In this paper, the technical basis and latest progress of X-ray tube for CT systems are introduced, with emphasis on material innovation, superconducting technology, liquid metal bearing, low dose scanning and electron beam filtration. As the core component of CT equipment, the technological innovation of CT X-ray tubes significantly improves image quality, reduces radiation dose, improves efficiency, and extends the service life of the X-ray tubes. Domestic and foreign manufacturers have made remarkable progress in the field of CT X-ray tubes. Domestic manufacturers, such as the 12th Institute of CLP, have made important progress in the development of CT X-ray tubes, and successfully achieved independent research and development of high-end CT X-ray tubes. Foreign manufacturers such as Siemens, GE, Philips and other manufacturers continue to innovate in liquid metal bearings, superconducting technology, new targets and other aspects to maintain technology leadership. In the future, CT X-ray tubes will develop in the direction of personalization, intelligence, long life, miniaturization and portability, providing more accurate and low-risk technical support for medical image diagnosis.
Tomography, X-Ray Computed/instrumentation* ; Equipment Design

Liver fibrosis is a chronic liver injury resulting from factors like viral hepatitis, autoimmune hepatitis, non-alcoholic steatohepatitis, fatty liver disease, and cholestatic liver disease. Liver transplantation is currently the gold standard for treating severe liver diseases. However, it is limited by a shortage of donor organs and the necessity for lifelong immunosuppressive therapy. Mesenchymal stem cells (MSCs) can differentiate into various liver cells and enhance liver function when transplanted into patients due to their differentiation and proliferation capabilities. Therefore, it can be used as an alternative therapy for treating liver diseases, especially for liver cirrhosis, liver failure, and liver transplant complications. However, due to the potential tumorigenic effects of MSCs, researchers are exploring a new approach to treating liver fibrosis using extracellular vesicles (exosomes) secreted by stem cells. Many studies show that exosomes released by stem cells can promote liver injury repair through various pathways, contributing to the treatment of liver fibrosis. In this review, we focus on the molecular mechanisms by which stem cell exosomes affect liver fibrosis through different pathways and their potential therapeutic targets. Additionally, we discuss the advantages of exosome therapy over stem cell therapy and the possible future directions of exosome research, including the prospects for clinical applications and the challenges to be overcome.

Liver fibrosis is a chronic liver injury resulting from factors like viral hepatitis, autoimmune hepatitis, non-alcoholic steatohepatitis, fatty liver disease, and cholestatic liver disease. Liver transplantation is currently the gold standard for treating severe liver diseases. However, it is limited by a shortage of donor organs and the necessity for lifelong immunosuppressive therapy. Mesenchymal stem cells (MSCs) can differentiate into various liver cells and enhance liver function when transplanted into patients due to their differentiation and proliferation capabilities. Therefore, it can be used as an alternative therapy for treating liver diseases, especially for liver cirrhosis, liver failure, and liver transplant complications. However, due to the potential tumorigenic effects of MSCs, researchers are exploring a new approach to treating liver fibrosis using extracellular vesicles (exosomes) secreted by stem cells. Many studies show that exosomes released by stem cells can promote liver injury repair through various pathways, contributing to the treatment of liver fibrosis. In this review, we focus on the molecular mechanisms by which stem cell exosomes affect liver fibrosis through different pathways and their potential therapeutic targets. Additionally, we discuss the advantages of exosome therapy over stem cell therapy and the possible future directions of exosome research, including the prospects for clinical applications and the challenges to be overcome.

Liver fibrosis is a chronic liver injury resulting from factors like viral hepatitis, autoimmune hepatitis, non-alcoholic steatohepatitis, fatty liver disease, and cholestatic liver disease. Liver transplantation is currently the gold standard for treating severe liver diseases. However, it is limited by a shortage of donor organs and the necessity for lifelong immunosuppressive therapy. Mesenchymal stem cells (MSCs) can differentiate into various liver cells and enhance liver function when transplanted into patients due to their differentiation and proliferation capabilities. Therefore, it can be used as an alternative therapy for treating liver diseases, especially for liver cirrhosis, liver failure, and liver transplant complications. However, due to the potential tumorigenic effects of MSCs, researchers are exploring a new approach to treating liver fibrosis using extracellular vesicles (exosomes) secreted by stem cells. Many studies show that exosomes released by stem cells can promote liver injury repair through various pathways, contributing to the treatment of liver fibrosis. In this review, we focus on the molecular mechanisms by which stem cell exosomes affect liver fibrosis through different pathways and their potential therapeutic targets. Additionally, we discuss the advantages of exosome therapy over stem cell therapy and the possible future directions of exosome research, including the prospects for clinical applications and the challenges to be overcome.

