Modification of natural zeolite clinoptilolite and ITS application in the adsorption of herbicides

The clinoptilolite natural zeolites (NZs) posses low herbicide adsorption capacity demanding acid-, alkali-, or salt chemical modifications that enhance its adsorption. However, this may affect the material structure and charge distribution. Alternatively, zeolites may be synthesized at a high cost and time-consuming process. Consequently, new methods, such as the hydrothermal method, for NZ modification needs to be studied. In this sense, a novel surface-modified zeolite (SMZ), using hexadecyltrimethylammonium bromide (CTAB), in acid media was produced by the hydrothermal method and applied for the adsorption of Atrazine (ATZ), Diuron (DIU) and 2,4-D. Commercial NZ and SMZ were characterized by SEM, XRD, TGA, FT-IR, AA spectroscopy, pHPZC, Zeta potential and N2-physisorption. The SMZ chosen for the adsorption experiments was the one with the highest modification yield and adsorption capacity obtained from a complete design of experiments (CTAB=0.74 ; D=12 Mesh; HCl=0.1 M; t=6 h and T=205 ºC). The adsorption experiments revealed that the SMZ adsorption capacity for the herbicide 2,4-D (qmax=9.02 mg/g) was greater than that obtained for ATZ (qmax=2.11 mg/g) and DIU (qmax=1.85 mg/g), which was explained by the presence of the hydroxyl group and by geometric characteristics of the 2,4-D. Adsorption models' fitting showed that the adsorption of 2,4-D onto SMZ were best described by pseudo-second order kinetic (k2=0.005-0.006 g/mg.min; qe,exp=7.122-8.614 mg/g) and Langmuir isothermal model (KL=0.283-0.499 L/mg; qm=7.167-7.995 mg/g). These results indicate that the hydrothermal method is a viable alternative to enable the use of NZs for the adsorption of emerging contaminants from wastewater.

A novel magnetic adsorbent from activated carbon fiber and iron oxide nanoparticles for 2,4-D removal from aqueous medium

Carbonaceous materials have been widely applied as adsorbents, but there are some factors that affect their efficiency. In this context, advances in nanotechnology provide new and more efficient methodologies for water treatment. This study evaluated the efficiency of a novel carbon-based adsorbent developed from Brazilian polyacrylonitrile textile fiber and functionalized with iron oxide magnetic nanoparticles for the removal of 2,4-dichlorophenoxyacetic acid (2,4-D) from the aqueous medium. The synthesized adsorbent (ACF-Fe3O4) was characterized by FTIR, XRD, VSM, Zeta potential, SEM, EDX, and TEM. The characterization techniques showed that the adsorbent has peaks characteristic of its precursors and superparamagnetic characteristics, confirming the efficiency of the synthesis method. The adsorption tests evaluated the influence of adsorbent dosage, pH of the contaminant solution, contact time and temperature on the removal of 2,4-D. The experimental data were better adjusted by the pseudo-second order kinetic model and by the Langmuir isothermal model. The thermodynamic parameters revealed that the process is exothermic, spontaneous and thermodynamically favorable. Under the best experimental conditions, the maximum adsorption capacity obtained was 51.10 mg g-1 with an adsorbent concentration of 0.33 g L-1, natural pH of the solution, temperature of 288 K at the equilibrium time of six hours. Adsorbent reusage was studied in four desorption cycles. The adsorption mechanism can be explained through π-π bonds, hydrogen bonds and electrostatic interactions. The prepared material presented high-efficiency adsorption capacity of 2,4-D compared to other carbonaceous materials present in the literature, demonstrating its viability for the removal of this contaminant from the aqueous medium.

Continuous removal of pharmaceutical drug chloroquine and Safranin-O dye from water using agar-graphene oxide hydrogel: Selective adsorption in batch and fixed-bed experiments

