Impact of Transition Metal Layer Vacancy on the Structure and Performance of P2 Type Layered Sodium Cathode Material

This study explores the impact of introducing vacancy in the transition metal layer of rationally designed Na_(0.6)[Ni_(0.3)Ru_(0.3)Mn_(0.4)]O_(2)(NRM)cathode material.The incorporation of Ru,Ni,and vacancy enhances the structural stability during extensive cycling,increases the operation voltage,and induces a capacity increase while also activating oxygen redox,respectively,in Na_(0.7)[Ni_(0.2)V_(Ni0.1)Ru_(0.3)Mn_(0.4)]O_(2)(V-NRM)compound.Various analytical techniques including transmission electron microscopy,X-ray absorption near edge spectroscopy,operando X-ray diffraction,and operando differential electrochemical mass spectrometry are employed to assess changes in the average oxidation states and structural distortions.The results demonstrate that V-NRM exhibits higher capacity than NRM and maintains a moderate capacity retention of 81%after 100 cycles.Furthermore,the formation of additional lone-pair electrons in the O 2p orbital enables V-NRM to utilize more capacity from the oxygen redox validated by density functional calculation,leading to a widened dominance of the OP4 phase without releasing O_(2) gas.These findings offer valuable insights for the design of advanced high-capacity cathode materials with improved performance and sustainability in sodium-ion batteries.

Correction:Impact of Transition Metal Layer Vacancy on the Structure and Performance of P2 Type Layered Sodium Cathode Material

Following publication of the original article[1],the authors reported that the author Hun-Gi Jung should be affiliated as 3,4 and 5 instead of 4 and 5.The author’s name“A.-Yeon Kim”needed to be updated to“A-Yeon Kim”,removing the period.The correct author’s name and affiliation have been provided in this Correction.The original article[1]has been corrected.

Stability of Ag@SiO2 core–shell particles in conditions of photocatalytic overall water-splitting

Core–shell nanoparticles containing plasmonic metals（Ag or Au） have been frequently reported to enhance performance of photo-electrochemical（PEC） devices. However, the stability of these particles in water-splitting conditions is usually not addressed. In this study we demonstrate that Ag@SiOcore–shell particles are instable in the acidic conditions in which WO-based PEC cells typically operate, Ag in the core being prone to oxidation, even if the SiOshell has a thickness in the order of 10 nm. This is evident from in situ voltammetry studies of several anode composites. Similar to the results of the PEC experiments, the Ag@SiOcore–shell particles are instable in slurry-based, Pt/ZnO induced photocatalytic water-splitting. This was evidenced by in situ photodeposition of Ag nanoparticles on the Pt-loaded ZnO catalyst, observed in TEM micrographs obtained after reaction. We explain the instability of Ag@SiOby OH-radical induced oxidation of Ag, yielding dissolved Ag+. Our results imply that a decrease in shell permeability for OH-radicals is necessary to obtain stable, Ag-based plasmonic entities in photo-electrochemical and photocatalytic water splitting.

COHERENT ANTI-STOKES RAMAN SCATTERING MICROSCOPY TO MONITOR DRUG DISSOLUTION IN DIFFERENT ORAL PHARMACEUTICAL TABLETS

Coherent anti-Stokes Raman scattering(CARS)microscopy is used to visualize the release of a model drug(theophylline)from a lipid(tripalmitin)based tablet during dissolution.The effects of transformation and dissolution of the drug are imaged in real time.This study reveals that the manufacturing process causes significant differences in the release process:tablets prepared from powder show formation of theophylline monohydrate on the surface which prevents a controlled drug release,whereas solid lipid extrudates did not show formation of monohydrate.This visualization technique can aid future tablet design.

Breath monitoring,sleep disorder detection,and tracking using thin-film acoustic waves and open-source electronics

Apnoea,a major sleep disorder,affects many adults and causes several issues,such as fatigue,high blood pressure,liver conditions,increased risk of type II diabetes,and heart problems.Therefore,advanced monitoring and diagnosing tools of apnoea disorders are needed to facilitate better treatment,with advantages such as accuracy,comfort of use,cost effectiveness,and embedded computation capabilities to recognise,store,process,and transmit time series data.In this work we present an adaptation of our apnoea-Pi open-source surface acoustic wave(SAW)platform(Apnoea-Pi)to monitor and recognise apnoea in patients.The platform is based on a thin-film SAW device using bimorph ZnO and Al structures,including those fabricated as Al foils or plates,to achieve breath tracking based on humidity and temperature changes.We applied open-source electronics and provided embedded computing characteristics for signal processing,data recognition,storage,and transmission of breath signals.We show that the thin-film SAW device out-performed standard and off-the-shelf capacitive electronic sensors in terms of their response and accuracy for human breath-tracking purposes.This in combination with embedded electronics makes a suitable platform for human breath monitoring and sleep disorder recognition.

