Open-cycle multi-megawatt MHD space nuclear power facility

The results of calculations of the characteristics and development of a scheme and technical make-up of an open-cycle space power facility based on a high-temperature nuclear reactor for a nuclear rocket motor and a 20 MW Faraday MHD generator are presented. A heterogeneous channel-vessel IVG-1 reactor, which heated hydrogen to 3100 K, with the pressure at the exit from the reactor core up to 5 MPa, burn rate 5 kg/sec, and thermal power up to 220 MW is examined. The main parameters of the MHD generator are determined: Cs seed fraction 20%, stopping pressure at the entrance 2 MPa, electric conductivity ≈ 30 S/m, Mach number ≈ 0.7, magnetic induction 6 T, electric power 20 MW, specific energy extraction ∼4 MJ/kg. The construction of the scheme of a MHD facility with zero-moment exhaust of the working body and its main characteristics are presented. Translated from Atomnaya énergiya, Vol. 105, No. 3, pp. 135–144, September, 2008.     

The effect of osteotomy on bowing and height in children with X-linked hypophosphatemia

Extracellular matrices (ECM) are utilized for obtaining better cell attachment to polymer surfaces in cell cultures. To establish beneficial bioartificial renal tubules, tubular epithelial cells and ECM were investigated in this study. MDCK cells and KU-2 cells were seeded onto 96 well plates which had been precoated with collagen types I and IV, laminin, and fibronectin. The culture media were removed and replaced with new ones at 15, 30, 60, 90, 120, and 150 min and 24 h after start time to evaluate the incubation time effects. The degrees of cell attachment onto ECM were measured by MTT assay. In the MDCK cell culture, better cell attachment was observed between 60 min and 24 h after incubation start time with the use of laminin at a concentration of 5 microg/ml, 60 min and more after incubation start time with the use of fibronectin at the concentrations of 1 and 4 microg/ml, or 30 min and more after incubation start time with the use of fibronectin at the concentrations of 16 and 32 microg/ml. On the other hand, in the KU-2 cell culture, better cell attachment was observed between 15 and 60 min after the incubation start time or 24 h after the incubation start time with the use of laminin at a concentration of 40 microg/ml. These data suggest that various cells possibly each have a most suitable ECM kind, best concentration, and best incubation time.     

Atmospheric corrosion in tropical and subtropical climate zones: 3. Modeling corrosion and dose-response function for structural metals

The results of statistical analysis of a corrosion-climate database are presented. New dose-response functions have been obtained by methods of multiple and nonlinear analysis for evaluating corrosion-related weight losses of structural metals in the regions with humid tropical and subtropical climate. Original Russian Text ? A.A. Mikhailov, P.V. Strekalov, Yu.M. Panchenko, 2007, published in Korroziya: Materialy, Zashchita, 2006, No. 7, pp. 2–10. For part 2, see [1].     

Protective role of the free glucocorticoid pool in development of autoimmune hemolytic anemia

OBJECTIVE: Patients with type II diabetes mellitus have an increased risk of coronary he disease. We investigated the efficacy and safety of pravastatin in the treatment of patients with diabetic nephropathy and hypercholesterolemia. METHOD: In this 6-months study, 12 patients (4 men, 8 women, mean age 60.5 +/- 10.8 years), with diabetic nephropathy and hypercholesterolemia (fasting plasma low-density lipoprotein cholesterol levels -LDL-C- > 130 mg/dl) received pravastatin 10 mg/day. The dose could be doubled after 4 weeks. Seven patients have chronic renal failure. RESULTS: Significant reductions in LDL-C (-19.1%, p < 0.05), total cholesterol (-16%, p < 0.01), very-low-density lipoprotein cholesterol (-29.2%, p < 0.05), apolipoprotein B (-21.5%, p < 0.05), and triglycerides (-26.0%, p < 0.01) were noted. No changes were found either in high-density-cholesterol or its fractions (HDL2 and HDL3) or in apolipoprotein A plasmatic levels. Pravastatin was well tolerated and no one side effect was detected. No clinically significant changes on the control of diabetes, renal function, as assessed by plasmatic creatinin and creatinin clearance, and proteinuria were seen during the follow-up time. CONCLUSIONS: The results of the study demonstrate that pravastatin is well tolerated and effective in lowering total cholesterol and LDL-C in patients with diabetic nephropathy and hypercholesterolemia.     

