In the working process, the load mass of the thrust magnetic bearing has a significant change. If the load mass changes greatly, the original fixed control parameters cannot ensure that the system is ...in the optimal stable suspension state, and the performance of the system will become worse or even self-excited. Firstly, a single freedom degree of the suspension control system model is established, and the critical condition of the system is analyzed when a self-excited oscillation occurs. Then, a linear adaptive control law is proposed for the system with variable parameters, which can tolerate the wide range of load mass. The simulation results show that the adaptive control law can keep the stability of the system when the load mass varies in a large range and avoid the self-excited vibration.
Osteoporosis is a systemic metabolic bone disease characterized by a reduction in bone mass, bone quality, and microarchitectural deterioration. An imbalance in bone remodeling that is caused by more ...osteoclast-mediated bone resorption than osteoblast-mediated bone formation results in such pathologic bone disorder. Traditional Chinese medicines (TCM) have long been used to prevent and treat osteoporosis and have received extensive attentions and researches at home and abroad, because they have fewer adverse reactions and are more suitable for long-term use compared with chemically synthesized medicines. Here, we put the emphasis on osteoblasts, summarized the detailed research progress on the active compounds derived from TCM with potential anti-osteoporosis effects and their molecular mechanisms on promoting osteoblast-mediated bone formation. It could be concluded that TCM with kidney-tonifying, spleen-tonifying, and stasis-removing effects all have the potential effects on treating osteoporosis. The active ingredients derived from TCM that possess effects on promoting osteoblasts proliferation and differentiation include flavonoids, glycosides, coumarins, terpenoids (sesquiterpenoids, monoterpenoids, diterpenoids), phenolic acids, phenols and others (tetrameric stilbene, anthraquinones, diarylheptanoids). And it was confirmed that the bone formation effect induced by the above natural products was regulated by the expressions of bone specific matrix proteins (ALP, BSP, OCN, OPN, COL I), transcription factor (Runx2, Cbfa1, Osx), signal pathways (MAPK, BMP), local factors (ROS, NO), OPG/RANKL system of osteoblasts and estrogen-like biological activities. All the studies provided theoretical basis for clinical application, as well as new drug research and development on treating osteoporosis.
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Despite the growing interest in the effects of neighborhood environments on cognitive function, most studies on older people are based on cross-sectional survey data from developed countries. This ...study examines the relationship between neighborhood environments and decline in cognitive function over time among middle-aged and older people in China and whether this relationship varies between rural and urban residents.
The three waves of China Health and Retirement Longitudinal Study (CHARLS 2011-2015) were used. The sample included 12,131 respondents living in 298 rural villages and 4,059 respondents living in 150 urban communities. Three-level linear growth curve models were estimated to track trajectories of cognitive change over a 4-year period.
Chinese older people who lived in neighborhoods with more handicap access, more bus lines, employment service, and higher socioeconomic status (SES) had slower cognitive decline. Neighborhood basic infrastructures, number of days that roads were unpassable, outdoor exercise facilities, and average social activity participation were associated with baseline cognitive function in both rural and urban areas, but neighborhood environments had more impact on cognitive decline among rural older adults than urban older adults.
Findings from this study call for increased infrastructure development and community building programs in rural China.
Carbon-based electrothermal or photothermal actuators have attracted intense attention recently. They can directly convert electrical or light energy into thermal energy and exhibit obvious ...deformations. However, if the actuation mechanism is only limited to thermal expansion, the deformation amplitude is difficult to increase further. Moreover, complex shape-deformation is still challenging. Although a few materials were reported to realize twisting or untwisting actuation by cutting the samples into strips along different orientations, each single strip could perform only one shape-deformation mode. In this work, we propose multi-responsive actuators based on a graphene oxide (GO) and biaxially oriented polypropylene (BOPP) composite, which are designed with different shapes (strip-shape and helical-shape). The strip-shape GO/BOPP actuator shows great bending actuations when driven by humidity (curvature of up to 3.1 cm
). Due to a developed dual-mode actuation mechanism, the actuator shows a bending curvature of 2.8 cm
when driven by near infrared (NIR) light. The great actuation outperforms most other carbon-based actuators. Then, an intelligent robot based on the GO/BOPP composite is fabricated, which can switch between the protection mode and weightlifting mode with different external stimuli. Inspired from plant tendrils, a bioinspired helical GO/BOPP actuator is further realized to show both twisting and untwisting actuations in a single actuator, fully mimicking the deformation of plant tendrils. Finally, a robot arm consisting of strip-shape and helical GO/BOPP actuators can grasp an object that is 2.9 times heavier than itself, demonstrating promising bioinspired applications.
Sentiment analysis technology has made it possible to precisely calculate the daily reactions and opinions of investors, which has been found to have a significant influence on financial asset ...pricing. Thus, in this study, we examine the impacts that predictive power investor sentiment has over the price of China's crude oil. We first constructed investor sentiment indexes of China's crude oil futures based on specific economic variables and comments found on one of the most active online financial forums. Then, five popular machine learning tools were utilized to generate predictions. According to our findings, the long short-term memory model combined with the composite sentiment index performed the best due to a lower rate of prediction errors and greater directional accuracy for time-series forecasting of one-day-ahead prices. In this way, this study could aid researchers to more effectively investigate the energy sector which is rapidly changing and highly speculative in nature
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•We investigate whether investor sentiment indicators can help predict the price of China's crude oil futures.•We crawled comments from financial forums and performed sentiment analysis using APIs from three Internet companies.•The LSTM model containing the sentiment index constructed by voting methods is the most accurate forecasting method.•Our results can provide useful implications for both investors and policy regulators.
