Multidrug-resistant (MDR) bacterial infections have emerged as a serious challenge of global public health crisis. The overuse and misuse of conventional antibiotics have dramatically accelerated the emergence, evolution and worldwide spread of drug-resistant bacterial strains, necessitating urgent exploration of novel antibacterial strategies. Bacteriophages serve as natural bacterial predators offering distinct advantages including high host specificity, autonomous self-replication capabilities and cost-effective large-scale production. However, wild-type phages present significant clinical limitations due to their narrow host ranges, susceptibility to rapid immune clearance and poor penetration of bacterial biofilms, which severely restrict their therapeutic applications. The convergence of synthetic biology, nanotechnology and advanced gene editing technologies has accelerated the development of engineered bacteriophage platforms, providing programmable, scalable and clinically translatable pathways to overcome these inherent biological constraints. Here, we systematically delineate four fundamental strategies for engineered bacteriophage development. Chemical modification utilizes reactive functional groups such as amino, carboxyl and thiol moieties on capsid proteins through esterification, amidation or click chemistry reactions to achieve precise drug conjugation and surface functionalization. In vivo editing encompasses ultraviolet or chemical mutagenesis for random mutation induction, homologous recombination for targeted genetic alterations, recombineering methodologies including electroporation-mediated bacteriophage recombination engineering, and CRISPR-Cas systems for precise genome editing to enable exact genetic reconstruction and host range reprogramming. In vitro synthesis leverages genome engineering platforms where intact phage genomes are transferred into yeast or host bacteria to facilitate highly efficient homologous recombination, enabling large DNA fragment assembly and cross-gene host range expansion without bacterial toxicity constraints. Directed evolution combines artificial selection through mutation library screening with rational design approaches involving chimeric receptor binding protein construction or site-specific mutagenesis, effectively balancing the discovery of unknown adaptive pathways with targeted host specificity modification. Moreover, we comprehensively discuss therapeutic applications across diverse clinical scenarios. Engineered bacteriophage effectively disrupt bacterial biofilms through sophisticated functionalized delivery platforms including nanozyme-conjugated phages, phage-liposome nanoconjugates and bio-responsive hydrogels, demonstrating significantly enhanced bactericidal efficiency compared to unmodified free phages. These bioengineered vectors attenuate bacterial virulence and resensitize pathogens to antibiotics by delivering CRISPR-Cas systems or base editors to disrupt critical virulence factors such as pili, capsule synthesis machineries and quorum sensing systems, or by inactivating antibiotic resistance determinants including beta-lactamase genes. As an intelligent nanomedicine delivery platform, engineered bacteriophage enable precise pathogen elimination an through photocatalytic reactive oxygen species generation, immunomodulatory interventions, or controlled release of antibacterial drugs. Furthermore, oral administration of engineered bacteriophage facilitates microbiota modulation, which selectively eliminate intestinal pathogens while preserve beneficial commensal microbiota, thereby restoring microbial community balance and preventing complications associated with dysbiosis. Finally, we critically analyze persistent challenges including host strain matching complexity, evolution of bacterial resistance mechanisms, pharmacokinetic optimization requirements, optimal administration route selection, large-scale production quality control standards and clinical dosing determination protocols. Through multidisciplinary integration of synthetic biology, infectious disease medicine and immunology, future translational medicine studies of bacteriophage should establish comprehensive technical platforms encompassing rapid phage screening, intelligent rational design, rigorous in vivo evaluation and standardized clinical validation processes, ultimately advancing engineered bacteriophage from laboratory innovations to clinically approved therapeutics for effectively combating MDR bacterial infections.

