Hepatocellular carcinoma (HCC), with its ineffective therapeutic options and poor prognosis, represents a global threat. In the present study, we show that RAD52 motif 1 (RDM1), a key regulator of ...DNA double‐strand break repair and recombination, is downregulated in HCC tissues and suppresses tumor growth. In clinical HCC samples, low expression of RDM1 correlates with larger tumor size, poor tumor differentiation, and unfavorable survival. In vitro and in vivo data demonstrate that knockdown of RDM1 increases HCC cell proliferation, colony formation, and cell population at G2/M phase, whereas RDM1 overexpression results in the opposite phenotypes. Mechanistically, RDM1 binds to the tumor suppressor p53 and enhances its protein stability. In the presence of p53, RDM1 suppresses the phosphorylation of Raf and ERK. Overexpression of p53 or treatment with ERK inhibitor significantly abolishes cell proliferation induced by the depletion of RDM1. In addition, overexpression of methyltransferase‐like 3 markedly induces N6‐methyladenosine modification of RDM1 mRNA and represses its expression. Taken together, our study indicates that RDM1 functions as a tumor suppressor and may be a potential prognostic and therapeutic factor for HCC.
Loss of RAD52 motif 1 (RDM1), induced by methyltransferase‐like 3 (METTL3)‐mediated m6A modification, correlates with unfavorable clinical outcomes, promotes hepatocellular carcinoma (HCC) cell growth, and induces G2/M cell cycle arrest. Overexpression of p53 or treatment with ERK inhibitor significantly abolishes cell proliferation induced by the depletion of RDM1. The newly identified METTL3/RDM1/p53/ERK axis provides potential prognostic and therapeutic targets for HCC treatment.
This paper studies the platoon formation control problem for unmanned surface vehicles, in the presence of modeling uncertainties and time-varying external disturbances. The control objective is to ...make the vehicular platoons proceed along a given trajectory while maintaining a desired line-of-sight (LOS) range between each vehicle and its predecessor. To provide transient performance specifications on formation errors, including LOS range and angle errors, we enforce prescribed performance guarantees in the control design. The prescribed performance guarantees mean that formation errors evolve always within the predefined regions that are bounded by exponentially decaying functions of time. Using prescribed performance control methodology, neural network approximation, disturbance observers, dynamic surface control technique, and Lyapunov synthesis, we propose an adaptive formation control that ensures internal stability of closed-loop systems with guaranteed prescribed performance. Meanwhile, both collision avoidance and connectivity maintenance between two consecutive vehicles are guaranteed during the whole operation. The proposed formation control is decentralized in the sense that the control action on each vehicle depends only on information from its immediate predecessor. Simulation results demonstrate the performance of the proposed control.
Deregulation of alternative splicing contributes to the malignant progression of cancer. Little is known about the significant alternative splicing events in hepatocellular carcinoma (HCC). ...High‐throughput sequencing revealed that coiled‐coil domain containing 50 (CCDC50) pre‐mRNA is aberrantly spliced in 50% of our HCC cases. A BaseScope assay was performed to examine the expression of CCDC50S (a truncated oncogenic splice variant) in HCC tissues. Compared with benign liver tumors and several other types of solid tumors, CCDC50S mRNA was up‐regulated in HCC, with a diagnostic potential (sensitivity, 0.711; specificity, 0.793). High expression of CCDC50S mRNA in HCC was significantly correlated with poor tumor differentiation, advanced tumor node metastasis (TNM) stage, and unfavorable prognosis. Overexpression of CCDC50S exerted tumorigenic activities that promoted HCC growth and metastasis by activation of Ras/forkhead box protein O4 (Foxo4) signaling. Either suppression of mitogen‐activated protein kinase kinase (MEK)/extracellular signal‐regulated kinase (ERK) phosphorylation or overexpression of Foxo4 markedly attenuated CCDC50S‐mediated phenotypes. Furthermore, serine‐ and arginine‐rich splicing factor 3 (SRSF3) directly bound to CCDC50S mRNA to maintain its stability in the cytoplasm. The cytosolic retention of SRSF3 was mediated by the interaction of hepatitis B virus–encoded X protein (HBx) and 14‐3‐3β. Ectopic HBx expression induced expression of cytosolic SRSF3 and CCDC50S. Conclusion: Our study provided compelling evidence that up‐regulation of CCDC50S was modulated by HBx/SRSF3/14‐3‐3β complex and enhanced oncogenic progression of HCC through the Ras/Foxo4 signaling pathway. These data suggest that CCDC50S may serve as a diagnostic and prognostic biomarker and probably a promising therapeutic target in HCC.
