OR Logic Gates Research Articles

Cyclic Enzymatic Signal Amplification-Driven DNA Logic Nanodevices on Framework Nucleic Acid for Highly Sensitive Electrochemiluminescence Detection of Dual Myocardial miRNAs.

MicroRNAs (miRNAs) have emerged as promising biomarkers for acute myocardial infarction (AMI). There is an urgent imperative to develop analytical methodologies capable of intelligently discerning multiple circulating miRNAs. Here, we present a dual miRNA detection platform for AMI using DNA logic gates coupled with an electrochemiluminescence (ECL) response. The platform integrates DNA truncated square pyramids as capture probes on gold-deposited electrodes, enabling precise quantification of miRNA associated with AMI. The cyclic enzymatic signal amplification principle of strand displacement amplification enhances the miRNA detection sensitivity. AND and OR logic gates have been successfully constructed, enabling intelligent identification of miRNAs in AMI. Calibration curves show strong linear correlations between ECL intensity and target miRNA concentration (10 fM to 10 nM), with excellent stability in consecutive measurements. When applied to clinical serum samples, the biosensor exhibits consistent performance, underscoring its reliability for clinical diagnostics. This innovative approach not only demonstrates DNA nanotechnology's potential in biosensing but also offers a promising solution for improving AMI diagnosis and prognosis through precise miRNA biomarker detection.

Realization of logic gates in bi-directionally coupled nonlinear oscillators.

Implementation of logic gates has been investigated in nonlinear dynamical systems from various perspectives over the years. Specifically, logic gates have been implemented in both single nonlinear systems and coupled nonlinear oscillators. The majority of the works in the literature have been done on the evolution of single oscillators into OR/AND or NOR/NAND logic gates. In the present study, we demonstrate the design of logic gates in bi-directionally coupled double-well Duffing oscillators by applying two logic inputs to the drive system alone along with a fixed bias. The nonlinear system, comprising both bi-directional components, exhibits varied logic behaviors within an optimal range of coupling strength. Both attractive and repulsive couplings yield similar and complementary logic behaviors in the first and second oscillators. These couplings play a major role in exhibiting fundamental and universal logic gates in simple nonlinear systems. Under a positive bias, both the first and second oscillators demonstrate OR logic gate for the attractive coupling, while exhibiting OR and NOR logic gates, respectively, for the repulsive coupling. Conversely, under a negative bias, both the first and second oscillators display AND logic gate for the attractive coupling, and AND and NAND logical outputs for the repulsive coupling. Furthermore, we confirm the robustness of the bi-directional oscillators against moderate noise in maintaining the desired logical outputs.

A Tunable Threshold Colorimetric DNA Logic Gate for Intuitive Assessment of Chemical Contaminant Exceedance.

Current molecular logic gates are predominantly focused on the qualitative assessment of target presence, which has certain limitations in scenarios requiring quantitative assessment, such as chemical contaminant monitoring. To bridge this gap, we have developed a novel DNA logic gate featuring a tunable threshold, specifically tailored to the limits of contaminants. At the core of this logic gate is a DNA-gold nanoparticle (AuNP) hybrid film that incorporates aptamer sequences to selectively bind to acetamiprid (ACE) and atrazine (ATR). Upon interaction with these contaminants, the film degrades, releasing AuNPs that, in the presence of Hg2+, catalyze the oxidation of TMB, resulting in a visible blue coloration on test paper. This aptamer-enabled process effectively establishes an OR logic gate, with ACE and ATR as inputs and the appearance of blue color as the output. A key innovation of our system is its tunable input threshold. By adjusting the concentration of Hg2+, we can fine-tune the color mutation points to match the input threshold to predefined limits, such as Maximum Residue Limits (MRLs). This alignment allows semiquantitative assessment of contaminant levels, providing intuitive visual feedback of contaminant exceedance. Validation experiments with spiked samples confirm its accuracy and reliability by closely matching HPLC results. Therefore, our colorimetric DNA logic gate is emerging as a promising tool for easy and semiquantitative monitoring of chemical contaminants across diverse applications.

