1.The mechanism of Laggerae Herba in improving chronic heart failure by inhibiting ferroptosis through the Nrf2/SLC7A11/GPX4 signaling pathway
Jinling XIAO ; Kai HUANG ; Xiaoqi WEI ; Xinyi FAN ; Wangjing CHAI ; Jing HAN ; Kuo GAO ; Xue YU ; Fanghe LI ; Shuzhen GUO
Journal of Beijing University of Traditional Chinese Medicine 2025;48(3):343-353
Objective:
To investigate the role and mechanism of the heat-clearing and detoxifying drug Laggerae Herba in regulating the nuclear factor-erythroid 2-related factor-2(Nrf2)/solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) signaling pathway to inhibit ferroptosis and improve chronic heart failure induced by transverse aortic arch constriction in mice.
Methods:
Twenty-four male ICR mice were divided into the sham (n=6) and transverse aortic arch constriction groups (n=18) according to the random number table method. The transverse aortic arch constriction group underwent transverse aortic constriction surgery to establish models. After modeling, the transverse aortic arch constriction group was further divided into the model, captopril, and Laggerae Herba groups according to the random number table method, with six mice per group. The captopril (15 mg/kg) and Laggerae Herba groups (1.95 g/kg) received the corresponding drugs by gavage, whereas the sham operation and model groups were administered the same volume of ultrapure water by gavage once a day for four consecutive weeks. After treatment, the cardiac function indexes of mice in each group were detected using ultrasound. The heart mass and tibia length were measured to calculate the ratio of heart weight to tibia length. Hematoxylin and eosin staining were used to observe the pathological changes in myocardial tissue. Masson staining was used to observe the degree of myocardial fibrosis. Wheat germ agglutinin staining was used to observe the degree of myocardial cell hypertrophy. Prussian blue staining was used to observe the iron deposition in myocardial tissue. An enzyme-linked immunosorbent assay was used to detect the amino-terminal pro-brain natriuretic peptide (NT-proBNP) and glutathione (GSH) contents in mice serum. Colorimetry was used to detect the malondialdehyde (MDA) content in mice serum. Western blotting was used to detect the Nrf2, GPX4, SLC7A11, and ferritin heavy chain 1 (FTH1) protein expressions in mice cardiac tissue.
Results:
Compared with the sham group, in the model group, the ejection fraction (EF) and fractional shortening (FS) of mice decreased, the left ventricular end-systolic volume (LVESV) and left ventricular end-systolic diameter (LVESD) increased, the left ventricular anterior wall end-systolic thickness (LVAWs) and left ventricular posterior wall end-systolic thickness (LVPWs) decreased, the ratio of heart weight to tibia length increased, the myocardial tissue morphology changed, myocardial fibrosis increased, the cross-sectional area of myocardial cells increased, iron deposition appeared in myocardial tissue, the serum NT-proBNP and MDA levels increased, the GSH level decreased, and Nrf2, GPX4, SLC7A11, and FTH1 protein expressions in cardiac tissue decreased (P<0.05). Compared with the model group, in the captopril and Laggerae Herba groups, the EF, FS, and LVAWs increased, the LVESV and LVESD decreased, the ratio of heart weight to tibia length decreased, the myocardial cells were arranged neatly, the degree of myocardial fibrosis decreased, the cross-sectional area of myocardial cells decreased, the serum NT-proBNP level decreased, and the GSH level increased. Compared with the model group, the LVPWs increased, the iron deposition in myocardial tissue decreased, the serum MDA level decreased, and Nrf2, GPX4, SLC7A11, and FTH1 protein expressions in cardiac tissue increased (P<0.05) in the Laggerae Herba group.
Conclusion
Laggerae Herba improves the cardiac function of mice with chronic heart failure caused by transverse aortic arch constriction, reduces the pathological remodeling of the heart, and reduces fibrosis. Its mechanism may be related to Nrf2/SLC7A11/GPX4 pathway-mediated ferroptosis.
2.Establishment and evaluation of an animal model of heart failure with preserved ejection fraction integrating disease and syndrome based on the "deficiency-blood stasis-toxin" pathogenesis
Xiaoqi WEI ; Xinyi FAN ; Feng JIANG ; Wangjing CHAI ; Jinling XIAO ; Fanghe LI ; Kuo GAO ; Xue YU ; Wei WANG ; Shuzhen GUO
Journal of Beijing University of Traditional Chinese Medicine 2025;48(4):501-515
Objective:
This study aimed to construct an animal model of heart failure with preserved ejection fraction (HFpEF) that integrates disease and syndrome based on the "deficiency-blood stasis-toxin" pathogenesis and to evaluate it comprehensively.
