Testosterone response (in blood serum and seminal plasma) to anti-estrogen stimulation test in fertile men and patients with disturbances of spermatogenesis

Testosterone concentrations in blood serum and seminal plasma in basic conditions and in antiestrogen test (Clostilbegyt 100 mg daily for 10 days) were evaluated for 21 fertile males, 24 males with normogonadotropic oligozoospermia and 25 azoospermia patients. Average output testosterone concentration in blood serum of the analysed groups did not differ statistically significantly, but in antiestrogen test it increased statistically significantly. Average output testosterone concentration in semen plasma in fertile men was 0.66 +/- 0.26 ng/ml (about 10 times lower than in blood serum) and idiopatic oligozoospermic patients had a half of this number. Clostilbegyt test caused increase of testosterone concentration in semen plasma in all groups (except for normospermic) what proves the relation of hormonal reactions observed in blood serum with the ones in semen plasma.     

Synthesis, spectral and antimicrobial properties of 5-chloroarylidene aromatic derivatives of imidazoline-4-one

The synthesis of new chloro-benzylidene substituted derivatives of hydantoin and their antimicrobial activity is reported. The structure-activity relationships showed that the antibacterial effect of investigated compounds depends on the distance of the phenyl ring from the amine residue and the kind of substitutes on the phenyl ring. In the investigated group of derivatives, 5-(2-chlorobenzylidene)-2-(4-fluorobenzylamine)-imidazoline-4-one and 5-(2-chlorobenzylidene)-2-(2-phenylethylamine)-imidazoline-4-one showed the best antibacterial activity against Moraxella catarrhalis.     

Pattern learning in humans and electronic learning nets

The letter reports on a previously unseen similarity between an associative memory model recently proposed for the brain and some electronic systems that have been developed for practical learning machines. This similarity is analysed, and its implications are discussed. Results of a comparison between the learning behaviour of an electronic network and a group of human subjects in a pattern-recognition task are given to complete the comparative study.     

Pattern-recognition properties of r.a.m./r.o.m. arrays

Arrays of r.a.m.s may be used as trainable logic devices in arrays whose object is to recognise patterns. The way in which such a system is organised is presented and some of the characteristics of the nature of the recognition are discussed     

Control of coercivity in NiFe films for single-level masking bubble devices

Methods of reducing Hcin thick NiFe films deposited on evaporated Au have been studied for applications in conductor-first single-level masking bubble device fabrication. Results obtained using surface modification techniques, such as ion implantation, plasma etching, and semiconducting intermediate layers (TiOx) are described. In addition, the performance of actual 5-μm and 2-μm devices is discussed.     

Effects of annealing on propagation in ion-implanted contiguous-disk bubble devices

Bubble propagation margins are found to be affected by heat treatment in ion-implanted contiguous-disk devices fabricated on liquid-phase epitaxial (LPE) grown double-layer garnet films which support 1-μm bubbles. When an optical reflector is deposited directly on the driving layer interfacial diffusion takes place, and this raises the coercivity of the implanted layer, which in turn causes a severe degradation of propagation margins. In samples fabricated with optical reflectors isolated from the driving layer, the adverse effects of annealing on propagation margins are stronger in close-packed minor loops due to interaction of long-range charged walls as compared with isolated loops and isolated disks, and they cease to propagate bubbles after annealing in the temperature range of 350-400°C, whereas the loss of margins in the isolated loops and disks are typically less than 30 percent after 600-650°C annealing treatments. Stress gradients caused by the discontinuity in the overlay patterns contribute significantly to the increase of threshold drive field after anealing. The rapid degradation of propagation margins found after annealing in the temperature range of 350-400°C in all samples is caused by reordering of the damaged lattice.     

The GC/AED studies on the reactions of sulfur mustard with oxidants

A gas chromatograph coupled with an atomic emission detector was used to identify and to determine the products formed on oxidation of sulfur mustard. The oxidation rate and the resulting oxidates were studied in relation to oxidant type and reaction medium parameters. Hydrogen peroxide, sodium hypochlorite, sodium perborate, potassium monopercarbonate, ammonium peroxydisulfate, potassium peroxymonosulfate (oxone), and tert-butyl peroxide were used as oxidants. Oxidations were run in aqueous media or in solvents of varying polarities. The oxidation rate was found to be strongly related to oxidant type: potassium peroxymonosulfate (oxone) and sodium hypochlorite were fast-acting oxidants; sodium perborate, hydrogen peroxide, ammonium peroxydisulfate, and sodium monopercarbonate were moderate oxidants; tert-butyl peroxide was the slowest-acting oxidant. In non-aqueous solvents, the oxidation rate was strongly related to solvent polarity. The higher the solvent polarity, the faster the oxidation rate. In the acid and neutral media, the mustard oxidation rates were comparable. In the alkaline medium, oxidation was evidently slower. A suitable choice of the initial oxidant-to-mustard concentration ratio allowed to control the type of the resulting mustard oxidates. As the pH of the reaction medium was increased, the reaction of elimination of hydrogen chloride from mustard oxidates becomes more and more intensive.     

Spatial distributions of residuals produced inside a spallation target

The spallation target model of an accelerator driven system (ADS), consisting of six 5 cm thick and 16 cm in diameter Pb segments, was constructed. Three sets of 17 Bi samples (1/2 inch in diameter and 1 mm thick) were placed in 3 Pb disc-shaped holders inside the target at 5, 10 and 15 cm from its front. After irradiation with 660 MeV proton beam gamma-spectra of radioisotopes produced in Bi were collected several times for each sample with the use of HPGe detectors in order to identify the radioisotopes and to determine their absolute activities. Their spatial distributions were then compared with respective values obtained in the calculations made with the use of FLUKA and/or MCNPX code. A fair agreement with the experiment has been observed.     

Lipidic membranes are potential "catalysts" in the ligand activity of the multifunctional pentapeptide neokyotorphin

Neokyotorphin (NKT) is a multifunctional pentapeptide that is involved in biological functions as diverse as analgesia, antihibernatic regulation and proliferation stimulus of tumour cells. The interaction of neokyotorphin with cell membranes is potentially important to all these multiple biological processes since receptor-mediated processes are thought to be involved in neokyotorphin action. Sargent and Schwyzer proposed in their "membrane catalysis" model that ligands interact with membrane lipids in order to adopt the necessary conformation for cell receptors. We have used fluorescence techniques to study the depth, orientation and extent of incorporation of NKT with model membrane systems (lipidic vesicles). The roles of lipid charge, membrane phase and sterol presence were investigated. The phenolic ring of tyrosine is located in a shallow position in membranes. The extent of partition is less in gel crystalline membranes than in liquid crystalline membranes. Addition of cholesterol causes a reorientation of the tyrosine ring at the interface of lipidic bilayers. Lipidic membranes meet all the conditions required for acting as potential "catalysts" in the ligand activity of the multifunctional pentapeptide NKT, because they modulate the exposure and orientation of the phenolic ring, which is most likely involved in docking to receptors.