ObjectiveTo analyze the epidemiological and etiological characteristics of a cluster of human metapneumovirus (HMPV) infection in a kindergarten in Gongshu District of Hangzhou City in May 2024, and to provide reference for the prevention and control of similar outbreaks. MethodsAn on-site investigation was conducted using an epidemiological case investigation form. Throat swab specimens collected from cases were screened for 13 respiratory pathogens using real-time fluorescent polymerase chain reaction (PCR). For HMPV nucleic acid positive specimens, the F gene of HMPV was used as the target gene for amplification and sequencing. The sequencing results were then compared with sequences in GenBank database to determine the virus subtypes and perform phylogenetic analyses. ResultsThe outbreak occurred in a kindergarter junior class with a total of 28 preschoolers and 3 teachers and childcare workers. A total of 11 cases (10 preschoolers and 1 teacher) were identified, including 8 male cases and 3 female cases. Clinical manifestations included fever in all 11 cases (100.00%), cough in 8 cases (72.72%), catarrhal symptoms in 4 cases (36.36%), and headache in 3 cases (27.27%). All symptoms were mild, and no severe cases were observed. A total of 11 throat swab samples were collected. Real-time fluorescent PCR test results showed that 3 samples were positive for HMPV nucleic acid, 2 samples were positive for both HMPV and Streptococcus pneumoniae, and 1 sample was positive for both HMPV and rhinovirus. The sequences of the 6 HMPV nucleic acid positive specimens were amplified and analyzed using specific primers, and all were determined to be HMPV subtype A2b. The F gene fragment sequence showed the highest similarity to PV081665.1/Brazil/2024 (99.65%), and also exhibited high similarity to PP683455.1/Indonesia/2021 (99.48%), PV016275.1/Beijing/2024 (99.31%), and PV052230.1/USA/2024 (99.13%). ConclusionThis cluster of acute respiratory tract infection was caused by HMPV subtype A2b, with co-infection of rhinovirus and Streptococcus pneumoniae. The F gene fragment sequences of the HMPV in this outbreak were highly homologous to those of the A2b strains isolated from Brazil, Beijing, Indonesia, and the the United States.

Metabolic dysfunction-associated fatty liver disease （MAFLD） is the most prevalent chronic liver disease worldwide， with a complex pathogenesis. Mitochondria play a pivotal role in this disease process， and studies have confirmed that mitochondrial dysfunction can exacerbate metabolic disorders and induce innate immune imbalance， while mitochondrial DNA （mtDNA） is the core molecule mediating these two pathological effects. After the abnormal release of mtDNA， it can be recognized by intracellular pattern recognition receptors， which in turn triggers innate immune responses and causes tissue damage， forming a pathological pathway of “mtDNA release-immune activation-tissue damage”. Currently， there is a lack of systematic reviews summarizing the mechanism of action of this pathway in different stages of MAFLD and the intervention strategies targeting this pathway. This article systematically reviews the core molecular mechanism of this pathway， its pathological role in the development and progression of MAFLD， and the current intervention strategies targeting this mechanism， in order to provide a theoretical basis for analyzing the pathogenesis of MAFLD and developing novel therapeutic strategies.

