Higher risk of incident diabetes among patients with primary hyperparathyroidism.

Objectives: There is relatively scarce data regarding the association between primary hyperparathyroidism (PHPT) and incident diabetes in large population-based longitudinal studies. We aimed to evaluate the risk of incident diabetes in individuals with and without PHPT and investigate the association between serum calcium concentrations and the risk of incident diabetes in patients with PHPT.

Methods: We included 2749 PHPT patients and 13,745 age, sex and index year matched non-PHPT individuals during 2000-2019.

Chinese normotensive and essential hypertensive reference intervals for plasma aldosterone and renin activity by liquid chromatography-tandem mass spectrometry.

Objectives: The renin-angiotensin-aldosterone system (RAAS) regulates blood pressure. Plasma renin activities (PRA) and plasma aldosterone concentrations (PAC) are biomarkers related to RAAS. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based measurements for PRA and PAC have become popular.

Application of Plasma-Printed Paper-Based SERS Substrate for Cocaine Detection.

Surface-enhanced Raman spectroscopy (SERS) technology is an attractive method for the prompt and accurate on-site screening of illicit drugs. As portable Raman systems are available for on-site screening, the readiness of SERS technology for sensing applications is predominantly dependent on the accuracy, stability and cost-effectiveness of the SERS strip. An atmospheric-pressure plasma-assisted chemical deposition process that can deposit an even distribution of nanogold particles in a one-step process has been developed.

Nanozymes for Environmental Pollutant Monitoring and Remediation.

Nanozymes are advanced nanomaterials which mimic natural enzymes by exhibiting enzyme-like properties. As nanozymes offer better structural stability over their respective natural enzymes, they are ideal candidates for real-time and/or remote environmental pollutant monitoring and remediation. In this review, we classify nanozymes into four types depending on their enzyme-mimicking behaviour (active metal centre mimic, functional mimic, nanocomposite or 3D structural mimic) and offer mechanistic insights into the nature of their catalytic activity.

Strong enhancement of gold nanoparticle chemiresistor response to low-partitioning organic analytes induced by pre-exposure to high partitioning organics.

Exposing a thiol-functionalised gold nanoparticle film chemiresistor to methanol in aqueous solution results in only a small electric current response as the thiol ligand/water partition coefficient of methanol is small, leading to only minor swelling of the chemiresistor film. Nevertheless, the current response to methanol can be enhanced if the chemiresistor becomes pre-exposed to a molecule with a large ligand/water partition coefficient P (e.g.

Toward Paper-Based Sensors: Turning Electrical Signals into an Optical Readout System.

Paper-based sensors are gaining increasing attention for their potential applications in resource-limited settings and for point-of-care analysis. However, chemical analysis of paper-based electronic sensors is frequently interpreted using complex software and electronic displays which compromise the advantages of using paper. In this work, we present two semiquantitative paper-based readout systems that can visually measure a change in resistance of a resistive-based sensor.

High-throughput fabrication and screening improves gold nanoparticle chemiresistor sensor performance.

Chemiresistor sensor arrays are a promising technology to replace current laboratory-based analysis instrumentation, with the advantage of facile integration into portable, low-cost devices for in-field use. To increase the performance of chemiresistor sensor arrays a high-throughput fabrication and screening methodology was developed to assess different organothiol-functionalized gold nanoparticle chemiresistors. This high-throughput fabrication and testing methodology was implemented to screen a library consisting of 132 different organothiol compounds as capping agents for functionalized gold nanoparticle chemiresistor sensors.

Association of Neisseria gonorrhoeae Opa(CEA) with dendritic cells suppresses their ability to elicit an HIV-1-specific T cell memory response.

Infection with Neisseria gonorrhoeae (N. gonorrhoeae) can trigger an intense local inflammatory response at the site of infection, yet there is little specific immune response or development of immune memory. Gonococcal surface epitopes are known to undergo antigenic variation; however, this is unlikely to explain the weak immune response to infection since individuals can be re-infected by the same serotype.

Recent advances in paper-based sensors.

Paper-based sensors are a new alternative technology for fabricating simple, low-cost, portable and disposable analytical devices for many application areas including clinical diagnosis, food quality control and environmental monitoring. The unique properties of paper which allow passive liquid transport and compatibility with chemicals/biochemicals are the main advantages of using paper as a sensing platform. Depending on the main goal to be achieved in paper-based sensors, the fabrication methods and the analysis techniques can be tuned to fulfill the needs of the end-user.

