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Superbug infections and transmission have become major challenges in the contemporary medical field. The development of novel antibacterial strategies to efficiently treat bacterial infections and conquer the problem of antimicrobial resistance (AMR) is extremely important. In this paper, a bimetallic CuCo-doped nitrogen–carbon nanozyme-functionalized hydrogel (CuCo/NC-HG) has been successfully constructed. It exhibits photoresponsive-enhanced enzymatic effects under near-infrared (NIR) irradiation (808 nm) with strong peroxidase (POD)-like and oxidase (OXD)-like activities. Upon NIR irradiation, CuCo/NC-HG possesses photodynamic activity for producing singlet oxygen(1O2), and it also has a high photothermal conversion effect, which not only facilitates the elimination of bacteria but also improves the efficiency of reactive oxygen species (ROS) production and accelerates the consumption of GSH. CuCo/NC-HG shows a lower hemolytic rate and better cytocompatibility than CuCo/NC and possesses a positive charge and macroporous skeleton for restricting negatively charged bacteria in the range of ROS destruction, strengthening the antibacterial efficiency. Comparatively, CuCo/NC and CuCo/NC-HG have stronger bactericidal ability against methicillin-resistant Staphylococcus aureus(MRSA) and ampicillin-resistant Escherichia coli(AmprE. coli) through destroying the cell membranes with a negligible occurrence of AMR. More importantly, CuCo/NC-HG plus NIR irradiation can exhibit satisfactory bactericidal performance in the absence of H2O2, avoiding the toxicity from high-concentration H2O2. In vivo evaluation has been conducted using a mouse wound infection model and histological analyses, and the results show that CuCo/NC-HG upon NIR irradiation can efficiently suppress bacterial infections and promote wound healing, without causing inflammation and tissue adhesions.

The objective of this study is to develop a deep-learning-based detection and diagnosis technique for carotid atherosclerosis (CA) using a portable freehand 3-D ultrasound (US) imaging system. A total of 127 3-D carotid artery scans were acquired using a portable 3-D US system, which consisted of a handheld US scanner and an electromagnetic (EM) tracking system. A U-Net segmentation network was first applied to extract the carotid artery on 2-D transverse frame, and then, a novel 3-D reconstruction algorithm using fast dot projection (FDP) method with position regularization was proposed to reconstruct the carotid artery volume. Furthermore, a convolutional neural network (CNN) was used to classify healthy and diseased cases qualitatively. Three-dimensional volume analysis methods, including longitudinal image acquisition and stenosis grade measurement, were developed to obtain the clinical metrics quantitatively. The proposed system achieved a sensitivity of 0.71, a specificity of 0.85, and an accuracy of 0.80 for diagnosis of CA. The automatically measured stenosis grade illustrated a good correlation ( ${r}$ = 0.76) with the experienced expert measurement. The developed technique based on 3-D US imaging can be applied to the automatic diagnosis of CA. The proposed deep-learning-based technique was specially designed for a portable 3-D freehand US system, which can provide a more convenient CA examination and decrease the dependence on the clinician’s experience.

High alumina slag will cause severe corrosion at the interface of alumina refractory, and the wetting behavior of slag is a key factor influencing the corrosion resistance of refractory ceramics. The static magnetic field is a promising solution for improvement in the slag resistance of refractory. The wetting of alumina refractory ceramics with different basicities of high alumina slags under a weak static magnetic field was analyzed, given that a weak static magnetic field can affect the corrosion behavior of refractory ceramics. Taking slag S3as an example, when there was an external static magnetic field of 1.0 mT at 1600 °C, the thickness of calcium aluminate reaction layer at the interface decreased by 36.7%, the denting depth of interface decreased by 35.6%, and the apparent wetting angle increased by 20%. The living radicals and their formation path in oxide melts were verified by first-principles calculation combined with electron paramagnetic resonance spectroscopy analysis. The influence of the flux density of a weak static magnetic field on the wetting behavior of slags was also explored. The contact angle of the slags increased owing to the inhibitory effect of magnetic field on the radical-involved reaction at the interface of the slag and the alumina refractory ceramic. The relationships between the magnetic flux density, diffusion coefficient, slag microstructure (hyperfine coupling constant), and contact angle were established. This provides a theoretical basis for the field control of radical involved reactive wetting between inorganic oxide slags and solid oxide ceramics.

