Cristais Líquidos Ferroelétricos - CLF. Uma abordagem sintética

Synthetic methods used for the synthesis of the Ferroelectric Liquid Crystals (FLCs) will be considered with emphasis on the chiral synthesis methodologies and mesomorphic electrooptical properties.

Polímeros impressos com íons: fundamentos, estratégias de preparo e aplicações em química analítica

Chemical imprinting technology has been widely used as a valuable tool in selective recognition of a given target analyte (molecule or metal ion), yielding a notable advance in the development of new analytical protocols. Since their discovery, molecularly imprinted polymers (MIPs) have been extensively studied with excellent reviews published. However, studies involving ion imprinted polymers (IIPs), in which metal ions are recognized in the presence of closely related inorganic ions, remain scarce. Thus, this review involved a survey of different synthetic approaches for preparing ion imprinted adsorbents and their application for the development of solid phase extraction methods, metal ion sensors (electrodes and optodes) and selective membranes.

Estimating Attractor Dimension on the Nonlinear Pendulum Time Series

Chaotic dynamical systems exhibit trajectories in their phase space that converges to a strange attractor. The strangeness of the chaotic attractor is associated with its dimension in which instance it is described by a noninteger dimension. This contribution presents an overview of the main definitions of dimension discussing their evaluation from time series employing the correlation and the generalized dimension. The investigation is applied to the nonlinear pendulum where signals are generated by numerical integration of the mathematical model, selecting a single variable of the system as a time series. In order to simulate experimental data sets, a random noise is introduced in the time series. State space reconstruction and the determination of attractor dimensions are carried out regarding periodic and chaotic signals. Results obtained from time series analyses are compared with a reference value obtained from the analysis of mathematical model, estimating noise sensitivity. This procedure allows one to identify the best techniques to be applied in the analysis of experimental data.

An Investigation into Mechanisms of Loss of Safe Basins in a 2 D.O.F. Nonlinear Oscillator

In this work we consider the transient stability of coupled motions of a 2 D.O.F. nonlinear oscillator that can represent, for example, the motions of a sea vessel under the action of trains of regular lateral waves. Instability is studied as the escape of the system from a safe potential well. The set of initial conditions in phase space that lead to acceptable motions constitutes its safe basin. We investigate the evolution of these safe basins under variation of parameters such as frequency and amplitude of waves, and an internal tuning parameter. Complex nonlinear phenomena are known to play an important role in determining the loss of safe basins as, say, wave amplitude is increased. We therefore investigate those processes, and attempt to classify them in terms of their speed relative to changes in parameter values. "Mechanism basins" are produced depicting regions of parameter space in which rapid or slow losses of safe basin are observed. We propose that a comprehensive understanding of mechanisms of loss of safe basins can be a valuable tool in assessing stability properties of these systems, and we give a conceptual view of how such information could be used.

Calomys callosus: an alternative model to study fibrosis in Schistosomiasis mansoni: the pathology of the acute phase

Twenty Calomys callosus, Rengger, 1830 (Rodentia-Cricetidae) were studied in the early stage of the acute schistosomal mansoni infection (42nd day). The same number of Swiss Webster mice were used as a comparative standard. Liver and intestinal sections, fixed in formalin-Millonig and embedded in paraffin, were stained with hematoxilin and eosin, PAS-Alcian Blue, pH = 1.0 and 2.5, Lennert's Giemsa, Picrosirius plus polarization microscopy, Periodic acid methanamine silver, Gomori's silver reticulin and resorcin-fuchsin. Immunohistological study (indirect immunofluorescence and peroxidase labeled extravidin-biotin methods) was done with antibodies specific to pro-collagen III, fibronectin, elastin, condroitin-sulfate, tenascin, alpha smooth muscle actin, vimentin and desmin. The hepatic granulomas were small, reaching only 27 of the volume of the hepatic Swiss Webster granuloma. They were composed mainly by large immature macrophages, often filled by schistosomal pigment, characterizing an exsudative-macrophage granuloma type. The granulomas were situated in the parenchyma and in the portal space. They were often intravascular, poor of extracellular matrix components, except fibronectin and presented, sometimes alpha smooth muscle actin and vimentin positive cells. The C. callosus intestinal granulomas were similar to Swiss Webster, showing predominance of macrophages. Therefore, the C. callosus acquire very well the Schistosoma mansoni infection, without developing strong hepatic acute granulomatous reaction, suggesting lack of histopathological signs of hypersensitivity.

