949 resultados para Entire functions of exponential type


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We report for the first time the genetic and biological characterization of 10 HIV-1 primary isolates representing CRF28_BF and CRF29_BF together with additional unique BF recombinant forms (URFs) obtained by PBMC cocultivation. Recombination is an important factor promoting the increase in the genetic diversity of HIV-1. Notably, more than 20% of HIV-1 sequences worldwide were recombinants. Several recombinant viruses were reported in Brazil, and six circulating recombinant forms (CRFs) have been identified (CRF28_BF, CRF29_BF, CRF31_BC, CRF39_BF, CRF40_BF, and CRF46_BF). CRF28_BF and CRF29_BF were found to infect almost 30% of the patients in Sao Paulo State. The near full-length genomes of these 10 primary isolates were amplified by nested PCR in three overlapping segments, purified, and sequenced. Three samples were related to CRF28_BF, three to CRF29_BF, and four were unique recombinant forms (URFs), as determined by their breakpoint profile determined with the jpHMM program. Additionally, the coreceptor usage of these isolates was investigated in vitro using GHOST assays, which revealed three dual-tropic (X4/R5) viruses, four lymphotropic (X4) viruses, and three macrophage-tropic (R5) viruses with different V3-loop motifs, which challenges the notion that GWGR-carrying viruses are macrophage-tropic only. In sum, we report a much-anticipated well-characterized panel of viruses representing CRF28_BF, CRF29_BF, and URFs from Sao Paulo State, Brazil.

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A fast method was optimized and validated in order to quantify amphetamine-type stimulants (amphetamine, AMP; methamphetamine, MAMP; fenproporex, FPX; 3,4-methylenedioxymethamphetamine, MDMA; and 3,4-methylenedioxyamphetamine, MDA) in human hair samples. The method was based in an initial procedure of decontamination of hair samples (50 mg) with dichloromethane, followed by alkaline hydrolysis and extraction of the amphetamines using hollow-fiber liquid-phase micro extraction (HF-LPME) in the three-phase mode. Gas chromatography-mass spectrometry (GC-MS) was used for identification and quantification of the analytes. The LoQs obtained for all amphetamines (around 0.05 ng/mg) were below the cut-off value (0.2 ng/mg) established by the Society of Hair Testing (SoHT). The method showed to be simple and precise. The intra-day and inter-day precisions were within 10.6% and 11.4%, respectively, with the use of only two deuteratecl internal standards (AMP-d5 and MDMA-d5). By using the weighted least squares linear regression (1/x(2)), the accuracy of the method was satisfied in the lower concentration levels (accuracy values better than 87%). Hair samples collected from six volunteers who reported regular use of amphetamines were submitted to the developed method. Drug detection was observed in all samples of the volunteers. (c) 2012 Elsevier B.V. All rights reserved.

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In this work, the energy response functions of Si(Li), SDD and CdTe detectors were studied in the mammographic energy range through Monte Carlo simulation. The code was modified to take into account carrier transport effects and the finite detector energy resolution. The results obtained show that all detectors exhibit good energy response at low energies. The most important corrections for each detector were discussed, and the corrected mammographic x-ray spectra obtained with each one were compared. Results showed that all detectors provided similar corrected spectra, and, therefore, they could be used to accurate mammographic x-ray spectroscopy. Nevertheless, the SDD is particularly suitable for clinic mammographic x-ray spectroscopy due to the easier correction procedure and portability. (C) 2011 Elsevier Ltd. All rights reserved.

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Desmoid-type fibromatosis is an uncommon and aggressive neoplasia, associated with a high rate of recurrence. It is characterized by an infiltrative but benign fibroblastic proliferation occurring within the deep soft tissues. There is no consensus about the treatment of those tumors. We present a surgical series of four cases, involving the brachial plexus (two cases), the median nerve and the medial brachial cutaneous nerve. Except for the last case, they were submitted to multiple surgical procedures and showed repeated recurrences. The diagnosis, the different ways of treatment and the prognosis of these tumoral lesions are discussed. Our results support the indication of radical surgery followed by radiotherapy as probably one of the best ways to treat those controversial lesions.