In this work, we successfully constructed Mn-coordinated nitrogen–carbon nanoparticles (Mn–N–C NPs) exhibiting multienzyme-like activities. In a bacterial infectious microenvironment, the POD-like and OXD-like activities of Mn–N–C NPs could synergistically trigger the generation of ROS (OH and O2−), causing oxidative damage to the bacterial cell membrane for killing bacteria. Alternatively, in neutral or weak alkaline normal tissues, the excessive O2−could be converted into O2and H2O2viathe SOD-like ability of Mn–N–C NPs, and subsequently their CAT-like activity catalyzed excess H2O2into H2O and O2for protecting normal cells through the antioxidant defense. Mn–N–C NPs also possessed a good NIR-photothermal performance, which could enhance their POD-like and OXD-like activities. Furthermore, Mn–N–C NPs could facilitate the GSH oxidation process and disrupt the intrinsic balance in the bacterial protection microenvironment with the assistance of H2O2, which is beneficial for rapid bacterial death. Undoubtedly, the Mn–N–C NPs + H2O2system showed the highest antibacterial activity when irradiated with an 808 nm laser, destroying the bacterial membrane and causing the efflux of proteins. Moreover, the Mn–N–C NPs + H2O2system was immune to the development of bacterial resistance and could efficiently disrupt the formation of a bacterial biofilm with negligible cytotoxicity and low hemolysis ratio. Finally, Mn–N–C NPs exhibited an excellent antibacterial performance in vivoand could accelerate wound healing without cellular inflammation production. Therefore, due to their significant therapeutic effects, Mn–N–C NPs show great potential in fighting antibiotic-resistant bacteria.

In this work, positively charged N-carbazoleacetic acid decorated CuxO nanoparticles (CuxO-CAA NPs) as novel biocompatible nanozymes have been successfully prepared through a one-step hydrothermal method. CuxO-CAA can serve as a self-cascading platform through effective GSH-OXD-like and POD-like activities, and the former can induce continuous generation of H2O2through the catalytic oxidation of overexpressed GSH in the bacterial infection microenvironment, which in turn acts as a substrate for the latter to yield OH viaFenton-like reaction, without introducing exogenous H2O2. Upon NIR irradiation, CuxO-CAA NPs possess a high photothermal conversion effect, which can further improve the enzymatic activity for increasing the production rate of H2O2and OH. Besides, the photodynamic performance of CuxO-CAA NPs can produce 1O2. The generated ROS and hyperthermia have synergetic effects on bacterial mortality. More importantly, CuxO-CAA NPs are more stable and biosafe than Cu2O, and can generate electrostatic adsorption with negatively charged bacterial cell membranes and accelerate bacterial death. Antibacterial results demonstrate that CuxO-CAA NPs are lethal against methicillin-resistant Staphylococcus aureus(MRSA) and ampicillin-resistant Escherichia coli(AREC) through destroying the bacterial membrane and disrupting the bacterial biofilm formation. MRSA-infected animal wound models show that CuxO-CAA NPs can efficiently promote wound healing without causing toxicity to the organism.

A commercially available and versatile dehydrative amidation catalyst, featuring a thianthrene boron acid structure, has been developed. The catalyst shows high catalytic activity to both aliphatic and less reactive aromatic carboxylic acid substrates, including several bioactive or clinical molecules with a carboxylic acid group.

Pancreatic ductal adenocarcinoma is a lethal disease with limited treatment options and poor survival. We studied 83 spatial samples from 31 patients (11 treatment-naïve and 20 treated) using single-cell/nucleus RNA sequencing, bulk-proteogenomics, spatial transcriptomics and cellular imaging. Subpopulations of tumor cells exhibited signatures of proliferation, KRAS signaling, cell stress and epithelial-to-mesenchymal transition. Mapping mutations and copy number events distinguished tumor populations from normal and transitional cells, including acinar-to-ductal metaplasia and pancreatic intraepithelial neoplasia. Pathology-assisted deconvolution of spatial transcriptomic data identified tumor and transitional subpopulations with distinct histological features. We showed coordinated expression of TIGIT in exhausted and regulatory T cells and Nectin in tumor cells. Chemo-resistant samples contain a threefold enrichment of inflammatory cancer-associated fibroblasts that upregulate metallothioneins. Our study reveals a deeper understanding of the intricate substructure of pancreatic ductal adenocarcinoma tumors that could help improve therapy for patients with this disease.