•Bubble–bubble interaction can suppress or enlarge the radial pulsations of bubbles.•The suppression or enlargement depends on the ultrasound parameters, the radii, the distances and the bubble ...number.•The frequency response curve of expansion ratio decreases and shifts to left due to bubble–bubble interaction.•The larger the coupling strength is, the more the left-shifting is.
Using a model that with or without considering the interaction between bubbles through the radiated pressure waves, numerical simulations of cavitation bubbles have been performed in order to study the effect of the bubble–bubble interaction on radial pulsations of bubbles. Comparing the results obtained by with or without considering the bubble–bubble interaction, it is suggested that the suppression or enlargement property of expansion ratios of bubbles due to the bubble–bubble interaction largely depends on the ultrasound parameters, the ambient bubble radii, the distances between bubbles and the number of bubbles (in multi-bubble environment, the last two aspects can be expressed using the coupling strength). The frequency response curve of expansion ratio decreases and shifts to left due to the bubble–bubble interaction and the larger the coupling strength is, the more the left-shifting is.
Extracellular vesicles (EVs) are involved in the regulation of cell physiological activity and the reconstruction of extracellular environment. Matrix vesicles (MVs) are a type of EVs released by ...bone-related functional cells, and they participate in the regulation of cell mineralization. Here, we report bioinspired MVs embedded with black phosphorus (BP) and functionalized with cell-specific aptamer (denoted as Apt-bioinspired MVs) for stimulating biomineralization. The aptamer can direct bioinspired MVs to targeted cells, and the increasing concentration of inorganic phosphate originating from BP can facilitate cell biomineralization. The photothermal effect of the Apt-bioinspired MVs can also promote the biomineralization process by stimulating the upregulated expression of heat shock proteins and alkaline phosphatase. In addition, the Apt-bioinspired MVs display outstanding bone regeneration performance. Our strategy provides a method for designing bionic tools to study the mechanisms of biological processes and advance the development of medical engineering.
Collagen triple helix repeat containing-1 (CTHRC1) has been identified as cancer-related protein. CTHRC1 expresses mainly in adventitial fibroblasts and neointimal smooth muscle cells of ...balloon-injured vessels and promotes cell migration and tissue repair in response to injury. CTHRC1 plays a pivotal role in some pathophysiological processes, including increasing bone mass, preventing myelination, and reversing collagen synthesis in many tumor cells. The ascended expression of CTHRC1 is related to tumorigenesis, proliferation, invasion, and metastasis in various human malignancies, including gastric cancer, pancreatic cancer, hepatocellular carcinoma, keloid, breast cancer, colorectal cancer, epithelial ovarian cancer, esophageal squamous cell carcinoma, cervical cancer, non-small-cell lung carcinoma, and melanoma. And molecules that regulate the expression of CTHRC1 include miRNAs, lncRNAs, WAIF1, and DPAGT1. Many reports have pointed that CTHRC1 could exert different effects through several signaling pathways such as TGF-β, Wnt, integrin β/FAK, Src/FAK, MEK/ERK, PI3K/AKT/ERK, HIF-1α, and PKC-δ/ERK signaling pathways. As a participant in tissue remodeling or immune response, CTHRC1 may promote early-stage cancer. Several recent studies have identified CTHRC1 as an effectual prognostic biomarker for predicting tumor recurrence or metastasis. It is worth noting that CTHRC1 has different cellular localization and mechanisms of action in different cells and different microenvironments. In this article, we focus on the advances in the signaling pathways mediated by CTHRC1 in tumors.
Pathogenic bacterial infections and drug resistance make it urgent to develop new antibacterial agents with targeted delivery. Here, a new targeting delivery nanosystem is designed based on the ...potential interaction between bacterial recognizing receptors on macrophage membranes and distinct pathogen‐associated molecular patterns in bacteria. Interestingly, the expression of recognizing receptors on macrophage membranes increases significantly when cultured with specific bacteria. Therefore, by coating pretreated macrophage membrane onto the surface of a gold–silver nanocage (GSNC), the nanosystem targets bacteria more efficiently. Previously, it has been shown that GSNC alone can serve as an effective antibacterial agent owing to its photothermal effect under near‐infrared (NIR) laser irradiation. Furthermore, the nanocage can be utilized as a delivery vehicle for antibacterial drugs since the gold–silver nanocage presents a hollow interior and porous wall structure. With significantly improved bacterial adherence, the Sa‐M‐GSNC nanosystem, developed within this study, is effectively delivered and retained at the infection site both via local or systemic injections; the system also shows greatly prolonged blood circulation time and excellent biocompatibility. The present work described here is the first to utilize bacterial pretreated macrophage membrane receptors in a nanosystem to achieve specific bacterial‐targeted delivery, and provides inspiration for future therapy based on this concept.
To solve the challenge of targeted delivery, macrophage‐membrane‐coated nanocages with the ability to recognize bacteria with photo‐thermal effect is designed to enhance efficient and effective targeted delivery at the infection site. This novel therapy shows excellent bacterial binding with great antibacterial properties, and demonstrates Sa‐M‐GSNCs are promising prospects in the field of antibacterial agents and drug delivery.
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