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The structure and function of biological macromolecules change due to intermolecular deuterium bond formation or deuterium substitution with environmental D2O. In this study, surface-enhanced Raman spectroscopy (SERS) was used to detect interaction sites between D2O and ssDNA and their action mechanisms. SERS peaks of ssDNA changed with increasing D2O proportions, and the site of action mainly involved A and G bases, whose number strengthened the interaction between sequences and D2O and hence the SERS peak intensities. Fixing the number of A and G bases prevented changes in their positions from significantly altering the map. We also identified the interaction between ssDNA sequences that easily formed a G-quadruplex structure and D2O. The amplitude of the SERS peak intensity change reflected the ssDNA structural stability and number of active sites. These findings are highly significant for exploring genetic exchanges and mutations and could be used to determine the stability and structural changes of biological macromolecules. [ABSTRACT FROM AUTHOR]

Nucleic acids with G-quadruplex (G4) structures play an important role in physiological function, analysis and detection, clinical diagnosis and treatment, and new drug research and development. Aptamers obtained using systematic evolution of ligands via exponential enrichment (SELEX) screening technology do not always have the best affinity or binding specificity to ligands. Therefore, the establishment of a structure-oriented experimental method is of great significance. To study the potential of surface-enhanced Raman spectroscopy (SERS) in aptamer optimization, marine biotoxin gonyautoxin (GTX)1/4 and its G4 aptamer obtained using SELEX were selected. The binding site and the induced fit of the aptamer to GTX1/4 were confirmed using SERS combined with two-dimensional correlation spectroscopy. The intensity of interaction between GTX1/4 and G4 was also quantified by measuring the relative intensity of SERS bands corresponding to intramolecular hydrogen bonds. Furthermore, the interaction between GTX1/4 and optimized aptamers was analyzed. The order of intensity change in the characteristic bands of G4 aptamers was consistent with the order of affinity calculated using microscale thermophoresis and molecular dynamics simulations. SERS provides a rapid, sensitive, and economical post-SELEX optimization of aptamers. It is also a reference for future research on other nucleic acid sequences containing G4 structures. [ABSTRACT FROM AUTHOR]

In iterative reconstruction algorithms, it is very important to calculate the weighting factor quickly and accurately, which directly affects the reconstruction efficiency and accuracy of computed tomography images. In this paper, a new calculation method for accurate length weighting factor is developed. Firstly, the ray equation is determined according to the coordinates of the source and the ray's projection. Second, the intersections of the ray and the equidistant parallel planes along three coordinate axes are calculated, and the points intersecting with the reconstructed object are put into a set. Finally, when the X‐axis coordinates of all points in the set are different, the points are arranged according to their X‐axis coordinates; when the X‐axis coordinates of all points are same, the points are arranged according to their Y‐axis coordinates. The sorted point set is the intersections that the ray traverses the reconstructed object in sequence. The index and weighting factor of all voxels that the ray passes through can be determined by the sorted point set. Compared with the classical Siddon's method, it avoids the step of describing the intersections with parameters, and its calculation speed is increased by nearly 20%. The numerical simulations and real data reconstruction experiments are conducted to validate the proposed calculation method of exact length weighting factor. [ABSTRACT FROM AUTHOR]

Instability is a common problem in deep belief network–back propagation forecasting model, and the trend of traffic data will affect the forecasting results of the model. Therefore, this paper proposes a short-term traffic flow forecasting method based on deep belief network–support vector regression. Support vector regression classifier SVR is used at the top of the model. Data processing is from bottom to top. Firstly, at the bottom of the model, the input traffic flow data are processed differently; then, the DBN model is used to learn the traffic flow characteristics. Finally, SVR is used to predict the traffic flow at the top of the model. The average absolute error of the prediction is 9.57%, and the average relative error is 5.91%. The relationship between the predicted value and the actual traffic flow data is found through simulation experiments. The predicted value of the model proposed in this paper is in good agreement with the measured value, and the prediction accuracy is high. The model can effectively predict short-term traffic flow. Finally, compared with the traditional DBN prediction model and other common prediction models, the proposed prediction model has higher prediction accuracy. [ABSTRACT FROM AUTHOR]

