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Poly(ionic liquid)s (PIL) are common precursors for heteroatom-doped carbon materials. Despite a relatively higher carbonization yield, the PIL-to-carbon conversion process faces challenges in preserving morphological and structural motifs on the nanoscale. Assisted by a thin polydopamine coating route and ion exchange, imidazolium-based PIL nanovesicles were successfully applied in morphology-maintaining carbonization to prepare carbon composite nanocapsules. Extending this strategy further to their composites, we demonstrate the synthesis of carbon composite nanocapsules functionalized with iron nitride nanoparticles of an ultrafine, uniform size of 3–5 nm (termed “FexN@C”). Due to its unique nanostructure, the sulfur-loaded FexN@C electrode was tested to efficiently mitigate the notorious shuttle effect of lithium polysulfides (LiPSs) in Li–S batteries. The cavity of the carbon nanocapsules was spotted to better the loading content of sulfur. The well-dispersed iron nitride nanoparticles effectively catalyze the conversion of LiPSs to Li2S, owing to their high electronic conductivity and strong binding power to LiPSs. Benefiting from this well-crafted composite nanostructure, the constructed FexN@C/S cathode demonstrated a fairly high discharge capacity of 1085 mAh g–1at 0.5 C initially, and a remaining value of 930 mAh g–1after 200 cycles. In addition, it exhibits an excellent rate capability with a high initial discharge capacity of 889.8 mAh g–1at 2 C. This facile PIL-to-nanocarbon synthetic approach is applicable for the exquisite design of complex hybrid carbon nanostructures with potential use in electrochemical energy storage and conversion.

ABSTRACTCircular RNAs (circRNAs), the new stars of endogenous non-coding RNAs, are dysregulated in various tumors including pancreatic cancer. Here, we aimed to investigate the biological functions of hsa_circ_0071036 in the tumourigenesis and progression of pancreatic ductal adenocarcinoma (PDAC) and its clinical implications. The differential expression profile of circRNAs in 4 pairs of PDAC tissues was analyzed by microarray assay. Quantitative real-time PCR and fluorescence in situ hybridization (FISH) were utilized to determine the expression patterns and their clinical significance. Functional experiments in vitroand in vivowere performed to explore whether hsa_circ_0071036 functions as an oncogenic circRNA in PDAC. Mechanistically, RT-qPCR, dual luciferase reporter and RNA pull-down assays were conducted to identify the interaction between hsa_circ_0071036 and miR-489 in PDAC. Hsa_circ_0071036 was remarkably overexpressed in PDAC cell lines and tissue samples, which negatively correlated with miR-489 expression. Aberrant expression of hsa_circ_0071036 correlated with poor clinicopathological characteristics and prognoses of PDAC patients. Knockdown of hsa_circ_0071036 suppressed proliferation and invasion and induced apoptosis in vitro. Moreover, the in vivoxenograft model confirmed that silencing of hsa_circ_0071036 attenuated tumor growth. Mechanistic analyses indicated that hsa_circ_0071036 acted as an efficient miRNA sponge for miR-489 in PDAC. In summary, our study revealed that upregulated hsa_circ_0071036 promotes PDAC pathogenesis and progression by directly sponging miR-489, which implies an important role for this circRNA-miRNA functional network.

“Water-in-salt” (WIS) electrolytes have emerged as an excellent superconcentrated ionic medium for high-power energy storage systems such as supercapacitors due to their extended working potential compared to the conventional dilute aqueous electrolyte. In this work, we have investigated the performance of WIS supercapacitors using hollow carbon nanoplates as electrodes and compared it to that based on the conventional “salt-in-water” electrolytes. Moreover, the potentiostatic electrochemical impedance spectroscopy has been employed to provide an insightful look into the charge transport properties, which also, for the first time, reveals the formation of a solid-electrolyte interphase (SEI) and their temperature-dependent impedance for charge transfer and adsorption. Furthermore, the effect of temperature on the electrochemical performance of the WIS supercapacitors in the temperature range from 15 to 60 °C has been studied, which presents a gravimetric capacitance of 128 F g–1and a volumetric capacitance of 197.12 F cm–3at 55 °C compared to 87.5 F g–1and 134.75 F cm–3at 15 °C. The in-depth understanding about the formation of SEI layer and the electrochemical performance at different temperatures for WIS supercapacitors will assist the efforts toward designing better aqueous electrolytes for supercapacitors.

