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.

Objective:To conduct signal detection and analysis of cardiovascular-related adverse events associated with second-generation H1 antihistamines(sgAH)in the elderly population, utilizing the Food and Drug Administration adverse event reporting system(FAERS)database.The findings provide a reference for assessing the clinical drug safety of sgAH in the elderly.Methods:A cross-sectional study was conducted.Four methods were utilized to detect signals of cardiovascular-related adverse events associated with sgAHs in the FAERS database, covering the period from the first quarter of 2004 to the first quarter of 2024.These methods included the reporting odds ratio, the Medicines and Healthcare Products Regulatory Agency method, the Bayesian Confidence Propagation Neural Network method, and the multi-item gamma Poisson shrinker method.Subgroup analyses were performed on both the overall population and the elderly population(aged ≥65).Results:A total of 1 065 reports of cardiovascular-related adverse events involving sgAHs such as loratadine, desloratadine, cetirizine, levocetirizine, and fexofenadine were collected.In the overall population, palpitations were identified as a positive signal, while desloratadine also demonstrated positive signals for tachycardia and prolonged electrocardiogram QT interval.In the elderly population, both palpitations and prolonged electrocardiogram QT interval were recognized as positive signals, exhibiting higher information component(IC)values and empirical Bayesian geometric mean(EBGM)values compared to the overall population.Furthermore, loratadine and desloratadine were also identified as positive signals for prolonged electrocardiogram QT interval in the elderly.Conclusions:Palpitations have been identified as a significant indicator of cardiovascular-related adverse events associated with sgAHs.Elderly patients should be particularly vigilant regarding the risk of prolonged QT intervals on electrocardiograms.

Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.

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.

The structure and potential antigenic epitopes of FliCEcN were analysed using bioinformat-ics technology.With the help of ClonExpress? homologous recombination technology,primers were designed to deletion of different structural domains in the highly variable region of FliCEcN and cloned into pET-28a(+)expression vector for expression.The expressed flagellin variants were identified by SDS-PAGE and Western blot.Endotoxin residues in the flagellin variants were detected by horseshoe crab reagent chromatography,and Caco-2 cells were stimulated with differ-ent concentrations of flagellin variants.The biological activity of each flagellin variant was assessed by detecting the secretion level of IL-8.Bioinformatic analysis showed that most of the structural domains in the highly variable region of FliCEcN were predicted to contain potential antigenic epitopes.PC R results showed that fliC△820-1 518,fliC△736-963,fliC△985-1 200,fliC △748-828,fliC△1 114-1 191,andfliC△1 225-1311 were approximately 1 095,1 566,1 578,1 713,1 716 and 1 707 bp,respectively.SDS-PAGE results showed that the sizes of the flagellin variants treated with nickel column purifi-cation and dialysis replication were about 41.36,57.06,57.50,61.97,61.95 and 61.56 kDa,respec-tively.Western blot results showed that all six flagellin variants reacted specifically with anti-His monoclonal antibody and E.coli H7 antigen diagnostic serum.The results of TLR5 activity assay showed that the flagellin variants missing different structural domains retained their TLR5 agonist function.In this study,six flagellin variants with different structural domains of FliCEcN deletion hypervariable region were successfully constructed,and all of them retained their TLR5 agonist function and showed good biological properties.This provides a reference for further research on the adjuvant effect of flagellin after deletion of different structural domains and the effect of flagel-lin antibody titer on its adjuvant effect.

The 16S rRNA sequencing,whole genome sequencing and drug sensitivity tests were used to identify the isolates molecularly and to detect and analyse their virulence genes,resistance genes and drug resistance.The results showed that the isolate was highly homologous to Klebsiella pneumoniae X4 and located on the same branch by 16S rRNA sequence analysis,and it was named as KLKp10.Whole genome sequencing results showed that the KLKp10 genome was 5 342 841 bp in length,containing 5 138 genes,346 repetitive segments,6 rRNAs and 81 tRNAs,with a GC con-tent of 57.30％.MLST analysis showed that KLKp10 belongs to the ST-4263 type.The functions of 4 097 of the genes encoding proteins were classified and annotated by COG,and there were also 382 genes with unknown functions.A total of 50 functional classifications were involved in the an-notation results based on the GO database;33 kinds of signaling pathways were covered based on the signaling pathway annotations in the KEGG database.A total of 443 virulence genes were screened in the VFDB database,of which 339 belonged to the Set A database and could encode 124 virulence factors.The 101 resistance genes were predicted by comparing with the CARD database,among which there were more resistance genes against β-lactam antibiotics.The results of drug sensitivity test showed that KLKp10 was highly sensitive to ceftazidime,gentamicin,azithro-mycin,chloramphenicol,norfloxacin,ofloxacin,and enrofloxacin;moderately sensitive to ceftriax-one,neomycin,kanamycin,and streptomycin;and resistant to ciprofloxacin,tetracycline,amoxicil-lin,and penicillin.In this study,we systematically revealed the gene-wide characterization,virulence factors and drug resistance of Klebsiella pneumoniae KLKp10 of Kole pig origin,which provides important data support for the study of Klebsiella pneumoniae at the overall level of its genome.

