2,059 research outputs found

    Evaluation of the effects of photobiomodulation on vertebras in two rat models of experimental osteoporosis

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    The aim of this study was to evaluate the effects of photobiomodulation (PBM) on cancellous bone in rat models of ovariectomized induced osteoporosis (OVX-D) and glucocorticoid-induced osteoporosis (GIOP). The experiment comprised of nine groups. A group of healthy rats was used for baseline evaluations. The OVX-D rats were further divided into groups as follows: control rats with osteoporosis, OVX-D rats that received alendronate (1 mg/kg 60 days), OVX-D rats treated with pulsed wave laser (890 nm, 80 Hz, 900 s, 0.0061 W/cm(2), 5.5 J/cm(2), three times a week, 60 days), and OVX-D rats treated with alendronate + pulsed laser. Dexamethasone was administered to the remaining rats that were split into four groups: control, alendronate-treated rats, laser-treated rats, and GIOP rats treated with alendronate + laser. T12, L1, L2, and L3 vertebrae were subjected to laser. Results of the current study demonstrated that OVX-D and GIOP significantly decreased some stereological parameters, and type 1 collagen gene expression compared to the healthy group. There was a significant increase in osteoclast number in both OVX-D and glucocorticoid administration compared to the healthy group. However, the detrimental effect of the OVX-D procedure on bone was more serious than glucocorticoid administration. Results showed that laser alone had a detrimental effect on trabecular bone volume, and cortical bone volume in groups GIOP and OVX-D compared to those in the healthy group. Alendronate significantly improved total vertebral bone volume, trabecular bone volume, and cortical bone volume, in GIOP and OVX-D groups compared to the laser-treated groups. Furthermore, the alendronate + laser in OVX-D rats and GIOP rats produced significantly increased osteoblast number and type 1 collagen gene expression and caused a significant decrease in osteoclast number compared to the controls

    A Review On Green Methods for Synthesis of Silver Nano Particles

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    Metal nano particles are one of the most attractive aspects of nano materials in recent years. The reason for this growing attraction is because of their special physical and chemical properties, which are more enhanced from bulk material. Hence they find wide application in various fields like catalysis, photonics, optoelectronics, information storage, antibacterial applications, etc. While considering metal nano particles, electrical conductivity is one of the most important properties that can be used for humans’ benefit and should be enhanced. Silver nano particles can be used in the electronics industry as conductive fillers because of their unique properties such as high electrical and thermal conductivity, high resistance to oxidation. It is impressive that eco friendly methods are being developed for synthesizing these nano particles, using different kinds of plant extracts and water soluble component as capping agents, which results in different forms of particle morphologies. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3523

    Nonlinear free vibration analysis of tapered beams by hamiltonian approach

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    In this paper the Hamiltonian approach is applied to the analysis of the nonlinear free vibration of a tapered beam. The considered problem presents the governing equation of the nonlinear, large-amplitude free vibrations of the beams. The effect of vibration amplitude on the nonlinear frequency is considered. This analytical representation provides excellent approximations to the exact solutions for the whole range of the oscillation amplitudes, reducing the respective error of angular frequency in comparison with the Hamiltonian approach. It is predicted that those methods can find wide application in engineering problems as indicated in this paper

    Initializing an unmodulated spin chain to operate as a high quality quantum data-bus

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    We study the quality of state and entanglement transmission through quantum channels described by spin chains varying both the system parameters and the initial state of the channel. We consider a vast class of one-dimensional many-body models which contains some of the most relevant experimental realizations of quantum data-buses. In particular, we consider spin-1/2 XY and XXZ model with open boundary conditions. Our results show a significant difference between free-fermionic (non-interacting) systems (XY) and interacting ones (XXZ), where in the former case initialization can be exploited for improving the entanglement distribution, while in the latter case it also determines the quality of state transmission. In fact, we find that in non interacting systems the exchange with fermions in the initial state of the chain always has a destructive effect, and we prove that it can be completely removed in the isotropic XX model by initializing the chain in a ferromagnetic state. On the other hand, in interacting systems constructive effects can arise by scattering between hopping fermions and a proper initialization procedure. Remarkably our results are the first example in which state and entanglement transmission show maxima at different points as the interactions and initializations of spin chain channels are varied.Comment: 10 pages, 7 figure

