Bias-dependent photoresponse of Td-WTe2grown by chemical vapor deposition.

The type-II Weyl semimetal Td-WTe2is one of the wonder materials for high-performance optoelectronic devices. We report the self-powered Td-WTe2photodetectors and their bias-dependent photoresponse in the visible region (405, 520, 638 nm) driven by the bulk photovoltaic effect. The device shows the responsivity of 15.8 mAW-1and detectivity of 5.2 × 109Jones at 520 nm. Besides, the response time of the WTe2photodetector shows the strong bias-voltage dependent property. This work offers a physical reference for understanding the photoresponse process of Td-WTe2photodetectors.

Laser Shock Peening Improves the Corrosion Resistance of an E690 High-Strength Steel Cladding Layer.

To investigate the effect of laser shock peening parameters on the corrosion resistance of an E690 high-strength steel cladding layer, NVE690 high-strength steel powder was selected for testing at various power densities of pulse lasers. The surface roughness and residual stress of the treated samples were measured, and the microstructure morphology of the sample surface was observed. The electrochemical corrosion tests were conducted with an electrochemical workstation to measure the electrometer polarization, obtain the impedance curve, and observe the electrochemical corrosion. As the laser power density increased, the surface grains of the E690 high-strength steel cladding layer continued to refine until nanocrystals formed, and the residual compressive stress on the surface increased. The residual compressive stress on the surface rendered the passivation film stable and dense; furthermore, the refinement of surface grains inhibited the initiation and propagation of microcracks. The positive shift of the corrosion potential increased from -1.004 to -0.771 V, the corrosion current density decreased from 114.5 to 5.41 µA/cm2, the radius of the impedance spectrum curve increased, and the peeling pits, as well as corrosion micropores on the surface, gradually became no longer evident after electrochemical corrosion. After laser shock treatment, the corrosion resistance of the cladding layer sample was substantially improved.

High-Sensitivity, Low-Field 19F-MRI Approach Using High Manganese Ferrite Concentrations.

Fluorine-19 (19F) MRI (19F-MRI) is a promising method for quantifying biomedical research and clinical applications without background interference. Nevertheless, dependency on high-field MRI systems limits the applicability of 19F-MRI. Low-field MRI systems are more common than high-field MRI systems. Hence, developing 19F-MRI at low-field MRI devices can promote the 19F-MRI translation in medical diagnosis. The detection sensitivity of fluorine agents is critical in 19F-MRI. Reduction of the 19F spin-lattice relaxation time (T1) enables an improved detection sensitivity while requiring ultrashort echo time (UTE) imaging methods to reduce the negative spin-spin relaxation (T2) decay effect. However, conventional UTE sequences require hardware with high performance. Herein, we introduce the k-space scaling imaging (KSSI) MRI sequence that accomplishes sampling k-space with variable scales to implement hardware-friendly UTE 19F-MRI compatible with low-field MRI systems. We implemented experiments with swine bone, a perfluorooctyl bromide (PFOB) phantom, and one tumor-bearing mouse on two self-customized low-field MRI systems. The swine bone imaging validated the ultrashort TE of KSSI. Under high concentrations of manganese ferrite, a high signal-to-noise ratio was shown in the imaging of a fluorine atom concentration of 658 mM, which indicated high-sensitivity detection of KSSI. Moreover, the KSSI sequence exhibited a 7.1 times signal-to-noise ratio of spin echo sequence on the PFOB phantom imaging with a fluorine atom concentration of 3.29 M. Additionally, the various concentrations of the PFOB phantom imaging revealed quantifiable capacity. Finally, the 1H/19F imaging was implemented with KSSI on one tumor-bearing mouse. This method provides the potential for clinical translation of fluorine probes at low-field MRI systems.

Effect of Annular Laser Metal Deposition (ALMD) Process Parameters on Track Geometry and Thermal History on Ti6Al4V Alloy Clad.

Annular laser metal deposition (ALMD) is a rising technology that fabricates near-net-shaped components. In this research, a single factor experiment with 18 groups was designed to study the influence of process parameters on the geometric characteristics (bead width, bead height, fusion depth, and fusion line) and thermal history of Ti6Al4V tracks. The results show that discontinuous and uneven tracks with pores or large-sized incomplete fusion defects were observed when the laser power was less than 800 W or the defocus distance was -5 mm. The laser power had a positive effect on the bead width and height, while the scanning speed had the opposite effect. The shape of the fusion line varied at different defocus distances, and the straight fusion line could be obtained with the appropriate process parameters. The scanning speed was the parameter that had the greatest effect on the molten pool lifetime and solidification time as well as the cooling rate. In addition, the microstructure and microhardness of the thin wall sample were also studied. Many clusters with various sizes in different zones were distributed within the crystal. The microhardness ranged from 330 HV to 370 HV.