Gold nanoparticle chemiresistors operating in biological fluids.

Functionalised gold nanoparticle (Au(NP)) chemiresistors are investigated for direct sensing of small organic molecules in biological fluids. The principle reason that Au(NP) chemiresistors, and many other sensing devices, have limited operation in biological fluids is due to protein and lipid fouling deactivating the sensing mechanism. In order to extend the capability of such chemiresistor sensors to operate directly in biofluids, it is essential to minimise undesirable matrix effects due to protein and lipidic components.

Dynamic response of gold nanoparticle chemiresistors to organic analytes in aqueous solution.

We investigate the response dynamics of 1-hexanethiol-functionalized gold nanoparticle chemiresistors exposed to the analyte octane in aqueous solution. The dynamic response is studied as a function of the analyte-water flow velocity, the thickness of the gold nanoparticle film and the analyte concentration. A theoretical model for analyte limited mass-transport is used to model the analyte diffusion into the film, the partitioning of the analyte into the 1-hexanethiol capping layers and the subsequent swelling of the film.

Gold nanoparticle chemiresistor sensor array that differentiates between hydrocarbon fuels dissolved in artificial seawater.

Gold nanoparticle films (Au(NPF)) functionalized with a range of hydrophobic and hydrophilic thiols were assembled in chemiresistor sensor arrays that were used to differentiate between complex mixtures of analytes in the aqueous phase. A chemiresistor array sampled a simple system of linear alcohols (methanol, ethanol, propan-1-ol, and butan-1-ol) dissolved in water over a range of concentrations. Discriminant analysis confirmed that the response patterns of the array could be used to successfully distinguish between the different alcohol solutions at concentrations above 20 mM for all of the alcohols except methanol, which was distinguished at concentrations above 200 mM.

Anthrax lethal toxin promotes dephosphorylation of TTP and formation of processing bodies.

Anthrax lethal toxin (LeTx) is composed of protective antigen (PA) and lethal factor (LF) - PA is the receptor-binding moiety and LF is a protease that cleaves mitogen-activated protein kinase kinases (MAPKKs). LeTx subverts the immune response to Bacillus anthracis in several ways, such as downregulating interleukin-8 (IL-8) by increasing the rate of IL-8 mRNA degradation. Many transcripts are regulated through cis-acting elements that bind proteins that either impede or promote degradation.

Inkjet-printed gold nanoparticle chemiresistors: influence of film morphology and ionic strength on the detection of organics dissolved in aqueous solution.

The influence of film morphology on the performance of inkjet-printed gold nanoparticle chemiresistors has been investigated. Nanoparticles deposited from a single-solvent system resulted in a "coffee ring"-like structure with most of the materials deposited at the edge. It was shown that the uniformity of the film could be improved if the nanoparticles were deposited from a mixture of solvents comprising N-methyl-2-pyrrolidone and water.

The cytoplasmic domain of anthrax toxin receptor 1 affects binding of the protective antigen.

The protective antigen (PA) component of anthrax toxin binds the I domain of the receptor ANTXR1. Integrin I domains convert between open and closed conformations that bind ligand with high and low affinities, respectively; this process is regulated by signaling from the cytoplasmic domains. To assess whether intracellular signals might influence the interaction between ANTXR1 and PA, we compared two splice variants of ANTXR1 that differ only in their cytoplasmic domains.

Multi-analyte sensing: a chemometrics approach to understanding the merits of electrode arrays versus single electrodes.

A peptide-modified electrode array with a different peptide on each electrode is compared with a single electrode modified with many peptides for the voltammetric measurement of concentrations of Cu(2+), Cd(2+) and Pb(2+) in solution. The single gold electrode was modified simultaneously with peptides Gly-Gly-His, glutathione and angiotensin I each coupled to thioctic acid, and thioctic acid itself, and the calibration of mixtures of ions was compared with previously published data from an array of four sensors each with an individual modification. Calibration at the multi-peptide single-electrode sensor was by two-way partial least squares (voltammetric current measured with variables 'sample' x 'potential') and for the electrode array by three-way NPLS1 ('sample' x 'potential' x 'electrode').

Gold nanoparticle chemiresistor sensors: direct sensing of organics in aqueous electrolyte solution.

