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In this paper, fault estimation and active fault‐tolerant control are studied for a class of nonlinear systems with simultaneous actuator and sensor faults, as well as unknown external disturbances. Firstly, the state equation of a class of nonlinear systems is transformed into an augmented system state equation by extending the sensor fault as an auxiliary state. Then, a novel fault estimation observer based on iterative learning with unknown inputs is designed to estimate the system state, as well as actuator and sensor faults. Subsequently, by using the fault estimation information, a dynamic output feedback active fault‐tolerant control scheme is proposed to compensate for the influence of faults on the system. Lyapunov stability theory is used to prove the stability of the closed‐loop system and the convergence of the fault estimation observer. The gain matrices of the fault estimation observer and fault‐tolerant controller are obtained by solving linear matrix inequalities. Furthermore, the paper avoids the use of the λ norm in the convergence proof of the conventional iterative learning algorithm, which reduces the amount of calculation in the derivation process. Finally, the effectiveness and accuracy of the proposed method are verified through simulation of the DC motor angular velocity system. [ABSTRACT FROM AUTHOR]

Circulating tumor cell (CTC)‐enrichment by using aptamers has a number of advantages, but the issue of compromised binding affinities and stabilities in real samples hinders its wide applications. Inspired by the high efficiency of the prey mechanism of the octopus, we engineered a deterministic lateral displacement (DLD)‐patterned microfluidic chip modified with multivalent aptamer‐functionalized nanospheres (AP‐Octopus‐Chip) to enhance capture efficiency. The multivalent aptamer–antigen binding efficiency improves 100‐fold and the capture efficiency is enhanced more than 300 % compared with a monovalent aptamer‐modified chip. Moreover, the captured cancer cells can be released through a thiol exchange reaction with up to 80 % efficiency and 96 % viability, which is fully compatible with downstream mutation detection and CTC culture. Using the chip, we were able to find CTCs in all cancer samples analyzed. Octopus chip cell capture: Inspired by the high efficiency of the prey mechanism of the octopus, an aptamer‐tailed octopus chip (AP‐Octopus‐Chip) for CTC enrichment was developed. The design of the chip and the high binding affinity of the multivalent structures against the target cells significantly improved the CTC capture efficiency and enrichment. The enriched cancer cells can be released through a thiol exchange reaction, which is fully compatible with downstream mutation detection and CTC culture. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate that a very familiar, yet underutilized, physical parameter-gas pressure-can serve as signal readout for highly sensitive bioanalysis. Integration of a catalyzed gas-generation reaction with a molecular recognition component leads to significant pressure changes, which can be measured with high sensitivity using a low-cost and portable pressure meter. This new signaling strategy opens up a new way for simple, portable, yet highly sensitive biomedical analysis in a variety of settings. [ABSTRACT FROM AUTHOR]

An aptamer‐functionalized nanointerface for capture and release of circulating tumor cells (CTCs) is described by C. Yang et al. in their Communication on page 2236 ff. Inspired by the prey capture mechanism of the octopus, an aptamer‐tailed octopus chip was engineered, which combines a multivalence effect to enhance binding affinity, size‐selective enhancement of cell–micropillar collisions to improve capture efficiency, and a thiol–gold interface for nondestructive release of CTCs for downstream analysis. [ABSTRACT FROM AUTHOR]

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Biomedical Analysis. Gas pressure can be used as the signal readout for a simple and highly sensitive bioanalytical device as shown by C. Yang and co‐workers in their Communication on page 10448 ff. By combining H2O2 decomposition with an antibody assay, various analytes can be detected. [ABSTRACT FROM AUTHOR]