134 resultados para equivalent circuit synthesis
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An efficient (12 steps, 12% overallyield) and stereoselective total synthesis of (±)-serricornine (1) the sex pheromone of the cigarette beetle (Lasioderma serricornine F) is described. The preparation of intermediate 5, which encompasses the proper relative configuration of three contiguous chiral centers of (±)-invictolide, (3), is discussed.
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By means of ethereal washing of insect pheromone glands of female moths, GC-MS detection along with microchemical reactions and electroantennogram (EAG) survey, six economically important insect species were targeted for pheromone identification. The discovery of a natural pheromone inhibitor, chemo-selectivity and species isolation by pheromone will be described. The modified triple bond migration and triethylamine liganded vinyl cuprate were applied for achiral pheromone synthesis in double bond formation. Some optically active pheromones and their stereoisomers were synthesized through chiral pool or asymmetric synthesis. Some examples of chiral recognition of insects towards their chiral pheromones will be discussed. A CaH2 and silica gel catalyzed Sharpless Expoxidation Reaction was found in shortening the reaction time.
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Rats experimentally infected with Trypanosoma cruzi Y strain exhibited hypertrophy of the submandibular gland at 18 days after infection.SDS-PAGE of infected rats saliva revealed the presence of an additional band with an apparent molecular weight of about 13KDa. Electrophoresis of protein salivaand immunochemical analysis with antibody against rat cystatin S confirmed that the protein was identical to that induced by beta adrenergic stimulation.
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Eosinophils are prominent inflammatory cells in asthma and other allergic disorders, as well as in helminthic parasite infections. Recently, eosinophils have been reported to synthesize and store a range of regulatory proteins within their secretory granules (eokines). Eokines comprise a group of cytokines, chemokines, and growth factors which are elaborated by eosinophils. These proteins, and the messages which encode them, appear to be identical to those produced by lymphocytes and other tissues. Interestingly, immunoreactivity to many of these eokines has been found to co-localize to the eosinophil´s secretory granules. In this review, we have discussed the repertoire of 18 eokines so far identified in eosinophils, and focused on four of these, namely, interleukin-2 (IL-2), IL-4, granulocyte/macrophage colony-stimulating factor (GM-CSF), and RANTES. These four eokines co-localize to the crystalloid granules in eosinophils, as shown in studies using subcellular fractionation and immunogold labeling in electron microscopy. During stimulation by physiological triggers, for example, with serum-coated particles, eosinophils release these mediators into the surrounding supernatant. In addition, eokines are likely to be synthesized within eosinophils rather than taken up by endocytosis, as show in detection of mRNA for each of these proteins using in situ hybridization, RT-PCR, and in the case of RANTES, in situ RT-PCR. Eokines synthesis and release from eosinophils challenges the commonly held notion that these cells act downstream of key elements in immune system, and indicate that they may instead belong to the afferent arm of immunity.
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A cell-free system from Plasmodium falciparum able to translate endogenous mRNA was used to determine the effect of artemisinin, chloroquine and primaquine on the protein synthesis mechanism of the parasite. The antimalarial drugs did not inhibit the incorporation of [³H] methionine into parasite proteins even at concentrations higher than the ones found to strongly inhibit the parasite growth. Results clearly indicate that these compounds do not have a direct effect on protein synthesis activity of P. falciparum coded by endogenous mRNA.
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The effects of mucosally added Escherichia coli heat stable enterotoxin (STa 30 ng ml-1) on the basal short-circuit current (Isc in µA cm-2) across stripped and unstripped sheets of jejuna and ilea taken from fed, starved (4 days, water ad lib) and undernourished (50% control food intake for 21 days) gerbil (Gerbillus cheesmani) were investigated. The effect of neurotoxin tetrodotoxin (TTX 10 µM) and the effects of replacing chloride by gluconate or the effects of removing bicarbonate from bathing buffers on the maximum increase in Isc induced by STa were also investigated. The maximum increase in Isc which resulted from the addition of STa were significantly higher in jejuna and ilea taken from starved and undernourished gerbils when compared with the fed control both using stripped and unstripped sheets. In the two regions of the small intestine taken from fed and starved animals TTX reduced the maximum increase in Isc induced by STa across unstripped sheets only. Moreover in jejuna and ilea taken from undernourished gerbils TTX reduced significantly the maximum increase in Isc induced by STa across stripped and unstripped sheets. Replacing chloride by gluconate decreased the maximum increase in Isc induced by STa across jejuna and ilea taken from undernourished gerbils only. Removing bicarbonates from bathing buffer decreased the maximum increase in Isc across the jejuna and ilea taken from starved and undernourished gerbils.
Delay in maturation of the submandibular gland in Chagas disease correlates with lower DNA synthesis
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It has been demonstrated that the acute phase of Trypanosoma cruzi infection promotes several changes in the oral glands. The present study examined whether T. cruzi modulates the expression of host cell apoptotic or mitotic pathway genes. Rats were infected with T. cruzi then sacrificed after 18, 32, 64 or 97 days, after which the submandibular glands were analyzed by immunohistochemistry. Immunohistochemical analyses using an anti-bromodeoxyuridine antibody showed that, during acute T. cruzi infection, DNA synthesizing cells in rat submandibular glands were lower than in non-infected animals (p < 0.05). However, after 64 days of infection (chronic phase), the number of immunolabeled cells are similar in both groups. However, immunohistochemical analysis of Fas and Bcl-2 expression did not find any difference between infected and non-infected animals in both the acute and chronic stages. These findings suggest that the delay in ductal maturation observed at the acute phase of Chagas disease is correlated with lower expression of DNA synthesis genes, but not apoptotic genes.
