Objective To evaluate ketamine-induced cerebral protection in mice with traumatic brain injury (TBI) by magnetic resonance imaging (MRI).Methods Thirty-two pathogen-free healthy male C57BL/6 mice,aged 8 weeks,weighing 26-30 g,were divided into 4 groups using a random number table:control group (group C,n=7),ketanine group (group K,n=7),TBI group (n=9) and TBI plus ketamine group (group TBI+K,n =9).TBI was produced with a pneumatically driven controlled cortical impact device.Ketamine 150 mg/kg was intraperitoneally injected at l h after operation in TBI+K and K groups,while the equal volume of normal saline was given instead in TBI and C groups.Open field test was conducted at 24 h,72 h and 7 days after operation.The animals in TBI and TBI+K groups were scanned by T1-weighted MRI at 6,24 and 72 h after operation,the animals in C and K groups were scanned by MRI at 24 h after operation,and the development of cerebral edema was observed.Results MRI scan showed no cerebral edema in C and K groups,and different degrees of cerebral edema were found in TBI and TBI+K groups.Compared with group C,the locomotor distance was significantly shortened at 24 and 72 h after operation in group TBI (P＜0.05).Compared with group TBI,the size of cerebral edema was significantly decreased,and the locomotor distance was prolonged at 24 and 72 h after operation in group TBI+K (P＜0.05 or 0.01).Conclusion MRI method further clarifies that ketamine can produce cerebral protection to some extent in mice with TBI.

In order to understand the prevalence and genetic variation of H9N2 subtype avian influ-enza virus in Shandong,a total 492 tracheal and lung tissue samples collected from chicken farms with respiratory symptoms in partial areas in Shandong were detected by H9 subtype AIV real-time RT-PCR,and the positive samples were inoculated with chicken embryos for two generations.Whole genome sequences of the positive strains by applying Illumina Miaseq platform,and genetic evolution and mutation at positions associating with viral pathogenicity and transmissibility were analyzed.The results showed that there were 72 samples were positive for H9 subtype AIV among the 492 samples,with a positive rate of 14.63％.Thirty-four strains of H9 subtype AIV were ob-tained from the positive samples after passing through chicken embryo,meanwhile,the 34 isolates were all H9N2 subtype AIV by whole genome sequencing analysis.By analyzing the evolutionary tree of HA and NA genes,HA and NA genes of the 34 H9N2 AIV strains belonged to Y280-like branch and F/98-like branch,respectively.Meanwhile,based on above branches,there were obvious time node subbranch,which one was"isolates before 2013",another one was"isolates after 2013".The HA cleavage sites of thirty-four H9N2 strains were all 325PSRSSR↓GLF333,which met the se-quence characteristics of the lowly pathogenic avian influenza virus,and the HA receptor binding site 226 amino acid was leucine,which had the characteristics of blinding to a-2,6 mammalian sialic acid receptors.Among the internal amino acid sites that are key to mammalian adaptation,all strains had an I368V mutation in the PB1 gene that enhanced viral transmissibility in mammals and the PB2 genes of some strains were mutated to enhance the mammalian adaptation of I292 V and A588 V.The above results illustrated that the H9N2 subtype AIV gene segments in Shandong have different degrees of recombination and gene variation,so it is necessary to strengthen the monito-ring of virus variation.

Objective To analyze the trends,cooperation,topics and hotspots of researches about multi-level rehabilitation service system in China. Methods The literature on multi-level rehabilitation service system in China was searched and screened in databases of CNKI from 1983 to 2023.The number of the articles was described,and the cooperation,research hotspots and changing trend were analyzed using VOSviewer. Results A total of 4 643 articles were included.The number of the articles tended to increase and developed in stages.Nine groups with five or more researchers were found,and seven of them cooperated with each other.The most frequent keywords were community-based rehabilitation(occurrence 1 251 with connection strength 1 780),stroke(occurrence 674 with connection strength 1 126),family rehabilitation(occurrence 412 with connection strength 514),rehabilitation nursing(occurrence 178 with connection strength 240)and quality of life(occur-rence 156 with connection strength 311).The researchers initially focused on disability rehabilitation,then fo-cused on community-based rehabilitation and family rehabilitation,and gradually focused on the quality of life,activities of daily living,satisfaction,mental health,negative emotion and healthcare consortium in recent years. Conclusion The researches about multi-level rehabilitation service system are developing in China,focusing on commu-nity-based rehabilitation,stroke,family rehabilitation,rehabilitation nursing and quality of life.The cooperation among scholar groups need to be strengthened.Quality of life,activities of daily living,satisfaction,mental health,negative emotion and healthcare consortium may be the hotspots in the future.