Neural Network Inspired Binder Enables Fast Li-Ion Transport and High Stress Adaptation for Si Anode.

Extensive investigations have proven the effectiveness of elastic binders in settling the challenge of structural damage posed by volume expansion of high-capacity anode used in nanoscale silicon. However, the sluggish ionic conductivity of polymer binder severely restricts the electrode reactions, making it unsuitable for practical applications. Inspired by the biological tissues with rapid neurotransmission and robust muscles, we propose a biomimetic binder that contains ionic conductive polymer (by polymerization reaction of poly(ethylene glycol) diglycidyl ether and polyethylenimine) and rigid polymer backbone (polyacrylic acid), which can effectively mitigate both Li-ion transport resistance and lithiation stress to stabilize the silicon nanoparticles during cycles. Consequently, the silicon anode with biomimetic binder achieves a rate capability of 1897 mAh g-1 at 8.0 A g-1 and capacity retention of 87% after 150 cycles under areal capacity upon 3.0 mAh cm-2. These results demonstrate the possibility of decoupling ionic conductivity from mechanical properties toward practical high-capacity anodes for energy-dense batteries.

Monosymmetric Fe-N4 sites enabling durable proton exchange membrane fuel cell cathode by chemical vapor modification.

The limited durability of metal-nitrogen-carbon electrocatalysts severely restricts their applicability for the oxygen reduction reaction in proton exchange membrane fuel cells. In this study, we employ the chemical vapor modification method to alter the configuration of active sites from FeN4 to the stable monosymmetric FeN2+N'2, along with enhancing the degree of graphitization in the carbon substrate. This improvement effectively addresses the challenges associated with Fe active center leaching caused by N-group protonation and free radicals attack due to the 2-electron oxygen reduction reaction. The electrocatalyst with neoteric active site exhibited excellent durability. During accelerated aging test, the electrocatalyst exhibited negligible decline in its half-wave potential even after undergoing 200,000 potential cycles. Furthermore, when subjected to operational conditions representative of fuel cell systems, the electrocatalyst displayed remarkable durability, sustaining stable performance for a duration exceeding 248 h. The significant improvement in durability provides highly valuable insights for the practical application of metal-nitrogen-carbon electrocatalysts.

Modular multi-degree-of-freedom soft origami robots with reprogrammable electrothermal actuation.

Soft robots often draw inspiration from nature to navigate different environments. Although the inching motion and crawling motion of caterpillars have been widely studied in the design of soft robots, the steering motion with local bending control remains challenging. To address this challenge, we explore modular origami units which constitute building blocks for mimicking the segmented caterpillar body. Based on this concept, we report a modular soft Kresling origami crawling robot enabled by electrothermal actuation. A compact and lightweight Kresling structure is designed, fabricated, and characterized with integrated thermal bimorph actuators consisting of liquid crystal elastomer and polyimide layers. With the modular design and reprogrammable actuation, a multiunit caterpillar-inspired soft robot composed of both active units and passive units is developed for bidirectional locomotion and steering locomotion with precise curvature control. We demonstrate the modular design of the Kresling origami robot with an active robotic module picking up cargo and assembling with another robotic module to achieve a steering function. The concept of modular soft robots can provide insight into future soft robots that can grow, repair, and enhance functionality.

Corrigendum: Altered expression of inflammation-associated molecules in striatum: an implication for sensitivity to heavy ion radiations.

[This corrects the article DOI: 10.3389/fncel.2023.1252958.].

Early-stage effect of HIBD on neuro-motor function and organic composition of neurovascular units in neonatal rats.

