943 resultados para Formaldehyde-assisted isolation of regulatory elements


Relevância:

100.00% 100.00%

Publicador:

Resumo:

One reason for the recent asset price bubbles in many developed countries could be regulatory capital arbitrage. Regulatory and legal changes can help traditional banks to move their assets off their balance sheets into the lightly regulated shadows and thus enable regulatory arbitrage through the securitized sector. This paper adopts a global vector autoregression (GVAR) methodology to assess the effects of regulatory capital arbitrage on equity prices, house prices and economic activity across 11 OECD countries/ regions. A counterfactual experiment disentangles the effects of regulatory arbitrage following a change in the net capital rule for investment banks in April 2004 and the adoption of the Basel II Accord in June 2004. The results provide evidence for the existence of an international finance multiplier, with about half of the countries overshooting U.S. impulse responses. The counterfactual shows that regulatory arbitrage via the U.S. securitized sector may enhance the cross-country reallocation of capital from housing markets towards equity markets.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Trace element contamination is one of the main problems linked to the quality of compost, especially when it is produced from urban wastes, which can lead to high levels of some potentially toxic elements such as Cu, Pb or Zn. In this work, the distribution and bioavailability of five elements (Cu, Zn, Pb, Cr and Ni) were studied in five Spanish composts obtained from different feedstocks (municipal solid waste, garden trimmings, sewage sludge and mixed manure). The five composts showed high total concentrations of these elements, which in some cases limited their commercialization due to legal imperatives. First, a physical fractionation of the composts was performed, and the five elements were determined in each size fraction. Their availability was assessed by several methods of extraction (water, CaCl2–DTPA, the PBET extract, the TCLP extract, and sodium pyrophosphate), and their chemical distribution was assessed using the BCR sequential extraction procedure. The results showed that the finer fractions were enriched with the elements studied, and that Cu, Pb and Zn were the most potentially problematic ones, due to both their high total concentrations and availability. The partition into the BCR fractions was different for each element, but the differences between composts were scarce. Pb was evenly distributed among the four fractions defined in the BCR (soluble, oxidizable, reducible and residual); Cu was mainly found in the oxidizable fraction, linked to organic matter, and Zn was mainly associated to the reducible fraction (iron oxides), while Ni and Cr were mainly present almost exclusively in the residual fraction. It was not possible to establish a univocal relation between trace elements availability and their BCR fractionation. Given the differences existing for the availability and distribution of these elements, which not always were related to their total concentrations, we think that legal limits should consider availability, in order to achieve a more realistic assessment of the risks linked to compost use.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Adult human neural crest-derived stem cells (NCSCs) are of extraordinary high plasticity and promising candidates for the use in regenerative medicine. Here we describe for the first time a novel neural crest-derived stem cell population within the respiratory epithelium of human adult inferior turbinate. In contrast to superior and middle turbinates, high amounts of source material could be isolated from human inferior turbinates. Using minimally-invasive surgery methods isolation is efficient even in older patients. Within their endogenous niche, inferior turbinate stem cells (ITSCs) expressed high levels of nestin, p75(NTR), and S100. Immunoelectron microscopy using anti-p75 antibodies displayed that ITSCs are of glial origin and closely related to nonmyelinating Schwann cells. Cultivated ITSCs were positive for nestin and S100 and the neural crest markers Slug and SOX10. Whole genome microarray analysis showed pronounced differences to human ES cells in respect to pluripotency markers OCT4, SOX2, LIN28, and NANOG, whereas expression of WDR5, KLF4, and c-MYC was nearly similar. ITSCs were able to differentiate into cells with neuro-ectodermal and mesodermal phenotype. Additionally ITSCs are able to survive and perform neural crest typical chain migration in vivo when transplanted into chicken embryos. However ITSCs do not form teratomas in severe combined immunodeficient mice. Finally, we developed a separation strategy based on magnetic cell sorting of p75(NTR) positive ITSCs that formed larger neurospheres and proliferated faster than p75(NTR) negative ITSCs. Taken together our study describes a novel, readily accessible source of multipotent human NCSCs for potential cell-replacement therapy.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND: Chemical chitin extraction generates large amounts of wastes and increases partial deacetylation of the product. Therefore, the use of biological methods for chitin extraction is an interesting alternative. The effects of process conditions on enzyme assisted extraction of chitin from the shrimp shells in a systematic way were the focal points of this study. RESULTS: Demineralisation conditions of 25C, 20 min, shells-lactic acid ratio of 1:1.1 w/w; and shells-acetic acid ratio of 1:1.2 w/w, the maximum demineralisation values were 98.64 and 97.57% for lactic and acetic acids, respectively. A total protein removal efficiency of 91.10% by protease from Streptomyces griseus with enzyme-substrate ratio 55 U/g, pH 7.0 and incubation time 3 h is obtained when the particle size range is 50-25 μm, which was identified as the most critical factor. The X-ray diffraction and 13C NMR spectroscopy analysis showed that the lower percent crystallinity and higher degree of acetylation of chitin from enzyme assisted extraction may exhibit better solubility properties and less depolymerisation in comparison with chitin from the chemical extraction. CONCLUSION: The present work investigates the effects of individual factors on process yields, and it has shown that, if the particle size is properly controlled a reaction time of 3 h is more than enough for deproteination by protease. Physicochemical analysis indicated that the enzyme assisted production of chitin seems appropriate to extract chitin, possibly retaining its native structure.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