In this work, Chloroquine diphosphate, and the cationic dye Safranin-O were selectively removed from water using the agar-graphene oxide (A-GO) hydrogel, produced via simple one-step jellification process. The morphology of the A-GO biocomposite was characterized and batch experiments were performed, with adsorption isotherms satisfactorily fitting (R² > 0.98) Sips (Safranin-O) and Freundlich (Chloroquine) isotherms. Driving force models and Fick's diffusion equation were applied to the modeling of kinetic data, and a satisfactory fit was obtained. Selective adsorption carried out in batch indicated that competitive adsorption occurs when both components are mixed in water solution - the adsorptive capacities dropped ∼10 mg g^-1 for each component, remaining 41 mg g^-1 for safranin-O and 31 mg g^-1 for chloroquine. Fixed-bed breakthrough curves obtained in an adsorption column showed adsorption capacities over 63 mg g^-1 and 100 mg g^-1 for chloroquine and safranin-O, respectively, also exhibiting outstanding regenerative potentials. Overall, the biocomposite produced using graphene oxide proved to be a viable and eco-friendly alternative to continuously remove both contaminants from water.

Adsorption of Safranin-O dye by copper oxide nanoparticles synthesized from Punica granatum leaf extract

The development of new technologies for water and wastewater treatment is a growing need due to the occurrence of micropollutants, such as dyes, in water resources. In this sense, green-synthesized nanoparticles are being extensively studied, due to their low cost, non-toxicity, and high efficiency in adsorption processes. Thus, the present study reports the green synthesis of copper oxide nanoparticles (CuO-NP), obtained from pomegranate (Punica granatum) leaf extract, employed for the removal of Safranin-O (SO) dye. CuO-NP was characterized by physicochemical analysis. These analyzes suggested that the redox process occurred efficiently. Also, the material presented interesting elements for the removal of cationic dyes such as negative surface charge, high specific surface area, and predominance of mesopores. The kinetic data fitted the pseudo-second-order model, reaching equilibrium in 480 min. The equilibrium study resulted in a maximum adsorption capacity of 189.54 mg g^-1 at 298 K and the experimental data best fitted the Langmuir model. The effect of pH and ionic strength did not present significant changes, which demonstrates an advantage of this adsorbent over other materials. The regeneration study allowed to verify the possibility of reuse CuO-NP, since after 4 cycles the adsorption capacity was 44% of the initial value. Considering the results found, CuO-NP has a high potential for applicability in the treatment of water contaminated by dyes.

A tubular ceramic membrane coated with TiO2-P25 for radial addition of H2O2 towards AMX removal from synthetic solutions and secondary urban wastewater

This work aims to integrate several hydrogen peroxide (H₂O₂) activation mechanisms, photolysis (UVC irradiation), chemical electron transfer (TiO₂-P25 photocatalysis), and reaction with TiO₂-P25 in dark conditions, for reactive oxygen species (ROS) generation towards the removal of contaminants of emerging concern (CECs), in a single unit operated in continuous-flow mode. An H₂O₂ stock solution is fed by the lumen side of a tubular ceramic membrane, delivering the oxidant to the (i) catalyst immobilized in the membrane shell-side and (ii) annular reaction zone (ARZ, space between membrane shell-side and outer quartz tube) where CECs contaminated water flows with a helix trajectory, being activated by UV light provided by four lamps placed symmetrically around the reactor. First, the effect of several parameters in the removal of a CEC target molecule, amoxicillin (AMX), was evaluated using a synthetic solution ([AMX]_inlet = 2.0 mg L^-1): (i) light source (UVA or UVC radiation), (ii) H₂O₂ dose, (iii) H₂O₂ injection method (radial permeation vs. upstream injection), and (iv) number of TiO₂-P25 layers deposited on the membrane. The UVC/H₂O₂/TiO₂ system with radial addition of H₂O₂ (20 mg L^-1) and 9-TiO₂-P25 layers provided the highest AMX removal efficiency (72.2 ± 0.5%) with a UV fluence of 45 mJ cm^-2 (residence time of 4.6 s), due to the synergic effect of four mechanisms: (i) AMX photolysis, (ii) H₂O₂ photocleavage, (iii) TiO₂-P25 photoactivation, and (iv) chemical reactions between H₂O₂ and TiO₂-P25. The urban wastewater matrix showed a negative effect on AMX removal (~44%) due to the presence of ROS scavengers and light-filtering species.

