RESUMEN
Herein, we studied the novel and emerging group of 2D materials namely MXene along with its nanocomposites. This work entails detailed experimental as well as computational study of the electrochemical behavior of vanadium carbide (V2CTx) MXene and MnO2-V2C nanocomposite with varying percentages of MnO2. A specific capacitance of 551.8 F/g was achieved for MnO2-V2C nanocomposite in 1 M KOH electrolyte solution, which is more than two times higher than the gravimetric capacitance of 196.5 F/g obtained for V2C. The cyclic stability achieved for the MnO2-V2C nanocomposite resulted in a retentivity of 96.5% until 5000 cycles. The c-lattice parameter achieved for MXene is 22.6 Å, which was 13.01 Å for MAX phase. The nanocomposite resulted in a c-lattice parameter of 27.2 Å, which showed that the spatial distance between the MXene layers was efficiently obtained. The method of wet etching was used for the preparation of pristine MXene and the liquid phase precipitation method was opted for the synthesis of the MnO2-V2C nanocomposite. Density functional theory calculation was exercised so as to complement the experimental results and to understand the microscopic details, such as structure stability and electronic structure. The current report presents a comprehensive experimental and computational study on 2D MXenes for future energy storage applications.
RESUMEN
MXenes present unique features as materials for energy storage; however, limited interlayer distance, and structural stability with ongoing cycling limit their applications. Here, we have developed a unique method involving incorporating Nb atoms into MXene (Ti3C2) to enhance its ability to achieve higher ionic storage and longer stability. Computational analysis using density functional theory was performed that explained the material structure, electronic structure, band structure, and density of states in atomistic detail. Nb-doped MXene showed a good charge storage capacity of 442.7 F/g, which makes it applicable in a supercapacitor. X-ray diffraction (XRD) indicated c-lattice parameter enhancement after Nb-doping in MXene (from 19.2A° to 23.4A°), which showed the effect of the introduction of an element with a larger ionic radius (Nb). Also, the bandgap changes from 0.9 eV for pristine MXene to 0.1 eV for Nb-doped MXene, which indicates that the latter has the signature of increased conductivity due to more metallic nature, in support of the experimental results. This work presents not only the effect of doping in MXene but also helps to explain the phenomena involved in changes in physical parameters, advancing the field of energy storage based on 2D materials.
RESUMEN
OBJECTIVE: To evaluate the effects of platelet-rich plasma injection on histological changes of osteoarthritis using the modified Mankin score in monoiodoacetate-induced rat knee model. STUDY DESIGN: Laboratory-based experimental study. PLACE AND DURATION OF STUDY: Department of Anatomy, Army Medical College, Rawalpindi and National Institute of Health (NIH), Islamabad from March to May 2018. METHODOLOGY: Thirty-two pathogen-free male rats aged 3-4 months were selected and divided into two groups with 8 and 24 animals, respectively. Groups A was used as control. Experimental group B was further subgrouped as B1, B2 and B3 with 8 animals, in each subgroup. Monoiodoacetate solution was injected into the articular cavity of the right knee joint of all the animals in group B. Both the control (A) and experimental group B1 were sacrificed after 2 weeks of MIA injection, for observing the histological changes in the articular cartilage. Group B2 received a single injection of platelet rich plasma (PRP) while group B3 was reared as such. Both groups were sacrificed after 4 weeks of intra-articular administration of PRP. Articular cartilage was collected, processed and stained with hematoxylin and eosin (H and E) and toludine blue (T.B). Routine histological study was done and Mankin score was calculated to determine the grade of arthritis. SPSS Version 21 was used for the statistical analysis and p-value was considered significant at the cut-off value of 0.05. RESULTS: The mean Mankin score of group B3 (9.37) was significantly higher than that of group B2 (7.37, p=0.003). CONCLUSION: Platelet-rich plasma treatment controls the histological changes of chemically-induced osteoarthritis in rat knee.