65 research outputs found

    Further Dimensions for Sensing in Biofluids: Distinguishing Bioorganic Analytes by the Salt-Induced Adaptation of a Cucurbit[7]uril-Based Chemosensor

    Get PDF
    Insufficient binding selectivity of chemosensors often renders biorelevant metabolites indistinguishable by the widely used indicator displacement assay. Array-based chemosensing methods are a common workaround but require additional effort for synthesizing a chemosensor library and setting up a sensing array. Moreover, it can be very challenging to tune the inherent binding preference of macrocyclic systems such as cucurbit[n]urils (CBn) by synthetic means. Using a novel cucurbit[7]uril-dye conjugate that undergoes salt-induced adaptation, we now succeeded in distinguishing 14 bioorganic analytes from each other through the facile stepwise addition of salts. The salt-specific concentration-resolved emission provides additional information about the system at a low synthetic effort. We present a data-driven approach to translate the human-visible curve differences into intuitive pairwise difference measures. Ion mobility experiments combined with density functional theory calculations gave further insights into the binding mechanism and uncovered an unprecedented ternary complex geometry for CB7. TThis work introduces the non-selectively binding, salt-adaptive cucurbit[n]uril system for sensing applications in biofluids such as urine, saliva, and blood serum

    A non-invasive approach to monitor chronic lymphocytic leukemia engraftment in a xenograft mouse model using ultra-small superparamagnetic iron oxide-magnetic resonance imaging (USPIO-MRI).

    Get PDF
    This work was supported by: Associazione Italiana Ricerca sul Cancro (AIRC) [Grant 5 x mille n.9980, (to M.F., F.M. and A. N.)]; AIRC I.G. [n. 14,326 (to M.F.)], [n.10136 and 16,722 (A.N.)], [n.15426 (to F.F.)]. AIRC and Fondazione CaRiCal co-financed Multi Unit Regional Grant 2014 [n.16695 (to F.M.)]. Italian Ministry of Health 5 × 1000 funds (to F.F). A.G R. was supported by Associazione Italiana contro le Leucemie-Linfomi-Mielomi (AIL) Cosenza - Fondazione Amelia Scorza (FAS). S.M. C.M., F.V., L. E., S. B., were supported by AIRC.Peer reviewedPostprin

    Chemical and dynamical identification of emission outflows during the HALO campaign EMeRGe in Europe and Asia

    Get PDF
    The number of large urban agglomerations is steadily increasing worldwide. At a local scale, their emissions lead to air pollution, directly affecting people\u27s health. On a global scale, their emissions lead to an increase of greenhouse gases, affecting climate. In this context, in 2017 and 2018, the airborne campaign EMeRGe (Effect of Megacities on the transport and transformation of pollutants on the Regional to Global scales) investigated emissions of European and Asian major population centres (MPCs) to improve the understanding and predictability of pollution outflows. Here, we present two methods to identify and characterise pollution outflows probed during EMeRGe. First, we use a set of volatile organic compounds (VOCs) as chemical tracers to characterise air masses by specific source signals, i.e. benzene from anthropogenic pollution of targeted regions, acetonitrile from biomass burning (BB, primarily during EMeRGe-Asia), and isoprene from fresh biogenic signals (primarily during EMeRGe-Europe. Second, we attribute probed air masses to source regions and estimate their individual contribution by constructing and applying a simple emission uptake scheme for the boundary layer which combines FLEXTRA back trajectories and EDGAR carbon monoxide (CO) emission rates (acronyms are provided in the Appendix). During EMeRGe-Europe, we identified anthropogenic pollution outflows from northern Italy, southern Great Britain, the Belgium–Netherlands–Ruhr (BNR) area and the Iberian Peninsula. Additionally, our uptake scheme indicates significant long-range transport of pollution from the USA and Canada. During EMeRGe-Asia, the pollution outflow is dominated by sources in China and Taiwan, but BB signals from Southeast Asia and India contribute as well. Outflows of pre-selected MPC targets are identified in less than 20 % of the sampling time, due to restrictions in flight planning and constraints of the measurement platform itself. Still, EMeRGe combines in a unique way near- and far-field measurements, which show signatures of local and distant sources, transport and conversion fingerprints, and complex air mass compositions. Our approach provides a valuable classification and characterisation of the EMeRGe dataset, e.g. for BB and anthropogenic influence of potential source regions and paves the way for a more comprehensive analysis and various model studies

    Impact of the South Asian monsoon outflow on atmospheric hydroperoxides in the upper troposphere

