Biomedical subjects

G Faber

Publications and source records attributed to G Faber.

9 recordsLinked to original sources

PubMed2002

Redox-mediated decolorization of synthetic dyes by fungal laccases.

Laccases from the lignin-degrading basidiomycetes Trametes versicolor, Polyporus pinisitus and the ascomycete Myceliophthora thermophila were found to decolorize synthetic dyes to different extents. Differences were attributed to the specific catalytic properties of the individual enzymes and to the structure of the dyes. Due to their higher oxidative capacities, the laccases from the two basidiomycetes decolorized dyes more efficiently than that of the ascomycete. The azo dye Direct Red 28, the indigoid Acid Blue 74 and anthraquinonic dyes were directly enzymatically decolorized within 16 h. The addition of 2 mM of the redox-mediator 1-hydroxybenzotriazole further improved and facilitated the decolorization of all nine dyes investigated. Laccases decolorized dyes both individually and in complex mixtures in the presence of bentonite or immobilized in alginate beads. Our data suggest that laccase/mediator systems are effective biocatalysts for the treatment of effluents from textile, dye or printing industries.

Anthraquinones↗

PubMed2001

The complexity of external acoustic detection of defects in Björk-Shiley convexoconcave heart valves.

Fractures in Björk-Shiley convexoconcave (BScc) heart valves have raised questions about the feasibility of early diagnosis of technical defects by means of acoustic assessment. Three laboratory tests were conducted. To establish acoustic fingerprints, 66 valves with a defect, such as single-leg fracture (SLF) or single-leg separation (SLS), or without a defect were connected with a contact sensor and excited by dropping a small metal ball onto the outlet strut. In the second test, we simulated the valve sound propagation within the thorax. In the third test, intact, SLF, and SLS valves were placed in a mock heart immersed in a large water tank. We observed a resonance frequency corresponding with valve size and presence of defects. The second test showed that both the chest wall and the lungs created numerous reflections. This led to a substantial overlap of the original pulse frequencies and the frequencies measured. The third test confirmed that submersion of the chest in water can significantly reduce chest wall reflections. Reliable noninvasive assessment of BScc valve clicks for the presence of defects of the outlet strut is hampered by complex sound propagation within the thorax and variability of valve excitation. Acoustic fingerprints to diagnose mechanical defects should be integrated in valve design.

Heart Valve Prosthesis↗

PubMed1995

[Diagnosis of performance anxiety in educational spelling tests: new results of the psychometric properties and validity of a relevant brief scale].

In the present study the psychometric properties and the criterion-related validity of a short scale for measuring students' spelling-specific test anxiety were analyzed. This scale consists of 13 self-rating items which reflect students' worry and emotionality reactions in face of spelling requirements at school. Along with some concurrent criterion variables (such as general self-esteem, academic and spelling-related self-concept, and spelling-related attributions, spelling and mathematics achievement, regressive classroom behavior), data were gathered at the beginning (N = 274) and, nearly 11 months later, at the end (N = 257) of the school year. At both measurement times, principal component analyses correspondingly revealed one common test anxiety factor and led to an overall scale format. This final scale solutions appeared to be sufficiently reliable and stable. Furthermore, their relationships to the various criterion variables largely turned out as theoretically expected. Especially, the spelling-specific test anxiety scores could be best predicted by spelling-specific self-concept and by spelling achievement, respectively. Thus, the findings of the present study could replicate the results of a previous pilot study and provided further support for the construct validity of interpretations based upon the spelling-specific test anxiety scale.

Anxiety↗

PubMed1994

Association of pancreatic adenocarcinoma, mild lung disease, and delta F508 mutation in a cystic fibrosis patient.

A case of adenocarcinoma of the pancreas and mild lung disease in a 39-year-old man homozygous for the delta F508 cystic fibrosis mutation is presented. Cystic fibrosis is the most common lethal genetic disease in Caucasians, and is most commonly associated with severe obstructive lung disease. To our knowledge, this is only the fifth case of adenocarcinoma of the pancreas in a CF patient to be reported and the first case for which molecular data are available. The rare incidence of this type of malignancy in the general population suggests a possible association of CF with this malignant disease.

Adenocarcinoma↗

PubMed1986

[Regional differences in frequency-corrected QT duration in multi-electrode ECG in ventricular extrasystole].

Issuing from the pathophysiological significance of a prolongation of the QT-time for the diagnostics and therapy of ventricular arrhythmias examinations on 15 patients with ventricular extrasystoles by means of multi-electrode-ECG are demonstrated in comparison to 10 test persons with healthy heart. 2 regions on the thoracic surface with significant prolongation of the QT-time in the group of patients are described: Regio hypochondriaca parasternally left and left posterior axillary line at the level of the 7th and 8th thoracic vertebral body.

Arrhythmias, Cardiac↗

PubMed1985

Transducers in medical ultrasound: Part Two. Vibration modes, matching layers and grating lobes.

The performance of transducers used for medical diagnosis depends to a great extent on matching layer, backing impedance and geometry of the active surface. In this paper special attention is given to the element vibrational modes, the optimum matching, the grating lobe and change of the real acoustic impedance into an imaginary impedance as a function of the product of the width and wavelength. Grating lobes on the echo image and the effect of a mismatch of the matching layer are illustrated. Suggestions are made for the design of linear and phased array transducers considering the above-mentioned aspects.

Humans↗

PubMed1980

[Prenatal and postnatal diagnosis of triploidy in man (author's transl)].

Prenatal amniocentesis, chromosome analysis, as well as clinical and pathologicoanatomic approaches are some of the ways by which to diagnose triploidy. The methods are described against the background of triploidy (karyotype 69 XXX) in a bipara, 24 years of age. Prenatal examination of hydramnion, particularly in cases with concomitant gestosis, should include amnion cell culturing for early detection of triploidy. Postnatal diagnosis, in response to typical malformation of the foetus and placenta, is possible, provided that thought is given to that aspect.

Adult↗

PubMed1979

[Lactation inhibition by the early postpartum administration of Methylergobrevin].

Lactation was found to be significantly inhibited by greater than or equal to 2.0 mg methylergometrin-bimaleinate administered during the early postpartal period, particularly when the treatment was started as early as on the first or second day of puerperium. Therefore, such ergometrin treatment should be avoided as far as possible in order to improve breast-feeding, which was shown to be of great importance for the mental, psychic and physical development of the newborn.

Breast Feeding↗

PubMed1978

[Evaluation of fetal lung maturity using a modified lecithin-sphingomyelin determination and Clements' foam test].

The modified thin layer chromatographic method for the determination of the phospholipids lecithin and sphingomyelin from amniotic fluid is useful in estimating fetal pulmonary maturity. The foam test of Clements is a simple rapid method for screening of suspicious cases of pregnancies at risk and of great value as bed side test even performing by the doctor. In comparing Clements-Test with thin layer chromatographic for L/S-Ratio determination we found a good correlation of 81,8% of all cases.

Amniocentesis↗