Coupled electrostatic and hydrophobic destabilisation of the gelsolin-actin complex enables facile detection of ovarian cancer biomarker lysophosphatidic acid

Lysophosphatidic acid (LPA) is a promising biomarker candidate to screen for ovarian cancer (OC) and potentially stratify and treat patients according to disease stage. LPA is known to target the actin-binding protein gelsolin which is a key regulator of actin filament assembly. Previous studies have shown that the phosphate headgroup of LPA alone is inadequate to bind to the short chain of amino acids in gelsolin known as the PIP2 -binding domain. Thus, the molecular-level detail of the mechanism of LPA binding is poorly understood. Here, we model LPA binding to the PIP2 - binding domain of gelsolin in the gelsolin-actin complex through extensive ten-microsecond atomistic molecular dynamics (MD) simulations. We predict that LPA binding causes a local conformational rearrangement due to LPA interactions with both gelsolin and actin residues. These conformational changes are a result of the amphipathic nature of LPA, where the anionic phosphate, polar glycerol and ester groups, and lipophilic aliphatic tail mediate LPA binding via charged electrostatic, hydrogen bonding, and van der Waals interactions. The negatively-charged LPA headgroup binds to the PIP2 - binding domain of gelsolin-actin while its hydrophobic tail is inserted into actin, creating a strong LPA-insertion pocket that weakens the gelsolin–actin interface. The computed structure, dynamics, and energetics of the ternary gelsolin–LPA–actin complex confirms that a quantitative OC assay is possible based on LPA-triggered actin release from the gelsolin-actin complex</p

Utilizing a Key Aptamer Structure-Switching Mechanism for the Ultrahigh Frequency Detection of Cocaine

Aptasensing of small molecules remains a challenge as detection often requires the use of labels or signal amplification methodologies, resulting in both difficult-to-prepare sensor platforms and multistep, complex assays. Furthermore, many aptasensors rely on the binding mechanism or structural changes associated with target capture by the aptameric probe, resulting in a detection scheme customized to each aptamer. It is in this context that we report herein a sensitive cocaine aptasensor that offers both real-time and label-free measurement capabilities. Detection relies on the electromagnetic piezoelectric acoustic sensor (EMPAS) platform. The sensing interface consists of a <i>S</i>-(11-trichlorosilyl-undecanyl)­benzenethiosulfonate (BTS) adlayer-coated quartz disc onto which a structure-switching cocaine aptamer (MN6) is immobilized, completing the preparation of the MN6 cocaine aptasensor (M6CA). The EMPAS system has recently been employed as the foundation of a cocaine aptasensor based on a structurally rigid cocaine aptamer variant (MN4), an aptasensor referred to by analogy as M4CA. M6CA represents a significant increase in terms of analytical performance, compared to not only M4CA but also other cocaine aptamer-based sensors that do not rely on signal amplification, producing an apparent <i>K</i>_d of 27 ± 6 μM and a 0.3 μM detection limit. Remarkably, the latter is in the range of that achieved by cocaine aptasensors relying on signal amplification. Furthermore, M6CA proved to be capable not only of regaining its cocaine-binding ability via simple buffer flow over the sensing interface (i.e., without the necessity to implement an additional regeneration step, such as in the case of M4CA), but also of detecting cocaine in a multicomponent matrix possessing potentially assay-interfering species. Finally, through observation of the distinct shape of its response profiles to cocaine injection, demonstration was made that the EMPAS system in practice offers the possibility to distinguish between the binding mechanisms of structure-switching (MN6) vs rigid (MN4) aptameric probes, an ability that could allow the EMPAS to provide a more universal aptasensing platform than what is ordinarily observed in the literature

Beyond the stable handling limits: nonlinear model predictive control for highly transient autonomous drifting

Autonomous vehicles that can reliably operate outside the stable handling limits would have access to a wider range of maneuvers in emergencies, improving overall safety. To that end, this paper presents a novel Nonlinear MPC approach for vehicle control with deeply saturated rear tires. Longitudinal slip management is elevated from the chassis control layer into the optimisation problem by using a coupled-slip tire model, and explicitly including wheelspeed dynamics. Terminal costs on sideslip stability help compensate for the finite horizon, while road bounds and static obstacles are encoded using slack constraints. Experiments on a racetrack with a modified Toyota GR Supra validate the controller's ability to smoothly transition from dynamic, non-equilibrium drifting to grip driving. Further experiments demonstrate robustness to significant longitudinal force and wheelspeed disturbances, and showcase the controller flexibly transitioning in and out of the sliding tire regime to balance slack constraints with tracking objectives.</p

New Functionalizable Alkyltrichlorosilane Surface Modifiers for Biosensor and Biomedical Applications