Modified Moringa oleifera Lam. Seed husks as low-cost biosorbent for atrazine removal

Atrazine is an herbicide which is widely applied in sugarcane and corn crops. Its frequent use has resulted in environmental impacts, and its traces have been verified in surface and groundwater. Thus, it is necessary to remove this pollutant, and an alternative is the adsorption due to its universal nature, low-cost and ease of operation. Therefore, the objective of the present work was to study the adsorption capacity of atrazine by modified Moringa oleifera Lam. seed husks, a low-cost adsorbent. The biosorbent was subjected to c hemical and thermal treatment and was characterised by structural, morphological and textural analysis, which showed porous and heterogeneous characteristics, with a specific surface area of 5.77 m² g^-1. The kinetic study demonstrated equilibrium at 1200 min, with an adsorption capacity of 1.90 mg g^-1 and the best fit was for the pseudo-second-order model. The isotherms were obtained at 298, 308 and 318 K. The Freundlich, Temkin and Langmuir models were applied to the experimental data, the latter being the best. The values of the thermodynamic parameters indicated that the biosorption was spontaneous, endothermic and reversible. The highest adsorption capacity obtained was 10.32 mg g^-1, which was higher than several values found in the literature. The biosorbent was regenerated over three cycles, indicating its potential of atrazine removal from surface water.

Deposition of graphene nanoparticles associated with tannic acid in microfiltration membrane for removal of food colouring

A modified microfiltration (MF) membrane was prepared by flow-through coating method. First the sulfuric acid solution was vacuum filtered on the polyethersulfone (PES) MF membrane, providing the introduction of a sulfonic acid group to the backbone of PES. Sequentially, the polyethyleneimine solution was vacuum filtered to provide amine groups on the membrane surface. Finally, the graphene oxide solution, functionalized with different masses of tannic acid, was vacuum filtered on the membrane surface, producing the cross-linked modified membranes. These were efficient in the removal of anionic food colouring, achieving high removal rates and low fouling, compared to unmodified membrane. The best membrane in terms of bright blue dye removal was the MF PEI₅GO₁TA₄, capable of removing all the feed solution, and demonstrating its possibility of reuse in five cycles of operation.

Application of magnetic coagulant based on fractionated protein of Moringa oleifera Lam. seeds for aqueous solutions treatment containing synthetic dyes

The aim of the present study was to evaluate the efficiency of a new magnetic coagulant, obtained from Moringa oleifera seeds protein functionalized with iron oxide nanoparticles to remove four anionic synthetic dyes with coagulation/flocculation assays followed by magnetic sedimentation. The results showed that the presence of a magnetic field during sedimentation considerably accelerates the separation and increases the dye removal efficiency. Amaranth dye removal increased from 45 to 86% and Sunset Yellow from 15 to 69% with the presence of magnetic field, while Reactive Black 5 and Brilliant Blue reached 94% and 52% removal, respectively. For AM and SY dyes, the best protein concentration is 150 mg L^-1, for RB5 dye is 115 mg L^-1, and for BB dye is 75 mg L^-1. The sedimentation time decreased from 30 to 5 min with magnetic sedimentation. The residual value of AM dye decreased from 10.76 mg L^-1 to approximately 2.71 mg L^-1, and with SY the residual concentration decreased from approximately 16.79 mg L^-1 to 6.36 mg L^-1. The removal of BB and RB5 dyes reached an approximate final value of 48.2 mg L^-1 (52%) and 1.18 mg L^-1 (94%).

Mathematical modelling applied to the rate-limiting mass transfer step determination of a herbicide biosorption onto fixed-bed columns

The herbicide removal of Diuron in a fixed-bed column packed with the Moringa oleifera bark biosorbent was investigated experimentally and through phenomenological mathematical modelling. To understand the physical phenomena involved, the steps of external mass transfer resistance, internal mass transfer resistance and the adsorption phenomenon itself were considered as possible limiting steps in the herbicide mass transfer from the liquid to the solid phase. In the developing process of the internal mass transfer resistance model, two hypotheses were considered: constant mass transfer coefficient and mass transfer coefficient as a function of the herbicide concentration in the biosorbent. The experimental breakthrough curves were obtained for different flow rates and feed concentrations, in order to evaluate the model's predictive capacity. The mass transfer parameter values of the mathematical models were estimated using the simplex downhill optimization method. The model that considers the resistance a mass transfer internal with parameter K_s variable represented effectively the dynamic behaviour of the herbicide biosorption process in fixed-bed column, in the various evaluated conditions, indicating that this mechanism controls the biosorption process. Thus, the phenomenological mathematical modelling proved to be an analysis important tool, understanding and the herbicide adsorption systems design in a fixed-bed column.

