1.The Diversity of Filamentous Morphologies and Magnetic Sensitivity Modulated by Diverse MagR Expression in Bacteria
Ya-Fei CHANG ; Jing ZHANG ; Peng ZHANG ; Xiu-Juan ZHOU ; Meng-Ke WEI ; Tian-Tian CAI ; Pei-Qi HE ; Jun-Feng WANG ; Can XIE
Progress in Biochemistry and Biophysics 2026;53(5):1439-1456
Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe2+), whereas clMagR favors ferric iron (Fe3+) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe2+-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe2+/Fe3+ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.
2.The Diversity of Filamentous Morphologies and Magnetic Sensitivity Modulated by Diverse MagR Expression in Bacteria
Ya-Fei CHANG ; Jing ZHANG ; Peng ZHANG ; Xiu-Juan ZHOU ; Meng-Ke WEI ; Tian-Tian CAI ; Pei-Qi HE ; Jun-Feng WANG ; Can XIE
Progress in Biochemistry and Biophysics 2026;53(5):1439-1456
Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe2+), whereas clMagR favors ferric iron (Fe3+) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe2+-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe2+/Fe3+ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.
3.Neuroelectromagnetic Activities Across Temporal Scales
Zhuo-Qun SHEN ; Xiao-Fei XU ; Yan-Qing WANG ; Jing-Xin LI ; Lan TIAN ; Wei GUO ; Jing-Jing XU
Progress in Biochemistry and Biophysics 2026;53(6):1541-1560
Although global brain science research has progressed rapidly in recent decades, several fundamental questions in neuroscience remain unresolved. In particular, the physical mechanism underlying neural signal transmission remains controversial, and the carriers responsible for neural information storage and retrieval have not yet been fully clarified. These unresolved issues motivate us to re-examine the processes of neural information generation, transmission, integration, storage, and retrieval from multiple perspectives. A key observation is that neural electromagnetic activities are closely associated with time. Their duration, temporal structure, and dynamic evolution play crucial roles in neural information processing. In this work, we analyze neural electromagnetic activities from the perspective of temporal scales (referred to here as the “time course”). By reviewing and integrating findings from previous studies, we examine the characteristic time requirements and dynamic features of neural processes occurring at different stages of information processing. These stages include neural signal generation, signal transmission along axons, synaptic integration, synaptic plasticity, and memory formation and retrieval. Based on this temporal analysis, we outline a framework describing neural electromagnetic activities across a wide range of time scales, spanning from microseconds to minutes, hours, or even longer periods associated with long-term memory, which suggests that neural information processing involves multiple physical processes operating at different time levels. Rapid electromagnetic events may occur on microsecond scales, whereas electrophysiological phenomena such as action potentials typically last on the order of milliseconds. Longer time scales are associated with synaptic plasticity and memory-related processes. From this perspective, we propose that the physical carrier of neural information may be transient electromagnetic pulses with durations on the microsecond scale. In this framework, action potentials can be interpreted as the macroscopic electrophysiological manifestation of underlying electromagnetic processes triggered by ionic currents across neuronal membranes. Rather than being the fundamental neural signal itself, the action potential may represent a measurable membrane-level response associated with the successful activation of these electromagnetic events. Moreover, we discuss a possible mechanism for long-term memory storage. Considering the apparent temporal contradiction between the millisecond-scale excitation of neurons and the long-term persistence of memories, we believe that long-term memory information may be stored within neural network topologies formed by electrical synapse coupling. Such structures, referred to as electrically coupled memory networks (ECMNs), may enable neurons within the same network to respond rapidly and synchronously to stimuli, thereby facilitating efficient memory retrieval. Overall, this study emphasizes the importance of considering the temporal organization of neural electromagnetic activities when interpreting neural signaling mechanisms. It may provide new insights into the physical nature of neural information carriers and the mechanisms of memory storage and retrieval. Furthermore, highlighting the potential role of electromagnetic interactions in neural activity may contribute to the development of new theoretical frameworks and experimental approaches in neuroscience. Such perspectives may also offer valuable references for future research on neural coding, brain function mechanisms, and neuromodulation technologies.
4.Electroacupuncture Promotes Gastric Motility by Suppressing Pyroptosis via NLRP3/Caspase-1/GSDMD Signaling Pathway in Diabetic Gastroparesis Rats.
