1.Mechanisms of Jiangtang No. 3 Prescription in Alleviating Adipose Tissue Insulin Resistance in Diabetic Rats via TLR4/NF-κB/NLRP3 Signaling Pathway-mediated Inflammation
Tongxun WANG ; Lantian LIU ; Runqi LI ; Haoxiang LI ; Yi ZHAO ; Tian TIAN ; Rufeng MA ; Sihua GAO ; Dandan ZHAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(4):109-117
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.
2.Olfactory Receptors Expressed in The Intestine and Their Functions
Pei-Wen YANG ; Meng-Meng YUAN ; Ying ZHOU ; Peng LI ; Gui-Hong QI ; Ying YANG ; Zhong-Yi MAO ; Meng-Sha ZHOU ; Xiao-Shuang MAO ; Jian-Ping XIE ; Yi-Nan YANG ; Shi-Hao SUN
Progress in Biochemistry and Biophysics 2026;53(3):534-549
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.
3.The Dual Role of p21 in Hormone-related Cancers and Its Therapeutic Implications
Jia-Wen LI ; Yang CHEN ; Jia-Qi WANG ; Yu-Kai MA ; Zhi-Yi GUO
Progress in Biochemistry and Biophysics 2026;53(3):593-608
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.
4.Assessment of ochratoxin A exposure in the diets of pregnant women in Shanghai
Kailin LI ; Renjie QI ; Hua CAI ; Xia SONG ; Jingjin YANG ; Danping QIU ; Zhenni ZHU ; Yi HE ; Baozhang LUO ; Hong LIU
Shanghai Journal of Preventive Medicine 2026;38(3):181-186
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.
5.SIRT5 Potentiates Hepatocarcinogenesis by Modulating Protein Acylation in Mice
Yu ZHANG ; Feng-Rui REN ; Jia-Yun LI ; Xiang-Yu CHEN ; Zi-Yi WANG ; Qi SUN ; Jun-Cheng ZHAO ; Ye ZHANG ; Zhen HUANG ; Hao HU ; Tao-Tao WEI ; Min XIAO
Progress in Biochemistry and Biophysics 2026;53(6):1712-1722
ObjectiveHepatocellular carcinoma (HCC) represents 90% of all primary liver cancers. The main risk factors associated with HCC include viral hepatitis (B and/or C), alcohol abuse, and metabolic dysfunction-associated steatotic liver disease (MASLD), which progressively advance to liver fibrosis, cirrhosis, and ultimately evolve into HCC. Surgical resection represents the most effective treatment for HCC, while recent advances in immunotherapy, including immune checkpoint inhibitors and adoptive cell therapies, have provided improved treatment prospects for patients with unresectable HCC. However, the complex metabolic heterogeneity of HCC limits the therapeutic efficacy. Metabolic intermediates acyl-CoA not only provide energy and substrates for numerous biochemical reactions but also serve as donors for protein lysine acylation, a major class of post-translational modification (PTM). Therefore, a deeper understanding of the molecular mechanisms underlying protein lysine acylation and hepatocarcinogenesis is urgently needed. MethodsThe levels of protein lysine acylation and silence information regulator 5 (SIRT5) expression levels in clinical HCC samples were analyzed by Western blot. Quantitative malonylome and succinylome of HCC samples were analyzed by antibody-based affinity enrichment coupled with tandem mass spectrometry. The proliferation of HCC cells was analyzed with Cell Counting Kit-8 (CCK-8) assays, the apoptosis was quantified by Annexin V-FITC/propidium iodide (PI) staining coupled with flow cytometry, and the ability of cells to migrate was assayed by Transwell assays. The enzymatic activity of glutathione S-transferase Mu 1 (GSTM1) was quantified. Transgenic mice with hepatic overexpression of SIRT5 were constructed using CRISPR-Cas9, and primary hepatocarcinogenesis was induced by administration of diethylnitrosamine. ResultsWestern blot analysis indicated that the expression level of SIRT5 was elevated in clinical samples from HCC patients, and the levels of lysine malonylation, glutarylation, and succinylation were significantly reduced in HCC tissues. Knockout of SIRT5 in MHCC-97H and MHCC-97L hepatoma cells suppressed cell proliferation, and increased the percentage of apoptotic cells significantly. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the differentially malonylome and succinylome of HCC samples revealed significant enrichment in two major classes of biological processes: core energy metabolism (e.g., glycolysis/gluconeogenesis, tricarboxylic acid metabolic process, fatty acid beta oxidation) and detoxification and oxidative stress response (e.g., response to toxic substance, chemical carcinogenesis, reactive oxygen species (ROS)). SIRT5 removes malonylation from lysine residues in GSTM1 and restores its detoxification activity, which is crucial for the survival of hepatocytes under stressed conditions. More importantly, in vivo experiment indicated that hepatic-specific overexpression of SIRT5 in mice accelerated diethylnitrosamine-induced liver fibrosis and hepatocarcinogenesis, indicating the critical role of SIRT5 in HCC progression. ConclusionThis study highlights the previously unrecognized SIRT5-GSTM1 axis as a key regulator in hepatocarcinogenesis, and suggests a potential target for the treatment of patients with HCC.
6.Expert consensus on apical microsurgery.
