The Determining Effective Testing in Emergency Departments and Care Coordination on Treatment Outcomes (DETECT) for Hepatitis C (Hep C) Screening Trial: rationale and design of a multi-center pragmatic randomized clinical trial of hepatitis C screening in emergency departments.

Background: Early identification of HCV is a critical health priority, especially now that treatment options are available to limit further transmission and provide cure before long-term sequelae develop. Emergency departments (EDs) are important clinical settings for HCV screening given that EDs serve many at-risk patients who do not access other forms of healthcare. In this article, we describe the rationale and design of The Determining Effective Testing in Emergency Departments and Care Coordination on Treatment Outcomes (DETECT) for Hepatitis C (Hep C) Screening Trial.

Rapid diagnosis of drug agglomeration and crystallinity in pharmaceutical preparations by electrospray laser desorption ionization mass spectrometry imaging.

In this study we evaluate the applicability of electrospray laser desorption ionization mass spectrometry imaging (ELDI-MSI) to interrogate tablet formulations for the spatial distributions of ingredients. Tablet formulations with varying amounts of crystalline acetaminophen (the active pharmaceutical ingredient, API) were analyzed to determine if crystallinity could be evaluated via ELDI-MSI. ELDI-MSI concurrently imaged the (API, binders, and surfactants.

Light-Dependent Changes in the Spatial Localization of Metabolites in (Coleus Henna) Visualized by Matrix-Free Atmospheric Pressure Electrospray Laser Desorption Ionization Mass Spectrometry Imaging.

The visualization of foliage color in plants provides immediate insight into some of the compounds that exist in the leaf. However, many non-colored compounds are also present; their cellular distributions are not readily identifiable optically. In this study we evaluate the applicability of mass spectrometry imaging (MSI) via electrospray laser desorption ionization (ELDI) to reveal the spatial distribution of metabolites.

Abundance and Impact of Doubly Charged Polyatomic Argon Interferences in ICPMS Spectra.

Doubly charged molecular ions of alkaline earth metals and argon could be identified as spectral interferences in an inductively coupled plasma mass spectrometer. These molecular ions were found to occur at abundances reaching about 10(-4) relative to the alkaline earth atomic ion abundances. They can thus substantially affect ultratrace analyses and, when present at similar concentration as the analyte elements, also isotope ratio measurements.

Mass Spectrometric Observation of Doubly Charged Alkaline-Earth Argon Ions.

Doubly charged diatomic ions MAr(2+) where M=Mg, Ca, Sr or Ba have been observed by mass spectrometry with an inductively coupled plasma ion source. Abundance ratios are quite high, 0.1 % for MgAr(2+) , 0.

Giant magnetic anisotropy and tunnelling of the magnetization in Li₂(Li(1-x)Fe(x))N.

Large magnetic anisotropy and coercivity are key properties of functional magnetic materials and are generally associated with rare earth elements. Here we show an extreme, uniaxial magnetic anisotropy and the emergence of magnetic hysteresis in Li₂(Li(1-x)Fe(x))N. An extrapolated, magnetic anisotropy field of 220 T and a coercivity field of over 11 T at 2 K outperform all known hard ferromagnets and single-molecular magnets.

High-resolution time-of-flight mass spectrometry fingerprinting of metabolites from cecum and distal colon contents of rats fed resistant starch.

Time-of-flight mass spectrometry along with statistical analysis was utilized to study metabolic profiles among rats fed resistant starch (RS) diets. Fischer 344 rats were fed four starch diets consisting of 55 % (w/w, dbs) starch. A control starch diet consisting of corn starch was compared against three RS diets.

Analysis of resistant starches in rat cecal contents using Fourier transform infrared photoacoustic spectroscopy.

Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) qualitatively and quantitatively measured resistant starch (RS) in rat cecal contents. Fisher 344 rats were fed diets of 55% (w/w, dry basis) starch for 8 weeks. Cecal contents were collected from sacrificed rats.

Infectious prion protein alters manganese transport and neurotoxicity in a cell culture model of prion disease.