Development of an activated carbon impregnation process with iron oxide nanoparticles by green synthesis for diclofenac adsorption

The objective of this study was to impregnate the surface of palm coconut activated carbon with nanoparticles of iron compounds using Moringa oleifera leaf extracts and pomegranate leaf by a green synthesis method and to evaluate its adsorption capacity for sodium diclofenac. The adsorbent material was characterized by zeta potential, X-ray diffraction (XRD), N₂ adsorption/desorption (BET method), transmission electronic microscopy (TEM), and scanning electronic microscopy (SEM) coupled to dispersive energy spectrometry X-ray (EDX) methods. To evaluate the adsorption capacity of sodium diclofenac, the influence of pH, kinetics, isotherms, and thermodynamic properties were analysed. The impregnated adsorbents showed efficiency in the adsorption of sodium diclofenac. The kinetic model that best fit the experimental data was the pseudo-second-order model, and the equilibrium model was the Langmuir model. As for the thermodynamic study, it was verified that the adsorption reaction for all adsorbents occurs in a spontaneous, favourable way, and it is endothermic by physisorption. Therefore, this process is promising because it is a clean and non-toxic method when compared with chemical methods for the synthesis of nanoparticles.

Production of Sodium Bicarbonate from CO2 Reuse Processes: A Brief Review

Research activities discuss about the global environmental impacts of carbon dioxide (CO2) emissions. Government authorities and international conferences aim to reduce greenhouse gas emissions and encourage the development of sustainable processes using renewable sources. In order to reduce emissions from the industrial sector, CO2 capture and reuse as a raw material in the production of marketable products have encouraged the development of technologies. Among many possible chemical products manufactured from CO2, sodium bicarbonate appears in this context as an important compound in the chemical, food, textile and pharmaceutical industries. Then, the main objective of this work was to carry out a bibliographical review of the main production processes available in the literature for synthesis of sodium bicarbonate and the main chemical reactions involved in the crystallization reactor. Regarding to the processes, soda ash carbonation from trona, the Solvay process and the sodium sulfate route were assessed and compared. Among the main raw materials used in the production process of sodium bicarbonate, sodium chloride is presented as most economically feasible while sodium carbonate and sodium sulfate are indicated as the most environmentally viable alternatives. Beyond, the global processes were presented for each route discussing advantages and disadvantages for the separation and purification steps required after the reaction. It is notable that the main raw material is sodium chloride due to its easy possibility of obtaining, from seawater, and large availability for applications at the food industry. Indeed, the production of sodium bicarbonate by means of the Solvay process was the route that presented the best results regarding to the technology development and economic cost. Use of sodium sulfate as raw material has proved to be a possible route, besides presenting numerous advantages such as production of valuable byproducts. However, this route may be not totally viable compared to conventional routes due to the complexity of products separation and purification. The review showed that there is a lack in the scientific literature regarding to the development of studies evaluating sodium bicarbonate crystallization and purification in a cost effective and technical detailed approach.

Activated carbon of Babassu coconut impregnated with copper nanoparticles by green synthesis for the removal of nitrate in aqueous solution

The present study was conducted to impregnate the surface of a carbon of vegetable origin with copper nanoparticles by the green synthesis method with the aqueous extract of Hibiscus sabdariffa flowers, rich in phenolic compounds, which are responsible for the reduction and impregnation of metal nanoparticles. Batch adsorption assays were conducted aimed at nitrate removal with pure (GAC) and impregnated (IGAC) carbon, for comparative purposes. It was found that impregnation increases the efficiency of the carbon by four times in terms of the maximum adsorption capacity, which was 10.13 mg g^-1 at 45°C for GAC and 45.01 mg g^-1 at 15°C for IGAC, indicating that this is a promising material for the removal of nitrate in waters with an excess of this ion.

