The diverse properties reported for starch-based materials indicate their potential for use in the preparation of biodegradable flexible actuators. However, their natural brittleness and lack of ...durability after modification limit their practical application. Therefore, we propose a strategy for preparing flexible starch-based composites. The results of macro/micro property characterizations and molecular dynamics simulations indicated that using starch, maleic anhydride, and stearic acid (SA), the mobility of the starch chains was enhanced and retrogradation was inhibited through the synergistic effects induced by chain breaking, complex formation with SA, and esterification of the starch molecules. In addition, the elongation at break of the modified starch (MS) reached 2070 %, and considerable ductility (>1000 %) as well as well-complexed structure were maintained after six months. Furthermore, the MS was able to undergo self-healing after fracture or a temperature-controlled stiffness transition. Moreover, it underwent complete degradation in soil within 30 d. Finally, an actuator was prepared by doping the MS with nano-Fe3O4 particles to realize a dual magnetic and optical response. Dynamic monitoring was also achieved based on the electrical signal, thereby demonstrating the broad application scope of this material in the development of biodegradable flexible actuators.
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Developing photoactive materials with wide spectral response is critical to improve the sensitivity of PEC biosensors. Herein, a sensitive photoelectrochemical (PEC) aptasensor was fabricated based ...on Bi surface plasmon resonance (SPR)-promoted BiVO4/g-C3N4 (Bi/BiVO4/g-C3N4) as photoactive material for the detection of oxytetracycline (OTC). Ternary Z-scheme Bi/BiVO4/g-C3N4 heterojunction exhibited widest spectral response and best PEC activity compared to g-C3N4, BiVO4, Bi/BiVO4, and BiVO4/g-C3N4. The wide spectral response and high PEC activity could be attributed to three reasons: Firstly, the SPR effect of Bi could greatly increase light harvesting; Secondly, Bi served as an electron conduction bridge between BiVO4 and g-C3N4 to form Z-scheme structure, significantly accelerating the separation of photogenerated carriers; Thirdly, the synergism of Z-scheme heterojunction and the SPR effect of Bi efficiently boosted the photoelectric response. Based on the above sensitization strategies, the proposed PEC aptasensor for OTC determination showed a wide linear range of 0.01–1000 nM and a low detection limit (S/N = 3) of 3.3 × 10−3 nM. Moreover, the high stability, satisfactory repeatability and favorable practicability of the fabricated PEC aptasensor revealed the potential applications for accurate monitoring of antibiotics in environmental media.
•A ternary Z-scheme Bi/BiVO4/g-C3N4 heterojunction was prepared by in-situ reduction of BiVO4/g-C3N4.•Plasmonic Bi served as an electron conduction bridge between BiVO4 and g-C3N4 to form the Z-scheme structure.•The Bi/BiVO4/g-C3N4 displayed highest photocurrent compared with g-C3N4, BiVO4, Bi/BiVO4, and BiVO4/g-C3N4.•A PEC aptasensor was successfully established for detection of oxytetracycline.•The constructed oxytetracycline aptasensor showed a wide linear range and low detection limit.
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•Co/CoSe heterojunctions were constructed as bifunctional electrocatalysts via partial reduction.•The charge redistribution is revealed by systematic characterizations and DFT ...calculations.•Both ORR and OER activities are promoted due to the Mott-Schottky effect of Co/CoSe heterojunction.•The Co/CoSe-based Zn-air battery delivers high energy output and excellent cyclability.
Design of low-cost and high-performance bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a key topic in the development of zinc-air batteries. In this work, a facile in-situ partial reduction strategy is proposed to fabricate Co/CoSe Schottky junctions encapsulated in carbon (Co/CoSe@NC). The heterojunction in the Co/CoSe@NC can tune Fermi level and charge redistribution to accelerate the charge transfer, while the metal–organic framework derived skeleton provides well-defined structure and abundant mesopores to facilitate mass transport. The accelerated charge transfer through the Mott-Schottky heterostructure can improve the intrinsic electrocatalytic activities for both electron-gaining ORR and electron-losing OER, which are confirmed by systematic characterizations and density functional theory calculations. Furthermore, the Zn-air battery with the as-prepared Co/CoSe@NC heterojunction shows better performance than the Pt/RuO2-based counterpart, demonstrating good feasibility for practical applications.