Objective: This study aimed to investigate the effects of neonatal hypoxic-ischemic brain damage (HIBD) on early-stage neuro-motor function, cerebral blood flow, and the neurovascular unit. Methods: Twenty-four Sprague-Dawley newborn rats aged 7 days were obtained and randomly assigned to either the sham or the model group using a random number table. The HIBD model was established using the Rice-Vannucci method. After the induction of HIBD, the body weight of the rats was measured and their neuro-motor function was assessed. Further, cerebral blood flow perfusion was evaluated using laser speckle flow imaging, and immunofluorescent staining techniques were employed for examining the activation of specific markers and their morphological changes in different cell populations, which included vascular endothelial cells, neurons, astrocytes, and microglia within the motor cortex. Results: After HIBD, the model group exhibited impaired neuro-motor function and growth. Cerebral blood flow perfusion decreased in both the hemispheres on day 1 and in the ipsilateral brain on day 4. However, no significant difference was observed between the two groups on day 7. Moreover, the CD31 and NeuN showed a sharp decline on day 1, which was followed by a gradual increase in the expression levels. The activated microglia and astrocytes formed clusters in the injured cortex. Notably, the regions with positive staining for Arg-1, Iba-1, CD68, and GFAP consistently displayed higher values in the model group as compared to that in the sham group. The total number of branch endpoints and microglia branches was higher in the model group than in the sham group. Immunofluorescent co-localization analysis revealed no co-staining between Iba-1 and Arg-1; however, the Pearson's R-value for the co-localization of Iba-1 and CD68 was higher in the model group, which indicated an increasing trend of co-staining in the model group. Conclusion: Early-stage neuro-motor function, cerebral blood flow, microvasculature, and neurons in neonatal rats exhibited a trend of gradual recovery over time. The activation and upregulation of neuroglial cells continued persistently after HIBD. Furthermore, the impact of HIBD on early-stage neuro-motor function in newborn rats did not synchronize with the activation of neuroglial cells. The recovery of neuro-motor function, microvasculature, and neurons occurred earlier than that of neuroglial cells.

Altered expression of inflammation-associated molecules in striatum: an implication for sensitivity to heavy ion radiations.

Background and objective: Heavy ion radiation is one of the major hazards astronauts face during space expeditions, adversely affecting the central nervous system. Radiation causes severe damage to sensitive brain regions, especially the striatum, resulting in cognitive impairment and other physiological issues in astronauts. However, the intensity of brain damage and associated underlying molecular pathological mechanisms mediated by heavy ion radiation are still unknown. The present study is aimed to identify the damaging effect of heavy ion radiation on the striatum and associated underlying pathological mechanisms. Materials and methods: Two parallel cohorts of rats were exposed to radiation in multiple doses and times. Cohort I was exposed to 15 Gy of 12C6+ ions radiation, whereas cohort II was exposed to 3.4 Gy and 8 Gy with 56Fe26+ ions irradiation. Physiological and behavioural tests were performed, followed by 18F-FDG-PET scans, transcriptomics analysis of the striatum, and in-vitro studies to verify the interconnection between immune cells and neurons. Results: Both cohorts revealed more persistent striatum dysfunction than other brain regions under heavy ion radiation at multiple doses and time, exposed by physiological, behavioural, and 18F-FDG-PET scans. Transcriptomic analysis revealed that striatum dysfunction is linked with an abnormal immune system. In vitro studies demonstrated that radiation mediated diversified effects on different immune cells and sustained monocyte viability but inhibited its differentiation and migration, leading to chronic neuroinflammation in the striatum and might affect other associated brain regions. Conclusion: Our findings suggest that striatum dysfunction under heavy ion radiation activates abnormal immune systems, leading to chronic neuroinflammation and neuronal injury.

County augmented transformer for COVID-19 state hospitalizations prediction.

The prolonged COVID-19 pandemic has tied up significant medical resources, and its management poses a challenge for the public health care decision making. Accurate predictions of the hospitalizations are crucial for the decision makers to make informed decision for the medical resource allocation. This paper proposes a method named County Augmented Transformer (CAT). To generate accurate predictions of four-week-ahead COVID-19 related hospitalizations for every states in the United States. Inspired by the modern deep learning techniques, our method is based on a self-attention model (known as the transformer model) that is actively used in Natural Language Processing. Our transformer based model can capture both short-term and long-term dependencies within the time series while enjoying computational efficiency. Our model is a data based approach that utilizes the publicly available information including the COVID-19 related number of confirmed cases, deaths, hospitalizations data, and the household median income data. Our numerical experiments demonstrate the strength and the usability of our model as a potential tool for assisting the medical resources allocation.

Multimodal-Synergistic-Modulation Neuromorphic Imaging Systems for Simulating Dry Eye Imaging.