Water decontamination containing nitrate using biosorption with Moringa oleifera in dynamic mode

This study was conducted to assess the feasibility of using Moringa oleifera Lam. (MO) seeds in the biosorption of nitrate present in aqueous solutions by means of batch and fixed-bed column biosorption processes. The batch assays showed that nitrate biosorption is enhanced under experimental conditions of pH 3 and a biosorbent mass of 0.05 g. For the experiments in dynamic mode, the results obtained from the statistical parameters showed that lesser pH, lesser feed flow rate, and higher initial concentration will result in an increase of the maximum capacity of the bed. These conditions were confirmed by experimental analysis. The best experimental conditions, according to the values for percentage removal (91.09%) and maximum capacity (7.69 mg g^-1) of the bed, were those used in assay 1, which utilized pH 3, feed flow rate of 1 mL min^-1, and initial nitrate concentration of 100 mg L^-1.

Environmentally friendly biosorbents (husks, pods and seeds) from Moringa oleifera for Pb(II) removal from contaminated water

Lead is a heavy metal considered highly toxic, responsible for causing several health problems as well as being extremely harmful to fauna and flora. Given this fact, several techniques have been studied for the removal of this metal from contaminated water, in which stands out adsorption. In this sense, the objective of this study was to evaluate the potential of lead(II) biosorption from contaminated water by seed husks, seeds and pods of Moringa oleifera Lam (moringa). Biomass was characterized by energy-dispersive X-ray spectroscopy, Scanning Electron Microscopy and Fourier transform infrared spectroscopy analyses. From the studied parameters, the optimal conditions obtained for the three analyzed biosorbents are: 30 min to equilibrium, pH 6 and 25°C temperature. The pseudo-second-order kinetic model was the best fitted to the experimental data for the three evaluated biosorbents. Regarding the adsorption isotherms, the model that best fitted to the experimental data for seed and seed husk was that proposed by Freundlich, and for the pod the Langmuir model. The analysis of the obtained thermodynamic data showed that the adsorption process is favorable and of exothermic nature. Through the results it was concluded that the evaluated biosorbents are efficient in lead(II) biosorption.

Bloodstream infection caused by extensively drug-resistant Acinetobacter baumannii in cancer patients: high mortality associated with delayed treatment rather than with the degree of neutropenia

This study aimed to describe severe infections with extensively drug-resistant Acinetobacter baumannii-calcoaceticus complex (XDR-ABC), as well as to investigate risk factors for mortality, in cancer patients. It was a retrospective study including all patients diagnosed with XDR-ABC bacteraemia during hospitalization in the intensive care unit of a cancer hospital between July 2009 and July 2013. Surveillance cultures were collected weekly during the study period, and clonality was analysed using pulsed field gel electrophoresis (PFGE). We analysed underlying diseases, oncology therapy, neutrophil counts, infection site and management of infection, in terms of their correlation with 30-day mortality. During the study period, 92 patients with XDR-ABC bacteraemia were identified, of whom 35 (38.0%) were patients with haematological malignancy. We identified XDR-ABC strains with four different profile patterns, 91.3% of patients harbouring the predominant PFGE type. Of the 92 patients with XDR-ABC bacteraemia, 66 (71.7%) had central line-associated bloodstream infections; infection occurred during neutropenia in 22 (23.9%); and 58 (63.0%) died before receiving the appropriate therapy. All patients were treated with polymyxin, which was used in combination therapy in 30 of them (32.4%). The 30-day mortality rate was 83.7%. Multivariate analysis revealed that septic shock at diagnosis of XDR-ABC infection was a risk factor for 30-day mortality; protective factors were receiving appropriate therapy and invasive device removal within the first 48 h. Among cancer patients, ineffective management of such infection increases the risk of death, more so than do features such as neutropenia and infection at the tumour site.

TEM characterization of As-deposited and annealed Ni/Al multilayer thin film

Reactive multilayer thin films that undergo highly exothermic reactions are attractive choices for applications in ignition, propulsion, and joining systems. Ni/Al reactive multilayer thin films were deposited by dc magnetron sputtering with a period of 14 nm. The microstructure of the as-deposited and heat-treated Ni/Al multilayers was studied by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) in plan view and in cross section. The cross-section samples for TEM and STEM were prepared by focused ion beam lift-out technique. TEM analysis indicates that the as-deposited samples were composed of Ni and Al. High-resolution TEM images reveal the presence of NiAl in small localized regions. Microstructural characterization shows that heat treating at 450 and 700°C transforms the Ni/Al multilayered structure into equiaxed NiAl fine grains.

