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The Special Position of 99mTc in Nuclear Medicine
Published in Frank Helus, Lelio G. Colombetti, Radionuclides Production, 2019
In this apparatus the irradiated molybdenum trioxide is loaded into a horizontal tube furnace through which is flowing a stream of oxygen; the temperature is raised to 850°C at which the 99mTc sublimes and is carried from the furnace to a condenser by the oxygen stream. Some of the molybdenum trioxide is volatilized at this temperature and is removed from the gas stream by a porous plug which is maintained at a temperature between that of the furnace and the boiling point of Tc2O7 (310°C). The vapor of the 99mTc compound enters the condenser after passing through the porous plug and condenses on a cooled surface.
Slime molds response to carbon nanotubes exposure: from internalization to behavior
Published in Nanotoxicology, 2021
Manon Ternois, Maxence Mougon, Emmanuel Flahaut, Audrey Dussutour
We used the CCVD (catalytic chemical vapor deposition) technique to synthesize the DWCNTs. Magnesia (MgO) was used as support material for in situ generated catalytic nanoparticles of cobalt and molybdenum (Flahaut et al. 2003). CCVD is a widely used method due to its capacity to produce CNTs with a high yield and possibly also a high purity with easily controllable reaction conditions to tune the desired type of carbon nanotubes (Yeoh et al. 2009). First, the catalytic powder was placed in a ceramic container which was positioned in a tube furnace. The synthesis was performed with dihydrogen (H2) and a methane (CH4) mixture flow. Methane served as the source of carbon by catalytic decomposition on the cobalt and molybdenum nanoparticles, leading to the formation of carbon nanotubes. The obtained black nanocomposite powder was composed of DWCNTs and the catalytic support, which was dissolved by addition of a concentrated aqueous solution of hydrochloric acid (3.5 mL of deionized water and 15 mL of 37% HCl for 1 g of powder) and left overnight. Then, a vacuum filtration was carried out using a nitrocellulose membrane (0.45 µm pore size). Successive filtrations were performed to remove the excess of HCl and the solution of Mg, Co and Mo salts. Finally, the last washing was carried out using tap water.
Development of graphene based nanocomposites towards medical and biological applications
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2020
Seyyed Mojtaba Mousavi, Foo Wah Low, Seyyed Alireza Hashemi, Chin Wei Lai, Younes Ghasemi, Sadaf Soroshnia, Amir Savardashtaki, Aziz Babapoor, Nelson Pynadathu Rumjit, Su Mei Goh, Nowshad Amin, Sieh Kiong Tiong
Chemical exfoliation, a scalable technique, towards the production of reducing of GO (rGO) from GO, commonly sustains the solution at temperature between the range of 85–100 °C (moisture) [30]. GO is an exfoliated form of graphite, which comprises various oxygen-containing functionalities and is usually synthesised via ultrasonication methods in deionised water condition. Furthermore, it has the capability to produce large quantities of GO in low-cast manner. For the experimental observe point, the conversion of GO to rGO is ordinarily identified by the colour change from bright yellow to dark colour, which indicates high contain of oxidised functional groups [17]. In this reduction process, several reducing agents were used to reduce the GO into rGO, such as thiourea organosulfur compound, hydrazine hydrate, alkali metal borohydrides, hydrohalic acid solvent, and alkali metals [31]. Such reducing agents are reported to be producing significant deoxygenate degrees of rGO. Nevertheless, the possibility of conversion from GO into rGO is very high when in thermal at high temperature (= >1000 °C) in a specific tube furnace in the presence of inert gas. Accordingly, it could create pressure towards graphene sheets in order to reduce the van der Waals force. However, of the large energy demand is one of the major drawbacks for thermal reduction process [32]. Fortunately, a one-step facile route to form rGO from GO suspension on substrate has been identified by electrochemical reduction method, as known as cyclic voltammetry (CV) principle [33].
Role of gold and silver nanoparticles in cancer nano-medicine
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Heerak Chugh, Damini Sood, Ishita Chandra, Vartika Tomar, Gagan Dhawan, Ramesh Chandra
The physical method includes two approaches for synthesis of metallic NPs – evaporation-condensation and laser ablation. Evaporation-condensation is a gas phase route that uses a horizontal tube furnace to produce NPs at atmospheric pressure. Within the centre of the tube, furnace is a boat carrying the metal source material for synthesis which is vaporized into the carrier gas [18]. To this method, a change or modification in the reactor system controls the yield, concentration and the size of the NPs finally produced, for example indium NPs have been synthesized in great quantity using an aerosol generator [19] and aluminium nanopowder have been synthesized by using an aerosol flow reactor [20]. Moreover, AgNPs have been efficiently synthesized in high concentration by replacing the tube furnace with ceramic heater which overcomes various disadvantages of the tube furnaces [21].