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Ni is the second most abundant element in the Earth's core. Yet, its effects on the inner core's structure and formation process are usually disregarded because of its electronic and size similarity with Fe. Using ab initio molecular dynamics simulations, we find that the bcc phase can spontaneously crystallize in liquid Ni at temperatures above Fe's melting point at inner core pressures. The melting temperature of Ni is shown to be 700 to 800 K higher than that of Fe at 323 to 360 GPa. hcp, bcc, and liquid phase relations differ for Fe and Ni. Ni can be a bcc stabilizer for Fe at high temperatures and inner core pressures. A small amount of Ni can accelerate Fe's crystallization at core pressures. These results suggest that Ni may substantially impact the structure and formation process of the solid inner core.
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Interference from task-irrelevant stimuli can occur during the semantic and response processing stages. Previous studies have shown both common and distinct mechanisms underlying semantic conflict processing and response conflict processing in the visual domain. However, it remains unclear whether common and/or distinct mechanisms are involved in semantic conflict processing and response conflict processing in the cross-modal domain. Therefore, the present electroencephalography study adopted an audiovisual 2-1 mapping Stroop task to investigate whether common and/or distinct mechanisms underlie semantic conflict and response conflict. Behaviorally, significant cross-modal semantic conflict and significant cross-modal response conflict were observed. Electroencephalography results revealed that the frontal N2 amplitude and theta power increased only in the semantic conflict condition, while the parietal N450 amplitude increased only in the response conflict condition. These findings indicated that distinct neural mechanisms were involved in cross-modal semantic conflict and response conflict processing, supporting the domain-specific cognitive control mechanisms from a cross-modal multistage conflict processing perspective.
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Encéfalo , Semântica , Encéfalo/fisiologia , Tempo de Reação/fisiologia , Eletroencefalografia , Teste de StroopRESUMO
The mechanisms of semantic conflict and response conflict in the Stroop task have mainly been investigated in the visual modality. However, the understanding of these mechanisms in cross-modal modalities remains limited. In this electroencephalography (EEG) study, an audiovisual 2-1 mapping Stroop task was utilized to investigate whether distinct and/or common neural mechanisms underlie cross-modal semantic conflict and response conflict. The response time data showed significant effects on both cross-modal semantic and response conflicts. Interestingly, the magnitude of semantic conflict was found to be smaller in the fast response time bins than in the slow response time bins, whereas no such difference was observed for response conflict. The EEG data demonstrated that cross-modal semantic conflict specifically increased the N450 amplitude. However, cross-modal response conflict specifically enhanced theta band power and theta phase synchronization between the medial frontal cortex (MFC) and lateral prefrontal electrodes as well as between the MFC and motor electrodes. In addition, both cross-modal semantic conflict and response conflict led to a decrease in P3 amplitude. Taken together, these findings provide cross-modal evidence for domain-specific mechanism in conflict detection and suggest both domain-specific and domain-general mechanisms exist in conflict resolution.
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Eletroencefalografia , Semântica , Mapeamento Encefálico , Lobo Frontal/fisiologia , Tempo de Reação/fisiologiaRESUMO
Ultra-high-field (UHF) magnetic resonance imaging (MRI) stands as a pivotal cornerstone in biomedical imaging, yet the challenge of false imaging persists, constraining its full potential. Despite the development of dual-mode contrast agents improving conventional MRI, their effectiveness in UHF remains suboptimal due to the high magnetic moment, resulting in diminished T1 relaxivity and excessively enhanced T2 relaxivity. Herein, we report a DNA-mediated magnetic-dimer assembly (DMA) of iron oxide nanoparticles that harnesses UHF-tailored nanomagnetism for fault-free UHF-MRI. DMA exhibits a dually enhanced longitudinal relaxivity of 4.42 mM-1·s-1 and transverse relaxivity of 26.23 mM-1·s-1 at 9 T, demonstrating a typical T1-T2 dual-mode UHF-MRI contrast agent. Importantly, DMA leverages T1-T2 dual-modality image fusion to achieve artifact-free breast cancer visualization, effectively filtering interference from hundred-micrometer-level false-positive signals with unprecedented precision. The UHF-tailored T1-T2 dual-mode DMA contrast agents hold promise for elevating the accuracy of MR imaging in disease diagnosis.
