Global research trends and hotspots of artificial intelligence research in spinal cord neural injury and restoration-a bibliometrics and visualization analysis.

Background: Artificial intelligence (AI) technology has made breakthroughs in spinal cord neural injury and restoration in recent years. It has a positive impact on clinical treatment. This study explores AI research's progress and hotspots in spinal cord neural injury and restoration. It also analyzes research shortcomings related to this area and proposes potential solutions. Methods: We used CiteSpace 6.1.R6 and VOSviewer 1.6.19 to research WOS articles on AI research in spinal cord neural injury and restoration. Results: A total of 1,502 articles were screened, in which the United States dominated; Kadone, Hideki (13 articles, University of Tsukuba, JAPAN) was the author with the highest number of publications; ARCH PHYS MED REHAB (IF = 4.3) was the most cited journal, and topics included molecular biology, immunology, neurology, sports, among other related areas. Conclusion: We pinpointed three research hotspots for AI research in spinal cord neural injury and restoration: (1) intelligent robots and limb exoskeletons to assist rehabilitation training; (2) brain-computer interfaces; and (3) neuromodulation and noninvasive electrical stimulation. In addition, many new hotspots were discussed: (1) starting with image segmentation models based on convolutional neural networks; (2) the use of AI to fabricate polymeric biomaterials to provide the microenvironment required for neural stem cell-derived neural network tissues; (3) AI survival prediction tools, and transcription factor regulatory networks in the field of genetics were discussed. Although AI research in spinal cord neural injury and restoration has many benefits, the technology has several limitations (data and ethical issues). The data-gathering problem should be addressed in future research, which requires a significant sample of quality clinical data to build valid AI models. At the same time, research on genomics and other mechanisms in this field is fragile. In the future, machine learning techniques, such as AI survival prediction tools and transcription factor regulatory networks, can be utilized for studies related to the up-regulation of regeneration-related genes and the production of structural proteins for axonal growth.

Strongly Localized Moiré Exciton in Twisted Homobilayers.

Artificially molding exciton flux is the cornerstone for developing promising excitonic devices. In the emerging hetero/homobilayers, the spatial separated charges prolong exciton lifetimes and create out-plane dipoles, facilitating electrically control exciton flux on a large scale, and the nanoscale periodic moiré potentials arising from twist-angle or/and lattice mismatch can substantially alter exciton dynamics, which are mainly proved in the heterostructures. However, the spatially indirect excitons dynamics in homobilayers without lattice mismatch remain elusive. Here the nonequilibrium dynamics of indirect exciton in homobilayers are systematically investigated. The homobilayers with slightly twist-angle can induce a deep moiré potential (>50 meV) in the energy landscape of indirect excitons, resulting in a strongly localized moiré excitons insulating the transport dynamics from phonons and disorder. These findings provide insights into the exciton dynamics and many-body physics in moiré superlattices modulated energy landscape, with implications for designing excitonic devices operating at room temperature.

Phonon-assisted upconversion in twisted two-dimensional semiconductors.

Phonon-assisted photon upconversion (UPC) is an anti-Stokes process in which incident photons achieve higher energy emission by absorbing phonons. This letter studies phonon-assisted UPC in twisted 2D semiconductors, in which an inverted contrast between UPC and conventional photoluminescence (PL) of WSe2 twisted bilayer is emergent. A 4-fold UPC enhancement is achieved in 5.5° twisted bilayer while PL weakens by half. Reduced interlayer exciton conversion efficiency driven by lattice relaxation, along with enhanced pump efficiency resulting from spectral redshift, lead to the rotation-angle-dependent UPC enhancement. The counterintuitive phenomenon provides a novel insight into a unique way that twisted angle affects UPC and light-matter interactions in 2D semiconductors. Furthermore, the UPC enhancement platform with various superimposable means offers an effective method for lighting bilayers and expanding the application prospect of 2D stacked van der Waals devices.

Giant excitonic upconverted emission from two-dimensional semiconductor in doubly resonant plasmonic nanocavity.

Phonon-assisted upconverted emission is the heart of energy harvesting, bioimaging, optical cryptography, and optical refrigeration. It has been demonstrated that emerging two-dimensional (2D) semiconductors can provide an excellent platform for efficient phonon-assisted upconversion due to the enhanced optical transition strength and phonon-exciton interaction of 2D excitons. However, there is little research on the further enhancement of excitonic upconverted emission in 2D semiconductors. Here, we report the enhanced multiphoton upconverted emission of 2D excitons in doubly resonant plasmonic nanocavities. Owing to the enhanced light collection, enhanced excitation rate, and quantum efficiency enhancement arising from the Purcell effect, an upconverted emission amplification of >1000-fold and a decrease of 2~3 orders of magnitude in the saturated excitation power are achieved. These findings pave the way for the development of excitonic upconversion lasing, nanoscopic thermometry, and sensing, revealing the possibility of optical refrigeration in future 2D electronic or excitonic devices.

