Effects of Catalysis and Separator Functionalization on High-Energy Lithium–Sulfur Batteries:A Complete Review

Lithium–sulfur(Li-S)batteries have the advantages of high theoretical specific capacity(1675 mAh g^(−1)),rich sulfur resources,low production cost,and friendly environment,which makes it one of the most promising next-generation rechargeable energy storage devices.However,the“shuttle effect”of polysulfide results in the passivation of metal lithium anode,the decrease of battery capacity and coulombic efficiency,and the deterioration of cycle stability.To realize the commercialization of Li-S batteries,its serious“shuttle effect”needs to be suppress.The commercial separators are ineffective to suppress this effect because of its large pore size.Therefore,it is an effective strategy to modify the separator surface and introduce functional modified layer.In addition to the blocking strategy,the catalysis of polysulfide conversion reaction is also an important factor hindering the migration of polysulfides.In this review,the principles of separator modification,functionalization,and catalysis in Li-S batteries are reviewed.Furthermore,the research trend of separator functionalization and polysulfide catalysis in the future is prospected.

Ultraviolet metalens and metalens array of focused vortex beams

The solar-blind ultraviolet(UV)wavelength is particularly interesting within the range of 200 nm–300 nm.Here,we propose a focusing metalens,focusing vortex beam(VB)metalens and metalens array that specifically work in the UV band to focus a beam or VB.Firstly,a high numerical aperture(NA)focusing metalens working at a wavelength of 214.2 nm was designed,and the NA reached 0.83.The corresponding conversion efficiency of the unit structure reached as high as 94%,and the full width at half maximum was only 117.2 nm.Metalenses with large NA can act as optical tweezers and can be applied to trap ultracold atoms and molecules.Secondly,a focused VB metalens in the wavelength range of200 nm–300 nm was also designed,which can convert polarized light into a VB and focus the VB simultaneously.Finally,a metalens array was developed to focus VBs with different topological charges on the same focal plane.This series of UV metalenses could be widely used in UV microscopy,photolithography,photonics communication,etc.

Calcium-chelating peptides from rabbit bone collagen:characterization,identification and mechanism elucidation

This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism.Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion(ICSE)combined with enzymatic hydrolysis,followed by chelation reaction to prepare rabbit bone peptide-calcium chelate(RBCP-Ca).The chelating sites were further analyzed by liquid chromatography-tandem mass(LC-MS/MS)spectrometry while the chelating mechanism and binding modes were investigated.The structural characterization revealed that RBCP successfully chelated with calcium ions.Furthermore,LC-MS/MS analysis indicated that the binding sites included both acidic amino acids(Asp and Glu)and basic amino acids(Lys and Arg),Interestingly,three binding modes,namely Inter-Linking,Loop-Linking and Mono-Linking were for the first time found,while Inter-Linking mode accounted for the highest proportion(75.1%),suggesting that chelation of calcium ions frequently occurred between two peptides.Overall,this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.

A review on electrocatalytic CO_(2) conversion via C-C and C-N coupling

Electrochemical C-C and C-N coupling reactions with the conversion of abundant and inexpensive small molecules,such as CO_(2) and nitrogencontaining species,are considered a promising route for increasing the value of CO_(2) reduction products.The development of high-performance catalysts is the key to the both electrocatalytic reactions.In this review,we present a systematic summary of the reaction systems for electrocatalytic CO_(2) reduction,along with the coupling mechanisms of C-C and C-N bonds over outstanding electrocatalytic materials recently developed.The key intermediate species and reaction pathways related to the coupling as well as the catalyst-structure relationship will be also discussed,aiming to provide insights and guidance for designing efficient CO_(2) reduction systems.

