715 research outputs found

    Effect of carboxymethyl cellulose-based coatings incorporated with Zataria multiflora Boiss. essential oil and grape seed extract on the shelf life of rainbow trout fillets

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    To prolong the shelf life of seafood products, lipid oxidation and growth of microorganisms should be retarded. The objective of the current study was evaluating the potential application of carboxymethyl cellulose (CMC) coatings incorporated with Zataria multiflora Boiss. essential oil (ZMEO) and grape seed extract (GSE) on chemical (thiobarbituric acid reactive substances (TBARS) and total volatile basic nitrogen (TVB-N)), microbial (total viable count, lactic acid bacteria and Pseudomonas spp.) and organoleptic attributes of rainbow trout fillets during refrigerated storage for twenty days. GCeMS analysis showed that ZMEO is rich in monoterpene phenols such as thymol and carvacrol. The following results were obtained after 20 days of storage: The minimum level of TVB-N was measured in the fillets coated with CMC + 2 v/v ZMEO + 0.5 v/v GSE. The minimum number of total viable bacteria, lactic acid bacteria and Pseudomonas spp. were determined in the fillets coated with CMC + 2 v/v ZMEO + 1 v/v GSE. The fillets coated with CMC + 1 v/v ZMEO + 1 v/v GSE showed the best organoleptic properties. Our results revealed that CMC-based coatings incorporated with ZMEO and GSE could improve chemical, microbial and sensorial characteristics of rainbow trout fillets during cold storage. © 2015 Elsevier Ltd

    Dependence of chaotic behavior on optical properties and electrostatic effects in double beam torsional Casimir actuation

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    We investigate the influence of Casimir and electrostatic torques on double beam torsional microelectromechanical systems with materials covering a broad range of conductivities of more than three orders of magnitude. For the frictionless autonomous systems, bifurcation and phase space analysis shows that there is a significant difference between stable and unstable operating regimes for equal and unequal applied voltages on both sides of the double torsional system giving rise to heteroclinic and homoclinic orbits, respectively. For equal applied voltages, only the position of a symmetric unstable saddle equilibrium point is dependent on the material optical properties and electrostatic effects, while in any other case there are stable and unstable equilibrium points are dependent on both factors. For the periodically driven system, a Melnikov function approach is used to show the presence of chaotic motion rendering predictions of whether stiction or stable actuation will take place over long times impossible. Chaotic behavior introduces significant risk for stiction, and it is more prominent to occur for the more conductive systems that experience stronger Casimir forces and torques. Indeed, when unequal voltages are applied, the sensitive dependence of chaotic motion on electrostatics is more pronounced for the highest conductivity systems.Comment: 24 pages, 11 figure

    Effect of Zataria multiflora Boiss Essential Oil and Grape Seed Extract on the Shelf Life of Raw Buffalo Patty and Fate of Inoculated Listeria monocytogenes

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    The present study was conducted to investigate the effect of Zataria multiflora Boiss essential oil (ZEO) and grape seed extract (GSE) on microbial and chemical changes in raw buffalo patty at a temperature of 8C. First, chemical composition and minimum inhibitory concentration of oil against Listeria monocytogenes were identified. Then, ZEO and GSE were added in raw buffalo patties and analyzed for spoilage microorganism count, lipid oxidation, pH, sensory attributes and inoculated L.monocytogenes survival at 8C for 9 days. Results revealed that samples containing 0.1 ZEO+0.2 GSE showed significant decrease in the growth of all tested microbial groups as well as the most decrease in the level of lipid oxidation at the end of storage period. Control and samples with 0.1 ZEO were the most preferred samples by sensory panelist, indicating that ZEO and GSE can be practically applied in food systems especially in meat in order to extend the shelf life. Practical Applications: Buffalo meat is highly prone to microbial and chemical spoilage as they are rich in essential nutrients and putrefying in nature. The adverse effects of various chemical preservatives caused to attract the consumer's attention to natural alternatives. Therefore, in order to increase the shelf life and quality characteristics of meat, new processing technologies and new ingredient systems that are associated with natural and organic foods are applied. These results demonstrate the potential combined use of grape seed extract and Zataria multiflora Boiss essential oil to the meat industry in the development of novel healthy meat products with improved shelf life and superior product quality. © 2015 Wiley Periodicals, Inc

    Sensitivity of actuation dynamics on normal and lateral Casimir forces:Interaction of phase change and topological insulator materials

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    We investigated here the influence of the lateral and normal Casimir force on the actuation dynamics between sinusoidal corrugated surfaces undergoing both normal and lateral displacements. The calculations were performed for topological insulators and phase change materials that are of high interest for device applications. The results show that the lateral Casimir force becomes stronger by increasing the material conductivity and the corrugations toward similar sizes producing wider normal separation changes during lateral motion. In a conservative system, bifurcation and Poincaré portrait analysis shows that larger but similar in size corrugations and/or higher material conductivity favor stable motion along the lateral direction. However, in the normal direction, the system shows higher sensitivity on the optical properties for similar in size corrugations leading to reduced stable operation for higher material conductivity. Furthermore, in non-conservative systems, the Melnikov function with the Poincaré portrait analysis was combined to probe the possible occurrence of chaotic motion. During lateral actuation, systems with more conductive materials and/or the same but high corrugations exhibit lower possibility for chaotic motion. By contrast, during normal motion, chaotic behavior leading to stiction of the moving components is more likely to occur for systems with more conductive materials and similar in magnitude corrugations