    Get PDF
    During the OMO (Oxidation Mechanism Observation) mission, trace gas measurements were performed on board the HALO (High Altitude Long Range) research aircraft in summer 2015 in order to investigate the outflow of the South Asian summer monsoon and its influence on the composition of the Asian monsoon anticyclone (AMA) in the upper troposphere over the eastern Mediterranean and the Arabian Peninsula. This study focuses on in situ observations of hydrogen peroxide (H2_{2}O2_{2}obs^{obs}) and organic hydroperoxides (ROOHobs^{obs}) as well as their precursors and loss processes. Observations are compared to photostationary-state (PSS) calculations of H2_{2}O2_{2}PSS^{PSS} and extended by a separation of ROOHobs^{obs} into methyl hydroperoxide (MHPPSS^{PSS}) and inferred unidentified hydroperoxide (UHPPSS^{PSS}) mixing ratios using PSS calculations. Measurements are also contrasted to simulations with the general circulation ECHAM–MESSy for Atmospheric Chemistry (EMAC) model. We observed enhanced mixing ratios of H2_{2}O2_{2}obs^{obs} (45 %), MHPPSS^{PSS} (9 %), and UHPPSS (136 %) in the AMA relative to the northern hemispheric background. Highest concentrations for H2_{2}O2_{2}obs^{obs} and MHPPSS^{PSS} of 211 and 152 ppbV_{V}, respectively, were found in the tropics outside the AMA, while for UHPPSS^{PSS}, with 208 pptV_{V}, highest concentrations were found within the AMA. In general, the observed concentrations are higher than steady-state calculations and EMAC simulations by a factor of 3 and 2, respectively. Especially in the AMA, EMAC underestimates the H2_{2}O2_{2}EMAC^{EMAC} (medians: 71 pptV_{V} vs. 164 pptV_{V}) and ROOHEMAC (medians: 25 pptV_{V} vs. 278 pptV_{V}) mixing ratios. Longitudinal gradients indicate a pool of hydroperoxides towards the center of the AMA, most likely associated with upwind convection over India. This indicates main contributions of atmospheric transport to the local budgets of hydroperoxides along the flight track, explaining strong deviations from steady-state calculations which only account for local photochemistry. Underestimation of H2_{2}O2_{2}EMAC^{EMAC} by approximately a factor of 2 in the Northern Hemisphere (NH) and the AMA and overestimation in the Southern Hemisphere (SH; factor 1.3) are most likely due to uncertainties in the scavenging efficiencies for individual hydroperoxides in deep convective transport to the upper troposphere, corroborated by a sensitivity study. It seems that the observed excess UHPPSS is excess MHP transported to the west from an upper tropospheric source related to convection in the summer monsoon over Southeast Asia

    Testing of the measuring instruments in non-governmental networks for the purpose of environmental monitoring of ionising radiation

    Get PDF
    Non-governmental networks for environmental monitoring employ a wide range of radiation protection instruments from different manufacturers, which provide the public with often unreliable dosimetric data. These Measuring Instruments in Non-governmental Networks (MINN) are mostly based on Geiger-Muller tube gas detectors, which represent low-cost easily operated instruments. An extensive testing of these devices was performed in order to validate the data acquired with MINN within the 16ENV04 Preparedness EMPIR project. In total, 16 different dosemter types were selected, with a sample size of four dosemeters per dosemeter type. Performance testing included the energy dependence and the linearity tests of the dosemeter response. Additionally, during the Researcher Mobility Grant associated with the 16ENV04 project, two Geiger-Muller based dosemeter types, with a sample size of two dosemeters per type were included in the testing. These instruments were subjected to the angular dependence testing in both horizontal and vertical planes, besides the energy dependence and linearity tests in the reference Cs-137 field at Physikalisch-Technische Bundesanstalt (PTB). For all the dosemeter types, inherent background, response to secondary cosmic radiation and the response to small changes of dose rate were determined at the metrological facilities of PTB. The sensitivity of the measuring instruments used in non-governmental networks to small variations of the ambient dose equivalent rate was examined by exposing the dosemeters to low dose rate Cs-137, Co-60 and Ra-226 radiation sources, in order to estimate the effect of environmental radioactive contamination with artificially produced radionuclides. For the comparison purposes, besides the measuring instruments used in non-governmental networks, a previously characterized CdZnTe-based spectrodosemeter was irradiated with the aforementioned radiation fields. The measured values were compared with a reference Reuter-Stokes ionisation chamber used for low-dose rate level measurements.RAP 2020 : International conference on radiation applications; Book of abstracts; Virtual conference, 202

    Chemical and dynamical identification of emission outflows during the HALO campaign EMeRGe in Europe and Asia

