A BUSINESS CASE STUDY FOR COMPARING THE MANUFACTURING OF IMPLANT-SUPPORTED DENTURE FRAMES THROUGH DIRECT METAL LASER SINTERING TO CONVENTIONAL CASTING AND MACHINING PROCESSES

Conference ProceedingsRetaining dentures in edentulous patients is a common problem which can be overcome through the use of implant-supported denture frames. These frames are conventionally manufactured through the lost wax investment casting processes or through computer aided machining in cobalt chrome. Although Additive Manufacturing (AM) processes are now commonly used in the manufacturing of crowns and bridges in dentistry, the manufacturing of implant-supported denture frames is less common. This study aimed to investigate the feasibility of manufacturing these frames through AM from a business point of view compared to conventional casting and machining. A case study is presented where a full overdenture frame is designed and manufactured in Titanium-6Aluminium-4Vanadium (Ti-6Al-4V) alloy through the Direct Metal Laser Sintering (DMLS) process. This is compared to manufacturing the same frame in cobalt chrome through traditional processes in terms of manufacturing time and cost. Results from the study showed that it is more expensive and takes longer to produce overdenture frames through DMLS compared to conventional manufacturing techniques. Although costs and time can be reduced by producing a number of frames simultaneously on the DMLS machine’s building platform, the manufacturing process is still not considered viable for overdenture frames from a business point of view

The Global Health System: Actors, Norms, and Expectations in Transition

In the first in a series of four articles highlighting the changing nature of global health institutions, Nicole Szlezák and colleagues outline the origin and aim of the series

Characterization of the model for experimental testicular teratoma in 129/SvJ-mice

An animal model of experimental testicular teratoma has been established to study how a teratoma affects the host testis and how the host testis reacts against the teratoma. 129/SvJ-mice were used as experimental animals. To induce the experimental testicular teratoma, male gonadal ridges from 12-day-old 129/SvJ-mouse fetuses were grafted into the testes of adult mice for 1-12 weeks. The developing tumour was analysed by light and electron microscopy and by immunocytochemical localization of transcription factors SOX9 and c-kit, glial fibrillary acidic protein (GFAP) and type IV collagen. Testicular teratoma was observed in 36 out of 124 testes with implanted fetal gonadal ridges (frequency 29%). One spontaneous testicular teratoma was observed in this material from 70 male mice (1.5%). One week after implantation intracordal clusters of cells were seen in embryonic testicular cords of the graft as the first sign of testicular teratomas. Four weeks after implantation the embryonic testicular cords had totally disappeared from grafts with teratomas, and the tumour tissue had enlarged the testis and invaded the interstitium of the host testis. It consisted of solitary pieces of immature cartilage as well as of glial cells and of primitive neuroepithelium. Six to eight weeks after implantation the tumour tissue had expanded so that the enlarged testis could be detected by macroscopic enlargement of the scrotum. The testicular tissue of the host had practically disappeared, and only solitary disrupted seminiferous tubules of the host were seen surrounding the teratoma. Neuroepithelial structures of some teratomas cultured for 8 weeks had cells with a granular nucleus as a sign of obvious apoptosis. Eleven to 12 weeks after implantation the growth of the teratoma had stopped, and the histology corresponded to that of a mature cystic teratoma. GFAP, SOX9 and type IV collagen were strongly positive in some parts of the tumours cultured for 4 and 8 weeks, while only occasional c-kit-positive areas were observed in tumours cultured for 8 weeks. As conclusions: (1) the metastasizing capacity of the experimental testicular teratoma is very low during 12 weeks, but the behaviour of the tumour in the testicular tissue of the graft is invasive; (2) the growth of experimental testicular teratomas cease 6-8 weeks after implantation of the fetal gonadal ridges with the obvious apoptosis of the immature tissue components; (3) the model of experimental testicular teratoma in the mouse is suitable for studying how the teratoma affects the host testis and how the host testis reacts to teratoma

Probing the Links between Political Economy and Non-Traditional Security: Themes, Approaches, and Instruments

This is a pre-print of an article published in International Politics. The definitive publisher-authenticated version of: Hameiri, Shahar, and Lee Jones. "Probing the links between political economy and non-traditional security: Themes, approaches and instruments." International Politics (2015), is available online at: http://dx.doi.org/10.1057/ip.2015.1In recent decades, the security agenda for states and international organisations has expanded dramatically to include a range of ‘non-traditional’, transnational security issues. It is often suggested that globalisation has been a key driver for the emergence or intensification of these problems, but, surprisingly, little sustained scholarly effort has been made to examine the link between responses to the new security agenda and the changing political economy. This curious neglect largely reflects the mutual blind-spots of the sub-disciplines of International Security Studies and International Political Economy, coupled with the dominance of approaches that tend to neglect economic factors. This special issue, which this article introduces, aims to overcome this significant gap. In particular, it focuses on three key themes: the broad relationship between security and the political economy; what is being secured in the name of security, and how this has changed; and how things are being secured – what modes of governance have emerged to manage security problems. In all of these areas, the contributions point to the crucial role of the state in translating shifting state-economy relations to new security definitions and practices

Synergism between particle-based multiplexing and microfluidics technologies may bring diagnostics closer to the patient

In the field of medical diagnostics there is a growing need for inexpensive, accurate, and quick high-throughput assays. On the one hand, recent progress in microfluidics technologies is expected to strongly support the development of miniaturized analytical devices, which will speed up (bio)analytical assays. On the other hand, a higher throughput can be obtained by the simultaneous screening of one sample for multiple targets (multiplexing) by means of encoded particle-based assays. Multiplexing at the macro level is now common in research labs and is expected to become part of clinical diagnostics. This review aims to debate on the “added value” we can expect from (bio)analysis with particles in microfluidic devices. Technologies to (a) decode, (b) analyze, and (c) manipulate the particles are described. Special emphasis is placed on the challenges of integrating currently existing detection platforms for encoded microparticles into microdevices and on promising microtechnologies that could be used to down-scale the detection units in order to obtain compact miniaturized particle-based multiplexing platforms

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta