Application of TCM Rehabilitation in Joint Function Recovery After Treatment of Distal Radius Fractures: A Meta-Analysis.

Objective: To evaluate the effect of traditional Chinese medicine (TCM) rehabilitation on the postoperative function of patients with distal radius fractures by Meta-analysis. Methods: PubMed, Embase, CNKI, Wanfang, and other databases were searched for retrospective controlled trials and prospective randomized controlled trials on the effect of traditional Chinese medicine rehabilitation on the function of patients with distal radius fractures after surgery from the establishment of the database to May 2023. Revman version 5.3 software was used to analyze the extracted and screened index data. Results: Eight studies involving 455 patients were included. Meta-analysis results showed Overall analysis showed that there was a significant difference in wrist function between the TCM rehabilitation group and the control group (MD = -12.16, 95%CI:-17.21 to -7.11, P < .00001), low heterogeneity (I2=40%, P = .17), the difference in dorsiflexion function between the TCM rehabilitation group and the control group was statistically significant (MD = -1.16, 95%CI:-2.24 to -0.08, P = .04), with high heterogeneity (I2=79%, P = .003), that there was a significant difference in grip strength between the TCM rehabilitation group and the control group at 6 weeks (MD= 0.48, 95%CI: 0.24 to 0.71, P < .0001) with low heterogeneity (I2=45%, P = .12), there was no significant difference between the TCM rehabilitation group and the control group (OR= -0.00, 95%CI: -0.08 to 0.08, P = .99), and there was no heterogeneity (I2=0%, P = .66). Conclusion: Traditional Chinese medicine rehabilitation treatment of distal radius fractures can increase the range of motion of wrist joints, reduce pain, shorten the rehabilitation time of patients, improve the quality of life, and is conducive to the standardized treatment of patients.

The Heterogeneity of Symptom Burden and Fear of Progression Among Kidney Transplant Recipients: A Latent Class Analysis.

Purpose: Kidney transplant recipients (KTRs) may experience symptoms that increase their fear of progression (FoP), but a dearth of research examines the issue from a patient-centered perspective. Our study aimed to first determine the category of symptom burden, then to explore the differences in characteristics of patients in different subgroups, and finally to analyze the impact of symptom subgroup on FoP. Patients and Methods: Sociodemographic and Clinical Characteristics, Symptom Experience Scale, and Fear of Progression Questionnaire-Short Form were used. Latent class analysis was used to group KTRs according to the occurrence of symptoms. We used multivariate logistic regression to analyze the predictors of different subgroups. The differences in FoP among symptom burden subgroups were analyzed by hierarchical multiple regression. Results: Three subgroups were identified, designated all-high (20.5%), moderate (39.9%), and all-low (39.6%) according to their symptom occurrence. Multivariate logistic regression showed that gender, post-transplant time, per capita monthly income, and hyperuricemia were the factors that distinguished and predicted the all-high subgroup (P < 0.05). Hierarchical multiple regression showed that symptom burden had a significant effect on FoP (class1 vs class3: ß = 0.327, P < 0.001; class2 vs class3: ß = 0.104, P = 0.046), explaining the 8.0% variance of FoP (ΔR2 = 0.080). Conclusion: KTRs generally experience moderate or low symptom burden, and symptom burden is an influencing factor in FoP. Identifying the traits of KTRs with high symptom burden can help clinicians develop targeted management strategies and ease FoP of KTRs.

Multifunctional nanocoatings with synergistic controlled release of zinc ions and cytokines for precise modulation of vascular intimal reconstruction.

Vascular stent implantation remains the major therapeutic method for cardiovascular diseases currently. We here introduced crucial biological functional biological function factors (SDF-1α, VEGF) and vital metal ions (Zn2+) into the stent surface to explore their synergistic effect in the microenvironment. The combination of the different factors is known to effectively regulate cellular inflammatory response and selectively regulate cell biological behavior. Meanwhile, in the implemented method, VEGF and Zn2+ were loaded into heparin and poly-l-lysine (Hep-PLL) nanoparticles, ensuring a controlled release of functional molecules with a multi-factor synergistic effect and excellent biological functions in vitro and in vivo. Notably, after 150 days of implantation of the modified stent in rabbits, a thin and smooth new intima was obtained. This study offers a new idea for constructing a modified surface microenvironment and promoting tissue repair.