All-solid-state Li-ion batteries promise safer electrochemical energy storage with larger volumetric and gravimetric energy densities. A major concern is the limited electrochemical stability of solid electrolytes and related detrimental electrochemical reactions, especially because of our restricted understanding. Here we demonstrate for the argyrodite-, garnet- and NASICON-type solid electrolytes that the favourable decomposition pathway is indirect rather than direct, via (de)lithiated states of the solid electrolyte, into the thermodynamically stable decomposition products. The consequence is that the electrochemical stability window of the solid electrolyte is notably larger than predicted for direct decomposition, rationalizing the observed stability window. The observed argyrodite metastable (de)lithiated solid electrolyte phases contribute to the (ir)reversible cycling capacity of all-solid-state batteries, in addition to the contribution of the decomposition products, comprehensively explaining solid electrolyte redox activity. The fundamental nature of the proposed mechanism suggests this is a key aspect for solid electrolytes in general, guiding interface and material design for all-solid-state batteries.

Prevention of mechanical and finally electrochemical failures of lithium batteries is a critical aspect to be considered during their design and performance, especially for those with high specific capacities. Internal failure is observed as one of the most serious factors, including loss of electrode materials, structure deformation and dendrite growth. It usually incubates from atomic/molecular level and progressively aggravates along with lithiation. Understanding the internal failure is of great importance for developing solutions of failure prevention and advanced anode materials. In this research, different internal failure processes of anode materials for lithium batteries are discussed. The progress on observation technologies of the anode failure is further summarized in order to understand their mechanisms of internal failure. On top of them, this review aims to summarize innovative methods to investigate the anode failure mechanisms and to gain new insights to develop advanced and stable anodes for lithium batteries.

Alzheimer’s disease (AD) is a growing global healthcare burden affecting the aging population and society. Given the lack of effective treatment to AD, early detection at the prodromal stage and timely monitoring of changes during progression are considered the best approach to control and intervene in disease progression. “Liquid biopsy” of AD biomarkers amyloid-β peptides (Aβs) and tau proteins in the cerebrospinal fluid (CSF) or blood samples holds great promises for cost-effective, widely accessible, and easy-administrated noninvasive detection and follow-up of AD. However, current in vitrodetection methods have not yet demonstrated sufficient sensitivity and specificity using neither Aβs nor tau proteins biomarkers. One major challenge of accurate detection and measurement of biomarker levels in biofluidic samples is the biofouling effect with nonspecific adsorption of unwanted biomolecules, such as various serum proteins, on the surface of targeted detecting agents or devices, causing false-positive and false-negative findings. In this study, antibiofouling polymer polyethylene glycol-block-allyl glycidyl ether (PEG-b-AGE) coated magnetic iron oxide nanoparticles (IONPs) capable of suppressing the nonspecific interactions with biomolecules, especially proteins, were investigated for the immunomagnetic capturing of Aβ40 and Aβ42 peptides and tau protein spiked in CSF- and serum-mimicking samples using corresponding antibodies conjugated as targeting ligands. Antibody-conjugated antibiofouling IONPs demonstrated improved specificity (>90%) and sensitivity (>95%) over those of antibody-conjugated magnetic micron beads (Dynabeads, ∼50% specificity and 30–40% sensitivity) widely used as magnetic separating agents under the same experimental conditions with the presence of nontargeted interfering proteins. The antibody-conjugated IONPs also exhibited significantly higher sensitivities (80–90%) and better performance of capturing Aβs and tau protein from the human whole blood samples than antibody-conjugated Dynabeads (∼20%).

In our efforts to address the issues of Si based anodes for Li ion batteries, such as limited active mass loading, rapid capacity degradation and low scalability in manufacturing, we reported a scalable, high mass loading, and additive-free Si nanoparticles (NP) deposition based electrode, but the achieved capacity and cycle life were still limited. In order to improve the reversible capacity and cycling stability of this Si NP deposition electrode, in this work, we have investigated various substrates for Si deposition, including carbon paper (CP), preheated CP and stainless steel felt/mesh (SSF/SSM), and their influences on the electrochemical Li-ion storage performance of the Si NP electrodes. Meanwhile, protective encapsulations of amorphous carbon or silicon nitride on Si NP has been performed and the capabilities of these coatings in improving the cycling stability of Si NP electrodes have been researched. It is found that a carbon-coated Si NP deposition on an SSM substrate achieves an extraordinary cycling stability in electrochemical Li-ion storage for 500 cycles with an average capacity loss of 0.09% per cycle, showing significantly improved commercial viability of Si NP deposition based electrodes in high-energy-density Li-ion batteries.

