Graphical Abstract Highlights d The degree of drug-tolerant cells being dormant can be measured by ''dormancy depth'' d Cellular dark foci, proved to be protein aggresomes, indicate dormancy depth d Depletion of intracellular ATP is the major force driving aggresomes formation d DnaK is vital in the disaggregation of aggresomes when a dormant cell resuscitates In this work, Pu et al. introduced a concept of ''dormancy depth'' that provides a unifying framework for understanding both persisters and viable but non-culturable cells. Subsequent mechanistic investigations revealed how ATP-dependent dynamic protein aggregation regulates cellular dormancy and resuscitation, the fine control of which facilitates bacterial drug tolerance. SUMMARYCell dormancy is a widespread mechanism used by bacteria to evade environmental threats, including antibiotics. Here we monitored bacterial antibiotic tolerance and regrowth at the single-cell level and found that each individual survival cell shows different ''dormancy depth,'' which in return regulates the lag time for cell resuscitation after removal of antibiotic. We further established that protein aggresome-a collection of endogenous protein aggregates-is an important indicator of bacterial dormancy depth, whose formation is promoted by decreased cellular ATP level. For cells to leave the dormant state and resuscitate, clearance of protein aggresome and recovery of proteostasis are required. We revealed that the ability to recruit functional DnaK-ClpB machineries, which facilitate protein disaggregation in an ATP-dependent manner, determines the lag time for bacterial regrowth. Better understanding of the key factors regulating bacterial regrowth after surviving antibiotic attack could lead to new therapeutic strategies for combating bacterial antibiotic tolerance.

Mesoporous silica nanoparticles (MSNs) with controlled size, morphology, and tunable porosity have been receiving much attention due to their applications in the fields of drug delivery, catalysis, adsorption, separation, and fuel cells. [1][2][3] Various MSNs with different functional groups and structures have been prepared and utilized for drug and gene delivery, [4,5] while mesoporous nanoparticles composed of carbon and nitrogen are of particular interest for basic catalysis and the capture of carbon dioxide. Carbon nitride (CN) is a well known and fascinating material that has attracted worldwide attention because the incorporation of nitrogen atoms in the carbon nanostructure can enhance the mechanical, conducting, field-emission, and energy-storage properties. [6][7][8][9][10][11][12][13][14] Mesoporous CN (MCN) materials with large surface areas, small particle sizes, and tunable pore diameters promise access to an even wider range of applications due to their interesting electrical and conducting properties. Recently, Vinu et al. reported the preparation of mesoporous carbon nitride with tunable pore size using mesoporous silica SBA-15 as template. [15][16][17] Unfortunately, the materials had a low nitrogen content due to their low thermal stability and exhibited a large particle size.Ultrafine mesoporous nanoparticles are expected to provide excellent textural parameters and high chemical, thermal, and mechanical stability, which may help to achieve high nitrogen content in the walls of the CN framework. Controlling the nitrogen content in the mesoporous carbon matrix is extremely important, as the nitrogen atoms in the wall structure of MCN can offer basic sites in the form of amine or imine groups which dictate the basic character and basic catalytic performance of the materials. However, to the best of our knowledge, there has been no report on the preparation of MCNs with high nitrogen content and their application in base-catalyzed reactions. Herein we report for the first time on the preparation of well-ordered mesoporous CN nanoparticles with a size smaller than 150 nm (MCN-3) and a high nitrogen content (C 4 N 2 ) by using mesoporous ultrasmall silica nanoparticles as template. The nitrogen content of MCN-3 is twice that of MCN-1 and MCN-2, which were prepared from SBA-15 and SBA-16, respectively. [15][16][17] We also demonstrate for the first time the basic catalytic properties of MCN-3, which is the first highly ordered, mesoporous, metal-free basic catalyst, in the transesterification of b-keto esters; MCN-3 shows superior performance in the transesterification of b-keto esters with excellent conversion and 100 % product selectivity.The templates for the fabrication of MCN-3 are ultrasmall mesoporous silica nanoparticles, which were prepared by a process mediated by fluorocarbon polymer and Pluronic P123 surfactant, reported by Ying et al., and denoted IBN-4. [18] IBN-4 has two-dimensional hexagonally ordered mesoporous structure with a channel-type pore system and rod-shaped morphology. Th...

