Wearable Motion Analysis System for Thoracic Spine Mobility With Inertial Sensors.

This study presents a wireless wearable portable system designed for the automatic quantitative spatio-temporal analysis of continuous thoracic spine motion across various planes and degrees of freedom (DOF). This includes automatic motion segmentation, computation of the range of motion (ROM) for six distinct thoracic spine movements across three planes, tracking of motion completion cycles, and visualization of both primary and coupled thoracic spine motions. To validate the system, this study employed an Inter-days experimental setting to conduct experiments involving a total of 957 thoracic spine movements, with participation from two representatives of varying age and gender. The reliability of the proposed system was assessed using the Intraclass Correlation Coefficient (ICC) and Standard Error of Measurement (SEM). The experimental results demonstrated strong ICC values for various thoracic spine movements across different planes, ranging from 0.774 to 0.918, with an average of 0.85. The SEM values ranged from 0.64° to 4.03°, with an average of 1.93°. Additionally, we successfully conducted an assessment of thoracic spine mobility in a stroke rehabilitation patient using the system. This illustrates the feasibility of the system for actively analyzing thoracic spine mobility, offering an effective technological means for non-invasive research on thoracic spine activity during continuous movement states.

A Laboratory Experimental Study on Enhancing the Oil Recovery Mechanisms of Polymeric Surfactants.

In order to evaluate the physical and chemical properties of polymer surfactants and analyze their oil displacement mechanisms, three types of poly-surfactant used in the Daqing oil field were chosen to be researched, and the oil displacement effects were studied using poly-surfactants of different viscosity, dehydrating rate, and core permeability. The main purpose is to determine the reasonable range of different characteristic indexes of polymeric surfactant flooding. The oil displacement effect of 15 cores was analyzed, and the effects of viscosity, the dehydrating rate of emulsion, and permeability on EOR (Enhanced Oil Recovery) were analyzed. The oil displacement mechanisms of polymeric surfactants were researched using a photolithographic glass core. This paper explores the mechanism underlying production enhancement as an EOR target, while simultaneously conducting laboratory tests to assess the physical and chemical properties of polymeric surfactants. The poly-surfactant agents exhibit a notable increase in viscosity, with the optimal displacement effect observed at a core effective permeability exceeding 400 mD, resulting in a potential EOR of 15% or higher. Moreover, at a viscosity ranging between 40 and 70 mPa·s, the total EOR can reach 73%, with the peak efficiency occurring at a viscosity of 60 mPa·s. The water loss rate of the emulsion, ranging between 30% and 70%, achieves optimal performance at 50%. The poly-surfactants' higher viscosity extends the oil sweep area, enhancing recovery efficiency, and noticeably reducing residual oil compared to water flooding. During poly-surfactant flooding, a substantial amount of residual oil is extracted and transformed into droplets. The rapid emulsification of the polymeric surfactant solution with crude oil forms a stable emulsion, contributing to its significant oil recovery effect. This research provides valuable technical support for EOR in thin and low-quality reservoirs of onshore multi-layered sandstone reservoirs.

Heavy Metal-Induced Assembly of DNA Network Biosensor from Double-Loop Hairpin Probes for Ultrasensitive Detection of UO22+ in Water and Soil Samples.

The uranyl ion (UO22+) is the most stable form of uranium, which exhibits high toxicity and bioavailability posing a severe risk to human health. The construction of ultrasensitive, reliable, and robust sensing techniques for UO22+ detection in water and soil samples remains a challenge. Herein, a DNA network biosensor was fabricated for UO22+ detection using DNAzyme as the heavy metal recognition element and double-loop hairpin probes as DNA assembly materials. UO22+-activated specific cleavage of the DNAzyme will liberate the triggered DNA fragment, which can be utilized to launch a double-loop hairpin probe assembly among Hab, Hbc, and Hca. Through multiple cyclic cross-hybridization reactions, hexagonal DNA duplex nanostructures (n[Hab•Hbc•Hca]) were formed. This DNA network sensing system generates a high fluorescence response for UO22+ monitoring. The biosensor is ultrasensitive, with a detection limit of 2 pM. This sensing system also displays an excellent selectivity and robustness, enabling the DNA network biosensor to work even in complex water and soil samples with excellent accuracy and reliability. With the advantages of enzyme-free operation, outstanding specificity, and high sensitivity, our proposed DNA network biosensor provides a reliable, simple, and robust method for trace levels of UO22+ detection in environmental samples.

