ObjectiveTo investigate the effects of modified Ditan tang on genes related to the transcription-translation feedback loop （TTFL） of biorhythm in the rat model of non-alcoholic fatty liver disease （NAFLD） and its mechanism for prevention and treatment of NAFLD. MethodsSixty-five healthy SPF male SD rats were randomly assigned into blank （n=20）， model （n=15）， and low-， medium-， and high-dose （2.68， 5.36， and 10.72 g·kg^-1·d^-1， respectively） modified Ditan tang （n=10） groups. Other groups except the blank group were fed a high-fat diet for 12 weeks. The modified Ditan tang groups were treated with the decoction at corresponding doses by gavage， and the blank and model groups were treated with an equal volume of normal saline from the 9th week for 4 weeks. The levels of triglyceride （TG）， total cholesterol （TC）， low-density lipoprotein cholesterol （LDL-C）， high-density lipoprotein cholesterol （HDL-C）， aspartate aminotransferase （AST）， and alanine aminotransferase （ALT） in the serum were measured by an automatic biochemical analyzer. TG and non-esterified fatty acid （NEFA） assay kits were used to measure the levels of TG and NEFA in the liver. The pathological changes in the hypothalamus and liver were observed by hematoxylin-eosin staining， and the lipid deposition in the liver was observed by oil red O staining. The levels of brain-muscle ARNT-like protein 1 （BMAL1/ARNTL） in the hypothalamus and liver were determined by immunohistochemical staining. The mRNA and protein levels of BMAL1， circadian locomotor output cycles kaput （CLOCK）， period circadian clock 2 （PER2）， and cryptochrome1 （Cry1） in the hypothalamus and liver were determined by Real-time PCR and Western blot， respectively. ResultsCompared with the blank group， the model group showed elevated levels of TG， TC， LDL-C， AST， and ALT （P<0.01） and a lowered level of HDL-C （P<0.05） in the serum， elevated levels of TG and NEFA in the liver （P<0.01）， pyknosis and deep staining of hypothalamic neuron cells， and a large number of vacuoles in the brain area. In addition， the model group showed lipid deposition in the liver， up-regulated mRNA and protein levels of CLOCK and BMAL1 （P<0.01）， and down-regulated mRNA and protein levels of Cry1 and PER2 （P<0.01） in the hypothalamus and liver. Compared with the model group， all the three modified Ditan tang groups showed lowered levels of TG， TC， LDL-C， ALT， and AST （P<0.05， P<0.01） and an elevated level of HDL-C （P<0.05） in the serum， and lowered levels of TG and NEFA （P<0.05， P<0.01） in the liver. Furthermore， the three groups showed alleviated pyknosis and deep staining of hypothalamic neuron cells， reduced lipid deposition in the liver， down-regulated mRNA and protein levels of CLOCK and BMAL1 （P<0.05， P<0.01）， and up-regulated mRNA and protein levels of Cry1 and PER2 （P<0.05， P<0.01） in the hypothalamus and liver. ConclusionModified Ditan tang can reduce lipid deposition in the liver and regulate the expression of CLOCK， BMAL1， Cry1， and PER2 in the TTFL of NAFLD rats.

