Objective To investigate the differences in acute mountain sickness between individuals en-tering the plateau for the first time and those with multiple plateau experiences,and to examine the impact on psychological stress.Methods A total of 2 337 young plateau-acclimatized individuals from an acclimatization rotation area during November 2023 to January 2024 were selected as the study subjects.Those entering the plateau for the first time were classified into Group A(n=425),while those with previous plateau experience(at least one prior visit)were classified into Group B(n=1 912).Differences were analyzed between the two groups in terms of general characteristics,as well as acute mountain sickness(AMS)scores,Self-Rating De-pression Scale(SDS)scores,Symptom Checklist-90(SCL-90)scores,and various vital signs at the following time points:before entering the plateau(T0),on the 1st day(T1),4th day(T2),7th day(T3),and 10th day(T4)after entering the plateau.Results Group A was younger than Group B,with a statistically significant difference(P<0.05).At T1,T2,and T3,AMS scores in Group A were significantly higher than those in Group B(P<0.05).At T4,there was no statistically significant difference in AMS scores between the two groups(P>0.05).At T1,T2,and T3,blood oxygen saturation was lower and heart rate higher in Group A than in Group B,with statistically significant differences(P<0.05).After high-altitude acclimatization,no statistically significant differences in blood oxygen saturation or heart rate were observed between the groups at T4(P>0.05).At T1,there were no statistically significant differences in systolic or diastolic blood pres-sure between the groups(P>0.05).At T2,both systolic and diastolic blood pressure were higher in Group A than in Group B(P<0.05).At T3 and T4,after high-altitude acclimatization,systolic blood pressure de-creased in both groups but remained higher in Group A than in Group B(P<0.05).On the SDS scale,men-tal-emotional and somatic symptom scores were significantly higher in Group A than in Group B(P<0.001).On the SCL-90,all nine symptom factor scores were higher in Group A than in Group B(P<0.05).Conclusion Indi-viduals entering high-altitude areas for the first time experience more severe acute mountain sickness and more pronounced psychological stress.Therefore,enhanced monitoring,psychological counseling,and tailored pre-vention and treatment strategies should be implemented.

Objective:To explore the interventional effect of β-sitosterol on ovalbumin(OVA)-induced allergic asthma rats and its potential mechanism.Methods:SD male rats were randomly divided into normal group(CON),model group(M),positive drug dexamethasone group(DEX,0.075 mg/kg)and β-sitosterol group(Sit,50 mg/kg).A rat model of allergic asthma was estab-lished by intraperitoneal injection of OVA with aluminum hydrogen solution,and nebulized inhalation of OVA to stimulate.Rats were given intragastric administration 30 min before aerosol challenge,and after continuous administration for 7 days,the indicators of cough and asthma and tracheal phenol red excretion were detected.HE staining was used to observe pathological changes of lung tis-sue.Flow cytometry was used to detect reactive oxygen species(ROS)generation,apoptosis level and ratios of Th17 and Treg cells in peripheral blood.Biochemical method was used to detect contents of MDA,and activities of T-SOD and GSH-Px in rat lung tissues.ELISA was used to detect levels of Th17 and Treg-related cytokines(TNF-α,IL-4,IL-6,IL-17A,and IL-35).Results:Compared with model group,β-sitosterol significantly prolonged the incubation period of cough and gasp in rats with allergic asthma,reduced the frequency of cough and gasping,and promoted the excretion of phenol red in trachea;significantly reduced inflammatory infiltration in lung tissue of asthmatic rats;observably reduced MDA content in lung tissue,ROS of primary lung cell and apoptosis levels of asthmatic rats,increased the activities of T-SOD and GSH-Px;markedly reduced proportion of Th17 cells and levels of pro-inflammatory cyto-kines TNF-α,IL-4,IL-6 and IL-17A,increased proportion of Treg cells and levels of anti-inflammatory cytokine IL-35.Conclusion:β-sitosterol can ameliorate airway inflammation and oxidative damage in OVA-induced allergic asthmatic rats,and its mecha-nism may be related to the regulation of β-sitosterol on Th17/Treg immune imbalance and oxidative stress response.