Extension of dynamic range of sensitive nanoparticle-based immunoassays

Peer reviewe

Sediment properties, biota and local habitat structure explain variation in the erodibility of coastal sediments

Sediment resuspension is a frequent phenomenon in coastal areas and a key driver for many ecosystem functions. Sediment resuspension is often linked to biological and anthropogenic activities, which in combination with hydrodynamic forcing initiate sediment erosion and resuspension, if the erosion threshold (tau(c)) is exceeded. Despite its importance to ecosystem functions very few studies have provided measurements on natural assemblages for subtidal sediments. The aim of this study was to determinate key environmental variables regulating sediment resuspension potential across a sedimentary gradient in a subtidal coastal environment. In order to explore this, we sampled 16 sites encompassing a wide variety in environmental variables (e.g., grain size distribution, macrofaunal communities, vegetation) in the Gulf of Finland, Baltic Sea. A core-based erosion device (EROMES) was used to determine sediment resuspension potential measures of erosion threshold, erosion rate (ER), and erosion constant (m(e)). Based on abiotic and biotic properties sampled, sediments diverged into two distinct groups; cohesive (muddy) and noncohesive (sandy) sediments. Results showed that abiotic sediment properties explained 38-53% and 15-36% of the total variation in resuspension potential measures in muddy and sandy sediments, respectively. In cumulative models, biota accounted for 12-26% and 6-24% to the total variation in muddy and sandy sediments, respectively. Sediment erodibility and resuspension potential of natural sediments is highly variable from local habitats to a larger seascape scale. Our results underline the importance of biota to resuspension potential measures in spatially variable environments.Peer reviewe

Sensitive and quantitative detection of Cardiac Troponin I with upconverting nanoparticle lateral flow test with minimized interference

Measurement of cardiac troponin I (cTnI) should be feasible for point-of-care testing (POCT) to diagnose acute myocardial infarction (AMI). Lateral flow immunoassays (LFIAs) have been long implemented in POCT and clinical settings. However, sensitivity, matrix effect and quantitation in lateral flow immunoassays (LFIAs) have been major limiting factors. The performance of LFIAs can be improved with upconverting nanoparticle (UCNP) reporters. Here we report a new methodological approach to quantify cTnI using UCNP-LFIA technology with minimized plasma interference. The performance of the developed UCNP-LFIA was evaluated using clinical plasma samples (n = 262). The developed UCNP-LFIA was compared to two reference assays, the Siemens Advia Centaur assay and an in-house well-based cTnI assay. By introducing an anti-IgM scrub line and dried EDTA in the LFIA strip, the detection of cTnI in plasma samples was fully recovered. The UCNP-LFIA was able to quantify cTnI concentrations in patient samples within the range of 30–10,000 ng/L. The LoB and LoD of the UCNP-LFIA were 8.4 ng/L and 30 ng/L. The method comparisons showed good correlation (Spearman’s correlation 0.956 and 0.949, p </p

Transfer across the air-sea interface

The efficiency of transfer of gases and particles across the air-sea interface is controlled by several physical, biological and chemical processes in the atmosphere and water which are described here (including waves, large- and small-scale turbulence, bubbles, sea spray, rain and surface films). For a deeper understanding of relevant transport mechanisms, several models have been developed, ranging from conceptual models to numerical models. Most frequently the transfer is described by various functional dependencies of the wind speed, but more detailed descriptions need additional information. The study of gas transfer mechanisms uses a variety of experimental methods ranging from laboratory studies to carbon budgets, mass balance methods, micrometeorological techniques and thermographic techniques. Different methods resolve the transfer at different scales of time and space; this is important to take into account when comparing different results. Air-sea transfer is relevant in a wide range of applications, for example, local and regional fluxes, global models, remote sensing and computations of global inventories. The sensitivity of global models to the description of transfer velocity is limited; it is however likely that the formulations are more important when the resolution increases and other processes in models are improved. For global flux estimates using inventories or remote sensing products the accuracy of the transfer formulation as well as the accuracy of the wind field is crucial

Glycovariant-based lateral flow immunoassay to detect ovarian cancer–associated serum CA125

Cancer antigen 125 (CA125) is a widely used biomarker in monitoring of epithelial ovarian cancer (EOC). Due to insufficient cancer specificity of CA125, its diagnostic use is severely compromised. Abnormal glycosylation of CA125 is a unique feature of ovarian cancer cells and could improve differential diagnosis of the disease. Here we describe the development of a quantitative lateral flow immunoassay (LFIA) of aberrantly glycosylated CA125 which is widely superior to the conventional CA125 immunoassay (CA125IA). With a 30 min read-out time, the LFIA showed 72% sensitivity, at 98% specificity using diagnostically challenging samples with marginally elevated CA125 (35–200 U/mL), in comparison to 16% sensitivity with the CA125IA. We envision the clinical use of the developed LFIA to be based on the substantially enhanced disease specificity against the many benign conditions confounding the diagnostic evaluation and against other cancers.</p