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.

p21 (encoded by the CDKN1A gene) is a critical cell cycle regulatory protein endowed with versatile biological functions. In various sex hormone-related cancers, p21 exhibits a paradoxical dual role, capable of both inhibiting tumorigenesis and promoting cancer progression, exerting dual, often opposing, effects on cellular fate that are dictated by the specific context. The clinical targeting of p21 remains elusive, largely due to its functionally pleiotropic and context-dependent nature within intricate regulatory networks. During the initial, hormone-dependent phase of cancers like breast and prostate cancer, p21 expression and activity are largely governed by the transcriptional programs of estrogen or androgen receptor signaling. This hormonal regulation contributes to the control of tumor cell proliferation and underpins the initial efficacy of endocrine therapies. In contrast, as these diseases advance to late stages or evolve into non-hormone-dependent subtypes—exemplified by castration-resistant prostate cancer (CRPC) and specific forms of triple-negative breast cancer (TNBC)—these conventional hormonal control mechanisms often become dysfunctional or are entirely bypassed. This fundamental transition creates a critical therapeutic void, highlighting the urgent need to identify and exploit alternative molecular pathways to effectively target p21’s function. Promising strategies may include the precise modulation of its upstream transcriptional regulators, downstream effector proteins, or the intersecting parallel signaling networks that critically influence its activity. This review provides a systematic synthesis of the intricate and interconnected mechanisms that underpin the dual effects of p21 in sex hormone-related tumors. These mechanisms are categorized into three core, interrelated functional domains. (1) cell cycle regulation: p21 executes its canonical tumor-suppressive role by binding to and inhibiting cyclin-dependent kinases (CDKs) and by directly interacting with proliferating cell nuclear antigen (PCNA), thereby inducing cell cycle arrest, predominantly at the G1/S checkpoint; (2) apoptosis modulation: p21 exerts a highly context-dependent influence on programmed cell death, functioning either as a pro-apoptotic agent under severe genotoxic stress or as a pro-survival factor by inhibiting apoptosis through interactions with proteins like Bcl-2; (3) hormonal and signaling crosstalk: p21 is an integral node within broader cellular networks, engaging in direct physical interactions with hormone receptors(e.g., AR, ER) and participating in complex feedback loops with key oncogenic pathways, including PI3K/AKT, MAPK/ERK, and p53. Critically, the role of p21 is not static but highly dynamic. It can undergo a functional switch from tumor-suppressive to tumor-promoting in response to therapeutic pressures, metabolic alterations, or evolving tumor microenvironment cues. These adaptive shifts are frequently implicated in the development of therapy resistance and disease recurrence, particularly in advanced, hormone-resistant cancers. By synthesizing these insights, this review aims to establish a coherent theoretical framework to guide the future development of novel therapeutic strategies that target the p21 pathway. It underscores the necessity of moving beyond a simplistic, binary view of p21 and emphasizes the forthcoming challenges, such as the discovery of reliable biomarkers to predict its functional state and the rational design of context-specific pharmacological modulators to selectively harness its therapeutic potential.

