1.Analysis of dilemmas and recommendations for value assessment of antitumor combination therapies
Xuerong WANG ; Ting ZHOU ; Yan LI ; Hongchao LI
China Pharmacy 2026;37(11):1447-1451
OBJECTIVE To systematically identify the dilemmas in value assessment of antitumor combination therapies, and to provide evidence for health insurance coverage, drug pricing, and clinical decision-making. METHODS The concept of “surplus value space” was introduced to cons truct a value assessment framework, under which the dilemmas in three assessment scenarios were analyzed. Optimization recommendations were proposed by drawing on international research addressing similar challenges. RESULTS & CONCLUSIONS The core dilemma of value assessment for antitumor combination therapies lies in insufficient surplus value space. When the cost of the backbone therapy exceeds its corresponding health value, the add-on drug encounters a “free but uneconomical”problem. Existing international value assessment methods have limitations such as flawed evaluation frameworks, difficulty in operationalizing the quality-adjusted life year allocation framework, and frequent occurrence of the “free but uneconomical”problem, rendering them inadequate for the complex scenarios of antitumor combination therapies. To address these dilemmas, strategies such as adjusting payment thresholds, exploring discounted pricing, conducting multi-product linkage negotiations, and delaying insurance access are recommended to improve the rationality and feasibility of value assessment for antitumor combination therapies.
2.Skeleton Binding Protein 1 of Plasmodium berghei Influences Deformability and Cytoskeletal Ultrastructure of Infected Erythrocyte
Xin-Yue GUO ; Huan-Qi ZHAO ; Yan-Xuan ZHONG ; Ru-Meng JIANG ; Yao-Xian LI ; Lei-Ting PAN ; Qian WANG ; Xiao-Yu SHI
Progress in Biochemistry and Biophysics 2026;53(4):1015-1027
ObjectiveThe malaria parasites remodel the host erythrocyte structure by exporting parasite proteins that interact with the membrane skeleton proteins of red blood cells (RBCs), facilitating their intracellular survival and pathogenicity. Skeleton-binding protein 1 (SBP1) is a conserved exported protein across Plasmodium species. In Plasmodium falciparum, SBP1 has been reported to interact with erythrocyte membrane skeleton proteins 4.1R and spectrin, while its contribution to erythrocyte remodeling and parasite virulence in Plasmodium berghei (Pb) remains unclear. This study aims to determine whether PbSBP1 associates with the host cytoskeletal protein 4.1R and to investigate its role in the remodeling of host RBCs and the pathogenicity of Plasmodium berghei. MethodsIn Plasmodium berghei, the relationship between PbSBP1 and the erythrocyte cytoskeletal protein 4.1R was examined using co-immunoprecipitation. A Pbsbp1 gene knockout mutant of Plasmodium berghei (Pbsbp1∆) was generated based on the principle of double crossover homologous recombination. The deformability of erythrocytes infected with Pbsbp1∆ parasites was assessed using microfluidic methods. Microchannels with an array of cylindrical pillars were used to detect modifications in infected RBC deformability. The infected RBCs were squashed between the rows and recovered between the columns and the transit velocity (μm/s) of infected RBCs travelling through the microchannel was recorded. The component of the erythrocyte membrane skeleton junctional complex, tropomodulin (TMOD), was fluorescently labeled, and the cytoskeletal network of infected erythrocytes was imaged using super-resolution stochastic optical reconstruction microscopy (STORM) to analyze ultrastructural changes in the cytoskeleton of wild-type (WT) and Pbsbp1∆-infected erythrocytes. Actin-based junctional complexes were displayed as individual clusters by the labeled TMOD in the STORM images, and the cluster densities and distances between adjacent clusters of infected RBCs were calculated. Additionally, rodent malaria models (BALB/c mice) and experimental cerebral malaria models (C57BL/6 mice) were employed to monitor the growth of Pbsbp1∆ and WT parasites during the intraerythrocytic stage and their capacity to induce cerebral malaria in mice. ResultsPbSBP1 may participate in the remodeling of infected erythrocytes through direct or indirect interaction with the erythrocyte cytoskeletal protein 4.1R. Microfluidic assays revealed that the deformability of erythrocytes infected with Pbsbp1∆ parasites was significantly enhanced compared to those infected with WT parasites. STORM imaging further demonstrated that the ultrastructure of the erythrocyte cytoskeleton in Pbsbp1∆-infected cells was altered relative to that in WT-infected erythrocytes. The distances between nearest neighbors of clusters had a tendency to increase while the cluster densities were decreased in Pbsbp1∆-infected RBCs compared to WT-infected RBCs. Subsequent phenotypic analysis indicated that the growth rate of Pbsbp1∆ parasites during the intraerythrocytic stage was significantly slower than that of WT parasites, and their ability to induce cerebral malaria in mice was also attenuated. These findings suggest that PbSBP1 is involved in the remodeling of the erythrocyte membrane skeleton, likely through its direct or indirect interaction with protein 4.1R, thereby regulating the deformability of infected erythrocytes and influencing the pathogenicity of the blood-stage parasites. ConclusionThis study establishes a role for PbSBP1 in host erythrocyte remodeling and parasite virulence, providing new research strategies for the prevention and treatment of malaria.
