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Biochemical functionalization of surfaces is an increasingly utilized mechanism to promote or inhibit adhesion of cells. To promote mammalian cell adhesion, one common functionalization approach is surface conjugation of adhesion peptide sequences such as Arg-Gly-Asp (RGD), a ligand of transmembrane integrin molecules. It is generally assumed that such functionalization does not alter the local mechanical properties of the functionalized surface, as is important to interpretations of macromolecular mechanotransduction in cells. Here, we examine this assumption systematically, through nanomechanical measurement of the nominal elastic modulus of polymer multilayer films of nanoscale thickness, functionalized with RGD through different processing routes. We find that the method of biochemical functionalization can significantly alter mechanical compliance of polymeric substrata such as weak polyelectrolyte multilayers (PEMs), increasingly utilized materials for such studies. In particular, immersed adsorption of intermediate functionalization reagents significantly decreases compliance of the PEMs considered herein, whereas polymer-on-polymer stamping of these same reagents does not alter compliance of weak PEMs. This finding points to the potential unintended alteration of mechanical properties via surface functionalization and also suggests functionalization methods by which chemical and mechanical properties of cell substrata can be controlled independently.

BACKGROUND: Many patients with advanced malignant dysphagia are not suitable for definitive treatment. The best option for palliation of dysphagia varies between patients. This paper looks at a simple technique for enhancing laser recanalisation. AIM: To assess the value of adjunctive brachytherapy in prolonging palliation of malignant dysphagia by endoscopic laser therapy. PATIENTS: Twenty two patients with advanced malignant dysphagia due to adenocarcinoma of the oesophagus or gastric cardia, unsuitable for surgery or radical chemoradiotherapy. METHODS: Patients able to eat a soft diet after laser recanalisation were randomised to no further therapy or a single treatment with brachytherapy (10 Gy). Results were judged on the quality and duration of dysphagia palliation, need for subsequent intervention, complications, and survival. RESULTS: The median dysphagia score for all patients two weeks after initial treatment was 1 (some solids). The median dysphagia palliated interval from the end of initial treatment to recurrent dysphagia or death increased from five weeks (control group) to 19 weeks (brachytherapy group). Three patients had some odynophagia for up to six weeks after brachytherapy. There was no other treatment related morbidity or mortality. Further intervention was required in 10 of 11 control patients (median five further procedures) compared with 7/11 brachytherapy patients (median two further procedures). There was no difference in survival (median 20 weeks (control), 26 weeks (brachytherapy)). CONCLUSIONS: Laser therapy followed by brachytherapy is a safe, straightforward, and effective option for palliating advanced malignant dysphagia, which is complementary to stent insertion.

Cancers of the upper aerodigestive tract, collectively known as head and neck cancers, arise from a multiplicity of sites. In the West, excess tobacco and alcohol consumption are the most important of the known predisposing factors; elsewhere in the world, notably in India and China, the aetiology, pattern of primary sites, and clinical behaviour are different. Clinically these tumours pose exceptional problems in management, and skilled multidisciplinary teams are necessary in order to achieve the highest level of service and research. Historically, surgery and radiotherapy have been the most important treatment modalities; chemotherapy is now increasingly employed but not yet fully established. Successful rehabilitation of patients with head and neck cancers requires access to high quality speech therapists and other support staff with training in functional pharyngeal disorders. Current research efforts are largely directed towards defining the proper role of chemotherapy and assessing the possible advantage of unconventional radiation approaches. In recent years the roles of primary, reconstructive, and salvage surgery have also become better defined. Many patients are suitable for randomisation into ongoing prospective clinical trials which have been specifically designed to address these issues.

A hybrid propulsion system for torpedo propulsion applications was developed. The hybrid system utilizes a solid oxide fuel cell (SOFC) to provide low power propulsion and hotel loads supplemented by a high power turbine for high speed pursuit, with both systems using common fuel and oxidant sources. A solid LiClO4 oxidant source was investigated. Individual subsystems including the SOFC stack and LiClO4 oxidant source were physically tested. Trade studies were performed comparing various fuel, oxidant, low power, and high power sources, based on testing performance of the subsystems. The SOFC low power system was demonstrated to provide the longest low power range while maintaining the necessary high power reserve for target pursuit.