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Meios de Contraste , DNA , Imageamento por Ressonância Magnética , Imageamento por Ressonância Magnética/métodos , Meios de Contraste/química , Humanos , DNA/química , Camundongos , Nanopartículas Magnéticas de Óxido de Ferro/química , Feminino , Animais , Neoplasias da Mama/diagnóstico por imagem , Nanopartículas de Magnetita/química , Linhagem Celular TumoralRESUMO
The objective of this study was to construct a prognostic model by utilizing serine/glycine metabolism-related genes (SGMGs), thus establishing a risk score for lung adenocarcinoma (LUAD). Based on the TCGA-LUAD and SGMG data set, two subtypes with different SGMG expression levels were identified by clustering analysis. Thirteen differential expression genes were used to construct RiskScore by Cox regression. GSE72094 data set was used for validation. The survival characteristics, immune features, and potential benefits of chemotherapy drugs were analyzed for two risk groups. RiskScore was constructed based on the genes ABCC12, RIC3, CYP4B1, SFTPB, CACNA2D2, IGF2BP1, NTSR1, DKK1, CREG2, PITX3, RGS20, FETUB, and IGFBP1. Patients in the low-risk (LR) group exhibited a superior overall survival. In addition, aDCs, iDSs, mast cells, neutrophils, HLA, and type II IFN were more abundant in the LR group with higher IPS scores and lower TIDE scores. In contrast, NK cells, APC coinhibition, and MHC-I were more common in the high-risk (HR) group, which may be more sensitive to chemotherapy drugs such as cisplatin, oxaliplatin, and nilotinib. RiskScore was a promising biomarker that can be used to distinguish LUAD prognosis, immune features, and sensitivity to chemotherapy drugs.
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Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Prognóstico , Fatores de Risco , Adenocarcinoma de Pulmão/genética , Neoplasias Pulmonares/genética , Glicina , Proteínas RepressorasRESUMO
Under resource distribution context, individuals have a strong aversion to unfair treatment not only toward themselves but also toward others. However, there is no clear consensus regarding the commonality and distinction between these two types of unfairness. Moreover, many neuroimaging studies have investigated how people evaluate and respond to unfairness in the abovementioned two contexts, but the consistency of the results remains to be investigated. To resolve these two issues, we sought to summarize existing findings regarding unfairness to self and others and to further elucidate the neural underpinnings related to distinguishing evaluation and response processes through meta-analyses of previous neuroimaging studies. Our results indicated that both types of unfairness consistently activate the affective and conflict-related anterior insula (AI) and dorsal anterior cingulate cortex/supplementary motor area (dACC/SMA), but the activations related to unfairness to self appeared stronger than those related to others, suggesting that individuals had negative reactions to both unfairness and a greater aversive response toward unfairness to self. During the evaluation process, unfairness to self activated the bilateral AI, dACC, and right dorsolateral prefrontal cortex (DLPFC), regions associated with unfairness aversion, conflict, and cognitive control, indicating reactive, emotional and automatic responses. In contrast, unfairness to others activated areas associated with theory of mind, the inferior parietal lobule and temporoparietal junction (IPL-TPJ), suggesting that making rational judgments from the perspective of others was needed. During the response, unfairness to self activated the affective-related left AI and striatum, whereas unfairness to others activated cognitive control areas, the left DLPFC and the thalamus. This indicated that the former maintained the traits of automaticity and emotionality, whereas the latter necessitated cognitive control. These findings provide a fine-grained description of the common and distinct neurocognitive mechanisms underlying unfairness to self and unfairness to others. Overall, this study not only validates the inequity aversion model but also provides direct evidence of neural mechanisms for neurobiological models of fairness.
