• Title/Summary/Keyword: molecular assembly

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Surface Modification of High Energetic Materials by Molecular Self-assembly (자기조립법을 이용한 고에너지물질의 표면개질 연구)

  • Kim, Ja-Young;Jeong, WonBok;Shin, Chae-Ho;Kim, Jin-Seok;Lee, Keundeuk;Lee, Kibong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.2
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    • pp.18-23
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    • 2016
  • Self-assembly of organic molecules is formed spontaneously on surfaces by electrostatic interaction with substrate. This research has shown that the self-assembly improves safety and handling tractability of high-energetic materials (HEMs). According to the recent study, control of the specific crystal size for reducing the internal defects is mightily important, because the internal defects are a factor in unstability of HEMs. In turn, we performed self-assembly of organic molecules and HEMs by using nano-sized HEMs, which were produced by drowing-out or milling/crystallization. Surface modification efficiency was decided by size distribution, zeta-potential, friction sensitivity and electrostatic charge.

Status of Philippine Mango Genomics: Enriching Molecular Genomics Towards a Globally Competitive Philippine Mango Industry

  • Eureka Teresa M. Ocampo;Cris Q. Cortaga;Jhun Laurence S. Rasco;John Albert P. Lachica;Darlon V. Lantican
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.28-28
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    • 2022
  • This paper presents the first genome assemblies of Philippine mangoes that provide valuable reference for varietal improvement and genomic studies on mango and related fruit crops. WE sequenced whole genomes of3 species, Mangifera odorata (Huani), Mangifera altissima (Paho), and Mangifera indica 'Carabao' (Sweet Elena). 'Carabao' is the major export variety of the Philippines; Paho is identified as vulnerable by the IUCN Red List of Threatened Species; Huani has fruit sap acrid which is the primary defense mechanism against insects and birds. We used Falcon, a diploid aware -de novo assembler to assemble SMRT generated long-read sequences. Falcon-unzip was employed to phase the output assembly producing larger contig sets (primary contigs) and shorter contigs corresponding to haplotypes (haplotigs). Assembly statistics were generated by comparing the assembly to a reference genome, Tommy Atkins, using Quality Assessment Tool (QUAST). Moreover, the extent of duplication and completeness of gene content was measured using Benchmarking Universal Single-Copy Orthologs (BUSCO). Draft assemblies with high duplications were processed using Purge Haplotigs and Purge Dups to lessen duplications with minimal impact on genome completeness. De novo assemblies of Huani, Paho and 'Carabao' were then generated with primary contig sizes of 463.64 Mb, 508.95 Mb and 401.51 Mb respectively. These draft assemblies of Huani, Paho and 'Carabao' showed 96.90%, 95.17% and 99.07% complete BUSCOs respectively which is comparable to 'Tommy Atkins' genome (98.6%). Using two mango transcriptome data (pooled RNA-seq from different mango varieties and tissues), 91-96% or 24-30 million reads were successfully mapped back for each generated assembly indicating high degree of completeness. The results obtained demonstrated the highly contiguous, phased, and near complete genome assembly of three Philippine mango species for structural and functional annotation of gene units, especially those with economic importance.

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How Chromosome Mis-Segregation Leads to Cancer: Lessons from BubR1 Mouse Models

  • Lee, Hyunsook
    • Molecules and Cells
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    • v.37 no.10
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    • pp.713-718
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    • 2014
  • Alteration in chromosome numbers and structures instigate and foster massive genetic instability. As Boveri has seen a hundred years ago (Boveri, 1914; 2008), aneuploidy is hall-mark of many cancers. However, whether aneuploidy is the cause or the result of cancer is still at debate. The molecular mechanism behind aneuploidy includes the chromosome mis-segregation in mitosis by the compromise of spindle assembly checkpoint (SAC). SAC is an elaborate network of proteins, which monitor that all chromosomes are bipolarly attached with the spindles. Therefore, the weakening of the SAC is the major reason for chromosome number instability, while complete compromise of SAC results in detrimental death, exemplified in natural abortion in embryonic stage. Here, I will review on the recent progress on the understanding of chromosome missegregation and cancer, based on the comparison of different mouse models of BubR1, the core component of SAC.

Fabrication and Electrical Properties of MIM Devices In Self-assembled Organic Thin Film (자기조립 유기박막의 제작과 MIM소자의 전기적 특성)

  • Son, Jung-Ho;Shin, Hoon-Kyu;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05b
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    • pp.24-26
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    • 2002
  • In this paper, we discuss the electrical properties of self-assembled (2'-amino-4,4-di(ethynylphenyl)-5'-nitro-l-(thioacetyl)benzene), which has been well known as a conducting molecule having possible application to molecular level NDR device. The phenomenon of negative differential resistance (NDR) is characterized by decreasing current through a junction at increasing voltage. also fabrication of MIM-type molecular electronic and the Molecular Level Using Scanning Tunneling Microscopy

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Pathogenic Groups Identified Among Isolates of Rhynchosporium secalis

  • Arabi, Mohammad Imad Eddin;Al-Shehadah, Eyad;Jawhar, Mohammad
    • The Plant Pathology Journal
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    • v.26 no.3
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    • pp.260-263
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    • 2010
  • Scald, caused by Rhynchosporium secalis has been the major yield-reducing factor for barley production during the last decade. In this study, pathogenic groups of R. secalis were identified to obtain a global picture of the assembly of isolates involved in Syrian populations which is essential for the development of scald-resistant barley cultivars. To identify a number of pathogenic groups, 49 isolates collected over ten years from major barley growing areas in Syria were evaluated on five differential barley genotypes. Genotypes presented a continuous range of response from highly susceptible to moderately resistant, but none were immune to the disease. A cluster analysis placed isolates in six distinct differential pathogenic groups. Mean disease rating of 39.24% was the separation point between avirulent and virulent reactions. Isolate Rs46 exhibited distinct differential virulence patterns associated with high frequency across all genotypes. Hence, the data presented here provides crucial information for future selection of isolates to develop durable barley scald resistance.

