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The spin-orbital coupling (SOC) effect and magnetic anisotropy energy (MAE) of 13-atom Fe-Pt, Co-Pt and Ni-Pt clusters were investigated by density functional theory. The result shows that the Fe-Pt system has a higher MAE than Co-Pt and Ni-Pt. In the Fe8Pt5 cluster, the main contribution of MAE comes from SOC interaction between d orbitals around the Fermi level in Pt atoms. The giant positive MAE is mainly due to the SOC interaction between the majority spin states of $ {\textrm{d}_{{x^2}}} $ d x 2 and $ {\textrm{d}_{xy}} $ d x y orbitals. [ABSTRACT FROM AUTHOR]

Shear wave splitting (SWS) is currently considered to be the most robust seismic attribute to characterize fractures in geological formations. Despite its importance, the influence of fluid pressure communication between connected fractures on SWS remains largely unexplored. Using a 3-D numerical upscaling procedure based on the theory of poroelasticity, we show that fracture connectivity has a significant impact on SWS magnitude and can produce a 90° rotation in the polarization of the fast quasi-shear wave. The simulations also indicate that SWS can become insensitive to the type of fluid located within connected fractures. These effects are due to changes of fracture compliance in response to wave-induced fluid pressure diffusion. Our results improve the understanding of SWS in fractured formations and have important implications for the detection and monitoring of fracture connectivity in hydrocarbon and geothermal reservoirs as well as for the use of SWS as a forecasting tool for earthquakes and volcanic eruptions. [ABSTRACT FROM AUTHOR]

Out-of-hospital cardiac arrest (OHCA) is a leading cause of global mortality, with numerous factors influencing the patient survival rate and prognosis. This study aimed to evaluate the OHCA epidemiology in China and elaborate on the current Hangzhou emergency system status. This retrospective analysis was based on the medical history system of the Hangzhou Emergency Center registered from 2015–2021. We provided a detailed description of OHCA characteristics and investigated the factors affecting the success rate of emergency treatment in terms of epidemiology, causes of onset, bystander rescue, and outcome factors. We included 9585 out-of-hospital cardiac arrest cases, of which 5442 (56.8%) had evidence of resuscitation. Patients with underlying diseases constituted the vast majority (80.1%); trauma and physicochemical factors accounted for 16.5% and 3.4%, respectively. Only 30.4% of patients (about 80.0% of bystanders witnessed) received bystander first aid. The outcome rate of emergency doctors dispatched by emergency centres was significantly higher than doctors dispatched by hospitals. Additionally, physician's first-aid experience, emergency response time, emergency telephone availability, initial heart rhythm, out-of-hospital defibrillation, out-of-hospital intubation, and using of epinephrine significantly can significantly improve the out-of-hospital return of spontaneous circulation in patients. All steps in pre-hospital care are important for patients, especially for bystander first aid and physician's first-aid experience. The popularity of first-aid training and the public emergency medical system are not potent enough. We should take those key factors into consideration when developing a pre-hospital care system for OHCA. [ABSTRACT FROM AUTHOR]

We present a novel coupled fluid‐poroelastic model and an associated numerical upscaling procedure to calculate seismic attenuation and velocity dispersion in porous rocks induced by fluid pressure diffusion (FPD) in the presence of mesoscopic fluid‐saturated voids, such as, for example, vugs or factures. By applying appropriate interface conditions, the proposed model couples the Navier‐Stokes equations for viscous fluids with Biot's equations of poroelasticity to model the mesoscopic voids and the embedding background, respectively. A finite element method is employed to solve the coupled problem for a set of three relaxation tests, which enables us to compute the complex‐valued and frequency‐dependent equivalent stiffness matrix of the considered synthetic sample. The newly proposed fluid‐poroelastic approach is compared with a purely poroelastic one as well as a fluid‐elastic approach in a benchmark model containing interconnected mesoscopic fractures embedded in a poroelastic background. We obtain excellent agreement for the proposed approach and the purely poroelastic model by optimizing the material properties of the fractures for the latter, which demonstrates both the correctness and advantages of our method over the purely poroelastic approach for modeling fluid‐saturated mesoscopic voids. We also observe that, while the coupled fluid‐elastic approach and the proposed method provide consistent results with regard to seismic attenuation due to the fracture‐to‐fracture FPD, the latter also allows to account for the effects of fracture‐to‐background FPD. Finally, we employ the proposed methodology to explore the seismic characteristics of a synthetic "vuggy" carbonate‐type sample, for which we visualize and interpret the resulting seismic attenuation in terms of FPD between the microscopic and mesoscopic pores. Plain Language Summary: Seismic waves are commonly employed to study porous and/or fractured geological formations in the Earth's upper crust. In the presence of relatively small heterogeneities, such as fluid‐saturated fractures or vugs, seismic waves may exhibit velocity variation and amplitude decay due to fluid pressure diffusion processes, which are important characteristics of seismic waves. To date, it remains difficult to understand how complex and fluid‐saturated voids impact these seismic characteristics. To address this problem, we propose a novel coupled fluid‐poroelastic model and develop a corresponding numerical upscaling procedure to calculate seismic characteristics of porous media containing mesoscopic heterogeneities. Our results demonstrate that the proposed approach is more accurate and flexible than previous related models, which, in turn, opens new and interesting perspectives for the seismic exploration of corresponding geological environments. Key Points: We develop a numerical upscaling procedure to calculate seismic signatures based on a novel coupled fluid‐poroelastic modelIn the presence of fluid‐saturated mesoscopic voids, the newly proposed coupled approach is more flexible and more accurate than existing methodologiesApplication to a synthetic "vuggy" carbonate‐type rock sample provides new insights into seismic energy dissipation related to fluid pressure diffusion between microscale and mesoscale pores [ABSTRACT FROM AUTHOR]