    Role of histaminegic and calcium channels in the inhibitory effects of hydroalcoholic extract of matricaria recutita L. on isolated rabbit jejunum

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    Introduction: Considering the long traditional history of anti-inflammatory and anti-spasmodic effects of Matricria spices on the gastrointestinal system, the present study aimed to investigate the role of calcium channels and Histamine receptors in the inhibitory effects of hydroalcoholic dry extract of German chamomile (Matricaria recutita L.) on the isolated rabbit jejunum. Methods: All experiments were done on the isolated jejunum of New Zealand rabbits (1.8-2.5 kg). Dry extract of aerial parts of M. recutita was obtained by the maceration technique. The study was performed on two groups (n=6 in each group). In the first group, the effects of cumulative concentrations of M. recutita (3×10-3-1×10-2 mg/ml) on normal and K+-induced contractions (50 mM) of isolated jejunum were studied. In the second group, the inhibitory role of M. recutita (3 – 13×10-3 mg/ml) was evaluated in the presence and absence of histamine and cetrizine. In the presence and absence of 10 μM certizine, a histamine H1-antagonist, a concentration-dependent inhibitory effect of M. recutita extract in the range of 3-13×10-3 mg/ml was recorded the rabbit jejunum. Results: Results showed that EC50 of M. recutita in the absence and presence of K+ was 6.3×10-3 and 6.5×10- 3mg/ml, respectively. IC50 values for two concentrations of M. recutita (8×10-3 , 1×10-2 ) to abrogated contractive phase of Histamine was 9.55 × 10-6 and 1.57 × 10-6 μM. Cetrizine (10 μM) abolished inhibitory effects of M. recutita (IC50=3.6×10-3), (p< 0.001). Conclusion: Dry extract of matricaria recutita had inhibitory effects on the contractions of isolated rabbit jejunum. Calcium channels and histamine were involved in these antispasmodic effects

    Low-control and robust quantum refrigerator and applications with electronic spins in diamond

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    We propose a general protocol for low-control refrigeration and thermometry of thermal qubits, which can be implemented using electronic spins in diamond. The refrigeration is implemented by a probe, consisting of a network of interacting spins. The protocol involves two operations: (i) free evolution of the probe; and (ii) a swap gate between one spin in the probe and the thermal qubit we wish to cool. We show that if the initial state of the probe falls within a suitable range, and the free evolution of the probe is both unital and conserves the excitation in the zz-direction, then the cooling protocol will always succeed, with an efficiency that depends on the rate of spin dephasing and the swap gate fidelity. Furthermore, measuring the probe after it has cooled many qubits provides an estimate of their temperature. We provide a specific example where the probe is a Heisenberg spin chain, and suggest a physical implementation using electronic spins in diamond. Here the probe is constituted of nitrogen vacancy (NV) centers, while the thermal qubits are dark spins. By using a novel pulse sequence, a chain of NV centers can be made to evolve according to a Heisenberg Hamiltonian. This proposal allows for a range of applications, such as NV-based nuclear magnetic resonance of photosensitive molecules kept in a dark spot on a sample, and it opens up possibilities for the study of quantum thermodynamics, environment-assisted sensing, and many-body physics

    Land use effects on heavy metal pollution of river sediments in Guilan, southwest of the Caspian sea

