Preparation and Crystal Structure of Ruthenium Metaphosphate Ru(PO3)3with an 8-fold Superstructure. Analysis of Structural Frustration with a Simple Model

1997 ◽  
Vol 36 (19) ◽  
pp. 4172-4181 ◽  
Author(s):  
Hideo Imoto ◽  
Hiroshi Fukuoka ◽  
Shigenori Tsunesawa ◽  
Hisaya Horiuchi ◽  
Takao Amemiya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Simple Model

Simple model designed to generate new crystal structures derived from a mother phase; application to molecular compounds

2002 ◽  
Vol 58 (4) ◽  
pp. 662-672 ◽  
Author(s):  
Claire Gervais ◽  
Gérard Coquerel
Keyword(s):  
Crystal Structure ◽  
Simple Model ◽  
Three Dimensional ◽  
Second Step ◽  
Two Dimensional ◽  
Basic Principles ◽  
Space Groups ◽  
Step Procedure ◽  
Symmetry Operators ◽  
Molecular Compounds

The basic principles of a model predicting new lattices from a known crystal structure are described. The first of the two-step procedure consists of extracting one- or two-dimensional periodic fragments (PF) from the mother structure. In the second step, symmetry operators are added to the PFs in order to generate one or several new three-dimensional lattices consistent with the 230 space groups. Most of the examples are related to polymorphism, but relationships between racemic compounds and enantiomers, twinning and lamellar epitaxy phenomena are also exemplified.

A Simple Model for the Enzyme-Substrate-Complex of the Quercetinase Reaction. Crystal Structure of Flavonolatocobalt(III)(salen)

1992 ◽  
Vol 47 (8) ◽  
pp. 1185-1188 ◽  
Author(s):  
Wolfgang Hiller ◽  
Akira Nishinaga ◽  
Anton Rieker
Keyword(s):  
Crystal Structure ◽  
Simple Model ◽  
Triclinic Space Group ◽  
Space Group ◽  
Substrate Complex ◽  
Enzyme Substrate

Flavonolatocobalt(III)(salen), a model enzyme-substrate-complex for the quercetinase reaction, was synthesized and its crystal structure determined. C31H23CoN2O5 · 2 CH2Cl2, M = 732.35, triclinic, space group P 1̅ , a = 12.463(2), b = 13.270(2), c = 10.041(2) Å, α = 97.89(1)°, β= 108.08(1)°, γ= 83.56(1)°, U = 1559.4 Å3, Z = 2.

The magnetic properties of praseodymium metal

1963 ◽  
Vol 276 (1364) ◽  
pp. 39-50 ◽  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Simple Model ◽  
Specific Heat ◽  
Field Model ◽  
Hexagonal Symmetry ◽  
Crystal Fields ◽  
Magnetic Specific Heat ◽  
Crystal Field Parameters ◽  
Two Parameter

The magnetic properties of praseodymium metal are interpreted in term s of a simple model suggested by the crystal structure where alternate layers of ions are subjected to crystal fields of face-centred cubic and hexagonal symmetry. The crystal field parameters are found by fitting the magnetic specific heat anomaly, and the variation of the susceptibility with temperature can be explained using a two-parameter molecular field model. The exchange intemaction is predominantly ferromagnetic in sign. The origin of the hyperfine specific heat is discussed, and attributed to interaction effects, though these must be larger than can be accounted for by simple theoretical estimates.