Objective To observe the effects of electroacupuncture(EA)on morphine-induced microglia activation and analgesic tolerance,and explore the potential mechanism of EA in the treatment of morphine analgesic tolerance.Methods A total of 60 clean-grade SD rats were randomly assigned to control group,morphine group,morphine+EA group,and morphine+EA+colony-stimulating factor 1(CSF1)group,with 15 rats in each group.Morphine analgesic tolerance model was established by continuous 7-d intrathecal injection of morphine in the morphine,morphine+EA and morphine+EA+CSF1 groups.EA was given in the rats of morphine+EA and morphine+EA+CSF1 groups at"Zusanli"and"Sanyinjiao"acupoints,with dilatational wave,frequency of 2/100 Hz,stimulation intensities of 0.5,1.0,and 1.5 mA(10 min per intensity),once a day,for 7 consecutive days.Rats in morphine+EA+CSF1 group were given intrathecal injection with recombinant CSF1 protein for 7 consecutive days.The effect of EA on morphine analgesic tolerance in rats was observed by mechanical withdrawal threshold(MWT).After 7 d,the rats were sacrificed,and the L4-6 spinal dorsal horn and dorsal root ganglion tissues were isolated.The expression of CSF1 protein and mRNA in the dorsal root ganglia and spinal dorsal horn was detected by Western blotting and quantitative polymerase chain reaction.The expression of ionized calcium-binding adapter molecule 1(IBA-1),a marker of microglia in the spinal dorsal horn,was detected by immunofluorescence method,and the expression of interleukin(IL)-1β,IL-6 and tumor necrosis factor(TNF)-α in the spinal cord was detected by enzyme-linked immunosorbent assay(ELISA).Results After intrathecal injection of morphine,the percentage of maximal possible potential effect(%MPE)in the morphine group was decreased progressively,indicating that the morphine analgesic tolerance model was successfully constructed.Compared with the morphine group,the%MPE in the morphine+EA group was increased after intrathecal injection at 3,5 and 7 d(all P＜0.05).Compared with the morphine+EA group,the%MPE in the morphine+EA+CSF1 group was all decreased after intrathecal injection at 3,5 and 7 d(all P＜0.05).Compared with the control group,the expression of CSF1 protein and mRNA in dorsal root ganglion and the expression of CSF1 protein in spinal dorsal horn in the morphine group were increased(all P＜0.05).Compared with the morphine group,the expression levels of CSF1 protein and mRNA in dorsal root ganglion and CSF1 protein in spinal dorsal horn in the morphine+EA group were decreased(all P＜0.05).There was no significant difference in the expression of CSF1 mRNA in the spinal dorsal horn among those groups(all P＞0.05).Compared with the control group,the expression of IBA-1 in the spinal dorsal horn of the morphine group was increased(P＜0.05).Compared with the morphine group,the expression of IBA-1 in the spinal dorsal horn of the morphine+EA group was decreased(P＜0.05).Compared with the morphine+EA group,the expression of IBA-1 in the spinal dorsal horn of the morphine+EA+CSF1 group was increased(P＜0.05).Conclusion EA can inhibit the activation of microglia in the spinal dorsal horn of rats and improve morphine analgesic tolerance in rats.The mechanism may be related to the reduction of CSF1 protein expression in the spinal dorsal horn.

Objective To observe the value of 68Ga-DOTA-NOC PET/CT for diagnosing pheochromocytoma(PCC)and paraganglioma(PGL).Methods Thirty-eight patients with suspected or confirmed PCC/PGL who underwent 68 Ga-DOTA-NOC PET/CT were retrospectively enrolled,among them 20 cases underwent 131I-metaiodobenzylguanidine(MIBG)SPECT/CT during the same period.The value of 68Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL at individual and lesion levels were analyzed and compared to the results of 131I-MIBG SPECT/CT.Results Among 38 cases,there were 20 cases of PCC,14 cases of PGL,1 case of adrenocortical carcinoma and 3 cases of benign adrenal hyperplasia.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of 68 Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL in all 38 cases was 87.88％(29/33),60.00％(3/5),93.55％(29/31),42.86％(3/7)and 84.21％(32/38),respectively.Totally 188 lesions were detected in 34 cases,with detection rate of 89.95％(188/209).For 20 patients who underwent both 2 kinds examinations,the detection rate of bone,lymph node,liver,lung metastases and the overall lesions of 68Ga-DOTA-NOC PET/CT were all higher than those of 131I-MIBG SPECT/CT(all P＜0.05).No significant difference of diagnostic accuracy of PCC/PGL was found between 68 Ga-DOTA-NOC PET/CT and 131I-MIBG SPECT/CT(P＞0.05).Conclusion The value of 68 Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL was comparable to that of 131I-MIBG SPECT/CT,but the former showed higher detection rate of metastases,hence being helpful to staging and risk stratification of PCC/PGL.

