Objective This study aimed to investigate whether photodynamic therapy(PDT)with methylene blue(MB)as a photosensitizer can induce ferroptosis in melanoma cells and its potential mechanisms.Methods The paraffin sections of malignant melanoma patients(5 cases)and malignant melanoma patients with lymph node metastasis(5 cases)were collected.Prussian blue,TUNEL and immunohistochemical staining were performed to compare the degree of ferroptosis between the two groups.CCK-8 assay and scratch assay were used to detect the cytotoxic effect of methylene blue and methylene-blue-mediated photodynamic therapy on B16F10 under different treatment conditions and the effect of cell migration ability.The expression of ferroptosis-related proteins(glutathione peroxidase 4,GPX4、solute carrier family 7 member 11,SLC7A11)in B16F10 cells was detected by Western blot.The expression levels of intracellular malondialdehyde(MDA)and GSH/GSSG were detected by microplate reader.The expression levels of reactive oxygen species(ROS),Fe2+and lipid peroxide(LPO)in B16F10 cells were detected by flow cytometry.Results Compared with melanoma cells transferred to lymph nodes,the non-metastatic group had a higher degree of ferroptosis and a lower expression level of SLC7A11.The cytotoxicity of MB and MB-PDT on B16F10 was dose-dependent(P＜0.000 1).The results of scratch assay showed that MB-PDT inhibited the migration ability of B16F10 cells(P＜0.001).Compared with the control group,after MB-PDT treatment,the expression levels of GPX4,SLC7A11 and GSH/GSSG were decreased(P＜0.05),and the expression levels of ROS,Fe2+,LPO and MDA were increased(P＜0.05)in B16F10 cells.Pretreatment with Ferrostatin-1,an inhibitor of ferroptosis,inhibited MB-PDT-induced cytotoxicity and ferroptosis in B16F10 cells(P＜0.05).Conclusion MB-PDT can induce ferroptosis of melanoma cells by inhibiting SLC7A11 expression,thereby inhibiting the progression of melanoma.

Objective This study aimed to investigate whether photodynamic therapy(PDT)with methylene blue(MB)as a photosensitizer can induce ferroptosis in melanoma cells and its potential mechanisms.Methods The paraffin sections of malignant melanoma patients(5 cases)and malignant melanoma patients with lymph node metastasis(5 cases)were collected.Prussian blue,TUNEL and immunohistochemical staining were performed to compare the degree of ferroptosis between the two groups.CCK-8 assay and scratch assay were used to detect the cytotoxic effect of methylene blue and methylene-blue-mediated photodynamic therapy on B16F10 under different treatment conditions and the effect of cell migration ability.The expression of ferroptosis-related proteins(glutathione peroxidase 4,GPX4、solute carrier family 7 member 11,SLC7A11)in B16F10 cells was detected by Western blot.The expression levels of intracellular malondialdehyde(MDA)and GSH/GSSG were detected by microplate reader.The expression levels of reactive oxygen species(ROS),Fe2+and lipid peroxide(LPO)in B16F10 cells were detected by flow cytometry.Results Compared with melanoma cells transferred to lymph nodes,the non-metastatic group had a higher degree of ferroptosis and a lower expression level of SLC7A11.The cytotoxicity of MB and MB-PDT on B16F10 was dose-dependent(P＜0.000 1).The results of scratch assay showed that MB-PDT inhibited the migration ability of B16F10 cells(P＜0.001).Compared with the control group,after MB-PDT treatment,the expression levels of GPX4,SLC7A11 and GSH/GSSG were decreased(P＜0.05),and the expression levels of ROS,Fe2+,LPO and MDA were increased(P＜0.05)in B16F10 cells.Pretreatment with Ferrostatin-1,an inhibitor of ferroptosis,inhibited MB-PDT-induced cytotoxicity and ferroptosis in B16F10 cells(P＜0.05).Conclusion MB-PDT can induce ferroptosis of melanoma cells by inhibiting SLC7A11 expression,thereby inhibiting the progression of melanoma.