In this paper, a new method is proposed to manipulate seismic Rayleigh waves using phase-gradient metasurfaces. This highly compact artificial structure enables the anomalous refraction of Rayleigh waves according to the generalized Snell's law (GSL). The soil-embedded metasurface is composed of only one column of commercial rubber blocks, which can provide an accurate phase shift to the Rayleigh wave. To verify the flexibility of this method, several metasurfaces are designed. Numerical results demonstrate that the Rayleigh waves can be focused, split, or converted into evanescent waves by using specific phase gradient configurations. The investigation also suggests the strong potential of metasurface as a smart device for shielding of seismic surface waves. [ABSTRACT FROM AUTHOR]

[Display omitted] • To our knowledge, NB-BIBRA is the first near-infrared fluorescent probe for detection and imaging of hTERT in living cells and in vivo. • This probe fluorescence turns on sharply within 20 s in hTERT solution or just incubating with living cells for 10 min. • NB-BIBRA exhibited low detection limit, high selectivity and fast response to hTERT. Identifying the expression levels of human telomerase reverse transcriptase (hTERT) is important for early cancer diagnosis and cancer-related drug screening. However, a small-molecule fluorescent probe has rarely been used for rapidly determining the hTERT level with high sensitivity has been scarce. Herein, we designed and synthesized a novel near-infrared fluorescent probe (NB-BIBRA) by conjugating an inhibitor analog (BIBRA) to the fluorophore Nile blue (NB) for specific imaging of hTERT in living cells and in vivo. In the absence of hTERT, NB-BIBRA mainly exists in aggregates, exhibiting self-quenching photoactivity. However, once NB-BIBRA interacts with hTERT, NB-BIBRA aggregates are disrupted and their fluorescence intensity is drastically enhanced. Notably, the probe exhibited a low detection limit, high selectivity and rapid response to hTERT, allowing rapid imaging of hTERT in living cells and solid tumor tissue in vivo. To the best of our knowledge, NB-BIBRA is the first near-infrared fluorescent probe for the detection and imaging of hTERT in living cells and in vivo , thus providing a powerful tool for early cancer diagnosis and cancer-related drug screening. [ABSTRACT FROM AUTHOR]

The catalytic decomposition of hydrazine using metallic nanoparticles has recently attracted considerable attention as this provides a promising means for highly efficient hydrogen release desired for a cleaner economy; however, the efficient catalytic nanoparticles model is still controversial. To shed further light on the optimal morphology of rhodium nanoparticles reported as the most efficient catalyst for this reaction, a more realistic nanocluster (Rhn) model is implemented here to compare the adsorption energies of hydrazine on these nanoclusters using the density functional theory. These nanoclusters (Rhn) comprise a varied number of Rh atom (n = 13–201), with their pre-constructed shapes but further defined by the highest energy optimization. Our calculations unravel that the vertex atoms of an Rhn nanocluster are the most favoured sites for N2H4 adsorption, in comparison with edge atoms or inner atoms of facets. Notably, the computed adsorption energies (Eads) clearly exhibit a linear dependence on their sizes effective particle diameter (r), with the equation Eads = − 1.30 + (− 0.24) r established. Further calculations on the introduction of adatoms to the regular nanoclusters demonstrated that the stepped facet plays a decisive role in determining the adsorption energy. Moreover, the electronic structure and charge transfer calculations revealed the dative-type binding nature of the N–Rh bond. These results highlight the importance of a more realistic particle model used for such adsorption studies and provide new insights into the design and development of nanocatalysts for the decomposition of hydrazine. [ABSTRACT FROM AUTHOR]

The dynamic response of foam-core composite sandwich plates subjected to low-velocity impact is thoroughly investigated by means of drop-weight impact tests and numerical simulations in this paper. The influences of impact energy, foam-core thickness, and punch-head shape and size on the impact mechanical behavior including the impact force time history, the dynamic displacement time history, the residual plastic deformation, the energy absorption capacity, and the back plate deflection are contrastively studied through the control-variant approaches. Several conclusions drawn are useful and helpful to the related product design. The top faceplates of specimens with large foam-core thickness are demonstrated to be vulnerable to the low-velocity impact under stepped levels of impact energy, while large foam-core thickness can reduce deformation of the interior plates effectively. Moreover, among the three representative types of punch heads, the sharper hemispherical one is checked to be the most destructive with the lowest impact force peak. Besides, a finite element model was built to investigate the damage of faceplates and foam cores. The numerical method was proved to be accurate and efficient. A series of results were obtained revealing the damage mode of faceplates and cores under different impact energies. [ABSTRACT FROM AUTHOR]

