Electroregulation of graphene-nanofluid interactions to coenhance water permeation and ion rejection in vertical graphene membranes.

Graphene oxide (GO) membranes with nanoconfined interlayer channels theoretically enable anomalous nanofluid transport for ultrahigh filtration performance. However, it is still a significant challenge for current GO laminar membranes to achieve ultrafast water permeation and high ion rejection simultaneously, because of the contradictory effect that exists between the water-membrane hydrogen-bond interaction and the ion-membrane electrostatic interaction. Here, we report a vertically aligned reduced GO (VARGO) membrane and propose an electropolarization strategy for regulating the interfacial hydrogen-bond and electrostatic interactions to concurrently enhance water permeation and ion rejection. The membrane with an electro-assistance of 2.5 V exhibited an ultrahigh water permeance of 684.9 L m-2 h-1 bar-1, which is 1-2 orders of magnitude higher than those of reported GO-based laminar membranes. Meanwhile, the rejection rate of the membrane for NaCl was as high as 88.7%, outperforming most reported graphene-based membranes (typically 10 to 50%). Molecular dynamics simulations and density-function theory calculations revealed that the electropolarized VARGO nanochannels induced the well-ordered arrangement of nanoconfined water molecules, increasing the water transport efficiency, and thereby resulting in improved water permeation. Moreover, the electropolarization effect enhanced the surface electron density of the VARGO nanochannels and reinforced the interfacial attractive interactions between the cations in water and the oxygen groups and π-electrons on the VARGO surface, strengthening the ion-partitioning and Donnan effect for the electrostatic exclusion of ions. This finding offers an electroregulation strategy for membranes to achieve both high water permeability and high ion rejection performance.

Highly Efficient Acidic Electrosynthesis of Hydrogen Peroxide at Industrial-Level Current Densities Promoted by Alkali Metal Cations.

Acidic H2O2 synthesis through electrocatalytic 2e- oxygen reduction presents a sustainable alternative to the energy-intensive anthraquinone oxidation technology. Nevertheless, acidic H2O2 electrosynthesis suffers from low H2O2 Faradaic efficiencies primarily due to the competing reactions of 4e- oxygen reduction to H2O and hydrogen evolution in environments with high H+ concentrations. Here, we demonstrate the significant effect of alkali metal cations, acting as competing ions with H+, in promoting acidic H2O2 electrosynthesis at industrial-level currents, resulting in an effective current densities of 50-421 mA cm-2 with 84-100 % Faradaic efficiency and a production rate of 856-7842 µmol cm-2 h-1 that far exceeds the performance observed in pure acidic electrolytes or low-current electrolysis. Finite-element simulations indicate that high interfacial pH near the electrode surface formed at high currents is crucial for activating the promotional effect of K+. In situ attenuated total reflection Fourier transform infrared spectroscopy and ab initio molecular dynamics simulations reveal the central role of alkali metal cations in stabilizing the key *OOH intermediate to suppress 4e- oxygen reduction through interacting with coordinated H2O.

Mitochondrial introgression and mito-nuclear discordance obscured the closely related species boundaries in Cletus Stål from China (Heteroptera: Coreidae).

Accurate taxonomy and delimitation are of great importance for pest control strategies and management programs. Here, we focus on Cletus (Insecta: Hemiptera: Coreidae), which includes many crop pests. The species boundaries still conflict and only cytochrome c oxidase subunit I (COI) barcoding has been previously used for molecular studies. We generated new mitochondrial genome and nuclear genome-wide SNPs to explore the species boundaries of 46 Cletus samples from China using multiple species delimitation approaches. All results recovered a monophyly with high support, except for two closely related species in clade I - C. punctiger and C. graminis. Mitochondrial data demonstrated admixture in clade I, while genome-wide SNPs unambiguously identified two separate species, which were confirmed by morphological classification. Inconsistent nuclear and mitochondrial data indicated mito-nuclear discordance. Mitochondrial introgression is the most likely explanation, and more extensive sampling and more comprehensive data are needed to ascertain a pattern. Accurate species delimitation will shed light on species status; thus, an accurate taxonomy is of particular concern, as there is a pressing need to implement precise control of agricultural pests and to perform further research on diversification.

Electrochemical Opening of Impermeable Nanochannels in Laminar Graphene Membranes for Ultrafast Nanofiltration.

