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The degradation of organic pollutants in plants involves uptake and diffusion through the roots, trunk or leaves, transformation, accumulation and/or volatilization of soil- and aqueous-phase contaminants. 2,4,6-trinitrotoluene (TNT), the most widely used explosive, is toxic to a number of photosynthetic organisms, poses hazards to human health and pollutes the environment because it is recalcitrant to degradation. In this study, we investigated the nitroreductase gene from Citrobacter freundii in transgenic Arabidopsis thaliana plants. Transgenic plants showed a promising ability to tolerate, take up and detoxify TNT. Our results suggest that transgenic plants show higher potential for removing and transformation of TNT. The expression of nitroreductase in Arabidopsis could be useful for phytoremediation and could be explored for the effective cleanup of TNT-contaminated sites. [ABSTRACT FROM AUTHOR]

It is very significant to comprehensively evaluate corrosion-resistant levels of an organic coating system after accelerated tests or outdoor exposures. In this study, the comprehensive evaluation model of the tested or exposed organic coating systems was established with Analytic Hierarchy Process (AHP) based on their eight types of the often observable and measureable failure modes, and that this model was verified by the electrochemical impedance data based on their electrochemical impedances spectroscopies (EIS). The corrosion-resistant performance levels of the tested or exposed organic coating systems were defined based on the comprehensively evaluated values. The relationship of their comprehensively evaluated values with the electrochemical impedances of the tested or exposed organic coating systems was proposed. Finally, this model was used to assess the corrosion-resistant performances of the coated aluminum alloys with three types of availably commercial organic coatings after accelerated tests. The results showed that the comprehensive evaluation model was verified to be reasonable to straightforwardly and comprehensively assess the corrosion-resistant performance levels of the tested or exposed organic coating systems after accelerated tests in a laboratory which simulate different corrosive atmospheric environments. [ABSTRACT FROM AUTHOR]

This article considers an inverse eigenvalue problem for bisymmetric matrices under a central principal submatrix constraint and the corresponding optimal approximation problem. We first discuss the specified structure of bisymmetric matrices and their central principal submatrices. Then we study a special form for the matrix of independent eigenvectors for a bisymmetric matrix. Based on these, we give some necessary and sufficient conditions for the solvability of the inverse eigenvalue problem, and we derive an expression for its general solution. Finally, we obtain an expression for the solution to the corresponding optimal approximation problem. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we consider a linear restriction problem of Hermitian reflexive matrices and its approximation. By using the properties and structure of Hermitian reflexive matrices and the special properties of reflexive vectors and anti-reflexive vectors, we convert the linear restriction problem to an equivalence problem trickily, which is a special feature of this paper and is a different method from other articles. Then we solve this problem completely and also obtain its optimal approximate solution. Moreover, an algorithm provided for it and the numerical examples show that the algorithm is feasible. [Copyright &y& Elsevier]

Abstract: A matrix is called a bisymmetric matrix if its elements satisfy the properties and for . This paper considers least squares solutions to the matrix equation for A under a central principal submatrix constraint and the optimal approximation. A central principal submatrix is a submatrix obtained by deleting the same number of rows and columns in edges of a given matrix. We first discuss the specified structure of bisymmetric matrices and their central principal submatrices. Then we give some necessary and sufficient conditions for the solvability of the least squares problem, and derive the general representation of the solutions. Moreover, we also obtain the expression of the solution to the corresponding optimal approximation problem. [Copyright &y& Elsevier]

Abstract: In this paper, an inverse problem of constructing a linear n degree of freedom mass-spring system from part of its physical parameters and part of modality of its maximal or minimal natural frequencies is considered. The solvability and the expression of the solution is derived. The numerical algorithms and some numerical examples are given. [Copyright &y& Elsevier]

Abstract: An iteration method for the matrix equation AX = B is constructed. By this iteration method, the least-norm solution for the matrix equation can be obtained when the matrix equation is consistent and the least-norm least-squares solutions can be obtained when the matrix equation is not consistent. The related optimal approximation solution is also obtained by this iteration method. A preconditioned method for improving the iteration rate is put forward. Finally, some numerical examples are given. [Copyright &y& Elsevier]

Abstract: This paper mainly discusses the following two problems: The necessary and sufficient conditions for the existence of and the expressions for the general solutions of Problem I are given. Moreover, the optimal approximation solution, an algorithm and a numerical example of Problem II are provided. [Copyright &y& Elsevier]

Abstract: Let ∥·∥ be the Frobenius norm of matrices. We consider (I) the set S E of symmetric and generalized centro-symmetric real n × n matrices R n with some given eigenpairs (λ j , q j ) (j =1,2,…, m) and (II) the element in S E which minimizes for a given real matrix R ∗. Necessary and sufficient conditions for S E to be nonempty are presented. A general form of elements in S E is given and an explicit expression of the minimizer is derived. Finally, a numerical example is reported. [Copyright &y& Elsevier]

Abstract: We study the completion problem for an orthogonal projector A of from knowledge of one or several of its columns, as well as the related matrix inverse problem of finding an orthogonal projector A with AX =Y for two given n by k matrices X and Y. Using geometric properties of orthogonal projections and of the singular value decomposition, we derive theoretical and numerical solutions for these problems. We give algorithms and test their MATLAB implementations. [Copyright &y& Elsevier]

