Published Article / Long-term growth in the additive fabrication industry will come from designs that are difficult, time-consuming, costly, or impossible to produce using standard techniques. Growth will occur with advances in the current additive processes, coupled with breakthroughs in new materials, which are expected to emerge over the next five to 10 years. These advanced materials will better satisfy the design requirements of many new products. The paper considers currently available technologies and discusses recent advancements in direct metal freeform fabrication and its potential of revolutionising the medical industry.

Dielectric properties play an influential role in the development of medical devices. Understanding the behavior of these properties and how they respond to external stimuli, such as heat, over an extended frequency has yet to be researched. The focus of this study is to examine the impact of temperature on dielectric properties from 500 MHz to 10 GHz in order to better match the antenna properties of medical applications to the dielectric properties of biological tissue in question; more specifically, microwave ablation, microwave hyperthermia, and thermal modeling of brown adipose tissue’s metabolic processes. The dielectric properties of biological tissue samples from porcine lung, liver, heart, skin, fat, and muscle as well as brown adipose tissue and white adipose tissue from rat have been tested. These results have then been used to develop medical applications involving microwave antennas.

Soon after the discovery of radioactivity it was shown that radionuclides can be used both for diagnostic and therapeutic studies, depending on the characteristic radiations emitted by them. By 1960’s the radionuclide production technology using nuclear reactors was well established. In early 1970’s a renaissance of the cyclotrons occurred because many of the neutron deficient radionuclides could only be produced using irradiations with charged particles, like protons, deuterons, α-particles, etc. Initially, interest was directed towards radioactive gases for inhalation studies and other radionuclides for scintigraphy. Later, with the advent of emission tomography, i.e. Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET), the emphasis shifted to 123I and positron emitters [cf. 1–3], and tremendous progress ensued. In order to keep abreast of the fast developments, a Symposium was organized at the Brookhaven National Laboratory (BNL), USA, in 1976, with the title “Radiopharmaceutical Chemistry”. This became a biennial event, with alternate meetings in North America and Europe. It included all aspects of radionuclide and radiopharmaceutical research. About a decade later, however, it was realized that for discussion of technical aspects, a separate forum would be more appropriate. A group of experts therefore convened the first Targetry Workshop in Heidelberg in 1985. Thereafter it was established as a recurring Workshop, with its scope enlargened to include also nuclear and radiochemical problems. Today, the major conference on Radiopharmaceutical Sciences and the specialist International Workshop on Target-ry and Target Chemistry are held in alternate years. The present Workshop is No. 15 in the series and it is being jointly held by the research groups in Dresden and Prague, both of which have a long tradition of cyclotron production of radionuclides. In this talk, some personal reminiscences and impressions of the historical de-velopments in the field over the last 40 years will be briefly described.

The aim of the research presented in this thesis is to investigate and develop novel nitric oxide (NO) delivery systems, specifically designed for application in medical areas. The initial work has focused on utilising metal organic frameworks (MOFs) as a delivery system for this radical gas, NO. Due to their high porosity, high thermal stability and the presence of coordinated unsaturated metal sites (CUSs) when fully activated, the CPO-27 (Coordination Polymer of Oslo) family of MOFs has been selected as a suitable host framework. CPO-27 (Ni), CPO-27 (Mg) and CPO-27 (Zn) have been prepared using reflux and room temperature processes without recourse to the use of any toxic or harmful solvents. The resulting products are characterised by powder XRD (X-ray diffraction) and SEM (Scanning electron microscopy), and their NO adsorption, storage and release properties are reported. The results indicate that the crystallinity, particle size and NO adsorption, storage and release performance are comparable to those of equivalent samples synthesised via traditional solvothermal methods, paving the way for a more easily scalable and environmentally friendly synthetic procedure for these types of MOF. Depending on which metal is employed; the NO uptake, storage and release varies, the more toxic nickel based framework shows enhanced performance in terms of concentration and duration of NO released against either the magnesium or zinc counterparts. In order therefore to reduce the risk of toxicity whilst retaining good performance, Ni (II) ions were doped into the 3D framework of CPO-27 (Mg) and CPO-27 (Zn) using novel water-based reflux and room temperature crystallization methods. Several characterization techniques strongly support the effective incorporation of Ni (II) ions into the 3D framework. Nitric oxide (NO) adsorption/release data, as well as in vitro tests demonstrate that NO dosage and biological response can be tuned via the Ni doping process allowing enhanced performance without the high toxicity of pure Ni MOFs. Such materials would be extremely advantageous and more applicable for use in medical fields. NONOates and other NO-complexes have also been investigated as alternative NO delivery systems. This study has focused on developing NO-drug complexes using a variety of different compounds commonly used by clinicians, namely the antiseptic (chlorhexidine, CHx), the antibiotic (ciprofloxacin) and diuretic (furosemide). A unique high pressure NO loading methodology has been developed to coordinate nitric oxide to these drug molecules and their NO release performance has been evaluated. The resulting NO-drug complexes are characterised using a series of spectroscopic techniques and the collected data highlights that the radical gas coordinates with the secondary amine groups present in the drug molecules. The interaction between the amine group and the gas is reversible; in fact the release of NO from these complexes can be triggered using water (11% RH) and/or UV-light. In addition, chlorhexidine has been incorporated into the pores of the CPO-27 framework. The amount of antiseptic incorporated was determined using a variety of characterisation techniques. The controlled release of significant concentrations of CHx from the CPO-27 materials are achieved by exposing each CHx loaded sample to a water solution, in doing so topical conditions are simulated. The CHx loaded samples have also been activated and NO loaded following the novel high pressure procedure specifically developed during this research. The resulting NO loaded material released the radical gas in the presence of water and/or UV-light. By incorporating the CHx into the MOF and NO loading this complex the duration and release of NO was greatly enhanced over that of either of the components alone. On formulating the CHx loaded 3D frameworks into pellets, or even into a polyurethane polymer film, their ability to release the antiseptic under simulated topical conditions was maintained. The NO-CHx-CPO-27 composite film that has been prepared has proven to be able to simultaneously store and release both NO and CHx. Each component of the complex has more than one function and the quantity and duration of release of NO is again higher and longer than either of the two moieties alone. The release of these two antibacterial agents from a MOF is novel and is very exciting as it opens up the possibility of engineering products with multiple actions to fight infection. Owing to their high stability and shape persistence properties, the CC3 cage series (CC3, RCC3, FT-RCC3 and AT-RCC3) was chosen as the basis of an investigation into the potential use of porous organic cages as delivery systems for nitric oxide gas. NO has been stored in these porous materials through coordination to amine groups forming Nnitrosamine groups. Release of NO from these types of compounds can be triggered by various mechanisms including water and UV-light, the amine group being regenerated after the release of NO. The release performance significantly increased when the materials were exposed to UV-light and/or suspended in water. As a result of this investigation, these covalent organic molecular cages can now be added to the existing list of NO-based therapies available to medical professionals.

