ObjectiveThis paper aims to explore the in vitro anti-psoriasis activity and potential mechanism of Kangfuxin liquid （KFX liquid）， providing experimental evidence for the anti-psoriasis effect of KFX liquid. MethodsFirstly， the uninduced human immortalized keratinocyte cells （HaCaT cells） were divided into seven groups， namely the control group and KFX liquid groups with different doses （5， 10， 20， 40， 80， 160 g·L^-1）. After being treated with different concentrations of KFX liquid， the effect of KFX liquid on the normal cell proliferation was detected by using the cell counting kit-8 （CCK-8） method. Secondly， the uninduced HaCaT cells were divided into six groups， namely the control group and recombinant human interleukin-7A （rh-IL-7A） groups with different doses （5， 10， 50， 100， 120 g·L^-1）. After being treated with different concentrations of recombinant human interleukin-17A （rh IL-17A） liquid， the effect of rh IL-17A on cell proliferation was detected. The optimal induction concentration was screened. Then， normal HaCaT cells were divided into a control group and KFX liquid groups with different doses （5， 10， 20， 40， 80， 160 g·L^-1）. Except for the control group， the other groups established psoriasis cell models with the optimal induction concentration of rh IL-17A. After being treated with different concentrations of KFX liquid， the effects of KFX liquid on the psoriasis-like HaCaT cell proliferation were investigated. Finally， the uninduced HaCaT cells were divided into six groups， namely the control group， rh IL-17A group， methotrexate （MTX） group， and KFX liquid groups with different doses （20， 40， 80 g·L^-1）. Except for the control group， the other groups used the optimal induction concentration of rh IL-17A to establish psoriasis cell models. After being treated with different drugs， the cell migration levels were detected through scratch assays， and real-time quantitative polymerase chain reaction （Real-time PCR） was used to detect the relative mRNA expression levels of Ki-67 antigen （Ki67）， S100 calcium-binding protein A7 （S100A7）， S100 calcium-binding protein A8 （S100A8）， and S100 calcium-binding protein A9 （S100A9）， thereby comprehensively evaluating the in vitro anti-psoriasis activity of KFX liquid. By detecting the relative mRNA expression levels of interleukin-1β （IL-1β）， interleukin-6 （IL-6）， and chemokine-20 （CXCL-20） inflammatory-related factors in psoriasis-like HaCaT cells and the protein expression levels of Janus kinase 3 （JAK3）， phosphorylated Janus kinase 3 （p-JAK3）， signal transducer and activator of transcription 3 （STAT3）， and phosphorylated signal transducer and activator of transcription 3 （p-STAT3）， the mechanism was explored. ResultsCompared with that of control group， when treated with 80 g·L^-1 KFX liquid for 72 h （P<0.05） and at different times with 160 g·L^-1 KFX liquid， the HaCaT cell proliferation activity was significantly affected （P<0.01）， while the other concentrations of KFX liquid had no significant differences in cell morphology and cell proliferation activity at different times， indicating that the KFX liquid is relatively safe for HaCaT cells and has no obvious toxic side effects. Compared with that of control group， when treated with different concentrations of rh IL-17A for 24 h， the HaCaT cell proliferation activity was significantly enhanced， and the cell activity was the strongest when the concentration was 100 μg·L^-1 （P<0.05）， with a density close to 100% and intact cell morphology， indicating that 100 μg·L^-1 is the optimal concentration for inducing HaCaT cell proliferation. The results of the KFX liquid treatment on rh IL-17A-induced psoriasis-like cells show that the KFX liquid not only effectively inhibits the rh IL-17A-induced psoriasis-like HaCaT cell proliferation activity （P<0.01）， but also significantly reduces the migration ability of rh IL-17A-induced psoriasis-like HaCaT cells （P<0.01）， and the relative mRNA expression levels of Ki67， S100A7， S100A8， and S100A9 （P<0.01）. Moreover， the KFX liquid can significantly reduce the relative mRNA expression levels of IL-1β， IL-6， and CXCL-20 in rh IL-17A-induced psoriasis-like cells （P<0.01）， and significantly inhibit the phosphorylation levels of JAK3 and STAT3 proteins （P<0.05， P<0.01）. ConclusionThe KFX liquid has no obvious toxicity to uninduced HaCaT cells. It can inhibit rh IL-17A-induced psoriasis-like HaCaT cell proliferation， reduce the cell migration ability， and has good in vitro anti-psoriasis activity. Its action mechanism may be related to downregulating the expression levels of inflammation-related cytokines in the JAK3/STAT3 signaling pathway and inhibiting the phosphorylation levels of JAK3 and STAT3 proteins.

