Explore chapters and articles related to this topic
IBS™ bioresorbable scaffold by Lifetech
Published in Yoshinobu Onuma, Patrick W.J.C. Serruys, Bioresorbable Scaffolds, 2017
Deyuan Zhang, Wenjiao Lin, Haiping Qi
Pure iron shows inferior mechanical performance to permanent stent materials, but a lot of methods can be used to enhance its mechanical performance. Nitriding technology makes it possible that the IBS made of nitrided iron-based alloy with very thin struts could still show high mechanical performance, comparable to those of the best permanent stents. Moreover, similar stent design to current permanent stents allows IBS the same overdilation and side-branch dilation capability, specifications coverage, and procedural manipulation without any compromise. These merits entitle IBS the only potential bioresorbable scaffold to cover all specifications of the current permanent stents, when compared with the bioresorbable polymer-based and magnesium-based scaffolds.
Industrial Applications
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
Ion beam processing has for several years been well established in the semiconductor industry. In recent years ion implantation of tool steels ceramics and even plastics has gained increasing industrial awareness. The development of ion implantation to a commercially viable surface treatment of tools and spare parts working in production type environments is very dependent on technical merits, economic considerations, competing processes and highly individual barriers to acceptance for each particular application. Some examples of this will be discussed. The development of the process is very closely linked with the development of high current accelerators and their ability to efficiently manipulate the samples being treated, or to make sample manipulation superfluous by using special beam systems like the PSII. Furthermore, the ability to produce high beam currents (mA) of a wide variety of ions is crucial. Previously, it was broadly accepted that ion implantation of tools on a commercial basis generally had to be limited to nitrogen implantation. The development of implanters that can produce high beam currents of B, C, Ti, Cr and other elements ions is rapidly changing this situation, and today an increasing number of commercial implantation are performed with these ions although nitrogen is still successfully used in the majority of commercial implantations. Overall, the recent development of equipment makes it possible to a higher extent than before to tailor the implantation to a specific situation Furthermore, very interesting results have been obtained recently by implanting nitrogen at elevated temperatures, which yields a relatively deep penetration of the implanted ions. Direct nitrogen implantation and implantation combined with nitriding of aluminum have both shown interesting tribological potential (Straede 1992).
Effect of leukocyte-platelet fibrin-rich wound reconstruction followed by full-thickness skin grafting in the treatment of diabetic foot Wagner grade 4 ulcer gangrene (toe area)
Published in Platelets, 2023
Yuqi Wang, Yanyan Wang, Xiaotao Wang, Yi Zhao, Siyuan Ruan, Hong Cao
From the microscopic point of view, the mechanism of diabetic foot ulcer formation is very complex, and has not yet been systematically elaborated upon. Oxidative stress plays a key role in the development of diabetic complications [14]. On the one hand, the hyperglycemic state in the body leads to an enhanced nitriding stress response and an increase in the production of nitric oxide (NO). NO promotes to some extent the angiogenesis, migration and proliferation of epithelial and endothelial cells, fibroblasts and keratinocytes. Oxidative stress increases the production of vascular peroxides. These peroxides inactivate nitric oxide, thereby promoting the activation of proinflammatory processes and vascular dysfunction [15,16]. On the other hand, oxidative stress may also increase circulatory diacylglycerol and protein kinase C, leading to vascular dysfunction. Intracellular accumulation of advanced glycation end-products (AGEs) enhances the expression of receptors for advanced glycation end-products (RAGE) and leads to the expression of pro-inflammatory molecules [17,18]. In addition, when the hyperglycemic state persists in the body, it can lead to epithelial cell dysfunction, resulting in reduced proangiogenic signaling and reduced nitric oxide production. The loss of nitric oxide reduces vasodilation and accelerates limb/nerve ischemia. In the course of chronic hyperglycemia, peripheral arterial endothelial cell dysfunction and smooth muscle cell abnormalities lead to decreased endothelial-derived vasodilators, resulting in vasoconstriction and an increased risk of limb ischemia [1,19–21].
Analytical review on the biocompatibility of surface-treated Ti-alloys for joint replacement applications
Published in Expert Review of Medical Devices, 2022
Kao et al. [98] evaluated the tribological, corrosion resistance, and biocompatibility of Ti6Al4V alloy samples generated by selective laser melting (SLM) and treated with surface nitriding and coating (CN and DLC) techniques. Ti6Al4V samples coated with amorphous carbon nitride (CN) or DLC-doped Ti (TieC:H), X-ray diffraction for microstructures, nanoindentation testing for mechanical characteristics, and Rockwell hardness tests for coating adhesion strengths are performed. Then In 0.89 wt percent NaCl solution, 316 L, Si3N4, and Ti6Al4V balls were subjected to reciprocating sliding wear tests under a load of 10 N for 1440 seconds to assess their tribological capabilities. Techniques such as potentiodynamic polarization tests are used to assess corrosion characteristics. The findings revealed that a duplex treatment combining nitriding and DLC coating deposition (DLC-N3DTs) had the most excellent tribological characteristics, corrosion resistance, and wear resistance.