Langmuir-Blodgett films on non-centrosymmetric azobenzene dyes for non-linear optical applications

The preparation and characterization of Langmuir-Blodgett films containing 4-(N-hydroxyalkyl)amino-4′-nitroazobenzene dyes (with alkyl≡hexyl and dodecyl) are discussed in this paper. High quality films of these hydroxyalkyl-substituted aminoazobenzenes have not been obtained in pure form. Instead, monolayer films of these dyes in mixtures with stearic acid have been prepared on glass and fused quartz substrates. Centrosymmetric and non-centrosymmetric multilayer films of the dye/ stearic acid systems have also been built up on glass and quartz. Molecular ordering of the non-centrosymmetric azobenzene dyes in the films is indicated by polarized electronic absorption spectroscopy and by second-harmonic generation from the films.     

Retrovirus-mediated in vitro gene transfer into chicken male germ line cells

Chicken testicular cells, including spermatogonia, transplanted into the testes of recipient cockerels sterilized by repeated gamma-irradiation repopulate the seminiferous epithelium and resume the exogenous spermatogenesis. This procedure could be used to introduce genetic modifications into the male germ line and generate transgenic chickens. In this study, we present a successful retroviral infection of chicken testicular cells and consequent transduction of the retroviral vector into the sperm of recipient cockerels. A vesicular stomatitis virus glycoprotein G-pseudotyped recombinant retroviral vector, carrying the enhanced green fluorescent protein reporter gene was applied to the short-term culture of dispersed testicular cells. The efficiency of infection and the viability of infected cells were analyzed by flow cytometry. No significant CpG methylation was detected in the infected testicular cells, suggesting that epigenetic silencing events do not play a role at this stage of germ line development. After transplantation into sterilized recipient cockerels, these retrovirus-infected testicular cells restored exogenous spermatogenesis within 9 weeks with approximately the same efficiency as non-infected cells. Transduction of the reporter gene encoding the green fluorescent protein was detected in the sperms of recipient cockerels with restored spermatogenesis. Our data demonstrate that, similarly as in mouse and rat, the transplantation of retrovirus-infected spermatogonia provides an efficient system to introduce genes into the chicken male germ line.     

The influence of ammonium and methods for removal during the anaerobic treatment of poultry manure

The addition of exogenous NH₄Cl to poultry manure and synthetic medium was used to study the effect of ammonia-nitrogen on the activity and composition of a methanogenic consortium. Results indicated that the production of biogas and methane was not affected by the variation in NH₄Cl concentration within the range 2–10 g dm⁻³ (0·5–2·6 g N-NH₄ dm⁻³). At higher values of ammonium (10–30 g dm⁻³ or 2–8 g N-NH₄ dm⁻³) a significant decline in both parameters (by 50–60% for biogas and 80–90% for methane) was observed. A significant decrease in the numbers of bacteria of all physiological groups (especially proteolytic and methanogenic) was observed when more than 30 g NH₄Cl dm⁻³ (7·8 g N-NH₄ dm⁻³) was added to the fermentation medium. The addition of 10% (w/v) of powdered phosphorite ore enhanced the production of biogas and methane at NH₄Cl concentrations up to 30 g dm⁻³, and also changed the composition of the methanogenic consortium. A partial recovery in the numbers of proteolytic and methanogenic bacteria coupled with the decrease in the density of sulphate-reducers was observed. High concentrations (more than 50 g dm⁻³) of NH₄Cl seemed to cause irreversible inhibition of methanogenesis which could not be eliminated by the addition of phosphorites. ©1997 SCI     

Structured catalyst supports and catalysts for the methane indirect internal steam reforming in the intermediate temperature SOFC

Open cell metal foams made from Ni, Fe–Cr steel and Ni–Al intermetallic were studied as candidate catalyst supports for the internal indirect methane steam reforming. All the samples exhibited good corrosive resistance during 500–1000 h testing in H₂–H₂O–Ar environment at 600 °C. NiO/8YSZ composite based catalysts doped with fluorite-like (Pr_0.3Ce_0.35Zr_0.35O₂) or perovskite-like (La_0.8Pr_0.2Mn_0.2Cr_0.8O₃) complex oxides with high lattice oxygen mobility and promoted with Pt or Ru were prepared and deposited on the foam-structure supports. Both good catalyst adhesion and stable catalyst performance were achieved in the case of the Ni–Al foam supported catalysts. The Fe–Cr support reacted with the catalytic active components resulting in fast catalyst deactivation. The foam supported catalyst performance was compared with the same catalyst prepared in a form of 0.25 mm fraction. Porous supports with different porosities were prepared by the metal foam deformation and the catalyst performance depending on the support porosity (75–95%) was studied.     

Kunitz-Type Peptides from Sea Anemones Protect Neuronal Cells against Parkinson’s Disease Inductors via Inhibition of ROS Production and ATP-Induced P2X7 Receptor Activation

Parkinson’s disease (PD) is a socially significant disease, during the development of which oxidative stress and inflammation play a significant role. Here, we studied the neuroprotective effects of four Kunitz-type peptides from Heteractis crispa and Heteractis magnifica sea anemones against PD inductors. The peptide HCIQ1c9, which was obtained for the first time, inhibited trypsin less than other peptides due to unfavorable interactions of Arg17 with Lys43 in the enzyme. Its activity was reduced by up to 70% over the temperature range of 60–100 °C, while HCIQ2c1, HCIQ4c7, and HMIQ3c1 retained their conformation and stayed active up to 90–100 °C. All studied peptides inhibited paraquat- and rotenone-induced intracellular ROS formation, in particular NO, and scavenged free radicals outside the cells. The peptides did not modulate the TRPV1 channels but they affected the P2X7R, both of which are considered therapeutic targets in Parkinson’s disease. HMIQ3c1 and HCIQ4c7 almost completely inhibited the ATP-induced uptake of YO-PRO-1 dye in Neuro-2a cells through P2X7 ion channels and significantly reduced the stable calcium response in these cells. The complex formation of the peptides with the P2X7R extracellular domain was determined via SPR analysis. Thus, these peptides may be considered promising compounds to protect neuronal cells against PD inductors, which act as ROS production inhibitors and partially act as ATP-induced P2X7R activation inhibitors.     

THE TRUEX PROCESS - A PROCESS FOR THE EXTRACTION OF THE TKANSURANIC ELEMENTS EROM NITRIC AC In WASTES UTILIZING MODIFIED PUREX SOLVENT*

ABSTRACT

A generic transurantc (TRU) element extraction/recovery process was developed based on the use of octyl(phenyl)-N,N-diiso-butylcarbamoylmetliylphosphine oxide, 0φD(iB)CMPO, dissolved in PUREX process solvent (tribntyl phosphate, TBP, in normal paraffluic hydrocarbon, NPH). The process (called TRUEX) is capable of reducing the TRU concentration by many orders of magnitude In waste solutions containing a wide range of nitric acid, salt, and fission product concentrations. A major feature of the process is that it is readily adaptable for waste processing in existing fuel reprocessing facilities.