. Based on the identified electric field- and rate-dependent Bouc-Wen model, a novel finite element (FE) model was also proposed to analyse the effect of electrical and mechanical coupling on the piezoelectric movement. [Display omitted] • The dependence of hysteresis of the piezoelectric shear motion on the electric field and frequency is characterised. • The Bouc-Wen model is identified under different conditions of electric fields and frequencies. • An electric field- and rate-dependent hysteresis model based on the Bouc-Wen model is established. • A novel FE modelling approach is proposed to analyse the piezoelectric motion under coupled electrical-mechanical loads. [ABSTRACT FROM AUTHOR]

The development of a green, efficient, and reusable photocatalyst is of great importance for pollution remediation. Herein, a series of core-shell ZIF-8@NH 2 -MIL-125 composites (ZM-X) were prepared by epitaxial growth method. The in-situ homogeneous encapsulation of NH 2 -MIL-125 by ZIF-8 was achieved through the structural modulation, and the formed core-shell architecture exhibited outstanding synergistic effect of adsorption and photocatalysis for eliminating tetracycline hydrochloride (TCH), which dramatically enhanced the photocatalytic reaction rate. The results show that the TCH adsorption capacity of optimized ZIF-8@NH 2 -MIL-125 (ZM-2) is 70.25 mg g–1, which can be fitted well the pseudo-second-order and Langmuir isotherm modes. Under 100 min of visible light irradiation, the ZM-2 has the best synergistic removal rate on TCH (92.9%) compared with other samples, which is 6.5 times higher than of pristine NH 2 -MIL-125 (14.3%). The results of quenching experiments and ESR analysis clearly demonstrate that the superoxide radical (· O 2 –) dominates the TCH photodegradation reaction. In addition, ZM-2 can effectively remove TCH in different types of water systems (e.g., ultrapure water, tap water, lake water and actual pharmaceutical wastewater) through adsorption-photocatalytic synergy. Therefore, the novel core-shell material designed in this study has significant potential for environmental purification applications. [Display omitted] • The ZIF-8@NH 2 -MIL-125 was prepared with dense and uniform core-shell structure. • In situ growth of ZIF-8 on surface of NH 2 -MIL-125 to enhance its adsorption capacity. • The unique heterostructure realized efficient separation of photogenerated carriers. • High TCH removal rate was achieved by synergistic adsorption-photocatalytic. [ABSTRACT FROM AUTHOR]

The main purpose of this paper is to define prime and introduce non-commutative arithmetics based on Thompson's group F. Defining primes in a non-abelian monoid is highly non-trivial, which relies on a concept called "castling". Three types of castlings are essential to grasp the arithmetics. The divisor function τ on Thompson's monoid S satisfies τ(uv) ≤ τ(u)τ(v) for any u , v ∈ S . Then the limit τ 0 (u) = lim n → ∞ (τ (u n)) 1 / n exists. The quantity Ç (S) = sup 1 ≠ u ∈ S τ 0 (u) / τ (u) describes the complexity for castlings in S . We show that Ç (S) = 1 . Moreover, the Möbius function on S is calculated. And the Liouville function Ω on S is studied. [ABSTRACT FROM AUTHOR]

To study the decompression effects of shaft explosion-proof door at different lifting heights, this paper designed the gas explosion testing system. Based on the test results, this paper made a numeric analysis of the change regularities of the shock wave overpressure when the shaft explosion-proof door was lifted at different heights. Finally, this paper determined the proper lifting height of the shaft explosion-proof door and put forward the active decompression concept. The research showed that (1) the shock wave overpressure at the explosion-proof door decreased in a power exponential relationship as the lifting height increased. When the lifting height increased from 0 cm to 5 cm, the peak overpressure at the explosion-proof door decreased from 36.06 kPa to 22.47 kPa, dropping by 37.7%. When it was lifted at a height of 40 cm, the overpressure dropped to 11.20 kPa and the decompression reached 68.9%. (2) The overpressure at the ventilator decreased in a power exponential relationship as the lifting height increased. When the lifting height of the explosion-proof door increased from 0 cm to 5 cm, the decompression ratio reached the maximum 18.4%. After that, the decompression effect became worse and worse. (3) The explosion-proof door could depressurize and protect the ventilator at gas explosion but with limited effects. To protect the ventilator and the explosion-proof door to the maximum, it was suggested that the pressure sensor was set up somewhere in the mine where the gas explosion is likely to occur. In this way, the explosion was sensed in time and the explosion-proof door could be actively lifted for decompression. This paper was of great guiding significance in optimizing the design of the explosion-proof door equipment, reducing the loss of gas explosion accidents as well as carrying out the emergency rescue. [ABSTRACT FROM AUTHOR]

In the field of three‐dimensional (3D) cell culture and tissue engineering, great advance focusing on functionalized materials and desirable culture systems has been made to mimic the natural environment of cells in vivo. Mechanical loading is one of the critical factors that affect cell/tissue behaviors and metabolic activities, but the reported models or detection methods offer little direct and real‐time information about mechanically induced cell responses. Herein, for the first time, a stretchable and multifunctional platform integrating 3D cell culture, mechanical loading, and electrochemical sensing is developed by immobilization of biomimetic peptide linked gold nanotubes on porous and elastic polydimethylsiloxane. The 3D scaffold demonstrates very good compatibility, excellent stretchability, and stable electrochemical sensing performance. This allows mimicking the articular cartilage and investigating its mechanotransduction by 3D culture, mechanical stretching of chondrocytes, and synchronously real‐time monitoring of stretch‐induced signaling molecules. The results disclose a previously unclear mechanotransduction pathway in chondrocytes that mechanical loading can rapidly activate nitric oxide signaling within seconds. This indicates the promising potential of the stretchable 3D sensing in exploring the mechanotransduction in 3D cellular systems and engineered tissues. [ABSTRACT FROM AUTHOR]