Analyzing Dominant 13.5 and 27 day Periods of Solar Terrestrial Interaction:A New Insight into Solar Cycle Activities

Our analysis presents an explanation of the Sun–Earth coupling mechanism during declining phase of a solar cycle,and how the dominant 13.5 and 27 day periods play roles in the coupling mechanism which led to intense terrestrial magnetic storms during this declining phase compared to the rising phase of a solar cycle.Moreover,it is observed that while the 27 day period gets strongly modulated in the rising phase,the 13.5 day period modulation is more prominent during the declining phase.It is suggested that out of the 27 and 13.5 day periods of Sun–Earth interaction,the preferred period of modulation happens to be the one which is more dominant for the less random or quieter system participating in the coupling.It is reported for the first time that the 13.5 day period is more prominent in the Sun–Earth interaction during the declining phase of a solar cycle,as it is the most dominant period of Earth's magnetic system,which happens to be more persistent as a dynamical system and hence quieter or more receptive than the Sun.

Influence of Water Vapor on Silica Membrane： Adsorption Properties and Percolation Effect

The influence of water vapor on silica membrane with pore size of ,-4A has been investigated in terms of adsorption properties and percolation effect at 50 and 90 ℃. Two methods are employed： spectroscopic ellipsometry for water vapor adsorption and gas permeation of binary mixture of helium and H2O The adsorption behaviors on the silica membrane comply with the first-order Langmuir isotherm. The investigation demonstrates that helium flux through the silica membrane decreases dramatically in presence of H20 molecules. The transport of gas molecules through such small pores is believed not to be continuous any more, whereas it is reasonably assumed that the gas molecules hop from one occupied site to another unoccupied one under the potential gradient. When the coverage of H20 molecules on the silica surface increases, the dramatic decrease of helium flux could be related to percolation effect, where the adsorbed H20 molecules on the silica surface block the hopping of helium molecules.

Stepwise colloidal lithography toward scalable and various planar chiral metamaterials

Chiral metamaterials(CMs)composed by artificial chiral resonators have attracted great attentions in the recent decades due to their strong chiroptical resonance and identifiable interaction with chiral materials,facilitating practical applications in chiral biosensing,chiral emission,and display technology.However,the complex geometry of CMs improves the fabrication difficulty and hinders their scalable fabrication for practical applications,especially in the visible and ultraviolet wavelengths.One potential strategy is the colloidal lithography that enables parallel fabrication for scalable and various planar structures.Here,we demonstrate a stepwise colloidal lithography technique that uses sequential deposition from multiple CMs and expand their variety and complexity.The geometry and optical chirality of building blocks from single deposition are systematically investigated,and their combination enables a significant extension of the range of chiral patterns by multiple-step depositions.This approach resulted in a myriad of complex designs with different characteristic sizes,compositions,and shapes,which are particularly beneficial for the development of nanophotonic materials.In addition,we designed a flexible chiral device based on PDMS,which exhibits a good CD value and excellent stability even after multiple inward and outward bendings.The excellent compatibility to various substrates makes the planar CMs more flexible in practical applications in microfluidic biosensing.

A tribo-chemical view on astringency of plant-based food substances

Consumption of plant-based food products having high composition of polyphenols leads to the sensation of astringency.For sliding oral surfaces,friction is an essential property during the oral perception of roughness and dryness which are attributes associated with astringency.Different factors including the chemical composition of interacting layers,structure and operation of interfaces have an effect on the astringency development process.The manner of interactions occurring at oral interfaces suggest there is a system dependence of astringency and highlights the importance of adopting a tribosystems approach.Available measurement techniques have shown an existing relationship between salivary protein-polyphenol interaction and an astringent mouthfeel.Nevertheless,the tribo-chemistry involved in this multifaceted sensation remains largely unexplored in a comprehensive manner.In this review the underlying tribo-chemical processes useful in understanding the mechanism of astringency are highlighted and discussed considering current techniques employed to investigate astringency perception.Loss of lubrication on oral surfaces owing to the tribo-chemical interactions involving saliva and astringent plant proteins requires subsequent deformations of oral tissues which are significant enough to induce strains at mechanoreceptor locations,leading to the sensation of astringency.It is proposed that micro-scale contact modelling on the interaction of food particles/aggregates,boundary layers and oral surfaces shows potential in addressing the knowledge gap between tribo-chemical measurement techniques and panel tests,making it possible to attain a predictor for astringency.

