A nano-copper particle-modified zinc anode as a protective coating enables dendrite-free aqueous zinc-ion batteries.

Aqueous zinc-ion batteries (AZIBs) have become one of the hotspots in large-scale energy storage due to their advantages of high safety, low cost, and environmental friendliness. However, the metallic Zn anode is prone to dendritic growth and electrochemical corrosion on the surface during cycling, posing a serious challenge to the cycling life of AZIBs. Herein, a simple, low-cost and suitable for mass production method is reported to construct an anti-corrosive nano-copper particle protective coating on the surface of a metallic zinc (Cu-Zn) anode. The prepared nano-copper particles are evenly distributed on the surface of Zn, providing a uniform electric field distribution and successfully suppressing electrochemical corrosion on the surface. Importantly, it is confirmed microscopically that the Cu-Zn anode maintains homogeneous stripping and plating processes, effectively alleviating dendrite formation. Additionally, the resulting Cu-Zn anode exhibits a lower overpotential, which offers a lower interfacial transfer resistance of the battery. The symmetric battery test results show that the unmodified bare Zn anode fails after 58 h at 1 mA cm-2 and 0.5 mA h cm-2, while the Cu-Zn anode can remain stable for more than 3200 h. Furthermore, the assembled Cu-Zn||α-MnO2 battery delivers a capacity of 173.2 mA h g-1 after 2500 cycles at a high current density of 2000 mA g-1, and the capacity retention rate is 90.6%. The results indicate the great potential application of the nano-copper particle-modified zinc anode, which has provided an appealing strategy for improving the stability of AZIBs to promote the industrial development of the energy storage field.

Heterogeneous nuclear ribonucleoprotein A2/B1 as a novel biomarker in elderly patients for the prediction of postoperative neurocognitive dysfunction: A prospective nested case-control study.

Background and objective: Postoperative neurocognitive dysfunction (PND) occurs in up to 54% of older patients, giving rise to the heavy psychological and economic burdens to patients and society. To date, the development of PND biomarkers remains a challenge. Heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2/B1) is an RNA-binding protein whose prion-like structure is prone to mutation and hence leads to neurodegenerative diseases, but its expression changes in PND remains unclear. Here, we detect the preoperative hnRNPA2/B1 level in patients with PND, and to explore its value in the prediction and diagnosis of PND. Methods: The study included 161 elderly patients undergoing lumbar decompression and fusion in Nankai University Affinity the Third Central Hospital from September 2021 to July 2022. Neuropsychological and psychometric evaluations were performed before surgery, 1 week and 3 months after surgery to diagnose the occurrence of PND, then the peripheral blood was collected from patients before induction of anesthesia. The concentration in plasma of hnRNPA2/B1 and amyloid-ß 42 were determined by enzyme-linked immunosorbent assay. The median fluorescence intensity and mRNA levels of hnRNPA2/B1 in peripheral blood mononuclear cells was detected by indirect intracellular staining flow cytometry and quantitative real-time PCR, respectively. Results: The preoperative hnRNPA2/B1 level in patients with PND was higher both in short-time and long-time follow-up. We found significantly higher concentrations of hnRNPA2/B1 in PND at 7 days after surgery (median, 72.26 pg/mL vs. 54.95 pg/mL, p = 0.022) compared with patients without PND, and so as 3 months after surgery (median, 102.93 pg/mL vs. 56.38 pg/mL, p = 0.012). The area under the curve (AUC) was predicted to be 0.686 at 7 days after surgery and 0.735 at 3 months. In addition, when combining several clinical information, the diagnostic efficiency of hnRNPA2/B1 for PND could further increase (AUC, 0.707 at 7 days, 0.808 at 3 months). Conclusion: Based on the findings reported here, hnRNPA2/B1 may serve as a new and powerful predictive biomarker to identify elderly patients with PND.

Uniform Bi-Bi2O3 nanoparticles/reduced graphene oxide composites for high-performance aqueous alkaline batteries.

