利用探针跳跃式扫描离子电导显微镜技术揭示结直肠癌单细胞层面对H_(2)O_(2)良性应激的动态响应

Colorectal cancer(CRC),a widespread malignancy,is closely associated with tumor microenvironmental hydrogen peroxide(H_(2)O_(2))levels.Some clinical trials targeting H_(2)O_(2)for cancer treatment have revealed its paradoxical role as a promoter of cancer progression.Investigating the dynamics of cancer cell H_(2)O_(2)eustress at the single–cell level is crucial.In this study,non–contact hopping probe mode scanning ion conductance microscopy(HPICM)with high-sensitive Pt–functionalized nanoelectrodes was employed to measure dynamic extracellular to intracellular H_(2)O_(2)gradients in individual colorectal cancer Caco–2cells.We explored the relationship between cellular mechanical properties and H_(2)O_(2)gradients.Exposure to 0.1 or 1 mmol/L H_(2)O_(2)eustress increased the extracellular to intracellular H_(2)O_(2)gradient from 0.3 to 1.91 or 3.04,respectively.Notably,cellular F–actin–dependent stiffness increased at 0.1 mmol/L but decreased at 1 mmol/L H_(2)O_(2)eustress.This H_(2)O_(2)–induced stiffness modulated AKT activation positively and glutathione peroxidase 2(GPX2)expression negatively.Our findings unveil the failure of some H_(2)O_(2)-targeted therapies due to their ineffectiveness in generating H_(2)O_(2),which instead acts eustress to promote cancer cell survival.This research also reveals the complex interplay between physical properties and biochemical signaling in cancer cells'antioxidant defense,illuminating the exploitation of H_(2)O_(2)eustress for survival at the single–cell level.Inhibiting GPX and/or catalase(CAT)enhances the cytotoxic activity of H_(2)O_(2)eustress against CRC cells,which holds significant promise for developing innovative therapies targeting cancer and other H_(2)O_(2)-related inflammatory diseases.

Circularly polarized luminescence from a common alkoxy pillar[5]arene and its co-aggregates withπ-conjugated rods

Cylinder-shaped macrocycles composed ofπ-panels have attracted special attention as one of the best platforms for the development of organic molecule-based chi-roptical materials.Pillar[n]arenes are a class of macrocycles with the advantage of easy preparation but have not been extensively investigated from the perspective of luminescent molecules.However,common alkoxy pillar[n]arenes arefluorescent in non-haloalkane solvents,showing potential to be used for molecule-based chi-roptical materials.In this work,circularly polarized luminescence(CPL)spectra are reported for a pillar[5]arene with stable planar chirality using tetrahydrofu-ran(THF)and cyclohexane as solvents,which has been missing for many years.The pillar[5]arene also forms co-aggregates with 1,4-bis(phenylethynyl)benzene and 1,4-bis[(pentafluorophenyl)ethynyl]benzene in THF/H2O mixtures,owing to a hydrophobic effect.The co-aggregates with thefluorinatedπ-rod display a new low-energy absorption peak and broad emission band as well as intense circular dichroism and CPL signals.Chiral information from the enantiopure pillar[5]arene core is efficiently transmitted to the co-aggregates with theπ-conjugated rod,lead-ing to the highest dissymmetry factor for CPL(2.9×10-2 at 472 nm)among pillar[n]arene-based CPL materials.

Machine learning hydrogen adsorption on nanoclusters through structural descriptors

Catalytic activity of the hydrogen evolution reaction on nanoclusters depends on diverse adsorption site structures.Machine learning reduces the cost for modelling those sites with the aid of descriptors.We analysed the performance of state-of-the-art structural descriptors Smooth Overlap of Atomic Positions,Many-Body Tensor Representation and Atom-Centered Symmetry Functions while predicting the hydrogen adsorption(free)energy on the surface of nanoclusters.The 2D-material molybdenum disulphide and the alloy copper–gold functioned as test systems.Potential energy scans of hydrogen on the cluster surfaces were conducted to compare the accuracy of the descriptors in kernel ridge regression.By having recourse to data sets of 91 molybdenum disulphide clusters and 24 copper–gold clusters,we found that the mean absolute error could be reduced by machine learning on different clusters simultaneously rather than separately.The adsorption energy was explained by the local descriptor Smooth Overlap of Atomic Positions,combining it with the global descriptor Many-Body Tensor Representation did not improve the overall accuracy.We concluded that fitting of potential energy surfaces could be reduced significantly by merging data from different nanoclusters.

Materials structure genealogy and high-throughput topological classification of surfaces and 2D materials

Automated and verifiable structural classification for atomistic structures is becoming necessary to cope with the vast amount of information stored in various computational materials databases.Here we present a general recursive scheme for the structural classification of atomistic systems and introduce a structural materials map that can be used to organize the materials structure genealogy.We also introduce our implementation for the automatic classification of two-dimensional structures,especially focusing on surfaces and 2D materials.This classification procedure can automatically determine the dimensionality of a structure,further categorize the structure as a surface or a 2D material,return the underlying unit cell and also identify the outlier atoms,such as adsorbates.The classification scheme does not require explicit search patterns and works even in the presence of defects and dislocations.The classification is tested on a wide variety of atomistic structures and provides a high-accuracy determination for all of the returned structural properties.A software implementation of the classification algorithm is freely available with an opensource license.

One-, Two-, and Three-Dimensional Supramolecular Assemblies Based on Tubular and Regular Polygonal Structures of Pillar[n]arenes

Pillar[n]arenes,which were first reported by our groupin2008,arepromisingmacrocycliccompounds in supramolecular chemistry.The simple,tubular,and highly symmetrical shape of pillar[n]arenes has allowed various supramolecular assemblies with well-defined structures to be constructed.