The pathogenesis of osteoarthritis (OA) is related to a variety of factors such as mechanical overload, metabolic dysfunction, aging, etc., and is a group of total joint diseases characterized by intra-articular chondrocyte apoptosis, cartilage fibrillations, synovial inflammation, and osteophyte formation. At present, the treatment methods for osteoarthritis include glucosamine, non-steroidal anti-inflammatory drugs, intra-articular injection of sodium hyaluronate, etc., which are difficult to take effect in a short period of time and require long-term treatment, so the patients struggle to adhere to doctor’s advice. Some methods can only provide temporary relief without chondrocyte protection, and some even increase the risk of cardiovascular disease and gastrointestinal disease. In the advanced stages of OA, patients often have to undergo joint replacement surgery due to pain and joint dysfunction. Mitochondrial dysfunction plays an important role in the development of OA. It is possible to improve mitochondrial biogenesis, quality control, autophagy balance, and oxidative stress levels, thereby exerting a protective effect on chondrocytes in OA. Therefore, compared to traditional treatments, improving mitochondrial function may be a potential treatment for OA. Here, we collected relevant literature on mitochondrial research in OA in recent years, summarized the potential pathogenic factors that affect the development of OA through mitochondrial pathways, and elaborated on relevant treatment methods, in order to provide new diagnostic and therapeutic ideas for the research field of osteoarthritis.

Bacterial biofilms gave rise to persistent infections and multi-organ failure, thereby posing a serious threat to human health. Biofilms were formed by cross-linking of hydrophobic extracellular polymeric substances (EPS), such as proteins, polysaccharides, and eDNA, which were synthesized by bacteria themselves after adhesion and colonization on biological surfaces. They had the characteristics of dense structure, high adhesiveness and low drug permeability, and had been found in many human organs or tissues, such as the brain, heart, liver, spleen, lungs, kidneys, gastrointestinal tract, and skeleton. By releasing pro-inflammatory bacterial metabolites including endotoxins, exotoxins and interleukin, biofilms stimulated the body’s immune system to secrete inflammatory factors. These factors triggered local inflammation and chronic infections. Those were the key reason for the failure of traditional clinical drug therapy for infectious diseases.In order to cope with the increasingly severe drug-resistant infections, it was urgent to develop new therapeutic strategies for bacterial-biofilm eradication and anti-bacterial infections. Based on the nanoscale structure and biocompatible activity, nanobiomaterials had the advantages of specific targeting, intelligent delivery, high drug loading and low toxicity, which could realize efficient intervention and precise treatment of drug-resistant bacterial biofilms. This paper highlighted multiple strategies of biofilms eradication based on nanobiomaterials. For example, nanobiomaterials combined with EPS degrading enzymes could be used for targeted hydrolysis of bacterial biofilms, and effectively increased the drug enrichment within biofilms. By loading quorum sensing inhibitors, nanotechnology was also an effective strategy for eradicating bacterial biofilms and recovering the infectious symptoms. Nanobiomaterials could intervene the bacterial metabolism and break the bacterial survival homeostasis by blocking the uptake of nutrients. Moreover, energy-driven micro-nano robotics had shown excellent performance in active delivery and biofilm eradication. Micro-nano robots could penetrate physiological barriers by exogenous or endogenous driving modes such as by biological or chemical methods, ultrasound, and magnetic field, and deliver drugs to the infection sites accurately. Achieving this using conventional drugs was difficult. Overall, the paper described the biological properties and drug-resistant molecular mechanisms of bacterial biofilms, and highlighted therapeutic strategies from different perspectives by nanobiomaterials, such as dispersing bacterial mature biofilms, blocking quorum sensing, inhibiting bacterial metabolism, and energy driving penetration. In addition, we presented the key challenges still faced by nanobiomaterials in combating bacterial biofilm infections. Firstly, the dense structure of EPS caused biofilms spatial heterogeneity and metabolic heterogeneity, which created exacting requirements for the design, construction and preparation process of nanobiomaterials. Secondly, biofilm disruption carried the risk of spread and infection the pathogenic bacteria, which might lead to other infections. Finally, we emphasized the role of nanobiomaterials in the development trends and translational prospects in biofilm treatment.

ObjectiveThe scale of microalgae farming industry is huge. During farming, it is easy for microalgae to be affected by miscellaneous bacteria and other contaminants. Because of that, periodic test is necessary to ensure the growth of microalgae. Present microscopy imaging and spectral analysis methods have higher requirements for experiment personnel, equipment and sites, for which it is unable to achieve real-time portable detection. For the purpose of real-time portable microalgae detection, a real-time microalgae detection system of low detection requirement and fast detection speed is needed. MethodsThis study has developed a microalgae detection system based on deep learning. A microscopy imaging device based on bright field was constructed. With imaged captured from the device, a neural network based on YOLOv3 was trained and deployed on microcomputer, thus realizing real-time portable microalgae detection. This study has also improved the feature extraction network by introducing cross-region residual connection and attention mechanism and replacing optimizer with Adam optimizer using multistage and multimethod strategy. ResultsWith cross-region residual connection, the mAP value reached 0.92. Compared with manual result, the detection error was 2.47%. ConclusionThe system could achieve real-time portable microalgae detection and provide relatively accurate detection result, so it can be applied to periodic test in microalgae farming.