ObjectiveBased on analytic hierarchy process（AHP）-criteria importance through intercriteria correlation（CRITIC） hybrid weighting method， grey relational analysis and backpropagation artificial neural network（BP-ANN）， to optimize the water extraction process of Qizhi prescription， so as to provide an experimental basis for optimization of the preparation process of this prescription and the establishment of quality standards. MethodsL₉（3⁴） orthogonal test was employed， and the AHP-CRITIC hybrid weighting method was utilized to determine the weight coefficients of the quality fractions of various components， including astragaloside Ⅳ， polygalaxanthone Ⅲ， calycosin-7-O-β-D-glucoside， tenuifolin， and 3，6′-disinapoylsucrose， as well as the dry extract yield. The comprehensive score of each factor level combination in the orthogonal test were calculated as evaluation indicator to select the optimal extraction process parameters. The effects of extraction times， extraction time， and solvent dosage on the aqueous extraction process of the formula were investigated through intuitive analysis， variance analysis， and grey relational analysis. Meanwhile， a BP-ANN model was established to reverse-predict the optimal extraction process parameters of Qizhi prescription， and the optimized process parameters were validated. ResultsThe weight coefficients of the five index components（astragaloside Ⅳ， tenuifolin， calycosin-7-O-β-D-glucoside， polygalaxanthone Ⅲ， and 3，6′-disinapoylsucrose） and dry extract yield were 25.7%， 20.82%， 16.41%， 12.45%， 15.96% and 8.67%， respectively. The optimized extraction process parameters were extracted 3 times with 8， 6， 6 times the amount of water， each time for 1 h. The network prediction results of BP-ANN test samples were consistent with the orthogonal test results， and the mean square error（MSE） of the predicted and measured values of the network was <1%. The water extraction process of Qizhi prescription analyzed and predicted by relevant mathematical models was stable and feasible， which could effectively improve the extraction efficiency of the active ingredients of Astragali Radix and Polygalae Radix， and the average comprehensive score of the validation test was 90.85 with the relative standard deviation（RSD） of 1.55%. ConclusionThis study establishes a water extraction process for compound Qizhi granules， and the optimized extraction process can effectively improve the extraction efficiency of active ingredients， which provides useful references for the optimization of preparation process and the establishment of quality standards for other clinical experience formulas.

ObjectiveTo investigate the effect of Yiqi Yangyin Jiedu Huayu prescription on minimal hepatic encephalopathy in liver cirrhosis based on intestinal metabolomics. MethodsA total of 11 patients with liver cirrhosis who were hospitalized in Beijing Ditan Hospital， Capital Medical University， from March to May 2024， and were diagnosed with MHE based on psychometric hepatic encephalopathy score were enrolled as subjects， and 11 healthy family members of the patients were enrolled as control group. Fecal samples were collected for metabolomics analysis from the control group and the patients with MHE before and after treatment with Yiqi Yangyin Jiedu Huayu prescription， and a population cohort study was conducted to investigate the effect of Yiqi Yangyin Jiedu Huayu prescription on intestinal metabolism of patients with MHE. The Fisher’s exact test was used for categorical data between two groups； the independent samples t-test was used for comparison of normally distributed continuous data between two groups， the paired t-test was used for comparision before and after treatment within the same group， and the Wilcoxon rank-sum test was used for comparison of non-normally distributed continuous data between two groups. ResultsA total of 29 differentially expressed metabolites were detected between the MHE group and the control group， mainly amino acids， organic acids， organic amines， carbohydrates， fatty acids， and vitamins， and there were 12 upregulated metabolites and 17 downregulated metabolites in the MHE group， which were mainly enriched in the metabolic pathways of ornithine， branched-chain amino acid， and aromatic amino acid. After the treatment with Yiqi Yangyin Jiedu Huayu prescription， 80 differentially expressed metabolites were detected in the patients with MHE， mainly carbohydrates， organic acids， and amino acids， and there were 56 upregulated metabolites and 24 downregulated metabolites， which were mainly enriched in the metabolic pathways of ornithine， branched-chain amino acid， and aromatic amino acid. ConclusionYiqi Yangyin Jiedu Huayu prescription can exert a therapeutic effect on patients with MHE by regulating intestinal metabolism.