•Diffusion MRI measures the effect of tissue microstructures on Brownian motion of water to assess histopathology.•DTI radial diffusivity (reflecting demyelination and edema) predicts future tissue damage in MS.•Diffusion basis spectrum imaging (DBSI) models multiple diffusion tensors, improving pathologic specificity.•DBSI isotropic tensors (representing cellularity and edema) predict future tissue damage in MS.•DBSI may provide additional histopathologic insights in acute MS lesions.

The lack of targeted and high-efficiency drug delivery to the central nervous system (CNS) nidus is the main problem in the treatment of demyelinating disease. Extracellular vesicles (EVs) possess great promise as a drug delivery vector given their advanced features. However, clinical applications are limited because of their inadequate targeting ability and the “dilution effects” after systemic administration. Neural stem cells (NSCs) supply a plentiful source of EVs on account of their extraordinary capacity for self-renewal. Here, we have developed a novel therapeutic system using EVs from modified NSCs with high expressed ligand PDGF-A (EVPs) and achieve local delivery. It has been demonstrated that EVPs greatly enhance the target capability on oligodendrocyte lineage. Moreover, EVPs are used for embedding triiodothyronine (T3), a thyroid hormone that is critical for oligodendrocyte development but has serious side effects when systemically administered. Our results demonstrated that systemic injection of EVPs + T3, versus EVPs or T3 administration individually, markedly alleviated disease development, enhanced oligodendrocyte survival, inhibited myelin damage, and promoted myelin regeneration in the lesions of experimental autoimmune encephalomyelitis mice. Taken together, our findings showed that engineered EVPs possess a remarkable CNS lesion targeting potential that offers a potent therapeutic strategy for CNS demyelinating diseases as well as neuroinflammation.

The composition, morphology, size, and number of inclusions in Fe–22Mn–xAl–0.7C (x= 0.5%, 5.2%, and 10.5%) lightweight steels after smelting and heat treatment experiments are characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy from both 2D and 3D perspectives. The inclusions are classified into eight categories according to chemistry and morphology. For the steel sample with a low Al content (0.5%), the inclusions are MnS, AlN–MnS, and Al2O3–MnS, among which Al2O3–MnS is the primary type. With the increase in Al content in the steel sample (to 5.2%), the populations of AlN and AlN–MnS inclusions of 1–3 μm in diameter increase. A further increase in Al content (to 10.5%) leads to a significant decrease in the amount of AlN inclusions of 1–3 μm in diameter, and an increase in the amount of AlN–MnS inclusions. The precipitation behavior during the phase transformation is also studied by FactSage 8.0 thermodynamic software, and a precipitation mechanism is proposed based on the calculation results. During the heat treatment, AlN inclusions re-precipitate out, due to the interactions between Al and dissolved N in the steel matrix. However, AlN inclusions cannot grow large because of unfavorable kinetic conditions. The re-precipitation phenomenon of AlN is predominant under low Al and high N conditions but not at high Al cases.

Demyelination is a critical neurological disease, and there is still a lack of effective treatment methods. In the past two decades, stem cells have emerged as a novel therapeutic effector for neural regeneration. However, owing to the existence of the blood–brain barrier (BBB) and the complex microenvironment, targeted therapy still faces multiple challenges. Targeted exosome carriers for drug delivery may be considered a promising therapeutic method. Exosomes were isolated from mice neural stem cells. To develop targeting exosomes, we generated a lentivirus armed PDGFRαligand that could anchor the membrane. Exosome targeting tests were carried out in vitroand in vivo.The modified exosomes showed an apparent ability to target OPCs in the lesion area. Next, the exosomes were loaded with Bryostatin-1 (Bryo), and the cuprizone-fed mice were administered with the targeting exosomes. The data show that Bryo exhibits a powerful therapeutic effect compared with Bryo alone after exosome encapsulation. Specifically, this novel exosome-based targeting delivery of Bryo significantly improves the protection ability of the myelin sheath and promotes remyelination. Moreover, it blocks astrogliosis and axon damage, and also has an inhibitory effect on pro-inflammatory microglia. The results of this investigation provide a straightforward strategy to produce targeting exosomes and indicate a potential therapeutic approach for demyelinating disease.