Photonic crystal-enhanced fluorescence biosensor with logic gate operation based on one-pot cascade amplification DNA circuit for enzyme-free and ultrasensitive analysis of two microRNAs

The development of sensitive and efficient analytical methods for multiple biomarkers is crucial for cancer screening at early stage. MicroRNAs (miRNAs) are a kind of biomarkers with diagnostic potential for cancer. However, the ultrasensitive and logical analysis of multiple miRNAs with simple operation still faces some challenges. Herein, a photonic crystal (PC)-enhanced fluorescence biosensor with logic gate operation based on one-pot cascade amplification DNA circuit was developed for enzyme-free and ultrasensitive analysis of two cancer-related miRNAs. The fluorescence biosensor was performed by biochemical recognition amplification module (BCRAM) and physical enhancement module (PEM) to achieve logical and sensitive detection. In the BCRAM, one-pot cascade amplification circuit consisted of the upstream parallel entropy-driven circuit (EDC) and the downstream shared catalytic hairpin assembly (CHA). The input of target miRNA would trigger each corresponding EDC, and the parallel EDCs released the same R strand for triggering subsequent CHA; thus, the OR logic gate was obtained with minimization of design and operation. In the PEM, photonic crystal (PC) array was prepared easily for specifically enhancing the fluorescence output from BCRAM by the optical modulation capabilities; meanwhile, the high-throughput signal readout was achieved by microplate analyzer. Benefiting from the integrated advantages of two modules, the proposed biosensor achieved ultrasensitive detection of two miRNAs with easy logic gate operation, obtaining the LODs of 8.6 fM and 6.7 fM under isothermal and enzyme-free conditions. Hence, the biosensor has the advantages of high sensitivity, easy operation, multiplex and high-throughput analysis, showing great potential for cancer screening at early stage.

A Hardware-Based Orientation Detection System Using Dendritic Computation

Studying how objects are positioned is vital for improving technologies like robots, cameras, and virtual reality. In our earlier papers, we introduced a bio-inspired artificial visual system for orientation detection, demonstrating its superiority over traditional systems with higher recognition rates, greater biological resemblance, and increased resistance to noise. In this paper, we propose a hardware-based orientation detection system (ODS). The ODS is implemented by a multiple dendritic neuron model (DNM), and a neuronal pruning scheme for the DNM is proposed. After performing the neuronal pruning, only the synapses in the direct and inverse connections states are retained. The former can be realized by a comparator, and the latter can be replaced by a combination of a comparator and a logic NOT gate. For the dendritic function, the connection of synapses on dendrites can be realized with logic AND gates. Then, the output of the neuron is equivalent to a logic OR gate. Compared with other machine learning methods, this logic circuit circumvents floating-point arithmetic and therefore requires very little computing resources to perform complex classification. Furthermore, the ODS can be designed based on experience, so no learning process is required. The superiority of ODS is verified by experiments on binary, grayscale, and color image datasets. The ability to process data rapidly owing to advantages such as parallel computation and simple hardware implementation allows the ODS to be desirable in the era of big data. It is worth mentioning that the experimental results are corroborated with anatomical, physiological, and neuroscientific studies, which may provide us with a new insight for understanding the complex functions in the human brain.

Imparting As(III) Responsiveness to the Choline Response Transcriptional Regulator BetI.

The development of a low-cost and user-friendly sensor using microorganisms to monitor the presence of As(III) on earth has garnered significant attention. In conventional research on microbial As(III) sensors, the focus has been on transcription factor ArsR, which plays a role in As(III) metabolism. However, we recently discovered that LuxR, a quorum-sensing control factor in Vibrio fischeri that contains multiple cysteine residues, acted as an As(III) sensor despite having no role in As(III) metabolism. This finding suggested that any protein could be an As(III) sensor if cysteine residues were incorporated. In this study, we aimed to confer As(III) responsiveness to BetI, a transcriptional repressor of the TetR family involved in osmotic regulation of the choline response, unrelated to As(III) metabolism. Based on the BetI structure constructed using molecular dynamics calculations, we generated a series of mutants in which each of the three amino acids not critical for function was substituted with cysteine. Subsequent examination of their response to As(III) revealed that the cysteine-substituted mutant, incorporating all three substitutions, demonstrated As(III) responsiveness. This was evidenced by the fluorescence intensity of the downstream reporter superfolder green fluorescent protein expression regulated by the operator region. Intriguingly, the BetI cysteine mutant maintained its binding responsiveness to the natural ligand choline. We successfully engineered an OR logic gate capable of responding to two orthogonal ligands using a single protein.