ObjectiveTo unveil the mechanism of Jianpi Huogu prescription （JPHGP） in ameliorating the dyslipidemia of steroid-induced osteonecrosis of the femur head （SONFH） by oxylipidomics combined with transcriptomics. MethodsSixty SD rats were assigned into normal， model， low-， medium-， and high-dose （2.5， 5， 10 g·kg^-1， respectively） JPHGP， and Jiangushengwan （1.53 g·kg^-1） groups. Lipopolysaccharide was injected into the tail vein at a dose of 20 μg·kg^-1 on days 1 and 2， and methylprednisolone sodium succinate was injected at a dose of 40 mg·kg^-1 into the buttock muscle on days 3 to 5. The normal group received an equal volume of normal saline. Drug administration by gavage began 4 weeks after the last injection， and samples were taken after administration for 8 weeks. Hematoxylin-eosin staining was conducted to reveal the histopathological changes of the femoral head， and the number of adipocytes， the rate of empty bone lacunae， and the trabecular area were calculated. Micro-computed tomography was used for revealing the histological and histomorphometrical changes of the femoral head. Enzyme-linked immunosorbent assay was employed to measure the serum levels of triglyceride （TG）， total cholesterol （TC）， low-density lipoprotein （LDL）， high-density lipoprotein （HDL）， apolipoprotein A1 （ApoA1）， and apolipoprotein B （ApoB）. At the same time， the femoral head was collected for oxylipidomic and transcriptomic detection. The differential metabolites and differential genes were enriched and analyzed， and the target genes regulating lipid metabolism were predicted. The predicted target proteins were further verified by molecular docking， immunohistochemistry， and Western blot. ResultsCompared with the normal group， the model group showcased thinning of the femoral head， trabecular fracture， karyopyknosis， subchondral cystic degeneration， increases in the number of adipocytes and the rate of empty bone lacunae （P<0.01）， a reduction in the trabecular area （P<0.01）， decreases in BMD， Tb.Th， Tb.N， and BV/TV， and increases in Tb.Sp and BS/BV （P<0.01）. Compared with the model group， the JPHGP groups showed no obvious thinning of the femoral head or subchondroidal cystic degeneration. The high- and medium-dose JPHGP groups presented declines in the number of adipocytes and the rate of empty bone lacunae， an increase in the trabecular area （P<0.05， P<0.01）， rises in BMD， Tb.Th， Tb.N， and BV/TV， and decreases in Tb.Sp and BS/BV （P<0.05， P<0.01）. Compared with the normal group， the model group showcased raised serum levels of TG， TC， LDL， and ApoB and lowered serum levels of HDL and ApoA1 （P<0.01）. Compared with the model group， the JPHGP groups had lowered serum levels of TG， TC， LDL， and ApoB （P<0.05， P<0.01） and a risen serum level of ApoA1 （P<0.05， P<0.01）. Moreover， the serum level of HDL in the high-dose JPHGP group increased （P<0.01）. A total of 19 different metabolites of disease set and drug set were screened out by oxylipidomics of the femoral head， and 119 core genes with restored expression were detected by transcriptomics. The enriched pathways were mainly concentrated in inflammation， lipids， apoptosis， and osteoclast differentiation. Molecular docking， immunohistochemistry， and Western blot results showed that compared with the normal group， the model group displayed increased content of 5-lipoxygenase （5-LO） and peroxisome proliferator-activated receptor γ （PPARγ） in the femoral head （P<0.01）. Compared with the model group， medium- and high-dose JPHGP reduced the content of 5-LO and PPARγ （P<0.05， P<0.01）. ConclusionJPHGP can restore the levels of oxidized lipid metabolites by regulating the 5-LO-PPARγ axis to treat SONFH in rats. Relevant studies provide experimental evidence for the efficacy mechanism of JPHGP in the treatment of SONFH.

