1.The Structure and Function of The YopJ Family Effectors in The Bacterial Type III Secretion System
Ao-Ning LI ; Wen-Bo LI ; Yu-Ying LU ; Min-Hui ZHU ; Yu-Long QIN ; Yong ZHAO ; Zhao-Huan ZHANG
Progress in Biochemistry and Biophysics 2026;53(3):516-533
The Type III Secretion System (T3SS) serves as a pivotal virulence apparatus for numerous Gram-negative bacterial pathogens, enabling them to infect both animal and plant hosts. Functioning as a molecular syringe, the T3SS directly translocates bacterial effector proteins from the bacterial cytoplasm into the interior of eukaryotic host cells. These effectors are central weapons that precisely manipulate a wide spectrum of host cellular physiological processes, ranging from cytoskeletal dynamics to immune signaling, to establish a favorable niche for bacterial survival and proliferation. Among the diverse arsenal of T3SS effectors, the YopJ family constitutes a critical group of virulence factors. Members of this family are characterized by a conserved catalytic triad structure—a hallmark of the CE clan of cysteine proteases that has been evolutionarily repurposed to confer acetyltransferase activity. A defining and intriguing feature of these enzymes is their stringent dependence on a host-derived eukaryotic cofactor, inositol hexakisphosphate (IP6), for allosteric activation. This requirement acts as a sophisticated molecular safeguard, ensuring enzymatic activity only within the appropriate host environment, thereby preventing detrimental effects on the bacterium itself. While seminal studies on individual members such as Yersinia’s YopJ and Salmonella’s AvrA have provided deep mechanistic insights, a systematic and integrative understanding of the structure-function relationships across the entire family remains fragmented. Key questions persist regarding how a conserved catalytic core has diverged to recognize distinct host substrates in different kingdoms of life. To address this gap, this article provides a systematic review of the YopJ family, focusing on three interconnected aspects: their structural features, their catalytic mechanism, and their divergent immunosuppressive strategies in animal versus plant hosts. By conducting a comparative analysis of the sequences and resolved three-dimensional structures of three representative members (e.g., HopZ1a, PopP2, AvrA), we elucidate regions of significant variation embedded within the conserved core catalytic architecture. These variable regions, often involving surface loops and substrate-binding interfaces, are crucial determinants of target specificity and functional specialization. The functional divergence of this effector family is most apparent when comparing their modes of action in different hosts. In animal hosts, YopJ-family effectors primarily sabotage innate immune signaling pathways. They achieve this by acetylating key serine and threonine residues within the activation loops of critical kinases in the MAPK and NF‑κB pathways. This post-translational modification blocks the phosphorylation and subsequent activation of these kinases, leading to potent suppression of inflammatory cytokine production. Conversely, in plant hosts, the strategy broadens to dismantle the two-tiered plant immune system. YopJ homologs target a more diverse set of substrates, including immune-associated receptor-like cytoplasmic kinases (RLCKs), microtubule networks via tubulin acetylation (which disrupts cellular trafficking and signaling), and transcription factors central to defense gene regulation. This multi-target approach effectively suppresses both Pattern-Triggered Immunity (PTI) and Effector-Triggered Immunity (ETI). In conclusion, this synthesis aims to deepen the mechanistic understanding of YopJ family-mediated pathogenesis by integrating structural biology with cellular function across host kingdoms. Elucidating the precise molecular basis for substrate selection—how conserved platforms achieve target diversity—is a major frontier. Furthermore, this knowledge provides a vital theoretical foundation for developing novel anti-virulence strategies. Targeting the conserved IP6-binding pocket or the catalytic acetyltransferase activity itself represents a promising avenue for designing broad-spectrum inhibitors that could disarm this critical family of bacterial effectors, potentially offering new therapeutic approaches against a range of pathogenic bacteria.
