From inflation to acceleration, with phantom and canonical scalar fields in non-flat universe

AbstractMotivated by the recent work of Elizalde et al. [E. Elizalde, S. Nojiri, S.D. Odintsov, D. Saez–Gomez, V. Faraoni, Phys. Rev. D 77 (2008) 106005], we generalize their work to the non-flat case. We consider a universe filled with matter and show that it is possible to obtain both inflation and accelerated expansion at late times by using a single scalar field. Realistic examples are worked out in order to illustrate this fact. Then we extend the problem to the interacting case

Enterococcus faecium from meat, chicken and cheese

Background: Vancomycin-resistant enterococci (VRE) are important nosocomial pathogens and food chain has been considered as an assumed source for dissemination of VRE to human. Objectives: The presence of VRE isolates from food samples and typing of these isolates with Phene plate, a biochemical fingerprinting method, were investigated. Materials and Methods: Thirty samples of meat, chicken and cheese were analyzed for VRE during 2010. Antibiotic susceptibility tests and minimum inhibitory concentration (MIC) were also examined. VRE isolates were typed with the Phene plate system (PhPlate), a biochemical fingerprinting method. Results: A total of 70 VRE isolates were obtained and identified as Enterococcus faecium by species-specific PCR. All the isolates carried vanA, while none of them harbored vanB. The VRE isolates included 35, 27, and 8 isolates from meat, chicken and cheese, respectively. Typing with the PhPlate revealed a diversity index of 0.78 for E. faecium, containing 10 common and four single types. The results of antibiotic susceptibility and MIC tests showed an increased resistance to ciprofloxacin, erythromycin, ampicillin and gentamicin, to which, 100, 100, 100, and 95 of VRE isolates were resistant, respectively. Only 5 of the isolates were resistant to chloramphenicol and the MIC of the isolates for vancomycin and teicoplanin was � 256 μg/mL and for gentamicin-resistant isolates it was 1024 μg/mL. Conventional and molecular identification tests exhibited that all the isolates were E. faecium carrying vanA. None of the isolates harbored vanB. Conclusions: The results showed that enterococci are common contaminants in food. Indeed, this study indicates a high prevalence of multidrug-resistant enterococci in food of animal origin in Iran. Isolating some persisting enterococcal isolates revealed that continuous surveillance of antimicrobial resistance in enterococci from food is essential. © 2015, Ahvaz Jundishapur University of Medical Sciences

The solution of tachyon inflation in curved universe

In this paper, we have considered the curved universe which is filled by tachyonic field. We have found the exact solutions for the field, pressure, density, and scale factor and some cosmological parameters. In such universe, we have investigated the role of tachyonic field in different stages of k for the evolution of the universe. Finally we draw the graphs for the scale factor, Hubble's parameter, energy density, pressure, acceleration parameter, equation of state and potential for the different values of k. Also we obtained the exact form of field which shows that the tachyonic field has the kink form.Comment: 8 pages, 21 figure

Phytoremediation of Soils Contaminated with Heavy Metals Resulting from Acidic Sludge of Eshtehard Industrial Town using Native Pasture Plants

Phytoremediation of heavy metals is considered as an inexpensive and practical technique for purifying contaminated soil, especially when eco-friendly native pasture plants of the contaminated area are used. In this study, heavy metals in soil including Cr, Zn, Cd, Pb, and Ni and native pasture plants around Eshtehard industrial town, which were contaminated due to the entry of acidic sludge, were examined. In this regard, the hyperaccumulation and phytostabilization potential of the plants in the study area were investigated. Accordingly, A.tenuifolia in Cd, Pb and Ni, C.persica in Zn, C. arenarius in Ni, P. piptostigma in Cr and Zn, B. tectorum in Cd and Zn, S. hohenackeriana in Cr, Pb and Cd, P.aucheri in Zn, and P. harmala L in Pb and Ni.  Species with stabilizing potential include A. tenuifolia In Cd and Ni, N. persica in Zn, A.tauschii and B. tectorum in Ni, P.aucheri and P.harmala in Pb. Hyperaccumulating plants can be disposed of easily just like industrial wastes with heavy metals. Plants with stabilizing capacity can prevent the spread of heavy metal contamination to uncontaminated areas like the surrounding farms in addition to providing visual beauty for the region. Keywords: acidic sludge, heavy metals, phytoremediation, Eshtehard industrial tow

Phytoremediation of Soils Contaminated with Heavy Metals Resulting from Acidic Sludge of Eshtehard Industrial Town using Native Pasture Plants

Phytoremediation of heavy metals is considered as an inexpensive and practical technique for purifying contaminated soil, especially when eco-friendly native pasture plants of the contaminated area are used. In this study, heavy metals in soil including Cr, Zn, Cd, Pb, and Ni and native pasture plants around Eshtehard industrial town, which were contaminated due to the entry of acidic sludge, were examined. In this regard, the hyperaccumulation and phytostabilization potential of the plants in the study area were investigated. Accordingly, A.tenuifolia in Cd, Pb and Ni, C.persica in Zn, C. arenarius in Ni, P. piptostigma in Cr and Zn, B. tectorum in Cd and Zn, S. hohenackeriana in Cr, Pb and Cd, P.aucheri in Zn, and P. harmala L in Pb and Ni.  Species with stabilizing potential include A. tenuifolia In Cd and Ni, N. persica in Zn, A.tauschii and B. tectorum in Ni, P.aucheri and P.harmala in Pb. Hyperaccumulating plants can be disposed of easily just like industrial wastes with heavy metals. Plants with stabilizing capacity can prevent the spread of heavy metal contamination to uncontaminated areas like the surrounding farms in addition to providing visual beauty for the region. Keywords: acidic sludge, heavy metals, phytoremediation, Eshtehard industrial town