The determination of homocysteine (Hcy) is important because high levels are associated with a greater risk of developing heart disease or stroke. Herein, an electrochemical sensor of homocysteine was constructed based upon the self-assembly of 6-ferrocenylhexanethiol (FcC6SH) on a MoS2 nanoparticles-modified electrode with a Nafion coating. The sensor showed a favorable electrocatalytic activity for oxidation of homocysteine since 6-ferrocenylhexanethiol acted as a good electron transfer mediator. Moreover, the MoS2 nanoparticles served as modifiers to covalently immobilize FcC6SH and enhance the electrochemical active surface area. Highly sensitive determination of homocysteine was achieved with a linear range from 2.0 to 100 µmol L−1 and a minimum detectable concentration of 0.30 µmol L−1 by chronoamperometry. The constructed sensor was applied to the analysis of immunoglobulin G (IgG) samples with satisfactory results. [ABSTRACT FROM AUTHOR]

The work demonstrates a simple method for sensitive detection of Ca2+ ion by electrochemical response of alizarin red S (ARS) and Ca-ARS at a gold nanoparticle modified glassy carbon electrode (GCE). In the 0.1 M KOH, a sensitive reduction peak was observed at −0.795 V at the gold nanoparticles modified electrode. The peak currents were proportional to the concentrations of Ca2+ ion in the range of 2.0 × 10−7 M–1.2 × 10−4 M. For the different pulse voltammetry (DPV) methods, the detection limit was 2.57 × 10−8 M. The reaction mechanism was primarily determined by cyclic voltammetry, and the experimental results showed that the electrode processes were quasireversible responses of ARS and irreversible responses of ARS-Ca. In addition, the method was simple, fast, precise, and was used in the determination of calcium in blood serum with satisfactory results. [ABSTRACT FROM AUTHOR]

A mixed, self-assembled monolayer (SAM) of meso-2,3-dimercaptosuccinic acid (DMSA) and penicillamine (PCA) was prepared on a gold electrode. The mixed SAM of DMSA and PCA, for which the volume ratio of DMSA:PCA was 2:1, showed an obvious electrochemical activity for the oxidation of epinephrine (EP). In the phosphate buffer (pH 7.7), a sensitive oxidation peak was observed at 0.213 V on the DMSA and PCA modified Au electrode. The peak current was proportional to the concentration of EP in the range between 5.0×10-6 and 8.0×10-4 mol L-1. For the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods, the detection limits were 3.9×10-7 and 2.5×10-7 mol L-1, respectively. The reaction mechanism has been primarily discussed. The electrode reaction of EP was an irreversible process with two electrons and two protons transfer at the SAM gold electrode. The SAM gold electrode was applied to the determination of EP in epinephrine hydrochloride injection samples with satisfactory results. [ABSTRACT FROM AUTHOR]

Tight oil/gas medium is a special porous medium, which plays a significant role in oil and gas exploration. This paper is devoted to the derivation of wave equations in such a media, which take a much simpler form compared to the general equations in the poroelasticity theory and can be employed for parameter inversion from seismic data. We start with the fluid and solid motion equations at a pore scale, and deduce the complete Biot's equations by applying the volume averaging technique. The underlying assumptions are carefully clarified. Moreover, time dependence of the permeability in tight oil/gas media is discussed based on available results from rock physical experiments. Leveraging the Kozeny-Carman equation, time dependence of the porosity is theoretically investigated. We derive the wave equations in tight oil/gas media based on the complete Biot's equations under some reasonable assumptions on the media. The derived wave equations have the similar form as the diffusive-viscous wave equations. A comparison of the two sets of wave equations reveals explicit relations between the coefficients in diffusive-viscous wave equations and the measurable parameters for the tight oil/gas media. The derived equations are validated by numerical results. Based on the derived equations, reflection and transmission properties for a single tight interlayer are investigated. The numerical results demonstrate that the reflection and transmission of the seismic waves are affected by the thickness and attenuation of the interlayer, which is of great significance for the exploration of oil and gas. [ABSTRACT FROM AUTHOR]

The majority of the protein structures have been elucidated under equilibrium conditions. The aim herein is to provide a better understanding of the dynamic behavior inherent to proteins by fabricating a label‐free nanodevice comprising a single‐peptide junction to measure real‐time conductance, from which their structural dynamic behavior can be inferred. This device contains an azobenzene photoswitch for interconversion between a well‐defined cis, and disordered trans isomer. Real‐time conductance measurements revealed three distinct states for each isomer, with molecular dynamics simulations showing each state corresponds to a specific range of hydrogen bond lengths within the cis isomer, and specific dihedral angles in the trans isomer. These insights into the structural dynamic behavior of peptides may rationally extend to proteins. Also demonstrated is the capacity to modulate conductance which advances the design and development of bioinspired electronic nanodevices. [ABSTRACT FROM AUTHOR]