ObjectiveTo unveil the mechanism of Jianpi Huogu prescription （JPHGP） in ameliorating the dyslipidemia of steroid-induced osteonecrosis of the femur head （SONFH） by oxylipidomics combined with transcriptomics. MethodsSixty SD rats were assigned into normal， model， low-， medium-， and high-dose （2.5， 5， 10 g·kg^-1， respectively） JPHGP， and Jiangushengwan （1.53 g·kg^-1） groups. Lipopolysaccharide was injected into the tail vein at a dose of 20 μg·kg^-1 on days 1 and 2， and methylprednisolone sodium succinate was injected at a dose of 40 mg·kg^-1 into the buttock muscle on days 3 to 5. The normal group received an equal volume of normal saline. Drug administration by gavage began 4 weeks after the last injection， and samples were taken after administration for 8 weeks. Hematoxylin-eosin staining was conducted to reveal the histopathological changes of the femoral head， and the number of adipocytes， the rate of empty bone lacunae， and the trabecular area were calculated. Micro-computed tomography was used for revealing the histological and histomorphometrical changes of the femoral head. Enzyme-linked immunosorbent assay was employed to measure the serum levels of triglyceride （TG）， total cholesterol （TC）， low-density lipoprotein （LDL）， high-density lipoprotein （HDL）， apolipoprotein A1 （ApoA1）， and apolipoprotein B （ApoB）. At the same time， the femoral head was collected for oxylipidomic and transcriptomic detection. The differential metabolites and differential genes were enriched and analyzed， and the target genes regulating lipid metabolism were predicted. The predicted target proteins were further verified by molecular docking， immunohistochemistry， and Western blot. ResultsCompared with the normal group， the model group showcased thinning of the femoral head， trabecular fracture， karyopyknosis， subchondral cystic degeneration， increases in the number of adipocytes and the rate of empty bone lacunae （P<0.01）， a reduction in the trabecular area （P<0.01）， decreases in BMD， Tb.Th， Tb.N， and BV/TV， and increases in Tb.Sp and BS/BV （P<0.01）. Compared with the model group， the JPHGP groups showed no obvious thinning of the femoral head or subchondroidal cystic degeneration. The high- and medium-dose JPHGP groups presented declines in the number of adipocytes and the rate of empty bone lacunae， an increase in the trabecular area （P<0.05， P<0.01）， rises in BMD， Tb.Th， Tb.N， and BV/TV， and decreases in Tb.Sp and BS/BV （P<0.05， P<0.01）. Compared with the normal group， the model group showcased raised serum levels of TG， TC， LDL， and ApoB and lowered serum levels of HDL and ApoA1 （P<0.01）. Compared with the model group， the JPHGP groups had lowered serum levels of TG， TC， LDL， and ApoB （P<0.05， P<0.01） and a risen serum level of ApoA1 （P<0.05， P<0.01）. Moreover， the serum level of HDL in the high-dose JPHGP group increased （P<0.01）. A total of 19 different metabolites of disease set and drug set were screened out by oxylipidomics of the femoral head， and 119 core genes with restored expression were detected by transcriptomics. The enriched pathways were mainly concentrated in inflammation， lipids， apoptosis， and osteoclast differentiation. Molecular docking， immunohistochemistry， and Western blot results showed that compared with the normal group， the model group displayed increased content of 5-lipoxygenase （5-LO） and peroxisome proliferator-activated receptor γ （PPARγ） in the femoral head （P<0.01）. Compared with the model group， medium- and high-dose JPHGP reduced the content of 5-LO and PPARγ （P<0.05， P<0.01）. ConclusionJPHGP can restore the levels of oxidized lipid metabolites by regulating the 5-LO-PPARγ axis to treat SONFH in rats. Relevant studies provide experimental evidence for the efficacy mechanism of JPHGP in the treatment of SONFH.

[Objective] To validate and optimize the platelet transfusion refractoriness (PTR) prediction model for patients with hematological disorders established by our center. [Methods] The data of patients with hematological diseases who received platelet transfusions from December 2021 to December 2022 were used as the training set, and data from January 2023 to December 2023 as the validation set. The validation set data was used to validate the predictive model constructed on the training set. Relevant risk factors for PTR were collected through literature review and preliminary studies。 The patients were divided into effective and ineffective groups according to the corrected count increment (CCI) of platelet counts. Predictive factors were screened using univariate and multivariate logistic regression. The calibration of the model were assessed via calibration curves, while discrimination, accuracy, sensitivity, and specificity were evaluated using receiver operating characteristic (ROC) curves Clinical utility was further analyzed with decision curve analysis (DCA). [Results] The Hosmer-Lemeshow (H-L) goodness-of-fit test for the validation set yielded S: P=0.000, indicating that the original model needs optimization. Baseline comparisons and logistic regression identified the number of red blood cell units (RBCU) and platelet units (PLT-U) transfused as key predictors for the optimized model. The H-L goodness-of-fit test S: P values for the training and validation sets were 0.930 and 0.056, respectively; the ROC areas were 0.793 5 and 0.809 4, specificities 90.95% and 84.21%, sensitivities 59.26% and 70.04%, and accuracies 78.14% and 74.10%, respectively. DCA demonstrated clinical net benefit within a prediction probability threshold range of 0.2-0.8. [Conclusion] Transfusion volumes of RBC-U and PLT-U were inversely associated with PTR in hematological patients. The resulting PTR prediction model exhibits moderate predictive efficacy and clinical benefit.