ObjectiveThis paper aims to explore the in vitro anti-psoriasis activity and potential mechanism of Kangfuxin liquid （KFX liquid）， providing experimental evidence for the anti-psoriasis effect of KFX liquid. MethodsFirstly， the uninduced human immortalized keratinocyte cells （HaCaT cells） were divided into seven groups， namely the control group and KFX liquid groups with different doses （5， 10， 20， 40， 80， 160 g·L^-1）. After being treated with different concentrations of KFX liquid， the effect of KFX liquid on the normal cell proliferation was detected by using the cell counting kit-8 （CCK-8） method. Secondly， the uninduced HaCaT cells were divided into six groups， namely the control group and recombinant human interleukin-7A （rh-IL-7A） groups with different doses （5， 10， 50， 100， 120 g·L^-1）. After being treated with different concentrations of recombinant human interleukin-17A （rh IL-17A） liquid， the effect of rh IL-17A on cell proliferation was detected. The optimal induction concentration was screened. Then， normal HaCaT cells were divided into a control group and KFX liquid groups with different doses （5， 10， 20， 40， 80， 160 g·L^-1）. Except for the control group， the other groups established psoriasis cell models with the optimal induction concentration of rh IL-17A. After being treated with different concentrations of KFX liquid， the effects of KFX liquid on the psoriasis-like HaCaT cell proliferation were investigated. Finally， the uninduced HaCaT cells were divided into six groups， namely the control group， rh IL-17A group， methotrexate （MTX） group， and KFX liquid groups with different doses （20， 40， 80 g·L^-1）. Except for the control group， the other groups used the optimal induction concentration of rh IL-17A to establish psoriasis cell models. After being treated with different drugs， the cell migration levels were detected through scratch assays， and real-time quantitative polymerase chain reaction （Real-time PCR） was used to detect the relative mRNA expression levels of Ki-67 antigen （Ki67）， S100 calcium-binding protein A7 （S100A7）， S100 calcium-binding protein A8 （S100A8）， and S100 calcium-binding protein A9 （S100A9）， thereby comprehensively evaluating the in vitro anti-psoriasis activity of KFX liquid. By detecting the relative mRNA expression levels of interleukin-1β （IL-1β）， interleukin-6 （IL-6）， and chemokine-20 （CXCL-20） inflammatory-related factors in psoriasis-like HaCaT cells and the protein expression levels of Janus kinase 3 （JAK3）， phosphorylated Janus kinase 3 （p-JAK3）， signal transducer and activator of transcription 3 （STAT3）， and phosphorylated signal transducer and activator of transcription 3 （p-STAT3）， the mechanism was explored. ResultsCompared with that of control group， when treated with 80 g·L^-1 KFX liquid for 72 h （P<0.05） and at different times with 160 g·L^-1 KFX liquid， the HaCaT cell proliferation activity was significantly affected （P<0.01）， while the other concentrations of KFX liquid had no significant differences in cell morphology and cell proliferation activity at different times， indicating that the KFX liquid is relatively safe for HaCaT cells and has no obvious toxic side effects. Compared with that of control group， when treated with different concentrations of rh IL-17A for 24 h， the HaCaT cell proliferation activity was significantly enhanced， and the cell activity was the strongest when the concentration was 100 μg·L^-1 （P<0.05）， with a density close to 100% and intact cell morphology， indicating that 100 μg·L^-1 is the optimal concentration for inducing HaCaT cell proliferation. The results of the KFX liquid treatment on rh IL-17A-induced psoriasis-like cells show that the KFX liquid not only effectively inhibits the rh IL-17A-induced psoriasis-like HaCaT cell proliferation activity （P<0.01）， but also significantly reduces the migration ability of rh IL-17A-induced psoriasis-like HaCaT cells （P<0.01）， and the relative mRNA expression levels of Ki67， S100A7， S100A8， and S100A9 （P<0.01）. Moreover， the KFX liquid can significantly reduce the relative mRNA expression levels of IL-1β， IL-6， and CXCL-20 in rh IL-17A-induced psoriasis-like cells （P<0.01）， and significantly inhibit the phosphorylation levels of JAK3 and STAT3 proteins （P<0.05， P<0.01）. ConclusionThe KFX liquid has no obvious toxicity to uninduced HaCaT cells. It can inhibit rh IL-17A-induced psoriasis-like HaCaT cell proliferation， reduce the cell migration ability， and has good in vitro anti-psoriasis activity. Its action mechanism may be related to downregulating the expression levels of inflammation-related cytokines in the JAK3/STAT3 signaling pathway and inhibiting the phosphorylation levels of JAK3 and STAT3 proteins.