Characterization of new gibberellin-responsive semidwarf mutants of arabidopsis

Chemical mutagenesis of Arabidopsis thaliana (L.) Heynh. yielded four semidwarf mutants, all of which appeared to be gibberellin (GA)-biosynthesis mutants. All four had atypical response profiles to C20-GAs, suggesting that each had impaired 20-oxidation. One mutant, 11.2, was shown to be allelic to ga5 and has been named ga5-2. It had altered metabolism of [14C]GA15 relative to that in wild-type plants and undetectable levels of C19-GAs in young stems, consistent with the known function of GA5 as a stem-expressed GA 20-oxidase. Two mutants (2.1 and 10.3), which had very short inflorescences and siliques, were allelic to each other but not to the known GA-responding mutants, ga1 to ga5. The locus defined by these two mutations is provisionally named GA6 and is purported to encode an inflorescence- and silique-expressed GA 20-oxidase. A double mutant, ga5-2 ga6-2, had an extreme dwarf phenotype with very short siliques. The fourth mutation, 1.1, gave a phenotype like ga5, but was not allelic to any of the known ga mutations. It has not yet been given a gene symbol pending further studies.     

Identification and expression of plasmid genes participating in the synthesis of microcin C51

A structural gene of heptapeptide, which is a component of the microcin C51 molecule, was identified by hybridization of plasmid DNA fragments and a mixture of synthesized oligonucleotides with the sequence corresponding to that of amino acids in the peptide. Sequence analysis of the structural gene of microcin peptide and its promoter region was performed. The data obtained indicate that the peptide of microcin C51 is synthesized on ribosomes. Four polypeptides of 67, 39, 16, and 14 kDa were identified using the system of minicells. These polypeptides are specified by a DNA fragment responsible for microcin synthesis and immunity in a producer cell. Apparently, three of these polypeptides with molecular masses of 67, 39, and 16 kDa are responsible for microcin production and immunity. The 67 kDa polypeptide is involved in the expression of immunity to microcin and, probably, in microcin production.     

In vivo selection of Rous sarcoma virus mutants with randomized sequences in the packaging signal

Retrovirus genomes contain a sequence at the 5' end which directs their packaging into virions. In Rous sarcoma virus, previous studies have identified important segments of the packaging signal, Psi, and support elements of a secondary-structure prediction. To further characterize this sequence, we used an in vivo selection strategy to test large collections of mutants. We generated pools of full-length viral DNA molecules with short stretches of random sequence in Psi and transfected each pool into avian cells. Resulting infectious virus was allowed to spread by multiple passages, so that sequences could compete and the best could be selected. This method provides information on the kinds of sequences allowed, as well as those that are most fit. Several predicted stem-loop structures in Psi were tested. A stem at the base of element O3 was highly favored; only sequences which maintained base pairing were selected. Two other stems, at the base and in the middle of element L3, were not conserved: neither base pairing nor sequence was maintained. A single mutation, G213U, was seen upstream of the randomized region in all selected L3 stem mutants; we interpret this to mean that it compensates for the defects in L3. Randomized mutations adjacent to G213 maintained the wild-type base composition but not its sequence. The kissing-loop sequence at end of L3, postulated to function in genome dimerization, was not required for infectivity but was selected for over time. Finally, a deletion of L3 was constructed and found to be poorly infectious.     

Convergence of Lewy bodies and neurofibrillary tangles in amygdala neurons of Alzheimer's disease and Lewy body disorders

Amygdalae of patients with Alzheimer's disease (AD), Parkinson's disease, Down's syndrome, diffuse Lewy body disease or a combination of these diseases were probed with antibodies to neurofilament proteins as well as with Lewy body (LB)- and paired helical filament-specific antibodies. The results indicate that the amygdala is severely affected by the accumulation of both neurofibrillary tangles (NFTs) and LBs in most cases of the diseases mentioned above, and that amygdala LBs have a similar epitope composition to that of LBs in the brain stem and cerebral cortex. While large numbers of both LBs and NFTs were seen in different neurons within the amygdala, these two lesions frequently occurred together in the same neurons of the amygdala. These findings are in contrast to other sites that accumulate LBs and NFTs, but rarely both lesions in the same neuron. Thus, amygdala neurons may be selectively vulnerable to developing both LBs and NFTs, and these inclusions may play a role in the massive degeneration of these neurons in AD and LB disorders of the elderly.