The majority of the protein structures have been elucidated under equilibrium conditions. The aim herein is to provide a better understanding of the dynamic behavior inherent to proteins by fabricating a label‐free nanodevice comprising a single‐peptide junction to measure real‐time conductance, from which their structural dynamic behavior can be inferred. This device contains an azobenzene photoswitch for interconversion between a well‐defined cis, and disordered trans isomer. Real‐time conductance measurements revealed three distinct states for each isomer, with molecular dynamics simulations showing each state corresponds to a specific range of hydrogen bond lengths within the cis isomer, and specific dihedral angles in the trans isomer. These insights into the structural dynamic behavior of peptides may rationally extend to proteins. Also demonstrated is the capacity to modulate conductance which advances the design and development of bioinspired electronic nanodevices. [ABSTRACT FROM AUTHOR]

Dinoflagellate blooms are the results of rapid cell proliferation governed by cell cycle, a highly-ordered series of events that culminates in cell division. However, little is known about cell cycle progression of the in situ bloom cells. Here, we compared proteomes of the in situ blooming cells of a dinoflagellate Prorocentrum donghaiense collected at different cell cycle phases. The blooming P. donghaiense cells completed a cell cycle within 24 h with a high synchronization rate of 82.7%. Proteins associated with photosynthesis, porphyrin and chlorophyll synthesis, carbon, nitrogen and amino acid metabolisms exhibited high expressions at the G 1 phase; DNA replication and mismatch repair related proteins were more abundant at the S phase; while protein synthesis and oxidative phosphorylation were highly enriched at the G 2 /M phase. Cell cycle proteins presented similar periodic diel patterns to other eukaryotic cells, and higher expressions of proliferating cell nuclear antigen and cyclin dependent kinase 2 at the S phase ensured the smooth S-G 2 /M transition. Strikingly, four histones were first identified in P. donghaiense and highly expressed at the G 2 /M phase, indicating their potential roles in regulating cell cycle. This study presents the first quantitative survey, to our knowledge, of proteome changes at different cell cycle phases of the in situ blooming cells in natural environment and provides insights into cell cycle regulation of the blooming dinoflagellate cells. Unlabelled Image • The blooming P. donghaiense cells exhibited high growth and synchronization rates. • Quantitative proteomics revealed differentially expressed proteins within a cell cycle. • Histone proteins were firstly identified and highly expressed at the G 2 /M phase. • Periodic occurrence of the molecular events guaranteed cell cycle progression. [ABSTRACT FROM AUTHOR]

The Byssus, which is derived from the foot gland of mussels, has been proved to bind heavy metals effectively, but few studies have focused on the molecular mechanisms behind the accumulation of heavy metals by the byssus. In this study, we integrated high-throughput transcriptome and proteome sequencing to construct a comprehensive protein database for the byssus of Chinese green mussel (Perna viridis), aiming at providing novel insights into the molecular mechanisms by which the byssus binds to heavy metals. Illumina transcriptome sequencing generated a total of 55,670,668 reads. After filtration, we obtained 53,047,718 clean reads and subjected them to de novo assembly using Trinity software. Finally, we annotated 73,264 unigenes and predicted a total of 34,298 protein coding sequences. Moreover, byssal samples were analyzed by proteome sequencing, with the translated protein database from the foot transcriptome as the reference for further prediction of byssal proteins. We eventually determined 187 protein sequences in the byssus, of which 181 proteins are reported for the first time. Interestingly, we observed that many of these byssal proteins are rich in histidine or cysteine residues, which may contribute to the byssal accumulation of heavy metals. Finally, we picked one representative protein, Pvfp-5-1, for recombinant protein synthesis and experimental verification of its efficient binding to cadmium (Cd2+) ions. [ABSTRACT FROM AUTHOR]

Currently, detecting awareness in patients with disorders of consciousness (DOC) is a challenging task, which is commonly addressed through behavioral observation scales such as the JFK Coma Recovery Scale-Revised. Brain-computer interfaces (BCIs) provide an alternative approach to detect awareness in patients with DOC. However, these patients have a much lower capability of using BCIs compared to healthy individuals. This study proposed a novel BCI using temporally, spatially, and semantically congruent audiovisual stimuli involving numbers (i.e., visual and spoken numbers). Subjects were instructed to selectively attend to the target stimuli cued by instruction. Ten healthy subjects first participated in the experiment to evaluate the system. The results indicated that the audiovisual BCI system outperformed auditory-only and visual-only systems. Through event-related potential analysis, we observed audiovisual integration effects for target stimuli, which enhanced the discriminability between brain responses for target and nontarget stimuli and thus improved the performance of the audiovisual BCI. This system was then applied to detect the awareness of seven DOC patients, five of whom exhibited command following as well as number recognition. Thus, this audiovisual BCI system may be used as a supportive bedside tool for awareness detection in patients with DOC. [ABSTRACT FROM AUTHOR]