Modular operation of microfluidic chips for highly parallelized cell culture and liquid dosing via a fluidic circuit board

Microfluidic systems enable automated and highly parallelized cell culture with low volumes and defined liquid dosing.To achieve this,systems typically integrate all functions into a single,monolithic device as a“one size fits all”solution.However,this approach limits the end users’(re)design flexibility and complicates the addition of new functions to the system.To address this challenge,we propose and demonstrate a modular and standardized plug-and-play fluidic circuit board(FCB)for operating microfluidic building blocks(MFBBs),whereby both the FCB and the MFBBs contain integrated valves.A single FCB can parallelize up to three MFBBs of the same design or operate MFBBs with entirely different architectures.The operation of the MFBBs through the FCB is fully automated and does not incur the cost of an extra external footprint.We use this modular platform to control three microfluidic large-scale integration(mLSI)MFBBs,each of which features 64 microchambers suitable for cell culturing with high spatiotemporal control.We show as a proof of principle that we can culture human umbilical vein endothelial cells(HUVECs)for multiple days in the chambers of this MFBB.Moreover,we also use the same FCB to control an MFBB for liquid dosing with a high dynamic range.Our results demonstrate that MFBBs with different designs can be controlled and combined on a single FCB.Our novel modular approach to operating an automated microfluidic system for parallelized cell culture will enable greater experimental flexibility and facilitate the cooperation of different chips from different labs.

From chip-in-a-lab to lab-on-a-chip:a portable Coulter counter using a modular platform

The field of microfluidics has been struggling to obtain widespread market penetration.In order to overcome this struggle,a standardized and modular platform is introduced and applied.By providing easy-to-fabricate modular building blocks which are compatible with mass manufacturing,we decrease the gap from lab-to-fab.These standardized blocks are used in combination with an application-specific fluidic circuit board.On this board,electrical and fluidic connections are demonstrated by implementing an alternating current Coulter counter.This multipurpose building block is reusable in many applications.In this study,it identifies and counts 6 and 11μm beads.The system is kept in a credit card-sized footprint,as a result of in-house-developed electronics and standardized building blocks.We believe that this easy-to-fabricate,credit card-sized,modular,and standardized prototype brings us closer to clinical and veterinary applications,because it provides an essential stepping stone to fully integrated point-of-care devices.

Exploiting biased reptation for continuous flow preparative DNA fractionation in a versatile microfluidic platform

A new approach is presented for preparative,continuous flow fractionation of sub-10-kbp DNA fragments,which exploits the variation in the field-dependent mobility of the DNA molecules based on their length.Orthogonally pulsed electric fields of significantly different magnitudes are applied to a microchip filled with a sieving matrix of 1.2% agarose gel.Using this method,we demonstrate a high-resolution separation of 0.5,1,2,5,and 10 kbp DNA fragments within 2 min.During the separation,DNA fragments are also purified from other ionic species.Preparative fractionation of sub-10-kbp DNA molecules plays an important role in second-generation sequencing.The presented device performs rapid high-resolution fractionation and it can be reliably manufactured with simple microfabrication procedures.

Delivery of Micro RNAs by plant virus-based nanoparticles to functionally alter the osteogenic differentiation of human mesenchymal stem cells

Micro RNA-26a(miR-26a)has been verified to promote osteogenic differentiation of mesenchymal stem cells in recent years.The main obstacles to its application in bone regeneration are instability in the physiological environment and low efficiency of cellular membrane penetration.To overcome these problems,we constructed a novel plant virus gene delivery system based on Cowpea chlorotic mottle virus(CCMV).By encapsulating miR-26a with purified capsid protein(CP)dimers derived from CCMV,CPmiR-26a(CP26a)virus-like particles(VLPs)were obtained.CP26a retained a structure similar to the native CCMV and protected miR-26a from digestion with its exterior CP.Moreover,CP26a featured similar cellular uptake efficiency,osteogenesis promotion ability,and better biocompatibility compared with Lipofectamine2000-miR-26a(lipo26a),which indicated a promising prospect for CCMV as a novel gene delivery system.

