A substituição de importações no Brasil entre 1995 e 2000

This work estimates the import substitution process in Brazilian industrial sectors in a recent period and evaluates whether it is occurring naturally or is in part induced by some kind of external commercial policy. An index to measure import substitution was calculated for forty nine sectors of industry. A regression analysis with this index against effective tariffs and real effective exchange rate, during the period 1995-2000, shows that these variables (effective tariffs and real effective exchange rates) did affect the substitution index. From 1999 on, the influence of the exchange rate over the import substitution index was greater than the influence of the effective tariff, suggesting that the process of import substitution post the Brazilian currency depreciation occurred in 1999 contains elements that characterizes it as a "natural" process.

Combined External Pressure And Cu-substitution Studies On Bafe2as2 Single Crystals.

We report a combined study of external pressure and Cu-substitution on BaFe2As2 single crystals grown by the in-flux technique. At ambient pressure, the Cu-substitution is known to suppress the spin density wave (SDW) phase in pure BaFe2As2(TSDW ≈ 140 K) and to induce a superconducting (SC) dome with a maximum transition temperature [Formula: see text]. This [Formula: see text] is much lower than the Tc ∼ 15-28 K achieved in the case of Ru, Ni and Co substitutions. Such a lower Tc is attributed to a Cu(2+) magnetic pair-breaking effect. The latter is strongly suppressed by applied pressure, as shown herein, Tc can be significantly enhanced by applying high pressures. In this work, we investigated the pressure effects on Cu(2+) magnetic pair-breaking in the BaFe2-xCuxAs2 series. Around the optimal concentration (xopd = 0.11), all samples showed a substantial increase of Tc as a function of pressure. Yet for those samples with a slightly higher doping level (over-doped regime), Tc presented a dome-like shape with maximum Tc ≃ 8 K. Remarkably interesting, the under-doped samples, e.g. x = 0.02 display a maximum pressure induced Tc ≃ 30 K which is comparable to the maximum Tc's found for the pure compound under external pressures. Furthermore, the magnetoresistance effect as a function of pressure in the normal state of the x = 0.02 sample also presented an evolution consistent with the screening of the Cu(2+) local moments. These findings demonstrate that the Cu(2+) magnetic pair-breaking effect is completely suppressed by applying pressure in the low concentration regime of Cu(2+) substituted BaFe2As2.

A microscopic view of substitution reactions solvated by ionic liquids

The solvation effect of the ionic liquid 1-N-butyl-3-methylimidazolium hexafluorophosphate on nucleophilic substitution reactions of halides toward the aliphatic carbon of methyl p-nitrobenzenesulfonate (pNBS) was investigated by computer simulations. The calculations were performed by using a hybrid quantum-mechanical/molecular-mechanical (QM/MM) methodology. A semiempirical Hamiltonian was first parametrized on the basis of comparison with ab initio calculations for Cl(-) and Br(-) reaction with pNBS at gas phase. In condensed phase, free energy profiles were obtained for both reactions. The calculated reaction barriers are in agreement with experiment. The structure of species solvated by the ionic liquid was followed along the reaction progress from the reagents, through the transition state, to the final products. The simulations indicate that this substitution reaction in the ionic liquid is slower than in nonpolar molecular solvents proper to significant stabilization of the halide anion by the ionic liquid in comparison with the transition state with delocalized charge. Solute-solvent interactions in the first solvation shell contain several hydrogen bonds that are formed or broken in response to charge density variation along the reaction coordinate. The detailed structural analysis can be used to rationalize the design of new ionic liquids with tailored solvation properties. (c) 2008 American Institute of Physics.

Effect of the Partial Substitution of Soy Proteins by Highly Methyl-esterified Pectin on Chemical and Sensory Characteristics of Sausages

Pectin can be used as a natural emulsifier in food formulations. In this study, textured soybean protein (TSP), used as an emulsifier in commercial sausages, was partially replaced by a mixture containing pectin and isolated soybean proteins, which were either extruded (EXT) or not extruded (MIX), and the chemical and sensory characteristics of samples were evaluated after 60 days of storage at 4 degrees C. Responses such as oxidation measured by PV and TBARS, hardness, color, pH and sensory characteristics were compared with those of a commercial sausage (CON). The mixture containing highly methyl-esterified pectin, textured soybean proteins and isolated soybean proteins, as emulsifier agent, reduced the hardness (EXT: 21.69 +/- 0.98 and MIX: 20.17 +/- 2.76 N) and the pH (EXT: 5.46 +/- 0.03 and MIX: 5.29 +/- 0.01) of the samples and increased the concentration of peroxides (EXT: 0.10 +/- 0.01 and MIX: 0.15 +/- 0.01 meq/kg) when compared with samples formulated only with TSP (28.57 +/- 2.54 N, pH of 6.92 +/- 0.04 and PV = 0.07 +/- 0.01 meq/kg). These effects were likely caused by the anionic character of the emulsifier. However, no sensory difference was observed between the sausages containing highly methyl-esterified pectin, textured soybean proteins and isolated soybean proteins submitted to the extrusion process (EXT) and the control sausages, suggesting that the formulation proposed in this study can be a potential alternative for the further development of sausages that have functional properties or are free of artificial additives.

