Cherie L. Fisk

Development of NMR: From the Early Beginnings to the Early 1990s

A gas bag of high safety, responsibility and stability for attachment to a high speed moving vehicle, comprising a hollow bag body, a gas introducing hole means, and at least one restraining member provided in the hollow bag body for restraining the free deformation of said hollow bag body upon the pressing of the occupant thereagainst in the inflated condition, said restraining member having at least one breaking part which is broken when a predetermined tensile force is applied to the restraining member, whereby, when the occupant presses said inflated bag body in the sudden stop of the moving apparatus, at least one breaking part is broken and a rebounding force of the bag body against the occupant can be remarkably reduced.

An Overview of Biological Applications of NMR

Since its discovery in 1946, NMR has developed to one of the most widely used tools in chemistry and is rapidly becoming an essential technique in biology and medicine. In this introductory chapter the use of NMR in biology and biochemistry is traced from early studies of small molecules of biological interest, through the study in vitro of biopolymers and cell constituents, to the current applications of in vivo spectroscopy and imaging. The development of improved instruments and introduction of new methods that are essential to current uses are emphasized.

NMR: New techiques for chemical analysis and biological investigation

Nuclear magnetic resonance (NMR) has become an increasingly valuable technique over the last three decades for the study of molecular structure of organic compounds. Within recent years a number of major advances in experimental methods have led to an explosion in the information elicited from NMR spectra and to a spectacular increase in the kinds of samples that can be studied by NMR. With the use of higher magnetic fields and greatly improved electronic techniques, NMR has undergone orders of magnitude increase in sensitivity, so that low concentrations of materials can be studied in chemical samples and in living systems, from cells to whole animals and humans. The use of two-dimensional NMR methods permits the unravelling of complex spectra, and innovative pulse techniques provide high resolution NMR spectra in solids. NMR imaging furnishes information on spatial distribution of materials and permits discrimination among various kinds of tissues. This chapter reviews some fundamentals of NMR and presents an elementary account of the theory and methods used in modern NMR applications.

An Introduction to NMR Relaxation Mechanisms

The phenomena of spin-lattice and spin-spin relaxation and their effect on NMR signals are described. Pulse methods for measuring T1 and T2 are given. A simple picture of molecular motions and of interactions between nuclei and randomly varying fields is developed to provide a qualitative explanation of the observed phenomena. The various mechanisms for relaxation are discussed, with particular emphasis on those found most frequently in biological systems.