Ambient electrocatalytic synthesis of urea by co-reduction of NO_(3)^(-) and CO_(2) over graphene-supported In_(2)O_(3)

Urea plays a vital role in the sustainable development of mankind as it is one of the most important nitrogen fertilizers.Conventional synthesis of urea is accompanied by a high level of energy consumption while electrocatalytic methods suffer from low yields and poor selectivity.Our work achieves efficient synthesis of urea by designing the graphene-In_(2)O_(3)electrocatalysts for the co-activated reduction of nitrate and carbon dioxide,where the formation rate of urea,Faraday efficiency(FE)and carbon selectivity at-0.35 V vs.RHE can reach 357.47μg mg^(-1)h^(-1),10.46%and~100%,respectively.Herein,the key intermediates in the C–N coupling reaction are demonstrated to be*NH_(2)and*CO_(2),which is of novelty compared to previous reports.This work may provide inspiration for subsequent studies on the reaction mechanism of the electrochemical synthesis of urea,as well as theoretical guidance for the sustainable synthesis of some other important chemical substances.

Exploring reservoir computing:Implementation via double stochastic nanowire networks

Neuromorphic computing,inspired by the human brain,uses memristor devices for complex tasks.Recent studies show that self-organizing random nanowires can implement neuromorphic information processing,enabling data analysis.This paper presents a model based on these nanowire networks,with an improved conductance variation profile.We suggest using these networks for temporal information processing via a reservoir computing scheme and propose an efficient data encoding method using voltage pulses.The nanowire network layer generates dynamic behaviors for pulse voltages,allowing time series prediction analysis.Our experiment uses a double stochastic nanowire network architecture for processing multiple input signals,outperforming traditional reservoir computing in terms of fewer nodes,enriched dynamics and improved prediction accuracy.Experimental results confirm the high accuracy of this architecture on multiple real-time series datasets,making neuromorphic nanowire networks promising for physical implementation of reservoir computing.

Interfacial modification using the cross-linkable tannic acid for highly-efficient perovskite solar cells with excellent stability

Although the performance of perovskite solar cells(PSCs)has been dramatically increased in recent years,stability is still the main obstacle preventing the PSCs from being commercial.PSC device instability can be caused by a variety of reasons,including ions diffusion,surface and grain boundary defects,etc.In this work,the cross-linkable tannic acid(TA)is introduced to modify perovskite film through post-treatment method.The numerous organic functional groups(–OH and C=O)in TA can interact with the uncoordinated Pb^(2+)and I^(-)ions in perovskite,thus passivating defects and inhibiting ions diffusion.In addition,the formed TA network can absorb a small amount of the residual moisture inside the device to protect the perovskite layer.Furthermore,TA modification regulates the energy level of perovskite,and reduces interfacial charge recombination.Ultimately,following TA treatment,the device efficiency is increased significantly from 21.31%to 23.11%,with a decreased hysteresis effect.Notably,the treated device shows excellent air,thermal,and operational stability.In light of this,the readily available,inexpensive TA has the potential to operate as a multipurpose interfacial modifier to increase device efficiency while also enhancing device stability.

Rapid detection of pathogenic bacteria based on a universal dual-recognition FRET sensing system constructed with aptamer-quantum dots and lectin-gold nanoparticles

The threat to public health from bacterial infections has led to an urgent need to develop simpler,faster and more reliable bacterial detection methods.In this work,we developed a universal dual-recognition based sandwich fluorescence resonance energy transfer(FRET)sensor by using specific aptamer-modified quantum dots(Aptamer-QDs)as energy donor and lectin concanavalin A(Con A)modified gold nanoparticles(Con A-AuNPs)as energy acceptor to achieve rapid and sensitive detection of Escherichia coli(E.coli)within 0.5 h.In the presence of the target E.coli,the energy donor of Aptamer-QDs and acceptor of Con A-AuNPs were close to each other,causing changes of FRET signals.Based on the constructed FRET sensor,a linear detection range of from 10^(2)cfu/mL to 2×10^(8)cfu/mL with the detection limit of 45 cfu/mL for E.coli was achieved.Furthermore,the FRET sensor was applied to detect E.coli in the milk and orange juice with the detection limit of 300 cfu/mL and 200 cfu/mL,respectively and recovery rate from 83.1%to 112.5%.The strategy holds great promise in pathogenic bacteria detection due to its rapid and sensitivity.