While Shiga toxin–producing Escherichia coli(STEC) is a major foodborne pathogen worldwide, data on the molecular and phylogenetic properties of STEC isolates from retail beef samples in China remain scant. Fresh retail beef samples (n= 1062) were collected from eight provinces, and STEC isolates were recovered and characterized. PCR data showed that more than 50% of the samples were stxpositive, and 82 STEC isolates were recovered from 14.8% (79/535) stx-positive enriched broths. In contrast, all ciprofloxacin resistant isolates (n= 19) and 13 cefotaxime (CTX) resistant isolates were eaepositive and belonged to three serotypes: O111:H8, O26:H11, or O157:H7. Point mutations in quinolone resistance-determining regions and plasmid-mediated quinolone resistance determinants were identified in 16 and 20 isolates, respectively. BlaCTX-Mand a point mutation (C-42T) in ampCpromoter were detected in 15 and 8 of the CTX resistant isolates, respectively. In addition, macrolide resistance gene mphAwas identified in eight azithromycin resistant O111:H8 isolates and one O26:H11 isolate. Single nucleotide polymorphism analysis demonstrated that the O26 and O157 isolates had multiple origins, but the O111 isolates were closely related. Taken together, our data demonstrated that several sequence types associated with hemolytic uremic syndrome from the retail beef samples in China had developed into dangerous multidrug resistant pathogens. The resistant phenotype can facilitate their transmission among the farm animals and human beings when there is an antimicrobial selective pressure.

ABSTRACTIn arc-ion plating, the droplets ejected from the cathodic target inevitably contaminate the coating with macro-particles (MPs), causing defects that usually reduce the mechanical properties of the coating. Normally, MP formation is suppressed by electromagnetic filtration technology. To investigate the influence of the electromagnetic field on the structure and mechanical properties of coatings, this study applied various electromagnetic voltages (0–45 V) in the arc-ion plating preparation of CrAlN coatings. The proportion of MPs in the coatings was effectively reduced by adding the electromagnetic voltage, and was minimized at 25 V. The wear resistance of coatings was also comparatively studied. The wear of all coatings followed the same abrasive wear mechanism, but reducing the number of MPs improved the wear resistance. The enhancement of wear resistance was attributed to the improved fracture toughness of the coatings with fewer MPs.

In arc-ion plating, the droplets ejected from the cathodic target inevitably contaminate the coating with macro-particles (MPs), causing defects that usually reduce the mechanical properties of the coating. Normally, MP formation is suppressed by electromagnetic filtration technology. To investigate the influence of the electromagnetic field on the structure and mechanical properties of coatings, this study applied various electromagnetic voltages (0–45 V) in the arc-ion plating preparation of CrAlN coatings. The proportion of MPs in the coatings was effectively reduced by adding the electromagnetic voltage, and was minimized at 25 V. The wear resistance of coatings was also comparatively studied. The wear of all coatings followed the same abrasive wear mechanism, but reducing the number of MPs improved the wear resistance. The enhancement of wear resistance was attributed to the improved fracture toughness of the coatings with fewer MPs.

The objective of this study was to evaluate the efficacy and safety of radiofrequency-induced thermotherapy (RFiTT) combined with transilluminated powered phlebectomy (TIPP) in the treatment of lower limb varicose veins (VVs) in comparison with high ligation and stripping (HLS) combined with TIPP.

To improve the wear resistance, toughness, and hardness of alloy, the quenching and partitioning (Q&P) technology was applied in the VC particulate (VCp) reinforced wear-resistant alloys, which were prepared by adding different Mn contents (2–5 wt%). The effects of partitioning time on the distribution of alloying elements shown by EDX mapping, retained austenite fraction, microstructure, macro-hardness, and impact toughness were investigated. The results showed that the effect of carbon partitioning time on the hard phase of the wear-resistant alloy was not significant. However, the carbon partitioning time greatly affected the microstructure and the mechanical properties of alloys, such as retained austenite, hardness, and impact toughness, and there was also a strong correlation with the Mn content. When the Mn content was lower (2.51 wt%), the retained austenite content increased with the carbon partitioning time, which resulted in decreased hardness and increased impact toughness. However, when the Mn content was higher (4.52 wt%), the opposite results occurred. This study provided an application of the Q&P technology in a VCp-reinforced wear-resistant alloy.

