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Interstitial Microwave Hyperthermia for the Treatment of Brain Tumors *
Published in Leopold J. Anghileri, Jacques Robert, Hyperthermia in Cancer Treatment, 2019
Bernard E. Lyons, John W. Strohbehn, David W. Roberts, Terence Z. Wong, Richard H. Britt
The 12-probe gallium-arsenide (GaAs) system (Clini-Therm, Model 1200, Dallas, Tex.) based on the original work of Christensen57 is the system used in the experimental and clinical studies that are ongoing at Dartmouth College. Gallium-arsenide is a semiconductor whose band-edge absorption lies in the near infrared region of the spectrum. When radiation is passed through the sensor, a variable amount is absorbed by the process of exciting valence band electrons. The absorbed energy of GaAs varies with temperature, so the amount of return radiation is a function of the temperature of the sensor. For clinical applications these thermometer probes may be inserted in the nylon afterloading catheters alongside the antennas. In this fashion, direct power control at each antenna can be determined by a computer and multiple temperature points can be measured throughout the tumor volume using pull-back techniques during thermal mapping.
Assembly of Microscopic Three-Dimensional Structures and Their Applications in Three-Dimensional Photonic Crystals
Published in Iniewski Krzysztof, Integrated Microsystems, 2017
In this approach, the final 3D photonic crystal structure was considered as an ensemble of simple components. Unit components were prepared in the form of air-bridge plates using conventional semiconductor processing techniques for easy removal from a wafer during micromanipulation, and assembled into the designed 3D structure using a micromanipulation system. Here, InP was selected as the material for a 3D photonic crystal. Indium gallium arsenide (InGaAs) was deposited on an InP wafer using the metalorganic chemical vapor deposition (MOCVD) method as a sacrificial layer; then an InP layer was formed on it [2]. Subsequently, titanium and nickel layers, as a mask for dry etching processing, were formed using an evaporator, and a resist layer for electron-beam lithography was spin-coated onto the top (Figure 24.3).
Chapter Paper 1 Answers
Published in James Day, Amy Thomson, Tamsin McAllister, Nawal Bahal, Get Through, 2014
James Day, Amy Thomson, Tamsin McAllister, Nawal Bahal
Solids are classified as conductors, semi-conductors and insulators. This division is based on the solid’s ability to conduct electrons. This ability is due to the presence of unpaired electrons in the outer shells of the solid’s atoms. Most conductors are metallic, although the atomic structure of carbon in graphite allows it to act as a conductor. Insulators have firmly bound outer electrons such as rubber and glass, and will not allow an electrical current to flow. Semi-conductors under certain conditions, usually temperature, will allow an electrical current to flow. Examples include silicon, germanium, and gallium arsenide. Semi-conductors are used in thermistors, transistors and diodes. Electrical fuses are made of a metal wire and transformers consist of metal wire coiled around a ferromagnetic material.
Arsenic: an emerging role in adipose tissue dysfunction and muscle toxicity
Published in Toxin Reviews, 2022
Kaviyarasi Renu, Aditi Panda, Balachandar Vellingiri, Alex George, Abilash Valsala Gopalakrishnan
Arsenic presence in the environment can be both man-made and natural activities. It enters the environment naturally through groundwater, mineral ore, and geothermal processes. Its dispersion and spread in the environment are mainly provoked through mining, leaching, and commercial uses. It's a common by-product through the smelting process of metal ores like cobalt, gold, lead, nickel, and zinc, respectively. Other sources of arsenic include algaecides, herbicides, non-ferrous alloys, pesticides, defoliants, etc. It is also vastly used in glass manufacturing industries in the form of gallium arsenide and arsine gases used in semiconductor devices. However, both organic and inorganic forms of Arsenic can also be found in seafood like oysters, scallops, mussels, prawns, lobsters, etc. (Barringer and Reilly 2013).
‘Trojan-Horse’ stress-granule formation mediated by manganese oxide nanoparticles
Published in Nanotoxicology, 2020
Nina B. Illarionova, Ksenia N. Morozova, Dmitry V. Petrovskii, Marina B. Sharapova, Alexander V. Romashchenko, Sergey Y. Troitskii, Elena Kiseleva, Yuri M. Moshkin, Mikhail P. Moshkin
We observed that, after 2 h of U87 MG cells incubation with various NPs, only Mn3O4 NPs induced SGs formation in a concentration-dependent manner (one-way ANOVA F2, 42 = 26.6, p < 0.001) (Figure 1(A,B)). We have also performed a positive control treatment with oligomycin (10 µM, 2 h), mitochondria function uncoupler and SGs inducer, that showed a significant increase in the percentage of cells with SGs (Figure 1(B)) (t-test, t(32) = 5.4, p < 0.001). Shorter incubation time revealed that SGs assembly was initiated after 15 min of U87 MG cells incubation with Mn3O4 NPs (t-test, t(28) = 3.6, p < 0.01) (Figure 1(C)). Further incubation increased the percentage of SGs containing cells in a time-dependent manner (one-way ANOVA F4, 62 = 8.6, p < 0.001) (Figure 1(C)), but did not affect cell viability (Supplementary Figure 3). To confirm SGs staining we used an additional SGs marker – G3BP1, which overlapped with eIF3η (Figure 1(D)). Arsenide treatment (70 µM, 1 h) was used as a positive control (Figure 1(E)). From these, we conclude that only selective inorganic NPs are capable of initiating SGs formation. However, it has to be noted that the selected NPs had different surface charges (Supplementary Table 1) which might affect the efficacy of their intracellular uptake (Frohlich 2012; Oh and Park 2014).
Comparative study between multi-detector computed tomography and echocardiography in evaluation of congenital vascular rings
Published in Alexandria Journal of Medicine, 2018
Manal Hamisa, Fatma Elsharawy, Wafaa Elsherbeny, Suzan Bayoumy
DAA was the commonest type of vascular ring anomalies in this study (14 out of 21), 66% of cases, with right dominance in eight patients (57%) and co dominance in two patients (14%) most of the patients suffered from stridor and wheeze at presentation with feeding difficulties in six patients, Kussman et al.10 reported that double aortic representing 50–60% of vascular rings anomalies. In the study of Arsenide et al.21 81 patients with median age of 5 months, there is 91% of them presented by respiratory symptoms and 40% presented by chocking, the right branch is the dominant branch of double aortic arch in 72% while the left arch is only dominant in 20% of cases, while the two arches are equal in size in 5% of cases. DAA usually associated with intracardiac anomalies e.g. fallot tetralogy, VSD, transposition of the great arteries, ASD, and patent ductus arteriosus. While in this study only two cases showed DAA associated anomalies, one showed ASD and the other with APVD.