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 To evaluate the characteristics of different antigen-specific T cell immune responses to severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)after inoculation with 2 doses of SARS-CoV-2 inactivated vaccine for 12 months.Methods Fifteen healthy adults were enrolled in this study and blood samples collected at 12 months after receiving two doses of SARS-CoV-2 inactivated vaccine.The level and phenotypic characteristics of SARS-CoV-2 antigen-specific T lymphocytes were detected by activation-induced markers(AIM)based on polychromatic flow cytometry.Results After 12 months of inoculation with 2 doses of SARS-CoV-2 inactivated vaccine,more than 90%of adults had detectable Spike and Non-spike antigen-specific CD4+ T cells immune responses(Spike:14/15,P=0.0001;Non-spike:15/15,P<0.0001).80%of adults had detectable Spike and Non-spike antigen-specific CD8+ T cells immune responses(Spike:12/15,P=0.0463;Non-spike:12/15,P=0.0806).Antigen-specific CD4+ T cells induced by SARS-CoV-2 inactivated vaccination after 12 months were composed of predominantly central memory(CM)and effector memory 1(EM1)cells.On the other hand,in terms of helper subsets,antigen-specific CD4+ T cells mainly showed T helper 1/17(Th1/17)and T helper 2(Th2)phenotypes.Conclusions SARS-CoV-2 inactivated vaccination generates durable and extensive antigen-specific CD4+ T cell memory responses,which may be the key factor for the low proportion of severe coronavirus disease 2019(COVID-19)infection in China.

Objective:To investigate the correlation among physical activity,mild depressive symptoms and frontal alpha power asymmetry in college students.Methods:Seventy college students with mild depressive symp-toms who conformed to the standard of the Self-Rating Scale for Depression(SDS)of 53-62 and 70 normal col-lege students were recruited.The frontal alpha power was measured under quiet and closed-eye state,and the total physical activity(PA)was assessed with the International Physical Activity Questionnaire.Results:The college students with mild depressive symptoms had lower Total PA scores,right frontal alpha power and frontal alpha a-symmetry(FAA)than the normal controls(P＜0.001).In college students with mild depressive symptoms,the to-tal PA scores(r=-0.29,P＜0.05)and FAA(r=-0.41,P＜0.001)were negatively correlated with SDS scores,and the total PA scores were positively correlated with FAA(r=0.34,P＜0.01).Conclusion:The college students with mild depressive symptoms may have reduced physical activity and asymmetric right lateralization of frontal alpha power.There is a correlation among depressive symptoms,physical activity and frontal alpha power a-symmetry in college students with mild depressive symptoms.

Objective:To evaluate the values of 18F-PI-2620 PET/CT brain imaging with SUV ratio (SUVR) in the assessment of tau protein deposition in the brain of patients with different cognitive disorders and its correlation with cognition. Methods:This was a cross-sectional study. From December 2019 to November 2022, a total of 67 subjects including 54 patients with Alzheimer′s disease (AD; 21 males, 33 females, age (68.6±7.8) years), 7 patients with mild cognitive impairment (MCI; 1 male, 6 females, age (63.1±11.2) years) and 6 healthy controls (HC; 4 males, 2 females, age (69.0±5.8) years) were enrolled retrospectively in Renji Hospital. All participants were examined by 18F-PI-2620 PET/CT. SUVRs of brain regions were obtained, including frontal lobe, temporal lobe, occipital lobe, parietal lobe, insular lobe, whole brain, as well as 10 independent brain ROIs (amygdala, orbitofrontal cortex, cingulate gyrus, superior occipital gyrus, superior parietal gyrus, inferior angular gyrus, precuneus, inferior temporal gyrus, entorhinal cortex and parahippocampal gyrus), with inferior cerebellum cortex as the reference region. All participants were estimated by cognitive scales(mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA)). One-way analysis of variance and the least significant difference t test were used to compare the differences of SUVR in each brain region among HC, MCI and AD groups. ROC curve analysis was used to determine the optimal cut-off values of SUVR in each brain region for the differential diagnosis of AD-MCI and AD-HC. Pearson correlation analysis was employed to examine the correlations of SUVR with cognitive scale scores. Results:The SUVR of whole brain was 1.40±0.31 in AD group, 1.08±0.19 in MCI group, and 1.01±0.12 in HC group. SUVR analysis in the whole brain and each brain region could distinguish AD from HC, AD from MCI ( F values: 1.76-10.09, t values: 2.98-7.47, all P<0.05), but could not distinguish HC from MCI ( t values: 0.17-1.53, all P>0.05). ROC curve analysis showed that the best cut-off value of SUVR was 1.18 for whole brain (AUC=0.89), 1.13 for amygdala (AUC=0.94) and 1.26 for parahippocampal gyrus (AUC=0.94) for differential diagnosis of AD and HC, which was 1.06 for whole brain (AUC=0.82), 1.18 for amygdala (AUC=0.88) and 1.28 (AUC=0.88) for infratemporal gyrus to differential diagnosis of AD and MCI. SUVRs of the whole brain, frontal, occipital, parietal, temporal and insula were significantly negatively correlated with MMSE and MoCA cognitive scale scores ( r values: from -0.64 to -0.40, all P<0.05). Conclusions:SUVR quantitative analysis in 18F-PI-2620 PET imaging can assist the differential diagnosis of AD and HC, AD and MCI. The SUVRs of whole brain and five lobes show negative correlations with MMSE and MoCA scores.