Spatio-temporal variation of toxin-producing gene abundance in Microcystis aeruginosa from Poyang Lake.

Microcystis aeruginosa (M. aeruginosa) causes massive blooms in eutrophic freshwater and releases microcystin. Poyang Lake is the largest freshwater lake in China and has kept a mid-nutrient level in recent years. However, there is little research on microcystin production in Poyang Lake. In this study, water and sediment samples from ten sampling sites in Poyang Lake were collected from May to December in 2020, and from January to April in 2021 respectively. Microcystis genes (mcyA, mcyB, 16 s rDNA) were quantified by real-time fluorescence quantitative PCR analysis, and then the spatial and temporal variation of mcy genes, physicochemical factors, and bacterial population structure in the lake was analyzed. The relationship between the abundance of mcy genes and physicochemical factors in water column was also revealed. Results indicated that the microcystin-producing genes mcyA and mcyB showed significant differences in spatial and temporal levels as well, which is closely related to the physicochemical factors especially the water temperature (p < 0.05) and the nitrogen content (p < 0.05). The abundance of mcy genes in the sediment in December affected the abundance of mcy genes in the water column in the next year, while the toxic Microcystis would accumulate in the sediment. In addition to the toxic Microcystis, we also found a large number of non-toxic Microcystis in the water column and sediment, and the ratio of toxic to non-toxic species can also affect the toxicity production of M. aeruginosa. Overall, the results showed that M. aeruginosa toxin-producing genes in Poyang Lake distributed spatially and temporally which related to the physicochemical factors of Poyang Lake.

The effects of external cues on cross-border e-commerce product sales: An application of the elaboration likelihood model.

In response to the soaring demand for imported goods among Chinese consumers, this study innovatively investigates the role of external cues on consumer behavior on cross-border e-commerce platforms, utilizing advanced data crawling techniques to extract data from Tmall Global. Guided by the Elaboration Likelihood Model, this research unveils key determinants affecting consumer purchasing decisions, contributing novel insights to e-commerce literature and methodologies. Our analysis discovers that increased picture comments significantly boost sales and that source credibility, product collections, and price discounts also play pivotal roles, especially for experiential products. We further explore a nuanced, inverted U-shaped relationship between product title length and sales, offering a foundational understanding of non-linear relationships in consumer behavior and presenting practical implications for enhancing marketing strategies. This study, while acknowledging limitations like data access constraints, provides strategic insights into optimizing product information presentation and broadens understanding of consumer decision-making processes, thus adding substantial value to ongoing e-commerce discourse.

Continuous-Flow Microwave Milk Sterilisation System Based on a Coaxial Slot Radiator.

Microwave continuous-flow liquid food sterilisation, in which the liquid is mainly heated by microwaves, has the advantages of fast sterilisation speed, energy saving, comprehensive elimination, and less nutrient loss. Circular pipes are commonly used in microwave continuous-flow liquid heating processing. However, with circular pipes, which are widely used in the industry, the heating is uneven owing to the phenomenon of tube focusing when adopting external radiation. In this study, a novel microwave continuous-flow milk sterilisation system based on a coaxial slot radiator is proposed. First, the coaxial slot radiator was designed to realise efficient radiation through the establishment of multi-physics model. The structure of the system was then optimised by comparing the heating efficiency and uniformity of simulation results. The effect of microwave coaxial slot radiator rotation on heating uniformity was simulated and the results show that the heating uniformity is improved obviously. Experimental equipment was set up to verify the results of the simulation. The experimental results are consistent with the simulation results. Finally, the sensitivity analysis of the system is performed to confirm that, when the dielectric properties and types of liquid food change, the heating of the proposed microwave continuous-flow system remains efficient and uniform.

Molecular mechanism of lipopolysaccharide (LPS) in promoting biomineralization on bacterial surface.