Trypsin-responsive near-infrared fluorescent (NIRF) and magnetic resonance (MR) dual-imaging composite nanoparticle/polypeptide coacervate nanoprobes with tunable sizes, have been constructed herein via electrostatic interaction-induced self-assembly. Considering the requirements of in vivo metabolism on nanoparticle size, three coacervate nanoprobes with diameters of around 100, 200, and 300 nm were fabricated with a polydispersity of around 0.2. These coacervate nanoprobes consist of Fe3O4magnetic nanoparticles surface-decorated with poly acrylic acid and Cy5.5-modified poly-l-lysine (PLL-g-Cy5.5) serving as MR imaging and trypsin-responsive substrate/NIRF agents, respectively. The notable fluorescence signal from PLL-g-Cy5.5 is self-quenched due to the short distances between the fluorescent Cy5.5 molecules after construction of the coacervate nanoprobes. Remarkably, coacervate nanoprobes with a diameter of around 100 nm are selectively disintegrated into fragmented segments upon the hydrolysis of PLL by trypsin, resulting in an 18-fold amplification of the NIRF intensity in comparison with the self-assembled coacervate nanoprobes in the quenched state. Moreover, the MR imaging enhancement is also related to the disintegration of the coacervate nanoprobes. Cellular experiments and in vivo studies demonstrate that the coacervate nanoprobes exhibit remarkable trypsin-sensitive NIRF and MR dual-imaging capabilities and thus have excellent potential to serve as dual-imaging nanoprobes for the efficient mapping of malignant tumors in which trypsin is often overexpressed. In consideration of their excellent capability to enrich charged molecules, the coacervate nanoprobes provide a conceptually novel and promising platform toward in vivo trypsin mapping and controlled delivery of targeted payloads.

High-capacity germanium-based anode materials are alternative materials for outstanding electrochemical performance lithium-ion batteries (LIBs), but severe volume variation and pulverization problems during charging–discharging processes can seriously affect their electrochemical performance. In addressing this challenge, a simple strategy was used to prepare the self-assembled GeOX/Ti3C2TXcomposite in which the GeOXnanoparticles can grow directly on Ti3C2TXlayers. Nanoscale GeOXuniformly renucleates on the surface and interlayers of Ti3C2TX, forming the stable multiphase structure, which guarantees its excellent electrochemical performance. Electrochemical evaluation has shown that the rate capability and reversibility of GeOX/Ti3C2TXare both greatly improved, which delivers a reversible discharge specific capacity of above 1400 mAh g–1(at 100 mA g–1) and a reversible specific capacity of 900 mAh g–1after 50 cycles while it still maintains a stable specific capacity of 725 mAh g–1at 5000 mA g–1. Furthermore, the composite exhibits an exceptionally superior rate capability, making it a good electrochemical performance anode for LIBs.

Purpose: The aim of this study was to systematically compare the safety and effectiveness of percutaneous endoscopic transforaminal discectomy (PETD) versus percutaneous endoscopic interlaminar discectomy (PEID) for the treatment of lumbar disc herniation (LDH). Material and methods: All studies that were performed to compare PETD with PEID to treat LDH and published until 31 August 2017 were acquired through a comprehensive search in various databases. A meta-analysis was performed using the Cochrane Collaboration’s RevMan 5.3 software. Results: A total of 13 trials with 974 cases consisting of 3 randomized controlled trials, 3 prospective studies and 7 retrospective studies were included. The results suggest that patients treated with PEID experienced more significant advantages with shorter operation time, less intraoperative blood loss and less intraoperative fluoroscopy times but more complications than those treated with PETD; however, the two operative approaches did not significantly differ in terms of LDH recurrence, hospital stay, Oswestry disability index (ODI) scores, visual analogue scale (VAS) scores, Japanese Orthopaedic Association (JOA) scores and MacNab criteria at the final follow-up. Conclusion: Based on the results of this study, although PEID may be superior to PETD in certain ways, some of its advantages have yet to be verified and the two interventions were not significantly different in terms of relief of symptoms and functional recovery. Therefore, PEID would be recommended for treating LDH especially at L5/S1 under certain conditions but a prudent attitude is necessary to choose between the two operative approaches before a large sample and high quality randomized controlled trials have been performed.

The optimal treatment method for femoropopliteal (FP) artery in-stent restenosis (ISR) remains controversial. We assess the efficacy and safety of combination of Rotarex thrombectomy and drug-coated balloon (DCB) for the treatment of FP ISR.

