Gas emissions, minerals, and tars associated with three coal fires, Powder River Basin, USA.

Ground-based surveys of three coal fires and airborne surveys of two of the fires were conducted near Sheridan, Wyoming. The fires occur in natural outcrops and in abandoned mines, all containing Paleocene-age subbituminous coals. Diffuse (carbon dioxide (CO(2)) only) and vent (CO(2), carbon monoxide (CO), methane, hydrogen sulfide (H(2)S), and elemental mercury) emission estimates were made for each of the fires. Additionally, gas samples were collected for volatile organic compound (VOC) analysis and showed a large range in variation between vents. The fires produce locally dangerous levels of CO, CO(2), H(2)S, and benzene, among other gases. At one fire in an abandoned coal mine, trends in gas and tar composition followed a change in topography. Total CO(2) fluxes for the fires from airborne, ground-based, and rate of fire advancement estimates ranged from 0.9 to 780mg/s/m(2) and are comparable to other coal fires worldwide. Samples of tar and coal-fire minerals collected from the mouth of vents provided insight into the behavior and formation of the coal fires

Total Dose Dependence of Oxide Charge, Interstrip Capacitance and Breakdown Behavior of sLHC Prototype Silicon Strip Detectors and Test Structures of the SMART Collaboration

Abstract For the future luminosity upgrade proposed for the Large Hadron Collider (LHC) silicon strip detectors (SSD) and test structures were fabricated on various high-resistivity substrates (p-type MCz and FZ, n-type FZ) within the INFN funded SMART project. They were irradiated with 60 Co to test total dose (TID) effects, in order to study the impact of surface radiation damage on the detector properties (interstrip capacitance and resistance, break-down voltage). Selected results from the pre-rad and post-rad characterization of detectors and test structures are presented, in particular interstrip capacitance, breakdown voltage, flatband voltage and oxide charge. They show saturation at about 150 kRad. Annealing are performed both at room and at elevated temperature

Lipid (per) oxidation in mitochondria:an emerging target in the ageing process?

Lipids are essential for physiological processes such as maintaining membrane integrity, providing a source of energy and acting as signalling molecules to control processes including cell proliferation, metabolism, inflammation and apoptosis. Disruption of lipid homeostasis can promote pathological changes that contribute towards biological ageing and age-related diseases. Several age-related diseases have been associated with altered lipid metabolism and an elevation in highly damaging lipid peroxidation products; the latter has been ascribed, at least in part, to mitochondrial dysfunction and elevated ROS formation. In addition, senescent cells, which are known to contribute significantly to age-related pathologies, are also associated with impaired mitochondrial function and changes in lipid metabolism. Therapeutic targeting of dysfunctional mitochondrial and pathological lipid metabolism is an emerging strategy for alleviating their negative impact during ageing and the progression to age-related diseases. Such therapies could include the use of drugs that prevent mitochondrial uncoupling, inhibit inflammatory lipid synthesis, modulate lipid transport or storage, reduce mitochondrial oxidative stress and eliminate senescent cells from tissues. In this review, we provide an overview of lipid structure and function, with emphasis on mitochondrial lipids and their potential for therapeutic targeting during ageing and age-related disease

High performance magneto-fluorescent nanoparticles assembled from terbium and gadolinium 1,3-diketones

Polyelectrolyte-coated nanoparticles consisting of terbium and gadolinium complexes with calix[4]arene tetra-diketone ligand were first synthesized. The antenna effect of the ligand on Tb(III) green luminescence and the presence of water molecules in the coordination sphere of Gd(III) bring strong luminescent and magnetic performance to the core-shell nanoparticles. The size and the core-shell morphology of the colloids were studied using transmission electron microscopy and dynamic light scattering. The correlation between photophysical and magnetic properties of the nanoparticles and their core composition was highlighted. The core composition was optimized for the longitudinal relaxivity to be greater than that of the commercial magnetic resonance imaging (MRI) contrast agents together with high level of Tb(III)-centered luminescence. The tuning of both magnetic and luminescent output of nanoparticles is obtained via the simple variation of lanthanide chelates concentrations in the initial synthetic solution. The exposure of the pheochromocytoma 12 (PC 12) tumor cells and periphery human blood lymphocytes to nanoparticles results in negligible effect on cell viability, decreased platelet aggregation and bright coloring, indicating the nanoparticles as promising candidates for dual magneto-fluorescent bioimaging

Acinetobacter baumannii OxyR regulates the transcriptional response to hydrogen peroxide

Acinetobacter baumannii is a Gram-negative opportunistic pathogen that causes diverse infections, including pneumonia, bacteremia, and wound infections. Due to multiple intrinsic and acquired antimicrobial-resistance mechanisms, A. baumannii isolates are commonly multidrug resistant, and infections are notoriously difficult to treat. The World Health Organization recently highlighted carbapenem-resistant A. baumannii as a "critical priority" for the development of new antimicrobials because of the risk to human health posed by this organism. Therefore, it is important to discover the mechanisms used by A. baumannii to survive stresses encountered during infection in order to identify new drug targets. In this study, by use of in vivo imaging, we identified hydrogen peroxide (H2O2) as a stressor produced in the lung during A. baumannii infection and defined OxyR as a transcriptional regulator of the H2O2 stress response. Upon exposure to H2O2, A. baumannii differentially transcribes several hundred genes. However, the transcriptional upregulation of genes predicted to detoxify hydrogen peroxide is abolished in an A. baumannii strain in which the transcriptional regulator oxyR is genetically inactivated. Moreover, inactivation of oxyR in both antimicrobial-susceptible and multidrug-resistant A. baumannii strains impairs growth in the presence of H2O2 OxyR is a direct regulator of katE and ahpF1, which encode the major H2O2-degrading enzymes in A. baumannii, as confirmed through measurement of promoter binding by recombinant OxyR in electromobility shift assays. Finally, an oxyR mutant is less fit than wild-type A. baumannii during infection of the murine lung. This work reveals a mechanism used by this important human pathogen to survive H2O2 stress encountered during infection

Elucidation of a Copper Binding Site in Proinsulin C‑peptide and Its Implications for Metal-Modulated Activity

The connecting peptide (C-peptide) is a hormone with promising health benefits in ameliorating diabetes-related complications, yet mechanisms remain elusive. Emerging studies point to a possible dependence of peptide activity on bioavailable metals, particularly Cu(II) and Zn(II). However, little is known about the chemical nature of the interactions, hindering advances in its therapeutic applications. This work uncovers the Cu(II)-binding site in C-peptide that may be key to understanding its metal-dependent function. A combination of spectroscopic studies reveal that Cu(II) and Zn(II) bind to C-peptide at specific residues in the N-terminal region of the peptide and that Cu(II) is able to displace Zn(II) for C-peptide binding. The data point to a Cu(II)-binding site consisting of 1N3O square-planar coordination that is entropically driven. Furthermore, the entire random coil peptide sequence is needed for specific metal binding as mutations and truncations reshuffle the coordinating residues. These results expand our understanding of how metals influence hormone activity and facilitate the discovery and validation of both new and established paradigms in peptide biology