    Dynamical Casimir actuation under non-equilibrium conditions:The influence of optical properties from different interacting bodies

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    In this work we investigated the dynamical actuation of microsystems with non-identical material components in the presence of non-equilibrium Casimir forces between Au and highly doped SiC that show significant difference in conductivity. For autonomous systems, the bifurcation and phase space analysis revealed that when the less conductive material operates at higher temperature, then at short separations the non-equilibrium force causes instability. Furthermore, for periodically driven systems the Melnikov function and Poincare portrait analysis showed that the devices are more robust against chaotic motion when the less conductive component is at low temperature at short separations. At larger separations chaotic behavior is more likely to occur for systems with the more conductive component at higher temperature.</p

    Obstructive Sleep Apnea and Hypertrophic Cardiomyopathy Obiter Dictum or More?

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    Genotype and allele frequency of CYP2C19*17 in a healthy Iranian population

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    Background: Cytochrome P450 2C19 (CYP2C19) is important in metabolism of wide range of drugs. CYP2C19*17 is a novel variant allele which increases gene transcription and therefore results in ultra-rapid metabolizer phenotype (URM). Distribution of this variant allele has not been well studied worldwide. The aim of present study was to investigate allele and genotype frequencies of CYP2C19*17 in a healthy Iranian population and compare them with other ethnic groups. Methods: One hundred eighty healthy unrelated Iranian volunteer took part in this study and were genotyped for CYP2C19 *2, *3, *17 (-3402) by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and CYP2C19*17 (-806) by a nested-PCR assays. The distribution of CYP2C19*17 polymorphism in Iranian population was then compared with other ethnic groups. Results: The CYP2C19*17 allele frequency was 21.6 in Iranian population. Among studied subjects 5.5 were homozygous for CYP2C19*17 and phenotyped as ultra-rapid metabolizers; 28.8 were genotyped as CYP2C19*1*17 (extensive metabolizers) and 3.3 as CYP2C19*2*17 (intermediate metabolizers). Conclusion: The CYP2C19*17 genetic distribution in Iranian population is similar to Middle East or European countries. The high frequency of CYP2C19*17 in Iranian population highlights the importance of this new variant allele in metabolism of CYP2C19 substrates. Thus, future association studies are required to reveal clinical consequence of this genetic polymorphism in carrier individuals

    Elevation of CD56brightCD16- lymphocytes in MDR pulmonary tuberculosis

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    Background: Protective immune responses induced in the majority of people infected with Mycobacterium tuberculosis enable them to control TB infection. Objective: The aim of this study was to investigate CD56 and CD16 positive peripheral blood mononuclear cells (PBMCs) and leukocyte subsets from multi-drug resistant pulmonary tuberculosis (MDR-TB), and compare them with nonresistant (NR) TB patients and healthy controls. Methods: 13 MDR-tuberculosis patients, 20 NR-TB individuals and 40 healthy subjects were included. Peripheral blood mononuclear cells were double stained with fluorochrome conjugated antibodies against CD56 and CD16 cell surface markers. The phenotype of positive cells was then analyzed by flow cytometry and the percent- ages of CD56+ CD16+, CD56- CD16+, CD56dimCD16+/-, and CD56brightCD16+/- subsets were calculated. Results: There was a significant decline in the percentage of CD56+CD16+ lymphocytes in both MDR and NR-TB patients compared with healthy controls. We also observed lower proportions of CD56dim/brightCD16+ in addition to higher percentages of CD56dim/brightCD16- subsets in all TB patients (p�0.05). In MDR- TB, our findings demonstrated a distinct phenotypic feature with increased levels of CD56brightCD16- in comparison with both NR-TB and healthy subjects. Conclusion: Considering the function of CD56/CD16 expressing cells in TB, we suggest that pheno- typic characteristics of PBMCs in MDR-TB may correlate with their status of drug re- sistance and probably with their high mortality rates

    Study of NGEP expression in androgen sensitive prostate cancer cells: A potential target for immunotherapy

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    Background: Prostate cancer is one of the leading causes of cancer deaths among men. New gene expressed in prostate (NGEP), is a prostate-specific gene expressed only in normal prostate and prostate cancer tissue. Because of its selective expression in prostate cancer cell surface, NGEP is a potential immunotherapeutic target. To target the NGEP in prostate cancer, it is essential to investigate its expression in prostate cancer cells. Methods: In the present study, we investigated NGEP expression in LNCaP and DU145 cells by real time and RT-PCR, flow cytometric and immunocytochemical analyses. Results: Real time and RT-PCR analyses of NGEP expression showed that NGEP was expressed in the LNCaP cells but not in DU145 cells. The detection of NGEP protein by flow cytometric and immunocytochemistry analyses indicated that NGEP protein was weakly expressed only in LNCaP cell membrane. Conclusion: Our results demonstrate that LNCaP cell line is more suitable than DU145 for NGEP expression studies; however, its low-level expression is a limiting issue. NGEP expression may be increased by androgen supplementation of LNCaP cell culture medium
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