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Calcium carbonate is one of the most important biominerals, and it is the main constituent of pearls, seashells, and teeth. The in vitro crystallization of calcium carbonate using different organic matrices as templates has been reported. In this work, the growth of calcium carbonate thin films on special organic matrices consisting of layer-by-layer (LbL) polyelectrolyte films deposited on a pre-formed phospholipid Langmuir-Blodgett (LB) film has been studied. Two types of randomly coiled polyelectrolytes have been used: lambda-carrageenan and poly(acrylic acid). A precoating comprised of LB films has been prepared by employing a negatively charged phospholipid, the sodium salt of dimyristoilphosphatidyl acid (DMPA), or a zwitterionic phospholipid, namely dimyristoilphosphatidylethanolamine (DMPE). This approach resulted in the formation of particulate calcium carbonate continuous films with different morphologies, particle sizes, and roughness, as revealed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The crystalline structure of the calcium carbonate particles was analyzed by Raman spectroscopy. The randomly coiled conformation of the polyelectrolytes seems to be the main reason for the formation of continuous films rather than CaCO3 isolated crystals. (C) 2012 Elsevier B.V. All rights reserved.

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The Diptera collection of the Natural History Museum Berlin holds one of the most important collections of Neriidae. In this paper, the type specimens (holotypes, lectotypes, paratypes, paralectotypes, syntypes) of this historical collection are listed. 28 species-group taxa are dealt with. A lectotype designation is made for the species Brachantichir purpusianus Enderlein, 1922 in order to fix the identity of the name. Holotypes are recognized by monotypy of the species Chaetomeristes bullatus Enderlein, 1922; Chaetomeristes peruanus Enderlein, 1922; Derocephalus angusticollis Enderlein, 1922; Glyphidops limbatus Enderlein, 1922; Longina abdominalis Wiedemann, 1830; Loxozus clavicornis Enderlein, 1922; Oncopsia mexicana Enderlein, 1922; Paranerius fibulatus Enderlein, 1922; Telostylinus dahli Enderlein, 1922; Telostylus latibrachium Enderlein, 1922; and Telostylinus luridus Enderlein, 1922. Syntypes are labelled and listed for Brachantichir robusta Enderlein, 1922; Nerius terebratus Enderlein, 1922; Odontoloxozus punctulatus Enderlein, 1922; Telostylinus apicalis Enderlein, 1922; Telostylinus obscuratus Enderlein, 1922; and Telostylinus ornatipennis Enderlein, 1922. The account concludes with geographic and taxonomic summaries; an appendix listing the abbreviations, localities, and collectors cited in the text; and a bibliography. ((c) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

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The role of different types of emulsifying saltssodium citrate (TSC), sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP) and tetrasodium pyrophosphate (TSPP)on microstructure and rheology of requeijao cremoso processed cheese was determined. The cheeses manufactured with TSC, TSPP, and STPP behaved like concentrated solutions, while the cheese manufactured with SHMP exhibited weak gel behavior and the lowest values for the phase angle (G/G). This means that SHMP cheese had the protein network with the largest amount of molecular interactions, which can be explained by its highest degree of fat emulsification. Rotational viscometry indicated that all the spreadable cheeses behaved like pseudoplastic fluids. The cheeses made with SHMP and TSPP presented low values for the flow behavior index, meaning that viscosity was more dependent on shear rate. Regarding the consistency index, TSPP cheese showed the highest value, which could be attributed to the combined effect of its high pH and homogeneous fat particle size distribution.

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The effect of the addition of passion fruit peel powder (PFPP) on the fermentation kinetics and texture parameters, post-acidification and bacteria counts of probiotic yoghurts made with two milk types were evaluated during 28 days of storage at 4 degrees C. Milks were fermented by Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (CY340), and one strain of probiotic bacteria: Lactobacillus acidophilus (L10 and NCFM), Bifidobacterium animalis subsp. lactis (8104 and HN019). The addition of PFPP reduced significantly fermentation time of skim milk co-fermented by the strains L10, NCFM and HN019. At the end of 28-day shelf-life, counts of B. lactis Bl04 were about 1 Log CFU mL(-1) higher in whole yoghurt fermented with PFPP regarding its control but, in general, the addition of PFPP had less influence on counts than the milk type itself. The titratable acidity in yoghurts with PFPP was significantly higher than in their respective controls, and in skim yoghurts higher than in the whole ones. The PFPP increased firmness, consistency (except for the NCFM strain of L acidophilus) and cohesiveness of all skim yoghurts. The results point out the suitability of using passion fruit by-product in the formulation of both skim and whole probiotic yoghurts. (C) 2012 Elsevier Ltd. All rights reserved.

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The emissive properties of terpolymers with fluorene, thiophene and phenylene groups, forming alternating PPV type structures, are discussed in terms of their composition, photo- and electroluminescence properties. The fluorene groups were inserted in each phenylene-vinylene and thiophene-vinylene units, and their concentration did not vary, representing 50% of the molar composition. The ratio of thiophene-vinylene/phenylene-vinylene varied in the range 25,50 and 75%. Photo- and electroluminescence properties were strongly dependent on the thiophene-vinylene content and were compared with the fluorene-vinylene-thiophene and fluorene-vinylene-phenylene parent copolymers. (C) 2012 Elsevier B.V. All rights reserved.