[Study of fundamental parameters of inductively coupled plasma for slurry nebulization--electron density determination].

The electron density of the plasma for slurry nebulization inductively coupled plasma emission spectrometry was determined and reported in the present paper. The Stark broadening method of Hg line (486.1 nm) was chosen and used to determine the electron density of the plasma for nebulization into the inductively coupled plasma with both the aqueous solution and different concentration titanium slurry. There are approximately the same plasma electron density results of 10(15) cm(-3) for the two nebulization ways. The experiment verified that the plasma electron density only shows a litter decrease with 10% TiO2 suspension nebulization into the inductively coupled plasma. This means that the plasma electron density does not change remarkably with high content suspension nebulization into the inductively coupled plasma emission spectrometry instrument. It will help trace elements determination by using high concentration suspension nebulization into the inductively coupled plasma emission spectrometry instrument.

[Study of fundamental parameters of inductively coupled plasma with slurry nebulization--I. Excitation temperature determination].

The excitation temperature of plasma with slurry nebulization into inductively coupled plasma emission spectrometry was determined and reported in the present paper. Ti-lines and multi spectrum lines method were chosen and used to determine the excitation temperature with nebulization into the inductively coupled plasma with both aqueous solution and 0.05% titanium slurry. There were approximately the same plasma excitation temperatures of 5 000-6 000 K for the two nebulization ways. The experiment verified that the excitation temperature only showed a little increase with RF power increasing. This means that the atomization efficiency did not change remarkably with slurry nebulization into the inductively coupled plasma if only the RF power was increased. Therefore, the analytical results were not much improved in the inductively coupled plasma emission spectrometry with slurry nebulization when only changing RF power.

[Research advance in slurry sample introduction for plasma emission spectrometry/mass spectrometry].

The present review is focused on the advances and applications of slurry introduction for plasma spectrometry/mass spectrometry. Preparation and characterization of the suspensions are described, including the methods for decreasing the particle size such as the bottle and bead method, mixing mill method, vibration mill method, and supersonic mill method. Dispersion of the particles can be controlled via adding dispersant and pH adjustment. Some methods for particle size measurement, namely, sedimentation, optical microscopy, photosedimentometry, laser diffraction, scanning electron microscopy and transmission electron microscopy, are also described. Effects of suspension concentration and calibration techniques, including calibration by simple aqueous standard, internal standard, correction by empirical correction factors, standard additions, intrinsic internal standardization, and standard slurries, are discussed. Fundamental study of slurry introduction and its applications to plasma spectrometry/mass spectrometry are reviewed.

Direct determination of impurities in high purity silicon carbide by inductively coupled plasma optical emission spectrometry using slurry nebulization technique.

A novel method for the determination of Al, Ca, Cr, Cu, Fe, Mg, Mn, Ni and Ti in high purity silicon carbide (SiC) using slurry introduction axial viewed inductively coupled plasma optical emission spectrometry (ICP-OES) was described. The various sizes of SiC slurry were dispersed by adding dispersant polyethylene imine (PEI). The stability of slurry was characterized by zeta potential measurement, SEM observation and signal stability testing. The optimal concentration of PEI was found to be 0.5 wt% for the SiC slurry. Analytical results of sub-mum size SiC by the slurry introduction were in good accordance with those by the alkaline fusion method which verified that determination could be calibrated by aqueous standards. For mum size SiC, results of most elements have a negative deviation and should be calibrated by the Certified Reference Material slurry. Owing to a rather low contamination in the sample preparation and stability of the slurry, the limits of detection (LODs), which are in the range of 40-2000 ng g(-1), superior to those of the conventional nebulization technique by ICP-OES or ICP-MS.

[Direct determination of Nb in titanium oxide using slurry sample introduction by axial viewing inductively coupled plasma optical emission spectrometry].

By using dispersant polyacrylate amine (NH4PAA) to disperse TiO2, effects of different dispersants, pH value and the amount of dispersant on TiO2 slurry were investigated. The pH value of the medium and the dispersant amount were optimized, and a stable and homogeneous suspension was prepared. Nb in TiO2 was determined by an axial viewing ICP-OES spectrometer. At the same time, the performance of the axial viewing ICP-OES using solid powder analysis was discussed. Under the optimum experimental conditions, the detection limit of the present method is 3.0 microg x L(-1) and the RSD is 3.1% (n = 3, c = 0.3 mg x L(-1)).