Search

AIM: To detect the expression levels of long non-coding RNA(lncRNA)X-inactive specific transcript(XIST)and silencing information regulatory factor 2 associated enzyme 1(SIRT1)in serum of patients with type 2 diabetes mellitus(T2DM), and to explore their correlation with diabetic retinopathy(DR)and their diagnostic value. METHODS: Prospective study. A total of 214 patients with T2DM admitted to our hospital from January 2022 to February 2023 were selected as the research subjects. Based on whether retinopathy occurred, they were divided into 126 cases(126 eyes)in the non-DR group and 88 cases(88 eyes)in the DR group. An additional 130 healthy individuals who underwent a physical examination during the same period were selected as the control group. The serum levels of lncRNA XIST and SIRT1 in the three groups were measured and compared. The relationship between lncRNA XIST and SIRT1 expression with DR was analyzed using Pearson's method. The receiver operating characteristic(ROC)curve was used to evaluate the predictive value of serum lncRNA XIST, SIRT1, and their combination for DR. Multivariate Logistic regression analysis was performed to investigate the factors affecting the occurrence of DR in T2DM patients.RESULTS: Compared with the control group, the levels of serum lncRNA XIST and SIRT1 in the non-DR group and DR group were successively decreased(all P

This paper combines augmented learning algorithms and data mining techniques for an intelligent recommendation system for computer course projects to optimize the allocation of learning resources and improve learning efficiency and effectiveness. The research methodology includes an improved association rule mining algorithm and an augmented learning model applying deep Q-network and adaptive reward function. The research results show that the system can effectively mine knowledge point associations and achieve personalized recommendation. In particular, the accuracy of knowledge point associations and the customized level of recommendation are improved by multi-support strategy improvement and knowledge point association correction. Experiments show that on the edX dataset, the recommendation recall reaches 0.347 at k=10 and 0.433 at k=20, significantly better than the traditional recommendation algorithm. This intelligent recommendation system can effectively improve the learning effect of computer course projects, and it has a positive impact on both learning attitude and independent learning ability, especially helping the backward students significantly and reducing the learning differences between classes.

This paper adopts a nonlinear support vector machine to categorize the information on students’ ideology and politics in colleges and universities, and completes the construction of a dynamic early warning mechanism for ideology and politics education. Firstly, it builds the early warning system, establishes the students’ civic and political information file, designs the user information module of the system, then sets the index system according to the opinions of the civic and political teachers in colleges and universities, and designs the civic and political dynamics early warning module based on this. Following the completion of the design, four groups of tests were conducted. Colleges A and B were used to implement the system for individual testing, followed by early warning testing using data from multiple colleges simultaneously. Finally, the most significant indicators were tested using group condition analysis. The various tests show that the system response speed is 322ms, which is lower than the industry requirement of 1s. Among the three metrics tested, the system accuracy of this paper is the highest, at 87.2%, 88.1%, and 80.7%, respectively. The X5 scores of 87.56% of the students in each university were generally low, in the range of 1 to 2, indicating that the students were not clear about the importance of the Civics program, but the X12 scores of 94.52% of the students were high, indicating that they believed that the Civics program should be retained. Obtaining a high level of Civics education is made possible by achieving a mission responsibility consistency score of 0.865.

The two-dimensional discriminant locally preserved projections (2DDLPP) algorithm adds a between-class weighted matrix and a within-class weighted matrix into the objective function of the two-dimensional locally preserved projections (2DLPP) algorithm, which overcomes the disadvantage of 2DLPP, i.e., that it cannot use the discrimination information. However, the small sample size (SSS) problem still exists, and 2DDLPP processes the whole original image, which may contain a large amount of redundant information in the retained features. Therefore, we propose a new algorithm, two-dimensional exponential sparse discriminant local preserving projections (2DESDLPP), to address these problems. This integrates 2DDLPP, matrix exponential function and elastic net regression. Firstly, 2DESDLPP introduces the matrix exponential into the objective function of 2DDLPP, making it positive definite. This is an effective method to solve the SSS problem. Moreover, it uses distance diffusion mapping to convert the original image into a new subspace to further expand the margin between labels. Thus more feature information will be retained for classification. In addition, the elastic net regression method is used to find the optimal sparse projection matrix to reduce redundant information. Finally, through high performance experiments with the ORL, Yale and AR databases, it is proven that the 2DESDLPP algorithm is superior to the other seven mainstream feature extraction algorithms. In particular, its accuracy rate is 3.15%, 2.97% and 4.82% higher than that of 2DDLPP in the three databases, respectively. [ABSTRACT FROM AUTHOR]

