Olfactory receptors (ORs) form the largest superfamily of G protein-coupled receptors (GPCRs). Traditionally recognized for their role in the nasal olfactory epithelium, where they mediate the sense of smell, accumulating evidence has firmly established their ectopic expression in non-olfactory tissues, including the intestine, lungs, and kidneys. The intestine, as the primary site for nutrient digestion and absorption, harbors a highly complex chemical environment. To adapt to this environment, the gut employs a sophisticated network of “chemosensors” to monitor luminal contents and maintain homeostasis. Among these sensors, intestinal ORs have emerged as crucial functional components, serving as a molecular bridge that connects environmental chemical signals—such as food-derived odorants—to specific physiological responses. This discovery has significantly deepened our understanding of how dietary flavors and compounds influence intestinal physiology at the molecular level. This review systematically summarizes the expression profiles, ligand classification, and biological functions of ORs within the gastrointestinal tract. Studies indicate that intestinal ORs exhibit distinct spatial distribution patterns across different gut segments and display cell-type specificity, particularly within enterocytes and enteroendocrine cells. These receptors function as versatile sensors capable of recognizing a wide variety of ligands, including exogenous dietary components, gut microbiota metabolites such as short-chain fatty acids, and endogenous small molecules like azelaic acid. Upon activation by specific ligands, intestinal ORs trigger intracellular signaling cascades, primarily involving the AC-cAMP-PKA pathway or calcium influx channels. A major focus of this review is to elucidate the molecular mechanisms by which these receptors regulate the secretion of gut hormones. Activation of specific ORs in enteroendocrine cells has been shown to stimulate the release of hormones such as glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and serotonin (5-HT), thereby modulating systemic energy metabolism, glucose homeostasis, and gastrointestinal motility. Furthermore, the review addresses the critical roles of ORs in immune regulation and pathology. Evidence suggests that specific ORs contribute to the maintenance of intestinal immune homeostasis and may offer protection against inflammation. Beyond their involvement in inflammatory responses, ORs such as Olfr78 have been shown to regulate the differentiation and function of intestinal endocrine cells. Similarly, Olfr544 has been demonstrated to alleviate intestinal inflammation by remodeling the gut microbiome and metabolome. These findings collectively suggest that specific ORs hold promise as therapeutic targets for mitigating intestinal inflammation and maintaining gut homeostasis. Additionally, the review explores the emerging role of ORs in cancer. Although OR expression is often downregulated in tumor tissues compared to normal mucosa, activation of specific ORs by certain ligands can inhibit tumor cell proliferation and migration and induce apoptosis via pathways such as MEK/ERK and p38 MAPK. Conversely, other receptors, such as OR7C1, may serve as biomarkers for cancer-initiating cells. In conclusion, intestinal ORs represent a vital component of the gut’s sensory network. The review also discusses the translational potential of these findings. By elucidating the precise pairing relationships between dietary components and specific ORs, novel therapeutic strategies could be developed. Intestinal ORs may thus emerge as promising targets for nutritional and pharmacological interventions in metabolic diseases, inflammatory bowel diseases, and malignancies.

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.

Objective This study conducted molecular biological identification of the viruses carried by Culex pipiens pallens specimens collected in Shunyi District, Beijing in 2023, and observed the changes in the infection rate of the viruses carried by Cx. pipiens pallens at different collection times. Methods Cx. pipiens pallens were collected using carbon dioxide mosquito traps. The mosquito samples were ground in batches and analyzed by molecular biology technologies. The virus infection rate at different collection times was analyzed statistically. Results 17 strains of Culex pipiens pallens densovirus(CppDNV)were identified from Cx. pipiens pallens samples collected in Shunyi District, Beijing, in 2023. The nucleotide sequence analysis of the virus genome coding region showed that CppDNV was a single-stranded DNA virus with a total length of 3 335 nt, encoding 2 non-structural proteins(NS1, NS2)and 1 capsid protein(VP). The nucleotide(amino acid)sequence lengths of the three proteins were 2 376 nt(791 aa),1 092 nt(363 aa)and 1 071 nt(356 aa), respectively. Phylogenetic analysis showed that CppDNV was located in genus Brevihamaparvovirus. Statistical analysis showed no significant difference in infection rates across collection times(χ2=4.429, P=0.194). Conclusions CppDNV was identified in Cx. pipiens pallens in Beijing, and it was stably maintained in this natural population.

