No abstract

No abstract

No abstract

Starch based green composites have been studied as potential materials to be used in several biomedical applications. This paper explores utilizing starch based composites reinforced with pseudostem banana fibers in fabricating biodegradable maxillofacial bone plates. Corn starch plasticized by 30 wt.% glycerin and 20 wt.% distilled water was used as a matrix. The produced thermoplastic starch (TPS) matrix is reinforced with pseudostem banana fibers at different weight fractions using hot pressing at 5 MPa and 160ºC for 30 minutes. Our experimental results showed that increasing the banana fibers weight fraction progressively improved the mechanical properties reaching a maximum at 50 wt.% fibers. The improvement in the mechanical properties of starch/banana fibers composite was attributable to the strong interaction between fibers and the starch matrix, as evidenced by a series of scanning electron micrographs of the fracture surface. Furthermore, experiments investigating thermal properties and water uptake also showed that the best results are achieved at the 50 wt.% banana fibers. The experimental results show that the starch matrix-banana fiber composites satisfy the maxillofacial bone fixation requirements.

Introduction: The non-invasive nature of bioimpedance technique is the reason for the adoption of this technique in the wide field of bio-research. This technique is useful in the analysis of a variety of diseases and has many advantages. Cardiovascular diseases are the most dangerous diseases leading to death in many regions of the world. Vascular diseases are disorders that affect the arteries and veins. Most often, vascular diseases have greater impacts on the blood flow, either by narrowing or blocking the vessel lumen or by weakening the vessel wall. The most common vascular diseases are atherosclerosis, wall swelling (aneurysm), and occlusion. Atherosclerosis is a disease caused by the deposition of plaques on the inner vessel wall, while a mural aneurysm is formed as a result of wall weakness. The main objective of this study was to investigate the effects of vascular diseases on vessel impedance. Furthermore, this study aimed to develop the measurement of vessel abnormalities as a novel method based on the bioimpedance phenomenon. Methods: Mathematical models were presented to describe the impedance of vessels in different vascular cases. In addition, a 3D model of blood vessels was simulated by COMSOL MULTIPHYSICS.5, and the impedance was measured at each vascular condition. Results: The simulation results clarify that the vascular disorders (stenosis, blockage or aneurysm) have significant impact on the vessel impedance, and thus they can be detected by using the bio-impedance analysis. Moreover, using frequencies in KHz range is preferred in detecting vascular diseases since it has the ability to differentiate between the healthy and diseased blood vessel. Finally, the results can be improved by selecting an appropriate electrodes configuration for analysis. Conclusion: From this work, it can be concluded that bioimpedance analysis (BIA) has the ability to detect vascular diseases. Furthermore, the proposed mathematical models are successful at describing different cases of vascular disorders.

In this investigation, multi-wall carbon nanotubes (MWCNT) with various percentages (0.6%, 1%, 1.4%, 2%) were combined into   ​and High-density polyethylene HDPE (60) wt. % and hydroxyapatite (40) wt. % to form biocomposite using hot-press techniques. The surface topography by AFM images illustrates differences in the roughness of the sample's surface with different adding percentages of MWCNT. The DSC technique exhibits the effect of adding MWCNT in different percentages with the degree of crystallinity, which its effect on mechanical properties for samples. The in vitro bioactivity was investigated by immersion the samples in Ringer's solution as simulated body fluid (SBF) at (0, 3, 6, 9, 12) days (after immersing). The FE-SEM and EDx image explained the apatite layers formation on the sample's surface after 3 days immersed in Ringer solution. Based on XRD Technique, after immersion days in the Ringer solution, the crystallographic structure of hydroxyapatite is formed, forming the monetite.  ​The enhancement of bioactivity has been shown during the incorporation of MWCNT into HA/HDPE composite. These results exhibited excellent indications of biocompatibility properties with the possibility of making promising biomaterials for making bone substitute applications.

With declaring the highly transmissible COVID-19 as a pandemic, an unprecedented strain on healthcare infrastructures worldwide occurred. An enormous shortage in the personal protective equipment (PPE) and the spare parts (SP) for the mechanical ventilators ensued as a consequence of the failure of the centralized global supply chains. Additive manufacturing and Industrial Internet of Things (IIoT), as the pillars of Industry 4.0, arose as the robust noncentralized alternatives. When gathered and properly managed in the IIoT, 3D Printers (3DPs) can complement and support Healthcare 4.0 to face the current and future pandemics. Thus, this paper proposes a real-time green allocation and scheduling architecture designed and dedicated particularly for the large-scale distributed 3D printing tasks (3DPTs) of both PPE and SPs. Our proposed architecture comprises; a broker (B) and a cluster manager (CM). Dynamic status check for the 3DPs and admission control for 3DPTs are among the interconnected roles of CM. CM also performs task allocation and scheduling according to our proposed Online Ascending Load-Balancing Modified Best-Fit (OALMBF) allocation algorithm and Green Real-time Nesting Priority-Based Adaptive (GRNPA) scheduling algorithm. The performance of the proposed architecture was investigated under extremely highload environments which resulted in a success ratio and a response rate of 99.9667% and 10.9665 seconds, respectively, for the 3000 3DPTs trial. These results proved the robustness and the scalability of our architecture that surpasses its state-of-the-art counterparts. Besides respecting the real-time requirements of the 3DPTs, the proposed architecture improves the utilization of the 3DPs and guarantees an even workload distribution.

No abstract