Adaptive Event-triggered Control of a Class of Series Elastic Actuator System

Tingting Gao,Jiangshuai Huang,Rui Ling,Yong Zhou 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.7

In this paper, the event-triggered adaptive control for a class of series elastic actuator systems is considered. To solve this problem, firstly we propose an adaptive control scheme with a novel one-step design framework such that both the controller expression and parameter estimator are much simpler than related existing recursive design approaches. Then a set of event-triggering conditions is designed which is updated for each triggering. The ISS assumption is not needed for control design. It is shown that the proposed control schemes guarantee that allthe closed-loop signals are semi-globally bounded and the stabilization error converges to the origin asymptotically. The Zeno behavior is avoided. Simulation results illustrate the effectiveness of our scheme.

Parental Psychological Aggression and Phubbing in Adolescents: A Moderated Mediation Model

Tingting Gao,Songli Mei,Hua Cao,Leilei Liang,Chengchao Zhou,Xiangfei Meng 대한신경정신의학회 2022 PSYCHIATRY INVESTIGATION Vol.19 No.12

Objective The present study aimed to examine the mediated moderation effect underlying the association between parental psychological aggression and phubbing, as well as the mediating role of anxiety and moderating role of sex and grade. Methods Based on a cross-sectional study, a total of 758 Chinese junior high school students had completed measures on socio-demographic characteristics, parental psychological aggression, anxiety and phubbing. Structural equation modeling was adopted to examine the mediating effect of anxiety on the association between parental psychological aggression and phubbing. Multigroup analyses were conducted to explore whether the path coefficients differed by sex and grade. Results Mediation analysis indicated that anxiety could mediate the association between parental psychological aggression and phubbing. The indirect effect of parental psychological aggression on phubbing via anxiety was 0.12. Multigroup analyses revealed that the higher mediation effect of anxiety was more likely to be reported by boys and students from grade eight. Conclusion Findings of the present study may inform prevention and intervention programs for phubbing in adolescents exposed to parental psychological aggression, by decreasing the anxiety and adopting selective strategies for different sex and grade groups.

Lactic acid bacterial inoculant effects on the vitamin content of alfalfa and Chinese leymus silage

Tingting Jia,Zhiqiang Sun,Run Gao,Zhu Yu 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.12

Objective: Information regarding the vitamin content of silage is limited. This study investigated the changes in the vitamin content of alfalfa and Chinese leymus silages with or without a lactic acid bacterial inoculant. Methods: Alfalfa at the early flowering stage and Chinese leymus at the full-bloom stage were harvested. The treatments for each forage type were control (deionized water only) and 1×106 colony-forming units Lactobacillus plantarum (LP)/g fresh matter. After 45 days of ensiling, all silages were sampled for evaluating the vitamin content, fermentation quality and chemical composition. Results: The LP inoculant decreased the pH value and ammonia nitrogen content of the alfalfa and Chinese leymus silages and significantly (p<0.05) increased the lactic acid, acetic acid concentrations and Flieg’s points. Prior to ensiling, the levels of five B-group vitamins (thiamin, riboflavin, niacin, pantothenic acid, and pyridoxine) and α-tocopherol in alfalfa were significantly (p<0.01) higher than those in Chinese leymus. Ensiling decreased the levels of the five B-group vitamins in both alfalfa and Chinese leymus while increasing the α-tocopherol content of Chinese leymus. The thiamin, riboflavin, niacin and pantothenic acid levels in the LP-treated silage were significantly (p<0.05) lower than those in the untreated silage for the alfalfa and Chinese leymus. The α-tocopherol content in the LP-treated alfalfa silage was significantly (p<0.05) higher than that in the untreated alfalfa silage. There was no significant (p>0.05) difference in pyridoxine content between the untreated and LP-treated silages for both forages. Conclusion: With or without LP inoculation, the levels of the five B-group vitamins (thiamin, riboflavin, niacin, pantothenic acid, and pyridoxine) in alfalfa and Chinese leymus decreased after 45 days of ensiling, while the α-tocopherol content of Chinese leymus increased. The LP inoculant improved the fermentation quality of both the alfalfa and Chinese leymus silages but increased the thiamin, riboflavin, niacin, and pantothenic acid loss in the two forages after fermentation.

