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Non-transition metal doping, especially for Mg, has been gradually employed to optimize the electrochemical performance of Li-rich cathode material Li2MnO3. However, the effects of Mg doping on the electrochemical behavior of Li2MnO3 have not been studied extensively. In this work, we investigate the effect of Mg doping at both the 2b (in the Li/Mn mixed layer) and 4h (in the Li layer) Li sites on the electrochemical properties of Li2MnO3 through first-principles calculations and ab initio molecular dynamics simulations. The local lattice structure, electronic density of states, Bader charge, delithiation voltage, lattice oxygen stability and Li diffusion kinetics are examined. Electronic structure analysis shows that Mg can activate the electrochemical activity of surrounding Mn by charge transfer, making Mn participate in charge compensation at the initial delithiation stage. Mg doping can also cause an increase in the average oxygen vacancy formation energy and hence depress the oxygen release during the delithiation process. Molecular dynamics simulations show that the diffusion kinetics of Li ions in Mg2b-Li2MnO3 is enhanced with respect to the undoped one, whereas Mg doped at the 4h site cannot improve the diffusion kinetics of Li ions. Further studies found that Mg doped at the 2b site results in a decrease in the energy barrier for the intra-layer diffusion and an increase in the energy barrier for the inter-layer diffusion of the nearby Li vacancies.
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Chronic wound healing is a common clinical challenge, characterized by bacterial infection, protracted inflammatory response, oxidative stress, and insufficient neovascularization. Nanozymes have emerged as a promising solution for treating skin wounds due to their antioxidant, antibacterial, and angiogenic properties. In recent years, combining nanozymes with hydrogels to jointly promote wound healing has attracted increasing research interest. However, most of the current nanocomposite hydrogels are still not effective in simultaneously controlling inflammatory, oxidative stress and bacterial invasion in wound healing. Improving the therapeutic functional diversity and efficacy of nanocomposite hydrogels remains a problem that needs to be addressed. In this study, we prepared nanocomposite hydrogels (GelMD-Cur@ZHMCe) by combining methylacrylated gelatin modified with dopamine (GelMD) with Zinc-doped hollow mesoporous cerium oxide nanoparticles loaded with curcumin (Cur@ZHMCe). The resulting hydrogels exhibited excellent water absorption, adhesion, and biocompatibility. In vitro and in vivo studies have demonstrated that GelMD-Cur@ZHMCe has excellent antioxidant, antibacterial, anti-inflammatory and vasculature-promoting properties, which enable it to rapidly promote wound repair. The wound healing rate of the rat total skin defect infection model treated with GelMD-Cur@ZHMCe reached 98.5±4.9â¯% after 14â¯days of treatment. It was demonstrated that this multifunctional nanocomposite hydrogel provides a promising therapeutic strategy for skin repair.
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Background: Skin wounds are a prevalent issue that can have severe health consequences if not treated correctly. Nanozymes offer a promising therapeutic approach for the treatment of skin wounds, owing to their advantages in regulating redox homeostasis to reduce oxidative damage and kill bacteria. These properties make them an effective treatment option for skin wounds. However, most of current nanozymes lack the capability to simultaneously address inflammation, oxidative stress, and bacterial infection during the wound healing process. There is still great potential for nanozymes to increase their therapeutic functional diversity and efficacy. Methods: Herein, copper-doped hollow mesopores cerium oxide (Cu-HMCe) nanozymes with multifunctional of antioxidant, antimicrobial and pro-vascularity is successfully prepared. Cu-HMCe can be efficiently prepared through a simple and rapid solution method and displays sound physiological stability. The biocompatibility, pro-angiogenic, antimicrobial, and antioxidant properties of Cu-HMCe were assessed. Moreover, a full-thickness skin defect infection model was utilized to investigate the wound healing capacity, as well as anti-inflammatory and pro-angiogenic properties of nanozymes in vivo. Results: Both in vitro and in vivo experiments have substantiated Cu-HMCe's remarkable biocompatibility. Moreover, Cu-HMCe possesses potent antioxidant enzyme-like catalytic activity, effectively clearing DPPH radicals (with a scavenging rate of 80%), hydroxyl radicals, and reactive oxygen species. Additionally, Cu-HMCe exhibits excellent antimicrobial and pro-angiogenic properties, with over 70% inhibition of both E. coli and S. aureus. These properties collectively promote wound healing, and the wound treated with Cu-HMCe achieved a closure rate of over 90% on the 14th day. Conclusion: The results indicate that multifunctional Cu-HMCe with antioxidant, antimicrobial, and pro-angiogenic properties was successfully prepared and exhibited remarkable efficacy in promoting wound healing. This nanozymes providing a promising strategy for skin repair.