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Mapeamento Encefálico , Imageamento por Ressonância Magnética , Humanos , Mapeamento Encefálico/métodos , Encéfalo/fisiologia , Encéfalo/diagnóstico por imagem , Emoções/fisiologiaRESUMO
Methyltransferase like 3 (METTL3), a primary N6-methyladenosine (m6A) methyltransferase, has been implicated in various biological and pathological processes including immune responses. However, the functions and mechanisms of METTL3 in pathogenic T helper (Th)17 cells are poorly understood. Here we found significantly decreased METTL3 expression along with reduced m6A levels in eyeballs and T cells of experimental autoimmune uveitis (EAU). Overexpression of METTL3 ameliorated the development of EAU and suppressed pathogenic Th17 cell responses in vivo and in vitro. Mechanistically, METTL3 promoted the expression of absent, small, or homeotic-like 1 (ASH1L) via enhancing its stability in a YT521-B homology domain containing 2 (YTHDC2)-dependent manner, which further decreased the expression of IL-17 and IL-23 receptor (IL-23R), resulting in reduced pathogenic Th17 responses. Together, our data reveal a pivotal role of METTL3 in regulating pathogenic Th17 responses, which may contribute to human uveitis therapy.
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Proteínas de Ligação a DNA , Histona-Lisina N-Metiltransferase , Metiltransferases , Células Th17 , Uveíte , Proteínas de Ligação a DNA/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Metiltransferases/genética , Metiltransferases/metabolismo , RNA Mensageiro/genética , Uveíte/genética , Uveíte/metabolismo , Animais , Doenças Autoimunes , Modelos Animais de DoençasRESUMO
We present a one-pot reaction that offers an efficient approach to synthesizing tetrasubstituted vinyl sulfides with high stereoselectivity. This method involves the sequential Wolff rearrangement, ylide formation, and [1,4]-aryl transfer by utilizing aryl and alkyl thiols and α-diazo carbonyl compounds as substrates. Notably, this reaction features commercially available materials, straightforward operation, atom economy, and broad substrate scope. Moreover, the primary photophysical properties (aggregation-induced emission effect) of the products were also investigated, which might be useful in functional materials via structural modification.
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A pair of water-stable and highly porous homochiral fluorescent silver-organic framework enantiomers, namely, R-Ag-BPA-TPyPE (R-1) and S-Ag-BPA-TPyPE (S-1), had been prepared as enantioselective fluorescence sensors. Combining homochiral 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (BPA) with an AIE-based ligand tetrakis[4-(pyridin-4-yl)phenyl]ethene (TPyPE) in complexes R-1 and S-1 made them possess favorable circularly polarized luminescence (CPL) properties, and their CPL spectra were almost mirror images of each other. The luminescence dissymmetry factors (glum) are ±2.2 × 10-3 for R-1 and S-1, and the absolute fluorescence quantum yields (ΦFs) are 32.0% for R-1 and S-1, respectively. Complex R-1 could enantioselectively recognize two enantiomers of amino acids in water or DMF with high Stern-Volmer constants of 236-573 M-1 and enantioselectivity ratios of 1.40-1.78.
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In mammals, CD4 is found to be expressed on T cells and innate immune cells, however, teleost cells bearing CD4 have not been well identified and characterized. In this study, we identified two different CD4-1+ cell subsets in grass carp (Ctenopharyngodon idella): CD4-1+ lymphocytes (Lym) and CD4-1+ myeloid cells (Mye), both of which had the highest proportions in the head kidney. The mRNA expression analysis showed that CD4-1, CD4-2, TCRß, CD3γ/δ, and LCK1 are highly expressed in CD4-1+ Lym and also expressed in CD4-1+ Mye. Furthermore, we found that CD4-1+ Lym have a Lym morphology and highly express T-cell cytokines, suggesting that they are CD4+ T cells equivalent to mammalian Th cells. On the other hand, CD4-1+ Mye were found to have a morphology of macrophage and highly express macrophage marker gene MCSFR, indicating that they are macrophages. In addition, functional analysis revealed that CD4-1+ Mye possess phagocytic ability and great antigen-processing ability. Taken together, our study sheds further light on the composition and function of CD4+ cells in teleost fish.
