Library

X
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
    Characterization of natural colloids from a river and spring in a karstic basin (1998)
    Springer
    Environmental geology 34 (1998), S. 257-269 
    Details
    ISSN: 1432-0495
    Keywords: Key words Colloids ; Particle size distribution ; Karstic aquifer ; Analytical techniques ; Bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  Colloids are known to transport contaminants over long distances in natural media. Despite this potentially harmful effect, very few studies have been undertaken in subsurface aquifers. This paper presents the first results of a study of natural colloids and particles in a karstic aquifer. The site was chosen for its coverage by clay layers and peat which deliver various and numerous particle types in water. The methodological part describes three methods used for size determination and sample fractionation of surface water and spring water. These methods have been adapted for the treatment of multiple samples due to the rapid discharge variation typical of karstic aquifers. The analysis of many particle size distributions (PSD) shows that they can be described by a Pareto law. The variation of the slope of the PSD at the spring is mainly dependent on discharge. This behavior is interpreted as a washing of the karstic drains during the first phase of high flow events. Fractionation of the samples allowed application of various characterization techniques to particle size classes. X-ray diffraction (XRD) patterns showed that most of the mineral particles originated from Quaternary deposits and limestones. However the use of scanning electron micrsocopy with energy-dispersive spectrometer (SEM-EDS) detailed the composition of individual particles and revealed particles not found by XRD. These techniques also showed the high complexity of the natural particles and the important place of coprecipitation in their formation. Consequences on the fluxes of particulate matter and its potential role as a carrier of contaminants are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002540050277
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Early detection of IgA specific antibodies in HIV-1 infected children by peptide-ELISA and peptide time-resolved fluoro-immunoassay (1993)
    Springer
    European journal of pediatrics 152 (1993), S. 484-489 
    Details
    ISSN: 1432-1076
    Keywords: Mother-to-child transmission ; HIV-1 ; IgA antibodies ; Peptide-ELISA ; Time-resolved fluoro-immunoassay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The presence of specific IgA antibodies in sera from 25 infants born to HIV-1 seropositive mothers was investigated by peptide-ELISA and peptide time-resolved fluoro-immunoassay (TR-FIA). The infants had been monitored at different times after birth for clinical signs and/or symptoms of HIV-1 infection and for detection of HIV-1 in lymphocyte cultures. Serum samples had also been tested for HIV-1 IgG antibodies by commercial ELISA and Western blot and for p24 antigen. Eleven of 25 children were then identified as infected. IgA detection was performed after rProtein G treatment to remove interfering IgG. In the infected group, IgA specific antibodies to a synthetic peptide representing a highly conserved region of the transmembrane glycoprotein gp41 (env: 594–613) were detected in 27 (73%) out of 37 serum samples (9 of 11 children) by the peptide-ELISA test. IgA specific antibodies to the same peptide were found in 30 (81%) sera (9 of 11 children) by the peptide-TR-FIA. Specific HIV-1 IgA antibodies were detected as early as 2 months of age in serum samples from five out of seven children (71% sensitivity) using peptide-ELISA and from six out of seven (86% sensitivity) by peptide-TR-FIA. Conversely, IgA specific antibodies to HIV-1 were absent in two infected children as well as in the sera of all uninfected children tested during the follow up period. Since maternal IgA does not cross the placenta, IgA detection in the serum of the infant is indicative of HIV-1 infection. Indeed, the early demonstration of HIV-1 IgA antibodies in infected infants shows that both peptide-ELISA and peptide-TR-FIA can be used for an early diagnosis of HIV-1 infection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01955055
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Detection of antibodies to human immunodeficiency virus type I by using synthetic peptides and time-resolved fluoroimmunoassay (TR-FIA) (1992)
    Springer
    European journal of epidemiology 8 (1992), S. 298-304 
    Details
    ISSN: 1573-7284
    Keywords: HIV-1 ; Time-resolved fluoroimmunoassay ; Synthetic peptides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A simple, rapid, reproducible and sensitive peptide-Time-Resolved-Fluoroimmunoassay (TR-FIA) method is described which allows the detection of antibodies to the Human Immunodeficiency Virus type 1 (HIV-1). By using a panel of synthetic peptide antigens that covered env, gag and pol amino acid sequences, a 20 amino acid peptide (GIWGCSGKLICTTAVPWNAS) describing an immunodominant and conserved domain on the gp41 region of the BH10 clone was found to be the most reactive in this study. Optimal conditions for antigen concentration, serum dilution and incubation time were established. The peptide-TR-FIA is specific, as assessed by testing HIV-1 positive sera which included samples from AIDS, ARC patients and HIV-positive drug users. The test was used to detect HIV antibodies in 250 well characterized HIV-1 positive sera and 50 normal sera. Peptide-TR-FIA results indicate that the env peptide was highly reactive with HIV-positive sera showing a sensitivity of 100%. None of the 50 control sera showed positive reactivity against the synthetic peptide. Furthermore the peptide-TR-FIA allowed a fine titration of antibodies to defined epitopes of immunodominant HIV structural proteins that usually cannot be achieved by peptide-ELISA assays.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00144818
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...