Effect of the Heterogeneity of Metamaterials on Casimir-Lifshitz Interaction

The Casimir-Lifshitz interaction between metamaterials is studied using a model that takes into account the structural heterogeneity of the dielectric and magnetic properties of the bodies. A recently developed perturbation theory for the Casimir-Lifshitz interaction between arbitrary material bodies is generalized to include non-uniform magnetic permeability profiles, and used to study the interaction between the magneto-dielectric heterostructures within the leading order. The metamaterials are modeled as two dimensional arrays of domains with varying permittivity and permeability. In the case of two semi-infinite bodies with flat boundaries, the patterned structure of the material properties is found to cause the normal Casimir-Lifshitz force to develop an oscillatory behavior when the distance between the two bodies is comparable to the wavelength of the patterned features in the metamaterials. The non-uniformity also leads to the emergence of lateral Casimir-Lifshitz forces, which tend to strengthen as the gap size becomes smaller. Our results suggest that the recent studies on Casimir-Lifshitz forces between metamaterials, which have been performed with the aim of examining the possibility of observing the repulsive force, should be revisited to include the effect of the patterned structure at the wavelength of several hundred nanometers that coincides with the relevant gap size in the experiments.Comment: 9 pages, 13 figures. Rewriting equations (10) and (12) and increasing the size of the lettering/numeral in figure

Organizational culture and the organizational commitment; Correlational study in hospital staffs

Organizations need the committed manpower to provide effectiveness and progress which is an important factor in order to achieve organizational goals. According to this, organizational culture increases employees commitment in the organization by their accepted norms and values. Actually, the organization environment & its prevailing culture, affects on the organizational commitment of staff. This study was conducted to assess relationship between the organizational culture and the organizational commitment among staff of elected hospirals in Tehran University of Medical Sciences. This descriptive study accomplished at 2013. The study population was hospitals affiliated to Tehran University of Medical Sciences included the two hospitals �Vali Asr� & �farabi�. Also in hospitals, study populations were all hospital staffs (Administrative and Clinical). Data collection was done using a three parts questionnaire including: the first one contains background information, the second part consists of questions related to organizational culture based on Denison model and the third part includes questions related to organizational Commitment based on Porter model. Validity and reliability were confirmed through getting the opinions of experts and using Cronbach�s alpha. Data analysis was done by SPSS software using Pearson correlation test and the test �t� to determine the relation between the areas of culture and commitment to the type of hospitals. In organizational culture, maximum average & standard deviation has been seen in professional identity (4.74±1.38). Except for the two dimentions of conflict & communication patterns, a significant relation between the organizational culture dimentions and two hospitalas was seen. Also, in the organizational commitment, the maximum average & standard deviation was seen in continuous commitment scope. Overally, average & standard deviation (3.18±0.76) has been obtained for organizational commitment component; also there was significant relation between the emotional commitment dimention & the type of the hospital. This relationship wasn�t meaningful in another dimentions. Except for the conflict dimension, there was significant correlations between the organizational culture dimension& the organizational commitment (p<0.05). Also, this correlation was between the organizational culture and the organizational commitment (r=0.552) Designing an appropriate and justified "reward mechanism" and development of "teamwork" skills between employees can increase their organizational commitment positively and improve hospital performances. © 2015, Canadian Center of Science and Education. All right reserved

Rapid and efficient ultrasonic assisted adsorption of diethyl phthalate onto FeIIFe2 IIIO4@GO: ANN-GA and RSM-DF modeling, isotherm, kinetic and mechanism study

Herein, an ultrasonic assisted dispersive magnetic solid-phase adsorption method along with a high-performance liquid chromatography system for the diethyl phthalate (DEP) removal was developed. In this regard, magnetic iron oxide/graphene oxide (MGO) nanocomposites were prepared by a simple and effective chemical co-precipitation method, followed by nucleation and growth of nanoparticles. The structure and morphology of MGO was identified by Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) spectroscopy X-ray diffraction (XRD), Vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption techniques. The interactive and main effect of parameters such as pH, adsorbent dosage, sonication time and concentration of DEP involved in the adsorption process were set within the ranges 3.0�11.0, 0.10�0.50 g L�1, 1�5 min, 5�10 mg/L, respectively. Root means square error (RMSE), mean absolute error (MAE), absolute average deviation (AAD), and coefficient of determination (R2) was employed to examine the applicability of the response surface methodology (RSM) and artificial neural network (ANN) models for the description of experimental data. Compared to RSM, the ANN showed a more accurate performance for modeling the process of DEP adsorption. Using genetic algorithm-ANN, optimum conditions were set to 5.38, 334.7 mg/L, 3.723 min and 4.21 mg/L for pH, adsorbent dose, sonication time and concentration of DEP, respectively. Under the optimized conditions, the maximum adsorption capacity and adsorption factors were 116.933 mg/g and 100, respectively, while the relative standard deviations (RSDs) was &lt;1.6 (N = 5). The isotherm models display that the Langmuir has the best fit with the equilibrium data, and adsorption kinetics followed the pseudo-second-order model. The thermodynamic results confirmed that the sorption was endothermic and occurred spontaneously. The results exhibited that MGO has excellent potential as an adsorbent for the removal of phthalates from the contaminated water. © 2019 Elsevier B.V