Objective To design a night vision simulation training system to provide pilots with practical training on ground night vision goggles.Methods The system had its hardware composed of a control stick,a throttle lever,rudder pedals,a head-up display(HUD),a control box,a computer,a projector and a screen.The HUD and control box were designed using night vision-compatible lighting technology to simulate the ambient light conditions pilots experienced when flying with night vision goggles.The software of the system consisted of five ones developed with C++programming languge for visual scene simulation,instrument simulation,flight performance simulation,integrated management control and cockpit manage-ment.Night vision images and computer-rendered images of typical scenes with varying brightness levels were collected.Objective image evaluation metrics such as contrast and brightness were used as inputs,while subjective evaluation data served as outputs to construct and train a support vector machine(SVM)model.Totally 30 typical night vision training scenarios were selected based on model validation and optimization to evaluate the system's optical fidelity.Results The average fidelity score for the 30 typical night vision training scenarios was 8.05,indicating that the system could realistically simulate terrain and landscapes under various lighting and weather conditions during night flights and static and dynamic targets in the air,on the ground and at sea.Conclusion The system meets the desired requirements and effectively facilitates night vision training for pilots.[Chinese Medical Equipment Journal,2025,46(3):21-26]

Aim To investigate the intestinal protection and possible mechanism of magnolol(MG)in newborn rats with necrotizing enterocolitis(NEC).Methods The rats were randomly divided into control group(Ctrl group),model group(NEC group)and treatment group(MG group).The NEC model was induced by hypoxia,cold stimulation,deep formula milk and LPS intragastric administration in 7-day-old rats for four days.They were killed after five days of treatment with MG(20 mg·kg-1).HE staining was used to observe the intestinal pathological injury.Western blot was used to detect the expressions of IL-1 β,TNF-α,NL-RP3,ASC,caspase-1 and tight junction protein in the distal ileum of rats.Colon contents were collected for 16S rDNA sequencing to understand the gut microbio-ta.Results MG improved the body mass and intesti-nal injury of NEC neonatal rats.The expressions of in-testinal IL-1β,TNF-α,NLRP3,ASC and caspase-1 proteins were down-regulated,and the expressions of Claudin,Occludin and ZO-1 proteins were up-regula-ted.16S rDNA showed that MG increased the diversity of intestinal flora,and at the phylum level,MG in-creased the abundance of firmicutes and bacteroides in NEC model,and decreased the abundance of pro-teobacteria.At the genus level,MG treatment in-creased the abundance of Lactobacillus,unclassified_Muribaculaceae,Racteroides,but decreased the abun-dance of Escherichia_Shigella,Rodentibacter and Fuso-bacterium.Conclusion MG intervention can protect the intestinal tract of NEC rats by potentially improving barrier function,and regulating the intestinal microbiota through the NLRP3/ASC/caspase-1 signaling pathway.

Glaesserella parasuis is the causative agent of Gl?sser's disease in pigs.However,the pathogenic mechanisms underlying its virulence is not yet fully understood.The RuvB protein,a member of the AAA+superfamily,is implicated in various cellular processes,yet its specific role in the virulence of Glaesserella parasuis has not been fully characterized.In this study,we con-structed a RuvB gene deletion mutant,designated ΔRuvB,using the serotype 13 Glaesserella pa-rasuis strain ZJ1208 and a suicide plasmid-mediated natural transformation approach.To elucidate the functional role of the RuvB gene,we comprehensively evaluated the biological characteristics of the ΔRuvB strain through a series of assays,including growth kinetics,colony morphology,bac-terial staining,transmission electron microscopy(TEM),osmotic stress tolerance,high-tempera-ture tolerance,heat shock resistance,UV resistance,capsular polysaccharide quantification,serum bactericidal assays,and murine virulence experiments.Our findings revealed that the growth rate of ΔRuvB showed no significant difference compared to the parental strain.TEM revealed a notable increase in bacterial cell length;however,the number of outer membrane vesicles(OMVs)on the surface of ΔRuvB did not significantly increase.Notably,the ΔRuvB strain displayed a significant reduction in capsular polysaccharide production and serum resistance,as well as diminished toler-ance to UV radiation and high temperatures.Significant alterations were observed in its resistance to osmotic stress or oxidative stress.In the mouse toxicity challenge experiment,in com-parison with the parental strain ZJ1208,the mortality rate dropped by 20 percentage points,suggesting that the virulence of ΔRuvB has been weakened to some extent.Collectively,these results underscore the critical role of the RuvB gene in enhancing the environmental adaptability of Glaesserella parasuis.

