An Efficient Method for the Synthesis of Acyl-diazenes Using NaNO_2/NaHSO_4·H_2O

An efficient and convenient method for the synthesis of acyl-diazenes is reported. Ten acyl-diazenes have been synthesized from acylhydrazines in excellent yields under mild conditions. There are eight new substances among these compounds.

A Rapid and Efficient Synthesis of Diaryl Thioureas via Solvent-Free Reaction Using Microwave

A rapid and efficient method for the preparation of diaryl thiourea compounds was reported for the first time. Twelve diaryl thiourea compounds that possessing biological activity have been synthesized in excellent yields (91-97%). The reaction proved to be extremely simple and highly efficient (in 1.5-4.5 min).

One-step synthesis of carbon-supported copper nanoparticles from biomass for N-arylation of pyrazole

Carbon-supported copper catalyst was prepared for the first time in one-step with copper nitrate and corn stalk through calcination under different temperatures. Uniformly dispersed nanoparticles were obtained and were identified to be Cu（0） and Cu（Ⅰ） in XRD patterns. Excellent catalytic activity and selectivity were achieved in the N-arylation of pyrazole under ligand and protection gas free conditions. About90.4% of product yield was achieved with only 0.5 mol% of copper catalyst（Cu-C-300）, which was considerably more efficient than previous reports. XPS results suggested that the N-arylation of pyrazole activity was closely related to the surface Cu（Ⅰ） species.

Functional carbon materials for high-performance Zn metal anodes

The realization of“carbon peak”and“carbon neutralization”highly depends on the efficient utilization of renewable energy sources.Exploring reliable and low-cost electrochemical energy storage systems is an ever-growing demand for renewable energy integration.Among available candidates,aqueous zinc-ion batteries(AZIBs)receive extensive researchers'attention because of their material abundance,high capacity,high safety,and environmental friendliness.However,the irreversible issues of Zn anode in terms of notorious dendric Zn growth,Zn corrosion/hydrogen evolution,and passivation significantly impede the commercialization of high-performance AZIBs.Carbon materials have advantages of large specific surface area,low cost,high electrical conductivity,controllable structure,and good stability.Their application provides remedies for improving the comprehensive performance of Zn anodes.In this review,the fundamentals and issues of Zn anodes,and the research progress with functional carbon materials for Zn anodes in recent years are presented.Three major strategies are described in detail,including the use of carbon materials(carbon nanotubes,graphene,carbon fiber,metal-organic framework(MOF)derived host,etc.)as Zn plating/stripping substrates,as protective coating layers on Zn,and as electrolyte additives.Finally,the remaining challenges and perspectives of carbon materials in high-performance AZIBs are outlined.

Colorimetric Recognition of 3,4-Dihydroxy-D,L-phenylalanine with Tetrapeptide-modified Copper Nanoparticles as Chiral Nanozymes

The construct of artificial nanocatalyts by simulating natural enzymes and thereby bringing new properties for practical applications is still a challenging task to date.In this study,chiral tetrapeptide(L-phenylalanine-L-phenylalanine-L-cysteine-L-histidine)-engineered copper nanoparticles(FFCH@CuNPs)were fabricated as an artificial peroxidase(POD).More interestingly,the nano-catalysts exhibited chiral identification function.In comparison with other nanocatalysts like L-cysteine-,L-histidine-,chiral dipeptide(L-cysteine-L-histidine)-,or chiral tripeptide(L-phenylalanine-L-cysteine-L-histidine)-modified CuNPs,FFCH@CuNPs demonstrated higher POD-mimetic catalytic activity in the 3,3',5,5'-tetramethylbenzidine(TMB)-H_(2)O_(2) system and stronger enantioselectivity in the recognition of 3,4-dihydroxy-D,L-phenylalanine(D,L-DOPA)enantiomers.Considering the strength difference between the intermolecular hydrogen bonding and theπ-πinteractions,the principle behind the chiral discrimination of D,L-DOPA was explored.Furthermore,higher contents of surface Cu2+ions and hydroxyl radicals were found in the FFCH@CuNPs-D-DOPA-TMB-H_(2)O_(2) system than in the FFCH@CuNPs-L-DOPA-TMB-H_(2)O_(2) system.Based on these results,a protocol for distinguishing between D,L-DOPA enantiomers through colorimetric recognition was established.This study provides a new insight into the design and fabrication of oligopeptides@CuNPs-based chiral nanozymes with improved catalytic performance and features additional to those of natural enzymes.