MCM2 is involved in subtyping and tamoxifen resistance of ERα-positive breast cancer by acting as the downstream factor of ERα.

Tamoxifen (TAM) resistance is finally developed in over 40% of patients with estrogen receptor α-positive breast cancer (ERα+ -BC), documenting that discovering new molecular subtype is needed to confer perception to the heterogeneity of ERα+ -BC. We obtained representative gene sets subtyping ERα+ -BC using gene set variation analysis (GSVA), non-negative matrix factorization (NMF), and COX regression methods on the basis of METABRIC, TCGA, and GEO databases. Furthermore, the risk score of ERα+ -BC subtyping was established using least absolute shrinkage and selection operator (LASSO) regression on the basis of genes in the representative gene sets, thereby generating the two subtypes of ERα+ -BC. We further found that minichromosome maintenance complex component 2 (MCM2) functioned as the hub gene subtyping ERα+ -BC using GO, KEGG, and MCODE. MCM2 expression was capable for specifically predicting 1-year overall survival (OS) of ERα+ -BC and correlated with T stage, AJCC stage, and tamoxifen (TAM) sensitivity of ERα+ -BC. The downregulation of MCM2 expression inhibited proliferation, migration, and invasion of TAM-resistant cells and promoted G0/G1 arrest. Altogether, tamoxifen resistance entails that MCM2 is a hub gene subtyping ERα+ -BC, providing a novel dimension for discovering a potential target of TAM-resistant BC.

Preparation of GO/Diatomite/Polyacrylonitrile Functional Separator and Its Application in Li-S Batteries.

Lithium-sulfur (Li-S) batteries have received extensive attention due to their numerous advantages, including a high theoretical specific capacity, high energy density, abundant reserves of sulfur in cathode materials, and low cost. Li-S batteries also face several challenges, such as the insulating properties of sulfur, volume expansion during charging and discharging processes, polysulfide shuttling, and lithium dendritic crystal growth. In this study, a composite of a porous multi-site diatomite-loaded graphene oxide material and a PAN fiber membrane is developed to obtain a porous and high-temperature-resistant GO/diatomite/polyacrylonitrile functional separator (GO/DE/PAN) to improve the electrochemical performance of Li-S batteries. The results show that the use of GO/DE/PAN helps to inhibit lithium phosphorus sulfide (LPS) shuttling and improve the electrolyte wetting of the separator as well as the thermal stability of the battery. The initial discharge capacity of the battery using GO/DE/PAN is up to 964.7 mAh g-1 at 0.2 C, and after 100 cycles, the reversible capacity is 683 mAh g-1 with a coulombic efficiency of 98.8%. The improved electrochemical performance may be attributed to the porous structure of diatomite and the layered composite of graphene oxide, which can combine physical adsorption and spatial site resistance as well as chemical repulsion to inhibit the shuttle effect of LPS. The results show that GO/DE/PAN has great potential for application in Li-S batteries to improve their electrochemical performance.

Vanadium Nitride Nanoparticles Grown on Carbon Fiber Cloth as an Advanced Binder-Free Anode for the Storage of Sodium and Potassium Ions.