Objective: To evaluate the effects of green tea extract (GTE) and its main catechin monomers on erythrocyte lesion (such as hemolysis, decreased energy metabolism and oxidative stress) during in vitro storage, and to explore its potential as a novel additive for erythrocyte preservation solutions. Methods: The composition of GTE was analyzed by high-performance liquid chromatography (HPLC). Using an in vitro simulated storage model, erythrocytes were stored in CPDA-1 preservation solution supplemented with GTE and the three most abundant catechin monomers (EGCG, ECG, EGC) for 60 days. Hemolysis rate and ATP content were dynamically monitored during storage. Flow cytometry was used to analyze phosphatidylserine (PS) exposure. Meanwhile, the protective effects of each component were verified in an acute oxidative stress model, and erythrocyte membrane stability was assessed by osmotic fragility test. Results: After 60 days of storage at 4℃, the hemolysis rate at the end of storage in the GTE group was <0.8%, which was superior to that in the control group and the single catechin-supplemented groups. Erythrocyte osmotic fragility assay showed that GTE could enhance the stability of erythrocyte membranes. In the acute oxidative stress experiment, the protective rate of GTE against erythrocyte injury exceeded 99%, which was better than that of the single catechin groups. At the initial stage of storage, ATP content decreased in all catechin-treated groups, but PS exposure was not significantly increased. Conclusion: The addition of GTE can effectively alleviate storage lesions of erythrocytes, with efficacy superior to that of single catechins. GTE enhances the antioxidant capacity and membrane stability of stored erythrocytes. Our results provide new experimental evidence for the development of GTE-based erythrocyte preservation additives.

Objective To investigate the effect of spontaneous hypertension on the remodeling of cardiac and aortic tissues in rats, with special attention to the changes in the content of collagen fibers, elastic fibers and secreted Frizzled-related protein 2 （sFRP2） in cardiac and aortic tissues. Methods 28-week-old SHR rats （Spontaneously Hypertensive rats） and WKY （Wistar-Kyoto rats） of the same age were selected as experimental animals. Cardiac load was assessed by calculating the cardiac weight index. Collagen fibers and elastic fibers were isolated from the rat thoracic aorta by hot alkali method, and their content was determined by biochemical analysis. In addition, pathological evaluation of tissue sections of the left ventricle and thoracic aorta were performed by H&E staining, Sirius red staining, and lichen red staining. Western blotting was used to determine the expression level of sFRP2 protein in cardiac tissues. Results Compared with WKY rats, the heart weight index of SHR rats increased significantly （P<0.001）, and the results of biochemical analysis and staining of pathological sections showed that the content of collagen fibers in the aorta in the SHR group was higher than that in the WKY group, while the content of elastic fibers was lower, but the difference did not have statistical significance. The content of collagen fibers in the heart of the SHR group was significantly higher than that in the WKY group （P<0.01）. Western blotting showed that there was no significant difference in the expression level of sFRP2 protein in heart tissues between the two groups. Conclusion The remodeling of cardiac and aortic tissues in a rat model of spontaneous hypertension may involve complex molecular mechanisms, not just changes in the content of collagen fibers and elastic fibers. The detailed mechanism of the progression of spontaneous hypertension and target organs damage still need further investigation.

