Microscope-based imaging platform for large-scale analysis of oral biofilms.

A microscopic method for noninvasively monitoring oral biofilms at the macroscale was developed to describe the spatial distribution of biofilms of different bacterial composition on bovine enamel surfaces (BES). For this purpose, oral biofilm was grown in situ on BES that were fixed at approximal sites of individual upper jaw acrylic devices worn by a volunteer for 3 or 5 days. Eubacteria, Streptococcus spp., and Fusobacterium nucleatum were stained using specific fluorescence in situ hybridization (FISH) probes. The resulting fluorescence signals were subsequently tested by confocal laser scanning microscopy (CLSM) and monitored by an automated wide-field microscope-based imaging platform (Scan∧R). Automated image processing and data analysis were conducted by microscope-associated software and followed by statistical evaluation of the results. The full segmentation of biofilm images revealed a random distribution of bacteria across the entire area of the enamel surfaces examined. Significant differences in the composition of the microflora were recorded across individual as well as between different enamel surfaces varying from sparsely colonized (47.26%) after 3 days to almost full surface coverage (84.45%) after 5 days. The enamel plates that were positioned at the back or in the middle of the oral cavity were found to be more suitable for the examination of biofilms up to 3 days old. In conclusion, automated microscopy combined with the use of FISH can enable the efficient visualization and meaningful quantification of bacterial composition over the entire sample surface. Due to the possibility of automation, Scan∧R overcomes the technical limitations of conventional CLSM.

Immobilization of uranium and arsenic by injectible iron and hydrogen stimulated autotrophic sulphate reduction.

The main object of the study was the development of a long-term efficient and inexpensive in-situ immobilization technology for uranium (U) and arsenic (As) in smaller and decentralized groundwater discharges from abandoned mining processing sites. Therefore, corrosion of grey cast iron (gcFe) and nano-scale iron particles (naFe) as well as hydrogen stimulated autotrophic sulphate reduction (aSR) were investigated. Two column experiments with sulphate reducing bacterias (SRB) (biotic gcFe , biotic naFe) and one abiotic gcFe-column experiment were performed. In the biotic naFe column, no particle translocation was observed and a temporary but intensive naFe corrosion indicated by a decrease in E(h), a pH increase and H(2) evolution. Decreasing sulphate concentrations and (34)S enrichment in the column effluent indicated aSR. Fe(II) retention could be explained by siderite and consequently FeS precipitation by geochemical modeling (PhreeqC). U and As were completely immobilised within the biotic naFe column. In the biotic gcFe column, particle entrapment in open pore spaces resulted in a heterogeneous distribution of Fe-enriched zones and an increase in permeability due to preferential flow. However, Fe(II) concentrations in the effluent indicated a constant and lasting gcFe corrosion. An efficient immobilization was found for As, but not for U.

A clinical evaluation of the Nidek Autorefractor.

A blind study using the Nidek Autorefractor was carried out on 178 eyes to validate the instrument against conventional refractive techniques. A measure of the NAR's reliability was obtained by repeated measurements of the 178 eyes. The NAR overall performance is compared with current autorefractors .

Modifications of B, I, i, and Lewisb antigens in a patient with DiGuglielmo's erythroleukemia.

Loss of red blood cell antigens has been documented in patients with acute myelocytic leukemia and includes loss of A, B, and H antigens in the ABO system as well as antigens of the Rh, MNSsU, Lewis and Ii systems. The following case represents partial loss of the B, I and Lewisb antigens in a patient with erythroleukemia. Also, the loss of the I antigen was associated with a concomitant increase in i antigen, a known but rare finding. These changes within the ABO, Ii, and Lewis systems do not appear to be coincidental, as these blood group systems share a common biochemical backbone.