• Title/Summary/Keyword: natural recombination

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Construction of a Novel Baculovirus Autographa californica Nuclear Polyhedrosis Virus Producing the Fluorescent Polyhedra

  • Je, Yeon-Ho;Jin, Byung-Rae;Roh, Jong-Yul;Chang, Jin-Hee;Kang, Seok-Kwon
    • International Journal of Industrial Entomology and Biomaterials
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    • v.1 no.1
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    • pp.19-23
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    • 2000
  • A novel recombinant baculovirus Autographa californica nuclear polyhedrosis virus (ACNPV) producing the green fluorescent polyhedra was constructed and characterized. The recombinant virus was stably produced fluorescent polyhedra in the infected cells and the morphology of the polyhedra was nearly similar to that of wild-type AcNPV. For the production of the fluorescent polyhedral the green fluorescent protein (GFP) gene was introduced under the control of polyhedrin gene promoter of AcNPV by translational fusion in the front and back of intact polyhedrin gene. The recombinant baculovirus was named as CXEP, As expected, the 93 kDa fusion protein was expressed in the CXEP-infected cells. Interestingly, however, the cells infected with CXEP also showed a 33 kDa protein band as cells infected with wild-type AcNPV. The results of Southern blot analysis and plaque assay suggested that two types of baculoviruses expressing the GFP fusion protein or only native polyhedrin were formed through homologous recombination between two polyhedrin genes in the same orientation. Thus, this system can be applied for the production of recombinant polyhedra with foreign gene product of diverse interest.

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Application of CFD model for passive autocatalytic recombiners to formulate an empirical correlation for integral containment analysis

  • Vikram Shukla;Bhuvaneshwar Gera;Sunil Ganju;Salil Varma;N.K. Maheshwari;P.K. Guchhait;S. Sengupta
    • Nuclear Engineering and Technology
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    • v.54 no.11
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    • pp.4159-4169
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    • 2022
  • Hydrogen mitigation using Passive Autocatalytic Recombiners (PARs) has been widely accepted methodology inside reactor containment of accident struck Nuclear Power Plants. They reduce hydrogen concentration inside reactor containment by recombining it with oxygen from containment air on catalyst surfaces at ambient temperatures. Exothermic heat of reaction drives the product steam upwards, establishing natural convection around PAR, thus invoking homogenisation inside containment. CFD models resolving individual catalyst plate channels of PAR provide good insight about temperature and hydrogen recombination. But very thin catalyst plates compared to large dimensions of the enclosures involved result in intensive calculations. Hence, empirical correlations specific to PARs being modelled are often used in integral containment studies. In this work, an experimentally validated CFD model of PAR has been employed for developing an empirical correlation for Indian PAR. For this purpose, detailed parametric study involving different gas mixture variables at PAR inlet has been performed. For each case, respective values of gas mixture variables at recombiner outlet have been tabulated. The obtained data matrix has then been processed using regression analysis to obtain a set of correlations between inlet and outlet variables. The empirical correlation thus developed, can be easily plugged into commercially available CFD software.

Steady-State and Transient Response Analysis of DSSC Based on Electron Diffusion Coefficient and Chemical Capacitance

  • J. C. Gallegos;J. Manriquez;R. Rodriguez;S. Vargas;D. Rangel
    • Journal of Electrochemical Science and Technology
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    • v.15 no.2
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    • pp.276-290
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    • 2024
  • A study of the transition from transitory state to steady state in DSSCs based on natural dyes is presented; cochineal was used as dye and Li+, Na+, and K+ were the ions added to the electrolyte. The photocurrent profiles were obtained as a function of time. Several DSSCs were prepared with different cations and their role and the transitory-to-steady transition was determined. A novel hybrid charge carrier source model based on the Heaviside function H(t) and the Lambert-Beer law, was developed and applied to analysis of the transient response of the output photocurrent. Additionally, the maximum effective light absorption coefficient α and the electronic extraction rate κ for each ion were determined: ${\alpha}_{Li^+,Na^+,K^+}\,=\,(0.486,\,0.00085,\,0.1126)\,cm^{-1}$, and also the electronic extraction rate ${\kappa}^{Li^+,Na^+,K^+}_{ext.}\,=\,(1410,\,19.07,\,19.69)\,cm\,s^{-1}$. The impedance model using Fick's second law was developed for carrier recombination to characterize the photocurrent.