Aqueous alkaline batteries (AABs) with the merits of both high energy density and power density have emerged as one of the most promising candidates for the new generation of energy storage devices, while their practical applications are still limited by the lack of high-performance electrode materials, especially for the anode materials. Herein, metallic bismuth-bismuth oxide nanoparticles (Bi-Bi2O3), with numerous heterogeneous interfaces, are successfully anchored and uniformly distributed on reduced graphene oxide (rGO) sheets. When Bi-Bi2O3/rGO-20 electrode is used as the anode material for an AAB, it shows a high specific capacity of 288.0 mA h g-1 (1036.9 F g-1) at 1 A g-1 and good rate capability (74.7% of capacity retention ratio at 20 A g-1). Additionally, in order to match well with a Bi-Bi2O3/rGO-20 anode, CoVSx thin sheets decorated with Ni-Co layered double hydroxide sheets (NiCo-LDH) were successfully constructed via a facile multistep hydrothermal method and a subsequent electrodeposition process. The resulting cathode exhibits a high specific capacity of 306.0 mA h g-1 (2448 F g-1) at 1 A g-1. The assembled CoVSx@NiCo-LDH//Bi-Bi2O3/rGO-20 AAB delivers an outstanding energy density of 106.1 Wh kg-1 at a power density of 789.6 W kg-1. Besides, the as-synthesized Bi-based electrode is also used in aqueous Zn alkaline batteries to further extend its application and the assembled Bi-Bi2O3/rGO-20//Zn batteries possess an ultralong flat discharge plateau and exhibit a specific capacity of 250.6 mA h g-1 at 1 A g-1. The results demonstrate that the as-assembled AAB has huge potential for practical applications and provides an inspiration for the next-generation energy storage devices.

Antioxidant Effect of Propofol in Gliomas and Its Association With Divalent Metal Transporter 1.

BACKGROUND: Oxidative stress enhances tumor invasion and metastasis in brain cancer. The activation of divalent metal transporter 1 (DMT1), which is regulated by glutamate receptors, can result in the increase of oxidative stress and risk of cancer development. Propofol, an anesthetic with antioxidant capacity, has been shown to decrease oxidative stress in several different types of cancer. However, the underlying mechanism remains unclear. Therefore, the present study aimed to elucidate the mechanism underlying the suppression of oxidative stress in glioma cells by propofol. It was hypothesized that propofol may inhibit oxidative stress in gliomas via suppressing Ca2+-permeable α-amino-3-hydroxyl-5-methylisoxazole-4-propionic acid (AMPA) receptor (CPAR)-DMT1 signaling. METHODS: Male Wistar rats with C6 gliomas, which were established by intracranial injection of C6 glioma cells, were either treated with propofol or not for 6 h before being sacrificed. The levels of AMPA receptor subunit GluR2 and DMT1 protein expression were assessed using western blotting. The association between CPARs and DMT1 was confirmed in vitro using the AMPA receptor activator (R, S)-AMPA. Glutathione and reactive oxygen species assay kits were used to evaluate tumor oxidative stress. The effect of propofol on glioma proliferation was evaluated by determining tumor weight, cell cycles and a growth curve. RESULTS: Propofol infusion at either 20 or 40 mg/kg-1/h-1 increased GluR2 levels and downregulated DMT1 expression as well as glutathione content markedly in the periphery compared with that in the glioma core. The in vitro results revealed that (R, S)-AMPA increased DMT1 expression and reactive oxygen species levels, which were partly reversed by propofol treatment. CONCLUSION: Propofol regulated DMT1 expression by modulating CPARs, resulting in the inhibition of tumor oxidative stress and glioma growth. The present study provides evidence for optimizing the selection of anesthetic drugs in perioperative management and prognosis of patients with glioma.

Flexible Sensor Array Based on Transient Earth Voltage for Online Partial Discharge Monitoring of Cable Termination.

