Doublets
Mostrando 13-24 de 110 artigos, teses e dissertações.
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13. Estudo ultra-estrutural da espermiogenese e dos espermatozoides de Cosmopolites sordidus germar (Coleoptera : Curculionidae)
The spermiogenesis of Cosmopolites sordidus was investigated with the use of thin sections, negative staining preparations, and scanning electron microsoopy of spermatic cells obtained from the testicles or spermathecae.1n this species as with insects in general, this process is characterized by the following events: flagellar formation, chromatin condensati
Publicado em: 1993
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14. Distribution of short paired duplications in mammalian genomes
Mammalian genomes are densely populated with long duplicated sequences. In this paper, we demonstrate the existence of doublets, short duplications between 25 and 100 bp, distinct from previously described repeats. Each doublet is a pair of exact matches, separated by some distance. The distribution of these intermatch distances is strikingly nonrandom. An u
National Academy of Sciences.
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15. Repetitive doublets in human flexor carpi radialis muscle.
Single-motor-unit activity was recorded from flexor carpi radialis of two human subjects. 2. A large number of units showed repetitive doublets at the onset of slow recruitment. A unit starting with doublets would transfer to a normal firing pattern as the force increased. 3. At different speeds of ramp contractions, the number of doublets discharging at the
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16. The incidence of initial doublets in the discharges of motoneurones of two different inspiratory muscles in the cat.
1. Trains of action potentials in motoneurones frequently commence with an initial doublet; i.e. a uniquely short interspike interval. Previous authors have speculated on the functional importance of initial doublets. Here we test the hypotheses that these doublets are associated with particular classes of motoneurones or particular physiological conditions.
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17. Kinetics and locus of failure of receptor-ligand-mediated adhesion between latex spheres. II. Protein-protein bond.
In an extension of the previous paper, we describe the force dependence of break-up of doublets of latex spheres cross-linked by protein G-IgG bonds via the Fc region of the antibody. The receptor, the monoclonal Bear-1 antibody, was either covalently linked to 4.75-microns aldehyde/sulfate (A/S) latex spheres in a one-step reaction, or physically adsorbed t
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18. Spore location patterns in sporulating doublets of Bacillus cereus and Bacillus megaterium, derived from single doublet isolates with differing sporulation geometry.
The distribution of spore loci in pairs of Bacillus cereus and B. megaterium showed different degrees of polarization from random location towards location at the old end of the sporangium. When individual doublets containing both spores at either the old or new ends of the sporangia were isolated by micromanipulation, subsequent culture showed the same spor
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19. Sequence-Directed Base Mispairing in Human Oncogenes
The most frequently observed mutations in ras oncogenes in solid human tumors are GC→AT transitions at the 3′ G residue of the GG doublet in codon 12 of these oncogenes. We had shown previously that mutagenesis by thymidine occurred with the same sequence specificity in mammalian cells, in that mutagenesis occurred preferentially at the 3′ G of GG doub
American Society for Microbiology.
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20. Simulation of Cyclic Dynein-Driven Sliding, Splitting, and Reassociation in an Outer Doublet Pair
A regular cycle of dynein-driven sliding, doublet separation, doublet reassociation, and resumption of sliding was previously observed by Aoyama and Kamiya in outer doublet pairs obtained after partial dissociation of Chlamydomonas flagella. In the work presented here, computer programming based on previous simulations of oscillatory bending of microtubules
The Biophysical Society.
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21. Kinetics and locus of failure of receptor-ligand-mediated adhesion between latex spheres. I. Protein-carbohydrate bond.
We previously described the use of a counter-rotating cone and plate rheoscope to measure the time and force dependence of break-up of doublets of sphered, swollen, and fixed red cells (SSRC) cross-linked by monoclonal IgM antibody. It has been shown that doublet break-up can occur by extraction of receptors from the membrane, rather than by antibody-antigen
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22. Interaction forces between red cells agglutinated by antibody. IV. Time and force dependence of break-up.
We report on an extension of a previously described method to measure the hydrodynamic force to separate doublets of fixed, sphered and swollen red cells cross-linked by antibody (S. P. Tha, J. Shuster, and H. L. Goldsmith. 1986. Biophys. J. 50:1117-1126). With a traveling microtube apparatus, doublets are tracked and videotaped in a slowly accelerating Pois
The Biophysical Society.
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23. Isolation and Partial Characterization of α- and β-Tubulin from Outer Doublets of Sea-Urchin Sperm and Microtubules of Chick-Embryo Brain
Two kinds of tubulin (α and β) have been described in microtubules from many different systems. In this study a discontinuous acrylamide-gel system containing sodium dodecyl sulfate was used to separate milligram quantities of α- and β-tubulin from microtubules of chick-embryo brain and from outer doublets of sea-urchin sperm. The isolated tubulins were
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24. Electron transfer in DNA duplexes containing 2-methyl-1,4-naphthoquinone
2-Methyl-1,4-naphthoquinone (menadione, MQ) was linked to synthetic oligonucleotides and exposed to near-UV light to generate base radical cations in DNA. This model system of electron transfer induced alkali-labile breaks at GG doublets, similar to anthraquinone and metallointercalators systems. In sharp contrast to other systems, the photolysis of MQ–DNA
Oxford University Press.