Synthesis of radio frequency plasma polymerized non-synthetic Terpinen-4-ol thin films

Recent advancements in the area of organic polymer applications demand novel and advanced materials with desirable surface, optical and electrical properties to employ in emerging technologies. This study examines the fabrication and characterization of polymer thin films from non-synthetic Terpinen-4-ol monomer using radio frequency plasma polymerization. The optical properties, thickness and roughness of the thin films were studied in the wavelength range 200–1000 nm using ellipsometry. The polymer thin films of thickness from 100 nm to 1000 nm were fabricated and the films exhibited smooth and defect-free surfaces. At 500 nm wavelength, the refractive index and extinction coefficient were found to be 1.55 and 0.0007 respectively. The energy gap was estimated to be 2.67 eV, the value falling into the semiconducting Eg region. The obtained optical and surface properties of Terpinen-4-ol based films substantiate their candidacy as a promising low-cost material with potential applications in electronics, optics, and biomedical industries.

Intracellular effects of atmospheric-pressure plasmas on melanoma cancer cells

Gas discharge plasmas formed at atmospheric pressure and near room temperature have recently been shown as a promising tool for cancer treatment. The mechanism of the plasma action is attributed to generation of reactive oxygen and nitrogen species, electric fields, charges, and photons. The relative importance of different modes of action of atmospheric-pressure plasmas depends on the process parameters and specific treatment objects. Hence, an in-depth understanding of biological mechanisms that underpin plasma-induced death in cancer cells is required to optimise plasma processing conditions. Here, the intracellular factors involved in the observed anti-cancer activity in melanoma Mel007 cells are studied, focusing on the effect of the plasma treatment dose on the expression of tumour suppressor protein TP73. Over-expression of TP73 causes cell growth arrest and/or apoptosis, and hence can potentially be targeted to enhance killing efficacy and selectivity of the plasma treatment. It is shown that the plasma treatment induces dose-dependent up-regulation of TP73 gene expression, resulting in significantly elevated levels of TP73 RNA and protein in plasma-treated melanoma cells. Silencing of TP73 expression by means of RNA interference inhibited the anticancer effects of the plasma, similar to the effect of caspase inhibitor z-VAD or ROS scavenger N-acetyl cysteine. These results confirm the role of TP73 protein in dose-dependent regulation of anticancer activity of atmospheric-pressure plasmas.

Pro-apoptotic NOXA is implicated in atmospheric-pressure plasma-induced melanoma cell death

Atmospheric-pressure plasma (APP) has been successfully used to treat several types of cancers in vivo and in vitro, with the effect being primarily attributed to the generation of reactive oxygen species (ROS). However, the mechanisms by which APP induces apoptosis in cancer cells require further elucidation. In this study, the effects of APP on the expression of 500 genes in melanoma Mel007 cancer cells were examined. Pro-apoptotic phorbol-12-myristate-13-acetate-induced protein (PMAIP1), also known as NOXA, was highly expressed as a result of APP treatment in a dose-dependent manner. Blocking of ROS using scavenger NAC or silencing of NOXA gene by RNA interference inhibited the APP-induced NOXA genes upregulation and impaired caspases 3/7 mediated apoptosis, confirming the important role plasma-generated ROS species and pro-apoptotic NOXA play in APP-induced cancer cell death.

Changes in atmospheric concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls between the 1990s and 2010s in an Australian city and the role of bushfires as a source

Over recent decades, efforts have been made to reduce human exposure to atmospheric pollutants including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) through emission control and abatement. Along with the potential changes in their concentrations resulting from these efforts, profiles of emission sources may have also changed over such extended timeframes. However relevant data are quite limited in the Southern Hemisphere. We revisited two sampling sites in an Australian city, where the concentration data in 1994/5 for atmospheric PAHs and PCBs were available. Monthly air samples from July 2013 to June 2014 at the two sites were collected and analysed for these compounds, using similar protocols to the original study. A prominent seasonal pattern was observed for PAHs with elevated concentrations in cooler months whereas PCB levels showed little seasonal variation. Compared to two decades ago, atmospheric concentrations of ∑13 PAHs (gaseous + particle-associated) in this city have decreased by approximately one order of magnitude and the apparent halving time ( t 1 / 2 ) was estimated as 6.2 ± 0.56 years. ∑6 iPCBs concentrations (median value; gaseous + particle-associated) have decreased by 80% with an estimated t 1 / 2 of 11 ± 2.9 years. These trends and values are similar to those reported for comparable sites in the Northern Hemisphere. To characterise emission source profiles, samples were also collected from a bushfire event and within a vehicular tunnel. Emissions from bushfires are suggested to be an important contributor to the current atmospheric concentrations of PAHs in this city. This contribution is more important in cooler months, i.e. June, July and August, and its importance may have increased over the last two decades.

Re-imagining public journalism for community radio news-gathering

This paper explores the use of public journalism within a community radio news context. It argues that, the central tenets of the public journalism movement can help to frame, more adequately, a news gathering and production approach Tailored to the needs of community media. . Community radio stations generally enjoy strong relationships with their listeners and play an important role in the formation of the community itself (Lowrey et al., 2008). This paper argues that such strong community ties, in conjunction with public journalism news gathering approaches give community radio stations a strong opportunity to produce relevant, local news sourced driven by their listeners. In this regard ,this paper examines a particular case of public journalism used within the The Wire, a national, daily current affairs program broadcast on community radio. In the case study examined here ,public journalism informed story production that were designed to better meet the needs of community radio stations and their audiences.