ObjectiveTo investigate the effects of the combination of components from Tripterygii Radix et Rhizoma and Chuanxiong Rhizoma on rheumatoid arthritis fibroblast-like synoviocytes （RA-FLSs） and the underlying mechanism. MethodsRA-FLSs were grouped as follows： blank control， positive control （methotrexate）， Tripterygii Radix et Rhizoma components， Chuanxiong Rhizoma components， and components from Tripterygii Radix et Rhizoma+Chuanxiong Rhizoma. The cell-counting kit-8 （CCK-8） assay was employed to the cell proliferation， invasion， and apoptosis. The levels of tumor necrosis factor （TNF）-α， interleukin （IL）-6， reactive oxygen species （ROS）， and malondiadehyde （MDA） in cells were measured. Western blot was employed to determine the protein levels of nuclear factor erythroid 2-related factor 2 （Nrf2）， heme oxygenase-1 （HO-1）， nuclear factor-kappa B （NF-κB） p65， phosphorylated inhibitory subunit of NF-κBα （p-IκBα）， cysteinyl aspartate-specific protease-3 （Caspase-3）， and B-cell lymphoma 2 （Bcl-2）. Real-time PCR was employed to determine the mRNA levels of Nrf2， HO-1， and NF-κB p65. ResultsThe cells in the groups of positive control， Tripterygii Radix et Rhizoma components， Chuanxiong Rhizoma components， and components from Tripterygii Radix et Rhizoma+Chuanxiong Rhizoma were treated with 2.50 mg·L^-1 methotrexate， 0.20 mg·L^-1 triptolide + 0.20 mg·L^-1 celastrol， 5.00 mg·L^-1 ferulic acid + 20.00 mg·L^-1 ligustrazine， 0.20 mg·L^-1 triptolide + 0.20 mg·L^-1 celastrol + 5.00 mg·L^-1 ferulic acid + 20.00 mg·L^-1 ligustrazine， respectively. Compared with the blank control group， drug administration reduced the proliferation and invasion and increased the apoptosis of cells （P<0.01）， lowered the levels of TNF-α， IL-6， ROS， and MDA （P<0.01）， up-regulated the mRNA and protein levels of Caspase-3， Nrf2， and HO-1 （P<0.01）， and down-regulated the mRNA and protein levels of Bcl-2， NF-κB p65， and p-IκBα （P<0.01）. Compared with the Tripterygii Radix et Rhizoma components group， the combination of components from Tripterygii Radix et Rhizoma+Chuanxiong Rhizoma inhibited the proliferation and invasion （P<0.05） and promoted the apoptosis of RA-FLSs， up-regulated the mRNA levels of Nrf2 and HO-1 and protein levels of Nrf2 and Caspase-3 （P<0.05）， and down-regulated the protein levels of NF-κB p65 and p-IκBα （P<0.05）. ConclusionThe combination of components from Chuanxiong Rhizoma and Tripterygii Radix et Rhizoma can inhibit the proliferation and invasion and promote the apoptosis of RA-FLSs and alleviate oxidative stress and inflammation by inhibiting the NF-κB signaling pathway， activating the Nrf2/HO-1 pathway， and regulating the expression of Bcl-2/Caspase-3.

