Objective: To investigate the effects of different doses of X ⁃rays irradiation combined with allogeneic lymphocyte infusion on the establishment of aplastic anemia in mice. Methods: Forty BALB/c mice were randomly divided into four groups : the 3 Gy group (n = 9) , the 4 Gy group (n = 9) , the 5 Gy group (n = 10) , and the con⁃trol group (n = 12) . In the 3 Gy , 4 Gy , and 5 Gy groups , the experimental mice were exposed to corresponding do⁃ses of X ⁃ray and then intravenously infused with 0. 2 mL mixed suspension of the thymus and spleen cells from DBA/2 mice , at a concentration of 1 × 107 cells/mL , within 4 hours after irradiation. The control group did not un⁃dergo X ⁃ray irradiation and infused with an equivalent volume of physiological saline instead. Blood samples were collected from the orbital venous plexus of BALB/c mice and analyzed using an animal automated hematology analy⁃zer to measure peripheral blood parameters , including red blood cells ( RBC) , white blood cells ( WBC) , and platelets (PLT) . The general condition of mice was monitored daily , and survival rates were recorded for each group. At the experimental endpoint , the tibias were harvested for hematoxylin and eosin (HE) staining , while the femurs were used to prepare bone marrow smears for morphological examination. For the 5 Gy group , T ⁃cell subsets(ELISA) at the endpoint. Results : In the 3 Gy group , pancytopenia was observed , but platelet recovery occured rapidly , returning to normal levels by day 17 post⁃modeling. No deaths occurred during the observation period. At myeloid⁃to⁃erythroid (M/E) ratio , and no significant morphological abnormalities were noted in cells at any devel⁃with hematopoietic cells. In the 4 Gy group , pancytopenia persisted throughout the observation period. The survival rate was 90% . Endpoint analysis showed hypocellular marrow by morphological examination. HE staining indicated minimal fatty infiltration in the bone marrow tissue. In the 5 Gy group , pancytopenia was observed , though erythro⁃cyte counts returned to normal levels by day 24. The survival rate during the observation period was 50% . Endoint analysis revealed vacuolization of marrow particles and reduced hematopoietic cells with predominantly non⁃hematopoietic cells in bone marrow morphology. HE staining demonstrated severe fatty infiltration in the bone mar⁃row tissue , with scarcity of immature cells and hematopoietic precursor cells. Flow cytometry analysis showed a de⁃creased proportion of CD4 + T cells (% ) and an increased proportion of CD8 + T cells (% ) . ELISA confirmed elevated secretion of negative hematopoietic regulators : interferon⁃gamma ( IFN⁃γ) and tumor necrosis factor⁃alpha (TNF⁃α ) . Conclusion Combined administration of varying radiation doses with allogeneic lymphocyte infusion consistently induced peripheral blood cytopenia in mice , characterized by reductions in RBC , WBC , and PLT counts. Integrated analysis of bone marrow morphology , histopathological assessment via HE staining , and immuno logical parameters confirmed that a mouse model of aplastic anemia can be successfully established using 5 Gy X ⁃ ray irradiation coupled with infusion of 2 × 106 allogeneic lymphocytes.

Objective: To analyze the current situation and research update on campus air quality in China, and to provide reference for effective campus environment improvement. Methods: The documents of China national knowledge internet (CNKI) from 1980 to 2020 were extracted and the key words related to campus air quality were analyzed by CiteSpace software. Microorganisms, formaldehyde and benzene were selected, data of 200 literatures were classified and sorted out in different functional areas. Results: Studies on campus air quality in China has been increasing gradually since 2004, especially focusing on indoor air, PM 2.5 and benzene series. The primary microorganism in the air environment of Chinese campuses was bacteria with the concentration of 2 309.31 cfu/m 3 . The ranking of the overall load of bacteria in air of different functional areas was consistent with that of microorganisms: living service area > landscape leisure area > public transport area > scientific research and teaching area > administrative office area > sports activity area. The average value of microbial indicators in indoor air of computer room, office area and campus living areas were more likely exceed the standard. The formaldehyde concentration in the computer room and reading room was high. The health of students exposed to formaldehyde and benzene on campus evaluated by using the evaluation model of the U.S. Environmental Protection Agency proved out to be in the safe range. Conclusion The concentrations of microorganisms, formaldehyde and benzene in campus environment mostly meet the requirements. Further measures need to be taken to reduce microbial concentration and strengthen formaldehyde monitoring and pollution source management in computer room and reading room.