TiO_(2)-Fe_(2)TiO_(5)heterostructure hollow spheres enable high-performance lithium-sulfur batteries via interfacial engineering

The shuttle effect of lithium polysulfides between sulfur cathode and lithium anode is a notorious problem in the commercial application of lithium-sulfur batteries.Herein,heterostructured TiO_(2)-Fe_(2)TiO_(5)hollow spheres were proposed and synthesized as efficient sulfur host to address theshuttle behavior of poly sulfides.

Cyanobacteria-based near-infrared light-excited self-supplying oxygen system for enhanced photodynamic therapy of hypoxic tumors

Tumor hypoxia has been considered to induce tumor cell resistance to radiotherapy and anticancer chemotherapy,as well as predisposing for increased tumor metastases.Therefore,strategies for the eradication of the hypoxic tumor are highly desirable.Photodynamic therapy(PDT)is a new technique that can be used to treat tumors using laser irradiation to photochemically activate a photosensitizer.Compared to traditional radiotherapy and chemotherapy,photodynamic therapy has many advantages,such as good selectivity,low toxicity,and less trauma and resistance.However,PDT is oxygen-dependent,and the lack of oxygen in hypoxic tumors renders photodynamic therapy ineffective.Cyanobacteria,the earliest photosynthetic oxygen-generating organisms,can utilize water as an electron donor to reduce CO_(2) into organic carbon compounds along with continuously releasing oxygen under sunlight.Inspired by this,herein,cyanobacteria were used as a living carrier of photosensitizer conjugated upconversion nanoparticles(UCNP)to construct a self-supplying oxygen PDT system.Improvement in the PDT efficiency for hypoxic tumors can be achieved as a result of in situ oxygen production by cyanobacteria under near-infrared(NIR)light using UCNP as a light harvesting antenna.A successful demonstration of this concept would be of great significance and could open the door to a new generation of carrier systems in the field of hypoxia-targeted drug transport platforms.

Gold nanorods-mediated efficient synergistic immunotherapy for detection and inhibition of postoperative tumor recurrence

Tumor recurrence after surgery is the main cause of treatment failure.However,the initial stage of recurrence is not easy to detect,and it is difficult to cure in the late stage.In order to improve the life quality of postoperative patients,an efficient synergistic immunotherapy was developed to achieve early diagnosis and treatment of post-surgical tumor recurrence,simultaneously.In this paper,two kinds of theranostic agents based on gold nanorods(AuNRs)platform were prepared.AuNRs and quantum dots(QDs)in one agent was used for the detection of carcinoembryonic antigen(CEA),using fluorescence resonance energy transfer(FRET)technology to indicate the occurrence of in situ recurrence,while AuNRs in the other agent was used for photothermal therapy(PTT),together with antiPDL1 mediated immunotherapy to alleviate the process of tumor metastasis.A series of assays indicated that this synergistic immunotherapy could induce tumor cell death and the increased generation of CD3;/CD4;T-lymphocytes and CD3+;CD8;T-lymphocytes.Besides,more immune factors(IL-2,IL-6,and IFN-γ)produced by synergistic immunotherapy were secreted than mono-immunotherapy.This cooperative immunotherapy strategy could be utilized for diagnosis and treatment of postoperative tumor recurrence at the same time,providing a new perspective for basic and clinical research.

Measurement of CO_(2) concentration based on supercontinuum laser absorption spectroscopy

The concentrations of CO_(2) were measured by the supercontinuum laser at normal temperature and variable temperature accurately in this paper. The absorption spectra of CO_(2) at different concentrations(1.2%—9.0%) were measured in the wavelength range of 1 425—1 445 nm under the optical path of 26.4 m at 293 K and 1 atm. The experimental results showed that the positions of the primary and secondary absorption peaks(1 432 nm, 1 437 nm) were consistent with the HITRAN database. A linear model of concentration and signal intensity at 1 432 nm was established. The maximum relative error of the concentration measurement was 3.3%. The line intensities of 99.9% CO_(2) in the 1 425—1 445 nm at different temperatures(298—373 K, interval of 15 K) were measured. The influence of temperature changes on the concentration measurement result was corrected and the relative error of the concentration measurement was reduced to 1.4%. Finally, the source of the uncertainty of the entire spectrum measurement system was analyzed and evaluated. This paper demonstrate that the supercontinuum laser can achieve the long-distance measurement of the CO_(2) under normal temperature or variable temperature environment accurately, which provide an important reference for the long-distance gas detection on site and simultaneous detection of multi-component gases.

