Long-term spaceflight exposes astronauts to multiple extreme environmental factors, such as cosmic radiation, microgravity, social isolation, and circadian rhythm disruption, that markedly increase the risk of depressive symptoms, posing a direct threat to mental health and mission safety. However, the underlying biological mechanisms remain complex and incompletely understood. The potential mechanisms of spaceflight-induced depressive symptoms involve multiple domains, including alterations in brain structure and function, dysregulation of neurotransmitters and neurotrophic factors, oxidative stress, neuroinflammation, neuroendocrine system imbalance, and gut microbiota disturbances. Collectively, these changes may constitute the biological foundation of depressive in astronauts during spaceflight. Space-related stressors may increase the risk of depressive symptoms through several pathways: impairing hippocampal neuroplasticity, suppressing dopaminergic and serotonergic system function, reducing neurotrophic factor expression, triggering oxidative stress and inflammatory responses, activating the hypothalamic-pituitary-adrenal axis, and disrupting gut microbiota homeostasis. Future research should integrate advanced technologies such as brain-computer interfaces to develop individualized monitoring and intervention strategies, enabling real-time detection and effective prevention of depressive symptoms to safeguard astronauts' psychological well-being and mission safety.
Space Flight ; Humans ; Astronauts/psychology* ; Depression/physiopathology* ; Gastrointestinal Microbiome ; Weightlessness/adverse effects* ; Oxidative Stress ; Brain/physiopathology* ; Hypothalamo-Hypophyseal System ; Neuronal Plasticity ; Pituitary-Adrenal System

During long-duration manned space missions, the complex and extreme space environment exerts significant impacts on astronauts' physiological, psychological, and cognitive functions, thereby posing direct risks to mission safety and operational efficiency. As a key bridge between the brain and external devices, brain-computer interface (BCI) technology enables precise acquisition and interpretation of neural signals, offering a novel paradigm for human-machine collaboration in manned spaceflight. Non-invasive BCI technology shows broad application prospects across astronaut selection, mission training, in-orbit task execution, and post-mission rehabilitation. During mission preparation, multimodal signal assessment and neurofeedback training based on BCI can effectively enhance cognitive performance and psychological resilience. During mission execution, BCI can provide real-time monitoring of physiological and psychological states and enable intention-based device control, thereby improving operational efficiency and safety. In the post-mission rehabilitation phase, non-invasive BCI combined with neuromodulation may improve emotional and cognitive functions, support motor and cognitive recovery, and contribute to long-term health management. However, the application of BCI in space still faces challenges, including insufficient signal robustness, limited system adaptability, and suboptimal data processing efficiency. Looking forward, integrating multimodal physiological sensors with deep learning algorithms to achieve accurate monitoring and individualized intervention, and combining BCI with virtual reality and robotics to develop intelligent human-machine collaboration models, will provide more efficient support for space missions.
Brain-Computer Interfaces ; Humans ; Space Flight ; Astronauts/psychology* ; Neurofeedback ; Cognition ; Electroencephalography ; Man-Machine Systems