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Carpas , Proteínas de Peixes , Animais , Carpas/imunologia , Carpas/genética , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Linfócitos T CD4-Positivos/imunologia , Antígenos CD4/genética , Antígenos CD4/imunologia , Antígenos CD4/metabolismo , Rim Cefálico/imunologia , Rim Cefálico/citologia , Células Mieloides/imunologia , Imunidade Inata/genéticaRESUMO
BACKGROUND AND AIMS: Hybrid endoscopic submucosal dissection (H-ESD), a modified ESD with a snare, has become increasingly utilized to overcome the limitations of conventional ESD (C-ESD). This study aimed to compare the efficacy and safety of Planned H-ESD and C-ESD for colorectal lesions. METHODS: Propensity score matching was performed to control for confounding variables in this retrospective study. Outcomes included en bloc resection and complete resection (R0) rates, procedure time, adverse event rates, and local recurrence rate. RESULTS: 1286 lesions were enrolled in the study. After matching, 263 lesions were assigned to each group. The Planned H-ESD group has lower en bloc rate but similar R0 resection rate compared to the C-ESD group (90.9% vs 98.1%, P = 0.001; 77.2% vs 77.9%, P = 0.917). The median procedure time was shorter in the Planned H-ESD group (27.0 min vs 35.0 min, P = 0.001). There were no significant differences in adverse events rates or local recurrence rate. Subgroup analysis based on lesion size revealed that a significantly lower en bloc resection rate in the Planned H-ESD group compared to the C-ESD group for lesions ≥ 40 mm (71.0% vs 94.3%, P = 0.027), but there was no significant difference for lesions < 40 mm. CONCLUSION: The Planned H-ESD has a lower en bloc resection rate but a similar R0 resection rate, adverse event rates, local recurrence rate, and shorter procedure duration. Compared to C-ESD, Planned H-ESD presents advantages for managing colorectal neoplasms below 40 mm.
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Neoplasias Colorretais , Ressecção Endoscópica de Mucosa , Humanos , Resultado do Tratamento , Ressecção Endoscópica de Mucosa/efeitos adversos , Ressecção Endoscópica de Mucosa/métodos , Pontuação de Propensão , Estudos Retrospectivos , Neoplasias Colorretais/patologiaRESUMO
Numerous studies have demonstrated the role of making choices as an internal motivator to improve performance, and recent studies in the domain of memory have focused on adults. To chart the developmental trend of the choice effect on memory, we conducted a series of seven experiments involving children, adolescents, and young adults. Participants (N = 512) aged 5 to 26 years performed a choice encoding task that manipulated the opportunities to choose and then took a memory test. Using different types of experimental materials and corroborated by a mini meta-analysis, we found that the choice effect on memory was significant in childhood and early adolescence but not significant in late adolescence and early adulthood. The developmental changes were statistically significant, particularly evident during the transition from early to late adolescence. These findings suggest that the internal value of choice decreases across development and contributes to our understanding of developmental differences in the role of choice in memory.
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Desenvolvimento Infantil , Comportamento de Escolha , Humanos , Adolescente , Comportamento de Escolha/fisiologia , Feminino , Masculino , Criança , Adulto Jovem , Adulto , Pré-Escolar , Desenvolvimento Infantil/fisiologia , Memória , Fatores EtáriosRESUMO
BACKGROUND: In ageing societies such as the United States, evaluating the incidence and survival rates of cancer in older adults is essential. This study aimed to analyse the incidence and survival rates of cancer in individuals aged 55 years or older in the United States. METHODS: This retrospective study (1975-2019) was conducted using combined registry data from the Surveillance, Epidemiology, and End Results database. Data from the 9, 12, and 17 Registries (Nov 2021 Sub) datasets were used. RESULTS: In 2019, the incidence of cancer in individuals older than 55 years and the overall population was 1322.8 and 382.1 per 100,000 population, respectively. From 2000 to 2019, the incidence of cancer in individuals older than 55 years showed a decreasing trend, whereas their five-year survival rates showed an increasing trend. The incidence of cancer in the 75-79 and 80-84 year age groups was the highest among all age groups. CONCLUSIONS: The incidence of colon cancer declined significantly, whereas that of intrahepatic bile duct cancer increased considerably. These trends may be due to increased screening for cancers with high incidence rates and improved control of the risk factors for cancer. Rapid development of targeted therapy and immunotherapy combined with early tumour detection may be an important reason for the improved survival rates.