This paper addresses a decentralized leader-follower formation control problem for a group of fully actuated unmanned surface vehicles with prescribed performance and collision avoidance. The ...vehicles are subject to time-varying external disturbances, and the vehicle dynamics include both parametric uncertainties and uncertain nonlinear functions. The control objective is to make each vehicle follow its reference trajectory and avoid collision between each vehicle and its leader. We consider prescribed performance constraints, including transient and steady-state performance constraints, on formation tracking errors. In the kinematic design, we introduce the dynamic surface control technique to avoid the use of vehicle's acceleration. To compensate for the uncertainties and disturbances, we apply an adaptive control technique to estimate the uncertain parameters including the upper bounds of the disturbances and present neural network approximators to estimate uncertain nonlinear dynamics. Consequently, we design a decentralized adaptive formation controller that ensures uniformly ultimate boundedness of the closed-loop system with prescribed performance and avoids collision between each vehicle and its leader. Simulation results illustrate the effectiveness of the decentralized formation controller.
This paper studies neural learning control with predefined tracking error bound for a marine surface vessel whose accurate dynamics could not be obtained a priori . With the introduction of an error ...transformation function, the constrained tracking control of the original vessel is transformed into the stabilization of an unconstrained system. A filtered tracking error is introduced based on the error transformation, and radial basis function (RBF) neural networks (NNs) are employed to approximate unknown vessel dynamics. Subsequently, stable adaptive NN control is proposed to ensure ultimate boundedness of all the signals in the closed-loop system and to guarantee prescribed tracking performances. Under persistent excitation (PE) condition, the proposed adaptive NN control is shown to be capable of acquiring knowledge on the vessel dynamics and of storing the learned knowledge in memory. The stored knowledge is reused to develop neural learning control such that the improved control performance with faster tracking convergence rate and less computational burden could be achieved, while prescribed transient and steady-state tracking control performances are guaranteed. Simulation studies are performed to demonstrate the effectiveness of the proposed design techniques.
This paper presents a fixed-time leader-follower formation control protocol for a swarm of unicycle-type mobile robots with visibility and performance constraints. Under a vision-based formation ...control framework, mobile robots calculate their control signals with only the local relative distance and bearing angle provided by onboard stereo or RGB-D cameras. Since the sensing capability of the fixed onboard cameras is subject to limited range and angle of view, the field-of-view constraints are considered to ensure that each follower can always detect its leader, meanwhile avoid collision with the leader. The time-varying and asymmetric performance constraints on formation tracking errors are applied to guarantee the transient and stead-state performance. Furthermore, the proposed control protocol can be extended to address the control design problem without constraint requirements. Based on the fixed-time control design and Lyapunov analysis, formation tracking errors are shown to converge into a small neighborhood of zero in fixed settling time. Simulation and experiment studies are performed to illustrate the effectiveness of the formation control protocol.
The high viscosity and low fluidity of heavy crude oil hinder its sorption by conventional porous sorbents, so the efficient clean‐up of such heavy crude oil spills is challenging. Recently, Joule ...heating has been emerging as a new tool to reduce the viscosity of heavy crude oil dramatically. However, this direct‐contact heating approach presents a potential risk due to the high voltage applied. To develop a non‐contact recovery of viscous crude oil, here, a new approach for the fabrication of a series of ferrimagnetic sponges (FMSs) with hydrophobic porous channels is reported, whose surface can be remotely heated to 120 °C within 10 s under an alternating magnetic field (f = 274 kHz, H = 30 kA m−1). Compared with the solar‐driven superficial heating, the integral magnetic heating in FMSs can result in a higher internal temperature of the sponges because of the confinement of thermal transport in the porous channels, which contributes to a dramatic decrease in oil viscosity and a significant increase in oil flow into the pores of FMSs. Furthermore, FMSs assembled with a self‐priming pump can achieve continuous recovery of viscous crude oil (33.05 g h−1 cm−2) via remotely magnetic heating.
