Step-by-step desolvation enables high-rate and ultra-stable sodium storage in hard carbon anodes.

Hard carbon is regarded as the most promising anode material for sodium-ion (Na-ion) batteries, owing to its advantages of high abundance, low cost, and low operating potential. However, the rate capability and cycle life span of hard carbon anodes are far from satisfactory, severely hindering its industrial applications. Here, we demonstrate that the desolvation process defines the Na-ion diffusion kinetics and the formation of a solid electrolyte interface (SEI). The 3A zeolite molecular sieve film on the hard carbon is proposed to develop a step-by-step desolvation pathway that effectively reduces the high activation energy of the direct desolvation process. Moreover, step-by-step desolvation yields a thin and inorganic-dominated SEI with a lower activation energy for Na+ transport. As a result, it contributes to greatly improved power density and cycling stability for both ester and ether electrolytes. When the above insights are applied, the hard carbon anode achieves the longest life span and minimum capacity fading rate at all evaluated current densities. Moreover, with the increase in current densities, an improved plateau capacity ratio is observed. This step-by-step desolvation strategy comprehensively enhances various properties of hard carbon anodes, which provides the possibility of building practical Na-ion batteries with high power density, high energy density, and durability.

Reconfigurable multi-channel microwave photonic receiver for a multi-band signal based on cascaded microring resonator banks.

What we believe to be a novel reconfigurable multi-channel microwave photonic (MWP) receiver for multi-band RF signal is demonstrated for the first time, to the best of our knowledge. A reconfigurable MWP signal processing chip based on two cascaded microring filter banks is employed in the proposed receiver, which slices the multi-band RF input into several narrow band signals and selects optical frequency comb lines for frequency converting of each channel. Due to the significant reconfigurability of the signal processing chip, the proposed receiver can flexibly choose the output frequency band of each channel, and thus different frequency components of the multi-band RF input can be down converted to the intermediate frequency (IF) band for receiving or converted to other frequency band for forwarding. A multi-band RF signal composed of a linear frequency modulation (LFM) signal with 2 GHz bandwidth and a quad-phase shift keyed (QPSK) signal with 100 Mbit/s rate is experimentally received and reconstructed by the proposed receiver, where the reconstructed LFM component exhibits a signal to noise ratio (SNR) of 10.2 dB, and the reconstructed QPSK component reaches a high SNR of 26.1 dB and a great error vector magnitude (EVM) of 11.73%. On the other hand, the QPSK component of the multi-band RF signal centered at 13.5 GHz is successfully converted to 3.1 GHz.

Spaced Double Hydrogen Bonding in an Imidazole Poly Ionic Liquid Composite for Highly Efficient and Selective Photocatalytic Air Reductive H2O2 Synthesis.

Photocatalytic oxygen reductive H2O2 production is a promising approach to alternative industrial anthraquinone processes while suffering from the requirement of pure O2 feedstock for practical application. Herein, we report a spaced double hydrogen bond (IC-H-bond) through multi-component Radziszewski reaction in an imidazole poly-ionic-liquid composite (SI-PIL-TiO2) and levofloxacin hydrochloride (LEV) electron donor for highly efficient and selective photocatalytic air reductive H2O2 production. It is found that the IC-H-bond formed by spaced imino (-NH-) group of SI-PIL-TiO2 and carbonyl (-C=O) group of LEV can switch the imidazole active sites characteristic from a covered state to a fully exposed one to shield the strong adsorption of electron donor and N2 in the air, and propel an intenser positive potential and more efficient orbitals binding patterns of SI-PIL-TiO2 surface to establish competitive active sites for selectivity O2 chemisorption. Moreover, the high electron enrichment of imidazole as an active site for the 2e- oxygen reduction ensures the rapid reduction of O2. Therefore, the IC-H-bond enables a total O2 utilization and conversion efficiency of 94.8 % from direct photocatalytic air reduction, achieving a H2O2 production rate of 1518 µmol/g/h that is 16 and 23 times compared to poly-ionic-liquid composite without spaced imino groups (PIL-TiO2) and TiO2, respectively.

Tailoring the Nanoporosity and Photoactivity of Metal-Organic Frameworks With Rigid Dye Modulators for Toluene Purification.