Hanguo WANG ; Xin XU ; Zhuan BIAN ; Jingping LIANG ; Zhi CHEN ; Benxiang HOU ; Lihong QIU ; Wenxia CHEN ; Xi WEI ; Kaijin HU ; Qintao WANG ; Zuhua WANG ; Jiyao LI ; Dingming HUANG ; Xiaoyan WANG ; Zhengwei HUANG ; Liuyan MENG ; Chen ZHANG ; Fangfang XIE ; Di YANG ; Jinhua YU ; Jin ZHAO ; Yihuai PAN ; Shuang PAN ; Deqin YANG ; Weidong NIU ; Qi ZHANG ; Shuli DENG ; Jingzhi MA ; Xiuping MENG ; Jian YANG ; Jiayuan WU ; Yi DU ; Junqi LING ; Lin YUE ; Xuedong ZHOU ; Qing YU
International Journal of Oral Science 2025;17(1):2-2
Apical microsurgery is accurate and minimally invasive, produces few complications, and has a success rate of more than 90%. However, due to the lack of awareness and understanding of apical microsurgery by dental general practitioners and even endodontists, many clinical problems remain to be overcome. The consensus has gathered well-known domestic experts to hold a series of special discussions and reached the consensus. This document specifies the indications, contraindications, preoperative preparations, operational procedures, complication prevention measures, and efficacy evaluation of apical microsurgery and is applicable to dentists who perform apical microsurgery after systematic training.
Microsurgery/standards*
;
Humans
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Apicoectomy
;
Contraindications, Procedure
;
Tooth Apex/diagnostic imaging*
;
Postoperative Complications/prevention & control*
;
Consensus
;
Treatment Outcome
7.Expert consensus on the diagnosis and treatment of cemental tear.
Ye LIANG ; Hongrui LIU ; Chengjia XIE ; Yang YU ; Jinlong SHAO ; Chunxu LV ; Wenyan KANG ; Fuhua YAN ; Yaping PAN ; Faming CHEN ; Yan XU ; Zuomin WANG ; Yao SUN ; Ang LI ; Lili CHEN ; Qingxian LUAN ; Chuanjiang ZHAO ; Zhengguo CAO ; Yi LIU ; Jiang SUN ; Zhongchen SONG ; Lei ZHAO ; Li LIN ; Peihui DING ; Weilian SUN ; Jun WANG ; Jiang LIN ; Guangxun ZHU ; Qi ZHANG ; Lijun LUO ; Jiayin DENG ; Yihuai PAN ; Jin ZHAO ; Aimei SONG ; Hongmei GUO ; Jin ZHANG ; Pingping CUI ; Song GE ; Rui ZHANG ; Xiuyun REN ; Shengbin HUANG ; Xi WEI ; Lihong QIU ; Jing DENG ; Keqing PAN ; Dandan MA ; Hongyu ZHAO ; Dong CHEN ; Liangjun ZHONG ; Gang DING ; Wu CHEN ; Quanchen XU ; Xiaoyu SUN ; Lingqian DU ; Ling LI ; Yijia WANG ; Xiaoyuan LI ; Qiang CHEN ; Hui WANG ; Zheng ZHANG ; Mengmeng LIU ; Chengfei ZHANG ; Xuedong ZHOU ; Shaohua GE
International Journal of Oral Science 2025;17(1):61-61
Cemental tear is a rare and indetectable condition unless obvious clinical signs present with the involvement of surrounding periodontal and periapical tissues. Due to its clinical manifestations similar to common dental issues, such as vertical root fracture, primary endodontic diseases, and periodontal diseases, as well as the low awareness of cemental tear for clinicians, misdiagnosis often occurs. The critical principle for cemental tear treatment is to remove torn fragments, and overlooking fragments leads to futile therapy, which could deteriorate the conditions of the affected teeth. Therefore, accurate diagnosis and subsequent appropriate interventions are vital for managing cemental tear. Novel diagnostic tools, including cone-beam computed tomography (CBCT), microscopes, and enamel matrix derivatives, have improved early detection and management, enhancing tooth retention. The implementation of standardized diagnostic criteria and treatment protocols, combined with improved clinical awareness among dental professionals, serves to mitigate risks of diagnostic errors and suboptimal therapeutic interventions. This expert consensus reviewed the epidemiology, pathogenesis, potential predisposing factors, clinical manifestations, diagnosis, differential diagnosis, treatment, and prognosis of cemental tear, aiming to provide a clinical guideline and facilitate clinicians to have a better understanding of cemental tear.
Humans
;
Dental Cementum/injuries*
;
Consensus
;
Diagnosis, Differential
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Cone-Beam Computed Tomography
;
Tooth Fractures/therapy*
8.Development of A High-performance Rectangular Ion Trap for Multi-reflection Time-of-Flight Mass Spectrometer
Xiao-Xia CHEN ; Yi REN ; Qi HUANG ; Da-Jun XIANG ; Chang-Wei LI ; Yi HONG ; Lei LI ; Zheng-Xu HUANG ; Mei LI ; Jing-Wei XU ; Zhen ZHOU
Chinese Journal of Analytical Chemistry 2025;53(1):38-46
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.
9.Laccase-like Nanozyme Prepared with Coordination Strategy and Their Analytical Applications
Bin-Fu WANG ; Zi-Ruo ZHANG ; Qi GAO ; Hao-Di XU ; Wen-Ying LI ; Ding-Yi TONG
Chinese Journal of Analytical Chemistry 2025;53(2):164-175
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.
10.Ion Filtering and Reactivity Investigation Based on Tandem Ion Mobility Spectrometry
Yi-Qian XU ; Qi-Mu YANG ; Man-Man PAN ; Dan-Dan JIANG ; Chuang CHEN ; Hai-Yang LI
Chinese Journal of Analytical Chemistry 2025;53(5):740-748
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.

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