Efficient Catalytic Conversion of Polysulfides by Biomimetic Design of “Branch‑Leaf” Electrode for High‑Energy Sodium–Sulfur Batteries

Rechargeable room temperature sodium–sulfur(RT Na–S)batteries are seriously limited by low sulfur utilization and sluggish electrochemical reaction activity of polysulfide intermediates.Herein,a 3D“branch-leaf”biomimetic design proposed for high performance Na–S batteries,where the leaves constructed from Co nanoparticles on carbon nanofibers(CNF)are fully to expose the active sites of Co.The CNF network acts as conductive“branches”to ensure adequate electron and electrolyte supply for the Co leaves.As an effective electrocatalytic battery system,the 3D“branch-leaf”conductive network with abundant active sites and voids can effectively trap polysulfides and provide plentiful electron/ions pathways for electrochemical reaction.DFT calculation reveals that the Co nanoparticles can induce the formation of a unique Co–S–Na molecular layer on the Co surface,which can enable a fast reduction reaction of the polysulfides.Therefore,the prepared“branch-leaf”CNF-L@Co/S electrode exhibits a high initial specific capacity of 1201 mAh g^−1 at 0.1 C and superior rate performance.

Current diagnostic and therapeutic strategies for COVID-19

The outbreak and spread of novel coronavirus disease 2019(COVID-19) with pandemic features, which is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), have greatly threatened global public health. Given the perniciousness of COVID-19 pandemic, acquiring a deeper understanding of this viral illness is critical for the development of new vaccines and therapeutic options. In this review, we introduce the systematic evolution of coronaviruses and the structural characteristics of SARS-CoV-2. We also summarize the current diagnostic tools and therapeutic strategies for COVID-19.

A Novel Molecular Imprinted Polymers-Based Lateral Flow Strip for Sensitive Detection of Thiodiglycol

Traditional detection of thiodiglycol(TDG),a metabolic marker for sulfur mustard poisoning,requires not only professional operators,but also expensive reagents and large instruments.Herein,we developed a novel molecular imprinted polymers(MIPs)-based lateral flow assay(LFA)strategy for the quick,sensitive,and selective detection of TDG.Gold nanoparticles(Au NPs),MIPs,and metallothioneins(MTs)were respectively loaded on the conjugate pad,test line(T line)and control line(C line).After adding TDG,Au NPs on the conjugate pad reacted with TDG through the Au-S bond first.Then,under the action of capillary force,the conjugates of TDG and Au NPs were trapped by the MIPs as they traveled to the T line,and the residual Au NPs bound with the MTs on the C line,exhibiting two obvious red bands on T line and C line,respectively.In contrast,a single red band could be observed on C line without TDG.This method exhibited a wide linear range from 10.0 pg/m L to 10,000.0 ng/m L and its limit of detection(LOD)was as low as 0.41 pg/m L.This method was successfully utilized to detect TDG in human urine,presenting significant potential in the point-of-care testing of TDG in clinical samples of the sulfur mustard poisoning patients.

Synthesis and Biological Evaluation of Quinazolonethiazoles as New Potential Conquerors towards Pseudomonas Aeruginosa

Novel quinazolonthiazoles were designed and synthesized as new potential antimicrobial agents by facile multi-step procedure from o-aminobenzoic acids and 2-acetylthiazole.A series of biological evaluation showed that compound 7d was the most effective quinazolonethiazole with superior activity to reference drugs chloramphenicol and norfloxacin.This active molecule displayed unob-vious bacterial resistance against P.aeruginosa,the low toxicity to normal hepatocytes,suitable pharmacokinetics and drug-likeness.The preliminary biological interaction suggested that quinazolonethiazole 7d might induce bacterial death by disturbing the membrane permeability,whilst preventing bacteria from growth by integrating into DNA and binding with topoisomerase IV.These findings provided significant background for the further development of quinazolonethiazoles as new potential drugs in combating drug-resistant pathogens.

Design and Synthesis of Sulfanilamide Aminophosphonates as Novel Antibacterial Agents towards Escherichia coli

The limit ability of traditional antibiotics to treat drug resistant bacteria calls for new therapeutic alter natives.A class of unique sul-fanilamide aminophosphonates as new potential agents against microbes was synthesized by one-pot three-component reaction.