Neuroscientific studies on the function of the basal ganglia often examine the behavioral performance of patients with movement disorders, such as Parkinson's disease (PD) and dystonia (DT), while ...simultaneously examining the underlying electrophysiological activity during deep brain stimulation surgery. Nevertheless, to date, there have been no studies comparing the cognitive performance of PD and DT patients during surgery. In this study, we assessed the memory function of PD and DT patients with the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE). We also tested their cognitive performance during the surgery using a continuous recognition memory test. The results of the MoCA and MMSE failed to reveal significant differences between the PD and DT patients. Additionally, no significant difference was detected by the intraoperative memory test between the PD and DT patients. The intraoperative memory test scores were highly correlated with the MMSE scores and MoCA scores. Our data suggest that DT patients perform similarly to PD patients in cognitive tests during surgery, and intraoperative memory tests can be used as a quick memory assessment tool during surgery.
Background:
Subthalamic nucleus deep brain stimulation (STN-DBS) improves sleep qualities in Parkinson’s disease (PD) patients; however, it remains elusive whether STN-DBS improves sleep by directly ...influencing the sleep circuit or alleviates other cardinal symptoms such as motor functions, other confounding factors including stimulation intensity may also involve. Studying the effect of microlesion effect (MLE) on sleep after STN-DBS electrode implantation may address this issue.
Objective:
To examine the influence of MLE on sleep quality and related factors in PD, as well as the effects of regional and lateral specific correlations with sleep outcomes after STN-DBS electrode implantation.
Study Design:
Case–control study; Level of evidence, 3.
Data Sources and Methods:
In 78 PD patients who underwent bilateral STN-DBS surgery in our center, we compared the sleep qualities, motor performances, anti-Parkinsonian drug dosage, and emotional conditions at preoperative baseline and postoperative 1-month follow-up. We determined the related factors of sleep outcomes and visualized the electrodes position, simulated the MLE-engendered volume of tissue lesioned (VTL), and investigated sleep-related sweet/sour spots and laterality in STN.
Results:
MLE improves sleep quality with Pittsburgh Sleep Quality Index (PSQI) by 13.36% and Parkinson’s Disease Sleep Scale-2 (PDSS-2) by 17.95%. Motor (P = 0.014) and emotional (P = 0.001) improvements were both positively correlated with sleep improvements. However, MLE in STN associative subregions, as an independent factor, may cause sleep deterioration (r = 0.348, P = 0.002), and only the left STN showed significance (r = 0.327, P = 0.004). Sweet spot analysis also indicated part of the left STN associative subregion is the sour spot indicative of sleep deterioration.
Conclusion:
The MLE of STN-DBS can overall improve sleep quality in PD patients, with a positive correlation between motor and emotional improvements. However, independent of all other factors, the MLE in the STN associative subregion, particularly the left side, may cause sleep deterioration.
Rational design of cost-effective electrocatalysts for oxygen reduction reaction (ORR) is essential for developing metal-air batteries. In this work, we propose a pre-self-assembled strategy to ...prepare controllable B–N coordinated active sites anchored on carbon supports as an efficient electrocatalyst for ORR. The precisely coordinated B–N coordination from the pre-self-assembled boronate-amino ligands are sealed on the in-situ formed carbon dots (CDs) for preservation and further converted into B–N coordinated active sites on the carbon support. The B–N coordinated active sites anchored on the graphene aerogel (denoted as B–N-G) exhibit Pt/C competitive ORR catalytic activity in both alkaline and neutral media, which are attributed to the high content of efficient B–N coordinated active sites with expanded lattice spacing. The operando Fourier transform infrared (FTIR) spectroscopy and density functional theory (DFT) calculations explain the catalytic mechanism and identify the active sites of the B–N coordination. Furthermore, the B–N-G is directly processed into an integrated air cathode, and the Al-air batteries with the B–N-G integrated air cathode exhibit superior discharge performance and good stability in both NaOH and NaCl electrolytes. This study demonstrates a feasible pre-self-assembled approach to achieve designed B–N coordination in carbon-based electrocatalysts for metal-air batteries.
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•A pre-self-assembled strategy is proposed to prepare controllable B–N coordinated active sites.•The B–N coordination with expanded lattice spacing contributes to improved ORR activity.•The B–N-G shows comparable ORR performance with Pt/C.•The B–N active sites are identified by Operando FTIR and DFT.•The Al-air battery displays superior discharge performance and stability.
