373 research outputs found
Experimental infection of pigs with the newly identified swine hepatitis E virus (swine HEV), but not with human strains of HEV
A novel virus of pigs, swine hepatitis E virus (swine HEV), was recently identified and shown to be antigenically and genetically related to human HEV. In the present study, we attempted to infect specific-pathogen-free (SPF) pigs experimentally with swine HEV or with human strains of HEV. Serum samples collected from naturally infected pigs were used as the source of swine HEV. Pigs inoculated intravenously with serum samples containing swine HEV seroconverted to anti-HEV 4 to 8 weeks postinoculation, and the virus spread to an uninoculated pig. Swine HEV was detected in nasal and rectal swab materials as early as 2 weeks postinoculation and for 4 to 8 weeks thereafter. Viremia appeared 4 to 6 weeks postinoculation and lasted 1 to 3 weeks. The inoculated pigs appeared clinically normal and serum liver enzymes were not significantly elevated. In contrast, pigs were not infected when inoculated intravenously with about 105 monkey infectious doses of one of two human strains of HEV (Sar-55 or Mex-14)
Bioavailability and biochemical effects of diclofenac sodium 0.1% ophthalmic solution in the domestic chicken (Gallus gallus domesticus)
Objective To determine if topical ophthalmic diclofenac sodium 0.1% solution alters renal parameters in the domestic chicken, and to determine if the drug is detectable in plasma after topical ophthalmic administration.
Animals Thirty healthy domestic chickens
Procedures Over seven days, 6 birds were treated unilaterally with 1 drop of artificial tear solution (group 1), 12 birds were treated unilaterally (group 2) and 12 bilaterally (group 3) with diclofenac sodium 0.1% ophthalmic solution. Treatments were provided for 7 days, every 12 hours in all groups. Pre- and post-treatment plasma samples from all birds were evaluated for changes in albumin, total protein, and uric acid. Post-treatment samples of all birds were also analyzed by HPLC-MS for detection of diclofenac sodium.
Results Changes in pre- and post-treatment plasma albumin were significant (P \u3c 0.05) in groups 2 and 3, but not for group 1. Pre- and post-treatment changes in total protein and uric acid pre- and post-treatment were not significant for any group. Diclofenac sodium was not detectable (limit of detection = 0.10 ng/mL) in plasma samples from birds in group 1. Concentration of drug in group 3 was statistically greater than group 2 (P = 0.0008).
Conclusions and Clinical Relevance Topical ophthalmic diclofenac sodium 0.1% administered every 12 hours in one or both eyes for 7 days is detectable in systemic circulation in the domestic chicken at 15 minutes post-administration, but did not cause overt changes in parameters used to monitor renal physiology
DEPORTMENT AND MANAGEMENT OF METALS PRODUCED DURING COMBUSTION OF CCA-TREATED TIMBERS
Abstract Experiments were conducted to study CCA-treated wood combustion over a range of temperature and oxygen concentrations with a view to understanding the factors affecting energy and metals recovery from waste treated timber. CCA-treated wood was burned in a furnace at temperatures from 400-940ºC and oxygen concentrations between 5-21%. The ash and condensed volatiles were digested for total concentrations of metals and subjected to leaching tests to determine the stabilized concentrations of metals. Arsenic volatilization increased with increasing furnace temperature whereas the copper and chromium reported mainly to the ash product. The effect of oxygen concentration was weak although it appeared that more arsenic volatilizes at higher oxygen concentrations. However, a larger proportion of the arsenic in the ash generated at lower oxygen concentrations is solubilized during leaching tests, hence the concentration of stabilized arsenic in the ash is relatively unaffected by oxygen concentration
Spatiotemporal information transfer pattern differences in motor selection
Analysis of information transfer between variables in brain images is currently a popular topic, e.g. [1]. Such work typically focuses on average information transfer (i.e. transfer entropy [2]), yet the dynamics of transfer from a source to a destination can also be quantified at individual time points using the local transfer entropy (TE) [3]. This local perspective is known to reveal dynamical structure that the average cannot. We present a method to quantify local TE values in time between source and destination regions of variables in brain-imaging data, combining: a. computation of inter-regional transfer between two regions of variables (e.g. voxels) [1], with b. the local perspective of the dynamics of such transfer in time [3]. Transfer is computed over samples from all variables – there is no training in or subset selection of variables to use. We apply this method to a set of fMRI measurements where we could expect to see differences in local information transfer between two conditions at specific time steps. The fMRI data set analyzed (from [4]) contains brain activity recorded from 7 localized regions while 12 subjects (who gave informed written consent) were asked to freely decide whether to pus
Reaction of Fumonisin with Glucose Prevents Promotion of Hepatocarcinogenesis in Female F344/N Rats while Maintaining Normal Hepatic Sphinganine/Sphingosine Ratios
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An Investigation to Resolve the Interaction Between Fuel Cell, Power Conditioning System and Application Loads
Solid-Oxide Fuel Cell (SOFC) stacks respond quickly to changes in load and exhibit high part- and full-load efficiencies due to its rapid electrochemistry. However, this is not true for the thermal, mechanical, and chemical balance-of-plant subsystem (BOPS), where load-following time constants are, typically, several orders of magnitude higher. This dichotomy diminishes the reliability and performance of the electrode with increasing demand of load. Because these unwanted phenomena are not well understood, the manufacturers of SOFC use conservative schemes (such as, delayed load-following to compensate for slow BOPS response or expensive inductor filtering) to control stack responses to load variations. This limits the applicability of SOFC systems for load-varying stationary and transportation applications from a cost standpoint. Thus, a need exists for the synthesis of component- and system-level models of SOFC power-conditioning systems and the development of methodologies for investigating the system-interaction issues (which reduce the lifetime and efficiency of a SOFC) and optimizing the responses of each subsystem, leading to optimal designs of power-conditioning electronics and optimal control strategies, which mitigate the electrical-feedback effects. Equally important are ''multiresolution'' finite-element modeling and simulation studies, which can predict the impact of changes in system-level variables (e.g., current ripple and load-transients) on the local current densities, voltages, and temperature (these parameters are very difficult or cumbersome, if not impossible to obtain) within a SOFC cell. Towards that end, for phase I of this project, sponsored by the U.S. DOE (NETL), we investigate the interactions among fuel cell, power-conditioning system, and application loads and their effects on SOFC reliability (durability) and performance. A number of methodologies have been used in Phase I to develop the steady-state and transient nonlinear models of the SOFC stack subsystem (SOFCSS), the power-electronics subsystem (PES), and the BOPS. Such an approach leads to robust and comprehensive electrical, electrochemical, thermodynamic, kinetic, chemical, and geometric models of the SOFSS, PES and application loads, and BOPS. A comprehensive methodology to resolve interactions among SOFCSS, PES and application loads and to investigate the impacts of the fast- and slow-scale dynamics of the power-conditioning system (PCS) on the SOFCSS has been developed by this team. Parametric studies on SOFCSS have been performed and the effects of current ripple and load transients on SOFC material properties are investigated. These results are used to gain insights into the long-term performance and reliability of the SOFCSS. Based on this analysis, a novel, efficient, and reliable PES for SOFC has been developed. Impacts of SOFC PCS control techniques on the transient responses, flow parameters, and current densities have also been studied and a novel nonlinear hybrid controller for single/parallel DC-DC converter has been developed
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