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    Studies have showed the River Siahroud is the main contributor to the present pollution of Anzali Wetland in Guilan. Therefore, this study was initiated to evaluate the spatial distribution of metals pollution on the River Siahroud sediments in Guilan. Surfacial river sediment samples along this river were taken during five consecutive seasons at eight sampling stations and analyzed for availability of Fe, Mn, Pb, Zn, Cu, Cr, Cd metals. Canonical correlation demonstrated that the total organic carbon (TOC) was of great importance in co-precipitation of Zn while Cu and Pb were mainly related to hydrous iron oxides. Also, in the interest of pollutant finger printing, factor analysis showed that extractable Zn, Cu, Fe, Cd and Mn were attributed to the present agricultural fields while industrial site of Rasht City was the major contributing factor for the extended levels of Cr in the study area. Moreover, Pb level was mainly relevant to urban land use in Rasht. Cluster analysis demonstrated that there was a rising metal pollution level in the River Siahroud from upstream to downstream suggesting that Anzali Wetland pollution could be highly related to loading of heavy metals by the River Siahroud sediment

    Comparison of Antibacterial Activity of Green Synthesized Silver Nanoparticles with Different Morphologies, Using MIC Method

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    In this work silver nanoparticles were produced using tannic acid solution as reducing and capping agent. Results of UV-Vis and XRD ensured the existence of silver nanoparticles in the final samples. Nanoparticles with different morphologies were detected using FE-SEM micrographs. The antibacterial activity of the obtained silver nanoparticles was investigated against six bacteria strains (Gram-positive and Gram-negative) using Minimum Inhibitory Concentration (MIC) method. The results of MIC tests for these silver nanoparticles demonstrated the inhibition of growth for most bacteria, including Klebsiella pneumonia, Bacillus subtilis, Acinetobacter baumanii, Escherichia coli and Proteus mirabilis

    Mathematical models describing disappearance of Lucerne hay in the rumen using the nylon bag technique

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    It is essential to study the dynamics of rumen degradation of feeds before their potential use in formulating diets for ruminants. Various mathematical models have been developed to describe this degradation. The non-lagged exponential model (Model I), the lagged exponential model (Model II), the Gompertz model (Model III), and the generalized Mitscherlich model (Model IV) were examined using two alternative software (SAS and MATLAB) to determine their efficacy in accounting for variation in ruminal disappearance of dry matter (DM) and crude protein (CP) of lucerne hay from three cuttings. All models described DM degradability well (R2 &gt;0.98). Only Models I and II converged when fitted to CP degradability data (R2 &gt;0.98). It was concluded that any of these models could be used to describe the degradation of DM, whereas only Models I and II could be used to describe the degradation of CP from three cuttings of Lucerne hay. All the models that were fitted to the DM degradation data performed reasonably well, with only minor differences in goodness of fit. However, these models differed in values of the parameter estimates. Additionally, SAS failed to converge in the analyses of CP with Models III and IV, and MATLAB converged to nonsensical values with Model III. Model I might be recommended because it fitted the data well and required estimates of the fewest parameters Keywords: alfalfa hay, in situ digestion, model selection, nonlinear regressio

    Entanglement Transfer via XXZ Heisenberg chain with DM Interaction

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    The role of spin-orbit interaction, arises from the Dzyaloshinski-Moriya anisotropic antisymmetric interaction, on the entanglement transfer via an antiferromagnetic XXZ Heisenberg chain is investigated. From symmetrical point of view, the XXZ Hamiltonian with Dzyaloshinski-Moriya interaction can be replaced by a modified XXZ Hamiltonian which is defined by a new exchange coupling constant and rotated Pauli operators. The modified coupling constant and the angle of rotations are depend on the strength of Dzyaloshinski-Moriya interaction. In this paper we study the dynamical behavior of the entanglement propagation through a system which is consist of a pair of maximally entangled spins coupled to one end of the chain. The calculations are performed for the ground state and the thermal state of the chain, separately. In both cases the presence of this anisotropic interaction make our channel more efficient, such that the speed of transmission and the amount of the entanglement are improved as this interaction is switched on. We show that for large values of the strength of this interaction a large family of XXZ chains becomes efficient quantum channels, for whole values of an isotropy parameter in the region 2Δ2-2 \leq \Delta \leq 2.Comment: 21 pages, 9 figure
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