Biomaterial Database

An ultrasonic study of the thermotropic transition of dipalmitoyl phosphatidylcholine. 1979

J E Harkness, and R D White

The acoustic absorption of sonicated and unsonicated suspensions of dipalmitoyl phosphatidylcholine has been studied as a function of temperature at frequencies between 0.6 and 4.0 MHz. The absorption at a fixed frequency passes through a maximum at a temperature which is dependent on the sample preparation and history and somewhat dependent on the frequency of observation, with sonicated vesicles exhibiting a temperature of maximum absorption 2--3 degrees C below that found for unsonicated dispersions. The temperature dependence of the absorption at fixed frequency suggests a cooperative process while the frequency dependence of the absorption at fixed temperature indicates that more than a single relaxation time is required to describe the acoustic absorption.

UI	MeSH Term	Description	Entries
D008081	Liposomes	Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.	Niosomes,Transferosomes,Ultradeformable Liposomes,Liposomes, Ultra-deformable,Liposome,Liposome, Ultra-deformable,Liposome, Ultradeformable,Liposomes, Ultra deformable,Liposomes, Ultradeformable,Niosome,Transferosome,Ultra-deformable Liposome,Ultra-deformable Liposomes,Ultradeformable Liposome
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D011663	Pulmonary Surfactants	Substances and drugs that lower the SURFACE TENSION of the mucoid layer lining the PULMONARY ALVEOLI.	Surfactants, Pulmonary,Pulmonary Surfactant,Surfactant, Pulmonary
D013816	Thermodynamics	A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)	Thermodynamic
D014465	Ultrasonics	A subfield of acoustics dealing in the radio frequency range higher than acoustic SOUND waves (approximately above 20 kilohertz). Ultrasonic radiation is used therapeutically (DIATHERMY and ULTRASONIC THERAPY) to generate HEAT and to selectively destroy tissues. It is also used in diagnostics, for example, ULTRASONOGRAPHY; ECHOENCEPHALOGRAPHY; and ECHOCARDIOGRAPHY, to visually display echoes received from irradiated tissues.	Ultrasonic