Methods:
The HFpEF mouse model was constructed using a combination of Nω-nitro-L-arginine methyl ester (L-NAME) and a high-fat diet. According to the random number table method, SPF-grade male C57BL/6J mice were randomly assigned to the control, L-NAME, high-fat diet, and model groups, 10 in each group. Comprehensive observations and data collection on macroscopic signs (e.g., fur condition, mental state, stool and urine, oral and nasal condition, paw and body condition, etc.) and cardiac function were performed after 10 and 16 weeks of model induction. Additionally, the syndrome evolution was elucidated based on diagnostic criteria for clinical syndromes of heart failure. Furthermore, pathological and molecular biological examinations of myocardial tissue were performed to assess the stability and reliability of the model.
Results:
Mice in the model group showed typical characteristics of syndrome of qi deficiency and blood stasis, as well as syndrome of internal heat accumulation, including lethargy, slow response, dull paw color and oral/nasal color, exercise intolerance, abnormal platelet activation, dry feces, and dark yellow urine. The time window for these syndromes was between 10 and 16 weeks post-modeling. Cardiac function assessments revealed severe diastolic dysfunction, concentric myocardial hypertrophy, and myocardial fibrosis in the model group. Pathological examinations showed a significantly increased collagen deposition in the myocardial interstitium, enlarged cross-sectional area of cardiomyocytes, and sparse coronary microvasculature in the model group. Molecular biological analyses indicated marked activation of the inducible nitric oxide synthase/nuclear factor kappa-light-chain-enhancer of activated B cells/NOD-like receptor family pyrin domain containing 3 inflammatory pathway and significantly elevated inflammation levels in the myocardial tissue of the model group. Although mice in the L-NAME and high-fat diet groups also showed certain manifestations of qi deficiency syndrome, the substantial cardiac damage was relatively limited compared to the control group.
Conclusion
This study has constructed an animal model of HFpEF that integrates disease and syndrome based on the "deficiency-blood stasis-toxin" pathogenesis. The macroscopic and microscopic characteristics of this model are consistent with the manifestations of syndrome of qi deficiency and blood stasis, toxin syndrome, and syndrome of internal heat accumulation. Moreover, it can stably simulate the HFpEF state and reflect phenotypic changes in human disease. This model provides a suitable experimental platform to explore the pathogenesis of HFpEF, evaluate the effectiveness of traditional Chinese medicine (TCM) treatment regimens, and promote in-depth research on TCM syndromes of heart failure.
3.Real-world long-term outcomes of non-small cell lung cancer patients undergoing neoadjuvant treatment with or without immune checkpoint inhibitors.
Bolun ZHOU ; Lin LI ; Fan ZHANG ; Qilin HUAI ; Liang ZHAO ; Fengwei TAN ; Qi XUE ; Wei GUO ; Shugeng GAO
Chinese Medical Journal 2025;138(22):2963-2973
BACKGROUND:
Immune checkpoint inhibitors (ICIs) have been included in various neoadjuvant therapy (NAT) regimens for non-small cell lung cancer (NSCLC). However, due to the relatively short period for the use of ICIs in NAT, patients' clinical outcomes with different regimens are uncertain. Our study aims to examine the efficacy of neoadjuvant immunotherapy (NAIT) for NSCLC patients and compare the overall survival (OS) and event-free survival (EFS) of patients receiving different NAT regimens.
METHODS:
This study retrospectively included 308 NSCLC patients treated with different NAT regimens and subsequent surgery in National Cancer Center between August 1, 2016 and July 31, 2022. Kaplan-Meier survival analysis and Cox proportional hazards regression analysis were conducted to evaluate the prognosis of patients.