Objective To construct risk models for predicting the occurrence of high altitude de-acclimatization syndrome(HADAS)in the population returning from the plateau to the plain based on different machine learning algorithms and validate the predicting efficiency of these models.Methods Field or online surveys were conducted on the individuals who had ended their high-altitude living and returned to the plain areas from November 2020 to February 2024.Basic information,chronic mountain sickness(CMS),HADAS symptoms and other data were collected.With the inclusion and exclusion criteria,totally 1 095 individuals were subjected and assigned into the modeling group.Positive events were defined as HADAS score>5.Then the modelling group was divided into a training set(n=766)and an internal test set(n=329)in a 7∶3 ratio.Least absolute shrinkage and selection operator(LASSO)regression was used to select independent variables.Risk prediction models for high-altitude adaptation symptoms were built based on 8 machine learning methods,including multiple factor logistic regression(LR),decision tree(DT),random forest(RF),eXtreme gradient boosting(XGB),support vector machine(SVM),K-nearest neighbor(KNN),light gradient boosting(LGB)and na?ve bayes(NB).The models were compared and evaluated using receiver operating characteristic(ROC)curves,calibration curves and confusion matrices in the internal test set.The final model was presented using a nomogram or Shapley additive explanations(SHAP)algorithm.In August 2024,another 132 individuals who returned to the plains and met the same criteria were recruited and served as the external validation group.Results There were 549 individuals(50.14%)out of the 1 095 subjects having HADAS symptoms.LASSO regression identified CMS score,age and duration of high-altitude residence as significant predictors.Among the 8 machine learning algorithms,the LR model was identified as the best,with an area under the curve(AUC)value of 0.819(95%CI:0.789～0.850)and 0.841(95%CI:0.799～0.884),and an F1 score of 0.801 in the internal test set,respectively,and the AUC value and F1 score of the LR model were the largest among the 8 models in the internal test set.Spiegelhalter Z test of the calibration curve of the LR model indicated that its P=0.703 in the training set while P=0.281 in the internal test set.The AUC value of the LR model was 0.867(95%CI:0.765～0.969)in the external validation set.Conclusion The LR model constructed based on indicators including CMS score,age and duration of high-altitude residence has a good overall performance in the internal test set,and good discriminating effect in the external validation set.The constructed nomogram is convenient for application.

Objective To explore the prevention effectiveness of a mode,conducting targeted corrective training based on motor dysfunction detected by military joint function screening,on military training injuries in new recruits during recruit basic training in order to cope with the high incidence of military training injuries among them.Method A military personnel joint function screening was conducted on the new recruits in a training base of Joint Logistics Support Force.Based on the results of screening,the new recruits with a single action score of 1 and a total score of<10 were subjected and served as corrective training participants.Through cluster sampling,the new recruits were randomly divided into an experimental group(n=223)and a control group(n=223).The control group were trained according to the regular training plan,while the experimental group completed their designated training tasks and a 2-month corrective training for motor dysfunction at the same time.The entire corrective training process was carried out by our key personnel who had received relevant training.Medical records of the medical security department of the experimental unit were collected and evaluated for the injury situation.The score of joint function screening was analyzed using independent sample t test.The incidence of training injuries was analyzed using Chi-square test or Fisher's exact test.Result After corrective training,the score of joint function was higher in the experimental group than the score before training(15.12±2.13 vs 10.58±2.83),and the score was also higher than that of the control group(15.12±2.13 vs 14.19±1.97,P<0.05).During the recruit basic training period,the incidence of training injuries was notably lower in the experimental group than the control group(12.5％vs 34.5％,Chi-square=5.469,P=0.001).Only for those who were injured during the training,11 people(39.2％)in the experimental group scored less than 10,which was obviously lower than the 49 people(63.6％)in the control group(Chi-square=4.972,P=0.026).Conclusion Our mode,corrective training based on the results of military personnel joint function screening,can effectively reduce the incidence of military training injuries in new recruits during recruit basic training,and exerts a good preventive effect against military training injuries.

Objective To identify recruit movement dysfunction based on military joint function screening and assessment,implement targeted corrective training,explore the impact of this assessment-correction system on knowledge-attitude-belief-practice(KABP)related factors,and scientifically evaluate its efficacy in preventing recruit military training injuries within the knowledge-attitude-belief-practice theoretical framework.Methods A cluster randomized controlled trial was conducted at a recruit training base of the Joint Logistics Support Force from March to May 2025,enrolling 446 recruits.Participants were randomly assigned to an experimental group(n=223)or control group(n=223)using a random number table.The control group followed the routine training program,while the experimental group additionally received a 2-month targeted corrective training for movement dysfunction alongside the established training tasks.Knowledge-attitude-belief-practice questionnaires were administered to both groups at the initial,intermediate,and advanced stages of the corrective training.Univariate logistic regression was used to preliminarily screen KABP-related factors,and a multivariate logistic regression model was further constructed to analyze the role of KABP factors in the corrective training.Results The experimental group had a cumulative training injury incidence of 40 cases(17.9%),which was significantly lower than that of the control group(83 cases,37.2%;χ2=20.757,P<0.001).The experimental group showed varying degrees of improvement in knowledge,attitude and belief,and practice dimensions(P<0.05),while the control group exhibited no significant changes in the three KABP dimensions across the three surveys.Logistic regression analysis revealed:In the first round,total practice score was significantly negatively associated with training injury incidence rate(OR=0.863,95%CI:0.822～0.906,P<0.001),whereas knowledge and attitude-belief dimensions showed no significant association;In the second round,both total knowledge score(OR=0.925,95%CI:0.903～0.946,P<0.001)and total practice score(OR=0.906,95%CI:0.874～0.940,P<0.001)significantly reduced the risk of military training injuries,with attitude-belief dimension still showing no significant effect;In the third round,all three KABP dimensions were significantly negatively associated with military training injury incidence rate(knowledge:OR=0.905,95%CI:0.884～0.926,P<0.001;attitude and belief:OR=0.942,95%CI:0.899～0.988,P=0.013;behavior:OR=0.882,95%CI:0.841～0.924,P<0.001).Conclusion Joint function screening and corrective training can significantly reduce the incidence of recruit training injuries,primarily by optimizing knowledge mastery and movement behavior;belief cultivation,however,requires long-term practical accumulation.