ObjectiveTo observe the effects of Jiangtang No. 3 prescription on inflammatory pathways and insulin resistance-related indicators in rats with type 2 diabetes mellitus （T2DM）， and to elucidate its molecular mechanism in combating diabetes. MethodsA T2DM rat model was established using a high-fat diet combined with intraperitoneal injection of streptozotocin （STZ）. Successfully modeled rats were randomly assigned to the model group， metformin group， and low-， medium-， and high-dose Jiangtang No. 3 prescription groups， and a normal group was also set. Daily gavage was administered for 8 weeks as follows： metformin at 0.1 g·kg^-1·d^-1， Jiangtang No. 3 prescription granules at 1.62， 3.24， 6.48 g·kg^-1·d^-1 for the respective dose groups， and sterile water for the normal and model groups. Rat body weight， fasting blood glucose （FBG）， oral glucose tolerance test （OGTT）， and insulin tolerance test （ITT） were measured. After drug intervention， enzyme-linked immunosorbent assay （ELISA） was used to determine serum levels of total cholesterol （TC）， triglycerides （TG）， low-density lipoprotein cholesterol （LDL）， high-density lipoprotein cholesterol （HDL）， non-esterified fatty acids （NEFA）， interleukin （IL）-1β， IL-18， and insulin （INS）. Hematoxylin-eosin （HE） staining was used to observe morphological changes in adipose tissue. Real-time quantitative PCR was used to detect the mRNA expression of Toll-like receptor 4 （TLR4）， nuclear factor-κB （NF-κB）， NOD-like receptor protein 3 （NLRP3）， Caspase-1， IL-1β， IL-18， and gasdermin D （GSDMD） in adipose tissue. Western blot was used to measure the corresponding protein expression levels. ResultsCompared with the model group， Jiangtang No. 3 prescription groups exhibited significantly increased body weight （P<0.05， P<0.01）， significantly reduced FBG （P<0.05， P<0.01）， significant reductions in TC， TG， NEFA， and LDL （P<0.05， P<0.01）， and a significant increase in HDL （P<0.01）. Serum levels of inflammatory mediators IL-1β and IL-18 were significantly decreased （P<0.01）， the homeostatic model assessment of insulin resistance （HOMA-IR） index was significantly reduced （P<0.05， P<0.01）， and adipose tissue pathology was improved. The protein expression levels of TLR4， NF-κB， NLRP3， Caspase-1， IL-1β， IL-18， and GSDMD were markedly decreased （P<0.05， P<0.01）， and the mRNA expression levels of these indicators were also significantly downregulated （P<0.05， P<0.01）. Some effects were superior to those of the positive control drug metformin， and certain indicators exhibited dose-dependent improvements. ConclusionT2DM rats display significant inflammatory responses， disordered glucose and lipid metabolism， and insulin resistance. Jiangtang No. 3 prescription effectively suppresses inflammatory mediators， improves glucose and lipid metabolism and insulin resistance， and ameliorates pathological changes in adipose tissue. Its mechanism may be related to the regulation of the TLR4/NF-κB/NLRP3 signaling pathway in visceral adipose tissue， thereby influencing downstream inflammatory mediators.

ObjectiveTo investigate the contamination status of ochratoxin A (OTA) in commercially available food products in Shanghai, and to assess OTA exposure levels and the associated non-carcinogenic and carcinogenic risks among pregnant women by integrating dietary consumption data of this population. MethodsThe levels of OTA contamination in 1 520 food samples collected in Shanghai from 2022 to 2023 were determined using liquid chromatography-tandem mass spectrometry. An exposure assessment model was developed based on the dietary consumption levels of pregnant women from the 2016‒2017 Shanghai Pregnant Women Dietary Monitoring Survey to calculate the estimated daily intake (EDI) of OTA, the margin of exposure for non-carcinogenic toxicity (MOE₁), and the margin of exposure for carcinogenic toxicity (MOE₂). An MOE₁ greater than 200 and an MOE₂ greater than 10 000 indicate that the non-carcinogenic toxicity and carcinogenic toxicity resulting from exposure are negligible, respectively. For samples with OTA contamination levels below the limit of detection (LOD), which accounted for more than 80% of the samples, the OTA levels were assigned values of 0 and LOD, respectively, for subsequent calculations. ResultsThe detection rates of OTA in cereals, nuts, dried fruits, and alcohol samples collected in 2022 were 2.03%, 0, 0, and 0, respectively. The OTA detection rates in cereals, nuts, dried fruits, beans, and alcohol samples collected in 2023 were 2.50%, 0.39%, 2.47%, 1.67%, and 13.33%, respectively. For pregnant women in Shanghai in 2022, simulation results indicated that when assigning a value of 0 and the LOD, theP₅₀ values of EDI for dietary OTA exposure were 0.05 and 0.72 ng·(kg·d)^-1, respectively, and the P₉₅ values of EDI for dietary OTA exposure were 0.25 and 2.40 ng·(kg·d)^-1, respectively. For pregnant women in Shanghai in 2023, the P₅₀ values of EDI for dietary OTA exposure were 0.04 and 1.00 ng·(kg·d)^-1, respectively, and the P₉₅ values of EDI for dietary OTA exposure were 0.23 and 2.67 ng·(kg·d)^-1, respectively, both substantially below the tolerable daily intake (TDI) for OTA [17 ng·(kg·d)^-1]. The EDI for dietary OTA exposure in 100.0% of Shanghai pregnant women was lower than the TDI, indicating an overall low level of dietary OTA exposure among this population. For 100.0% of pregnant women, the MOE₁ for dietary OTA exposure exceeded 200. When assigned a value of 0, the MOE₂ for 100.0% of pregnant women in both 2022 and 2023 exceeded10 000. When assigned the LOD value, 72.3% and 81.8% of pregnant women in 2022 and 2023, respectively, had an MOE₂ exceeding 10 000. ConclusionFrom 2022 to 2023, samples of cereals, nuts, dried fruits, beans, and alcohol sold in Shanghai exhibited varying degrees of OTA contamination. The overall EDI of OTA exposure among pregnant women in Shanghai remained at a low level. The non-carcinogenic and carcinogenic risks associated with OTA exposure were generally low and at controllable levels.