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Two-dimensional (2D) molecular porous networks (MPNs) self-assembled on surfaces are of great interest due to their potential applications in nanoscience. [1][2][3] Conventionally, the assembled molecules are held together by non-covalent interactions, [4][5][6][7][8][9][10] among which the hydrogen bond (HB) is frequently adopted for structural controllability owing to its desirable bonding strength, selectivity, and directionality. [1] This strategy has been utilized in both uni- [6] and bimolecular [11][12][13][14][15] systems. Generally speaking, hydrogen bonds of similar bond strength are less versatile than hierarchical ones in tuning the assembled structures. In nature, hierarchical hydrogen-bond systems with disparate bonding capabilities and strengths are widely adopted by biosystems such as DNA and bioactive structures which consist of only limited building blocks. Researchers have utilized metal coordination [16,17] or hydrogen bonds [4,18] to form various porous networks on surfaces. Controls of the network pattern and the resulting pore size and shape can be achieved by tuning parameters [17,[19][20][21] such as ligand chain lengths or molecular backbones, [19] surface coverage [20] and substrate temperature.[22] These strategies have been demonstrated for a number of uni- [16,20] or bimolecular systems. [18,23] For example, by adjusting the metal-to-ligand ratio and the annealing temperature, mononuclear, 1D-polymeric and 2D-reticulated metal-organic coordination networks can be obtained by vapor deposition of 1,4-benzenedicarboxylic acid molecules and iron atoms on a Cu(100) surface, giving rise to an interesting series of square, rectangular and rhombic pores. [16] Another excellent example demonstrating controls of the network pattern and pore morphology is the 2D mono-and bicomponent self-assembly of three closely related diaminotriazine-based molecular building blocks and a complementary perylenetetracarboxylic diimide on Au(111) surface. The interplay, and the hierarchy, of hydrogen bonding, metalligand coordination, and dipolar interactions, resulted in various MPNs. In one case, mixtures of square, rhombic, and hexagonal nanopores were obtained.[24] A third example illustrating the construction of tunable 2D binary molecular nanostructures on an inert surface is the co-deposition of copper hexadecafluorophthalocyanine with p-sexiphenyl, pentacene, or diindenoperylene on graphite. By varying the binary molecular ratio and the molecular geometry, various molecular networks with tunable intermolecular distances were fabricated. [18,25] Yet other studies of porous networks via coadsorption of multi-component or multi-functional adsorbates or solvent incorporation on surfaces, producing a wide variety of interesting nanostructures, can also be found in the literature. [26][27][28][29][30][31] These results offer various routes for fabricating tunable molecular networks with tailorable nanopores potentially useful in engineering molecular sensors, molecular spintronic devices, and molecular nano h...

Herein, an effective top‐down etching route is presented to in situ fabricate CuO/CeO2 nanohybrids on the surface of Cu2O microcube templates. This method has well taken into account the factors both in thermodynamics and in kinetics, including surface structural nanocrystallization, construction of mesopores, formation of stable core@shell structures, and strengthened synergistic effects, in order to realize the structural design and hence greatly improve catalytic performance caused by surface nanocrystallization of Cu2O cubes. After etched by aid of ammonia and Ce3+ ions the final products are in a well‐defined spiny yolk@shell structures, in which the unetched part of Cu2O cubes serves as the core and the shell is composed by the CuO nanothorns encapsulated by CeO2 nanoparticles. Systematical characterizations including scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, H2‐temperature programmed reduction, N2 sorption, firmly disclose the relationship between the catalytic properties and the structures of samples. By simply tuning the usage amount of ammonia and Ce3+ ions, the samples show a typical volcano curve in the model reaction of catalytic CO oxidation. Sample CuO@CeO2‐0.05 exhibits the optimal catalytic activity and stability. It is believed that this top‐down strategy has shown promising future to design high‐performance catalysts for the practical need of application.

Mesoporous silica nanoparticles (MSNs) with controlled size, morphology, and tunable porosity have been receiving much attention due to their applications in the fields of drug delivery, catalysis, adsorption, separation, and fuel cells. [1][2][3] Various MSNs with different functional groups and structures have been prepared and utilized for drug and gene delivery, [4,5] while mesoporous nanoparticles composed of carbon and nitrogen are of particular interest for basic catalysis and the capture of carbon dioxide. Carbon nitride (CN) is a well known and fascinating material that has attracted worldwide attention because the incorporation of nitrogen atoms in the carbon nanostructure can enhance the mechanical, conducting, field-emission, and energy-storage properties. [6][7][8][9][10][11][12][13][14] Mesoporous CN (MCN) materials with large surface areas, small particle sizes, and tunable pore diameters promise access to an even wider range of applications due to their interesting electrical and conducting properties. Recently, Vinu et al. reported the preparation of mesoporous carbon nitride with tunable pore size using mesoporous silica SBA-15 as template. [15][16][17] Unfortunately, the materials had a low nitrogen content due to their low thermal stability and exhibited a large particle size.Ultrafine mesoporous nanoparticles are expected to provide excellent textural parameters and high chemical, thermal, and mechanical stability, which may help to achieve high nitrogen content in the walls of the CN framework. Controlling the nitrogen content in the mesoporous carbon matrix is extremely important, as the nitrogen atoms in the wall structure of MCN can offer basic sites in the form of amine or imine groups which dictate the basic character and basic catalytic performance of the materials. However, to the best of our knowledge, there has been no report on the preparation of MCNs with high nitrogen content and their application in base-catalyzed reactions. Herein we report for the first time on the preparation of well-ordered mesoporous CN nanoparticles with a size smaller than 150 nm (MCN-3) and a high nitrogen content (C 4 N 2 ) by using mesoporous ultrasmall silica nanoparticles as template. The nitrogen content of MCN-3 is twice that of MCN-1 and MCN-2, which were prepared from SBA-15 and SBA-16, respectively. [15][16][17] We also demonstrate for the first time the basic catalytic properties of MCN-3, which is the first highly ordered, mesoporous, metal-free basic catalyst, in the transesterification of b-keto esters; MCN-3 shows superior performance in the transesterification of b-keto esters with excellent conversion and 100 % product selectivity.The templates for the fabrication of MCN-3 are ultrasmall mesoporous silica nanoparticles, which were prepared by a process mediated by fluorocarbon polymer and Pluronic P123 surfactant, reported by Ying et al., and denoted IBN-4. [18] IBN-4 has two-dimensional hexagonally ordered mesoporous structure with a channel-type pore system and rod-shaped morphology. Th...

Bacteria use subcellular proteinaceous liquid droplets to survive stress.