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Optical imaging in the second near-infrared (NIR-II; 900–1880 nm) window is currently a popular research topic in the field of biomedical imaging. This study aimed to explore the application value of NIR-II fluorescence imaging in foot and ankle surgeries. A lab-established NIR-II fluorescence surgical navigation system was developed and used to navigate foot and ankle surgeries which enabled obtaining more high-spatial-frequency information and a higher signal-to-background ratio (SBR) in NIR-II fluorescence images compared to NIR-I fluorescence images; our result demonstrates that NIR-II imaging could provide higher-contrast and larger-depth images to surgeons. Three types of clinical application scenarios (diabetic foot, calcaneal fracture, and lower extremity trauma) were included in this study. Using the NIR-II fluorescence imaging technique, we observed the ischemic region in the diabetic foot before morphological alterations, accurately determined the boundary of the ischemic region in the surgical incision, and fully assessed the blood supply condition of the flap. NIR-II fluorescence imaging can help surgeons precisely judge surgical margins, detect ischemic lesions early, and dynamically trace the perfusion process. We believe that portable and reliable NIR-II fluorescence imaging equipment and additional functional fluorescent probes can play crucial roles in precision surgery.

Multi-label text classification (MLTC) aims to assign appropriate labels to each document from a given set. Prior research has acknowledged the significance of label information, but its utilization remains insufficient. Existing approaches often focus on either label correlation or label textual semantics, without fully leveraging the information contained within labels. In this paper, we propose a multi-perspective contrastive model (MPCM) with an attention mechanism to integrate labels and documents, utilizing contrastive methods to enhance label information from both textual semantic and correlation perspectives. Additionally, we introduce techniques for contrastive global representation learning and positive label representation alignment to improve the model’s perception of accurate labels. The experimental results demonstrate that our algorithm achieves superior performance compared to existing methods when evaluated on the AAPD and RCV1-V2 datasets.

In order to obtain the best extraction process of sulfated polysaccharides from Kappaphycus alvarezii and determine its antiallergic activity, the single factor experiments were carried out firstly. The polysaccharides yield of Kappaphycus alvarezii was chose as the investigation index, and the ratio of material to liquid, ultrasonic pretreatment time and extraction time were selected for Box-Behnken response surface design. Then the extracted crude polysaccharides was purified through the DEAE-52 cellulose chromatography column. The effects of the purified polysaccharides on RBL-2H3 cell viability, inhibition of cell degranulation and regulation of histamine release were measured by RBL-2H3 cell model method. The results showed that the optimum extraction condition of polysaccharides from Kappaphycus alvarezii was as follows: The ratio of material to liquid (w/v) was 1:92 g/mL, the ultrasonic pretreatment time was 40 min, and the extraction time was 4 h. Under the optimum extraction conditions, the extraction rate of polysaccharides from Kappaphycus alvarezii was 13.92%. The KSP（Kappaphycus alvarezii Sulfated Polysaccharides）, a component purified by DEAE-52 cellulose chromatography, had no significant inhibition on the activity of RBL-2H3 cells in the concentration range from 50 to 1200 μg/mL, and also had no cytotoxicity. The β-Hexosaminidase activity and histamine release inhibition rates of RBL-2H3 cells stimulated by 2,4-Dinitrophenyl-Bovine Serum Albumin (DNP-BSA) with 25, 50 and 100 μg/mL KSP were 36.3%, 37.0%, 51.7%, and 17.5%, 18.3%, 42.0% respectively. In conclusion, the process parameters obtained in this test are feasible, KSP had no obvious toxicity to RBL-2H3 cells and showed significant inhibition of degranulation and histamine release, with good in vitro anti-allergic activity. This study can provide a reference for the development of nutritional functional food with anti-allergic activity using Kappaphycus alvarezii as raw material.

The assembled corrugated steel initial support structure is a new prefabricated structure in highway tunnel engineering, achieving a balance between economy and safety. This study proposes a simplified calculation method and elucidates the mechanical mechanisms of assembled corrugated steel initial support structures. Firstly, the stiffness characteristics of corrugated steel plates were studied based on full-scale tests. A general equivalent stiffness coefficient table was established. Numerical simulations of corrugated steel flange joints were conducted to explore their bending mechanical properties. A two-stage rotational stiffness model for corrugated steel flange joints was proposed. Finally, a plane strain-spring simplified calculation method for the assembled corrugated steel initial support structure was developed, and the monitoring data from the Qipanshan Tunnel validated the correctness and reliability of the proposed method. The results demonstrate that (1) the plane strain-spring simplified model consists of the planar strain equivalent calculation method for corrugated steel plates and the two-line stiffness equivalent spring of the corrugated steel flange joint. The simplified model was validated as effective by monitoring data. (2) Corrugated steel plates exhibit two stages under loading, namely gap elimination and elastic stages. The elastic stage stiffness of corrugated steel plates decreases with increasing ratio of depth to pitch (RDP), positively correlating with plate thickness when the RDP exceeds 0.333 and otherwise negatively correlated. (3) Corrugated steel lining flange joints exhibit distinct elastic and plastic stages in their linear moment–rotation curves under loading.

