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 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 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 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.

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.

Objective:To design a single-line low-temperature plasma ablation electrode, aiming to solve the problem of uniform, continuous and stable microbubbles generated by conventional electrodes, and improve the ablation and cutting effect of low-temperature plasma.Methods:The structures of low temperature plasma three-wire electrode and single-line electrode were modeled in SolidWorks 2021 3D modeling software, and the prototype was made by 3D printing. The finite element analysis of electric field and temperature field of the two kinds of electrode ablation process was carried out by COMSOL Multiphysics 6.1 software, and the validity and correctness of the finite element simulation model were verified by temperature test experiment, and the ablation effect and plasma excitation process of the two kinds of electrode were compared by tissue ablation experiment and low temperature plasma excitation experiment.Results:The results of finite element analysis showed that the maximum surface temperature of three-wire electrode and single-wire electrode were 70.2 and 63.3 ℃, respectively, and the surface temperature of single-wire electrode was more ideal, and the maximum electric field intensity of the two electrodes was more than 1.0 × 10 7 V/m, which met the electric field condition of microbubble breakdown. The electric field intensity of the two ends of the three-wire electrode was much higher than that of the other regions, while the electric field intensity of the single-wire electrode had no obvious sudden change and fluctuation. The experimental values of the temperature at the electrode surface and a distance of 1 cm on the electrode surface were basically consistent with the simulation values, the degree of fit was good, and the relative error was 3.2%. The highest ablation temperature of single linear electrode on pig fat was 46.8 ℃. After ablation, there was no coking area in morphology, and the tissue cutting depth of 0.5 mm could be reached in 1 s. When connected to the energy platform, microbubbles would occur on the working electrode surface of the single-wire electrode; when 6 ms was electrified, the working electrode surface was completely covered by microbubbles; when 9 ms was energized, the low-temperature plasma was excited and the blue-purple plasma could be seen; when 25 ms was energized, the microbubbles were still regular and stable. Conclusions:A kind of single-line low-temperature plasma ablation electrode is designed, which can produce uniform, continuous and stable microbubbles and achieve better ablation and cutting effect than the traditional electrode.

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.

Butyric acid is a type of short chain fatty acid and an important nutrient in intestinal epithelial cells.In addition to its important role in intestinal health,it has application value in anti-tumor,treatment of neuritis and di-abetes.At the same time,based on the demand for green development in the livestock industry,its anti-inflammato-ry effect can avoid the abuse of antimicrobial agents.As a green,pollution-free,and residue-free new feed,butyric acid ensures the sustainable and healthy development of the livestock industry.This article mainly summarizes the production of butyric acid in the intestine,its effects on the balance of gut microbiota,digestion ability,and inflam-mation in humans and animals,elaborates its application in human health and animal production.

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.