Controlling size and distribution of Ag nanoparticles in near surface of SiO2 glass by low-energy ion implantation

Ag nanoparticles were embedded in the near surface of SiO2 substrate and fabricated by low-energy ion implantation method in this study. The optical and structural properties of Ag implanted samples were investigated using optical spectroscopy, transmission electron microscope (TEM) and atomic force microscopy (AFM). The grain size and distribution of nanoparticles embedded in the substrate were characterized by TEM and AFM characterization. Results showed that the grain size and depth of distribution of nanoparticles were controlled by changing the ion implantation energy and dose. Furthermore, the Ag nanoparticles embedded near surface of substrate prepared by this low-energy ion implantation method had strong local surface plasmon resonance (LSPR) characteristics. Our work demonstrates a practical means for fabrication of metal nanoparticles with controllable size and distribution using ion implantation technology, which is helpful to the application of local plasmon resonance effect of metal nanoparticles.

Is Fat Tissue a Suitable Source of Stem Cells for Musculoskeletal Regenerative Medicine Therapies: Literature Review

This review found that adipose-derived stem cells are suitable for treating osteoarthritis. Besides joint replacement the current treatments do not reverse the underlining pathology, whereas this therapy replaces lost or damaged tissue and could represent a cure. Bone marrow is the traditional source of stem cells, however adipose tissue is more appropriate because of ease of harvesting, abundance, the concentration of stem cells and potential cosmetic benefits. Subcutaneous fat-derived stem cells are more effective for treating osteoarthritis when compared to visceral fat-derived. Human and animal models have shown its efficacy but with limitations. It has been less successful in older and/or patients with greater joint degeneration. Its cost-effectiveness when compared to current treatment has not been shown. A gold standard production and implantation method have yet to be developed, meaning there are no guidelines for its use. Current studies aim to address these issues, with implementation on the horizon.

Modeling of Hemodynamics in a Vascular Bioprosthesis

The study of blood flow in vascular bioprostheses is a rather complicated task, since the shape of the inner surface of the bioprosthesis is variable, due to xenogenic origin. Because of this, vortex zones can occur inside the vascular bioprosthesis. In addition, the flow structure may contain sections where the flow velocity is abnormally high. It is all the more difficult to assess the nature of the course when using this vascular bioprosthesis as a shunt. A numerical comparison of the blood flow in a bioprosthesis connected to the main vascular bed using the «end-to-end» and «end-to-side» methods (bypass) taking into account the heart rate and blood pressure was performed. It is shown that, due to the nonlinearity of the initial bioprosthesis geometry, the implantation method affects the blood flow. Because of this, vortex zones arise and, with certain combinations of parameters, the effects of «separation» of vortices.

High CO Adsorption Performance of CuCl-Modified Diatomites by Using the Novel Method “Atomic Implantation”

An atomic implantation method was used to modify diatomite with CuCl. The CuCl/diatomite samples were characterized by different techniques, including FTIR, XRD, BET, SEM-TEM, EDX, and CO-TPR. Characterization results revealed the formation of CuCl particles of 50–60 nm highly dispersed on diatomite surface. CO adsorption measurements showed that 2CuCl/diatomite exhibits the highest CO adsorption capacity among all CuCl-modified samples with diatomite. Its CO adsorption capacity of 2.96 mmol/g at 30°C is 10 times higher than that of unmodified diatomite (0.29 mmol/g). The CO adsorption on CuCl-modified diatomites was found to fit well with the Langmuir–Freundlich model.