Dual-Band All-Optical Logic Gates by Coherent Absorption in an Amorphous Silicon Graphene Metasurface.

The dual-band polarization-independent all-optical logic gate by coherent absorption effect in an amorphous silicon (a-Si) graphene metasurface is investigated theoretically and numerically. Taking the substrate effect into consideration, the coherent perfect absorption condition of the a-Si graphene metasurface is derived on the basis of the Cartesian multipole method. The coherent nearly perfect absorption of the a-Si graphene metasurface is realized by the interference of multipole moments and the interband transition of monolayer graphene, achieving peak values of 91% and 92% at 894.5 nm and 991.5 nm, respectively. The polarization independence of the coherent absorption is revealed due to the center symmetry of the structure of the a-Si graphene metasurface. The dual-band polarization-independent all-optical XOR and OR logic gates are implemented at 894.5 nm and 991.5 nm by the a-Si graphene metasurface based on the coherent nearly perfect absorption, which has the opportunity to be utilized in all-optical computing, all-optical data processing, and future all-optical networks.

All-optical simultaneous OR and NAND gates using photonic crystal ring resonator and Kerr effect

All-optical simultaneous OR and NAND gates design is proposed using a simple nonlinear photonic crystal ring resonator based on the chalcogenide glass (Ag20As32Se48) material which is one of the promising materials for all-optical devices. The structure consists of an octagonal ring resonator between two waveguides, which uses the switching threshold mechanism based on the Kerr effect to perform two simultaneous logic gates functions. The plane wave expansion (PWE) method is used to obtain the band diagram in the proposed structure, and the two-dimensional finite difference time domain (2D-FDTD) method is used in the simulation to evaluate the performance of the proposed design. The resonance wavelength is 1551.3 nm, with a high transmission and coupling efficiency of about 100%. The proposed optical OR and NAND logic gates have high contrast ratios of 21.15 dB and 28.19 dB, respectively, with a quality factor of 596.65. The operating power intensity of the proposed structure is 1 kW μm−2, and the threshold power intensity is obtained at 2.8 kW μm−2. The proposed gates provide transmitted power of not less than 0.5. The size of the structure is 20.5 μm × 18.17 μm. The proposed structure is compact, works on low operational power intensity, and has the ability for dense integration. The simplicity and small size of the structure make it easy to fabricate for future integration in all-optical circuits.

Quantum controlled teleportation with OR-logic-gate-like controllers in noisy environment

We evaluate a one-way, bidirectional, and cyclic quantum controlled teleportation with two controllers. We show that the controllers’ agreement mimics the OR logic gate, i.e., the teleportation succeeds with only one of the controllers’ cooperation, and it does not matter which one. This result is generalized to multi-way quantum controlled teleportation with N controllers. The proposed protocols are evaluated by considering a noisy environment in the form of phase-damping noise and amplitude-damping noise and the dependence of fidelity only on the decoherence rate and the initial state’s amplitude parameter were established. It is interesting to note that for the phase-damping noise case, there are states with perfect fidelity (and the entropy equal to zero) even in a noisy environment. We discuss the novelty of the proposed protocols and highlight that they can be useful if the information to be teleported needs an OR-logic-gate-like controllers’ agreement combination, which cannot be done with other existing protocols.

