scholarly journals Terminal Deoxynucleotidyl Transferase Extension-Dominated In Situ Signal Attenuation-Free Electrochemical Platform and Its Logic Gate Manipulation

Author(s):  
Qi Wang ◽  
Tingting Hao ◽  
Kaiyue Hu ◽  
Lingxia Qin ◽  
Xinxin Ren ◽  
...  

Abstract Signal generation of traditional electrochemical biosensors suffers from the random diffusion of electroactive probes in a electrolyte solution, which is accompanied by poor reaction kinetics and low signal stability from complex biological systems. Herein, a novel circuit system with autonomous compensation solution ohmic drop (noted as “fast-scan cyclic voltammetry (FSCV)”) is developed to solve the above problems, and employed to achieve terminal deoxynucleotide transferase (TdT) and its small molecule inhibitor analysis. At first, a typical TdT-mediated catalytic polymerization in the conditions of original DNA, deoxythymine triphosphate (dTTP) and Hg2+ is applied for the electrode assembly. The novel electrochemical method can provide some unattenuated signals due to in-situ Hg redox reaction, thus improving reaction kinetics and signal stability. This approach is mainly dependent on TdT-mediated reaction, so it can be applied properly for TdT investigation, and a detection limit of 0.067 U/mL (S/N=3) is achieved successfully. More interesting, we also mimic the function of TdT-related signal communication in various logic gates such as YES, NOT, AND, N-IMPLY, and AND-AND-N-IMPLY cascade circuit. This study provides a new method for the detection of TdT biomarkers in many types of diseases and the construction of a signal attenuation-free logic gate.

2021 ◽  
Author(s):  
Bei Li ◽  
Dongsheng Zhao ◽  
Feng Wang ◽  
Xiaoxian Zhang ◽  
Wenqian Li ◽  
...  

This review covers the latest advancements of molecular logic gates based on LMOF. The classification, design strategies, related sensing mechanisms, future developments, and challenges of LMOFs-based logic gates are discussed.


2019 ◽  
Vol 28 (10) ◽  
pp. 1950171 ◽  
Author(s):  
Vinay Kumar ◽  
Ankit Singh ◽  
Shubham Upadhyay ◽  
Binod Kumar

Power dissipation has been the prime concern for CMOS circuits. Approximate computing is a potential solution for addressing this concern as it reduces power consumption resulting in improved performance in terms of power–delay product (PDP). Decrease of power consumption in approximate computing is achieved by approximating the demand of accuracy as per the error tolerance of the system. This paper presents a new approach for designing approximate adder by introducing inexactness in the existing logic gate(s). Approximated logic gates provide flexibility in designing low power error-resilient systems depending on the error tolerance of the applications such as image processing and data mining. The proposed approximate adder (PAA) has higher accuracy than existing approximate adders with normalized mean error distance of 0.123 and 0.1256 for 16-bit and 32-bit adder, respectively, and lower PDP of 1.924E[Formula: see text]18[Formula: see text]J for 16-bit adder and 5.808E[Formula: see text]18[Formula: see text]J for 32-bit adder. The PAA also performs better than some of the recent approximate adders reported in literature in terms of layout area and delay. Performance of PAA has also been evaluated with an image processing application.


2016 ◽  
Vol 16 (5&6) ◽  
pp. 465-482
Author(s):  
Taoufik Said ◽  
Abdelhaq Chouikh ◽  
Karima Essammouni ◽  
Mohamed Bennai

We propose an effective way for realizing a three quantum logic gates (NTCP gate, NTCP-NOT gate and NTQ-NOT gate) of one qubit simultaneously controlling N target qubits based on the qubit-qubit interaction. We use the superconducting qubits in a cavity QED driven by a strong microwave field. In our scheme, the operation time of these gates is independent of the number N of qubits involved in the gate operation. These gates are insensitive to the initial state of the cavity QED and can be used to produce an analogous CNOT gate simultaneously acting on N qubits. The quantum phase gate can be realized in a time (nanosecond-scale) much smaller than decoherence time and dephasing time (microsecond-scale) in cavity QED. Numerical simulation under the influence of the gate operations shows that the scheme could be achieved efficiently within current state-of-the-art technology.


2006 ◽  
Vol 1 ◽  
pp. 117727190600100 ◽  
Author(s):  
Dorien M. Schrijvers ◽  
Guido R.Y. De Meyer ◽  
Mark M. Kockx ◽  
Arnold G. Herman ◽  
Wim Martinet

Efficient phagocytosis of cells undergoing apoptosis by macrophages is important to prevent immunological responses and development of chronic inflammatory disorders such as systemic lupus erythematosus, cystic fibrosis and atherosclerosis. To study phagocytosis of apoptotic cells (AC) by macrophages in tissue, we validated different apoptosis markers (DNA fragmentation, caspase-3 activation and cleavage of its substrate poly(ADP-ribose)polymerase-1) in combination with macrophage immunostaining. Human tonsils were used as a model because they show a high apoptosis frequency under physiological conditions as well as efficient phagocytosis of AC by macrophages. On the other hand, advanced human atherosclerotic plaques were examined since plaques show severely impaired phagocytosis of AC. Our results demonstrate that the presence of non-phagocytized terminal deoxynucleotidyl transferase end labelling (TUNEL)-positive AC represents a suitable marker of poor phagocytosis by macrophages in situ. Other markers for apoptosis, such as cleavage of caspase-3 or PARP-1, should not be used to assess phagocytosis efficiency, because activation of the caspase cascade and cleavage of their substrates can occur in AC when they have not yet been phagocytized by macrophages.


2019 ◽  
Vol 43 (32) ◽  
pp. 12734-12743 ◽  
Author(s):  
Mahesh P. Bhat ◽  
Madhuprasad Kigga ◽  
Harshith Govindappa ◽  
Pravin Patil ◽  
Ho-Young Jung ◽  
...  

A reversible chemosensor for the development of a multi-input molecular logic gate was shown.


2019 ◽  
Vol 16 (158) ◽  
pp. 20190190
Author(s):  
Matthew Egbert ◽  
Jean-Sébastien Gagnon ◽  
Juan Pérez-Mercader

It has been shown that it is possible to transform a well-stirred chemical medium into a logic gate simply by varying the chemistry’s external conditions (feed rates, lighting conditions, etc.). We extend this work, showing that the same method can be generalized to spatially extended systems. We vary the external conditions of a well-known chemical medium (a cubic autocatalytic reaction–diffusion model), so that different regions of the simulated chemistry are operating under particular conditions at particular times. In so doing, we are able to transform the initially uniform chemistry, not just into a single logic gate, but into a functionally integrated network of diverse logic gates that operate as a basic computational circuit known as a full-adder.


Sign in / Sign up

Export Citation Format

Share Document