Facile synthesis of hierarchically porous metal-organic frameworks (MOFs) with adjustable porosity and high crystallinity attracts great attention yet remains challenging. Herein, a micromolar amount of dye-based modulator (Rhodamine B (RhB)) is employed to easily and controllably tailor the pore size of a Ti-based metal-organic framework (MIL-125-NH2 ). The RhB used in this method is easily removed by washing or photodegradation, avoiding secondary posttreatment. It is demonstrated that the carboxyl functional group and the steric effects of RhB are indispensable for enlarging the pore size of the MIL-125-NH2 . The resulting hierarchically porous MIL-125-NH2 (RH-MIL-125-NH2 ) exhibits optimized adsorption and photocatalytic activity because the newly formed mesopore with defects concurrently facilitates mass transport of guest molecules (toluene) and photogenerated charge separation. This work offers a meaningful basis for the construction of hierarchically porous MOFs and demonstrates the superiority of the hierarchical pore structure for adsorption and heterogeneous catalysis.

Bilateral angle closure glaucoma with retinitis pigmentosa in young patients: case series.

BACKGROUND: To report the ocular characteristics and management of three cases of retinitis pigmentosa (RP) concurrent primary angle closure glaucoma (PACG). CASE PRESENTATION: Three middle-aged patients presenting with diminished vision, high intraocular pressure (IOP), and typical fundus manifestations of RP were clinically evaluated. The individualized treatment was based on the ocular conditions of each case. A novel genetic alteration in ZNF408 was identified in one patient. Two patients with short-axial eyes received unilateral combined trabeculectomy, cataract surgery, and Irido-zonulo-hyaloid-vitrectomy. One of them had a subluxated lens, managed with a capsular tension ring implantation. Their contralateral eyes, respectively, underwent laser peripheral iridotomy (LPI) and transscleral cyclophotocoagulation. The third patient underwent bilaterally combined laser peripheral iridoplasty, LPI, and medication. Ultimately, all patients achieved the target IOP during a two-year follow-up. CONCLUSION: Young patients with RP may have a risk of developing angle closure glaucoma, and conversely, patients with angle closure glaucoma at younger age should be aware of the presence of RP. Therefore, routine gonioscopy and IOP monitoring are required for RP patients, and detailed fundus examinations are warranted for young PACG patients.

OTUB2 Regulates YAP1/TAZ to Promotes the Progression of Esophageal Squamous Cell Carcinoma.

OBJECTIVE: The effects of Otubain-2 (OTUB2) on the proliferation, invasion, and migration of esophageal squamous cell carcinoma (ESCC) were investigated by interfering with OTUB2 expression. METHODS: Bioinformatics analysis was used to analyze OTUB2 expression in esophageal carcinoma and interactions between OTUB2 and YAP1/TAZ. Paraffin-embedded ESCC tissues (n = 183) were selected for immunohistochemical staining to detect OTUB2, YAP1, TAZ, CTGF and their relationship with clinicopathological parameters, then the survival prognosis of ESCC patients was analyzed. Immunofluorescence, western blotting, and qRT-PCR were used to evaluate OTUB2 in ESCC cell lines. Cell lines with the highest expression of OTUB2 were transfected with lentivirus to knockdown OTUB2 levels. Changes in KYSE150 cell proliferation, migration, and invasion were measured using CCK-8, wound healing, and clone formation assays. The Transwell test and flow cytometry identified OTUB2 targets and explored roles and mechanisms involved in ESCC. Effects of OTUB2 on YAP1/TAZ signaling were also observed. RESULTS: Bioinformatics analysis revealed OTUB2 was highly expressed in esophageal cancer and was associated with YAP1/TAZ. Immunohistochemistry showed that OTUB2 expression was increased in ESCC samples compared to parcancerous tissue. YAP1 and TAZ were higher expression in ESCC tissues, mainly localized in the nucleus. Compared with controls, the proliferation, migration, and invasion ability of KYSE150 cells after OTUB2 knockdown were significantly reduced (P < 0.05). The protein expression levels of YAP1, TAZ and CTGF decreased after knocking down the expression of OTUB2 (P < 0.05). OTUB2 knockdown in ESCC cell lines suppressed YAP1/TAZ signaling. CONCLUSIONS: OTUB2 regulated the protein expression of YAP1/TAZ to promote cell proliferation, migration, invasion, and tumor development. Therefore, OTUB2 may represent a biomarker for ESCC and a potential target for ESCC treatment.