Sepsis is a syndrome of systemic inflammatory response in which the body′s response to infection is dysregulated, and is characterized by persistent infection, excessive inflammation and immunosuppression, etc. It often leads to organ dysfunction and can be life threatening, and also a common complication after trauma. The pathogenesis of post-traumatic sepsis is still unclear at present due to the complexity of its etiology, progression and prognosis. Multi-omics technology is a method to combine two or more single omics for comprehensive analysis, which can reveal the interaction network among the disease-associated molecules from multiple perspectives and aspects and is of great significance for the analysis of the pathogenesis of post-traumatic sepsis. To this end, the authors reviewed the research progress on the role of multi-omics technology in elucidating the pathogenesis of post-traumatic sepsis from the perspectives of genomics, transcriptomics, proteomics, metabolomics, single-cell transcriptomics and combination of multi-omics technologies, etc so as to provide a reference for the researches on post-traumatic sepsis.

Breast cancer remains a leading cause of mortality in women worldwide.Triple-negative breast cancer(TNBC)is a particularly aggressive subtype characterized by rapid progression,poor prognosis,and lack of clear therapeutic targets.In the clinic,delineation of tumor heterogeneity and development of effective drugs continue to pose considerable challenges.Within the scope of our study,high hetero-geneity inherent to breast cancer was uncovered based on the landscape constructed from both tumor and healthy breast tissue samples.Notably,TNBC exhibited significant specificity regarding cell prolif-eration,differentiation,and disease progression.Significant associations between tumor grade,prog-nosis,and TNBC oncogenes were established via pseudotime trajectory analysis.Consequently,we further performed comprehensive characterization of the TNBC microenvironment.A crucial epithelial subcluster,E8,was identified as highly malignant and strongly associated with tumor cell proliferation in TNBC.Additionally,epithelial-mesenchymal transition(EMT)-associated fibroblast and M2 macrophage subclusters exerted an influence on E8 through cellular interactions,contributing to tumor growth.Characteristic genes in these three cluster cells could therefore serve as potential therapeutic targets for TNBC.The collective findings provided valuable insights that assisted in the screening of a series of therapeutic drugs,such as pelitinib.We further confirmed the anti-cancer effect of pelitinib in an orthotopic 4T1 tumor-bearing mouse model.Overall,our study sheds light on the unique characteristics of TNBC at single-cell resolution and the crucial cell types associated with tumor cell proliferation that may serve as potent tools in the development of effective anti-cancer drugs.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

BACKGROUND:Scaffold materials serve as platforms that provide space and structure,playing a crucial role in the regeneration of cartilage tissue.Scholars from around the world are exploring different approaches to fabricate more ideal scaffold materials. OBJECTIVE:To review the design principles and preparation methods of cartilage scaffolds,and to further explore the advantages and limitations of various preparation methods. METHODS:Literature searches were conducted on the databases of CNKI,WanFang Data,PubMed,and FMRS from 1998 to 2023.The search terms were"cartilage repair,cartilage tissue engineering,cartilage scaffold materials,preparation"in Chinese and English.A total of 57 articles were ultimately reviewed. RESULTS AND CONCLUSION:(1)The articular cartilage has a unique structure and limited self-repair capacity after injury.Even if self-repair occurs,the newly formed cartilage is typically fibrocartilage,which is far inferior to normal articular cartilage in terms of structure and mechanical properties.It is difficult to maintain normal function and often leads to degenerative changes.Currently,the design and fabrication of scaffold materials for cartilage repair need to consider the following aspects:biocompatibility and biodegradability,suitable pore structure and porosity,appropriate mechanical properties,and bioactivity.(2)Research on the preparation of cartilage scaffolds has made significant progress,continuously introducing new preparation methods and optimization strategies.These methods have their advantages and disadvantages,providing more possibilities for customized preparation and functional design of cartilage scaffolds according to specific requirements.

