Improving Plasmonic Photothermal Therapy of Lung Cancer Cells with Anti-EGFR Targeted Gold Nanorods

Lung cancer is a particularly difficult form of cancer to diagnose and treat, due largely to the inaccessibility of tumours and the limited available treatment options. The development of plasmonic gold nanoparticles has led to their potential use in a large range of disciplines, and they have shown promise for applications in this area. The ability to functionalise these nanoparticles to target to specific cancer types, when combined with minimally invasive therapies such as photothermal therapy, could improve long-term outcomes for lung cancer patients. Conventionally, continuous wave lasers are used to generate bulk heating enhanced by gold nanorods that have accumulated in the target region. However, there are potential negative side-effects of heat-induced cell death, such as the risk of damage to healthy tissue due to heat conducting to the surrounding environment, and the development of heat and drug resistance. In this study, the use of pulsed lasers for photothermal therapy was investigated and compared with continuous wave lasers for gold nanorods with a surface plasmon resonance at 850 nm, which were functionalised with anti-EGFR antibodies. Photothermal therapy was performed with both laser systems, on lung cancer cells (A549) in vitro populations incubated with untargeted and targeted nanorods. It was shown that the combination of pulse wave laser illumination of targeted nanoparticles produced a reduction of 93%±13% in the cell viability compared with control exposures, which demonstrates a possible application for minimally invasive therapies for lung cancer

Impurity-free seeded crystallization of amorphous silicon by nanoindentation

We demonstrate that nanoindents formed in amorphous Si films, with dimensions as small as ∼20 nm, provide a means to seed solid phase crystallization. During post-indentation annealing at ∼600 °C, solid phase crystallization initiates from the indented sites, effectively removing the incubation time for random nucleation in the absence of seeds. The seeded crystallization is studied by optical microscopy, cross-sectional transmission electron microscopy, and electrical characterization via Hall measurements. Full crystallization can be achieved, with improved electrical characteristics attributed to the improved microstructure, using a lower thermal budget. The process is metal contaminant free and allows for selective area crystallization.The authors gratefully acknowledge financial support from the Australian Research Council and the Natural Sciences and Engineering Research Council of Canada

Electrical conduction of silicon oxide containing silicon quantum dots

Current-voltage measurements have been made at room temperature on a Si-rich silicon oxide film deposited via Electron-Cyclotron Resonance Plasma Enhanced Chemical Vapor Deposition (ECR-PECVD) and annealed at 750 - 1000$^\circ$C. The thickness of oxide between Si quantum dots embedded in the film increases with the increase of annealing temperature. This leads to the decrease of current density as the annealing temperature is increased. Assuming the Fowler-Nordheim tunneling mechanism in large electric fields, we obtain an effective barrier height $\phi_{eff}$ of $\sim$ 0.7 $\pm$ 0.1 eV for an electron tunnelling through an oxide layer between Si quantum dots. The Frenkel-Poole effect can also be used to adequately explain the electrical conduction of the film under the influence of large electric fields. We suggest that at room temperature Si quantum dots can be regarded as traps that capture and emit electrons by means of tunneling.Comment: 14 pages, 5 figures, submitted to J. Phys. Conden. Mat

Modifications of Gait as Predictors of Natural Osteoarthritis Progression in STR/Ort Mice

OBJECTIVE: Osteoarthritis (OA) is a common chronic disease for which disease-modifying therapies are not currently available. Studies to seek new targets for slowing the progress of OA rely on mouse models, but these do not allow for longitudinal monitoring of disease development. This study was undertaken to determine whether gait can be used to measure disease severity in the STR/Ort mouse model of spontaneous OA and whether gait changes are related to OA joint pain. METHODS: Gait was monitored using a treadmill-based video system. Correlations between OA severity and gait at 3 treadmill speeds were assessed in STR/Ort mice. Gait and pain behaviors of STR/Ort mice and control CBA mice were analyzed longitudinally, with monthly assessments. RESULTS: The best speed to identify paw area changes associated with OA severity in STR/Ort mice was found to be 17 cm · seconds(−1). Paw area was modified with age in CBA and STR/Ort mice, but this began earlier in STR/Ort mice and correlated with the onset of OA at 20 weeks of age. In addition, task noncompliance appeared at 20 weeks. Surprisingly, STR/Ort mice did not show any signs of pain with OA development, even when treated with the opioid antagonist naloxone, but did exhibit normal pain behaviors in response to complete Freund's adjuvant–induced arthritis. CONCLUSION: The present results identify an animal model in which OA severity and OA pain can be studied in isolation from one another. The findings suggest that paw area and treadmill noncompliance may be useful tools to longitudinally monitor nonpainful OA development in STR/Ort mice. This will help in providing a noninvasive means of assessing new therapies to slow the progression of OA