Biomineralization on bacterial surface is affected by biomolecules of bacterial cell surface. Lipopolysaccharide (LPS) is the main and outermost component on the extracellular membrane of Gram-negative bacteria. In the present study, the molecular mechanism of LPS in affecting biomineralization of Ag+/Cl- colloids was investigated by taking advantages of two LPS structural deficient mutants of Escherichia coli. The two mutants were generated by impairing the expression of waaP or wbbH genes with CRISPR/Cas9 technology and it induced deficient polysaccharide chain of O-antigen (ΔwbbH) or phosphate groups of core oligosaccharide (ΔwaaP) in LPS structures. There were significant changes of the cell morphology and surface charge of the two mutants in comparing with that of wild type cells. LPS from ΔwaaP mutant showed increased ΔHITC upon interacting with free Ag+ ions than LPS from wild type cells or ΔwbbH mutant, implying the binding affinity of LPS to Ag+ ions is affected by the phosphate groups in core oligosaccharide. LPS from ΔwbbH mutant showed decreased endotherm (ΔQ) upon interacting with Ag+/Cl- colloids than LPS from wild type or ΔwaaP mutant cells, implying LPS polysaccharide chain structure is critical for stabilizing Ag+/Cl- colloids. Biomineralization of Ag+/Cl- colloids on ΔwbbH mutant cell surface showed distinctive morphology in comparison with that of wild type or ΔwaaP mutant cells, which confirmed the critical role of O-antigen of LPS in biomineralization. The present work provided molecular evidence of the relationship between LPS structure, ions, and ionic colloids in biomineralization on bacterial cell surface.

Phosphorylation of Ser82 on IRF3 acts as negative-feedback regulation of IRF3-dependent innate immunity.

Interferon Regulatory Factor 3 (IRF3) is essential for the production of type I interferon (IFN) during virus infection; however, the mechanism underlying its regulation remains to be elucidated. Here we have identified a novel negative regulatory phosphorylation site on IRF3. In this study, we discovered that Ser82 phosphorylation on IRF3 abrogates virus-induced IFN-ß activation. Furthermore, our results clarified the mechanism in which Ser82 phosphorylation on IRF3 retains the function of dimerization and nuclear import, but abolishes the promoter binding ability of IRF3. In addition, Ser82 phosphorylation on IRF3 serves as a negative feedback mechanism for the type I IFN response. These findings elucidate a previously unknown mechanism for negatively regulating IRF3 to finely tune type I IFN response.

Lipopolysaccharide-stabilized ionic colloids induce biomineralization.

Biomineralization inducing by bacteria is common in nature. It involves interactions between bacterial surface and metal ions that are usually present in the form of ionic colloids. Lipopolysaccharide (LPS) is the major component of Gram-negative bacterial surfaces. In the present study, interactions between LPS and metal ions (Ag+, Fe3+, Cd2+, Co2+, Cu2+, Mn2+, Ni2+), as well as ionic colloids (Ag+/Cl-, Fe3+/OH-) were evaluated by means of isothermal titration calorimetry and Zeta potential measurement. It was found that LPS increases the energy barrier for the collapse of ionic colloids and prevents ionic colloids from aggregation. The roles of LPS-stabilized ionic colloids in inducing biomineralization on the bacterial surface were explored by means of scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray Diffraction. It showed that reducing colloidal stability by increasing the ionic strength significantly inhibited biomineralization of ionic colloids on bacterial surfaces. While the formation of ionic colloids promoted biomineralization on bacterial surfaces. This study provides a novel insight into biomineralization as well as biomineralization-based techniques with biological stabilizers for producing biominerals.

Functional Immobilization of a Biofilm-Releasing Glycoside Hydrolase Dispersin B on Magnetic Nanoparticles.

Dispersin B (DspB) is a member of glycoside hydrolase family 20 (GH20) and catalyzes degradation of biofilms forming by pathogenic bacteria such as Staphylococcus aureus. Magnetoreceptor (MagR) is a magnetic protein that can be used as a fusion partner for functionally immobilizing proteins on magnetic surfaces. In the present study, a recombinant protein DspB-MagR was constructed by fusing MagR to the C-terminus of DspB and expressed in Escherichia coli. Magnetic immobilization of purified DspB-MagR on magnetic core-shell structured Fe3O4@SiO2 nanoparticles was achieved and characterized by means of various techniques including SDS-PAGE, Fourier transform infrared spectroscopy, thermogravimetric analysis, zeta potential measurement, and scanning electron microscopy. It was evaluated the influence of temperature, pH, and storage time on the performance of immobilized DspB-MagR on Fe3O4@SiO2 nanoparticles. Removal of biofilms forming by Staphylococcus aureus and other medical sourced bacterial species was achieved by using Fe3O4@SiO2 nanoparticles loading with DspB-MagR. This work promoted potential applications of DspB and similar enzymes for medical purposes.

Redox potential-induced regulation of extracellular polymeric substances in an electroactive mixed community biofilm.