Reduced graphene oxide (rGO) could be theoretically used to construct highly permeable laminar membranes with nearly frictionless nanochannels for water treatment. However, their pristine (sp2 C-C) regions usually restack into impermeable channels as a result of van der Waals interactions, resulting in a much low permeance. In this study, we demonstrate that the restacked regions could be electrochemically expanded to form ultrafast water transport nanochannels by providing a low positive potential (e.g., +1.00 V vs SCE) to the rGO membrane. Experimental investigations indicate that the structural expansion is attributed to the intercalation of water molecules into the restacked regions, driven by hydrogen bond interactions between water molecules and hydroxyl groups that are electrochemically produced on edges of rGO nanosheets. The structural expansion could be promoted by weakening the graphene-OH- interactions through intermittent application of the potential. As a result of more ultrafast water transport nanochannels available, the electrochemically treated rGO membranes could have a permeance 2 orders of magnitude higher than that of the pristine one and ∼3 times higher than that of graphene oxide membranes. Because of their smaller average pore size, the rGO membranes also have a higher ionic/molecular rejection performance than graphene oxide membranes.

Improving the Performance of the Lamellar Reduced Graphene Oxide/Molybdenum Sulfide Nanofiltration Membrane through Accelerated Water-Transport Channels and Capacitively Enhanced Charge Density.

Graphene is promising in the construction of next-generation nanofiltration membranes for wastewater treatment and water purification. However, the application of graphene-based membranes has still been prohibited by their deficiencies in permeability and ion rejection. Herein, regulating the 2D channel and enhancing the charge density are co-adopted for simultaneous enhancement of the water flux and salt rejection of reduced graphene oxide (rGO) membranes through the intercalation of molybdenum sulfide (MoS2) nanosheets and external electrical assistance. The fabricated rGO/MoS2 membranes possess expanded nanochannels with less friction and a higher water molecule transport velocity gradient (from 8.57 to 14.07 s-1) than those of rGO membranes. Consequently, their water permeance increases from 0.92 to 34.9 L m-2 h-1 bar-1. Meanwhile, benefiting from the high capacitance and negative potential of -1.1 V versus the saturated calomel electrode given to the membranes, their rejection rates toward NaCl reach 87.2% and those toward Na2SO4 reach 93.7%. The Donnan steric pore model analysis indicates that the capacitively and electrically increased surface charge density make great contributions to the higher ion rejection rate. This work gives new insights into membrane design for high water flux and salt rejection efficiency.

The association between three-dimensional measurement of posterior tilt angle in impacted femoral neck fractures and osteonecrosis of the femoral head.

BACKGROUND: Hollow screw internal fixation is commonly used in clinical treatment of impacted femoral neck fractures. Previous studies have demonstrated a correlation between the preoperative posterior tilt angle of the femoral head and failure of internal fixation, but there are fewer studies related to the occurrence of postoperative femoral head necrosis and the posterior tilt angle. METHODS: To examine the relationship between three-dimensional posterior tilt angle measurements in affected femoral neck fractures and postoperative osteonecrosis of the femoral head and related risk variables. We retrospectively examined 130 Yantaishan Hospital patients with affected femoral neck fractures from 2019 to 2022. Three-dimensional reconstruction technology assessed the posterior tilt angle of the femoral head and separated patients into necrosis and non-necrosis groups based on postoperative femoral head necrosis. Univariate analysis compared clinical data between groups, and multivariate logistic regression analyzed risk variables for femoral head necrosis. Postoperative femoral head necrosis was predicted by posterior tilt angle using Receiver operating characteristic (ROC) curve analysis. RESULTS: Out of 130 patients who were followed up for 16-68 months postoperatively, 20 developed femoral head necrosis. Multivariate logistic regression analysis indicated that the posterior tilt angle and reduction quality level C were risk factors for the occurrence of femoral head necrosis. The ROC curve analysis showed that the three-dimensional measurement of the posterior tilt angle had predictive value for postoperative femoral head necrosis, with a cut-off value of 20.6°. CONCLUSIONS: These results suggest that, for patients with impacted femoral neck fractures, the posterior tilt angle and reduction quality level C are risk factors for femoral head necrosis following closed reduction and internal fixation surgery. Fracture patients with a posterior tilt angle ≥ 20.6°are more likely to experience postoperative femoral head necrosis.

3D printing of self-standing and vascular supportive multimaterial hydrogel structures for organ engineering.