Objective To analyze the medication rules of Chinese herbal concentrated-granule for the treatment of hypertension nationwide using data mining and knowledge graph methods,thus to provide evidence for expanding its application in treating hypertension.Methods From January 2022 to March 2023,Chinese herbal concentrated-granule prescriptions for hypertension prescribed by traditional Chinese medicine experts nationwide were collected.Microsoft Excel was used to analyze the frequency,properties and flavors,meridian tropism,and efficacy categories of the medicinals.Hierarchical clustering was applied for cluster analysis,and the Neo4j graph database was utilized to construct an information knowledge graph illustrating the relationships between regions and medicinals.Results A total of 2 600 Chinese herbal concentrated-granule prescriptions were included,involving 370 medicinals.The top six frequently-used medicinals were Poria(Fuling),Glycyrrhizae Radix et Rhizoma(Gancao),Atractylodis Macrocephalae Rhizoma(Baizhu),Citri Reticulatae Pericarpium(Chenpi),Paeoniae Radix Alba(Baishao),and Angelicae Sinensis Radix(Danggui).The properties of the medicinals were mainly warm and mild,and their flavors were usually sweet,pungent,and bitter.The medicinals frequently have the meridian tropism of the spleen,lung,and liver meridians.Hierarchical clustering yielded seven clusters.The information knowledge graph of region-medicinals relationships revealed that medicinals used in five or more regions were Baishao,Baizhu,Chenpi,Pinelliae Rhizoma(Banxia),Fuling,Gastrodiae Rhizoma(Tianma),Bupleuri Radix(Chaihu),Chuanxiong Rhizoma(Chuanxiong),Salviae Miltiorrhizae Radix et Rhizoma(Danshen),Danggui,Gancao,and Astragali Radix(Huangqi).Conclusion Chinese herbal concentrated-granule for hypertension usually consist of tonifying medicinals,with sweet and warm properties,and having the meridian tropism of the spleen meridian.And the medicinals composed of the prescriptions often have the actions of calming the liver and suppressing yang,strengthening the spleen and removing dampness,and nourishing the liver and kidney.