Background: Circular RNAs (CircRNAs) have been recently implicated in the progression of pancreatic cancer (PC). Aims: To investigate the involvement of CircCCT3 in PC and studying its interactions and functioning during the progression of PC in vitro and in vivo, using methods of molecular biology and bioinformatics. Study Design: Experimental study. Methods: The expressions of CircCCT3 and miR-613 in pancreatic carcinoma tissues and cell lines were evaluated by quantitative real-time polymerase chain reaction (PCR). The relationship between clinical pathologic features as well as the survival rate and CircCCT3 expression was analyzed with chi-square test and the Kaplan--Meier method. CCK-8, wound healing, transwell assays, and the fluorescein isothiocyanate-AnnexinV/propidium iodide (FITC-AnnexinV/PI) assay were used to assess cell proliferation, migration, invasion, and apoptosis after CircCCT3 overexpression or downregulation. The Dual- Luciferase reporter assay, RNA immunoprecipitation (RIP), RNA pull-down and fluorescence in situ hybridization (FISH) assays were performed to validate the potential interaction of CircCCT3, miR-613, and vascular endothelial growth factor (VEGFA). The nude mouse xenograft tumor assay was used to detect CircCCT3 effects on pancreatic tumorigenesis in vivo. Western blotting analysis was performed to examine the VEGFA and the vascular endothelial growth factor receptor 2 (VEGFR2) protein expressions following. Results: CircCCT3 expression was significantly increased in PC tissues (3.41 ± 0.57 vs. 1.00 ± 0.10, P < .01) and cell lines (Patu8988 2.57 ± 0.20; SW1990 2.88 ± 0.10; BxPC-3 2.45 ± 0.20; Panc02 2.99 ± 0.10 vs. H6c7 1.00 ± 0.10; all P < .001). CircCCT3 expression was negatively correlated with miR-613 expression. PC patients with high CircCCT3 expression exhibited significantly poorer overall survival rate than those patients with low CircCCT3 expression (P = .013). Moreover, it was found that CircCCT3 promoted cell proliferation, migration, and invasion, and inhibited cell apoptosis in PC cells. The CircCCT3 acted as a sponge for the miR-613 to facilitate VEGFA and VEGFR2 expression. si-CirCCT3 also inhibited tumor growth of PC in nude mice. si-CircCCT3 reduced VEGFA and VEGFR2 expression, whereas overexpression of CircCCT3 increased VEGFA and VEGFR2 expression. Conclusion: Increased CircCCT3 suggests a poor prognosis for PC patients and promotes the migration and invasion through targeting VEGFA/VEGFR2 signaling. CircCCT3 may serve as a potential and promising therapeutic target for PC treatment. [ABSTRACT FROM AUTHOR]

In the field of three‐dimensional (3D) cell culture and tissue engineering, great advance focusing on functionalized materials and desirable culture systems has been made to mimic the natural environment of cells in vivo. Mechanical loading is one of the critical factors that affect cell/tissue behaviors and metabolic activities, but the reported models or detection methods offer little direct and real‐time information about mechanically induced cell responses. Herein, for the first time, a stretchable and multifunctional platform integrating 3D cell culture, mechanical loading, and electrochemical sensing is developed by immobilization of biomimetic peptide linked gold nanotubes on porous and elastic polydimethylsiloxane. The 3D scaffold demonstrates very good compatibility, excellent stretchability, and stable electrochemical sensing performance. This allows mimicking the articular cartilage and investigating its mechanotransduction by 3D culture, mechanical stretching of chondrocytes, and synchronously real‐time monitoring of stretch‐induced signaling molecules. The results disclose a previously unclear mechanotransduction pathway in chondrocytes that mechanical loading can rapidly activate nitric oxide signaling within seconds. This indicates the promising potential of the stretchable 3D sensing in exploring the mechanotransduction in 3D cellular systems and engineered tissues. [ABSTRACT FROM AUTHOR]

Complex time series data exists widely in actual systems, and its forecasting has great practical significance. Simultaneously, the classical linear model cannot obtain satisfactory performance due to nonlinearity and multicomponent characteristics. Based on the data-driven mechanism, this paper proposes a deep learning method coupled with Bayesian optimization based on wavelet decomposition to model the time series data and forecasting its trend. Firstly, the data is decomposed by wavelet transform to reduce the complexity of the time series data. The Gated Recurrent Unit (GRU) network is trained as a submodel for each decomposition component. The hyperparameters of wavelet decomposition and each submodel are optimized with Bayesian sequence model-based optimization (SMBO) to develop the modeling accuracy. Finally, the results of all submodels are added to obtain forecasting results. The PM2.5 data collected by the US Air Quality Monitoring Station is used for experiments. By comparing with other networks, it can be found that the proposed method outperforms well in the multisteps forecasting task for the complex time series. [ABSTRACT FROM AUTHOR]

