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DNA compaction is required for the condensation and resolution of chromosomes during mitosis, but the relative contribution of individual chromatin factors to this process is poorly understood. We developed a physiological, cell-free system using high-speed Xenopus egg extracts and optical tweezers to investigate real-time mitotic chromatin fiber formation and force-induced disassembly on single DNA molecules. Compared to interphase extract, which compacted DNA by ~60%, metaphase extract reduced DNA length by over 90%, reflecting differences in whole-chromosome morphology under these two conditions. Depletion of the core histone chaperone ASF1, which inhibits nucleosome assembly, decreased the final degree of metaphase fiber compaction by 29%, while depletion of linker histone H1 had a greater effect, reducing total compaction by 40%. Compared to controls, both depletions reduced the rate of compaction, led to more short periods of decompaction, and increased the speed of force-induced fiber disassembly. In contrast, depletion of condensin from metaphase extract strongly inhibited fiber assembly, resulting in transient compaction events that were rapidly reversed under high force. Altogether, these findings support a speculative model in which condensin plays the predominant role in mitotic DNA compaction, while core and linker histones act to reduce slippage during loop extrusion and modulate the degree of DNA compaction.

To explore the influence of high-frequency microwave transmission on the power change of EEG in pain-induced brain activity. we propose a method, to measure and evaluate the relative changes in the Electroencephalographic (EEG) power for microwave frequencies 4.5, 5, and 5.5 GHz in no pain (NP) and cold pain (CP) conditions. The relative power changes of EEG frequency bands in delta, theta, alpha1, alpha2, beta1, and beta2 were calculated with and without (Sham) microwave transmission. Then, the standardized low-resolution brain electromagnetic tomography (sLORETA) was used to analyze the source localization of different pain types. In addition, a pain brain activity detection experiment was designed to verify the feasibility and accuracy of microwave detection of pain. At 5 GHz microwave transmission, the average EEG power of delta, beta1, and beta2 increased by 10–35%, which was substantially higher than that of Sham. In source localization analysis, the source activity changes of the activated brain regions were enhanced under high frequency microwave radiation. The proposed method can better reflect the variation of active state EEG power under high-frequency electromagnetic radiation. In the test of pain detection, microwave transcranial (MT) signal has certain correlation with the spectrum characteristics of EEG signal in the same test state, and the experimental results confirm that MT signal is indeed related to pain brain activity. This study provides a basis for microwave detection of neural activity induced by cold pain and has great significance for clinical diagnosis of pain-induced diseases.

Learning control is applicable to systems that operate periodically or over finite time intervals. Currently, there is a lack of research results about learning control approaches to infinite-duration tracking, without requiring periodicity or repeatability. This article addresses the problem of adaptive learning control (ALC) for systems performing infinite-duration tasks. Instead of using integral adaptation, incremental adaptive mechanisms are exploited, by which the numerical integration for implementation can be avoided. The comparison with the conventional integral adaptive mechanisms indicates that the suggested methodology can be an alternative to the adaptive system designs. Using an error-tracking approach, the approximation-based backstepping design is carried out for systems in the strict-feedback form, where a novel integral Lyapunov function is shown to be efficient in the treatment of state-dependent control gain. Theoretical results for the performance analysis are presented in detail. In particular, the robust convergence of the tracking error is established, while the boundedness of the variables of the closed-loop system is characterized, with the aid of a key technical lemma. It is shown that the proposed control method can provide satisfactory tracking performance and simplify the controller designs. Numerical results are presented to demonstrate effectiveness of the learning control schemes.

The analysis of convergence of extended state observers (ESOs) requires the total disturbance to be differentiable. However, this requirement is not satisfied in many control engineering practices. In this paper, we attempt to analyze the convergence of ESOs for nonlinear systems with non-differentiable uncertainties. A decomposition method is first presented to divide the non-differentiable total disturbance into a differentiable signal and a bounded but non-differentiable signal. Based on this decomposition, we give out the convergence of both nonlinear and linear ESOs (NLESO/LESO), low- and high-power ESOs (LPESO/HPESO), and fixed-time ESO (FxESO). We also derive the explicit formulas for the estimation errors of these ESOs. Simulations and experiments demonstrate the correctness of the analysis results.

Herein, the alkynyl groups are grafted on g-C3N4 via ball milling of g-C3N4 and CaC2. The successful functionalization of g-C3N4 by alkynyl is demonstrated by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Ultrathin wrinkle-like structure with abundant pores is observed for the resulted alkynyl functionalized g-C3N4 nanosheets, which can furnish abundant photocatalytic active sites. The photocatalytic NH3 production rate of 0.12 mmol·gcat-1·h-1 is gained for alkynyl functionalized g-C3N4 under UV-visible irradiation, which is 2.0-folds higher than pristine g-C3N4 (0.058 mmol·gcat-1·h-1). A maximum of 1.9 and 1.5 folds enhancements are achieved for the photodegradation of rhodamine B and levofloxacin over functionalized g-C3N4 compared to pristine g-C3N4. The improved mechanism is investigated by linear sweep voltammetry, transient photo-current, Tafel plots, electrochemical impedance spectroscopy, Mott-Schottky curves, turnover frequency, transient decay time, photoluminescence spectra, etc. The modification technique proposed in this paper can also be adopted to prepare other alkynyl functionalized semiconductors for photocatalytic application.

Herein, a series of TiO2/Bi0.5Na0.5TiO3 heterojunctions with different mass ratio are first constructed under ultrasound irradiation, which shows superior sonocatalytic and photoelectrochemical properties. The improved performance is attributed to the internal electric field and close interfacial contact of TiO2 and Bi0.5Na0.5TiO3, which promote the transfer of photoinduced electrons from TiO2 to Bi0.5Na0.5TiO3. The spontaneous polarization of ferroelectrics in the heterostructures can be adjusted by ultrasonic treatment durations, which further influences the internal electric field. The TiO2/Bi0.5Na0.5TiO3 sample with mass ratios of 5:1 and ultrasonic treatment for 15 min presents the highest sonocatalytic degradation of Rhodamine B. Moreover, the sonocatalytic activity also shows a close relevant to the ultrasonic temperature and frequency of degradation process. And, the •OH radicals are mainly responsible for Rhodamine B sonodegradation. This work provides a novel TiO2/Bi0.5Na0.5TiO3 heterojunctions and promotes the application of ferroelectrics modified materials in sono-/photo-catalysis.