As a new generation of time-of-flight mass spectrometry,multiple-reflection time-of-flight mass spectrometry(MR-TOF-MS)has been increasingly applied in the fields such as nuclear physics,chemistry,and biology due to its ultra-high resolution and rapid analysis capabilities.However,the analytical performance of MR-TOF-MS largely depends on the ion bunch state entering the mass analyzer.In this study,a rectangular ion trap(RIT)was developed,designed and processed using printed circuit board technology,as an ion accumulating and focusing device for MR-TOF mass analyzer.Compared to traditional ion traps composed of two sets of planar electrodes,this RIT had higher voltage utilization efficiency,resulting in more efficient ion collection and focusing.The ions were cooled to a sufficiently small bunch for precise mass measurement with MR-TOF-MS mass spectrometry in only 1 ms of cooling time in the RIT,then orthogonally ejected to the MR-TOF mass spectrometer for mass analysis.Experimental results indicated that the working cycle,ion flux,and ion focusing state of the RIT fully met the requirements of the MR-TOF mass analyzer.When coupled with the MR-TOF mass analyzer,the RIT enabled MR-TOF-MS to achieve a mass resolution of 1.5×105.

Laccase is a type of polyphenol oxidase that can catalyze the oxidation of various substances,including phenols,aromatic amines,and catecholamines.It has been widely utilized in pollutant degradation and analytical applications.However,the high cost of preparation of natural laccase and its susceptibility to environmental factors,which can lead to denaturation and inactivation,limit its practical applications.Nanozymes,which are nanomaterials that exhibit enzyme-like properties,offer advantages such as easy preparation,adjustable activity,and exceptional stability.Currently,many types of nanozymes have been developed.Inspired by the coordination of Cu2+with amino acids in the active site of natural laccase,researchers have employed coordination synthetic strategies to prepare laccase-like nanozymes.The metal nodes in these laccase-like nanozymes include copper,manganese,and cerium,while the ligands involve a variety of chemicals like nucleotides,amino acids,polypeptides,and aromatic acids.By manipulating factors such as the metal-to-ligand ratio,reducing capacity of ligands,buffer solutions,chloride ions,bromine ions,the catalytic activity of laccase-like nanozymes can be finely tuned.In this paper,laccase-like nanozymes developed through coordination strategies were categorized and summarized,along with review of their analytical applications in detection of phenolic compounds,disease biomarkers,antibiotics,pesticides,sulfur-containing pollutants,and time-temperature indicators.Furthermore,the challenges currently faced in the research of laccase-like nanozymes and future research directions were discussed.

In analytical techniques such as ion mobility spectrometry(IMS)and mass spectrometry(MS),the ionization efficiency of target analytes is primarily constrained by the type of ionization source and factors such as the species and number density of the reactant ions.Systematic investigation into the reactivity differences of various reactant ions under varying conditions can not only significantly enhance the detection sensitivity of target compound product ions but also provide a theoretical foundation for establishing efficient detection methods based on ion-molecule reaction mechanisms.In this study,the pressure of a pressure-tunable photoionization tandem ion mobility spectrometry(PI-tandem-IMS)was reduced from ambient pressure(100 kPa)to low pressure(20 kPa)to systematically examine the reactivity differences between two negative reactant ions,CO3-and CO4-,and methyl salicylate(MeSA)under varying pressures.When the pressure decreased,the increased relative signal intensity of CO4-significantly influenced the detection sensitivity of the characteristic product ion[MeSA·O2]-.Based on differences in ion mobility(k0),the delay time for the opening of TPG2 was adjusted to selectively inject CO-3 and CO-4 in the drift region 2.Independent characterization of the reactivity of these reactant ions with MeSA in the reaction region confirmed that CO4-exhibited superior reactivity toward MeSA.The theoretical model revealed an Arrhenius plot for the ion-molecule reaction between CO4-and MeSA,showing a positive correlation between the reaction rate coefficient(k)and temperature,the activation energy Ea was 62.45 kJ/mol.Furthermore,controlling parameters such as pressure or temperature significantly influenced the progression of this ion-molecule reaction,demonstrating the technical advantages of PI-tandem-IMS in mechanistic studies and regulation of ion-molecule reactions.

