1.Influence of CYP2C19 gene polymorphism on platelet function and inflammatory cytokines and analysis of factors associated with poor prognosis in elderly patients with ischemic stroke
Hai LIANG ; Hong ZHANG ; Runan XIA ; Huijuan CHEN ; Mengyu JIANG ; Fanqin LI ; Panpan DI ; Miao YANG
China Pharmacy 2026;37(6):782-787
OBJECTIVE To investigate the influence of CYP2C19 gene polymorphism on platelet function and inflammatory cytokines in elderly patients with ischemic stroke, and to analyze potential factors associated with poor prognosis. METHODS A retrospective study was conducted on elderly patients with ischemic stroke admitted to our hospital from June 2024 to June 2025, wh o underwent CYP2C19 genotype testing and received antiplatelet therapy with clopidogrel. The levels of platelet function indicators and inflammatory cytokines before and after treatment were compared among patients with different metabolic phenotypes. Based on the prognosis at 6 months post-treatment, patients were divided into poor prognosis group and good prognosis group. Univariate analysis was performed on general data, metabolic phenotype, the levels of platelet function indicators and inflammatory cytokines. Variables with P <0.05 and the levels of inflammatory cytokines before treatment were included in a multivariate Logistic regression analysis to identify independent risk factors for poor prognosis. Multiple linear regression was used to further analyze the relationship between metabolic phenotypes and inflammatory cytokines. RESULTS A total of 448 elderly patients with ischemic stroke were included; among them, 162 cases were normal metabolic phenotype, 218 were intermediate metabolic phenotype, and 68 were poor metabolic phenotype. No rapid or ultrarapid metabolic phenotypes were observed. After treatment, platelet aggregation rate, the levels of P-selectin and platelet activated complex-1 (PAC-1), high-sensitivity C-reactive Protein (hs-CRP), interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) in the normal metabolic phenotype group, intermediate metabolic phenotype group, and poor metabolic phenotype group (except for platelet aggregation rate, and the levels of P-selectin and PAC-1 in the poor metabolic phenotype group) were significantly lower than those before treatment in the same group. Moreover, the above indicators in the normal metabolic phenotype group were significantly lower than those in the intermediate and poor metabolic phenotype groups at the corresponding time, and the levels of platelet function indicators in the intermediate metabolic phenotype group were significantly lower than those in the poor metabol ic phenotype group at the corresponding time ( P <0.05). Univariate and multivariate Logistic regression analyses showed that combined with hypertension, combined with diabetes mellitus, and intermediate or poor metabolic genotypes were independent risk factors for poor prognosis in elderly patients with ischemic stroke ( P <0.05). Multiple linear regression analysis showed that serum levels of hs-CRP, IL-1β, IL-6 and TNF-α before treatment were significantly higher in patients with intermediate and poor metabolic genotypes compared to those with normal metabolic genotype ( P <0.05), with a greater magnitude of increase in inflammatory cytokines observed in the patients with poor metabolic genotype. CONCLUSIONS The elderly ischemic stroke patients with CYP2C19 intermediate and poor metabolic genotypes have poor inhibition effect on platelet and higher levels of inflammatory cytokines than normal metabolic genotype; CYP2C19 gene polymorphism, and in combination with hypertension and diabetes, can be used as independent predictors of poor prognosis.
