The treatment burden of cystic fibrosis: a day-to-day experience with treatment as someone with cystic fibrosis.

https://bit.ly/36PZnSL.

Microstructural Evolution in 2101 Lean Duplex Stainless Steel During Low- and Intermediate-Temperature Aging.

The microstructural evolution of a 2101 lean duplex stainless steel (DSS) during isothermal aging from room temperature to 470 °C was investigated using thermoelectric power (TEP) measurements to follow the kinetics, atom probe tomography, and transmission electron microscopy. Despite the low Ni, Cr, and Mo contents, the lean DSS was sensitive to α-α' phase separation and Ni-Mn-Si-Al-Cu clustering at intermediate temperatures. The time-temperature pairs characteristic of the early stages of ferrite decomposition were determined from the TEP kinetics.

M23C6 carbides and Cr2N nitrides in aged duplex stainless steel: A SEM, TEM and FIB tomography investigation.

The precipitation evolution during ageing of a 2101 lean duplex stainless steel was investigated, revealing that the precipitate type and morphology depends on the nature of the grain boundary. Triangular M23C6 carbides precipitate only at γ/δ interfaces and rod-like Cr2N nitrides precipitate at both γ/δ and δ/δ interfaces. After 15min of ageing, the M23C6 size no longer evolves, whereas that of the Cr2N continues to evolve.

Cellular relationship impairment in maturation arrest of human spermatogenesis: an ultrastructural study.

Ultrastructural examination of testicular biopsies from cases of maturation arrest showed that there were characteristic abnormalities of the Sertoli cell junctional connections. These abnormalities together with the meiotic failure afford an explanation for the severe oligospermia or azoospermia noted in patients with maturation arrest. Premature setting up of ectoplasmic specializations in front of early spermatids and/or spermatocytes were also observed.

Heterosynapsis in two fertile but hypoprolific boars carriers of reciprocal translocations.

The authors report here two new cases of reciprocal translocations in two fertile and hypoprolific boars. Silver stained synaptonemal complexes in surface-spread pachytene nuclei from a boar heterozygous for a reciprocal translocation, and from another one carrying two different reciprocal translocations, were analyzed by electron microscopy. In such heterozygotes, cross-shaped quadrivalent configurations are expected to form in order to allow homologous pairing.

Reproductive failure and pericentric inversion in man.

Pachytene analysis was carried out on an infertile man heterozygous for a pericentric inversion of chromosome 6. The synaptic behavior of the bivalent 6 inversion was analyzed using electron microscopy in silver stained surface microspread of the inversion-bearing spermatocytes. Possible mechanisms of the sterilizing effect caused by the autosomal inversion are discussed.

Polysaccharidic material in chloride cell of teleostean gill: modifications according to salinity.

The gill epithelium is known to be implicated in the hydromineral regulation of teleosts, especially owing to its "chloride cells." We have examined the polysaccharides of chloride cells from euryhaline teleosts adapted to fresh- or saltwater. The use of periodic acid-chromic acid-silver methenamine, colloidal thorium, or radioautography after incorporation of [3H]glucosamine has shown that chloride cells are characterized by a high concentration of polysaccharides in their apical region (at the level of the vesiculotubular system) and by a special polysaccharidic cell coat.

The surface epithelium of teleostean fish gills. Cellular and junctional adaptations of the chloride cell in relation to salt adaptation.

Various species of teleostean fishes were adapted to fresh or salt water and their gill surface epithelium was examined using several techniques of electron microscopy. In both fresh and salt water the branchial epithelium is mostly covered by flat respiratory cells. They are characterized by unusual outer membrane fracture faces containing intramembranous particles and pits in various stages of ordered aggregation.

Effects of epinephrine on branchial non-electrolyte permeability in rainbow trout.

Using isolated heads perfused at constant pressure, at rates close to those occurring in vivo, the permeability of the gills of the trout Salmo gairdneri to a range of solutes was measured. Under epinephrine-free conditions, butanol and water showed similar high branchial permeability coefficients. Urea, inulin and dextrans (mol.

Microtubules in the "chloride cell" of the gill and disruptive effects of colchicine on the salt balance of the sea water adapted Mugil capito.

Electron-microscopic examination of the gill of the grey mullet, Mugil capito adapted to sea water, reveals the presence of numerous microtubules in the apical region of the mitochondria-rich cells. No microtubules are found in other types of epithelial cell. Exposure of the fish to colchicine (10(-4)M) for four hours induces a 20% increase of plasma Na and Cl.

Epinephrine effects on branchial water and urea flux in rainbow trout.

In isolated trout heads, perfused at constant pressure, epinephrine (10(-6) M) was found to double water and urea efflux but increased Ringer perfusion rate by only 33%. Drastic changes in perfusion rate (by clamping) produced smaller changes of both efflux rates. Epinephrine-stimulated increase in water and urea efflux, and perfusion rate, was blocked by propranolol (beta-blocker) but not by phentolamine (alpha-blocker).

Branchial sodium exchange in seawater-adapted Tilapia mossambica: effects of prolactin and hypophysectomy.

The effects of exogenous prolactin and hypophysectomy were tested on Na exchange across the gills of Tilapia mossambica adapted to sea-water. Exogenous prolactin produced a 75% decrease of both total Na influx and Na efflux. Total Na influx was measured simultaneously with the drinking rate.

A study of the unidirectional fluxes of Na and Cl across the gills of the dogfish Scyliorhinus canicula (Chondrichthyes).

The gills of the dogfish Scyliorhinus canicula are more permeable to Cl than to Na. In sea water, influx of Na and Cl exceeded the efflux of these ions. Under these conditions the fish were slightly electronegative, by about 2 mV, to the external solution.

Transport of ions and water across the epithelium of fish gills.

The teleostean gill is characterized by an exceptionally low permeability to water. Water moves along the osmotic gradient across the gill, being gained in fresh water and lost in sea water. Coupling of water movement to solute movement has not been reported.

Environmental salinity and sodium and chloride exchanges across the gill of Tilapia mossambica.

10 Freshwater-(FW)-adapted, one-third seawater (1/3 SW)-adapted and seawater (SW) adapted Tilapia mossambica were compared for their branchial Na+ influx and efflux as well as Cl- efflux. Na+ and Cl- effluxes were identical. Rates of effluxes were in 1/3 SW- and in SW-adapted fish 10 times and 200 times higher respectively than in FW specimens.

Branchial effects of epinephrine in the seawater-adapted mullet. II. Na+ and Cl- extrusion.

Injection of epinephrine into Mugil capito adapted to seawater is followed by a 40-60% inhibition of the Na and Cl effluxes. Simultaneously the Na influx is decreased by 30%, the overall result being a reduction of the net sodium extrusion rate by the gill. The change in Na influx is in part explained by a 75-80% decrease of the oral ingestion of seawater.