Vision-aided nonlinear control framework for shake table tests

The structural response under the earthquake excitations can be simulated by scaled-down model shake table tests or full-scale model shake table tests. In this paper, adaptive control theory is used as a nonlinear shake table control algorithm which considers the inherent nonlinearity of the shake table system and the Control-Structural Interaction (CSI) effect that the linear controller cannot consider, such as the Proportional-Integral-Derivative (PID) controller. The mass of the specimen can be assumed as an unknown variation and the unknown parameter will be replaced by an estimated value in the proposed control framework. The signal generated by the control law of the adaptive control method will be implemented by a loop-shaping controller. To verify the stability and feasibility of the proposed control framework, a simulation of a bare shake table and experiments with a bare shake table with a two-story frame were carried out. This study randomly selects Earthquake recordings from the Pacific Earthquake Engineering Research Center (PEER) database. The simulation and experimental results show that the proposed control framework can be effectively used in shake table control.Comment: 10 pages, 7 figures, accepted in the Canadian Conference - Pacific Conference on Earthquake Engineering 2023, Vancouver, British Columbi

Nucleocapsid mutations R203K/G204R increase the infectivity, fitness, and virulence of SARS-CoV-2

Previous work found that the co-occurring mutations R203K/G204R on the SARS-CoV-2 nucleocapsid (N) protein are increasing in frequency among emerging variants of concern or interest. Through a combination of in silico analyses, this study demonstrates that R203K/G204R are adaptive, while large-scale phylogenetic analyses indicate that R203K/G204R associate with the emergence of the high-transmissibility SARS-CoV-2 lineage B.1.1.7. Competition experiments suggest that the 203K/204R variants possess a replication advantage over the preceding R203/G204 variants, possibly related to ribonucleocapsid (RNP) assembly. Moreover, the 203K/204R virus shows increased infectivity in human lung cells and hamsters. Accordingly, we observe a positive association between increased COVID-19 severity and sample frequency of 203K/204R. Our work suggests that the 203K/204R mutations contribute to the increased transmission and virulence of select SARS-CoV-2 variants. In addition to mutations in the spike protein, mutations in the nucleocapsid protein are important for viral spreading during the pandemic

Inflammation-related research within the field of bladder cancer: a bibliometric analysis

BackgroundIn recent years, the link between inflammation and bladder cancer(BC) has received much attention. However, there were no relevant bibliometric studies to analyze the inflammation-related research within this field of BC.MethodsWe selected Web of Science Core Collection (WOSCC) as the data source to obtain articles and reviews on inflammation-related research within te field of BC from WOSCC’s inception to October 10, 2022. The collected data were meticulously and manually screened, after which we used VOSviewer, CiteSpace, Biblioshiny and an online analysis platform (https://bibliometric.com/) to perform bibliometric analysis on the data and visualize the results.ResultsA total of 4301 papers related to inflammation-related research within this field of BC were included in this study.The number of publications has steadily increased over the last decades (R²=0.9021). The top contributing country was the United States, O’Donnell, Michael A was the most published authors, the leading contributing institution was the University of Texas, and the leading contributing journal was JOURNAL OF UROLOGY. The keywords co-occurrence analysis indicated that “immunotherapy,” “inflammation-related biomarkers,” and “tumor microenvironment” were the hot spots and frontiers of research in this field.ConclusionThis study clarifies the contribution of countries, institutions, authors, and journals in inflammation-related research within this field of BC through a bibliometric approach and identifies research hotspots and frontiers in the field. Notably, these findings can help researchers to understand more clearly the relationship between inflammation and BC

A safety check method to maximize the effective reserve by optimizing the power of the tie-line in the power market