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Neoplasias do Colo , Idoso , Humanos , Neoplasias do Colo/mortalidade , Incidência , Sistema de Registros , Estudos Retrospectivos , Programa de SEER , Taxa de Sobrevida , Estados Unidos/epidemiologiaRESUMO
With the rapid development of novel energy vehicles, power generation, photovoltaics, and other industries, power electronic devices have gained considerable attention. Insulated-gate bipolar transistors (IGBTs) have been widely used in those fields. With the emergence of intelligent manufacturing concepts such as Germany's "Industry 4.0" and China's "Made in China 2025", conventional manufacturing which needs to be upgraded with higher efficiency and yield is rapidly pivoting toward digitalization and intelligence. The digital twin methodology has been extensively used in various industries for constructing virtual models of physical entities, facilitating real-time data interconnection to reduce costs and improve efficiency. This study proposes a modular intelligent IGBT production line based on the digital twin. Real-time data are transmitted from a physical line to a digital line for storage and analysis. The digital line is visualized, and an intelligent management platform containing multiple functions is developed. Additionally, a process simulation database is established to obtain the optimal process parameters. Numerous quality issues that can arise during each process of IGBT packaging are addressed using a problem-solving approach based on the digital twin methodology. Consequently, this digital-twin-based IGBT intelligent production line effectively enhances yield rates and efficiency. IGBT modules with various packaging forms such as ACF, ACE, and ACD are manufactured.
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This paper presents an in-depth analysis of the oscillation phenomenon occurring in multi-chip parallel automotive-grade power modules under short-circuit conditions and investigates three suppression methods. We tested and analyzed two commercial automotive-grade power modules, one containing two chips and the other containing a single chip, and found that short-circuit gate oscillations were more likely to occur in multi-chip parallel packaged modules than in single-chip packaged modules. Through experimental and simulation analyses, we observed that gate oscillations were mainly caused by the interaction between internal parasitic parameters of the module and the external drive circuit, and we found that high drive resistance and low common emitter inductance between parallel chips could effectively suppress gate voltage oscillations. We also analyzed the two mainstream suppression schemes, increasing the drive gate resistance and placing the drive capacitors in parallel. Unfortunately, we found that these suppression schemes were not ideal solutions because both schemes changed the switching characteristics of the power module. As an alternative, we propose a simple and effective solution that involves adding parallel connections between the parallel chips. Simulation calculations showed that this optimized method reduced the emitter inductance between parallel chips in the upper bridge arm by about 30% and in the lower bridge arm by 35%. Through short-circuit experiments conducted at different DC bus voltages, it has been verified that the new optimized solution effectively resolves gate oscillation issues without affecting the switching characteristics of the power module.
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As one of the most essential types of heterocyclic compounds, pyrazines have a characteristic smell and taste and have a wide range of commercial applications, especially in the food industry. With the development of the food industry, the demand for pyrazines has increased. Therefore, understanding the properties, functions, and synthetic pathways of pyrazines is one of the fundamental methods to produce, control, and apply pyrazines in food or medical systems. In this review, we provide an overview of the synthesis pathways and physiological or pharmacological functions of naturally occurring pyrazines. In particular, we focus on the biosynthesis and pharmacological effects of 2,3,5,6-Tetramethylpyrazine (TTMP), 2,5-Dimethylpyrazine (2,5-DMP), and 2,3,5-trimethylpyrazine (TMP). Furthermore, areas where further research on pyrazines is needed are discussed in this work.