RESULTS:
With a median follow-up of 27.5 months, the 1-year OS rates were 98.8% and 96.2%, and the 2-year OS rates were 96.6% and 85.8% in patients of the NAIT and neoadjuvant chemotherapy (NACT) group, respectively (hazard ratio [HR], 0.339; 95% confidence interval [CI], 0.160-0.720; P = 0.003). The 1-year EFS rates were 96.0% and 88.0%, and the 2-year EFS rates were 92.0% and 77.7% for patients in the NAIT and NACT groups, respectively (HR, 0.438; 95% CI, 0.276-0.846; P = 0.010). For patients who did not achieve pathological complete response (pCR), significantly longer OS ( P = 0.012) and EFS ( P = 0.019) were observed in patients receiving NAIT than those receiving NACT. Different NAT regimens had little effect on surgery and the postoperative length of stay (6 [4, 7] days vs . 6 [4, 7] days, Z = -0.227, P = 0.820).
CONCLUSIONS
NAIT exhibited superior efficacy to NACT for NSCLC, resulting in longer OS and EFS. The OS and EFS benefits were also observed among patients in the NAIT group who did not achieve pCR.
Humans
;
Carcinoma, Non-Small-Cell Lung/mortality*
;
Male
;
Female
;
Lung Neoplasms/mortality*
;
Middle Aged
;
Immune Checkpoint Inhibitors/therapeutic use*
;
Neoadjuvant Therapy/methods*
;
Retrospective Studies
;
Aged
;
Adult
;
Kaplan-Meier Estimate
;
Treatment Outcome
;
Immunotherapy/methods*
4.Adherence to blood glucose self-monitoring guidance and glycemic control in Chinese patients with type 2 diabetes mellitus initiating basal insulin: A mobile health-based prospective cohort study.
Lixin GUO ; Dalong ZHU ; Kaining CHEN ; Yaoming XUE ; Chao ZHOU ; Ping LIU ; Zhaohui HU ; Pei GU ; Wei ZHANG ; Huijie DONG ; Wanjun XIE ; Liqing GUAN
Chinese Medical Journal 2025;138(21):2832-2834
5.Ameliorative effects of Lycii Fructus-Chrysanthemi Flos at different ratios on retinal damage in mice.
Bing LI ; Sheng GUO ; Yue ZHU ; Xue-Sen WANG ; Dan-Dan WEI ; Hong-Jie KANG ; Wen-Hua ZHANG ; Jin-Ao DUAN
China Journal of Chinese Materia Medica 2025;50(3):732-740
This study aimed to compare the ameliorative effects of Lycii Fructus and Chrysanthemi Flos at different ratios on retinal damage in mice and to elucidate the underlying mechanisms. A retinal injury model was established by intraperitoneal injection of sodium iodate(NaIO_3) solution. The mice were divided into the following groups: blank group, model group, positive drug(AREDS 2) group, low-and high-dose groups of Lycii Fructus and Chrysanthemi Flos at 1∶1, low-and high-dose groups at 3∶1, and low-and high-dose groups at 1∶3. Administration was carried out 15 days after modeling. The visual acuity of the mice was assessed using the black-and-white box test. The fundus was observed using an optical coherence tomography device, and retinal thickness was measured. HE staining was used to observe the morphology and pathological changes of the retina. The levels of oxidative factors in serum and ocular tissues were measured using assay kits. The levels of inflammatory factors in serum and ocular tissues were detected by enzyme-linked immunosorbent assay(ELISA), and the expression of Nrf2, HO-1, and NF-κB proteins in ocular tissues was analyzed by Western blot. The results showed that after administration of Lycii Fructus and Chrysanthemi Flos at different ratios, the model group showed improved retinal thinning and disordered arrangement of retinal layers, elevated content of SOD and GSH in the serum and ocular tissues, and reduced levels of MDA, TNF-α, IL-1β, and IL-6. Lycii Fructus and Chrysanthemi Flos at 1∶1 and 1∶3 showed better improvement effects. The combination significantly upregulated the expression levels of Nrf2 and HO-1 and downregulated the expression of NF-κB p65. These results indicate that Lycii Fructus and Chrysanthemi Flos at different ratios can improve retinal damage, reduce oxidative stress, and alleviate inflammation in both the body and ocular tissues of mice. The mechanism may be related to the regulation of the Nrf2/HO-1 and NF-κB signaling pathways in ocular tissues. These findings provide a theoretical basis for the clinical application of Lycii Fructus and Chrysanthemi Flos in the treatment of dry age-related macular degeneration.
