Gyógypaedagogiai Szemle 05 (1903) 04

Gyógypaedagogiai Szemle 5. évfolyam, 4. szám Budapest, 1903. április 1. A lap a 6. évfolyam 1. számtól (1904) "Szemle a siketnémák, vakok, hülyék, gyengeelméjűek, dadogók és hebegők oktatásával foglalkozók szakközlönye" cím alatt jelent meg

Estimation of Fluid Distribution in the Arm Using Electrical Impedance Spectroscopy

Fluid distribution in the human arm was estimated using impedance measurements in the frequency range from 100 Hz to 1 MHz from six males and three females. Changes in fluid distributions were induced by postural changes and partial venous occlusion. Impedance measurements were made with an existing four terminal system employing a 100 uA constant current source and phase sensitive detector in conjunction with ancillary circuits. With the use of impedance spectroscopy, data were fitted to an equivalent circuit model. Model parameters were used to determine critical frequency and fitted as a function of time and fluid volume. The resultant model was used to demonstrate fluid distribution in the human forearm and correlated with plethysmography measurements. Data demonstrated sensitivity to small fluid changes due to capillary filtration in distribution of 1.36 ml/ 100 ml tissue

Torsiemodulus en inwendige demping van plastisch gedeformeerd koper tussen -196 en 50° C

Technische MateriaalwetenschappenApplied Science

InSb/CdTe heterostructures grown by MBE

InSb/CdTe heterostructures were grown by MBE, including a 10 layer “superlattice”. The structures were characterized by X-ray diffraction, van der Pauw measurements, and SNMS depth profiling. The interfaces widen because of interdiffusion and through the formation of an interface compound from the reaction of Te with the InSb surface. The interface compound is identified as strained InTe(II). The interfaces are still too wide for practical devices. Thermochemical analysis indicates that the reaction can be suppressed by applying a Cd overpressure. The diffusion of In and Sb in CdTe is very fast and will necessitate a MEE growth scheme at lower temperatures

Mechanisms of neuronal chloride accumulation in intact mouse olfactory epithelium

When olfactory receptor neurons respond to odours, a depolarizing Cl− efflux is a substantial part of the response. This requires that the resting neuron accumulate Cl− against an electrochemical gradient. In isolated olfactory receptor neurons, the Na+–K+–2Cl− cotransporter NKCC1 is essential for Cl− accumulation. However, in intact epithelium, a robust electrical olfactory response persists in mice lacking NKCC1. This response is largely due to a neuronal Cl− efflux. It thus appears that NKCC1 is an important part of a more complex system of Cl− accumulation. To identify the remaining transport proteins, we first screened by RT-PCR for 21 Cl− transporters in mouse nasal tissue containing olfactory mucosa. For most of the Cl− transporters, the presence of mRNA was demonstrated. We also investigated the effects of pharmacological block or genetic ablation of Cl− transporters on the olfactory field potential, the electroolfactogram (EOG). Mice lacking the common Cl−/HCO3− exchanger AE2 had normal EOGs. Block of NKCC cotransport with bumetanide reduced the EOG in epithelia from wild-type mice but had no effect in mice lacking NKCC1. Hydrochlorothiazide, a blocker of the Na+–Cl− cotransporter, had only a small effect. DIDS, a blocker of some KCC cotransporters and Cl−/HCO3− exchangers, reduced the EOG in epithelia from both wild-type and NKCC1 knockout mice. A combination of bumetanide and DIDS decreased the response more than either drug alone. However, no combination of drugs completely abolished the Cl− component of the response. These results support the involvement of both NKCC1 and one or more DIDS-sensitive transporters in Cl− accumulation in olfactory receptor neurons