A two component generalization Camassa–Holm equation with peakon is proposed, which is associated with a 2 × 2 matrix spectral problem with two potentials. As its reduction, a new integrable peakon equation is derived. Then positive flows associated with the 2 × 2 matrix spectral problem are discussed, a new hierarchy of nonlinear evolution equations is obtained. Subsequently, N -peakon of the peakon equation are constructed and the dynamical system with which the N -peakon evolve is deduced. As an example, exact single peakon and 2-peakon are given and their figures are plotted. Moreover, infinitely many conserved quantities of the peakon equation are obtained. [ABSTRACT FROM AUTHOR]

Conventional frequency modulated LLC topology is unsuitable for ultrawide voltage range applications and suffers from poor voltage regulation performance at light load conditions. To cope with those issues, this article proposes a novel two-phase dual LLC resonant converter. The primary side of the proposed converter is two paralleled half-bridges LLC, and the transformers’ secondary sides are in reverse series with shared full bridge rectifier. Both resonant tanks are driven by two fixed-frequency square waves, whose frequencies are always tuned at the optimal resonant frequency. A phase shift is introduced between those two square waves to regulate the output voltage. The proposed topology demonstrates good voltage regulation performance, which is weakly dependent on the load condition. Zero-voltage switching and zero-current switching are well realized on the power mosfets and diodes in a wide range. A 1-kW rated laboratory prototype is designed to convert 390 V input to 10–420 V output. The prototype demonstrates a 98.1% peak efficiency and good voltage regulation capability. The experimental results agree well with the theoretical analysis. [ABSTRACT FROM AUTHOR]

In order to accurately grasp the characteristics and influencing factors of gas explosion in heading face, the mathematical model of gas explosion was determined. According to the actual size of a heading face of a coal mine, a 3D geometric model with a length of 100 m was established, and the effects of ignition energy and gas explosion equivalent on the gas explosion characteristics of the heading face were analyzed. The results show the following. (1) The mathematical models for numerical simulation of gas explosion can accurately simulate the gas explosion and its propagation process. The time-space step size has a great influence on the simulation results. The grid spacing for numerical simulation of mine gas explosion is determined to be 0.1 m and the time step length is determined to be 0.001 s. (2) The ignition energy has a limited effect on gas explosion characteristics. It only has a certain influence on the gas explosion process, but has little influence on the overpressure of shock wave. The larger the ignition energy is, the faster the explosion reaction speed is, and the maximum overpressure increases slightly. When the ignition energy increases to a certain value, the time of peak shock wave and the maximum overpressure both tend to be stable. The ignition energy has little effect on gas explosion characteristics when an explosion accident occurs underground with a large amount of gas accumulation. (3) The gas explosion equivalent has a great influence on the overpressure of gas explosion shock wave. The higher the explosion equivalent is, the greater the pressure is, and the peak value of the shock wave overpressure increases with the explosion equivalent as a power function. The research results have important guiding significance for the research and development of new technology for prevention and control of gas explosion. [ABSTRACT FROM AUTHOR]

To explore the mechanical failure and permeability characteristics of porous gas-bearing coal under triaxial stress, the triaxial compression experiment was carried out for porous and conventional gas-bearing coal samples based on the triaxial creep-seepage experiment system and sound emission signal acquisition system. Acoustic emission testing was carried out at the same time of loading failure. The experimental results showed that (1) under fixed gas pressure but changing confining pressure, the porous gas-bearing coal sample had higher peak strength and elastic modulus but lower peak strain; under changing gas pressure but fixed confining pressure, the porous gas-bearing coal sample had lower peak strength and peak strain but higher elastic modulus. When either confining pressure or gas pressure was changed, the mechanical properties of the two kinds of gas-bearing coal samples showed a good consistency, but the mechanical parameters differed greatly, with the peak strength, peak strain, and elastic modulus of porous coal samples are reduced by 1/4, 2/3, and 3/4, respectively. (2) When either the confining pressure or gas pressure was changed, the permeability of the porous gas-bearing coal sample was larger than that of the conventional gas-bearing coal sample. However, the change rules of permeability characteristics of the two were basically the same, except that there was a large difference in permeability value that the porous gas-bearing coal sample increases nearly twice as much as that of the conventional gas-bearing coal sample. (3) In the whole stress-strain process, the acoustic emission characteristics of the porous gas-bearing coal sample differed significantly from those of the conventional gas-bearing coal sample. The maximum ringdown count of the porous gas-bearing coal sample can be reduced by one-third at most, the maximum energy can be reduced by nearly half at most, and the maximum amplitude changes little with only 1–3 dB reduction. The research results have important guiding significance for the prediction of failure and instability of coal tunnel and the development of relevant protective techniques. [ABSTRACT FROM AUTHOR]

Using the borehole instability model based on theory of microscopic scale elastic damage, the authors conducted numerical analysis of deformation characteristics of drainage borehole at different burial depths and proposed the deformation instability mode for drainage borehole. Results showed that (1) the borehole at shallow depth had less deformation and remained in quasi-circular shape; as the burial depth increased, the deformation of borehole wall became more significant, the top area of borehole showed slight caving, the lower area of borehole displayed coal spalling, and the whole borehole changed into "ellipse-like shape"; the borehole at large burial depth was subjected to severe collapse or even blocking, and the buckling failure mode of the borehole was featured by collapses at upper area (forming a collapse area) and breaks at left and right sides (forming a broken zone). (2) The deeper the burial depth was, the higher the deformation degree was, the larger the pressure released zone around borehole was, and the more significant the gas permeability change of surrounding coal mass caused by borehole deformation was; in general, the instability and deformation of borehole had a less impact on the gas permeability of surrounding borehole. The gas permeability change of surrounding coal mass approximately followed "V shape" rule. (3) According to the creep deformation properties of coal mass and the deformation mechanism of borehole and combining the numerical analysis results and results of previous researches, this study presents the deformation modes of three types of boreholes (complete, collapsed, and blocked boreholes) and corresponding on-site preventive measures. The results of this study are of great guiding significance for the improvement of coal seam gas extraction effect. [ABSTRACT FROM AUTHOR]

