Structural variation of the human genome sequence is the insertion, deletion, or rearrangement of stretches of DNA sequence sized from around 1,000 to millions of base pairs. Over the past few years, structural variation has been shown to be far more common in human genomes than previously thought. Very little is currently known about the effects…

It is not often realized by chemists that the special theory of relativity is behind several aspects of quantum chemistry. The Schrdinger equation itself is based on relations between space-time and energy-momentum four vectors. Electron spin is, of course, the most obvious manifestation of relativity. The chemistry of some heavy elements is…

Smaller, faster computers, bullet-proof t-shirts, and itty-bitty robots--such are the promises of nanotechnology and the cylinder-shaped collection of carbon molecules known as nanotubes. But for these exciting ideas to become realities, scientists must understand how these miracle molecules perform under all sorts of conditions. This brief…

Nanotechnology is viewed by those in favor of its development in two different ways, and the divide is not recent. This article describes the origins of the differing visions of nanotechnology and examines their broader impacts. The typical history of the field tells nothing about these differing visions, which perhaps misleads. At least two…

Hydrogen activation on the (100) surface of MoS[2] structures was investigated by means of density functional theory calculations. Linear and quadratic synchronous transit methods with a conjugate gradient refinement of the saddle point were used to localize transition states. The calculations include heterolytic and homolytic dissociation of…

In the first phase of the research project Nanotechnologies for Tomorrow's Society (www.nanosoc.be), the research consortium explored a variety of futuristic visions or technoscientific imaginaries. This exploration took the form of a Policy Delphi, adapted to the particular objective of jointly constructing nano-imaginaries, taking participants'…

Compares the coulumbic point charge model for hydrogen chloride with the valence bond model. It is not possible to assign either a nonpolar or ionic canonical form of the valence bond model, while the covalent-ionic bond distribution does conform to the point charge model. (JM)

Describes the chemical structure of paper, including subatomic particles, atoms and molecules, and the forces that bond atoms into molecules, molecules into chains, chains into sheets, and sheets into layers. Acid is defined, and the deleterious role of acid in breaking the forces that bond atoms into molecules is detailed. (EJS)

Supplies information to answer typical student questions relating to the significance of "plus" and "minus" superscripts used for electronic states of linear molecules. (SK)

Organic v inorganic dichotomy in chemistry has begun to disappear while a new formal research discipline, bioinorganic chemistry, is emerging. The field has been developed with the realization that a third of all proteins and bioenzymes contain an inorganic element such as a metal critical to their chemical nature. (Author/RE)

This study assessed the effectiveness of computer-based biomolecular visualization activities on the development of high school biology students' representational competence as a means of understanding and visualizing protein structure/function relationships. Also assessed were students' attitudes toward these activities. Sixty-nine students…

The story of researcher Joseph V. Smith's solution to the chemical structure of a zeolite known as boggsite is presented. The value of the solution and the use of boggsite are discussed. (CW)

An introductory undergraduate physical organic chemistry exercise that introduces the harmonic oscillator's use in vibrational spectroscopy is developed. The analysis and modeling exercise begins with the students calculating the stretching modes of common organic molecules with the help of the quantum mechanical harmonic oscillator (QMHO) model.

Proposes a simple experiment based on the procedure of Guggenheim and Smith for the determinatin of the dipole moments of two isomeric compounds in nonpolar solvents. Provides background information, laboratory procedures, sample data, results of least squares analysis and discussion of results. (JM)

Describes features of a new type of chemical database which provides the ability to search for substances sharing particular structural characteristics. Search concepts are examined in detail, and menu selection of "screens," system commands, and interpretation of results (which appear in the form of chemical bond structures) are…