Head Space Solid Phase Micro-Extraction (HS - SPME) of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636)

The aim of the present study was the assessment of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636) using methyl and ethyl ricinoleate, ricinoleic acid and castor oil as precursors. The analysis of the volatile organic compounds was carried out using Head Space Solid Phase Micro-Extraction (HS - SPME). Factorial experimental design was used for investigating extraction conditions, verifying stirring rate (0-400 rpm), temperature (25-60 ºC), extraction time (10-30 minutes), and sample volume (2-3 mL). The identification of volatile organic compounds was carried out by Gas Chromatography with Mass Spectrum Detector (GC/MSD). The conditions that resulted in maximum extraction were: 60 ºC, 10 minutes extraction, no stirring, sample volume of 2.0 mL, and addition of saturated KCl (1:10 v/v). In the bio-production of volatile organic compounds the effect of stirring rate (120-200 rpm), temperature (23-33 ºC), pH (4.0-8.0), precursor concentration (0.02-0.1%), mannitol (0-6%), and asparagine concentration (0-0.2%) was investigated. The bio-production at 28 ºC, 160 rpm, pH 6,0 and with the addition of 0.02% ricinoleic acid to the medium yielded the highest production of VOCs, identified as 1,4-butanediol, 1,2,2-trimethylciclopropilamine, beta-ionone; 2,3-butanodione, pentanal, tetradecane, 2-isononenal, 4-octen-3-one, propanoic acid, and octadecane.

Eosinophil levels in the acute phase of experimental chagas' disease

Eosinophil dynamics, in bone marrow, blood and peritoneal exudate, of resistant C57B1/6 (C57) and susceptible A/Snell (A/Sn) mice was comparatively studied during the acute phase of infection by Trypanosoma cruzi Y strain. A decline was observed in bone marrow eosinophil levels in A/Sn, but not in C57 mice, soon after infection, those of the former remaining significantly below those of the latter up to the 4th day of infection. Bone marrow eosinophil levels of C57 mice declined subsequently to levels comparable to those of A/Sn mice, the number of these cells in this compartment remaining 50% those of non infected controls, in both strains, up to the end of the experiment on the 14th day of infection. The fluctuations in eosinophil levels in blood and peritoneal space were similar in both mice strains studied. Concomitantly with depletion of eosinophils in the marrow, depletion in blood and a marked rise of these cells in the peritoneal space, initial site of infection, occurred in both strains. The difference in eosinophil bone marrow levels, between C57 and A/Sn mice, observed in the first four days of infection, suggests a higher eosinopoiesis capacity of the former in this period, which might contribute to their higher resistance to T. cruzi infection.

EFFECTS OF VITAMIN C SUPPLEMENTATION ON THE CHRONIC PHASE OF CHAGAS DISEASE

Introduction:In order to examine the effectiveness of vitamin C (ascorbic acid) in combating the oxidative insult caused by Trypanosoma cruzi during the development of the chronic phase of Chagas disease, Swiss mice were infected intraperitoneally with 5.0 × 104 trypomastigotes of T. cruzi QM1strain.Methods:Mice were given supplements of two different doses of vitamin C for 180 days. Levels of lipid oxidation (as indicated by thiobarbituric acid reactive substances-TBARS), total peroxide, vitamin C, and reduced glutathione were measured in the plasma, TBARS, total peroxide and vitamin C were measured in the myocardium and histopathologic analysis was undertaken in heart, colon and skeletal muscle.Results:Animals that received a dose equivalent to 500 mg of vitamin C daily showed increased production of ROS in plasma and myocardium and a greater degree of inflammation and necrosis in skeletal muscles than those that received a lower dose or no vitamin C whatsoever.Conclusion:Although some research has shown the antioxidant effect of vitamin C, the results showed that animals subject to a 500 mg dose of vitamin C showed greater tissue damage in the chronic phase of Chagas disease, probably due to the paradoxical actions of the substance, which in this pathology, will have acted as a pro-oxidant or pro-inflammatory.

Schistosoma mansoni granuloma in late evolutive phase, in a case of tumoral form in man

INTRODUCTION: Authors describe human schistosomal granuloma in late chronic phase, from the morphological and evolutionary viewpoints. METHODS: The study was based on a histological analysis of two fragments obtained from a surgical biopsy of peritoneum and large intestine of a 42-year-old patient, with a pseudotumoral form mimicking a peritoneal carcinomatosis associated to the schistosomiasis hepatointestinal form. RESULTS: Two hundred and three granulomas were identified in the pseudotumor and 27 in the intestinal biopsy, with similar morphological features, most in the late chronic phase, in fibrotic healing. A new structural classification was suggested for granulomas: zone 1 (internal), 2 (intermediate) and 3 (external). CONCLUSIONS: Regarding granuloma as a whole, we may conclude that fibrosis is likely to be controlled by different and independent mechanisms in the three zones of the granuloma. Lamellar fibrosis in zone 3 seems to be controlled by matrix mesenchymal cells (fibroblasts and myoepithelial cells) and by inflammatory exudate cells (lymphocytes, plasmocytes, neutrophils, eosinophils). Annular fibrosis in zone 2, comprising a dense fibrous connective tissue, with few cells in the advanced phase, would be controlled by epithelioid cells involving zone 1 in recent granulomas. In zone 1, replacing periovular necrosis, an initialy loose and tracery connective neoformation, housing stellate cells or with fusiform nuclei, a dense paucicellular nodular connctive tissue emerges, probably induced by fibroblasts. In several granulomas, one of the zones is missing and granuloma is represented by two of them: Z3 and Z2, Z3 and Z1 or Z2 and Z1 and, ultimately, by a scar.