BACKGROUND:Bone formation is the process by which osteoblasts synthesize and secrete osteoid and promote its mineralization,which generally involves mechanical signal transduction.Osteoblasts are primarily regulated by mechanical factors such as gravity,compressive stress,tensile stress,fluid shear stress,and hydrostatic pressure in vivo,and different mechanical stimuli modulate the proliferation,differentiation,and apoptosis of osteoblasts through various mechanisms,including hormones,cytoskeletal proteins,and microRNAs.By clarifying the effects of biomechanical forces on osteoblasts,it provides ideas and a reference basis for the treatment of osteometabolic diseases involving osteoblasts. OBJECTIVE:To review the effects of different biomechanical forces on the biological characteristics of osteoblasts. METHODS:We conducted a literature search using PubMed,Web of Science,FMRS,CNKI,and WanFang databases for relevant publications published from 2000 to 2023,covering basic research and tissue engineering studies related to the effects of biomechanical forces on osteoblasts.Ultimately,a total of 70 articles were reviewed. RESULTS AND CONCLUSION:Different biomechanical forces have an impact on the biological characteristics of osteoblasts,including proliferation,differentiation,and apoptosis,and these effects are dependent on the intensity and duration of the applied force.Specifically,the effects are as follows:(1)Under microgravity conditions,osteoblast proliferation and differentiation are inhibited,resulting in a decrease in bone density and the development of osteoporosis.(2)Compared to microgravity,hypergravity has a promoting effect on osteoblast proliferation.(3)The effects of compressive stress on osteoblasts are dependent on the loading intensity and time.Appropriate compressive stress can promote osteoblast proliferation and differentiation,which is beneficial for bone tissue formation and repair,while excessive compressive stress can cause osteoblast apoptosis and bone tissue destruction.(4)The biological effects of different types of tensile stress on osteoblasts differ.Studies have shown that a strain rate within the range of 0-12%has a promoting effect on osteoblast proliferation.(5)Fluid shear stress can promote osteoblast proliferation and differentiation and enhance the bone-inducing effect of biomaterials.(6)Static hydrostatic pressure can affect the biological behavior of osteoblasts,including proliferation,differentiation,and apoptosis,and these effects are closely related to the time and intensity of the pressure.Understanding the effects of different biomechanical forces on osteoblasts is of great significance for a deeper understanding of bone growth and maintenance mechanisms.

convalescents, and to screen for broad-spectrum neutralizing antibodies against the SARS-CoV-2 RBD. Methods Using biotinylated RBD as a molecular probe, flow cytometry was employed to perform single-cell sorting of B cells from peripheral blood mononuclear cells (PBMCs) of convalescents. The obtained B cells were lysed and subjected to reverse transcription, followed by nested PCR amplification of the heavy and light chains of antibodies was conducted using random primers. The amplified products were cloned into corresponding expression vectors, and the respective matched heavy-light chain plasmids were co-transfected into 293F cells for expression. Monoclonal antibodies were then purified using Protein A column chromatography. Neutralization experiments were conducted with the wild-type (WT) pseudovirus, and antibodies with IC50<0.1 μg/mL were selected for further testing of neutralizing breadth and potency against the wild-type (WT), Beta variant (B.1.351), Delta variant (B.1.617.2), and currently prevalent pseudovirus strains (XBB, BA.5, BF.7). Results A total of 21 RBD-specific monoclonal B cells were obtained from two recovered patients, resulting in the isolation of 13 pairs of antibody light/heavy chains. Nine antibodies were successfully expressed, with P1-A1, P1-B6, and P1-B9 exhibiting IC50 values below 0.1 μg/mL against the pseudovirus of the wild-type strain (WT). Specifically, P1-B6 effectively neutralized the wild-type strain (WT), Beta variant (B.1.351), and Delta variant (B.1.617.2), with IC50 values reaching 0.01 μg/mL. P1-B9 demonstrated effective neutralization against the wild-type strain (WT), Beta variant (B.1.351), Delta variant (B.1.617.2), and Gamma variant (P.1) pseudoviruses, with IC50 values of 0.42 μg/mL, 0.63 μg/mL, 0.28 μg/mL, and 2.50 μg/mL, respectively. Additionally, P1-B6 exhibited good neutralization against BA.5 and BF.7 pseudoviruses, with IC50 values of 0.06 μg/mL and 0.09 μg/mL, respectively. Conclusions Infection with the SARS-CoV-2 WT strain can induce the generation of neutralizing antibodies with broad-spectrum activity. Generating these broadly neutralizing antibodies does not require an excessively high somatic hypermutation. The obtained antibodies can be used as candidates for SARS-CoV-2 diagnosis and prevention.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.