Transcription factor TERF1 promotes seed germination through HEXOKINASE 1 (HXK1)-mediated signaling pathway.

Seed germination, a vital process for plant growth and development, is regulated by ethylene. Previously, we showed that Tomato Ethylene Responsive Factor 1 (TERF1), an ethylene-responsive factor (ERF) transcription factor, could significantly promote seed germination by increasing glucose content. As glucose can function as a signaling molecule to regulate plant growth and development through HEXOKINASE 1 (HXK1), we aim to illustrate how TERF1 promotes seed germination through the HXK1-mediated signaling pathway. We showed that seeds overexpressing TERF1 exhibited more resistance to N-acetylglucosamine (NAG), an inhibitor of the HXK1- mediated signaling pathway. We identified genes regulated by TERF1 through HXK1 based on transcriptome analysis. Gene expression and phenotype analysis demonstrated that TERF1 repressed the ABA signaling pathway through HXK1, which promoted germination through activating the plasma membrane (PM) H+-ATPase. TERF1 also alleviated the endoplasmic reticulum (ER) stress to accelerate germination by maintaining reactive oxygen species (ROS) homeostasis through HXK1. Our findings provide new insights into the mechanism regulated by ethylene through the glucose-HXK1 signaling pathway during seed germination.

Synthesis and Characterization of Azido-Functionalized 1,2,3-Triazole and Fused 1,2,3-Triazole.

Here, we report the nitration of NH on the 1,2,3-triazole ring and the synthesis of several nitrogen-rich energetic compounds based on key intermediate 4-azido-5-(chlorodinitromethyl)-2-nitro-2H-1,2,3-triazole (5). Starting from 4-amino-1H-1,2,3-triazole-5-carbonitrile (1), we successfully constructed compound 5 through four steps. Subsequently, the dechlorination of compound 5 gave potassium 4-azido-5-(dinitromethyl)-2H-1,2,3-triazole (6) (IS = 1 J, vD = 8802 m s-1). Additionally, diammonium (8) and dihydrazinium (9) salts based on 4-azido-5-(dinitromethyl)-2H-1,2,3-triazole were also successfully synthesized and characterized. A novel fused nitrogen-rich heterocycle, namely, 6H-[1,2,3]triazolo[4,5-d][1,2,3] triazine-6,7-diamine (10), was surprisingly obtained, which has a high nitrogen content of 73.66% and shows good thermal stability (Tdec = 203 °C) and insensitivity to mechanical stimuli, while the detonation velocity (vD) and detonation pressure (P) reach 8421 m s-1 and 26.0 GPa, respectively.

Dislocation Mechanism and Grain Refinement of Surface Modification of NV E690 Cladding Layer Induced by Laser Shock Peening.

To investigate the relationship between the dislocation configuration and the grain refinement in the NV E690 cladding layer caused by laser shock peening, NV E690 high-strength steel powder was used to repair prefabricated pits in samples of 690 high-strength steel by laser cladding, where the laser shock peening of the cladding layer was performed by laser shock at different power densities. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to observe the microstructures of these samples before and after the laser shock process. The results showed that the metallurgical bonding between the cladding layer and the substrate after laser cladding repair was good. When the laser power density was 4.77 GW/cm2, multiple edge dislocations, dislocation dipoles, and extended dislocations were distributed over the cladding layer. When the laser power density was 7.96 GW/cm2, a geometrically necessary dislocation divided the large original grain into two subgrains with different orientations. When the laser power density was 11.15 GW/cm2, geometric dislocations divided the entire large grain into fine grains. The grain refinement model of the NV E690 cladding layer, when treated by laser shock peening, can describe the grain refinement process induced by the dislocation movement of this cladding layer.

Dynamic risk evaluation method of collapse in the whole construction of shallow buried tunnels and engineering application.

The collapse is the most frequent and harmful geological hazard during the construction of the shallow buried tunnel, which seriously threatens the life and property safety of construction personnel. To realize the process control of collapse in the tunnel construction, a three-stage risk evaluation method of collapse in the whole construction process of shallow tunnels was put forward. Firstly, according to the engineering geology and hydrogeology information obtained in the prospecting stage, a fuzzy model of preliminary risk evaluation based on disaster-pregnant environment factors was proposed to provide a reference for the optimization design of construction and support schemes in the design stage. Secondly, the disaster-pregnant environment factors were corrected based on the obtained information, such as advanced geological forecast and geological sketch, and the disaster-causing factors were introduced. An extension theory model of secondary risk evaluation was established to guide the reasonable excavation and primary support schemes. Finally, the disaster-pregnant and disaster-causing factors were corrected according to the excavation condition, an attribute model of final risk evaluation for the collapse was constructed combined with the mechanical response index of the surrounding rock. Meanwhile, the risk acceptance criteria and construction decision-making method of the collapse in the shallow buried tunnels were formulated to efficiently implement the multi-level risk control of this hazard. The proposed method has been successfully applied to the Huangjiazhuang tunnel of the South Shandong High-Speed Railway. The comparison showed that the evaluation results are highly consistent for these practical situations, which verify the application value of this study for guiding the safe construction of shallow buried tunnels.