Cable termination is a weak point in an underground cable system. The transient earth voltage (TEV) method is an effective and nonintrusive method for estimating the insulation condition of cable termination. However, the practical application of TEV detection is mainly focused on switchgears, generators, and transformers with a flat and conductive shell. A flexible sensor array based on the TEV method is presented for online partial discharge (OLPD) monitoring of the cable termination. Each sensing element is designed with a dual-capacitor structure made of flexible polymer material to obtain better and more stable sensitivity. Based on the electromagnetic (EM) wave propagation theory, the partial discharge (PD) propagation model in the cable termination is built to analyze and verify the rationality and validity of the sensor unit. Some influencing factors are discussed regarding the response characteristics of sensors. Finally, the performance of the sensor array is verified by simulations and experiments. Besides, an OLPD monitoring system is introduced. The monitoring system is composed of the on-site monitoring device and the remote monitoring host. The two parts of the system exchange the data through wireless networks using a wireless communication module. The experiment results show that the monitoring device could supply the PD condition monitoring demand for cable termination.

A New Rat Model of Chronic Cerebral Hypoperfusion Resulting in Early-Stage Vascular Cognitive Impairment.

OBJECTIVE: Currently, most models of vascular cognitive impairment are established by occluding the carotid arteries uni- or bilaterally to reduce the cerebral blood flow mimicking chronic cerebral hypoxia. Due to the sudden blood flow interruption, a gradual narrowing of the carotid artery cannot be completely imitated. This paper aims to establish a bilateral carotid stenosis model with mild cognitive dysfunction and mild white matter changes to simulate patients with vascular predementia. METHODS: Aged Wistar rats (18 months old) underwent either bilateral common carotid artery stenosis (BCAS) or occlusion (BCAO) surgery or a sham operation (control group). The cerebral blood flow in the frontal cortex was measured using Doppler flowmetry. Thirty days after surgery, cognitive function impairments were determined with the Morris water maze; cerebral magnetic resonance imaging was performed to detect changes in fractional anisotropy to assess white matter injuries, and histological studies were performed. RESULTS: The aged rats in the BCAS group showed a more gradual cerebral blood flow reduction and a lower mortality rate (11%) compared to rats in the BCAO group. The water maze test revealed a more marginal impairment affecting spatial learning and memory in rats with BCAS than in rats with BCAO. Diffusion tensor imaging detected white matter injuries in the hippocampus and cerebral cortex of BCAS rats. Particularly, a small portion of nerve fibers of the lateral somatosensory cortex was significantly different between rats of the BCAO and BCAS groups. In the BCAS group, the microscopic structure of the hippocampal CA1 region changed slightly after 30 days and sustained a slight mitochondrial crista crack. Fluorescence staining indicated that the number of GFAP-positive cells was increased in rat brains of the BCAS group, and this phenomenon was even more pronounced in the BCAO group. The hnRNPA2/B1 and GABAAR-α1 expression levels were significantly decreased in the hippocampus of rats with BCAS compared to those of controls. CONCLUSION: Severe bilateral carotid stenosis induced mild cognitive dysfunction and slight structural changes in the brains of aged rats. Thus, a chronic cerebral hypoperfusion model was successfully established.

Superior electrochemical performance of a novel LiFePO4/C/CNTs composite for aqueous rechargeable lithium-ion batteries.