Three dimensional printable formulation of self-standing and vascular-supportive structures using multi-materials suitable for organ engineering is of great importance and highly challengeable, but, it could advance the 3D printing scenario from printable shape to functional unit of human body. In this study, the authors report a 3D printable formulation of such self-standing and vascular-supportive structures using an in-house formulated multi-material combination of albumen/alginate/gelatin-based hydrogel. The rheological properties and relaxation behavior of hydrogels were analyzed before the printing process. The suitability of the hydrogel in 3D printing of various customizable and self-standing structures, including a human ear model, was examined by extrusion-based 3D printing. The structural, mechanical, and physicochemical properties of the printed scaffolds were studied systematically. Results supported the 3D printability of the formulated hydrogel with self-standing structures, which are customizable to a specific need. In vitro cell experiment showed that the formulated hydrogel has excellent biocompatibility and vascular supportive behavior with the extent of endothelial sprout formation when tested with human umbilical vein endothelial cells. In conclusion, the present study demonstrated the suitability of the extrusion-based 3D printing technique for manufacturing complex shapes and structures using multi-materials with high fidelity, which have great potential in organ engineering.

The first complete mitochondrial genome of Dufouriellini (Hemiptera: Anthocoridae) and implications for its phylogenetic position.

The mitochondrial genome (mitogenome) is extensively used to better understand the phylogenetic relationships within the family level, but there are still limited representations at the tribe level of Anthocoridae. Here we describe the first complete mitogenome of Dufouriellini. The mitogenome of Cardiastethus sp. is 15,209 bp in size, containing 13 typical protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region. All genes are arranged in the same gene order as the most other known cimicomorphan mitogenomes. The phylogenetic relationships based on mitogenomes using Bayesian inference and maximum likelihood methods show that Dufouriellini is sister to Anthocorini, and then both of them together form sister group with Oriini. The monophyly of each superfamily of Cimicomorpha is generally well supported. Reduvioidea is basal within Cimicomorpha. The topology of the remaining superfamily is as follows: (Miroidea + (Cimicoidea + (Velocipedoidea + Nabioidea))). This study will help to enhance our understanding of mitochondrial genomic evolution and phylogenetic relationships in the tribe level of Anthocoridae and also superfamily level of Cimicomorpha.

Si-thiol supported atomic-scale palladium as efficient and recyclable catalyst for Suzuki coupling reaction.

Atomic-scale catalysts leverage the advantages of both heterogeneous catalysts for their stability and reusability and homogeneous catalysts for their isolated active sites. Here, a palladium catalyst supported by Si-thiol, a commercially available mercaptopropyl-modified and TMS-passivated amorphous silica, was synthesized and characterized by SEM,TEM, aberration-corrected STEM-HAADF, XRD, FT-IR and XPS. Statistical analysis revealed that the catalytic Pd species predominantly consisted of intermediate sized nanoparticles (<2 nm), small amounts of essentially isolated atoms (ca. 0.1 nm), and limited amounts of somewhat larger nanoparticles (<5 nm). The nanoscale atomic clusters dominated the reactivity and served as the key active sites for Suzuki coupling. The outcomes of the reaction were greatly affected by the choice of solvents, and Pd/Si-thiol was demonstrated to be reusable for more than three times without a noticeable loss of catalytic activity. [Formula: see text].

Electrokinetic Enhancement of Water Flux and Ion Rejection through Graphene Oxide/Carbon Nanotube Membrane.

Graphene oxide (GO) is promising for constructing next-generation high-performance membranes for water treatment and desalination. However, GO-based membranes are still subjected to low ion rejection or limited water flux. Herein, the electrokinetic effect is employed as a new strategy for the coenhancement of water flux and ion rejection through an ethylenediamine-polystyrenesulfonate intercalated graphene oxide/carbon nanotube (GO&EDA-PSS/CNT) asymmetric membrane. Benefiting from the external voltage applied across the GO&EDA-PSS layer, the electrokinetically driven water transport velocity is significantly increased from 0 to 23.7 µm s-1 with increasing the voltage from 0 to 3.0 V. As a result, the water flux is improved from 9.1 to 17.4 L m-2 h-1 under a transmembrane pressure of 1 bar. Simultaneously, the rejection rate for NaCl is increased from 52.4% to 78.3%. Numerical analysis reveals that the increased rejection rate is attributed to the electrokinetic enhancements of water transport through the membrane and ion partitioning between the membrane and bulk solution. These results indicate that the assistance of the electrokinetic effect is an effective means to improve membrane filtration performance, which provides a new perspective on the design of advanced membranes for achieving high water flux and rejection efficiency.

Evolutionary history of a beautiful damselfly, Matrona basilaris, revealed by phylogeographic analyses: the first study of an odonate species in mainland China.