2.Protective effect and mechanism of chikusetsu saponin Ⅳa on the kidney in diabetic nephropathy rats
Yongli WANG ; Hai CHEN ; Xiaofang TIAN ; Xuechun WANG ; Liying YUAN ; Dan LIU ; Zhongfa LI ; Yanfang MENG ; Xiuyong YANG
China Pharmacy 2026;37(7):908-913
OBJECTIVE To study the protective effect and potential mechanism of chikusetsu saponin Ⅳ a (chsⅣ) on renal function in diabetic nephropathy (DN) model rats. METHODS DN rat model was established by high-fat diet combined with streptozotocin injection. Thirty-six model rats were randomly divided into model group (i.g. administration of normal saline, high-fat diet), chsⅣ low-dose and high-dose groups (i.g. administration of 90, 180 mg/kg chsⅣ, high-fat diet), with 12 rats in each group. Additionally, 10 normal rats were set as the control group (i.g. administration of normal saline, regular diet). From the 5th to the 12th week after streptozotocin injection, they were given intragastric administration of relevant drug or normal saline, once a day. After the last medication, the levels of fasting blood glucose, fasting insulin, blood urea nitrogen, serum creatinine and urine protein as well as the levels of reduced glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) in renal tissues were measured. Additionally, the insulin resistance index was calculated. Hematoxylin-eosin, periodic acid-Schiff, and Masson staining techniques were employed to examine the histopathological alterations in the renal tissue. The expressions of Notch signaling pathway-related proteins in renal tissue were detected by immunohistochemical staining and Western blot methods. RESULTS Compared with model group, the histomorphological of renal tissues in the chsⅣ low- and high-dose groups were significantly improved, with significant decreases in renal histological scores, mesangial expansion index, and glomerulosclerosis scores ( P <0.05); the levels of fasting blood glucose, fasting insulin, blood urea nitrogen, serum creatinine, urine protein and homeostasis model assessment for insulin resistance, as well as MDA content, the expression levels of Notch1, Notch intracellular domain, hairy and enhancer of Split 1 and Delta-like protein 1 in renal tissue were all significantly decreased ( P <0.05). The levels of GSH and SOD in renal tissue were significantly elevated ( P <0.05). Moreover, the improvement in these indicators was significantly more pronounced in the chsⅣ high-dose group compared to the chsⅣ low-dose group ( P <0.05). CONCLUSIONS ChsⅣ can ameliorate renal pathological damage and functional impairment in DN rats. Its underlying mechanisms include restoration of glucose homeostasis and insulin sensitivity, attenuation of renal oxidative stress, and suppression of aberrant Notch signaling pathway activation.
3.Thread embedding pretreatment at Xinshu(BL 15)improves cardiac function of acute myocardial ischemia rats
Xiaoqing CHEN ; Luyao BIAN ; Xingyu LU ; Tao YANG ; Li Xiang HAI
Chinese Journal of Tissue Engineering Research 2026;30(4):882-891
BACKGROUND:Acupuncture at Xinshu(BL 15)can significantly improve cardiac function and protect myocardial cells in acute myocardial ischemia,but the effect and mechanism of thread embedding treatment at Xinshu(BL 15)on cardiac function in acute myocardial ischemia are yet unclear.Nuclear factor κB activation often appears as an intranuclear translocation of the P65 isoform,and activation of the nuclear factor κB signaling pathway is marked by elevated P65 levels.OBJECTIVE:To explore the effects of thread embedding pretreatment at Xinshu(BL 15)on cardiac function and the expression levels of interleukin-10,tumor necrosis factor-α,P65 genes and proteins in rats with acute myocardial ischemia.METHODS:Thirty-two male Sprague-Dawley rats were randomly divided into a blank group,a model group,a Xinshu(BL 15)acupoint group,and a non-meridian/non-acupoint group using a random number table method,with eight rats in each group.Rat models of acute myocardial ischemia were established in the latter three groups.The Xinshu(BL 15)acupoint group had thread embedding at Xinshu(BL 15)for 14 days,followed by subcutaneous injection of isoproterenol hydrochloride into the back to establish an acute myocardial ischemia rat model.The non-meridian/non-acupoint group had local thread embedding for 14 days,and the rest procedures were the same as above.In the model group,Xinshu(BL 15)was only marked,and the rest procedures were the same as above.In the blank group,Xinshu(BL 15)was only marked,and then an equal amount of physiological saline was injected subcutaneously into the back.After 24 hours of modeling,electrocardiogram and cardiac ultrasound were performed.Abdominal aorta blood was extracted for detection of serum creatine kinase and creatine kinase isoenzyme levels using enzyme-linked immunosorbent assay.Subsequently,the rats were euthanized and samples were collected.Hematoxylin-eosin and TUNEL staining were used to observe the pathological changes of myocardial tissue and the apoptosis of myocardial cells.Real-time fluorescence quantitative PCR(RT-qPCR)and western blot were used to detect the mRNA and protein expression of tumor necrosis factor-α,interleukin-10,and P65 in myocardial tissue respectively.RESULTS AND CONCLUSION:(1)Electrocardiogram:Compared with the blank group,the model group,non-meridian/non-acupoint group,and Xinshu(BL 15)acupoint group had significantly elevated ST segment in lead Ⅱ of the electrocardiogram.