Inspired by human eyes, the neuromorphic visual system employs a highly efficient imaging and recognition process, which offers tremendous advantages in image acquisition, data pre-processing, and dynamic storage. However, it is still an enormous challenge to simultaneously simulate the structure, function, and environmental adaptive behavior of the human eye based on one device. Here, a multimodal-synergistic-modulation neuromorphic imaging system based on ultraflexible synaptic transistors is successfully presented and firstly simulates the dry eye imaging behavior at the device level. Moreover, important functions of the human visual system in relation to optoelectronic synaptic plasticity, image erasure and enhancement, real-time preprocessing, and dynamic storage are simulated by versatile devices. This work not only simplifies the complexity of traditional neuromorphic visual systems, but also plays a positive role in the publicity of biomedical eye care.

COUnty aggRegation mixup AuGmEntation (COURAGE) COVID-19 prediction.

The global spread of COVID-19, the disease caused by the novel coronavirus SARS-CoV-2, has casted a significant threat to mankind. As the COVID-19 situation continues to evolve, predicting localized disease severity is crucial for advanced resource allocation. This paper proposes a method named COURAGE (COUnty aggRegation mixup AuGmEntation) to generate a short-term prediction of 2-week-ahead COVID-19 related deaths for each county in the United States, leveraging modern deep learning techniques. Specifically, our method adopts a self-attention model from Natural Language Processing, known as the transformer model, to capture both short-term and long-term dependencies within the time series while enjoying computational efficiency. Our model solely utilizes publicly available information for COVID-19 related confirmed cases, deaths, community mobility trends and demographic information, and can produce state-level predictions as an aggregation of the corresponding county-level predictions. Our numerical experiments demonstrate that our model achieves the state-of-the-art performance among the publicly available benchmark models.

From Black Liquor to Green Energy Resource: Positive Electrode Materials for Li-O2 Battery with High Capacity and Long Cycle Life.

Black liquor has caused a tremendous degree of pollution and waste. Exploring the utilization of lignin, which is the major component of black liquor, has become a key factor in dealing with the problem. In this study, lignin derived from black liquor was used as a raw material to prepare carbon materials through different activation methods including KOH, H3PO4, and steam activation. The structure and properties of obtained samples were characterized as well as electrochemical performance when applied on a lithium-oxygen battery. Results of N2 adsorption/desorption showed that all obtained samples possessed high surface area of over 1000 m2/g. XRD, Raman, and XPS also indicated that obtained samples possessed a large defect area and many functional groups. Electrochemical measurements illustrated that all obtained samples exhibited a high discharge capacity over 2.8 mAh/cm2 at 0.02 mA/cm2, while LKAC exhibited the highest discharge capacity of 7.2 mAh/cm2. Cycling tests of all obtained samples indicated a long cycle life of at least 300 cycles. LSAC maintained a 100% retention rate of capacity and stable terminal voltage even after 800th cycle, and its cycling performance was investigated further by XRD and EIS. This study demonstrated excellent performance for lignin-based carbon materials, and provided alternative materials for positive electrode of lithium-oxygen battery.

Recycling supercapacitor activated carbons for adsorption of silver (I) and chromium (VI) ions from aqueous solutions.

In this study, we reported on the recycling of carbon materials from spent commercial supercapacitors and its application as low-cost adsorbent for high-efficiency removal of Ag(I) and Cr(VI) ions from aqueous solutions. Adsorption kinetics and isotherms, and effects of initial pH were carried out to investigate the adsorption performance of the recycled supercapacitor activated carbon (RSAC), whereas a series of characterizations such as SEM, EDX, BET, XPS, XRD and FTIR were employed to detailedly analyse the adsorption mechanism. The RSAC showed maximal adsorption capacity for Ag(I) and Cr(VI) of 104.0 and 96.3 mg g-1, respectively, with adsorbent dosage of 2 g L-1 and initial ions concentration of ∼2000 mg L-1 at room temperature (23 ±â€¯1 °C), and the adsorption was rapid and influenced by the initial pH value. The outstanding adsorption performance of RSAC was attributed to the high specific surface area (1403 m2 g-1) and abundant multifarious oxygenic groups which could participate in the electrostatic attraction and reduction reaction of Ag(I) and Cr(VI) during the adsorption process. Furthermore, the predominate species of the adsorbed toxic Ag(I) and Cr(VI) on the surface of RSAC was metallic silver particle (about 2 µm) and harmless Cr(III), respectively, thus it was possible for further recycling and disposal.

