• Title/Summary/Keyword: Molecular modelling

Search Result 39, Processing Time 0.024 seconds

MULTISCALE MODELLING FOR THE FISSION GAS BEHAVIOUR IN THE TRANSURANUS CODE

  • Van Uffelen, P.;Pastore, G.;Di Marcello, V.;Luzzi, L.
    • Nuclear Engineering and Technology
    • /
    • v.43 no.6
    • /
    • pp.477-488
    • /
    • 2011
  • A formulation is proposed for modelling the process of intra-granular diffusion of fission gas during irradiation of $UO_2$ under both normal operating conditions and power transients. The concept represents a simple extension of the formulation of Speight, including an estimation of the contribution of bubble motion to fission gas diffusion. The resulting equation is formally identical to the diffusion equation adopted in most models that are based on the formulation of Speight, therefore retaining the advantages in terms of simplicity of the mathematical-numerical treatment and allowing application in integral fuel performance codes. The development of the new model proposed here relies on results obtained by means of molecular dynamics simulations as well as finite element computations. The formulation is proposed for incorporation in the TRANSURANUS fuel performance code.

In silico characterisation, homology modelling and structure-based functional annotation of blunt snout bream (Megalobrama amblycephala) Hsp70 and Hsc70 proteins

  • Tran, Ngoc Tuan;Jakovlic, Ivan;Wang, Wei-Min
    • Journal of Animal Science and Technology
    • /
    • v.57 no.12
    • /
    • pp.44.1-44.9
    • /
    • 2015
  • Background: Heat shock proteins play an important role in protection from stress stimuli and metabolic insults in almost all organisms. Methods: In this study, computational tools were used to deeply analyse the physicochemical characteristics and, using homology modelling, reliably predict the tertiary structure of the blunt snout bream (Ma-) Hsp70 and Hsc70 proteins. Derived three-dimensional models were then used to predict the function of the proteins. Results: Previously published predictions regarding the protein length, molecular weight, theoretical isoelectric point and total number of positive and negative residues were corroborated. Among the new findings are: the extinction coefficient (33725/33350 and 35090/34840 - Ma-Hsp70/ Ma-Hsc70, respectively), instability index (33.68/35.56 - both stable), aliphatic index (83.44/80.23 - both very stable), half-life estimates (both relatively stable), grand average of hydropathicity (-0.431/-0.473 - both hydrophilic) and amino acid composition (alanine-lysine-glycine/glycine-lysine-aspartic acid were the most abundant, no disulphide bonds, the N-terminal of both proteins was methionine). Homology modelling was performed by SWISS-MODEL program and the proposed model was evaluated as highly reliable based on PROCHECK's Ramachandran plot, ERRAT, PROVE, Verify 3D, ProQ and ProSA analyses. Conclusions: The research revealed a high structural similarity to Hsp70 and Hsc70 proteins from several taxonomically distant animal species, corroborating a remarkably high level of evolutionary conservation among the members of this protein family. Functional annotation based on structural similarity provides a reliable additional indirect evidence for a high level of functional conservation of these two genes/proteins in blunt snout bream, but it is not sensitive enough to functionally distinguish the two isoforms.

Computational Study on the Binding of Aux/IAA17 and ARF5 Involved in Auxin's Transcriptional Regulation using Molecular Docking

  • Kwon, Sohee;Lee, Gyu Rie;Seok, Chaok
    • Proceeding of EDISON Challenge
    • /
    • 2017.03a
    • /
    • pp.16-26
    • /
    • 2017
  • Auxin response factor (ARF) and Aux/IAA transcriptional repressor family proteins play a major role in auxin's signalling process. Using the GALAXY protein modelling programs, monomer, dimer and oligomer structures of Aux/IAA17 and ARF5 protein were predicted based on the known experimental structures. By analysing the proposed complex structures, key interacting residues on binding site could be determined, and further suggestions for experimental studies were made.

  • PDF

MODELLING THE 3 MICRON REGION IN AKARI IRC SPECTRA

  • Hammonds, Mark;Mori, Tamami;Usui, Fumihiko;Onaka, Takashi
    • Publications of The Korean Astronomical Society
    • /
    • v.32 no.1
    • /
    • pp.93-95
    • /
    • 2017
  • The existence of polycyclic aromatic hydrocarbons (PAHs) astronomically is well accepted, but the specific molecular forms observed remain uncertain. To better understand the molecular structures which may be present along a given sightline, the $3.0-3.6{\mu}m$ region is modelled with careful consideration given to the underlying sub-features arising from specific structures within emitting molecules.

The Design of Photobiological Active Molecular Model For Photodynamic Therapy

  • Choi, Chang-Shik
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2019.05a
    • /
    • pp.521-524
    • /
    • 2019
  • The design of photobiological active photosensitizing molecular model for photodynamic therapy has been attracted as a research for the development of cancer treatment, and has been interested in the effective method for cancer treatment and the photosensitizer having more stable wavelength. Furthermore, the development of photosensitizer has been already carried out from the first generation molecule to the third one, and the research of smart photosensitizer as the fourth generation has been requested. As a fact, the selective killing of the only cancer cell is very difficult problem, and the present photodynamic therapy has the problem of killing of the normal cell. So, I have designed the new modelling of photosensitizer having the smart recognizing unit and the magnetic nanoparticle as well as having the several effective recognizing unit. In particular, the new model design of the photosensitizer having lanthanide metal has suggested for the development of photodynamic therapy. The model design of these new photosensitizing molecules will be introduced in the poster section for the new turning point of the development of photosensitizer.