In situ TEM study of grain growth in nanocrystalline copper thin films

Nanocrystalline metals demonstrate a range of fascinating properties, including high levels of mechanical strength. However, as these materials are exposed to high temperatures, it is critical to determine the grain size evolution, as this process can drastically change the mechanical properties. In this work, nanocrystalline sputtered Cu thin films with 43 +/- 2 nm grain size were produced by dc-magnetron sputtering. Specimens were subsequently annealed in situ in a transmission electron microscope at 100, 300 and 500 degrees C. Not only was grain growth more evident at 500 degrees C but also the fraction of twins found. An analysis of grain growth kinetics revealed a time exponent of 3 and activation energy of 35 kJ mol(-1). This value is explained by the high energy stored in the form of dislocation, grain boundaries and twin boundaries existing in nanocrystalline copper, as well as the high probability for atoms to move across grains in nanocrystalline materials.

Compartmental models of mammalian motoneurons of types S, FR and FF and their computer simulation

Mathematical models of motoneurons (MNs) of types S, FR and FF were developed based on cat MN data. Each of the three models has an initial segment, a soma and a dendritic tree. The initial segment and the soma include models of several types of ionic currents, including a calcium-dependent slow potassium current. The dendritic tree is modeled as a series association of several electrically passive cylinders. Afterhyperpolarization parameters, current to frequency relation and the responses to input current steps, ramps and sinusoids were used for model validation. The effects of sinusoidally varying synaptic inputs at different levels of the dendritic tree were studied by computer simulation. The corresponding frequency response functions resulted of lowpass type with cutoff frequencies from 10 to 40 Hz, for synapses occurring more distally or more proximally, respectively. The nonlinear effects caused by two sinusoidally varying synaptic conductances (at 7 and 11 Hz), acting at different dendritic segments, were quantified by spectral analysis of the current reaching the soma. The simulations pointed to two main nonlinear effects: (i) harmonics of the two input frequencies (e.g., 14 Hz) and (ii) intermodulation terms (e.g., 4 Hz). When the two synaptic inputs occurred on more distal dendritic compartments the nonlinear effects were more pronounced.

[Evaluation of nutritional recovery pattern of malnourished children examined at the center of Recovery and Educational Nutrition, Brazil]

PURPOSE

To assess the pattern of nutritional recovery in malnourished children. This prospective analysis was conducted between September 1995 and November 1996 at the Center for Recovery and Nutrition Education (CREN) in São Paulo, Brazil. Of the thirty-eight children studied, 47.4% were infants (nine girls and nine boys) and 52.6% preschool children (twelve boys and eight girls).

METHOD

Thirty eight children were studied by velocity of W/A and H/A gain in standard deviation or Z score, according to weight and height median of NCHS.

RESULTS

There was a statistically significant increase in the weight-for-age (W/A)(p = 0.012), height-for-age (H/A) (p = 0.001) from the time of admission. The difference in the velocity of W/A gain between infants (0.299-Z/year) and preschool children (0.684-Z/year) with more than six months of treatment, was found to be statistically significant (p = 0.038). The difference in the velocity of H/A gain for infants (0.794-Z/year) and for preschool children (0.506-Z/year), was not statistically significant (p = 0.166). In regards to gender, there was not a statistically significant difference between boys and girls in the velocity of W/A gain (0.540 and 0.524-Z/year, respectively). The difference in velocity of H/A gain was statistically significant, 0.485-Z/year for boys and 0.856-Z/year for girls (p = 0.043).

CONCLUSION

These findings show that there are differences in the nutritional recovery patterns between gender and age groups.

Diagnosis of bacterial meningitis and septicemia by serum counterimmunoelectrophoresis

We compare the results obtained by counterimmunoelectrophoresis in samples of serum and cerebrospinal fluid with microbiologic methods for 3,298 patients suspected of bacterial meningitis and/or septicemia at Instituto Adolfo Lutz, São Paulo, in a retrospective study of the period from July 1998 to July 1994. Of the 415 patients (12.6% of the total cases studied) who were positive by the serum test, only 249 (7.6% of the total cases studied) were also positive when cerebrospinal fluid was assayed. Thus, 40% of the positives (5.6% of the total) were identifiable by analysis of serum but not of cerebrospinal fluid. Neisseria meningitidis accounted for 77.7% (129) and Haemophilus influenzae for 22.3% (37) of the positive results obtained only when serum was examined. These data show that although sensitivity and specificity of serum counterimmunoelectrophoresis are relatively low compared to cerebrospinal fluid counterimmunoelectrophoresis, the serum test is necessary to complement cerebrospinal fluid counterimmunoelectrophoresis data.