ObjectiveTo explore the effect of gypenosides （GPs） on liver lipid deposition in metabolism-associated fatty liver disease （MAFLD） mice and its mechanism based on classical/non-classical ferroptosis. MethodsEight male C57BL/6 mice in a blank group and 32 male apolipoprotein E gene knockout （ApoE^-/-） mice were randomly divided into a model group， a low-dose GPs （GPs-L） group， a high-dose GPs （GPs-H） group， and a simvastatin （SV） group. Starting from the second week， mice in the blank group were given a maintenance diet， and the other four groups were fed a high-fat diet daily. After eight weeks of feeding， mice in the GPs-L and GPs-H groups were given GPs of 1.487 mg·kg^-1·d^-1 and 2.973 mg·kg^-1·d^-1， respectively， and mice in the SV group were given simvastatin of 2.275 mg·kg^-1·d^-1. Mice in the blank group and the model group were given saline of equal volume by gavage for four weeks. The content of total cholesterol （TC）， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， high-density lipoprotein cholesterol （HDL-C）， alanine aminotransferase （ALT）， and aspartate aminotransferase （AST） in the serum of mice in each group was detected by an automatic biochemical analyzer. The level of non-esterified fatty acid （NEFA） and TG in the mouse liver was measured by the kit. The change in liver tissue structure and lipid deposition was observed by hematoxylin-eosin （HE） and oil red O staining. The levels of coenzyme Q₁₀ （CoQ₁₀）， glutathione （GSH）， malondialdehyde （MDA）， and Fe²⁺ in serum， as well as nicotinamide adenine dinucleotide phosphate ［NAD（P）H］ in the liver were detected by enzyme-linked immunosorbent assay （ELISA）. The expression of ferroptosis suppressor protein 1 （FSP1） in the liver of mice was observed by the immunohistochemical （IHC） method， and the expression of genes and proteins related to classical and non-classical ferroptosis pathways was analyzed by real-time polymerase chain reaction （Real-time PCR） and Wes automated protein expression analysis system. ResultsCompared with those in the blank group， the levels of TC， TG， LDL-C， ALT， and AST in serum and TG and NEFA in the liver in the model group were significantly increased， and the level of HDL-C in serum was significantly decreased （P<0.01）. The liver tissue structure changed， and there were fat vacuoles of different sizes and a large number of red lipid droplets， with obvious lipid deposition. The level of CoQ10 and GSH in serum and NADH in the liver were significantly decreased， while the level of MDA and Fe²⁺ in serum was significantly increased （P<0.01）. The mRNA and protein expressions of cystine/glutamate transporter （xCT/SLC7A11）， glutathione peroxidase （GPX4）， p62， nuclear factor E₂-related factor 2 （Nrf2）， and FSP1 were significantly decreased， and the mRNA and protein expressions of tumor antigen （p53）， spermidine/spermine N1-acetyltransferase 1 （SAT1）， arachidonate 15-lipoxygenase （ALOX15）， and Kelch-like epichlorohydrin-associated protein-1 （Keap1） were significantly increased （P<0.01）. Compared with those in the model group， the level of TC， TG， LDL-C， ALT， and AST in serum and TG and NEFA in the liver of mice in the GPs-L， GPs-H， and SV groups were decreased， while the level of HDL-C in serum was significantly increased （P<0.05， P<0.01）. The liver tissue structure and lipid deposition were improved. The levels of CoQ10 and GSH in serum and NADH in the liver were significantly increased， while the levels of MDA and Fe²⁺ in serum were significantly decreased （P<0.05， P<0.01）. The mRNA and protein expressions of xCT， GPX4， p62， Nrf2， and FSP1 were significantly increased， while the mRNA and protein expressions of p53， SAT1， ALOX15， and Keap1 were significantly decreased （P<0.05， P<0.01）. ConclusionGPs can interfere with liver lipid deposition in MAFLD mice through classical/non-classical ferroptosis pathways.

