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K Potter

Publications and source records attributed to K Potter.

33 records · Page 2Linked to original sources
PubMed1996

Assay for bacteria in porous media by diffusion-weighted NMR.

In this work, an NMR technique capable of detecting bacterial cells and measuring the cell density in suspension and in porous media has been developed. It is based on the pulsed-field-gradient technique and relies on the fact that extracellular water diffuses freely while intracellular water is completely restricted by the relatively impermeable cell wall of the bacterium. At high wave vectors, the signal from extracellular water is completely suppressed while the signal from intracellular water is comparatively unaffected. This technique has been applied to the mapping of bacterial distributions in porous media. This method is presented as a non-destructive, real-time technique for biomass characterization within laboratory column and flow cell experiments, and possibly for monitoring in situ bioremediation.

Biodegradation, Environmental↗
PubMed1996

Ion transport studies in calcium alginate gels by magnetic resonance microscopy.

Polyelectrolyte biopolymers such as calcium alginate are becoming increasingly important for the recovery of heavy metals from aqueous solutions. To understand the mechanism of ion transport in these biopolymer systems, the transport of copper ions into calcium alginate gels was investigated using proton nuclear magnetic resonance (NMR) microscopy. Copper ion transport was imaged using an inversion recovery technique which utilizes the paramagnetic effect of copper on water proton relaxation times. Diffusion experiments were performed in a diffusion cell designed to approximate a semi-infinite slab geometry at temperatures between 278 and 313 K using copper reservoir concentrations between 10 and 60 mM. The diffusion coefficient of copper in these gels was calculated from the NMR data to fit a combined diffusion-reaction model involving a diffusion term (D) and a kinetic binding term (k). At 23 degrees C, the diffusion coefficients in 1, 2, and 3% (w/v) gels were 3.1 x 10(10), 2.0 x 10(10), and 1.4 x 10(10) m2/s, respectively. The activation energy for diffusion in the 2% (w/v) gel was 28 kJ/mol.

Alginates↗
PubMed1994

Magnetic resonance imaging (MRI) of calcium alginate gels.

The spatial heterogeneity of calcium alginate gels has been visualised by the variation of image intensity across the gel by one-, two-, and three-dimensional MRI. From the linear dependence of (T2)-1 on alginate concentration it is now possible to use MRI to map alginate concentration gradients within calcium alginate gels noninvasively. Since the concentration of alginate determines the pore size of the gel matrix, those alginate concentration maps will be useful in determining the pore size distribution within the gel, which is important in controlled release applications.

Alginates↗
PubMed1991

Clinical and pathologic features of endometrial hyperplasia, pyometra, and endometritis in cats: 79 cases (1980-1985).

Records of 79 cats determined to have endometrial hyperplasia (EH) with or without pyometra or endometritis were studied. Forty-eight cats (61%) were spayed or died because of complications relating to reproductive tract disease. All other cats were free of clinical signs of disease, and lesions were found incidentally during routine ovariohysterectomy or at necropsy. Prevalence of uterine lesions was greater in cats greater than or equal to 5 years old. Breeding, age at first breeding, and queening could not be correlated with clinical or pathologic signs of disease. Seventy-one percent (34/48) of cats with clinical signs referable to the reproductive tract had histologic evidence of pyometra or endometritis, whereas only 19% (6/31) of cats without clinical signs had histologic evidence of either disease. Only 23% (9/39) of cats without pyometra or endometritis had corpora lutea (CL) in at least one ovary, whereas 40% (16/40) of cats with either pyometra or endometritis had CL. We concluded that the prevalence of EH in cats increases with age in sexually intact female cats, and that most cases of pyometra or endometritis, but not EH, in cats are associated with retained CL.

Age Factors↗
PubMed1986

A review of eosinophil chemotaxis and function in Taenia taeniaeformis infections in the laboratory rat.

The eosinophil has long been associated with diseases of acute hypersensitivity and with parasite infections, but its exact role in the pathogenesis of these conditions remains uncertain. Characterization of factors associated with migration of eosinophils into tissues has helped to elucidate eosinophil function. Eosinophil chemotactic factors associated with acute hypersensitivity reactions include the eosinophil chemotactic factors of anaphylaxis, histamine, and arachidonic acid metabolites, all of which are released from mast cells, and the lymphokine eosinophil stimulation promoter (ESP). Eosinophilotaxins associated with parasitic diseases include the lymphokine ESP and the low molecular weight factor ECF-G, both associated with schistosome infection in mice. In addition, in several parasite infections parasite-derived protein eosinophil chemotactic factors have been identified and characterized. The proteins associated with Ascaris, Anisakis, and Schistosoma infections appear to be distinct from one another. We have recently partially characterized a protein from Taenia taeniaeformis larvae which has marked chemotactic activity for eosinophils. In addition we have demonstrated eosinophil chemotactic activity associated with metabolism of arachidonic acid by T. taeniaeformis metacestodes. The results of studies in taeniasis and other parasite infections, therefore, indicate that parasite-derived factors may directly influence migration of eosinophils.

Animals↗
PubMed1977

My universe.

Explore the source record for details and available documents.

Female↗
PubMed1976

The adjunct consumer group.

Little by little, the community is becoming aware of the Weber Mental Health Center and PAAG. A recent study shows that the community approach leads to high visibility; PAAG activities were known by 37% of 1,000 people recently interviewed. This compares to 5%, 7%, and 15% having knowledge of other more traditional medical centers in Utah. It is felt that this approach is an important part in putting the community mental health center in proper perspective in the community. It is felt that the adjunct consumer group provides almost infinite flexibility to meet human needs. As a result, the Northern Utah Unit of the State Hospital will remain closed, largely because PAAG is serving the community.

Adult↗
PubMedDate not supplied

Cutaneous mast cell tumors in cats: 32 cases (1991-1994).

Case records of 32 cats with cutaneous mast cell tumors (CMCTs) were reviewed. Using the Patnaik system for grading canine mast cell tumors, the relationships between histopathological grade and patient survival time and tumor recurrence were examined. Tumor histopathological grade had no prognostic significance. One-, two-, and three-year tumor recurrence rates following surgical excision were 16%, 19%, and 13%, respectively. Incomplete excision was not associated with a higher rate of tumor recurrence.

Animals↗
PubMedDate not supplied

Cholangiocarcinoma in a yellow-faced Amazon parrot (Amazona xanthops).

A cholangiocarcinoma in a 3 1/2-year-old yellow-faced Amazon parrot (Amazona xanthops) is reported. The parrot presented with a prolapsed cloaca and died after a 6-week clinical course of progressive weight loss. The tumor replaced much of the normal hepatic architecture but apparently did not metastasize. Cholangiocarcinomas have been reported rarely in several species of domestic and captive wild birds, but this appears to be the first reported case in a large psitticiform bird.

Adenoma, Bile Duct↗