ObjectivePhotoacoustic pump-probe imaging can effectively eliminate the interference of blood background signal in traditional photoacoustic imaging, and realize the imaging of weak phosphorescence molecules and their triplet lifetimes in deep tissues. However, background differential noise in photoacoustic pump-probe imaging often leads to large fitting results of phosphorescent molecule concentration and triplet lifetime. Therefore, this paper proposes a novel triplet lifetime fitting method for photoacoustic pump-probe imaging. By extracting the phase of the triplet differential signal and the background noise, the fitting bias caused by the background noise can be effectively corrected. MethodsThe advantages and feasibility of the proposed algorithm are verified by numerical simulation, phantom and in vivo experiments, respectively. ResultsIn the numerical simulation, under the condition of noise intensity being 10% of the signal amplitude, the new method can optimize the fitting deviation from 48.5% to about 5%, and has a higher exclusion coefficient (0.88>0.79), which greatly improves the fitting accuracy. The high specificity imaging ability of photoacoustic pump imaging for phosphorescent molecules has been demonstrated by phantom experiments. In vivo experiments have verified the feasibility of the new fitting method proposed in this paper for fitting phosphoometric lifetime to monitor oxygen partial pressure content during photodynamic therapy of tumors in nude mice. ConclusionThis work will play an important role in promoting the application of photoacoustic pump-probe imaging in biomedicine.

Objective To investigate the role of poly(rC)-binding protein 1(PCBP1)in cadmium(Cd)-induced ferroptosis in mouse neuroblastoma Neuro-2a(N2A)cells.Methods N2A cells were exposed to a concentration gradient of CdCl?(0,1,2,4 μmol/L)for 72 h.Cell viability was assessed by trypan blue staining.Western blotting was employed to detect the expression of ferroptosis-related proteins(GPX4,HMOX1,ACSL4)and PCBP1.Intracellular Fe2? level and lipid peroxidation were detected using FerroOrange and BODIPY581/591 C11 probes,respectively.Ferrostatin-1(Fer-1),a ferroptosis inhibitor,was applied to confirm the critical role of ferroptosis in Cd-induced cytotoxicity.Molecular docking was performed to elucidate the interaction between PCBP1 and ferritin,as well as the binding sites of Cd2?.PCBP1 overexpression plasmid was further constructed for functional validation.Results Cd exposure suppressed cell viability in N2A cells in a dose-dependent manner(P<0.01),significantly down-regulated GPX4 expression(P<0.05),up-regulated HMOX1 expression(P<0.01),and induced Fe2? overload and lipid peroxidation(P<0.01).Molecular docking revealed that Cd2? directly bound to the KH2 domain of PCBP1 and then co-localized on the outer surface of ferritin heavy chain.Overexpression of PCBP1 markedly reversed Cd-induced Fe2? accumulation,GPX4 down-regulation,lipid peroxidation,and cell death.Conclusion Cd exposure disrupts PCBP1-mediated iron homeostasis via transcriptional suppression and competitive displacement of metal ions,and then synergistically drives Fe2? overload-triggered ferroptosis cascades,ultimately leading to neurotoxicity.Targeting PCBP1-mediated iron homeostasis can effectively mitigate Cd-induced neurotoxicity,and may serve as a novel therapeutic strategy.

Breast cancer is one of the most common malignant tumors among women worldwide, with an increasing incidence rate year by year, making it a significant public health concern. With the continuous advancement of tumor biology research, N 6-methyladenosine (m 6A) modification, as an important form of RNA modification, has attracted growing attention. The m 6A modification, the most prevalent RNA modification in eukaryotes, occurs in almost all types of RNA and plays a critical role in the occurrence, progression, and metastasis of breast cancer. It influences cell proliferation, apoptosis, and alterations in the tumor microenvironment, though the specific mechanisms underlying these effects require further in-depth investigation. Moreover, the specific patterns of m 6A modification demonstrate its potential as a novel biomarker for breast cancer, which could provide new directions for early diagnosis and prognosis evaluation.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