The escalating demand for sustainable and high-performance energy storage systems has led to the exploration of alternative battery technologies for lithium-ion batteries. Sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) have emerged as promising candidates because of their abundant Na/K resources, inexpensive costs, and similar chemistries to lithium-ion batteries. However, inherent challenges, such as large ionic radii, sluggish kinetics, and serious volume expansion, necessitate the development of robust and efficient anode materials for SIBs and PIBs. Vanadium nitride has attracted increasing attention as a viable anode due to its high electronic conductivity and potential capacity. In this study, we report on a flexible electrode for SIBs and PIBs that creates binder-free anodes by synthesizing vanadium nitride nanoparticles grown directly on carbon fiber cloths (VN/CFC). The unique architecture and binder-free nature of this anode ensure a robust electrode-electrolyte interface and enhance its electron/ion transport kinetics. The results demonstrate that the material exhibits an outstanding specific discharge capacity of 227 mAh g-1 after undergoing 1000 cycles at a current density of 2 A g-1 for SIBs. An electrochemical analysis indicated that the excellent performance of the material is attributed to the bind-free structure of carbon fiber cloth and the fast kinetics of surface pseudo-capacitive contribution. Furthermore, the material continues to demonstrate an impressive performance, even for PIBs, with a specific discharge capacity of 125 mAh g-1 after 1000 cycles at a current density of 1 A g-1. This study provides a new perspective for designing and developing advanced binder-free anodes for the storage of sodium and potassium ions, paving the way for high-performance energy storage applications.

The Mediating Role of Self-Perceived Burden Between Social Support and Fear of Progression in Renal Transplant Recipients: A Multicenter Cross-Sectional Study.

Purpose: To explore the mechanism of social support and fear of progression (FoP) in renal transplant recipients (RTRs) and the self-perceived burden that acts as a mediator between social support and FoP. Patients and Methods: Sociodemographic and clinical characteristics, the Social Support Rating Scale (SSRS), the Self-Perceived Burden Scale (SPBS), and the Fear of Progression-Questionnaire-Short Form (FoP-Q-SF) were used. Structural equation modeling (SEM) was used to examine the mediating role of self-perceived burden. Results: Our results showed that social support was negatively related to the self-perceived burden (r = -0.28, p < 0.001) and FoP (r = -0.37, p < 0.001). Moreover, we determined that self-perceived burden was positively related to FoP (r = 0.58, p < 0.001) and that the indirect effect of social support on FoP via self-perceived burden was significant (ß = -0.172, 95% CI: -0.253, -0.097), and with a mediating effect value of 36.9%. Conclusion: The FoP in RTRs is a concern. Higher social support and lower self-perceived burden can reduce the risk of FoP. Healthcare professionals (HCPs) should assist RTRs in correctly evaluating an individual's social support system, helping them optimize social support to reduce the self-perceived burden and the development of FoP.

MiR-204-5p-targeted AP1S2 is necessary for papillary thyroid carcinoma.

MiR-204-5p, as a tumour suppressor, has been found in several cancers. However, whether miR-204-5p is involved in papillary thyroid carcinoma (PTC) has not yet been investigated. In this study, we identified miR-204-5p as a down-regulated miRNA in PTC tissues, unveiling that the levels of miR-204-5p in serum of patients with PTC were linked to PTC risk, and that the expression in patients concomitant with both PTC and benign lesions was much lower than that in patients only with PTC. Furthermore, we documented that miR-204-5p inhibited proliferation, migration, invasion, and cell cycle progression and triggered apoptosis of PTC cells via cell biology experiments. Finally, we identified that AP1S2 was a target of miR-204-5p using RNA-seq, iTRAQ, and bioinformatics prediction. Overall, miR-204-5p functions as a suppressor for PTC pathogenesis via the miR-204-5p/AP1S2 axis.

Iron oxide-EDTA nanoparticles for chelation-enhanced chemodynamic therapy and ion interference therapy.

As an emerging anti-tumor strategy, chemodynamic therapy (CDT) utilizes a Fenton/Fenton-like reaction to generate highly toxic hydroxyl radicals to kill tumor cells. However, the efficiency of CDT is still hindered by the low Fenton/Fenton-like reaction rate. Herein, we report the combination of ion interference therapy (IIT) and chemodynamic therapy (CDT) via an amorphous iron oxide (AIO) nanomedicine with encapsulated EDTA-2Na (EDTA). Iron ions and EDTA are released from the nanomedicine in acidic tumors and chelate to form iron ion-EDTA, which improves the efficiency of CDT and promotes the generation of reactive oxygen species (ROS). In addition, EDTA can disrupt the homeostasis of Ca2+ in tumor cells by chelating with Ca2+ ions, which induces the separation of tumor cells and affects normal physiological activities. Both in vitro and in vivo experiments show that the nano chelating drugs exhibit significant improvement in Fenton reaction performance and excellent anti-tumor activity. This study based on chelation provides a new idea for designing efficient catalysts to enhance the Fenton reaction and provides more revelations on future research on CDT.

