32 research outputs found
Towards self-powered and autonomous wearable glucose sensor
Blood glucose diagnostic systems are a world-wide
success story. Nevertheless, all the painless solutions available
are too expensive to be disposable. We aim to bridge this gap by
developing a painless disposable diabetes diagnostic patch. Our
envisaged device is fully integrated and autonomous: harvests the
required energy from the environment and features sensor autocalibration in real-time. In this paper, we present the design
and preliminary results of the different parts in the wearable
patch: electrochemical glucose sensor developed on scalable PCB
technology, biofuel cell based on glucose in the biofluid sample,
and instrumentation electronics designed on a PCB with energy
and data management blocks
Competitive Interactions between Invasive Nile Tilapia and Native Fish: The Potential for Altered Trophic Exchange and Modification of Food Webs
Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus), in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus). Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass) was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes) will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important
Investigating the molecular mechanisms of fraction size sensitivity in irradiated cells
Fractionated radiotherapy is used clinically when it spares healthy tissue relative to the cancer; the healthy tissue is described as more fraction size sensitive. However, a molecular understanding of the mechanisms that determine this sensitivity are limited. The recently demonstrated response of breast and prostate cancers to hypofractionation highlights the need to understand the mechanisms of fraction size sensitivity in order to improve dose regimens. We must also develop biomarkers and drugs that leverage this sensitivity to individualise and improve radiotherapy outcomes. DNA double-strand breaks (DSB) are the most deleterious form of damage caused by irradiation due to their potential for misrepair. The cell cycle stage influences the availability of DSB repair pathways. There is a tight inverse association between fraction size sensitivity and proliferation rate. We hypothesise that the enhanced fidelity of Homologous Recombination (HR) repair in S/G2 phase decreases fraction size sensitivity through a reduction of misrepair. Using a non-cancerous repair-proficient fibroblast model, we show that fraction size sensitivity is comparable across all cell cycle phases by clonogenic survival. Chromosome aberration analyses are consistent with survival and suggest that mis-repair events in G1 and G2 phase cells are spared by fractionation. We conclude that the availability of HR in G2 does not impact fraction size sensitivity. Using y-H2AX foci as a surrogate for DSBs we show that induction and kinetics of repair do not alter between fractions, however after complete repair persistent foci are shown to increase with dose and are spared with fractionation, suggesting a role for unrepaired DSBs. The chromatin environment can impact repair pathway choice, we demonstrate through global changes to chromatin state with histone deacetylase inhibition (HDAC) and CRISPR-Cas9 guided BRG1 mutations that these changes do not impact fraction size sensitivity. Finally, a single cell sequencing approach begins to establish a mutational signature for irradiation
Towards self-powered and autonomous wearable glucose sensor
Blood glucose diagnostic systems are a world-wide success story. Nevertheless, all the painless solutions available are too expensive to be disposable. We aim to bridge this gap by developing a painless disposable diabetes diagnostic patch. Our envisaged device is fully integrated and autonomous. It harvests the required energy from the environment and features sensor auto-calibration in real-time. In this paper, we present the design and preliminary results of the different parts in the patch including an electrochemical glucose sensor, an enzymatic biofuel cell, and a wireless instrumentation electronics all designed and implemented on the printed circuit board (PCB) technology
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Independent verification of reprocessing input and process volumes. Progress report
One of the most difficult challenges in the nuclear fuel cycle is to establish a material balance for tanks containing spent fuel solutions. These tanks present an extremely hostile environment to the analyst, making determination of the amount of fissile material in them difficult. Historic methods used to determine the volumes of solutions in these tanks are usually based on use of tank geometry in conjunction with depth and density measurements, both of which vary with temperature and are normally controlled by the operator of the facility. Changes in the interior geometry of tanks due to addition of various types of equipment, minor structural modifications, and accumulation of insoluble materials at the bottom and on the interior surfaces of the tanks affect the available volume and make difficult its accurate measurement. For safeguards purposes, it is thus desirable to have a repeatable method of volume determination independent of the operator and other factors. To determine the quantity of uranium and plutonium in a given tank, aliquots are withdrawn and subjected to analysis; both isotopic abundances and the amount of each element present are determined. Isotope dilution mass spectrometry is the method of choice for quantitative measurements in this application and yields values more precise and accurate than other methods. In the research that is the focus of this project, the application of isotope dilution mass spectrometry has been extended, through use of a double lutetium spike, to the determination of the volume (or weight) of the solution in tanks of any size and shape, regardless of the nature of the solutions within them. The goal of the work described in this report was to develop hot-cell compatible chemical separation procedures for lutetium and to try to devise a better method for quantitatively introducing natural lutetium to the tank