Fabrication of high temperature surface acoustic wave devices for sensor applications

Surface acoustic devices have been shown to be suitable not only for signal processing but also for sensor applications. In this paper high temperature surface acoustic wave devices based on gallium orthophosphate have been fabricated, using a lift-off technique and tested for high frequency applications at temperatures up to 600 ºC. The measured S-parameter (S11) has been used to study the mass loading effect of the platinum electrodes and turnover temperature of GaPO4 with a 5? cut. The analysis of these results shows that the mass loading effect can be used to predict the desired resonant frequency of the SAW devices. Also two different adhesion layers for Pt metallisation were studied. Our results show that Zirconium is a more suitable under layer than Titanium

Modeling viral coevolution: HIV multi-clonal persistence and competition dynamics

The coexistence of different viral strains (quasispecies) within the same host are nowadays observed for a growing number of viruses, most notably HIV, Marburg and Ebola, but the conditions for the formation and survival of new strains have not yet been understood. We present a model of HIV quasispecies competition, that describes the conditions of viral quasispecies coexistence under different immune system conditions. Our model incorporates both T and B cells responses, and we show that the role of B cells is important and additive to that of T cells. Simulations of coinfection (simultaneous infection) and superinfection (delayed secondary infection) scenarios in the early stages (days) and in the late stages of the infection (years) are in agreement with emerging molecular biology findings. The immune response induces a competition among similar phenotypes, leading to differentiation (quasi-speciation), escape dynamics and complex oscillations of viral strain abundance. We found that the quasispecies dynamics after superinfection or coinfection has time scales of several months and becomes even slower when the immune system response is weak. Our model represents a general framework to study the speed and distribution of HIV quasispecies during disease progression, vaccination and therapy.Comment: 20 pages, 10 figure

The nonlinear time-dependent response of isotactic polypropylene

Tensile creep tests, tensile relaxation tests and a tensile test with a constant rate of strain are performed on injection-molded isotactic polypropylene at room temperature in the vicinity of the yield point. A constitutive model is derived for the time-dependent behavior of semi-crystalline polymers. A polymer is treated as an equivalent network of chains bridged by permanent junctions. The network is modelled as an ensemble of passive meso-regions (with affine nodes) and active meso-domains (where junctions slip with respect to their positions in the bulk medium with various rates). The distribution of activation energies for sliding in active meso-regions is described by a random energy model. Adjustable parameters in the stress--strain relations are found by fitting experimental data. It is demonstrated that the concentration of active meso-domains monotonically grows with strain, whereas the average potential energy for sliding of junctions and the standard deviation of activation energies suffer substantial drops at the yield point. With reference to the concept of dual population of crystalline lamellae, these changes in material parameters are attributed to transition from breakage of subsidiary (thin) lamellae in the sub-yield region to fragmentation of primary (thick) lamellae in the post-yield region of deformation.Comment: 29 pages, 12 figure

655MO Quality of life in patients with p16+ oropharyngeal cancer receiving accelerated radiotherapy (RT) with either cisplatin or cetuximab in NRG/RTOG 1016

Background: This phase 3 randomized non-inferiority de-escalation trial compared cetuximab (cetux) vs cisplatin (cis), concurrent with accelerated RT 70 Gy/6 weeks, in p16+ oropharyngeal cancer (OPC). Quality of life (QOL) was an important secondary endpoint. Methods: EORTC QLQ-C30/HN35 was completed at baseline, end of treatment, 3, 6, and 12 months post. The substudy aimed for 400 eligible patients. We report completion rates and compare by arm for change from baseline in each domain (0.05 two-sided alpha and MID of 10 points) using linear mixed models. Results: Consent was 91% (381/419 offered substudy); 6 protocol deviations excluded (n=375). No significant differences in patient/tumor characteristics were found by participation status. Completion rates (%) at the 5 times did not differ by arm (cis/cetux): 92/94, 74/77, 76/81, 76/81, and 73/74. The swallowing domain of HN35 (previously reported) did not differ significantly by arm. No significant difference was seen by arm for the 6-mo change from baseline on any domain. At end of RT (only), dry mouth was significantly worse for RT+cetux. At end of treatment, all domains showed statistically and clinically significant mean worsening across both arms except Emotional Functioning, Dyspnea, Diarrhea, and Teeth. Most domains returned within 10 points of baseline by 6 mo, with the following maintaining significant impairment: Senses (taste/smell), Social Eating, Opening Mouth, Dry Mouth, Sticky Saliva. At 12 mo post-treatment, worsening from baseline persisted for Senses, Dry Mouth, Sticky Saliva, and Weight Gain. Pain Killer use improved significantly from baseline to 3, 6, and 12 mo. Conclusions: Although replacing RT+cis with RT+cetux did not benefit QOL, this study has confirmed the responsiveness of EORTC QLQ-C30/HN35 to the effects of concurrent systemic/RT for OPC. Dry Mouth, Sticky Saliva, and Senses showed large, significant, and persistent impairments, and remain worthwhile targets for future de-escalation efforts. Domains related to eating (Swallowing, Appetite, Nutritional Supplements, Social Eating, Weight Loss) did not show sustained significant impairment on this instrument in this study. Clinical trial identification: NCT01302834

Human Metapneumovirus Glycoprotein G Inhibits Innate Immune Responses

Human metapneumovirus (hMPV) is a leading cause of acute respiratory tract infection in infants, as well as in the elderly and immunocompromised patients. No effective treatment or vaccine for hMPV is currently available. A recombinant hMPV lacking the G protein (rhMPV-ΔG) was recently developed as a potential vaccine candidate and shown to be attenuated in the respiratory tract of a rodent model of infection. The mechanism of its attenuation, as well as the role of G protein in modulation of hMPV-induced cellular responses in vitro, as well as in vivo, is currently unknown. In this study, we found that rhMPV-ΔG-infected airway epithelial cells produced higher levels of chemokines and type I interferon (IFN) compared to cells infected with rhMPV-WT. Infection of airway epithelial cells with rhMPV-ΔG enhanced activation of transcription factors belonging to the nuclear factor (NF)-κB and interferon regulatory factor (IRF) families, as revealed by increased nuclear translocation and/or phosphorylation of these transcription factors. Compared to rhMPV-WT, rhMPV-ΔG also increased IRF- and NF-κB-dependent gene transcription, which was reversely inhibited by G protein expression. Since RNA helicases have been shown to play a fundamental role in initiating viral-induced cellular signaling, we investigated whether retinoic induced gene (RIG)-I was the target of G protein inhibitory activity. We found that indeed G protein associated with RIG-I and inhibited RIG-I-dependent gene transcription, identifying an important mechanism by which hMPV affects innate immune responses. This is the first study investigating the role of hMPV G protein in cellular signaling and identifies G as an important virulence factor, as it inhibits the production of important immune and antiviral mediators by targeting RIG-I, a major intracellular viral RNA sensor