A ferrimagnetic sponge with the skeletons coated with poly(dimethylsiloxane) and iron oxide nanoparticles is developed to achieve continuous recovery of viscous crude oil. Under the exposure of an alternating magnetic field, the viscosity of the viscous oil around the sponge decreases sharply, thus accelerating its absorption.
Oil sorbents play a very important part in the remediation processes of oil spills. To enhance the oil‐sorption properties and simplify the oil‐recovery process, various advanced oil sorbents and ...oil‐collecting devices based on them have been proposed recently. Here, we firstly discuss the design considerations for the fabrication of oil sorbents and describe recently developed oil sorbents based on modification strategy. Then, recent advances regarding oil sorbents mainly based on carbon materials and swellable oleophilic polymers are also presented. Subsequently, some additional properties are emphasized, which are required by oil sorbents to cope with oil spills under extreme conditions or to facilitate the oil‐collection processes. Furthermore, some oil‐collection devices based on oil sorbents that have been developed recently are shown. Finally, an outlook and challenges for the next generation of oil‐spill‐remediation technology based on oil‐sorbents materials are given.
Hydrophobic and oleophilic sorbent materials are demonstrated as promising candidates for the cleanup of oil spills. An overview of the latest developments and advances in the fabrication of oil sorbents through modification strategy, carbon‐based oil sorbents, and polymer‐based oil sorbents, as well as some smart oil sorbents and oil‐collecting devices based on oil‐sorbent materials are presented.
We present an iron‐containing metal–organic framework, MIL‐100(Fe), for ozone removal. MIL‐100(Fe) exhibits long‐lasting ozone conversion efficiency of 100 % for over 100 h under a relative humidity ...of 45 % and space velocity of 1.9×105 h−1 at room temperature, which is well beyond the performance of most porous or metal catalysts such as activated carbon and α‐MnO2. We also investigated the impact of humidity level and elucidated the plausible reaction mechanism, which is further confirmed by DFT calculations. Furthermore, MIL‐100(Fe) can be processed into films and used as filtration layer in a mask to protect personnel against ozone contamination. This study demonstrates the promising potential of MOFs in ozone pollution control, and also offers new insights for the design of ozone decomposition catalysts.
Ozone overthrown: The iron containing metal–organic framework MIL‐100(Fe) exhibits a long‐lasting ozone conversion efficiency of 100 % for over 100 h under 45 % relative humidity, which is well beyond the performance of most porous or metal catalysts such as activated carbon and α‐MnO2. MIL‐100(Fe) has also been incorporated into air filters for efficient protection against ozone under humid conditions.
In this article, we study the formation tracking control problem for a group of nonholonomic mobile robots under communication constraints. We use a simple leader-follower formation tracking control ...strategy, in which only the leading robot of the robotic group obtains the given trajectory's information, and each robot only receives information from its immediate leader. Thus, the communication graph forms a static and simple directed spanning tree. We assume that the information exchange among the robots is limited by some given communication radius. Under the limited communication range, the leader-follower distance and bearing angle constraints are considered in the formation control design. To provide the given specifications on the transient and steady-state performances of formation tracking errors, the boundaries of the predefined constraints are enforced by designer-specified performance requirements, which are functions of time. Consequently, we incorporate the barrier Lyapunov function into formation control design to mathematically prove that the formation tracking errors evolve always within the predefined regions and converge asymptotically to zero. The proposed formation control strategy can also guarantee the connectivity maintenance and collision avoidance between the leader and the follower. Simulation results show the performance of the proposed formation tracking control.
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