The growth, survival rate and reproductive characteristics of Artemia urmiana fed by Dunaliella tertiolecta, Tetraselmis suecica, Nannochloropsis oculata, Chaetoceros sp., Chlorella sp. and Spirolina sp. as feeding microalgae

This study was performed to compare the efficiency of six microalgae namely Dunaliella tertiolecta, Tetraselmis suecica, Nannochloropsis oculata, Chaetoceros sp., Chlorella sp. and Spirolina sp. on the growth, survival rate and reproduction efficacy in Artemia urmiana in laboratory conditions. Artemia cysts were harvested from Urmia Lake and hatched according to the standard method. Live microalgae were cultured using the f/2 culture medium. Artemia survival was determined in treatments on days 8, 11, 14, 17 and 20. A highly significant difference (p<0.01) were found among three microalgae in terms of length growth, survival rates and reproduction characteristics in A. urmiana. In spite of higher length growth of A.urmiana fed on N. oculata than A. urmiana fed by T. suecica but survival and reproduction in the latter was better than the first treatment. In general, D. tertiolecta was more efficient than other microalgae examined in the present study on A. urmiana concerning not only to growth and survival but also to reproduction mode. So, it is preferred to feed A. urmiana

Transcription and translation of human F11R gene are required for an initial step of atherogenesis induced by inflammatory cytokines

<p>Abstract</p> <p>Background -</p> <p>The F11 Receptor (F11R; aka JAM-A, JAM-1) is a cell adhesion protein present constitutively on the membrane surface of circulating platelets and within tight junctions of endothelial cells (ECs). Previous reports demonstrated that exposure of ECs to pro-inflammatory cytokines causes insertion of F11R molecules into the luminal surface of ECs, ensuing with homologous interactions between F11R molecules of platelets and ECs, and a resultant adhesion of platelets to the inflamed ECs. The main new finding of the present report is that the first step in this chain of events is the <it>de-novo </it>transcription and translation of F11R molecules, induced in ECs by exposure to inflammatory cytokines.</p> <p>Methods -</p> <p>The experimental approach utilized isolated, washed human platelet suspensions and cultured human venous endothelial cells (HUVEC) and human arterial endothelial cells (HAEC) exposed to the proinflammatory cytokines TNF-alpha and/or IFN-gamma, for examination of the ability of human platelets to adhere to the inflamed ECs thru the F11R. Our strategy was based on testing the effects of the following inhibitors on this activity: general mRNA synthesis inhibitors, inhibitors of the NF-kappaB and JAK/STAT pathways, and small interfering F11R-mRNA (siRNAs) to specifically silence the F11R gene.</p> <p>Results -</p> <p>Treatment of inflamed ECs with the inhibitors actinomycin, parthenolide or with AG-480 resulted in complete blockade of F11R- mRNA expression, indicating the involvement of NF-kappaB and JAK/STAT pathways in this induction. Transfection of ECs with F11R siRNAs caused complete inhibition of the cytokine-induced upregulation of F11R mRNA and inhibition of detection of the newly- translated F11R molecules in cytokine-inflamed ECs. The functional consequence of the inhibition of F11R transcription and translation was the significant blockade of the adhesion of human platelets to inflamed ECs.</p> <p>Conclusion -</p> <p>These results prove that <it>de novo </it>synthesis of F11R in ECs is required for the adhesion of platelets to inflamed ECs. Because platelet adhesion to an inflamed endothelium is crucial for plaque formation in non-denuded blood vessels, we conclude that the <it>de-novo </it>translation of F11R is a crucial early step in the initiation of atherogenesis, leading to atherosclerosis, heart attacks and stroke.</p

Performance evaluation of nanocomposit magnetic graphene sheet- iron oxide in removal of nitrate from water using Taguchi experimental design