The hierarchy of coupled Boussinesq equations related to a 4 × 4 matrix spectral problem is derived by using the zero-curvature equation and Lenard recursion equations. The characteristic polynomial of the Lax matrix is employed to introduce the associated tetragonal curve and Riemann theta functions. The detailed theory of resulting tetragonal curves is established by exploring the properties of Baker–Akhiezer functions and a class of meromorphic functions. The Abel map and Abelian differentials are used to precisely determine the linearization of various flows. Finally, algebro-geometric solutions for the entire hierarchy of coupled Boussinesq equations are obtained. [ABSTRACT FROM AUTHOR]

The falling ball tests were carried out on the F125 mm diameter Carbidic Austempered Ductile Iron (CADI) grinding balls with Mn content of 2.0wt.%, 2.3wt.%, 2.6wt.% and 3.0wt.%, respectively, and the kind of grinding ball with the most serious spalling was selected for stress simulation. The stress distribution between four grinding balls in the elbow of the falling ball test device when they collided with each other was simulated based on ANSYS. Results of the falling ball tests show that the spalling and mass loss of a CADI grinding ball increases with the increase of Mn content, and the CADI grinding ball with 3.0wt.% Mn shows the most obvious spalling and mass loss. The simulation results of stress distribution of a CADI grinding ball show that the maximum impact stress does not appear in the center of the contact area, but in the annular area (inner diameter of ~20 mm and outer diameter of ~50 mm) in the section with a depth of 5-15 mm below the grinding ball surface. The actual spalling of the ball is consistent with the simulation results, and the oxide-based impurities in CADI grinding ball accelerate the spalling of the grinding ball in service. [ABSTRACT FROM AUTHOR]

In this paper, an LLC type converter with two interleaved pulsewidth modulation (PWM) rectifiers is proposed. Compared with the conventional LLC converter, it achieves a wide voltage regulation range independent of load. In the proposed structure, each secondary-side PWM rectifier can operate individually. With the interleaving technique and shared primary-side switching network, the circuit secondary-side current stress is halved and the primary-side current stress is largely reduced. Besides, the filter capacitor requirement is reduced. Therefore, the proposed structure is a good option for medium/high power wide output range applications. The symmetrical LLC resonant tanks always operate at the resonant frequency, which marks the optimal operation point of the LLC resonant tank. Therefore, the conduction loss is effectively mitigated. In the proposed converter, zero-voltage turning-on (ZVS) of the primary-side MOSFETs can be ensured and is independent of the load. Moreover, the turning-off currents of the primary-side MOSFETs are small and are also load independent. This brings the benefits of minimized circulating current and negligible turning-off loss and no MOSFET turning-off voltage spike. The secondary-side auxiliary MOSFETs turn-on with ZVS and rectifying diodes turn-off with limited di/dt. Topological analysis and experimental results of a 1.3 kW/100 kHz prototype generating 230–440 V output from 390-V input are presented. The prototype demonstrates 97.31% peak efficiency and good performance over a wide output range. [ABSTRACT FROM AUTHOR]

Utilizing Nevanlinna's value distribution theory of meromorphic functions, we study transcendental entire solutions of the following type nonlinear differential equations in the complex plane f n (z) + P (z , f , f ′ , ... , f (t)) = P 1 e α 1 z + P 2 e α 2 z + P 3 e α 3 z , $$\begin{array}{} \displaystyle f^{n}(z)+P(z,f,f',\ldots,f^{(t)})=P_{1}\text{e}^{\alpha_{1}z}+P_{2}\text{e}^{\alpha_{2}z}+P_{3}\text{e}^{\alpha_{3}z}, \end{array}$$ where Pj and αi are nonzero constants for j = 1, 2, 3, such that |α1| > |α2| > |α3| and P(z, f, f′, ..., f(t) is an algebraic differential polynomial in f(z) of degree no greater than n – 1. [ABSTRACT FROM AUTHOR]

In this paper, the influences of tip wear of atomic force microscope (AFM) on evaluating the surface quality were studied. Three typical ultra-precision machined surfaces respectively machined by ultra-precision grinding, ultra-precision turning, and ultra-precision polishing were chosen, and the silicon tips with different wear degrees, the new tip, the moderately worn tip, and the badly worn tip, were employed to scan these three surfaces. By analyzing the AFM scanning results from different tips, each type of surface was characterized with the methods of 3D surface texture parameters and power spectral density (PSD). It was found that the tip wear would mainly degrade the ability of tip on measuring the valley structure and cause more artifacts when measuring the peak structure, which resulted in the effects on evaluating surface roughness parameters and identifying the high-frequency harmonic components. Moreover, due to the different topography characteristics of these three ultra-precision machined surfaces, the influences caused by tip wear on the evaluation of the surface quality were reflected in different aspects. [ABSTRACT FROM AUTHOR]

