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Cognitive impairment is typically reflected in the time and frequency variations of electroencephalography (EEG). Integrating time-domain and frequency-domain analysis methods is essential to better understand and assess cognitive ability. Timely identification of cognitive levels in early Parkinson's disease (ePD) patients can help mitigate the risk of future dementia. For the investigation of the brain activity and states related to cognitive levels, this study recruited forty ePD patients for EEG microstate analysis, including 13 with mild cognitive impairment (MCI) and 27 without MCI (control group). To determine the specific frequency band on which the microstate analysis relies, a deep learning framework was employed to discern the frequency dependence of the cognitive level in ePD patients. The input to the convolutional neural network consisted of the power spectral density of multi-channel multi-point EEG signals. The visualization technique of gradient-weighted class activation mapping was utilized to extract the optimal frequency band for identifying MCI samples. Within this frequency band, microstate analysis was conducted and correlated with the Montreal Cognitive Assessment (MoCA) Scale. The deep neural network revealed significant differences in the 1-11.5Hz spectrum of the ePD-MCI group compared to the control group. In this characteristic frequency band, ePD-MCI patients exhibited a pattern of global microstate disorder. The coverage rate and occurrence frequency of microstate A and D increased significantly and were both negatively correlated with the MoCA scale. Meanwhile, the coverage, frequency and duration of microstate C decreased significantly and were positively correlated with the MoCA scale. Our work unveils abnormal microstate characteristics in ePD-MCI based on time-frequency fusion, enhancing our understanding of cognitively related brain dynamics and providing electrophysiological markers for ePD-MCI recognition.

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Multistimuli-responsive conductive hydrogels have been appealing candidates for multifunctional ionic skin. However, the fabrication of the multistimuli-responsive conductive hydrogels with satisfactory mechanical property to meet the practical applications is still a great challenge. In this study, a novel poly(N-isopropylacrylamide-co-sodium acrylate)/alginate/hectorite clay Laponite XLS (PNIPAM-SA/ALG/XLS) double cross-linked hydrogel with excellent mechanical property, self-recovery ability, temperature/pH-responsive ability, and strain/temperature-sensitive conductivity was fabricated. The PNSAX hydrogel possessed a moderate tensile strength of 290 kPa at a large elongation rate of 1120% and an excellent compression strength of 2.72 MPa at 90%. The hydrogel also possessed excellent mechanical repeatability and self-recovery ability. Thus, the hydrogel could withstand repetitive deformations for long time periods. Additionally, the hydrogel could change its transparency and volume once at a temperature of 44 °C and change its volume at different pHs. Thus, the visual temperature/pH-responsive ability allowed the hydrogel to qualitatively harvest environmental information. Moreover, the hydrogel possessed an excellent conductivity of 0.43 S/m, and the hydrogel could transform large/subtle deformation and temperature information into electrical signal change. Thus, the ultrafast strain/temperature-sensitive conductivity allowed the hydrogel to quantitatively detect large/small-scale human motions as well as environmental temperature. A cytotoxicity test confirmed the good cytocompatibility. Taken together, the hydrogel was suitable for human motion detecting and environmental information harvesting for long time periods. Therefore, the hydrogel has a great application potential as a multifunctional ionic skin and smart sensor.

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In this work, we report the fabrication and functional demonstration of a kind of dually responsive nanoparticles (NPs) as a potential drug delivery vector. The pH value, corresponding to the acidic microenvironment at the tumor site, and mannitol, to the extracellular trigger agent, were employed as the dually responsive factors. The function of dual responses was achieved by breaking the dynamic covalent bonds between phenylboronic acid (PBA) groups and diols at low pH value (pH 5.0) and/or under the administration of mannitol, which triggered the decomposition of the complex NPs and the concomitant release of anticancer drug of doxorubicin (DOX) loaded inside the NPs. The NPs were composed of modified chitosan (PQCS) with quaternary ammonium and PBA groups on the side chains, heparin (Hep), and poly(vinyl alcohol) (PVA), in which quaternary ammonium groups offer the positive charge for the cell-internalization of NPs, PBA groups serve for the formation of dynamic bonds in responding to pH change and mannitol addition, PVA furnishes the NPs with diol groups for the interaction with PBA groups and the formation of dynamic NPS, and Hep plays the roles of reducing the cytotoxicity of highly positively-charged chitosan and forming of complex NPs for DOX up-loading. A three-step fabrication process of drug-loaded NPs was described, and the characterization results were comprehensively demonstrated. The sustained drug release from the drug-loaded NPs displayed obvious pH and mannitol dependence. More specifically, the cumulative DOX release was increased more than 1.5-fold at pH 5.0 with 20 mg mL-1 mannitol. Furthermore, the nanoparticles were manifested with effective antitumor efficient and apparently enhanced cytotoxicity in response to the acidic pH value and/or mannitol.

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Efficient charge separation, in particular bulk charge separation (BCS), is one of the most critical factors in determining the performance of photoelectrochemical (PEC) water-splitting. The BCS enhancement of CdS/BaTiO3 (CdS/BTO) nanowires (NWs) in photoelectrocatalysis has rarely been reported. This paper describes a remarkable PEC properties promotion of the CdS/BTO NWs, which is confirmed to be a result of the enhanced BCS efficiency induced by the ferroelectric polarization. The vertical arrays of BTO NWs endow fast transfer of carriers. Meanwhile, CdS is decorated uniformly on the surface of BTO NWs, which ensures a wide range of light absorption. After two negative polarizations, the CdS/BTO NWs have successfully obtained a remarkable photocurrent density, achieving 459.53 µA cm-2 at 1.2 V(vs.RHE), which is 2.86 times that of the unpolarized sample. However, after two positive polarizations, the photocurrent density dramatically decreases to 40.18 µA cm-2 at 1.2 V(vs.RHE), which is merely 0.25 times the original value. More importantly, the photocurrent density reaches up to a prominent value of -71.09 mA cm-2 at -0.8 V(vs.RHE) after two successive negative polarizations, which is a 40.87 mA cm-2 enhancement with respect to the sample without poling. Significantly, at -0.8 V(vs.RHE), the BCS efficiency of the CdS/BTO NWs is as high as 91.87% after two negative polarizations. The effects of ferroelectric polarization on the PEC performance of CdS/BTO NWs have been systematically studied. The results demonstrate that ferroelectric polarization, especially negative polarization, results in an internal electric field to tune band bending of CdS/BTO NWs, thus prominently enhancing the PEC performance.