Hao HUANG ; Yan PENG ; Le XIAO ; Jing WANG ; Yu-Hong XIN ; Tian-Hua ZHANG ; Xiao-Yu LI ; Xing WEI
Chinese journal of integrative medicine 2025;31(5):448-457
OBJECTIVE:
To investigate the mechanism of electroacupuncture (EA) in treating diabetic gastroparesis (DGP) by inhibiting the activation of Nod-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome and pyroptosis mediated via NLRP3/cysteinyl aspartate specific proteinase-1 (caspase-1)/gasdermin D (GSDMD) signaling pathway.
METHODS:
Forty Sprague-Dawley rats were randomly divided into 4 groups including the control, DGP model, EA, and MCC950 groups. The DGP model was established by a one-time high-dose intraperitoneal injection of 2% streptozotocin and a high-glucose and high-fat diet for 8 weeks. EA intervention was conducted at Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6) with sparse-dense wave for 15 min, and was administered for 3 courses of 5 days. After intervention, the blood glucose, urine glucose, gastric emptying, and intestinal propulsive rate were observed. Besides, HE staining was used to observe histopathological changes in gastric antrum tissues, and TUNEL staining was utilized to detect DNA damage. Protein expression levels of NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), pro-caspase-1, caspase-1 and GSDMD were measured by Western blot. Immunofluorescence staining was employed to assess the activity of GSDMD-N. Lactate dehydrogenase (LDH) levels were detected by using a biochemical kit.
RESULTS:
DGP rats showed persistent hyperglycemia and a significant decrease in gastrointestinal motility (P<0.05 or P<0.01), accompanied by pathological damage in their gastric antrum tissues. Cellular DNA was obviously damaged, and the expressions of NLRP3, ASC, pro-caspase-1, caspase-1 and GSDMD proteins were significantly elevated, along with enhanced fluorescence signals of GSDMD-N and increased LDH release (P<0.01). EA mitigated hyperglycemia, improved gastrointestinal motility in DGP rats and alleviated their pathological injury (P<0.05). Furthermore, EA reduced cellular DNA damage, lowered the protein levels of NLRP3, ASC, pro-caspase-1, caspase-1 and GSDMD, suppressed GSDMD-N activity, and decreased LDH release (P<0.05 or P<0.01), demonstrating effects comparable to MCC950.
CONCLUSION
EA promotes gastrointestinal motility and repairs the pathological damage in DGP rats, and its mechanism may be related to the inhibition of NLRP3 inflammasome and pyroptosis mediated by NLRP3/caspase-1/GSDMD pathway.
Animals
;
Electroacupuncture
;
NLR Family, Pyrin Domain-Containing 3 Protein/metabolism*
;
Pyroptosis
;
Rats, Sprague-Dawley
;
Caspase 1/metabolism*
;
Gastroparesis/physiopathology*
;
Signal Transduction
;
Male
;
Diabetes Mellitus, Experimental/physiopathology*
;
Phosphate-Binding Proteins/metabolism*
;
Gastrointestinal Motility
;
Rats
;
Intracellular Signaling Peptides and Proteins/metabolism*
;
Diabetes Complications/physiopathology*
;
Gasdermins
5.Unveiling nonribosomal peptide synthetases from the ergot fungus Claviceps purpurea involved in the formation of diverse ergopeptines.
Jing-Jing CHEN ; Ting GONG ; Wei-Bo WANG ; Tian-Jiao CHEN ; Jin-Ling YANG ; Ping ZHU
Acta Pharmaceutica Sinica B 2025;15(6):3321-3337
Ergopeptines or their derivatives are widely used for treating neurodegenerative and cerebrovascular diseases. The nonribosomal peptide synthetase-d-lysergyl peptide synthetase A (LPSA) determines ergopeptine formation but the detailed mechanism remains to be elucidated. Here, we characterized two LPSAs from Claviceps purpurea Cp-1 strain through heterologous expression in Aspergillus nidulans feeding with d-lysergic acid. We proved that Cp-LPSA1 catalyzed the formation of ergocornine, α-ergocryptine, and β-ergocryptine, precisely controlled by the substrate specificity of its three modules. Cp-LPSA2 was initially inactive but could be restored to catalyze α-ergosine formation. Using this platform, we validated that P1-LPSA1 and P1-LPSA2 from the reported C. purpurea P1 strain catalyzed ergotamine and α-ergocryptine formation, respectively. Typically, the non-ribosomal peptide codes implicated in every module of the LPSAs were defined and elucidated, in which certain key residues could play a switched role for substrate specificity and product interconversion. By constructing chimeric LPSAs through module assembly, the production of the desired ergopeptines was achieved. Notably, 1.46 mg/L of α-ergocryptine and 1.09 mg/L of ergotamine were produced respectively by mixed-culture of C. paspali No. 24 (fermentation supernatant) and the recombinants of A. nidulans. Our findings provide insights into the biosynthetic mechanism of ergopeptines and lay a foundation for directed ergopeptine biosynthesis.