2.Establishment and Preliminary Analysis of GP73 Interactome Using Proximity-dependent Labeling Technology
Mu-Yi LIU ; Chang ZHANG ; Meng-Xin YANG ; Xin-Long YAN ; Lu-Ming WAN ; Cong-Wen WEI
Progress in Biochemistry and Biophysics 2026;53(3):711-723
ObjectiveProtein-protein interactions (PPIs) are fundamental to the execution of biological functions within living cells. However, traditional biochemical methods, such as co-immunoprecipitation (Co-IP), often fail to capture transient, weak, or membrane-associated interactions due to the stringent detergent requirements for cell lysis. Proximity labeling (PL) has emerged in recent years as a transformative technology for mapping the proteomes of specific subcellular compartments and identifying dynamic interactomes in situ. Golgi protein 73 (GP73, also known as GOLPH2), a resident type II Golgi transmembrane protein, is a well-recognized clinical biomarker for liver diseases, including hepatocellular carcinoma (HCC). Despite its clinical significance, the comprehensive physiological and pathological functions of GP73 remain partially understood. This study aims to establish an APEX2-mediated proximity labeling system specifically targeting GP73 to map its interactome in a living cellular environment, thereby providing new insights into its molecular roles and regulatory mechanisms. MethodsTo achieve spatial specificity, we first constructed a stable cell line expressing a fusion protein consisting of GP73 and the engineered soybean peroxidase APEX2. The localization of the GP73-APEX2 fusion protein was validated to ensure it correctly targeted the Golgi apparatus. The proximity labeling reaction was initiated by incubating the cells with biotin-phenol (BP) for 30 min, followed by a brief (1 min) treatment with1 mmol/L hydrogen peroxide (H2O2). This catalytic reaction converts BP into highly reactive, short-lived biotin-phenoxyl radicals that covalently attach to endogenous proteins within a small labeling radius of the GP73-APEX2 enzyme. Subsequently, the cells were quenched, and biotinylated proteins were enriched using high-affinity streptavidin-coated magnetic beads. The captured “neighbor” proteins were subjected to on-bead digestion and analyzed via liquid chromatography-tandem mass spectrometry (LC-MS/MS) for high-throughput identification. Rigorous bioinformatics analysis, including Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and protein-protein interaction network mapping, was performed to interpret the biological significance of the identified candidates. ResultsOur results demonstrate the successful establishment of a robust and sensitive APEX2-based proximity labeling system for GP73. We identified a total of 95 high-confidence interacting proteins that were significantly enriched in the GP73 proximity proteome compared to control groups. Bioinformatics analysis revealed that these interactors were predominantly associated with biological processes such as vesicular transport, protein localization, and, most notably, molecular functions related to “ribosome binding” and “translation regulation”. This suggested an unexpected role for the Golgi-resident GP73 in the cellular translation machinery. To validate these findings, we performed targeted biochemical assays which confirmed a direct interaction between GP73 and the subunits of the eukaryotic translation initiation factor 3 (eIF3) complex, specifically EIF3G and EIF3I. Furthermore, functional validation using the surface sensing of translation (SUnSET) assay—a non-radioactive method to monitor protein synthesis—revealed that the overexpression of GP73 significantly promoted global protein translation levels in the cell, whereas its depletion or inhibition resulted in reduced translation efficiency. ConclusionThis study successfully utilized APEX2-mediated proximity labeling to provide the first systematic map of GP73 interactome in living cells. Our findings uncover a novel, unconventional function of GP73 as a regulator of cellular protein translation, likely mediated through its interaction with the eIF3 complex. This discovery significantly broadens our understanding of the biological roles of GP73 beyond its traditional function in the Golgi apparatus and suggests that it may act as a bridge between Golgi-related trafficking and the protein synthesis machinery. Furthermore, the technical framework established in this study provides a valuable template for investigating other complex organelle-associated protein networks and resolving transient macromolecular interactions in various physiological and pathological contexts.
