Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    JBIC 2 (1997), S. 393-398 
    ISSN: 1432-1327
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract  Nature has engineered a universe of redox proteins to efficiently control the oxidation and reduction of substrates and to convert redox energy into a delocalized transmembrane proton gradient power source. Some rapid physiologically relevant electron transfers are rate limited by electron tunneling. Distance appears to be the principle means naturally selected to control the speed of electron tunneling; free energy and reorganization energy can play important auxiliary roles. Thus, an electron from a biological redox center can tunnel in any direction and is likely to reduce the closest redox center with a favorable free energy. Although it is clearly possible to facilitate electron tunneling by designing covalent bridges in the regions between donors and acceptors, this does not seem to be a strategy that evolution has used. Evolutionary mutagenic adjustment of a bridge-like quality of the amino acid medium may be difficult in the face of heavy selection on the folding, stability and other properties of the protein medium. Repositioning cofactors by even a few angstroms has more profound effects on promoting and retarding rates, independent of the structure of the amino acid medium.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 208 (1984), S. 507-514 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Plain silastic intrauterine devices or those containing 270 m̈g of indomethacin were inserted into the caudal portion of one uterine horn of mature Wistar rats. After a 3-week period animals were fixed by perfusion on the morning of day 2 after estrus. Segments of uterine tissue corresponding to regions adjacent to and cranial to the devices as well as an equivalent portion of the contralateral horn were embedded in glycol methacrylate. A group of control animals without any form of device were treated in an identical manner. Sections cut from these segments were evaluated by grid-point stereology to ascertain changes in tissue volumes and cell populations. It was found that the presence of plain devices induced hypertrophy in the stroma and myometrium of the portion of the uterus adjacent to the device. The presence of indomethacin in such devices prevented stromal hypertrophy.No changes in populations of fibroblasts or areas of glandular or vascular tissue were evident in any treatment group. Cell populations of neutrophils, eosinophils, and mononuclear cells, however, were elevated in the superficial stroma of the horns bearing either type of device; this feature was more pronouced for neutrophils in the presence of the indomethacin devices. Neutrophils, rather than eosinophils, predominated in the epithelia of the uterus bearing either type of IUD. Conversely, eosinophil populations were reduced in the superficial tissues cranial to the devices delivering indomethacin. Neutrophils and mononuclear cells were also found to be elevated in the deep stroma of tissues adjacent to both the plain and medicated device.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...