Animals
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Mice
;
Retina/injuries*
;
Male
;
Lycium/chemistry*
;
Drugs, Chinese Herbal/administration & dosage*
;
Chrysanthemum/chemistry*
;
NF-kappa B/genetics*
;
Humans
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Retinal Diseases/metabolism*
;
NF-E2-Related Factor 2/metabolism*
;
Oxidative Stress/drug effects*
;
Flowers/chemistry*
;
Heme Oxygenase-1/genetics*
6.Berberine promotes expression of AQP4 in astrocytes by regulating production of miR-383-5p in HepG2 cell-derived exosomes under insulin resistance.
Xue-Ling LIN ; Ying LI ; Meng-Qing GUO ; Yan-Jun ZHANG ; Qing-Sheng YIN ; Peng-Wei ZHUANG
China Journal of Chinese Materia Medica 2025;50(3):768-775
This study aims to explore the role and mechanism of berberine in promoting the expression of aquaporin 4(AQP4) in astrocytes by regulating the expression of miR-383-5p in HepG2 cell-derived exosomes under insulin resistance(IR). The IR-HepG2 cell model was established with 1×10~(-6) mol·L~(-1) insulin. With metformin as the positive control, the safe concentrations of berberine and metformin were screened by cell counting kit-8(CCK-8) and lactate dehydrogenase(LDH) leakage assays, and the effect of berberine on the IR of HepG2 cells was evaluated by glucose consumption. NanoSight was used to measure the particle size and concentration of exosomes secreted by HepG2 cells in each group. HepG2 cell-derived exosomes in each group were incubated with astrocytes for 24 h, and the protein and mRNA levels of AQP4 in HA1800 cells were determined by Western blot and qRT-PCR, respectively. qRT-PCR was performed to determine the expression of miR-383-5p in HepG2 cell-derived exosomes and HA1800 cells after co-incubation. Western blotting was employed to determine the expression levels of miRNAs and proteins associated with exosome production and release in HepG2 cells. The results showed that 10 μmol·L~(-1) berberine and 1 mmol·L~(-1) metformin significantly alleviated the IR of HepG2 cells and reduced the concentration of exosomes in HepG2 cells. The exosomes of HepG2 cells treated with berberine and metformin significantly up-regulated the protein and mRNA levels of AQP4 in HA1800 cells. The mRNA level of miR-383-5p in HepG2 cell exosomes and HA1800 cells co-incubated with berberine and metformin decreased significantly. The intervention with berberine and metformin significantly down-regulated the expression of proteins associated with the production of miRNAs(Dicer, Drosha) as well as the production(Alix, Vps4A) and release(Rab35, VAMP3) of exosomes in IR-HepG2 cells. In conclusion, berberine can promote the expression of AQP4 in astrocytes by inhibiting the production and release of miR-383-5p in HepG2-derived exosomes under IR.
Humans
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MicroRNAs/metabolism*
;
Berberine/pharmacology*
;
Hep G2 Cells
;
Exosomes/genetics*
;
Aquaporin 4/metabolism*
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Insulin Resistance
;
Astrocytes/drug effects*
7.Mechanism of Jiming Powder in improving mitophagy for treatment of myocardial infarction based on PINK1-Parkin pathway.
Xin-Yi FAN ; Xiao-Qi WEI ; Wang-Jing CHAI ; Kuo GAO ; Fang-He LI ; Xue YU ; Shu-Zhen GUO
China Journal of Chinese Materia Medica 2025;50(12):3346-3355
In the present study, a mouse model of coronary artery ligation was employed to evaluate the effects of Jiming Powder on mitophagy in the mouse model of myocardial infarction and elucidate its underlying mechanisms. A mouse model of myocardial infarction post heart failure was constructed by ligating the left anterior descending branch of the coronary artery. The therapeutic efficacy of Jiming Powder was assessed from multiple perspectives, including ultrasonographic imaging, hematoxylin-eosin(HE) staining, Masson staining, and serum cardiac enzyme profiling. Dihydroethidium(DHE) staining was employed to evaluate the oxidative stress levels in the hearts of mice from each group. Mitophagy levels were assessed by scanning electron microscopy and immunofluorescence co-localization. Western blot was employed to determine the levels of key proteins involved in mitophagy, including Bcl-2-interacting protein beclin 1(BECN1), sequestosome 1(SQSTM1), microtubule-associated protein 1 light chain 3 beta(LC3B), PTEN-induced putative kinase 1(PINK1), phospho-Parkinson disease protein(p-Parkin), and Parkinson disease protein(Parkin). The results demonstrated that compared with the model group, high and low doses of Jiming Powder significantly reduced the left ventricular internal diameter in systole(LVIDs) and left ventricular internal diameter in diastole(LVIDd) and markedly improved the left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS), effectively improving the cardiac function in post-myocardial infarction mice. Jiming Powder effectively reduced the levels of myocardial injury markers such as creatine kinase(CK), creatine kinase isoenzyme(CK-MB), and lactate dehydrogenase(LDH), thereby protecting ischemic myocardium. HE staining revealed that Jiming Powder attenuated inflammatory cell infiltration after myocardial infarction. Masson staining indicated that Jiming Powder effectively inhibited ventricular remodeling. Western blot results showed that Jiming Powder activated the PINK1-Parkin pathway, up-regulated the protein level of BECN1, down-regulated the protein level of SQSTM1, and increased the LC3Ⅱ/LC3Ⅰ ratio to promote mitophagy. In conclusion, Jiming Powder exerts therapeutic effects on myocardial infarction by inhibiting ventricular remodeling. The findings pave the way for subsequent pharmacological studies on the active components of Jiming Powder.