Abstract: To optimize the parameters of electrical elements contained in an equivalent circuit for electrochemical impedance spectroscopy, we proposed a simple, intuitive and universal tree structure code (TSC) to encode an arbitrary complex circuit, then designed a genetic algorithm for parameter optimization (GAPO) to work with the TSC and estimate the parameter values of electrical elements. The GAPO uses a novel crossover operator that performs by the non-convex linear combination of multiple parents and sets up a crossover subspace to enhance the global search. We first examined the effects of some key control parameters in the GAPO on the optimization process by selecting a relatively complex equivalent circuit to generate simulated data and comparing the parameters obtained by GAPO with the original values. Secondly, to examine the effectiveness and robustness of GAPO, we chose a set of simulated data generated by a relatively simple circuit, three sets of real impedance data on modified gold electrodes and a set of real impedance data on the anode of lithium-ion battery to run the GAPO and compared their calculated results with those obtained by complex nonlinear least square method (CNLS) supported by LEVM software. Finally, we compared the effects of five representative weighting strategies on the GAPO based on a set of simulated data generated by a relatively complicated circuit but with up to 10% Gaussian noise and the set of real impedance data on the anode of lithium-ion battery. All of these experimental results show that the GAPO works more quickly, efficiently and stably than CNLS when optimizing the element parameters. We also found that appropriate weighting strategies can help reduce the effects of experimental errors on GAPO, but the effects really depend on the nature of the specific impedance data. [Copyright &y& Elsevier]

The artificially periodic structures with the bandgap (BG) features provide a fantastic way for elastic wave manipulation. However, omnidirectional control of elastic waves at low-frequency remains a challenge, especially in the engineering application, due to the great different material parameters of the structure's components. In this work, we present the design of a three-dimensional syndiotactic metastructure (STM) and isotactic metastructure (ITM) composed of a single material with the same density and stiffness. A low-frequency broad bandgap occurs in the global band structure of STM. Meanwhile, it also retains the same high-frequency ultra-wide BG as that of ITM. The formation of the low-frequency BG of STM is attributed to the simultaneous activation of rotation and translation modes. The static deformation analysis indicates that STM has a unique translational and rotational coupling mechanism. The frequency response results reveal that the coupling mechanism can also enhance the attenuation of high-frequency BG. • Three-dimensional syndiotactic elastic metastructure with single-phase material. • Realization of ultra-low frequency band gap with the same stiffness and density. • High-frequency broad bandgap is realized by modal separation. • The attenuation of high-frequency bandgap in syndiotactic metastructure is enhanced. [ABSTRACT FROM AUTHOR]

Cognitive motor dissociation describes a subset of patients with disorders of consciousness who show neuroimaging evidence of consciousness but no detectable command-following behaviours. Although essential for family counselling, decision-making, and the design of rehabilitation programmes, the prognosis for patients with cognitive motor dissociation remains under-investigated. The current study included 78 patients with disorders of consciousness who showed no detectable command-following behaviours. These patients included 45 patients with unresponsive wakefulness syndrome and 33 patients in a minimally conscious state, as diagnosed using the Coma Recovery Scale-Revised. Each patient underwent an EEG-based brain-computer interface experiment, in which he or she was instructed to perform an item-selection task (i.e. select a photograph or a number from two candidates). Patients who achieved statistically significant brain-computer interface accuracies were identified as cognitive motor dissociation. Two evaluations using the Coma Recovery Scale-Revised, one before the experiment and the other 3 months later, were carried out to measure the patients' behavioural improvements. Among the 78 patients with disorders of consciousness, our results showed that within the unresponsive wakefulness syndrome patient group, 15 of 18 patients with cognitive motor dissociation (83.33%) regained consciousness, while only five of the other 27 unresponsive wakefulness syndrome patients without significant brain-computer interface accuracies (18.52%) regained consciousness. Furthermore, within the minimally conscious state patient group, 14 of 16 patients with cognitive motor dissociation (87.5%) showed improvements in their Coma Recovery Scale-Revised scores, whereas only four of the other 17 minimally conscious state patients without significant brain-computer interface accuracies (23.53%) had improved Coma Recovery Scale-Revised scores. Our results suggest that patients with cognitive motor dissociation have a better outcome than other patients. Our findings extend current knowledge of the prognosis for patients with cognitive motor dissociation and have important implications for brain-computer interface-based clinical diagnosis and prognosis for patients with disorders of consciousness. [ABSTRACT FROM AUTHOR]

An acoustic metasurface (AM) is proposed to achieve a sound tunnel with switchable functionalities of asymmetric transmission and bidirectional sound isolation, which is composed of an array of steel containers filled with two inert gases, argon and xenon. Acoustic asymmetric transmission can be observed when the AM is placed vertically. The functionality of the tunnel can be switched to bidirectional sound isolation by simply rotating the AM without changing the physical structure of the device. The proposed switchable tunnel has broadband multi-functional response with a simple adjustment method, showing potential for bidirectional sound isolation and sound sensing. [ABSTRACT FROM AUTHOR]