Multibranched-Based Fluorinated Materials:Tailor-Made Design of ^(19)F‑MRI Probes

CONSPECTUS: Future medicine is primarily aiming at the development of novel approachesfor an early diagnosis of diseases and a personalized therapy for patients. For achieving theseobjectives, a key role is played by medical imaging. Among available noninvasive imagingtechniques, Fluorine-19 (^(19)F) Magnetic Resonance Imaging (MRI) is emerging as a powerfulquantitative detection modality for clinical use both for molecular imaging and for cell tracking.The strength of using ^(19)F-MRI is mainly related to the lack of endogenous organic fluorine intissues, with no background, enabling the visualization of fluorinated tracers as hot-spot images,adding secondary independent information to the anatomical features provided by thegrayscale ^(1)H-MRI. The main challenge for ^(19)F-MRI clinical application is the intrinsic reducedsensitivity of MRI. To improve sensitivity, undoubtedly the use of a high field MRI scanner andcryogenic radiofrequency probes is advantageous, but there is a clear need of developingincreasingly effective fluorinated tracers.The ideal tracer should bear as many as possible magnetically equivalent fluorine atoms andshow optimal magnetic resonance relaxivity properties (i.e., T_(1) and T_(2)), which enable reduced acquisition time with the possibility toapply fast imaging methods. Moreover, it should be biocompatible with reduced tendency to bioaccumulate in tissues, which is oneof the main drawbacks in using perfluorocarbons (PFCs), together with their difficulty to be chemically modified with functionalgroups. In fact, PFCs such as perfluorooctyl bromide (PFOB), perfluoro-15-crown-5-ether (PFCE), and linear perfluoropolyethers(PFPE) are currently the most used tracers in ^(19)F-MRI preclinical and clinical studies, with the above-mentioned limitations. In thisregard, molecules bearing short branched fluorinated chains gained a lot of attention for their high number of equivalent fluorinesand expected capability of reducing bioaccumulation concerns. A valuable building block for branched fluorinated tracers isperfluoro-tert-butanol (PFTB), with nine magnetically equivalent fluorines and easy availability and modification.In this Account we will discuss the main challenges that ^(19)F-MRI has to overcome for increasing its clinical use, highlighting on onehand the need of developing customized fluorinated materials for increasing sensitivity and enabling multimodal properties, and onthe other hand, the importance of the ultrastructure of the final formulation for the final biological response (i.e., clearance). In thiscontext, our group has been focusing on the synthesis and development of branched fluorinated tracers, for which the originator is amolecule called PERFECTA (from suPERFluorinatEdContrasT Agent), bearing 36 equiv ^(19)F atoms, which showed not only optimalrelaxometry properties but also a very specific and intense Raman signal. Thus, PERFECTA and its derivatives represent a newfamily of multimodal tracers enabling multiscale analysis, from whole body imaging (^(19)F-MRI) to microscopic detection at thecellular/tissue level (Raman microscopy). We believe that our proposed PFTB strategy can strongly promote the production ofincreasingly effective ^(19)F-MRI materials with additional functionalities, facilitating the clinical translation of this imaging modality.

High-gain waveguide amplifiers in SigN4 technology via double-layer monolithic integration

Silicon nitride(SiN)-on-SiO,attracts increasing interest in integrated photonics owing to its low propagation loss and wide transparency window,extending from^400 nm to 2350 nm.Scalable integration of active devices such as amplifiers and lasers on the Si;N,platform will enable applications requiring optical gain and a much-nceded alternative to hybrid integration,which suffers from high cost and lack of high-volume manufacturability.We demonstrate a high-gain optical amplifier in Al2O3:Er^3+ monolithically integrated on the Si3N4 platform using a double photonic layer approach.The device exhibits a net Si3N4-to-Si3N4 gain of 18.11±0.9 dB at 1532 nm,and a broadband gain operation over 70 nm covering wavelengths in the S-,C-and L-bands.This work shows that rare-carth-ion-doped materials and in particular,rare-earth-ion-doped Al.05,can provide very high net amplification for the Si3N4 platform,paving the way to the development of different active devices monolithically integrated in this passive platform.

