China
Africa
Explore chapters and articles related to this topic
Application of RNA Aptamers in Nanotechnology and Therapeutics
Published in Peixuan Guo, Kirill A. Afonin, RNA Nanotechnology and Therapeutics, 2022
Most biological functions arise from molecular interactions rather than individual molecules. These interactions are often highly specific; that is, they are molecular recognition processes. In the course of natural evolution, biological functionality is expanded by the generation of new and specific molecular interactions (through gene duplication and differentiation), especially those between proteins and other macromolecules. Subversion or deception of native molecular recognition in a biological system through mimicry is the modus operandi of most, if not all, bioactive substances, including pharmaceuticals. In the past, most drugs were discovered serendipitously when they happened to be able to bind a receptor tightly and cause a desirable phenotypic change in a cell or organism. The advent of RNA aptamers made it possible to create ligands for intended targets in a more efficient way (Ellington and Szostak 1990; Tuerk and Gold 1990) through a “molecular breeding” process. Like small organic molecules, aptmers are able to rapidly and tightly bind specific protein domains or a specific site on a domain in living cells or organisms. Like antibodies, they can be made to order specifically for a predetermined target.
Kurstakin molecules facilitate diesel oil assimilation by Acinetobacter haemolyticus strain 2SA through overexpression of alkane hydroxylase genes
Published in Environmental Technology, 2021
Mamadou Malick Diallo, Caner Vural, Umut Şahar, Guven Ozdemir
Thus, the existence of different alkane hydroxylase genes in the gDNA (alkB, almA and cyp153) allowed 2SA more effect and versatile nutrition. Various microbial strains produce multiple alkane hydroxylase enzymes that can degrade wide range of alkanes (C4–C40). Among them, alkB and cyp153 genes are the most harboured in genomic and plasmid DNA of microorganisms [64–66]. AlkB and CYP153 enzymes are involved in the degradation of short- and medium-chain length alkanes [67]. The oxidation of long-chain-length alkanes depends on both the Flavin-binding monooxygenase (AlmA) and LadA enzymes [11,68,69]. Thus, the presence of different alkane hydroxylase genes in the same gDNA of some hydrocarbon-degrading microorganisms have been described in previous studies [70,71]. Different variants of alkB gene were isolated from genomic and plasmid DNA [72,73]. A recent research also reported that horizontal gene transfer, gene duplication and gene fusion, which resulted in the rapid evolution phenomena, contributed to the diversity of both the alkB and cyp153 genes [74].
Research on reducing fuzzy test sample set based on heuristic genetic algorithm
Published in Systems Science & Control Engineering, 2021
Zhihua Wang, Manman Cheng, Yongjian Wang
In the actual genetic process, due to the fact that the chromosomes generated by the mutation operation are not suitable for the problem set, this article no longer repairs the mutant genes of new individuals, but discards the new individuals generated by the mutation directly (Since the original data are similar, the probability of new gene appearing is very small). After the genetic algorithm is executed, all the generated chromosomes will be retained, so the role of the heuristic algorithm includes the following two points: Eliminate the redundancy caused by gene duplication;Choose better quality chromosomes (more genes and richer gene combinations).
Minimising total tardiness for the identical parallel machine scheduling problem with splitting jobs and sequence-dependent setup times
Published in International Journal of Production Research, 2020
Jae-Gon Kim, Seokwoo Song, BongJoo Jeong
We apply the GA to the considered problem using the two solution representation schemes presented in Sections 4.1 and 4.2. A solution (chromosome) of the GA is represented by one string or two strings using either the one-string encoding scheme or two-string encoding scheme, respectively. For a one-string GA solution, a job sequence represents a chromosome and it is modified by two operators, crossover and mutation, with probabilities of and , respectively, to generate candidate solutions for the next generation. In crossover, two chromosomes are selected probabilistically from the current population and their genomes are recombined by exchanging a certain randomly selected part of the two solutions with each other. If gene duplication occurs in another part of the chromosome after the exchange, duplicated genes are randomly replaced with missing genes to avoid duplication. Figure 8 depicts an example of crossover operation. In the example, genes 3, 7, and 4 of parent 1 are exchanged with genes 5, 3 and 1 of parent 2 to generate child 1, and then genes 1 and 5 are replaced with genes 7 and 4, respectively, to avoid duplication in child 1. In the case of mutation, a chromosome is selected and the two-way exchange given in Section 4.3 is applied to it.