Abstract: An n×n real matrix X is said to be a skew-symmetric orthogonal matrix if XT=−X and XTX=I. Using the special form of the C–S decomposition of an orthogonal matrix with skew-symmetric k×k leading principal submatrix, this paper establishes the necessary and sufficient conditions for the existence of and the expressions for the skew-symmetric orthogonal solutions of the matrix equation AX=B. In addition, in corresponding solution set of the equation, the explicit expression of the nearest matrix to a given matrix in the Frobenius norm have been provided. Furthermore, the Procrustes problem of skew-symmetric orthogonal matrices is considered and the formula solutions are provided. Finally an algorithm is proposed for solving the first and third problems. Numerical experiments show that it is feasible. [Copyright &y& Elsevier]

In this paper, we consider least-square solutions of inverse problem for Hermitian generalized Hamiltonian matrices and their optimal approximation. We obtain a general expression of the least-square solution by using the singular value decomposition method. For any n × n complex matrix, we derive the representation of its unique optimal approximation in the least-square solutions set. [Copyright &y& Elsevier]

The necessary and sufficient conditions for the solvability of the inverse eigenvalue problem AX=XΛ over the class of the symmetrizable matrices are discussed, the general expression of the solution is given. Moreover, the related optimal approximation problem to a given matrix over the solution set is solved. [Copyright &y& Elsevier]

In this paper, we are concerned with the following two problems. In Problem I, we describe the set S of real n × n symmetric and antipersymmetric matrices such that minimize the Frobenius norm of LG − E for G, E in Rn × n. In Problem II, we find the unique Lˇ in the setsfS, satisfying ∥L* − L∥ = minL∊S ∥L* − L∥, where L* ∊ Rn × n is a given matrix and ∥ · ∥ is the Frobenius norm. We derive a general expression of the set S. For Problem II, we prove the existence and the uniqueness of the solution and provide the expression of this unique solution. We also report some numerical results to support the theory established in the paper. [Copyright &y& Elsevier]

Purpose. The purpose of this study was to examine the effects of Baduanjin sequential therapy (BST) on the quality of life and cardiac function in patients with AMI after PCI. Subjects. 96 patients with AMI after PCI were randomly assigned as subjects to two groups: BST group who received 24 weeks of BST training and control group who received no training. Methods. The methods used in this study included the changes in SF-36 subscales, the measures of left ventricular ejection fraction (LVEF), N-terminal pro-B-type natriuretic peptide (NT-pro-BNP), the body mass index (BMI), and the abdominal circumference. Results. Of the 96 participants, 82 total patients completed the entire study. At 12 weeks, role physical and health transition of SF-36 were significantly different between the two groups, with a difference of 26.12 (95% CI, 11.59 to 40.64) in role physical and a difference of 15.94 (95% CI, 5.60 to 26.28) in health transition (p < 0.05). However, there were statistically significant differences in all aspects of SF-36 between the two groups at 24 weeks (p < 0.05). The BST also lowered abdominal circumference and BMI as compared with the control group. In the 24-week follow-up, a significant difference was found in the decline of the LVEF in the control group (p = 0.020), while there was a nonsignificant difference in the BST group (p = 0.552). Compared with the control group, the BST group reduced 50 pg/ml on the NT-pro-BNP at 24 weeks (p = 0.013). The effects of BST exercise were maintained at 24 weeks after the intervention. No serious adverse events were observed. Conclusions. The BST appears to improve the quality of life in patients with AMI after PCI, with additional benefits of lowered abdominal circumference and BMI and improved level of cardiac function. This trial is registered with NCT02693795. [ABSTRACT FROM AUTHOR]

Compared to single coatings, multiple-layer coatings or composite coatings could provide better and more durable corrosion protection to magnesium alloys. In this paper, a MgAl-LDH/Ni composite coating was successfully prepared on magnesium alloy AZ31B via preparation of a LDH primer, an electroless-deposited Ni-B (ENB) intermediate layer, and an electroless-deposited Ni-P(ENP) top layer. The surface morphologies, chemical compositions, and corrosion resistance of the composite coating were characterized and discussed. The results showed that nano-scale Ag particles acting as the activation sites were introduced onto the surface of the LDH layer after the activation process. Ni particles were deposited in the areas where Ag particles exist, and an intact Ni-B layer formed after 15 min of ENB plating. The total thickness of the composite coating is about 38 µm, in which the LDH layer is ~13 µm, and the EN coating is ~25 µm. The composite coating does not show any perforation after exposure to a 3.5 wt% NaCl solution for 210 h or 0.1 mol·dm−3 HCl solution for 30 h, attributed to the amorphous structure of the electroless-deposited nickel layer and the P-rich layer formed at the surface to hamper nickel oxidation. In comparison, obvious corrosion holes appeared on the LDH coating after immersion in a 3.5 wt% NaCl solution for 20 h or in a 0.1 mol·dm−3 HCl solution for 30 min. Furthermore, the EIS test results confirmed the durable corrosion protection of the composite coating to the magnesium alloy substrate. [Display omitted] [ABSTRACT FROM AUTHOR]