As China accelerates its efforts in deep space exploration and long-duration space missions, including the operationalization of the Tiangong Space Station and the development of manned lunar missions, safeguarding astronauts’ physiological and cognitive functions under extreme space conditions becomes a pressing scientific imperative. Among the multifactorial stressors of spaceflight, microgravity emerges as a particularly potent disruptor of neurobehavioral homeostasis. Dopamine (DA) plays a central role in regulating behavior under space microgravity by influencing reward processing, motivation, executive function and sensorimotor integration. Changes in gravity disrupt dopaminergic signaling at multiple levels, leading to impairments in motor coordination, cognitive flexibility, and emotional stability. Microgravity exposure induces a cascade of neurobiological changes that challenge dopaminergic stability at multiple levels: from the transcriptional regulation of DA synthesis enzymes and the excitability of DA neurons, to receptor distribution dynamics and the efficiency of downstream signaling pathways. These changes involve downregulation of tyrosine hydroxylase in the substantia nigra, reduced phosphorylation of DA receptors, and alterations in vesicular monoamine transporter expression, all of which compromise synaptic DA availability. Experimental findings from space analog studies and simulated microgravity models suggest that gravitational unloading alters striatal and mesocorticolimbic DA circuitry, resulting in diminished motor coordination, impaired vestibular compensation, and decreased cognitive flexibility. These alterations not only compromise astronauts’ operational performance but also elevate the risk of mood disturbances and motivational deficits during prolonged missions. The review systematically synthesizes current findings across multiple domains: molecular neurobiology, behavioral neuroscience, and gravitational physiology. It highlights that maintaining DA homeostasis is pivotal in preserving neuroplasticity, particularly within brain regions critical to adaptation, such as the basal ganglia, prefrontal cortex, and cerebellum. The paper also discusses the dual-edged nature of DA plasticity: while adaptive remodeling of synapses and receptor sensitivity can serve as compensatory mechanisms under stress, chronic dopaminergic imbalance may lead to maladaptive outcomes, such as cognitive rigidity and motor dysregulation. Furthermore, we propose a conceptual framework that integrates homeostatic neuroregulation with the demands of space environmental adaptation. By drawing from interdisciplinary research, the review underscores the potential of multiple intervention strategies including pharmacological treatment, nutritional support, neural stimulation techniques, and most importantly, structured physical exercise. Recent rodent studies demonstrate that treadmill exercise upregulates DA transporter expression in the dorsal striatum, enhances tyrosine hydroxylase activity, and increases DA release during cognitive tasks, indicating both protective and restorative effects on dopaminergic networks. Thus, exercise is highlighted as a key approach because of its sustained effects on DA production, receptor function, and brain plasticity, making it a strong candidate for developing effective measures to support astronauts in maintaining cognitive and emotional stability during space missions. In conclusion, the paper not only underscores the centrality of DA homeostasis in space neuroscience but also reflects the authors’ broader academic viewpoint: understanding the neurochemical substrates of behavior under microgravity is fundamental to both space health and terrestrial neuroscience. By bridging basic neurobiology with applied space medicine, this work contributes to the emerging field of gravitational neurobiology and provides a foundation for future research into individualized performance optimization in extreme environments.

Objective Based on the “excellent” performance achieved by our institution in the 2024 national intercomparison of monitoring individual dose from external exposure, this paper systematically summarizes key technical elements and optimization experiences in instrument calibration, operational protocols, and data analysis, aiming to provide methodological references and practical support for continuously enhancing the accuracy and reliability of individual dose monitoring. Methods As a participant in the intercomparison activity, our laboratory strictly followed the technical protocol formulated by the Chinese Center for Disease Control and Prevention. Results In the 2024 national intercomparison of monitoring individual dose from external exposure, the measurement results met the criteria of single-group performance \begin{document}$ \left|{P}_{i}\right| $\end{document} ≤ 0.10 and comprehensive performance B² + S² ≤ 0.10², and were rated as excellent. Conclusion The accuracy and reliability of monitoring individual dose from external exposure depend on the precision of instrument calibration, standardization of operations, and strictness of quality control. The effectiveness of the above quality control methods has been confirmed by the practice of our laboratory. These methods can be used to ensure the accuracy of measurement results.

