Use of QuEChERS as a manual and automated high-throughput protocol for investigating environmental matrices

Environmental pollution has strong links to adverse human health outcomes with risks of pollution through production, use, ineffective wastewater (WW) remediation, and/or leachate from landfill. 'Fit-for-purpose' monitoring approaches are critical for better pollution control and mitigation of harm, with current sample preparation methods for complex environmental matrices typically time-consuming and labour intensive, unsuitable for high-throughput screening. This study has shown that a modified 'Quick Easy Cheap Effective Rugged and Safe' (QuEChERS) sample preparation is a viable alternative for selected environmental matrices required for pollution monitoring (e.g. WW effluent, treated sludge cake and homogenised biota tissue). As a manual approach, reduced extraction times (hours to ∼20 min/sample) with largely reproducible (albeit lower) recoveries of a range of pharmaceuticals and biocidal surfactants have been reported. Its application has shown clear differentiation of matrices via chemometrics, and the measurement of pollutants of interest to the UK WW industry at concentrations significantly above suggested instrument detection limits (IDL) for sludge, indicating insufficient removal and/or bioaccumulation during WW treatment. Furthermore, new pollutant candidates of emerging concern were identified - these included detergents, polymers and pharmaceuticals, with quaternary ammonium compound (QAC) biocides observed at 2.3-70.4 mg/kg, and above levels associated with priority substances for environmental quality regulation (EQSD). Finally, the QuEChERS protocol was adapted to function as a fully automated workflow, further reducing the resource to complete both the preparation and analysis to 62%), and when applied to a largely un-investigated clay matrix, acceptable recovery (88.0-131.1%) and precision (≤10.3% RSD) for the tested pharmaceuticals and biocides was maintained. Therefore, this preliminary study has shown the successful application of a high-throughput QuEChERS protocol across a range of environmental solids for potential deployment in a regulated laboratory

High sensitivity terahertz detector using two-dimensional electron gas absorber and tunnel junction contacts as a thermometer

We describe a new type of terahertz (THz) detector for astronomical observation using a two-dimensional electron gas (2DEG) as the absorbing medium. The detection principle is based on the hot electron effect in 2DEGs. Electrons are heated by THz radiation and the electron temperature is read out by two symmetrical superconductor - 2DEG tunnelling junctions. Hot electrons are removed via tunnelling through a barrier into the superconducting contacts. The energy gap in the superconducting contacts prevents the escape of the colder, non-photoexcited electrons from the 2DEG. The high mobility 2DEG itself is created within AlGaAs/GaAs heterostructure with a single quantum well. In this paper we present low temperature DC measurements of 2DEG detectors, and measurements of the electron-phonon thermal conductivity of a 2DEG at 4.2 K and 300 mK as a function of electron temperature and magnetic field (in the 4.2 K case). From these measurements we estimate the noise equivalent power (NEP) of an element in a filled array of S-2DEG-S detectors at 4.2 K to be on the order of ≈ 10-14W/√Hz with a response time of ≈ 1ns; at 300 mK, an NEP on the order of ≈ 10-19W/√Hz and a response time of ≈ 0.1μs. Using measured parameters for the normal resistance of the S-2DEG-S contacts, we calculate the effect of using a voltage bias to cool the electrons in the absorber to significantly below a 300 mK base temperature. In this configuration, S-2DEG-S detectors can achieve sufficient sensitivity to detect individual THz photons

Integrated cellular and plasma proteomics of contrasting B-cell cancers reveals common, unique and systemic signatures

