查看更多>>摘要：Energy dissipation is of fundamental interest and crucial importance in quantum systems.However,whether energy dissipation can emerge without backscattering inside topological systems remains a question.As a hallmark,we propose a microscopic picture that illustrates energy dissipation in the quan-tum Hall(QH)plateau regime of graphene.Despite the quantization of Hall,longitudinal,and two-probe resistances(dubbed as the quantum limit),we find that the energy dissipation emerges in the form of Joule heat.It is demonstrated that the non-equilibrium energy distribution of carriers plays much more essential roles than the resistance on energy dissipation.Eventually,we suggest probing the phenomenon by measuring local temperature increases in experiments and reconsidering the dissipation typically ignored in realistic topological circuits.
查看更多>>摘要：The paradigm shift of Hermitian systems into the non-Hermitian regime profoundly modifies inherent property of the topological systems,leading to various unprecedented effects such as the non-Hermitian skin effect(NHSE).In the past decade,the NHSE has been demonstrated in quantum,optical and acoustic systems.Beside those wave systems,the NHSE in diffusive systems has not yet been observed,despite recent abundant advances in the study of topological thermal diffusion.In this work,we design a thermal diffusion lattice based on a modified Su-Schrieffer-Heeger model and demonstrate the diffusive NHSE.In the proposed model,the asymmetric temperature field coupling inside each unit cell can be judiciously realized by appropriate configurations of structural parameters.We find that the temperature fields trend to concentrate toward the target boundary which is robust against initial excitation conditions.We thus experimentally demonstrated the NHSE in thermal diffusion and verified its robustness against various defects.Our work provides a platform for exploration of non-Hermitian physics in the diffusive systems,which has important applications in efficient heat collection,highly sen-sitive thermal sensing and others.
查看更多>>摘要：Simultaneously achieving room-temperature phosphorescence(RTP)and multiple-stimuli responsive-ness in a single-component system is of significance but remains challenging.Crystallization has been recognized to be a workable strategy to fulfill the above task.However,how the molecular packing mode affects the intersystem crossing and RTP lifetime concurrently remains unclear so far.Herein,four eco-nomic small-molecular compounds,analogues of the famous drug raloxifene(RALO),are facilely synthe-sized and further explored as neat single-component and stimuli-responsive RTP emitters via crystallization engineering.Thanks to their simple structures and high ease to crystallize,these raloxifene analogues function as models to clarify the important role of molecular packing in the RTP and stimuli-responsiveness properties.Thorough combination of the single-crystal structure analysis and theoretical calculations clearly manifests that the tight antiparallel molecular packing mode is the key point to their RTP behaviors.Interestingly,harnessing the controllable and reversible phase transitions of the two poly-morphs of RALO-OAc driven by mechanical force,solvent vapor,and heat,a single-component multilevel stimuli-responsive platform with tunable emission color is established and further exploited for optical information encryption.This work would shed light on the rational design of multi-stimuli responsive RTP systems based on single-component organics.
查看更多>>摘要：Adequate drug delivery across the blood-brain barrier(BBB)is a critical factor in treating central nervous system(CNS)disorders.Inspired by swimming fish and the microstructure of the nasal cavity,this study is the first to develop swimming short fibrous nasal drops that can directly target the nasal mucosa and swim in the nasal cavity,which can effectively deliver drugs to the brain.Briefly,swimming short fibrous nasal drops with charged controlled drug release were fabricated by electrospinning,homogenization,the π-π conjugation between indole group of fibers,the benzene ring of leucine-rich repeat kinase 2(LRRK2)inhibitor along with charge-dipole interaction between positively charged poly-lysine(PLL)and negatively charged surface of fibers;this enabled these fibers to stick to nasal mucosa,prolonged the residence time on mucosa,and prevented rapid mucociliary clearance.In vitro,swimming short fibrous nasal drops were biocompatible and inhibited microglial activation by releasing an LRRK2 inhibi-tor.In vivo,luciferase-labelled swimming short fibrous nasal drops delivered an LRRK2 inhibitor to the brain through the nasal mucosa,alleviating cognitive dysfunction caused by sepsis-associated encephalopathy by inhibiting microglial inflammation and improving synaptic plasticity.Thus,swim-ming short fibrous nasal drops is a promising strategy for the treatment of CNS diseases.
查看更多>>摘要：Metabolic reprogramming is a mechanism by which cancer cells alter their metabolic patterns to pro-mote cell proliferation and growth,thereby enabling their resistance to external stress.2-Deoxy-D-glucose(2DG)can eliminate their energy source by inhibiting glucose glycolysis,leading to cancer cell death through starvation.However,a compensatory increase in mitochondrial metabolism inhibits its efficacy.Herein,we propose a synergistic approach that combines photodynamic therapy(PDT)with starvation therapy to address this challenge.To monitor the nanodrugs and determine the optimal trig-gering time for precise tumor therapy,a multifunctional nano-platform comprising lanthanide-doped nanoparticle(LnNP)cores was constructed and combined with mesoporous silicon shells loaded with 2DG and photosensitizer chlorin e6(Ce6)in the mesopore channels.Under 980 nm near-infrared light excitation,the downshifted 1550 nm fluorescence signal in the second near-infrared(NIR-Ⅱ,1000-1700 nm)window from the LnNPs was used to monitor the accumulation of nanomaterials in tumors.Furthermore,upconverted 650 nm light excited the Ce6 to generate singlet oxygen for PDT,which dam-aged mitochondrial function and enhanced the efficacy of 2DG by inhibiting hexokinase 2 and lactate dehydrogenase A expressions.As a result,glucose metabolism reprogramming was inhibited and the effi-ciency of starvation therapy was significantly enhanced.Overall,the proposed NIR-Ⅱ bioimaging-guided PDT-augmented starvation therapy,which simultaneously inhibited glycolysis and mitochondria,facili-tated the effects of a cancer theranostic system.
NETL
NSTL
万方数据