Periodic nanostructures: preparation, properties and applications.

Periodic nanostructures, a group of nanomaterials consisting of single or multiple nano units/components periodically arranged into ordered patterns (e.g., vertical and lateral superlattices), have attracted tremendous attention in recent years due to their extraordinary physical and chemical properties that offer a huge potential for a multitude of applications in energy conversion, electronic and optoelectronic applications. Recent advances in the preparation strategies of periodic nanostructures, including self-assembly, epitaxy, and exfoliation, have paved the way to rationally modulate their ferroelectricity, superconductivity, band gap and many other physical and chemical properties. For example, the recent discovery of superconductivity observed in "magic-angle" graphene superlattices has sparked intensive studies in new ways, creating superlattices in twisted 2D materials. Recent development in the various state-of-the-art preparations of periodic nanostructures has created many new ideas and findings, warranting a timely review. In this review, we discuss the current advances of periodic nanostructures, including their preparation strategies, property modulations and various applications.

Building a Beyond Concentrated Electrolyte for High-Voltage Anode-Free Rechargeable Sodium Batteries.

Low-cost and scalable sodium ion (Na-ion) batteries serve as an ideal alternative to the current lithium-ion batteries. To compensate for the shortage of energy density, the most accessible solution is developing a high-voltage anode-free configuration comprising a lightweight Al current collector on the anode and a high-voltage sodiumized cathode. However, it imposes stringent Na reversibility and high-voltage stability requirements on the electrolyte. A 3A zeolite molecular sieve film is rationally designed, and a highly aggregated solvation structure is constructed through the size effect. It suppresses the trace but continuous oxidative decomposition and extends the oxidative stability to 4.5 V without sacrificing the Na reversibility of the anode (99.91 %). Thus, we can make anode-free cells with high energy density of 369 and 372 W h kg-1 for 4.0 and 4.25 V class cells, respectively. Furthermore, this strategy enables a long lifespan (250 cycles) for 4.0 V-class anode-free cells.

Electrolyte Sieving Chemistry in Suppressing Gas Evolution of Sodium-Metal Batteries.

The sodium (Na)-metal batteries hold great promise as a sustainable technology owing to the high element abundance and low cost. However, the generally used carbonate electrolytes remain highly reactive towards Na metal, leading to flammable gas evolution. Here, we propose an electrolyte sieving strategy to separate anion-mediated ion-pairs from dilute electrolytes by introducing a 3A zeolite molecular sieve film. The anion-mediated ion-pair firstly weakens the electron-withdrawing property of the cation, which effectively suppresses the gassing. In addition, the sieved electrolyte promotes the formation of robust inorganic-dominated solid electrolyte interphases. Therefore, it contributes to stable Na plating/stripping in Na|Al half cells with Coulombic efficiency maintaining at 98.5 % and a long service life of 800 cycles in full cells. Moreover, the electrode stability is well preserved even under harsh conditions of high temperature and ester-based electrolytes with higher reactivity.

Universal nanodroplet branches from confining the Ouzo effect.

We report the self-organization of universal branching patterns of oil nanodroplets under the Ouzo effect [Vitale S, Katz J (2003) Langmuir 19:4105-4110]-a phenomenon in which spontaneous droplet formation occurs upon dilution of an organic solution of oil with water. The mixing of the organic and aqueous phases is confined under a quasi-2D geometry. In a manner analogous to the ramification of ground stream networks [Devauchelle O, Petroff AP, Seybold HF, Rothman DH (2012) Proc Natl Acad Sci USA 109: 20832-20836 and Cohen Y, et al. (2015) Proc Natl Acad Sci USA 112:14132-14137] but on a scale 10 orders of magnitude smaller, the angles between the droplet branches are seen to exhibit remarkable universality, with a value around 74° ± 2°, independent of the various control parameters of the process. Numerical simulations reveal that these nanodroplet branching patterns are governed by the interplay between the local concentration gradient, diffusion, and collective interactions. We further demonstrate the ability of the local concentration gradient to drive autonomous motion of colloidal particles in the highly confined space, and the possibility of using the nucleated nanodroplets for nanoextraction of a hydrophobic solute. The understanding obtained from this work provides a basis for quantitatively understanding the complex dynamical aspects associated with the Ouzo effect. We expect that this will facilitate improved control in nanodroplet formation for many applications, spanning from the preparation of pharmaceutical polymeric carriers, to the formulation of cosmetics and insecticides, to the fabrication of nanostructured materials, to the concentration and separation of trace analytes in liquid-liquid microextraction.

