Green and Near-Infrared Dual-Mode Afterglow of Carbon Dots and Their Applications for Confidential Information Readout

Near-infrared(NIR),particularly NIR-containing dual-/multimode afterglow,is very attractive in many fields of application,but it is still a great challenge to achieve such property of materials. Herein,we report a facile method to prepare green and NIR dual-mode afterglow of carbon dots(CDs) through in situ embedding o-CDs(being prepared from o-phenylenediamine) into cyanuric acid(CA) matrix(named o-CDs@CA). Further studies reveal that the green and NIR afterglows of o-CDs@CA originate from thermal activated delayed fluorescence(TADF) and room temperature phosphorescence(RTP) of o-CDs,respectively. In addition,the formation of covalent bonds between o-CDs and CA,and the presence of multiple fixation and rigid e ects to the triplet states of o-CDs are confirmed to be critical for activating the observed dual-mode afterglow. Due to the shorter lifetime and insensitiveness to human vision of the NIR RTP of o-CDs@CA,it is completely covered by the green TADF during directly observing. The NIR RTP signal,however,can be readily captured if an optical filter(cut-o wavelength of 600 nm) being used. By utilizing these unique features,the applications of o-CDs@CA in anti-counterfeiting and information encryption have been demonstrated with great confidentiality. Finally,the as-developed method was confirmed to be applicable to many other kinds of CDs for achieving or enhancing their afterglow performances.

Capsid destabilization and epitope alterations of human papillomavirus 18 in the presence of thimerosal

Thimerosal has been widely used as a preservative in drug and vaccine products for decades.Due to the strong propensity to modify thiols in proteins,conformational changes could occur due to covalent bond formation between ethylmercury(a degradant of thimerosal)and thiols.Such a conformational change could lead to partial or even complete loss of desirable protein function.This study aims to investigate the effects of thimerosal on the capsid stability and antigenicity of recombinant human papillomavirus(HPV)18 virus-like particles(VLPs).Dramatic destabilization of the recombinant viral capsid upon thimerosal treatment was observed.Such a negative effect on the thermal stability of VLPs preserved with thimerosal was shown to be dependent on the thimerosal concentration.Two highly neutralizing antibodies,13H12 and 3C3,were found to be the most sensitive to thimerosal treatment.The kinetics of antigenicity loss,when monitored with 13H12 or 3C3 as probes,yielded two distinctly different sets of kinetic parameters,while the data from both monoclonal antibodies(mAbs)followed a biphasic exponential decay model.The potential effect of thimerosal on protein function,particularly for thiolcontaining proteinaceous active components,needs to be comprehensively characterized during formulation development when a preservative is necessary.

传统文化蕴含的化学智慧在元素无机化学教学中的有机融入

在讲授元素无机化学时,把中国传统文化中所包含的化学知识、化学智慧有机地融入课堂教学,将元素无机化学讲授与课程思政教学有机融合,从而增加理科课堂的文化性、知识性和趣味性,激发学生的学习兴趣;同时培养学生的文化自信,激发学生的民族自豪感。

A new hybrid method—combined heat flux method with Monte-Carlo method to analyze thermal radiation

A new hybrid method, Monte-Carlo-Heat-Flux (MCHF) method, was presented to analyze the radiative heat transfer of participating medium in a three-dimensional rectangular enclosure using combined the Monte-Carlo method with the heat flux method. Its accuracy and reliability was proved by comparing the computational results with exact results from classical 'Zone Method'.

To understand the brain – the 2016 annual meeting of society for neurosciences:a conference report

Overview:Over 30,000 neuroscientists participated in the 46^(th) annual meeting of the Society for Neurosciences(Sf N 2016),which was held in San Diego,California from November 12th to16^(th).More than 15,000 research projects were presented or discussed in the world’s largest conference in biomedical sciences.The scope of Sf N 2016 broadly covered numerous fields of brain researches,such as neural development,neural excitability

Generation of color-controllable room-temperature phosphorescence via luminescent center engineering and in-situ immobilization

Materials with controllable luminescence colors are highly desirable for numerous promising applications, however, the preparation of such materials, particularly with color-controllable room-temperature phosphorescence(RTP), remains a formidable challenge. In this work, we reported on a facile strategy to prepare color-controllable RTP materials via the pyrolysis of a mixture containing 1-(2-hydroxyethyl)-urea(H-urea) and boric acid(BA). By controlling the pyrolysis temperatures, the as-prepared materials exhibited ultralong RTP with emission colors ranging from cyan, green, to yellow. Further studies revealed that multiple luminescent centers formed from H-urea, which were in-situ embedded in the B2O3matrix(produced from BA) during the pyrolysis process. The contents of the different luminescent centers could be regulated by the pyrolysis temperatures, resulting in color-tunable RTP. Significantly, the luminescent center engineering and in-situ immobilization strategy not only provided a facile method for conveniently preparing color-controllable RTP materials, but also endowed the materials prepared at relatively lower temperatures with color-changeable RTP features under thermal stimulus. Considering their unique properties, the potential applications of the as-obtained materials for advanced anti-counterfeiting and information encryption were preliminarily demonstrated.

