Objective To evaluate inhibitory effects of the Chlamydiaphage phiCPG1 capsid protein Vp1 on Chlamydia psittaci strain guinea pig inclusion conjunctivitis (GPIC) and Chlamydia trachomatis (Ct) serovar E,and to provide new ideas for the treatment of Ct infection.Methods The Chlamydiaphage phiCPG1 capsid protein Vp1 was expressed in Escherichia coli BL21 transfected with the recombinant plasmid Vp1-pET30a (+),identified by Western blot analysis and purified by using dialysis bags.Bicinchonininc acid (BCA) assay was performed to determine the concentration of Vp1 protein.GPIC and Ct serovar E strains were both classified into 4 groups to be firstly incubated with Vp1 protein (Vp1 group),Tris-glycine solution (Tris group),S protein (S group) or Dulbecco's Modified Eagle Medium (DMEM,DMEM group) at room temperature for 3 hours,then were used to infect Hela cells followed by 72-hour (GPIC) or 48-hour (Ct serovar E) culture with the presence of Vp 1 protein (Vp 1 group),Tris-glycine solution (Tris group),S protein (S group) or DMEM (DMEM group).Subsequently,immunofluorescence staining was conducted to observe and count chlamydial inclusions.Results The number of GPIC inclusions was significantly different between the 4 groups after 72-hour culture (F=476.632,P＜ 0.05),and lower in the Vp1 group (5.0 ± 1.5) than in the Tris group (24 ± 1.2,P＜ 0.05),S group (25 ± 1.7,P＜ 0.05) and DMEM group (25 ± 1.5,P＜ 0.05),but insignificantly different between the latter 3 groups (P ＞ 0.05).Compared with the DMEM group,the Vp1 group showed a significant decrease of 80.2％ ± 3.99％ and 77.2％ ± 1.79％ in the number of GPIC and Ct serovar E inclusions respectively,with no significant difference in the inhibitory effect of Vp1 on GPIC versus Ct serovar E (t =2.057,P ＞ 0.05).Conclusion The phiCPG1 capsid protein Vp1 can obviously inhibit GPIC and Ct serovar E infections to a similar degree.

Hydrogel is a kind of three-dimensional matrix scaffold material with chemical or physical cross-linked structure, with high moisture retention and high water absorption, but insoluble in water. Because of its good biocompatibility and the ability to imitate the natural cytoplasmic matrix, hydrogel has broad practical significance and application prospects in the fields of tissue engineering and biomedicine. Nerve tissue engineering is a fast-growing field that is expected to address severe neurological diseases. Choosing the right matrix scaffold material to promote neural cell differentiation and axon growth is critical to the overall design of nerve tissue engineering. Hydrogels have been widely used to deliver neurotrophic factors, antagonists of nerve growth inhibitors and other neural growth-promoting agents to tissues to improve the difficult regeneration of the nervous system, and have proven to be excellent matrix scaffold materials for neural tissue engineering. In this review paper, a variety of hydrogel systems that have been applied to neuro-related research were classified and discussed, and their advantages and disadvantages were analyzed. The prospects and challenges of hydrogels in neural tissue engineering were also discussed.

Objective: To investigate the milk drinking behavior and bone mineral density level of pupils in Hainan Province, and to explore the correlation between bone mineral density and milk drinking behavior, in order to provide scientific basis for promoting the healthy development of bones in children and adolescents. Methods: In November 2021, a cross sectional survey including demographic characteristics, milk intake, unhealthy eating behavior, physical activity and sleep was conducted among 696 students from grades 3 to 5 in Sanya and Baisha, Hainan by stratified cluster random sampling, and bone mineral density at the distal 1/3 of the right forearm was measured by dual energy X-ray absorptiometry. t-test was used to compare the differences in bone mineral density among different milk drinking behaviors of pupils, and multiple linear regression was used to analyze the correlation between milk consumption and bone mineral density. Results: About 25.3% students consumed milk daily and 13.9% consumed ≥ 300 g of milk daily. The mean bone mineral density at the distal 1/3 of the right forearm was (0.237±0.041)g/cm 2. The bone mineral density was greater in the group with daily milk intake than in the group without daily milk intake [(0.250± 0.037 )(0.204±0.034) g/cm 2 , t=15.00, P <0.01], and the bone mineral density was greater in the group with daily average milk intake ≥300 g than in the group with daily average milk intake <300 g [(0.284±0.036)(0.229±0.037)g/cm 2, t=13.48, P < 0.01 ]. Multiple linear regression analysis showed that daily average milk intake was positively correlated with bone mineral density, with a correlation coefficient ( β=0.020, t=21.46, P <0.01). Conclusion Milk consumption among pupils is inadequate, and milk drinking behavior has a positive impact on bone mineral density, so effective milk drinking intervention should be carried out to promote children s bone development.