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Abstract Background Dengue is the most important arbovirus disease in tropical and subtropical countries. The viral envelope (E) protein is responsible for cell receptor binding and is the main target of neutralizing antibodies. The aim of this study was to analyze the diversity of the E protein gene of DENV-3. E protein gene sequences of 20 new viruses isolated in Ribeirao Preto, Brazil, and 427 sequences retrieved from GenBank were aligned for diversity and phylogenetic analysis. Results Comparison of the E protein gene sequences revealed the presence of 47 variable sites distributed in the protein; most of those amino acids changes are located on the viral surface. The phylogenetic analysis showed the distribution of DENV-3 in four genotypes. Genotypes I, II and III revealed internal groups that we have called lineages and sub-lineages. All amino acids that characterize a group (genotype, lineage, or sub-lineage) are located in the 47 variable sites of the E protein. Conclusion Our results provide information about the most frequent amino acid changes and diversity of the E protein of DENV-3.

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Hyperthyroidism is characterized by increased vascular relaxation and decreased vascular contraction and is associated with augmented levels of triiodothyronine (T3) that contribute to the diminished systemic vascular resistance found in this condition. T3 leads to augmented NO production via PI3K/Akt signaling pathway, which in turn causes vascular smooth muscle cell (VSMC) relaxation; however, the underlying mechanisms involved remain largely unknown. Evidence from human and animal studies demonstrates that the renin-angiotensin system (RAS) plays a crucial role in vascular function and also mediates some of cardiovascular effects found during hyperthyroidism. Thus, in this study, we hypothesized that type 2 angiotensin II receptor (AT2R), a key component of RAS vasodilatory actions, mediates T3 induced-decreased vascular contraction. Marked induction of AT2R expression was observed in aortas from T3-induced hyperthyroid rats (Hyper). These vessels showed decreased protein levels of the contractile apparatus: α-actin, calponin and phosphorylated myosin light chain (p-MLC). Vascular reactivity studies showed that denuded aortic rings from Hyper rats exhibited decreased maximal contractile response to angiotensin II (AngII), which was attenuated in aortic rings pre-incubated with an AT2R blocker. Further study showed that cultured VSMC stimulated with T3 (0.1 µmol/L) for 24 hours had increased AT2R gene and protein expression. Augmented NO levels and decreased p-MLC levels were found in VSMC stimulated with T3, both of which were reversed by a PI3K/Akt inhibitor and AT2R blocker. These findings indicate for the first time that the AT2R/Akt/NO pathway contributes to decreased contractile responses in rat aorta, promoted by T3, and this mechanism is independent from the endothelium.

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Signal transduction pathways mediated by cyclic-bis(3'→5')-dimeric GMP (c-di-GMP) control many important and complex behaviors in bacteria. C-di-GMP is synthesized through the action of GGDEF domains that possess diguanylate cyclase activity and is degraded by EAL or HD-GYP domains with phosphodiesterase activity. There is mounting evidence that some important c-di-GMP-mediated pathways require protein-protein interactions between members of the GGDEF, EAL, HD-GYP and PilZ protein domain families. For example, interactions have been observed between PilZ and the EAL domain from FimX of Xanthomonas citri (Xac). FimX and PilZ are involved in the regulation of type IV pilus biogenesis via interactions of the latter with the hexameric PilB ATPase associated with the bacterial inner membrane. Here, we present the crystal structure of the ternary complex made up of PilZ, the FimX EAL domain (FimXEAL) and c-di-GMP. PilZ interacts principally with the lobe region and the N-terminal linker helix of the FimXEAL. These interactions involve a hydrophobic surface made up of amino acids conserved in a non-canonical family of PilZ domains that lack intrinsic c-di-GMP binding ability and strand complementation that joins β-sheets from both proteins. Interestingly, the c-di-GMP binds to isolated FimXEAL and to the PilZ-FimXEAL complex in a novel conformation encountered in c-di-GMP-protein complexes in which one of the two glycosidic bonds is in a rare syn conformation while the other adopts the more common anti conformation. The structure points to a means by which c-di-GMP and PilZ binding could be coupled to FimX and PilB conformational states