  • PDF

Computational continuum modelling to analysis the dynamic and static stability of a cantilever nano-scale system

  • Jiangjiang Li
    • Advances in Computational Design
    • /
    • v.8 no.1
    • /
    • pp.77-96
    • /
    • 2023
  • Calculating size-dependent mechanical properties of the nano-scale materials usually involves cumbersome numerical and theoretical works. In this paper, we aim to present a closed-form relation to calculate the length-dependent Young's modulus of carbon nanotubes (CNTs) based on nonlocal elasticity theory. In this regard, a single wall carbon nanotube (SWCNT) is considered as a rod structure and the governing nonlocal equations are developed under uniaxial tensile load. The equations are solved using analytical methods and strain distribution, total displacement and the size-dependent equivalent Young's modulus are obtained. Further, the results are compared with the molecular dynamics results from the literature. The outcome indicates that the calculated relations are coincident with the molecular dynamics results.

Fibrobacter succinogenes, a Dominant Fibrolytic Ruminal Bacterium: Transition to the Post Genomic Era

  • Jun, H.S.;Qi, M.;Ha, J.K.;Forsberg, C.W.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.20 no.5
    • /
    • pp.802-810
    • /
    • 2007
  • Fibrobacter succinogenes, a Gram-negative, anaerobic ruminal bacterium is a major fibre digesting species in the rumen. It intensively degrades plant cell walls by an erosion type of mechanism, burrowing its way through the complex matrix of cellulose and hemicellulose with the release of digestible and undigested cell wall fragments. The enzymes involved in this process include a combination of glucanases, xylanases, arabinofuranosidase(s) and esterases. The genome of the bacterium has been sequenced and this has revealed in excess of 100 putative glycosyl hydrolase, pectate lyase and carbohydrate esterase genes, which is greater than the numbers reported present in other major cellulolytic organisms for which genomes have been sequenced. Modelling of the amino acid sequences of two glycanases, CedA and EGB, by reference to crystallized homologs has enabled prediction of the major features of their tertiary structures. Two dimensional gel electrophoresis in conjunction with mass spectroscopy has permitted the documentation of proteins over expressed in F. succinogenes grown on cellulose, and analysis of the cell surfaces of mutant strains unable to bind to cellulose has enabled the identification of candidate proteins with roles in adhesion to the plant cell wall substrate, the precursor to cellulose biodegradation.

Theoretical Investigation on the Structure, Detonation Performance and Pyrolysis Mechanism of 4,6,8-Trinitro-4,5,7,8-tetrahydro -6H-furazano[3,4-f]-1,3,5-triazepine

  • Li, Xiao-Hong;Zhang, Rui-Zhou;Zhang, Xian-Zhou
    • Bulletin of the Korean Chemical Society
    • /
    • v.35 no.5
    • /
    • pp.1479-1484
    • /
    • 2014
  • Based on the full optimized molecular geometric structures at B3LYP/cc-pvtz method, a new designed compound, 4,6,8-trinitro-4,5,7,8-tetrahydro-6H-furazano[3,4-f ]-1,3,5-triazepine was investigated in order to look for high energy density compounds (HEDCs). The analysis of the molecular structure indicates that the seven-membered ring adopts chair conformation and there exist intramolecular hydrogen bond interactions. IR spectrum and heat of formation (HOF) were predicted. The detonation velocity and pressure were evaluated by using Kamlet-Jacobs equations based on the theoretical density and condensed HOF. The bond dissociation energies and bond orders for the weakest bonds were analyzed to investigate the thermal stability of the title compound. The results show that $N_1-N_6$ bond is the trigger bond. The crystal structure obtained by molecular mechanics belongs to $Pna2_1$ space group, with lattice parameters Z = 4, a = 15.3023 ${\AA}$, b = 5.7882 ${\AA}$, c = 11.0471 ${\AA}$, ${\rho}=2.06gcm^{-3}$. In addition, the analysis of frontier molecular orbital shows the title compound has good stability and high chemical hardness.

Anthocyanins: Targeting of Signaling Networks in Cancer Cells

  • Sehitoglu, Muserref Hilal;Farooqi, Ammad Ahmad;Qureshi, Muhammad Zahid;Butt, Ghazala;Aras, Aliye
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.5
    • /
    • pp.2379-2381
    • /
    • 2014
  • It is becoming progressively more understandable that phytochemicals derived from edible plants have shown potential in modelling their interactions with their target proteins. Rapidly accumulating in-vitro and in- vivo evidence indicates that anthocyanins have anticancer activity in rodent models of cancer. More intriguingly, evaluation of bilberry anthocyanins as chemopreventive agents in twenty-five colorectal cancer patients has opened new window of opportunity in translating the findings from laboratory to clinic. Confluence of information suggests that anthocyanins treated cancer cells reveal up-regulation of tumor suppressor genes. There is a successive increase in the research-work in nutrigenomics and evidence has started to shed light on intracellular-signaling cascades as common molecular targets for anthocyanins. In this review we bring to l imelight how anthocyanins induced apoptosis in cancer cells via activation of extrinsic and intrinsic pathways.

A Study on Spectra of Laser Induced Fluorescence in Phantom (Phantom에서 Laser Induced Fluorescence의 스펙트라에 관한 연구)

  • Kim, Ki-Jun;Sung, Ki-Chun
    • Journal of the Korean Applied Science and Technology
    • /
    • v.16 no.4
    • /
    • pp.329-335
    • /
    • 1999
  • The influences of fluorophor, scatterer, and absorber in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength. The molecular properties have been studied by laser induced fluorescence spectroscopy in phantom. It has been found that the effects of optical properties in scattering media could be investigated by the optical parameters(${\mu}_a$, ${\mu}_a$, ${\mu}_t$). Experimental and Monte Carlo Simulation method for modelling light transport in tissue was applied. The experimental results using a phantom were discussed and compared with those obtained through Monte Carlo Simulation. It may also aid in designing the best model for oil chemistry, medicine and application of medical engineering.