The resolving power and sensitivity are critical for on-site detection of hazardous chemicals using stand-alone ion mobility spectrometry(IMS).However,improving the sensitivity and resolving power of IMS has long been a prominent research hot spot.In the commonly used IMS based on the Bradbury-Nielsen gate(BNG),the gating voltage difference(GVD)applied between the two sets of grid wires affects the electric field distribution in the ionization region and the drift region.This,in turn,influences the spatial distribution and temporal width of the injected ion swarm,and has an impact on the ion mobility discrimination,sensitivity,and resolving power of the instrument.This study showed that increasing the GVD could induce an ion converging effect,boosting the ion number density in front of the BNG by nearly 300％.To simultaneously utilize temporal compression and ion converging effects,a novel BNG controlling mode was proposed by adding a chopping state to the conventional controlling mode.This chopping state reduced the mobility discrimination effects between ions with mobility differences up to about 0.90 cm2/(V·s)to 1/22 of their original value.When analyzing hazardous chemical mixtures using the novel BNG controlling mode,compared with conventional mode,the signal intensity of low-mobility methyl salicylate ions(MS·O2)-increased by 18-fold while the resolving power maintained around 100,and the detection limit for MS was improved from 3.75 μg/L to 97 ng/L.This novel BNG controlling mode only added a potential wave to the low voltage wires,with no requirement of changing the structure of the drift tube,and was easy to apply to existing commercial instruments.

Detection of poor-water-soluble substances typically requires an organic solvent containing solution,and therefore,the biosensors that can operate in such conditions are highly promising for practical applications.However,most existing biosensors have been developed in aqueous solution and it is hard to work effectively in organic solvent systems.In this work,we uncovered that the G-quadruplex(G4)/hemin DNAzyme(G4HD)could be strongly reactivated by NH4 in organic solvents at concentration up to 30％,and the activity was significantly higher than that in aqueous solutions containing K+.Based on this discovery,a biosensing system was developed for small molecule in 40％methanol by coupling G4HD with our previously identified RNA-cleaving DNAzyme(E3).This system comprised an ATP-activated aptazyme that was made of E3 and a G4HD that was activated by the cleavage product of the aptazyme.By using a manmade pipette tip filter to separate the reaction products,the subsequent colorimetric reaction of the G4HD could be triggered.This biosensing system enabled the visualization of target molecules in organic cosolvents without any other instruments.The activable DNAzyme-cascade sensing system had potential in point-of-care detection of poor-water-soluble pollutants,thereby enhancing the practical values of functional nucleic acid-based biosensors in real-world detection conditions.

A solid-phase extraction-ultra-performance liquid chromatography-tandem mass spectrometry(SPE-UPLC-MS/MS)method was established for simultaneous determination of 10 kinds of neonicotinoid pesticide residues in aquaculture water.Based on the chemical properties of neonicotinoid pesticides and the matrix characteristics of aquaculture water,suitable temporary storage methods for water samples and appropriate solid-phase extraction columns were selected,and the extraction conditions(including elution solvents and sample loading volumes)were optimized.The method employed acetonitrile and 5 mmol/L ammonium acetate solution(containing 0.1%formic acid)as the mobile phase and an Oasis HLB solid-phase extraction column combined with PSA as a dispersive sorbent for sample purification.The method exhibited good linearity in detection of neonicotinoid in concentration range of 0.2-50 ng/mL(R2>0.99797),with a detection limit of 0.5 ng/L and a quantification limit of 1 ng/L,which were significantly lower than the maximum acceptable method detection limits(9-500 ng/L)for neonicotinoid insecticides in water published by the European Commission.In pond water,rice-fish water,and seawater,the average recoveries of the 10 target analytes were 74.6%-114.1%,with relative standard deviations ranging from 0.3%to 9.6%.Using this method,actual sample tests were conducted on the Pearl River water,Zhaoqing pond water,and Qingyuan rice-fish aquaculture water.The total concentration of five neonicotinoid pesticides in the Pearl River water ranged from 154.8 to 246.6 ng/L,the total concentration of four neonicotinoid pesticides in the Zhaoqing pond water was 95.0-176.1 ng/L,and the total concentration of three neonicotinoid pesticides in the Qingyuan rice-fish aquaculture water was 2.3-11.7 ng/L.This method was simple in operation,highly sensitive,and had strong resistance to interference.It was suitable for detection of trace neonicotinoid pesticides in aquaculture water and could provide technical support for construction of a green aquaculture environment and resolution of international trade disputes.