Protein misfolding and aggregation are considered key features of many neurodegenerative diseases, but biochemical mechanisms underlying protein misfolding and the propagation of protein aggregates are not well understood. Prion disease is a classical neurodegenerative disorder resulting from the misfolding of endogenously expressed normal cellular prion protein (PrP(C)). Although the exact function of PrP(C) has not been fully elucidated, studies have suggested that it can function as a metal binding protein.

Electron beam synthesis of metal and semiconductor nanoparticles using metal-organic frameworks as ordered precursors.

We demonstrate a versatile, bottom-up method of forming metal and semiconducting nanoparticles by exposing precursor metal-organic frameworks (MOFs) to an electron beam. Using a transmission electron microscope to initiate and observe growth, we show that the composition, size, and morphology of the nanoparticles are determined by the chemistry and structure of the MOF, as well as the electron beam properties. Zinc oxide, metallic indium and copper particles were produced with narrow and tunable size distributions comparable to those obtained from state-of-the-art methods.

Selenium-modified TiO2 and its impact on photocatalysis.

This work describes the preparation of a selenium-modified TiO(2) photocatalyst and a preliminary evaluation of its photocatalytic activity. Se-TiO(2) displayed greater visible absorption than undoped TiO(2) and was still capable of degrading quinoline at a slightly faster rate than undoped TiO(2) under UV light. Se-TiO(2) was also able to degrade organic molecules under purely visible light by a single electron transfer pathway.

Effects of ion/ion proton transfer reactions on conformation of gas-phase cytochrome c ions.

Positive ions from cytochrome c are studied in a 3-D ion trap/ion mobility (IM)/quadrupole-time-of-flight (TOF) instrument with three independent ion sources. The IM separation allows measurement of the cross section of the ions. Ion/ion reactions in the 3-D ion trap that remove protons cause the cytochrome c ions to refold gently without other degradation of protein structure, i.

Atmospheric pressure laser desorption/ionization of plant metabolites and plant tissue using colloidal graphite.

Colloidal graphite is a promising matrix for atmospheric pressure laser desorption/ionization mass spectrometry. Intact [M+H](+) and [M-H](-) ions are readily produced from a wide range of small molecule plant metabolites, particularly anthocyanins, fatty acids, lipids, glycerides, and ceramides. Compared with a more traditional organic acid matrix, colloidal graphite provides more efficient ionization for small hydrophobic molecules and has a much cleaner background spectrum, especially in negative ion mode.

Silver cluster formation, dynamics, and chemistry in metal-organic frameworks.

Synthetic methods used to produce metal nanoparticles typically lead to a distribution of particle sizes. In addition, creation of the smallest clusters, with sizes of a few to tens of atoms, remains very challenging. Nanoporous metal-organic frameworks (MOFs) are a promising solution to these problems, since their long-range crystalline order creates completely uniform pore sizes with the potential for both steric and chemical stabilization.

Vanadium induces dopaminergic neurotoxicity via protein kinase Cdelta dependent oxidative signaling mechanisms: relevance to etiopathogenesis of Parkinson's disease.

Environmental exposure to neurotoxic metals through various sources including exposure to welding fumes has been linked to an increased incidence of Parkinson's disease (PD). Welding fumes contain many different metals including vanadium typically present as particulates containing vanadium pentoxide (V2O5). However, possible neurotoxic effects of this metal oxide on dopaminergic neuronal cells are not well studied.

Reduction of matrix effects in inductively coupled plasma mass spectrometry by flow injection with an unshielded torch.

Solution samples with matrix concentrations above approximately 0.1% generally present difficulties for analysis by inductively coupled plasma mass spectrometry (ICP-MS) because of cone clogging and matrix effects. Flow injection (FI) is coupled to ICP-MS to reduce deposition from samples such as 1% sodium salts (as NaCl) and seawater (approximately 3% dissolved salts).

An ion trap-ion mobility-time of flight mass spectrometer with three ion sources for ion/ion reactions.

This instrument combines the capabilities of ion/ion reactions with ion mobility (IM) and time-of-flight (TOF) measurements for conformation studies and top-down analysis of large biomolecules. Ubiquitin ions from either of two electrospray ionization (ESI) sources are stored in a three dimensional (3D) ion trap (IT) and reacted with negative ions from atmospheric sampling glow discharge ionization (ASGDI). The proton transfer reaction products are then separated by IM and analyzed via a TOF mass analyzer.