Dynamics of the self-interacting chameleon cosmology

In this article we study the properties of the flat FRW chameleon cosmology in which the cosmic expansion of the Universe is affected by the chameleon field and dark energy. In particular, we perform a detailed examination of the model in the light of numerical analysis. The results illustrate that the interacting chameleon filed plays an important role in late time universe acceleration and phantom crossing.Comment: 13 pages, 8 figures, to appear in Astrophysics and Space Sc

Geometric and thermodynamic properties in Gauss-Bonnet gravity

In this paper, the generalized second law (GSL) of thermodynamics and entropy is revisited in the context of cosmological models in Gauss-Bonnet gravity with the boundary of the universe is assumed to be enclosed by the dynamical apparent horizon. The model is best fitted with the observational data for distance modulus. The best fitted geometric and thermodynamic parameters such as equation of state parameter, deceleration parameter and entropy are derived. To link between thermodynamic and geometric parameters, the "entropy rate of change multiplied by the temperature" as a model independent thermodynamic state parameter is also derived. The results show that the model is in good agreement with the observational analysis.Comment: 13 pages, 13 figures, to be published in Astrophysics and Space Sc

Interacting new agegraphic Phantom model of dark energy in non-flat universe

In this paper we consider the new agegraphic model of interacting dark energy in non-flat universe. We show that the interacting agegraphic dark energy can be described by a phantom scalar field. Then we show this phantomic description of the agegraphic dark energy and reconstruct the potential of the phantom scalar field.Comment: 8 pages, no figur

Overexpression of bHLH domain of HIF-1 failed to inhibit the HIF-1 transcriptional activity in hypoxia

Background: Hypoxia inducible factor-1 (HIF-1) is considered as the most activated transcriptional factor in response to low oxygen level or hypoxia. HIF-1 binds the hypoxia response element (HRE) sequence in the promoter of different genes, mainly through the bHLH domain and activates the transcription of genes, especially those involved in angiogenesis and EMT. Considering the critical role of bHLH in binding HIF-1 to the HRE sequence, we hypothesized that bHLH could be a promising candidate to be targeted in hypoxia condition. Methods: We inserted an inhibitory bHLH (ibHLH) domain in a pIRES2-EGFP vector and transfected HEK293T cells with either the control vector or the designed construct. The ibHLH domain consisted of bHLH domains of both HIF-1a and Arnt, capable of competing with HIF-1 in binding to HRE sequences. The transfected cells were then treated with 200 μM of cobalt chloride (CoCl2) for 48 h to induce hypoxia. Real-time PCR and western blot were performed to evaluate the effect of ibHLH on the genes and proteins involved in angiogenesis and EMT. Results: Hypoxia was successfully induced in the HEK293T cell line as the gene expression of VEGF, vimentin, and β-catenin were significantly increased after treatment of untransfected HEK293T cells with 200 μM CoCl2. The gene expression of VEGF, vimentin, and β-catenin and protein level of β-catenin were significantly decreased in the cells transfected with either control or ibHLH vectors in hypoxia. However, ibHLH failed to be effective on these genes and the protein level of β-catenin, when compared to the control vector. We also observed that overexpression of ibHLH had more inhibitory effect on gene and protein expression of N-cadherin compared to the control vector. However, it was not statistically significant. Conclusion: bHLH has been reported to be an important domain involved in the DNA binding activity of HIF. However, we found that targeting this domain is not sufficient to inhibit the endogenous HIF-1 transcriptional activity. Further studies about the function of critical domains of HIF-1 are necessary for developing a specific HIF-1 inhibitor. © 2020 The Author(s)

Effect of vitamins A, E, C and omega-3 fatty acids supplementation on the level of catalase and superoxide dismutase activities in streptozotocin-induced diabetic rats

Background: Since free radicals and antioxidant enzymes may play an important role in the development of diabetes, the present study was designed to assess the effect of supplementation with vitamins A, E and C and �-3 fatty acids on catalase and superoxide dismutase activity in streptozotocin (STZ)-induced diabetic rats. Methods: A total of 64 male Wistar rats weighing 250 g were divided into four groups as normal control, diabetic control, diabetic supplemented with vitamin A, E and C and diabetic supplemented with �-3 fatty acids. After four weeks the rats were anesthetized and catalase (CAT) and superoxide dismutase (SOD) activities were investigated in blood samples, liver and heart homogenates. Results: In diabetic rats, the activity levels of heart SOD (p < 0.001) and heart and liver CAT (p < 0.001) were significantly lower than in normal control rats. Supplementation with vitamins A, E and C significantly increased heart CAT (p = 0.05). No significant change was observed in diabetic rats supplemented with �-3 fatty acids. Conclusion: Supplementation with vitamins A, E and C and �-3 fatty acids was found to increase heart CAT activity in diabetic rats and they can be valuable candidates in the treatment of the complications of diabetes