A split-type electrochemical biosensor using enzyme-linked DNA magnetic beads realizes the detection of BCR/ABLp210 fusion gene in clinical samples: Duplex ligation chain reaction coupled with OR logic gate design

Detection of BCR/ABLp210 transcript levels, allowing for the early diagnosis of chronic myelocytic leukemia (CML) and its minimal residual disease (MRD) monitoring, plays a decisive role in the cure of CML. Herein, to realize the sensitive detection of BCR/ABLp210 transcript by electrchemical DNA (E-DNA) sensors in clinical samples, a split-type strategy using enzyme-linked DNA magnetic beads (MBs) was intelligently provided. Specifically, the utilization of magnetic separation makes the target recognition event separate from electrochemical measurements, avoiding the interference of complex matrices on the sensing interface. Besides, the MBs adopted as dispersible electrodes could improve mass transfer of target compared to that of a planarelectrode. Consequently, the proposed E-DNA sensor combined with the ligation chain reaction (LCR) could achieve an exceptional performance with a low detection limit of 1 aM, a broad linear concentration range, and a remarkable specificity with a single-base resolution. Also, K562 cells in up to a 1000-fold excess of NB4 cells could be successfully detected by this E-DNA sensor. Finally, the integration of duplex LCR and OR logic gate into the E-DNA sensor has enabled the detection of e13a2/e14a2/both isoforms of BCR/ABLp210 transcript in a single assay in both newly diagnosed CML patients and those undergoing or having undergone treatment by tyrosine kinase inhibitors. Therefore, this method offers an alternative for the early diagnosis of CML and its MRD monitoring, and holds a huge potential of clinical translation due to its advantage of low cost, ease of miniaturization and generalizability.

Ultrafast nonlinear absorption in MoTe2 and MoTe2/MoS2 nanocomposite films and its application to all-optical logic gates

We present a detailed theoretical analysis of ultrafast saturable absorption (SA) and reverse SA (RSA) in MoTe2 nano-films with femtosecond (fs) laser pulses at 800 nm. A transition from RSA to SA occurs on increasing the thickness from 30 nm to 80 nm at a constant pump intensity of 141 GW cm−2. On the other hand, a transition from SA to RSA occurs upon increasing the pump intensity in an 80 nm thick MoTe2 nano-film. Theoretical results are in good agreement with reported experimental results. The effect of pump pulse intensity, pulse width, nonlinear absorption coefficient and sample thickness has been studied to optimize the SA ↔ RSA transition. The results for low-power and high contrast all-optical switching in MoTe2 nano-films have been used to design all-optical fs NOT, OR, AND, as well as the universal all-optical NOR and NAND logic gates. The SA behavior of MoTe2/MoS2 nanocomposite films has been used to design all-optical AND and OR logic gates. The nanocomposite films of MoTe2/MoS2 possess a larger nonlinear optical response in comparison to MoTe2 and MoS2 nano-films and, therefore, all-optical logic gates designed using nanocomposite films result in a good switching contrast compared to pure MoTe2 nano-films. Ultrafast operation at relatively low pump intensities demonstrates the applicability of MoTe2 and MoTe2/MoS2 nano-films for ultrafast all-optical information processing.

Lysine based dipeptides-molecular rectifiers with very high rectification ratio and their application towards designing logic gates

In this research paper, we have enquired the dipeptides (i.e., smallest peptides) consisting of oppositely charged amino acids namely, Lysine-Aspartic and Lysine-Glutamic, where l-Lysine is positively charged, and both L-Aspartic and L-Glutamic are negatively charged amino acids. The l-Glutamic acid has only one extra CH2 chain as compared with l-Aspartic acid. These two dipeptides are stringed to Au, Ag and Cu electrodes, to form molecular devices. Distinct parameters including conductance, Homo-Lumo gap, dipole moment, current-voltage characteristics are intrigued using NEGF-DFT technique. Au-Lysine-Aspartic-Au offers the negative differential resistance regime with the highest peak-to-valley current ratio of 28.79. Lysine-Aspartic with Cu electrodes and Lysine-Glutamic with Au electrodes offers the highest rectification ratio of 146.96 and 34.31 respectively, as compared with other electrodes. Lysine-Aspartic based dipeptides offer higher rectification ratio as compared with Lysine-Glutamic based dipeptides. Moreover, these two dipeptides offer opposite correlation between dipole moment, coupling strength and switching regimes. The reason behind rectification ratio and negative differential resistance is elaborated using transmission spectra, molecular projected self-Hamiltonian states and transmission pathway. The OR, AND and XOR logic gates are proposed using switching regimes of Au-Lysine-Aspartic-Au. We have also detected the thermal stability of one of the heterostructure using ab initio molecular dynamics simulation.

