Instabilities and pattern formation during the self-organized growth of nanoparticles on graphite

SUMMARYIn each cell cycle, centrioles are duplicated to produce a single copy of each pre-existing centriole. At the onset of centriole duplication, the master regulator Polo-like kinase 4 (Plk4) undergoes a dynamic change in its spatial pattern on the periphery of the pre-existing centriole, forming a single duplication site. However, the significance and mechanisms of this pattern transition remain largely unknown. Using super-resolution imaging, we found that centriolar Plk4 exhibits periodic discrete patterns resembling pearl necklaces, frequently with single prominent foci. We constructed mathematical models that simulated the pattern formation of Plk4 to gain insight into the discrete ring patterns. The simulations incorporating the self-organization properties of Plk4 successfully generated the experimentally observed patterns. We therefore propose that the self-patterning of Plk4 is crucial for the regulation of centriole duplication. These results, defining the mechanisms of self-organized regulation, provide a fundamental principle for understanding centriole duplication.

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Tuning the Spatially Controlled Growth, Structural Self-Organizing and Cluster-Assembling of the Carbyne-Enriched Nanostructured Metamaterials during Ion-Assisted Pulse-Plasma Deposition

10.20944/preprints202103.0350.v1 ◽

2021 ◽

Author(s):

Alexander Lukin ◽

Oğuz Gülseren

Keyword(s):

Pattern Formation ◽

Electric Field ◽

Spatial Structure ◽

Plasma Deposition ◽

The Self ◽

Self Organization ◽

Structure And Properties ◽

Self Organized ◽

Wave Patterns ◽

Self Organizing

Structural self-organizing and pattern formation are universal and key phenomena observed during growth and cluster-assembling of the carbyne-enriched nanostructured metamaterials at the ion-assisted pulse-plasma deposition. Fine tuning these universal phenomena opens access to designing the properties of the growing carbyne-enriched nano-matrix. The structure of bonds in the grown carbyne-enriched nano-matrices can be programmed by the processes of self-organization and auto-synchronization of nanostructures. We propose the innovative concept, connected with application of the universal Cymatics phenomena during the predictive growth of the carbyne-enriched nanostructured metamaterials. We also propose the self-organization approach for increase stability of the long linear carbon chains. The main idea of suggested concept is manipulating by the self-organized wave patterns excitation phenomenon and their distribution by the spatial structure and properties of the nanostructured metamaterial grows region through the new synergistic effect. Mentioned effect will be provided through the vibration-assisted self-organized wave patterns excitation along with simultaneous manipulating by their properties through the electric field. We propose to use acoustic activation of the plasma zone of nano-matrix growing. Interaction between the inhomogeneous electric field distribution generated on the vibrating layer and the plasma ions will serve as the additional energizing factor controlling the local pattern formation and self-organizing of the nano-structures. Suggested concept makes it possible to provide precise predictive designing the spatial structure and properties of the advanced carbyne-enriched nanostructured metamaterials.

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Problem behavior in autism spectrum disorders: A paradigmatic self-organized perspective of network structures

Behavioral and Brain Sciences ◽

10.1017/s0140525x18001188 ◽

2019 ◽

Vol 42 ◽

Author(s):

Lucio Tonello ◽

Luca Giacobbi ◽

Alberto Pettenon ◽

Alessandro Scuotto ◽

Massimo Cocchi ◽

...

Keyword(s):

Autism Spectrum Disorder ◽

Problem Behaviors ◽

Autism Spectrum ◽

The Self ◽

Network Structures ◽

Self Organized ◽

Critical Equilibrium ◽

Self Organized Criticality ◽

Acute Agitation ◽

Spectrum Disorders

AbstractAutism spectrum disorder (ASD) subjects can present temporary behaviors of acute agitation and aggressiveness, named problem behaviors. They have been shown to be consistent with the self-organized criticality (SOC), a model wherein occasionally occurring “catastrophic events” are necessary in order to maintain a self-organized “critical equilibrium.” The SOC can represent the psychopathology network structures and additionally suggests that they can be considered as self-organized systems.