6.Perspective on strengthening dementia prevention and control system: a comprehensive framework for national health.
Bin CONG ; Hengge XIE ; Yongan SUN ; Jingnian NI ; Jing SHI ; Mingqing WEI ; Fuyao LI ; Huali WANG ; Luning WANG ; Bin QIN ; Jing CHENG ; Demin HAN ; Wei XIAO ; Boli ZHANG ; Jinzhou TIAN
Frontiers of Medicine 2025;19(5):865-870
7.Brain functional changes following electroacupuncture in a mouse model of comorbid pain and depression: A resting-state functional magnetic resonance imaging study.
Xuan YIN ; Xiao-Ling ZENG ; Jing-Jing LIN ; Wen-Qing XU ; Kai-Yu CUI ; Xiu-Tian GUO ; Wei LI ; Shi-Fen XU
Journal of Integrative Medicine 2025;23(2):159-168
OBJECTIVE:
Comorbid pain and depression are common but remain difficult to treat. Electroacupuncture (EA) can effectively improve symptoms of depression and relieve pain, but its neural mechanism remains unclear. Therefore, we used resting-state functional magnetic resonance imaging (rs-fMRI) to detect cerebral changes after initiating a mouse pain model via constriction of the infraorbital nerve (CION) and then treating these animals with EA.
METHODS:
Forty male C57BL/6J mice were divided into 4 groups: control, CION model, EA, and sham acupuncture (without needle insertion). EA was performed on the acupoints Baihui (GV20) and Zusanli (ST36) for 20 min, once a day for 10 consecutive days. The mechanical withdrawal threshold was tested 3 days after the surgery and every 3 days after the intervention. The depressive behavior was evaluated with the tail suspension test, open-field test, elevated plus maze (EPM), sucrose preference test, and marble burying test. The rs-fMRI was used to detect the cerebral changes of the functional connectivity (FC) in the mice following EA treatment.
RESULTS:
Compared with the CION group, the mechanical withdrawal threshold increased in the EA group at the end of the intervention (P < 0.05); the immobility time in tail suspension test decreased (P < 0.05); and the times of the open arm entry and the open arm time in the EPM increased (both P < 0.001). There was no difference in the sucrose preference or marble burying tests (both P > 0.05). The fMRI results showed that EA treatment downregulated the amplitude of low-frequency fluctuations and regional homogeneity values, while these indicators were elevated in brain regions including the amygdala, hippocampus and cerebral cortex in the CION model for comorbid pain and depression. Selecting the amygdala as the seed region, we found that the FC was higher in the CION group than in the control group. Meanwhile, EA treatment was able to decrease the FC between the amygdala and other brain regions including the caudate putamen, thalamus, and parts of the cerebral cortex.
CONCLUSION
EA can downregulate the abnormal activation of neurons in the amygdala and improve its FC with other brain regions, thus exerting analgesic and antidepressant effects. Please cite this article as: Yin X, Zeng XL, Lin JJ, Xu WQ, Cui KY, Guo XT, Li W, Xu SF. Brain functional changes following electroacupuncture in a mouse model of comorbid pain and depression: a resting-state functional magnetic resonance imaging study. J Integr Med. 2025; 23(2): 159-168.
Animals
;
Electroacupuncture
;
Male
;
Magnetic Resonance Imaging
;
Depression/diagnostic imaging*
;
Mice, Inbred C57BL
;
Brain/diagnostic imaging*
;
Disease Models, Animal
;
Mice
;
Pain/diagnostic imaging*
;
Acupuncture Points
8.Occupational Hazard Factors and the Trajectory of Fasting Blood Glucose Changes in Chinese Male Steelworkers Based on Environmental Risk Scores: A Prospective Cohort Study.
Ming Xia ZOU ; Wei DU ; Qin KANG ; Yu Hao XIA ; Nuo Yun ZHANG ; Liu FENG ; Fei Yue LI ; Tian Cheng MA ; Ya Jing BAO ; Hong Min FAN
Biomedical and Environmental Sciences 2025;38(6):666-677
OBJECTIVE:
We aimed to investigate the patterns of fasting blood glucose (FBG) trajectories and analyze the relationship between various occupational hazard factors and FBG trajectories in male steelworkers.