Cylindrical polymer brushes-anisotropic unimolecular micelle drug delivery system for enhancing the effectiveness of chemotherapy

Polymer systems can be designed into different structures and morphologies according to their physical and chemical performance requirements,and are considered as one of the most promising controlled delivery systems that can effectively improve the cancer therapeutic index.However,the majority of the polymer delivery systems are designed to be simple spherical nanostructures.To explore morphology/size-oriented delivery performance optimization,here,we synthesized three novel cylindrical polymer brushes(CPBs)by atom transfer radical polymerization(ATRP),which were cellulose-g-(CPT-b-OEGMA)(CCO)with different lengths(~86,~40,and~21 nm).The CPBs are composed of bio-degradable cellulose as the carrier,poly(ethylene glycol)methyl ether methacrylate(OEGMA)as hydrophily block,and glutathione(GSH)-responsive hydrophobic camptothecin(CPT)monomer as loaded anticancer drug.By controlling the chain length of the initiator,three kinds of polymeric prodrugs with different lengths(CCO-1,CCO-2,and CCO-3)could be self-organized into unimolecular micelles in water.We carried out comparative studies of three polymers,whose results verified that the shorter CPBs exhibited higher drug release efficiency,more cellular uptake,and enhanced tumor permeability,accompanied by shortened blood circulation time and lower tumor accumulation.As evidenced by in vivo experiments,the shorter CPBs exhibited higher anti-tumor efficiency,revealing that the size advantage has a higher priority than the anisotropic structure advantage.This provided vital information as to design an anisotropic polymer-based drug delivery system for cancer therapy.

CDs assembled metal-organic framework:Exogenous coreactant-free biosensing platform with pore confinement-enhanced electrochemiluminescence

Despite the various synthesis approachs to obtain luminous carbon dots(CDs),it is still quite challenging to construct the efficient electrochemiluminescence(ECL)owing to their low ECL reactivity and easy agglomeration.Herein,an efficient and concise ECL system was skillfully constructed by taking advantage of the nitrogen and sulfur co-doped CDs(N,S-CDs)with surfaces rich in hydrazide groups as luminophors to emit intense ECL,and metal-organic framework(MOF)as the matrix to confine CDs in its nanospace.Surprisingly,the proposed CDs assembled MOF(CDs/ZIF-8)enhanced anodic ECL signal up to 250%of pure CDs under the exogenous coreactant-free condition.As a proof of concept,the highly sensitive detection of uric acid(UA)was realized by the constructed ECL platform with a low detection limit of 3.52 nmol/L ranging from 10 nmol/L to 50μmol/L.This work expanded ideas for the application of pore confinement effect,and provided references for the detection of disease biomarkers of gout and hyperuricemia.

Engineering prodrug nanomicelles as pyroptosis inducer for codelivery of PI3K/mTOR and CDK inhibitors to enhance antitumor immunity

Aberrant activation of oncogenic signaling pathways in tumors can promote resistance to the antitumor immune response.However,single blockade of these pathways is usually ineffective because of the complex crosstalk and feedback among oncogenic signaling pathways.The enhanced toxicity of free small molecule inhibitor combinations is considered an insurmountable barrier to their clinical applications.To circumvent this issue,we rationally designed an effective tumor microenvironment-activatable prodrug nanomicelle(PNM)for cancer therapy.PNM was engineered by integrating the PI3K/m TOR inhibitor PF-04691502(PF)and the broad spectrum CDK inhibitor flavopiridol(Flav)into a single nanoplatform,which showed tumor-specific accumulation,activation and deep penetration in response to the high glutathione(GSH)tumoral microenvironment.The codelivery of PF and Flav could trigger gasdermin E(GSDME)-based immunogenic pyroptosis of tumor cells to elicit a robust antitumor immune response.Furthermore,the combination of PNM-induced immunogenic pyroptosis with antiprogrammed cell death-1(a PD-1)immunotherapy further boosted the antitumor effect and prolonged the survival time of mice.Collectively,these results indicated that the pyroptosis-induced nanoplatform codelivery of PI3K/m TOR and CDK inhibitors can reprogram the immunosuppressive tumor microenvironment and efficiently improve checkpoint blockade cancer immunotherapy.