Bacterial agents isolated from cerebrospinal fluid of patients with acquired immunodeficiency syndrome (AIDS) and neurological complications

Cerebrospinal fluid (CSF) samples from 2083 patients with acquired immunodeficiency syndrome (AIDS) and neurological complications were bacteriologically examined during a period of 7 years (1984-1990). The percentage of patients who had at least one bacterial agent cultured from the CSF was 6.2%. Mycobacterium tuberculosis was the most frequently isolated agent (4.3%), followed by Mycobacterium avium complex or MAC (0.7%), Pseudomonas spp (0.5%), Enterobacter spp (0.4%), and Staphylococcus aureus (0.3%). Among 130 culture positive patients, 89 (68.5%) had M. tuberculosis and 15 (11.6%) had MAC. The frequency of bacterial isolations increased from 1988 (5.2%) to 1990 (7.2%), partly due to the increase in MAC isolations. Bacterial agents were more frequently isolated from patients in the age group 21-30 years and from women (p < 0.05).

Medindo o impacto da promoção do aleitamento materno em serviços de atenção primária à saúde em Pelotas, Rio Grande do Sul, Brasil

Através da aplicação de um questionário padronizado a todas as mães que procuraram os serviços de puericultura das unidades sanitárias (US) da Universidade Federal de Pelotas (UFPel), RS, em setembro de 1990, buscou-se conhecer o impacto dos grupos de gestantes na promoção do aleitamento materno. Os resultados obtidos para 347 crianças revelaram que quase metade delas pertencia a famílias com renda inferior a dois salários mínimos mensais; 1/4 de suas mães apresentavam escolaridade inferior a quatro anos, sendo estas as que mais frequentaram os grupos. Apesar da maioria das mães ter feito pré-natal e pouco menos da metade ter participado dos grupos de gestantes, 1/3 das crianças estavam desmamadas aos três meses de idade e cerca de 80% delas haviam recebido chás nos primeiros meses. Os dados obtidos revelam um serviço com sérias deficiências em incentivar o aleitamento e em retardar a introdução de outros alimentos na dieta infantil. Espera-se, a partir dos dados obtidos, poder contribuir para a reestruturação dos programas existentes, bem como poder demonstrar que, a partir de recursos mínimos e de uma metodologia relativamente simples, é possível avaliar a qualidade dos serviços oferecidos à população.

Biotypes and serotypes of Haemophilus influenzae from patients with meningitis in the city of São Paulo, Brazil

A total of 1,094 Haemophilus influenzae isolates from cerebrospinal fluid were examined by biochemical and serological means. Most of them belonged to biotype I (70.9%) and to serotype b (99.4%). The relationship of biotypes I and II to the ages of the patients was shown to be significant (P < 0.001).

[Serotypes of Streptococcus pneumoniae isolated from cerebrospinal fluid in 1977-1988 in São Paulo City, Brazil]

Since 1977, the Instituto Adolfo Lutz (IAL) is having interest in the serotyping of S. pneumoniae or pneumococcus from infections caused by this bacteria. The isolated strains have been sent to the WHO Pneumococcal Reference Center, Pennsylvania, U.S.A.. From 1977 to 1988, 1.000 pneumococcus strains isolated from cerebrospinal fluid were typed, according to Danish nomenclature, and 60 serotypes were identified. The most frequent serotypes were 1, 6B, 18C, 14, 5, 3, 6A, 23F, 19F, and 38. Among different age groups, they showed a variable incidence, with serotype 6B in the ages of zero to almost 2 years old, serotype 1 in the age group of 2 to 50 years old, and serotype 3 in the ages over 50. During the 12 years study, 25 serotypes showed some uniformity in the frequency, the same as with the seasonal fluctuations. Concerning the severity of the pneumococcal infections, chiefly meningitis, and the few information related to pneumococcus serotypes which occur in the area, it was considered of high relevance to have the information of serotypes, once polysaccharide vaccines have been employed with success to prevent these infections.