OBJECTIVES: To investigate the impact of incorrect specification of the working correlation structure matrix on estimated sample size in a 2×2 crossover design based on the generalized estimating equation (GEE). METHODS: Based on Monte Carlo simulation, the influence of incorrect specification of the work-related structure matrix on the sample size estimation under different conditions was evaluated after controlling the total sample size n, the proportion of subjects assigned to AB sequence (s=1) θ, the correlation coefficient ρ, and the placebo effect OR. Bias and mean square error (MSE) were used to assess the difference between the sample size estimates and the theoretical values. RESULTS: When the correctly specified working correlation structure matrix is independent, the sample size estimation effect of correctly specifying the working correlation structure matrix is better than that of incorrect specification. But when the correctly specified working correlation structure matrix is equal and the correlation coefficient is closer to 0, with other factors being smaller (n≤50, θ≤0.5, OR=2 in this article), there is a situation where the bias of the sample size estimation value for the correctly specified working correlation structure matrix is greater than the bias for the incorrectly specified working correlation structure matrix. CONCLUSIONS Under most conditions, incorrectly specifying the working correlation structure matrix can cause the estimated sample size to deviate significantly from the theoretical value, but under certain conditions, the impact of incorrectly specifying the working correlation structure matrix can be small on the estimated sample size.
Sample Size ; Monte Carlo Method ; Humans ; Cross-Over Studies ; Computer Simulation ; Research Design ; Bias

Respiratory syncytial virus (RSV) is an enveloped, negative-sense, single-stranded RNA virus of the Orthopneumovirus  genus of the Pneumoviridae family in the order Mononegavirales. RSV can cause acute upper and lower respiratory tract infections, sometimes with extrapulmonary complications. The disease burden of RSV infection is enormous, mainly affecting infants and older adults aged 75 years or above. Currently, treatment options for RSV are largely supportive. Prevention strategies remain a critical focus, with efforts centered on vaccine development and the use of prophylactic monoclonal antibodies. To date, three RSV vaccines have been approved for active immunization among individuals aged 60 years and above. For children who are not eligible for these vaccines, passive immunization is recommended. A newly approved prophylactic monoclonal antibody, Nirsevimab, which offers enhanced neutralizing activity and an extended half-life, provides exceptional protection for high-risk infants and young children. This review provides a comprehensive and detailed exploration of RSV's virology, immunology, pathogenesis, epidemiology, clinical manifestations, treatment options, and prevention strategies.
Humans ; Respiratory Syncytial Virus Infections/prevention & control* ; Respiratory Syncytial Viruses/pathogenicity* ; Respiratory Syncytial Virus, Human/pathogenicity* ; Antiviral Agents/therapeutic use*

Objective:To explore the effect of hyperbaric oxygen（HBO）combined with paclitaxel（PTX）on the proliferation，level of reactive oxygen species（ROS），and cell cycle of human gastric cancer AGS cell line cultured in vitro. Methods:After the completion of in vitro culture，the AGS cells were divided into four groups，including control group，PTX group，HBO group，and HBO+PTX group. Cell Counting Kit-8（CCK-8）assay was used to detect the inhibitory effect of HBO combined with PTX on the proliferation of AGS cells. Flow cytometry was adopted to detect the intracellular ROS level and cell cycle arrest. Western blotting was used to assess the expression levels of cell cycle-related proteins. Results:The survival rate of AGS cells in the HBO+PTX group was significantly lower than those in the control group and the HBO group（ P<0.01），and also lower than that in the PTX group（ P<0.05）. The ROS level of AGS cells in the HBO+PTX group was significantly higher than those in the control group and the HBO group（ P<0.01），and also higher than that in the PTX group（ P<0.05）. PTX blocked the AGS cell cycle in S phase（ P<0.05），and the percentage of cells at S phase in the HBO+PTX group was found slightly higher than that in the PTX group（ P>0.05）. The expression level of Cyclin A1 in the HBO+PTX group was significantly lower than those in the other three groups（ P<0.05 or P<0.01）；the expression level of CDK2 in the HBO+PTX group was lower than those in the control group and the HBO group（ P<0.05），and also slightly lower than that in the PTX group（ P>0.05）. Conclusion:HBO can effectively enhance the inhibitory effect of PTX on the proliferation of AGS cells，increase the intracellular ROS level in AGS cells，and block the cell cycle，thereby inhibiting the differentiation and proliferation of AGS cells.

