Interception of small particles by flocculent structures, sessile ciliates, and the basic layer of a wastewater biofilm.

We investigated attachment processes of hydrophobic and hydrophilic particles (diameter = 1 microm) to mature biofilms grown on clay marbles in a sequencing batch biofilm reactor. During a treatment cycle with filtered wastewater containing different fluorescent beads, the progression of particle density in various biofilm compartments (carrier biofilm, basic biofilm layer, biofilm flocs, and sessile ciliates) was determined by flow cytometry, confocal laser scanning microscopy and automated image analysis. Particles were almost completely removed from wastewater by typical processes of particle retention: up to 58% of particles attached to clay marbles, up to 15% were associated with suspended flocs, and up to 10% were ingested by sessile ciliates.

Realistic computerized human phantoms.

To estimate the risk resulting from exposures to ionizing radiation, the organ and tissue doses should be assessed. A convenient method is the calculation of these doses using representations of the human body, called models or phantoms, together with computer codes simulating the transport of radiation in the body. Most commonly used are mathematical phantoms whose external and internal volumes are defined by simple geometric bodies.

Crude or recombinant proteins applied to latex agglutination, complement fixation and enzyme-linked immunosorbent assays for the serodiagnosis of invasive amebiasis.

Three different agglutination tests were developed for the detection of serum antibodies against Entamoeba histolytica. These tests are based on carboxylated polystyrene beads loaded either with a purified recombinant E. histolytica protein, designated recEh-P1, or a soluble fraction, or a membrane fraction (M-LA) both prepared from E.

Sensitive and specific serodiagnosis of invasive amebiasis by using a recombinant surface protein of pathogenic Entamoeba histolytica.

A recombinantly expressed protein, recEh-P1, representing part of an immunodominant surface antigen of pathogenic Entamoeba histolytica, was used for serodiagnosis of invasive amebiasis. Expression was performed under the control of a T7-RNA promoter by using a modified procaryotic expression vector, designated pHisT7. This vector allowed high-yield expression of recEh-P1 fused to a stretch of sequence containing eight histidine residues, which facilitated purification by metal chelate affinity chromatography on Ni2+ columns under highly denatured conditions.

[The scientific accomplishments of coworkers of the Bernhard Nocht Institute between 1900 and 1960. A short historical review].

The historical review presents outstanding scientific achievements obtained by members of the institute during the first 60 years of its existence. They may be summarized as follows: 1. The significance of Gustav Giemsa for stabilizing the Romanowsky stain and revealing its mechanism.