METHODS:
The study cohort included 3,728 workers who met the selection criteria for the Tanggang Occupational Cohort (TGOC) between 2017 and 2022. A group-based trajectory model was used to identify the FBG trajectories. Environmental risk scores (ERS) were constructed using regression coefficients from the occupational hazard model as weights. Univariate and multivariate logistic regression analyses were performed to explore the effects of occupational hazard factors using the ERS on FBG trajectories.
RESULTS:
FBG trajectories were categorized into three groups. An association was observed between high temperature, noise exposure, and FBG trajectory ( P < 0.05). Using the first quartile group of ERS1 as a reference, the fourth quartile group of ERS1 had an increased risk of medium and high FBG by 1.90 and 2.21 times, respectively (odds ratio [ OR] = 1.90, 95% confidence interval [ CI]: 1.17-3.10; OR = 2.21, 95% CI: 1.09-4.45).
CONCLUSION
An association was observed between occupational hazards based on ERS and FBG trajectories. The risk of FBG trajectory levels increase with an increase in ERS.
Humans
;
Male
;
Adult
;
Blood Glucose/analysis*
;
China
;
Prospective Studies
;
Occupational Exposure/adverse effects*
;
Risk Factors
;
Middle Aged
;
Steel
;
Fasting/blood*
;
Metal Workers
;
East Asian People
9.Associations of Exposure to Typical Environmental Organic Pollutants with Cardiopulmonary Health and the Mediating Role of Oxidative Stress: A Randomized Crossover Study.
Ning GAO ; Bin WANG ; Ran ZHAO ; Han ZHANG ; Xiao Qian JIA ; Tian Xiang WU ; Meng Yuan REN ; Lu ZHAO ; Jia Zhang SHI ; Jing HUANG ; Shao Wei WU ; Guo Feng SHEN ; Bo PAN ; Ming Liang FANG
Biomedical and Environmental Sciences 2025;38(11):1388-1403
OBJECTIVE:
The study aim was to investigate the effects of exposure to multiple environmental organic pollutants on cardiopulmonary health with a focus on the potential mediating role of oxidative stress.
METHODS:
A repeated-measures randomized crossover study involving healthy college students in Beijing was conducted. Biological samples, including morning urine and venous blood, were collected to measure concentrations of 29 typical organic pollutants, including hydroxy polycyclic aromatic hydrocarbons (OH-PAHs), bisphenol A and its substitutes, phthalates and their metabolites, parabens, and five biomarkers of oxidative stress. Health assessments included blood pressure measurements and lung function indicators.
RESULTS:
Urinary concentrations of 2-hydroxyphenanthrene (2-OH-PHE) ( β = 4.35% [95% confidence interval ( CI): 0.85%, 7.97%]), 3-hydroxyphenanthrene ( β = 3.44% [95% CI: 0.19%, 6.79%]), and 4-hydroxyphenanthrene (4-OH-PHE) ( β = 5.78% [95% CI: 1.27%, 10.5%]) were significantly and positively associated with systolic blood pressure. Exposures to 1-hydroxypyrene (1-OH-PYR) ( β = 3.05% [95% CI: -4.66%, -1.41%]), 2-OH-PHE ( β = 2.68% [95% CI: -4%, -1.34%]), and 4-OH-PHE ( β = 3% [95% CI: -4.68%, -1.29%]) were negatively associated with the ratio of forced expiratory volume in the first second to forced vital capacity. These findings highlight the adverse effects of exposure to multiple pollutants on cardiopulmonary health. Biomarkers of oxidative stress, including 8-hydroxy-2'-deoxyguanosine and extracellular superoxide dismutase, mediated the effects of multiple OH-PAHs on blood pressure and lung function.
CONCLUSION
Exposure to multiple organic pollutants can adversely affect cardiopulmonary health. Oxidative stress is a key mediator of the effects of OH-PAHs on blood pressure and lung function.
Humans
;
Oxidative Stress/drug effects*
;
Male
;
Cross-Over Studies
;
Female
;
Young Adult
;
Environmental Pollutants/toxicity*
;
Environmental Exposure/adverse effects*
;
Biomarkers/blood*
;
Adult
;
Blood Pressure/drug effects*
;
Polycyclic Aromatic Hydrocarbons/urine*
;
Beijing
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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