To ensure the stability of the electricity spot market and the safety of the provincial and regional power systems, a safety check method is proposed to maximize the effective reserve resources in the power system by optimizing the power of each tie-line. This safety check method accurately models the tie-line equipment and the effective reserve resources and is coupled with each constraint of the electricity spot market clearing model to form a safety check algorithm to optimize the power of tie-line power. The model involved in this paper is a linear model, which has a clear implementation method in practical dispatching applications. Through this method, the power configuration scheme of each tie-line to meet the electricity spot market constraints can be obtained, and the safety check results have the executability of the power market. The rationality and feasibility of the safety check algorithm results are verified by simulating the provincial-scale electricity spot market. According to the simulation results, this method can release effective reserve resources and provide more guarantees for the safe operation of the power grid. In addition, this method can save up to 4.9% of the total operation cost of the power system and improve the dispatching economy of the power system. This method is of great significance to ensure the safe operation of the power system and the day-ahead market and real-time market scheduling in the actual power spot system. In addition, this method also has great guiding significance for the analysis of the actual reserve situation of the power market after the event

Cathelicidin LL-37 promotes EMT, migration and metastasis of hepatocellular carcinoma cells in vitro and mouse model

ABSTRACTThe effect of cathelicidin hCAP18/LL-37 in hepatocellular carcinoma (HCC) metastasis remains unclear. Here, we confirmed that LL-37 expression enhanced endothelial-mesenchymal transition (EMT), migration and invasion in HCC cells. And the HER2/EGFR-MAPK/ERK signal participated in the process above. More frequent lung metastases were observed in an LL-37-overexpressing hematogenous metastasis model. Interestingly, 1,25(OH)2D3 together with si-LL-37 significantly enhanced 1,25(OH)2D3-induced inhibition of migration and invasion in PLC/PRF-5 cells, and also enhanced reversion of the EMT process. Therefore, LL-37 is involved in HCC metastases, and may act as an important factor to attenuate the inhibitory activity of 1,25(OH)2D3 on HCC metastasis. Targeting hCAP18/LL-37 may offer a potential strategy to improve the anticancer activity of 1,25(OH)2D3 in HCC therapy

A Fractional-Order Creep Model of Water-Immersed Coal

The long-term stability of a coal pillar dam is a serious concern for coal mine underground reservoirs because of the creep behavior of coal in complex water immersion and mechanical environments. In order to investigate the characteristics of creep deformation of water-immersed coal and develop a proper creep model, this paper implemented a series of creep experiments of coal via multistage loading at various water-immersion times. The experiment data were analyzed, in terms of immersion-induced damage, elasto-plastic performance, creep behavior, etc., suggesting obvious mechanical properties’ degradation of coal by water. The elastic modulus and peak strength of water-immersed coal decrease exponentially with the immersion time, while the creep rate of coal shows an upward tendency with the promoted immersion time. According to the remarked relationships of elastic, viscoelastic, and viscoplastic properties versus the stress levels and water-immersion time, a creep model based on conformable fractional derivatives is proposed, considering the influence of the water-immersion time and variable stress level. The proposed model was verified using the experiment data, showing a good capacity of the creep model for reproducing the creep process of water-immersed coal. This paper provides a fundamental model for further studying the stability of coal pillars and their influence on the safety of underground water reservoirs

Prospects of underground gas storage in China under the strategy of carbon neutrality

For China to achieve carbon neutrality by 2060, the profound transformation from high-carbon to low-carbon and carbon-free energy sources is required for the energy supply and demand structure. In the future, the gas consumption will grow in large scale in China. It is estimated that the natural gas consumption in China will be about 6 000×108 m3 by 2030 and 6 500×108 m3 to 7 500×108 m3 by 2060. Due to the impact of the resource reserves, the capability to acquiring international resources, the safety of import channels and other factors on China's natural gas, it is necessary to build underground gas storages in large scale to ensure the growth of China's natural gas consumption. From the perspective of natural gas consumption safety, the underground gas storages with a gas storage capacity of 1 200×108 m3 to 1 300×108 m3 should be constructed, so as to meet the requirements for peak sheaving of natural gas in China and maintain the strategic reserves required. At present, the working gas capacity of China's underground gas storages is only about 150×108 m3, and it is necessary to further expand the field of storage construction to form the space layout of "1+3+N" gas storage base. In the process of China's energy transition, the related technologies of gas storage will be deeply integrated with the carbon storage, hydrogen storage, helium storage, compressed gas storage and other technologies in the future, for the purpose of maximizing the role of underground gas storages in energy field and facilitating to realize the strategic objective of carbon neutrality