Biochars preparation from waste sludge and composts under different carbonization conditions and their Pb(II) adsorption behaviors.

This study prepared nine biochars from three biomass wastes (CompostA, CompostB and Sludge) through different carbonization conditions. The adsorption behaviors and mechanisms of these biochars for Pb(II) were tested by a series of adsorption experiments and properties analysis. Preliminary experiments showed biochars obtained from CompostA and Sludge had better Pb(II) adsorption performance than CompostB and the optimum carbonization temperature of CompostA was lower than that of Sludge. Adsorption experimental results demonstrated that CompostA600 (numbers represent carbonization temperatures) had the largest adsorption capacity of 57.34 mg/g for Pb(II) among samples, followed by Sludge800 of 50.00 mg/g. The kinetic adsorption of CompostA600 and Sludge800 were both described by the Nth-order model very well. Pb(II) adsorption of CompostA600 most appropriately followed the Langmuir-Freundlich model and the Redlich-Peterson model. Characterization analysis suggested diverse carbonization temperatures and precursors caused discrepant pore size distributions and element contents, which determined the deposition of lead compound crystals on materials. This study examined the effects of raw materials and carbonization temperatures on obtained biochars and provided an inexpensive and environmental-friendly way for biochar sorbent preparation and heavy metal wastewater treatment.

Effect of the Activation Process on the Microstructure and Electrochemical Properties of N-Doped Carbon Cathodes in Li-O2 Batteries.

Lithium-oxygen (Li-O2) batteries have the potential to provide high energy densities; however, they suffer from low actual specific capacity and poor cycle performance. Hence, it is urgent to design a satisfactory oxygen electrode for a Li-O2 battery. In this study, carbonaceous materials, denominated CA, CB, and CC, from chitin were prepared by the three activators of H3PO4, KOH, and KHCO3 as oxygen electrode materials for Li-O2 batteries. The different carbon structural characteristics from the same precursor were regulated and controlled by different chemical reagents. Finally, the spherical particle cluster structure of CA has a high specific surface area, rich N doping, good connectivity, and uniform surface chemistry, so that CA acts as an oxygen electrode presenting excellent electron conductivity, providing sufficient, and stable electrochemical activity sites for oxygen reduction reaction and storing abundant discharge products. The electrochemical measurements indicate that at a current density of 0.02 mA/cm2, a CA-based battery delivers a high specific capacity of 16 600 mA h/g and a stable cycle performance of 210 cycles. This study proposes a functional carbonaceous material from chitin as a cathode oxygen electrode, which provides an economical and sustainable way for the improvement of oxygen electrodes and the application of Li-O2 batteries.

Single-Atom Cr-N4 Sites Designed for Durable Oxygen Reduction Catalysis in Acid Media.

Single-atom catalysts (SACs) are attracting widespread interest for the catalytic oxygen reduction reaction (ORR), with Fe-Nx SACs exhibiting the most promising activity. However, Fe-based catalysts suffer serious stability issues as a result of oxidative corrosion through the Fenton reaction. Herein, using a metal-organic framework as an anchoring matrix, we for the first time obtained pyrolyzed Cr/N/C SACs for the ORR, where the atomically dispersed Cr is confirmed to have a Cr-N4 coordination structure. The Cr/N/C catalyst exhibits excellent ORR activity with an optimal half-wave potential of 0.773 V versus RHE. More excitingly, the Fenton reaction is substantially reduced and, thus, the final catalysts show superb stability. The innovative and robust active site for the ORR opens a new possibility to circumvent the stability issue of the non-noble metal ORR catalysts.

Self-Nitrogen-Doped Carbon from Plant Waste as an Oxygen Electrode Material with Exceptional Capacity and Cycling Stability for Lithium-Oxygen Batteries.