Animals
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Myocardial Infarction/physiopathology*
;
Mitophagy/drug effects*
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Mice
;
Drugs, Chinese Herbal/administration & dosage*
;
Protein Kinases/genetics*
;
Male
;
Ubiquitin-Protein Ligases/genetics*
;
Humans
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Disease Models, Animal
;
Mice, Inbred C57BL
;
Signal Transduction/drug effects*
8.Mechanism of Jiming Powder in inhibiting ferroptosis in treatment of myocardial infarction based on NRF2/HO-1/GPX4 pathway.
Xin-Yi FAN ; Xiao-Qi WEI ; Wang-Jing CHAI ; Fang-He LI ; Kuo GAO ; Xue YU ; Shu-Zhen GUO
China Journal of Chinese Materia Medica 2025;50(11):3108-3116
This study employed a mouse model of coronary artery ligation to assess the effect and mechanism of Jiming Powder on mitochondrial autophagy in mice with myocardial infarction. The mouse model of heart failure post-myocardial infarction was established by ligating the left anterior descending coronary artery. The pharmacological efficacy of Jiming Powder was evaluated through echocardiographic imaging, hematoxylin-eosin(HE) staining, and Masson staining. The levels of malondialdehyde(MDA), Fe~(2+), reduced glutathione(GSH), and superoxide dismutase(SOD) in heart tissues, as well as MDA immunofluorescence of heart tissues, were measured to assess lipid peroxidation and Fe~(2+) levels in the hearts of mice in different groups. Ferroptosis levels in the groups were evaluated using scanning electron microscopy and Prussian blue staining. Western blot analysis was conducted to detect the levels of key ferroptosis-related proteins, including nuclear factor erythroid 2-related factor 2(NRF2), ferritin heavy chain(FTH), glutathione peroxidase 4(GPX4), solute carrier family 7 member 11(SLC7A11), heme oxygenase 1(HO-1), and Kelch-like ECH-associated protein 1(KEAP1). The results showed that compared with the model group, both the high-and low-dose Jiming Powder groups exhibited significantly reduced left ventricular internal diameter in systole(LVIDs) and left ventricular internal diameter in diastole(LVIDd), while the left ventricular ejection fraction(EF) and left ventricular fractional shortening(FS) were significantly improved, effectively enhancing cardiac function in mice post-myocardial infarction. HE staining revealed that Jiming Powder attenuated myocardial inflammatory cell infiltration post-infarction, and Masson staining indicated that Jiming Powder effectively reduced fibrosis in the infarct margin area. Treatment with Jiming Powder reduced the levels of MDA and Fe~(2+), indicators of lipid peroxidation post-myocardial infarction, while increasing GSH and SOD levels, thus protecting ischemic myocardium. Western blot results demonstrated that Jiming Powder reduced KEAP1 protein accumulation, activated the NRF2/HO-1/GPX4 pathway, and up-regulated the protein expression of FTH and SLC7A11, exerting an inhibitory effect on ferroptosis. This study reveals that Jiming Powder exerts a therapeutic effect on myocardial infarction by inhibiting ferroptosis through the NRF2/HO-1/GPX4 pathway, providing a foundation for subsequent research on the pharmacological effects of Jiming Powder.
