In this research, we compared the visual neuron responses for LGN, A18 and PMLS of old and young cats with extracellular single-neuron recording techniques. We used firing rate vector to characterize information, and response irregularity of cells to evaluate the degeneration of visual characters. Response irregularity is characterized by means of the two coefficients of variation of firing rate vectors: Cv and Cv2. We found that there was no significant change of the response irregularity in LGN areas during the aging process from young to old cats. But in the other two areas, neurons of old cats exhibited significantly larger response irregularity than those of young cats. The result indicated that the information processing function of advanced visual cortex was impaired by aging. This result also provids a reference for the research of the other neuronal system changes during aging process.
Action Potentials ; physiology ; Aging ; physiology ; Animals ; Cats ; Neural Conduction ; Neurons ; physiology ; Visual Cortex ; physiology

Knockout is an important method for gene function study, while vector is the core of gene knockout. In order to obtain an effective vector for rapid construction of mutant and essentiality identification of the corresponding gene, we constructed a recombinant plasmid named plDM-T based on the temperature-sensitive and replication- defective plasmid plDM1 by inserting an Xcm I adapter into the EcoR I and Pst I sites of pIDM1. Digesting with Xcm I, pIDM-T can be prepared as a linear T-vector for PCR products cloning and be used to knockout the corresponding gene in the genome with insertion duplication mutagenesis. After the verification of temperature sensitivity of the replication of the plasmid, we cloned two Salmonella pullorum genes eno and ybdr into the constructed pIDM-T, and two recombinant plasmids pIDM-T_eno and pIDM-T_ybdr were identified. The recombinant plasmids were then transformed into S. pullorum strain CVCC527 and the IPC (Integration rate per cell) values were calculated. As a result, we identified the eno gene as an essential gene and the ybdr as a non-essential gene in CVCC527. We verified the correctness of recombination site in ybdr recombinant 527 clones (Sal delta ybdr) by PCR and sequencing. The pIDM-T vector can be used for gene knockout in S. pullorum, as well as the identification of essentiality of the corresponding genes, which offers an effective and rapid tool for gene function study in Salmonella.
Cloning, Molecular ; Gene Knockout Techniques ; Genetic Vectors ; genetics ; metabolism ; Plasmids ; genetics ; Recombinant Proteins ; genetics ; metabolism ; Recombination, Genetic ; Salmonella ; classification ; genetics

This study aims to analyze the current construction of massive open online course (MOOC) of medical humanities in China, promote the sharing of high-quality curriculum resources, and provide information reference for curriculum design and planning. Mathematical statistics and mind map analysis were used to analyze 42 medical humanities MOOCs on 17 online course platforms during the epidemic, and the results showed that: ①the scale and quantity of medical humanities MOOCs need to be expanded; ②there is regional imbalance in MOOCs construction, with the largest number in East China; ③most of the courses are taught by teachers in a team, teachers with senior professional titles are the main force of the team, and some teams have multidisciplinary backgrounds; ④there are rich teaching contents related to humanistic knowledge and ability, but the content related to medical humanistic spirit cognition needs to be added appropriately. According to the above analysis, it's suggested that the construction of MOOC should focus on systematism and standardization, equip a team of teachers with multidisciplinary backgrounds, value curriculum design and planning, and pay full attention to the feedback and evaluation of learners to find out deficiencies.

In view of the lack of teaching methods in the cultivation of medical professionalism, this paper puts forward some important strategies for improving medical students' professionalism through discussion-based film and television appreciation. High-quality discussion-based film and television appreciation can be designed according to the four links of film selection, concentrated viewing, independent discussion and summary feedback. At the same time, in practice, attention should be paid to three key issues: selecting appropriate films, ensuring the quality and depth of discussion, and paying attention to feedback and evaluation. Practice has proved that discussion-based film and television appreciation makes the cultivation of professionalism more attractive, and can promote the professional knowledge and professional spirit, enhance students' professional enthusiasm, promote the understanding of the connotation of professionalism and reflection on related issues. Medical colleges should continue to improve the design of film viewing in practice, so as to help students better absorb humanistic nutrients from the discussion and enhance the teaching effect of professionalism.

Objective:To examine the influencing factors of endothelial injury using the structural equation model (SEM).Methods:A total of 6 861 asymptomatic individuals free of cardiovascular disease underwent health examinations at the health management center of the third Xiangya hospital, Central South University from May 2015 to August 2020. And collected their questionnaire and checkup data. Spearman′s rank correlation coefficient was used to analyze metabolic factors and brachial artery flow-mediated dilatation (FMD). Exploratory factor analysis (3 430/6 861) and confirmatory factor analysis (3 431/6 861) were conducted on the diet items. An SEM was constructed using the diet pattern data, cardiovascular risk factors and FMD, and using multi-path regression analysis to determine the correlation between the indicators.Results:Based on the factor analysis, diet items were divided into three patterns: healthy food, meat, and supplementary food. The SEM indicated that age ( β=0.27) and blood pressure ( β=0.12) had obvious effects on low FMD. Triglyceride ( β=0.03), fasting blood glucose ( β=0.04), and body mass index ( β=0.08) were positively correlated with low FMD. On the upstream, healthy food was negatively correlated with blood pressure ( β=-0.04) and body mass index ( β=-0.04), meat was positively correlated with triglyceride ( β=0.33), blood pressure ( β=0.06), fasting blood glucose ( β=0.20), and body mass index ( β=0.16), and supplementary food was negatively correlated with fasting blood glucose ( β=-0.30). This was the only pattern that was directly correlated with FMD ( β=0.05). Conclusions:SEM is an effective method to analyze the influence of various risk factors on the population and the relationship between individual indicators. This study revealed direct and indirect correlations between age, diet pattern, cardiovascular-metabolic risk, and FMD impairment. Comprehensive control of dietary patterns and metabolic indicators could prevent and improve early cardiovascular injury.