Soon after the discovery of radioactivity it was shown that radionuclides can be used both for diagnostic and therapeutic studies, depending on the characteristic radiations emitted by them. By 1960’s the radionuclide production technology using nuclear reactors was well established. In early 1970’s a renaissance of the cyclotrons occurred because many of the neutron deficient radionuclides could only be produced using irradiations with charged particles, like protons, deuterons, α-particles, etc. Initially, interest was directed towards radioactive gases for inhalation studies and other radionuclides for scintigraphy. Later, with the advent of emission tomography, i.e. Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET), the emphasis shifted to 123I and positron emitters [cf. 1–3], and tremendous progress ensued. In order to keep abreast of the fast developments, a Symposium was organized at the Brookhaven National Laboratory (BNL), USA, in 1976, with the title “Radiopharmaceutical Chemistry”. This became a biennial event, with alternate meetings in North America and Europe. It included all aspects of radionuclide and radiopharmaceutical research. About a decade later, however, it was realized that for discussion of technical aspects, a separate forum would be more appropriate. A group of experts therefore convened the first Targetry Workshop in Heidelberg in 1985. Thereafter it was established as a recurring Workshop, with its scope enlargened to include also nuclear and radiochemical problems. Today, the major conference on Radiopharmaceutical Sciences and the specialist International Workshop on Target-ry and Target Chemistry are held in alternate years. The present Workshop is No. 15 in the series and it is being jointly held by the research groups in Dresden and Prague, both of which have a long tradition of cyclotron production of radionuclides. In this talk, some personal reminiscences and impressions of the historical de-velopments in the field over the last 40 years will be briefly described.

A detailed dosimetric comparison between Inverse Planning by Simulated Annealing (IPSA) and Dose Points (DP) optimized treatment plans has been performed for High Dose Rate (HDR) brachytherapy of skin lesions using Freiburg Flap applicator in order to find out whether or not IPSA offers better clinical dosimetric outcomes for lesions categorized into four different curvatures. Without compromising target coverage, IPSA reduced the volume of Planning Target Volume (lesion) that received at least 125% of the prescription dose on average by 41%. It also reduced the volume of the healthy skin surrounding the lesion that receives at least 100% of the prescription dose on average by 42%. IPSA did not show any advantage over DP in sparing normal structures underlying the lesions treated. Although DP optimization algorithm has been regularly used at Lynn Cancer Institute for HDR brachytherapy of skin lesions, recent upgrades in IPSA software have made IPSA more amenable to rapid treatment planning and therefore IPSA can be used either in place of DP or as its alternative. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

During the last decade medical applications of textile sensors have been growing rapidly and textile sensors are the focal research point for many sensor projects. Textile sensors are still not available as a mainstream product to replace conventional electric sensors and electrodes. Textile sensors can be integrated in a textile garment to measure vital signs of a human being. In this regard stretch sensors are able to measure breathing rate of a person. In this project we use seamless knitting technique to make stretch sensors using conductive fibers. The resistance difference between stretching and relaxing of these sensors gives a pattern for human breathing. Four knitting structures with different conductive fibers are made and tested with cyclic tester to construct a graph between resistance and time to find the knitting structure which gives the best results. Tests are also done to check the results after washing. These sensors can be used in breathing monitoring of patients during daily life. / Program: Master Programme in Textile Technology

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2015.

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