K-Carrageenan Stimulates Pre-Osteoblast Proliferation and Osteogenic Differentiation: A Potential Factor for the Promotion of Bone Regeneration?

Current cell-based bone tissue regeneration strategies cannot cover large bone defects. K-carrageenan is a highly hydrophilic and biocompatible seaweed-derived sulfated polysaccharide, that has been proposed as a promising candidate for tissue engineering applications. Whether κ-carrageenan can be used to enhance bone regeneration is still unclear. In this study, we aimed to investigate whether κ-carrageenan has osteogenic potential by testing its effect on pre-osteoblast proliferation and osteogenic differentiation in vitro. Treatment with κ-carrageenan (0.5 and 2 mg/mL) increased both MC3T3-E1 pre-osteoblast adhesion and spreading at 1 h. K-carrageenan (0.125–2 mg/mL) dose-dependently increased pre-osteoblast proliferation and metabolic activity, with a maximum effect at 2 mg/mL at day three. K-carrageenan (0.5 and 2 mg/mL) increased osteogenic differentiation, as shown by enhanced alkaline phosphatase activity (1.8-fold increase at 2 mg/mL) at day four, and matrix mineralization (6.2-fold increase at 2 mg/mL) at day 21. K-carrageenan enhanced osteogenic gene expression (Opn, Dmp1, and Mepe) at day 14 and 21. In conclusion, κ-carrageenan promoted MC3T3-E1 pre-osteoblast adhesion and spreading, metabolic activity, proliferation, and osteogenic differentiation, suggesting that κ-carrageenan is a potential osteogenic inductive factor for clinical application to enhance bone regeneration.     

Damped vibration of a graphene sheet using a higher-order nonlocal strain-gradient Kirchhoff plate model

A higher-order nonlocal strain-gradient model is presented for the damped vibration analysis of single-layer graphene sheets (SLGSs) in hygrothermal environment. Based on Kirchhoff plate theory in conjunction with a higher-order (bi-Helmholtz) nonlocal strain gradient theory, the equations of motion are obtained using Hamilton's principle. The higher-order nonlocal strain gradient theory has lower- and higher-order nonlocal parameters and a material characteristic parameter. The presented model can reasonably interpret the softening effects of the SLGS, and indicates a reasonably good match with the experimental flexural frequencies. Finally, the roles of viscous and structural damping coefficients, small-scale parameters, hygrothermal environment and elastic foundation on the vibrational responses of SLGSs are studied in detail.     

A novel technique for active vibration control,based on optimal tracking control

Determination of concentration of major elements such as Ca, Si, Al, and Fe in cement is very important for quality control during its production, correct classification according to the existing standards, and thus for appropriate use in the construction industry. For this purpose, neutron activation analysis is very suitable. In this preliminary theoretical work, the irradiation and consecutive measurement of the percentage of the constituent elements in different cement samples were done using MCNPX with γ-ray spectra as the output. Specific peaks of Ca, Si, Al, and Fe obtained from these spectra were used as input for artificial neural network (18 of them for training and 8 for testing) resulting in the determination of each element in the given sample. The mean absolute errors of the results are less than 0.4%, which is very promising for the future experimental work where the uncertainties are usually one order higher.     

Specific Fluorescence Probe for Direct Recognition of Dimethoate Using Molecularly Imprinting Polymer on ZnO Quantum Dots

ZnO quantum dots (QDs) based molecularly imprinting polymer (MIP)-coated composite was described for specific detection of the dimethoate (DM) as a template. The MIP was synthesized by simple self-assembly of 3-aminopropyl triethoxysilane (APTES) monomers and tetraethyl ortho-silicate as cross linking agent in the presence of template molecules. The used imprinting course can improve the tendency of the prepared QDs toward the DM template molecules. The MIP-coated ZnO QDs showed a strong fluorescence emission which undergoes a quenching effect in the presence of DM. So, a selective probe could be designed based on these composites to recognize DM in water samples. Under optimized experimental conditions, a linear relationship between the emission intensity of MIP-coated ZnO QDs and concentration of DM, in the range of 0.02–3.2 mg L^?1 with a detection limit of 0.006 mg L^?1. Combination of high specificity of MIP element and distinct fluorescence features of ZnO QDs provides a sensitive and selective recognizing method for pesticide detection. The developed method was successfully applied for the determination of DM contamination in environmental water samples.     

