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Summary: Sleep loss with work overload can impact human cognitive performance. However, the brain's response to an increased working memory load following total sleep deprivation (TSD) remains unclear. In the present study, we focussed on the dynamic response of the hippocampus to increased working memory load before and after total sleep deprivation of 36 h. A total of 16 male participants completed a verbal working memory task under functional magnetic resonance imaging. After whole‐brain activation analysis and region of interest analysis of the hippocampus, the generalised form of context‐dependent psychophysiological interactions (gPPI) was used to analyse the hippocampal functional connectivity with the whole brain. The results revealed that as the working memory load increased within a small range, from 0‐back to 1‐back task, the left hippocampal functional connectivity decreased with the left supplementary motor area, left pars opercularis, left rolandic operculum, right superior frontal gyrus, bilateral precentral gyrus, and left middle cingulate cortex following total sleep deprivation compared with that observed in resting wakefulness. When the working memory load further increased from 1‐back to 2‐back task, the connectivity increased between the left hippocampus and the left superior parietal lobule as well as between the left hippocampus and right lingual gyrus after total sleep deprivation compared with that observed in resting wakefulness. Moreover, the left hippocampus gPPI effect on the left middle cingulate cortex and left superior parietal lobule could predict the behavioural test accuracy in 1‐back and 2‐back task, respectively, following total sleep deprivation. These findings indicated that increased working memory load after total sleep deprivation disrupts working memory processes. The brain reacts to these disruptions in a dynamic and flexible manner, involving not only brain activation but also hippocampus‐related functional network connections. [ABSTRACT FROM AUTHOR]

Many studies have demonstrated the impairment of sustained attention due to total sleep deprivation (TSD). However, it remains unclear whether and how TSD affects the processing of visual selective attention. In the current study, 24 volunteers performed a visual search task before and after TSD over a period of 36 h while undergoing spontaneous electroencephalography. Paired-sample t-tests of behavioral performance revealed that, compared with baseline values, the participants showed lower accuracy and higher variance in response time in visual search tasks performed after TSD. Analysis of the event-related potentials (ERPs) showed that the mean amplitude of the N2-posterior-contralateral (N2pc) difference wave after TSD was less negative than that at baseline and the mean amplitude of P3 after TSD was more positive than that at baseline. Our findings suggest that TSD significantly attenuates attentional direction/orientation processing and triggers a compensatory effect in the parietal brain to partially offset the impairments. These findings provide new evidence and improve our understanding of the effects of sleep loss. [ABSTRACT FROM AUTHOR]

We have synthesized nitrogen-doped carbon quantum dots (N-CQDs) via one-step hydrothermal method by using citric acid and urea as carbon sources, In order to solve the agglomeration effect of carbon quantum dots and increase its recognition sites, and then combined the N-CQDs with 3,4,9,10-perylenetetracarboxylic acid (PTCA) to synthesize an self-assembled carbon quantum dots-3,4,9,10-perylenetetracarboxylic acid (N-CQDs/PTCA) composite, which has strong fluorescent properties. The fluorescence spectrum showed that the prepared self-assembled composite (N-CQDs/PTCA) has strong yellow-green light emission near 510 nm. The characterizations such as ultraviolet–visible absorption, X-ray electron spectroscopy, Fourier infrared spectroscopy, and transmission electron microscopy have confirmed that the N-CQDs and PTCA were combined together successfully. And the prepared self-assembled N-CQDs/PTCA was independent of excitation. It has stable and strong fluorescence properties and can be used as a fluorescent probe. The study also found that in the presence of Fe3+ ions, the fluorescence of self-assembled carbon quantum dots N-CQDs/PTCA will be quenched, and the quenching efficiency had a good linear relationship with the concentration of Fe3+ ions. Therefore, we proposed to use the self-assembled carbon quantum dots N-CQDs/PTCA as a fluorescent probe to detect Fe3+ selectively. The results showed that the method was fast, reliable, obvious detection signal, selective, and not affected by incubation time. The detection limit is 0.041 μM, which provides a new idea for the detection of Fe3+ ions by using self-assembled method and has broad application prospects. [ABSTRACT FROM AUTHOR]

Electroencephalographic Neurofeedback Training (EEG NFT) aims to improve sport performance by teaching athletes to control their mental states, leading to better cognitive, emotional, and physical outcomes. The psychomotor efficiency hypothesis suggests that optimizing brain function could enhance athletic ability, indicating the potential of EEG NFT. However, evidence for EEG-NFT's ability to alter critical brain activity patterns, such as sensorimotor rhythm and frontal midline theta-key for concentration and relaxation-is not fully established. Current research lacks standardized methods and comprehensive studies. This shortfall is due to inconsistent EEG target selection and insufficient focus on coherence in training. This review aims to provide empirical support for EEG target selection, conduct detailed control analyses, and examine the specificity of electrodes and frequencies to relation to the psychomotor efficiency hypothesis. Following the PRISMA method, 2,869 empirical studies were identified from PubMed, Science Direct, Web of Science, Embase, CNKI, and PsycINFO. Thirteen studies met the inclusion criteria: (i) proficient skill levels; (ii) use of EEG; (iii) neurofeedback training (NFT); (iv) motor performance metrics (reaction time, precision, dexterity, balance); (v) control group for NFT comparison; (vi) peer-reviewed English-language publication; and (vii) randomized controlled trial (RCT) design. Studies indicate that NFT can enhance sports performance, including improvements in shooting accuracy, golf putting, and overall motor skills, as supported by the psychomotor efficiency hypothesis. EEG NFT demonstrates potential in enhancing sports performance by optimizing performers' mental states and psychomotor efficiency. However, the current body of research is hampered by inconsistent methodologies and a lack of standardized EEG target selection. To strengthen the empirical evidence supporting EEG NFT, future studies need to focus on standardizing target selection, employing rigorous control analyses, and investigating underexplored EEG markers. These steps are vital to bolster the evidence for EEG NFT and enhance its effectiveness in boosting sport performance., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer ES declared a past co-authorship with the authors M-YC to the handling editor., (Copyright © 2024 Cheng, Yu, An, Wang, Tsai, Qi and Wang.)

Precise monitoring of the subtle pH fluctuation during biological events remains a big challenge. Previously, we reported an ultra-pH-sensitive (UPS) nanoprobe library with a sharp pH response using co-polymerization of two tertiary amine-containing monomers with distinct pK a . Currently, we have generalized the UPS nanoparticle library with tunable pH transitions (pH t ) by copolymerization of a tertiary amine-containing monomer with a series of non-ionizable monomers. The pH t of nanoparticles is fine-tuned by the non-ionizable monomers with different hydrophobicity. Each non-ionizable monomer presents a constant contribution to pH tunability regardless of tertiary amine-containing monomers. Based on this strategy, we produced two libraries of nanoprobes with continuous pH t covering the entire physiological pH range (5.0-7.4) for fluorescent imaging of endosome maturation and cancers. This generalized strategy provides a powerful toolkit for biological studies and cancer theranostics., (© 2022 Wiley-VCH GmbH.)