Why does early childhood deprivation increase the risk for depression and anxiety in adulthood? A developmental cascade model

Abstract Background: Using data from the English & Romanian Adoptees (ERA) study we recently reported that early time-lmited exposure to severe institutional deprivation is associated with early onset and persistent neurodevelopmental problems and later onset emotional problems. Here we examine possible reasons for the late emergence of emotional problems in this cohort. Our main focus is on testing a developmental cascade mediated via the functional impact of early-appearing neurodevelopmental problems on late adolescent functioning. We also explore a second putative pathway via sensitization to stress. Methods: The ERA study includes 165 Romanian individuals who spent their early lives in grossly depriving institutions and were subsequently adopted into UK families, along with 52 UK adoptees with no history of deprivation. Age six years symptoms of neurodevelopmental problems and age 15 anxiety/depression symptoms were assessed via parental reports. Young adult symptoms of depression and anxiety were assessed by both parent and self-reports; young adults also completed measures of stress reactivity , exposure to adverse life events and functioning in work and interpersonal relationships. Results: The path between early institutional deprivation and adult emotional problems was mediated via the impact of early neurodevelopmental problems on unemployment and poor friendship functioning during the transition to adulthood. The findings with regard to early deprivation, later life stress reactivity and emotional problems were inconclusive. Conclusions: Our analysis suggests that the risk for adult depression and anxiety following extreme institutional deprivation is explained through the effects of early neurodevelopmental problems on later social and vocational functioning. Future research should more fully examine the role of stress susceptibility in this model

Effect of catalyst layer defects on local membrane degradation in polymer electrolyte fuel cells

© 2016 Elsevier B.V. All rights reserved. Aiming at durability issues of fuel cells, this research is dedicated to a novel experimental approach in the analysis of local membrane degradation phenomena in polymer electrolyte fuel cells, shedding light on the potential effects of manufacturing imperfections on this process. With a comprehensive review on historical failure analysis data from field operated fuel cells, local sources of iron oxide contaminants, catalyst layer cracks, and catalyst layer delamination are considered as potential candidates for initiating or accelerating the local membrane degradation phenomena. Customized membrane electrode assemblies with artificial defects are designed, fabricated, and subjected to membrane accelerated stress tests followed by extensive post-mortem analysis. The results reveal a significant accelerating effect of iron oxide contamination on the global chemical degradation of the membrane, but dismiss local traces of iron oxide as a potential stressor for local membrane degradation. Anode and cathode catalyst layer cracks are observed to have negligible impact on the membrane degradation phenomena. Notably however, distinct evidence is found that anode catalyst layer delamination can accelerate local membrane thinning, while cathode delamination has no apparent effect. Moreover, a substantial mitigating effect for platinum residuals on the site of delamination is observed

Epibionts provide their basibionts with associational resistance to predation but at a cost

Epibiosis is increasingly considered a survival strategy in space-limited environments. However, epibionts can create a new interface between its host, environment and potential predators which may alter predator-prey relationships and biological functioning. Ex-situ experiments investigated the potential costs and benefits of epibiont barnacles on mortality and feeding rate of the mussel, Mytilus edulis, and its predator, the whelk Nucella lapillus. Mussels with living epibiont barnacles suffered no mortality from whelk predation, but when barnacles were absent, mortality was ∼21% over 48 days. Further comparisons revealed the structural complexity of barnacles provided mussels with protection from whelk predation, while the presence of living barnacles increased predator-prey encounters but led to predators targeting barnacles over mussels. Feeding trials revealed feeding rate increased by ∼24% in mussels with living epibionts over mussels with dead or without epibionts, indicating potential costs of hosting epibionts. Our results show that epibionts provide important associational resistance for mussels against whelk predation but a potential cost to the mussel of hosting epibionts requiring increased energy acquisition. These findings advance our understanding of associational resistance derived from epibionts and serve to highlight the potential trade-offs affecting basibiont functioning while showing the importance of positive ecological interactions in ecosystem structure and functioning