ObjectiveTo explore the molecular mechanism through which modified Guizhi Fulingwan （MGZFLW） promotes apoptosis and inhibits prostate cancer through the miR-34a-5p/δ-like protein 1 （DLL1）/Notch signaling pathway based on the traditional Chinese medicine theory of Yang transforming Qi while Yin constituting form. MethodsThe optimal intervention conditions of MGZFLW-containing serum and docetaxel （DXT） were screened by the cell counting kit-8 （CCK-8） method. Human prostate cancer cells （PC-3） were allocated into blank， MGZFLW （10%）， and DXT （30 nmol·L^-1） groups. The effects of MGZFLW-containing serum on the migration and proliferation of PC-3 cells were evaluated by cell scratch and colony formation assays， and the apoptosis of PC-3 cells was detected by terminal-deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling （TUNEL） assay. The cells were transfected with miR-34a-5p mimics and miR-34a-5p inhibitor. The mRNA levels of miR-34a-5p， DLL1， Notch1 and its downstream effector factors Notch1 intracellular domain （NICD1）， Hes family basic helix-loop-helix transcription factor 1 （Hes1）， and hairy/enhancer-of-split related with YRPW motif 1 （Hey1） were determined by Real-time PCR. The protein levels of DLL1， Notch1， NICD1， Hes1， and Hey1 were determined by a WES fully automatic protein system. The effect of miR-34a-5p on the DLL1-mediated Notch pathway was evaluated based on the results. Further， after MGZFLW-containing serum intervention， the expression of DLL1 and Notch1 was detected by the immunofluorescence （IF） assay， and the mRNA and protein levels of miR-34a-5p/DLL1/Notch pathway-related molecules were quantified by Real-time PCR and the WES fully automatic protein system， respectively， to explore the regulatory effect of MGZFLW-containing serum on the miR-34a-5p/DLL1/Notch pathway. ResultsMGZFLW-containing serum inhibited the viability， migration， and proliferation and promote the apoptosis of PC-3 cells （P<0.01）. The overexpression of miR-34a-5p down-regulated the mRNA and protein levels of key molecules in the DLL1/Notch signaling pathway and promoted cell apoptosis （P<0.01）， while inhibition of miR-34a-5p had the opposite effects. MGZFLW-containing serum reversed the activation of the DLL1/Notch pathway and the inhibition of apoptosis caused by miR-34a-5p inhibition， up-regulated the expression of miR-34a-5p， and down-regulated the expression of related molecules in this pathway （P<0.01）. ConclusionMGZFLW can up-regulate the expression of miR-34a-5p to inhibit the DLL1/Notch signaling pathway and promote the apoptosis of prostate cancer cells， thereby inhibiting prostate cancer. This study provides experimental evidence for clarifying the molecular mechanism of the anti-prostate cancer effect of this formula.

Objective To investigate gender differences and age-related changes in body composition(BC)among Miao adults in Rongshui,Guangxi Province,and to provide the basis for assessing nutritional status and health.Methods With informed consent,630 Miao adults(218 males,412 females)were randomly selected for this study.Body composition was assessed using bioelectrical impedance analysis(BIA).Results Weight,fat-free mass,muscle mass,trunk muscle mass,limb muscle mass,waist-to-hip ratio(WHR),body water,presumtion of bone mass and protein were significantly higher in males than in females.And the fat mass,trunk fat mass,limb fat mass,visceral fat content,subcutaneous fat content and percentage of body fat were significantly higher in females than in males.According to the evaluation of body mass index(BMI)and WHR,the proportion of overweight and obesity of Miao adults was higher than the average level of Miao residents,and their obesity was characterized by central obesity.With age,weight,fat mass,muscle mass,fat-free mass,limb muscle mass,limb fat mass,subcutaneous fat content,percentage of body fat,body water,presumtion of bone mass,and protein of Rongshui Miao adults showed a gradual decreasing trend,while visceral fat content and WHR increased progressively.BMI in male Miao adults,along with BMI,fat mass,trunk fat mass,subcutaneous fat content,percentage of body fat,and body water in female Miao adults,showed a trend of increasing followed by decreasing,peaking at the age of 40-49 years.Conclusion The body composition of Miao adults in Rongshui,Guangxi,exhibits significant gender differences and age-related variation change patterns,which may increase the risk of sarcopenia and metabolic diseases with aging.