Detection of scene-irrelevant head movements via eye-head coordination information

Background Accurate motion tracking in head-mounted displays(HMDs)has been widely used in immersive VR interaction technologies.However,tracking the head motion of users at all times is not always desirable.During a session of HMD usage,users may make scene-irrelevant head rotations,such as adjusting the head position to avoid neck pain or responding to distractions from the physical world.To the best of our knowledge,this is the first study that addresses the problem of scene-irrelevant head movements.Methods We trained a classifier to detect scene-irrelevant motions using temporal eye head-coordinated information sequences.To investigate the usefulness of the detection results,we propose a technique to suspend motion tracking in HMDs where scene-irrelevant motions are detected.Results/Conclusions Experimental results demonstrate that the scene-relevancy of movements can be detected using eye-head coordination information,and that ignoring scene-irrelevant head motions in HMDs improves user continuity without increasing sickness or breaking immersion.

Built-in electric field induced S-scheme g-C_(3)N_(4)homojunction for efficient photocatalytic hydrogen evolution:Interfacial engineering and morphology control

S-scheme possesses superior redox capabilities compared with the II-scheme,providing an effective method to solve the innate defects of g-C_(3)N_(4)(CN).In this study,S-doped g-C_(3)N_(4)/g-C_(3)N_(4)(SCN-tm/CN)S-scheme homojunction was constructed by rationally integrating morphology control with interfacial engineering to enhance the photocatalytic hydrogen evolution performance.In-situ Kelvin probe force microscopy(KPFM)confirms the transport of photo-generated electrons from CN to SCN.Density functional theory(DFT)calculations reveal that the generation of a built-in electric field between SCN and CN enables the carrier separation to be more efficient and effective.Femtosecond transient absorption spectrum(fs-TAS)indicates prolonged lifetimes of SCN-tm/CN_(3)(τ1:9.7,τ2:110,andτ3:1343.5 ps)in comparison to those of CN(τ1:4.86,τ2:55.2,andτ3:927 ps),signifying that the construction of homojunction promotes the separation and transport of electron hole pairs,thus favoring the photocatalytic process.Under visible light irradiation,the optimized SCN-tm/CN_(3)exhibits excellent photocatalytic activity with the hydrogen evolution rate of 5407.3μmol·g^(−1)·h^(−1),which is 20.4 times higher than that of CN(265.7μmol·g^(−1)·h^(−1)).Moreover,the homojunction also displays an apparent quantum efficiency of 26.8%at 435 nm as well as ultra-long and ultra-stable cycle ability.This work offers a new strategy to construct highly efficient photocatalysts based on the metal-free conjugated polymeric CN for realizing solar energy conversion.

Tumor-specific and photothermal-augmented chemodynamic therapy by ferrocene-carbon dot-crosslinked nanoparticles

Extensive research have been devoted to the exploration of multifunctional theranostic agents for cancer,but the poor tumor specificity and unsatisfactory treatment efficacy are some of the critical obstacles for their clinical translations.Herein,ferrocene-carbon dot-crosslinked nanoparticles(Fc-CD NPs)were designed and fabricated for achieving highly specific and photothermal-augmented chemodynamic therapy(CDT).The Fc-CD NPs were found not only to inherit the immanent fluorescence,photoacoustic,and photothermal properties of carbon dots(CDs),but also be endowed with CDT that could occur selectively in tumor microenvironment(TME)due to the presence of Fc for triggering Fenton reaction.Moreover,the enlarged particle size of Fc-CD NPs facilitated their effective accumulation at tumor sites,thus realizing great improvement for antitumor treatment outcomes.Once docking at tumor and being exposed to 660 nm laser irradiation,significantly amplified CDT effect of Fc-CD NPs was observed due to heataccelerating generation of reactive oxygen species(ROS).More interestingly,since the produced ROS could in turn alleviate the thermal-resistance of photothermal therapy(PTT),the therapeutic efficiency of integrated PTT and CDT was synergized to the maximum extent.This study on the one hand provides a facile approach to fabricate CDs-based multifunctional theranostic nanoplatform with enhanced tumor accumulation and specificity,on the other hand emphasizes the merits of synergizing mutually beneficial therapeutic modalities for more efficient cancer therapy.

Exosome-Coated Zeolitic Imidazolate Framework Nanoparticles for Intracellular Detection of ATP

The intracellular delivery of metal-organic frameworks(MOFs)encapsulated with functional biomolecules represents a promising av-enue in the field of biomedicine and biosensing.To improve the cellular uptake efficiency of MOFs,here we report the fabrication of cancer cell-derived exosome membra ne(EM)-coated zeolitic imidazolate framework-8(EM-ZIF-8)nan oparticles by using a microfluidic son ication device.

