Scanning Thermal Microscopy and Ballistic Phonon Transport in Lateral Spin Valves

Using scanning thermal microscopy, we have mapped the spatial distribution of temperatures in an operating nanoscale device formed from a magnetic injector, an Ag connecting wire, and a magnetic detector. An analytical model explained the thermal diffusion over the measured temperature range (2-300 K) and injector-detector separation (400-3000 nm). The characteristic diffusion lengths of the Peltier and Joule heat differ remarkably below 60 K, a fact that can be explained by the onset of ballistic phonon heat transfer in the substrate.

Reversible spin storage in metal oxide-fullerene heterojunctions

We show that hybrid MnO_x/C₆₀ heterojunctions can be used to design a storage device for spin-polarized charge: a spin capacitor. Hybridization at the carbon-metal oxide interface leads to spin-polarized charge trapping after an applied voltage or photocurrent. Strong electronic structure changes, including a 1-eV energy shift and spin polarization in the C₆₀ lowest unoccupied molecular orbital, are then revealed by x-ray absorption spectroscopy, in agreement with density functional theory simulations. Muon spin spectroscopy measurements give further independent evidence of local spin ordering and magnetic moments optically/electronically stored at the heterojunctions. These spin-polarized states dissipate when shorting the electrodes. The spin storage decay time is controlled by magnetic ordering at the interface, leading to coherence times of seconds to hours even at room temperature.

Developing a national database for metastatic colorectal cancer management: perspectives and challenges

BACKGROUND

The changing treatment landscape for metastatic colorectal cancer creates multiple potential treatment strategies. An Australian-centric database capturing comprehensive information across a range of treatment locations would create a valuable resource enabling multiple important research questions to be addressed.

AIMS

To establish a collection of a consensus dataset capturing treatment and outcomes at multiple public and private hospitals across Australia.

METHODS

An electronic database was developed by a panel of clinicians, to capture an agreed dataset for patients with newly diagnosed metastatic colorectal cancer. Of particular interest were clinician decision-making, the impact of comorbidities and the frequency of major adverse events.

RESULTS

Since July 2009, data collection has been established at six public and eight private hospitals across three Australian states and territories. Successful linkage and analysis, with support from BioGrid Australia, of selected data on the initial 864 patients demonstrates that data can be captured from diverse sites, including public and private practice, that multiple factors impact on treatment delivered and outcomes achieved and that comprehensive data on rare but important adverse events can be captured. As a clinical research tool, the project has been highly successful, generating multiple presentations at national and international conferences related to a diverse range of research questions.

CONCLUSIONS

Multistate, project-specific data collection involving large numbers of patients is achievable. Providing invaluable insight into the routine clinical management of metastatic colorectal cancer in the era of targeted therapies, this also creates a significant resource for research, including many questions not being addressed by clinical trials.

Biomarkers of genotoxicity of urban air pollution. Overview and descriptive data from a molecular epidemiology study on populations exposed to moderate-to-low levels of polycyclic aromatic hydrocarbons: the AULIS project

Epidemiologic studies indicate that prolonged exposure to high pollution levels is associated with increased risk of cancer, especially lung cancer. However, under conditions of moderate or low air pollution, epidemiologic evidence does not permit reliable conclusions. Biomarker-based population studies may serve as complementary tools providing a better understanding of the relative contribution of ambient atmospheric pollution to the overall genotoxic burden suffered by city dwellers. However, past efforts to apply biomarkers to studies of low levels exposure to urban air pollution have given inconclusive results, partly because of the absence of adequate data on personal exposure, covering a time-window which is appropriate for the biomarkers being examined, as well as a battery of biomarkers reflecting different stages of the carcinogenic process. In the present paper, the potential of biomarker-based population studies to aid the assessment of the genotoxic and carcinogenic effects of urban air pollution is reviewed by reference to the achievements and limitations of earlier reported studies. The design and methodology adopted in a recently completed large-scale population study, carried out in the context of the European Union Environment and Climate Programme, known by the short name of AULIS project, is discussed and descriptive statistics of the main findings of the project are presented. These findings indicate that for cohorts suffering moderate-to-low exposures to airborne particulate-bound polycyclic aromatic hydrocarbons (PAHs), no simple correlation with biomarkers of genotoxicity existed and suggest that additional factors made a significant contribution to the overall genotoxic burden.

Cytogenetic analysis in peripheral lymphocytes of cancer patients treated with cytostatic drugs: results from an EC Collaborative Study

Many of the cytostatic drugs commonly used in cancer chemotherapy treatments have been shown to be genotoxic in vivo and in vitro. We present a cytogenetic collaborative study on 13 cancer patients treated with different antitumor agents. For comparison we also carried out a cytogenetic analysis on 14 healthy untreated controls. The frequency of sister chromatid exchanges and structural chromosome aberrations in peripheral blood lymphocytes of the cancer patients was determined prior to the treatment, just after it and 3-7 weeks later. The results obtained show clear differences between the basal levels of cytogenetic alterations in cancer patients, even though the mean value is higher in this group than the basal levels of the group of healthy individuals. Treatment with cytostatics increases the frequency of both cytogenetic biomarkers analyzed, which declined to values similar to those initially observed several weeks after the treatment. Our data are in qualitative and quantitative agreement with other results previously found by other authors.