ObjectiveTo explore the effect of gypenosides （GPs） on liver lipid deposition in metabolism-associated fatty liver disease （MAFLD） mice and its mechanism based on classical/non-classical ferroptosis. MethodsEight male C57BL/6 mice in a blank group and 32 male apolipoprotein E gene knockout （ApoE^-/-） mice were randomly divided into a model group， a low-dose GPs （GPs-L） group， a high-dose GPs （GPs-H） group， and a simvastatin （SV） group. Starting from the second week， mice in the blank group were given a maintenance diet， and the other four groups were fed a high-fat diet daily. After eight weeks of feeding， mice in the GPs-L and GPs-H groups were given GPs of 1.487 mg·kg^-1·d^-1 and 2.973 mg·kg^-1·d^-1， respectively， and mice in the SV group were given simvastatin of 2.275 mg·kg^-1·d^-1. Mice in the blank group and the model group were given saline of equal volume by gavage for four weeks. The content of total cholesterol （TC）， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， high-density lipoprotein cholesterol （HDL-C）， alanine aminotransferase （ALT）， and aspartate aminotransferase （AST） in the serum of mice in each group was detected by an automatic biochemical analyzer. The level of non-esterified fatty acid （NEFA） and TG in the mouse liver was measured by the kit. The change in liver tissue structure and lipid deposition was observed by hematoxylin-eosin （HE） and oil red O staining. The levels of coenzyme Q₁₀ （CoQ₁₀）， glutathione （GSH）， malondialdehyde （MDA）， and Fe²⁺ in serum， as well as nicotinamide adenine dinucleotide phosphate ［NAD（P）H］ in the liver were detected by enzyme-linked immunosorbent assay （ELISA）. The expression of ferroptosis suppressor protein 1 （FSP1） in the liver of mice was observed by the immunohistochemical （IHC） method， and the expression of genes and proteins related to classical and non-classical ferroptosis pathways was analyzed by real-time polymerase chain reaction （Real-time PCR） and Wes automated protein expression analysis system. ResultsCompared with those in the blank group， the levels of TC， TG， LDL-C， ALT， and AST in serum and TG and NEFA in the liver in the model group were significantly increased， and the level of HDL-C in serum was significantly decreased （P<0.01）. The liver tissue structure changed， and there were fat vacuoles of different sizes and a large number of red lipid droplets， with obvious lipid deposition. The level of CoQ10 and GSH in serum and NADH in the liver were significantly decreased， while the level of MDA and Fe²⁺ in serum was significantly increased （P<0.01）. The mRNA and protein expressions of cystine/glutamate transporter （xCT/SLC7A11）， glutathione peroxidase （GPX4）， p62， nuclear factor E₂-related factor 2 （Nrf2）， and FSP1 were significantly decreased， and the mRNA and protein expressions of tumor antigen （p53）， spermidine/spermine N1-acetyltransferase 1 （SAT1）， arachidonate 15-lipoxygenase （ALOX15）， and Kelch-like epichlorohydrin-associated protein-1 （Keap1） were significantly increased （P<0.01）. Compared with those in the model group， the level of TC， TG， LDL-C， ALT， and AST in serum and TG and NEFA in the liver of mice in the GPs-L， GPs-H， and SV groups were decreased， while the level of HDL-C in serum was significantly increased （P<0.05， P<0.01）. The liver tissue structure and lipid deposition were improved. The levels of CoQ10 and GSH in serum and NADH in the liver were significantly increased， while the levels of MDA and Fe²⁺ in serum were significantly decreased （P<0.05， P<0.01）. The mRNA and protein expressions of xCT， GPX4， p62， Nrf2， and FSP1 were significantly increased， while the mRNA and protein expressions of p53， SAT1， ALOX15， and Keap1 were significantly decreased （P<0.05， P<0.01）. ConclusionGPs can interfere with liver lipid deposition in MAFLD mice through classical/non-classical ferroptosis pathways.