3.Research progress on stem cells in the treatment of sepsis
Ting CHEN ; Linlin CHEN ; Zhao CHEN ; Junping ZHANG ; Yan WANG
Journal of Pharmaceutical Practice and Service 2026;44(2):59-64
At present, the treatment of sepsis depends largely on non-specific methods, highlighting an urgent need for novel therapeutic strategies. Stem cells have garnered significant attention in the treatment of various diseases due to their unique biological properties. Stem cells enhance sepsis survival through mechanisms such as reducing bacterial burden, modulating inflammation, and ameliorating organ dysfunction. Recent studies have shown that stem cells can increase the survival rate of sepsis patients through multiple pathways such as reducing the bacterial load of the host, regulating inflammatory homeostasis, and improving multi-organ dysfunction. Their derivatives, exosomes, can also alleviate the imbalanced immune response in sepsis patients. Recent advances in stem cell-based therapies for sepsis were summarized in this paper.
4.Pseudolaric Acid B-linked Double-network Hydrogel Alleviates Pruritus by Inhibiting The Growth of Staphylococcus aureus
Ye YOU ; Yan YANG ; Tong-Yu LI ; Cheng-Long CAI ; Ting WANG ; Chan ZHU ; Zong-Xiang TANG
Progress in Biochemistry and Biophysics 2026;53(6):1734-1745
ObjectiveThis study aimed to elucidate the mechanistic role of Staphylococcus aureus in the pathogenesis of atopic dermatitis (AD), a chronic inflammatory skin disorder characterized by pruritus and barrier dysfunction. A key focus was screening traditional Chinese medicine (TCM) active components with dual antibacterial and antipruritic efficacy, followed by systematic evaluation of their in vitro antibacterial activity. Additionally, a novel drug delivery system was constructed to enable localized efficient drug delivery, inhibiting S. aureus proliferation and alleviating its induced pruritus, thereby providing new strategies for targeted AD therapy. MethodsMale C57BL/6J mice aged 6-8 weeks (body weight 18-22 g) were used to establish an AD model via repeated oxazolone sensitization. On day 14, microbial samples were collected from the lesional area (1 cm²) using sterile cotton swabs, followed by vortex mixing, serial dilution, and plating on 5% sheep blood agar plates (incubated at 37°C for 24 h). Single colonies with complete transparent β-hemolytic zones were isolated and identified as vancomycin-intermediate S. aureus (VISA) via 16S rRNA sequencing. An S. aureus mono-infection animal model was then established by applying gauze saturated with bacterial suspension (McFarland turbidity 0.1) to the nape and back skin of mice. The pruritic phenotype and inflammatory cell infiltration induced by S. aureus were evaluated using comprehensive approaches including behavioral assays (e.g., scratching frequency recording), hematoxylin-eosin (HE) staining, and toluidine blue staining. The in vitro antibacterial efficacy of the TCM monomer pseudolaric acid B (PAB) and double network hydrogel (DN) was separately assessed by disk diffusion assay, while the minimum inhibitory concentration (MIC) of PAB was determined via broth dilution method. Further validation of the pharmacodynamic characteristics of the composite system (PAB@DN, composed of PAB and DN) was conducted through behavioral assays, HE staining, and dermatitis scoring, with its drug release profile evaluated by mass