To promote the development of electric automobiles, high energy density and high-power batteries are urgently needed. More and more attention has been paid to look for high-performance cathode catalysts for Li-O2 batteries. However, the sluggish kinetic reaction, the stacking of electrical insulation product of Li2O2, and the undesired parasitic reaction restrict their capacity and present poor cycling performance. Here, we prepared nitrogen self-doped activated carbons (N-PIACs) derived from the plant waste (poplar inflorescence) through the activation and slow pyrolysis carbonization method, exhibiting several advantages. The materials presented a three-dimensional interconnecting pore structure and a high surface area. Besides, defects and functional groups doped by nitrogen as active sites improved electrochemical catalysis activity. The Li∥N-PIACs-O2 battery delivered a high specific capacity of 12060 mAh/g, which was 2.3 times that of the pristine plant waste-based Li-O2 battery (N-PICs). In addition, it presented more excellent cycling stability than other common carbon materials. In this study, we developed a functional carbon nanomaterial from cheap natural materials, which might become a highly attractive subject, indicating that this strategy could strengthen the properties of Li-O2 batteries.

Simulated Microgravity Reduces Focal Adhesions and Alters Cytoskeleton and Nuclear Positioning Leading to Enhanced Apoptosis via Suppressing FAK/RhoA-Mediated mTORC1/NF-κB and ERK1/2 Pathways.

Simulated-microgravity (SMG) promotes cell-apoptosis. We demonstrated that SMG inhibited cell proliferation/metastasis via FAK/RhoA-regulated mTORC1 pathway. Since mTORC1, NF-κB, and ERK1/2 signaling are important in cell apoptosis, we examined whether SMG-enhanced apoptosis is regulated via these signals controlled by FAK/RhoA in BL6-10 melanoma cells under clinostat-modelled SMG-condition. We show that SMG promotes cell-apoptosis, alters cytoskeleton, reduces focal adhesions (FAs), and suppresses FAK/RhoA signaling. SMG down-regulates expression of mTORC1-related Raptor, pS6K, pEIF4E, pNF-κB, and pNF-κB-regulated Bcl2, and induces relocalization of pNF-κB from the nucleus to the cytoplasm. In addition, SMG also inhibits expression of nuclear envelope proteins (NEPs) lamin-A, emerin, sun1, and nesprin-3, which control nuclear positioning, and suppresses nuclear positioning-regulated pERK1/2 signaling. Moreover, rapamycin, the mTORC1 inhibitor, also enhances apoptosis in cells under 1 g condition via suppressing the mTORC1/NF-κB pathway. Furthermore, the FAK/RhoA activator, toxin cytotoxic necrotizing factor-1 (CNF1), reduces cell apoptosis, restores the cytoskeleton, FAs, NEPs, and nuclear positioning, and converts all of the above SMG-induced changes in molecular signaling in cells under SMG. Therefore, our data demonstrate that SMG reduces FAs and alters the cytoskeleton and nuclear positioning, leading to enhanced cell apoptosis via suppressing the FAK/RhoA-regulated mTORC1/NF-κB and ERK1/2 pathways. The FAK/RhoA regulatory network may, thus, become a new target for the development of novel therapeutics for humans under spaceflight conditions with stressed physiological challenges, and for other human diseases.

Facile low-temperature one-step synthesis of pomelo peel biochar under air atmosphere and its adsorption behaviors for Ag(I) and Pb(II).

This study prepared a novel low-cost surface functionalized carbon adsorbent (PPC) from biomass waste (pomelo peel) through a facile low-temperature (250 °C) one-step method under regular air atmosphere. The adsorption performance and mechanism of the carbon material for Ag(I) and Pb(II) were investigated by a range of sorption experiments and characterizations including SEM, EDX, XRD and FTIR. Sorption experimental results suggested that PPC had high adsorption capacities of 137.4 and 88.7 mg/g for Ag(I) and Pb(II), respectively, with adsorbent dosage of 2 g/L at unadjusted solution pH and room temperature (23 ±â€¯1 °C). The characterization results indicated high-efficiency removal of the heavy metals by PPC was attributed to the strong chemical adsorption involving that Ag(I) ions were reduced as metallic Ag particles by oxygenic functional groups and Pb(II) ions were precipitated as Pb5(PO4)3OH crystals by phosphorous functional groups on the carbon surfaces. This study provides the possibility of synthesis high-efficient adsorbent using economic and environmental-friendly approach with low energy consumption.