3.Efficient Loading and Targeted Delivery of Plant Exosomes
Meng XU ; Long-Jiao ZHU ; Jie LI ; Chong-Bin LEI ; Yang-Zi ZHANG ; Hong-Tao TIAN ; Wen-Tao XU
Progress in Biochemistry and Biophysics 2026;53(6):1597-1608
Plant-derived extracellular vesicles (PDEVs) are nanoscale extracellular vesicles secreted by plant cells, characterized by a lipid bilayer structure. These vesicles carry a variety of bioactive molecules, including proteins, nucleic acids, and lipids, and play essential roles in intercellular communication and physiological regulation in plants. Compared to animal-derived extracellular vesicles, PDEVs offer several advantages, such as a broad range of sources, high biocompatibility, low immunogenicity, and low production costs. Furthermore, PDEVs have demonstrated remarkable potential as natural nanocarriers for drug delivery, due to their ability to efficiently traverse biological barriers, such as the blood-brain barrier, making them promising candidates for drug delivery systems. This review systematically elaborates on the complex composition of PDEVs, which consists of lipids, proteins, and nucleic acids, the typical structural characteristics of their lipid bilayers ranging from 30 to 150 nm, and their versatile loading capabilities as drug carriers, efficiently encapsulating various types of therapeutic agents such as hydrophilic small molecules, hydrophobic drugs, nucleic acids, and proteins. We systematically summarize the recent advancements in strategies for enhancing the loading efficiency of PDEVs, which include methods such as co-incubation, ultrasound-assisted loading, electroporation, freeze-thaw cycles, and microfluidic technology. These techniques are evaluated based on their underlying principles, suitable drug types, and their respective advantages. In addition to loading strategies, we focus on the engineered approaches to achieve targeted delivery using PDEVs, such as genetic engineering modifications, chemical ligand conjugation, membrane fusion technology, and polyethylene glycol (PEG) modification. We discuss the mechanisms of these strategies in enhancing targeting efficiency, prolonging in vivo circulation time, and improving therapeutic efficacy. Further, this review highlights the application of PDEVs in various disease models, including tumor, skin inflammation, metabolic disorders, and neurodegenerative diseases, showcasing their therapeutic potential as multifunctional delivery platforms. The ability of PDEVs to encapsulate diverse therapeutic agents and target specific tissues or cells opens up new avenues for the treatment of complex diseases, offering advantages over conventional drug delivery systems. However, despite the promising applications of PDEVs, several challenges remain in their development and clinical translation. These challenges include variability in source materials, standardization of preparation processes, quality control, scalability of production, and the need for clinical validation. To overcome these obstacles, the integration of advanced technologies such as artificial intelligence-assisted design and multi-omics analysis is proposed as a way to facilitate the precise development of PDEVs. These emerging technologies hold the potential to further enhance the precision and effectiveness of plant-based drug delivery systems, ultimately advancing the field of precision medicine. In conclusion, the use of PDEVs as a platform for drug delivery represents a promising area of research with the potential to revolutionize therapeutic strategies. Their ability to encapsulate and deliver a wide variety of bioactive molecules, along with their inherent advantages in biocompatibility and versatility, makes them a valuable tool in the development of more efficient and targeted therapeutic interventions. Continued research and innovation in this field will pave the way for the clinical implementation of PDEVs in the treatment of various diseases, offering new hope for more effective and sustainable therapeutic options.