The 16S rRNA sequencing,whole genome sequencing and drug sensitivity tests were used to identify the isolates molecularly and to detect and analyse their virulence genes,resistance genes and drug resistance.The results showed that the isolate was highly homologous to Klebsiella pneumoniae X4 and located on the same branch by 16S rRNA sequence analysis,and it was named as KLKp10.Whole genome sequencing results showed that the KLKp10 genome was 5 342 841 bp in length,containing 5 138 genes,346 repetitive segments,6 rRNAs and 81 tRNAs,with a GC con-tent of 57.30％.MLST analysis showed that KLKp10 belongs to the ST-4263 type.The functions of 4 097 of the genes encoding proteins were classified and annotated by COG,and there were also 382 genes with unknown functions.A total of 50 functional classifications were involved in the an-notation results based on the GO database;33 kinds of signaling pathways were covered based on the signaling pathway annotations in the KEGG database.A total of 443 virulence genes were screened in the VFDB database,of which 339 belonged to the Set A database and could encode 124 virulence factors.The 101 resistance genes were predicted by comparing with the CARD database,among which there were more resistance genes against β-lactam antibiotics.The results of drug sensitivity test showed that KLKp10 was highly sensitive to ceftazidime,gentamicin,azithro-mycin,chloramphenicol,norfloxacin,ofloxacin,and enrofloxacin;moderately sensitive to ceftriax-one,neomycin,kanamycin,and streptomycin;and resistant to ciprofloxacin,tetracycline,amoxicil-lin,and penicillin.In this study,we systematically revealed the gene-wide characterization,virulence factors and drug resistance of Klebsiella pneumoniae KLKp10 of Kole pig origin,which provides important data support for the study of Klebsiella pneumoniae at the overall level of its genome.

The structure and potential antigenic epitopes of FliCEcN were analysed using bioinformat-ics technology.With the help of ClonExpress? homologous recombination technology,primers were designed to deletion of different structural domains in the highly variable region of FliCEcN and cloned into pET-28a(+)expression vector for expression.The expressed flagellin variants were identified by SDS-PAGE and Western blot.Endotoxin residues in the flagellin variants were detected by horseshoe crab reagent chromatography,and Caco-2 cells were stimulated with differ-ent concentrations of flagellin variants.The biological activity of each flagellin variant was assessed by detecting the secretion level of IL-8.Bioinformatic analysis showed that most of the structural domains in the highly variable region of FliCEcN were predicted to contain potential antigenic epitopes.PC R results showed that fliC△820-1 518,fliC△736-963,fliC△985-1 200,fliC △748-828,fliC△1 114-1 191,andfliC△1 225-1311 were approximately 1 095,1 566,1 578,1 713,1 716 and 1 707 bp,respectively.SDS-PAGE results showed that the sizes of the flagellin variants treated with nickel column purifi-cation and dialysis replication were about 41.36,57.06,57.50,61.97,61.95 and 61.56 kDa,respec-tively.Western blot results showed that all six flagellin variants reacted specifically with anti-His monoclonal antibody and E.coli H7 antigen diagnostic serum.The results of TLR5 activity assay showed that the flagellin variants missing different structural domains retained their TLR5 agonist function.In this study,six flagellin variants with different structural domains of FliCEcN deletion hypervariable region were successfully constructed,and all of them retained their TLR5 agonist function and showed good biological properties.This provides a reference for further research on the adjuvant effect of flagellin after deletion of different structural domains and the effect of flagel-lin antibody titer on its adjuvant effect.

Objective:To conduct signal detection and analysis of cardiovascular-related adverse events associated with second-generation H1 antihistamines(sgAH)in the elderly population, utilizing the Food and Drug Administration adverse event reporting system(FAERS)database.The findings provide a reference for assessing the clinical drug safety of sgAH in the elderly.Methods:A cross-sectional study was conducted.Four methods were utilized to detect signals of cardiovascular-related adverse events associated with sgAHs in the FAERS database, covering the period from the first quarter of 2004 to the first quarter of 2024.These methods included the reporting odds ratio, the Medicines and Healthcare Products Regulatory Agency method, the Bayesian Confidence Propagation Neural Network method, and the multi-item gamma Poisson shrinker method.Subgroup analyses were performed on both the overall population and the elderly population(aged ≥65).Results:A total of 1 065 reports of cardiovascular-related adverse events involving sgAHs such as loratadine, desloratadine, cetirizine, levocetirizine, and fexofenadine were collected.In the overall population, palpitations were identified as a positive signal, while desloratadine also demonstrated positive signals for tachycardia and prolonged electrocardiogram QT interval.In the elderly population, both palpitations and prolonged electrocardiogram QT interval were recognized as positive signals, exhibiting higher information component(IC)values and empirical Bayesian geometric mean(EBGM)values compared to the overall population.Furthermore, loratadine and desloratadine were also identified as positive signals for prolonged electrocardiogram QT interval in the elderly.Conclusions:Palpitations have been identified as a significant indicator of cardiovascular-related adverse events associated with sgAHs.Elderly patients should be particularly vigilant regarding the risk of prolonged QT intervals on electrocardiograms.