Matrona basilaris Selys, 1853 is a damselfly distributed mainly in mainland China. A total of 423 individuals from 48 populations covering almost the entire range were sampled to explore the genetic diversity, phylogeographic structure, and demographic dynamics of the species using sequences of three mitochondrial genes (COI, COII, and ND1) and a nuclear (ITS1 + 5.8 S + ITS2) gene. Phylogenetic tree, median-joining network, and BAPS analyses indicated a four-group division of the entire population, and the divergence event was estimated to have occurred in the middle Pleistocene. The diverse terrain of mainland China as well as past climatic oscillations were assumed to have shaped the current phylogeographic pattern of M. basilaris. Multiple lines of evidence supported population expansion in Group 1 and Group 2 but not in Group 3 or Group 4. The expansion times corresponded to the transition phase from the LIG (∼0.14-0.12 Mya) to the LGM (∼0.021-0.018 Mya). The pre-LGM expansion model reflected a different pattern affecting the historical dynamics of the population of East Asian species caused by Pleistocene climatic changes. Interestingly, Group 2 exhibited a disjunctive distribution pattern. The possible reasons were introgression caused by female-biased dispersal or human phoresy during construction of the Forbidden City during the Ming Dynasty of China.

Improving Ion Rejection of Conductive Nanofiltration Membrane through Electrically Enhanced Surface Charge Density.

Nanofiltration (NF) is considered a promising candidate for brackish and seawater desalination. NF exhibits high multivalent ion rejection, but the rejection rate for monovalent ions is relatively low. Besides, great challenges remain for conventional NF membranes to achieve high ion rejection without sacrificing water flux. This work presents an effective strategy for improving the ion rejection of conductive NF membrane without decreasing the permeability through electrically assisted enhancement of surface charge density. When external voltage is increased from 0 to 2.5 V, the surface charge density of the membrane increases from 11.9 to 73.0 mC m-2, which is 6.1× higher than that without external voltage. Correspondingly, the rejection rate for Na2SO4 increases from 81.6 to 93.0% and that for NaCl improves from 53.9 to 82.4%; meanwhile, the membrane retains high permeabilities of 14.0 L m-2 h-1 bar-1 for Na2SO4 filtration and 14.5 L m-2 h-1 bar-1 for NaCl filtration. The Donnan steric pore model analysis suggests that the Donnan potential difference between the membrane and bulk solution is increased under electrical assistance, leading to increased ion transfer resistance for improved ion rejection. This work provides new insight into the development of advanced NF technologies for desalination and water treatment.

miR-19 promotes osteosarcoma progression by targeting SOCS6.

microRNAs (miRNAs) play critical roles in cancer development and progression. This study investigated the effects of miR-19 in human osteosarcoma (OS) development. Here, we showed that miR-19 was frequently upregulated in OS tissues and cell lines. Moreover the expression of miR-19 was associated with TNM stage, metastasis, size and poor overall survival. Mechanistically, miR-19 dramatically suppressed OS growth in vitro and in vivo. Bioinformatics analyses predicted that SOCS6 is a potential target gene of miR-19 in OS, which was confirmed by luciferase-reporter assay. We also found that SOCS6 expression was downregulated and negatively correlated with miR-19 expression in OS tissues clinically. Moreover, ectopic SOCS6 could reverse miR-19 induced OS growth. Finally, JAK2/STAT3 signaling pathway involves miR-19/SOCS6-mediated OS progression. Together, our data provide important evidence for miR-19 mediated SOCS6 in OS growth and revealed miR-19/SOCS6/JAK2/STAT3 pathway as a potential therapeutic strategy for OS patients.

Combined Effects of Surface Charge and Pore Size on Co-Enhanced Permeability and Ion Selectivity through RGO-OCNT Nanofiltration Membranes.

Nanofiltration (NF) has received much attention for wastewater treatment and desalination. However, NF membranes generally suffer from the trade-off between permeability and selectivity. In this work, the coenhancement of permeability and ion selectivity was achieved through tuning the surface charge and pore size of oxidized carbon nanotube (OCNT) intercalated reduced graphene oxide (RGO) membranes. With the increase of OCNT content from 0 to 83%, the surface charge and the pore size were increased. The permeability increased to 10.6 L m-2 h-1 bar-1 and rejection rate reached 78.1% for Na2SO4 filtration at a transmembrane pressure of 2 bar, which were 11.8 and 1.3 times higher than those of pristine RGO membrane. The composite membrane also showed 11.1 times higher permeability (11.1 L m-2 h-1 bar-1) and 2.9 times higher rejection rate (35.3%) for NaCl filtration. The analyses based on Donnan steric pore model suggest that the increased permeability is attributed to the combined effects of enlarged pore size and increased surface charge, while the enhanced ion selectivity is mainly dependent on the electrostatic interaction between the membrane and target ions. This finding provides a new insight for the development of high-performance NF membranes in water treatment and desalination.