We report herein three unprecedented alkyltrichlorosilane surface modifiers bearing pentafluorophenyl ester (PFP), benzothiosulfonate (BTS), or novel β-propiolactone (BPL) functionalizable terminal groups. Evidence is provided that these molecules can be prepared in very high purity (as assessed by NMR) through a last synthetic step of Pt-catalyzed alkene hydrosilylation then directly employed, without further purification, for the surface modification of quartz and medical grade stainless steel. Subsequent on-surface functionalizations with amine and thiol model molecules demonstrate the potential of these molecular adlayers to be important platforms for future applications in the bioanalytical and biomedical fields

Comparison between conventional crosses and breeding vessel.

<p>Data for time, total embryos produced, and embryo viability are mean ± standard deviation. For embryo production and viability values, means with different superscript letters within each row are significantly different (Student's t-test, p<0.05).</p

Architecture of the zebrafish breeding vessel.

<p>(A) The three primary components of the breeding vessel. (B) Framework of the bottom or “floor” of the spawning platform, showing variation in topography. (C) The breeding vessel, with all three primary components engaged and ready for operation.</p

Schema depicting the operation of the breeding vessel, cross-sectional view.

<p>(A) The breeding vessel is filled with conditioned water, and fish are added to it so that female fish and male fish are contained within the spawning platform, below and above the separator, respectively. (B) The separator is removed and the male and female fish swim together in deep water. (C) The platform is raised within the outer chamber so that the male and female fish swim together and spawn in shallow water. The fertilized embryos fall through the floor of the spawning platform. (D) After the fish are removed from the breeding vessel, the fertilized embryos that have settled at the bottom of the outer chamber are collected.</p

On-chip glucose detection based on glucose oxidase immobilized on a platinum-modified, gold microband electrode

We report the microfabrication and characterization of gold microband electrodes on silicon using standard microfabrication methods, i.e., lithography and etching techniques. A two-step electrodeposition process was carried out using the on-chip platinum reference and gold counter electrodes, thus incorporating glucose oxidase onto a platinum-modified, gold microband electrode with an o-phenylenediamine and ß-cyclodextrin mixture. The as-fabricated electrodes were studied using optical microscopy, scanning electron microscopy, and atomic force microscopy. The two-step electrodeposition process was conducted in low sample volumes (50 µL) of both solutions required for biosensor construction. Cyclic voltammetry and electrochemical impedance spectroscopy were utilised for electrochemical characterization at each stage of the deposition process. The enzymatic based microband biosensor demonstrated a linear response to glucose from 2.5–15 mM, using both linear sweep voltammetry and chronoamperometric measurements in buffer-based solutions. The biosensor performance was examined in 30 µL volumes of fetal bovine serum. Whilst a reduction in the sensor sensitivity was evident within 100% serum samples (compared to buffer media), the sensor demonstrated linear glucose detection with increasing glucose concentrations (5–17 mM

WHAT IS THE ROLE OF PEER-REVIEWED PUBLICATIONS IN COMMUNICATING CLINICAL DATA TO HEALTH-CARE PROFESSIONALS?

Objective: To understand the role of peer-reviewed publications in communicating clinical data to health-care professionals (HCPs). Challenge/problem: Peer-reviewed publications are seen as the “gold standard” for sharing clinical trial data, but do we fully understand how HCPs use them? Solution: Two anonymous surveys assessed the extent to which HCPs access, interact with, and use clinical data published in peer-reviewed journals. A pilot survey was sent to 51 HCPs actively involved in publication development, followed by a more comprehensive survey distributed to primary care physicians (n=50) and oncologists (n=50) from the USA (n=25 for each specialty) and all EU5 countries (n=5 per country for each specialty). Outcome: 21 respondents completed the pilot survey. All respondents reported reading peer-reviewed articles on either a monthly (5%), weekly (50%), or daily (45%) basis, with the abstract being the most frequently read section (75%). All respondents read original research and review articles published in journals linked to their specialty, while only 50% read general medical journals; 70% indicated that paywalls had prevented them reading articles. Notably, 90% of respondents indicated that the information they read informed their clinical decision-making. Further results will be presented examining how HCPs access clinical data and use peer-reviewed publications; how communicating clinical data can be improved; and how this differs according to involvement in developing publications, region, and specialty. Benefits: This research will help to improve the way clinical data are communicated to HCPs, ensuring timely and effective sharing of information that will ultimately improve patient car

Additional file 1: of The effect of North Carolina free clinics on hospitalizations for ambulatory care sensitive conditions among the uninsured

Confirmation of free clinics. Processes used to identify free clinics. (DOCX 12 kb