(2)Cardiac ultrasound:Compared with the model group,the Left ventricular end-systolic dimension in the Xinshu(BL 15)acupoint group were significantly reduced(P<0.05),while left ventricular ejection fraction and left ventricular fractional shortening rate were significantly increased(P<0.05).(4)Serum creatine kinase and creatine kinase isoenzyme:Compared with the model group,the Xinshu(BL 15)acupoint group showed a significant decrease in serum creatine kinase and creatine kinase isoenzyme levels(P<0.05).(4)Hematoxylin-eosin staining:Compared with the model group,the arrangement of myocardial fibers in the Xinshu(BL 15)acupoint group was basically neat,with less edema and a small amount of inflammatory cell infiltration.(5)TUNEL staining:Compared with the model group,the fluorescence intensity of myocardial cell apoptosis in the Xinshu(BL 15)acupoint group was significantly reduced,and its apoptosis rate was significantly reduced(P<0.05).(6)RT-qPCR and western blot:Compared with the model group,the myocardial tissue interleukin-10 level in the Xinshu(BL 15)acupoint group was significantly increased(P<0.05),while tumor necrosis factor-α and P65 levels were significantly decreased(P<0.05).These findings indicate that thread embedding pretreatment at Xinshu(BL 15)can improve cardiac function in rats with acute myocardial ischemia,and its mechanism of action may be related to the inhibition of the activation of the nuclear factor-κB signaling pathway.
4.Thread embedding pretreatment at Xinshu(BL 15)improves cardiac function of acute myocardial ischemia rats
Xiaoqing CHEN ; Luyao BIAN ; Xingyu LU ; Tao YANG ; Li Xiang HAI
Chinese Journal of Tissue Engineering Research 2026;30(4):882-891
BACKGROUND:Acupuncture at Xinshu(BL 15)can significantly improve cardiac function and protect myocardial cells in acute myocardial ischemia,but the effect and mechanism of thread embedding treatment at Xinshu(BL 15)on cardiac function in acute myocardial ischemia are yet unclear.Nuclear factor κB activation often appears as an intranuclear translocation of the P65 isoform,and activation of the nuclear factor κB signaling pathway is marked by elevated P65 levels.OBJECTIVE:To explore the effects of thread embedding pretreatment at Xinshu(BL 15)on cardiac function and the expression levels of interleukin-10,tumor necrosis factor-α,P65 genes and proteins in rats with acute myocardial ischemia.METHODS:Thirty-two male Sprague-Dawley rats were randomly divided into a blank group,a model group,a Xinshu(BL 15)acupoint group,and a non-meridian/non-acupoint group using a random number table method,with eight rats in each group.Rat models of acute myocardial ischemia were established in the latter three groups.The Xinshu(BL 15)acupoint group had thread embedding at Xinshu(BL 15)for 14 days,followed by subcutaneous injection of isoproterenol hydrochloride into the back to establish an acute myocardial ischemia rat model.The non-meridian/non-acupoint group had local thread embedding for 14 days,and the rest procedures were the same as above.In the model group,Xinshu(BL 15)was only marked,and the rest procedures were the same as above.In the blank group,Xinshu(BL 15)was only marked,and then an equal amount of physiological saline was injected subcutaneously into the back.After 24 hours of modeling,electrocardiogram and cardiac ultrasound were performed.Abdominal aorta blood was extracted for detection of serum creatine kinase and creatine kinase isoenzyme levels using enzyme-linked immunosorbent assay.Subsequently,the rats were euthanized and samples were collected.Hematoxylin-eosin and TUNEL staining were used to observe the pathological changes of myocardial tissue and the apoptosis of myocardial cells.Real-time fluorescence quantitative PCR(RT-qPCR)and western blot were used to detect the mRNA and protein expression of tumor necrosis factor-α,interleukin-10,and P65 in myocardial tissue respectively.RESULTS AND CONCLUSION:(1)Electrocardiogram:Compared with the blank group,the model group,non-meridian/non-acupoint group,and Xinshu(BL 15)acupoint group had significantly elevated ST segment in lead Ⅱ of the electrocardiogram.(2)Cardiac ultrasound:Compared with the model group,the Left ventricular end-systolic dimension in the Xinshu(BL 15)acupoint group were significantly reduced(P<0.05),while left ventricular ejection fraction and left ventricular fractional shortening rate were significantly increased(P<0.05).