Objective To explore the effectiveness of"near peer learning"(NPL)in the electromyo-graphy(EMG)teaching module for neurology residents.Methods The Department of Neurology,Peking Union Medical College Hospital implemented an NPL instructional design for a course on EMG for residents from November 2020 to March 2024.This teaching session was held annually,in which senior residents in-structed juniors who were 1 or 2 years earlier in their training.The residents participated in the pre-course/post-course tests and completed a feedback survey at the end of the session.This evaluation method was used to un-derstand the effectiveness of the NPL intervention in EMG teaching.Results Over four years,a total of 83 residents participated.Among them,there were 24 postdoctoral students,52 postgraduates and 7 junior resi-dents.The results showed that the post-course test scores were significantly improved compared with pre-course test scores(74.33±2.43 vs.70.11±2.49,P=0.005),with the most remarkable improvements seen for"tu-tees"(73.84±20.53 vs.70.29±21.46,P=0.020),postgraduates(74.04±22.51 vs.68.97±21.40,P=0.009),first-year residents(70.19±4.02 vs.63.59±3.59,P=0.040)and first-time participating resi-dents(65.23±3.24 vs.60.97±3.21,P=0.030).The post-program feedback showed that both tutors and tu-tees thought highly of NPL,believing that it enabled them to gain knowledge and helped them to improve teaching skills.Conclusions The NPL intervention is suitable for the teaching of EMG,because of its contri-bution to knowledge acquisition and basic clinical skills improvement.The NPL is worth replicating in other teaching and learning programs.

As an independent first-level discipline,an appropriate classification of nursing science is significant.In China,each nursing degree-granting institution has developed its own secondary-level discipline directions based on its research characteristics and strengths,with varying names and research scopes.Furthermore,there is no unified global classification system.This paper,based on the characteristics of nursing as a discipline and combined with China's discipline classification principles,used literature analysis,comprehensive classification,philosophical reflection,logical reasoning,and expert consultation methods to explore the connotation of nursing,its unique research objects and scope,and to construct a secondary-level discipline classification system for nursing science that is suitable for China's national conditions.The paper also discussed the challenges faced by the nursing discipline and its future development directions,providing theoretical and practical guidance for the development of the nursing discipline.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

In the process of strontium(Sr)isotope analysis,the separation and purification of Sr are crucial for obtaining high-precision Sr isotope ratios.In this work,ammonia solution was used as a precipitating agent to initially separate and purify Sr from geological samples through coprecipitation,followed by the combination with cation-exchange resin to quickly and effectively obtain high-purity Sr components.The experimental conditions of ammonia coprecipitation reaction were optimized using typical high Rb/Sr ratio(mass ratio)standard sample JR-2.The results showed that using 3 mL of ammonia(1 mol/L)as the precipitating agent,at 120℃for 1 h,could effectively remove more than 90%of Rb,Na and K,with Sr recovery exceeding 95%.To verify the stability and applicability of this separation process,geological standard samples(JR-2,BCR-2,AGV-2,BHVO-2,GSP-2,W-2a)with different rock types and Rb/Sr ratios were practically validated.The results demonstrated that the coprecipitation process with ammonia solution removed more than 90%of Rb,Na and K,with Sr recovery greater than 95%.To further assess the applicability of this method for samples with high Rb/Sr ratios,Rb was added to the rhyolite standard material JR-2,adjusting its Rb/Sr ratio to 500.The results showed that this separation process could still effectively achieve the separation of Rb and Sr,and high-precision Sr isotope analysis results were successfully obtained by combining thermal ionization mass spectrometer(TIMS).Ammonia solution,as a precipitating agent,offered advantages such as low cost,low procedural blanks,simplicity,and a wide range of applicability.Therefore,the combination of ammonia solution coprecipitation and cation-exchange resin enabled rapid Sr purification from geological samples,providing a novel separation approach for high-precision Sr isotope analysis of samples with high Rb/Sr ratios,with broad application prospects.