Increasing the amplitude of event-related potential is one of the key methods to improve the accuracy of the potential-based brain-computer interface, e.g., P300-based brain-computer interface. The brain-computer interface systems often use symbols or controlled objects as vision stimuli, but what visual stimuli can induce more obvious event-related potential is still unknown. This paper designed three kinds of visual stimuli, i.e., a square, an arrow, and a robot attached with an arrow, to analyze the influence of concreteness degree of the graph on the N200 and P300 potentials, and applied a support vector machine to compare the performance of the brain-computer interface under different stimuli. The results showed that, compared with the square, the robot attached with arrow and the arrow both induced larger N200 potential (P = 1.6 × 10−3, P = 4.2 × 10−2) and longer P300 potential (P = 2.2 × 10−3, P = 1.9 × 10−2) in the frontal area, but the amplitude under the arrow condition is smaller than the one under the robot attached with arrow condition. The robot attached with arrow increased the N200 potential amplitude of the square and arrow from 3.12 μV and 5.19 μV to 7.21 μV (P = 1.6 × 10−3, P = 8.9 × 10−2), and improved the accuracy rate from 59.95%, 61.67% to 74.45% (P = 2.1 × 10−2, P = 1.6 × 10−2), and the information transfer rate from 35.00 bits/min, 35.98 bits/min to 56.71 bits/min (P = 2.6 × 10−2, P = 1.6 × 10−2). This study shows that the concreteness of graphics could affect the N200 potential and the P300 potential. The abstract symbol could represent the meaning and evoke potentials, but the information contained in the concrete robot attached with an arrow is more correlated with the human experience, which is helpful to improve the amplitude. The results may provide new sight in modifying the stimulus interface of the brain-computer interface.
As pigs are similar to humans in anatomy, physiology and pathology, nutrition metabolism and disease characteristics, genetically modified pigs are already used for the studies of disease mechanism, pathology and toxicology and the evaluation of drugs. But the production of large modified animals is difficult, cumbersome, time-consuming and costly. With the breakthrough of gene editing technology, clustered regularly interspersed short palindromic repeat (CRISPR)/CRISPR-associated 9( Cas9)(CRISPR/Cas9) technology has greatly improved the mutation efficiency, reduced the cost and simplified the steps, and promoted the widespread application of genetically modified pigs. In this paper, the production methods of genetically modified pigs and the research progress of genetically modified pigs by CRISPR/Cas9 in the medical field were reviewed.
Anterior mediastinal inflammatory myofibroblastoma is a rare tumor with insidious onset and easy misdiagnosis. In this report, we presented a case of anterior mediastinal inflammatory myofibroblastoma with thymoma. The mediastinal tumor was found by physical examination, and the prognosis was good after surgical treatment. For this disease, operation is an effective method for definite diagnosis and treatment, and complete excision can achieve good outcomes.
Objective To summarize the methods and experience of animal experiment ethics training at home and abroad, analyze the opportunities and problems, and explore the ethics training methods suitable for the current situation of animal experiments in China. Methods Documents relating to animal experiment ethics training from January 2012 to February 2022 were searched in PubMed, Embase, China National Knowledge Infrastructure and Wanfang Data databases. After literature screening and data extraction by 2 researchers independently, descriptive analysis was performed. Results A total of 44 documents were selected, including 19 in Chinese and 25 in English, involving 44 institutions. According to the literature analysis, in the United States, Britain and other developed countries, the welfare and ethical laws for laboratory animals were relatively perfect, such as the Animal Welfare Act of the United States, the Animals (Scientific Procedures) Act of Britain, the Animal Welfare Act of German, and the Act on Welfare and Management of Animals of Japan, while in China administrative regulations were the main ones, and most of the institutions were restricted by management regulations; the ethics of personnel involved in animal experiments were uneven; the training time of some domestic institutions was less than that of institutions abroad; domestic training methods and contents needed to be improved. Basing on the comparative results at home and abroad and combining the training experience, West China Hospital of Sichuan University improved the animal experiment ethics training system. Conclusion It is suggested that the animal experimental institutions in China should improve the training methods, to enhance the awareness and cognition of people involved in animal experiments more systematically and scientifically, and strengthen the ethical review.
Magnetic resonance imaging (MRI) is an important medical imaging method, whose major limitation is its long scan time due to the imaging mechanism, increasing patients’ cost and waiting time for the examination. Currently, parallel imaging (PI) and compress sensing (CS) together with other reconstruction technologies have been proposed to accelerate image acquisition. However, the image quality of PI and CS depends on the image reconstruction algorithms, which is far from satisfying in respect to both the image quality and the reconstruction speed. In recent years, image reconstruction based on generative adversarial network (GAN) has become a research hotspot in the field of magnetic resonance imaging because of its excellent performance. In this review, we summarized the recent development of application of GAN in MRI reconstruction in both single- and multi-modality acceleration, hoping to provide a useful reference for interested researchers. In addition, we analyzed the characteristics and limitations of existing technologies and forecasted some development trends in this field.