NbN, NbN-Ag and NbN/NbN-Ag multilayer nanocomposite films were successfully deposited by an arc ion plating system (AIP), and their microstructures, mechanical and tribological properties were systematically investigated. The results show that all the films had a polycrystalline structure, and the Ag in the Ag-doped films existed independently as a face-centered cubic phase. The content of Ag in NbN-Ag and NbN/NbN-Ag films was 20.11 and 9.07 at.%, respectively. NbN films fabricated by AIP technique had excellent mechanical properties, and their hardness and critical load were up to 44 GPa and 34.6 N, respectively. The introduction of Ag into NbN films obviously reduced the friction coefficient at room temperature, while the mechanical properties and wear resistance were degraded sharply in comparison with that of NbN films. However, the NbN/NbN-Ag films presented better hardness, H/E*, H3/E*2, adhesive strength and wear resistance than NbN-Ag films. Additionally, analysis of wear surfaces of the studied films and Al2O3 balls using 3D images, depth profiles, energy dispersive spectrometry (EDS) and Raman spectra indicated that the main wear mechanisms of NbN and NbN/NbN-Ag films were adhesive and oxidation wear with slight abrasive wear, while the severe abrasive and oxidation wear were the dominant wear mechanism for NbN-Ag films. [ABSTRACT FROM AUTHOR]

In this paper, a pest management predator–prey model with weak Allee effect on predator and state feedback impulsive control on prey is introduced and analysed, where the yield of predator released and intensity of pesticide sprayed are assumed to be linearly dependent on the selected pest control level. For the proposed model, the existence and stability of the order-1 periodic orbit of the control system are discussed. Meanwhile, with the aim of minimizing the input cost in practice, an optimization model is constructed to determine the optimal quantity of the predator released and the intensity of pesticide sprayed. The theoretical results and numerical simulations indicated that the number of pests can be limited to below an economic threshold and displays periodic variation under the proposed control strategy. In addition, it indicated in numerical simulations that an order-2 periodic orbit exists for some certain parameters. [ABSTRACT FROM AUTHOR]

NiCrAlY coatings were fabricated by atmospheric plasma spraying. The influence of the heat treatment on the corrosion–wear behavior of the coatings in artificial seawater was investigated. The microstructure of the coatings became denser and more homogeneous after the heat treatment. After heat treatment at 1100 °C, the coating had the fewest pores and cracks and the oxide dispersive strengthening phase of Y2O3 was clearly increased to form a layer approximately 10 nm thick and uniformly distributed in the matrix. The heat treatment effectively improved the microhardness and corrosion–wear properties of the coatings. This coating had the highest microhardness of 371.1 HV, the lowest friction coefficient, and a wear rate of 0.24 and 1.01 × 10−6 mm3/Nm and the lowest corrosion rate after heat treatment at 1100 °C, giving it excellent corrosion–wear properties. [ABSTRACT FROM AUTHOR]

In this work, the structural and mechanical properties, tribological performance, and lubrication mechanism from room temperature to 900 °C of TiN/MoS2/Ag composite films were investigated in detail. Nanostructured TiN/MoS2/Ag composite film was obtained by assembling targets using pulsed laser deposition. The incorporation of lubricant layered MoS2 and soft metal Ag led to degraded mechanical properties, which could contribute to the lower friction coefficients at low temperatures. When the temperature increased to above 500 °C, the generated high-temperature lubricant MoO3 and silver molybdates played a critical synergetic lubrication effect, which formed a layer of lubricating film and reduced the friction coefficient. Thus, the cooperation of various lubrication phases contributed to improvement of tribological performance and resulted in continuous lubrication from room temperature to 900 °C. [ABSTRACT FROM AUTHOR]

