A robotic arm control system with simultaneous and sequential modes combining eye-tracking with steady-state visual evoked potential in virtual reality environment

At present, single-modal brain-computer interface (BCI) still has limitations in practical application, such as low flexibility, poor autonomy, and easy fatigue for subjects. This study developed an asynchronous robotic arm control system based on steady-state visual evoked potentials (SSVEP) and eye-tracking in virtual reality (VR) environment, including simultaneous and sequential modes. For simultaneous mode, target classification was realized by decision-level fusion of electroencephalography (EEG) and eye-gaze. The stimulus duration for each subject was non-fixed, which was determined by an adjustable window method. Subjects could autonomously control the start and stop of the system using triple blink and eye closure, respectively. For sequential mode, no calibration was conducted before operation. First, subjects’ gaze area was obtained through eye-gaze, and then only few stimulus blocks began to flicker. Next, target classification was determined using EEG. Additionally, subjects could reject false triggering commands using eye closure. In this study, the system effectiveness was verified through offline experiment and online robotic-arm grasping experiment. Twenty subjects participated in offline experiment. For simultaneous mode, average ACC and ITR at the stimulus duration of 0.9 s were 90.50% and 60.02 bits/min, respectively. For sequential mode, average ACC and ITR at the stimulus duration of 1.4 s were 90.47% and 45.38 bits/min, respectively. Fifteen subjects successfully completed the online tasks of grabbing balls in both modes, and most subjects preferred the sequential mode. The proposed hybrid brain-computer interface (h-BCI) system could increase autonomy, reduce visual fatigue, meet individual needs, and improve the efficiency of the system

The Impact of Urbanization on Urban Heat Island: Predictive Approach Using Google Earth Engine and CA-Markov Modelling (2005-2050) of Tianjin City, China

Urbanization has adverse environmental effects, such as rising surface temperatures. This study analyzes the relationship between the urban heat island (UHI) intensity and Tianjin city's land cover characteristics. The land use cover change (LUCC) effects on the green areas and the land surface temperature (LST) were also studied. The land cover characteristics were divided into five categories: a built-up area, an agricultural area, a bare area, a forest, and water. The LST was calculated using the thermal bands of spatial images taken from 2005 to 2020. The increase in the built-up area was mainly caused by the agricultural area decreasing by 11.90%. The average land surface temperature of the study area increased from 23.50 to 36.51 °C, and the region moved to a high temperature that the built-up area's temperature increased by 1.5%. Still, the increase in vegetation cover was negative. From 2020 to 2050, the land surface temperature is expected to increase by 9.5 °C. The high-temperature areas moved into an aerial distribution, and the direction of urbanization determined their path. Urban heat island mitigation is best achieved through forests and water, and managers of urban areas should avoid developing bare land since they may suffer from degradation. The increase in the land surface temperature caused by the land cover change proves that the site is becoming more urbanized. The findings of this study provide valuable information on the various aspects of urbanization in Tianjin and other regions. In addition, future research should look into the public health issues associated with rapid urbanization.Reconstructing the Architecture System based on the coherence mechanism of “Architecture-human-environment” in the Chinese context, Key project of National Natural Science Foundation of China, grant number 52038007, 2021-01-2025-12.Peer reviewe

Enhance immune response to H9 AIV DNA vaccine based on polygene expression and DGL nanoparticle encapsulation

ABSTRACT: DNA vaccination has great potential to treat or prevent avian influenza pandemics, but the technique may be limited by low immunogenicity and gene delivery in clinical testing. Here, to improve the immune efficacy of DNA vaccines against avian influenza, we prepared and tested the immunogenicity of 4 recombinant DNA vaccines containing 2 or 3 AIV antigens. The results revealed that chickens and mice immunized with plasmid DNA containing 3 antigens (HA gene from H9N2, and NA and HA genes from H5N1) exhibited a robust immune response than chickens and mice immunized with plasmid DNAs containing 2 antigenic genes. Subsequently, this study used pβH9N1SH5 as a model antigen to study the effect of dendritic polylysine (DGL) nanoparticles as a gene delivery system and adjuvant on antigen-specific immunity in mice models. At a ratio of 1:3 DGL/pβH9N1SH5 (w/w), the pβH9N1SH5/DGL NPs showed excellent physical and chemical properties, induced higher levels of HI antibodies, and larger CD3+/CD4+ T lymphocyte and CD3+/CD8+ T lymphocyte population, as well as the production of cytokines, namely, interferon (IFN)-γ, interleukin (IL)-2 compared with the naked pβH9N1SH5. Therefore, multiantigen gene expression methods using DGL as a delivery system may have broad application prospects in gene therapy