In the field of artificial intelligence, the development of many technologies requires technical support for relational classification. Recently, deep learning has been applied more and more to text-based entity relationship classification tasks, but most of the previous methods need to use syntax or dependency structure feature. However, due to the time and space complexity of syntactic parsing, the structural features are inconvenient to use directly in the pre-processing stage. In addition, structural features may have serious domain dependence problems. This paper studies the current recommendation algorithm, analyzes the current research status of the recommendation system, and deeply analyzes the research of deep learning in the field of recommendation systems, based on BPSO algorithm, the context complex segmentation method is applied, and then the deep convolutional neural network is applied for feature extraction. The extracted feature set is sent to WordEmbedding, and using the technology to generates the word vector, the input layer of the CBOW is used to represent the size of the training window. The experimental results show that the model has obvious advantages over the methods proposed in other literature. It can adapt to multi-category context semantic analysis, more accurate related recommendations, and obtain a better user experience. [ABSTRACT FROM AUTHOR]

.In this note, some results concerning Abel ergodicity of quasi-pseudo-resolvents are obtained. [ABSTRACT FROM AUTHOR]

Abstract This paper deals with some mathematical models of a class of chemical ions exchange reactions which take place in the process of transport of ground water in aquifer. These models can be described by the system of four strongly coupled reaction-diffusion equations. The existence, uniqueness and boundedness of the global solutions for this kind of models axe proved by using the classical analysis and methods, such as semigroup theorey, upper -lower solutions method and energy integral. [ABSTRACT FROM AUTHOR]

In this paper, two kinds of initial boundary value problems for Kuramoto-Sivashinsky equation are considered. Some prior estimates are derived by Galerkin methods. The existence, uniqueness and regularities of the generalized global solutions and the classical global solutions for the equation are proved. Morever, the asymptotic behavior of these solutions are considered under some conditions. [ABSTRACT FROM AUTHOR]

The traditional FOO e-voting protocols adopt centralized and non-transparent count center, which leads to distrust to the center and doubts the fairness and correctness of the vote. However, blockchain is the most innovative technology in the current era and promises to solve the trust problem in the system with one center. In this paper, an improved FOO e-voting protocol is proposed using blockchain, which tries to address the limitation or weakness in existing systems. The traditional trusted third party is replaced by smart contract; specifically, our scheme is deployed using hyperledger fabric. The implementation is enforced by the consensus mechanism, which ensures the security of the blockchain. Through the analysis, the proposed scheme is proved to satisfy the necessary requirements for an e-voting protocol; meantime the trust assumption is reduced significantly. Therefore, the proposed protocol is more versatile and practical. [ABSTRACT FROM AUTHOR]

In computed tomography (CT) image reconstruction, the iterative algorithms have many advantages that the analytic algorithms don't have. However, the calculation of system matrix is time-consuming, which affects their application in real-time CT image reconstruction. In this paper, a fast system matrix calculation method is proposed on the basis of that the distance between the voxel and the adjacent rays reflects the contribution of the voxel to the ray projections. Firstly, every voxel is projected at a projection angle, and then the weighting factor is determined according to the distance between the voxel's projection and the adjacent ray projection on the detector. Finally, the ray equations and weighting factors corresponding to every voxel at all projection angles are obtained. The calculation amount of the proposed method are greatly improved compared with the current grid traversal (GT) method, and it has good parallel computing performance. In the simulation experiment, the Shepp-Logan head phantom is reconstructed by using the proposed system matrix calculation method and algebraic reconstruction technique (ART). Compared with GT method, its cost is reduced by nearly 30 %, and its acceleration ratio is four times that of the GT method. The experimental results show that it is a fast and effective method to calculate the system matrix. [ABSTRACT FROM AUTHOR]

In many applications of circular cone-beam computed tomography (CT), it is common that the reconstructed specimens are plate-like. In this paper, a novel method is presented to reconstruct plate-like specimens in a super-short scan, thus reducing imaging time and increasing practical CT system throughput. The algorithm of the proposed method is an improved backprojection-filtration (BPF) algorithm using an integral operator with a fixed integral interval. The results of numerical simulation and real data reconstructions show that the proposed method is a good choice for reconstructions of plate-like specimens, because not only can it yield images with a quality comparable to those obtained with existing algorithms, but it can also reduce imaging time and increase CT system throughput. [ABSTRACT FROM AUTHOR]