An apparatus for altering the mechanical load of the respiratory system

We describe an apparatus for altering the mechanical load against which the respiratory muscles operate in humans. A closed system incorporates a rolling seal spirometer. The spirometer piston shaft is coupled to a fast-responding linear actuator that develops force in proportion to desired command signals. The command signal may be flow (resistive loading or unloading), volume (elastic loading or unloading), constant voltage (continuous positive or negative pressure), or any external function. Combinations of loads can be applied. Logic circuits permit application of the load at specific times during the respiratory cycle, and the magnitude of the loads is continuously adjustable. Maximum pressure output is +/- 20 cmH2O. The apparatus permits loading or unloading over a range of ventilation extending from resting levels to those observed during high levels of exercise (over 100 l/min). In response to a square-wave input, pressure rises exponentially with a time constant of 20 ms.     

Identification of Yeast Strains Isolated from Agricultural Soils for Releasing Potassium-bearing Minerals

Thirty-five yeast strains were isolated from soil samples that were collected from different locations in Upper Egypt. The purified isolates were screened for the release potassium from mica on Aleksandrov agar medium. Two yeast isolates (KSY-29 and KSY-33) showed an ability to solubilize potassium by inducing clear zones around their colonies. They were identified as Pichia anomala and Rhodotorula glutinis, respectively, based on PCR analysis of the ITSI-26S region that was amplified by NL1/NL4 species-specific primers. The amount of K released from muscovite mica in the broth culture of the yeast isolates was measured after 5, 10, 15 and 20 days of the incubation at 25°C. Both yeast isolates were very effective in releasing K of muscovite in broth culture, recording 8.11–13.21 μg/ml that were released from muscovite mica after 20 days of incubation. The inoculation of maize (Zea maize) plants with these yeast isolates under different K levels (25, 50 and 100% of recommended dose of potassium, RDK) as potassium sulfate was tested on growth and K uptake by these plants in the greenhouse. Significant increases (p < 0.05) in plant height, root and shoot dry weights as well as K uptakes by shoots and roots maize plants occurred through the inoculation with KSY-29 or KSY-33 isolates.     

Models for metal-sulfur coordination in copper proteins.

The oxidation state of copper in several model compounds containing copper coordinated to sulfur, some of which are suggested model compounds for naturally occurring Cu-S chromophores, was determined employing x-ray photoelectron spectrometry. Copper was found to be present in a 3d10 state, which is characteristic for Cu(I). An initial photoreduction is excluded, as Cu(ethylenediamine)2 (SCN)2, in which a Cu-S bond is also present, was found to contain Cu(II) (3d9). As was the case with native parsley plastocyanin, the model compounds reacted effectively with superoxide anion radicals. We suggest that the electrons of the metal-sulfur chromophore in blue copper proteins are delocalized and that an equilibrium: RS--Cu(II) in equilibrium or formed from RS.Cu(I) exists.     

Thermodynamic, spectroscopic studies and catechol oxidase activity of copper (II) complexes with amphiphilic d-galacturonic acid derived ligands

The interactions of three amphiphilic glycoligands derived from d-galacturonic acid (L¹, L² and L³) with copper (II) ions were investigated in aqueous solution and/or in aqueous-methanol media. The combination of potentiometry, UV-Vis spectrophotometry and Electron Paramagnetic Resonance (EPR) was used to determine the formation constants of the complexes and their relative structures in solution. The complexation sites were identified using electronic absorption and EPR spectroscopies. Copper complexes were obtained as square planar or square pyramidal mononuclear or dinuclear species. Solid compounds were synthesized and tested as catalysts in the autooxidation of catechols in methanol and in aqueous micellar media. Mononuclear species were found to be catalytically active in both media, whereas dinuclear ones do not show any significant catecholase activity.