Finite Element Method (FEM) using 26-node isoparametric finite elements was applied for modeling saddle-shaped head coils used in Magnetic Resonance Imaging (MRI) generating linearly polarized radiofrequency (RF) pulses at 64 MHz. The human head was modeled from MR scans of a volunteer and additional information were taken from Atlas of Sectional Human Anatomy. The physical dimensions of the head coil and the head permit a calculation of the outside magnetic field by a quasistatic approach. Of course, a full-wave approach was applied within the head. Values of specific energy--specific absorption (SA)--as well as of specific power--specific absorption rate (SAR)--were calculated by the method, simulating the real exposure conditions during MRI. Although the results of the used numerical method were compared previously to the results of the analytical solution with homogeneous sphere and to the results of RF measurements on heterogeneous phantom, a comparison between the numerical results of the modeled human head and in vivo measurements performed on the human head of the volunteer was made once more. Since the results are in excellent agreement, they argue for the correctness of the numerical method. The "worst-case" temperature elevations delta theta of the "hot-spots" were calculated, as well. Finally, the results of SA, SAR, and delta theta are compared to the existing recommendations.
Independent living of older adults is one of the main challenges linked to the ageing population. Especially those living with diseases like COPD, MCI or frailty, need more Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation support in everyday life and this is by itself a big societal challenge with impact in multiple sectors. In this paper we present eWALL, an innovative open-source eHealth platform that aims to address these challenges by means of an advanced cloud-based infrastructure. eWALL is designed in an innovative manner and achieved technical breakthroughs in eHealth platforms, while prioritizing user and market needs that are often abandoned and are the major reason for technically sound solutions that fail. We consider this as an opportunity and we aim to change the eHealth systems' experience for older adults and break the barriers for the penetration of ICT solutions.
The mobile ad-hoc networks (MANET) are an emerging research area with applications. It has features like working as a router, dynamic topology and autonomous. In MANET, nodes have limited resources like battery power, storage space and bandwidth. There is a need to do more research for Denial of Service (DoS) attacks in MANET as compared to wire line DoS attacks. MANET is vulnerable to different types of DoS attack in which packets are drop. Black hole attack, packet drop attack and gray hole attack are an event that eliminates a network's capacity to perform its expected function. These attacks are type of DoS attack which we examine in this paper. This paper shows the effects of black hole attack, packet drop attack and gray hole attack on AODV protocol under different performance metrics throughput, packet drop rate and end-to-end delay. The simulation is done in Network Simulator (NS) 2.
Nutritional stress disturbs the cellular redox-status, which is characterized by the increased generation of reactive oxygen species (ROS). The NRF2-NQO1 axis represents a protective mechanism against ROS. Its strength is cell type-specific. FaDu, Cal 27 and Detroit 562 cells differ with respect to basal NQO1 activity. These cells were grown for 48 hours in nutritional conditions (NC): (a) Low glucose–NC2, (b) no glucose, no glutamine–NC3, (c) no glucose with glutamine–NC4. After determining the viability, proliferation and ROS generation, NC2 and NC3 were chosen for further exploration. These conditions were also applied to IMR-90 fibroblasts. The transcripts/transcript variants of NRF2 and NQO1 were quantified and transcript variants were characterized. The proteins (NRF2, NQO1 and TP53) were analyzed by a western blot in both cellular fractions. Under NC2, the NRF2-NQO1 axis did not appear activated in the cancer cell lines. Under NC3, the NRF2-NQO1axis appeared slightly activated in Detroit 562. There are opposite trends with respect to TP53 nuclear signal when comparing Cal 27 and Detroit 562 to FaDu, under NC2 and NC3. The strong activation of the NRF2-NQO1 axis in IMR-90 resulted in an increased expression of catalytically deficient NQO1, due to NQO1*2/*2 polymorphism (rs1800566). The presented results call for a comprehensive exploration of the stress response in complex biological systems.
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