Animals
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Ferroptosis/drug effects*
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Myocardial Infarction/physiopathology*
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NF-E2-Related Factor 2/genetics*
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Mice
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Drugs, Chinese Herbal/administration & dosage*
;
Male
;
Heme Oxygenase-1/genetics*
;
Phospholipid Hydroperoxide Glutathione Peroxidase/genetics*
;
Humans
;
Mice, Inbred C57BL
;
Signal Transduction/drug effects*
;
Disease Models, Animal
9.Potential mechanism of Yueju Pills in improving depressive symptoms of psychocardiac diseases based on metabolomics and network pharmacology.
Cheng-Yu DU ; Xue-Feng GUO ; Han-Wen ZHANG ; Jian LIANG ; Huan ZHANG ; Guo-Wei HUANG ; Ping NI ; Hai-Jun MA ; You YU ; Rui YU
China Journal of Chinese Materia Medica 2025;50(16):4564-4573
The therapeutic effects of Yueju Pills on depression and cardiovascular diseases have been widely recognized. Previous studies have shown that the drug can significantly improve depressive-like behaviors induced by chronic unpredictable mild stress(CUMS) combined with atherosclerosis(AS). Given the complex pathogenesis of psychocardiac diseases, this study integrated metabolomics and network pharmacology to systematically elucidate the mechanism of Yueju Pills in alleviating depressive symptoms in psychocardiac diseases. The results demonstrate that, after Yueju Pill intervention, the levels of 9 abnormal metabolites in the hippocampus restore to normal ranges, primarily involving key pathways or signaling pathways, including the cyclic adenosine monophosphate(cAMP), mammalian target of rapamycin(mTOR), glycine/serine/threonine metabolism, and aminoacyl-tRNA biosynthesis. In a high-fat diet-induced CUMS ApoE~(-/-) mouse model, Yueju Pills significantly increases adenosine monophosphate(AMP) levels and decreases L-alanine and D-glyceric acid levels in the hippocampus. In conclusion, Yueju Pills exert antidepressant effects by regulating multiple metabolic axes, including glycine/serine/threonine metabolism and the cAMP, mTOR signaling pathways. Network pharmacology predictions reveal that the treatment of CUMS combined with AS by its core active components may be realized through modulating pathways concerning neuroinflammation and synaptic plasticity, including serine/threonine-protein kinase 1(AKT1), mitogen-activated protein kinase 1(MAPK1), and prostaglandin-endoperoxide synthase 2(PTGS2). This study provides a theoretical reference for the clinical application of Yueju Pills in alleviating the depressive symptoms of psychocardiac diseases.
Animals
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Network Pharmacology
;
Mice
;
Drugs, Chinese Herbal/administration & dosage*
;
Metabolomics
;
Male
;
Depression/genetics*
;
Humans
;
Hippocampus/drug effects*
;
Mice, Inbred C57BL
;
Signal Transduction/drug effects*
10.Simulation analysis of adaptability of large airborne negative pressure isolation cabin to aviation conditions.
Lei GUO ; Falin LI ; Lang JIANG ; Haibo DU ; Bingjie XUE ; Wei YONG ; Yuanyuan JIANG ; Muzhe ZHANG
Journal of Biomedical Engineering 2025;42(4):775-781
In order to solve the problems of difficult test, high cost and long cycle in the development of large-scale airborne negative pressure isolation system, the simulation analysis of negative pressure response characteristics is carried out around various aviation conditions such as aircraft ascending, leveling and descending, especially rapid decompression, based on the computational fluid dynamics (CFD) method. The results showed that the isolation cabin could achieve -50 Pa pressure difference environment and form a certain pressure gradient. The exhaust air volume reached the maximum value in the early stage of the aircraft's ascent, and gradually decreased with the increase of altitude until it was level flying. In the process of aircraft descent, the exhaust fan could theoretically maintain a pressure difference far below -50 Pa without working; Under the special condition of rapid pressure loss, it was difficult to deal with the rapid change of low pressure only by the exhaust fan, so it was necessary to design safety valve and other anti-leakage measures in the isolation cabin structure. Therefore, the initial stage of aircraft ascent is the key stage for the adjustment and control of the negative pressure isolation system. By controlling the exhaust air volume and adjusting parameters, it can adapt to the change of low pressure under normal flight conditions, form a relatively stable negative pressure environment, and meet the needs of biological control, isolation and transport.
Aircraft
;
Computer Simulation
;
Aviation/instrumentation*
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Humans
;
Hydrodynamics
;
Air Pressure
;
Equipment Design
;
Pressure


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