End-to-End Automated Lane-Change Maneuvering Considering Driving Style Using a Deep Deterministic Policy Gradient Algorithm.

Changing lanes while driving requires coordinating the lateral and longitudinal controls of a vehicle, considering its running state and the surrounding environment. Although the existing rule-based automated lane-changing method is simple, it is unsuitable for unpredictable scenarios encountered in practice. Therefore, using a deep deterministic policy gradient (DDPG) algorithm, we propose an end-to-end method for automated lane changing based on lidar data. The distance state information of the lane boundary and the surrounding vehicles obtained by the agent in a simulation environment is denoted as the state space for an automated lane-change problem based on reinforcement learning. The steering wheel angle and longitudinal acceleration are used as the action space, and both the state and action spaces are continuous. In terms of the reward function, avoiding collision and setting different expected lane-changing distances that represent different driving styles are considered for security, and the angular velocity of the steering wheel and jerk are considered for comfort. The minimum speed limit for lane changing and the control of the agent for a quick lane change are considered for efficiency. For a one-way two-lane road, a visual simulation environment scene is constructed using Pyglet. By comparing the lane-changing process tracks of two driving styles in a simplified traffic flow scene, we study the influence of driving style on the lane-changing process and lane-changing time. Through the training and adjustment of the combined lateral and longitudinal control of autonomous vehicles with different driving styles in complex traffic scenes, the vehicles could complete a series of driving tasks while considering driving-style differences. The experimental results show that autonomous vehicles can reflect the differences in the driving styles at the time of lane change at the same speed. Under the combined lateral and longitudinal control, the autonomous vehicles exhibit good robustness to different speeds and traffic density in different road sections. Thus, autonomous vehicles trained using the proposed method can learn an automated lane-changing policy while considering safety, comfort, and efficiency.

Lipoxin A4 delays the progression of retinal degeneration via the inhibition of microglial overactivation.

BACKGROUND: Retinal degeneration (RD) is characterized by progressive photoreceptor degeneration, and emerging evidence has demonstrated that activated microglia-mediated inflammation exacerbates the progression of RD. Lipoxin A4 (LXA4) is an endogenous neuroprotective lipid mediator, but the potential therapeutic roles of LXA4 in RD have not been evaluated. METHODS: Electroretinogram (ERG) recordings and behavioral tests were used to analyze whether the intravitreal injection (IVI) of LXA4 restored visual function in RD1 mice. Immunostaining, qPCR, western blotting and mouse cytokine arrays using an ex-vivo retinal explant model were successively performed to explore the mechanisms underlying the effects of LXA4. RESULTS: The key rate-limiting enzyme in LXA4 biosynthesis and the LXA4 receptor were substantially downregulated in end-stage RD1 retinas. LXA4 maintained visual function in RD1 mice from postnatal days 15-21 (PN15 to PN21). Moreover, LXA4 modulated microglial activities, significantly inhibited proinflammatory gene expression, and thereby attenuated photoreceptor apoptosis. CONCLUSIONS: LXA4 delayed the progression of RD, and thus, the use of LXA4 might be a novel approach for ameliorating dysfunction in neurodegenerative disorders.

An Isolated Zinc-Cobalt Atomic Pair for Highly Active and Durable Oxygen Reduction.

A competitive complexation strategy has been developed to construct a novel electrocatalyst with Zn-Co atomic pairs coordinated on N doped carbon support (Zn/CoN-C). Such architecture offers enhanced binding ability of O2 , significantly elongates the O-O length (from 1.23 Što 1.42 Å), and thus facilitates the cleavage of O-O bond, showing a theoretical overpotential of 0.335 V during ORR process. As a result, the Zn/CoN-C catalyst exhibits outstanding ORR performance in both alkaline and acid conditions with a half-wave potential of 0.861 and 0.796 V respectively. The in situ XANES analysis suggests Co as the active center during the ORR. The assembled zinc-air battery with Zn/CoN-C as cathode catalyst presents a maximum power density of 230 mW cm-2 along with excellent operation durability. The excellent catalytic activity in acid is also verified by H2 /O2 fuel cell tests (peak power density of 705 mW cm-2 ).