(4)Serum creatine kinase and creatine kinase isoenzyme:Compared with the model group,the Xinshu(BL 15)acupoint group showed a significant decrease in serum creatine kinase and creatine kinase isoenzyme levels(P<0.05).(4)Hematoxylin-eosin staining:Compared with the model group,the arrangement of myocardial fibers in the Xinshu(BL 15)acupoint group was basically neat,with less edema and a small amount of inflammatory cell infiltration.(5)TUNEL staining:Compared with the model group,the fluorescence intensity of myocardial cell apoptosis in the Xinshu(BL 15)acupoint group was significantly reduced,and its apoptosis rate was significantly reduced(P<0.05).(6)RT-qPCR and western blot:Compared with the model group,the myocardial tissue interleukin-10 level in the Xinshu(BL 15)acupoint group was significantly increased(P<0.05),while tumor necrosis factor-α and P65 levels were significantly decreased(P<0.05).These findings indicate that thread embedding pretreatment at Xinshu(BL 15)can improve cardiac function in rats with acute myocardial ischemia,and its mechanism of action may be related to the inhibition of the activation of the nuclear factor-κB signaling pathway.
5.Electroacupuncture Ameliorates NLRP3-mediated Pyroptosis in Spinal Cord Injury Rats by Reshaping The Gut Microbiota
Yin-Jie CUI ; Hong-Ru LI ; Jing-Yi LIU ; Hai-Lin DU ; Shu-Wen LIU ; Yuan YANG ; Chen-Guang ZHENG ; Jian-Qin XIANG ; Xiao-Juan SONG
Progress in Biochemistry and Biophysics 2026;53(5):1132-1153
ObjectiveSpinal cord injury (SCI) directly impairs the regulatory function of the autonomic nervous system, induces intestinal dysfunction, and significantly reduces patients’ quality of life. Preclinical studies have shown that electroacupuncture (EA) therapy can regulate the brain-gut axis and is used to treat central nervous system diseases such as major depressive disorder, Alzheimer’s disease and Parkinson’s disease. Recent research has established that fecal microbiota transplantation (FMT) from EA-treated SCI rats restored intestinal motility and colonic morphology. However, it remains unclear whether the regulation of gut microbiota by EA therapy directly contributes to neural repair after SCI. This study aims to explore whether gut microbiota mediates the neuroprotective effect of EA in the treatment of SCI and its possible mechanism. MethodsThe study employed RNA transcriptome analysis of spinal cord tissue to characterize gene expression profiles and to identify key signaling pathways following EA treatment for SCI. Hematoxylin-Eosin (HE) staining and Nissl staining were used to observe the morphological changes in spinal cord tissue. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) were applied to detect the effects of EA on the expression of proteins related to nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) -dependent pyroptosis. Using 16S rDNA sequencing, the study observed alterations in gut microbiota diversity and community composition in SCI rats. Prior to establishing SCI models, rats were pretreated with an antibiotic cocktail to induce gut dysbiosis, and the effects on intestinal function and spinal cord neural repair were evaluated. FMT was performed to investigate the regulatory effects of post-EA FMT on motor function, general status, liver and spleen indices, and NLRP3-mediated pyroptosis in SCI rats. ResultsEA improved motor function and reduced regulated neuronal cell death in SCI rats. Transcriptomic analysis demonstrated the activation of immune- and inflammation-related pathways post-SCI, including NOD-like receptors, nuclear factor-kappa B(NF-κB), and Toll-like receptor (TLR) pathways. EA primarily influenced intestinal inflammation and autoimmune functions. 16S rDNA sequencing illustrated that EA did not alter the diversity of gut microbiota. However, EA altered the gut microbiota composition in SCI rats, increasing Lactobacillus and Akkermansia genera while rebalancing the Firmicutes/Bacteroidetes ratio. Furthermore, depletion of gut microbiota by antibiotics disrupted the intestinal barrier, reduced the expression of intestinal barrier proteins Zonula Occludens-1 (ZO-1) and Occludin, elevated serum lipopolysaccharide-binding protein (LBP) levels, exacerbated spinal cord tissue damage, and hindered motor function recovery in SCI rats. FMT from donors treated with EA reduced LBP levels in the intestine, blood, and spinal cord of rats, inhibited the TLR4 myeloid differentiation primary response protein 88 (MyD88)-NF‑κB pathway and NLRP3-dependent pyroptosis, and improved motor function. On the other hand, FMT treatment resulted in decreased body weight and food intake, whereas FMT using EA-treated donors effectively alleviated these alterations. ConclusionEA effectively alleviated neuroinflammatory responses in rats with SCI, primarily through regulating the gut microbiota and suppressing the NLRP3-dependent pyroptosis signaling pathway.
