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Biomedical subjects

U Breuer

Publications and source records attributed to U Breuer.

11 recordsLinked to original sources
PubMed2003

XRF and SIMS/SNMS analyses of BaxSr1-xTiO3 dielectrics.

The development of analytical tools and procedures for process control is a prerequisite for the integration of high permittivity and/or ferroelectric materials in CMOS devices. The thickness and composition of perovskite oxide films were determined by wavelength dispersive X-ray fluorescence analysis (XRF) with special emphasis on the ratio of the group-II elements to the Ti content, and a precision of 0.5% was achieved for a typical film thickness of 20-30 nm. Secondary ion mass spectrometry (SIMS) and sputtered neutrals mass spectrometry (SNMS) was used for depth profiling to determine film homogeneity and elemental interdiffusion at hetero-interfaces. Examples are given for Ba(x)Sr(1-x)TiO(3) and SrTiO(x) thin films which were grown in a prototype MOCVD production tool. No interdiffusion was observed for films grown at 600 degrees C on Pt electrodes in contrast to films grown directly on Si.

Journal Article↗
PubMed2001

Physiology, regulation, and limits of the synthesis of poly(3HB).

The properties of poly(3-hydroxybutyrate) combined with the fact that it can be produced easily by numerous prokaryotes from renewable resources and even from potentially toxic waste products using well-known fermentation processes have generated keen interest in this biopolyester as a substitute for chemo-synthetic petroleum-derived polymers in many applications. However, the high price of poly(3HB) compared with the conventional synthetic materials currently in use has restricted its availability in a wide range of applications. If the economic viability of poly(3HB) production and its competitiveness are to be improved, more must be found out about the phenotypic optimization and the upper limits of bacterial systems as the factory of poly(3HB). In this chapter, two aspects of poly(3HB) are reviewed--poly(3HB) formation as a physiological response to external limitations and overcoming internal bottlenecks, and poly(3HB) as a commercially attractive polyester. From a physiological viewpoint, the ability to synthesize and degrade poly(3HB) is considered an investment in the future and provides organisms with a selective advantage. Poly(3HB) is presented as a strategic survival polymer, and it is shown that growth-associated synthesis is not as rare as reported. The influence of the efficiency and velocity of cell multiplication and product formation, of poly(3HB) content and of productivity on the overall yield, and finally on the economics of the whole process are discussed and evaluated from the technological or consumer's point of view. The specific production rate and poly(3HB) content appear to be more important than the yield coefficients.

Chemical Engineering↗
PubMed1993

Outpatient treatment of unilateral diabetic foot ulcers with 'half shoes'.

The impact of 'half shoes' in the treatment of neuropathic forefoot ulcers was studied in two groups of diabetic patients, who were treated either by standard treatment alone (retrospective controls, n = 22), or by standard treatment plus 'half shoes' (cases, n = 26). The groups were matched for sex, age, type, and duration of diabetes and ulcer grading. The 'half-shoe' cases' vs controls' median overall healing time was 70 vs 118 days, the median difference being 48 (95% CI: -5 to 82) days (NS). In the case group, hospitalization was required in 1/26 (4%) of patients, vs 9/22 (41%) of the control patients (chi-square, p < 0.01). The home nursing service was required in 23% of the cases vs 18% of the controls (NS). It is concluded that the use of half-shoes, in conjunction with standard treatment provided by a specialized diabetic foot clinic, may reduce the overall healing time and does reduce the hospitalization rate. This has implications for a rational strategy of treating unilateral diabetic neuropathic foot ulcers.

Adult↗
PubMed1976

[Skin tests with phytohaemagglutinin (PHA). Correlation with other parameters of cell-mediated immunity (author's transl)].

100 healthy persons were investigated to find out whether there is a correlation between a lymphocyte stimulation (3H-thymidine incorporation in the lymphocyte transformation test) with phytohaemagglutinin, pokeweed mitogen and concanavalin A and the in vivo reactivity to intracutaneous phytohaemagglutinin application (measured as medium diameter of infiltrates). Further we searched for an influence of positive or negative reactivity to the specific antigens trichophytin, candidin and streptokinase-streptodornase. 1. There is a good qualitative correlation in normal persons between in vitro lymphocyte stimulation by phytohaemagglutinin, pokeweed mitogen and concanavalin A and the medium diameter of infiltrates after intracutaneous application of 2 mug phytohaemagglutinin. Using lower doses of phytohaemagglutinin no such correlation could be found. A quantitative correlation between the medium diameter of infiltrates and lymphocyte transformation by phytohaemagglutinin and pokeweed mitogen cannot be demonstrated. For concanavalin A there is a negative correlation significant at the 99% level. 2. In vivo reactivity to phytohaemagglutinin does not differ in persons with negative and positive reactions to the specific antigens. 3. Lymphocyte stimulation by phytohaemagglutinin, pokeweed mitogen and concanavalin A of persons with positive reactions to trichophytin, candidin and streptokinase-streptodornase is significantly greater than in those with negative reactivity. 4. The results indicate in vivo phytohaemagglutinin testing as a good screening method to judge cell-mediated immunocompetence. The general applicability for differentiation of immunodeficient and immunocompetent patients is to be further investigated.

Adolescent↗
PubMedDate not supplied

Diabetic patient's compliance with bespoke footwear after healing of neuropathic foot ulcers.

OBJECTIVES: To define personal attributes and factors associated with compliance to wearing protective footwear in severely neuropathic diabetic patients with a history of foot ulceration. DESIGN: Case-control study. SETTING: Diabetic foot clinic. SUBJECTS: 85 patients regularly attending the foot clinic were assessed after healing of neuropathic foot ulceration. INTERVENTION: Recommendation of wearing cushioned bespoke shoes instead of normal shoes, prescription of up to 2 pairs of bespoke shoes on request. MAIN OUTCOME MEASURES: Clinical characteristics and attitudes of compliant patients wearing bespoke shoes (cases) versus non-compliant control patients wearing normal shoes on a random day. RESULTS: The 51 case patients were significantly older and more often amputated than the 34 controls; they more frequently rated their feets' sickness and their overall health status as less favourable than did controls (p < 0.05). The controls, however, were more often on renal replacement therapy. Although the appearance of bespoke shoes was disliked by all of the patients, and 47% of the cases and 100% of the controls would favour normal shoes for cosmetic reasons, all case patients wore their bespoke shoes according to the physicians recommendation, as compared to 26% of the controls (p < 0.01). CONCLUSION: Differences in age, perception of foot abnormalities and health status, and other distressing medical conditions (i.e. renal replacement therapy, previous minor amputations) in addition to cosmetic reasons may affect the patients' compliance with bespoke protective footwear.

Diabetic Foot↗