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Pirazinas , Pirazinas/química , Pirazinas/farmacologia , Pirazinas/síntese química , Humanos , Animais , Vias Biossintéticas/efeitos dos fármacosRESUMO
Ultra-high field (UHF) magnetic resonance imaging (MRI) has emerged as a focal point of interest in the field of cancer diagnosis. Despite the ability of current paramagnetic or superparamagnetic smart MRI contrast agents to selectively enhance tumor signals in low-field MRI, their effectiveness at UHF remains inadequate due to inherent magnetism. Here, we report a ligand-mediated magnetism-conversion nanoprobe (MCNP) composed of 3-mercaptopropionic acid ligand-coated silver-gadolinium bimetallic nanoparticles. The MCNP exhibits a pH-dependent magnetism conversion from ferromagnetism to diamagnetism, facilitating tunable nanomagnetism for pH-activatable UHF MRI. Under neutral pH, the thiolate (-S- ) ligands lead to short τ'm and increased magnetization of the MCNPs. Conversely, in the acidic tumor microenvironment, the thiolate ligands are protonated and transform into thiol (-SH) ligands, resulting in prolonged τ'm and decreased magnetization of the MCNP, thereby enhancing longitudinal relaxivity (r1) values at UHF MRI. Notably, under a 9â T MRI field, the pH-sensitive changes in Ag-S binding affinity of the MCNP lead to a remarkable (>10-fold) r1 increase in an acidic medium (pHâ 5.0). In vivo studies demonstrate the capability of MCNPs to amplify MRI signal of hepatic tumors, suggesting their potential as a next-generation UHF-tailored smart MRI contrast agent.
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Imageamento por Ressonância Magnética , Neoplasias , Humanos , Ligantes , Imageamento por Ressonância Magnética/métodos , Meios de Contraste , Concentração de Íons de Hidrogênio , Microambiente TumoralRESUMO
Prior to clinical application, reliability of percutaneous ventricular assist devices(pVAD) requires to be tested systematically. Currently, there's a lack of dedicated reliability testing equipment and methodologies for pVAD. Considering the structural and functional aspects of percutaneous ventricular assist devices, this study conducts research on pVAD reliability test engineering. Test setups, clinical conditions, failure modes, effects analysis, and evaluation models have been investigated. A highly feasible methodological approach for percutaneous ventricular assist device reliability assessment has been formed. This study offers valuable insights into standardizing their reliability evaluation in clinical settings.
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Coração Auxiliar , Resultado do Tratamento , Reprodutibilidade dos TestesRESUMO
In magnetic resonance examination, the interaction between implants and the radio frequency (RF) fields induces heating in human tissue and may cause tissue damage. To assess the RF-induced heating of implants, three steps should be executed, including electromagnetic model construction, electromagnetic model validation, and virtual human body simulations. The crucial step of assessing RF-induced heating involves the construction of a test environment for electromagnetic model validation. In this study, a hardware environment, comprised of a RF generation system, electromagnetic field measurement system, and a robotic arm positioning system, was established. Furthermore, an automated control software environment was developed using a Python-based software development platform to enable the creation of a high-precision automated integrated test environment. The results indicate that the electric field generated in this test environment aligns well with the simulated electric field, making it suitable for assessing the RF-induced heating effects of implants.
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Campos Eletromagnéticos , Temperatura Alta , Próteses e Implantes , Ondas de Rádio , Software , Humanos , Imageamento por Ressonância MagnéticaRESUMO
EphB6 belongs to the receptor tyrosine kinase, whose low expression is associated with shorter survival of colorectal cancer (CRC) patients. But the role and mechanism of EphB6 in the progression of CRC need further study. In addition, EphB6 was mainly expressed in intestinal neurons. But how EphB6 is involved in functions of intestinal neurons has not been known. In our study, we constructed a mouse xenograft model of CRC by injecting CMT93 cells into the rectum of EphB6-deficient mice. We found that the deletion of EphB6 in mice promoted tumor growth of CMT93 cells in a xenograft model of CRC, which was independent of changes in the gut microbiota. Interestingly, inhibition of intestinal neurons by injecting botulinum toxin A into rectum of EphB6-deficient mice could eliminate the promotive effect of EphB6 deficiency on tumor growth in the xenograft model of CRC. Mechanically, the deletion of EphB6 in mice promoted the tumor growth in CRC by increasing GABA in the tumor microenvironment. Furthermore, EphB6 deficiency in mice increased the expression of synaptosomal-associated protein 25 in the intestinal myenteric plexus, which mediated the release of GABA. Our study concluded that EphB6 knockout in mice promotes tumor growth of CMT93 cells in a xenograft model of CRC by modulating GABA release. Our study found a new regulating mechanism of EphB6 on the tumor progression in CRC that is dependent on intestinal neurons.