Highlights
Fe single atoms supported on porous carbon nanofiber are prepared by spatial confinement.
The iron single atoms supported on porous nitrogen-doped carbon nanofibers (FeSAs-NCF) can promote ...the reversible conversion between aluminum polysulfides.
The FeSAs-NCF can chemically anchor the polysulfides to suppress shuttle effect.
Rechargeable aluminum–sulfur (Al–S) batteries have been considered as a highly potential energy storage system owing to the high theoretical capacity, good safety, abundant natural reserves, and low cost of Al and S. However, the research progress of Al–S batteries is limited by the slow kinetics and shuttle effect of soluble polysulfides intermediates. Herein, an interconnected free-standing interlayer of iron single atoms supported on porous nitrogen-doped carbon nanofibers (FeSAs-NCF) on the separator is developed and used as both catalyst and chemical barrier for Al–S batteries. The atomically dispersed iron active sites (Fe–N
4
) are clearly identified by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption near-edge structure. The Al–S battery with the FeSAs-NCF shows an improved specific capacity of 780 mAh g
−1
and enhanced cycle stability. As evidenced by experimental and theoretical results, the atomically dispersed iron active centers on the separator can chemically adsorb the polysulfides and accelerate reaction kinetics to inhibit the shuttle effect and promote the reversible conversion between aluminum polysulfides, thus improving the electrochemical performance of the Al–S battery. This work provides a new way that can not only promote the conversion of aluminum sulfides but also suppress the shuttle effect in Al–S batteries.
•We have established a new dataset that provides more basic PSCs parameters to accurately predict the PCE of PSCs from a more data-driven perspective.•We successfully predicted the optimal values of ...various underlying parameters of PSC at 23% PCE using Bayesian algorithm.•We have established a PCE model that can quickly and efficiently predict PSCs.
The development of perovskite solar cells (PSCs) has received much attention in recent years, but material selection schemes based on trial-and-error methods have made the enhancement of perovskite solar cell performance a huge challenge. Here, we propose a machine learning framework to predict the Photoelectric conversion efficiency (PCE) of PSCs with high speed and accuracy and use a Bayesian algorithm to inverse predict the optimal values of the underlying parameters (band gap, thickness of each layer, defect density, etc.) of PSC devices. Four different machine learning models, including the Extremely Randomized Trees (ExtRa Trees), k-nearest neighbor (KNN), light gradient boosting machine (LGBM), and random forest regression (RF) were adopted for training, with the ExtRa Trees model giving the best prediction performance (R2 = 0.71). In addition interpretable machine learning was applied to extract the performance-structure relationship for the PSCs. A Bayesian approach was used to rapidly derive optimal values for the cell device parameters at a PCE of 23%, which greatly accelerated the PSC manufacturing process. This work demonstrates the great potential of machine learning to accelerate the development of PSCs.
Subthalamic nucleus deep brain stimulation (STN-DBS) has the potential to delay Parkinson's disease (PD) progression. Whether oxidative stress participates in the neuroprotective effects of DBS and ...related signaling pathways remains unknown. To address this, we applied STN-DBS to mice and monkey models of PD and collected brain tissue to evaluate mitophagy, oxidative stress, and related pathway. To confirm findings in animal experiments, a cohort of PD patients was recruited and oxidative stress was evaluated in cerebrospinal fluid. When PD mice received STN stimulation, the mTOR pathway was suppressed, accompanied by elevated LC3 II expression, increased mitophagosomes, and a decrease in p62 expression. The increase in mitophagy and balance of mitochondrial fission/fusion dynamics in the substantia nigra caused a marked enhancement of the antioxidant enzymes superoxide dismutase and glutathione levels. Subsequently, fewer mitochondrial apoptogenic factors were released to the cytoplasm, which resulted in a suppression of caspase activation and reservation of dopaminergic neurons. While interfaced with an mTOR activator, oxidative stress was no longer regulated by STN-DBS, with no neuroprotective effect. Similar results to those found in the rodent experiments were obtained in monkeys treated with chronic STN stimulation. Moreover, antioxidant enzymes in PD patients were increased after the operation, however, there was no relation between changes in antioxidant enzymes and motor impairment. Collectively, our study found that STN-DBS was able to increase mitophagy via an mTOR-dependent pathway, and oxidative stress was suppressed due to removal of damaged mitochondria, which was attributed to the dopaminergic neuroprotection of STN-DBS in PD.
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