A series of sulfide and sulfone substituted perylene diimides (PDIs) with different LUMO levels covering a range of 0.72 eV were synthesized through simple sulfur redox chemistry. The LUMO level of phenylsulfone substituted PDI reached a record-breaking −4.75 eV. In addition, the maximum emission ranged from 540 to 692 nm. [ABSTRACT FROM AUTHOR]

Gelsolin is a severing and capping protein that targets filamentous actin and regulates filament lengths near plasma membranes, contributing to cell movement and plasma membrane morphology. Gelsolin binds to the plasma membrane via phosphatidylinositol 4,5-bisphosphate (PIP2) in a state that cannot cap F-actin, and gelsolin-capped actin filaments are uncapped by PIP2 leading to filament elongation. The process by which gelsolin is removed from PIP2 at the plasma membrane is currently unknown. Gelsolin also binds ATP with unknown function. Here we characterize the role of ATP on PIP2-gelsolin complex dynamics. Fluorophore-labeled PIP2 and ATP were used to study their interactions with gelsolin using steady-state fluorescence anisotropy, and Alexa488-labeled gelsolin was utilized to reconstitute the regulation of gelsolin binding to PIP2-containing phospholipid vesicles by ATP. Under physiological salt conditions ATP competes with PIP2 for binding to gelsolin, while calcium causes the release of ATP from gelsolin. These data suggest a cycle for gelsolin activity. Firstly, calcium activates ATP-bound gelsolin allowing it to sever and cap F-actin. Secondly, PIP2-binding removes the gelsolin cap from F-actin at low calcium levels, leading to filament elongation. Finally, ATP competes with PIP2 to release the calcium-free ATP-bound gelsolin, allowing it to undergo a further round of severing. [ABSTRACT FROM AUTHOR]

The mechanism associated with Toll-like receptor 4 (TLR4) in neurological injury remains unclear. The aim of the present study was to investigate the pathology of TLR4 in middle cerebral artery occlusion (MCAO)/reperfusion rat models via the regulation of collapsin response mediator protein 2 (CRMP2) phosphorylation. The modified neurological severity score (mNSS) was applied to assess neurological recovery. Immunofluorescence and western blotting were used to detect the protein expressions of TLR4, Rho-associated protein kinase 2 (ROCK-II) and CRMP2 following the intracerebroventricular administration of TLR4-specific agonist, lipopolysaccharide (LPS) and TLR4-neutralizing antibody, the ROCK-II specific inhibitor Y-27632 or LPS+Y-27632 30 min prior to MCAO. The expression levels of TLR4 and the phosphorylation of CRMP2 significantly increased in response to LPS-mediated induction and/or MCAO; however, they were reversed by treatment with LPS+TLR4-neutralizing antibody. Y-27632 decreased the expression of ROCK-II and phosphorylated (p)-CRMP2, and suppressed the increased ROCK-II and p-CRMP2 induced by LPS; however, no effect on the levels of TLR4 expression was observed. The neurological function as measured by mNSS score was reduced in the LPS group when compared with the MCAO group, whereas the LPS+Y-27632 group reversed the reduced neurological function at 7 and 14 days post-MCAO. The results of the present study suggested that TLR4 may promote the phosphorylation of CRMP2 via the activation of ROCK-II in MCAO rats, which further characterizes the pathological mechanism of TLR4 in stroke, and that modulation of TLR4 could be a potential target to limit secondary post-stroke brain damage. [ABSTRACT FROM AUTHOR]

Current achievements on electrochemical monitoring of cells are often gained on two-dimensional (2D) substrates, which fail in mimicking the cellular environments and accurately reproducing the cellular functions within a three-dimensional (3D) tissue. In this regard, 3D scaffold concurrently integrated with the function of cell culture and electrochemical sensing is conceivably a promising platform to monitor cells in real time under their in vivo-like 3D microenvironments. However, it is particularly challenging to construct such a multifunctional scaffold platform. Herein, we developed a 3-aminophenylboronic acid (APBA) functionalized graphene foam (GF) network, which combines the biomimetic property of APBA with the mechanical and electrochemical properties of GF. Hence, the GF network can serve as a 3D scaffold to culture cells for a long period with high viability and simultaneously as an electrode for highly sensitive electrochemical sensing. This allows monitoring of gaseous messengers H[sub 2]S released from the cells cultured on the 3D scaffold in real time. This work represents considerable progress in fabricating 3D cell culture scaffold with electrochemical properties, thereby facilitating future studies of physiologically relevant processes. [ABSTRACT FROM AUTHOR]

With a high potential in generating clean electricity, hydropower energy is an important resource of producing clean energy. In this article, a critical assessment of economics of hydropower energy in developed and developing countries such as USA, Canada, India, and China was carried out. From the literature, China potential of installed hydropower systems was estimated around 600 GW but due to some economic and technical problems, it is currently concentrated on the nominal capacity of 500 GW but aims to increase its installed hydropower capacity to 350 GW by 2020. After the critical assessment, the social and environmental impacts of dam construction on the quality of life of people, and flora and fauna, living in the vicinity of dams were studied. As a result, dam construction makes it necessary, in many cases, to destroy a large part of forests and wildlife. This, in turn, can trigger rare plant and animal species’ risk of extinction. [ABSTRACT FROM AUTHOR]