Liposome-based multifunctional nanoplatform as effective therapeutics for the treatment of retinoblastoma

Photothermal therapy has the characteristics of minimal invasiveness,controllability,high efficiency,and strong specificity,which can effectively make up for the toxic side effects and tumor resistance caused by traditional drug treatment.However,due to the limited tissue penetration of infrared light,it is difficult to promote and apply in clinical practice.The eye is the only transparent tissue in human,and infrared light can easily penetrate the eye tissue,so it is expected that photothermal therapy can be used to treat fundus diseases.Here in,a new nano-platform assembled by liposome and indocyanine green(ICG) was used to treat retinoblastoma.ICG was assembled in liposomes to overcome some problems of ICG itself.For example,ICG is easily quenched,self-aggregating and instability.Moreover,liposomes can prevent free ICG from being cleared through the systemic circulation.The construction of the nano-platform not only ensured the stability of ICG in vivo,but also realized imaging-guide photothermal therapy,which created a new strategy for the treatment of retinoblastoma.

Studies on the rheological, phase morphologic, thermal and mechanical properties of poly(trimethylene terephthalate)/ ethylene propylene diene monomer copolymer grafted with maleic anhydride/metallocene polyethylene blends

The rheological,phase morphologic,thermal andmechanicalpropertiesofpoly(trimethyleneterephthalate)/metallocene polyethylene(PTT/mPE)blends in the presence of ethylene propylene diene monomer copolymer grafted with maleic anhydride(EPDM-g-MAH)as compatibilizer are studied by means of a capillary rheometer,scanning electron microscopy(SEM),differential scanning calorimetry(DSC)and thermogravimetric analyzer(TGA).Results suggest that the compatibility of PTT/mPE blends is improved greatly after the addition of a compatibilizer.The radius of the dispersed phase in the system decreases greatly when the compatibilizer is added into the blend.When the amount of compatibilizer exceeds 8 wt-%,the size of dispersed phase becomes larger again.This phenomena could be attributed to the higher viscosity of the EPDM-g-MAH phase,which is dispersed more difficulty in the PTT phase of lower viscosity,thus the mixing efficiency is apparently decreased during the melt blending process.Moreover,the melt viscosity of the blend reaches the maximal value in case of 4 wt-%compati-bilizer content,above which it would decrease again.This result is associated with the generation of more and bigger dispersed phase inside the bulk phase,thus the grafting efficiency at the interface is decreased,which could result in lower viscosity.The DSC results suggest that the mPE component shows a nucleating effect,and could increase the overall degree and rate of PTT crystallization,while the addition of a compatibilizer might slightly diminish these effects.In addition,the blend with 4 wt-%compatibilizer shows the best thermal stability.Furthermore,the Izod impact strength and the tensile strength at room temperature of the blend are also markedly improved by the addition of a 4–8 wt-%compatibilizer.

Study on the crystal morphology and melting behavior of isothermally crystallized composites of short carbon fiber and poly(trimethylene terephthalate)

The spherulites of the short carbon fiber(SCF)/poly(trimethyleneterephthalate)(PTT)compositesformedin limited space at designed temperatures,and their melting behaviors were studied by the polarized optical microscopy,atomic force microscopy(AFM),and scanning electron microscopy(SEM),respectively.The results suggest that SCF content,isothermal crystallization temperatures,and the film thicknesses influence the crystal morphology of the composites.The dimension of the spherulites is decreased with increasing SCF content,but whether banded or nonbanded spherulites will form in the composites is not dependent on SCF content.However,the crystal morphology of the composites depends strongly on the temperature.When the isothermal crystallization temperatures increase from 180℃ to 230℃,the crystal morphology of SCF/PTT composites continuously changes in the following order:nonbanded→banded→nonbanded spherulites.Disconti-nuous circle lines form in the film when the film thickness increases from 30 to 60μm.Basing on the SEM observation,it is found that these circle lines are cracks formed due to the constriction difference of the different parts of the spherulites.These cracks are formed when the film is cooled from the isothermal crystallization temperature to the room tempera-ture at a slow cooling rate;while they will disappear gradually at different temperatures in the heating process.The crack will appear/disappear first around the center of the spherulite when the film was cooled/heated.The nontwisted or slightly twisted lamellas will reorganize to form highly twisted lamellas inducing apparent banded texture of the spherulites.