spectrometry analysis. Based on scratching behavioral analysis and dermatitis scoring, the optimal ratio and concentration of PAB@DN were optimized. ResultsThe S. aureus load in AD lesional tissues was significantly higher than in normal skin ((5.3±0.33)×10⁶ CFU vs. (3.6±0.26)×10⁷ CFU, P<0.001). In the S. aureus mono-infection group, mice exhibited a 6.7-fold increase in scratching frequency compared to the control group. HE staining revealed marked epidermal thickening ((10.4±2.39) μm vs. (85.6±1.95) μm, P<0.000 1), and toluidine blue staining showed a 23-fold increase in mast cell degranulation. Pseudolaric acid B exhibited a significant concentration-dependent inhibitory effect onS. aureus growth, with its in vitro antibacterial effect being 57% that of the antibiotic cefepime (inhibition zone diameter: PAB (1.885±0.036) cm vs. cefepime (3.636±0.005) cm, P<0.000 1) and a minimum inhibitory concentration (MIC) of 1 g/L. The carrier double network hydrogel (DN) itself lacked direct antibacterial activity (no significant difference in inhibition zone diameter compared to the control) but effectively ameliorated the dry symptoms of AD-like lesions. The PAB@DN composite system demonstrated a synergistic effect compared to individual components, resulting in a 50% reduction in scratching behavior, an 86% decrease in dermatitis score, and a 60% reduction in epidermal thickening. It also reduced the S. aureus load in mouse skin by approximately 34%, with the optimal effective formulation being PAB at 1 g/L loaded onto DN. ConclusionS. aureus colonization plays a critical driving role in the onset and progression of AD. Using an S. aureus infection model, this study confirmed that the pseudolaric acidB-hydrogel composite delivery system (PAB@DN) can effectively alleviate S. aureus-induced pruritus and skin damage, providing experimental evidence for microbiota-targeted therapy of AD.
5.The first record of Anopheles messeae (Diptera: Culicidae) parasitized by water mites in China
Xue-ru CHEN ; Wen-zhen YAO ; Yu-hao LI ; Gui-chang LI ; Tao MENG ; Qun-ling FENG ; Xin-hui LIU ; Li-hong QIAO ; Xiang-ting WU ; Xue-feng ZHANG ; Cheng-lin LI ; Xue-cheng DONG ; Da-wei WANG ; Xiao-yan SI ; Yu-hong GUO
Acta Parasitologica et Medica Entomologica Sinica 2026;33(1):53-57
Objective This study reports on the obligatory parasitism of water mites Arrenurus sp. on Anopheles messeae at the Manzhouli Port, Inner Mongolia, China. Methods Duing July 2024, a survey on the mosquito diversity was conducted at the Manzhouli Port. Captured mosquitoes and their ectoparasites were identified to species level. Results A total of 1840 adult mosquitoes were collected, representing species from three genera: Culex(Cx. modestus, Cx. pipiens pallens), Aedes(Ae. dorsalis, Ae. flavidorsalis, Ae. flavescens), and Anopheles (An. messeae). Among all the mosqutioes specimens,3 out of 150 captured An. messeae were found to carry ectoparasitic mites, with number of 2,4,27 mites separately. Morphological and molecular identification reached the same result as water mites(Hydrachnidiae, Hydracrina). COI gene sequence showed 94% similarity with the closest species Arrenurus truncatellus. Conlusions Literature review suggests water mites are host-specific parasitism of mosquito species and herein with the first record of Arrenurus sp. parasiting on An. Messeae in the most high-latitude region globally.
