An initial forecast model of BP neural networks is established, and is trained using the history data of our hospital inventory. This model is applied to forecasting the demand of medical equipment in Daping Hospital. The result indicates that the inventory cost is reduced enormously. The model is useful in the purchase and inventory management of medical equipment.

Objective To investigate the effects of different concentration hyperoxic exposure on the lung development of neonatal rats for providing theoretical basis for the preparation of bronchopulmonary dys-plasia model. Methods A total of 128 newborn rats were randomly and equally assigned to one of the fol-lowing four groups:group A(FiO2 >0. 9,n＝32),group B ( FiO2 ＝0. 6,n＝32),group C(FiO2 ＝0. 4,n＝32) and the air group(21% O2,n＝32). Lung tissue were collected at day 3,7,14 and 21 for histological analysis. Body weights were recorded,pulmonary morphology and radical alveoli count(RAC),mean alveolar diameter(MAD),alveolar septal thickness(AST) were carried out. Results Compared with the air group of the same time,the body weight of group A significantly decreased at 3 d( P <0. 05),the body weight of group B significantly decreased at 7 d(P<0. 05),the body weight of group C slightly decreased at every time point,but there was no statistical significance(P>0. 05). HE staining showed that the alveolar cavity signifi-cantly increased,alveolar structure was simplified and the alveolar spacing was thickened in different degrees in group A and group B. Furthermore,the reduction in the number of alveoli was more obvious and the alveo-lar septum was thicker in group A. The change of alveoli in group C was obviously weaker than group A and group B. The RAC of group A and group B were significantly lower than those in the air group(P<0. 05). The RAC of group C was slightly lower than those in the air group,and had statistical significance at 14 d (P<0. 05). The MAD and AST of group A and group B were significantly higher than those in the air group at 7 d (P<0. 05). The MAD and AST of group C decreased slightly over time,and had statistical signifi-cance at 21 d( P<0. 05). Conclusion Different concentrations of oxygen can have an impact on alveolar development. Severe alveolar dysplasia can be seen after continuous inhalation of more than 60% oxygen concentration. It provides a model basis for the study of the pathogenesis of bronchopulmonary dysplasia.

Objective To explore the value of prophylactic anticoagulation in the 28-day prognosis of patients with severe COVID-19.Methods The clinical data of COVID-19 patients admitted to Guangdong Provincial People's Hospital from December 2022 to January 2023 were collected,including age,gender,past medical history,routine blood test,liver and renal function,procalcitonin,coagulation function,Padua prediction score,antiviral therapy,hormonotherapy,immunotherapy and anticoagulation therapy.The patients were divided into an anticoagula-tion group and a non-anticoagulation group.The differences in various indicators were compared between the two groups.Cox regression was performed to assess the independent risk factors for 28-day mortality and the anticoagula-tion efficacy between the subgroups.Results Among 158 patients,128 received anticoagulation;There were significant differences between the two groups in case number of hypertension and critical condition,lymphocyte count,prothrombin time,D-dimer,and case number of immunotherapy.COX logistic regression showed that antico-agulation(HR = 2.25,95%CI:1.01～5.01,P = 0.048)was an independent risk factor for all-cause mortality of COVID-19 patients within 28 days.Subgroup analysis showed that anticoagulation therapy led to an increase in the 28-day mortality as level of procalcitonin of≥0.5 pg/mL(HR = 2.72,95%CI:1.05～7.04)or D-dimer of<2 000 ng/mL(HR = 9.16,95%CI:1.63～51.48).Conclusions Prophylactic anticoagulation did not reduce all-cause mortality of COVID-19 within 28 days.