Thermal decomposition of poly(ethylene terephthalate)/mesoporous molecular sieve composites

The nonisothermal and isothermal degradation processes of poly(ethylene terephthalate)/mesoporous molecular sieve(PET/MMS)composites synthesized by in-situ polymerization were studied by using thermogravimetric analysis in nitrogen.The nonisothermal degradation of the composite is found to be the first-order reaction.An iso-conversional procedure developed by Ozawa is used to calcu-late the apparent activation energy(E),which is an average value of about 260 kJ/mol with the weight conversion from 0%to 30%,and is higher than that of neat PET.Isothermal degradation results are confirmed with the nonisothermal process,in which PET/MMS showed higher thermal stability than neat PET.The polymer in mesoporous channels has more stability due to the protection of the inorganic pore-wall.These results indicate that mesoporous MMS in PET/MMS composites improve the stability of the polymer.

Aggregation-induced emission of copper nanoclusters

Copper nanoclusters(Cu NCs)have recently emerged as promising luminophores,featuring ultra-small size,reasonable photostability,large Stokes shift,and long emission lifetimes.Aggregation-induced emission(AIE)has been often used to further improve both the emission intensity and stability of these clusters,with plenty of potential applications in the fields of chemical sensing and bioimaging.This review starts with a summary of the current understanding of emission mechanisms of Cu NCs and proceeds with the analysis of contributions from the Cu metal core and the organic ligands.We summarize the recent research progress on the design of ligands,and the ways on how to induce aggregation of the Cu NCs through electrostatic charge neutralization,host-guest interactions,and the use of templates.We also discuss the current understanding of emission mechanisms of Cu NCs experiencing AIE,such as the often-cited restriction of intramolecular motion and contributions from Cu(I)molecular complexes.We finish this review by providing concluding remarks and offering our own perspective on the active field of AIE of Cu NCs,with a hope to further promote the research on the fundamental aspects of this useful phenomenon.

Thermo-sensitive Porous Polymer Membrane-immobilized Cellulose as a Switchable Enzyme Reactor for Tuning Its Enzymolysis via Variation Temperature

Immobilization of enzymes onto porous membranes has attracted considerable attention in recent years.However,enhancing the enzymolysis efficiency of the resulting enzyme reactors by varying the environmental conditions poses a great challenge.In this work,poly(styrene-maleic anhydride-N,N-dimethylacrylamide)was prepared and utilized to construct a thermo-sensitive porous polymer membrane-based enzyme reactor(TS-PPMER)after cellulase was immobilized onto the support by covalent bonding.The catalytic activity of the nano-reactor was evaluated by measuring the yield of the product,glucose,at different temperatures with carboxymethylcellulose as the substrate.Interestingly,the polymer chains coiled and formed numerous nano-pores at a high temperature,which induced the confine effect and greatly boosted the enzymolysis efficiency of TS-PPMER.Furthermore,the proposed TS-PPMER was applied in the hydrolysis of green plant leaves in Epipremnum aureum.This work shows great potential in obtaining biological resources by an environmentally friendly approach using smart polymer-based nano-reactors.

Liposome-coated CaO_(2)nanoblockers for enhanced checkpoint blockade therapy by inhibiting PD-L1 de novo biosynthesis

The blocking of the immune checkpoint pathway with antibodies,especially targeting to programmed death-1/programmed death ligand-1(PD-1/PD-L1)pathway,was currently a widely used treatment strategy in clinical practice.However,the shortcomings of PD-L1 antibodies were constantly exposed with the deepening of its research and their therapeutic effect was limited by the translocation and redistribution of intracellular PD-L1.Herein,we proposed to improve immune checkpoint blockade therapy by using liposomes-coated CaO_(2)(CaO_(2)@Lipo)nanoparticles to inhibit the de novo biosynthesis of PD-L1.CaO_(2)@Lipo would produce oxygen and reduce hypoxia-inducible factor-1α(HIF-1α)level,which then downregulated the expression of PD-L1.Our in vitro and in vivo results have confirmed CaO_(2)@Lipo promoted the degradation of HIF-1αand then downregulated the expression of PD-L1 in cancer cells for avoiding immune escape.Furthermore,to mimicking the clinical protocol of anti-PD-L1 antibodies+chemo-drugs,CaO_(2)@Lipo was combined with doxorubicin(DOX)to investigate the tumor inhibition efficiency.We found CaO_(2)@Lipo enhanced DOX-induced immunogenic cell death(ICD)effect,which then promoted the infiltration of T cells,strengthened the blocking effect,thus provided an effective means to overcome the traditional immune checkpoint blockade treatment.

