Novel organic semiconductors for light-emitting diodes

The intriguing properties of organic semiconductors in various optoelectronic applications, ranging from molecular wires for integrated circuits, to organic photovoltaics (OPV), organic transistors (OFET) and organic light-emitting diodes (OLEDs) have motivated the work presented in this thesis. More precisely, this thesis focuses on narrow energy gap materials, suitable for OLEDs emitting in the red and near-infrared (NIR) regions. Conjugated materials emitting at low energies face great challenges to have efficient light emission. This thesis proposes two very interesting and novel strategies to cope with the limiting factors of efficient light-emission from conjugated compounds. // Firstly, a series of porphyrin oligomers is presented. With emission ranging from red to pure NIR, three architectures of these oligomers were studied. Zinc oligomers at various length that allowed for fine tuning of the emission, five hexamers with different coordinating metals at the centre of each unit, allowing for phosphorescence emission, and a pentamer, with single acetylene instead of butadiyne bonds connecting porphyrin units, resulting in a shorter oligomer with an extended pi-conjugation and a bathochromic shift of the emission. Two limitations can be identified for efficient NIR emission, the so-called ``energy-gap law’’ and aggregation quenching. Both limitations are addressed, resulting in unprecedented external quantum efficiencies when the oligomers are used in OLEDs and remarkable devices lifetimes, considering the non-optimised diodes. // Secondly, three diketopyrrolopyrrole-based copolymers are presented and their photophysical properties discussed. These polymers represent a different strategy to prevent aggregation; by engineering covalent bonds, the conjugated core is sheathed within its cyclic sidechains. The strategy is proven highly successful and the three polymers are compared with their unprotected counterparts, where emission is severely quenched. The advantages of the encapsulation are more pronounced when the polymers are incorporated in OLEDs, where the encapsulated ones achieved up to 16 times higher external quantum efficiencies compared to the unprotected ones

Status of DMRadio-50L and DMRadio-m3^3

Recent theoretical advancements have made the QCD axion a stronger dark matter candidate, especially in the sub-$\mu\text{eV}$ range. While cavity haloscopes have made significant progress in excluding QCD axions in the $1 - 100\ \mu\text{eV}$ region, the $1 \text{ peV} - 1\ \mu\text{eV}$ region remains unexplored. The DMRadio program consists of a series of experiments designed to probe low mass axions. DMRadio-50L uses a 1 T average field toroidal magnet and a high-Q LC-oscillator with target sensitivity to axions of $g_{a\gamma\gamma} <5\times10^{-15}\text{ GeV}^{-1}$ between 5 kHz and 5 MHz. DMRadio-m$^3$ consists of a higher frequency LC-oscillator in a 4 T peak field solenoidal magnet with sensitivity to the DFSZ model of QCD axions between 30 MHz and 200 MHz. In this work, we present the status of DMRadio-50L and DMRadio-m$^3$.Comment: 8 pages, 2 figures. v2: minor edits following reviewer comment

Free microvascular tissue transfer for the reconstruction of midfacial defects in oncological patients

This study reviews our experience with free microvascular tissue transfer for the repair of midfacial defects in surgical oncology. From 2000 to 2008, eight patients with maxillectomy defects were immediately reconstructed using free flaps. Their clinical charts were retrospectively reviewed to record demographic data, ablative and reconstructive procedures, complications and outcome. Free tissue transfer was successful in all patients, giving an overall success rate of 100%. The mean follow-up time was 4 to 101 months (mr: 43.8). Three patients died from the disease giving a patient mortality of 30%, while five patients are alive, free of disease and back to their normal daily activities. The restoration of function and improvement of patients? quality of life was a common feature in all our reconstructions. The development of free tissue transfer has made surgical treatment of oncological patients with maxillectomy defects previously considered inoperable possible, improving at the same time their quality of life

Immunotherapy of Head and Neck Cancer: Current and Future Considerations

Patients with head and neck squamous cell carcinoma (HNSCC) are at considerable risk for death, with 5-year relative survival rates of approximately 60%. The profound multifaceted deficiencies in cell-mediated immunity that persist in most patients after treatment may be related to the high rates of treatment failure and second primary malignancies. Radiotherapy and chemoradiotherapy commonly have severe acute and long-term side effects on immune responses. The development of immunotherapies reflects growing awareness that certain immune system deficiencies specific to HNSCC and some other cancers may contribute to the poor long-term outcomes. Systemic cell-mediated immunotherapy is intended to activate the entire immune system and mount a systemic and/or locoregional antitumor response. The delivery of cytokines, either by single cytokines, for example, interleukin-2, interleukin-12, interferon-γ, interferon-α, or by a biologic mix of multiple cytokines, such as IRX-2, may result in tumor rejection and durable immune responses. Targeted immunotherapy makes use of monoclonal antibodies or vaccines. All immunotherapies for HNSCC except cetuximab remain investigational, but a number of agents whose efficacy and tolerability are promising have entered phase 2 or phase 3 development

KM3NeT:a large underwater neutrino telescope in the Mediterranean Sea

High energy neutrinos produced in astrophysical processes will allow for a new way of studying the universe. In order to detect the expected flux of high energy neutrinos from specific astrophysical sources, neutrino telescopes of a scale of a km^3 of water will be needed. A Northern Hemisphere detector is being proposed to be sited in a deep area of the Mediterranean Sea. This detector will provide complimentary sky coverage to the IceCube detector being built at the South Pole. The three neutrino telescope projects in the Mediterranean (ANTARES, NEMO and NESTOR) are partners in an effort to design, and build such a km^3 size neutrino telescope, the KM3NeT. The EU is funding a 3-year Design Study; the status of the Design Study is presented and some technical issues are discussed.Comment: 4 pages, 3 figures, Prepared for the 10th International Conference on Astroparticle and Underground Physics (TAUP 2007), Sendai, Japan, 11-15 Sep 200

Infected lingual osseous choristoma : report of a case and review of the literature

Osseous choristoma is a rare, benign lesion of the oral cavity occurring usually in the tongue. It appears as a tumorous mass of normal bony structure with mature cells in an ectopic position. The case of a 72 years Caucasian male is presented and analyzed along with 52 similar cases reported in the English literature between 1967 and 2007. Lingual choristoma shows a female predilection, whereas the commonest anatomic location is the posterior third of the tongue, occurring at or close to the foramen caecum and the circumvallate papillae. Histologically the lesions show signs of a well-circumscribed mass of vital bone located under the surface oral epithelium. Some lesions represent developmental malformations, whereas others may be reactive lesions after trauma or chronic irritation. Treatment of lingual osseous choristoma consists of simple excision