Identification of Dynamic Active Sites Among Cu Species Derived from MOFs@CuPc for Electrocatalytic Nitrate Reduction Reaction to Ammonia

Direct electrochemical nitrate reduction reaction(NITRR)is a promising strategy to alleviate the unbalanced nitrogen cycle while achieving the electrosynthesis of ammonia.However,the restructuration of the high-activity Cu-based electrocatalysts in the NITRR process has hindered the identification of dynamical active sites and in-depth investigation of the catalytic mechanism.Herein,Cu species(single-atom,clusters,and nanoparticles)with tunable loading supported on N-doped TiO_(2)/C are successfully manufactured with MOFs@CuPc precursors via the pre-anchor and post-pyrolysis strategy.Restructuration behavior among Cu species is co-dependent on the Cu loading and reaction potential,as evidenced by the advanced operando X-ray absorption spectroscopy,and there exists an incompletely reversible transformation of the restructured structure to the initial state.Notably,restructured CuN_(4)&Cu_(4) deliver the high NH_(3) yield of 88.2 mmol h^(−1)g_(cata)^(−1) and FE(~94.3%)at−0.75 V,resulting from the optimal adsorption of NO_(3)^(−) as well as the rapid conversion of^(*)NH_(2)OH to^(*)NH_(2) intermediates originated from the modulation of charge distribution and d-band center for Cu site.This work not only uncovers CuN_(4)&Cu_(4) have the promising NITRR but also identifies the dynamic Cu species active sites that play a critical role in the efficient electrocatalytic reduction in nitrate to ammonia.

Mixing Dynamics and Synthesis Performance of Staggered Herringbone Micromixer for Limit Size Lipid Nanoparticles

Staggered herringbone micromixer has shown good efficiency of mixing and performance of synthesizing nanoparticles.To bring a detailed understanding of the mixing dynamics and syn-thesis performance of this kind of micromixer,this paper carries out a high-fidelity numerical simu-lation and a parametrial experimental study on a well-established design.A passive tracer is induced in the numerical simulation to analyze mixing dynamics induced by the staggered herring-bone structures.Three effects are identified to reveal the underlying mechanisms,including folding,stretching,and splitting.To the authors’knowledge,the splitting effect is identified for the first time by the isosurface of the passive tracer,to show the high efficiency of the staggered herring-bone design.The micromixer is then used to synthesize lipid nanoparticles by mixing a mixture of lipid and poly(lactic-co-glycolic acid)(PLGA)solutions with deionized water.Under a wide mass ratio of lipid and PLGA solutions,nanoparticles with good monodispersity are synthesized to reflect the good compatibility of the micromixer and the mixture.In addition,an optimized mass ratio is identified from the parametrical experiment.

The radioresistant and survival mechanisms of Deinococcus radiodurans

Deinococcus radiodurans (D. radiodurans) is distinguished by the most radioresistant organism ever known, and can tolerate extreme environments such as ionizing radiation, ultraviolet radiation, oxidation, and desiccation. D. radiodurans is an important model for studying DNA damage/repair and redox regulation upon high dose ionizing radiation. How D. radiodurans response and repair ROS-induced oxidative damage remains a subject of ongoing investigation. This review provides an overview of the radioresistance characteristics of D. radiodurans. Among them, the DNA damage repair pathway and high-efficiency antioxidant defense system are summarized in detail. Furthermore, a novel model that protects the cell against the ionizing radiation is proposed. This review also discusses the potential application , future challenges and directions in advancing towards D. radiodurans studies.

Comparative study on Photobiomodulation between 630 nm and 810 nm LED in diabetic wound healing both in vitro and in vivo

Photobiomodulation(PBM)promoting wound healing has been demonstrated by many studies.Currently,630 nm and 810 nm light-emitting diodes(LEDs),as light sources,are frequently used in the treatment of diabetic foot ulcers(DFUs)in clinics.However,the dose-effect relationship of LED-mediated PBM is not fully understood.Furthermore,among the 630 nm and 810 nm LEDs,which one gets a better effect on accelerating the wound healing of diabetic ulcers is not clear.The aim of this study is to evaluate and compare the effects of 630 nm and 810 nm LED-mediated PBM in wound healing both in vitro and in vivo.Our results showed that both 630 nm and 810 nm LED irradiation significantly promoted the proliferation of mouse fibroblast cells(L929)at different light irradiances(1,5,and 10 mW/cm^(2)).The cell proliferation rate increased with the extension of irradiation time(100,200,and 500 s),but it decreased when the irradiation time was over 500 s.Both 630 nm and 810nm LED irradiation(5 mW/cm^(2))significantly improved the migration capability of L929 cells.No difference between 630 nm and 810 nm LED-mediated PBM in promoting cell proliferation and migration was detected.In vivo results presented that both 630 nm and 810 nm LED irradiation promoted the wound healing and the expression of the vascular endothelial growth factor(VEGF)and transforming growth factor(TGF)in the wounded skin of type 2 diabetic mice.Overall,these results suggested that LED-mediated PBM promotes wound healing of diabetic mice through promoting fibroblast cell proliferation,migration,and the expression of growth factors in the wounded skin.LEDs(630 nm and 810 nm)have a similar outcome in promoting wound healing of type 2 diabetic mice.

Breaking pore size limit of metal–organic frameworks:Bio-etched ZIF-8 for lactase immobilization and delivery in vivo

Expanding pore size range of metal–organic frameworks(MOFs)promotes their versatility and feasibility for various biomedical applications.However,natural pore size greatly restricts large guest molecule accommodation.Customizing and tailoring pore apertures ranging from micropores to mesopores controllably is desired but still critically challenging.Herein,we developed a facile method with super mildness based on pH-sensitive zeolitic imidazolate framework(ZIF)-8 to increase porosity,providing pore size with maximum 20 nm,which is 8 times larger than average.Glucose oxidase(GOx)was introduced in ZIF-8 for bioetching,benefitted from the resultant acidic microe-nvironment during biocatalytic process.Different synthesis methods were assessed for obtaining different morphologies and size distributions.Reaction time,GOx encapsulation efficiency,and Zn2+concentration was optimized to precisely control the mesopore size distribution of MOFs.It was found that bio-etching strategy was capable of producing stable mesopores which were large enough for loading lactase with good enzymatic activity retained,verified both in vitro and in vivo.This strategy breaks natural pore size limitation of MOFs and thereby facilitates biomolecule delivery,catalysis,and other biomedical applications with enhanced stability and performance.

Deep Membrane Proteome Profiling of Rat Hippocampus in Simulated Complex Space Environment by SWATH

Despite the development and great progress in the field of space biology,the astronauts are still facing many challenges in space.The space environment in which astronauts stay includes microgravity,noise,circadian rhythms disorder,and confinement,which has deep effect both on the physiology and psychology of astronauts.It was reported that long-term flight could cause the astronauts’anxiety and depression.However,the underlying mechanism is not yet fully understood.Therefore,in the present study,the rat tail suspension model with noise,circadian rhythms,and confinement was employed to simulate complex space environment.We found that the rats exhibited the depressive-like behavior by the sucrose preference,forced swimming,and open-field tests.The membrane proteome of the rat hippocampus was investigated by“SWATH quantitation”technology both in control and simulated complex space environment(SCSE)groups.Out of 4520 quantified proteins,244 differentially expressed membrane proteins were obtained between the SCSE and control rats,which were functionally enriched in a series of biological processes,such as translation,protein phosphorylation,brain development,endocytosis,nervous system development,axonogenesis,and vesicle-mediated transport.We found a reduction level of neurexin-2,the light,medium,heavy polypeptide of neurofilament,rab 18,synaptogyrin 1,and syntaxin-1A and an increase level of neuroligin-1,munc18,snapin,synaptotagmin XII,complexin-1,etc.,which may play a key part in the development of depression.Furthermore,GSK-3βprotein was upregulated in mass spectrometry,which was further validated by western blotting.The results of the study do the favor in designing the effective countermeasures for the astronauts in the future long-term spaceflight.

Single-atom cobalt nanozymes promote spinal cord injury recovery by anti-oxidation and neuroprotection

Oxidative stress and inflammation are central pathophysiological processes in a traumatic spinal cord injury(SCI).Antioxidant therapies that reduce the reactive oxygen and nitrogen species(RONS)overgeneration and inflammation are proved promising for improving the outcomes.However,efficient and long-lasting antioxidant therapy to eliminate multiple RONS with effective neuroprotection remains challenging.Here,a single-atom cobalt nanozyme(Co-SAzyme)with a hollow structure was reported to reduce the RONS and inflammation in the secondary injury of SCI.Among SAzymes featuring different single metal-N sites(e.g.,Mn,Fe,Co,Ni,and Cu),this Co-SAzyme showed a versatile property to eliminate hydrogen peroxide(H_(2)O_(2)),superoxide anion(O_(2)·^(-)),hydroxyl radical(·OH),nitric oxide(·NO),and peroxynitrite(ONOO^(-))that overexpressed in the early stage of SCI.The porous hollow structure also allowed the encapsulation and sustained release of minocycline for neuroprotection in synergy.In vitro results showed that the Co-SAzyme reduced the apoptosis and pro-inflammatory cytokine levels of microglial cells under oxidative stress.In addition,the Co-SAzyme combined with minocycline achieved remarkable improved functional recovery and neural repairs in the SCI-rat model.

Piezoelectric wearable atrial fibrillation prediction wristband enabled by machine learning and hydrogel affinity

Atrial fibrillation(AF)is a common and serious disease.Its diagnosis usually requires 12-lead electrocardiogram,which is heavy and inconvenient.At the same time,the venue for diagnosis is also limited to the hospital.With the development of the concept of intelligent medical,a wearable,portable,and reliable diagnostic method is needed to improve the patient’s comfort and alleviate the patient’s pain.Here,we reported a wearable atrial fibrillation prediction wristband(AFPW)which can provide longterm monitoring and AF diagnosis.AFPW uses polyvinylidene fluoride piezoelectric film as sensing material and hydrogel as skin bonding material,of which the structure and design have been optimized and improved.The hydrogel skin bonding layer has good stability and skin affinity,which can greatly improve the user experience.AFPW has enhanced signal,strong signal-tonoise ratio,and wireless transmission function.After a sample library of 385 normal people/patients is analyzed and tested by linear discriminant analysis,the diagnostic success rate of atrial fibrillation is 91%.All these excellent performances demonstrate the great application potential of AFPW in wearable device diagnosis and intelligent medical treatment.

Natural killer cell-derived extracellular vesicle significantly enhanced adoptive T cell therapy against solid tumors via versatilely immunomodulatory coordination

Insufficient tumor tropism,MHC classⅠmolecules(MHC-I)defects of tumor cells,and immunosuppressive tumor microenvironment(TME)seriously imperil the efficacy of adoptive T cell therapy on solid tumors.Here,natural killer cell-derived extracellular vesicle(Nev)is used as a versatile toolkit to synergistically improve adoptive T cell therapy for solid tumors.Specifically,Nev is modified with dibenzocyclooctynes(DBCO)linked with p H-sensitive benzoic-imine bonds;meanwhile,cytotoxic T lymphocyte(CTL)is decorated with azide groups.Then CTL is armed with Nev(CTL-Nev)through the click chemistry reaction.After systematic administration,Nev obviously promotes the tumor-targeting accumulation of CTL coming from its native tumor-tropism capability.Then,the cleavage of benzoic-imine bonds in the slightly acidic TME leads to the release of Nev,which not only directly induces tumor apoptosis but also promotes the action of CTL via multiplex pathways,such as up-regulating the MHC-I expression on tumor cells,reprogramming tumor-associated macrophages from pro-tumoral M2 phenotypes to tumoricidal M1 phenotypes.The all-around coordination of Nev with CTL results in potent tumor repression.

Telluride semiconductor nanocrystals:progress on their liquid-phase synthesis and applications

The synthesis of colloidal telluride semiconductor nanocrystals(CT-SNCs)is more challenging than that of chalcogenides,due to the smaller electron affinity of tellurium than that of sulfur and selenium,which is attributed to its metalloid property.While some new potential strategies were developing with the increasing demand of CT-SNCs,the cation exchange reaction(CER)has particularly become a new strategy to synthesize highquality CT-SNCs and their corresponded hetero-nanostructures.This review summarizes the synthesis strategies of CT-SNCs,including traditional methods and new methods with emphasis on CERs,and their resulting CTSNCs with well-controlling size,shape,composition,crystallization and hetero-interfaces cooperatively.The progressive synthesis methods give rise to the excellent optical properties of CT-SNCs.This review also covers the recent progress of their applications in the field of photoelectric detection,catalysis,batteries and biology.The new hybrid CT-SNCs nanostructures are also emphasized and systematically discussed due to their enhanced properties.

A novel polyethyleneimine-decorated FeOOH nanoparticle for efficient siRNA delivery

Despite the promising prospect of small interfering RNA(siRNA) for the treatment of diverse diseases,it remains challenging to develop novel delive ry materials to desired tissues and cells.In this study,a novel iron oxyhydroxide(FeOOH) nanoparticle(NP) whose surface was modified with branched polyetherimide(PEI) was developed to deliver siRNA into the cancer cells.It was demonstrated that PEI-FeOOH(PFeOOH) efficiently complexed siRNA,mediated effective cellular uptake and endosomal escape,thereby triggering robust gene silencing in vitro.In addition,PFeOOH/siRNA formulation loading with anti-RRM2 siRNA effectively inhibited the growth of tumor tissues,and exhibited excellent safety profiles in vivo.Therefore,this study conceptually provided a FeOOH-based nucleic acid delivery vesicle which can potentially use to achieve diagnosis and therapy simultaneously.

Bioinspired Hydrogels with Muscle-Like Structure for AIEgen-Guided Selective Self-Healing

Living systems,including human beings,animals,and plants,display the power to self-heal spontaneously after being damaged.The self-healing is usually selective,which means that the healing efficiency is related to the spatial distribution of dynamic interfacial interactions of the two rupturing surfaces.Current artificial systems use noncovalent interactions or dynamic covalent bonds to prepare self-healing materials.However,they can only show nonselective self-healing due to their homogeneous internal structures.Herein,we report the construction of a composite hydrogel Gel-C consisting of three different self-healing hydrogels(Gel-Y,Gel-G,and Gel-O)through the use of classic bilayer hydrogel technology.When the composite hydrogel was cut into two pieces,the relative orientation of the parts was rotated through different angles to study the differences in self-healing.Owing to the heterogeneous internal structure of the composite hydrogel and the recognition specificity of each included hydrogel,the interfacial dynamic interactions distribution of the two rupturing surfaces is diverse.The results of tensile tests demonstrated that these rotated samples exhibited different self-healing efficiencies.This system realized the transformation of artificial materials from nonselective self-healing to selective selfhealing,providing inspiration for the development of novel biological materials and engineering materials.