Objective To explore the protective effect and possible mechanism of modified Shenqi Dihuang Decoction on podocytes in db/db mice based on ROS/NLRP3/GSDMD signaling pathway.Methods Fifty 8-week-old male db/db mice(SPF grade)were randomly divided into the model group,losartan group and TCM low-,medium-and high-dosage groups,with 10 mice in each group.Ten heterozygous db/m mice served as the blank group.Interventions were administered respectively for 12 weeks.The body mass,random blood glucose,serum creatinine,blood urea nitrogen and 24 h urinary protein content were detected,HE,PAS,PASM,Masson and Sirius red staining was used to observe the morphology of renal tissue,transmission electron microscopy was used to observe the ultrastructure of renal tissue,fluorescent probes were used to observe the release of ROS in renal tissue,immunofluorescence staining was used to detect the expression of Nephrin,NLRP3,Cleaved Caspase-1 and GSDMD-N in renal tissue,and Western blot was used to detect the expression of NLRP3,Cleaved Caspase-1,GSDMD-N,IL-1β,IL-18,Nephrin,Podocin,PODXL,WT-1 and Desmin proteins.Results Compared with the blank group,the body mass and random blood glucose of the model group mice significantly increased(P<0.05),and the contents of serum creatinine,blood urea nitrogen and 24 h urinary protein were significantly increased(P<0.05);glomerular hypertrophy,dilation of renal glomeruli and tubules,thickening of basement membrane,matrix proliferation in mesangial area,abnormal deposition of collagen fibers in renal interstitium,accompanied by damage to renal tubular epithelial structure and focal glomerulosclerosis,significant increase in type Ⅰ collagen deposition,extensive fusion of podocyte processes,and scattered electron dense material in the basement membrane or subepithelial layer;the ROS content in renal tissue significantly increased(P<0.05),and the protein expression of NLRP3,Cleaved Caspase-1,GSDMD-N,IL-1β,IL-18 and Desmin significantly increased(P<0.05),the protein expression of Nephrin,Podocin,PODXL and WT1 significantly decreased(P<0.05).Compared with the model group,the body mass and random blood glucose of mice in each dosage of TCM group were relatively stable,the contents of serum creatinine,blood urea nitrogen and 24 h urinary protein decreased;the pathological damage to renal tissue was reduced,the ultrastructure of podocytes was improved,and the density of podocytes increased;the ROS content decreased,and the protein expression of NLRP3,Cleaved Caspase-1,GSDMD-N,IL-1β,IL-18 and Desmin decreased,while the protein expression of Nephrin,Podocin,WT1 and PODXL increased.With the dosage of modified Shenqi Dihuang Decoction increased,the improvement effect gradually strengthened,and the differences in TCM high-dose group was statistically significant(P<0.05).Conclusion Modified Shenqi Dihuang Decoction can protects podocytes in db/db mice,potentially by modulating the ROS/NLRP3/GSDMD signaling pathway.

Objective:To establish 30-day of age transcutaneous bilirubin (TcB) reference curves for healthy neonates, and to investigate regional variations in bilirubin dynamics.Methods:A multicenter retrospective cohort study was conducted. A total of 220 950 healthy neonates born at a gestational age of 35-<42 weeks, with a birth weight ≥2 000 g, who did not receive phototherapy within 60 h after birth were recruited. All of them underwent remote TcB monitoring using the Bilibaby remote jaundice monitoring system between August 1 st, 2020 and December 31 st, 2024 in 426 hospitals. TcB data were collected within the period from birth to 30-day of age. The P40, P75, and P95 of TcB values were calculated, and dynamic TcB curves for 30-day of age were constructed. Patterns of bilirubin change, rates of change, and transition outcomes were described. Regional comparisons between South and North were conducted using linear mixed-effects models for TcB trajectories and Pearson′s chi-square test for outcome differences. Results:A total of 220 950 neonates were included, of whom 101 711 (46.03%) were female. Gestational age at birth was (38.75±1.12) weeks, and birth weight was (3 272±417) g. TcB levels increased rapidly within 3-day of age, peaked at 4-6-day of age, with peak values at P40, P75, and P95 of 200.6, 239.7 and 275.4 μmol/L (11.8, 14.1 and 16.2 mg/dl), respectively. TcB levels gradually declined thereafter and stabilized after 13-day of age, with values at P40, P75, and P95 fluctuating between 147.9-159.8, 190.4-200.6, and 231.2-239.7 μmol/L (8.7-9.4, 11.2-11.8, 13.6-14.1 mg/dl), respectively. Notably, among neonates categorized as low-or low-intermediate-risk within 3-day of age, 6 700 (12.76%) progressed to intermediate-high or high risk between 4 and 30 days of age. Before 13-day of age, TcB levels in the southern regions were consistently higher than those in the northern regions ( P=0.039); from 14 to 30 days of age, the overall TcB levels had no statistically difference, but the temporal changes in TcB still showed regional differences (degrees of freedom=3, all interaction P<0.05). Among neonates classified as low-or low-intermediate risk within 3-day of age, 25 326 were from southern regions, of whom 4 254 (16.80%) progressed to intermediate-high or high risk between 4 and 30 days of age. In northern regions, 27 193 neonates were classified as low-or low-intermediate risk within 3-day of age, among whom 2 446 (8.99%) progressed to intermediate-high or high risk. The risk progression between the 2 regions had statistically difference ( χ2=716.49, P<0.001). Conclusions:A TcB percentile curve for neonates within 30-day of age was established, revealing that both the overall TcB level and its temporal trend were higher in southern than in northern newborns. These findings provide baseline data to support continuous management of neonatal jaundice.

Microalgae possess high photosynthetic efficiency, robust adaptability, and substantial biomass, serving as excellent biological resources for large-scale cultivation. Malic enzyme (ME), a ubiquitous metabolic enzyme in living organisms, catalyzes the decarboxylation of malate to produce pyruvate, CO₂, and NAD(P)H, playing a role in multiple metabolic pathways including energy metabolism, photosynthesis, respiration, and biosynthesis. In this study, we identified the Scenedesmus quadricauda malic enzyme gene (SqME) and its biological functions, aiming to provide excellent target genes for the genetic improvement of higher plants. Based on the RNA-seq data from S. quadricauda under the biofilm cultivation mode with high CO₂ and light energy transfer efficiency and small water use, a highly expressed gene (SqME) functionally annotated as ME was cloned. The physicochemical properties of the SqME-encoded protein were systematically analyzed by bioinformatics tools. The subcellular localization of SqME was determined via transient transformation in Nicotiana benthamiana leaves. The biological functions of SqME were identified via genetic transformation in Nicotiana tabacum, and the potential of SqME in the genetic improvement of higher plants was evaluated. The ORF of SqME was 1 770 bp, encoding 590 amino acid residues, and the encoded protein was located in chloroplasts. SqME was a NADP-ME, with the typical structural characteristics of ME. The ME activity in the transgenic N. tabacum plant was 1.8 folds of that in the wild-type control. Heterologous expression of SqME increased the content of chlorophyll a, chlorophyll b, and total chlorophyll by 20.9%, 26.9%, and 25.2%, respectively, compared with the control. The transgenic tobacco leaves showed an increase of 54.0% in the fluorescence parameter NPQ and a decrease of 30.1% in Fo compared with the control. Moreover, the biomass, total lipids, and soluble sugars in the transgenic tobacco leaves enhanced by 20.5%, 25.7%, and 9.5%, respectively. On the contrary, the starch and protein content in the transgenic tobacco leaves decreased by 22.4% and 12.2%, respectively. Collectively, the SqME-encoded protein exhibited a strong enzymatic activity. Heterologous expressing of SqME could significantly enhance photosynthetic protection, photosynthesis, and biomass accumulation in the host. Additionally, SqME can facilitate carbon metabolism remodeling in the host, driving more carbon flux towards lipid synthesis. Therefore, SqME can be applied in the genetic improvement of higher plants for enhancing photosynthetic carbon fixation and lipid accumulation. These findings provide scientific references for mining of functional genes from S. quadricauda and application of these genes in the genetic engineering of higher plants.
