Fabrication of nano-gap electrode arrays by the construction and selective chemical etching of nano-crosswire stacks

Methods of fabricating nano-gap electrode structures in array configurations, and the structures so produced. The fabrication method involves depositing first and second pluralities of electrodes comprising nanowires using processes such as lithography, deposition of metals, lift-off processes, and chemical etching that can be performed using conventional processing tools applicable to electronic materials processing. The gap spacing in the nano-gap electrode array is defined by the thickness of a sacrificial spacer layer that is deposited between the first and second pluralities of electrodes. The sacrificial spacer layer is removed by etching, thereby leaving a structure in which the distance between pairs of electrodes is substantially equal to the thickness of the sacrificial spacer layer. Electrode arrays with gaps measured in units of nanometers are produced. In one embodiment, the first and second pluralities of electrodes are aligned in mutually orthogonal orientations

Developing long-term monitoring of natural areas for a Unesco world heritage site: study case of la Reunion

La Réunion island, in the Mascarenes, has been recognized as a World Heritage site for its Piton, Cirques and Remparts since 2010. The site, coinciding with the core zone of La Réunion National Park, represents 100000 ha, equivalent to 40 % of the island. These dramatic landscapes of rugged terrain, impressive escarpments, forested gorges are dominated by three cliff-rimmed cirques and two volcanoes ― a dormant massif forming the highest peak, Piton des Neiges (3069 m), and in the eastern part of the island lies the very active volcano, the Piton de la Fournaise (2632 m). The island harbours a wide variety of natural habitats (tropical montane cloud forests, subalpine shrublands, lowland forests, dry forest…), now all remnant in the Mascarene archipelago, that host high levels of endemism for both flora and fauna. Thereby, La Réunion is the most significant contributor towards conservation of terrestrial biodiversity in the Mascarene islands. The Divines project (FEDER) aims at developing innovative methods for characterizing and monitoring terrestrial biodiversity in the long term for conservation managers to ensure the protection of this world heritage site. In this poster, a description of the goals, actions and preliminary results of the DIVINES project will be described from gene to ecosystem levels

GaN-based sensor nodes for in situ detection of gases

A system for detecting chemical/biological substances and a detection method. The system comprises a plurality of sensing units or nodes and a radiofrequency link. Each unit has several sensors with different sensing curves. Each sensor is able to transmit information related to the sensed substance on a specific frequency. The sensors preferably comprise AlGaN/GaN high electron mobility transistors

Arrays of Nano Tunnel Junctions as Infrared Image Sensors

Infrared image sensors based on high density rectangular planar arrays of nano tunnel junctions have been proposed. These sensors would differ fundamentally from prior infrared sensors based, variously, on bolometry or conventional semiconductor photodetection. Infrared image sensors based on conventional semiconductor photodetection must typically be cooled to cryogenic temperatures to reduce noise to acceptably low levels. Some bolometer-type infrared sensors can be operated at room temperature, but they exhibit low detectivities and long response times, which limit their utility. The proposed infrared image sensors could be operated at room temperature without incurring excessive noise, and would exhibit high detectivities and short response times. Other advantages would include low power demand, high resolution, and tailorability of spectral response. Neither bolometers nor conventional semiconductor photodetectors, the basic detector units as proposed would partly resemble rectennas. Nanometer-scale tunnel junctions would be created by crossing of nanowires with quantum-mechanical-barrier layers in the form of thin layers of electrically insulating material between them (see figure). A microscopic dipole antenna sized and shaped to respond maximally in the infrared wavelength range that one seeks to detect would be formed integrally with the nanowires at each junction. An incident signal in that wavelength range would become coupled into the antenna and, through the antenna, to the junction. At the junction, the flow of electrons between the crossing wires would be dominated by quantum-mechanical tunneling rather than thermionic emission. Relative to thermionic emission, quantum mechanical tunneling is a fast process

High-Sensitivity GaN Microchemical Sensors

Systematic studies have been performed on the sensitivity of GaN HEMT (high electron mobility transistor) sensors using various gate electrode designs and operational parameters. The results here show that a higher sensitivity can be achieved with a larger W/L ratio (W = gate width, L = gate length) at a given D (D = source-drain distance), and multi-finger gate electrodes offer a higher sensitivity than a one-finger gate electrode. In terms of operating conditions, sensor sensitivity is strongly dependent on transconductance of the sensor. The highest sensitivity can be achieved at the gate voltage where the slope of the transconductance curve is the largest. This work provides critical information about how the gate electrode of a GaN HEMT, which has been identified as the most sensitive among GaN microsensors, needs to be designed, and what operation parameters should be used for high sensitivity detection

Weight change and 15 year mortality: results from the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) cohort study.