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Anti-Infecciosos , Antioxidantes , Antioxidantes/farmacologia , Cobre/farmacologia , Escherichia coli , Staphylococcus aureus , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , HidrogéisRESUMO
A two-dimensional MXene (Ta4C3) was innovatively used herein to modulate the space group and electronic properties of vanadium oxides, and the MXene/metal-organic framework (MOF) derivative VO2(B)@Ta4C3 with 3D network cross-linking was prepared, which was then employed as a cathode to improve the performance of aqueous zinc ion batteries (ZIBs). A novel method combining HCl/LiF and hydrothermal treatments was used to etch Ta4AlC3 to obtain a large amount of accordion-like Ta4C3, and the V-MOF was then hydrothermally grown on the surface of the stripped Ta4C3 MXene. During the annealing process of V-MOF@Ta4C3, the addition of Ta4C3 MXene liberates the V-MOF from agglomerative stacking, allowing it to show additional active sites. More significantly, Ta4C3 prevents the V-MOF in the composite structure from converting into V2O5 of space group Pmmn but into VO2(B) of space group C2/m after annealing. A considerable advantage of VO2(B) for Zn2+ intercalation is provided by the negligible structural transformation during the intercalation process and the special tunnel transport channels, which have an enormous area (0.82 nm2 along the b axis). According to first-principles calculations, there is a strong interfacial interaction between VO2(B) and Ta4C3, which deliver remarkable electrochemical activity and kinetic performances for the storage of Zn2+. Therefore, the ZIBs prepared with the VO2(B)@Ta4C3 cathode material exhibit an ultra-high capacity of 437 mA h·g-1 at 0.1 A·g-1 while showing good cycle performance and dynamic performance. This study will offer a fresh approach and a reference for creating metal oxide/MXene composite structures.
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Background: Knee osteoarthritis (KOA) is a high incidence chronic joint disease that seriously affects patients' quality of life, and current treatment methods have limited efficacy. Self-management may be an effective strategy for KOA, and clinicians have been showing increased interest recently. However, the effectiveness of self-management for KOA remains controversial. Purpose: This study aims to systematically evaluate the effectiveness of self-management for KOA. Methods: We screened articles published in MEDLINE, Cochrane Library, EMBASE, and Web of Science until September 17, 2021. The main outcomes included pain, knee function, stiffness, WOMAC (total), physical function, arthritis self-efficacy (ASE-pain), arthritis self-efficacy (ASE-other symptoms), mental health, and quality of life. Results: Thirteen randomized controlled trials (RCTs) were finally included (n = 1610). Meta-analysis showed differences in pain, knee function, stiffness, ASE-pain, ASE-other symptoms, mental health, and quality of life between the self-management and control groups. Of the nine outcomes evaluated, four were highly heterogeneous, and the quality of evidence ranged from very low to moderate. Conclusion: The meta-analysis results showed that self-management might help improve the pain, knee function, stiffness, ASE, mental health, and quality of life in patients with KOA. However, it has no significant effect on WOMAC (total) and physical function. Considering that this study has some limitations, we cannot draw clear conclusions based on the results of this study. Nevertheless, we offer much needed insight and encourage more rigorously designed and implemented RCTs in the future to substantiate our conclusions.