Characterization of Antihypertensive Angiotensin I-Converting Enzyme Inhibitor from Recombinant E. coli (재조합 대장균으로부터 항고혈압 Angiotensin I-Converting Enzyme 저해제의 특성연구)

  • Kim, Jae-Ho;Jeong, Seung-Chan;Lee, Dae-Hyong;Lee, Jong-Soo
    • The Journal of Natural Sciences
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    • v.16 no.1
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    • pp.1-13
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    • 2005
  • The angiotensin I-converting enzyme (ACE) inhibitor has anti-hypertensive effects and has long been used as prevention or remedy of hypertension. This study were carried out to produce and purify a new ACE inhibitor from recombinant E. coli and further elucidate its structure-function relationship. Recombinant pGEX-4T-3 containing ACE inhibitory peptide gene of Saccharomyces cerevisiae was transformed into E. coli BL21(DE3). Glutathione-S transferase (GST) fusion protein from E. Coli BL21(DE3) harboring the recombination pGEX-4T-3 was obtained and the ACE inhibitory peptide was purified with Sephadex G-25 column chromatography. The purified ACE inhibitory peptide was a novel decapeptide with sequence Tyr-Asp-Gly-Gly-Val-Phe -Arg-Val-Tyr-Thr which shows very low similarity to the other ACE inhibitory peptide sequence. The purified ACE inhibitor competitively inhibited ACE.

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Expression profiles of human endogenous retrovirus (HERV)-K and HERV-R Env proteins in various cancers

  • Ko, Eun-Ji;Song, Kyoung Seob;Ock, Mee Sun;Choi, Yung Hyun;Kim, Suhkmann;Kim, Heui-Soo;Cha, Hee-Jae
    • BMB Reports
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    • v.54 no.7
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    • pp.368-373
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    • 2021
  • The vertebrate genome contains an endogenous retrovirus that has been inherited from the past millions of years. Although approximately 8% of human chromosomal DNA consists of sequences derived from human endogenous retrovirus (HERV) fragments, most of the HERVs are currently inactive and noninfectious due to recombination, deletions, and mutations after insertion into the host genome. Several studies suggested that Human endogenous retroviruses (HERVs) factors are significantly related to certain cancers. However, only limited studies have been conducted to analyze the expression of HERV derived elements at protein levels in certain cancers. Herein, we analyzed the expression profiles of HERV-K envelope (Env) and HERV-R Env proteins in eleven different kinds of cancer tissues. Furthermore, the expression patterns of both protein and correlation with various clinical data in each tissue were analyzed. The expressions of both HERV-K Env and HERV-R Env protein were identified to be significantly high in most of the tumors compared with normal surrounding tissues. Correlations between HERV Env expressions and clinical investigations varied depending on the HERV types and cancers. Overall expression patterns of HERV-K Env and HERV-R Env proteins were different in every individual but a similar pattern of expressions was observed in the same individual. These results demonstrate the expression profiles of HERV-K and HERV-R Env proteins in various cancer tissues and provide a good reference for the association of endogenous retroviral Env proteins in the progression of various cancers. Furthermore, the results elucidate the relationship between HERV-Env expression and the clinical significance of certain cancers.

