University of Minnesota

About: University of Minnesota is a education organization based out in Minneapolis, Minnesota, United States. It is known for research contribution in the topics: Population & Transplantation. The organization has 117432 authors who have published 257986 publications receiving 11944239 citations. The organization is also known as: University of Minnesota, Twin Cities & University of Minnesota-Twin Cities.

The Global Decline of Nonmarine Mollusks

Abstract: Invertebrate species represent more than 99% of animal diversity; however, they receive much less publicity and attract disproportionately minor research effort relative to vertebrates. Nonmarine mollusks (i.e., terrestrial and freshwater) are one of the most diverse and imperiled groups of animals, although not many people other than a few specialists who study the group seem to be aware of their plight. Nonmarine mollusks include a number of phylogenetically disparate lineages and species-rich assemblages that represent two molluscan classes, Bivalvia (clams and mussels) and Gastropoda (snails, slugs, and limpets). In this article we provide an overview of global nonmarine molluscan biodiversity and conservation status, including several case studies documenting the diversity and global decline of nonmarine mollusks. We conclude with a discussion of the roles that mollusks and malacologists should play in conservation, including research, conservation management strategies, and education and ou...

How Enzymes Work: Analysis by Modern Rate Theory and Computer Simulations

Abstract: Advances in transition state theory and computer simulations are providing new insights into the sources of enzyme catalysis. Both lowering of the activation free energy and changes in the generalized transmission coefficient (recrossing of the transition state, tunneling, and nonequilibrium contributions) can play a role. A framework for understanding these effects is presented, and the contributions of the different factors, as illustrated by specific enzymes, are identified and quantified by computer simulations. The resulting understanding of enzyme catalysis is used to comment on alternative proposals of how enzymes work.

Sub-10 nm imprint lithography and applications

Abstract: New developments, further details, and applications of imprint lithography are presented. Arrays of 10 nm diameter and 40 nm period holes were imprinted not only in polymethylmethacrylate (PMMA) on silicon, but also in PMMA on gold substrates. The smallest hole diameter imprinted in PMMA is 6 nm. All the PMMA patterns were transferred to a metal using a liftoff. In addition, PMMA mesa’s of a size from 45 nm to 50 μm were obtained in a single imprint. Moreover, imprint lithography was used to fabricate the silicon quantum dot, wire, and ring transistors, which showed the same behavior as those fabricated using electron (e)-beam lithography. Finally, imprint lithography was used to fabricate nanocompact disks with 10 nm features and 400 Gbits/in.2 data density—near three orders of magnitude higher than current critical dimensions (CDs). A silicon scanning probe was used to read back the data successfully. The study of wear indicates that due to the ultrasmall force in tapping mode, both the nano-CD and the ...