Hydrogen production via water splitting process in a molten-salt fusion breeder

This study presents the hydrogen production and fissile breeding potentials of Force-Free Helical Reactor (FFHR) fueled with the molten-salt mixtures. The sulfur–iodine (S–I) thermochemical water-splitting and high-temperature electrolysis cycles, which are the most promising water-splitting cycles, are selected to produce large-scale and pure hydrogen. The XSDRNPM/SCALE4.4a neutron transport code is used for the neutronic calculations. The analyses have been performed individually for four different molten-salt mixtures, (pure FLiBe, mixture of FLiBe and ThF₄, mixture of FLiBe and UF₄, and mixture of FLiBe, ThF₄ and ²³³UF₄). The numerical results bring out that the considered molten-salt fusion breeder reactor has a high neutronic performance and can produce a considerable amount of the hydrogen production (up to 40 kg/s), as well as the fissile fuel (up to 2.5 tons/yr).     

Transmutation-incineration potential of transuraniums discharged from PWR-UO2 spent fuel in modified PROMETHEUS fusion reactor

This study presents the potential of the burning and/or transmutation (B/T) of transuraniums (TRUs), discharged from the pressured water reactor PWR-UO₂ spent fuel, in the modified PROMETHEUS-H fusion reactor. Two different design shapes (Models A and B) were considered. The transmutation zone (TZ), which contains the mixture of TRU nuclides (10%), was located in the modified blankets. The volume fraction of Pu in the mixture is raised from 0 to 40% stepped by 10% to determine its effect on the B/T. The fuel spheres were cladded with SiC (5%) and cooled with high-pressured helium gas (85%) for nuclear heat transfer. The calculations were performed for an operation period (OP) of up to 10 years by 75% plant factor (η) under a neutron wall load (P) of 4.7 MW/m². The results bring out that: (1) the Model B transmutes the TRUs more rapidly than the Model A; (2) the effective half-lives decrease about 20 and 40% with the increase of Pu fraction in the cases of Models A and B, respectively; (3) the M values are quite high with respect to the M value of the original PROMETHEUS fusion reactor; (4) the blankets can produce substantial electricity in situ.     

The effect of live measles vaccines on serum vitamin A levels in healthy children

In chordate phylogeny, changes in the nervous system, jaws, and appendages transformed meek filter feeders into fearsome predators. Gene duplication is thought to promote such innovation. Vertebrate ancestors probably had single copies of genes now found in multiple copies in vertebrates and gene maps suggest that this occurred by polyploidization. It has been suggested that one genome duplication event occurred before, and one after the divergence of ray-finned and lobe-finned fishes. Holland et al., however, have argued that because various vertebrates have several HOX clusters, two rounds of duplication occurred before the origin of jawed fishes. Such gene-number data, however, do not distinguish between tandem duplications and polyploidization events, nor whether independent duplications occurred in different lineages. To investigate these matters, we mapped 144 zebrafish genes and compared the resulting map with mammalian maps. Comparison revealed large conserved chromosome segments. Because duplicated chromosome segments in zebrafish often correspond with specific chromosome segments in mammals, it is likely that two polyploidization events occurred prior to the divergence of fish and mammal lineages. This zebrafish gene map will facilitate molecular identification of mutated zebrafish genes, which can suggest functions for human genes known only by sequence.     

Infantile spasms as the initial symptom of biotinidase deficiency

Two patients with biotinidase deficiency had diagnoses of infantile spasms made at 1 month of age. Biotinidase deficiency may be seen early in the neonatal period without the characteristic findings such as alopecia and seborrheic dermatitis. This diagnosis should be considered in patients with infantile spasms.     

Reliability of human serum protein profiles generated with C8 magnetic beads assisted MALDI-TOF mass spectrometry

Protein profiling with mass spectrometry is a promising approach for classification and identification of biomarkers; however, there is debate about measurement quality and reliability. Here, we present a pipeline for preprocessing, statistical data analysis and presentation. Serum samples of 16 healthy individuals are used to generate protein profiles with high-resolution MALDI-TOF after isolation of peptides with C8 magnetic beads. Analysis of variance was performed after binning, baseline correction and normalization of the mean spectra. Relative variations in the spectra are expressed as coefficient of variation, which depending on the respective preanalytical variation parameter investigated, was found to range between 0.15 and 0.67 in this study. With this novel method, the reproducibility of our protein profiling procedure could be quantified. We showed that circadian rhythm and the number of freeze-thaw cycles had relatively limited influence on serum protein profiles, whereas the period between collection and serum centrifugation had a more pronounced effect.     