Abstract The limited signal of long-wavelength near-infrared-II (NIR-II, 900–1880 nm) fluorophores and the strong background caused by the diffused photons make high-contrast fluorescence imaging in vivo with deep tissue disturbed still challenging. Here, we develop NIR-II fluorescent small molecules with aggregation-induced emission properties, high brightness, and maximal emission beyond 1200 nm by enhancing electron-donating ability and reducing the donor-acceptor (D-A) distance, to complement the scarce bright long-wavelength emissive organic dyes. The convincing single-crystal evidence of D-A-D molecular structure reveals the strong inhibition of the π-π stacking with ultralong molecular packing distance exceeding 8 Å. The delicately-designed nanofluorophores with bright fluorescent signals extending to 1900 nm match the background-suppressed imaging window, enabling the signal-to-background ratio of the tissue image to reach over 100 with the tissue thickness of ~4–6 mm. In addition, the intraluminal lesions with strong negatively stained can be identified with almost zero background. This method can provide new avenues for future long-wavelength NIR-II molecular design and biomedical imaging of deep and highly scattering tissues.

Fluorescence imaging in the second near-infrared window (NIR-II, 900–1880[Formula: see text]nm) with less scattering background in biological tissues has been combined with the confocal microscopic system for achieving deep in vivo imaging with high spatial resolution. However, the traditional NIR-II fluorescence confocal microscope with separate excitation focus and detection pinhole makes it possess low confocal efficiency, as well as difficultly to adjust. Two types of upgraded NIR-II fluorescence confocal microscopes, sharing the same pinhole by excitation and emission focus, leading to higher confocal efficiency, are built in this work. One type is fiber-pinhole-based confocal microscope applicable to CW laser excitation. It is constructed for fluorescence intensity imaging with large depth, high stabilization and low cost, which could replace multiphoton fluorescence microscopy in some applications (e.g., cerebrovascular and hepatocellular imaging). The other type is air-pinhole-based confocal microscope applicable to femtosecond (fs) laser excitation. It can be employed not only for NIR-II fluorescence intensity imaging, but also for multi-channel fluorescence lifetime imaging to recognize different structures with similar fluorescence spectrum. Moreover, it can be facilely combined with multiphoton fluorescence microscopy. A single fs pulsed laser is utilized to achieve up-conversion (visible multiphoton fluorescence) and down-conversion (NIR-II one-photon fluorescence) excitation simultaneously, extending imaging spectral channels, and thus facilitates multi-structure and multi-functional observation.

The retention time and toxicity of synthetic NIR-II fluorophores limit long-term application. Here the authors use infrared fluorescent proteins (iRFPs) as NIR-II probes for prolonged continuous imaging in mice, and generate a transgenic mouse model which they use to image liver and pancreas.

The active substances derived from plants have received increasing attention owing to their wide range of pharmacological applications, including anti-tumor, anti-allergic, anti-viral, and anti-oxidative activities. The allergy epidemic is a growing global public health problem that threatens human health and safety. Polyphenols from plants have significant anti-allergic effects and are an important source of anti-allergic drug research and development. Here, we describe recent advances in the anti-allergic efficacy of plant polyphenols, including their comprehensive effects on cellular or animal models. The current issues and directions for future development in this field are discussed to provide a theoretical basis for the development and utilization of these active substances as anti-allergic products.

This study investigates the cooperative fault-tolerant tracking control problem of a train platoon in the presence of actuator failure, saturation limits, and unknown operating resistance. To construct a cooperative tracking control scheme, the proposed distributed controller is designed according to adjacent trains’ state information, including position, velocity, and acceleration. Radial basis function neural networks are introduced to tackle uncertain operational resistance, and the weight values of the neural network are updated online. Actuator failures with partial loss of effectiveness are estimated and compensated using adaptive methods. Another neuro-adaptive fault-tolerant control law is proposed to further solve the actuator saturation problem. The developed tracking controller remains fault-tolerant even under saturation limits while ensuring the stability of the closed-loop system. It is demonstrated using Lyapunov stability analysis that uniform ultimate boundedness is guaranteed for all signals of the closed-loop system. Numerical simulation results illustrate the effectiveness of the proposed control scheme.