Electroactive biofilms are promising in achieving efficient wastewater treatment and energy conversion in bioelectrochemical systems (BESs). Extracellular polymeric substances (EPS) are important for physical contact with electrode surface and extracellular electron transfer (EET) within biofilm. Redox potential is an important trigger for the regulation of EPS in microbial aggregates, but this yet is lacking for electroactive mixed community biofilms. This study first explored how redox potential affected EPS of electroactive mixed community biofilms, which were cultured in BES reactors with different anode potentials (-0.3 V, 0 V, +0.3 V, +0.6 V vs. SCE) using artificial brewery wastewater as substrate. The anode potential regulated biocurrent generation, overall EPS production, EPS composition and EPS redox properties. The biofilms poised at 0 V exhibited the highest current production (7.2 mA) and EPS redox capacity, while the +0.6 V biofilms had the lowest current production (1.2 mA) with lowest EPS redox capacity. The steady-state current exhibited a significant positive correlation with EPS redox capability, suggesting an important role of EPS in anode potential-dependent current production. Significant positive correlations between proteins or humic substances in EPS and EPS redox properties further verified that EPS redox feature raised from proteins and humic substances. This study provided a potential mechanism that anode potential determined the electroactivity of anode biofilm via regulating EPS composition and redox properties, and will facilitate the use of electroactive biofilms in bioelectrochemical applications.

Molecular Evidence of Bartonella melophagi in Ticks in Border Areas of Xinjiang, China.

Bartonella are gram-negative intracellular bacteria; certain species of Bartonella can cause diseases in mammals and humans. Ticks play a major role in the transmission of Bartonella. Xinjiang is the largest province in China according to land area and has one-third of the tick species in China; the infection rate of Bartonella in ticks in the Xinjiang border areas has not been studied in detail. Therefore, this study investigated tick infections by Bartonella in Xinjiang border areas, and the purpose of the study was to fill in gaps in information regarding the genetic diversity of tick infections by Bartonella in Xinjiang. We tested 1,549 tick samples from domestic animals (sheep and cattle) for Bartonella using ribC-PCR. Positive samples from the ribC-PCR assay for Bartonella spp. were further subjected to PCR assays targeting the ITS, rpoB and gltA genes followed by phylogenetic analyses. Bartonella DNA was detected in 2.19% (34/1,549) of tick samples, and the ITS, rpoB and gltA genes of ribC gene-positive samples were amplified to identify nine samples of Bartonella melophagi. In this study, molecular analysis was used to assess the presence and genetic diversity of B. melophagi in ticks collected from sheep and cattle from Xinjiang, China. This study provides new information on the presence and identity of B. melophagi in ticks from sheep and cattle.

Generation and application of a monoclonal antibody against the 18-kDa oncosphere antigen of Taenia pisiformis.

Taenia pisiformis is a parasite that causes cysticercosis pisiformis, which has acquired economic relevance because of its effects on animal welfare and production. A useful assay for the detection of T. pisiformis is needed for the prevention of cysticercosis pisiformis and control of the parasite. The 18-kDa oncosphere antigen is expressed in the oncosphere of several cysticerci in species of the genus Taenia, including T. pisiformis. This protein plays an important role in tissue invasion and has extensive applications in diagnosis. In this study, the T. pisiformis 18-kDa oncosphere antigen (TPO18) was expressed in soluble form and successfully purified for use in the production of monoclonal antibodies (MAbs) against TPO18. Twenty hybridomas were obtained using ELISA, and the subcloning process identified three positive hybridoma cell lines, which were designated as 4E8, 5G5, and 7E8. MAb 7E8 exhibited the highest titer and had an IgG2b heavy chain and a kappa light chain. Western blot analysis demonstrated that MAb 7E8 reacted with GST-TPO18. Immunohistochemistry showed that TPO18 was widely distributed in the drape and wall of uteri in adults of T. pisiformis adults and in the fibrous layer of the sucker and cyst cavity of T. pisiformis cysticerci. This research will provide a foundation for the development of diagnostic tools and will contribute to a better understanding of the functions of TPO18.

Escherichia coli templated iron oxide biomineralization under oscillation.

Motility is significant in organisms. Studying the influence of motility on biological processes provides a new angle in understanding the essence of life. Biomineralization is a representative process for organisms in forming functional materials. In the present study, we investigated the biomineralization of iron oxides templated by Escherichia coli (E. coli) cells under oscillation. The formation of iron oxide minerals with acicular and banded morphology was observed. The surface charge of E. coli cells contributed to the biomineralization process. The surface components of E. coli cells including lipids, carbohydrates and proteins also have roles in regulating the formation and morphology of iron oxide minerals. As-prepared mineralized iron oxide nanomaterials showed activity in photocatalytic degradation of methylene blue as well as in electrocatalytic hydrogen evolution reaction. This study is helpful not only in understanding motility in biological processes, but also in developing techniques for fabricating functional nanomaterials.