A novel chemiresistor sensor for detection of organic analytes in high-conductivity aqueous electrolyte solution is reported. The chemiresistor sensor is based on thin films of gold nanoparticles capped with a 1-hexanethiol monolayer that is inkjet printed onto a microelectrode. In order for a change in nanoparticle film resistance to be measured, the electronic conduction must preferentially occur through the nanoparticle film rather than through the high-conductivity electrolyte solution.

Extending the dynamic range of electrochemical sensors using multiple modified electrodes.

Multiple electrodes, combined with a chemometric strategy to calibrate the measurement response, have been used for the determination of an analyte across a broader dynamic range than is possible with a single electrode. The model system used for the detection of copper comprised electrodes modified with a self-assembled monolayer. The electrodes were modified with the copper-complexing species (3-mercaptopropionic acid, thioctic acid, and the peptides cysteine and Gly-Gly-His) and copper was determined over concentrations ranging from nanomolar to millimolar using voltammetric analysis.

CEACAM1 (CD66a) promotes human monocyte survival via a phosphatidylinositol 3-kinase- and AKT-dependent pathway.

CEACAM1 (also known as CD66a) is a transmembrane glycoprotein that mediates homophilic intercellular interactions that influence cellular growth, immune cell activation, and tissue morphogenesis. Various studies have suggested a link between CEACAM1 and cellular apoptosis, including a recent demonstration that ERK1/2 signaling is triggered downstream of CEACAM1. In this study, we reveal that CEACAM1-long binding confers survival signals to human peripheral blood mononuclear cells.

Application of N-PLS calibration to the simultaneous determination of Cu(2+), Cd(2+) and Pb(2+) using peptide modified electrochemical sensors.

The simultaneous determination of Cu(2+), Cd(2+) and Pb(2+) is demonstrated at four modified gold electrodes using N-PLS calibration. Three of the electrodes were modified with the peptides Gly-Gly-His, gamma-Glu-Cys Gly and human angiotensin I which were covalently attached to thioctic acid self-assembled monolayers and the fourth electrode was modified with thioctic acid only. Voltammetry at the modified electrodes in the presence of the three metal ions revealed one peak due to the reduction of copper and another due to the overlapping peaks of cadmium and lead which made quantification using conventional methods difficult.

Inhibition of mitogen-activated protein kinase signalling by Bacillus anthracis lethal toxin causes destabilization of interleukin-8 mRNA.

Bacillus anthracis must overcome host innate immune defences to establish a systemic anthrax infection. This is facilitated in part by lethal toxin (LT), a secreted virulence factor that consists of a cell-binding moiety, protective antigen (PA), and an enzymatic moiety, lethal factor (LF). PA binds cells through protein receptors and mediates the delivery of LF to the cytosol.

DNA recognition interfaces: the influence of interfacial design on the efficiency and kinetics of hybridization.

The effect of the surface chemistry of DNA recognition interfaces on DNA hybridization at a gold surface was investigated using both electrochemistry and the quartz crystal microbalance (QCM) technique. Different DNA recognition interfaces were prepared using a two-component self-assembled monolayer consisting of thiolated 20-mer probe single-stranded DNA (ss-DNA) containing either a 3'-mercaptopropyl or a 3'-mercaptohexyl linker group and an alcohol-terminated diluent layer with 2-, 6-, or 11-carbon length. The influence of the interfacial design on the hybridization efficiency, the affinity constant (Ka) describing hybridization, and the kinetics of hybridization was assessed.

Voltammetric detection of cadmium ions at glutathione-modified gold electrodes.

An electrochemical sensor for the detection of cadmium ions is described using immobilized glutathione as a selective ligand. First, a self-assembled monolayer of 3-mercaptopropionic acid (MPA) was formed on a gold electrode. The carboxyl terminus then allowed attachment of glutathione (GSH)via carbodiimide coupling to give the MPA-GSH modified electrode.

Exploring the use of the tripeptide Gly-Gly-his as a selective recognition element for the fabrication of electrochemical copper sensors.

The modification of electrodes with the tripeptide Gly-Gly-His for the detection of copper in water samples is described in detail. The tripeptide modified electrode was prepared by first self-assembling 3-mercaptopropionic acid (MPA) onto the gold electrode followed by covalent attachment of the tripeptide to the self-assembled monolayer using carbodiimide coupling. The electrodes were characterized using electrochemistry, a newly developed mass-spectrometry method and quantum mechanical calculations.