Simulated microgravity inhibits cell focal adhesions leading to reduced melanoma cell proliferation and metastasis via FAK/RhoA-regulated mTORC1 and AMPK pathways.

Simulated microgravity (SMG) was reported to affect tumor cell proliferation and metastasis. However, the underlying mechanism is elusive. In this study, we demonstrate that clinostat-modelled SMG reduces BL6-10 melanoma cell proliferation, adhesion and invasiveness in vitro and decreases tumor lung metastasis in vivo. It down-regulates metastasis-related integrin α6ß4, MMP9 and Met72 molecules. SMG significantly reduces formation of focal adhesions and activation of focal adhesion kinase (FAK) and Rho family proteins (RhoA, Rac1 and Cdc42) and of mTORC1 kinase, but activates AMPK and ULK1 kinases. We demonstrate that SMG inhibits NADH induction and glycolysis, but induces mitochondrial biogenesis. Interestingly, administration of a RhoA activator, the cytotoxic necrotizing factor-1 (CNF1) effectively converts SMG-triggered alterations and effects on mitochondria biogenesis or glycolysis. CNF1 also converts the SMG-altered cell proliferation and tumor metastasis. In contrast, mTORC inhibitor, rapamycin, produces opposite responses and mimics SMG-induced effects in cells at normal gravity. Taken together, our observations indicate that SMG inhibits focal adhesions, leading to inhibition of signaling FAK and RhoA, and the mTORC1 pathway, which results in activation of the AMPK pathway and reduced melanoma cell proliferation and metastasis. Overall, our findings shed a new light on effects of microgravity on cell biology and human health.

Preparation of MnO2-Modified Graphite Sorbents from Spent Li-Ion Batteries for the Treatment of Water Contaminated by Lead, Cadmium, and Silver.

Herein, a novel adsorbent was prepared via grafting MnO2 particles on graphite recovered from spent lithium-ion batteries to treat water contaminated by lead, cadmium, and silver. This is the first study reporting the recovery of spent LIB anode material and its application to heavy-metal-contaminated wastewater treatment. Characterizations using scanning electron microscopy, energy-dispersive X-ray analysis, and Fourier transform infrared showed that the adsorbent surface was coated with MnO2 ultrafine particles that served as the sorption mechanism to remove heavy-metal ions. In comparison to the raw artificial graphite (AG) powder, the MnO2-modified AG (MnO2-AG) exhibited a markedly improved removal capacity toward Pb(II), Cd(II), and Ag(I), whose removal rates reached as high as 99.9, 79.7, and 99.8%, respectively. The removal of the heavy metals by MnO2-AG was mainly through the ion exchange of hydroxyl groups. This study provides the possibility of synthesis of an efficient adsorbent by reusing the "waste", such as spent Li-ion batteries. It is an economic and environmentally friendly approach for both heavy-metal-contaminated water treatment and waste recycling.

Starvation after Cobalt-60 γ-Ray Radiation Enhances Metastasis in U251 Glioma Cells by Regulating the Transcription Factor SP1.

Radiation is of clinical importance during glioma therapy; however, vasculature damage is observed over the treatment course. This type of tissue damage might lead to starvation conditions, affecting tumor metastasis. To test this possibility, we compared starvation conditions in conjunction with radiation treatment to monitor metastatic ability in the U251 glioma cell line. Transcriptome, western blot, and immunofluorescence analyses were used to measure the RNA and protein expression changes of the U251 cells after various treatments. We found that starvation combined with radiation treatment yielded the most significant expression changes in metastasis-related factors compared to that in the control groups. In addition, a metastasis assay was used to directly measure the metastatic ability of the treated cells, which confirmed that the U251 cells treated with starvation combined with radiation possessed the highest metastatic ability. Furthermore, bioinformatics analysis demonstrated that SP1 represented a common transcription factor associated with changes in metastasis-related factors. Blocking SP1 activity by an inhibitor suppressed the starvation-plus-radiation treatment-mediated enhancement of U251 cell metastasis. Our study provides the first evidence that starvation caused by radiation might play a significant role in enhancing the ability of the glioma cell line U251 to metastasize via regulation of the transcription factor SP1.