scholarly journals Revisiting van der Waals Radii: From Comprehensive Structural Analysis to Knowledge‐Based Classification of Interatomic Contacts

ChemPhysChem ◽  
2020 ◽  
Vol 21 (5) ◽  
pp. 359-359
Author(s):  
Ivan Yu. Chernyshov ◽  
Ivan V. Ananyev ◽  
Evgeny A. Pidko
Keyword(s):  
Structural Analysis ◽  
Van Der Waals ◽  
Knowledge Based ◽  
Van Der Waals Radii

scholarly journals Revisiting Van Der Waals Radii: From Comprehensive Structural Analysis to Knowledge-Based Classification of Interatomic Contacts

2019 ◽  
Author(s):  
Ivan Chernyshov ◽  
Ivan Ananyev ◽  
Evgeny Pidko
Keyword(s):  
Noncovalent Interactions ◽  
Molecular Systems ◽  
Model Studies ◽  
Knowledge Based ◽  
Universal Approach ◽  
Molecular Sizes ◽  
Almost All ◽  
Van Der Waals Radii

Weak noncovalent interactions are responsible for structure and properties of almost all supramolecular systems, such as nucleic acids, enzymes, and pharmaceutical crystals. However, the analysis of their significance and structural role is not straightforward and commonly requires model studies. Herein we describe an efficient and universal approach for the analysis of noncovalent interactions and determination of vdW radii using the Line-of-Sight (LoS) concept. The LoS allows to unambiguously identify and classify the “direct” interatomic contacts in complex molecular systems. This approach not only provides an improved theoretical base to molecular “sizes” but also enables the quantitative analysis of specificity, anisotropy and steric effects of intermolecular interactions.

scholarly journals Revisiting Van Der Waals Radii: From Comprehensive Structural Analysis to Knowledge-Based Classification of Interatomic Contacts

2019 ◽  
Author(s):  
Ivan Chernyshov ◽  
Ivan Ananyev ◽  
Evgeny Pidko
Keyword(s):  
Noncovalent Interactions ◽  
Molecular Systems ◽  
Model Studies ◽  
Knowledge Based ◽  
Universal Approach ◽  
Molecular Sizes ◽  
Almost All ◽  
Van Der Waals Radii

Weak noncovalent interactions are responsible for structure and properties of almost all supramolecular systems, such as nucleic acids, enzymes, and pharmaceutical crystals. However, the analysis of their significance and structural role is not straightforward and commonly requires model studies. Herein we describe an efficient and universal approach for the analysis of noncovalent interactions and determination of vdW radii using the Line-of-Sight (LoS) concept. The LoS allows to unambiguously identify and classify the “direct” interatomic contacts in complex molecular systems. This approach not only provides an improved theoretical base to molecular “sizes” but also enables the quantitative analysis of specificity, anisotropy and steric effects of intermolecular interactions.

Die Kristallstruktur von Phosphortrichlorid bei –110 °C / The Crystal Structure of Phosphorus Trichloride at –110 °C

1979 ◽  
Vol 34 (7) ◽  
pp. 1035-1036 ◽  
Author(s):  
Hans Hartl ◽  
Michael Rama
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Low Temperature ◽  
Van Der Waals ◽  
Phosphorus Trichloride ◽  
X Ray ◽  
Bond Angles ◽  
Intermolecular Contacts ◽  
Van Der Waals Radii

Abstract A low temperature (-110°C) X-ray structural analysis of PCI3 yielded the bond distances P-Cl = 203.43(12) and 201.86(23) pm and bond angles Cl-P-Cl = 100.04(7)° and 100.19(7)°. The shortest intermolecular contacts P ··· Cl and Cl ···C1 are in the range of the sum of van der Waals-radii

Interpreting HVEM of muscle-cell impulse networks

1992 ◽  
Vol 50 (1) ◽  
pp. 126-127
Author(s):  
Paul DeCosta ◽  
Kyugon Cho ◽  
Stephen Shemlon ◽  
Heesung Jun ◽  
Stanley M. Dunn
Keyword(s):  
Structural Analysis ◽  
Muscle Cell ◽  
Electron Micrographs ◽  
Relative Size ◽  
Automatic Classification ◽  
Nerve Fibers ◽  
Analysis Algorithm ◽  
Structural Networks

Introduction: The analysis and interpretation of electron micrographs of cells and tissues, often requires the accurate extraction of structural networks, which either provide immediate 2D or 3D information, or from which the desired information can be inferred. The images of these structures contain lines and/or curves whose orientation, lengths, and intersections characterize the overall network.Some examples exist of studies that have been done in the analysis of networks of natural structures. In, Sebok and Roemer determine the complexity of nerve structures in an EM formed slide. Here the number of nodes that exist in the image describes how dense nerve fibers are in a particular region of the skin. Hildith proposes a network structural analysis algorithm for the automatic classification of chromosome spreads (type, relative size and orientation).

scholarly journals New crystal structures of alkali metal tetrakis(pentafluorophenyl)borates

2020 ◽  
Vol 43 (1) ◽  
pp. 99-101
Author(s):  
Daniel Duvinage ◽  
Artem Schröder ◽  
Enno Lork ◽  
Jens Beckmann
Keyword(s):  
Alkali Metal ◽  
Crystal Structures ◽  
Van Der Waals ◽  
Van Der Waals Radii

AbstractThe crystal structures of the salts [Li(1,2-F2C6H4)] [B(C6F5)4] (1) and Cs[B(C6F5)4] (2) comprise six Li···F contacts (1.965(3) − 2.312(3) Å) and twelve Cs···F contacts (3.0312(1) − 3.7397(2) Å), respectively, which are significantly shorter than the sum of van der Waals radii (3.29 and 4.90 Å).

A Method for Classification of Transient Events in EEG Recordings: Application to Epilepsy Diagnosis

2006 ◽  
Vol 45 (06) ◽  
pp. 610-621 ◽  
Author(s):  
A. T. Tzallas ◽  
P. S. Karvelis ◽  
C. D. Katsis ◽  
S. Giannopoulos ◽  
S. Konitsiotis ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Epileptic Activity ◽  
Knowledge Based System ◽  
Knowledge Based ◽  
Epilepsy Diagnosis ◽  
Transient Events ◽  
Artificial Neural ◽  
Eeg Recordings

Summary Objectives: The aim of the paper is to analyze transient events in inter-ictal EEG recordings, and classify epileptic activity into focal or generalized epilepsy using an automated method. Methods: A two-stage approach is proposed. In the first stage the observed transient events of a single channel are classified into four categories: epileptic spike (ES), muscle activity (EMG), eye blinking activity (EOG), and sharp alpha activity (SAA). The process is based on an artificial neural network. Different artificial neural network architectures have been tried and the network having the lowest error has been selected using the hold out approach. In the second stage a knowledge-based system is used to produce diagnosis for focal or generalized epileptic activity. Results: The classification of transient events reported high overall accuracy (84.48%), while the knowledge-based system for epilepsy diagnosis correctly classified nine out of ten cases. Conclusions: The proposed method is advantageous since it effectively detects and classifies the undesirable activity into appropriate categories and produces a final outcome related to the existence of epilepsy.

Sign in / Sign up

Export Citation Format

Share Document