Repurposing of Fluvastatin Against Candida albicans CYP450 Lanosterol 14 α-demethylase, a Target Enzyme for Antifungal Therapy: An In silico and In vitro Study

2019 ◽  
Vol 19 (7) ◽  
pp. 506-524 ◽  
Author(s):  
Ritika Rana ◽  
Ruchika Sharma ◽  
Anoop Kumar
Keyword(s):  
Crystal Structure ◽  
Mycobacterium Tuberculosis ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Simple Model ◽  
Cytotoxic Effect ◽  
Fungal Growth ◽  
Murine Splenocytes ◽  
Lanosterol Demethylase

Background: The incidence of fungal infections has increased significantly. Specifically the cases of candida albicans infection are increasing day by day and their resistance to clinically approved drugs is a major concern for humans. Various classes of antifungal drugs are available in the market for the treatment of these infections but unfortunately, none of them is able to treat the infection. Objective: Thus, in the present investigation, we have repurposed the well-known drug (Fluvastatin) in the treatment of Candida albicans infections by using in silico, in vitro and ex vivo techniques. Results: Firstly, we developed and validated a simple model of CYP45014α-lanosterol demethylase of Candida albicans by using crystal structure of Mycobacterium tuberculosis (1EA1). Further, fluvastatin was docked with a validated model of CYP45014α-lanosterol demethylase and revealed good binding affinity as that of fluconazole. In vitro results (Percentage growth retardation, Fungal growth kinetics, Biofilm test and Post antifungal test) have shown good antifungal activity of fluvastatin. Finally, the results of MTT assay have shown non-cytotoxic effect of fluvastatin in murine splenocytes and thymocytes. Results: Firstly, we developed and validated a simple model of CYP45014α-lanosterol demethylase of Candida albicans by using crystal structure of Mycobacterium tuberculosis (1EA1). Further, fluvastatin was docked with a validated model of CYP45014α-lanosterol demethylase and revealed good binding affinity as that of fluconazole. In vitro results (Percentage growth retardation, Fungal growth kinetics, Biofilm test and Post antifungal test) have shown good antifungal activity of fluvastatin. Finally, the results of MTT assay have shown non-cytotoxic effect of fluvastatin in murine splenocytes and thymocytes. Conclusion: However, further in vivo studies are required to confirm the complete role of fluvastatin as an antifungal agent.

Noncrystallographic symmetry and the sampling theorem

1974 ◽  
Vol 140 (5-6) ◽  
Author(s):  
P. M. Colman
Keyword(s):  
Crystal Structure ◽  
Simple Model ◽  
Local Symmetry ◽  
Real Space ◽  
Sampling Theorem ◽  
Model Structure ◽  
Asymmetric Unit ◽  
Structure Factors ◽  
Shannon Sampling Theorem ◽  
Space Method

AbstractWhen the asymmetric unit of a crystal structure expresses some noncrystallographic symmetry it is often found that these local symmetry elements involve only proper rotations. Under these conditions the relations between the structure factors resulting from this repetition within the crystallographic asymmetric unit reduce to a statement of the Whittaker-Shannon sampling theorem, and thereby suggest the real space method for solution. A simple model structure is solved as an example.

scholarly journals Simple Modeling of Crystal Structure of Carbon Tetrachloride, Diamond, and Fullerene using Molymods

TEM Journal ◽  
2021 ◽  
pp. 883-891
Author(s):  
Himawan Putranta ◽  
Heru Kuswanto ◽  
Wipsar Sunu Brams Dwandaru ◽  
Hery Setiyatna ◽  
Syella Ayunisa Rani ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Carbon Tetrachloride ◽  
Simple Model ◽  
Structure Model ◽  
Easy Method ◽  
Physics Learning ◽  
Test Sheet ◽  
Feasibility Test ◽  
Simple Modeling ◽  
The Ideal

This research aims to make simple modeling of the crystal structure of carbon tetrachloride, diamond, and fullerenes using molymod. The method used is a descriptive quantitative with the research stages including the selection, making, and testing the feasibility of crystal structure. The feasibility of the crystal structure was assessed using a product feasibility test sheet and analyzed using the ideal standard mean equation. The development of a crystal structure model was carried out using a simple and easy method to obtain equipment in the form of molymod. The results of this research indicate that the crystal structure of carbon tetrachloride, diamond, and fullerenes can be interpreted significantly and easily with the help of molymod. The simple model of the crystal structure is also suitable for use as a physics learning medium that can help students understand abstract crystal structure material.