Genetic polymorphisms in ERCC1 and ERCC2 genes are associated with response to chemotherapy in osteosarcoma patients among Chinese population: a meta-analysis.

BACKGROUND: There existed controversies about the association between the response to chemotherapy for osteosarcoma (OS) patients and the genetic polymorphisms in excision repair cross-complementation group (ERCC1 and ERCC2) genes. We aimed to perform a meta-analysis to comprehensively evaluate the association. METHOD: We searched multiple databases for literature retrieval including the PubMED (1966 ∼ 2017), Embase (1980 ∼ 2017), and the Web of science (1945 ∼ 2017). The overall odds ratios(OR) and their corresponding 95% confidence interval (CI) were calculated for the three polymorphisms under the dominant, recessive, and allelic models. RESULTS: From six eligible articles in our study, we found that for ERCC1 rs11615 polymorphism, a significant association was detected between the chemotherapy response and the polymorphism under all three models (dominant model: OR = 2.015, P = 0.005; recessive model: OR = 1.791, P = 0.003; allelic model: OR = 1.677, P = 0.003), and OS patients carrying C allele in rs11615 polymorphism were more likely to response to chemotherapy. In terms of ERCC2 rs1799793 polymorphism, this polymorphism was significantly associated with the response to chemotherapy for OS patients under recessive model (OR = 1.337, P = 0.036), and patients with AG + AA genotype in rs1799793 polymorphism were more appropriate to receive chemotherapy. With respect to ERCC2 rs13181 polymorphism, this polymorphism was not correlated with the response to chemotherapy for OS patients under all three models. CONCLUSIONS: Our meta-analysis suggested that among Chinese population, the rs11615 and rs1799793 polymorphisms were significantly correlated with the response to chemotherapy for patients with OS, and patients with CC or TC + CC genotypes in ERCC1 rs11615 polymorphism or AG + AA genotype in ERCC2 rs1799793 polymorphism were more suitable for chemotherapy.

miR-202 suppresses proliferation and induces apoptosis of osteosarcoma cells by downregulating Gli2.

Accumulating data have shown that microRNAs are involved in the pathogenesis of cancer. miR-202 has been confirmed to be downregulated in several types of human cancer. However, the expression and biological role of miR-202 in osteosarcoma (OS) carcinogenesis and progression remain unclear. In this study, we demonstrated that miR-202 expression is significantly decreased in human OS cell lines and specimens. Restoration of miR-202 expression could inhibit OS cell proliferation, induce cell apoptosis, and suppress tumor growth in nude mice models. We subsequently identified the transcription factor Gli2 as a direct target of miR-202. Overexpression of Gli2 blocked the inhibitory function of miR-202. Taken together, our results indicate that miR-202 acts as a novel tumor suppressor to regulate OS cell proliferation and apoptosis through downregulating Gli2 expression.

Morphological Integrated Preparation Method and Implementation of Inorganic/Organic Dual-Phase Composite Gradient Bionic Bone Scaffold.

Large bone defects caused by congenital deformities and acquired accidents are increasing day by day. A large number of patients mainly rely on artificial bone for repair. However, artificial bone cannot fully imitate the structure and composition of human bone, resulting in a large gap with autologous bone function. Therefore, this article proposes a continuous preparation method for inorganic/organic biphasic composite gradient biomimetic bulk bone scaffolds. First, a controllable gradient hybrid forming platform for inorganic/organic dual-phase biomaterials was constructed, and the feeding control strategy was studied to achieve precise control of the feeding of sodium alginate/gelatin composite organic materials and hydroxyapatite inorganic materials. The speed is, respectively, sent from the corresponding feeding nozzle to the mixing chamber to realize the uniform mixing of the biphasic material and the extrusion of the composite material, and the inorganic/organic biphasic composite gradient biomimetic bone scaffold with gradual structure and composition is prepared. Second, to prove the superiority of the preparation method, the physicochemical and biological properties of the prepared scaffolds were evaluated. The test results showed that the morphological characteristics of the biphasic composite gradient bone scaffold showed good microscopic porosity and the structure and composition showed gradients. The mechanical properties are close to that of human bone tissue and in vitro cell experiments show that the scaffold has good biocompatibility and bioactivity. In conclusion, this article provides a new type of bone scaffold preparation technology and equipment for the field of tissue engineering, which has research value and application prospects.