Poor response to azithromycin in cutaneous leishmaniasis leading to a premature interruption of a multicentric phase III clinical trial in Brazil

Introduction Parenteral antimony-based compounds are still the standard of care for cutaneous leishmaniasis (CL) treatment in many countries, despite their high toxicity. Previous studies showed that oral azithromycin could be an option for CL treatment. The aim of this study was to evaluate efficacy and safety of oral azithromycin (AZ) for CL treatment compared with injectable meglumine antimoniate (MA). Methods This was a randomized, open-label, 2-arm, non-inferiority clinical trial. Treatment-naïve patients with localized CL were treated with MA (15mg/kg/day up to 1,215mg) or AZ (500mg/day) during 20 consecutive days. The primary efficacy end point was a CL cure 90 days after treatment completion. The analysis was performed with intention-to-treat (ITT) and per protocol (PP) analyses. After an anticipated interim analysis, the study was interrupted due to the high failure rate in the azithromycin group. Results Twenty-four volunteers were included in each group. The MA group had a higher cure rate than the AZ group with the ITT and PP analyses, which were 54.2% versus 20.8% [relative risk (RR) 1.97; 95% confidence intervals (95%CI) 1.13-3.42] and 72.2% versus 23.8% (RR 3.03; 95%CI 1.34-6.87), respectively. No unexpected adverse events were observed. Conclusions Azithromycin is ineffective for CL treatment and does not seem to have a role in the therapeutic arsenal for CL.

Pulmonary tuberculosis in São Luis, State of Maranhão, Brazil: space and space-time risk clusters for death (2008-2012)

INTRODUCTION: The objective was to identify space and space-time risk clusters for the occurrence of deaths in a priority city for the control of tuberculosis (TB) in the Brazilian Northeast. METHODS: Ecological research was undertaken in the City of São Luis/Maranhão. Cases were considered that resulted in deaths in the population living in the urban region of the city with pulmonary TB as the basic cause, between 2008 and 2012. To detect space and space-time clusters of deaths due to pulmonary TB in the census sectors, the spatial analysis scan technique was used. RESULTS: In total, 221 deaths by TB occurred, 193 of which were due to pulmonary TB. Approximately 95% of the cases (n=183) were geocoded. Two significant spatial clusters were identified, the first of which showed a mortality rate of 5.8 deaths per 100,000 inhabitants per year and a high relative risk of 3.87. The second spatial cluster showed a mortality rate of 0.4 deaths per 100,000 inhabitants per year and a low relative risk of 0.10. A significant cluster was observed in the space-time analysis between 11/01/2008 and 04/30/2011, with a mortality rate of 8.10 deaths per 100,000 inhabitants per year and a high relative risk (3.0). CONCLUSIONS: The knowledge of priority sites for the occurrence of deaths can support public management to reduce inequities in the access to health services and permit an optimization of the resources and teams in the control of pulmonary TB, providing support for specific strategies focused on the most vulnerable populations.

Two decades of tuberculosis in a city in Northeastern Brazil: advances and challenges in time and space

Abstract: INTRODUCTION This study presents two decades of epidemiological data on tuberculosis (TB), in order to understanding the disease profile and its spatiotemporal dynamics. METHODS This descriptive study was performed in the City of Olinda/Pernambuco, Brazil, from 1991-2010, and it analyzed new patients with TB living in the city. We used the χ²-test with a p-value <0.05 to identify differences in trends. Incidence and cluster distribution were identified using spatial scan statistics. RESULTS In total, 6202 new cases were recorded during the two decades. The highest incidence occurred in 1995 (110 cases/100,000 inhabitants), and the lowest occurred in 2009 (65 cases/100,000 inhabitants) (β=-1.44; R²=0.43; p=0.0018). The highest mortality occurred in 1998 (16 deaths/100,000 inhabitants), and the lowest occurred in 2008 (5 deaths/100,000 inhabitants) (β=-0.19; R²=0.17; p=0.07). There was a male predominance (65%), and ages ranged from 20-49 years (65%). There was a substantial increase in the number of patients that were cured after treatment (60% to 67%; p<0.001) as well as those tested for HIV (1.9% to 58.5%; p<0.001). During the first decade, clusters with p-values <0.05 included 29% of the total notified cases, and in the second decade, that percentage was 12%. CONCLUSIONS We observed a decreasing trend in incidence, which was significant, and mortality rates, which was not significant. The increased number of laboratory tests performed reflects advances in surveillance, and a reduction in the proportion of cases in primary clusters suggests, among other things, that the disease is spreading across the region.