OBJECTIVE: The relationship between benign prostatic hyperplasia (BPH) and the oxidative balance score (OBS) will be discussed in this study. METHODS: The clinical data on 16 dimensions of diet and 4 dimensions of lifestyle from the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2008 were used to calculate OBS. We considered BPH as the outcome and investigated the linear and nonlinear relationships between the two. Additionally, subgroup analyses and interaction tests were conducted as well. Furthermore, the methods of machine learning including XGBoost, support vector machine (SVM) and naive Bayes (NB) were used to establish a predictive model for BPH. RESULTS: Higher OBS was consistently associated with an increased prevalence of BPH, with Restricted Cubic Splines highlighting a significant positive nonlinear association (P=0.015). Subgroup analyses revealed differences and interactive relationships based on alcohol consumption. Among the seven machine learning models that we included the OBS score in, the XGBoost model emerged as the best, with an AUC value of 0.769. CONCLUSION There is a significant association between OBS and the prevalence of BPH in the American population, which provides a valuable insight for further diagnosis and research of the disease.
Humans ; Male ; Prostatic Hyperplasia/epidemiology* ; Machine Learning ; Bayes Theorem ; Nutrition Surveys ; Support Vector Machine ; Life Style ; Oxidative Stress ; Aged ; Diet ; Prevalence

Objective： To investigate the relationship between the lipid metabolism-related gene sterol carrier protein 2(SCP2) and prostate cancer (PCa) from a multi-omics perspective using single-cell transcriptomes combined with Mendelian randomization. Methods： Single-cell transcriptome data of benign and malignant prostate tissues were obtained from GSE120716, GSE157703 and GSE141445 datasets, respectively. Integration, quality control and annotation were performed on the data to categorize the epithelial cells into high and low SCP2 expression groups, followed by further differential and trajectory analyses. Single nucleotide polymorphism (SNP) data for SCP2 expression quantitative trait loci (eQTL) were subsequently downloaded from Genotype-Tissue Expression (GTEx) and investigated from the PCa Society Cancer-Related Genomic Alteration Panel for the Investigation of Cancer-Related Alterations (PRACTICAL) to obtain PCa outcome data for Mendelian randomization analysis to validate the causal relationship between SCP2 and PCa. Results： High SCP2-expressing epithelial cells had higher energy metabolism and proliferation capacity with low immunotherapy response and metastatic tendency. Trajectory analysis showed that epithelial cells with high SCP2 expression may have a higher degree of malignancy, and SCP2 may be a key marker gene for differentiation of malignant epithelial cells in the prostate. Further Mendelian randomization results showed a significant causal relationship between SCP2 and PCa development (OR=1.045, 95% CI: 1.010 －1.083, P=0.011). Conclusion： By combining single-cell transcriptome and Mendelian randomization, the role of the lipid metabolism-related gene SCP2 in PCa development has been confirmed, and new targets and therapeutic directions for PCa treatment have been provided.
Humans ; Prostatic Neoplasms/genetics* ; Male ; Mendelian Randomization Analysis ; Polymorphism, Single Nucleotide ; Quantitative Trait Loci ; Single-Cell Analysis ; Sequence Analysis, RNA ; Carrier Proteins/genetics* ; Transcriptome ; Lipid Metabolism

BACKGROUND: Prolonged occupational noise exposure poses potential health risks, but its impact on mitochondrial DNA (mtDNA) damage and methylation patterns remains unclear. METHOD: We recruited 306 factory workers, using average binaural high-frequency hearing thresholds from pure-tone audiometry to assess noise exposure. MtDNA damage was evaluated through mitochondrial DNA copy number (mtDNAcn) and lesion rate, and mtDNA methylation changes were identified via pyrophosphate sequencing. RESULTS: There was a reduction in MT-RNR1 methylation of 4.52% (95% CI: -7.43% to -1.62%) among workers with abnormal hearing, whereas changes in the D-loop region were not statistically significant (β = -2.06%, 95% CI: -4.44% to 0.31%). MtDNAcn showed a negative association with MT-RNR1 methylation (β = -0.95, 95% CI: -1.23 to -0.66), while no significant link was found with D-loop methylation (β = -0.05, 95% CI: -0.58 to 0.48). Mediation analysis indicated a significant increase in mtDNAcn by 10.75 units (95% CI: 3.00 to 21.26) in those with abnormal hearing, with MT-RNR1 methylation mediating 35.9% of this effect. CONCLUSIONS These findings suggest that occupational noise exposure may influence compensatory increases in mtDNA content through altered MT-RNR1 methylation.
Humans ; DNA, Mitochondrial ; DNA Methylation ; Male ; Adult ; Noise, Occupational/adverse effects* ; Middle Aged ; Occupational Exposure/adverse effects* ; Biomarkers/blood* ; Female