Coaxial electrospun Ag-NPs-loaded endograft membrane with long-term antibacterial function treating mycotic aortic aneurysm.

The use of endovascular stent-graft has become an important option in the treatment of aortic pathologies. However, the currently used endograft membranes have limited ability to prevent bacterial colonization. This makes them unsuitable for the treatment of mycotic aneurysms, as the infection is prone to progress after endograft implantation. Moreover, even in non-mycotic aortic pathologies, endograft infections can occur in the short or long term, especially for patients with diabetes mellitus or in immune insufficiency conditions. So, this study aimed to develop a kind of Ag-NPs-loaded endograft membrane by coaxial electrospinning technique, and a series of physical and chemical properties and biological properties of the Ag-NPs-loaded membrane were characterized. Animal experiments conducted in pigs confirmed that the Ag-NPs-loaded membrane was basically non-toxic, exhibited good biocompatibility, and effectively prevented bacterial growth in a mycotic aortic aneurysm model. In conclusion, the Ag-NPs-loaded membrane exhibited good biocompatibility, good anti-infection function and slow-release of Ag-NPs for long-term bacteriostasis. Thus, the Ag-NPs-loaded membrane might hold potential for preventing infection progression and treating mycotic aortic aneurysms in an endovascular way.

Electrostatic-induced ion-confined partitioning in graphene nanolaminate membrane for breaking anion-cation co-transport to enhance desalination.

Constructing nanolaminate membranes made of two-dimensional graphene oxide nanosheets has gained enormous interest in recent decades. However, a key challenge facing current graphene-based membranes is their poor rejection for monovalent salts due to the swelling-induced weak nanoconfinement and the transmembrane co-transport of anions and cations. Herein, we propose a strategy of electrostatic-induced ion-confined partitioning in a reduced graphene oxide membrane for breaking the correlation of anions and cations to suppress anion-cation co-transport, substantially improving the desalination performance. The membrane demonstrates a rejection of 95.5% for NaCl with a water permeance of 48.6 L m-2 h-1 bar-1 in pressure-driven process, and it also exhibits a salt rejection of 99.7% and a water flux of 47.0 L m-2 h-1 under osmosis-driven condition, outperforming the performance of reported graphene-based membranes. The simulation and calculation results unveil that the strong electrostatic attraction of membrane forces the hydrated Na+ to undergo dehydration and be exclusively confined in the nanochannels, strengthening the intra-nanochannel anion/cation partitioning, which refrains from the dynamical anion-cation correlations and thereby prevents anions and cations from co-transporting through the membrane. This study provides guidance for designing advanced desalination membranes and inspires the future development of membrane-based separation technologies.

A novel semi-flexible coaxial nozzle based on fluid dynamics effects and its self-centering performance study.

Coaxial nozzles are widely used to produce fibers with core-shell structures. However, conventional coaxial nozzles cannot adjust the coaxiality of the inner and outer needles in real-time during the fiber production process, resulting in uneven fiber wall thickness and poor quality. Therefore, we proposed an innovative semi-flexible coaxial nozzle with a dynamic self-centering function. This new design addresses the challenge of ensuring the coaxiality of the inner and outer needles of the coaxial nozzle. First, based on the principles of fluid dynamics and fluid-structure interaction, a self-centering model for a coaxial nozzle is established. Second, the influence of external fluid velocity and inner needle elastic modulus on the centering time and coaxiality error is analyzed by finite element simulation. Finally, the self-centering performance of the coaxial nozzle is verified by observing the coaxial extrusion process online and measuring the wall thickness of the formed hollow fiber. The results showed that the coaxiality error increased with the increase of Young's modulus E and decreased with the increase of flow velocity. The centering time required for the inner needle to achieve force balance decreases with the increase of Young's modulus ( E ) and fluid velocity ( v f ). The nozzle exhibits significant self-centering performance, dynamically reducing the initial coaxiality error from 380 to 60 µm within 26 s. Additionally, it can mitigate the coaxiality error caused by manufacturing and assembly precision, effectively controlling them within 8 µm. Our research provides valuable references and solutions for addressing issues such as uneven fiber wall thickness caused by coaxiality errors.