Carrageenans with complex substitution patterns from red algae of the genus Erythroclonium

Extracellular polysaccharides from three Erythroclonium spp. were shown, by a combination of compositional, linkage analyses, and Fourier transform infrared and C-13-nuclear magnetic resonance spectroscopy, to be highly substituted carrageenans with at least five types of repeating disaccharide units. These are the carrabiose 2,4'-disulfate of iota-carrageenan, carrabiose 2-sulfate of alpha-carrageenan, the 6'-O-methylated counterparts of each of these repeating units, and 4',6'-O-(1-carboxyethylidene)carrabiose 2-sulfate. The polysaccharides also contain significant amounts of unsubstituted, 4-linked galactopyranose and small amounts of 4-linked 3-O-methylgalactopyranose and terminal glycosyl residues. The carrageenan preparations of the three species are similar, differing only in the proportions of some components. (C) 1998 Elsevier Science Ltd.

H-1-NMR structural studies of a cystine-linked peptide containing residues 71-93 of transthyretin and effects of a Ser84 substitution implicated in familial amyloidotic polyneuropathy

The Ile-->Ser84 substitution in the thyroid hormone transport protein transthyretin is one of over 50 variations found to be associated with familial amyloid polyneuropathy, a hereditary type of lethal amyloidosis. Using a peptide analogue of the loop containing residue 84 in transthyretin, we have examined the putative local structural effects of this substitution using H-1-NMR spectroscopy. The peptide, containing residues 71-93 of transthyretin with its termini linked via a disulfide bond, was found to possess the same helix-turn motif as in the corresponding region of the crystallographically derived structure of transthyretin in 20% trifluoroethanol (TFE) solution. It therefore, represents a useful model with which to examine the effects of amyloidogenic substitutions. In a peptide analogue containing the Ile84-->Ser substitution it was found that the substitution does not greatly disrupt the overall three-dimensional structure, but leads to minor local differences at the turn in which residue 84 is involved. Coupling constant and NOE measurements indicate that the helix-turn motif is still present, but differences in chemical shifts and amide-exchange rates reflect a small distortion. This is in keeping with observations that several other mutant forms of transthyretin display similar subunit interactions and those that have been structurally analysed possess a near native structure. We propose that the Ser84 mutation induces only subtle perturbations to the transthyretin structure which predisposes the protein to amyloid formation.

An Activated O N Acyl Transfer Auxiliary: Efficient Amide-Backbone Substitution of Hindered "Difficult" Peptides

Overcoming the phenomenon known as difficult synthetic sequences has been a major goal in solid-phase peptide synthesis for over 30 years. In this work the advantages of amide backbone-substitution in the solid-phase synthesis of difficult peptides are augmented by developing an activated N-alpha-acyl transfer auxiliary. Apart from disrupting troublesome intermolecular hydrogen-bonding networks, the primary function of the activated N-alpha-auxiliary was to facilitate clean and efficient acyl capture of large or beta-branched amino acids and improve acyl transfer yields to the secondary N-alpha-amine. We found o-hydroxyl-substituted nitrobenzyl (Hnb) groups were suitable N-alpha-auxiliaries for this purpose. The relative acyl transfer efficiency of the Hnb auxiliary was superior to the 2-hydroxy-4-methoxybenzyl (Hmb) auxiliary with protected amino acids of varying size. Significantly, this difference in efficiency was more pronounced between more sterically demanding amino acids. The Hnb auxiliary is readily incorporated at the N-alpha-amine during SPPS by reductive alkylation of its corresponding benzaldehyde derivative and conveniently removed by mild photolysis at 366 nm. The usefulness of the Hnb auxiliary for the improvement of coupling efficiencies in the chain-assembly of difficult peptides was demonstrated by the efficient Hnb-assisted Fmoc solid-phase synthesis of a known hindered difficult peptide sequence, STAT-91. This work suggests the Hnb auxiliary will significantly enhance our ability to synthesize difficult polypeptides and increases the applicability of amide-backbone substitution.