6.Mechanisms of Tongmai Yangxin Pills and Tongxinluo Capsules in Treating Myocardial No-reflow Based on Treating Same Disease with Different Methods
Siqi LIU ; Wenqing YANG ; Ting CHEN ; Yan TANG ; Ju WANG ; Yaxuan PENG ; Haoxue QIN ; Lanyue DENG ; Jialu GONG ; Ning XU ; Shuying ZHANG ; Wei ZHANG ; Ting CHEN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(17):125-133
ObjectiveTo investigate the mechanisms of Tongmai Yangxin pills (TMYX) and Tongxinluo capsules (TXL) in treating no-reflow (NR) after myocardial ischemia and reperfusion following the concept of treating the same disease with different methods, based on integrative pharmacology and experimental validation. MethodsEighty 8-week-old SPF-grade SD rats were randomly assigned into four groups (n=20): sham operation, NR, TMYX (4 g·kg-1), and TXL (2 mg·kg-1). A rat model of myocardial ischemia-reperfusion no-reflow was established by in-situ ligation of the left anterior descending coronary artery. Gastric gavage was first performed 4 h after the operation, and samples were collected on day 7. Thioflavin S staining was used to observe the NR area in rat myocardium. Echocardiography was performed to examine the cardiac function. Hematoxylin-eosin (HE) staining was conducted to observe the pathological changes of the myocardial tissue. An automatic biochemical analyzer was adopted to measure myocardial enzyme activity. Then, integrated pharmacology was applied for Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Finally, Western blot was employed to quantify the protein levels of key targets in the myocardial tissue, including soluble guanylyl cyclase (sGC), cyclic guanosine monophosphate (cGMP)/dependent protein kinase (PKG), phosphorylated phosphatidylinositol 3-kinase (p-PI3K), phosphorylated protein kinase B (p-Akt), and hypoxia-inducible factor-1α (HIF-1α). ResultsCompared with the sham operation group, the NR group showed increased NR area of myocardium, decreased left ventricular ejection fraction (EF), left ventricular fractional shortening (FS), left ventricular outflow tract peak velocity (LVOT Peak), and left ventricular stroke volume (LVSV) (P<0.01), fractured and disordered myocardial fibers as well as inflammatory cell infiltration in the myocardial tissue, enhanced activities of creatine kinase (CK), creatine kinase isoenzyme (CK-MB), and lactate dehydrogenase (LDH) in the myocardial tissue (P<0.01), and downregulated protein levels of sGC, PKG, phosphorylated (p)-PI3K (Tyr458), and p-Akt (Tyr315) in the myocardial tissue (P<0.05, P<0.01). The expression level of HIF-1α protein showed a downward trend. Compared with the NR group, the TMYX group and TXL group exhibited a decreasing trend in myocardial NR area, EF, FS, and LVOT Peak significantly increased (P<0.05, P<0.01), LVSV showed an upward trend, ameliorated myocardial pathological morphology and inflammatory infiltration, reductions in CK, CK-MB, and LDH activities (P<0.05, P<0.01), and upregulated protein levels of sGC, PKG, p-PI3K (Tyr458) in myocardial tissue (P<0.05, P<0.01), the protein expressions of p-Akt (Tyr315) and HIF-1α showed an upward trend. A comparison of the therapeutic effects between the two compound prescriptions showed that TMYX tended to exert a better effect in restoring cardiac function and protecting cardiac structure in NR rats, whereas TXL was more effective in reducing myocardial NR area and lowering myocardial enzyme activities in NR rats. Integrative pharmacology analysis combined with experimental verification demonstrated that both TMYX and TXL could alleviate NR through the following mechanisms: activating the cyclic cGMP/PKG signaling pathway to regulate vascular tone, activating the PI3K/Akt signaling pathway to dilate blood vessels, and activating the HIF-1 signaling pathway to inhibit oxidative stress. However, TMYX had an advantage in activating the cGMP/PKG pathway, while TXL was superior in activating the PI3K/Akt pathway. The two compound prescriptions exerted comparable effects on the HIF-1 signaling pathway, which might serve as their common therapeutic pathway. ConclusionBoth TMYX and TXL could alleviate NR damage. TMYX exerts its protective effect against NR mainly by activating the cGMP/PKG signaling pathway, while TXL exerts its effect mainly through the PI3K/Akt pathway. The HIF-1α signaling pathway may be a common pathway for the two compound prescriptions to exert their protective effects against NR. This study reveals the similarities and differences between TMYX and TXL in the treatment effect and mechanism for NR, providing an experimental basis and a theoretical basis for better clinical application of the two compound prescriptions.