Coxiella burnetii is widespread in ticks (Ixodidae) in the Xinjiang areas of China.

BACKGROUND: The gram-negative Coxiella burnetii bacterium is the pathogen that causes Q fever. The bacterium is transmitted to animals via ticks, and manure, air, dead infected animals, etc. and can cause infection in domestic animals, wild animals, and humans. Xinjiang, the provincial-level administrative region with the largest land area in China, has many endemic tick species. The infection rate of C. burnetii in ticks in Xinjiang border areas has not been studied in detail. RESULTS: For the current study, 1507 ticks were collected from livestock at 22 sampling sites in ten border regions of the Xinjiang Uygur Autonomous region from 2018 to 2019. C. burnetii was detected in 205/348 (58.91%) Dermacentor nuttalli; in 110/146 (75.34%) D. pavlovskyi; in 66/80 (82.50%) D. silvarum; in 15/32 (46.90%) D. niveus; in 28/132 (21.21%) Hyalomma rufipes; in 24/25 (96.00%) H. anatolicum; in 219/312 (70.19%) H. asiaticum; in 252/338 (74.56%) Rhipicephalus sanguineus; and in 54/92 (58.70%) Haemaphysalis punctata. Among these samples, C. burnetii was detected in D. pavlovskyi for the first time. The infection rate of Rhipicephalus was 74.56% (252/338), which was the highest among the four tick genera sampled, whereas the infection rate of H. anatolicum was 96% (24/25), which was the highest among the nine tick species sampled. A sequence analysis indicated that 63 16S rRNA sequences could be found in four newly established genotypes: MT498683.1 (n = 18), MT498684.1 (n = 33), MT498685.1 (n = 6), and MT498686.1 (n = 6). CONCLUSIONS: This study indicates that MT498684.1 might represent the main C. burnetii genotype in the ticks in Xinjiang because it was detected in eight of the tick species studied. The high infection rate of C. burnetii detected in the ticks found in domestic animals may indicate a high likelihood of Q fever infection in both domestic animals and humans.

Ultrasound-assisted extraction extracts from Stemona japonica (Blume) Miq. and Cnidium monnieri (L.) Cuss. could be used as potential Rhipicephalus sanguineus control agents.

Nicotiana tabacum, Stemona japonica, and Cnidium monnieri are common plants that are widely used for their anti-parasitic properties. The purpose of this study was to evaluate the acaricidal activity of extracts from these plants against the brown dog tick, Rhipicephalus sanguineus. A composition analysis of crude extracts by GC-MS was conducted to discover compounds with acaricidal effects. The toxicity of extraction against the engorged nymphs of R. sanguineus was evaluated by an immersion test. The results showed that the crude extracts of S. japonica and C. monnieri in varying ratios, concentrations, and from different extraction methods, had a killing effect on R. sanguineus. Lethality reached 76.67% ± 0.04410 when using a 1:1 extract of S. japonica:C. monnieri in 75% ethanol with ultrasonic extraction; the crude extract was determined at a concentration of 0.5 g/mL. GC-MS results showed that osthole and 5-hydroxymethylfurfural (5-HMF) are the main components of the extract. These results suggested that ultrasound-assisted extraction (UAE) extracts contained acaricidal components acting against R. sanguineus, which may result in the development of effective extracts of S. japonica and C. monnieri as a source of low-toxicity, plant-based, natural acaricidal drugs.

Physiological potential of extracellular polysaccharide in promoting Geobacter biofilm formation and extracellular electron transfer.

