+ Visit NASA.gov + Contact NASA   + Home Select Search Field * All Report - Patent Number Abstract *Accession Number *NASA Center *Author NameDocument IDKeywordsPublication Date *Title * Find Results With All of the words At least one of the words Enter Search Term  within returned results    Search Tips: Use only the fields with * to search NIX collection. Enclose terms in double quotation marks (") to search for exact phrases, ie: "space shuttle". NOTE: Commas and dashes are removed from search term by search engine. Select Reset Search button to start a new search. See Help for more tips. + NASA Center + Publication Year + Subject – Availability Options  + Online  + Order From CASI  + Order From Other Sources + Item/Media Type Selected Navigations: Author > Orgel, L. E. [x] Sort results by: NASA Center | Date Added to NTRS | Publication Year There are a total of 85 record(s) matching your query. Sorted by: Date Added To NTRS in Descending order 1 2 3 4 5 6 7 8 9 Next  Template polymerization of nucleotide analogues Author(s): Orgel, L. E. Abstract: Recent work on the template-directed reactions of the natural D-nucleotides has made it clear that l-nucleotides and nucleotide-like derivatives of other sugars would strongly inhibit the formation of long oligonucleotides. ... NASA Center: NASA (non Center Specific) Publication Year: 1991 Added to NTRS: 2008-06-01 Accession Number: 92N13617; Document ID: 19920004399 Cyclization of nucleotide analogues as an obstacle to polymerization Author(s): Hill, A. R. Jr; Nord, L. D.; Orgel, L. E.; Robins, R. K. Abstract: Cyclization of activated nucleotide analogues by intramolecular phosphodiester-bond formation is likely to compete very effectively with template-directed condensation except in the cases of ribo- and arabinonucleotides. ... NASA Center: NASA (non Center Specific) Publication Year: 1988 Added to NTRS: 2006-08-02 Document ID: 20050000913 The origin of life--how long did it take Author(s): Orgel, L. E. Abstract: We do not understand the steps leading from the abiotic early earth to the RNA world. Consequently, we cannot estimate the time required for the origins of life. Attempts to circumvent this essential difficulty are based on ... NASA Center: NASA (non Center Specific) Publication Year: 1998 Added to NTRS: 2006-08-02 Document ID: 20040112187 A highly enantio-selective hexitol nucleic acid template for nonenzymatic oligoguanylate synthesis Author(s): Kozlov, I. A.; Politis, P. K.; Pitsch, S.; Herdewijn, P.; Orgel, L. E. Abstract: No abstract available NASA Center: Goddard Space Flight Center Publication Year: 1999 Added to NTRS: 2006-08-02 Document ID: 20040089230 PCR with detachable primers Author(s): Silveira, M. H.; Orgel, L. E. Abstract: No abstract available NASA Center: NASA (non Center Specific) Publication Year: 1995 Added to NTRS: 2006-08-02 Document ID: 20050000218 Nucleic acid duplexes incorporating a dissociable covalent base pair Author(s): Gao, K.; Orgel, L. E. Abstract: We have used molecular modeling techniques to design a dissociable covalently bonded base pair that can replace a Watson-Crick base pair in a nucleic acid with minimal distortion of the structure of the double helix. We ... NASA Center: NASA (non Center Specific) Publication Year: 1999 Added to NTRS: 2006-08-02 Document ID: 20040141727 The origin of life--a review of facts and speculations Author(s): Orgel, L. E. Abstract: Three popular hypotheses attempt to explain the origin of prebiotic molecules: synthesis in a reducing atmosphere, input in meteorites and synthesis on metal sulfides in deep-sea vents. It is not possible to decide which is ... NASA Center: NASA (non Center Specific) Publication Year: 1998 Added to NTRS: 2006-08-02 Document ID: 20040142128 Polymerization on the rocks: negatively-charged alpha-amino acids Author(s): Hill, A. R. Jr; Bohler, C.; Orgel, L. E. Abstract: Oligomers of the negatively-charged amino acids, glutamic acid, aspartic acid, and O-phospho-L-serine are adsorbed by hydroxylapatite and illite with affinities that increase with oligomer length. In the case of ... NASA Center: NASA (non Center Specific) Publication Year: 1998 Added to NTRS: 2006-08-02 Document ID: 20040172675 Information transfer from DNA to peptide nucleic acids by template-directed syntheses Author(s): Schmidt, J. G.; Christensen, L.; Nielsen, P. E.; Orgel, L. E. Abstract: Peptide nucleic acids (PNAs) are analogs of nucleic acids in which the ribose-phosphate backbone is replaced by a backbone held together by amide bonds. PNAs are interesting as models of alternative genetic systems because ... NASA Center: NASA (non Center Specific) Publication Year: 1997 Added to NTRS: 2006-08-02 Document ID: 20040172811 Nonenzymatic oligomerization reactions on templates containing inosinic acid or diaminopurine nucleotide residues Author(s): Kozlov, I. A.; Orgel, L. E. Abstract: The template-directed oligomerization of nucleoside-5'-phosphoro-2-methyl imidazolides on standard oligonucleotide templates has been studied extensively. Here, we describe experiments with templates in which inosinic acid ... NASA Center: Goddard Space Flight Center Publication Year: 1999 Added to NTRS: 2006-08-02 Document ID: 20040088800 1 2 3 4 5 6 7 8 9 Next  + Back to Top + Sponsored by the NASA Scientific and Technical    Information Program + 2004 Vision for Space Exploration + Freedom of Information Act + NASA Web Privacy Policy and Important Notices + NASA Disclaimers, Copyright Notice,    and Terms and Conditions of Use NASA Official: Calvin Mackey Page Curator: NASA Center for AeroSpace Information (help@sti.nasa.gov) Last Updated: July 5, 2007