This study investigated the effects of epigallocatechin gallate (EGCG) on the growth performance and antioxidant capacity of 35-d-old broilers exposed to heat stress. Broilers, 14 d of age, were divided into four groups with six replicates per group (eight chickens/replicate). Thermoneutral group (Group TN) was fed the basal diet and maintained at 28°C for 24 h/d. The heat-stressed groups were housed at 35°C for 12 h/d and 28°C for 12 h/d and fed the basal diet supplemented with EGCG at 0, 300 and 600 mg/kg diet (Groups HS0, HS 300 and HS600, respectively). Compared with Group TN, heat-stressed groups showed significantly reduced gain, feed intake and serum total protein and glucose levels; inhibited serum alkaline phosphatase activities; and increased serum levels of uric acid, cholesterol and triglycerides and the activity of serum creatine kinase, lactate dehydrogenase and aspartate aminotransferase (p < 0.05). Compared with Group HS0, Group HS600 exhibited an increased gain and feed intake; and normalised blood parameters and enzyme activities. Compared with Group TN, the expression of antioxidant-related liver proteins was decreased in Group HS0 and increased in Groups HS300 and HS600 (p < 0.05). The results suggest that EGCG can improve the growth performance and alleviate the oxidant damage by modulating the antioxidant properties of broilers. [ABSTRACT FROM AUTHOR]

• Two classical models combined for modelling nonlinearity in shear-type piezo actuators. • Novel combined model applicable for high electric field and frequency signals. • Coupled mechanical-electrical finite element (FE) simulations implemented. • Experimental setup developed for corresponding vibration-assisted nanomachining operations. • Good agreement found between FE simulations and experiments. Recent research investigations have reported the benefit of enhancing conventional AFM-based nanoscale machining operations by the introduction of high frequency vibrations between the AFM tip and the processed material. The technique relies on piezoelectric actuation and is relatively straight forward to implement in practice. However, the non-linearity of piezoelectric actuators when operated under high electric field and frequency conditions can affect the dimensional accuracy of the fabricated nanostructures. To address these issues, the paper reports a method based on coupled mechanical-electrical Finite Element (FE) modelling to predict the relative motion between an AFM tip and a workpiece for vibration-assisted AFM-based nanomachining applications. In particular, the novelty of the proposed method is that it combines two classical approaches for modelling the nonlinear behaviour of piezoelectric materials. More specifically, two sources of non-linearity are considered simultaneously by combining the field-dependant model from Muller and Zhang with the frequency-dependant model from Damjanovic. The resulting combined model is employed to establish the piezoelectric constitutive equations implemented in the developed coupled field FE model. A further distinguishing characteristic of the work is that the proposed approach was subsequently validated by comparing the predicted widths of nanoscale grooves against those machined with a custom AFM-based vibration-assisted nanomachining configuration. [Display omitted] [ABSTRACT FROM AUTHOR]

Online denoising is motivated by real-time applications in the industrial process, where the data must be utilizable soon after it is collected. Since the noise in practical process is usually colored, it is quite a challenge for denoising techniques. In this paper, a novel online denoising method was proposed to achieve the processing of the practical measurement data with colored noise, and the characteristics of the colored noise were considered in the dynamic model via an adaptive parameter. The proposed method consists of two parts within a closed loop: the first one is to estimate the system state based on the second-order adaptive statistics model and the other is to update the adaptive parameter in the model using the Yule–Walker algorithm. Specifically, the state estimation process was implemented via the Kalman filter in a recursive way, and the online purpose was therefore attained. Experimental data in a reinforced concrete structure test was used to verify the effectiveness of the proposed method. Results show the proposed method not only dealt with the signals with colored noise, but also achieved a tradeoff between efficiency and accuracy. [ABSTRACT FROM AUTHOR]

Müller cell reactivation (gliosis) is an early response in glaucomatous retina. Previous studies have demonstrated that activation of P2X 7 receptors results in retinal ganglion cell (RGC) apoptosis. Here, the issues of whether and how activated Müller cells may contribute to RGC apoptosis through P2X 7 receptors were investigated. Either intravitreal injection of (S)-3,5-dihydroxyphenylglycine (DHPG), a group I metabotropic glutamate receptor (mGluR I) agonist, in normal rat retinas, or DHPG treatment of purified cultured rat retinal Müller cells induced an increase in glial fibrillary acidic protein (GFAP) expression, indicative of Müller cell gliosis. In addition, an increase in adenosine triphosphate (ATP) release from purified cultured Müller cells was detected during DHPG treatment (for 10 min to 48 h), which was mediated by the intracellular mGluR5/Gq/PI-PLC/PKC signaling pathway. Intravitreal injection of DHPG mimicked the reduction in the number of fluorogold retrogradely labeled RGCs in chronic ocular hypertension (COH) rats. Treatment with the conditioned culture medium (CM) obtained from the DHPG-activated Müller cell medium induced an increase in the number of TUNEL-positive cells in cultured RGCs, which was mimicked by benzoylbenzoyl adenosine triphosphate (BzATP), a P2X 7 receptor agonist, but was partially blocked by brilliant blue G (BBG), a P2X 7 receptor antagonist. Moreover, the CM treatment of cultured RGCs significantly increased Bax protein level and decreased Bcl-2 protein level, which was also mimicked by BzATP and partially blocked by BBG, respectively. These results suggest that reactivated Müller cells may release excessive ATP, in turn leading to RGC apoptosis through activating P2X 7 receptors in these cells. [ABSTRACT FROM AUTHOR]

