Two Modified Three-Term Type Conjugate Gradient Methods and Their Global Convergence for Unconstrained Optimization

Two modified three-term type conjugate gradient algorithms which satisfy both the descent condition and the Dai-Liao type conjugacy condition are presented for unconstrained optimization. The first algorithm is a modification of the Hager and Zhang type algorithm in such a way that the search direction is descent and satisfies Dai-Liao’s type conjugacy condition. The second simple three-term type conjugate gradient method can generate sufficient decent directions at every iteration; moreover, this property is independent of the steplength line search. Also, the algorithms could be considered as a modification of the MBFGS method, but with different zk. Under some mild conditions, the given methods are global convergence, which is independent of the Wolfe line search for general functions. The numerical experiments show that the proposed methods are very robust and efficient

Two Modified Three-Term Type Conjugate Gradient Methods and Their Global Convergence for Unconstrained Optimization

Two modified three-term type conjugate gradient algorithms which satisfy both the descent condition and the Dai-Liao type conjugacy condition are presented for unconstrained optimization. The first algorithm is a modification of the Hager and Zhang type algorithm in such a way that the search direction is descent and satisfies Dai-Liao's type conjugacy condition. The second simple three-term type conjugate gradient method can generate sufficient decent directions at every iteration; moreover, this property is independent of the steplength line search. Also, the algorithms could be considered as a modification of the MBFGS method, but with different . Under some mild conditions, the given methods are global convergence, which is independent of the Wolfe line search for general functions. The numerical experiments show that the proposed methods are very robust and efficient

Hydrothermal Preparation of TiO₂/Graphite Nanosheets Composites and Its Effect on Electrothermal Behavior

Nowadays, carbon materials are supposed to replace the resistance wire made of metal alloy to be the next generation of heat-generating materials due to their excellent electrical conductivity and corrosion resistance. In this study, TiO2/graphite nanosheets (GNs) composite was prepared by chemical exfoliation and hydrothermal methods. XRD, FTIR, and Raman spectra confirm TiO2 particles are on the surface of GNs. SEM photographs show TiO2 nanoparticles covering the surface of the GNs uniformly. We used TiO2/GNs and sodium silicate to produce the electrothermal film coated on the glass. As compared to raw GNs, the heating rate and maximum temperature have greatly improved. In order to find the reasons for the improvement, the BET and zeta potential of TiO2/GNs were tested, and we found that the enhancement of the surface area and the dispersion to the composite by TiO2 particles and sodium silicate make the distribution of GNs more uniform

Hydrothermal Preparation of TiO2/Graphite Nanosheets Composites and Its Effect on Electrothermal Behavior

Nowadays, carbon materials are supposed to replace the resistance wire made of metal alloy to be the next generation of heat-generating materials due to their excellent electrical conductivity and corrosion resistance. In this study, TiO2/graphite nanosheets (GNs) composite was prepared by chemical exfoliation and hydrothermal methods. XRD, FTIR, and Raman spectra confirm TiO2 particles are on the surface of GNs. SEM photographs show TiO2 nanoparticles covering the surface of the GNs uniformly. We used TiO2/GNs and sodium silicate to produce the electrothermal film coated on the glass. As compared to raw GNs, the heating rate and maximum temperature have greatly improved. In order to find the reasons for the improvement, the BET and zeta potential of TiO2/GNs were tested, and we found that the enhancement of the surface area and the dispersion to the composite by TiO2 particles and sodium silicate make the distribution of GNs more uniform

The Application of Polysaccharide Biocomposites to Repair Cartilage Defects

Owing to own nature of articular cartilage, it almost has no self-healing ability once damaged. Despite lots of restore technologies having been raised in the past decades, no repair technology has smoothly substituted for damaged cartilage using regenerated cartilage tissue. The approach of tissue engineering opens a door to successfully repairing articular cartilage defects. For instance, grafting of isolated chondrocytes has huge clinical potential for restoration of cartilage tissue and cure of chondral injury. In this paper, SD rats are used as subjects in the experiments, and they are classified into three groups: natural repair (group A), hyaluronic acid repair (group B), and polysaccharide biocomposites repair (hyaluronic acid hydrogel containing chondrocytes, group C). Through the observation of effects of repairing articular cartilage defects, we concluded that cartilage repair effect of polysaccharide biocomposites was the best at every time point, and then the second best was hyaluronic acid repair; both of them were better than natural repair. Polysaccharide biocomposites have good biodegradability and high histocompatibility and promote chondrocytes survival, reproduction, and spliting. Moreover, polysaccharide biocomposites could not only provide the porous network structure but also carry chondrocytes. Consequently hyaluronic acid-based polysaccharide biocomposites are considered to be an ideal biological material for repairing articular cartilage

Reorganization of Brain Functional Network during Task Switching before and after Mental Fatigue

Mental fatigue is a widely studied topic on account of its serious negative effects. But how the neural mechanism of task switching before and after mental fatigue remains a question. To this end, this study aims to use brain functional network features to explore the answer to this question. Specifically, task-state EEG signals were recorded from 20 participants. The tasks include a 400-s 2-back-task (2-BT), followed by a 6480-s of mental arithmetic task (MAT), and then a 400-s 2-BT. Network features and functional connections were extracted and analyzed based on the selected task switching states, referred to from Pre_2-BT to Pre_MAT before mental fatigue and from Post_MAT to Post_2-BT after mental fatigue. The results showed that mental fatigue has been successfully induced by long-term MAT based on the significant changes in network characteristics and the high classification accuracy of 98% obtained with Support Vector Machines (SVM) between Pre_2-BT and Post_2-BT. when the task switched from Pre_2-BT to Pre_MAT, delta and beta rhythms exhibited significant changes among all network features and the selected functional connections showed an enhanced trend. As for the task switched from Post_MAT to Post_2-BT, the network features and selected functional connectivity of beta rhythm were opposite to the trend of task switching before mental fatigue. Our findings provide new insights to understand the neural mechanism of the brain in the process of task switching and indicate that the network features and functional connections of beta rhythm can be used as neural markers for task switching before and after mental fatigue

The Cell Death Triggered by the Nuclear Localized RxLR Effector PITG_22798 from Phytophthora infestans Is Suppressed by the Effector AVR3b

Phytopathogenic oomycetes, such as Phytophthora infestans, potentially secrete many RxLR effector proteins into plant cells to modulate plant immune responses and promote colonization. However, the molecular mechanisms by which these RxLR effectors suppress plant immune responses are largely unknown. Here we describe an RxLR effector PITG_22798 (Gene accession: XM_002998349) that was upregulated during early infection of potato by P. infestans. By employment of agroinfiltration, we observed that PITG_22798 triggers cell death in Nicotiana benthamiana. Confocal microscopic examination showed that PITG_22798-GFP (Green Fluorescent Protein) located in the host nucleus when expressed transiently in N. benthamiana leaves. A nuclear localization signal (NLS) domain of PITG_22798 is important for nuclear localization and cell death-inducing activity. Sequence alignment and transient expression showed that PITG_22798 from diverse P. infestans isolates are conserved, and transient expression of PITG_22798 enhances P. infestans colonization of N. benthamiana leaves, which suggests that PITG_22798 contributes to P. infestans infection. PITG_22798-triggered cell death is dependent on SGT1-mediated signaling and is suppressed by the P. infestans avirulence effector 3b (AVR3b). The present research provides a clue for further investigation of how P. infestans effector PITG_22798 associates with and modulates host immunity