Photoactivity and Stability Co-Enhancement: When Localized Plasmons Meet Oxygen Vacancies in MgO.

Durability is still one of the key obstacles for the further development of photocatalytic energy-conversion systems, especially low-dimensional ones. Encouragingly, recent studies show that nanoinsulators such as SiO2 and MgO exhibit substantially enhanced photocatalytic durability than the typical semiconductor p25 TiO2 . Extending this knowledge, MgO-Au plasmonic defect nanosystems are developed that combine the stable photoactivity from MgO surface defects with energy-focusing plasmonics from Au nanoparticles (NPs), where Au NPs are anchored onto monodispersed MgO nanotemplates. Theoretical calculations reveal that the midgap defect (MGD) states in MgO are generated by oxygen vacancies, which provide the main avenues for upward electron transitions under photoexcitation. These electrons drive stable proton photoreduction to H2 gas via water splitting. A synergistic interaction between Au's localized plasmons and MgO's oxygen vacancies is observed here, which enhances MgO's photoactivity and stability simultaneously. Such co-enhancement is attributed to the stable longitudinal-plasmon-free Au NPs, which provide robust hot electrons capable of overcoming the interband transition barrier (≈1.8 eV) to reach proton reduction potential for H2 generation. The demonstrated plasmonic defect nanosystems are expected to open a new avenue for developing highly endurable photoredox systems for the integration of multifunctionalities in energy conversion, environmental decontamination, and climate change mitigation.

Formation of surface nanodroplets under controlled flow conditions.

Nanodroplets on a solid surface (i.e., surface nanodroplets) have practical implications for high-throughput chemical and biological analysis, lubrications, laboratory-on-chip devices, and near-field imaging techniques. Oil nanodroplets can be produced on a solid-liquid interface in a simple step of solvent exchange in which a good solvent of oil is displaced by a poor solvent. In this work, we experimentally and theoretically investigate the formation of nanodroplets by the solvent exchange process under well-controlled flow conditions. We find significant effects from the flow rate and the flow geometry on the droplet size. We develop a theoretical framework to account for these effects. The main idea is that the droplet nuclei are exposed to an oil oversaturation pulse during the exchange process. The analysis shows that the volume of the nanodroplets increases with the Peclet number Pe of the flow as ∝ Pe(3/4), which is in good agreement with our experimental results. In addition, at fixed flow rate and thus fixed Peclet number, larger and less homogeneously distributed droplets formed at less-narrow channels, due to convection effects originating from the density difference between the two solutions of the solvent exchange. The understanding from this work provides valuable guidelines for producing surface nanodroplets with desired sizes by controlling the flow conditions.

Unraveling the Growth Mechanism of Silica Particles in the Stöber Method: In Situ Seeded Growth Model.

In this work, we investigated the kinetic balance between ammonia-catalyzed hydrolysis of tetraethyl orthosilicate (TEOS) and subsequent condensation over the growth of silica particles in the Stöber method. Our results reveal that, at the initial stage, the reaction is dictated by TEOS hydrolysis to form silanol monomers, which is denoted as pathway I and is responsible for nucleation and growth of small silica particles via condensation of neighboring silanol monomers and siloxane network clusters derived thereafter. Afterward, the reaction is dictated by condensation of newly formed silanol monomers onto the earlier formed silica particles, which is denoted as pathway II and is responsible for the enlargement in size of silica particles. When TEOS hydrolysis is significantly promoted, either at high ammonia concentration (≥0.95 M) or at low ammonia concentration in the presence of LiOH as secondary catalyst, temporal separation of pathways I and II makes the Stöber method reminiscent of in situ seeded growth. This knowledge advance enables us not only to reconcile the most prevailing aggregation-only and monomer-addition models in literature into one consistent framework to interpret the Stöber process but also to grow monodisperse silica particles with sizes in the range 15-230 nm simply but precisely regulated by the ammonia concentration with the aid of LiOH.

Collective interactions in the nucleation and growth of surface droplets.