Objective To compare the gut fungal composition between gout patients and healthy individuals through high-throughput sequencing of ribosomal DNA internal transcribed spacer 1(ITS1).Methods Gout patients and healthy volunteers who visited our hospital from January 2023 to December 2024 were enrolled in this study.Then based on established medical guidelines,the gout patients were categorized into 3 groups:Group H(asymptomatic hyperuricemia,n=14),Group G(acute gouty arthritis,n=14),and Group I(intercritical period of gouty arthritis,n=15),and the healthy individuals were assigned into Group N(n=9).Fecal samples were collected from all the participants to undergo ITS1 sequencing analysis.The differences in diversity and composition of gut mycobiome,and FunGuild-derived fungal functions and nutritional status were compared among the 4 groups,and the correlation between the gut mycobiome and clinical indicators was analyzed.Results There were no significant differences in baseline features such as gender,age,glomerular filtration rate(GFR),and levels of serum creatinine(SCr)and serum urea among Group N and other gout groups,but obvious differences were observed in body mass index(BMI),erythrocyte sedimentation rate,and levels of C-reactive protein(CRP),serum uric acid(SUA),and IL-1β and IL-6(P<0.05).In terms of gut fungal diversity,ITS1 analysis showed there were no statistical differences in α-diversity or the principal coordinate analysis(PCoA)of β-diversity among the groups.However,as gout progressed,significant changes were observed in β-diversity indices,indicating a shift in the gut fungal community composition with disease advancement(P<0.05).The phyla Ascomycota,Basidiomycota,and Mucoromycotina were the dominant fungal phyla in all groups.Compared with the other 3 gout groups,the abundance of Pichia was significantly increased in Group N(P<0.05),that of Saccharomyces was in Group H(P<0.05),and that of Starmerella was in Group G(P<0.05).Correlation analysis between the gut mycobiome and clinical indices indicated that the relative abundance of Starmerella was significantly positively correlated with IL-1β(P<0.01)and IL-6(P<0.05).The relative abundance of Pichia was significantly positively correlated with IL-1β and IL-6 levels(P<0.05),and negatively correlated with serum urea level(P<0.05),and the relative abundance of Saccharomyces was negatively correlated with IL-1β and IL-6 levels(P<0.05).Conclusion There exist significant alterations in both the diversity and composition of gut fungi among patients with gout at various stages.Notably,the fluctuations in the relative abundance of Starmerella,Pichia and Saccharomyces appear to correlate with key clinical indicators.

Neuroscience,a cutting-edge field in interdisciplinary research,consistently draws considerable research interest,of which quantitatively probing the neurochemical dynamics is essential for brain science research.In vivoelectrochemical analysis,featuring with high sensitivity,high spatiotemporal resolution,free from transfection,and designable electrode/solution interfaces,provides important tools for in vivo neurochemicals sensing.Fast scan cyclic voltammetry combined with microelectrodes can not only enable precise detection of dopamine but also is compatible with existing neurosurgical equipment.This offers new opportunities for the clinical application of in vivo electrochemical analysis and paves new avenues for the diagnosis and treatment of neurological diseases.This review summarized recent progress of in vivo electrochemical techniques for brain neurochemistry and addressed key clinical challenges and their potential solutions.

Objective To observe the morphology of the superficial,middle,and deep layers of the masseter muscle and related bony structures in the lateral facial region of adults through gross anatomy,and to probe into the effects of these muscle layers on the bony structures of the lateral facial region.Methods The bilateral masseter muscles of 12 adult cadavers were exposed,and the superficial,middle,and deep layers were separated and measured for muscle length,tendon length,and muscle belly length.After the masseter muscles were stripped,the total thickness was measured,and the mandible and zygomatic arch were exposed to measure the angle of the mandibular angle,thickness of the zygomatic arch,and width of the zygomatic arch.Observations were made of the masseter tuberosities,and statistical analysis was conducted on their interrelations.Results The zygomatic arch thickness was positively correlated with the length of superficial,middle and deep masseter muscles and the length of superficial and middle masseter belly(r superficial masseter length=0.624,r middle masseter length=0.787,r deep masseter length=0.423,r superficial masseter belly length=0.493,r middle masseter belly length=0.548).The width of the zygomatic arch was positively correlated with the lengths of the superficial and middle muscle layers and the middle muscle belly length(r superficial masseter length=0.527,r middle masseter length=0.521,r middle masseterbelly length=0.437).The angle of the mandibular angle was only negatively correlated with the middle muscle belly length(r=-0.422).The tuberosities of the superficial and middle masseter muscles were not affected by the corresponding muscle layers;However,the tuberosity of the deep masseter was negatively correlated with the length of the deep muscle and the length of the deep tendon(r deep masseter length=-0.543,r deep masseter tendon length=-0.443).Conclusion In the masseter muscle layers of Chinese individuals,the superficial and middle layers have the most significant impact on the bony structures structures of the lateral facial region.These findings are of guiding significance for the remodeling of structures in the lateral facial region.