Approximately 800,000 leukaemia and lymphoma cases are diagnosed worldwide each year. Burkitt's lymphoma (BL) and chronic lymphocytic leukaemia (CLL), are examples of contrasting B-cell cancers; BL is a highly aggressive lymphoid tumour, frequently affecting children, whilst CLL typically presents as an indolent, slow-progressing leukaemia affecting the elderly. The B-cell-specific over-expression of the myc and tcl1 oncogenes in mice induce spontaneous malignancies modelling BL and CLL, respectively. Quantitative mass spectrometry proteomics and isobaric labelling were employed to examine the biology underpinning contrasting E?-myc and E?-TCL1 B-cell tumours. Additionally, the plasma proteome was evaluated using sub-proteome enrichment to interrogate biomarker emergence and the systemic effects of tumour burden. Over 10,000 proteins were identified (q<0.01) of which 8270 cellular and 2095 plasma proteins were quantitatively profiled. A common B-cell tumour signature of 695 over-expressed proteins highlighted ribosome biogenesis, cell-cycle promotion and chromosome segregation. E?-myc tumours over-expressed several methylating enzymes and under-expressed many cytoskeletal components. E?-TCL1 tumours specifically over-expressed ER stress response proteins and signalling components in addition to both subunits of the interleukin-5 (IL5) receptor. IL5 treatment promoted E?-TCL1 tumour proliferation, suggesting an amplification of IL5-induced AKT signalling by TCL1. Tumour plasma contained a substantial tumour lysis signature, most prominent in E?-myc plasma, whilst E?-TCL1 plasma contained signatures of immune-response, inflammation and microenvironment interactions, with putative biomarkers in early-stage cancer. These findings provide a detailed characterisation of contrasting B-cell tumour models, identifying common and specific tumour mechanisms. Integrated plasma proteomics allowed the dissection of a systemic response and a tumour lysis signature present in early- and late-stage cancers, respectively. Overall, this study suggests common B-cell cancer signatures exist and illustrates the potential of the further evaluation of B-cell cancer subtypes by integrative proteomics

Implications of sand extraction on the Lough Neagh and Lough Beg SPA and Ramsar site

APEM Scientific report for Northern Ireland Environment Agency

Integrated cellular and plasma proteomics of contrasting B-cell cancers reveals common, unique and systemic signatures

Approximately 800,000 leukemia and lymphoma cases are diagnosed worldwide each year. Burkitt's lymphoma (BL) and chronic lymphocytic leukemia (CLL) are examples of contrasting B-cell cancers; BL is a highly aggressive lymphoid tumor, frequently affecting children, whereas CLL typically presents as an indolent, slow-progressing leukemia affecting the elderly. The B-cell-specific overexpression of the myc and TCL1 oncogenes in mice induce spontaneous malignancies modeling BL and CLL, respectively. Quantitative mass spectrometry proteomics and isobaric labeling were employed to examine the biology underpinning contrasting Eμ-myc and Eμ-TCL1 B-cell tumors. Additionally, the plasma proteome was evaluated using subproteome enrichment to interrogate biomarker emergence and the systemic effects of tumor burden. Over 10,000 proteins were identified (q<0.01) of which 8270 cellular and 2095 plasma proteins were quantitatively profiled. A common B-cell tumor signature of 695 overexpressed proteins highlighted ribosome biogenesis, cell-cycle promotion and chromosome segregation. Eμ-myc tumors overexpressed several methylating enzymes and underexpressed many cytoskeletal components. Eμ-TCL1 tumors specifically overexpressed ER stress response proteins and signaling components in addition to both subunits of the interleukin-5 (IL5) receptor. IL5 treatment promoted Eμ-TCL1 tumor proliferation, suggesting an amplification of IL5-induced AKT signaling by TCL1. Tumor plasma contained a substantial tumor lysis signature, most prominent in Eμ-myc plasma, whereas Eμ-TCL1 plasma contained signatures of immune-response, inflammation and microenvironment interactions, with putative biomarkers in early-stage cancer. These findings provide a detailed characterization of contrasting B-cell tumor models, identifying common and specific tumor mechanisms. Integrated plasma proteomics allowed the dissection of a systemic response and a tumor lysis signature present in early- and late-stage cancers, respectively. Overall, this study suggests common B-cell cancer signatures exist and illustrates the potential of the further evaluation of B-cell cancer subtypes by integrative proteomics

Water-gated organic nanowire transistors

We gated both p-type, and n-type, organic nanowire (NW) films with an aqueous electric double layer (EDL) in thin-film transistor (TFT) architectures. For p-type NWs, we used poly(3-hexylthiophene) (P3HT) NWs grown via two different routes. Both can be gated with water, resulting in TFTs with threshold lower than for conventionally cast P3HT films under the same gating conditions. However, TFT drain currents are lower for NWs than for conventional P3HT films, which agrees with similar observations for ‘dry’ gated TFTs. For n-type NWs, we have grown ‘nanobelts’ of poly(benzimidazobenzophenanthroline) (BBL) by a solvent/non-solvent mixing route with later displacement of the solvent, and dispersion in a non-solvent. Water-gating such films initially failed to give an observable drain current. However, BBL nanobelts can be gated with the aprotic solvent acetonitrile, giving high n-type drain currents, which are further increased by adding salt. Remarkably, after first gating BBL NW films with acetonitrile, they can then be gated by water, giving very high drain currents. This behaviour is transient on a timescale of minutes. We believe this observation is caused by a thin protective acetonitrile film remaining on the nanobelt surface