Nicotiana/genetics* ; Photosynthesis/physiology* ; Malate Dehydrogenase/biosynthesis* ; Plant Leaves/genetics* ; Scenedesmus/enzymology* ; Carbon Cycle/genetics* ; Lipid Metabolism/genetics* ; Plants, Genetically Modified/metabolism*

Objective To analyze the diagnostic process and clinical characteristics of autoimmune gastritis(AIG)in order to improve the awareness and diagnostic proficiency of this disease.Methods A retrospective cohort study was conducted on 114 patients diagnosed with AIG in Army Medical Center of PLA between January 2021 and June 2024.Comprehensive statistical analysis was performed on clinical data,including demographic characteristics(age,sex),clinical symptoms,comorbidities,diagnostic process,Helicobacter pylori(H.pylori)infection and treatment history,laboratory indicators[results of routine blood test,anemia-related indices,thyroid function,anti-parietal cell antibody(APCA),intrinsic factor antibody(IFA)],and gastrointestinal endoscopic findings(frequency and endoscopic features).Results Among the 114 patients,males accounted for 28.1%(32/114)and females for 71.9%(82/114),and they were at a mean age of 56.3±8.4 years.Predominant symptoms included epigastric/upper abdominal pain(47.4%,54/114)and postprandial fullness(43.0%,49/114),while 24.6%(28/114)reported acid reflux or heartburn.Diagnostic delay occurred in 76.4%(87/114)of patients,with a median delay duration of 11.5 months.Primary diagnostic clues were endoscopic reverse gradient atrophy(significantly more severe mucosal atrophy in the gastric corpus/fundus versus antrum;53.5%,61/114)and repeated H.pylori eradication failure(≥2 attempts;22.8%,26/114).Positivity rate of thyroid peroxidase antibody(TPOAb)and thyroglobulin antibody(TgAb)was 56.9%(33/58)and 36.2%(21/58),respectively.APCA positive rate was 98.8%(81/82),IFA positive rate was 34.1%(28/82),and dual-antibody rate was 32.9%(27/82).Anemia was present in 25.7%(26/101)of the patients.Gastric neuroendocrine tumors(NET)were found in 12.2%(14/114),intraepithelial neoplasia in 5.3%(6/114),and gastric adenocarcinoma in 0.9%(1/114).Among colonoscopy-examined patients,tubular adenomas occurred in 25.0%(13/52)and colorectal malignancies in 3.4%(2/58).There were 18.4%(21/114)patients having gallbladder-related diseases,7.9%(9/114)having diabetes mellitus,and 1.8%(2/114)of subacute combined degeneration of the spinal cord.Conclusion AIG is frequently associated with diagnostic delay.The reverse pattern of atrophy on endoscopy serves as a critical diagnostic clue,necessitating enhanced recognition in endoscopists.Patients with recurrent H.pylori eradication failure(≥2 attempts)should be evaluated for AIG.

Objective To analyze the correlation between small patticle of lecithin,inflammatory factors,and immunoglobulins in prostatic fluid and chronic prostatitis(CP).Methods A total of 102 CP patients who were admitted to Beijing Puren Hospital from January 2022 to December 2023 were enrolled into CP group.According to the pathological classification of the National Institutes of Health in the United States,the patients were classified into type Ⅱ group(32 cases),type ⅢA group(39 cases),and type ⅢB group(31 cases).According to the severity of the disease,the patients were classified into mild group(33 cases),moderate group(43 cases),and severe group(26 cases).Meanwhile,34 healthy males who underwent physical examination were selected as controls.The levels of small patticle of lecithin(SPL),inflammatory factors,and immunoglobulins in prostate fluid were compared among groups.The relationship of these parameters with the pathological classification and severity of CP were analyzed.Results CP group had lower level of SPL and higher levels of tumor necrosis factor(TNF)-α,interleukin(IL)-6,IL-8,immunoglobulin(Ig)A,IgG,and IgM than control group(P<0.05).There was no significant difference in the SPL,IgA,IgG,or IgM among CP patients with different pathological types(P>0.05),but there were significant differences in the TNF-α,IL-6,and IL-8 levels(type Ⅱ group>type ⅢA group>type ⅢB group,P<0.05).There were significant differences in the SPL in CP patients with different severity levels(mild group>moderate group>severe group,P<0.05).So were the TNF-α,IL-6,IL-8,IgA,IgG,and IgM(severe group>moderate group>mild group,P<0.05).Spearman correlation analysis showed that SPL in the prostatic fluid was negatively correlated with the severity of CP(P<0.05);TNF-α,IL-6,and IL-8 were positively correlated with pathological classification and severity of CP(P<0.05);IgA,IgG,and IgM were positively correlated with the severity of CP(P<0.05).Conclusion SPL,TNF-α,IL-6,IL-8,IgA,IgG and IgM in prostatic fluid are closely related to the severity of CP.TNF-α,IL-6,and IL-8 in prostatic fluid are closely related to the pathological classification of CP.

Under the"Four Specials"conditions(special environments,special tasks,special equipment,and special personnel),complex tightly-coupled human-machine systems exhibit distinct characteristics such as human-in-the-loop,frequent human-machine interactions,and significant mutual influence between humans and machines.These features lead to prominent and typical human related safety issues.Through aggregating knowledge from literature review,accident case studies,and engineering practice,this paper elaborates on the characteristics of complex tightly-coupled human-machine systems,clarifies the definition of human related safety(including its research subjects,topics,and methods),and provides a systematic analysis framework on the causes of human related safety from a whole life-cycle perspective of system development.Furthermore,theoretical hypotheses are proposed for human related safety,along with its fundamental scientific research questions and methods.