Lithium-sulfur batteries are plagued by the shuttle effect and sluggish kinetics in the redox reaction of lithium polysulfides (LiPSs) to Li2S, resulting in a limited capacity and shortened lifetime. To address these issues, it is crucial to develop an efficient catalytic sulfur host by creating active sites that can both confine LiPSs and accelerate their conversion. Herein, we developed carbon-coated mesoporous Fe3O4(C@M−Fe3O4) nanospindles and applied them as sulfur host material to improve the electrochemical performance of Li–S batteries. Besides, the conductive C@M−Fe3O4particles with rich sites of electrolyte/Fe3O4/carbon ‘‘triple-phase’’ can also accelerate the conversion of LiPSs and promote the nucleation and growth of Li2S. With these merits, our C@M-Fe3O4/S electrode shows good cycling stability with a remaining capacity of 1064.3 mAh/g at 0.2 C after 100 cycles and delivers an initial capacity of 712.0 mAh/g at 2 C. The proposed synthetic method could pave the way for designing similar porous transition metal-based compounds with different precursors (e.g. carbonates, hydroxides, oxalates) for other electrochemical applications.

Nanostructured silicon has been intensively investigated as a high capacity Li-ion battery anode. However, the commercial introduction still requires advances in the scalable synthesis of sophisticated Si nanomaterials and electrodes. Moreover, the electrode degradation due to volume changes upon de-/lithiation, low areal electrode capacity, and application of large amounts of advanced conductive additives are some of the challenging aspects. Here we report a Si electrode, prepared from direct deposition of Si nanoparticles on a current collector without any binder or conducting additives, that addresses all of the above issues. It exhibits an excellent cycling stability and a high capacity retention taking advantages of what appears to be a locally protective, yolk-shell reminiscent, solid electrolyte interphase (SEI) formation. Cycling an electrode with a Si nanoparticle loading of 2.2mgcm−2achieved an unrivalled areal capacity retention, specifically, up to 4.2mAhcm−2and ~ 1.5mAhcm−2at 0.8mAcm−2and 1.6mAcm−2, respectively.

We report a one-step method for facile and sustainable synthesis of magnetic iron oxide nanorods (or IONRs) with mean lengths ranging from 25 to 50 nm and mean diameters ranging from 5 to 8 nm. The prepared IONRs are highly stable in aqueous media and can be surface functionalized for biomarker-targeted applications. This synthetic strategy involves the reaction of iron(III) acetylacetonate with polyethyleneimine in the presence of oleylamine and phenyl ether, followed by thermal decomposition. Importantly, the length and diameter as well as the aspect ratio of the prepared IONRs can be controlled by modulating the reaction parameters. We show that the resultant IONRs exhibit stronger magnetic properties compared to those of the widely used spherical iron oxide nanoparticles (IONPs) at the same iron content. The increased magnetic properties are dependent on the aspect ratio, with the magnetic saturation gradually increasing from 10 to 75 emu g–1when increasing length of the IONRs, 5 nm in diameter, from 25 to 50 nm. The magnetic resonance imaging (MRI) contrast-enhancing effect, as measured in terms of the transverse relaxivity, r2, increased from 670.6 to 905.5 mM–1s–1, when increasing the length from 25 to 50 nm. When applied to the immunomagnetic cell separation of the transferrin receptor (TfR)-overexpressed medulloblastoma cells using transferrin (Tf) as the targeting ligand, Tf-conjugated IONRs can capture 92 ± 3% of the targeted cells under a given condition (2.0 × 104cells/mL, 0.2 mg Fe/mL concentration of magnetic materials, and 2.5 min of incubation time) compared to only 37 ± 2% when using the spherical IONPs, and 14 ± 2% when using commercially available magnetic beads, significantly improving the efficiency of separating the targeted cells.

Super P carbon black (SPCB) has been widely used as a conducting additive in Li/Na ion batteries to improve the electronic conductivity. However, there has not yet been a comprehensive study on its structure and electrochemical properties for Li/Na ion uptake, though it is important to characterize its contribution in any study of active materials that uses this additive in non-negligible amounts. In this article the structure of SPCB has been characterized and a comprehensive study on the electrochemical Li/Na ion uptake capability and reaction mechanisms are reported. SPCB exhibits a considerable lithiation capacity (up to 310 mAh g–1) from the Li ion intercalation in the graphite structure. Sodiation in SPCB undergoes two stages: Na ion intercalation into the layers between the graphene sheets and the Na plating in the pores between the nano-graphitic domains, and a sodiation capacity up to 145 mAh g–1has been achieved. Moreover, the influence of the type and content of binders on the lithiation and sodiation properties has been investigated. The cycling stability is much enhanced with sodium carboxymethyl cellulose (NaCMC) binder in the electrode and fluoroethylene carbonate (FEC) in the electrolyte; and a higher content of binder improves the Coulombic efficiency during dis-/charge.