Objective:To investigate the association of exposure to PM 2.5 and its constituents during pregnancy and fetal growth and to further identify critical windows of exposure for fetal growth. Methods:We included 4 089 mother-child pairs from the Jiangsu Birth Cohort Study between January 2016 and October 2019. Data of general characteristics, clinical information, daily average PM 2.5 exposure, and its constituents during pregnancy were collected. Fetal growth parameters, including head circumference (HC), abdominal circumference (AC), and femur length (FL), were measured by ultrasound after 20 weeks of gestation, and then estimated fetal weight (EFW) was calculated. Generalized linear mixed models were adopted to examine the associations of prenatal exposure to PM 2.5 and its constituents with fetal growth. Distributed lag nonlinear models were used to identify critical exposure windows for each outcome. Results:A 10 μg/m 3 increase in PM 2.5 exposure during pregnancy was associated with a decrease of 0.025 ( β=-0.025, 95% CI: -0.048- -0.001) in HC Z-score, 0.026 ( β=-0.026, 95% CI: -0.049- -0.003) in AC Z-score, and 0.028 ( β=-0.028, 95% CI:-0.052--0.004) in EFW Z-score, along with an increased risk of 8.5% ( RR=1.085, 95% CI: 1.010-1.165) and 13.5% ( RR=1.135, 95% CI: 1.016-1.268) for undergrowth of HC and EFW, respectively. Regarding PM 2.5 constituents, prenatal exposure to black carbon, organic matter, nitrate, sulfate (SO 42-) and ammonium consistently correlated with decreased HC Z-score. SO 42- exposure was also associated with decreased FL Z-scores. In addition, we found that gestational weeks 2-5 were critical windows for HC, weeks 4-13 and 19-40 for AC, weeks 4-13 and 23-37 for FL, and weeks 4-12 and 20-40 for EFW. Conclusions:Our findings demonstrated that exposure to PM 2.5 and its constituents during pregnancy could adversely affect fetal growth and the critical windows for different fetal growth parameters are not completely consistent.

Objective To address the quality problems caused by high porosity in the preparation of dental cobalt-chrome alloy prosthetics based on selective laser melting(SLM)technology,we investigated the influence mechanism of different forming process parameters on the microstructure and properties of the materials.Moreover,the range of form-ing process parameters that can effectively reduce defects was precisely defined.Methods The effects of laser power,scanning speed,and scanning distance on the pore properties,surface roughness,and hardness of dental cobalt-chrome al-loy were investigated by adjusting the printing parame-ters in the process of SLM.Through metallographic anal-ysis,image analysis,and molten pool simulation,the pore formation mechanism was revealed,and the relation-ship between the porosity and energy density of SLM dental cobalt-chrome alloy was elucidated.Results When the linear energy density was higher than 0.18 J/mm,the po-rosity defect easily appeared at the bottom of the molten pool.When the laser energy density was lower than 0.13 J/mm,defects occurred in the gap of the molten pool due to insufficient melting of powder.In particular,when the linear energy density exceeded the threshold of 0.30 J/mm or was below 0.12 J/mm,the porosity increased significantly to more than 1%.In addition,we observed a negative correlation between free surface roughness and energy density and an inverse re-lationship between macroscopic hardness and porosity.Conclusion On the basis of the conditions of raw materials and molding equipment used in this study,the key process parameters of SLM of molding parts with porosity lower than 1%were successfully determined.Specifically,these key parameters included the line energy density,which ranged from 0.13 J/mm to 0.30 J/mm,and the scan spacing should be strictly controlled below 90 μm.