Immunomodulatory effects of Clostridium butyricum on human enterocyte-like HT-29 cells

Gao Quanxin,Wang Jinbo,Qi Lili,Wu Tianxing,Xia Tingting 한국통합생물학회 2013 Animal cells and systems Vol.17 No.2

Oral administration of Clostridium butyricum as probiotics is increasingly gaining importance in the treatment of intestinal inflammations and improvement of animal performance. The mechanisms of host cell receptor recognition of C. butyricum and downstream immune signaling pathways leading to this beneficial event, however, remain unclear. In this study, C. butyricum was investigated for its capability to influence the innate immune response of HT-29 cells to explore its mechanism of action. Our data showed that C. butyricum was able to stimulate toll-like receptor 2 (TLR2) production at mRNA level; however, TLR4, TLR5, TLR9, and myeloid differentiation primary response protein 88 (MyD88) transcription levels remain unaltered. The nuclear factor kB (NF-kB), interleukin-8 (IL-8), and tumor necrosis factor alpha (TNF-a) levels in response to C. butyricum were significantly increased, indicating that HT-29 cells were sensitised by C. butyricum. It is the first time that our findings have showed the specific signaling pathways in HT-29 cells stimulated by C. butyricum, which, at least in part, can help to explain the beneficial properties of C. butyricum.

Growth Inhibitory and Pro-Apoptotic Effects of Hirsuteine in Chronic Myeloid Leukemia Cells through Targeting Sphingosine Kinase 1

Gao Shan,Guo Tingting,Luo Shuyu,Zhang Yan,Ren Zehao,Lang Xiaona,Hu Gaoyong,Zuo Duo,Jia Wenqing,Kong Dexin,Yu Haiyang,Qiu Yuling 한국응용약물학회 2022 Biomolecules & Therapeutics(구 응용약물학회지) Vol.30 No.6

Chronic myeloid leukemia (CML) is a slowly progressing hematopoietic cell disorder. Sphingosine kinase 1 (SPHK1) plays established roles in tumor initiation, progression, and chemotherapy resistance in a wide range of cancers, including leukemia. However, small-molecule inhibitors targeting SPHK1 in CML still need to be developed. This study revealed the role of SPHK1 in CML and investigated the potential anti-leukemic activity of hirsuteine (HST), an indole alkaloid obtained from the oriental plant Uncaria rhynchophylla, in CML cells. These results suggest that SPHK1 is highly expressed in CML cells and that overexpression of SPHK1 represents poor clinical outcomes in CML patients. HST exposure led to G2/M phase arrest, cellular apoptosis, and downregulation of Cyclin B1 and CDC2 and cleavage of Caspase 3 and PARP in CML cells. HST shifted sphingolipid rheostat from sphingosine 1-phosphate (S1P) towards the ceramide coupled with a marked inhibition of SPHK1. Mechanistically, HST significantly blocked SPHK1/S1P/S1PR1 and BCR-ABL/PI3K/Akt pathways. In addition, HST can be docked with residues of SPHK1 and shifts the SPHK1 melting curve, indicating the potential protein-ligand interactions between SPHK1 and HST in both CML cells. SPHK1 overexpression impaired apoptosis and proliferation of CML cells induced by HST alone. These results suggest that HST, which may serve as a novel and specific SPHK1 inhibitor, exerts anti-leukemic activity by inhibiting the SPHK1/S1P/ S1PR1 and BCR-ABL/PI3K/Akt pathways in CML cells, thus conferring HST as a promising anti-leukemic drug for CML therapy in the future.

Energy-Saving for a Velocity Control System of a Pipe Isolation Tool Based on a Reinforcement Learning Method

Tingting Wu,Hong Zhao,Boxuan Gao,Fanbo Meng 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.1

The pipe isolation tool (PIT) demonstrates remarkable advantages in safety and efficiency compared with traditional plugging devices. However, its utilization in plugging operations is limited by the operation duration. In addition, the existing energy recovery system has low energy saving efficiency. In this paper, a real-time control energy-saving system of the PIT was designed based on a reinforcement learning algorithm. First, an experimental device for energy-saving was designed. Secondly, the energy distribution scheme of a hydraulic pump and accumulator based on experimental data was proposed. Finally, the reinforcement learning algorithm was used to adjust the opening of the hydraulic pump and the accumulator valves in real time during the plugging process to improving energy saving efficiency. The results verify that the energy saving efficiency of the PIT control system based on reinforcement learning could reach 23.71%, which satisfies the objectives of energy-saving and environmental applicability.

