scholarly journals Integration of photocatalytic and dark-operating catalytic biomimetic transformations through DNA-based constitutional dynamic networks

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chen Wang ◽  
Michael P. O’Hagan ◽  
Ehud Neumann ◽  
Rachel Nechushtai ◽  
Itamar Willner

AbstractNucleic acid-based constitutional dynamic networks (CDNs) have recently emerged as versatile tools to control a variety of catalytic processes. A key challenge in the application of these systems is achieving intercommunication between different CDNs to mimic the complex interlinked networks found in cellular biology. In particular, the possibility to interface photochemical ‘energy-harvesting’ processes with dark-operating ‘metabolic’ processes, in a similar way to plants, represents an up to now unexplored yet enticing research direction. The present study introduces two CDNs that allow the intercommunication of photocatalytic and dark-operating catalytic functions mediated by environmental components that facilitate the dynamic coupling of the networks. The dynamic feedback-driven intercommunication of the networks is accomplished via information transfer between the two CDNs effected by hairpin fuel strands in the environment of the system, leading to the coupling of the photochemical and dark-operating modules.

2021 ◽  
Author(s):  
Itamar Willner ◽  
Chen Wang ◽  
Ehud Neumann ◽  
Rachel Nechushtai

Abstract Integration of a photosynthetic network with an assimilation, metabolic network is the fundamental prerequisite to construct an “artificial leaf”. Nucleic acid-based constitutional dynamic networks provide the building modules to construct integrated, intercommunicated networks mimicking photosynthesis. Two constitutional dynamic networks composed each of four constituents provide the photosynthetic and metabolic networks. In the photosynthetic network, photoinduced electron transfer from the Zn(II)-protoporphyrin photosensitizer to a bipyridinium electron acceptor is activated, followed by the biocatalytic reduction of NADP+ to NADPH, in analogy to photosystem I in native photosynthesis. In the metabolic network, the biocatalyzed-oxidation of lactate to pyruvate proceeds, followed by the metabolic transformation of pyruvate to L-alanine. The guided dynamic feedback-driven intercommunication of the networks is accomplished, leading to the function as an “artificial leaf”.


2019 ◽  
Vol 5 (5) ◽  
pp. eaav5564 ◽  
Author(s):  
Liang Yue ◽  
Shan Wang ◽  
Itamar Willner

The triggered substitution of networks and their resulting functions play an important mechanism in biological transformations, such as intracellular metabolic pathways and cell differentiation. We describe the triggered, cyclic, reversible intersubstitution of three nucleic acid–based constitutional dynamic networks (CDNs) and the programmed catalytic functions guided by the interconverting CDNs. The transitions between the CDNs are activated by nucleic acid strand displacement processes acting as triggers and counter triggers, leading to the adaptive substitution of the constituents and to emerging catalytic functions dictated by the compositions of the different networks. The quantitative evaluation of the compositions of the different CDNs is achieved by DNAzyme reporters and complementary electrophoresis experiments. By coupling a library of six hairpins to the interconverting CDNs, the CDN-guided, emerging, programmed activities of three different biocatalysts are demonstrated. The study has important future applications in the development of sensor systems, finite-state logic devices, and selective switchable catalytic assemblies.


2021 ◽  
Vol 12 (15) ◽  
pp. 5473-5483
Author(s):  
Zhixin Zhou ◽  
Jianbang Wang ◽  
R. D. Levine ◽  
Francoise Remacle ◽  
Itamar Willner

A nucleic acid-based constitutional dynamic network (CDN) provides a single functional computational module for diverse input-guided logic operations and computing circuits.


Author(s):  
Aditi Paul ◽  
Indu Pandey

Energy harvesting wireless sensor network (EH-WSN) harvests energy from the environment to supply power to the sensor nodes which apparently enhances their lifetime. However, the unpredictable nature of the resources throws challenges to the sustainability of energy supply for the continuous network operation. This creates a gap between unstable energy harvesting rates & energy requirements of the nodes of the network. The state-of-the-art algorithms proposed so far to address this problem domain are not able to bridge the gap fully to standardize the framework. Hence there is considerable scope of research to create a trade-off between EH techniques and specially designed protocols for in EH-WSN. Current study evaluates the performance and efficiency of some futuristic techniques which incorporate advanced tools and algorithms. The study aims to identify the strength and weaknesses of the proposed techniques which can emerge specific research requirement in this field. Finally, we propose a research direction towards Multi-source Hybrid EH-WSN (MHEHWSN) which is able to maximize energy availability and functional efficiency. The scope of this study is to develop a notion of a framework which eliminates the limitations of very recent techniques of EH-WSN by including multiple energy resources to extract required energy even in presence of unpredictability. However, keeping in mind the ease of use and less complex structure Multi-source hybrid EH technique requires a careful design paradigm.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ying Mao ◽  
Jing Jin ◽  
Shurui Li ◽  
Yangyang Miao ◽  
Andrzej Cichocki

Tactile perception, the primary sensing channel of the tactile brain-computer interface (BCI), is a complicated process. Skin friction plays a vital role in tactile perception. This study aimed to examine the effects of skin friction on tactile P300 BCI performance. Two kinds of oddball paradigms were designed, silk-stim paradigm (SSP) and linen-stim paradigm (LSP), in which silk and linen were wrapped on target vibration motors, respectively. In both paradigms, the disturbance vibrators were wrapped in cotton. The experimental results showed that LSP could induce stronger event-related potentials (ERPs) and achieved a higher classification accuracy and information transfer rate (ITR) compared with SSP. The findings indicate that high skin friction can achieve high performance in tactile BCI. This work provides a novel research direction and constitutes a viable basis for the future tactile P300 BCI, which may benefit patients with visual impairments.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Kang Liu ◽  
Qi Zhu ◽  
Ying Wang

Energy harvesting (EH) combined with cooperative relying plays a promising role in future wireless communication systems. We consider a wireless multiple EH relay system. All relays are assumed to be EH nodes with simultaneous wireless and information transfer (SWIPT) capabilities, which means the relays are wirelessly powered by harvesting energy from the received signal. Each EH node separates the input RF signal into two parts which are, respectively, for EH and information transmission using the power splitting (PS) protocol. In this paper, a closed-form outage probability expression is derived for the cooperative relaying system based on the characteristic function of the system’s probability density function (PDF) with only one relay. With the approximation of the outage probability expression, three optimization problems are built to minimize the outage probability under different constraints. We use the Lagrange method and Karush–Kuhn–Tucker (KKT) condition to solve the optimization problems to jointly optimize the relay’s PS factors and the transmit power. Numerical results show that our derived expression of the outage probability is accuracy and gives insights into the effect of various system parameters on the performance of protocols. Meanwhile, compared with the no optimal condition, our proposed optimization algorithms can all offer superior performance under different system constraints.


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