Ultra-broadband and ultra-compact chip-integrated logic gates based on an inverse design method

The Si-based chip-integrated OR, XOR, NOR, AND and NAND all-optical logic gates (AO-LGs) with footprints of 2 μm × 2 μm are inversely designed based on an intelligent method, which combines the method of moving asymptotes (MMA) with the finite element method (FEM). In this method, the substrate is divided into many small units, and the refractive index of each unit will be perturbed according to design expectation. Therefore, the optimized refractive index will be gradient, which divorces from fabrication. Binary reconstruction is the process of changing the gradient media into binary media, by filtering out the gradient virtual media, smoothing the boundaries, and refilling Si or air on the substrate to form a new structure. Numerical simulations demonstrate that all the AO-LGs designed by this method work effectively. The contrast ratio (CR) of OR/XOR gate ranges from 23.50 dB to 25.50 dB, NOR gate ranges from 6.33 dB to 7.91 dB, AND gate ranges from 4.44 dB to 6.13 dB, and NAND gate ranges from 8.85 dB to 10.07 dB. And these designed AO-LGs achieve nearly ten times more broad bandwidth than the other reported conventional gates without suffering other performances too much. The OR/XOR, and NOR gate functions well in a broad band range from 800 nm to 1600 nm, and from 850 nm to 1350 nm. AND gate functions well from 1000 nm to 1240 nm and from 1310 nm to 1400 nm. NAND gate functions well from 1360 nm to 1530 nm. It is expected that such a robust method can serve extensive applications in designing photonic devices, and the compact logic gates may contribute to broad applications of future optical computing and signal processing.

Three-input logic gate based on DNA strand displacement reaction

In this paper, three kinds of three-input logic gates are designed based on DNA strand displacement reaction, which are three-input OR logic gate, three-input AND logic gate, and three-input MAJORITY logic gate. The logic gates designed in this paper takes different DNA strands as input and fluorescence signals as output. The biochemical experimental results verify my designs. The results show that DNA strand displacement technology has important application value in DNA computing, especially in the construction of DNA molecular logic gates.

Efficient design of all-optical AND and OR logic gates using fluid infiltration in silicon-based photonic crystal platform

Efficient design of all-optical AND and OR logic gates using fluid infiltration in silicon-based photonic crystal platform

Nonconformal Electrochemical Memristor through Vapor Phase Polymerization of Pyrrole

A nonvolatile organic synaptic memristor was fabricated utilizing a vapor phase polymerization technique for synthesizing polypyrrole. This synaptic memristor employed a bottom synaptic electrode in order to “read” the device’s conductance, termed the synaptic weight of this neuromorphic-capable device. Through a programming pulse of +1 V amplitude and a 1 s duration to the “writing” electrode, or top synaptic electrode, a resolution of 0.245 μS occurs per change for each programmed state. This organic synaptic memristor consumes a minimum programming power of 4.16 fJ mm–2 and can be further decreased via advanced patterning and layer deposition techniques. Operational applications are demonstrated for this organic synaptic memristor, including Boolean algebra (AND, NAND, OR, and NOR logic gates), as well as abacus calculations (addition, subtraction, and division).

Nanoscale plasmonic logic gates design by using an elliptical resonator.