Genetic structure of apical membrane antigen-1 in Plasmodium falciparum isolates from Pakistan

  • Komal Zaib;Asifullah Khan;Muhammad Umair Khan;Ibrar Ullah;Tuan Cuong Vo;Jung-Mi Kang;Huong Giang Le;Byoung-Kuk Na;Sahib Gul Afridi
    • Parasites, Hosts and Diseases
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    • v.62 no.3
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    • pp.302-312
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    • 2024
  • Plasmodium falciparum apical membrane antigen-1 (PfAMA-1) is a major candidate for the blood-stage malaria vaccine. Genetic polymorphisms of global pfama-1suggest that the genetic diversity of the gene can disturb effective vaccine development targeting this antigen. This study was conducted to explore the genetic diversity and gene structure of pfama-1 among P. falciparum isolates collected in the Khyber Pakhtunkhwa (KP) province of Pakistan. A total of 19 full-length pfama-1 sequences were obtained from KP-Pakistan P. falciparum isolates, and genetic polymorphism and natural selection were investigated. KP-Pakistan pfama-1 exhibited genetic diversity, wherein 58 amino acid changes were identified, most of which were located in ectodomains, and domains I, II, and III. The amino acid changes commonly found in the ectodomain of global pfama-1 were also detected in KP-Pakistan pfama-1. Interestingly, 13 novel amino acid changes not reported in the global population were identified in KP-Pakistan pfama-1. KP-Pakistan pfama-1 shared similar levels of genetic diversity with global pfama-1. Evidence of natural selection and recombination events were also detected in KP-Pakistan pfama-1.

Interleukin-7 Receptor is Indispensable for Proliferation and Survival in Thymic ${\gamma}{\delta}$T Cell Development

  • Kim, Dong-Hyun;Yoon, Byung-Hak;Jung, Joo-Eun;Kim, Hoog-Sook;Ko, Seong-Hee;Choi, Eun-Young;Lee, Kwang-Ho;Kim, Kyung-Jae;Ye, Sang-Kyu;Chung, Myung-Hee
    • IMMUNE NETWORK
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    • v.5 no.1
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    • pp.23-29
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    • 2005
  • Background: Interleukin-7 receptor (IL-7R) ${\alpha}$-deficient mice have small numbers of B cells and ${\alpha}{\beta}$T cells in periphery, they totally lack ${\gamma}{\delta}$T cells. In addition, the V-J recombination and transcription of TCR ${\gamma}$ genes is also severely impaired in IL-7R ${\alpha}$-deficient mice. Stat5, a signaling molecule of the IL-7R, induces germline transcription in the TCR ${\gamma}$ locus, and promotes V-J recombination and ${\gamma}{\delta}$T cell development. However, the roles for IL-7R signaling pathway in thymic or extrathymic ${\gamma}{\delta}$T cell development are largely unknown. Methods: To clarify the role of the IL-7 receptor in proliferation and survival of ${\gamma}{\delta}$T cells, we introduced the TCR ${\gamma}{\delta}$ transgene, $V_{{\gamma}2}/V{\delta}_5$, into IL-7R ${\alpha}$-deficient mice, and investigated the development of ${\gamma}{\delta}$T cells. Results: We found that $V_{{\gamma}2}/V{\delta}_5$ transgene restored ${\gamma}{\delta}$T cells in the epithelium of the small intestine (IEL) but not in the thymus and the spleen. Further addition of a bcl-2 transgene resulted in partial recovery of ${\gamma}{\delta}$T cells in the thymus and the spleen of these mice. Conclusion: Taken together, this study revealed that the IL-7R ${\alpha}$ is indispensable for proliferation and survival mainly in thymic ${\gamma}{\delta}$T cell development.

