Publications by authors named "Stick C"

Spatial measurements of the diffusely scattered sky radiance at a seaside resort under clear sky and slightly overcast conditions have been used to calculate the sky radiance distribution across the upper hemisphere. The measurements were done in the summer season when solar UV radiation is highest. The selected wavelengths were 307, 350 and 550 nm representing the UVB, UVA and VIS band.

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About four decades ago, Perl and collaborators were the first ones who unambiguously identified specifically nociceptive neurons in the periphery. In their classic work, they recorded action potentials from single C-fibers of a cutaneous nerve in cats while applying carefully graded stimuli to the skin (Bessou P, Perl ER. Response of cutaneous sensory units with unmyelinated fibers to noxious stimuli.

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Dermatologists recommend that people avoid exposure to the blazing sun around noontime. In most places in Europe there are considerable deviations between true solar time and standard time: Firstly, during summer the standard time in the European countries is set one hour ahead according to the summer time or daylight saving time. Secondly, in all countries of Western and Central Europe, except Great Britain, Ireland and Portugal, standard time uniformly is Central European Summer Time (CEST).

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As a consequence of the stratospheric ozone layer depletion biological systems can be damaged due to increased UV-B radiation. The aim of biological dosimetry is to establish a quantitative basis for the risk assessment of the biosphere. DNA is the most important target molecule of biological systems having special sensitivity against short wavelength components of the environmental radiation.

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The venous pressure in the saphenous vein at the ankle was measured in ten healthy subjects (5 men, 5 women) aged 19-33 years during supine posture, orthostasis and cycle ergometer exercise (50 W, 50 rpm). Measurements were made at 20, 28 and 36 degrees C at 50% relative humidity. A custom-built setup consisting of two pressure transducers and a differential amplifier was used to compensate for the hydrostatic effects, temperature influences and movement artefacts that disturbed the pressure measurements.

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The purpose of this study was to investigate whether ambient temperature influences both the rate of leg swelling during orthostasis and the oedema-preventing effect of the skeletal muscle pump. Using mercury-in-rubber strain gauges, volume changes were measured in the calf (n = 34) and near the ankle (n = 24) in healthy volunteers aged 19-33 years. Measurements were performed during 12 min of motionless standing in an upright posture and during 17 min of cycle exercise at intensities of 50 W and a pedalling rate of 50 rpm.

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This study investigates whether walking or running prevents the formation of edema in the lower leg. In 18 volunteers changes in calf volume were measured using strain gauge plethysmography during slow (3 km/h) and fast (6 km/h) walking or running (10 km/h) on a treadmill for 20 min each. Venous pressure was measured in a superficial vein near the ankle.

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Findings obtained in humans and test animals raised the question whether strong static magnetic fields as used in NMR-tomography may affect tissue perfusion. In two test series including 20 subjects, each skin blood flow at the thumb was determined by heat clearance, and forearm blood flow was measured by venous occlusion plethysmography. For comparative purposes, measurements were carried out bilaterally at both extremities.

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To study the transcapillary fluid movements in the human lower limb in the upright body position and during muscle exercise, the slow changes in thigh and calf volumes were measured by mercury-in-rubber-strain gauge plethysmography. Measurements were carried out on 20 healthy volunteers while sitting, standing and doing cycle ergometer exercise at intensities of 50 and 100-W. A plethysmographic recording of slow extravascular volume changes during muscle exercise was possible because movement artefacts were eliminated by low-pass filtering.

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During motionless standing an increased hydrostatic pressure leads to increased transcapillary fluid filtration into the interstitial space of the tissues of the lower extremities. The resulting changes in calf volume were measured using a mercury-in-silastic strain gauge. Following a change in body posture from lying to standing or sitting a two-stage change in calf volume was observed.

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The efficacy of various irradiation regimens in phototherapy of neonatal hyperbilirubinaemia was analysed. One hundred and one newborns were assigned to three groups at random. The best results were achieved when six special blue fluorescent lamps were used and the sides of the incubator were draped with white cloth to reflect the light diffusely.

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Two cases of dermatitis solaris in newborns after phototherapy with a halide burner gave reason to measure the UV-B radiation emitted by the instrument used. Values between 0.8 microW/cm2 and 1.

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On physiological edema in man's lower extremity.

Eur J Appl Physiol Occup Physiol

January 1986

To examine whether the so-called musculovenous pump counteracts the development of interstitial edema in the lower extremities of man in the upright position, the volume changes in the calf which occurred during twenty minutes of rhythmic muscular exercise were measured in twenty-three subjects by impedance-plethysmography. The results were compared with the volume increase found during quiet relaxed standing for the same length of time. Contrary to the hypothesis, and edema-protective effect of the musculovenous pump could only be shown in about half the number of the subjects.

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The effective radiant power of a metal halide lamp for phototherapy of neonatal jaundice was measured in an incubator. This new lamp is characterised by an extremely heterogeneous field of irradiance with a high intensity in the centre and a marked decrease towards the sides. The mean radiant intensity in a central area (20 X 40 cm) of the incubator can be compared with the values achieved with standard fluorescent lamps in an incubator lined with white cloth.

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A simple low cost device is described for measuring the irradiation intensity used in phototherapy of hyperbilirubinemia in newborns. The spectral selectivity of the sensor is adapted to the most effective wavelength for phototherapy. The device can be calibrated in W/m2.

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Knowledge of the effective irradiation dose is a prerequisite to predicting the efficacy of phototherapy. To gain this information, the field of irradiation of a phototherapy lamp was measured in an incubator. It became apparent that the radiant power is extremely heterogeneously distributed in the incubator.

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The idea of this paper is to examine, after a discussion of the theoretical foundations, to what extent impedance plethysmography enables us to measure changes in the volume of the human extremities caused by capillary fluid filtration. Possibilities of error shown up in this paper - e. g.

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[Transthoracic electrical impedance (author's transl)].

Eur J Appl Physiol Occup Physiol

July 1981

The measurement of transthoracic impedance is used by many authors to determine tidal volume and changes of intrathoracic fluid volume. In clinical diagnostics, too, this method has been introduced. Furthermore, the stroke volume of the heart is often said to be calculable from changes in impedance synchronous with the cardiac cycle.

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40 determinations of the stroke volume were carried out by impedance cardiography in one and the same subject. The stroke volume varied between 136 and 209 ml (x, x = 169 ml, S.D.

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The stroke volume at rest of 81 test subjects with no evident cardiac or circulatory dysfunction was determined by impedance cardiography and the measurements were repeated after 11 weeks. In order to attain comparable and reproducible conditions, 44 test subjects were chosen who showed heart rates at rest not higher than 83 beats per min, and whose changes in heart rate between the two tests were not greater than 11 beats per min. The stroke volumes determined by impedance cardiography are greater than those measured with the invasive methods reported by other authors.

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