4.Communication Between Mitochondria and Nucleus With Retrograde Signals
Wen-Long ZHANG ; Lei QUAN ; Yun-Gang ZHAO
Progress in Biochemistry and Biophysics 2025;52(7):1687-1707
Mitochondria, the primary energy-producing organelles of the cell, also serve as signaling hubs and participate in diverse physiological and pathological processes, including apoptosis, inflammation, oxidative stress, neurodegeneration, and tumorigenesis. As semi-autonomous organelles, mitochondrial functionality relies on nuclear support, with mitochondrial biogenesis and homeostasis being stringently regulated by the nuclear genome. This interdependency forms a bidirectional signaling network that coordinates cellular energy metabolism, gene expression, and functional states. During mitochondrial damage or dysfunction, retrograde signals are transmitted to the nucleus, activating adaptive transcriptional programs that modulate nuclear transcription factors, reshape nuclear gene expression, and reprogram cellular metabolism. This mitochondrion-to-nucleus communication, termed “mitochondrial retrograde signaling”, fundamentally represents a mitochondrial “request” to the nucleus to maintain organellar health, rooted in the semi-autonomous nature of mitochondria. Despite possessing their own genome, the “fragmented” mitochondrial genome necessitates reliance on nuclear regulation. This genomic incompleteness enables mitochondria to sense and respond to cellular and environmental stressors, generating signals that modulate the functions of other organelles, including the nucleus. Evolutionary transfer of mitochondrial genes to the nuclear genome has established mitochondrial control over nuclear activities via retrograde communication. When mitochondrial dysfunction or environmental stress compromises cellular demands, mitochondria issue retrograde signals to solicit nuclear support. Studies demonstrate that mitochondrial retrograde signaling pathways operate in pathological contexts such as oxidative stress, electron transport chain (ETC) impairment, apoptosis, autophagy, vascular tension, and inflammatory responses. Mitochondria-related diseases exhibit marked heterogeneity but invariably result in energy deficits, preferentially affecting high-energy-demand tissues like muscles and the nervous system. Consequently, mitochondrial dysfunction underlies myopathies, neurodegenerative disorders, metabolic diseases, and malignancies. Dysregulated retrograde signaling triggers proliferative and metabolic reprogramming, driving pathological cascades. Mitochondrial retrograde signaling critically influences tumorigenesis and progression. Tumor cells with mitochondrial dysfunction exhibit compensatory upregulation of mitochondrial biogenesis, excessive superoxide production, and ETC overload, collectively promoting metastatic tumor development. Recent studies reveal that mitochondrial retrograde signaling—mediated by altered metabolite levels or stress signals—induces epigenetic modifications and is intricately linked to tumor initiation, malignant progression, and therapeutic resistance. For instance, mitochondrial dysfunction promotes oncogenesis through mechanisms such as epigenetic dysregulation, accumulation of mitochondrial metabolic intermediates, and mitochondrial DNA (mtDNA) release, which activates the cytosolic cGAS-STING signaling pathway. In normal cells, miR-663 mediates mitochondrion-to-nucleus retrograde signaling under reactive oxygen species (ROS) regulation. Mitochondria modulate miR-663 promoter methylation, which governs the expression and supercomplex stability of nuclear-encoded oxidative phosphorylation (OXPHOS) subunits and assembly factors. However, dysfunctional mitochondria induce oxidative stress, elevate methyltransferase activity, and cause miR-663 promoter hypermethylation, suppressing miR-663 expression. Mitochondrial dysfunction also triggers retrograde signaling in primary mitochondrial diseases and contributes to neurodegenerative disorders such as Parkinson’s disease (PD) and Alzheimer’s disease (AD). Current therapeutic strategies targeting mitochondria in neurological diseases focus on 5 main approaches: alleviating oxidative stress, inhibiting mitochondrial fission, enhancing mitochondrial biogenesis, mitochondrial protection, and insulin sensitization. In AD patients, mitochondrial morphological abnormalities and enzymatic defects, such as reduced pyruvate dehydrogenase and α-ketoglutarate dehydrogenase activity, are observed. Platelets and brains of AD patients exhibit diminished cytochrome c oxidase (COX) activity, correlating with mitochondrial dysfunction. To model AD-associated mitochondrial pathology, researchers employ cybrid technology, transferring mtDNA from AD patients into enucleated cells. These cybrids recapitulate AD-related mitochondrial phenotypes, including reduced COX activity, elevated ROS production, oxidative stress markers, disrupted calcium homeostasis, activated stress signaling pathways, diminished mitochondrial membrane potential, apoptotic pathway activation, and increased Aβ42 levels. Furthermore, studies indicate that Aβ aggregates in AD and α‑synuclein aggregates in PD trigger mtDNA release from damaged microglial mitochondria, activating the cGAS-STING pathway. This induces a reactive microglial transcriptional state, exacerbating neurodegeneration and cognitive decline. Targeting the cGAS-STING pathway may yield novel therapeutics for neurodegenerative diseases like AD, though translation from bench to bedside remains challenging. Such research not only deepens our understanding of disease mechanisms but also informs future therapeutic strategies. Investigating the triggers, core molecular pathways, and regulatory networks of mitochondrial retrograde signaling advances our comprehension of intracellular communication and unveils novel pathogenic mechanisms underlying malignancies, neurodegenerative diseases, and type 2 diabetes mellitus. This review summarizes established mitochondrial-nuclear retrograde signaling axes, their roles in interorganellar crosstalk, and pathological consequences of dysregulated communication. Targeted modulation of key molecules and proteins within these signaling networks may provide innovative therapeutic avenues for these diseases.