Analysis of the Prevalence of Ventricular Late Potentials in the Late Phase of Myocardial Infarction Based on the Site of Infarction

OBJECTIVE: The initial site of myocardial infarction (MI) may influence the prevalence of ventricular late potentials (VLP), high-frequency signals, due to the time course of ventricular activation. The prevalence of VLP in a period of more than 2 years after acute MI was assessed focusing on the initially injured wall . METHODS: The prevalence of VLP in a late phase after MI (median of 924 days) in anterior/antero-septal and inferior/infero-dorsal wall lesion was analyzed using signal-averaged electrocardiogram in time domain. The diagnostic performance of the filters employed for analysis on was tested at high-pass cut-off frequencies of 25 Hz, 40 Hz and 80 Hz. RESULTS: The duration of the ventricular activation and its terminal portion were larger in inferior than anterior infarction, at high-pass cut-off frequencies of 40 Hz and 80 Hz. In patients with ventricular tachycardia, these differences were more remarked. The prevalence of ventricular late potentials was three times greater in inferior than anterior infarction. CONCLUSION: Late after myocardial infarction, the prevalence and the duration of ventricular late potentials are greater in lesions of inferior/infero-dorsal than anterior/antero-septal wall confirming their temporal process, reflecting their high-frequency content.

Assessment of Autonomic Function by Phase Rectification of RRInterval Histogram Analysis in Chagas Disease

Background:In chronic Chagas disease (ChD), impairment of cardiac autonomic function bears prognostic implications. Phase‑rectification of RR-interval series isolates the sympathetic, acceleration phase (AC) and parasympathetic, deceleration phase (DC) influences on cardiac autonomic modulation.Objective:This study investigated heart rate variability (HRV) as a function of RR-interval to assess autonomic function in healthy and ChD subjects.Methods:Control (n = 20) and ChD (n = 20) groups were studied. All underwent 60-min head-up tilt table test under ECG recording. Histogram of RR-interval series was calculated, with 100 ms class, ranging from 600–1100 ms. In each class, mean RR-intervals (MNN) and root-mean-squared difference (RMSNN) of consecutive normal RR-intervals that suited a particular class were calculated. Average of all RMSNN values in each class was analyzed as function of MNN, in the whole series (RMSNNT), and in AC (RMSNNAC) and DC (RMSNNDC) phases. Slopes of linear regression lines were compared between groups using Student t-test. Correlation coefficients were tested before comparisons. RMSNN was log-transformed. (α < 0.05).Results:Correlation coefficient was significant in all regressions (p < 0.05). In the control group, RMSNNT, RMSNNAC, and RMSNNDCsignificantly increased linearly with MNN (p < 0.05). In ChD, only RMSNNAC showed significant increase as a function of MNN, whereas RMSNNT and RMSNNDC did not.Conclusion:HRV increases in proportion with the RR-interval in healthy subjects. This behavior is lost in ChD, particularly in the DC phase, indicating cardiac vagal incompetence.

Improved Methods for the Diagnosis of African Trypanosomosis

The diagnosis of trypanosomosis in animals with low parasitaemia is hampered by low diagnostic sensitivity of traditional detection methods. An immunodiagnostic method based on a direct sandwich enzyme-linked immunosorbent assay (ELISA), using monoclonal antibodies, has been examined in a number of African laboratories for its suitability for monitoring tsetse control and eradication programmes. Generally, the direct sandwich ELISAs for the detection of trypanosomal antigens in serum samples have proved to be unsatisfactory with respect to diagnostic sensitivity when compared with traditional parasitological methods such as the dark ground/phase contrast buffy-coat technique. Consequently, antigen-detection systems exploiting various other direct, indirect and sandwich ELISA systems and sets of reagents are being developed to improve diagnosis. In addition, an existing indirect ELISA for the detection of antibodies has been improved and is being evaluated in the field in order to detect cattle that are or have been recently infected with trypanosomes. Developments and advantages of other diagnostic techniques, such as dip-stick assay and tests based on the polymerase chain reaction are also considered.