To introduce the biological properties and functions of individual blood-brain barrier components,and summarize the most widely used in vitro blood-brain barrier models,compare their strengths and weaknesses,and provide suggestions on model selection in blood-brain barrier research and new-drug research and development.

In this paper, taking Shijiazhuang city, Hebei province as an example, a random sampling of 30 streets in three districts were investigated the use of tactile ground surface indicator. The survey showed that 69% of the existing tactile ground surface indicator were used normally, while 8%were laid unreasonable, 11%were occupied and 12%were damaged. Suggestions were set from three aspects:sci-entific and reasonable laying, strengthening supervision and maintenance, and strengthening publicity and education, so as to improve the current situation of tactile ground surface indicator, improve the utilization rate, promote the participation of visually impaired persons in so-cial life and improve their quality of life.

Objective:To understand the pathogen infection and epidemiological characteristics of children with diarrhea in Tianjin.Methods:Stool samples from 1 466 children with diarrhea in Tianjin Children's Hospital from August 2017 to July 2018 were collected, and all samples were tested for five intestinal-related pathogens (norovirus, rotavirus, Clostridium difficile toxin, adenovirus, and astrovirus). Results:Among the 1 466 samples, 627 samples were positive for nucleic acid detection of intestinal pathogens, with a positive rate of 42.8%. The detection rate of norovirus was the highest (26.3%), followed by rotavirus (15.3%), Clostridium difficile toxin (4.6%), adenovirus (4.1%), and astrovirus (1.84%). The infection has obvious seasonality. The positive detection rates of the five pathogens were similar among children of different sexes, and only the positive detection rates of norovirus and rotavirus were statistically significant among different ages ( P<0.05). There were 110 cases of mixed infection, and the mixed infection of norovirus and rotavirus was the most common, with a total of 37 cases. Conclusions:The pathogen spectrum of infant infectious diarrhea in Tianjin is complex and diverse, and the main pathogens are norovirus and rotavirus.

Objective:To investigate the relationship between the prevalence of cervical spondylosis and occupational stress among employees in Jing 'an community health service centers in Shanghai. Methods:A concise occupational stress questionnaire was developed based on the pay return imbalance model. The prevalence of cervical spondylosis and the incidence of occupational stress were investigated with the questionnaire survey among employees of all 15 community health service centers in a district of Shanghai from September 2020 to November 2020. Multiple logistic regression was used to analyze the relationship between occupational stress factors and prevalence of cervical spondylosis.Results:Of total 1 816 employees in the community health service centers in the district, 1 515 independently completed the questionnaire (83.4%). The average age of responders was 39 years old. The prevalence of cervical spondylosis was 34.7% (526/1 515); and the incidence of occupational stress was 11.6% (175/1 515). The average score of pay factor in the sick group was higher than that in the non-sick group ( t=-8.04, P<0.001), the average score of return factor was lower than that of the non-sick group ( t=6.06, P<0.001), and the average score of internal input factor was higher than that of the non-sick group ( t=-8.39, P=0.004). Multivariate regression analysis showed that occupational stress ( OR=1.57, 95% CI: 1.05-2.36), medium investment ( OR=1.42, 95% CI: 1.02-2.00), high investment ( OR=1.93, 95% CI: 1.27-2.93) were the risk factors of cervical spondylosis (all P<0.05). Conclusions:Cervical spondylosis is associated with occupational stress among employees of community health service centers. To prevent the prevalence of cervical spondylosis, it is necessary to reduce occupational tension, alleviate the imbalance of pay and return, and prevent individuals from excessive internal investment.

Objective To investigate the clinical characteristics of DCD donor-derived CRKP infection and bleeding in kidney transplantation,and to summarize the experience of diagnosis,treatment and prevention.Methods A retrospective analysis was carried out from July 2016 to December 2017 in hospital,containing clinical data of 4 cases of CRKP-infected DCD donors and 7 cases of kidney transplantation recipients.Results In the CRKP culture of 4 cases of DCD donors,1 case was positive for blood culture,1 case was positive for urine culture,1 case was positive for sputum culture,and 1 case was negative for blood,urine and sputum culture.The corresponding 7 recipients were all positive for blood culture after renal transplantation,4 cases were positive for urine culture,3 cases were positive for sputum culture,and 5 cases were positive for perirenal drainage.Of the 7 patients,4 cases had renal artery hemorrhage,1 of them was died.The average bleeding time was 17.75 days after operation (14-19 days).In 7 patients with renal transplantation,CRP increasd.And in 3 cases of deaths,CRP was stably higher than normal.Meanwhile,CRP in 4 surviving patients gradually decreased to the normal range after effective anti-infection treatment.All 7 patients were treated with carbapenems;2 patients were dead without avibactam therapy;and 5 cases were treated with avibactam and carbapenems and survived,1 case died and 1 case had good renal function recovery.Conclusion Positive CRKP in blood,urine and sputum of DCD donors can lead to CRKP infection in kidney transplant recipients.Even if the body fluids of donors are all negative,the false negative results could not be excluded.Persistent or increased high-level CRP after operation is an early warning on CRKP infection.And CRP can be used as an indicator for evaluating the effectiveness of anti CRKP therapy.The combination of avibactam and carbapenem antibiotics is an effective regimen in the treatment of DCD donor-derived CRKP.