5.PRELIMINARY INVESTIGATION OF EHRLICHIA AND NEOEHRLICHIA IN RODENTS AT THE IMPORTANT PORTS ALONG THE"BELT AND ROAD"
Xiao-Long ZHANG ; Jia XU ; Shi-Liang MA ; Pi-Zheng WANG ; Juan PAN ; Jia-Yuan CAO ; Zhi-Wen SUN ; Hui-Lin GUO ; Li-Li XIAO
Acta Parasitologica et Medica Entomologica Sinica 2025;32(3):160-166
Objective This study aimed to investigate natural infection of rodents with Ehrlichia and Neoehrlichia at major Chinese land-border ports along the"Belt and Road".Methods In 2022,rodents were monitored in 10 ports in northern and southern China and identified based on diagnostic morphological characteristics.The 16S rRNA genes of Ehrlichia and Neoehrlichia were detected by PCR using universal primers from rodent samples and phylogenetic analysis was performed based on the sequences of the detected positive pathogens.Results A total of 356 rodents were sampled,including 2 orders,5 families,15 genera,and 20 species.Predominantly,73,61,56,and 58 were Meriones unguiculatus(20.51%),Rattus norvegicus(17.13%),Apodemus agrarius(15.73%),and Microtus gregalis(16.29%).Only one Microtus fortis from Suifenghe Port was infected with Ehrlichia sp.Moreover,12 rodents were infected with Neoehrlichia spp.(overall positivity rate:3.37%).Conclusions Natural infections with Ehrlichia spp.and Neoehrlichia spp.were demonstrated in rodents at important Chinese land-border ports.The positivity rate of Neoehrlichia spp.was high in some ports,indicating that surveillance for ticks and their prevention and control measures should be intensified in these regions.
6.Two-sample Mendelian randomization analysis of the association between dairy products and risk of osteoarthritis
Xuefeng LEI ; Wenzheng ZHANG ; Jiazhong JI ; Long XUE ; Tao YANG ; Tao WEN ; Tong MA ; Yihui TU ; Huaming XUE
Chinese Journal of Rheumatology 2025;29(8):668-673
Objective:A bidirectional Mendelian randomization approach was applied to dissect the causal association between dairy product consumption and osteoarthritis (OA), so to offering novel insights for the prevention, treatment, and prognosis assessment of knee osteoarthritis (KOA).Methods:A two-sample Mendelian randomization (MR) analysis was conducted using public available genome-wide association studies. The primary analysis was performed using the inverse variance weighted (IVW) method. To assess the stability and reliability of the results, we compared IVW and MR-Egger regression using Cochran′s Q test to evaluate SNP heterogeneity. MR-Egger regression was employed to assess pleiotropy, while a leave-one-out approach was used for sensitivity analysis. Results:Based on 207 instrumental variables (IVs), two-sample MR analysis revealed that for each standard deviation increase in genetically predicted cheese intake, the risk of OA was significantly negatively associated [ OR(95% CI)=0.98(0.98, 0.99), P<0.001], so did the risk of KOA [ OR(95% CI)=0.73(0.63, 0.85), P<0.001]. However, no significant association was found between OA risk and the intake of full-fat milk (30 IVs), semi-skimmed milk (15 IVs), skimmed milk (32 IVs), soy milk (25 IVs), or other types of milk (13 IVs), yogurt (11 IVs), or butter (3 IVs). Conclusion:The two-sample MR analysis revealed causally inverse associations between cheese intake and OA as well as KOA.