    Get PDF
    The airborne megacity campaign EMeRGe provided an unprecedented amount of trace gas measurements. We combine measured volatile organic compounds (VOCs) with trajectory-modelled emission uptakes to identify potential source regions of pollution. We also characterise the chemical fingerprints (e.g. biomass burning and anthropogenic signatures) of the probed air masses to corroborate the contributing source regions. Our approach is the first large-scale study of VOCs originating from megacities

    Investigation into the performance of dose rate measurement instruments used in non-governmental networks

    Get PDF
    In the aftermath of a nuclear or radiological accident, an extended mapping of reliable dose rate values is of key importance for any governmental decision and countermeasures. Presently, numerous dosimetry network stations, operated by the national governments of the member states in Europe, provide such dose rate data on an hourly basis. Nevertheless, there are large areas in Europe that are not covered at all by these early warning networks and other areas that show only a low density of governmental network stations. Hence, there may be a significant lack of information in case of a nuclear or radiological emergency. As a consequence of the Fukushima Daiichi nuclear power plant accidents in 2011, a number of non-governmental radiation monitoring networks (NRMN) appeared on the internet, providing dose rate data based on stationary as well as on mobile measurements of ionizing radiation by laypersons. Especially the mobile detectors are able to cover large areas in short time. Therefore, it is of considerable importance to investigate the feasibility of using dose rate data from non-governmental networks as a complementary input to the European Radiological Data Exchange Platform (EURDEP). Within the European Metrology Program for Innovation and Research (EMPIR), the project 16ENV04 “Preparedness” has studied the metrological relevance of such non-governmental dose rate data (also called crowd-sourced radiological monitoring) in the most comprehensive way so far. Sixteen different dose rate detector systems (in general 4 of each type, plus 2 types with 2 detectors, i.e. 68 detectors in total) used in NRMN have been investigated for the reliability of their data and the corresponding networks, and their data provision to the public were analyzed. The most relevant performance parameters of dosimetry systems (detector's inherent background, energy dependence and linearity of the response as well as the response to secondary cosmic radiation, the sensitivity to small increases of the dose rate and finally the stability of the detector's indication at various climatic conditions - temperature and humidity) have been investigated for fourteen representative types of non-governmental dose rate measuring instruments. Results of this comprehensive performance study of the simple, light-weighted and cheap dose rate meters used in NRMN, and conclusions on the feasibility of using their data for governmental monitoring in case of a nuclear or radiological emergency are presented. © 2021 The Author

    Program FFlexCom — High frequency flexible bendable electronics for wireless communication systems

    Get PDF
    Today, electronics are implemented on rigid substrates. However, many objects in daily-life are not rigid — they are bendable, stretchable and even foldable. Examples are paper, tapes, our body, our skin and textiles. Until today there is a big gap between electronics and bendable daily-life items. Concerning this matter, the DFG Priority Program FFlexCom aims at paving the way for a novel research area: Wireless communication systems fully integrated on an ultra-thin, bendable and flexible piece of plastic or paper. The Program encompasses 13 projects led by 25 professors. By flexibility we refer to mechanical flexibility, which can come in flavors of bendability, foldability and, stretchability. In the last years the speed of flexible devices has massively been improved. However, to enable functional flexible systems and operation frequencies up to the sub-GHz range, the speed of flexible devices must still be increased by several orders of magnitude requiring novel system and circuit architectures, component concepts, technologies and materials

    Strong impact of wildfires on the abundance and aging of black carbon in the lowermost stratosphere

    Get PDF
    Wildfires inject large amounts of black carbon (BC) particles into the atmosphere, which can reach the lowermost stratosphere (LMS) and cause strong radiative forcing. During a 14-month period of observations on board a passenger aircraft flying between Europe and North America, we found frequent and widespread biomass burning (BB) plumes, influencing 16 of 160 flight hours in the LMS. The average BC mass concentrations in these plumes (∌140 ng·m−3^{-3}, standard temperature and pressure) were over 20 times higher than the background concentration (∌6 ng·m−3^{-3}) with more than 100-fold enhanced peak values (up to ∌720 ng·m−3^{-3}). In the LMS, nearly all BC particles were covered with a thick coating. The average mass equivalent diameter of the BC particle cores was ∌120 nm with a mean coating thickness of ∌150 nm in the BB plume and ∌90 nm with a coating of ∌125 nm in the background. In a BB plume that was encountered twice, we also found a high diameter growth rate of ∌1 nm·h−1^{-1} due to the BC particle coatings. The observed high concentrations and thick coatings of BC particles demonstrate that wildfires can induce strong local heating in the LMS and may have a significant influence on the regional radiative forcing of climate
    • 

    corecore