The microgravity experienced during space flight induces physiological changes that affect astronauts' health and performance. Simulations such as prolonged bed rest can mimic some of these changes and provide study conditions that are more accessible than during space flight itself. Previous studies, including several long and short-term bed-rest campaigns supported by ESA, have yielded signif...

Changes in peritubular oncotic pressure do not alter the electrical resistance of distal convoluted tubules. Transverse specific electrical resistance decreases along the distal convoluted tubule in nondiuretic rats. This drop in resistance can be at least in part accounted for by the relative increae in osmolality of late distal fluid. Osmotic gradients influence the magnitude of intercellular...

Chiral nematic droplets with perpendicular surface alignment of liquid crystalline molecules frustrate the helical structure into convoluted 3D textures with complex topology. We observe the droplets with fluorescent confocal polarising microscopy (FCPM), and reconstruct and analyse for the first time the topology of the 3D director field using a novel method of director reconstruction from raw...

1. Urea is present in the cells of the proximal convoluted tubule in a concentration higher than that of the blood or than that of the cells of any of the other kidney tubules. 2. Such a condition can only be reconciled to an assumption of an active secretion (excretion) on the part of these cells. 3. Urea also passes through the glomerular filter with the other crystalloids of the blood plasma...

1. Definite morphological changes occur in the batonnets of the proximal convoluted tubule in stages of activity. 2. Atypical mitochondria but no batonnets exist in the regenerated cells found in chronic uranium nephritis. 3. No secretion of urea occurs in these cells which do not contain the cell organs. 4. The urea is secreted normally in the proximal convoluted tubule only (Leschke). 5. The ...

Two children with cutaneous convoluted lymphoblastic lymphoma are reported. Malignant cells from both patients contained cytoplasmic Mu heavy chains characteristic of pre-B-cells and expressed CALLA and la antigens as well. Most cases of convoluted lymphoblastic lymphoma are T-cell-derived neoplasms. The non-T, non-B phenotype found in these two children demonstrates that histology does not nec...

Both conventional and negative Poisson's ratio foams exhibit dispersion of acoustic waves as well as cut-off frequencies at which the group velocity tends to zero. This macroscopic behavior is attributed to micro-vibration of the foam cell ribs. The purpose of this article is to develop a micromechanical model of the cut-off frequency. This model is based on the resonance of ribs which may be s...