The characteristic life stages of infesting blowflies (Calliphoridae) such as Chrysomya megacephala (Fabricius) are powerful evidence for estimating the death time of a corpse, but an established reference of developmental times for local blowfly species is required. We determined the developmental rates of C. megacephala from southwest China at seven constant temperatures (16-34°C). Isomegalen and isomorphen diagrams were constructed based on the larval length and time for each developmental event (first ecdysis, second ecdysis, wandering, pupariation, and eclosion), at each temperature. A thermal summation model was constructed by estimating the developmental threshold temperature D0 and the thermal summation constant K. The thermal summation model indicated that, for complete development from egg hatching to eclosion, D0 = 9.07 ± 0.54°C and K = 3991.07 ± 187.26 h °C. This reference can increase the accuracy of estimations of postmortem intervals in China by predicting the growth of C. megacephala. [ABSTRACT FROM AUTHOR]

• The VOCs can be detected or monitored by analytical instruments or biosensors. • The VOCs formed different gallery plot fingerprints in the muscle tissues of the human dead body and seven animal species. • Some VOCs had high species specificity, demonstrating that all tested muscle tissue samples could be distinguished based on different VOCs. • HS-GC-IMS proved to be a rapid, high-throughput, high-sensitivity and specific species identification method. Species identification of unknown biological samples is crucial for forensic applications, especially in cases of explosion, disaster accidents, and body mutilation after murdering, as well as poaching, illegal trade in endangered animals, and meat food fraud. In this study, we identified 60 volatile organic compounds (VOCs) in fresh skeletal muscle tissues of seven different animal species (cattle, sheep, pigs, rabbits, rats, chickens and carp) and a human dead body by headspace-gas-chromatography ion-mobility spectrometry (HS-GC-IMS), and compared their differences by retention time, drift time and molecular weight. The results showed that these VOCs formed different gallery plot fingerprints in the skeletal muscle tissues of the human dead body and seven animal species. Principal component analysis (PCA) showed significantly different fingerprints between these species, and these fingerprints maintained good stability between the species and within the same species. Some VOCs have high species specificity, while VOCs of human fresh muscle tissues from different individual sources have little difference, demonstrating that all tested muscle tissue samples could be distinguished based on different VOCs. HS-GC-IMS has proved to be a rapid, high-throughput, highly sensitive and specific species identification method, which can be used for forensic species identification in criminal cases and disaster accidents, as well as detection in the field of food safety, such as meat fraud and adulteration. [ABSTRACT FROM AUTHOR]

In this study, a tip-based channel fabricating method on aluminum alloy material is studied using different tip moving trajectories. A three-sided pyramidal tip is driven by a three-axis piezoelectric actuator to do the movements of the circle, the sharp ellipse (major axis along the feeding direction), and the flat ellipse (minor axis along the feeding direction) revolutions are the three kinds of moving trajectories used for machining. In each revolution, due to the shapes of tip and moving trajectory, there would be two cutting edges participating in machining process. Under these three trajectories, the variations of uncut chip thickness and cutting rake angle with tip revolving and the cutting length of every edge in each tip revolution are different, which results in different sizes of chips and burrs formed. Effects of these three moving trajectories on the material removal are studied in detail. Through processing experiments, it was found that without any deburring method, the channel machined using the sharp ellipse trajectory has two edges with no burr formed and could obtain better bottom surface quality with a smaller feed rate, while channels machined using the other two both have burrs at the right side, which results from the accumulation of chips. Finally, to eliminate or reduce this chip accumulation further, a three-dimensional moving trajectory is designed as a deburring method and used to process channels. It was found that this deburring method plays a significant role on the circle trajectory, but it is ineffective on the flat ellipse trajectory. [ABSTRACT FROM AUTHOR]

In practical RFID tracking systems, usually it is impossible that the readers are placed right with a “grid” structure, so effective estimation method is required to obtain the accurate trajectory. Due to the data-driven mechanism, measurement of RFID system is sampled irregularly; therefore the traditional recursive estimation may fail from K to K+1 sampling point. Moreover, because the distribution density of the readers is nonuniform and multiple measurements might be implemented simultaneously, fusion of estimations also needs to be considered. In this paper, an irregular estimation strategy with parallel structure was developed, where the dynamic model update and states fusion estimation were processed synchronously to achieve real-time indoor RFID tracking. Two nonlinear estimation methods were proposed based on the extended Kalman filter (EKF) and unscented Kalman filter (UKF), respectively. The tracking performances were compared, and the simulation results show that the developed UKF method got lower covariance in indoor RFID tracking while the EKF one cost less calculating time. [ABSTRACT FROM AUTHOR]

Layered discretization is an efficient way of realizing thermal cloaks. The aim of this paper is to investigate the effect of nonlinear coordinate transformation on the thermal cloaking performance of multilayered cylindrical thermal cloak. Two indexes are defined to quantify the thermal cloaking performance. Nonlinear coordinate transformations with different forms are established to design the multilayered structures and the thermal cloaking performances are analyzed by full-wave simulations. The results show that the thermal cloaking performances of multilayered structures are directly influenced by the form of coordinate transformation which determines the distributions of heat flows in the cloak region. Through the active changing of the form of coordinate transformation, the thermal cloaking performance of multilayered structure can be controlled and optimized. In addition, a three-piecewise linear coordinate transformation is designed to concentrate the heat flux into the middle region of the cloak and the corresponding multilayered structure is demonstrated to have near-perfect thermal cloaking performance. These results may provide a beneficial guidance to achieve performance improvements for multilayered structures of thermal cloaks. [ABSTRACT FROM AUTHOR]

