7,197 research outputs found
The effect of Fe2Nio4 and Fe4Nio4Zn nanoparticles on hepatic, renal and spleen tissues in male wistar rat
Background and aims: Nanoparticles in a wide range of consumer products (cosmetics, health, industrial, ...) is used. The aim of this study is to evaluate the effect of the nanoparticle Fe2NiO4 and Fe4NiO4Zn on the Hepatic, Renal and Spleen Tissues.
Methods: This study of experimental was conducted on 40 male Wistar rats. The average weight was between 200-250g and divided into 5 groups. Group I: control group received 0.5ml saline. Respectively it was injected 0.5ml from second to fifth group with concentration 100 and 200 ppm of Fe4Nio4Zn and Fe2Nio4 nanoparticles. These injections were performed for 7 consecutive days with intraperitoneally injection.
Results: Results of H and E showed that Fe4NiO4Zn nanoparticles (200nm) had effect on the hepatic tissue and caused to damage tissues. Also, upper doze of (200nm) damaged to spleen tissue. Fe2NiO4 nanoparticle with doze (200nm) damaged the renal tissue, but, Fe2NiO4 nanoparticle with doze (100nm) had not no effect on hepatic, renal, and spleen tissues. The results of iron stain in the current study showed that iron has deposited on the spleen tissue in all of groups, but this iron sediment in the spleen in Fe4NiO4Zn treatment group (100, 200nm) was more compared with the control group (groups that contain zinc nanoparticles).
Conclusion: Both of Fe2NiO4 and Fe4NiO4Zn nanoparticles damage on Hepatic, renal and spleen tissues, but, damage in both of them was more in an upper doze, and iron stain showed that Fe4NiO4Zn caused more damage on spleen
Systematic Projected Shell Model Study of Even-Even Dysprosium Isotopes
Back-bending phenomenon is one of the important phenomena usually seen at high spin states of even - even heavy nuclei. As a result, any changes in the behavior of nuclear rotation, such as increase in moment of inertia versus rotational frequency can be shown in the usual back-bending plots which have been studied in many papers before. In this paper we show for the first time that these changes can be seen in the ratio of electromagnetic reduced transition probabilities B (E2) and B (M1) in even - even 152-164Dy isotopes using the Projected Shell Model (PSM) theory. The electric quadrupole transition probability B (E2) and the magnetic dipole transition probability B (M1) moments are sensitive to nuclear shape deformation and nuclear charge distribution, respectively. Our findings confirm the well-known back-bending previously seen and are in good agreement with experimental results. While intrinsic quadrupole moments are constant for each Dy isotope, the new findings show that spectroscopic quadrupole moments are increasing with spin
Growth responses and accumulation of heavy metals by fungus Agaricus bisporus
Ectomycorrhizal fungi are able to form symbiotic associations with tree roots, and therefore, plants gain different benefits. On metal-contaminated soils, these fungi may improve plant fitness through an enhanced nutrition or by reducing toxicity of the metals. Agaricus bisporus, an edible fungus has been noted to grow in large numbers under Pistacia vera plantations in orchards of Kerman, Iran, indicating that it may form ectomycorrhiza with the tree. This research describes the responses of this fungus to heavy metals in solid and liquid MMN media. The fungus was grown in vitro in liquid and solid cultures for 3 weeks on five different concentrations (0, 15, 30, 45, 60 ppm) of five heavy metals (Cu, Zn, Ni, Co, Mn) as sulphate and the effect of these metal on radial growth, biomass production and metal content of fungal biomass were determined. The result showed there was a strong variation in metal tolerance, so that Agaricus bisporus was more tolerant to Mn than other metals, while the reverse was true for Ni, so that the fungus had an increased growth in the presence of low concentrations of Co, Mn, and Zn, but Ni greatly inhibited increase in biomass and colony diameter even at concentrations as low as 15 mg/l
Chitosan-Raloxifene nanoparticle containing doxorubicin as a new double-effect targeting vehicle for breast cancer therapy
Background: treatment of breast cancer as one of the most common cancers in the world remains an important area of drug development based on nanoparticulate systems. Effective targeted therapy of affected cells based on ligand conjugate biocompatible polymeric nanoparticles is an attractive perspective in this context. Objective: In this study, a novel double effect nanoparticle based on Chitosan-Raloxifene conjugate was prepared for adjuvant therapy (hormone and chemo therapy) and drug targeting to breast cancer cells via estrogen receptor (ER). Methods: Chitosan-raloxifene conjugate was synthesized. Related nanoparticles containing doxorubicin (DOX) were prepared and characterized. Experimental design study was performed to determine the optimum levels of variables in the preparation of nanoparticle. Drug loading, release, nanoparticle stability, and the effect of nanoparticles on cell viability were evaluated. Further, inhibition tests were performed to demonstrate that the function of these novel nanoparticles is mediated via ER. Results: Chitosan-raloxifene conjugate was successfully synthesized. The prepared nanoparticles showed sizes within 25�35 nm, more than 95 drug loading, about 60 of drug release and desired stability after 24 h. XTT assay on MCF-7 cell line illustrated that these nanoparticles could inhibit the cellular growth up to 60. The results from inhibition tests revealed that prepared nanoparticles can inhibit cell growth via ER blocking. Conclusion: This study introduced chitosan-raloxifene nanoparticles containing doxorubicin as a novel targeting agent for adjuvant therapy of breast cancer. Figure not available: see fulltext.. © 2020, Springer Nature Switzerland AG
Decoupled UL/DL User Association in Wireless-Powered HetNets with Full-Duplex Small Cells