An efficient and rapid synthesis of 1-acetyl-1H-indol-3-yl acetate 1 and its derivatives 7 via the microwave-assisted cyclisation and decarboxylation of 2-[(carboxymethyl)amino]benzoic acids 5 is described. The latter were left to react with acetic anhydride using triethylamine as the base and were subjected to microwave irradiation for 1 minute, at 80 °C with initial power of 300 W. The target 1-acetyl-1H-indol-3-yl acetate 1 and derivatives 7 were isolated in 34-71% yield. In particular, synthesis of 1-acetyl-6-(trifluoromethyl)-1H-indol-3-yl acetate 7f and 1-acetyl-3-methyl-1H-indol-3-yl acetate 7h is reported for the first time.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The concept of frontline safety encapsulates an approach to occupational health and safety that emphasizes the 'other side of the regulatory relationship' – the ways in which safety culture, individual responsibility, organizational citizenship, trust, and compliance are interpreted and experienced at the local level. By exploring theoretical tensions over the most appropriate way of conceptualizing and framing frontline regulatory engagement, we can better identify the ways in which conceptions of individuals (as rational, responsible, economic actors) are constructed and maintained through workplace interactions and decision-making, as part of the fulfilment of the ideological and constitutive needs of neoliberal labor markets.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The abundance of heavy r-elements may provide a better understanding of the r-process, and the determination of several reference r-elements should allow a better determination of a star`s age. The space UV region (lambda < 3000 angstrom) presents a large number of lines of the heavy elements, and in the case of some elements, such as Bi, Pt, Au, detectable lines are not available elsewhere. The extreme ""r-process star"" CS 31082-001 ([Fe/H] = -2.9) was observed in the space UV to determine abundances of the heaviest stable elements, using STIS on board Hubble Space Telescope.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper deals with the morphological features of the tracheary elements of the vegetative organs in four Portulaca species (Portulaca hirsutissima Camb., P. halimoides L., P. wedermannii Poelln. and P. mucronata Link.) occurring in Southeast and Northeast Brazil. The vessel elements are small (< 25 mu m) and with simple perforation plate. The pattern of wall thickening varied from bordered pitting (in roots) to scalariform and helicoidal (stem and leaves). Statistical methods show variation in vessel-element diameter in different vegetative organs; wider elements were observed in roots. Tracheids occurring in leaves of P. hirsutissima and P. wedermannii, have morphological features that are similar to terminal tracheids or tracheoid idiolasts frequently associated with xerophytes. The paedomorphic features (juvenlism) observed here may be related, in part, to aspects of water transport and storage as described in Cactaceae.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Toll-like receptors (TLRs) present in innate immune cells recognize pathogen molecular patterns and influence immunity to control the host-parasite interaction. The objective of this study was to characterize the involvement of TLR4 in the innate and adaptive immunity to Paracoccidioides brasiliensis, the most important primary fungal pathogen of Latin America. We compared the responses of C3H/HeJ mice, which are naturally defective in TLR4 signaling, with those of C3H/HePas mice, which express functional receptors, after in vitro and in vivo infection with P. brasiliensis. Unexpectedly, we verified that TLR4-defective macrophages infected in vitro with P. brasiliensis presented decreased fungal loads associated with impaired synthesis of nitric oxide, interleukin-12 (IL-12), and macrophage chemotactic protein 1 (MCP-1). After intratracheal infection with 1 million yeasts, TLR4-defective mice developed reduced fungal burdens and decreased levels of pulmonary nitric oxide, proinflammatory cytokines, and antibodies. TLR4-competent mice produced elevated levels of IL-12 and tumor necrosis factor alpha (TNF-alpha), besides cytokines of the Th17 pattern, indicating a proinflammatory role for TLR4 signaling. The more severe infection of TLR4-normal mice resulted in increased influx of activated macrophages and T cells to the lungs and progressive control of fungal burdens but impaired expansion of regulatory T cells (Treg cells). In contrast, TLR4-defective mice were not able to clear their diminished fungal burdens totally, a defect associated with deficient activation of T-cell immunity and enhanced development of Treg cells. These divergent patterns of immunity, however, resulted in equivalent mortality rates, indicating that control of elevated fungal growth mediated by vigorous inflammatory reactions is as deleterious to the hosts as low fungal loads inefficiently controlled by limited inflammatory reactions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The synthesis of FDU-1 silica with large cage-like mesopores prepared with a new triblock copolymer Vorasurf 504 (R) (Eo)(38)(BO)(46)(EO)(38) was developed. The hydrothermal treatment temperature, the dissolution of the copolymer in ethanol, the HCl concentration, the solution stirring time and the hydrothermal treatment time in a microwave oven were evaluated with factorial design procedures. The dissolution in ethanol is important to produce a material with better porous morphology. Increases in the hydrothermal temperature (100 degrees C) and HCl concentration (2 M) improved structural, textural and chemical properties of the cubic ordered mesoporous silica. Also, longer times induced better physical and chemical property characteristics. (C) 2010 Elsevier Inc. All rights reserved.