ChemInform Abstract: Preparation and Crystal Structure of Ruthenium Metaphosphate Ru(PO3)3 with an 8-Fold Superstructure. Analysis of Structural Frustration with a Simple Model.

ChemInform ◽  
2010 ◽  
Vol 28 (47) ◽  
pp. no-no
Author(s):  
H. IMOTO ◽  
H. FUKUOKA ◽  
S. TSUNESAWA ◽  
H. HORIUCHI ◽  
T. AMEMIYA ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Simple Model

scholarly journals A Simple Model of Protein Folding: From Crystal Structure to the Living Cell

2012 ◽  
Vol 102 (3) ◽  
pp. 210a
Author(s):  
Maxim B. Prigozhin ◽  
Sharlene Denos
Keyword(s):  
Crystal Structure ◽  
Protein Folding ◽  
Simple Model ◽  
Living Cell

Crystal Structure Determination of Glycerol-Containing Lipids from Electron Diffraction Data. Use of Analog Compounds Based upon Configurational Isomers of Cyclopentane-1, 2, 3-TRIOL

1977 ◽  
Vol 35 ◽  
pp. 24-25
Author(s):  
Douglas L. Dorset ◽  
Anthony J. Hancock
Keyword(s):  
Crystal Structure ◽  
Electron Diffraction ◽  
Diffraction Data ◽  
Structure Determination ◽  
Crystal Surface ◽  
Coherent Scattering ◽  
Crystal Structure Determination ◽  
Electron Diffraction Data ◽  
Polar Group ◽  
Axis Orientation

Lipids containing long polymethylene chains were among the first compounds subjected to electron diffraction structure analysis. It was only recently realized, however, that various distortions of thin lipid microcrystal plates, e.g. bends, polar group and methyl end plane disorders, etc. (1-3), restrict coherent scattering to the methylene subcell alone, particularly if undistorted molecular layers have well-defined end planes. Thus, ab initio crystal structure determination on a given single uncharacterized natural lipid using electron diffraction data can only hope to identify the subcell packing and the chain axis orientation with respect to the crystal surface. In lipids based on glycerol, for example, conformations of long chains and polar groups about the C-C bonds of this moiety still would remain unknown.One possible means of surmounting this difficulty is to investigate structural analogs of the material of interest in conjunction with the natural compound itself. Suitable analogs to the glycerol lipids are compounds based on the three configurational isomers of cyclopentane-1,2,3-triol shown in Fig. 1, in which three rotameric forms of the natural glycerol derivatives are fixed by the ring structure (4-7).

Spherulitic crystal growth in the prodissoconch larval of Crassostrea virginica

1983 ◽  
Vol 41 ◽  
pp. 518-519
Author(s):  
George G. Cocks ◽  
Louis Leibovitz ◽  
DoSuk D. Lee
Keyword(s):  
Crystal Structure ◽  
Crassostrea Virginica ◽  
Crystal Orientation ◽  
Developmental Changes ◽  
Gastrula Stage ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Stages Of Growth ◽  
Early Stages ◽  
Initial Deposition

Our understanding of the structure and the formation of inorganic minerals in the bivalve shells has been considerably advanced by the use of electron microscope. However, very little is known about the ultrastructure of valves in the larval stage of the oysters. The present study examines the developmental changes which occur between the time of conception to the early stages of Dissoconch in the Crassostrea virginica(Gmelin), focusing on the initial deposition of inorganic crystals by the oysters.The spawning was induced by elevating the temperature of the seawater where the adult oysters were conditioned. The eggs and sperm were collected separately, then immediately mixed for the fertilizations to occur. Fertilized animals were kept in the incubator where various stages of development were stopped and observed. The detailed analysis of the early stages of growth showed that CaCO3 crystals(aragonite), with orthorhombic crystal structure, are deposited as early as gastrula stage(Figuresla-b). The next stage in development, the prodissoconch, revealed that the crystal orientation is in the form of spherulites.

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