Studies have reported a higher mortality risk associated with weight loss, particularly in middle-aged and older adults, although some of these studies did find that gaining weight was also associated with an increased mortality risk. We examined changes in weight in relation to mortality in a prospective population-based cohort study of men and women, resident in Norfolk, UK. Participants were assessed at baseline (1993-1997) and at a second examination (1998-2000), as part of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) study, and followed up to 2015 for mortality. Participants with a self-reported history of cancer or cardiovascular disease, body mass index  5 kg. Similar associations were observed after excluding deaths in the first 5 years of follow-up. Results for weight gain were inconclusive. We conclude that objectively measured weight loss, but not weight gain, was associated with subsequent higher mortality risk in this population-based study of middle-aged and elderly men and women. However, undiagnosed, pre-existing disease and the inability to account for weight cycling need to be remembered when interpreting these results. Unravelling the causal pathways underlying this association will require more detailed studies, including that of changes in body composition

Prospective associations and population impact of sweet beverage intake and type 2 diabetes, and effects of substitutions with alternative beverages.

AIMS/HYPOTHESIS: This study aimed to evaluate the association of types of sugar-sweetened beverages (SSB) (soft drinks, sweetened-milk beverages, sweetened tea/coffee), artificially sweetened beverages (ASB) and fruit juice with incident type 2 diabetes and determine the effects of substituting non-SSB for SSB and the population-attributable fraction of type 2 diabetes due to total sweet beverages. METHODS: Beverage consumption of 25,639 UK-resident adults without diabetes at baseline (1993-1997) in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk study was assessed using 7-day food diaries. During 10.8 years of follow-up 847 incident type 2 diabetes cases were verified. RESULTS: In adjusted Cox regression analyses there were positive associations (HR [95% CI] per serving/day]) for soft drinks 1.21 (1.05, 1.39), sweetened-milk beverages 1.22 (1.05, 1.43) and ASB 1.22 (1.11, 1.33), but not for sweetened tea/coffee 0.98 (0.94, 1.02) or fruit juice 1.01 (0.88, 1.15). Further adjustment for adiposity attenuated the association of ASB, HR 1.06 (0.93, 1.20). There was a positive dose-response relationship with total sweet beverages: HR per 5% energy 1.18 (1.11, 1.26). Substituting ASB for any SSB did not reduce the incidence in analyses accounting for energy intake and adiposity. Substituting one serving/day of water or unsweetened tea/coffee for soft drinks and for sweetened-milk beverages reduced the incidence by 14%-25%. If sweet beverage consumers reduced intake to below 2% energy, 15% of incident diabetes might be prevented. CONCLUSIONS/INTERPRETATION: The consumption of soft drinks, sweetened-milk beverages and energy from total sweet beverages was associated with higher type 2 diabetes risk independently of adiposity. Water or unsweetened tea/coffee appear to be suitable alternatives to SSB for diabetes prevention. These findings support the implementation of population-based interventions to reduce SSB consumption and increase the consumption of suitable alternatives.This work was supported by programme grants from the Medical Research Council (MRC) UK and Cancer Research UK. We acknowledge support from the MRC Epidemiology Unit (grant number MC_UU_12015/5).This is the final published version. It first appeared at http://link.springer.com/article/10.1007%2Fs00125-015-3572-1

Cod liver oil supplement consumption and health: cross-sectional results from the EPIC-Norfolk cohort study.

Supplement users (SU) make healthy lifestyle choices; on the other hand, SU report more medical conditions. We hypothesised that cod liver oil (CLO) consumers are similar to non-supplement users, since CLO use might originate from historical motives, i.e., rickets prevention, and not health consciousness. CLO consumers were studied in order to identify possible confounders, such as confounding by indication. The European Prospective Investigation into Cancer (EPIC) investigates causes of chronic disease. The participants were 25,639 men and women, aged 40-79 years, recruited from general practices in Norfolk, East-Anglia (UK). Participants completed questionnaires and a health examination between 1993 and 1998. Supplement use was measured using 7-day diet diaries. CLO was the most common supplement used, more prevalent among women and associated with not smoking, higher physical activity level and more favourable eating habits. SU had a higher occurrence of benign growths and bone-related diseases, but CLO was negatively associated with cardiovascular-related conditions. Although the results of SU characteristics in EPIC-Norfolk are comparable with studies worldwide, the CLO group is different from SU in general. Confounding by indication takes place and will need to be taken into account when analysing prospective associations of CLO use with fracture risk and cardiovascular diseases.The EPIC-Norfolk study received grants from the Medical Research Council (G9502233) and Cancer Research UK (SP2024-0201 and SP2024-0204).This is the final published version. It's also available from MDPI at http://www.mdpi.com/2072-6643/6/10/4320