The effect of borax pentahydrate addition to urea formaldehyde on the mechanical characteristics and free formaldehyde content of plywood

In this study, the effects of borax pentahydrate addition to urea formaldehyde (UF) on the bonding characteristics and free formaldehyde content have been studied. Experiments related to the bending strength, withdrawal shear strength and free formaldehyde content have been conducted on the three-layered beech and poplar plywood which are prepared by the addition of borax pentahydrate into their adhesive mixtures in certain amounts. Addition of borax pentahydrate into the adhesive mixture did not statistically affect the bending strength and withdrawal shear strength of the plywood but did reduce the free formaldehyde content.     

Antioxidants alleviate electric field-induced effects on lung tissue based on assays of heme oxygenase-1, protein carbonyl content, malondialdehyde, nitric oxide, and hydroxyproline

In order to test whether antioxidants have beneficiary effects on electric field induced damage, we determined the pulmonary levels of heme oxygenase-1 (HO-1), protein carbonyl content (PCO), malondialdehyde (MDA), nitric oxide (NO) and hydroxyproline (HP) under extremely low frequency (ELF) electric (E) field exposure (50 Hz, 12 kV/m, 7 days/for 8 h/day). While PCO levels significantly increased (p < 0.05), insignificant changes (p > 0.05) were observed in HO-1, MDA, NO and HP levels for electric field exposure groups compared to the control group. We have not observed any significant change in these parameters on the electric field group compared to the group where NAC and EGCG were separately applied along with electric field. However, during our previous studies, we have concluded that NAC and EGCG are potent antioxidants and we believe that new studies should be established by way of setting up different experimental conditions.     

Covalent Immobilization of a α-Amylase onto Poly(methyl methacrylate-2-hydroxyethyl methacrylate) Microspheres and the Effect of Ca2+ Ions on the Enzyme Activity

α-Amylase was covalently immobilized onto poly(methyl methacrylate-2-hydroxyethyl methacrylate) microspheres, which were activated by using either epichlorohydrin (ECH) or cyanuric chloride (C₃N₃Cl₃). The properties of the immobilized enzyme were investigated and compared with those of the free enzyme. For the assays carried out at 25 °C and pH 6.9, the relative activities were found to be 73.0% and 90.8% for epichlorohydrin and cyanuric chloride bound enzymes, respectively. Upon immobilization, the maximum activities were obtained at lower pH values and higher temperatures as compared with the free enzyme. Kinetic parameters were calculated as 2.51 g/L, 28.54 g/L and 15.50 g/L for K_m and 1.67 × 10⁻³ gL⁻¹ min⁻¹ 2.89 × 10⁻⁴ gL⁻¹ min⁻¹ and 1.89 × 10⁻³ gL⁻¹ min⁻¹ for V_max for free, epichlorohydrin and cyanuric chloride bound enzymes, respectively. Enzyme activities were found to be ca. 32.7% for ECH and 41.1% for C₃N₃Cl₃ activated matrices after storage for one month. On the other hand the free enzyme lost its activity completely within 20 days. Immobilization, storage stability and repeated use capability experiments carried out in the presence of Ca²⁺ ions demonstrated higher stability in the presence of these ions. The enzymes immobilized in the presence of Ca²⁺ ions retained 90.6% and 90.8% of the original activities even after 30 days in the case of ECH and C₃N₃Cl₃ activations, respectively. In repeated batch experiments, i.e., 20 uses of the enzyme in 3 days; in the absence of Ca²⁺ ions retentions of 79.2% and 77.1% of the original enzyme activities were observed for ECH and C₃N₃Cl₃ immobilized enzymes, respectively, whereas, in the case of addition of Ca²⁺ ions to the assay medium, these values were enhanced to 95.3% and 92.2%.     

Low molecular weight polyacrylic acid with nitrilodi(methylene-phosphonic acid) chain ends for scale inhibition

Poly(acrylic acid) with molecular weight of 5000 was produced by using 2-aminoethanethiol hydrochloride as chain transfer agent. Amine chain end groups of the resulting polyacrylic acid were transformed into nitrilodi(methylenephosphonic acid) by reacting formaldehyde-phosphorous acid in the presence of hydrogen chloride. ¹H NMR, ³¹P NMR and microanalysis were used for structural analysis.The modified polyacrylic acid had much better calcium carbonate scale inhibition effect than commercial poly(acrylic acid).     

Redox initiation system of ceric salt and α,ω‐dihydroxy poly(dimethylsiloxane)s for vinyl polymerization

The redox system of ceric salt and α,ω‐dihydroxy poly(dimethylsiloxane) is used to polymerize vinyl monomers such as acrylonitrile and styrene to produce block copolymers. The concentration and type of α,ω‐dihydroxy poly(dimethylsiloxane) affects the yield and the molecular weight of the copolymers. The copolymers have about 20°C lower glass‐transition temperatures and much higher contact angle values than of the corresponding homopolymer of vinyl monomers, although the weight percent of α,ω‐dihydroxy poly(dimethylsiloxane) of the copolymers is in the range of 1–2%. © 2006 Wiley Periodicals Inc. J Appl Polym Sci 102: 2112–2116, 2006