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The humoral immune response is dependent on the formation of antibodies. Antibodies are produced by terminally differentiated B cells, plasma cells. Plasma cells are generated either directly from antigen challenged B cells, memory cells or from cells that have undergone the germinal center (GC) reaction. The GC is the main site for class switch, somatic hypermutation and generation of memory cells. Different factors, both internal and external, shape the outcome of the immune response. In this thesis, we have studied a few factors that influence the maturation of the humoral response. We have studied how age affects the response, and we show that responses against thymus dependent antigens (TD) are more affected than responses to thymus independent (TI) antigens, in concordance with the view that the T cell compartment is more affected by age than the B cell compartment. Furthermore, we demonstrate that priming early in life have a big influence on the immune response in the aged individual. Priming with a TI form of the carbohydrate dextran B512 (Dx) induces a reduction of IgG levels in later TD responses against Dx. We have evaluated possible mechanisms for this reduction. The reduction does not seem to be caused by clonal exhaustion or antibody mediated mechanisms. We also showed that the reduced TD response after TI priming can be induced against another molecule than Dx. With the hypothesis that TI antigens induce a plasma cell biased maturation of the responding B cells, we examined the presence of Blimp-1, a master regulator of plasma cell differentiation, in GCs induced by TD and TI antigen. Blimp-1 was found earlier in GCs induced by TI antigen and the staining intensity in these GCs was stronger than in TD antigen induced GCs, indicating that plasma cells might be continuously recruited from these GCs. B cells undergoing the GC reaction are thought to be under a strict selection pressure that removes cells with low affinity for the antigen and also cells that have acquired self-reactivity. We investigated the effect of apoptotic deficiencies on the accumulation of somatic mutations in GC B cells. In mice lacking the death receptor Fas, lpr mice, the frequency of mutations was increased but the pattern of the mutations did not differ from wild type mice. In contrast, mice over-expressing the anti-apoptotic protein Bcl-2, had a lowered frequency of mutations and the mutations introduced had other characteristics.

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[EN]In this work, stiffness and damping functions of pile foundations with inclined end-bearing piles have been computed for square 2X2 and 3X3 pile groups embedded in a soft stratum overlaying a rigid bedrock. The paper algo invetigates the influence that the assumption of a perfectly rigid bedrock and fixed boundary conditions at the pile tips have on the impedance functions.

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Many potential diltiazem related L-VDCC blockers were developed using a multidisciplinary approach. This current study was to investigate and compare diltiazem with to the newly developed compounds by mouse Langendorff-perfused heart, Ca2+-transient and on recombinant L-VDCC. Twenty particular compounds were selected by the ligand-based virtual screening procedure (LBVS). From these compounds, five of them (5b, M2, M7, M8 and P1) showed a potent and selective inotropic activity on guinea-pig left atria driven 1 Hz. Further assays displayed an interesting negative inotropic effect of M2, M8, P1 and M7 on guinea pig isolated left papillary muscle driven at 1 Hz, a relevant vasorelaxant activity of 5b, M2, M7, M8 and P1 on K+-depolarized guinea-pig ileum longitudinal smooth muscle and a significant inhibition of contraction of 5b, M2, M8 and P1 on carbachol stimulated ileum longitudinal smooth muscle. Wild-type human heart and rabbit lung α1 subunits were expressed (combined with the regulatory α2δ and β3 subunits) in Xenopus Leavis oocytes using a two-electrode voltage clamp technique. Diltiazem is a benzothiazepine Ca2+ channel blocker used clinically for its antihypertensive and antiarrhythmic effects. Previous radioligand binding assays revealed a complex interaction with the benzothiazepine binding site for M2, M7 and M8. (Carosati E. et al. J. Med Chem. 2006, 49; 5206). In agreement with this findings, the relative order of increased rates of contraction and relaxation at lower concentrations s(≤10-6M) in unpaced hearts was M7>M2>M8>P1. Similar increases in Ca2+ transient were observed in cardiomyocytes. Diltiazem showed negative inotropic effects whereas 5b had no significant effect. Diltiazem blocks Ca2+current in a use-dependent manner and facilitates the channel by accelerating the inactivation and decelerating the recovery from inactivation. In contrast to diltiazem, the new analogs had no pronounced use-dependence. Application of 100 μM M8, M2 showed ~ 10% tonic block; in addition, M8, M2 and P1 shifted the steady state inactivation in hyperpolarized direction and the current inactivation time was significantly decreased compared with control (219.6 ± 11.5 ms, 226 ± 14.5 vs. 269 ± 12.9 vs. 199.28 ± 8.19 ms). Contrary to diltiazem, the recovery from the block by M8 and M2 was comparable to control. Only P1 showed a significantly decrease of the time for the recovery from inactivation. All of the compounds displayed the same sensitivity on the Ca2+ channel rabbit lung α1 except P1. Taken together, these findings suggest that M8, M2 and P1 might directly decrease the binding affinity or allow rapid dissociation from the benzothiazepine binding site.