An Upper Bound for the Total Domination Subdivision Number of a Graph

A set S of vertices of a graph G = (V, E) without isolated vertex is a total dominating set if every vertex of V(G) is adjacent to some vertex in S. The total domination number γ _t (G) is the minimum cardinality of a total dominating set of G. The total domination subdivision number sd_gt(G){{\rm sd}_{\gamma_t}(G)} is the minimum number of edges that must be subdivided (each edge in G can be subdivided at most once) in order to increase the total domination number. In this paper, we prove that sd_gt(G) ￡ 2g_t(G)-1{{\rm sd}_{\gamma_t}(G)\leq 2\gamma_t(G)-1} for every simple connected graph G of order n ≥ 3.     

Photodegradation kinetics of some thiols and thiones in aqueous suspension of zinc oxide

Photodegradation of several thiols and thiones including 2-pyrimidinethiol, thiazolidine-2-thione, imidazolidine-2-thione, 1,2,4- triazole 3-thiol and 2,5-dimercapto- 1,3,4-thiadiazole have been studied in aerated aqueous solution using zinc oxide under irradiation with 400W high pressure mercury lamp. Rate constants span the range from 2.44 x 10(-2) min x (-1) to 1.76 x 10(-1) min x (-1). The slower degradation rate of 2-imidazoline 2-thione could be related to oxidation potential of the corresponding ring. The Langmuir-Hinshelwood (L-H) rate constant k(r) and adsorption constant, (KA) for all five thiols and thiones are reported.     

Relativistic Oscillators in a Noncommutative Space and in a Magnetic Field

In this work, we study the relativistic oscillators in a noncommutative space and in a magnetic field. It is shown that the effect of the magnetic field may compete withthat of the noncommutative space and that is able to vanish the effect of the noncommutative space.     

Quantum correlations of helicity entangled states in non-inertial frames beyond single mode approximation

A helicity entangled tripartite state is considered in which the degree of entanglement is preserved in non-inertial frames. It is shown that Quantum Entanglement remains observer independent. As another measure of quantum correlation, Quantum Discord has been investigated. It is explicitly shown that acceleration has no effect on the degree of quantum correlation for the bipartite and tripartite helicity entangled states. Geometric Quantum Discord as a Hilbert–Schmidt distance is computed for helicity entangled states. It is shown that living in non-inertial frames does not make any influence on this distance, either. In addition, the analysis has been extended beyond single mode approximation to show that acceleration does not have any impact on the quantum features in the limit beyond the single mode. As an interesting result, while the density matrix depends on the right and left Unruh modes, the Negativity as a measure of Quantum Entanglement remains constant. Also, Quantum Discord does not change beyond single mode approximation.     

Preparation of new supramolecular liquid-crystalline polyesters containing 3-chloro-4-(alkoxy)benzoic acids

Supramolecular liquid-crystalline polyester complexes based on intermolecular hydrogen bonds between the carboxylic group and the pyridyl moieties was prepared by using non-liquid-crystalline H-donors, [3-chloro-4-(butyloxy)benzoic acid (2a), 3-chloro-4-(octyloxy)benzoic acid (2b), 3-chloro-4-(dodecyloxy)benzoic acid (2c) and 3-chloro-4-(tetradecyloxy)benzoic acid (2d)] and H-acceptor-polyester containing pyridyl units. Intermolecular hydrogen bond formation was confirmed by Fourier transform infrared spectroscopy. The liquid-crystalline behavior of the complex formed was established by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). The polyester complexes containing 2c and 2d donor components exhibit liquid crystalline mesophase and behave as side-chain liquid-crystalline polymers. Compared with unsubstituted parent acid, the presence of chloro group as a lateral substituent has a little negative effect on the induction of liquid crystallinity on the polyester complexes systems. The results show that the more stability of the obtained H-bonded complexes in comparison with analogues without 3-Cl substituents is due to the increased acidity of benzoic acid moiety.     

Investigation of Preparation up to Six and N-Atom Graph States

The aims of this paper is to propose a feasible scheme for preparation of graph states up to six vertices, which are not equivalent under LU (Local unitary) transformations and graph isomorphisms, and special kind of N-atoms graph state (GHZ state, cluster state, ring state and complete state). First we show a two-qubit system (two-atoms with two-levels) how to acquire the maximal entanglement after interaction time t _c . Then, we generalize this method to mentioned above cases.