This study presents a nanostructured Sn/SnOx@Ti3C2composite by in-situ growth of Sn/SnOxnanoparticles on the interlayer of 2D MXene (Ti3C2Tx) nanosheets through facile electrostatic attraction and liquid phase reduction. X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy results illustrate that Sn/SnOxnanoparticles are uniformly distributed into the MXene (Ti3C2Tx) interlayer, forming a sandwich-like nanostructured composite. MXene (Ti3C2Tx) nanosheets suppress Sn/SnOxnanoparticles’ volume expansion and agglomeration and accelerate the Li-ion and electron transition due to the distinguished confinement effect and excellent graphite-like layered structure. Furthermore, Sn/SnOxnanoparticles are embedded as pillars to enhance the longitudinal structural stability of MXene matrix by preventing the re-stacking of nanosheets during lithium insertion/extraction. The nanosized particles still reduce lithium migration path and increase active areas. Therefore, the Sn/SnOx@Ti3C2composite maintains 594.2 mAh g−1after 200 cycles with a capacity recovery after 100 cycles. The synergistic effect of Sn/SnOxon MXene facilitates Sn/SnOx@Ti3C2nanostructures, thereby exhibiting excellent electrochemical properties for lithium-ion batteries.

Gleeble-1500D thermal simulator was used to simulate the thermal cycle of different welding processes in C–Mn steel. The toughness of steel matrix and heat-affected zone (HAZ) was investigated, and the microstructure and inclusion were characterized as well. The results showed that the welding process has a great influence on the microstructure in HAZ. When t8/5(the cooling time from 800 to 500 °C) value of the welding process is less than 111 s, the microstructure in HAZ is mainly bainite/Widmanstätten in spite of the addition of rare earth. However, when t8/5value is more than 250 s, there are a lot of acicular ferrites in the steel containing rare earth, while the main microstructures are grain boundary ferrite and bainite/Widmanstätten in the steel without rare earth. The impact toughness of the HAZ at ambient temperature first decreases and then increases with the increase in t8/5value. The impact toughness is the worst when t8/5value is 111 s. Rare earth can improve the impact performance of HAZ at ambient temperature, especially when t8/5value of the welding process is 445 s. After the rare earth treatment, the cooling rate of forming acicular ferrite is about 0.5–7.5 °C/s. Acicular ferrite can form even during the welding process with larger t8/5value up to 600 s in rare earth-treated steel.

•Our results show that most patients have hypopituitarism and headaches, while some present with weakness and diabetes insipidus (DI).•In addition, typical magnetic resonance imaging (MRI) shows pa of equal or low intensity on T1-weighted imaging (T1WI) and high or equal intensity on T2-weighted imaging (T2WI) with enhanced edges.•The use of novel laboratory diagnostic technology (mNGS) can diagnose pathogens in time, which is conducive to antibiotic guidance after surgery.•Apart from pituitary adenoma, Rathke fissure cyst, craniopharyngioma and other common diseases, other rare pituitary lesions also need to be identified.•The choice of surgical method mostly depends on the surgeon, and there is no significant difference between nasal endoscopy and microscope.

An improved cavitation model was proposed to simulate the cavitation phenomenon in a water jet added with turbulent drag-reducing additives. The Cross model which expressed the shear-thinning properties of drag-reducer solution was also employed. The neglected viscous term and surface tension term in traditional cavitation models were reconsidered as viscosity, and surface tension force were important factors affecting bubbles’ motion in drag-reducer solution. The numerical solutions of bubble radius in drag-reducer solutions of different concentrations were fitted, and the change rates were added to the original mass transfer mechanism equations. The results showed that the modified cavitation model described the cavitation characteristics in drag-reducer solutions more accurately and effectively reflected that the cavitation region’s wake became longer with the increase concentration of the drag reducing agent. When the concentration increased, the distribution of cavitation cloud became more homogeneous, and the pressure curve and velocity curve both changed more smoothly.

This paper attempts to investigate the effects of fluid viscosity on cavitation generation. Different from the traditional cavitation models in which the Rayleigh–Plesset equation is simplified neglecting the second-order term and the surface tension force term, the primitive R–P equations with different dynamic viscosity values are solved by mathematical software and numerical solutions are obtained. Then, the method of curve fitting is selected to get the approximate expressions of bubble radius about time. Based on the expressions, the rate of change of bubble radius about time under different viscous conditions can be approximately obtained which will be written as in-house code to enhance the traditional cavitation models by UDFs. Numerical simulations of high-speed water jets issuing from a nozzle are carried out. The simulated cavitation characteristics match the supercavity experiments very well. The result shows a more homogenous distribution of vapor volume fraction while the viscosity of fluid increases. The pressure and velocity also change more slowly and smoothly along the nozzle under more viscous conditions. Simulations of external flow fields are also made based on the modified model to show the cavitation characteristics under submerged condition.