The measurement resolution of an atomic force microscope (AFM) is largely dependent on the radius of the tip. Meanwhile, when using AFM to study nanoscale surface properties, the value of the tip radius is needed in calculations. As such, estimation of the tip radius is important for analyzing results taken using an AFM. In this study, a geometrical model created by scanning a step structure with an AFM tip was developed. The tip was assumed to have a hemispherical cone shape. Profiles simulated by tips with different scanning radii were calculated by fast Fourier transform (FFT). By analyzing the influence of tip radius variation on the spectra of simulated profiles, it was found that low-frequency harmonics were more susceptible, and that the relationship between the tip radius and the low-frequency harmonic amplitude of the step structure varied monotonically. Based on this regularity, we developed a new method to characterize the radius of the hemispherical tip. The tip radii estimated with this approach were comparable to the results obtained using scanning electron microscope imaging and blind reconstruction methods. [ABSTRACT FROM AUTHOR]

Electrochemical devices are fast, sensitive, accurate, and convenient as sensing and mass or energy conversion platforms. Metal–organic frameworks (MOFs) attract much attention because of their intriguing properties. MOFs have great potential for electrochemical applications, but two challenges are confronted, including the design of redox-active MOFs (ra-MOFs) and the improvement of MOF conductivity. Redox or catalytic active sites can be introduced using active ligands or metal ions, and active complexes as building blocks. MOFs can also hold active guest molecules, enzymes, bacteria, and nanoparticles and promote electrochemical activity. In order to improve MOF conductivity, conductive ligands and metal nodes are rational choices to form long-range delocalized electrons for charge mobility. Integrating guest molecules or mixing with electrical conductors is the alternative. The MOF film attached on the substrate surface facilitates direct electron transfer and device building. High sensitivity and selectivity of MOF-based electrochemical sensors and improved mass or energy conversion are anticipated. [ABSTRACT FROM AUTHOR]

Darboux transformation for a nonlinear integrable equation associated with 3 × 3 matrix spectral problems, which is constructed by Lenells, is derived with the aid of the gauge transformation between the corresponding Lax pairs. By using the Darboux transformation, new explicit solutions for the nonlinear integrable equation are given and their figures are plotted. Finally, infinitely many conservation laws of this equation are deduced. [ABSTRACT FROM AUTHOR]

The marriage of metal-organic frameworks (MOFs) and electrochemiluminescence (ECL) can combine their merits together. Designing ECL-active MOF with a high electron transfer capacity and high stability is critical for ECL emission. Here we reported the ECL from a redox-active MOF prepared from {Ru[4,4′-(HO 2 C) 2 -bpy] 2 bpy} 2+ and Zn 2+ ; a property of MOFs has not been reported previously. The MOF structure is independent of its charge and is therefore stable electrochemically. The redox-activity and well-ordered porous structure of the MOF were confirmed by its electrochemical properties and ECL emission. The high ECL emission indicated the ease of electron transfer between the MOF and co-reactants. Furthermore, the MOF exhibited permselectivity, charge selectivity, and catalytic selectivity along with a stable and concentration-dependent ECL emission toward co-reactants. ECL mechanism was proposed based on the results. The detection and recovery of cocaine in the serum sample was used to validate the feasibility of MOF- based ECL system. The information obtained in this study provides a better understanding of the redox properties of MOFs and their potential electrochemical applications. [ABSTRACT FROM AUTHOR]

A new yttrium-zirconium-pillared montmorillonite (Y-Zr-MMT), was synthesized, characterized and used as a Ce catalyst support. The Y-Zr-MMT is a good support for dispersing cerium active sites and it is responsible for the high activity in the total oxidation of acetone, toluene and ethyl acetate. The Y-Zr-MMT shows greater advantages than the conventional alumina/cordierite honeycomb supports such as large specific surface area, lower cost and easier preparation. Catalytic tests demonstrated that Ce/Y-Zr-MMT (Ce loading 8.0%) was the most active, with the total oxidation of acetone, toluene and ethyl acetate being achieved at 220, 300 and 220°C, respectively. The catalyst displayed better activity for the oxidation of acetone and ethyl acetate than a conventional, supported Pd-catalyst under similar conditions. The special structure of the yttrium-doped zirconium-pillared montmorillonite can strengthen the interaction between the CeO2and Zr-MMT support and improve the dispersion of the Ce particles, which enhances the catalytic activity for the oxidation of VOCs. The new catalyst, 8.0%Ce/Y-Zr-MMT, could be promising for industrial applications due to its high catalytic activity and low cost. The support and the catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and BET specific surface area measurements. [ABSTRACT FROM AUTHOR]

In this paper a three-sided pyramidal tip was driven in a circular trajectory to perform micro-machining process. The circular trajectory was achieved by rotating the tip around a center point. Because of the asymmetry of the three-sided pyramidal tip, machining micro channels along different feeding directions would cause different cutting tracks, which influences the finish of channel sides. It was found that the variations of cutting rake angle and uncut chip thickness in each revolution mainly affected the burr formation. By studying effects of tip edge radius and tip geometry on machining process, a channel with slight burr at two sides was obtained. Using the optimized machining method and coordinating with feed motion of the work stage, perfect three-dimensional structures with well-finishing edges were obtained on aluminum alloy and polymethylmethacrylate (PMMA) surfaces. The dimension of fabricated 3D structures can be controlled in three dimensional directions, ranging from ten microns to several hundred microns. [ABSTRACT FROM AUTHOR]