Objective To investigate the drug-drug interaction between donepezil hydrochloride and moxifloxacin hydrochloride during combined administration through in vitro liver microsomal metabolism and changes in pharmacokinetic characteristics in rats.Methods A rat liver microsomal incubation system was constructed and optimized.Liquid chromatography-tandem mass spectrometry(LC-MS/MS)analysis of donepezil hydrochloride and high-performance liquid chromatography(HPLC)analysis of moxifloxacin hydro-chloride were performed.The pharmacokinetic and metabolic characteristics of the two drugs,alone and in combination,were compared in vitro using rat liver microsomes and in vivo using rats.Results In the liver microsomal system,the half-life(T1/2)of donepezil hydro-chloride in the combined administration 1 group was prolonged by 29.892％(P＜0.01)and the intrinsic clearance(CLint)was reduced by 23.194％(P＜0.01)compared with the donepezil hydrochloride group.Conversely,the metabolic parameters of moxifloxacin hydrochlo-ride in the combined administration 2 group did not differ significantly from that of the moxifloxacin hydrochloride group(P＞0.05).In the in vivo study,the AUC0～t and AUC0～∞ of donepezil hydrochloride in the combined administration 1 group increased by 44.259％and 44.496％,respectively,maximum plasma concentration(Cmax)increased by 117.723％,T1/2 was prolonged by 98.063％,and CLint was reduced by 35.293％,compared with that in the donepezil hydrochloride group.Moreover,the differences were all statistically significant(P＜0.05).The in vivo study findings were consistent with the results of the in vitro study.Conclusion A drug-drug interaction occurs when moxifloxacin hydrochloride is used in combination with donepezil hydrochloride.Moxifloxacin hydrochloride promotes the absorption of donepezil hydrochloride,inhibits its metabolism,slows its CLint,and increases donepezil exposure in the body.

Objective To observe the value of 68Ga-DOTA-NOC PET/CT for diagnosing pheochromocytoma(PCC)and paraganglioma(PGL).Methods Thirty-eight patients with suspected or confirmed PCC/PGL who underwent 68 Ga-DOTA-NOC PET/CT were retrospectively enrolled,among them 20 cases underwent 131I-metaiodobenzylguanidine(MIBG)SPECT/CT during the same period.The value of 68Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL at individual and lesion levels were analyzed and compared to the results of 131I-MIBG SPECT/CT.Results Among 38 cases,there were 20 cases of PCC,14 cases of PGL,1 case of adrenocortical carcinoma and 3 cases of benign adrenal hyperplasia.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of 68 Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL in all 38 cases was 87.88％(29/33),60.00％(3/5),93.55％(29/31),42.86％(3/7)and 84.21％(32/38),respectively.Totally 188 lesions were detected in 34 cases,with detection rate of 89.95％(188/209).For 20 patients who underwent both 2 kinds examinations,the detection rate of bone,lymph node,liver,lung metastases and the overall lesions of 68Ga-DOTA-NOC PET/CT were all higher than those of 131I-MIBG SPECT/CT(all P＜0.05).No significant difference of diagnostic accuracy of PCC/PGL was found between 68 Ga-DOTA-NOC PET/CT and 131I-MIBG SPECT/CT(P＞0.05).Conclusion The value of 68 Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL was comparable to that of 131I-MIBG SPECT/CT,but the former showed higher detection rate of metastases,hence being helpful to staging and risk stratification of PCC/PGL.