Narrow bandwidth and specific incident angle are the main drawbacks in real-life applications for the existed carpet cloaking based on the acoustic metasurface (AM). Here, we tackle to get over the problems by proposing a reprogrammable AM. The unit cell is composed of water sink and filling nozzle. By incorporating an external water pumping system into each individual unit cell, the reflected phase can be readily regulated. Since the pumping process is reversible, the AM is reprogrammable under the control of the water pumping system in the frequency range of 3430–6860 Hz. Both the acoustic cloaking and disguising are designed based on the proposed AM. The double security for the target object can be ensured to avoid being detected by combining the two designs. Simulated results with the finite element method indicate that the acoustic cloaking and disguising can work in the broad bandwidth of 66.7% of the central frequency with full-range incident angles from − 9 0 ∘ to 9 0 ∘ . Our design shows promise for applications in realizing the practical skin cloaking and disguising one step closer. [ABSTRACT FROM AUTHOR]

Low-frequency and broadband are the critical challenges in real-life applications. Here, we try to tackle the challenges by proposing a reconfigurable acoustic metasurface (AM) composed of the membrane-type metamaterial (MAM) structure of deep sub-wavelength scale. By employing the external air pumping system into each individual unit cell of the AM, the tension of the membrane can be readily tailored by the system with little interference from other unit cells. Two strategies of the constant pressure method (CPM) and constant volume method (CVM) are reported to design the MAM. And the CVM is adopted as the ultimate design strategy by comparing both methods from aspects of the dimension, operating frequency, and structure complexity. In order to validate the low-frequency and broadband performances of the AM, the Airy-like beams and the acoustic converging based on two identical Airy-like beams are introduced and proof-of-concept simulations are performed with the finite element method. The simulated results agree well with the theoretical predictions. Our design provides the little-interference active design method for the low-frequency and broadband AM to manipulate the wave front, and may have practical engineering applications in areas of the aerospace, high-speed train, marine vessel, and power transmission and transformation project. [ABSTRACT FROM AUTHOR]

Numerical simulation in coupled elastic and poroelastic media is important in oil and gas exploration. However, the interface between elastic and poroelastic media is a challenge to handle. In order to deal with the coupled model, the first‐order velocity–stress wave equations are used to unify the elastic and poroelastic wave equations. In addition, an arbitrary high‐order discontinuous Galerkin method is used to simulate the wave propagation in coupled elastic–poroelastic media, which achieves same order accuracy in time and space domain simultaneously. The interfaces between the two media are explicitly tackled by the Godunov numerical flux. The proposed forms of numerical flux can be used efficiently and conveniently to simulate the wave propagation at the interfaces of the coupled model and handle the absorbing boundary conditions properly. Numerical results on coupled elastic–poroelastic media with straight and curved interfaces are compared with those from a software that is based on finite element method and the interfaces are handled by boundary conditions, demonstrating the feasibility of the proposed scheme in dealing with coupled elastic–poroelastic media. In addition, the proposed method is used to simulate a more complex coupled model. The numerical results show that the proposed method is feasible to simulate the wave propagation in such a media and is easy to implement. [ABSTRACT FROM AUTHOR]

To improve the output performance of G-band extended interaction klystron (EIK), several practicable methods have been discussed. Firstly, the synchronization characteristics of the electron beam with the operating mode are analyzed in order to obtain large output power for optimized period. The influence of input gap voltage on the beam-wave interaction is studied, and the well-matched condition is established by optimizing the structure of input cavity. The gap length of output cavity is optimized to improve the electric field distribution. By adopting the optimized gap length and non-uniform gap lengths, the output power significantly increases from 360 to 570 W and 660 W, respectively; the corresponding bandwidth reaches to 650 MHz and 470 MHz. Moreover, AJDISK calculation is adopted to compare the results with CST simulation, and the similar gains and tendencies validate the relative reliability of our designed beam-wave interaction circuit. Therefore, our proposed methods for improving the output performance of G-band EIK are feasible and utilizable. [ABSTRACT FROM AUTHOR]

A beam-wave interaction model for G-band rectangular beam extended-interaction klystron (EIK) with unequal-length slots is proposed and analyzed to achieve high output power and broad bandwidth. The length ratio of long slot with short slot is carefully optimized to obtain a large effective characteristic impedance and wide mode separation. The influence of beam tunnel size on the effective characteristic impedance is studied with the beam aspect ratio of 2.3:1. The beam conductance for 5-gap, 7-gap, and 11-gap cavities are analyzed theoretically to optimize the beam-wave interaction stability. Furthermore, beam current and input power are investigated to obtain high performance. The analysis of fabrication tolerance and alignment tolerance indicates that less than 5- $\mu \text{m}$ machining precision is required. With beam current of 0.40 A and voltage of 16.5 kV, 3-D PIC simulation predicts peak power of 1139 W and 3-dB bandwidth of 1.15 GHz, with efficiency of 17.3% and gain of 37.5 dB. In addition, PIC simulations are compared with 1-D AJDISK calculations, the approximate results with similar tendencies indicate that our proposed beam-wave interaction model for G-band EIK is relatively reliable. [ABSTRACT FROM AUTHOR]