Constructing Ionic Self-Concentrated Electrolyte via Introducing Montmorillonite Toward High-Performance Aqueous Zn-MnO2 Batteries.

Aqueous zinc metal batteries are regarded as one of the most promising alternatives to lithium-ion batteries for large-scale energy storage due to the abundant zinc resources, high safety, and low cost. Herein, an ionic self-concentrated electrolyte (ISCE) is proposed to enable uniform Zn deposition and reversible reaction of MnO2 cathode. Benefitting from the compatibility of ISCE with electrodes and its adsorption on the electrode surface for guidance, the Zn/Zn symmetrical batteries exhibit the long-life cycle stability with more than 5000 and 1500 h at 0.2 and 5 mA cm-2 , respectively. The Zn/MnO2 battery also exhibits a high capacity of 351 mA h g-1 at 0.1 A g-1 and can enable a stability over 2000 cycles at 1 A g-1 . This work provides a new insight into electrolyte design for stable aqueous Zn-MnO2 battery.

Construction of Multiform Hollow-Structured Covalent Organic Frameworks via a Facile and Universal Strategy for Enhanced Sonodynamic Cancer Therapy.

The special structural morphology of hollow covalent organic frameworks (HCOFs) has an important influence on their applications. However, the rapid and precise control of morphology for HCOFs still remains largely challenging. Herein, we present a facile and universal two-step strategy based on solvent evaporation and oxidation of imine bond for the controllable synthesis of HCOFs. The strategy enables to prepare HCOFs in a greatly shortened reaction time and seven kinds of HCOFs are fabricated by the oxidation of imine bond via hydroxyl radicals (⋅OH) generated from Fenton reaction. Importantly, a fascinating library of HCOFs with diverse nanostructures, including bowl-like, yolk-shell, capsule-like and flower-like morphologies, has been ingeniously constructed. Owing to the large cavities, the obtained HCOFs are ideal candidates for drug delivery, which are employed to load five small molecule drugs, achieving the enhanced sonodynamic cancer therapy in vivo.

Microstructure and Properties of Nickel-Based Gradient Coatings Prepared Using Cold Spraying Combined with Laser Cladding Methods.

A cold spray-laser cladding composite gradient coating (CLGC) was successfully formed on a Cu substrate. In comparison with traditional laser cladding gradient coatings (LGC), cold spraying the pre-set Ni-Cu alloy's intermediate transition layer not only mitigates the negative impacts due to the high reflectivity of the copper substrate but also helps to minimize the difference in the coefficients of thermal expansion (CTE) between the substrate and coating. This reduces the overall crack sensitivity and improves the cladding quality of the coating. Besides this, the uniform distribution of hard phases in CLGC, such as Ni11Si12 and Mo5Si3, greatly increases its microhardness compared to the Cu substrate, thus resulting in the value of 478.8 HV0.5 being approximately 8 times that of the Cu substrate. The friction coefficient of CLGC is lowered compared to both the Cu substrate and LGC with respective values of 0.28, 0.54, and 0.43, and its wear rate is only one-third of the Cu substrate's. These results suggest CLGC has excellent anti-wear properties. In addition, the wear mechanism was determined from the microscopic morphology and element distribution and was found to be oxidative and abrasive. This approach combines cold spraying and laser cladding to form a nickel-based gradient coating on a Cu substrate without cracks, holes, or other faults, thus improving the wear resistance of the Cu substrate and improving its usability.

Study on the mechanism of biochar affecting the effectiveness of phosphate solubilizing bacteria.