In this paper, we propose two downlink (DL)-uplink (UL) decoupled (DUDe) user association schemes in wireless-powered full-duplex (FD) heterogeneous networks (HetNets). We consider a two-tier HetNet comprising of half-duplex (HD) massive multi-antenna macrocell base stations (MBSs) and dual-antenna FD small cell base stations (SBSs) to support UL and DL transmissions of FD user equipments (UEs). Each FD UE is first associated to one MBS/SBS, based on the mean maximum received power (MMP) scheme or maximum received power (MRP) to harvest energy. During the consecutive data transmission phase, UEs choose to receive DL traffic from the same MBSs/SBSs as that associated with during energy harvesting phase, and send UL traffic through the same/another SBS. Leveraging tools from the stochastic geometry, we develop an analytical framework to analyze the average harvested energy and derive expressions for the UL and DL coverage probabilities of the proposed DUDe user association schemes. Our results show that there is an optimal value for the SBS density in the wireless-powered FD HetNets, at which both DL and UL coverage probabilities are maximized. Moreover, by applying MMPA and MRPA scheme, wireless-powered FD HetNets with DUDe achieves up to and energy efficiency gain over the FD HetNets with DL/UL coupled user association scheme and without wireless power transfer, respectively
Generation of circular polarization of the CMB
According to the standard cosmology, near the last scattering surface, the
photons scattered via Compton scattering are just linearly polarized and then
the primordial circular polarization of the CMB photons is zero. In this work
we show that CMB polarization acquires a small degree of circular polarization
when a background magnetic field is considered or the quantum electrodynamic
sector of standard model is extended by Lorentz-noninvariant operators as well
as noncommutativity. The existence of circular polarization for the CMB
radiation may be verified during future observation programs and it represents
a possible new channel for investigating new physics effects.Comment: 28 pages, v3, Phys. Rev. D 81, 084035 (2010
Preconcentration of Trace Amounts of Pb(II) Ions without Any Chelating Agent by Using Magnetic Iron Oxide Nanoparticles prior to ETAAS Determination
This work investigates the potential of magnetic Fe3O4 nanoparticles as an adsorbent for separation and preconcentration of trace amounts of lead from water samples prior to electrothermal atomic absorption spectrometry (ETAAS) determination. No chemical modifier is required in graphite furnace. Pb(II) ion was adsorbed on magnetic Fe3O4 nanoparticles in the pH range of 5.5–6.5, and then magnetic nanoparticles (MNPs) were easily separated from the aqueous solution by applying an external magnetic field; so, no filtration or centrifugation was necessary. After extraction and collection of MNPs, the analyte ions were eluted using HNO3 1.0 mol L−1. Several factors that may affect the preconcentration and extraction process, such as pH, type, and volume of eluent, amount of MNPs, sample volume, salting out effect, and interference ions were studied and optimized. Under the best experimental conditions, linearity was maintained between 0.005–0.5 ng mL−1. Detection limits for lead were 0.8 ng L−1 based on 3Sb. The relative standard deviation of seven replicate measurements of 0.05 ng mL−1 of Pb(II) ions was 3.8%. Finally, the method was successfully applied to extraction and determination of lead ions in the water and standard samples
The Effectiveness of Doctoral Program in Nursing in Iran Based on the Patrick Model
Background: Doctoral program in nursing aims to train nursing professionals and managers to improve the quality of care and ultimately to promote public health. Some critics believe that in Iran this program mostly focuses on training instructors and researchers and neither improves the function and position of nursing discipline nor meets the needs of the community.
Objectives: The present study aimed to determine the effectiveness of nursing doctoral program based on the Patrick model from the perspective of nursing doctoral students.
Materials and Methods: This cross-sectional study was conducted on 90 nursing students who were conveniently selected from seven nursing schools. A questionnaire designed based on the Patrick model was used. Descriptive statistics, simple and multiple regression analysis were used to analyze the data. Percentage of the effectiveness scores was reported.
Results: The mean score of effectiveness of the nursing doctoral program was 84.76 ± 2.73, which assumed a good level. Multiple regression analysis showed that job status and being native in the field of education explains 11% of the variance in the effectiveness score.
Conclusions: Although the efficacy of nursing doctoral program is good, however, it needs revision to enhance the outcomes of the program in order to meet public needs and to increase learners’ satisfaction
The Farsi Version of the Strength and Difficulties Questionnaire Self Report Form: The Normative Data and Scale Properties
Objective:This study was performed to evaluate the normative data and psychometric properties and the internal consistency of the Farsi (Persian) version of the Strength and Difficulties Questionnaire (SDQ) self-report form, as a screening tool in a community-based sample of 12 to 17 year-old adolescents of urban Tehran.Materials & Methods: In this investigation, 1105 adolescents (12 to 17 years old), selected from 250 clusters from all the 22 municipality areas of Tehran, responded to 25 questions of the Farsi version of SDQ self-report form. The frequency of each symptom domains according to Goodman's cutoff points and 90th percentile and the mean score in each subscale were determined.Results:The 90th percentile cutoff points were somewhat different from those of the previous reports. Using Goodman's cutoff points, the prevalence of symptom domains was relatively high. For example, 13.7 percent of the adolescents studied had total scores equal to 20 or more. There were significant correlations between different subscales and their constituting questions.Conclusion:Self-report form of SDQ is a valuable tool in the screening of adolescent psychopathologies. Frequency of majority of the symptom domains seems to be higher in the adolescents in Tehran urban areas
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