Rapid laboratory technologies which can effectively distinguish active tuberculosis (ATB) from controls and latent tuberculosis infection (LTBI) are lacked.The objective of this study is to explore MTB biomarkers in serum that can distinguish ATB from LTBI. We constructed a tuberculosis protein microarray containing 64 MTB associated antigens. We then used this microarray to screen 180 serum samples, from patients with ATB and LTBI, and healthy volunteer controls. Both SAM (Significance analysis of microarrays) and ROC curve analysis were used to identify the differentially recognized biomarkers between groups. Extra 300 serum samples from patients with ATB and LTBI, and healthy volunteer controls were employed to validate the identified biomarkers using ELISA-based method. According to the results, the best biomarker combinations of 4 proteins (Rv1860, RV3881c, Rv2031c and Rv3803c) were selected. The biomarker panel containing these 4 proteins has reached a sensitivity of 93.3% and specificity of 97.7% for distinguishing ATB from LTBI, and a sensitivity of 86% and specificity of 97.6% for distinguishing ATB from HC. The biomarker combination in this study has high sensitivity and specificity in distinguishing ATB from LTBI, suggesting it is worthy for further validation in more clinical samples. [ABSTRACT FROM AUTHOR]

Background: For patients with disorders of consciousness such as coma, a vegetative state or a minimally conscious state, one challenge is to detect and assess the residual cognitive functions in their brains. Number processing and mental calculation are important brain functions but are difficult to detect in patients with disorders of consciousness using motor response-based clinical assessment scales such as the Coma Recovery Scale-Revised due to the patients' motor impairments and inability to provide sufficient motor responses for number- and calculation-based communication.Methods: In this study, we presented a hybrid brain-computer interface that combines P300 and steady state visual evoked potentials to detect number processing and mental calculation in Han Chinese patients with disorders of consciousness. Eleven patients with disorders of consciousness who were in a vegetative state (n = 6) or in a minimally conscious state (n = 3) or who emerged from a minimally conscious state (n = 2) participated in the brain-computer interface-based experiment. During the experiment, the patients with disorders of consciousness were instructed to perform three tasks, i.e., number recognition, number comparison, and mental calculation, including addition and subtraction. In each experimental trial, an arithmetic problem was first presented. Next, two number buttons, only one of which was the correct answer to the problem, flickered at different frequencies to evoke steady state visual evoked potentials, while the frames of the two buttons flashed in a random order to evoke P300 potentials. The patients needed to focus on the target number button (the correct answer). Finally, the brain-computer interface system detected P300 and steady state visual evoked potentials to determine the button to which the patients attended, further presenting the results as feedback.Results: Two of the six patients who were in a vegetative state, one of the three patients who were in a minimally conscious state, and the two patients that emerged from a minimally conscious state achieved accuracies significantly greater than the chance level. Furthermore, P300 potentials and steady state visual evoked potentials were observed in the electroencephalography signals from the five patients.Conclusions: Number processing and arithmetic abilities as well as command following were demonstrated in the five patients. Furthermore, our results suggested that through brain-computer interface systems, many cognitive experiments may be conducted in patients with disorders of consciousness, although they cannot provide sufficient behavioral responses. [ABSTRACT FROM AUTHOR]

In the 0.1 mol · L−1hydrochloric acid solution, oxymatrine reacted with tungstosilicic acid to form a 2:1 ion-association complexes. This results in a great enhancement of resonance Rayleigh scattering. The maximum resonance Rayleigh scattering wavelength was located at 393 nm. Resonance Rayleigh scattering intensity was proportional to the concentration of oxymatrine in the range of 1.5–26.4 µg · mL−1, and the detection limit (3σ) was 0.23 µg · mL−1. The optimum conditions and the effects of coexisting substances on the reaction were investigated. The method shows a wide linear range and high sensitivity, and was applied to the determination of oxymatrine in marine capsules and human urine samples with satisfactory results. Therefore, a highly sensitive, simple, and quick method has been developed for the determination of oxymatrine. [ABSTRACT FROM AUTHOR]