7.In vivo production of anti-CD19 CAR-T cells with T cell-targeted engineered exosomes to evaluate cytotoxicity against lymphoma cells
Dong TING ; Zhou YING ; Yu BOYU ; Xia XUEJIAO ; Ma YIGE ; Ma YAN ; Gao YANG ; Zhou MENGYING ; Wang CHANGJUN ; Li QIUYI ; Gu CHAOJIANG
Chinese Journal of Clinical Oncology 2025;52(6):279-286
Objective:Chimeric antigen receptor T-cell(CAR-T)immunotherapy has made major breakthroughs in the treatment of blood tu-mors.However,current CAR-T therapies face several limitations:they require autologous cells,involve a lengthy and costly production pro-cess,and use lentiviral transduction that carry risk of insertional carcinogenesis due to random integration.Therefore,there is an urgent need to develop a universal cost-effective cancer immunotherapy method generating CAR-T cells for in vivo cancer immunotherapy.Meth-ods:This study successfully established an exosome-mediated,T-cell targeted delivery system,demonstrating both precise design and func-tional efficacy for biomedical applications.To optimize CAR-T cell generation the transfection dose was adjusted,and the kinetics of CAR-T cell percentage were recorded.The cytotoxicity of the resulting CAR-T cells was evaluated in vitro by calcein-AM release.To test the tumor-killing in vivo of engineered exosomes,human PBMCs were injected into NPG mice via the tail vein to establish humanized mice,followed by intravenous injection of tumor cells to induce cancer.Results:To overcome the limitations of conditional autologous CAR-T cells,we de-veloped a T cell-targeted exosome system capable of specifically targeting human CD3+,CD4+,and CD8+T cells.CAR-T production was dose-dependent,with transfection efficiency reaching upto 97.8%at 106 particles/cell.Both in vitro cytotoxicity assays and in vivo animal experi-ments demonstrated that exosome-incubated CAR-T cells effectively eliminated CD19-positive Raji cells,highlighting their specificity and therapeutic potential in antigen-directed applications.Conclusions:We successfully established a CD8-targeting exosome delivery system for CAR-T cell production capable of transforming CD8+T cells into functional CAR-T cells,which showed significant tumor-killing ability in vitro and in mice.Compared with the traditional lentiviral vector for the preparation of CAR-T cells in vitro,in vivo-reprogrammed CAR-T cells us-ing our CD8-targeted exosome delivery system,with higher transfection efficiency,shorter production period,lower cost,and eliminated the risk of insertion carcinogenesis.This strategy promises to bring a new era of universal CAR-T medicine,which can improve cancer immuno-therapy and may hold promise as a therapeutic platform to treat various diseases.
8.Risk factors of cerebral infarction in elderly patients with hypertension and predictive value of lipoprotein a, Hcy and D-dimer
Clinical Medicine of China 2025;41(3):170-174
Objective:To investigate the risk factors of cerebral infarction in elderly patients with hypertension and the predictive value of lipoprotein a, homocysteine (Hcy) and D-dimer.Methods:A retrospective case-control study was conducted for this study. The clinical data of 234 elderly patients with hypertension in the First Hospital of Yulin were collected from January 2023 to March 2024, including 124 cases with cerebral infarction (observation group) and 110 cases without cerebral infarction (control group).Normally distributed quantitative data were expressed as xˉ?±s, two independent sample t test was used on comparison between groups. Skew distributed quantitative data were expressed as M( Q 1, Q 3), rank-sum test was used on comparison between groups. Counting data were expressed as n(%), chi-square test was used on comparison between groups. Risk factors of cerebral infarction in elderly hypertensive patients were explored by multivariate Logistic regression analysis. Receiver operating characteristic curve (ROC) was drawn to analyze the predictive value of lipoprotein a, Hcy and D-dimer on cerebral infarction in hypertensive patients. Results:The proportions of males and alcohol drinking [54.8%(68/124) vs. 40.0% (44/110), 21.8%(27/124) vs. 11.8% (13/110), χ2=5.14, P=0.023, χ2=4.08, P=0.043], systolic blood pressure [(160±13) mmHg (1 mmHg=0.133 kPa) vs. (149±13) mmHg, t=6.53, P<0.001] and levels of serum lipoprotein a, Hcy and D-dimer [234.4 (122.6, 491.8) mg/L vs. 137.3 (63.0, 230.0) mg/L, 18.6 (16.0, 23.2) μmol/L vs. 14.4 (11.9, 17.6) μmol/L, 0.62 (0.39, 1.18) mg/L vs. 0.33 (0.25, 0.54) mg/L, Z=4.20, 6.96, 5.82, all P<0.001] were higher in the observation group compared to the control group, and the age was older than that in the control group [72.0 (66.2, 78.0) years old vs. 68.0 (65.0, 73.2) years old, Z=3.08, P=0.002]. Multivariate Logistic regression analysis suggested that after excluding the influence of other factors, systolic blood pressure ( OR=1.06, 95% CI: 1.03-1.09, P<0.001), alcohol drinking ( OR=6.02, 95% CI: 1.88-19.29, P=0.003), lipoprotein a ( OR=1.00, 95% CI: 1.00-1.01, P<0.001), Hcy ( OR=1.22, 95% CI: 1.13-1.31, P<0.001) and D-dimer ( OR=1.96, 95% CI: 1.22-3.14, P=0.005) were risk factors for cerebral infarction in elderly patients with hypertension. The area under ROC curve(AUC) of combination of serum lipoprotein a, Hcy and D-dimer in predicting CI was greater than that of single detection (0.85 vs. 0.66, 0.76, 0.72, all P<0.001). Conclusions:Systolic blood pressure, alcohol drinking, lipoprotein a, Hcy, D-dimer are risk factors for cerebral infarction in elderly hypertensive patients. Serum lipoprotein a, Hcy and D-dimer have high diagnostic value on cerebral infarction, and combined detection has the highest diagnostic efficiency.