Objective To investigate the effect of prostaglandin family(PGs)on non-alcoholic fatty liver disease(NAFLD).Methods HepG2 cells,a human hepatocellular carcinoma cell line,were used as the research subject.The experiment was set up as a control group(Ctrl),fatty change group(FFA),prostaglandin B2(PGB2,10 μg/mL)treatment group,15-keto-prostaglandin E2(15-keto-PGE2,10 μg/mL)treatment group,and 8-iso-prostaglandin F2a(8-iso-PGF2α,10 μg/mL)treatment group.Cell activity was determined by the thiazolyl blue(MTT)assay and lipid deposition was detected by the oil red O staining.The expression levels of inflammatory factors and phosphorylated insulin receptor substrates(p-IRS)were determined by real-time fluorescence quantitative PCR(qRT-PCR)and Western blot,respectively.In addition,15 SPF-grade male C57BL/6J mice were randomly divided into a basic group(CD group,n=5,fed with 10％low-fat forage for 16 weeks),high-fat group(HFD group,n=5,fed with 60％high-fat forage for 16 weeks to model NAFLD),and PGB2 group(n=5,given 20 μg/kg PGB2 daily by tail vein injection for 2 weeks after 16 weeks of 60％high-fat diet feeding).The glucose tolerance level of the mice was detected by the intraperitoneal glucose tolerance test(IPGTT)and the degree of hepatic steatosis was determined by HE staining.Results Oil red O staining showed that PGs had no sig-nificant effect on the lipid deposition of NAFLD,but PGs were able to alleviate the inflammation associated with NAFLD.qRT-PCR re-sults showed that compared with the Ctrl group,the levels of IL-1β in the FFA group increased by 2.274±0.550 times(P=0.002 8),while under the action of 50 μg/mL PGB2,10 μg/mL 15-keto-PGE2 and 10 μg/mL 8-iso-PGF2α,the levels of IL-1β decreased to 0.720±0.036 times(P=0.003 1),0.857±0.225 times(P=0.006 4),and 1.767±0.725 times(P=0.029 7),respectively.Western blot results showed that after PGs treatment,the expression level of p-IRS protein was increased.The body weights of mice in the CD group,HFD group and PGB2 group were(28.560±2.028)g,(49.300±0.667)g,and(40.840±4.043)g,respectively,with statisti-cally significant differences between the groups(P=0.001 7).Moreover,the glucose tolerance results in the PGB2 group were better than those in the HFD group.HE staining results showed compared with the HFD group,the degree of hepatic steatosis in the PGB2 group was reduced.Conclusion PGB2,15-keto-PGE2,and 8-iso-PGF2α in the prostaglandin family can alleviate the occurrence and development of NAFLD by alleviating IL-1β-mediated inflammation,upregulating the expression of p-IRS,promoting the transmission of insulin signaling,and attenuating insulin resistance.

Objective:To explore the effects of the fat mass and obesity-associated gene(FTO)on apoptosis and the inflammatory response of chondrocytes in osteoarthritis(OA).Methods:Differences in FTO expression between normal human cartilage tissue samples and OA cartilage tissue samples were examined.Primary OA chondrocytes were isolated and cultured, and a rat OA model was constructed.The expression of FTO was detected in clinical, animal and cellular samples.Cells were treated with an FTO knockdown lentivirus vector(sh-FTO)and an m 6A methylation inhibitor(cycloleucine). The amount of m 6A and the expression levels of inflammatory cytokines, interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α), were detected.Flow cytometry was used to detect apoptosis in OA chondrocytes, and Western blot was used to detect the expression levels of B-cell lymphoma 2(Bcl-2)and Bcl-2-associated X protein(Bax). Results:Compared with the normal control group, FTO mRNA and protein expression in human OA cartilage tissue, rat OA cartilage tissue and OA chondrocytes was significantly increased(all P<0.05). After FTO knockdown, the level of m 6A increased, the levels of IL-6 and TNF-α decreased considerably, the apoptosis rate decreased, the expression of the proapoptotic protein Bax decreased considerably, and the expression of Bcl-2 increased considerably in primary OA chondrocytes.However, cycloleucine intervention clearly reduced the level of m6A, increased the levels of IL-6 and TNF-α, promoted cell apoptosis and the expression of apoptosis-related proteins, and reversed the effect induced by the FTO knockdown lentivirus in OA chondrocytes(all P<0.05). Conclusions:FTO may be involved in mechanisms related to the action of m 6A to promote OA chondrocyte apoptosis and the inflammatory response, thus accelerating the progression of OA.