Automatic train operation is an important part of the train control system. As train operating intervals continue to shorten and train speeds continue to increase, multiple train cooperative control is currently an important technology to further improve the efficiency of train operation and line passing capacity. However, considering various factors such as the nonlinearity and uncertainty of the train dynamics model and the complexity of the line conditions, this creates even greater demands on the design of the controller. In this study, we propose an adaptive cooperative tracking control method for multiple trains using adjacent information. For the multiple-train coordinated tracking control in the presence of model uncertainties, unknown parameters, and external disturbances, a distributed cooperative control scheme for multiple trains is designed using the displacement, velocity, and acceleration information of adjacent trains, combined with radial basis function neural networks and adaptive methods. A fast high-order sliding mode observer is used to estimate the train velocity and acceleration information. Stability and convergence are proved for single and multiple trains utilizing Lyapunov stability analysis. Simulation examples demonstrate the effectiveness of the proposed controller.

Fluorescence imaging-guided surgery is one of important techniques to realize precision surgery. Although second near-infrared window (NIR-II) fluorescence imaging has the advantages of high resolution and large penetration depth in surgical navigation, its major drawback is that NIR-II images cannot be detected by our naked eyes, which demands a high hand-eye coordination for surgeons and increases the surgical difficulty. On the contrary, visible fluorescence can be observed by our naked eyes but has poor penetration. Here, we firstly propose a kind of NIR-II and visible fluorescence hybrid navigation surgery assisted via a cocktail of aggregation-induced emission nanoparticles (AIE NPs). NIR-II imaging helps to locate deep targeted tissues and judge the residual, and visible fluorescence offers an easily surgical navigation. We apply this hybrid navigation mode in different animals and systems, and verify that it can accelerate surgical process and compatible with a visible fluorescence endoscopy. To deepen the understanding of lymph node (LN) labelling, the distribution of NPs in LNs after local administration is initially analyzed by NIR-II fluorescence wide-filed microscopy, and two fates of the NPs are summarized. An alternative strategy which combines indocyanine green and berberine is also reported as a compromise for rapidly clinical translation.

Here, the authors demonstrate the application of machine learning to optimize the device fabrication process for wafer-scale 2D semiconductors, and eventually fabricate digital, analog, and optoelectrical circuits.

Moderate light absorption by bio-tissue is conducive to the imaging performance. The second near-infrared window is perfected as 900–1880 nm, and 2080–2340 nm is proposed as the third near-infrared window.

This paper presents a high-gain D-band power amplifier (PA) fabricated with 28-nm CMOS technology for a sub-terahertz frequency modulated continuous wave imaging system. It adopts two-channel power combining using artificial transmission lines to absorb the parasitic capacitance of the ground-signal-ground pad. The layout of the transistors and neutralization capacitors are optimized to improve the maximum stable gain, stability, and robustness. Asymmetrically magnetically coupled resonators are used in inter-stage and input matching networks to extend the operating bandwidth. The PA achieves a peak power gain of 21.9 dB and maximum output power of 11.8 dBm with 10.7% of power-added efficiency. Also, this PA can achieve higher than 10 dBm output power over the frequency range of 120–150 GHz.

In this article, accurate physical and SPICE model of wafer-level monolayer molybdenum disulfide (MoS2) device are developed to guide the devices and circuits design, which is the foundation of high-performance analog chip design. Moreover, the proposed model considers the non-ideality of thin films and the influence of Schottky contact with higher accuracy. The mean percentage error (MPE) of the physical model simulation and measurement results is 4.49%. Based on the SPICE model implemented in this article, the amplifier circuit and current amplifying circuits are implemented to verify the manufacturing process and accuracy of the device models, which shows the MoS2 is potential material to realize industrial applications. The MPE of the SPICE model simulation and measurement results is within 7.00% which can be utilized for our analog circuit design.

This article presents an accurate quadrature phase-locked loop (PLL) with quadrature phase mismatch calibration for 32 GS/s analog-to-digital converter (ADC). Due to the mismatches of clock distribution in layout and variations of the active devices, the quadrature phase of the sampling clock is significantly deteriorated. To solve the problem, a novel quadrature divider with phase calibration is induced in PLL loop. Moreover, a theoretical model of the quadrature divider is proposed to predict the performance and potential ability for phase calibration. Based on the theoretical and model analysis, the proposed PLL can realize accurate quadrature phase for high-speed real-time sampling system. The output frequency of PLL is 8 GHz with quadrature phases for 32 GS/s sampling rate. The proposed clock can realize 8-bit signal to noise ratio requirement with 16 GHz bandwidth. The proposed PLL was fabricated in 65-nm CMOS process with 28 mW dc power consumption under 1.2 V supply voltage. Testing results show that the phase noise of the clock is -127 dBc/Hz @10 MHz-offset frequency when the sampling speed is 27.4 GS/s. With proposed methods, the range of the phase error calibration is around ±20°.