Hyaluronic acid-methacrylic anhydride/polyhexamethylene biguanide hybrid hydrogel with antibacterial and proangiogenic functions for diabetic wound repair

Diabetic wounds lead to a decrease in quality of life and an increase in mortality.Current treatment strategies include preventing bacterial adhesion while improving microcirculation.As a new type of wound dressing that imitates natural skin,hydrogel has gradually emerged with its excellent properties.However,existing hydrogels rarely achieve satisfactory results in promoting wound repair and antibacterial simultaneously.In this case,we prepared methacrylic anhydride chemically modified hyaluronic acid as a hydrogel matrix,added polyhexamethylene biguanide as an antibacterial component,and loaded sodium alginate/salidroside composite microspheres which could sustainably release salidroside and thus promote angiogenesis.Hybrid hydrogel(HAMA/PHMB-Ms)was synthesized via photocrosslinking,and its chemical structure,particle size distribution and microstructure were characterized.The satisfactory antibacterial properties of the HAMA/PHMB(15%)-Ms hydrogel were studied in vitro,and its antibacterial rates against E.coli and S.aureus were 97.85%and 98.56%,respectively.In addition,after demonstrating its good biocompatibility,we verified that the HAMA/PHMB-Ms hydrogel has increased granulation tissue formation,more collagen deposition,more subcutaneous capillary formation,and better wound healing than blank control,HAMA and HAMA/PHMB hydrogel on the back wound model of diabetic mice.The results confirmed that HAMA/PHMB-Ms hydrogel was a promising material for the treatment of the diabetic wounds.

L-Arginine based polyester amide/hyaluronic acid hybrid hydrogel with dual anti-inflammation and antioxidant functions for accelerated wound healing

Nowadays, there are still many challenges to skin regeneration. As a new type of skin substitute, hydrogel has emerging gradually with its excellent properties. However, it is still a challenge to combine with biological active agents to facilitate skin regeneration. Under the circumstance, we synthesized argininebased poly(ester amide)(Arg-PEA) and hyaluronic acid(HA-MA), and combined them into new hybrid hydrogels via photo-crosslinking. We found that the internal structure and physicochemical properties of hybrid hydrogels were greatly improved with the increase of content of Arg-PEA. Therefore, we designed hybrid hydrogels with 5 wt% and 10 wt% of Arg-PEA content, respectively. Besides, we selected the corresponding anti-inflammatory(CRP, TNF-α) indicators to detect the anti-inflammatory properties of the hybrid hydrogels at the protein level, and the corresponding antioxidant indicators(SOD, GSH/GSSG, MDA)were selected to investigate the antioxidant properties of hybrid hydrogels at the cellular level in vitro.In addition, we also selected relevant genes to test the effect of hybrid hydrogels on fibrosis and vascularization in the process of skin wound healing in vitro and verified them in vivo with a mouse dorsum wound model. The results confirmed that Arg-PEA/HA-MA(AH) hybrid hydrogel was a prospective scaffold material for skin regeneration.

Modularly designed peptide-based nanomedicine inhibits angiogenesis to enhance chemotherapy for post-surgical recurrence of esophageal squamous cell carcinomas

Traditional surgical treatment is difficult to thoroughly remove esophageal squamous cell carcinomas(ESCC),postoperative recurrence caused by residual tumor cells is a critical factor in the poor prognosis.Since surgical resection promotes the local angiogenesis at the tumor site,further exacerbating the proliferation and invasion of residual tumor cells,it is urgent to inhibit angiogenesis after surgery.Here,a functional peptide-based nanomedicine was obtained from peptide–drug conjugates,which are composed of a hydrophilic targeting motif(vascular endothelial growth factor family and their receptors(VEGFR)targeting peptide for anti-angiogenesis),an ester-linked hydrophobic oridonin(ORI).The nanomedicine exhibits esterase-catalyzed disassembly and drug release,significantly enhanced the anti-tumor efficacy of chemotherapeutics in a postoperative tumor recurrence model through synergistic anti-angiogenic strategies.This study provides an integrated solution for anti-angiogenesisaugmented chemotherapy and demonstrates the encouraging potential for postoperative treatment.

Curricular Robust Reinforcement Learning via GAN-Based Perturbation Through Continuously Scheduled Task Sequence

Reinforcement learning(RL),one of three branches of machine learning,aims for autonomous learning and is now greatly driving the artificial intelligence development,especially in autonomous distributed systems,such as cooperative Boston Dynamics robots.However,robust RL has been a challenging problem of reliable aspects due to the gap between laboratory simulation and real world.Existing efforts have been made to approach this problem,such as performing random environmental perturbations in the learning process.However,one cannot guarantee to train with a positive perturbation as bad ones might bring failures to RL.In this work,we treat robust RL as a multi-task RL problem,and propose a curricular robust RL approach.We first present a generative adversarial network(GAN)based task generation model to iteratively output new tasks at the appropriate level of difficulty for the current policy.Furthermore,with these progressive tasks,we can realize curricular learning and finally obtain a robust policy.Extensive experiments in multiple environments demonstrate that our method improves the training stability and is robust to differences in training/test conditions.