Low phosphorus utilization and phosphorus fertilizer pollution are serious issues primarily affecting soil health. To investigate the effects of biochar on the growth, phosphorus solubilization, and metabolites of phosphorus-solubilizing bacteria (PSB), rice husk biochar (RH) and rice straw biochar (RS) were incubated with Bacillus megatherium (BM1) and Bacillus mucilaginosus (BM2), respectively. The highest phosphorus solubilization was observed in BM2 following the addition of RS. The dissolved amount of phosphorus was 244.99 mg/L, which was 43.86% higher than that of the control group. Hence, biochar can improve the phosphorus solubilization capacity of PSB by affecting the organic acid and polysaccharide contents, and phosphatase activity secreted by the PSB, as the porous structure and surface characteristics of biochar ensured the adsorption of PSB. This study can help improve the functional activity of PSB and provide basis for improving the utilization of soil phosphorus, which in turn, aid in the development of biochar-based microbial fertilizers.

Transcription factor AP-2 gamma/Krüppel-like factor 10 axis is involved in miR-3656-related dysfunction of endothelial cells in hypertension.

BACKGROUND: Dysfunction of endothelial cells links to microvascular rarefaction, reflecting the pathogenesis of hypertension. Our previous studies found that miR-3656 reduces nitric oxide generation and von Willebrand factor (vWF) cleavage, thereby retarding blood flow and potentially increasing blood pressure. In this paper, we investigated mechanism of transcription regulation contributing to miR-3656-damaged endothelial cells in hypertension. METHODS: The effects of miR-3656 on function of endothelial cells were analyzed on the basis of proliferation, migration, tube formation, and apoptosis. The mRNA level and protein level of genes were examined using quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Dual-luciferase reporter assay was performed to confirm the binding between miR-3656 and 3' untranslated region (UTR) of transcription factor AP-2 gamma ( TFAP2C ). The binding between TFAP2C and the promoter region of Krüppel-like factor 10 ( KLF10 ) was confirmed by chromatin immunoprecipitation-qPCR assay. RESULTS: miR-3656 impaired the cell proliferation, migration, tube formation, and apoptosis of endothelial cells. miR-3656 inhibited the expression of TFAP2C by directly targeting 3'UTR of TFAP2C ; moreover, miR-3656-induced injury of endothelial cells was rescued by TFAP2C overexpression. Furthermore, downregulated TFAP2C decreased KLF10 expression by binding to KLF10 promoter region, and upregulated KLF10 reversed the effects of silencing TFAP2C on endothelial cells. These inhibitory processes led to interference of miR-3656 to KLF10-promoted function of endothelial cells. CONCLUSION: TFAP2C/KLF10 axis is involved in miR-3656-related dysfunction of endothelial cells in hypertension. The 3'UTR of TFAP2C and KLF10 promoter region are the hubs of the TFAP2C/KLF10 axis.

Fe(III)-Naphthazarin Metal-Phenolic Networks for Glutathione-Depleting Enhanced Ferroptosis-Apoptosis Combined Cancer Therapy.

Nowadays, Fenton chemistry-based chemodynamic therapy (CDT) is an emerging approach to killing tumor cells by converting endogenous H2 O2 into cytotoxic hydroxyl radicals (·OH). However, the elimination of ·OH by intracellular overexpressed glutathione (GSH) results in unsatisfactory antitumor efficiency. In addition, the single mode of consuming GSH and undesirable drug loading efficiency cannot guarantee the efficient cancer cells killing effect. Herein, a simple one-step strategy for the construction of Fe3+ -naphthazarin metal-phenolic networks (FNP MPNs) with ultrahigh loading capacity, followed by the modification of NH2 -PEG-NH2 , is developed. The carrier-free FNP MPNs can be triggered by acid and GSH, and rapidly release naphthazarin and Fe3+ , which is further reduced to Fe2+ that exerts Fenton catalytic activity to produce abundant ·OH. Meanwhile, the Michael addition between naphthazarin and GSH can lead to GSH depletion and thus achieve tumor microenvironment (TME)-triggered enhanced CDT, followed by activating ferroptosis and apoptosis. In addition, the reduced Fe2+ as a T1 -weighted contrast agent endows the FNP MPNs with magnetic resonance imaging (MRI) functionality. Overall, this work is the debut of naphthazarin as ligands to fabricate functional MPNs for effectively depleting GSH, disrupting intracellular redox homeostasis, and enhancing CDT effects, which opens new perspectives on multifunctional MPNs for tumor synergistic therapy.

