Small angle neutron scattering (SANS) and TEM studies of the internal porosity of three cultured diatom frustules.

Diatoms are microscopic algae that produce intricate silica cell walls, called frustules. These structures have well-defined pore classes that characterise the species of diatom. In this way a particular species is able to produce porous silica containing several highly monodisperse pore sizes. The ability to culture relatively large amounts of diatom frustules supports the investigation of pore size distribution in bulk samples with a small angle scattering technique. In this work, we compare SANS scattering curves for three species of diatoms with internal porosity visualised from frustule sections examined under TEM. We comment on the relative merits of each approach for determining the internal porosity of diatom frustules.The Royal Swedish Academy of Sciences through its Nobel Institute for Physics, and its Nobel Institute for Chemistry; The Swedish Research Council; Chalmers University of Technology; Goteborg University; International Union of Pure and Applied Physics (IUPAP); International Union of Pure and Applied Biophysics (IUPAB

Photoluminescence and cathodoluminescence studies of diatoms - nature’s own nano-porous silica structures.

Photoluminescence (PL) and cathodoluminescence (CL) data are presented for the silica frustules of some fresh water diatoms. The diatom frustules consist of a nano-porous silica structure that may possibly be exploited for optoelectronic or photonic applications. This work represents what we believe to be the first report of the CL and PL properties of this naturally occurring source of nano-porous silica.Australian and New Zealand Institutes of Physic

Environmental and effluent monitoring at ANSTO sites, 2002-2003.

This report presents the results of environmental and effluent monitoring at the Lucas Heights Science and Technology Centre (LHSTC) and the National Medical Cyclotron (NMC) from January 2002 to June 2003. Potential effective dose rates to the general public from airborne discharges from the LHSTC site were less than 0.01 mSv/year, well below the 1 mSv/year dose rate limit for long term exposure that is recommended by the Australian National Occupational Health and Safety Commission. The effective dose rates to hypothetical individuals potentially exposed to radiation in routine liquid effluent discharges from the LHSTC were recently calculated to be less than 0.001 mSv/year. This is much less than dose rates estimated for members of public potentially exposed to airborne emissions. The levels of tritium detected in groundwater and stormwater at the LHSTC were less than the Australian drinking water guidelines. The airborne and liquid effluent emissions from the NMC were below the ARPANSA-approved notification levels and NSW EPA limits, respectively. ANSTO's routine operations at the LHSTC and the NMC make only a very small addition to the natural background radiation dose experienced by members of the Australian public

Environmental and effluent monitoring at ANSTO sites, 2006-2007.

This report presents the results of ANSTO’s environmental and effluent monitoring at the Lucas Heights Science and Technology Centre (LHSTC) and the National Medical Cyclotron (NMC) sites, from July 2006 to June 2007. Estimated effective doses to the members of the public potentially affected by routine airborne emissions from the LHSTC were lower than in previous years due to the closure of the HIFAR research reactor. The maximum potential off-site dose of 0.002 mSv/year was 10% of the As Low As Reasonably Achievable (ALARA) objective of 0.02 mSv/year, and much lower than the public dose limit of 1 mSv/year that is recommended by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). The effective doses to the critical group potentially exposed to routine liquid effluent releases from the LHSTC have been realistically assessed at less than 25% of the estimated doses to the critical group for airborne releases. Based on releases of liquid effluent from the LHSTC during 2006-07, a radiological risk assessment was conducted for marine biota in the receiving environment at Potter Point. The possible dose-rates to various species of marine biota were evaluated against international criteria recommended for the protection of biota from radiological hazards. In all cases it was concluded that the radiological risk to marine biota from ANSTO’s effluent releases was negligible. The median tritium concentrations detected in groundwater and surface waters at the LHSTC were typically less than 2% of those set out in the Australian Drinking Water Guidelines. The airborne emissions from the NMC were below the ARPANSA-approved notification levels. Results of environmental monitoring at both ANSTO sites confirm that the facilities continue to be operated well within regulatory limits. ANSTO’s routine operations at the LHSTC and NMC make only a very small addition to the natural background radiation dose of approximately 1.5 mSv/year experienced by members of the Australian public

Environmental and effluent monitoring at ANSTO sites: 2003-2004.