6.Electroacupuncture Ameliorates NLRP3-mediated Pyroptosis in Spinal Cord Injury Rats by Reshaping The Gut Microbiota
Yin-Jie CUI ; Hong-Ru LI ; Jing-Yi LIU ; Hai-Lin DU ; Shu-Wen LIU ; Yuan YANG ; Chen-Guang ZHENG ; Jian-Qin XIANG ; Xiao-Juan SONG
Progress in Biochemistry and Biophysics 2026;53(5):1132-1153
ObjectiveSpinal cord injury (SCI) directly impairs the regulatory function of the autonomic nervous system, induces intestinal dysfunction, and significantly reduces patients’ quality of life. Preclinical studies have shown that electroacupuncture (EA) therapy can regulate the brain-gut axis and is used to treat central nervous system diseases such as major depressive disorder, Alzheimer’s disease and Parkinson’s disease. Recent research has established that fecal microbiota transplantation (FMT) from EA-treated SCI rats restored intestinal motility and colonic morphology. However, it remains unclear whether the regulation of gut microbiota by EA therapy directly contributes to neural repair after SCI. This study aims to explore whether gut microbiota mediates the neuroprotective effect of EA in the treatment of SCI and its possible mechanism. MethodsThe study employed RNA transcriptome analysis of spinal cord tissue to characterize gene expression profiles and to identify key signaling pathways following EA treatment for SCI. Hematoxylin-Eosin (HE) staining and Nissl staining were used to observe the morphological changes in spinal cord tissue. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) were applied to detect the effects of EA on the expression of proteins related to nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) -dependent pyroptosis. Using 16S rDNA sequencing, the study observed alterations in gut microbiota diversity and community composition in SCI rats. Prior to establishing SCI models, rats were pretreated with an antibiotic cocktail to induce gut dysbiosis, and the effects on intestinal function and spinal cord neural repair were evaluated. FMT was performed to investigate the regulatory effects of post-EA FMT on motor function, general status, liver and spleen indices, and NLRP3-mediated pyroptosis in SCI rats. ResultsEA improved motor function and reduced regulated neuronal cell death in SCI rats. Transcriptomic analysis demonstrated the activation of immune- and inflammation-related pathways post-SCI, including NOD-like receptors, nuclear factor-kappa B(NF-κB), and Toll-like receptor (TLR) pathways. EA primarily influenced intestinal inflammation and autoimmune functions. 16S rDNA sequencing illustrated that EA did not alter the diversity of gut microbiota. However, EA altered the gut microbiota composition in SCI rats, increasing Lactobacillus and Akkermansia genera while rebalancing the Firmicutes/Bacteroidetes ratio. Furthermore, depletion of gut microbiota by antibiotics disrupted the intestinal barrier, reduced the expression of intestinal barrier proteins Zonula Occludens-1 (ZO-1) and Occludin, elevated serum lipopolysaccharide-binding protein (LBP) levels, exacerbated spinal cord tissue damage, and hindered motor function recovery in SCI rats. FMT from donors treated with EA reduced LBP levels in the intestine, blood, and spinal cord of rats, inhibited the TLR4 myeloid differentiation primary response protein 88 (MyD88)-NF‑κB pathway and NLRP3-dependent pyroptosis, and improved motor function. On the other hand, FMT treatment resulted in decreased body weight and food intake, whereas FMT using EA-treated donors effectively alleviated these alterations. ConclusionEA effectively alleviated neuroinflammatory responses in rats with SCI, primarily through regulating the gut microbiota and suppressing the NLRP3-dependent pyroptosis signaling pathway.