7.Preparation of new hydrogels and their synergistic effects of immunochemotherapy
Wen-wen YAN ; Yan-long ZHANG ; Ming-hui CAO ; Zheng-han LIU ; Hong LEI ; Xiang-qian JIA
Acta Pharmaceutica Sinica 2025;60(2):479-487
In recent years, cancer treatment methods and means are becoming more and more diversified, and single treatment methods often have limited efficacy, while the synergistic effect of immunity combined with chemotherapy can inhibit tumor growth more effectively. Based on this, we constructed a sodium alginate hydrogel composite system loaded with chemotherapeutic agents and tumor vaccines (named SA-DOX-NA) with a view to the combined use of chemotherapeutic agents and tumor vaccines. Firstly, the tumor vaccine (named NA) degradable under acidic conditions was constructed by
8.Status of Clinical Practice Guideline Information Platforms
Xueqin ZHANG ; Yun ZHAO ; Jie LIU ; Long GE ; Ying XING ; Simeng REN ; Yifei WANG ; Wenzheng ZHANG ; Di ZHANG ; Shihua WANG ; Yao SUN ; Min WU ; Lin FENG ; Tiancai WEN
Medical Journal of Peking Union Medical College Hospital 2025;16(2):462-471
Clinical practice guidelines represent the best recommendations for patient care. They are developed through systematically reviewing currently available clinical evidence and weighing the relative benefits and risks of various interventions. However, clinical practice guidelines have to go through a long translation cycle from development and revision to clinical promotion and application, facing problems such as scattered distribution, high duplication rate, and low actual utilization. At present, the clinical practice guideline information platform can directly or indirectly solve the problems related to the lengthy revision cycles, decentralized dissemination and limited application of clinical practice guidelines. Therefore, this paper systematically examines different types of clinical practice guideline information platforms and investigates their corresponding challenges and emerging trends in platform design, data integration, and practical implementation, with the aim of clarifying the current status of this field and providing valuable reference for future research on clinical practice guideline information platforms.
9.Association between PM 2.5 Chemical Constituents and Preterm Birth: The Undeniable Role of Preconception H19 Gene Variation.
Ya Long WANG ; Pan Pan SUN ; Xin Ying WANG ; Jun Xi ZHANG ; Xiang Yu YU ; Jian CHAI ; Ruo DU ; Wen Yi LIU ; Fang Fang YU ; Yue BA ; Guo Yu ZHOU
Biomedical and Environmental Sciences 2025;38(8):1016-1022
10.Association between Serum Chloride Levels and Prognosis in Patients with Hepatic Coma in the Intensive Care Unit.
Shu Xing WEI ; Xi Ya WANG ; Yuan DU ; Ying CHEN ; Jin Long WANG ; Yue HU ; Wen Qing JI ; Xing Yan ZHU ; Xue MEI ; Da ZHANG
Biomedical and Environmental Sciences 2025;38(10):1255-1269
OBJECTIVE:
To explore the relationship between serum chloride levels and prognosis in patients with hepatic coma in the intensive care unit (ICU).
METHODS:
We analyzed 545 patients with hepatic coma in the ICU from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Associations between serum chloride levels and 28-day and 1-year mortality rates were assessed using restricted cubic splines (RCSs), Kaplan-Meier (KM) curves, and Cox regression. Subgroup analyses, external validation, and mechanistic studies were also performed.
RESULTS:
A total of 545 patients were included in the study. RCS analysis revealed a U-shaped association between serum chloride levels and mortality in patients with hepatic coma. The KM curves indicated lower survival rates among patients with low chloride levels (< 103 mmol/L). Low chloride levels were independently linked to increased 28-day and 1-year all-cause mortality rates. In the multivariate models, the hazard ratio ( HR) for 28-day mortality in the low-chloride group was 1.424 (95% confidence interval [ CI]: 1.041-1.949), while the adjusted hazard ratio for 1-year mortality was 1.313 (95% CI: 1.026-1.679). Subgroup analyses and external validation supported these findings. Cytological experiments suggested that low chloride levels may activate the phosphorylation of the NF-κB signaling pathway, promote the expression of pro-inflammatory cytokines, and reduce neuronal cell viability.
CONCLUSION
Low serum chloride levels are independently associated with increased mortality in patients with hepatic coma.
Humans
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Male
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Female
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Middle Aged
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Intensive Care Units
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Prognosis
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Chlorides/blood*
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Aged
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Coma/blood*
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Adult

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