This report presents the results of ANSTO's environmental and effluent monitoring at the Lucas Heights Science and Technology Centre (LHSTC) and the National Medical Cyclotron (NMC) sites, from July 2003 to June 2004. Effective doses to the critical group of members of the public potentially affected by routine airborne emissions from the LHSTC were less than 0.004 mSv/year. This estimated maximum potential dose is less than 20% of the ANSTO ALARA objective of 0.02 mSv/year and much lower than the public dose limit of 1 mSv/year that is recommended by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). The effective doses to the critical group of members of the public potentially exposed to routine liquid effluent releases from the LHSTC have been realistically estimated as a quarter (or less) of the estimated doses to the critical group for airborne releases. The levels of tritium detected in groundwater and stormwater at the LHSTC were less than the Australian Drinking Water Guidelines. The airborne and liquid effluent emissions from the NMC were below the ARPANSA-approved notification levels and NSW Department of Environment and Conservation limits, respectively. Results of environmental monitoring at both ANSTO sites confirm that the facilities continue to be operated well within regulatory limits. Members of the public are exposed to only very small doses of radiation from ANSTO's routine airborne and liquid effluent releases

Environmental and effluent monitoring at ANSTO sites, 2005-2006.

This report presents the results of ANSTO's environmental and effluent monitoring at Lucas Heights Science and Technology Centre (LHSTC) and the National Medical Cyclotron (NMC) sites, from July 2005 to June 2006. Estimated effective doses to the critical group of members of the public potentially affected by routine airborne emissions from the LHSTC were less that 0.005 mSv/year. The maximum potential dose was 23% of the ANSTO ALARA objective of 0.02 mSv/year, much lower than the public dose limit of 1mSv/year that is recommended by the Australian Radiation Protection and Nuclear Safety Authority (ARPANSA). The effective doses to the critical groups of members of the public potentially exposed to routine liquid effluent releases from the LHSTC have been realistically estimated as a quarter (or less) of the estimated doses to the critical group for airborne releases. The medium tritium concentrations detected in groundwater and surface waters at the LHSTC were typically less than 2% of those set out in the Australian Drinking Water Guidelines. The airborne emissions from the NMC were below the ARPANSA-approved notification levels. Results of environmental monitoring at both ANSTO sites confirm that the facilities continue to be operated well within regulatory limits. ANSTO's routine operations at the LHSTC and NMC make only a very small addition to the natural background radiation dose of ~1.5 mSv/year experienced by members of the Australian public

Environmental and effluent monitoring at ANSTO sites, 2004-2005.

This report presents the results of ANSTO's environmental and effluent monitoring at the Lucas Heights Science and Technology Centre (LHSTC) and the National Medical Cyclotron (NMC) sites, from July 2004 to June 2005. Effective doses to the critical group of members of the public potentially affected by routine airborne emissions from the LHSTC were less than 0.005 mSv/year. This estimated maximum potential dose is less than 24% of the ANSTO ALARA objective of 0.02 mSv/year, and much lower than the public dose limit of 1 mSv/year that is recommended by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). The effective doses to the critical group of members of the public potentially exposed to routine liquid effluent releases from the LHSTC have been realistically estimated as a quarter (or less) of the estimated doses to the critical group for airborne releases. The levels of tritium detected in groundwater and stormwater at the LHSTC were less than those set out in the Australian Drinking Water Guidelines. The airborne and liquid effluent emissions from the NMC were below both the ARPANSA-approved notification levels and Sydney Water limits for acceptance of trade wastewater to sewer. Results of environmental monitoring at both ANSTO sites confirm that the facilities continue to be operated well within regulatory limits. ANSTO's routine operations at the LHSTC and NMC make only a very small addition to the natural background radiation dose of ~1.5 mSv/year experienced by members of the Australian public

Quantifying metabolic heterogeneity in head and neck tumors in real time: 2-DG uptake is highest in hypoxic tumor regions