Interstitial Fluid Behavior and Diseases.

Living things comprise a typical hierarchical and porous medium, and their most fundamental logical architectures are interstitial structures encapsulating parenchymal structures. The recent discovery of the efficient transport mechanisms of interstitial streams has provided a new understanding of these complex activities. The substance transport of interstitial streams follows mesoscopic fluid behavior dynamics, which is intimately associated with material transfer in nanoconfined spaces and a unique signal transmission. Accordingly, the evaluation of interstitial stream transport behavior at the mesoscopic scale is essential. In this review, recent advances in physical and chemical properties, the substance transport model, and the characterization methods of interstitial streams at the mesoscopic scale, as well as the relationships between interstitial streams and disease are summarized. Interstitial stream transport can be used as a basis to fully mine hierarchal behavior in images to expand imaging behavior into an omics field. By starting from the perspective of soft matter, a new understanding can be gained of health and disease and quantitative physical markers for research, clinical diagnosis, and treatment can be provided, as well as prognosis evaluation in complex diseases such as cancer and Alzheimer's disease. This will provide a foundation for the development of medicine of soft matter.

Cutting Techniques in the Fish Industry: A Critical Review.

Fish and fishery products are among the most important sources of nutritional components for human health, including high-quality proteins, essential vitamins, minerals, and healthy polyunsaturated fatty acids. Fish farming and processing technologies are continuously evolving to improve and enhance the appearance, yield, and quality of fish and fish products from farm to fork throughout the fish supply chain, including growth, postharvest, treatment, storage, transportation, and distribution. Processing of fish involves a period of food withdrawal, collection and transportation, the process of stunning, bleeding, chilling, cutting, packaging, and byproduct recycling. Cutting is a set of crucial operations in fish processing to divide the whole fish into smaller pieces for producing fish products (e.g., fish fillets, steaks, etc.). Various techniques and machinery have been introduced in the field to advance and automate cutting operations. This review aims to provide a comprehensive review of fish cutting techniques, machine vision and artificial intelligence applications, and future directions in fish industries. This paper is expected to stimulate research on enhancing fish cutting yield, product diversity, safety and quality, as well as providing advanced solutions for engineering problems encountered in the fish industry.

[Research on 7.0 T Magnetic Resonance Based Electrical Properties Tomography Based on Bloch-Siegert Shift].

Magnetic resonance based electrical properties tomography (MREPT) is a different method from proton density imaging, Bloch-Siegert shift (BSS) is used in this paper to reconstruct the radiofrequency (RF) field amplitude and calculate the distribution of the permittivity constant. The phase of the RF field is approximated by the phase component of the magnetization intensity, and the conductivity distribution is calculated. In the experiment, Bruker 7.0 T magnetic resonance device was used to image two water models and in vivo Balb/c mice to obtain the image of electrical characteristics. Experimental results show that the Bloch-siegert B1+ image is significantly more efficient than the double-angle B1+ image. The study can provide a reference for selecting appropriate B1 mapping technology for B1 field imaging of electrical characteristics organizations, and provide basic research support for promoting the practical application of magnetic resonance characteristics.

An extravascular fluid transport system based on structural framework of fibrous connective tissues in human body.

OBJECTIVE: Interstitial fluid in extracellular matrices may not be totally fixed but partially flow through long-distance oriented fibrous connective tissues via physical mechanisms. We hypothesized there is a long-distance interstitial fluid transport network beyond vascular circulations. MATERIALS AND METHODS: We first used 20 volunteers to determine hypodermic entrant points to visualize long-distance extravascular pathway by MRI. We then investigated the extravascular pathways initiating from the point of thumb in cadavers by chest compressor. The distributions and structures of long-distance pathways from extremity ending to associated visceral structures were identified. RESULTS: Using fluorescent tracer, the pathways from right thumb to right atrium wall near chest were visualized in seven of 10 subjects. The cutaneous pathways were found in dermic, hypodermic and fascial tissues of hand and forearm. The perivascular pathways were along the veins of arm, axillary sheath, superior vena cava and into the superficial tissues on right atrium. Histological and micro-CT data showed these pathways were neither blood nor lymphatic vessels but long-distance oriented fibrous matrices, which contained the longitudinally assembled micro-scale fibres consistently from thumb to superficial tissues on right atrium. CONCLUSIONS: These data revealed the structural framework of the fibrous extracellular matrices in oriented fibrous connective tissues was of the long-distance assembled fibres throughout human body. Along fibres, interstitial fluid can systemically transport by certain driving-transfer mechanisms beyond vascular circulations.

