The objective were to: (1) evaluate associations between food security and women diagnosed with gestational diabetes mellitus (GDM) and (2) evaluate if women in food insecure (FI) households had adverse maternal and neonatal outcomes. This was an observational study from October 2018 until September 2019. Postpartum resident clinic patients who delivered term, singleton infant at 37 weeks' or longer gestation were screened. Participants completed a survey using the U.S. Household Food Security Survey Module (US HFSSM). Survey responses were classified as: food secure (FS) and FI (marginal, low, very low FS). The primary outcome was GDM. Our secondary outcome was neonatal intensive care unit (NICU) admissions for hypoglycemia. We evaluated the rate of GDM in FS and FI groups. Demographic data included: prepregnancy body mass index, total weight gain during pregnancy, birth weight, and mode of delivery. A logistic regression model was used to analyze the association between food insecurity and GDM. A p-value of less than 0.05 was considered statistically significant. There were 150 patients screened to participate; of these, 70 patients were enrolled (36 GDM and 34 without GDM [NGDM]). More patients in FI households, 71% (n = 17), were diagnosed with GDM, compared with 33% (n = 15) in the FS (FS) households (adjusted odds ratio 7.05; p < 0.01). Of patients who reported FI, 50% (n = 12) were black, 46% (n = 11) Hispanic, and 4% (n = 1) Caucasian, compared with 13% (n = 6) black, 30% (n = 14) Hispanic, and 57% (n = 26) Caucasian in patients who reported FS (p < 0.001). Although not significant, 25% (n = 6) of neonates from an FI household had an NICU admission for hypoglycemia compared with 7% (n = 3) from an FS household (p = 0.054). Pregnant women with GDM are more likely to experience FI than those with NGDM. Infants of mothers in FI households also had increased rates of NICU admission for hypoglycemia.

Factors affecting the enhanced amperometric signal observed at electrodes modified with polyelectrolyte-gold nanoparticle (Au-NP) composite films, which are potential interfaces for first-generation biosensors, were systematically investigated and optimized for hydrogen peroxide (H2O2) detection. Polyelectrolyte multilayer films embedded with citrate-stabilized gold nanoparticles exhibited high sensitivity toward the oxidation of H2O2. From this Au-NP film assembly, the importance of Au-NP ligand protection, film permeability, the density of Au-NPs within the film, and electronic coupling between Au-NPs (interparticle) and between the film and the electrode (interfacial) were evaluated. Using alternative Au-NPs, including those stabilized with thiols, polymers, and bulky ligands, suggests that the amperometric enhancement of H2O2 is optimized at poly-L-lysine-linked film assemblies embedded with Au-NPs possessing small, charged, and conductive (conjugated) peripheral ligands. As a potential application of these Au-NP film assemblies, an enhanced amperometric signal for H2O2 oxidation was shown for modified "needle" electrodes. The overall aim of this research is to gain a greater understanding of designing electrochemical sensing strategies that incorporate Au-NPs and target specific analytes.

Colloidal gold nanoparticles protected with alkanethiolate ligands called monolayer protected gold clusters (MPCs) are synthesized and subsequently incorporated into film assemblies that serve as adsorption platforms for protein monolayer electrochemistry (PME). PME is utilized as the model system for studying electrochemical properties of redox proteins by confining them to an adsorption platform at a modified electrode, which also serves as a redox partner for electron transfer (ET) reactions. Studies have shown that gold nanoparticle film assemblies of this nature provide for a more homogeneous protein adsorption environment and promote ET without distance dependence compared to the more traditional systems modified with alkanethiol self-assembled monolayers (SAM). [1][2][3] In this paper, MPCs functionalized with hexanethiolate ligands are synthesized using a modified Brust reaction 4 and characterized with ultraviolet visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and proton ( 1 H) nuclear magnetic resonance (NMR). MPC films are assembled on SAM modified gold electrode interfaces by using a "dip cycle" method of alternating MPC layers and dithiol linking molecules. Film growth at gold electrode is tracked electrochemically by measuring changes to the double layer charging current of the system. Analogous films assembled on silane modified glass slides allow for optical monitoring of film growth and cross-sectional TEM analysis provides an estimated film thickness. During film assembly, manipulation of the MPC ligand protection as well as the interparticle linkage mechanism allow for networked films, that are readily adaptable, to interface with redox protein having different adsorption mechanism. For example, Pseudomonas aeruginosa azurin (AZ) can be adsorbed hydrophobically to dithiol-linked films of hexanethiolate MPCs and cytochrome c (cyt c) can be immobilized electrostatically at a carboxylic acid modified MPC interfacial layer. In this report, we focus on the film protocol for the AZ system exclusively. Investigations involving the adsorption of proteins on MPC modified synthetic platforms could further the understanding of interactions between biomolecules and man-made materials, and consequently aid the development of biosensor schemes, ET modeling systems, and synthetic biocompatible materials. 5-8 Video LinkThe video component of this article can be found at http://www.jove.com/details.php?id=3441 Protocol Hexanethiolate Monolayer Protected Gold Clusters SynthesisHexanethiolate functionalized monolayer protected gold clusters (MPCs) are synthesized following a 2:1 1-hexanethiol (C6) to gold mole ratio to produce an average structure of Au225(C6)75. 4-9 Speciï¬c modiï¬cations to the Brust reaction, like ligand type, speciï¬c thiol-to-gold ratios, temperature, and reaction delivery rate, or post-synthesis treatments, 9-11 can yield a diverse range of MPCs with varying core sizes and functional protective groups, respectively. 4 The MPC approximate (average) compositio...

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