A Discussion of the Dependence of Cuticular Mobility on Molecular Volume

2009 ◽  
pp. 81-81-12
Author(s):  
JD Fowler
Keyword(s):  
Molecular Volume

scholarly journals Application of Dendrimers for Treating Parasitic Diseases

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 343
Author(s):  
Veronica Folliero ◽  
Carla Zannella ◽  
Annalisa Chianese ◽  
Debora Stelitano ◽  
Annalisa Ambrosino ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Water Solubility ◽  
Parasitic Infection ◽  
Three Dimensional ◽  
Medical Knowledge ◽  
High Ratio ◽  
Molecular Volume ◽  
Parasitic Infections ◽  
Parasitic Diseases ◽  
Wide Range

Despite advances in medical knowledge, parasitic diseases remain a significant global health burden and their pharmacological treatment is often hampered by drug toxicity. Therefore, drug delivery systems may provide useful advantages when used in combination with conventional therapeutic compounds. Dendrimers are three-dimensional polymeric structures, characterized by a central core, branches and terminal functional groups. These nanostructures are known for their defined structure, great water solubility, biocompatibility and high encapsulation ability against a wide range of molecules. Furthermore, the high ratio between terminal groups and molecular volume render them a hopeful vector for drug delivery. These nanostructures offer several advantages compared to conventional drugs for the treatment of parasitic infection. Dendrimers deliver drugs to target sites with reduced dosage, solving side effects that occur with accepted marketed drugs. In recent years, extensive progress has been made towards the use of dendrimers for therapeutic, prophylactic and diagnostic purposes for the management of parasitic infections. The present review highlights the potential of several dendrimers in the management of parasitic diseases.

In-situ high-pressure study of the ordered phase of ethyl propionate

2007 ◽  
Vol 63 (1) ◽  
pp. 111-117 ◽  
Author(s):  
Roman Gajda ◽  
Andrzej Katrusiak
Keyword(s):  
High Pressure ◽  
Degrees Of Freedom ◽  
Molecular Volume ◽  
Ethyl Propionate ◽  
Intermolecular Contacts ◽  
High Pressure Study ◽  
Pressure Phase ◽  
Three Degrees Of Freedom ◽  
Volume Difference

Ethyl propionate, C5H10O2 (m.p. 199 K), has been in-situ pressure-frozen and its structure determined at 1.34, 1.98 and 2.45 GPa. The crystal structure of the new high-pressure phase (denoted β) is different from phase α obtained by lowering the temperature. The freezing pressure of ethyl propionate at 296 K is 1.03 GPa. The molecule assumes an extended chain s-trans–trans–trans conformation, only slightly distorted from planarity. The closest intermolecular contacts in both phases are formed between carbonyl O and methyl H atoms; however, the ethyl-group H atoms in phase β form no contacts shorter than 2.58 Å. A considerable molecular volume difference of 24.2 Å3 between phases α and β can be rationalized in terms of degrees of freedom of molecules arranged into closely packed structures: the three degrees of freedom allowed for rearrangements of molecules confined to planar sheets in phase α, but are not sufficient for obtaining a densely packed pattern.

THE STRUCTURE OF AGGREGATES AND THE MOLECULAR KINEMATICS OF THE VISCOSITY OF A BERNAL LIQUID

1964 ◽  
Vol 42 (2) ◽  
pp. 304-320 ◽  
Author(s):  
F. W. Smith
Keyword(s):  
Coordination Number ◽  
Free Volume ◽  
Activation Volume ◽  
Molecular Volume ◽  
3 Dimensional ◽  
Theory Of Liquids ◽  
Kinetic Pressure ◽  
Steel Balls ◽  
Set Of Points ◽  
Structure Of Aggregates

The structure of 3-dimensional aggregates is discussed as a set of points on which graphs are constructed. By constructing the Voronoi honeycomb (Dirichlet regions) for the points and applying a small "irregularizing transformation", a "simplicial graph" and a "primitive coordination number" (whose value is close to 14 for all aggregates) can be defined universally for both regular and irregular aggregates. Recent studies of the geometry of irregular aggregates (of steel balls, crystal grains, etc.) are reviewed. The theory of liquids of J. D. Bernal is discussed and the simplicial graph is used to show that the "activation volume" of a Bernal liquid is about one-tenth of the molecular volume. The kinematics of flow of aggregates is discussed in terms of their graphs and in terms of a process of "volume exchange"—the production and destruction of free volume. Using these concepts, an equation is derived for the viscosity of a Bernal liquid as a product of five terms expressing respectively the kinematic, stoichiometric, kinetic, pressure-dependent, and shear-dependent factors.

Molecular volume, surface area, and curvature dependence of the configurational entropy change upon solvation: effects of molecular bonding

1998 ◽  
Vol 284 (3-4) ◽  
pp. 235-246 ◽  
Author(s):  
Seishi Shimizu ◽  
Mitsunori Ikeguchi ◽  
Shugo Nakamura ◽  
Kentaro Shimizu
Keyword(s):  
Surface Area ◽  
Configurational Entropy ◽  
Entropy Change ◽  
Molecular Volume ◽  
Solvation Effects ◽  
Molecular Bonding ◽  
Curvature Dependence

scholarly journals Phase diagram of solid hints new fundamental constant and sees atomic orbital

2021 ◽  
Author(s):  
Shapiullah Belalovich Abdulvagidov
Keyword(s):  
Phase Diagram ◽  
Solid State ◽  
Triple Point ◽  
Transition Metal Oxides ◽  
Atomic Orbital ◽  
Fundamental Constant ◽  
Molecular Volume ◽  
Zero Field ◽  
Covalent Bonds ◽  
State Tomography

Abstract Cold and pressure transform gas into liquid and then into solid. Van der Waals understood the phase diagram of liquefiable gas with the molecular volume and intermolecular attraction, however, was silent on how solid behaved1. Unfortunately, solid-state phase diagram have remained uncomprehended mystery; only its straight boundary2,3 was explained by struggle of order vs. chaos. Here we show that the volume of orbital overlap has its own energy, with the universal density 8.941 eV/Å3 announced as new fundamental atomic constant that determines the transition temperature TC. Furthermore, we devised solid-state tomography, valid to 5 TPa, - imaging orbital through the baric dependencies of TC. Triangle-shaped pattern of the diagram is explained by the only possible way, just as only one plane passes through triangle: -inflation of the intersection volume during the transition determines hysteresis, but its disappearance does triple point; -approaching ions, whose orbitals overlap, curves the line from zero-field-cooling (ZFC) TC to triple point; -the straight line between zero-field-heating (ZFH) TC and triple point is a consequence of straightening tilting angle. Diamond melting point, calculated from volumes of the tetrahedral covalent bonds, excellently agrees with real; furthermore, the points up to 2 TPa agree with experiment4. Our findings open up way to interpret antiferromagnetism and steric effect in mono, binary, and ternary transition-metal oxides and sulfides5-11, and advance in unravelling unconventional superconductivity12,13, ascertaining the roles of s- and p-hybridizations. Thereby, the importance of the solid-state tomography for organic conductors12,13 being high-compressible and interior of stars can scarcely be exaggerated.

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