Luminescent metal-organic frameworks.

Metal-organic frameworks (MOFs) display a wide range of luminescent behaviors resulting from the multifaceted nature of their structure. In this critical review we discuss the origins of MOF luminosity, which include the linker, the coordinated metal ions, antenna effects, excimer and exciplex formation, and guest molecules. The literature describing these effects is comprehensively surveyed, including a categorization of each report according to the type of luminescence observed.

A Colorimetric Chemodosimeter for Pd(II): A Method for Detecting Residual Palladium in Cross-Coupling Reactions.

A colorimetric chemodosimeter (SQ1) for the detection of trace palladium salts in cross-coupling reactions mediated by palladium is described. Decolorization of SQ1 is affected by nucleophilic attack of ethanethiol in basic DMSO solutions. Thiol addition is determined to have an equilibrium constant (K(eq)) of 2.

Stress-induced chemical detection using flexible metal-organic frameworks.

In this work we demonstrate the concept of stress-induced chemical detection using metal-organic frameworks (MOFs) by integrating a thin film of the MOF HKUST-1 with a microcantilever surface. The results show that the energy of molecular adsorption, which causes slight distortions in the MOF crystal structure, can be converted to mechanical energy to create a highly responsive, reversible, and selective sensor. This sensor responds to water, methanol, and ethanol vapors, but yields no response to either N2 or O2.

A linear ion trap mass spectrometer with versatile control and data acquisition for ion/ion reactions.

A linear ion trap (LIT) with electrospray ionization (ESI) for top-down protein analysis has been constructed. An independent atmospheric sampling glow discharge ionization (ASGDI) source produces reagent ions for ion/ion reactions. The device is also meant to enable a wide variety of ion/ion reaction studies.

Theoretical investigation of small polyatomic ions observed in inductively coupled plasma mass spectrometry: H(x)CO+ and H(x)N2(+) (x = 1, 2, 3).

Two series of small polyatomic ions, HxCO+ and HxN2(+) (x = 1, 2, 3), were systematically characterized using three correlated theoretical techniques: density functional theory using the B3LYP functional, spin-restricted second-order perturbation theory, and singles + doubles coupled cluster theory with perturbative triples. On the basis of thermodynamic data, the existence of these ions in inductively coupled plasma mass spectrometry (ICP-MS) experiments is not surprising since the ions are predicted to be considerably more stable than their corresponding dissociation products (by 30-170 kcal/mol). While each pair of isoelectronic ions exhibit very similar thermodynamic and kinetic characteristics, there are significant differences within each series.

Electrophilic coordination catalysis: a summary of previous thought and a new angle of analysis.

One of the most common, and yet least well understood, enzymatic transformations is proton abstraction from activated carbon acids such as carbonyls. Understanding the mechanism for these proton abstractions is basic to a good understanding of enzyme function. Significant controversy has arisen over the means by which a given enzyme might facilitate these deprotonations.

Normal cellular prion protein protects against manganese-induced oxidative stress and apoptotic cell death.

The normal prion protein is abundantly expressed in the central nervous system, but its biological function remains unclear. The prion protein has octapeptide repeat regions that bind to several divalent metals, suggesting that the prion proteins may alter the toxic effect of environmental neurotoxic metals. In the present study, we systematically examined whether prion protein modifies the neurotoxicity of manganese (Mn) by comparing the effect of Mn on mouse neural cells expressing prion protein (PrP(C)-cells) and prion-knockout (PrP(KO)-cells).

Carbonyl coordination chemistry from a new angle: a computational study of alpha-carbon acidity based on electrophile coordination geometry.

[reaction: see text] The dependence of acidity on Li+ coordination geometry to alpha-carbon acids is investigated by generating potential energy surfaces of Li+ complexation with acetaldehyde and its respective enolate. The global minimum for the enolate complex shows significant Li+-pi-system coordination to both oxygen and the alpha-carbon. The gas-phase acidity analysis reveals significantly more alpha-carbon coordination, which presumably enhances the lability of the cleaving proton in the transition state of deprotonation.