Form Properties of Moving Targets Bias Smooth Pursuit Target Selection in Monkeys.

During natural viewing, we often recognize multiple objects, detect their motion, and select one object as the target to track. It remains to be determined how such behavior is guided by the integration of visual form and motion perception. To address this, we studied how monkeys made a choice to track moving targets with different forms by smooth pursuit eye movements in a two-target task. We found that pursuit responses were biased toward the motion direction of a target with a hole. By computing the relative weighting, we found that the target with a hole exhibited a larger weight for vector computation. The global hole feature dominated other form properties. This dominance failed to account for changes in pursuit responses to a target with different forms moving singly. These findings suggest that the integration of visual form and motion perception can reshape the competition in sensorimotor networks to guide behavioral selection.

Recent Advances: From Cell Biology to Cell Therapy in Atherosclerosis Plaque via Stent Implantation.

Atherosclerosis is a multifactorial result of complicated pathophysiology. Changes in the expression of polygenes, coupled with environmental and lifestyle factors, trigger a cascade of adverse events involving a variety of cell types, such as vascular endothelial cells, smooth muscle cells, and macrophages. In this review, we summarize the function and therapeutic targets of atherosclerotic cells. This article reviews the role of endothelial cells, smooth muscle cells, macrophages and foam cells in the development of atherosclerosis and the progress in the treatment of atherosclerosis by targeting these cells. Atherosclerotic plaque involves a variety of cells and biomolecules, and its complex biological environment is a difficult point for the study and treatment of atherosclerosis. For treating atherosclerosis, a large number of studies emerged based on blocking or inhibiting factors affecting the formation and development of plaque. Cardiovascular stent intervention is currently the main method for the treatment of atherosclerosis. In recent decades, numerous studies on cardiovascular, stents mainly involve drug coating or biomolecular modification of stents to enhance anti-thrombosis, anti-restenosis and endothelialization. This paper introduces the research status of cardiovascular stents and new strategies for surface modification. The treatment of atherosclerosis based on the level of molecular biology and cell biology is becoming a research hotspot in the coming decades.

A Novel Superhard, Wear-Resistant, and Highly Conductive Cu-MoSi2 Coating Fabricated by High-Speed Laser Cladding Technique.

The pursuit of an advanced functional coating that simultaneously combines high hardness, wear resistance, and superior electrical conductivity has remained an elusive goal in the field of copper alloy surface enhancement. Traditional solid solution alloying methods often lead to a significant increase in electron scattering, resulting in a notable reduction in electrical conductivity, making it challenging to achieve a balance between high hardness, wear resistance, and high conductivity. The key lies in identifying a suitable microstructure where dislocation motion is effectively hindered while minimizing the scattering of conductive electrons. In this study, a novel Cu-MoSi2 coating was successfully fabricated on a CuCrZr alloy surface using the coaxial powder feeding high-speed laser cladding technique, with the addition of 10-30% MoSi2 particles. The coating significantly enhances the hardness and wear resistance of the copper substrate while maintaining favorable electrical conductivity. As the quantity of MoSi2 particles increases, the coating's hardness and wear resistance gradually improve, with minimal variance in conductivity. Among the coatings, the Cu-30%MoSi2 coating stands out with the highest hardness (974.5 HV0.5) and the lowest wear amount (0.062 mg/km), approximately 15 times the hardness of the copper base material (65 HV0.5) and only 0.45% of the wear amount (13.71 mg/km). Additionally, the coating exhibits a resistivity of 0.173 × 10-6 Ω·m. The extraordinary hardness and wear resistance of these coatings can be attributed to the dispersion strengthening effect of MoxSiy particles, while the high electrical conductivity is due to the low silicon content dissolved into the copper from the released MoSi2 particles, as well as the rapid cooling rates associated with the high-speed laser cladding process.