Species and Hybrid Identification of Genus Coreoleuciscus Species in Hwnag-ji Stream, Nakdong River Basin in Korea (낙동강 상류 황지천에 서식하는 쉬리속(genus Coreoleuciscus) 어류 집단의 종 동정 및 잡종 판별)

  • Song, Ha-Yoon;Kim, Jae-Hun;Seo, In-Young;Bang, In-Chul
    • Korean Journal of Ichthyology
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    • v.29 no.1
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    • pp.1-12
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    • 2017
  • A natural hybrid of interspecific between the Coreoleuciscus splendidus and C. aeruginos (Cypriniformes: Cyprinidae) was captured in the Hwang-ji Stream, a tributary of the Nakdong River basin in Korea. An interspecific hybrid between C. splendidus and C. aeruginos was genetically identified based on morphological characteristics and the sequence analysis of nuclear recombination activating gene 1 (RAG1) gene (1,334 bp) and mitochondrial cytochrome c oxidase subunit 1 (CO1) gene (1,551 bp). As a result of morphological variations, the natural hybrid appeared to have an intermediate character between two parental species (C. splendidus and C. aeruginos) in three variations of black array (s) on dorsal, caudal and anal fin rays. Phylogenetic analysis inferred from RAG1 and CO1 sequence data revealed that Coreoleuciscus populations from Hwang-ji stream consist of two pure Coreoleuciscus species and a hybrid individual group. The individuals were clearly identified the cross and reciprocal hybrid by CO1 gene analysis. In RAG1 gene, 13 nucleotide variation loci were detected and the hybrid individuals displayed the double peaks of sequence chromatograms at the 9 diagnostic positions. In this study, molecular data and morphological variations were clearly demonstrated that hybridization did occur between C. splendidus and C. aeruginos. However, F2 hybrid generation and reproductive capacity of F1 hybrid individuals were not demonstrated.

Characterization of an Improved Recombinant Baculovirus Producing Polyhedra that Contain Bacillus thuringiensis Cry1Ac Crystal Protein

  • Kim Jae-Su;Cho Jae-Young;Chang Jin-Hee;Shim Hee-Jin;Roh Jong-Yul;Jin Byung-Ae;Je Yeon-Ho
    • Journal of Microbiology and Biotechnology
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    • v.15 no.4
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    • pp.710-715
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    • 2005
  • A novel recombinant baculovirus, Bactrus, was constructed by the insertion of the Bacillus thuringiensis cry1Ac gene between two polyhedrin genes of Autographa californica nucleopolyhedrovirus (AcNPV) under the control of the polyhedrin gene promoter. Polyhedra produced by Bactrus in insect cells were incorporated with 130 kDa of polyhedrin-Cry1Ac-polyhedrin fusion protein, and 30 kDa of intact polyhedrin, resulting from a homologous recombination between two polyhedrin genes, was also expressed. The insecticidal activity of Bactrus against Spodoptera exigua larvae was similar to that of AcNPV, but it showed significantly higher toxicity towards Plutella xylostella larvae in comparison with that of AcNPV. The expression level of fusion protein and the insecticidal activity of recombinant polyhedra produced by the Bactrus against P. xylostella larvae were decreased after serial passages. In conclusion, the Bactrus had improved insecticidal activity and returned to wild-type AcNPV after several passages.

A Study on Design of Evolving Hardware using Field Programmable Gate Array (FPGA를 이용한 진화형 하드웨어 설계 및 구현에 관한 연구)

  • 반창봉;곽상영;이동욱;심귀보
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.5
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    • pp.426-432
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    • 2001
  • This paper is implementation of cellular automata neural network system using evolving hardware concept. This system is a living creatures'brain based on artificial life techniques. Cellular automata neural network system is based on the development and the evolution, in other words, it is modeled on the ontogeny and phylogney of natural living things. The phylogenetic mechanism are fundamentally non-deterministic, with the mutation and recombination rate providing a major source of diversity. Ontogeny is deterministic and local physics. Cellular automata is developed from initial cells, and evaluated in given environment. And genetic algorithms take a part in adaptation process. In this paper we implement this system using evolving hardware concept. Evolving hardware is reconfigurable hardware whose configuration si under the control of an evolutionary algorithm. We design genetic algorithm process for evolutionary algorithm and cells in cellular automata neural network for the construction of reconfigurable system. The effectiveness of the proposed system if verified by applying it to Exclusive-OR.

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