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:The rabbit model of steroid-induced osteonecrosis of femoral head is the most commonly used animal model of femoral head necrosis.The pathological changes of the femoral head are close to clinical practice,however,the conditions,methods and evaluation standards of animal models reported in and outside China are not uniform,which leads to the low scientific value of animal models and is difficult to popularize.This study aimed to clarify the influence of different mold-making conditions on the establishment of steroid-induced osteonecrosis of femoral head rabbit model and analyze the appropriate conditions for the successful model establishment. METHODS:We searched the CNKI,WanFang,VIP,CBM,WoS,PubMed and EMbsae databases for the literature on the modeling of steroid-induced osteonecrosis of femoral head rabbits up to April 1,2022,completed the screening of the literature according to the inclusion and exclusion criteria and literature quality evaluation,and extracted the outcome index data in the literature.RevMan Stata and ADDIS statistical software were used to conduct a meta-analysis of the included data. RESULTS:(1)A total of 82 articles with 1 366 rabbits were included in the study.The steroid-induced osteonecrosis of femoral head modeling methods were divided into three types:steroid-alone method,steroid combined lipopolysaccharide method and steroid combined serum method.Among these,33 articles used steroid-alone method;20 articles used steroid combined lipopolysaccharide method;29 articles used steroid combined serum method.(2)Meta-analysis results showed that the three modeling methods significantly increased the rate of empty bone lacunae in the femoral head of steroid-induced osteonecrosis of femoral head rabbits(P<0.001),and significantly decreased the ratio of the trabecular bone area in the femoral head of steroid-induced osteonecrosis of femoral head rabbits(P<0.001).The order of empty bone lacunae rate of each modeling method was:steroid combined with lipopolysaccharide method>steroid-alone method>steroid combined with serum method>normal group,and the order of trabecular bone area rate of each modeling method was:normal group>steroid combined with serum method>steroid-alone method>steroid combined with lipopolysaccharide method.(3)The results of subgroup analysis suggested that the rate of empty bone lacunae in the rabbit model induced by steroid alone might be related to the rabbit variety and the type of steroid used for modeling(difference between groups P<0.05),in which the combined effect amount of New Zealand white rabbits was higher than that of Chinese white rabbits(P<0.05)and Japanese white rabbits,and the combined effect amount of dexamethasone was higher than that of other steroids.The rate of empty bone lacunae induced by steroid combined with lipopolysaccharide was related to the administration mode of lipopolysaccharide and the type of steroid(P<0.05),among which the combined effect of methylprednisolone sodium succinate was significantly higher than that of other steroids(P<0.05),and the combined effect of prednisolone was significantly lower than that of other steroids(P<0.05).The combined effect of lipopolysaccharide 100 μg/kg×twice was significantly lower than 10 μg/kg×twice and 50 μg/kg×twice(P<0.05).The rate of empty bone lacunae in the model induced by steroid combined with serum was related to serum dose and steroid type(P<0.05),among which the combined effect amount of dexamethasone sodium phosphate was significantly higher than other steroid types(P<0.05),and the combined effect amount of dexamethasone was significantly lower than other steroid types(P<0.05);the combined effect amount of serum"10 mL/kg+6 mL/kg"combined dose was lower than other serum doses(P<0.05). CONCLUSION:(1)With the rate of empty bone lacunae and the ratio of trabecular bone area as the judgment standard for the successful establishment of the model,the three modeling methods can successfully construct the rabbit steroid-induced osteonecrosis of femoral head model,of which the steroid combined with lipopolysaccharide method is the best.(2)New Zealand white rabbits and dexamethasone are recommended when selecting the steroid-alone method.Methylprednisolone sodium succinate and low-dose lipopolysaccharide are recommended when selecting the steroid combined with lipopolysaccharide method.Dexamethasone sodium phosphate is recommended when selecting the steroid combined with serum modeling method.