The assessment of adverse drug events is an important basis for clinical safety evaluation and post-marketing risk control of drugs,and its causality assessment is gaining increasing attention.The existing methods for assessing the causal relationship between drugs and the occurrence of adverse reactions can be broadly classified into three categories:global introspective methods,standardized methods,and probabilistic methods.At present,there is no systematic introduction of the operational details of the various methods in the domestic literature.This paper compares representative causality assessment methods in terms of definition and concept,methodological steps,industry evaluation and advantages and disadvantages,clarifies the basic process of determining the causality of adverse drug reactions,and discusses how to further improve the adverse drug reaction monitoring and evaluation system,with a view to providing a reference for drug development and pharmacovigilance work in China.

Objective To investigate the attributable risk(AR)of Acinetobacter baumannii(AB)infection in criti-cally ill patients.Methods A multicenter retrospective cohort study was conducted among adult patients in inten-sive care unit(ICU).Patients with AB isolated from sterile body fluid and confirmed with AB infection in each cen-ter were selected as the infected group.According to the matching criteria that patients should be from the same pe-riod,in the same ICU,as well as with similar APACHE Ⅱ score(±5 points)and primary diagnosis,patients who did not infect with AB were selected as the non-infected group in a 1:2 ratio.The AR was calculated.Results The in-hospital mortality of patients with AB infection in sterile body fluid was 33.3％,and that of non-infected group was 23.1％,with no statistically significant difference between the two groups(P=0.069).The AR was 10.2％(95％CI:-2.3％-22.8％).There is no statistically significant difference in mortality between non-infected pa-tients and infected patients from whose blood,cerebrospinal fluid and other specimen sources AB were isolated(P＞0.05).After infected with AB,critically ill patients with the major diagnosis of pulmonary infection had the high-est AR.There was no statistically significant difference in mortality between patients in the infected and non-infec-ted groups(P＞0.05),or between other diagnostic classifications.Conclusion The prognosis of AB infection in critically ill patients is highly overestimated,but active healthcare-associated infection control for AB in the ICU should still be carried out.

Objective To analyze the atrioventricular synchronization rate after implantation of Micra AV leadless pacemaker,and the impact of postoperative programming optimization on atrioventricular synchronization rate.Methods A prospective cohort study was conducted to select patients with complete atrioventricular block who underwent Micra AV leadless pacemaker implantation at Beijing Anzhen Hospital from August 2022 to June 2023.Programming optimization were performed at 1 week,1 month,and 3 months postoperatively,and atrioventricular synchronization rate,electrical parameters,and echocardiography were recorded.Results A total of 68 patients with complete atrioventricular block implanted with Micra AV were selected,with an average age of(68.2±9.7)years,including 47 males(69.1％).All patients were successfully implanted with Micra AV,and there were no serious postoperative complications;The average threshold,sense,and impedance parameters were stable during 1 week,1 month,and 3 months after the procedure;There was no significant difference in the EF value of postoperative echocardiography(P=0.162);The average atrioventricular synchronization rates at 1 week,1 month,and 3 months postoperatively were(75.2％vs.83.8％vs.91.6％,P=0.001).Conclusions As an mechanical atrial sensing,Micra AV requires personalized adjustment of relevant parameters;Postoperative follow-up programming optimization plays an important role in the atrioventricular synchronization and comfort level in patients with complete atrioventricular block after implantation of Micra AV leadless pacemaker.

Objective To apply a COMSOL-based finite element analysis method to investigating the electric field effects produced by the human lower limb musculoskeletal system under the synergistic effects of stress field and electromagnetic field.Methods Firstly,a 3D human body model was constructed by Maxon Cinema 4D R21 software,and then imported into COMSOL 6.1 software in STL format.Secondly,an electromagnetic field intervention and stress loading model for the left lower limb of the human body was designed and constructed,in which 15 Hz quasi-pulse group current signals were used for electromagnetic field excitation and the stress field was realized by applying a vibration load with an average compressive force of about 90 N/cm2 to the left foot of the human body.Finally,the electromagnetic properties of human tissue were simulated by numerical simulation,and then the effects of stress field or elecromagnetic field or combined stress field and electromagnetic field on human bioelectric field were compared.Results Simulation results showed that the electric field intensity peaked at the leg joints under both electromagnetic and stress fields acting alone or synergistically,the bioelectric field intensity generated by the human body was related to the distance from the exogenous excitation loading location,and the electric field generated under synergistic action was equivalent to the linear superposition of the bioelectric field in the tissue induced by the electromagnetic field and the stress field acting alone.Conclusion Data supplement is provided for predicting bioelectric field changes within the musculoskeletal tissue,and theoretical foundation is laid for the development and application of multi-physics field synergistic intervention therapy for treating the disorders of the lower limb musculos-keletal system.[Chinese Medical Equipment Journal,2024,45(9):21-26]