Mechanisms of substitution reactions on cyclometallated platinum(IV) complexes: "Quasi-labile" systems

The substitution reactions of SMe2 by phosphines (PMePh2, PEtPh2, PPh3, P(4-MeC6H4)(3), P(3-MeC6H4)(3), PCy3) on Pt-IV complexes having a cyclometalated imine ligand, two methyl groups in a cis-geometrical arrangement, a halogen, and a dimethyl sulfide as ligands, [Pt(CN)(CH3)(2)(X)(SMe2)], have been studied as a function of temperature, solvent, and electronic and steric characteristics of the phosphines and the X and CN ligands. In all cases, a limiting dissociative mechanism has been found, where the dissociation of the SMe2 ligand corresponds to the rate-determining step. The pentacoordinated species formed behaves as a true pentacoordinated Pt-IV compound in a steady-state concentration, given the solvent independence of the rate constant. The X-ray crystal structures of two of the dimethyl sulfide complexes and a derivative of the pentacoordinate intermediate have been determined. Differences in the individual rate constants for the entrance of the phosphine ligand can only be estimated as reactivity ratios. In all cases an effect of the phosphine size is detected, indicating that an associative step takes place from the pentacoordinated intermediate. The nature of the (CN) imine and X ligands produces differences in the dimethyl sulfide dissociation reactions rates, which can be quantified by the corresponding DeltaS double dagger values (72, 64, 48, 31, and 78 J K-1 mol(-1) for CN/X being C6H4CHNCH2C6H5/Br, C6H4CHNCH2-(2,4,6-(CH3)(3))C6H2/Br, C6H4CHNCH2C6H5/Cl, C6Cl4CHNCH2C6H5/Cl, and C6W4CH2NCHC6H5/ Pr, respectively). As a whole, the donor character of the coordinated C-aromatic and X atoms have the greatest influence on the dissociativeness of the rate-determining step.

Import substitution and economic growth

Despite Latin America`s dismal performance between the 1950s and 1980s, the region experienced strong capital deepening. We suggest that these facts can be explained as a consequence of the restrictive trade regime adopted at that time. Our framework is based on a dynamic Heckscher-Ohlin model, with scale economies in the capital-intensive sector. Initially, the economy is open and produces only the labor-intensive good. The trade regime is modeled as a move to a closed economy. The model produces results consistent with the Latin American experience. Specifically, a Sufficiently small Country experiences no long-run income growth, but an increase in capital. (C) 2009 Elsevier B.V. All rights reserved.

Should patients with esophageal atresia be submitted to esophageal substitution before they start walking?

P>Esophagocoloplasty and gastric transposition are two major methods for esophageal substitution in children with esophageal atresia, and there is broad agreement that these operations should not be performed before the children start walking. However, there are some reported advantages of performing such operations in the first months of life or in the neonatal period. In this study, we compared our experience with esophageal substitution procedures performed in walking children with esophageal atresia, with the outcomes of children who had the operation before the third month of life reported in the literature. The purpose of this study was to establish if we have to wait until the children start walking before indicating the esophageal replacement procedure. From February 1978 to October 2009, 129 children with esophageal atresia underwent esophageal replacement in our hospital (99 colonic interpositions and 30 gastric transpositions). The records of these patients were reviewed for data regarding demographics, complications (leaks, graft failures, strictures, and graft torsion), and mortality and compared with those reported in the two main articles on esophageal replacement in the neonatal period or in patients less than 3 months of age. The main complication of our casuistic was cervical anastomosis leakage, which sealed spontaneously in all except in four patients. One patient of the esophagocoloplasty group developed graft necrosis and three patients in the gastric transposition group had gastric outlet obstruction, secondary to axial torsion of the stomach placed in the retrosternal space. The long-term outcome of the patients in both groups was considered good to excellent in terms of normal weight gain, absence of dysphagia, and other gastrointestinal symptoms. The comparisons of the main complications and mortality rates in walking children with esophageal substitutions performed in the first months of life showed that the incidences of cervical anastomotic leaks and graft failures were similar, but mortality rate in the first few months of life was significantly greater than that observed in our group of patients (P = 0.001). Based on the comparison of our results with those of published series, we conclude that the recommendation of performing esophagocoloplasty or total gastric transposition in children with esophageal atresia after they start walking is still valid.