Objective To investigate the short-term efficacy and safety of chemotherapy induced by nimotuzumab(NTZ)combined with TP regimen and sequential concurrent chemoradiotherapy in patients with epidermal growth factor receptor positive(EGFR-positive)locally advanced nasopharyngeal carcinoma.Methods A total of 48 patients with stage Ⅲ to Ⅳ A nasopharyngeal carcinoma in Guizhou Provincial People's Hospital from January 2020 to December 2022 were prospectively enrolled,and were randomized into two groups:NTP(NTZ+docetaxel/albumin-paclitaxel+cisplatin)group and TP(Docetaxel/albumin-paclitaxel+cisplatin)group(24 cases per group)by random number table method.After 2 or 3 cycles of induction chemotherapy in NTP group,NTZ was sequentially used in combination with cisplatin for concurrent chemoradiotherapy.Immunohistochemistry was used to detect the EGFR expression level,exploring EGFR expression intensity and the therapeutic effect of NTZ in NTP group patients.Meanwhile,short-term efficacy,withdrawal rate and toxic side effects were compared between the two groups after induction chemotherapy.Results In NTP group,the positive expression rate of EGFR was 100％,and EGFR expression intensity significantly correlated with the efficacy of NTZ-combined induction therapy(P<0.05).After induction chemotherapy,the objective response rate(ORR)of cervical lymph nodes in NTP group was significantly higher than that in TP group(75％vs.45.8％,P=0.039).The primary lesion ORR and overall(primary lesion and cervical lymph node)ORR showed no significant difference between the two groups(P>0.05).Comparison of adverse reactions between the two groups during induction therapy:leukopenia and gastrointestinal reaction in NTP group were lower than those in TP group(P<0.05),but rash was higher than those in TP group(P<0.05).There was no significant difference in liver function,hemoglobin and thrombocytopenia between two groups(P>0.05).Conclusions EGFR expression intensity varies in nasopharyngeal carcinoma tissues,with higher levels indicating greater clinical benefit of combined induction therapy with NTZ.NTZ combined with TP induction regimen demonstrates good short-term efficacy and safety for cervical lymph nodes in patients with locally advanced nasopharyngeal carcinoma.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective:The purpose of this study is to explore in depth the mechanism of the impact of brain drain on organizational cohesion,with a view to cracking the vicious circle problem caused by brain drain in the northeast region and eliminating the unfavorable factors affecting the core cohesion of public health institutions.Methods:A combination of convenience sampling and snowball sampling was used to survey11 912 valid questionnaires,and the data were systematically analyzed using descriptive statistics,regression analysis,and moderated mediated effects analysis.Results:Brain drain has a significant negative effect on organizational cohesion(β=-1.29,P<0.001);and role overload partially mediates between the two,with a significant mediating effect(effect value=-0.56,95%CI=-0.67～-0.46),and the indirect effect accounts for 43.4%of the total effect;and monthly income significantly moderates the effect of brain drain on organizational cohesion through role overload(β=1.00,P<0.001).Conclusion:It is recommended to alleviate the sense of role overload among public health personnel by adjusting the level of salary and benefits,and to reduce the negative impact of brain drain by adopting long-term incentive mechanisms and other strategies,thus enhancing organizational cohesion and providing theoretical and practical guidance for relevant institutions.

Organoids are three-dimensional cell complexes formed by stem cells or tumor cells cultured and self-organized in vitro,which have higher simulation in morphology and function than the traditional two-dimensional cell drug screening model.However,the conventional organoid culture technology based on matrigel dome in culture dish or well plate has the problems of low throughput and time-consuming,which limits the application of high-throughput organoid drug screening.Therefore,a series of microfluidic high-throughput organoid culture and drug screening technologies have been developed.From the perspective of microfluidic technology,this paper reviews the current application of high-throughput organoid drug screening in three aspects:organoid culture,drug delivery and result detection.According to the different forms of organoid culture units,organoid culture techniques are divided into three categories:microfluidic droplets,microwells,and micropillars.According to the structure and working mode of drug delivery system,drug delivery system is divided into microchannel network and drug droplet array.According to the different forms of information obtained,high-throughput results detection methods can be divided into four categories:microplate reader,microscope,high-content imaging analyzer and chip sensor.Based on the above technologies,the application of typical organoid drug screening is introduced.Finally,the summary and prospect of organoid drug screening are presented.