Purpose: Intratumoral metabolic heterogeneity may increase the likelihood of treatment failure due to the presence of a subset of resistant tumor cells. Using a head and neck squamous cell carcinoma (HNSCC) xenograft model and a real-time fluorescence imaging approach, we tested the hypothesis that tumors are metabolically heterogeneous, and that tumor hypoxia alters patterns of glucose uptake within the tumor. Experimental Design: Cal33 cells were grown as xenograft tumors (n = 16) in nude mice after identification of this cell line's metabolic response to hypoxia. Tumor uptake of fluorescent markers identifying hypoxia, glucose import, or vascularity was imaged simultaneously using fluorescent molecular tomography. The variability of intratumoral 2-deoxyglucose (IR800-2-DG) concentration was used to assess tumor metabolic heterogeneity, which was further investigated using immunohistochemistry for expression of key metabolic enzymes. HNSCC tumors in patients were assessed for intratumoral variability of 18F-fluorodeoxyglucose (18F-FDG) uptake in clinical PET scans. Results: IR800-2-DG uptake in hypoxic regions of Cal33 tumors was 2.04 times higher compared to the whole tumor (p = 0.0001). IR800-2-DG uptake in tumors containing hypoxic regions was more heterogeneous as compared to tumors lacking a hypoxic signal. Immunohistochemistry staining for HIF-1α, carbonic anhydrase 9, and ATP synthase subunit 5β confirmed xenograft metabolic heterogeneity. We detected heterogeneous 18F-FDG uptake within patient HNSCC tumors, and the degree of heterogeneity varied amongst tumors. Conclusion: Hypoxia is associated with increased intratumoral metabolic heterogeneity. 18F-FDG PET scans may be used to stratify patients according to the metabolic heterogeneity within their tumors, which could be an indicator of prognosis. © 2014 Nakajima et al

Obesity Is A Modifier of Autonomic Cardiac Responses to Fine Metal Particulates

Background: Increasing evidence suggests that obesity may impart greater susceptibility to adverse effects of air pollution. Particulate matter, especially PM$_{2.5}$ (particulate matter with aero-dynamic diameter ≤2.5 μm), is associated with increased cardiac events and reduction of heart rate variability (HRV).Objectives Our goal was to investigate whether particle-mediated autonomic modulation is aggravated in obese individuals.Methods We examined PM$_{2.5}$-mediated acute effects on HRV and heart rate (HR) using 10 24-hr and 13 48-hr ambulatory electrocardiogram recordings collected from 18 boilermakers (39.5 ± 9.1 years of age) exposed to high levels of metal particulates. Average HR and 5-min HRV [SDNN: standard deviation of normal-to-normal intervals (NN); rMSSD: square-root of mean squared-differences of successive NN intervals; HF: high-frequency power 0.15–0.4 Hz] and personal PM$_{2.5}$ exposures were continuously monitored. Subjects with body mass index ≥ 30 kg/m$^2$ were classified as obese. Mixed-effect models were used for statistical analyses. Results: Half (50%) of the study subjects were obese. After adjustment for confounders, each 1-mg/m$^3$ increase in 4-hr moving average PM$_{2.5}$ was associated with HR increase of 5.9 bpm [95% confidence interval (CI), 4.2 to 7.7] and with 5-min HRV reduction by 6.5% (95% CI, 1.9 to 11.3%) for SDNN, 1.7% (95% CI, –4.9 to 8.4%) for rMSSD, and 8.8% (95% CI, –3.8 to 21.3%) for HF. Obese individuals had greater PM$_{2.5}$-mediated HRV reductions (2- to 3-fold differences) than nonobese individuals, and had more PM$_{2.5}$-mediated HR increases (9-bpm vs. 4-bpm increase in HR for each 1-mg/m$^3$ increase in PM$_{2.5}$; p < 0.001). Conclusions: Our study revealed greater autonomic cardiac responses to metal particulates in obese workers, supporting the hypothesis that obesity may impart greater susceptibility to acute cardiovascular effects of fine particles