The synergistic antibacterial strategy of peroxidase mediated chemodynamic therapy(CDT)and photothermal therapy(PTT)has been proven to effectively resist bacteria.However,the antibacterial effect against Pseudomonas aeruginosa is severely limited due to the factors such as short lifespan of reactive oxygen species(ROS)(<200 ns)and limited diffusion distance(about 20?200 nm).In this study,glucopyranose functionalized MoO3-x(P-MoO3-x)nanoenzyme was successfully synthesized using a one-pot hydrothermal method.This nanoenzyme exhibited both peroxidase-like activity and a photothermal effect.The combined antibacterial performance and biological safety of P-MoO3-x was analyzed and verified.By utilizing specific interactions with glucopyranose and lectin,P-MoO3-x nanoenzyme could target the surface of Pseudomonas aeruginosa.This targeted approach effectively shortened the range of hydroxyl radicals,significantly enhancing the antibacterial effect against Pseudomonas aeruginosa.Under photothermal action,P-MoO3-x could reach the optimal reaction effect at 70℃.Even at low concentrations of hydrogen peroxide(50 μmol/L),it released more hydroxyl radicals.In vitro antibacterial analysis experiments demonstrated that the inactivation efficiency of the P-MoO3-x antibacterial system against Pseudomonas aeruginosa(106 CFU/mL)exceeded 99%.Furthermore,in vivo experiments confirmed the significant therapeutic effects of P-MoO3-x in treating methicillin-resistant Staphylococcus aureus(MRSA)infected wounds and promoting wound healing,without producing toxicity to cells.In conclusion,P-MoO3-x exhibited excellent antibacterial ability and good biocompatibility,making it a promising anti-infective nanoenzyme with broad application prospects.

Ketamine,an antagonist of the glutamate N-methyl-D-aspartate(NMDA)receptor,is cur-rently one of the most widely abused psychoactive substances.Prolonged abuse can result in damages to various systems in the body,making it crucial to investigate the regulatory mechanism of ketamine addic-tion and screening related biomarkers.In this study,zebrafish embryos/larvae were initially exposed a-cutely to ketamine.Then,a ketamine addiction model was established in 6-month-old zebrafish through conditioned place preference(CPP)experiments.The zebrafish brain transcriptome was analyzed using RNA-seq,while qPCR and Western blotting were employed to detect the expression of key genes.Results revealed significant reductions in the spontaneous tail coiling,embryo hatching rate,and survival rate of zebrafish embryos in the ketamine-treated group compared to the control group.The distance moved also decreased significantly,from 1904.2 mm in the control group to 319.0 mm in the high dose of ketamine group(300 μmol/L).Conditional positional preference experiments demonstrated that the control ze-brafish did not exhibit significant changes in activity in the CPP tank.In contrast,the ketamine-treated group increased their activity time in the light zone of the tank from 385.2 s before training to 706.4 s af-ter training,representing a 26.8％increase(***P＜0.001).This suggests a preference for ketamine stimulation in zebrafish.KEGG analysis indicated enrichment of differentially expressed genes in the neu-roactive ligand-receptor interaction pathway in the ketamine-treated samples.GSEA analysis further re-veals a significant upregulation of the glutamatergic synapse pathway(NES=1.5).In addition,compared with the control group,the mRNA levels of Grin2b and Gria2 in the ketamine group increased by 4.6 and 1.4 times,respectively,while the protein levels increased by 2.0 and 1.4 times,respectively.These findings suggest that ketamine can induce addiction in zebrafish,potentially through upregulation of the glutamatergic synaptic pathway.

Objective To investigate the effect of microplastic(MPs)exposure on learning and memory in mice,and its mechanism by observing the protein expression of brain-derived neurotrophic factor(BDNF)/tyrosine receptor kinase B(TrkB)/N-methyl-D-aspartate receptor subtype 2B(NR2B)signaling pathway and neurogenesis.Methods Forty male C57BL/6 mice were randomly divided into control group(Ctrl)and microplastics exposure group(MPs).Mice in MPs group were treated with 0.3 mg/(kg·d)microplastics,administered by gavage at a volume of 200 μl for 30 consecutive days.Morris water maze test was used to evaluate the spatial learning and memory ability of mice.Western blotting was used to detect the protein levels of BDNF,TrkB and NR2B in hippocampus of mice.Immunofluorescent staining was used to observe the number of doublecortin(DCX)and neuronal nuclei antigen(NeuN)positive cells in the hippocampus of mice to evaluate hippocampal neurogenesis.Results Compared with the control group,the ability of learning and memory decreased significantly in MPs group mice(P＜0.01).The expression levels of BDNF,TrkB and NR2B in the hippocampus of MPs group mice were significantly lower than those of control group(P＜0.05).The number of DCX and NeuN positive cells in the hippocampus of MPs group was significantly lower than that of control group(P＜0.01).Conclusion MPs exposure induces learning and memory impairment which may be related to inhibiting BDNF/TrkB/NR2B signaling pathway and reducing hippocampal neurogenesis.