DHEM: a deep heat energy method for steady-state heat conduction problems

Huanhuan Gao,Wenjie Zuo,Zengming Feng,Jinxing Yang,Tingting Li,Ping Hu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.11

Based on the deep energy method recently brought forward to handle linearelastic or hyper-elastic finite deformation problems in solid mechanics, in this paper, we propose a deep heat energy method (DHEM) which is specially tailored to deal with structural steady-state heat conduction problems with the help of deep learning techniques. In our work, the deep neural networks are utilized to construct the admissible temperature fields; secondly, the potential energy functional in the heat conduction process which works as the loss function of the deep neural networks is calculated by numerical integration techniques; finally, the parameters of the network including weights and bias, are optimized by the quasi-Newton method to yield the minimal of the potential energy functional which indicates the heat conduction has entered a steady state. Numerical examples with a diversity of materials, including the isotropic and homogeneous material, the orthotropic material, the non-homogeneous materials and temperature dependent materials, are carried out to illustrate the validity and capacity of DHEM in both linear uncoupled and thermal-material coupling heat conduction problems.

Backbone Cyclization of Flavin Mononucleotide-Based Fluorescent Protein Increases Fluorescence and Stability

Lin Tingting,Ge Yuanyuan,Gao Qing,Zhang Di,Chen Xiaofeng,Hu Yafang,Fan Jun 한국미생물·생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.12

Flavin mononucleotide-binding proteins or domains emit cyan-green fluorescence under aerobic and anaerobic conditions, but relatively low fluorescence and less thermostability limit their application as reporters. In this work, we incorporated the codon-optimized fluorescent protein from Chlamydomonas reinhardtii with two different linkers independently into the redox-responsive split intein construct, overexpressed the precursors in hyperoxic Escherichia coli SHuffle T7 strain, and cyclized the target proteins in vitro in the presence of the reducing agent. Compared with the purified linear protein, the cyclic protein with the short linker displayed enhanced fluorescence. In contrast, cyclized protein with incorporation of the long linker including the myc-tag and human rhinovirus 3C protease cleavable sequence emitted slightly increased fluorescence compared with the protein linearized with the protease cleavage. The cyclic protein with the short linker also exhibited increased thermal stability and exopeptidase resistance. Moreover, induction of the target proteins in an oxygen-deficient culture rendered fluorescent E. coli BL21 (DE3) cells brighter than those overexpressing the linear construct. Thus, the cyclic reporter can hopefully be used in certain thermophilic anaerobes.

Preparation and characterization of vanillin-conjugated chitosan-stabilized emulsions via a Schiff-base reaction

Jianfei Zhu,Tingting Huang,Xiaomei Chen,Dongling Tian,Lei Wang,Ruiping Gao 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.11

In the current work, vanillin-conjugated chitosan stabilized emulsions (CSVAEs) were successfully prepared and its characterization and antibacterial properties were investigated. Under stirring condition, CSVAEs were produced by a Schiff base reaction between the vanillin aldehyde group and the chitosan active amino group. The CSVAEs were described through Fourier transform infrared spectroscopy, X-ray diffraction, ultraviolet spectrophotometry and thermogravimetric analysis, which demonstrated the generation of Schiff bases between vanillin and chitosan. Furthermore, the CSVAEs displayed differences at different pH values, indicating their potential as pH-responsive materials. By studying their release behavior, pH 4 was a critical point at which the properties of the CSVAEs changed. The antibacterial tests showed that the CSVAEs had good pH-responsive antibacterial abilities against Staphylococcus aureus and Escherichia coli.

Photodegradation of 17α-ethynylestradiol in nitrate aqueous solutions

Dong Ren,Tingting Bi,Shumei Gao,Xukun Li,Bin Huang,Xuejun Pan 대한환경공학회 2016 Environmental Engineering Research Vol.21 No.2

17α-Ethynylestradiol (Ee₂) has gotten growing concerns due to its widely detected in the environment and high estrogenic potency. However, the knowledge on the photochemical behaviors of Ee₂ in natural waters is still limited. Herein, the photodegradation and estrogenic potency variation of Ee₂ induced by nitrate were studied using a sunlight simulator consisted by a 300 W medium pressure mercury lamp and 290 nm cut-off filters. It was found that Ee₂ could be photodegraded at a rate of 0.0193 h-1 in pure aqueous solutions, and the photodegradation of Ee₂ could be significantly promoted by nitrate. The photodegradation removal rate of Ee₂ was increased from 9% in Milli-Q water to 85% in 2.0 mM nitrate solutions. Reactive species scavenging experiments demonstrated that the photogenerated HO? contributed about 55% to Ee₂ degradation. Fe(III), Cl- and dissolved humic acid (DHA) could inhibit the photodegradation of Ee₂ by competing the incident light and photogenerated HO?, while HCO₃ - had no influence on Ee₂ photodegradation. Ee₂ was determined to be phototransformed into organic chemicals without estrogenic potency by GC-MS and MCF-7 cell proliferation toxicity tests. These findings could extend our knowledge on the photochemical behaviors of steroid estrogens and provide information for ecological risk assessment.