Olivine LiFePO4 covered flocculent carbon layers wrapped with carbon nanotubes (CNTs) prepared by sol-gel method and calcination is used as the cathode material for aqueous rechargeable lithium-ion batteries (ARLBs). The phase structures and morphologies of the composite material are characterized by X-ray diffraction (XRD), selected area electron diffraction (SAED), and transmission electron microscopy (TEM). The mechanism and method through which CNTs and flocculent carbon improve the electrochemical performance are investigated in an aqueous lithium-ion battery by setting up a comparative experiment. The ARLB system is assembled using a LiFePO4/C/CNTs cathode and a zinc anode in 1 mol L-1 ZnSO4·7H2O and saturated LiNO3 aqueous solution (pH = 6), which can deliver a capacity of 158 mA h g-1 at a rate of 1C. Even at a rate of 50C, it still has a capacity of 110 mA h g-1 after 250 cycles with fantastic capacity retention (95.7%). The lithium-ion diffusion coefficient increases by an order of magnitude due to the addition of CNTs together with flocculent carbon. Four LEDs are successfully powered by the ARLBs for more than one minute to demonstrate the practical application. The excellent rate capabilities and thrilling discharge capacity at a high rate indicate that this cathode material possesses excellent electrochemical performance, and this ARLB system exhibits excellent potential as a power source for environmental applications.

Superior cycling performance of a novel NKVO@polypyrrole composite anode for aqueous rechargeable lithium-ion batteries.

An aqueous rechargeable lithium-ion battery (ARLB) system has been assembled using as-prepared polypyrrole (PPy) to coat Na0.8K0.2K6O15 (NKVO) anode coupled with LiMn2O4 cathode, both immersed in an aqueous LiNO3 solution. The chemical polymerization techniques have been employed to uniformly coat the surface of NKVO with PPy. The phase of NKVO@PPy composite has been characterized by X-ray diffraction; for quantifying PPy content, the thermal gravimetric analysis was performed. Spectroscopy techniques have been used to visualize the microscale morphological changes on the particle surface of NKVO caused by PPy coating. The staircase cyclic voltammetry and galvanic charge-discharge tests have been conducted at various current rates in the voltage range of -1 to 1 V vs. saturated calomel electrode (SCE). The PPy coated NKVO material showed a similar intercalation/deintercalation mechanism to that of pristine NKVO. When subjected to cyclic performance evaluation at a higher rate of 4 A g-1, PPy-coated NKVO@PPy exhibited a preliminary discharge capacity of 115 mA h g-1 and 64.5 mA h g-1 following 400 cycles of charge-discharge with a retention rate of 55.6%, whereas the uncoated NKVO showed only 18.8% capacity retention rate. The significantly improved cyclic capacity retention has been attributed to the PPy coating, which acted as a protective layer preventing the unwanted side reactions, buffering the volume change and simultaneously increasing the electrical conductivity of pristine NKVO electrode during charge-discharge cycles. The decent performance demonstrated that NKVO@PPy is a promising electrode material for ARLB.

Three-dimensional nanocomposites with Co3O4 nanosheets parallelly embedded in carbon network walls for enhanced lithium-ion storage.

Three-dimensional Co3O4/C nanocomposites are synthesized via a hydrogel assisted synthesis route. The carbon has a three-dimensional interconnected network structure, and ultrathin Co3O4 nanosheets (≈5.0 nm) are parallelly and uniformly embedded in the two-dimensional carbon network walls. This unique structure restricts the aggregation and pulverization of active materials, and ensures the continuity and efficiency of electron and ion transmission during the lithiation/delithiation process. As a result, the Co3O4/C nanocomposites exhibit excellent cycling performance at different current densities. The discharge capacities remain at 905 mA h g-1 after 190 cycles at the current density of 100 mA g-1 and 561 mA h g-1 after 500 cycles at the current density of 2000 mA g-1. Since this approach is facile and large-scale, it is a rational way to engineer high capacity anodes to achieve improved electrochemical performances.

Annexin 1 inhibits remifentanil-induced hyperalgesia and NMDA receptor phosphorylation via regulating spinal CXCL12/CXCR4 in rats.