Poor delivery efficiency remains a major challenge in nanomaterial-based tumor-targeted imaging and drug delivery. This work demonstrates a strategy to improve nanoparticle delivery and intratumoral distribution using sub-5 nm (3.5 nm core size) ultrafine iron oxide nanoparticles (uIONP) that can easily extravasate from the tumor vasculature and readily diffuse into the tumor tissue compared to the iron oxide nanoparticle (IONP) with larger sizes, followed by self-assembling in the acidic tumor interstitial space to limit their re-entering into circulation. By combining enhanced extravasation and reduced intravasation, we achieved improved delivery and tumor retention of nanoparticles. Multiphoton imaging of mice bearing orthotopic tumors co-injected with fluorescent dye-labeled nanoparticles with different sizes showed that uIONPs exhibited more efficient extravasation out of tumor vessels and penetrated deeper into the tumor than larger sized IONP counterparts. Moreover, in vivomagnetic resonance imaging revealed that uIONPs exhibited “bright” T1contrast when dispersed in the tumor vasculature and peripheral area at 1 h after intravenous administration, followed by emerging “dark” T2contrast in the tumor after 24 h. Observed T1–T2contrast switch indicated that uIONPs single-dispersed in blood with T1contrast may self-assemble into larger clusters with T2contrast after entering the tumor interstitial space. Improved passive targeting and intratumoral delivery along with increased tumor retention of uIONPs are due to both easy extravasation into the tumor when single-dispersed and restricting intravasation back into circulation after forming clusters, thus exerting the enhanced permeability and retention effect for nanoparticle delivery to tumors.

Branched gold nanoparticles are synthesized via a soft-template-directed process using a biological buffer, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES). These branched Au nanoparticles are mainly tetrapods and show distinct absorption in the range of 700–1000 nm. A combined experimental and computational study suggests that at high concentration, the HEPES molecules self-assemble into structures with long-range order serving as soft templates to direct the formation of the anisotropic gold nanoparticles. Detailed analyses of surface chemistry and structure indicate the formation of a molecular bilayer structure for the stabilization of the branched Au nanostructures. Our density-functional theory (DFT) calculations predict that the sulfonate group of the HEPES molecules prefers to bind to the Au surfaces, while the free hydroxyl groups facilitate the self-assembly and bilayer formation through the formation of hydrogen bonds. By comparing three different buffer molecules, our study demonstrates the critical importance of ligand chemistry in the directed formation of anisotropic metallic nanoparticles.

Niobium pentoxides have received considerable attention and are promising anode materials for lithium-ion batteries (LIBs), due to their fast Li storage kinetics and high capacity. However, their cycling stability and rate performance are still limited owing to their intrinsic insulating properties and structural degradation during charging and discharging. Herein, a series of mesoporous Nb2O5@TiO2core–shell spherical heterostructures have been prepared for the first time by a sol–gel method and investigated as anode materials in LIBs. Mesoporosity can provide numerous open and short pathways for Li+diffusion; meanwhile, heterostructures can simultaneously enhance the electronic conductivity and thus improve the rate capability. The TiO2coating layer shows robust crystalline skeletons during repeated lithium insertion and extraction processes, retaining high structural integrity and, thereby, enhancing cycling stability. The electrochemical behavior is strongly dependent on the thickness of the TiO2layer. After optimization, a mesoporous Nb2O5@TiO2core–shell structure with a ∼13 nm thick TiO2layer delivers a high specific capacity of 136 mA h g–1at 5 A g–1and exceptional cycling stability (88.3% retention over 1000 cycles at 0.5 A g–1). This work provides a facile strategy to obtain mesoporous Nb2O5@TiO2core–shell spherical structures and underlines the importance of structural engineering for improving the performance of battery materials.

In our efforts to address the issues of Si based anodes for Li ion batteries, such as limited active mass loading, rapid capacity degradation and low scalability in manufacturing, we reported a scalable, high mass loading, and additive-free Si nanoparticles (NP) deposition based electrode, but the achieved capacity and cycle life were still limited. In order to improve the reversible capacity and cycling stability of this Si NP deposition electrode, in this work, we have investigated various substrates for Si deposition, including carbon paper (CP), preheated CP and stainless steel felt/mesh (SSF/SSM), and their influences on the electrochemical Li-ion storage performance of the Si NP electrodes. Meanwhile, protective encapsulations of amorphous carbon or silicon nitride on Si NP has been performed and the capabilities of these coatings in improving the cycling stability of Si NP electrodes have been researched. It is found that a carbon-coated Si NP deposition on an SSM substrate achieves an extraordinary cycling stability in electrochemical Li-ion storage for 500 cycles with an average capacity loss of 0.09% per cycle, showing significantly improved commercial viability of Si NP deposition based electrodes in high-energy-density Li-ion batteries.