Effects of electrotactile vestibular substitution on rehabilitation of patients with bilateral vestibular loss

The present study evaluated the effectiveness of electrotactile tongue biofeedback (BrainPort (R)) as a sensory substitute for the vestibular apparatus in patients with bilateral vestibular loss (BVL) who did not have a good response to conventional vestibular rehabilitation (VR). Seven patients with BVL were trained to use the device. Stimulation on the surface of the tongue was created by a dynamic pattern of electrical pulses and the patient was able to adjust the intensity of stimulation and spatially centralize the stimulus on the electrode array. Patients were directed to continuously adjust head orientation and to maintain the stimulus pattern at the center of the array. Postural tasks that present progressive difficulties were given during the use of the device. Pre- and post-treatment distribution of the sensory organization test (SOT) composite score showed an average value of 38.3 +/- 8.7 and 59.9 +/- 11.3, respectively, indicating a statistically significant improvement (p = 0.01). Electrotactile tongue biofeedback significantly improved the postural control of the study group, even if they had not improved with conventional VR. The electrotactile tongue biofeedback system was able to supply additional information about head position with respect to gravitational vertical orientation in the absence of vestibular input, improving postural control. Patients with BVL can integrate electrotactile information in their postural control in order to improve stability after conventional VR. These results were obtained and verified not only by the subjective questionnaire but also by the SOT composite score. The limitations of the study are the small sample size and short duration of the follow-up. The current findings show that the sensory substitution mediated by electrotactile tongue biofeedback may contribute to the improved balance experienced by these patients compared to VR. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

A single amino acid substitution in one of the lipases of Aspergillus nidulans confers resistance to the antimycotic drug undecanoic acid

A plausible approach to evaluate the inhibitory action of antifungals is through the investigation of the fungal resistance to these drugs. We describe here the molecular cloning and initial characterization of the A. nidulans lipA gene, where mutation (lipA1) conferred resistance to undecanoic acid, the most fungitoxic fatty acid in the C(7:0)-C(18:0) series. The lipA gene codes for a putative lipase with the sequence consensus GVSIS and WIFGGG as the catalytic signature. Comparison of the wild-type and LIP1 mutant strain nucleotide sequences showed a G -> A change in lipA1 allele, which results in a Glu(214) -> Lys substitution in LipA protein. This ionic charge change in a conserved LipA region, next to its catalytic site, may have altered the catalytic properties of this enzyme resulting in resistance to undecanoic acid.

Substitution of crude cell wall for neutral detergent fibre in the equations of the Cornell Net Carbohydrate and Protein System that predict carbohydrate fractions: application to sunflower (Helianthus annulus L.)

Prediction of carbohydrate fractions using equations from the Cornell Net Carbohydrate and Protein System (CNCPS) is a valuable tool to assess the nutritional value of forages. In this paper these carbohydrate fractions were predicted using data from three sunflower (Helianthus annuus L.) cultivars, fresh or as silage. The CNCPS equations for fractions B(2) and C include measurement of ash and protein-free neutral detergent fibre (NDF) as one of their components. However, NDF lacks pectin and other non-starch polysaccharides that are found in the cell wall (CW) matrix, so this work compared the use of a crude CW preparation instead of NDF in the CNCPS equations. There were no differences in the estimates of fractions B, and C when CW replaced NDF; however there were differences in fractions A and B2. Some of the CNCPS equations could be simplified when using CW instead of NDF Notably, lignin could be expressed as a proportion of DM, rather than on the basis of ash and protein-free NDF, when predicting CNCPS fraction C. The CNCPS fraction B(1) (starch + pectin) values were lower than pectin determined through wet chemistty. This finding, along with the results obtained by the substitution of CW for NDF in the CNCPS equations, suggests that pectin was not part of fraction B(1) but present in fraction A. We suggest that pectin and other non-starch polysaccharides that are dissolved by the neutral detergent solution be allocated to a specific fraction (B2) and that another fraction (B(3)) be adopted for the digestible cell wall carbohydrates.

A unique substitution at position 333 on the glycoprotein of rabies virus street strains isolated from non-hematophagous bats in Brazil

The amino acid R or K at position 333 on the glycoprotein of the rabies virus is considered necessary for virulence in adult mice. Although some exceptions exist, substitution at this position causes expression of a phenotype that is either less pathogenic or non-virulent. To date, such substitutions have only been found in fixed strains of rabies virus. In this study, the authors found 333H, 333N, and 333Q substitutions at this position in rabies virus street strains isolated from non-hematophagous bats in Brazil. These strains showed pathogenicity and lethality on passage using adult mice with the intracerebral route and were confirmed rabies-positive by immunofluorescent assay. This suggests that these strains maintain virulence. Our findings indicate that rabies virus street strains with these substitutions exist in the field and may result in infection cycles.