Objective To explore the impact of tumor-associated myeloid cell infiltration signatures on postoperative overall survival (OS) in patients with gastric cancer. Methods A retrospective analysis was performed on patients who underwent radical gastrectomy at Zhongshan Hospital, Fudan University from January 2005 to December 2019. Patients were randomly divided into a training set (n＝167) and an internal validation set (n＝168) at a 1:1 ratio. Meanwhile, 147 patients with gastric cancer treated at Zhongshan Hospital (Xiamen), Fudan University during the same period were enrolled as the external validation set (n＝147). Immunohistochemistry was used in all patients to evaluate the distribution characteristics of 18 immune markers in three regions of gastric cancer tissues, namely primary tumor (PT), invasive margin (IM), and normal tissue (NT). These markers include 11 myeloid cell markers (CD11b, CD33, CD11c, CD14, CD15, CD16, CD68, CD86, CD163, CD206, and CD66b) and 7 immune checkpoints (CD73, IDO, LAG3, PD-1, SIGLEC9, SIRPA, and TIM3). LASSO regression and Cox proportional hazards model were applied to screen immune markers associated with postoperative OS in gastric cancer patients, and a predictive model for 1-, 3-, and 5-year postoperative OS was established. Data from the internal and external validation set were used for internal and external verification of the predictive model. Receiver operating characteristic (ROC) curves were plotted and the area under the curve (AUC) was calculated to assess the discriminative ability of the model. Results In the training set, LASSO regression and Cox proportional hazards model identified 4 immune marker signatures (CD14_PT, CD15_PT, CD206_PT, and SIGLEC9_PT) to construct the predictive model. ROC curve analysis showed that the AUCs of the model for predicting 1-, 3-, and 5-year postoperative OS were 0.74, 0.75, and 0.84, respectively. When the model was applied to the internal and external validation sets, the AUCs for 1-, 3-, and 5-year postoperative OS were 0.74, 0.72, 0.72 (internal validation set) and 0.72, 0.71, 0.74 (external validation set), respectively. Cox multivariate regression analysis showed that the risk score was an independent risk factor for postoperative OS in patients with gastric cancer. Conclusion The model constructed based on LASSO-Cox regression exhibits good predictive performance and can effectively predict postoperative OS in gastric cancer patients, which may serve as a basis for intensive treatment of high-risk patients after surgery.

Objective To optimize the formulation of the sunscreen used in military training.Methods The different formulations of sunscreen were prepared according to the orthogonal design,and then applied on 3M adhesive tape posted on the color dish with a certain amount;the absorbance in 280 nm-320 nm and 320 nm-400 nm of them were measured and the arithmetic mean (A) was concluded.By comparing A,the protective effect and the main factors affecting preventive bask were determined.The preventive bask test of the optimum formula was carried out in human trials using the method of multi point increasing ultraviolet irradiation.Results OMC,TinosorbTM M,rutin,pearl powder and baicalin all had significant effects in preventing UVA.OMC had a significant effect in preventing UVB.The formula 1 (containing the five materials mentioned above) had the best effects in preventing both UVA (SPF 18) and UVB (PA+).Conclusions The formula 1 has the best effects in preventing both UVA and UVB.

Objective To study the application and significance of constructivism theory in pathological experiment teaching.Methods Six classes in total of 198 students majoring in clinical medicine were selected from grade 2009 of Guangdong medical college for research and were divided into experimental group (n=99) and control group (n=99) using random number table.Various teaching methods based on constructivism theory were used in experimental group while conventional teaching methods were applied in control group.The observing ability for specimen and slices,theoretical level and learning behavior of students were assessed with the same standard and anonymous homemade questionnaire survey was executed for students.SPSS 13.0 statistical software was used to analyze the results.The examination results of the two groups were compared using independent samples t-test.The questionnaire survey results of the two groups were compared using Wilcoxon rank-sum test.P＜0.05 represented the difference having statistical significance.Results The observing capability for specimen and slices,theoretical level and learning behavior of students in experimental group were significantly improved (P＜0.01)and the questionnaire survey results demonstrated that there were statistical difference in feedbacks between the two groups and the satisfaction rate was significantly improved in experiment group (P＜0.01).Conclusions Applying comprehensive teaching methods based on constructivism theory can stimulate students' interest and initiative in learning,improve students' learning behavior and learning strategies,and significantly improve the teaching quality.