7.Supramolecular Binding Behavior and Solubilization of Cationic Cyclodextrins towards Liquiritigenin
Ying-Hui DENG ; Dong-Jing ZHANG ; Hai-Kun WANG ; Jia-Xing CHEN ; Shuang SONG ; Bo YANG ; Xia-Li LIAO
Chinese Journal of Analytical Chemistry 2025;53(2):289-299,中插20-中插30
Liquiritigenin(LG)is a flavone of pharmacological importance,however,its application potential is severely limited due to its poor water solubility.LG could be disassociated slightly in water to form phenolate anion,therefore,better solubilization effect is expected by inclusion with cationic cyclodextrins(CCDs).In this work,four kinds of CCDs modified with amino groups at the primary face were synthesized,and their solid inclusion complexes with LG were successfully prepared by preparing their saturated solutions.The formation of the solid inclusion complexes was confirmed by scanning electron microscopy(SEM)and powder X-ray diffraction(PXRD),and their supramolecular binding behavior in solution was studied using multiple techniques.A 1∶1 inclusion stoichiometry of inclusion complexation was defined using Job plot by ultraviolet-visible(UV-vis)spectroscopy,and their binding stability constants(Ks)were determined as 2862.77,3494.70,6521.85 and 9599.48 L/mol using UV-vis spectroscopic titration,far more superior to that of nativeβ-CD(Ks=236.79 L/mol).This indicated that the amino side chains on CCDs could actively participate in the inclusion complexation through anion-cation interactions,significantly strengthening the host-guest binding between CCDs and LG.The inclusion modes were further elucidated based on proton and two-dimensional rotating-frame overhauser enhancement spectroscopy(2D-ROESY)nuclear magnetic resonance(NMR)experiments and molecular docking.Water solubility of LG was dramatically promoted up to 4.9 mg/mL,which was 70-fold higher than that of native LG.This study could draw inspiration for the binding and solubilization of phenols such as flavones by design of cationic macrocyclic molecules.
8.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.
9.Improvement of Performance of Ion Mobility Spectrometry Using A Low Discrimination Bradbury-Nielsen Gate Controlling Method
Qi-Mu YANG ; Yi-Qian XU ; Man-Man PAN ; Dan-Dan JIANG ; Chuang CHEN ; Hai-Yang LI
Chinese Journal of Analytical Chemistry 2025;53(6):875-884
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.
10.Development of A Low Field Ion Extraction System for Time-of-Flight Secondary Ion Mass Spectrometry
De-Ze WANG ; Chen-Xin WU ; Yi CHEN ; Fu-Xin DU ; Lei HUA ; Hai-Yang LI ; Jian-Hua WANG ; Ping CHEN
Chinese Journal of Analytical Chemistry 2025;53(7):1072-1081
Time-of-flight secondary ion mass spectrometer(TOF-SIMS)is a highly sensitive surface analysis instrument with high spatial resolution.Traditional TOF-SIMS instruments for sample targets use high field extraction methods.Although the ion collection efficiency is high,it is prone to issues such as low-energy ion beam defocusing,sample morphology sensitivity,and organic molecule ion dissociation.This study aimed to develope an efficient low-field ion extraction system suitable for TOF-SIMS with a continuous beam source.The SIMION simulation software was used to construct a model of the secondary ion optical extraction system.The key factors affecting the extraction efficiency were studied,and the structural parameters of the extraction cone were optimized.Using an indium target as the sample,an experimental test of the performance of the ion extraction system was carried out on the TOF-SIMS instrument.The influences of the voltages of the ion extraction cone and the single lens on the ion extraction efficiency were consistent with the simulation results.By adopting the technology of deflection and coaxial dynamic compensation,the imaging field of view of the ion extraction system was increased to 500 μm×500 μm.The energy window of the ion extraction system reached 10 eV,and the large imaging depth of field of 400 μm was achieved.In the test of a 5 mg/L cholesterol thin film sample,the signal-to-noise ratio of the characteristic peak[M-OH]+reached 4453.The results showed that this low-field secondary ion extraction system effectively improved the performance of the continuous beam TOF-SIMS instrument.

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