Chemokines related neuroinflammation and N-methyl-d-aspartate receptor (NMDAR) mediated nociceptive transmission are pivotal determinants in the pathogenesis of opioid-induced hyperalgesia (OIH), but little is known about specific mechanism and treatment. Chemokine CXCL12 with its receptor CXCR4 is implicated in different pathological pain, moreover, neurotoxicity of CXCL12 is associated with NMDAR activation. Recent studies recapitulate the anti-nociception of Annexin 1 (ANXA1) in inflammatory pain. This study examined whether ANXA1 prevented remifentanil-caused OIH through modulating CXCL12 and NMDAR pathway in rats. Acute exposure to remifentanil induced mechanical allodynia and thermal hyperalgesia, which was accompanied by the increase of spinal ANXA1 and CXCL12/CXCR4 expression. Central injection of Anxa12-26 attenuated behavioral OIH in a dose-dependent manner, facilitated ANXA1 production, and inhibited up-regulation of CXCL12/CXCR4 level and NR2B-containing NMDAR phosphorylation. Moreover, pretreatment with AMD3100 reduced hyperalgesia and NR2B-containing NMDAR phosphorylation. Also, exogenous CXCL12 elicited pain hypersensitivity and NMDAR activation in naïve rats, which was reversed by the supplemental delivery of Anxa12-26. These current findings indicate the participation of spinal CXCL12/CXCR4 and NR2B-containing NMDAR pathway in anti-hyperalgesic action of ANXA1 in OIH.

Superior lithium-ion insertion/extraction properties of a novel LiFePO4/C/graphene material used as a cathode in aqueous solution.

Herein, olivine LiFePO4 covered with graphene and carbon layers is prepared via a sol-gel method, followed by calcination, and the resultant composite is used as a cathode material in aqueous rechargeable lithium-ion batteries (ARLBs). The phase structure and morphology of the composite are characterized via X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and specific surface area analysis (BET). The ARLB system is fabricated using LiFePO4/C/graphene as the cathode and a zinc anode in 1 mol L-1 ZnSO4·7H2O and saturated LiNO3 aqueous solution without dissolved oxygen, which delivers a capacity of 153 mA h g-1 at 0.5C rate. Even at a 50C rate, it maintains a capacity of 95 mA h g-1 after 200 cycles. The excellent rate capabilities show that this cathode material exhibits good electrochemical performance and this novel ARLB has great potential in the fields of energy storage and high power sources.

Lithium-ion storage properties of a micro/nanosheet-like NaV6O15 anode in aqueous solution.

The micromorphologies of NaV6O15 materials synthesized using the hydrothermal method and calcination comprise staggered micro/nanosheet-like shapes. These materials can act as anode active materials in aqueous rechargeable lithium-ion batteries (ARLBs). NaV6O15 has a charge transfer resistance of several ohms in the ARLB, which is an order of magnitude smaller than in traditional lithium-ion batteries. The lithium-ion diffusion coefficients at 0.15, -0.21 and -0.65 V vs. saturated calomel electrode (SCE) were calculated as 7.3 × 10-9, 3 × 10-12, 7.6 × 10-11 cm2 s-1, respectively, from the Warburg spectrum, which were three orders of magnitude larger than in conventional lithium-ion batteries. Furthermore, NaV6O15 materials used in this ARLB have a high energy density of about 134.9 Wh kg-1 at a power of 640 W kg-1. In contrast to traditional LIB behavior, we found that the capacity retention and coulombic efficiency of the as-synthesized materials increased with the increasing ARLB discharge current density, which showed potential for this new ARLB system to be applied in the field of large-scale energy storage and power source devices.

Real-time micro-scale temperature imaging at low cost based on fluorescent intensity ratio.

Real-time temperature imaging with high spatial resolution has been a challenging task but also one with wide potential applications. To achieve this task, temperature sensor is critical. Fluorescent materials stand out to be promising candidates due to their quick response and strong temperature dependence. However, former reported temperature imaging techniques with fluorescent materials are mainly based on point by point scanning, which cannot fulfill the requirement of real-time monitoring. Based on fluorescent intensity ratio (FIR) of two emission bands of SrB4O7:Sm2+, whose spatial distributions were simultaneously recorded by two cameras with special filters separately, real-time temperature imaging with high spatial resolution has been realized with low cost. The temperature resolution can reach about 2 °C in the temperature range from 120 to 280 °C; the spatial resolution is about 2.4 µm and the imaging time is as fast as one second. Adopting this system, we observed the dynamic change of a micro-scale thermal distribution on a printed circuit board (PCB). Different applications and better performance could also be achieved on this system with appropriate fluorescent materials and high sensitive CCD detectors according to the experimental environment.