N6-methyladenosine (m6A) modification, as a widespread and high-profile type of epigenetic modification, can dynamically and reversibly regulate the whole process of RNA metabolism. This modification governs RNA stability, splicing, and translation via m6A regulators, which are categorized as Writers, Erasers, and Readers. m6A modification also plays a critical role in the development of tumors. Disruptions in the homeostasis of m6A modification levels lead to dysregulation of m6A regulators. Consequently, these dysregulated regulators modulate the proliferation, migration, and invasion of tumor cells and interfere with the normal functions of suppressor genes and oncogenes. This article aims to comprehensively elucidate the specific regulatory impacts of m6A modification on tumor-related gene expression. It focuses on the regulatory mechanisms of m6A modification on mRNA stability. Additionally, it explores the influence of m6A on the molecular translation of key signaling pathways. Moreover, it investigates the indirect regulatory effects mediated by non-coding RNAs (ncRNAs), etc. The intention is to offer a novel analysis of the pathogenesis of cancer at a new level, and also provide a theoretical basis for finding new effective treatment methods.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective:To investigate the effects of melatonin(MT)on spinal cord ischemia reperfusion injury(SCIRI)and its possible mechanisms in rats.Methods:Forty-two 6-week-old male Sprague Dawley rats were selected for the study and randomly divided into three groups:① Sham group(Sham group,n=14);② model group(model/SCIRI group,n=14);and ③ treatment group(MT group,n=14).Neurological function analysis was used to assess the motor conditions of rats in each group.Nissl staining and hematoxylin eosin(HE)staining were used to observe the number and morphology of neurons in each group,and TUNEL staining was used to evaluate the occurrence of apoptosis of neurons in each group.The expression levels of NOD-like receptor thermal protein domain-associated protein 3(NLRP3),apoptosis-associated speck-like protein(ASC),gasdermin D(GSDMD),the N-terminal fragment of gasdermin D(GSDMD-N),and cysteine proteinase 1(caspase-1)were evaluated using immunofluorescence,immunohistochemistry staining,and Western blot analysis.Results:Compared with the sham operation group,the neurological function score of the model group was significantly decreased,while the neurological function score of the treatment group was higher than that of the model group(P＜0.05).The model group had fewer Nissl corpuscles compared with that in the sham operation group and abnormal neuronal morphology(P＜0.05).Compared with the model group,the treatment group had a rise in the number of Nissl corpuscles and restored neuronal morphology(P＜0.05).Compared with the Sham group,the number of apoptotic neurons increased in the model group,and the protein expression levels of NLRP3,ASC,GSDMD,and caspase-1 increased(P＜0.05).Compared with the model group,The number of apoptotic neurons and the protein expressions of NLRP3,ASC,GSDMD and caspase-1 in the treatment group were significantly decreased(P＜0.05).Conclusions:MT may alleviate spinal cord ischemia-reperfusion injury by inhibiting pyroptosis in neurons.

N6-methyladenosine (m6A) modification, as a widespread and high-profile type of epigenetic modification, can dynamically and reversibly regulate the whole process of RNA metabolism. This modification governs RNA stability, splicing, and translation via m6A regulators, which are categorized as Writers, Erasers, and Readers. m6A modification also plays a critical role in the development of tumors. Disruptions in the homeostasis of m6A modification levels lead to dysregulation of m6A regulators. Consequently, these dysregulated regulators modulate the proliferation, migration, and invasion of tumor cells and interfere with the normal functions of suppressor genes and oncogenes. This article aims to comprehensively elucidate the specific regulatory impacts of m6A modification on tumor-related gene expression. It focuses on the regulatory mechanisms of m6A modification on mRNA stability. Additionally, it explores the influence of m6A on the molecular translation of key signaling pathways. Moreover, it investigates the indirect regulatory effects mediated by non-coding RNAs (ncRNAs), etc. The intention is to offer a novel analysis of the pathogenesis of cancer at a new level, and also provide a theoretical basis for finding new effective treatment methods.

Purpose This study aims to investigate the clinicopathological features of diffuse pulmonary menin-gotheliomatosis(DPM).Methods The clinical data of 10 patients with DPM undergoing video-assisted thoracic sur-gery(VATS)were collected,and their clinical and pathological characteristics were analyzed using immunohistochem-istry.Results The detection rate of DPM was 1.19‰,with 90％of the patients being female.DPM predominantly occurred in the age range of 40-60 years,with an average age at diagnosis of 50.7 years.Most patients had no smok-ing history.Pathological diagnosis combined with imaging findings was the main method for diagnosing DPM.80％of the patients were prone to concurrent early-stage invasive pulmonary adenocarcinoma.Laboratory indicators,including pulmonary function,were generally normal.Chest CT showed diffuse multiple ground-glass opacity or cystic nodules in both lungs,with the number of nodules in both lungs ranging from dozens to hundreds,and the maximum diameter of the nodules was 2-6 mm.The median volume and CT value of the pulmonary nodules were 35.32 mm3 and-566 HU,respectively.Pathological features mainly included multiple meningothelial-like nodules observed under the micro-scope.Immunophenotypically,CD56,EMA,PR,and vimentin were often positive.Conclusion DPM is a rare lung disease with no obvious clinical symptoms,and is more common in middle-aged and elderly women.Diffuse multiple nodules in both lungs are its main imaging features.Most DPM patients are complicated with lung adenocarcinoma,and regular follow-up is recommended.