Fabrication of Organic Thin Film by Using Self-Assembly and Negative Difference Resistance Research (자기조립법을 이용한 유기박막의 소자 제작과 부성저항특성 연구)

  • Son, Jung-Ho;Shin, Hoon-Kyu;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2002.07c
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    • pp.1572-1574
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    • 2002
  • In this paper, we discuss the electrical properties of self-assembled (2'-amino-4,4-di(ethynylp henyl)-5'-nitro-1-(thioacetyl)benzene), which has been well known as a conducting molecule having possible application to molecular level NDR device. The phenomenon of negative differential resi(NDR) is characterized by decreasing current th a junction at increasing voltage, also fabricatio MIM-type molecular electronic device and the Molecular Level Using Scanning Tunneling Microscopy.

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Two-dimensional Supramolecular Structures Mediated by Halogen Bonds: Comparing Cl and Br

  • Noh, Seung-Kyun;Chang, Min-Hui;Jeon, Jeong-Heum;Jang, Won-Jun;Yoon, Jong-Keon;Kahng, Se-Jong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.129-129
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    • 2012
  • Covalently bonded halogen ligands possess unusual charge distributions, attracting both electrophilic and nucleophilic molecular ligands to form halogen bonds. In many biochemical systems, halogen bonds coexist with hydrogen bonds, being complementary to them due to their similar bond strength and dissimilardirectionality. In this study, we directly visualize the individual molecular configuration of chlorinated 1,5-dichloroanthraquinone and brominated 1,5-dibromoanthraquinone molecules on Au(111) using scanning tunneling microscopy. The precise arrangements of observed molecular structures were explained in the context of halogen and hydrogen bonds. We discuss the distances and the strengths of the observed halogen and hydrogen bonds, which are consistent with previous bulk data.

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Heat Shock Proteins: A Review of the Molecular Chaperones for Plant Immunity

  • Park, Chang-Jin;Seo, Young-Su
    • The Plant Pathology Journal
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    • v.31 no.4
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    • pp.323-333
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    • 2015
  • As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs) functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs) or resistance (R) proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER) HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

Transcriptome analysis of internal and external stress mechanisms in Aster spathulifolius Maxim.

  • Sivagami, Jean Claude;Park, SeonJoo
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.04a
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    • pp.35-35
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    • 2019
  • Aster spathulifolius Maxim. is belongs to the Asteraceae family which is distributed only in Korea and Japan. It is recognize as a traditionally medicinal plants and economically valuable in ornamental field. However, among the Asteraceae family, the Aster genus, which is lacks in genomic resources and information of molecular function. Therefore, we used high throughput RNA-sequencing transcriptome data of the A. spathulifolius to know molecular level function. DeNovo assembly produced 98,660 unigene with N50 value 1126 bp. Unigenes was performed to analyses the functional annotation against NCBI database like plant database of nucleotide (Nt) and non-redundant protein (Nr), Pfam, Uniprot, KEGG and Transcriptional factor (TF). In addition, Distribution of SSR markers also analyzed for future perfectives. Further, Comparing with other two Asteraceae family species like, Karelinia caspica and Chrysanthemum morifolium to the A. spathulifolius shows the number of gene that regulated in internal and external stress respectively salt-tolerant and heat and drought stress to understand the molecular basis related to the different environments stress.

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Expression, Purification, and Characterization of Iron-Sulfur Cluster Assembly Regulator IscR from Acidithiobacillus ferrooxidans

  • Zeng, Jia;Zhang, Ke;Liu, Jianshe;Qiu, Guanzhou
    • Journal of Microbiology and Biotechnology
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    • v.18 no.10
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    • pp.1672-1677
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    • 2008
  • IscR (iron-sulfur cluster regulator) has been reported to be a repressor of the iscRSUA operon, and in vitro transcription reactions have revealed that IscR has a repressive effect on the iscR promoter in the case of [$Fe_{2}S_{2}$] cluster loading. In the present study, the iscR gene from A. ferrooxidans ATCC 23270 was cloned and successfully expressed in Escherichia coli, and then purified by one-step affinity chromatography to homogeneity. The molecular mass of the IscR was 18 kDa by SDS-PAGE. The optical and EPR spectra results for the recombinant IscR confirmed that an iron-sulfur cluster was correctly inserted into the active site of the protein. However, no [$Fe_{2}S_{2}$] cluster was assembled in apoIscR with ferrous iron and sulfide in vitro. Therefore, the [$Fe_{2}S_{2}$] cluster assembly in IscR in vivo would appear to require scaffold proteins and follow the Isc "AUS" pathway.