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Tripeptide Self-Assembly into Bioactive Hydrogels: Effects of Terminus Modification on Biocatalysis

Molecules ◽

10.3390/molecules26010173 ◽

2020 ◽

Vol 26 (1) ◽

pp. 173

Author(s):

Marina Kurbasic ◽

Ana M. Garcia ◽

Simone Viada ◽

Silvia Marchesan

Keyword(s):

Self Assembly ◽

The Self ◽

Chemical Modifications ◽

Ability To Work ◽

Active Compounds ◽

Future Design ◽

Self Organized ◽

The Future ◽

Bio Material ◽

Supramolecular Catalysts

Bioactive hydrogels based on the self-assembly of tripeptides have attracted great interest in recent years. In particular, the search is active for sequences that are able to mimic enzymes when they are self-organized in a nanostructured hydrogel, so as to provide a smart catalytic (bio)material whose activity can be switched on/off with assembly/disassembly. Within the diverse enzymes that have been targeted for mimicry, hydrolases find wide application in biomaterials, ranging from their use to convert prodrugs into active compounds to their ability to work in reverse and catalyze a plethora of reactions. We recently reported the minimalistic l-His–d-Phe–d-Phe for its ability to self-organize into thermoreversible and biocatalytic hydrogels for esterase mimicry. In this work, we analyze the effects of terminus modifications that mimic the inclusion of the tripeptide in a longer sequence. Therefore, three analogues, i.e., N-acetylated, C-amidated, or both, were synthesized, purified, characterized by several techniques, and probed for self-assembly, hydrogelation, and esterase-like biocatalysis. This work provides useful insights into how chemical modifications at the termini affect self-assembly into biocatalytic hydrogels, and these data may become useful for the future design of supramolecular catalysts for enhanced performance.

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Investigation of single-domain Au silicide nanowires on Si(110) formed for Au coverages in the monolayer regime

Scientific Reports ◽

10.1038/s41598-021-94106-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Stephan Appelfeller

Keyword(s):

Fermi Level ◽

Surface Structure ◽

Density Of States ◽

The Self ◽

Single Domain ◽

Photoemission Spectroscopy ◽

Annealing Temperatures ◽

Self Organized ◽

Scanning Tunnelling ◽

Tunnelling Microscopy

AbstractThe self-organized formation of single domain Au silicide nanowires is observed on Si(110). These nanowires are analysed using scanning tunnelling microscopy (STM) and spectroscopy (STS) as well as photoemission spectroscopy (PES). Core-level PES is utilised to confirm the formation of Au silicide and establish its presence as the top most surface structure, i.e., the nanowires. The growth of the Au silicide nanowires and their dimensions are studied by STM. They form for Au coverages of about 1 monolayer and are characterized by widths of about 2 to 3 nm and heights below 1 nm while reaching lengths exceeding 500 nm when choosing appropriate annealing temperatures. Valence band PES and STS indicate a small but finite density of states at the Fermi level typical for compound metals.

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Ion Beam Nanopatterning of Biomaterial Surfaces

Applied Sciences ◽

10.3390/app11146575 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6575

Author(s):

Yu Yang ◽

Adrian Keller

Keyword(s):

Material Properties ◽

Ion Beam ◽

The Self ◽

Solid Surfaces ◽

Beam Irradiation ◽

Ion Beam Irradiation ◽

Future Directions ◽

Self Organized ◽

Functional Surfaces ◽

Biomaterial Surfaces

Ion beam irradiation of solid surfaces may result in the self-organized formation of well-defined topographic nanopatterns. Depending on the irradiation conditions and the material properties, isotropic or anisotropic patterns of differently shaped features may be obtained. Most intriguingly, the periodicities of these patterns can be adjusted in the range between less than twenty and several hundred nanometers, which covers the dimensions of many cellular and extracellular features. However, even though ion beam nanopatterning has been studied for several decades and is nowadays widely employed in the fabrication of functional surfaces, it has found its way into the biomaterials field only recently. This review provides a brief overview of the basics of ion beam nanopatterning, emphasizes aspects of particular relevance for biomaterials applications, and summarizes a number of recent studies that investigated the effects of such nanopatterned surfaces on the adsorption of biomolecules and the response of adhering cells. Finally, promising future directions and potential translational challenges are identified.

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