Geobacter sulfurreducens biofilms have promising applications in renewable energy, pollutant bioremediation, and bioelectronic applications. Genetically manipulating G. sulfurreducens biofilms is an effective strategy to improve the capacity of extracellular electron transfer (EET). Extracellular polysaccharide, a sticky component surrounding microbes, plays an important role in EET. Herein, we constructed a mutant of G. sulfurreducens strain PCA overexpressing the gene GSU1501 (part of the ATP-dependent exporter of the polysaccharide biosynthesis gene operon), designated strain PCA-1501, to increase EET capacity. Experimental results showed that the overexpression of GSU1501 increased extracellular polysaccharide secretion by 25.5%, which promoted the formation of biofilm with higher thickness and viability, as well as the content of extracellular c-type cytochromes. Compared with the control strain, the mutant showed a higher capacity of Fe(III) oxide reduction and current generation (increased by 20.4% and 22.2%, respectively). Interestingly, the overexpression of GSU1501 hindered the pili formation by reducing the transcription level of pilA; a compensatory relationship between extracellular polysaccharide and pili in promoting biofilm formation deserves further investigation. This study provides a feasible method to promote the EET capacity of G. sulfurreducens biofilms, which benefit their bioelectrochemical applications.

Analysis of microRNA expression profiles dynamic in different life stages of Haemaphysalis longicornis ticks by deep sequencing of small RNA libraries.

The three-host tick Haemaphysalis longicornis is an obligate blood-sucking ectoparasite. In life-stage transitions, microRNAs (miRNAs) show a variety of expression changes. To investigate these changes, deep sequencing technology was applied to identify the conserved and potentially novel miRNAs expressed during the different life stages of H. longicornis. Total RNA from eggs, unfed larvae, unfed nymphs and unfed adults was extracted for deep sequence analysis. Deep sequencing on a Hiseq 4000 generated a total of 111,192,069 reads, grouped into four small RNA (sRNA) libraries, one for each of the four developmental stages of H. longicornis. Among these sequences, 78 conserved and 55 potentially novel miRNAs were identified, including stage-specific and differentially expressed miRNAs. Gene ontology (GO) analysis indicated significantly enriched GO terms related to cell proliferation and differentiation, including specific terms for the processes of development, growth, metabolism, regulation of biological functions, reproduction, and membrane enzyme regular activity. Kyoto Encyclopedia of Gene and Genomes (KEGG) analysis revealed a significant enrichment of the insulin, notch, Hippo, and Wnt signaling pathways for growth and development. Our data highlight the abundance of miRNA changes (conserved and potentially novel) in the different life stages of H. longicornis. In particular, stage-specific miRNAs, as observed, are essential regulators for the development of H. longicornis.

Clinical effects of apatinib mesylate for treatment of multiple brain micrometastases: Two case reports.

BACKGROUND: Apatinib is a small-molecule multitargeted tyrosine kinase inhibitor. Apatinib has demonstrated encouraging antitumor activities. This study aimed to observe the efficacy and safety of apatinib for the treatment of multiple brain micrometastases. CASE SUMMARY: We report two patients with multiple brain micrometastases after failure of second-line treatment. Both patients had extracerebral metastases. When the patients took 250 mg/d apatinib orally, the intracerebral lesions disappeared. The extracerebral lesions were partially alleviated. Both patients had a progression-free survival of more than 12 mo and were still stable. The safety was good. The main adverse events (AEs) were mild hypertension and proteinuria, which could be controlled. CONCLUSION: Apatinib has clear efficacy and good tolerance in patients with multiple brain micrometastases after failure of second-line treatment.

Synthesis of magnetic nanoparticles with an IDA or TED modified surface for purification and immobilization of poly-histidine tagged proteins.

Magnetic nanoparticles (MNPs) chelating with metal ions can specifically interact with poly-histidine peptides and facilitate immobilization and purification of proteins with poly-histidine tags. Fabrication of MNPs is generally complicated and time consuming. In this paper, we report the preparation of Ni(ii) ion chelated MNPs (Ni-MNPs) in two stages for protein immobilization and purification. In the first stage, organic ligands including pentadentate tris (carboxymethyl) ethylenediamine (TED) and tridentate iminodiacetic acid (IDA) and inorganic Fe3O4-SiO2 MNPs were synthesized separately. In the next stage, ligands were grafted to the surface of MNPs and MNPs with a TED or IDA modified surface were acquired, followed by chelating with Ni(ii) ions. The Ni(ii) ion chelated forms of MNPs (Ni-MNPs) were characterized including morphology, surface charge, structure, size distribution and magnetic response. Taking a his-tagged glycoside hydrolase DspB (Dispersin B) as the protein representative, specific interactions were confirmed between DspB and Ni-MNPs. Purification of his-tagged DspB was achieved with Ni-MNPs that exhibited better performance in terms of purity and activity of DspB than commercial Ni-NTA. Ni-MNPs as enzyme carriers for DspB also exhibited good compatibility and reasonable reusability as well as improved performance in various conditions.