Considering the fact that the production and provision of some vaccines are ordered and governed by the government according to the history data of disease, a kind of SIR model with constant vaccination rate and impulsive state feedback control is presented. The dynamical properties of semi-continuous three-dimensional SIR system can be obtained by discussing the properties of the corresponding two-dimensional system in the limit set. The existence and uniqueness of order-1 periodic solution are discussed by using the successive function and the compression mapping theorem. A new theorem for the orbital stability of order-1 periodic solution is proved by geometric method. Finally, numerical simulations are given to verify the mathematical results and some conclusions are given. The results show that the disease can be controlled to a lower level by means of impulsive state feedback control strategy, but cannot be eradicated. [ABSTRACT FROM AUTHOR]

On the basis of the ideas of non-traditional biomanipulation control in fresh water body, a kind of nutrient-algae fish model is presented to investigate the effects of constant releasing fish on the nutrient and the algae. The threshold conditions for the extinction of the algae are obtained by discussing the stability of boundary equilibrium. The conditions for the coexistence of the algae and the fish are obtained by discussing the existence and stability of positive equilibrium. Besides, Hopf bifurcation is also analyzed by considering the parameter about the amount of the released fish. Furthermore, a kind of optimal problem is presented, and the necessary condition for the existence of the optimal solution is given by Pontryagin maximum principle. Finally, the mathematical results are verified by numerical simulations. The mathematical results show that there is a threshold amount of the released fish, above which the activity of releasing fish can control the growth of the algae and further reduce the probability of the algae bloom, but can not decrease the eutrophication level of the water body. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this work, the pulsed laser deposition (PLD) technique is applied for direct physical deposition of narrow bandgap semiconductor Bi2S3 quantum dots (QDs) on one-dimensional TiO2 nanorod arrays to fabricate quantum dots sensitized solar cells (QDSSCs). Without regard for any protective packaging or surface treatment process for binding QDs, the QDSSCs exhibit excellent stability and high energy conversion efficiency in ambient air. Through varying the laser ablation pulses, the controlled coverage of QDs on nanorods is realized and an optimal energy conversion efficiency of 3.06% is obtained under one sun illumination (AM 1.5, 100 mW cm−2). The enhanced absorption in an extended wavelength range, quick interfacial charge transfer and few recombination chances for electrons with holes are believed to contribute to the improved performance of Bi2S3 QD-sensitized solar cells. Moreover, a sputtered plasma at high velocity can collide intensely with the surface of TiO2, which enables direct atomic contact and endows the QDSSCs with high stability. These promising results provide a potential option of using the PLD technique for the fabrication of QD-based solar cells or other thin film photo-absorption materials. [ABSTRACT FROM AUTHOR]

In this work, Ni-based alloy coatings with different CeO rare earth oxide contents were deposited on carbon steel by flame spray and fusing processing. The tribological behavior of the coatings was studied using a ball-on-flat wear tester under dry sliding, ambient conditions. Hardness testing, field emission gun scanning electron microscopy with attached energy dispersive spectroscopy and oscillating friction and wear testing were employed to characterize the microhardness, microstructure and tribological properties of the coatings. The results indicated that the addition of an appropriate amount of CeO could refine and purify the microstructure. The coatings containing 5 wt% CeO exhibited the highest wear-resistant properties. Moreover, a new compound phase, CeNiB, was formed within the coatings, such that the microhardness values containing this phase were higher than those in the other coatings. Finally, the effects of CeO on the coatings and the mechanism describing the sliding wear were discussed. [ABSTRACT FROM AUTHOR]

Wireless sensing devices have been widely used in civilian and military applications over the past decade. In some application scenarios, the sensors are sparsely deployed in the field and are costly or infeasible to have stable communication links for delivering the collected data to the destined server. A possible solution is to utilize the motion of entities that are already present in the environment to provide opportunistic relaying services for sensory data. In this paper, we design and propose a new scheduling scheme that opportunistically schedules data transmissions based on the optimal stopping theory, with a view of minimizing the energy consumption on network probes for data delivery. In fact, by exploiting the stochastic characteristics of the relay motion, we can postpone the communication up to an acceptable time deadline until the best relay is found. Simulation results validate the effectiveness of the derived optimal strategy. [ABSTRACT FROM AUTHOR]