Background and purpose: Nitrate is one of the chemical water contaminants which can be eliminated through physical, chemical and biological techniques. In this study we aimed for optimization of nitrate adsorption from water onto Magnetic Graphene sheet Nano Particles (G-Fe3O4 MNPs) via Taguchi experimental design. Materials and methods: Batch reactor was used for optimizing of the five parameters (pH, contact time, temperature, adsorbent dosage, and nitrate concentration) at four levels by Minitab software, based on Taguchi experimental design. Signal to noise ratio was used with �the highest is better� approach for optimization of experimental conditions and the highest nitrate removal efficiency. Results: The results revealed that in optimized status (pH=3, contact time= 60 min, initial concentration= 50 mg/L, adsorbent dose= 2g/L, temperature= 50°C) nitrate removal efficiency and adsorption capacity reached 86.4 and 39.37 mg/g, respectively. Contribution percentage of each variable implied that pH and initial concentration of nitrate with 40.20 and 7.49 had the highest and lowest influences on nitrate removal, respectively. Isotherm and kinetic studies illustrated that, nitrate adsorption complied with Langmuir isotherm model (R2>0.993) and pseudo second-order kinetics models (R2> 0.94). Conclusion: G-Fe3O4 MNPs can be used as an effective sorbent for nitrate removal from water or wastewater due to several advantages including easy and rapid separation from solution and high removal efficiency. © 2015, Mazandaran University of Medical Sciences. All rights reserved

Overexpression of UV-DAMAGED DNA BINDING PROTEIN 1 links plant development and phytonutrient accumulation in high pigment-1 tomato

Fruits of tomato plants carrying the high pigment-1 mutations hp-1 and hp-1w are characterized by an increased number of plastids coupled with enhanced levels of functional metabolites. Unfortunately, hp-1 mutant plants are also typified by light-dependent retardation in seedling and whole-plant growth and development, which limits their cultivation. These mutations were mapped to the gene encoding UV-DAMAGED DNA BINDING PROTEIN 1 (DDB1) and, recently, fruit-specific RNA interference studies have demonstrated an increased number of plastids and enhanced carotenoid accumulation in the transgenic tomato fruits. However, whole-plant overexpression of DDB1, required to substantiate its effects on seedling and plant development and to couple them with fruit phenotypes, has heretofore been unsuccessful. In this study, five transgenic lines constitutively overexpressing normal DDB1 in hp-1 mutant plants were analysed. Eleven-day-old seedlings, representing these lines, displayed up to ∼73- and ∼221-fold overexpression of the gene in hypocotyls and cotyledons, respectively. This overexpression resulted in statistically significant reversion to the non-mutant developmental phenotypes, including more than a full quantitative reversion. This reversion of phenotypes was generally accompanied by correlated responses in chlorophyll accumulation and altered expression of selected light signalling genes: PHYTOCHROME A, CRYPTOCHROME 1, ELONGATED HYPOCOTYL 5, and the gene encoding CHLOROPHYLL A/B-BINDING PROTEIN 4. Cumulatively, these results provide the missing link between DDB1 and its effects on tomato plant development

The effects of Pediococcus acidilactici as a probiotic on growth performance and survival rate of great sturgeon, Huso huso (Linnaeus, 1758)

This study was accomplished to investigate the effect of Artemia urmiana nauplii enriched with Pediococcus acidilactici as probiotic on growth performance and survival rate of great sturgeon, Huso huso. Artemia nauplii were enriched with P. acidilactici at a final concentration of 10^10 CFU mL^-1 in three time dependent treatments as 3 h (T3), 6 h (T6), 9 h (T9), and one non-enriched Artemia as the control treatment. All treatments were considered in triplicates. Since the nauplii enriched for 9 hours (T9) had the most significant CFU/g compared to other treatments (p0.05). On the other hand, a decreasing trend was recorded in food conversion ratio (FCR) and final biomass changed significantly for T9 in comparison with that recorded in the control group (p<0.05). The results indicated that P. acidilactici had a positive effect on growth and survival of beluga larvae, and a different time of enrichment had a significant effect on LAB effect. The best time of enrichment for beluga larvae was found to be 9 hours

Influence of trout farm effluents on water quality parameters and benthic macroinvertebrates

The aim of this study was to assess the influence of trout farm effluents on water quality parameters in the Dohezar Stream. In this study two trout farms and 7 stations were selected and physiochemical of water, including air and water temperatures, dissolved oxygen concentration (DO), pH, electrical conductivity (EC), water flow and biochemical oxygen demand (BOD) were measured every 30 days for one year. A combined total of 60 benthic macroinvertebrate taxa were collected from the seven sites of the stream. The results showed that trout farms had a significant impact on EC, pH, water flow and BOD in the water throughout the year and among stations (p<0.05). Only DO did not show significant differences in the one year survey. Macroinvertebrates had significant differences in abundance downstream from the trout farm effluent, particularly in stations 1 and 3 compared with others. However, the diversity of benthic macroinvertebrates significantly decreased, particularly in stations of 3, 4, 6 and 7. Regarding benthic macroinvertebrates, the abundance percentage of ephemeropterans, plecopterans and trichopterans (expressed as EPT %), and Biological Monitoring Working Party (BMWP) were much lower in station 3 than in other stations