6,601 research outputs found
Prevalence of Campylobacterin chickens from different production systems
info:eu-repo/semantics/draf
Application of experimental design methodology to optimize antibiotics removal by walnut shell based activated carbon
Three-level Box-Behnken experimental design with three factors (pH, temperature and antibiotic initial concentration) combined with response surface methodology (RSM) was applied to study the removal of Metronidazole and Sulfamethoxazole by walnut shell based activated carbon. This methodology enabled to identify the effects of the different factors studied and their interactions in the response of each antibiotic. The relationship between the independent variable (sorption capacity) and the dependent variables (pH, temperature and antibiotic concentration) was adequately modelled by second-order polynomial equation. The pH factor exerted a significant but distinct influence on the removal efficiency of both antibiotics. The removal of Metronidazole is favoured by increasing pH values, with the maximum value obtained for pH 8 - upper limit of the study domain; while Sulfamethoxazole displays a maximum value around 5.5, with a decrease in the extent of adsorption as the pH increases. The best conditions, predicted by the model, for the removal of the antibiotic Sulfamethoxazole (106.9 mg/g) are obtained at a temperature of 30 °C, initial concentration of 40 mg/L and a pH value of 5.5. For the antibiotic Metronidazole, the highest removal value (127 mg/g) is expected to occur at the maximum levels attributed to each of the factors (pH = 8, Cin = 40 mg/L, T = 30 °C). The results of isotherm experiments (at 20 °C and pH 6) displayed a good agreement with the models predictions. The maximum sorption capacity, estimated by the Langmuir model, was 107.4 mg/g for Metronidazole and 93.5 mg/g for Sulfamethoxazole.This work was financially supported by the projects POCI-01-0145-FEDER-006939 (LEPABE), POCI-010145-FEDER-007265 (REQUIMTE/LAQV) funded by the European Regional Development Fund (ERDF), through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) and by national funds, through FCT - Fundação para a Ciência e a Tecnologia (LEPABE - UID/EQU/00511/2013; REQUIMTE/LAQV - UID/QUI/50006/2013) and NORTE-01-0145-FEDER-000005 – LEPABE-2-ECO-INNOVATION, supported by North Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio
Monetary policy shocks and productivity measures in the G-7 countries
An implication of two-country international real business cycle mod- els is that total factor productivity should be an exogenous stochastic process. Economic theories which feature labor hoarding, variable capacity utilization, and increasing returns predict that measured productivity shifts are not exoge- nous; instead, expansionary aggregate demand shocks should lead to an increase in measured productivity. For each of the G-7 countries, this paper measures quarterly aggregate total factor productivity for the domestic country and its rest-of-world (G-6) counterpart. In each case the domestic productivity measures are not strictly exogenous: expansionary U.S. monetary policy shocks, as well as other G-6 monetary policy shocks, lead to productivity expansions. The evi- dence indicates that international business cycle models are misspecified unless they feature endogenous productivity mechanisms.info:eu-repo/semantics/publishedVersio
The pro-resolving lipid mediator Maresin 1 ameliorates pain responses and neuroinflammation in the spared nerve injury-induced neuropathic pain: A study in male and female mice
Specialized pro-resolving mediators (SPMs) have recently emerged as promising therapeutic approaches for neuropathic pain (NP). We evaluated the effects of oral treatment with the SPM Maresin 1 (MaR1) on behavioral pain responses and spinal neuroinflammation in male and female C57BL/6J mice with spared nerve injury (SNI)-induced NP. MaR1, or vehicle, was administered once daily, on post-surgical days 3 to 5, by voluntary oral intake. Sensory-discriminative and affective-motivational components of pain were evaluated with von Frey and place escape/avoidance paradigm (PEAP) tests, respectively. Spinal microglial and astrocytic activation were assessed by immunofluorescence, and the spinal concentration of cytokines IL-1 & beta;, IL-6, IL-10, and macrophage colony-stimulating factor (M-CSF) were evaluated by multiplex immunoassay. MaR1 treatment reduced SNI-induced mechanical hypersensitivity on days 7 and 11 in both male and female mice, and appeared to ameliorate the affective component of pain in males on day 11. No definitive conclusions could be drawn about the impact of MaR1 on the affective-motivational aspects of pain in female mice, since repeated suprathreshold mechanical stimulation of the