9.A Sensitive Ion Chromatography-Inductively Coupled Plasma Mass Spectrometry Method for Analysis of Iodine Speciation in Environmental Water Samples
Huan JIANG ; Ning CHEN ; Yan-Yun WANG ; Yu-Kun FAN ; Meng-Ting ZHANG ; Lu-Yuan ZHANG ; Xiao-Lin HOU
Chinese Journal of Analytical Chemistry 2025;53(2):278-288
Iodine speciations in aquatic environments are affected by dissolved oxygen,redox potential,microbial activity,organic matter decomposition,light reaction,etc.Accurate quantification of iodine speciation can not only help to understand the geochemical cycle of iodine,but also help to trace and study environmental processes.Based on the combination of ion chromatography(IC)and inductively coupled plasma mass spectrometry(ICP-MS),a rapid and sensitive method was established for determining the speciations of iodine in environmental water samples including seawater,river water,lake water,rainwater,groundwater,etc.The results presented here showed that IO3?and I?in seawater were quickly separated and measured within 120 s when using guard column AG22 and 8 mmol/L(NH4)2CO3 as the mobile phase.While for lake water,river water and precipitation samples with high soluble organically bond iodine(SOI),an AS22 separation column(250 mm×4 mm)connected with a guard column and using 50 mmol/L(NH4)2CO3 as mobile phase could effectively separate unknown SOI from IO3? to achieve accurate quantification of IO3?.For accurate correction of iodine measurement signal fluctuations,133Cs was directly added to the(NH4)2CO3 mobile phase as an internal standard.The SOI content was calculated by the total iodine concentrations minus the sum of IO3?and I?.The precision of the established iodine speciation analytical method was better than 3.5%,and the standard addition experiment showed that the analytical method was accurate.When the injection volume was 25 μL,the detection limits were 0.011?0.025 μg/L for IO3? and 0.023?0.031 μg/L for I?,respectively.The method was successfully used to analyze IO3?,SOI and I? in environmental water samples,such as seawater,river water,rainwater and groundwater.
10.Analyzing Promotion Effect of Rare Earth Species Located in Ce-HY on Polyethylene Upgrading
Xue-Ting WU ; Jing XU ; Xiao-Wei MU ; Long TIAN ; Xiao WANG ; Shu-Yan SONG ; Hong-Jie ZHANG
Chinese Journal of Analytical Chemistry 2025;53(5):794-803
The continuous accumulation of plastic waste such as polyethylene in the environment has caused serious environmental pollution issues.Considering the high similarity in the molecular structure of petroleum and polyolefin,it is feasible to apply rare earth-zeolite catalysts in polyolefin plastic upcycling,which is commonly used in fluid catalytic cracking(FCC)in the field of petroleum refining.In this study,Ce-modified HY(Ce-HY)zeolites were synthesized and characterized by a series of analytical methods,such as high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM),Fourier infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),etc.When introducing 5% Ce species into HY zeolites,the 5Ce-HY showed excellent catalytic performance in the catalytic cracking of low-density polyethylene(LDPE),which achieved 98.4% LDPE conversion with 91.5% selectivity of gaseous alkanes at 300℃,and 75.4% of them were isoparaffins.In addition,the effect of the location of rare earth species in Y zeolites on the catalytic performance was explored by fine X-ray diffraction(XRD)in the range of 11°-13°and in situ-Raman analyses.The Ce species located in the supercage of Y zeolites were more important,which enhanced the adsorption capacity and accessibility of substrate molecules,thus facilitating the entire catalytic cracking process.This method could be used to detect the location of rare earth elements in Y zeolites to understand the mechanism of rare earth catalysis.


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