scholarly journals The relationship between crystal structure and methyl and t-butyl group dynamics in van der Waals organic solids

2004 ◽  
Vol 120 (11) ◽  
pp. 5309-5314 ◽  
Author(s):  
Peter A. Beckmann ◽  
Carol Paty ◽  
Elizabeth Allocco ◽  
Maria Herd ◽  
Carolyn Kuranz ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Group Dynamics ◽  
Van Der Waals ◽  
Organic Solids ◽  
Butyl Group ◽  
The Relationship

scholarly journals Generation of an Isogenic Collection of Yeast Actin Mutants and Identification of Three Interrelated Phenotypes

Genetics ◽  
2001 ◽  
Vol 157 (2) ◽  
pp. 533-543
Author(s):  
Johanna L Whitacre ◽  
Dana A Davis ◽  
Kurt A Toenjes ◽  
Sharon M Brower ◽  
Alison E M Adams
Keyword(s):  
Crystal Structure ◽  
Growth Rates ◽  
Small Region ◽  
Wild Type ◽  
Large Collection ◽  
Growth Defects ◽  
Cytoskeletal Function ◽  
Highly Correlated ◽  
The Relationship ◽  
Mutant Cells

Abstract A large collection of yeast actin mutations has been previously isolated and used in numerous studies of actin cytoskeletal function. However, the various mutations have been in congenic, rather than isogenic, backgrounds, making it difficult to compare the subtle phenotypes that are characteristic of these mutants. We have therefore placed 27 mutations in an isogenic background. We used a subset of these mutants to compare the degree to which different actin alleles are defective in sporulation, endocytosis, and growth on NaCl-containing media. We found that the three phenotypes are highly correlated. The correlations are specific and not merely a reflection of general growth defects, because the phenotypes are not correlated with growth rates under normal conditions. Significantly, those actin mutants exhibiting the most severe phenotypes in all three processes have altered residues that cluster to a small region of the actin crystal structure previously defined as the fimbrin (Sac6p)-binding site. We examined the relationship between endocytosis and growth on salt and found that shifting wild-type or actin mutant cells to high salt reduces the rate of α-factor internalization. These results suggest that actin mutants may be unable to grow on salt because of additive endocytic defects (due to mutation and salt).

scholarly journals Crystal structure oftrans-N,N′-bis(3,5-di-tert-butyl-2-hydroxyphenyl)oxamide methanol monosolvate

2016 ◽  
Vol 72 (7) ◽  
pp. 918-921
Author(s):  
Miguel-Ángel Velázquez-Carmona ◽  
Sylvain Bernès ◽  
Francisco Javier Ríos-Merino ◽  
Yasmi Reyes Ortega
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Hydroxy Group ◽  
Molecular Conformation ◽  
Methanol Molecule ◽  
Molecular Symmetry ◽  
Methyl Group ◽  
Supramolecular Motifs ◽  
Butyl Group ◽  
Hydroxy Groups

The here crystallized oxamide was previously characterized as an unsolvated species [Jímenez-Pérezet al.(2000).J. Organomet. Chem.614–615, 283–293], and is now reported with methanol as a solvent of crystallization, C30H44N2O4·CH3OH, in a different space group. The introduction of the solvent influences neither the molecular symmetry of the oxamide, which remains centrosymmetric, nor the molecular conformation. However, the unsolvated molecule crystallized as an ordered system, while many parts of the solvated crystal are disordered. The hydroxy group in the oxamide is disordered over two chemically equivalent positions, with occupancies 0.696 (4):0.304 (4); onetert-butyl group is disordered by rotation about the C—C bond, and was modelled with three sites for each methyl group, each one with occupancy 1/3. Finally, the methanol solvent, which lies on a twofold axis, is disordered by symmetry. The disorder affecting hydroxy groups and the solvent of crystallization allows the formation of numerous supramolecular motifs using four hydrogen bonds, with N—H and O—H groups as donors and the oxamide and methanol molecule as acceptors.

scholarly journals Crystal structure of 2-(2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-ylidene)acetonitrile

2015 ◽  
Vol 71 (10) ◽  
pp. o792-o793
Author(s):  
K. Priya ◽  
K. Saravanan ◽  
S. Kabilan ◽  
S. Selvanayagam
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Chair Conformation ◽  
Equatorial Orientation ◽  
Amino Group ◽  
Phenyl Rings

In the title 3-azabicyclononane derivative, C22H22N2, both the fused piperidine and cyclohexane rings adopt a chair conformation. The phenyl rings attached to the central azabicylononane fragment in an equatorial orientation are inclined to each other at 23.7 (1)°. The amino group is not involved in any hydrogen bonding, so the crystal packing is stabilized only by van der Waals forces.

scholarly journals An ecosystemic approach to evaluating ecological, socioeconomic and group dynamics affecting the prevalence of Aedes aegypti in two Colombian towns

2009 ◽  
Vol 25 (suppl 1) ◽  
pp. s93-s103 ◽  
Author(s):  
Juliana Quintero ◽  
Gabriel Carrasquilla ◽  
Roberto Suárez ◽  
Catalina González ◽  
Victor A. Olano
Keyword(s):  
Group Dynamics ◽  
Epidemiological Methods ◽  
Inverse Association ◽  
Political Factors ◽  
Breeding Sites ◽  
Health Authorities ◽  
Social Dynamic ◽  
Public Health Authorities ◽  
Dengue Control ◽  
The Relationship

This article focuses on the epidemiological methods and results of a global Ecohealth study that explored the complexity of the relationship between ecological, biological, economical, social and political factors and vector presence. The study was carried out in two dengue endemic areas of Colombia. A transdisciplinary team gathered quantitative and qualitative data. A survey in randomly sampled households was applied and, simultaneously, direct observation of potential breeding sites was carried out. Logistic regressions and qualitative techniques were used. Qualitative and quantitative data were compared using triangulation. The presence of low water containers increases seven-fold the risk of finding immature forms ofAedes aegypti in the household (OR = 7.5; 95%CI: 1.7-32.2). An inverse association between socioeconomic stratum and presence of the vector was identified (Low stratum OR = 0.9; 95%CI: 0.6-1.4; High stratum OR =0.4; 95%CI: 0.07-1.7). Water management is a complex social dynamic associated with the presence of Ae. aegypti. Dengue control is a challenge for public health authorities and researchers as they should address promotion and prevention strategies that take into account cultural, behavioral, socioeconomic and health factors.

scholarly journals Crystal structure of 3-bromomethyl-2-chloro-6-(dibromomethyl)quinoline

2015 ◽  
Vol 71 (5) ◽  
pp. o354-o355
Author(s):  
Kasirajan Gayathri ◽  
Palathurai S. Mohan ◽  
Judith A. K. Howard ◽  
Hazel A. Sparkes
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Van Der Waals ◽  
Ring System ◽  
Quinoline Ring ◽  
Π Interactions ◽  
Compound C ◽  
Van Der Waals Radii

In the title compound, C11H7Br3ClN, the quinoline ring system is approximately planar (r.m.s. = 0.011 Å). In the crystal, molecules are linked by C—H...Br interactions forming chains along [10-1]. The chains are linked by C—H...π and π–π interactions involving inversion-related pyridine rings [intercentroid distance = 3.608 (4) Å], forming sheets parallel to (10-1). Within the sheets, there are two significant short interactions involving a Br...Cl contact of 3.4904 (18) Å and a Br...N contact of 3.187 (6) Å, both of which are significantly shorter than the sum of their van der Waals radii.

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