Photo-Isomerization Energy Storage Using Azobenzene and Nanoscale Templates: A Topical Review

Azobenzene(AZO) has attached tremendous attention in the field of photo-isomerization energy storage due to its advantages of absorbing light in ultraviolet-visible range and reversible isomerization. However, the issues of low energy density and short half-lifetime restrict the further development of AZO. Therefore, a method, by preparing hybrid photo-isomerization energy storage materials using nanoscale templates, was proposed to handle the above two issues. In this paper, a summary of hybrid photo-isomerization energy storage materials with AZO and nanoscale templates is conducted from the aspects of templates, preparation methods, derivatives and applications. The performances of template candidates, i.e. carbon nanotubes(CNTs) and graphene(GO) are reviewed and compared based on the analysis of grafting density, energy density, and half-lifetime of hybrid materials. Then, two major preparation methods of AZO hybrid materials including non-covalent and covalent functionalizations are discussed. Furthermore, the studies on AZO derivatives functionalized on nanoscale templates are summarized to further point to the direction of derivatization towards high performance AZO-functionalized materials. Finally, due to the superiority of AZO hybrid solid-state films in large-scale utilization, their current applications are reviewed to find out some promising applications.

Smart calcium peroxide with self-sufficience for biomedicine

Oxygen(O2)supplementation plays a key role in the treatment of some hypoxia-associated diseases,such as solid tumors,tissue damage,and type-1 diabetes(T1D).Various strategies have been developed to address the hypoxia aspect of these diseases,such as hyperbaric O2 and liquid or solid O2-generating materials.Calcium peroxide(CaO2)has been regarded as a promising O2 provider in the fields of re・generative medicine(Chang and Wang,2013)and tumor treatment(Huang et al.,2016)because of good biocompatibility,high O2 content(0.2222 g O2 g 1 CaO2),and longtime O2-releasing capacity.Moreover,as the"solid H2O2",CaO2 can react with water(H2O)and quickly generate H2O2,a common reactive O2 species(ROS),which can result in excellent antibacterial activity and antitumor effects.Here we focused on the applications of CaO2 in the field of bio・medicine and summarized the recent progress on this research(Figure 1).

Metal-organic framework-based nanocatalytic medicine for chemodynamic therapy

Chemodynamic therapy(CDT)is an emerging and promising strategy based on the Fenton or Fenton-like reaction in tumors[1–3].The tumor microenvironment(TME)has the characteristics of low acidity and overexpression of H2O2[4,5],thus providing favorable conditions for initiating the Fenton or Fenton-like reaction.In CDT,intratumoral H2O2 is decomposed into highly toxic hydroxyl radicals(·OH)through the Fenton or Fenton-like reaction catalyzed by a metal-based nanocatalyst,which will cause irreversible damage to DNA,lipids,and proteins[6,7].

Enzyme immobilization on a pH-responsive porous polymer membrane for enzymatic kinetics study

Immobilization of enzymes onto carriers is a rapidly growing research area aimed at increasing the stability,reusability and enzymolysis efficiency of free enzymes.In this work,the role of phaseseparation and a pH-responsive"hairy"brush,which greatly affected the topography of porous polymer membrane enzyme reactors(PMER),was explored.The porous polymer membrane was fabricated by phase-separation of poly(styrene-co-maleic anhydride-acrylic acid)and poly(styrene-ethylene glycol).Notably,the topography and pores size of the PMER could be controlled by phase-separation and a pHresponsive"hairy"brush.For evaluating the enzymolysis efficiency of D-amino acid oxidase(DAAO)immobilized carrier(DAAO@PMER),a chiral ligand exchange capillary electrophoresis method was developed with D-methionine as the substrate.The DAAO@PMER showed good reusability and stability after five continuous runs.Notably,comparing with free DAAO in solution,the DAAO@PMER exhibited a17.7-folds increase in catalytic velocity,which was attributed to its tailorable topography and pHresponsive property.The poly(acrylic acid)moiety of poly(styrene-co-maleic anhydride-acrylic acid)as the pH-responsive"hairy"brush generated topography changing domains upon adjusting the buffer pH,which enable the enzymolysis efficiency of DAAO@PMER to be tuned based upon the well-defined architectures of the PMER.This approach demonstrated that the topographical changes formed by phaseseparation and the pH-responsive"hairy"brush indeed made the proposed porous polymer membrane as suitable supports for enzyme immobilization and fitting for enzymolysis applications,achieving high catalytic performance.