S-adenosylhomocysteine (SAH) is an effective sedative, a good sleep modulator, and a new anticonvulsant. SAH can be synthesized from adenosine and homocysteine by using microbial S-adenosylhomocysteine hydrolase (SAHase). The extremely thermostable SAHase and lactate dehydrogenase (LDH) from Thermotoga maritima were successfully overexpressed in Escherichia coli, and purified by heat treatments. The SAHase exhibited the highest activity at 85°C and pH 8.0 with a specific activity of 6.2U/mg when NAD concentration was 1mM. However, optimal SAHase reaction conditions shifted to 100°C and pH 11.2, and its specific activity increased to 36.8U/mg after NAD concentration was raised to 8mM. Biosynthesis of SAH at 85°C largely increased the adenosine solubility which was a limiting factor for improving the titer of product. At 85°C and pH 8.0, 24μmol of SAH was obtained when 0.5mg of SAHase was applied to a 10ml reaction mixture. The SAH production was further increased to 153μmol by adding LDH and pyruvate into the reaction mixture for NAD regeneration. Therefore, extremely thermostable enzymes SAHase and LDH from T. maritima form an efficient NAD consumption and regeneration system for SAH biosynthesis. This method has great potential for industrial-scale enzymatic production of SAH. [ABSTRACT FROM AUTHOR]

Abstract: In Gram-negative bacteria, porins not only contribute to bacterial homeostasis, but also are involved in adherence to and invasion of host cells. Haemophilus parasuis outer membrane protein P2 (OmpP2), a member of the porin family, is an important surface protein involved in serum resistance. To further determine the features of OmpP2, the ability of ompP2 deficient mutant (ΔompP2) of a H. parasuis SC096 strain to interact with porcine umbilicus veins endothelial cells (PUVEC) and porcine kidney epithelial cells (PK-15) was evaluated in this study. The ΔompP2 mutant exhibited dramatically increased ability to adhere to and invade PUVEC and PK-15 cells. Conversely, pretreatment of cell lines with purified native OmpP2 porins significantly inhibited adhesion and invasion of the SC096 strain to the both host cells. To explain the unexpected phenomenon, a 2-dimensional gel electrophoresis-based proteomics comparison was performed between the wild-type SC096 and ΔompP2 mutant strains. There were 55 differentially expressed proteins identified from mutant. Among them, three overexpressed proteins of the ADP-l-glycero-d-mannoheptose-6-epimerase RfaD, thymidylate synthase ThyA and putative macrophage infectivity potentiator-related protein Mip were confirmed as molecular targets that modulated adherence and invasion capacities of the ΔompP2 mutant. Collectively, the OmpP2 of the H. parasuis SC096 strain mediated the adherence to and invasion of cells and loss of OmpP2 expression resulted in promoted cell-adherence and invasion properties which were due to the overexpression of RfaD, ThyA and Mip. [Copyright &y& Elsevier]

Abstract: Outer membrane protein A (OmpA) is a major structural component of the outer membranes and functions as a multifaceted molecular with many diverse roles in Gram-negative bacteria. In Haemophilus parasuis, OmpA has been recognized and named as OmpP5 in genomic literature. In this study, to determine the precise functions of OmpP5, an ompP5 deficient mutant (ΔompP5) of a H. parasuis serovar 4 filed strain SC096 was constructed using a natural transformation method. Compared to the wild-type SC096 strain, the ΔompP5 mutant displayed a detectable delay in growth. However, the wild-type and mutant strains were indistinguishable with respect to the other phenotypes including resistance to killing by porcine and rabbit sera, adhesion to and invasion of porcine umbilicus veins endothelial cells (PUVEC) and porcine kidney epithelial cells (PK-15). To analyze the differences of proteome expression between wild-type and mutant strains, a 2-dimensional gel electrophoresis (2-DE)-based proteomics comparison was performed. There were 24 differentially expressed proteins which were mainly involved in carbohydrate, lipid, nucleotide and amino acid metabolism, or served as transcription and translation factors and chaperone proteins. Collectively, loss of OmpP5 expression in the H. parasuis SC096 strain resulted in global protein expression changes which might be responsible for novel phenotypes occurred in ΔompP5 mutant. [Copyright &y& Elsevier]

Background: Currently, it is challenging to detect the awareness of patients who suffer disorders of consciousness (DOC). Brain-computer interfaces (BCIs), which do not depend on the behavioral response of patients, may serve for detecting the awareness in patients with DOC. However, we must develop effective BCIs for these patients because their ability to use BCIs does not as good as healthy users.Methods: Because patients with DOC generally do not exhibit eye movements, a gaze-independent audiovisual BCI is put forward in the study where semantically congruent and incongruent audiovisual number stimuli were sequentially presented to evoke event-related potentials (ERPs). Subjects were required to pay attention to congruent audiovisual stimuli (target) and ignore the incongruent audiovisual stimuli (non-target). The BCI system was evaluated by analyzing online and offline data from 10 healthy subjects followed by being applied to online awareness detection in 8 patients with DOC.Results: According to the results on healthy subjects, the audiovisual BCI system outperformed the corresponding auditory-only and visual-only systems. Multiple ERP components, including the P300, N400 and late positive complex (LPC), were observed using the audiovisual system, strengthening different brain responses to target stimuli and non-target stimuli. The results revealed the abilities of three of eight patients to follow commands and recognize numbers.Conclusions: This gaze-independent audiovisual BCI system represents a useful auxiliary bedside tool to detect the awareness of patients with DOC. [ABSTRACT FROM AUTHOR]