Objective:To investigate the effect of hyperbaric oxygen（HBO）on the resistance of gastric cancer AGS cells to irinotecan（ITC）and its related regulatory mechanisms.Methods:Gastric cancer AGS cells were cultured in vitro，and the cells were divided into four groups according to the experimental design：control group，ITC group，HBO group，and HBO + ITC group. The effect of ITC combined with HBO on the proliferation rate of gastric cancer cells was detected by Cell Counting Kit-8（CCK-8）；the changes of apoptosis rate after ITC combined with HBO treatment of AGS cells were detected by flow cytometry；and the changes in the expression of apoptosis-related and drug resistance-related proteins in AGS cells were detected by Western blotting assay. Results:Compared with control group and HBO group，the proliferation of AGS cells in the HBO + ITC group was further inhibited，and its proliferation rate was significantly lower than those of the control group and HBO group（ P<0.01），and also lower than that of the ITC group（ P<0.05）. Compared with those in the control group and the HBO group，the apoptosis rate of AGS cells in the HBO+ITC group was significantly higher than those in the control group and the HBO group（ P<0.01），and also higher than that in the ITC group（ P < 0.05）. In the ITC group and HBO+ITC group，the expression of apoptosis-related and drug resistance-related proteins，including Bcl-2，caspase-9 and P-gp，were significantly decreased，while the expression of Bad，caspase-3 and PARP were significantly increased，and the differences were statistically significant（ P<0.05 or P<0.01）. Compared with the control group and HBO group，p-JNK expression was increased and STAT3 expression was decreased in the ITC group（ P<0.01）；compared with the ITC group，p-JNK expression was increased and STAT3 expression was decreased in the HBO+ITC group（ P<0.05 or P<0.01）. Conclusion:HBO combined with ITC can effectively inhibit the proliferation of gastric cancer AGS cells，affect the apoptosis of AGS cells by regulating the JNK/STAT3 signaling pathway，and improve the cells’ drug resistance to a certain extent.

Objective:To investigate the effect of hyperbaric oxygen（HBO）on the resistance of gastric cancer AGS cells to irinotecan（ITC）and its related regulatory mechanisms.Methods:Gastric cancer AGS cells were cultured in vitro，and the cells were divided into four groups according to the experimental design：control group，ITC group，HBO group，and HBO + ITC group. The effect of ITC combined with HBO on the proliferation rate of gastric cancer cells was detected by Cell Counting Kit-8（CCK-8）；the changes of apoptosis rate after ITC combined with HBO treatment of AGS cells were detected by flow cytometry；and the changes in the expression of apoptosis-related and drug resistance-related proteins in AGS cells were detected by Western blotting assay. Results:Compared with control group and HBO group，the proliferation of AGS cells in the HBO + ITC group was further inhibited，and its proliferation rate was significantly lower than those of the control group and HBO group（ P<0.01），and also lower than that of the ITC group（ P<0.05）. Compared with those in the control group and the HBO group，the apoptosis rate of AGS cells in the HBO+ITC group was significantly higher than those in the control group and the HBO group（ P<0.01），and also higher than that in the ITC group（ P < 0.05）. In the ITC group and HBO+ITC group，the expression of apoptosis-related and drug resistance-related proteins，including Bcl-2，caspase-9 and P-gp，were significantly decreased，while the expression of Bad，caspase-3 and PARP were significantly increased，and the differences were statistically significant（ P<0.05 or P<0.01）. Compared with the control group and HBO group，p-JNK expression was increased and STAT3 expression was decreased in the ITC group（ P<0.01）；compared with the ITC group，p-JNK expression was increased and STAT3 expression was decreased in the HBO+ITC group（ P<0.05 or P<0.01）. Conclusion:HBO combined with ITC can effectively inhibit the proliferation of gastric cancer AGS cells，affect the apoptosis of AGS cells by regulating the JNK/STAT3 signaling pathway，and improve the cells’ drug resistance to a certain extent.

Objective:To explore the effect of hyperbaric oxygen（HBO）combined with paclitaxel（PTX）on the proliferation，level of reactive oxygen species（ROS），and cell cycle of human gastric cancer AGS cell line cultured in vitro. Methods:After the completion of in vitro culture，the AGS cells were divided into four groups，including control group，PTX group，HBO group，and HBO+PTX group. Cell Counting Kit-8（CCK-8）assay was used to detect the inhibitory effect of HBO combined with PTX on the proliferation of AGS cells. Flow cytometry was adopted to detect the intracellular ROS level and cell cycle arrest. Western blotting was used to assess the expression levels of cell cycle-related proteins. Results:The survival rate of AGS cells in the HBO+PTX group was significantly lower than those in the control group and the HBO group（ P<0.01），and also lower than that in the PTX group（ P<0.05）. The ROS level of AGS cells in the HBO+PTX group was significantly higher than those in the control group and the HBO group（ P<0.01），and also higher than that in the PTX group（ P<0.05）. PTX blocked the AGS cell cycle in S phase（ P<0.05），and the percentage of cells at S phase in the HBO+PTX group was found slightly higher than that in the PTX group（ P>0.05）. The expression level of Cyclin A1 in the HBO+PTX group was significantly lower than those in the other three groups（ P<0.05 or P<0.01）；the expression level of CDK2 in the HBO+PTX group was lower than those in the control group and the HBO group（ P<0.05），and also slightly lower than that in the PTX group（ P>0.05）. Conclusion:HBO can effectively enhance the inhibitory effect of PTX on the proliferation of AGS cells，increase the intracellular ROS level in AGS cells，and block the cell cycle，thereby inhibiting the differentiation and proliferation of AGS cells.