Microstructure and Wear Behavior of Ti-xFe-SiC In Situ Composite Ceramic Coatings on TC4 Substrate from Laser Cladding.

Titanium alloys are widely used in various structural materials due to their lightweight properties. However, the low wear resistance causes significant economic losses every year. Therefore, it is necessary to implement wear-resistant protection on the surface of titanium alloys. In this study, four types of in situ composite ceramic coatings with two-layer gradient structures were prepared on a Ti-6Al-4V (TC4) substrate using laser cladding. In order to reduce the dilution rate, a transition layer (Ti-40SiC (vol.%)) was first prepared on TC4 alloy. Then, a high-volume-fraction in situ composite ceramic working layer (Ti-xFe-80SiC (vol.%)) with different contents of Fe-based alloy powder (x = 0, 5, 10 and 15 vol.%) was prepared. The working surface of Ti-40SiC (TL) exhibited a typical XRD pattern of Ti, TiC, Ti5Si3, and Ti3SiC2. In comparison, both Ti-80SiC (WL-F0) and Ti-5Fe-80SiC (WL-F5) exhibited similar phase compositions to the TL coating, with no new phase identified in the coatings. However, the TiFeSi2 and SiC phases were presented in Ti-10Fe-80SiC (WL-F10) and Ti-15Fe-80SiC (WL-F15). It is proven that the addition of the Fe element could regulate the in situ reaction in the original Ti-Si-C ternary system to form the new phases with high hardness and good wear resistance. The hardness of the WL-F15 (1842.9 HV1) is five times higher than that of the matrix (350 HV1). Due to the existence of self-lubricating phases such as Ti5Si3 and Ti3SiC2, a lubricating film was presented in the WL-F0 and WL-F5 coatings, which could block the further damage of the friction pair and enhance the wear resistance. Furthermore, a wear-transition phenomenon was observed in the WL-F10 and WL-F15 coatings, which was similar to the friction behavior of structural ceramics. Under the load of 10 N and 20 N, the wear volume of WL-F15 coating is 5.2% and 63.7% of that in the substrate, and the depth of friction of WL-15 coating is only 14.4% and 80% of that in the substrate. The transition of wear volume and depth can be attributed to the wear mechanism changing from oxidation wear to adhesive wear.

Investigation of the Preparation, Corrosion Inhibition, and Wear Resistance of the Chromized Layer on the Surfaces of T9 and SPCC Steels.

To improve the corrosion inhibition and wear resistance of materials, the pack cementation method was used to prepare chromized coatings on the surfaces of high-carbon T9 steel and low-carbon SPCC steel. The results showed the formation of a uniform and dense double-layer structure with a thickness of ~10 µm on the surfaces of two different types of steel. The coating layer for T9 steel was mainly composed of Cr23C6 and Cr7C3, while that for SPCC steel was mainly composed of Cr23C6 and Fe-Cr solid solution. Additionally, both of the steels showed different hardness distributions. The hardness measurements of the outer layers of the T9 steel and SPCC steel were ~1737.72 HV and 1771.91 HV, while the hardness values of the secondary layers were 1378.31 HV and 448.52 HV, respectively. The polarization curves in 3.5 wt.% NaCl solution demonstrated the better corrosion resistance of the chromized coating. Chromizing increased the corrosion potential by ~0.2 V and reduced the corrosion current density by one order of magnitude. Under the presence of an 8 N load, the friction factor before and after the chromizing of T9 steel was about 0.69, and the mass wears were 2 mg and 0.6 mg, respectively. Meanwhile, the friction factor of the SPCC steel before and after chromizing was about 0.73, with respective mass wears of 2 mg and 2.9 mg. The wear resistance of T9 steel after chromizing was superior, but it became worse after chromizing for the SPCC steel.