Improved stimulated echo in diffusion magnetic resonance imaging: introducing a π pulse for SNR enhancement.

PURPOSE: Anomalous diffusion in biological tissues can be examined by diffusion MRI for various applications, including tumor diagnosis and measurement of brain fiber pathways. However, the measurement of anomalous diffusion requires high b-values for the diffusion gradient in MRI, and current MRI methods cannot provide a high SNR. This study aimed to improve on the standard stimulated echo (STE) to enhance the SNR in diffusion MRI with high b-values. METHODS: Because of hardware limitations and human safety considerations, prolonging the diffusion time (Δ) is 1 of the few methods available to realize high b-values. Here, we propose a new echo mechanism for diffusion MRI to enhance SNRs under long Δ. By introducing a π pulse at the midpoint between 2nd and 3rd π/2 pulses of STE, we refocus the magnetic moment vectors in the longitudinal plane before the third π/2 pulse is applied, which preserves the full echo signals. This sequence was compared with STE and spin echo (SE). Nine Δs were tested in a phantom. Multi b-values with 2 Δs were tested in a mouse liver, brain, and tumor. RESULTS: Compared with STE and SE, the proposed improved STE (ISTE) exhibited an improved SNR in the phantom experiment and improved performance in the in vivo experiments. CONCLUSION: By using the proposed echo mechanism in diffusion MRI, we enhanced the SNR of the images, which enables us to investigate diffusion behavior at higher b-values and further facilitates the development of quantitative diffusion MRI and radiomics.

One-step fabrication of functionalized poly(etheretherketone) surfaces with enhanced biocompatibility and osteogenic activity.

Polyetheretherketone (PEEK) has an elastic modulus similar to that of the bone; however, its use as a material for bone repair is limited by bio-inert surface chemistry and poor osteogenesis-inducing capacity. To address this issue, the PEEK surface was activated by ultraviolet radiation-induced grafting of methacrylated hyaluronic acid (MeHA) and titanium dioxide (TiO2) nanofibers via a one-step process. The modified PEEK surface was characterized by X-ray photoelectron and Fourier-transform infrared spectroscopy, and the extent of surface modification was evaluated by measuring static contact angles. Atomic force microscopy revealed that the PEEK surface grafted with electrospun TiO2 had abundant nanofibers and a roughness that was comparable to that of human cortical bone. In vitro experiment, rat bone mesenchymal stem cells showed increased adhesion, proliferation, and osteogenic differentiation capacity on TiO2-modified as compared to unmodified PEEK. Thus, PEEK that is surface-modified with electrospun TiO2 and MeHA has enhanced biocompatibility and can be an effective material for use in orthopedic implants and medical devices.

Role of matrix metalloproteinase-2/9 (MMP2/9) in lead-induced changes in an in vitro blood-brain barrier model.

Lead (Pb) is a well-known neurotoxicant and a risk factor for neurologic disorders. The blood brain barrier (BBB) plays an important role in the maintenance of optimal brain function. BBB is a target of Pb, and studies have shown that Pb induced barrier loss and decreased the expression of tight junction proteins, but the detailed mechanisms are not fully understood. Matrix metalloproteinases (MMPs) are important components of extracellular matrix proteasome and can affect the remodeling and degradation of tight junction (TJ). The role of MMP-2/9 in Pb-induced damage of BBB is not known. In our study, we used an in vitro BBB model by co-culturing human umbilical vascular endothelial cells (ECV304 cells) with rat glioma cells (C6 cells), and detected the expression of related TJ proteins and MMP-2/9. Our results showed that Pb increased the permeability of the in vitro BBB model, and stimulating C6 cells with Pb could decrease the protein level of ZO-1 (zonula occludens-1) and occludin in ECV304 cells. Pb could increase the mRNA and protein level of MMP-2/9 in C6 cells, and inhibition of MMP-2/9 by SB-3CT could partially alleviate Pb-induced down-regulation of TJ proteins in ECV304 cells and Pb-induced barrier damage in the in vitro BBB model. Our research established potential therapeutic targets for modulating and preserving optimal BBB function.