Conformer Analysis of a Biological G-Quadruplex Element in the Human c-MYC Promoter by Native Polyacrylamide Gel Electrophoresis

The G-quadruplexes undergo complex folding and conformation exchanges.G-quadruplex stability is substantially influenced by sequence,bufer and temperature.Mutational analysis together with nuclear magnetic resonance spectroscopy(NMR),X-ray crystallography and circular dichroism spectroscopy has been proved to be a powerful approach for G-quadruplex structural analysis.Herein,we used DNA sequence mutation and native polyacrylamide gel electrophoresis to investigate the topology and conformations of a G-quadruplex model molecule Pu18 found in the human c-MYC promoter.The guanines(G6,G9 or G18)which were not contributable to G-tetrad formation in c-MYC Pu18 sequence were mutated to thymine or adenine.We screened the buffer and temperature of gel electrophoresis for Pu18.Gel electrophoresis showed that two of the four conformers of c-MYC Pu18 in 100 mM K+buffer were resolved,which was in accordance with the conformations as determined by the 1 H NMR spectra in previous studies.This technique is expected as a general methodology for its easy operation and low cost to facilitate uncovering more yet unidentified G-quadruplex folds and functions,with the assistance of other analytical methods like NMR,X-ray crystallography and circular dichroism spectroscopy.

Target Recycling Transcription of Lighting-Up RNA Aptamers for Highly Sensitive and Label-Free Detection of ATP

We describe here a target recycling transcription of lighting-up aptamer strategy for detecting ATP in human serums in a label-free means with high sensitivity.ATP molecules specifically recognize the binding aptamer and result in the structure switching of the DNA assembly probes to imitate the target ATP molecule recycling cycles through the toehold-mediated strand displacement reaction,which causes the formation of many dsDNAs containing the RNA promoter sequences for subsequent transcription generation of large amounts of lighting-up aptamers.The organic dye,malachite green,then associates with these lighting-up aptamers to produce significantly enhanced fluorescence signals,which can sensitively detect ATP within a dynamic range from 10 to 500 nM in a label-free way.The sensing approach shows a detection limit of 7.3 nM and also has an excellent selectivity for ATP analogue molecules.In addition,this method can detect ATP molecules in diluted human serum samples sensitively,which proves the promising potential to diagnose ATP-related diseases.

Correction to:Conformer Analysis of a Biological G-Quadruplex Element in the Human c-MYC Promoter by Native Polyacrylamide Gel Electrophoresis

Correction to:Journal of Analysis and Testing(2021)5:188-194 https://doi.org/10.1007/s41664-021-00181-0 In the original publication of the article,the first author’s first name has been incorrectly published.The correct author name is Xiao-Li Hu.The original article was corrected.

Advanced Pt hollow nanospheres/rubrene nanoleaves coupled with M-shaped DNA walker for ultrasensitive electrochemiluminescence bioassay

Herein,an intense electrochemiluminescence(ECL)was achieved based on Pt hollow nanospheres/rubrene nanoleaves(Pt HNSs/Rub NLs)without the addition of any coreactant,which was employed for ultrasensitive detection of carcinoembryonic antigen(CEA)coupled with an M-shaped DNA walker(M-DNA walker)as signal switch.Specifically,in comparison with platinum nanoparticles(Pt NPs),Pt HNSs revealed excellent catalytic performance and pore confinement-enhanced ECL,which could significantly amplify ECL intensity of Rub NLs/dissolved O_(2)(DO)binary system.Then,the tracks and M-DNA walker were confined on the Pt HNSs simultaneously to promote the reaction efficiency,whose M-structure boosted the interaction sites between walking strands and tracks and reduced the rigidity of their recognition.Once the CEA approached the sensing interface,the M-DNA walker was activated based on highly specific aptamer recognition to recover ECL intensity with the assistance of exonucleaseⅢ(ExoⅢ).As proof of concept,the“on-off-on”switch aptasensor was constructed for CEA detection with a low detection limit of 0.20 fg/m L.The principle of the constructed ECL aptasensor also enables a universal platform for sensitive detection of other tumor markers.