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Osteoartrite do Joelho , Autogestão , Humanos , Articulação do Joelho , Osteoartrite do Joelho/terapia , Manejo da Dor/métodos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Background: The pathological mechanism of knee osteoarthritis (KOA) is unknown. KOA degeneration may be associated with changes in muscle strength, proprioception, biomechanics, and postural stability. Objective: This study aimed to assess asymmetries in muscle strength, proprioception, biomechanics, and postural stability of bilateral lower limbs in patients with unilateral KOA and healthy controls and analyze correlations between KOA and these parameters. Methods: A total of 50 patients with unilateral KOA (age range: 50-70) and 50 healthy subjects were recruited as study participants (age range: 50-70). Muscle strength, proprioception, femorotibial angle (FTA), femoral condylar-tibial plateau angle (FCTP), average trajectory error (ATE), and center of pressure (COP) sways areas were accessed in study participants, and the correlation between these variables was investigated. Results: In patients with unilateral KOA, lower limb muscle strength was significantly lower on the symptomatic side than on the asymptomatic side (p < 0.01), while the proprioception (degree error), FTA, FCTP, and ATE were substantially higher compared to the asymptomatic side (p < 0.01). However, no significant difference was observed in the healthy controls (p > 0.05). Patients with unilateral KOA had lower muscle strength than healthy controls (p < 0.05), but their proprioception (degree error: the difference between the target and reproduction angles), ATE, and COP sway areas were higher (p < 0.05). Muscle strength was found to be negatively correlated with ATE and COP sways areas (p < 0.05), whereas proprioception (degree error) was positively correlated with ATE and COP sways areas (p < 0.05) in all study participants. However, no correlation was found between FTA, FCTP, and ATE, COP sways areas in patients with unilateral KOA (p > 0.05). Conclusion: In patients with unilateral KOA, muscle strength, proprioception, biomechanics, and postural stability of bilateral limbs are asymmetrical in unilateral KOA patients. Muscle strength, proprioception, and postural stability are significantly associated variables, and changes in these variables should be considered in KOA prevention and rehabilitation.
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Background: There is an increasing interest in preoperative strength training for promoting post-operative rehabilitation, but the effectiveness of preoperative strength training for clinical outcomes after total knee arthroplasty (TKA) remains controversial. Objective: This study aims to systematically evaluate the effect of preoperative strength training on clinical outcomes before and after TKA. Methods: We systematically searched PubMed, Cochrane Library, Web of Science, and EMBASE databases from the inception to November 17, 2021. The meta-analysis was performed to evaluate the effects of preoperative strength training on clinical outcomes before and after TKA. Results: Seven randomized controlled trials (RCTs) were included (n = 306). Immediately before TKA, the pooled results showed significant improvements in pain, knee function, functional ability, stiffness, and physical function in the strength training group compared with the control group, but not in strength (quadriceps), ROM, and WOMAC (total). Compared with the control group, the results indicated strength training had a statistically significant improvement in post-operative knee function, ROM, and functional ability at less than 1 month and 3 months, and had a statistically significant improvement in post-operative strength (quadriceps), stiffness, and WOMAC (total) at 3 months, and had a statistically significant improvement in post-operative pain at 6 months. However, the results indicated strength training had no statistically significant improvement in post-operative strength (quadriceps) at less than 1 month, 6, and 12 months, had no statistically significant improvement in post-operative pain at less than 1 month, 3, and 12 months, had no statistically significant improvement in post-operative knee function at 6 and 12 months, and had no statistically significant improvement in post-operative physical function at 3 months. Conclusions: Preoperative strength training may be beneficial to early rehabilitation after TKA, but the long-term efficacy needs to be further determined. At the same time, more caution should be exercised when interpreting the clinical efficacy of preoperative strength training for TKA.