In the process of solvent exchange, oil droplets nucleate and grow on a solid substrate in response to the oversaturation generated through the displacement of a good oil solvent by a poor one. The mean size of the droplets depends on flow rate, flow geometry and solution conditions. In this work, we investigate the surface coverage of the droplets and the correlation between the base area of the droplets and of the bare zone surrounding the droplets for various flow and solution conditions during the solvent exchange. The surface coverage increases with the increase in the flow rate, channel height and the oil concentration, and reaches a plateau between 35% and 50%. The spatial correlation is analysed with the help of the radial distribution function g(r) and a Voronoi tessellation. When the surface coverage reaches ∼25-30%, the number density of the droplets starts to drop, reflecting the mutual interaction and merging of the droplets. With further decrease in the droplet spacing and increase in surface coverage, the Voronoi analysis shows that the base area of the droplets increases linearly with the area size of the depleted zone. The collective interaction in the growth of surface nanodroplets is universal, independent of the specific conditions that control the droplet growth.

Influence of Solution Composition on the Formation of Surface Nanodroplets by Solvent Exchange.

Solvent exchange is a simple process of forming surface nanodroplets on an immersed substrate. In this process, the droplets nucleate and grow in response to transient oversaturation when a good solvent of the droplet liquid is displaced by a poor solvent. Here we will show how the final droplet size is influenced by solution composition in the solvent exchange. To do this, we produced water droplets on a hydrophilic substrate and cyclohexane droplets on a hydrophobic substrate by using a tertiary system of cyclohexane, ethanol, and water. The composition of the good solvent was varied systematically in the one-phase region on the phase diagram. We found that the key feature closely related to the droplet size is the area (A) in the phase diagram defined by the phase boundary and the concentration ratio between the good solvent and the droplet liquid. This area reflects the excessive amount of droplet liquid in the tertiary mixture, which can be complicated by bulk droplet formation during solvent exchange. We will also show that the droplet volume per unit surface area also increases with A. The findings from this work will provide guideline for the selection of solution conditions to achieve a desirable droplet size and number density on the surface.

Dissolution of Sessile Microdroplets of Electrolyte and Graphene Oxide Solutions in an Ouzo System.

Manipulating the way a droplet shrinks by evaporation or dissolution is an effective approach for assembling dissolved nanomaterials. In this work, we investigate the dissolution dynamics of a submicroliter sessile droplet of electrolyte aqueous solution and of graphene oxide suspension immersed in a binary mixture of solvents, among which one is miscible and the other is immiscible with water (i.e., an Ouzo system). Our measurements reveal an interesting two-stage dissolution of the droplet: a fast initial stage and a slow second stage. The duration of the first stage is longer at a lower temperature, leading to a counterintuitive result that the dissolution completes faster at reduced temperature. The presence of graphene oxide in the droplet dramatically alters the dissolution dynamics, possibly due to its enrichment at the droplet surface. The finding from this work provides useful guideline for designing conditions to pack nanomaterials by dissolving droplets, especially for those temperature sensitive components.

Microwetting of pH-Sensitive Surface and Anisotropic MoS2 Surfaces Revealed by Femtoliter Sessile Droplets.

Understanding the microwettability of anisotropic molybdenum disulfide crystal is critically important in separation and processing of this material in liquid. In this work, static microwetting properties of MoS2 face (MF) and MoS2 edge (ME) surfaces in water are revealed by the morphology of femtoliter interfacial droplets. The oil droplets with different size distribution were produced from heterogeneous nucleation and growth of nanodroplets during the solvent exchange under controlled flow and solution conditions, and were polymerized for droplet morphology characterization to reveal the relative wettability of the droplets on surfaces. We first demonstrate that the shape of the nanodroplets is responsive to the surface charges on a model pH sensitive substrate of gold coated with a self-assembled monolayer of two types of thiol. The experimental results on MoS2 substrates indicate that (1) oil contact angle of the droplets on ME surface is much larger than that on MF surface at pH 3.0, suggesting that the ME surface is more hydrophilic than MF; (2) the droplets are pinned by the layered nanostructure on MoS2 edge. The fundamental understanding of microwettability elucidated in this study may allow for an improved control of the interaction between anisotropic MoS2 surfaces and the surrounding liquid environment, which is critically important for many industrial applications such as flotation and catalysis systems.