Facile synthesis of three-dimensional structured carbon fiber-NiCo2O4-Ni(OH)2 high-performance electrode for pseudocapacitors.

Two-dimensional textured carbon fiber is an excellent electrode material and/or supporting substrate for active materials in fuel cells, batteries, and pseudocapacitors owing to its large surface area, high porosity, ultra-lightness, good electric conductivity, and excellent chemical stability in various liquid electrolytes. And Nickel hydroxide is one of the most promising active materials that have been studied in practical pseudocapacitor applications. Here we report a high-capacitance, flexible and ultra-light composite electrode that combines the advantages of these two materials for pseudocapacitor applications. Electrochemical measurements demonstrate that the 3D hybrid nanostructured carbon fiber-NiCo2O4-Ni(OH)2 composite electrode shows high capacitance, excellent rate capability. To the best of our knowledge, the electrode developed in this work possesses the highest areal capacitance of 6.04 F cm(-2) at the current density of 5 mA cm(-2) among those employing carbon fiber as the conductor. It still remains 64.23% at 40 mA cm(-2). As for the cycling stability, the initial specific capacitance decreases only from 4.56 F cm(-2) to 3.35 F cm(-2) after 1000 cycles under a current density of 30 mA cm(-2).

Co3O4-carbon nanotube heterostructures with bead-on-string architecture for enhanced lithium storage performance.

In this report, alkylcarboxyl group-decorated carbon nanotubes (CNTs) with clustered functionalization patterns are achieved based on a modified Birch reduction in liquid ammonia. By using these functional CNTs (f-CNTs), a new type of Co3O4-CNT heterostructure is prepared via a simple hydrothermal method. SEM and TEM analyses reveal that the as-synthesized Co3O4-CNT heterostructures exhibit bead-on-string architecture, in which the Co3O4 spheres are threaded with CNTs. A possible growth mechanism is proposed to explain the formation of these Co3O4-CNT heterostructures. The electrochemical properties of the Co3O4-CNT heterostructures as anode materials for lithium ion batteries are investigated. The Co3O4-CNT heterostructures display high electrochemical activity, good cycle stability and improved rate performance. Such a large improvement of the electrochemical performance can be related to the robust necklace-like architectures which possess properties such as high mechanical stability, excellent electric conductivity and good strain accommodation.

Nano-sized SnSbAgx alloy anodes prepared by reductive co-precipitation method used as lithium-ion battery materials.

Nano-sized SnSbAgx alloy anode materials are prepared by reductive co-precipitation method combining with the aging treatment in water bath at 80 degrees C. The microstructure, morphology and electrochemical properties of synthesized SnSbAgx alloy powders are evaluated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), galvanostatical cycling tests and electrochemical impedance spectroscopy (EIS). The XRD results indicate that the phases are composed of beta-Sn, Sb, Ag3Sb, Ag3Sn and SnSb in the SnSbAgx alloy. The existence of inactive element Ag and the complex multi-step reaction mechanism in SnSbAgx alloy anodes are propitious to improve the structure stability and thus improve the cycling performance. When cycled at a constant current density of 0.1 mA cm(-2) between 0.1 and 1.50 V, SnSbAg alloy shows better performance that the first discharge capacity is 794 mAh g(-1) and the reversible capacity of 20th cycle attains to 327 mAh g(-1). EIS results show that the semicircle relates to the passivation on the surface in the higher frequency zone and the bias relates to the diffusion in the lower frequency zone.