Large-scale fabrication of highly ordered sub-20 nm noble metal nanoparticles on silica substrates without metallic adhesion layers

Periodic noble metal nanoparticles offer a wide spectrum of applications including chemical and biological sensors,optical devices,and model catalysts due to their extraordinary properties.For sensing purposes and catalytic studies,substrates made of glass or fused-silica are normally required as supports,without the use of metallic adhesion layers.However,precise patterning of such uniform arrays of silica-supported noble metal nanoparticles,especially at sub-100 nm in diameter,is challenging without adhesion layers.In this paper,we report a robust method to large-scale fabricate highly ordered sub-20 nm noble metal nanoparticles,i.e.,gold and platinum,supported on silica substrates without adhesion layers,combining displacement Talbot lithography(DTL)with dry-etching techniques.Periodic photoresist nanocolumns at diameters of~110 nm are patterned on metal-coated oxidized silicon wafers using DTL,and subsequently transferred at a 1:1 ratio into anti-reflection layer coating(BARC)nanocolumns with the formation of nano-sharp tips,using nitrogen plasma etching.These BARC nanocolumns are then used as a mask for etching the deposited metal layer using inclined argon ion-beam etching.We find that increasing the etching time results in coneshaped silica features with metal nanoparticles on the tips at diameters ranging from 100 nm to sub-30 nm,over large areas of 3×3 cm^(2).Moreover,subsequent annealing these sub-30 nm metal nanoparticle arrays at high-temperature results in sub-20 nm metal nanoparticle arrays with~10^(10) uniform particles.

On the friction and adhesion hysteresis between polymer brushes attached to curved surfaces: Rate and solvation effects

Computer simulations of friction between polymer brushes are usually simplified compared to real systems in terms of solvents and geometry.In most simulations,the solvent is only implicit with infinite compressibility and zero inertia.In addition,the model geometries are parallel walls rather than curved or rough as in reality.In this work,we study the effects of these approximations and more generally the relevance of solvation on dissipation in polymer-brush systems by comparing simulations based on different solvation schemes.We find that the rate dependence of the energy loss during the collision of brush-bearing asperities can be different for explicit and implicit solvent.Moreover,the non-Newtonian rate dependences differ noticeably between normal and transverse motion,i.e.,between head-on and off-center asperity collisions.Lastly,when the two opposing brushes are made immiscible,the friction is dramatically reduced compared to an undersaturated miscible polymer-brush system,irrespective of the sliding direction.

Hole-doping of mechanically exfoliated graphene by confined hydration layers

By the use of non-contact atomic force microscopy （NC-AFM） and Kelvin probe force microscopy （KPFM）, we measure the local surface potential of mechanically exfoliated graphene on the prototypical insulating hydrophilic substrate of CAF2（111）. Hydration layers confined between the graphene and the CaF2 substrate, resulting from the graphene＇s preparation under ambient conditions on the hydrophilic substrate surface, are found to electronically modify the graphene as the material＇s electron density transfers from graphene to the hydration layer. Density functional theory （DFT） calculations predict that the first 2 to 3 water layers adjacent to the graphene hole-dope the graphene by several percent of a unit charge per unit cell.

Tailoring the properties of quantum dot-micropillars by ultrafast optical injection of free charge carriers

We review recent studies of cavity switching induced by the optical injection of free carriers in micropillar cavities containing quantum dots.Using the quantum dots as a broadband internal light source and a streak camera as detector,we track the resonance frequencies for a large set of modes with picosecond time resolution.We report a record-fast switch-on time constant(1.5 ps)and observe major transient modifications of the modal structure of the micropillar on the 10 ps time scale:mode crossings are induced by a focused symmetric injection of free carriers,while a lifting of several mode degeneracies is observed when off-axis injection breaks the rotational symmetry of the micropillar.We show theoretically and experimentally that cavity switching can be used to tailor the dynamic properties of the coupled QD-cavity system.We report the generation of ultrashort spontaneous emission pulses(as short as 6 ps duration)by a collection of frequency-selected QDs in a switched pillar microcavity.These pulses display a very small coherence length,attractive for ultrafast speckle-free imaging.Moreover,the control of QD-mode coupling on the 10 ps time scale establishes cavity switching as an appealing resource for quantum photonics.

Nanoscale imaging of electric pathways in epitaxial graphene nanoribbons

Graphene nanoribbons (GNRs) are considered as major building blocks in future carbon-based electronics.The electronic performance of graphene nanostructures is essentially influenced and determined by their edge termination and their supporting substrate.In particular,semi-conducting,as well as metallic GNRs,can be fabricated by choosing the proper template which is favorable for device architecture designs.This study highlights the impact of microscopic details of the environment of the GNRs on the charge transport in GNRs.By means of lateral force,conductive atomic force and nanoprobe measurements,we explore the charge propagation in both zig-zag and armchair GNRs epitaxially grown on SiC templates.We directly image transport channels on the nanoscale and identify SiC substrate steps and nano-instabilities of SiC facets as dominant charge scattering centers.