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A series of seven limonene β-amino alcohol derivatives has been regioselectively synthesised in moderate to good yields. Two of these compounds were found to be significantly effective against in vitro cultures of the Leishmania (Viannia) braziliensis promastigote form in the micromolar range. The activities found for 3b and 3f were about 100-fold more potent than the standard drug, Pentamidine, in the same test, while limonene did not display any activity. This is the first report of antileishmanial activity by limonene β-amino alcohol derivatives.
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The control of Aedes aegypti is impaired due to the development of resistance to chemical insecticides. Insect Growth Regulators (IGR) exhibit distinct mechanisms of action and are considered potential vector control alternatives. Studies regarding the effects of sublethal IGR doses on the viability of resulting adults will contribute to eval-uating their impact in the field. We analyzed several aspects of Ae. aegypti adults surviving exposure to a partially lethal dose of triflumuron, a chitin synthesis inhibitor. A highly significant difference in the proportion of males and females was noted in the triflumuron-exposed group (65.0% males) compared to the controls (50.2% males). Triflumuron affected adult longevity, particularly for females; after 16 days, only 29.2% of males and 13.8% of females were alive, in contrast with 94% survival of the control mosquitoes. The locomotor activity was reduced and the blood-feeding ability of the treated females was also affected (90.4% and 48.4% of the control and triflumuron-exposed females, respectively, successfully ingested blood). Triflumuron-surviving females ingested roughly 30% less blood and laid 25% fewer eggs than the control females. The treated males and females exhibited a diminished ability to copulate, resulting in less viable eggs.
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The mosquito Aedes aegypti is the main focus of dengue control campaigns. Because of widespread resistance against conventional chemical insecticides, chitin synthesis inhibitors (CSIs) are considered control alternatives. We evaluated the resistance status of four Brazilian Ae. aegypti populations to both the organophosphate temephos and the pyrethroid deltamethrin, which are used in Brazil to control larvae and adults, respectively. All vector populations exhibited high levels of temephos resistance and varying rates of alterations in their susceptibility to pyrethroids. The effect of the CSI novaluron on these populations was also investigated. Novaluron was effective against all populations under laboratory conditions. Field-simulated assays with partial water replacement were conducted to evaluate novaluron persistence. Bioassays were continued until an adult emergence inhibition of at least 70% was attained. We found a residual effect of eight weeks under indoor conditions and novaluron persisted for five-six weeks in assays conducted in an external area. Our data show that novaluron is effective against the Ae. aegypti populations tested, regardless of their resistance to conventional chemical insecticides.
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Objective To describe the trans-cultural adaptation of the evaluation instrument entitled Atenció Sanitària de Les Demències: la visió de L' Atenció Primarià from Catalan into versions in Portuguese for doctors and nurses. This study evaluates the knowledge and perspectives of these professionals in their treatment of patients diagnosed with dementia in cases of primary care. Method The adaptation followed internationally accepted rules, which include the following steps: translation, synthesis, back-translation, revision by a committee of specialists, and a test run with 35 practicing doctors and 35 practicing nurses in Brazil's Family Health Strategy (Estratégia Saúde da Família, or ESF in Portuguese). Results The translation, synthesis, and back-translation steps were performed satisfactorily; only small adjustments were required. The committee of specialists verified the face validity in the version translated into Portuguese, and all of the items that received an agreement score lower than 80% during the initial evaluation were revised. In the test run, the difficulties presented by the health care professionals did not reach 15% of the sample, and therefore, no changes were made. Conclusion The Portuguese translation of the instrument can be considered semantically, idiomatically, culturally, and conceptually equivalent to the original Catalan version and is, therefore, appropriate for use in Brazil.
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This study aimed to carry out the cross-cultural adaptation of the Caregiver Reaction Assessment CRA for use in Brazil with informal caregivers of dependent elderly METHOD A methodological study, of five steps: initial translation, synthesis of translations, retro-translation, evaluation by a judge committee and a pre-test, with 30 informal caregivers of older persons in Fortaleza, Brazil. Content validity was assessed by five experts in gerontology and geriatrics. The cross-cultural adaptation was rigorously conducted, allowing for inferring credibility. RESULTS The Brazilian version of the CRA had a simple and fast application (ten minutes), easily understood by the target audience. It is semantically, idiomatically, experimentally and conceptually equivalent to the original version, with valid content to assess the burden of informal caregivers for the elderly (Content Validity Index = 0.883). CONCLUSION It is necessary that other psychometric properties of validity and reliability are tested before using in care practice and research.
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The contribution of humic substances of different composts to the synthesis of humin in a tropical soil was evaluated. Increasing doses (0, 13, 26, 52, and 104 Mg ha-1) of five different composts consisting of agroinpowderrial residues were applied to a Red-Yellow Latosol. These composts were chemically characterized and 13C NMR determined and the quantity of the functional alkyl groups of humic acids applied to the soil as compost was estimated. Thirty days after application of the treatments, organic matter samples were collected for fractionation of humic acids (HA), fulvic acids (FA) and humin (HU), from which the ratios HA/FA and (HA + FA)/HU were calculated. The application of the composts based on castor cake resulted in the highest HU levels in the soil; alkyl groups of the HA fraction of the composts were predominant in the organic components added to the HU soil fraction.
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The bridged sulphate complex [Pd2 (C²,dmba) (µ-SO4) (SO2)2] has been obtained by reacting a saturated solution of SO2 in methanol and the cyclometallated compound [Pd(C²,N-dmba)(µ-N3)] 2; (dmba = N,N-dimethylbenzylamine), at room temperature for 24 h. Reaction product was characterized by elemental analysis, NMR comprising 13C{¹H} and ¹H nuclei and I.R. spectrum's measurements. Thermal behavior has been investigated and residual products identified by X-ray powder diffraction.