affected paw in the dark compartment did not increase the preference of vehicle-treated SNI females for the light side, during the PEAP test session (a fundamental assumption for PAEP's validity). MaR1 treatment also reduced ipsilateral spinal microglial and astrocytic activation in both sexes and marginally increased M-CSF in males, while not affecting cytokines IL-1 & beta;, IL-6 and IL-10 in either sex. In summary, our study has shown that oral treatment with MaR1 (i) produces antinociception even in an already installed peripheral NP mouse model, and (ii) this antinociception may extend for several days beyond the treatment time-frame. These therapeutic effects are associated with attenuated microglial and astrocytic activation in both sexes, and possibly involve modulation of M-CSF action in males.& nbsp;This work was supported by University of Porto/Faculty of Medicine (https://sigarra.up.pt/fmup) and ESF - European Social Fund (https://ec. europa.eu/esf/home.jsp), through NORTE2020 - North Portugal Regional Operational Programme [NORTE-08-5369-FSE-000011-Doctoral Programmes - LTS' PhD fellowship], and by Fundacao Grunenthal Portugal (https://www. fundacaogrunenthal.pt), Bolsa Jovens Investigadores em Dor 2018 - LTS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
THE IMMUNOLOGY OF EXPERIMENTAL CHAGAS' DISEASE : III. REJECTION OF ALLOGENEIC HEART CELLS IN VITRO
Experiments that consisted of incubation of Trypanosoma cruzi-sensitized lymphocytes derived from chronically infected rabbits and from rabbits repeatedly immunized with a small particle or membrane fraction derived from homogenates of T. cruzi forms, showed destruction of allogeneic, parasitized and nonparasitized heart cells in vitro. Mononuclear cells collected from peripheral blood were incubated for 1 h at 37°C to isolate the lymphocytes. Following incubation, over 99% of the cells in the supernate were lymphocytes, which were utilized in these experiments. At the start of these experiments, 70–80% of the sensitized lymphocytes were unattached, small and round, with sparse filipodia. In the ensuing hours, marked heart cell destruction, similar to that seen in an active lesion when lymphocytes invade heart tissue, were observed. After 18 h incubation, about 65–70% of the lymphocytes were attached, larger, and rough surfaced. Inhibition of monocyte migration tests, each in the presence of the antigens of subcellular fractions of T. cruzi organisms and of allogeneic heart myofibers, indicated the presence of a cross-reacting antigen common to both the parasite and the heart in the small particle or membrane fractions. The particulate antigens of the 30,000 g, 35-min fraction of heart muscle gave rise to inhibition of monocyte migration as did the counterpart fraction derived from T. cruzi organisms. The destruction of nonparasitized target heart cells by T. cruzi-sensitized lymphocytes is an in vitro model of the chronic myocarditis of Chagas' disease, and the recognition of cross-reactive antigens of the host cell by T. cruzi-sensitized lymphocytes is believed to be the pathogenic basis for subsequent tissue injury in the chronic phase of this disease
Symbolic Computation of Variational Symmetries in Optimal Control
We use a computer algebra system to compute, in an efficient way, optimal
control variational symmetries up to a gauge term. The symmetries are then used
to obtain families of Noether's first integrals, possibly in the presence of
nonconservative external forces. As an application, we obtain eight independent
first integrals for the sub-Riemannian nilpotent problem (2,3,5,8).Comment: Presented at the 4th Junior European Meeting on "Control and
Optimization", Bialystok Technical University, Bialystok, Poland, 11-14
September 2005. Accepted (24-Feb-2006) to Control & Cybernetic
Fractionation of the major whey proteins and isolation of β-Lactoglobulin variants by anion exchange chromatography
A method for the separation and fractionation of the major whey proteins from a whey protein concentrate
(WPC80) by anion-exchange chromatography coupled to a Fast Protein Liquid Chromatography
(FPLC) system is proposed. The method is based on the use of an ionic column (Mono Q) and a salt gradient
elution by increasing the ionic strength of the elution buffer (Tris–HCl 20 mM plus 0 to 1 M NaCl).
The proposed method was found to be suitable to fractionate the major whey proteins from the WPC80 in
different fractions, namely one fraction containing all the a-Lactalbumin and immunoglobulins; another
fraction containing all the bovine serum albumin; and two distinct fractions each containing a different
variant of b-Lactoglobulin. A 60.5% (w/w) recovery of the two main b-Lactoglobulin variants was
obtained
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