This study implemented AND, NAND, OR, XOR, NOR, XNOR, and NOT plasmonic logic gates using the finite element method. The all-optical nanoscale logic gates were designed using a single structure based on the technology of insulator-metal-insulator nanoscale plasmonic waveguides. The phase of optical waves and the position of the control and input ports are the most important factors for attaining the optimal transmission value based on interference between the input and control ports. The transmission threshold is 35%, and 850 nm is the operating wavelength. This design creates nanoscale logic gates with a structure dimension of 250nm×250nm. The transmission threshold, modulation depth, contrast ratio, and insertion loss criteria were proposed to evaluate the efficacy of the all-optical gates.

Flexible and Efficient Multi-Keyword Ranked Searchable Attribute-Based Encryption Schemes

Currently, cloud computing has become increasingly popular and thus, many people and institutions choose to put their data into the cloud instead of local environments. Given the massive amount of data and the fidelity of cloud servers, adequate security protection and efficient retrieval mechanisms for stored data have become critical problems. Attribute-based encryption brings the ability of fine-grained access control and can achieve a direct encrypted data search while being combined with searchable encryption algorithms. However, most existing schemes only support single-keyword or provide no ranking searching results, which could be inflexible and inefficient in satisfying the real world’s actual needs. We propose a flexible multi-keyword ranked searchable attribute-based scheme using search trees to overcome the above-mentioned problems, allowing users to combine their fuzzy searching keywords with AND–OR logic gates. Moreover, our enhanced scheme not only improves its privacy protection but also goes a step further to apply a semantic search to boost the flexibility and the searching experience of users. With the proposed index-table method and the tree-based searching algorithm, we proved the efficiency and security of our schemes through a series of analyses and experiments.

Two enhancer binding proteins activate σ54-dependent transcription of a quorum regulatory RNA in a bacterial symbiont.

To colonize a host, bacteria depend on an ensemble of signaling systems to convert information about the various environments encountered within the host into specific cellular activities. How these signaling systems coordinate transitions between cellular states in vivo remains poorly understood. To address this knowledge gap, we investigated how the bacterial symbiont Vibrio fischeri initially colonizes the light organ of the Hawaiian bobtail squid Euprymna scolopes. Previous work has shown that the small RNA Qrr1, which is a regulatory component of the quorum-sensing system in V. fischeri, promotes host colonization. Here, we report that transcriptional activation of Qrr1 is inhibited by the sensor kinase BinK, which suppresses cellular aggregation by V. fischeri prior to light organ entry. We show that Qrr1 expression depends on the alternative sigma factor σ54 and the transcription factors LuxO and SypG, which function similar to an OR logic gate, thereby ensuring Qrr1 is expressed during colonization. Finally, we provide evidence that this regulatory mechanism is widespread throughout the Vibrionaceae family. Together, our work reveals how coordination between the signaling pathways underlying aggregation and quorum-sensing promotes host colonization, which provides insight into how integration among signaling systems facilitates complex processes in bacteria.

A Biocompatible Supercapacitor Diode with Enhanced Rectification Capability towards Ion/Electron Coupling Logic Operations.

The main challenge faced by the forthcoming human-computer interaction is that biological system and electronic device adopt two different information carriers, i.e., ions and electrons, respectively. To bridge the gap between these two systems, developing ion/electron coupling devices for logic operation is a feasible and effective approach. Accordingly, we herein develop a supercapacitor-based ionic diode (CAPode) that takes electrochemically amorphized molybdenum oxide as the working electrode. Benefiting from its unique size and charge dual ion-sieving effects, the molybdenum oxide electrode exhibits a record-high rectification ratio of 136, which is over 10 times higher than those of reported systems. It also delivers an ultrahigh specific capacitance of 448 F g-1 and an excellent cycling stability of up to 20,000 cycles, greatly outperforming those of previous works. These excellent rectification capability and electrochemical performances allow the as-built CAPode to work well in AND and OR logic gates, validating great potential in ion/electron coupling logic operations. More attractively, the superior biocompatibilities of molybdenum oxide and relevant constituent materials enable the constructed CAPode to be applied as bioelectronics without regard to biosafety, paving a new way towards forthcoming human-computer interaction. This article is protected by copyright. All rights reserved.