Objective:To investigate the influencing factors for microvascular invasion (MVI) in hepatocellular carcinoma based on three-dimensional visualization and the construction of its nomogram model.Methods:The retrospective cohort study method was conducted. The clinico-pathological data of 190 patients with hepatocellular carcinoma who were admitted to Henan University People′s Hospital from May 2018 to May 2021 were collected. There were 148 males and 42 females, aged (58±12)years. The 190 patients were randomly divided into the training set of 133 cases and the validation set of 57 cases by the method of random number table in the ratio of 7:3. The abdominal three-dimensional visualization system was used to characterize the tumor morphology and other imaging features. Observation indicators: (1) analysis of influencing factors for MVI in hepatocellular carcinoma; (2) construction and evaluation of nomogram model of MVI in hepatocellular carcinoma. Measurement data with normal distribution were expressed as Mean± SD, and independent sample t test was used for comparison between groups. Measurement data with skewed distribution were expressed as M( Q1, Q3), and non-parametric rank sum test was used for comparison between groups. Count data were expressed as absolute numbers, and the chi-square test was used for comparison between groups. Corresponding statistical methods were used for univariate analysis. Binary Logistic regression model was used for multivariate analysis. Receiver operator characteristic (ROC) curves were plotted, and the nomogram model was assessed by area under the curve (AUC), calibration curve, and decision curve. Results:(1) Analysis of influencing factors for MVI in hepatocellular carcinoma. Among 190 patients with hepatocellular carcinoma, there were 97 cases of positive MVI (including 63 cases in the training set and 34 cases in the validation set) and 93 cases of negative MVI (including 70 cases in the training set and 23 cases in the validation set). Results of multivariate analysis showed that alpha-fetoprotein, vascular endothelial growth factor, tumor volume, the number of tumors, and tumor morphology were independent factors affecting the MVI of patients with hepatocellular carcinoma ( odds ratio=5.06, 3.62, 1.00, 2.02, 2.59, 95% confidence interval as 1.61-15.90, 1.28-10.20, 1.00-1.01, 1.02-3.98, 1.03-6.52, P<0.05). (2) Construction and evaluation of nomogram model of MVI in hepatocellular carcinoma. The results of multivariate analysis were incorporated to construct a nomogram prediction model for MVI of hepatocellular carcinoma. ROC curves showed that the AUC of the training set of nomogram model was 0.85 (95% confidence interval as 0.79-0.92), the optimal fractional cutoff based on the Jordon′s index was 0.51, the sensitivity was 0.71, and the specificity was 0.84. The above indicators of validation set were 0.92 (95% confidence interval as 0.85-0.99), 0.50, 0.90, and 0.82, respectively. The higher total score of the training set suggested a higher risk of MVI in hepatocellular carcinoma. The calibration curves of both training and validation sets of nomogram model fitted well with the standard curves and have a high degree of calibration. The decision curve showed a high net gain of nomogram model. Conclusions:Alpha-fetoprotein, vascular endothelial growth factor, tumor volume, the number of tumors, and tumor morphology are independent influencing factors for MVI in patients with hepatocellular carcinoma. A nomogram model constructed based on three-dimensional visualized imaging features can predict MVI in hepatocellular carcinoma.

Purpose To investigate the value of 99Tcm-(methoxyisobutvlisonitrile,MIBI)bone uptake on hungry bone syndrome(HBS)in renal secondary hyperparathyroidism(SHPT)after parathyroidectomy.Materials and Methods From June 2014 to December 2021,106 renal SHPT patients who underwent successful parathyroidectomy in Jiangyin Hospital Affiliated Nantong University were retrospectively enrolled.Visual analysis was used to evaluate the abnormal bone uptake of 99Tcm-MIBI.The patients were divided into HBS group and non-HBS group based on whether occurred HBS.The clinical features,laboratory indicators and 99Tcm-MIBI bone uptake were compared between the two groups.Results Of 106 renal SHPT patients,42(39.62%)patients with bone uptake on visual assessment,showed diffusely increased tracer accumulation,particularly in sternum,clavicle and ribs.The age in HBS group was younger than that in non-HBS group(t=-3.058),the alkaline phosphatase and parathyroid hormone level in HBS group were higher than that in non-HBS group(Z=-5.148,-2.218),the serum corrected calcium in HBS group was lower than that in non-HBS group(Z=-2.102),the positive rate and number of 99Tcm-MIBI bone uptake in HBS group was 50%and 2(1,3),which was higher than that of 28%and 1(1,1)in non-HBS group(χ2=5.344,Z=-2.970),respectively,all showed statistically significant difference(all P<0.05).Conclusion Renal SHPT patient with HBS after parathyroidectomy is commonly related to a high level of alkaline phosphatase and parathyroid hormone,and more likely to develop abnormal 99Tcm-MIBI bone uptake.