Objective To investigate the changing antibiotic resistance profiles of E.coli isolated from patients in the 52 hospitals participating in the CHINET program from 2015 to 2021.Methods Antimicrobial susceptibility was tested for clinical isolates of E.coli according to the unified protocol of CHINET program.WHONET 5.6 and SPSS 20.0 software were used for data analysis.Results Atotal of 289 760 nonduplicate clinical strains ofE.coli were isolated from 2015 to 2021,mainly from urine samples(44.7±3.2)％.The proportion of E.coli strains isolated from urine samples was higher in females than in males(59.0％vs 29.5％).The proportion of E.coli strains isolated from respiratory tract and cerebrospinal fluid samples was significantly higher in children than in adults(16.7％vs 7.8％,0.8％vs 0.1％,both P＜0.05).The isolates from internal medicine department accounted for the largest proportion(28.9±2.8)％with an increasing trend over years.Overall,the prevalence of ESBLs-producing E.coli and carbapenem resistant E.coli(CREco)was 55.9％and 1.8％,respectively during the 7-year period.The prevalence of ESBLs-producing E.coli was the highest in tertiary hospitals each year from 2015 to 2021 compared to secondary hospitals.The prevalence of CREco was higher in children's hospitals compared to secondary and tertiary hospitals each year from 2015 to 2021.The prevalence of ESBLs-producing E.coli in tertiary hospitals and children's hospitals and the prevalence of CREco in children's hospitals showed a decreasing trend over the 7-year period.The prevalence of CREco in secondary and tertiary hospitals increased slowly.Antibiotic resistance rates changed slowly from 2015 to 2021.Carbapenem drugs(imipenem,meropenem)were the most active drugs amongβ-lactams against E.coli(resistance rate≤2.1％).The resistance rates of E.coli to β-lactam/β-lactam inhibitor combinations(piperacillin-tazobactam,cefoperazone-sulbactam),aminoglycosides(amikacin),nitrofurantoin and fosfomycin(for urinary isolates only)were all less than 10％.The resistance rate of E.coli strains to antibiotics varied with the level of hospitals and the departments where the strains were isolated,especially for cefazolin and ciprofloxacin,to which the resistance rate of E.coli strains from children in non-ICU departments was significantly lower than that of the strains isolated from other departments(P＜0.05).The E.coli isolates from ICU showed higher resistance rate to most antimicrobial agents tested(excluding tigecycline)than the strains isolated from other departments.The E.coli strains isolated from tertiary hospitals showed higher resistance rates to the antimicrobial agents tested(excluding tigecycline,polymyxin B,cefepime and carbapenems)than the strains from secondary hospitals and children's hospitals.Conclusions E.coli is an important pathogen causing clinical infection.More than half of the clinical isolates produced ESBL.The prevalence of CREco is increasing in secondary and tertiary hospitals over the 7-year period even though the overall prevalence is still low.This is an issue of concern.

The receptor-binding region(RBD)of the spike protein(S)on the surface of porcine epi-demic diarrhea virus(PEDV)is a critical structural domain mediating viral invasion of host cells and serves as a key target for inducing neutralizing antibodies.In order to prepare antibodies that can be used to study the biological function of PEDV RBD and develop novel diagnostic and thera-peutic methods,recombinant RBD protein expressed in Sf9 insect cells was utilized as an immuno-gen to immunize BALB/c mice.Monoclonal antibodies(mAbs)were generated via hybridoma tech-nology,and positive hybridoma clones were screened using indirect ELISA.The reactivity of the mAbs was subsequently characterized.The results of ELISA,Western blot,and indirect immuno-fluorescence assay(IFA)showed that three monoclonal antibodies screened(3E5,4F9 and 5A5)had good reactivity with the virus and RBD protein.Antibody subtype results showed that 3E5 and 4F9 were of IgG1 subtypes and 5A5 was of IgM subtype.Neutralization assay further revealed that 3E5 monoclonal antibody had viral neutralizing activity.In this study,three monoclonal antibodies against PEDV RBD proteins were successfully prepared,providing the basis for the study of the bi-ological function of RBD proteins,PEDV serologic detection and vaccine development.

Objective To investigate the applicability of D-dimer levels combined with the Tei index in assessing the volume load in patients with acute decompensated heart failure(ADHF).Methods Two hundred patients admitted to the Emergency Department of Taizhou TCM Hospital between 2022 and 2023 were selected as the subjects,who were divided into a low volume load group(n=121)and a high volume load group(n=79)based on plasma volume indices.The clinical indicators and parameters of cardiac function of these subjects were compared.Multivariate Logistic regression analysis was used for identification of potential risk factors for elevated volume loads.A model for prediction of elevated volume loads was developed via Chi-square automatic interaction detection,followed by internal validation via Bootstrapping.Logistic regression analysis was used to study the interactions between D-dimer levels and Tei indices in assessing the volume loads of patients with ADHF.Results Multivariate regression analysis showed that age,Tei index,D-dimer levels and B type natriuretic peptide(BNP)were risk factors for high volume loads in ADHF patients.The decision tree model established had 14 nodes and 8 terminal nodes.Four explanatory variables including age,Tei index,D-dimer levels and BNP were screened out.The area under curve(AUC),sensitivity,specificity and prediction accuracy of the classification tree model were higher than those of the regression model.When D-dimer levels ≥1.16 and Tei index ≥0.65 interacted and co-existed,ADHF patients were at higher risk of developing high volume loads(OR=6.526,95％CI:2.439-7.183).The results of restricted cubic spline analysis pointed to nonlinear dose response relationships in the correlation strength of D-dimer levels,Tei index and volume loads.Conclusion There are interactions between D-dimer levels and Tei index,and the risk of high volume loads in ADHF patients is significantly increased when D-dimer levels are 1.16 or above and Tei index is 0.65 or above.