Smart bibliometrics: an integrated method of science mapping and bibliometric analysis

Bibliometric techniques and science mapping are widely employed in the research environment to provide an overview of the state-of-the-art of scientific knowledge on a given topic. These techniques are essential to assist the researcher's work by guiding the compilation of the bibliography to support the theory discussion. To this objective, the Smart Bibliometrics was developed to facilitate bibliometric analysis and selection of theoretical references, embodied by a system that brings intelligence, dynamism, and agility to the scientific writing process. The innovation of this methodology is the fusion of two relevant criteria applied during the bibliometric analysis process: the application of a representative metric of classification of scientific papers and dynamic visuals strategically developed. The methodology differs for providing the user with dynamic navigation and interaction experience with the data collected, innovating the approach to reaching insights within the universe of discussions of the scientific community. In addition, as an innovation factor, the method is presented in a scalable Business Intelligence (BI) system that features blunt visuals, extensive analysis repertoire, intuitive navigation, and automated updating. The development was carried out in a cutting-edge technological platform to attend information and sharing intents by employing cloud computing resources, another feature that enables interaction among researcher groups also from different institutions. Additionally, it is not necessary to install any software. The output will be available for consultation, at any time and place, just by using one device with an internet connection.

     

Structural aspects of Langmuir-Blodgett and cast films of zinc phthalocyanine and zinc hexadecafluorophthalocyanine

The processing of macrocyclic phthalocyanines (Pc) in the form of thin, nanostructured films has been usually carried out via evaporation techniques, owing to the low solubility exhibited by these compounds. The fabrication of Pc ultrathin films via the Langmuir-Blodgett technique may be advantageous from a technological point of view, since parameters such as film architecture and organization can be achieved without post-thermal treatments. In this study, a parent zinc phthalocyanine (ZnPc) and its fluorinated derivative (F₁₆ZnPc) were synthesized and manipulated in the form of LB films. The morphological and structural features of ZnPc and F₁₆ZnPc Langmuir-Blodgett films containing up to 31 layers were investigated using Fourier transform infrared spectroscopy (FTIR), micro-Raman spectroscopy and X-ray diffraction analyses and were compared to ZnPc and F₁₆ZnPc cast films. The interplanar distance obtained by X-ray specular reflection decreases from 12.64 Å for ZnPc to 12.16 Å for F₁₆ZnPc. FTIR spectra indicated absence of order in the LB films from ZnPc and F₁₆ZnPc, at least in the direction perpendicular to the substrate surface. Therefore, the order observed in the X-ray diffractograms means that the molecules might be organized in crystallites that are randomly oriented in the film.     

Immobilization of humic acid in nanostructured layer-by-layer films for sensing applications

Humic acids (HAs), naturally occurring biomacromolecules, were incorporated into nanostructured polymeric films using the layer-by-layer (LbL) technique, in which HA layers were alternated with layers of poly(allylamine hydrochloride) (PAH). Atomic force microscopy (AFM) revealed very smooth films, with mean roughness varying from 0.89 to 1.19 nm for films containing 5 and 15 PAH/HA bilayers, respectively. The films displayed electroactivity, with the presence of only one reduction peak at ca. 0.675 V (vs Ag/AgCl). Such a well-defined electroactivity allowed the films to be used as highly sensitive pesticide sensors, with detection of pentachlorophenol (PCP) in solutions at concentrations as low as 10(-9) mol L(-1).     

Studies of the growth and cell dynamics of the intestinal epithelium in corn and sorghum-fed rats

A study was undertaken to compare the effects of corn and sorghum-based diets on the growth curve of young adult rats and on cell renewal in the intestinal epithelium of the jejunum and colon of the animals. Three groups of 10 rats each were studied: the first was submitted to a corn diet (Corn Group); the second to a sorghum diet (Sorghum Group), and the third to a casein diet (Control Group). The diets supplied about 7 g% protein. The experimental period lasted 13 weeks. Effects were measured in terms of weight curves, mitotic and calyciform cell indexes in the jejunum and colon. A special statistical analysis was applied allowing comparisons between the groups, and considering the sample size and the individual variations in the growth curves. The animals in the sorghum group revealed a lower growth rate, and those in the corn group showed more marked cell dynamics changes in the jejunal epithelium. Findings in the corn and sorghum-fed animals were different and cannot be explained solely in terms of niacin deficiency.     

Nanostructured polyaniline thin films as pH sensing membranes in FET-based devices

Polyaniline (PANI) has become an important conducting polymer for sensing due to its morphological and electrical properties. However, the processing of polyaniline in the form of nanostructured thin films is often limited by the low solubility of the polymer in water. We synthesized nanostructured polyaniline (N-PANI) aimed at improving its solubility to form layer-by-layer (LbL) thin films in conjunction with poly(vinyl sulfonic acid) (PVS) as counter ion. N-PANI was characterized via spectroscopic measurements and SEM images. After assembled as LbL thin films onto gold (Au) substrates, the PVS/N-PANI were employed as separative extended gate pH sensing membrane in FET-based devices presenting pH sensitivity around 58 mV/pH with small voltage drift. The results suggest that N-PANI can be easily processed to form suitable thin films for pH sensing and can be combined with biomolecules to be applied in FET-based biosensors.     

Using capacitance measurements as the detection method in antigen-containing layer-by-layer films for biosensing

The layer-by-layer technique is employed here to immobilize antigen-containing liposomes, so-called proteoliposomes, onto Au-interdigitated substrates, which are capable of molecular recognition of anti-pasteurellosis antibodies. Detection was carried out using a novel strategy entirely based upon capacitance measurements, and to enhance sensitivity, we combine the response of three different sensing units in a similar procedure used for taste sensors. With the three-electrode array immunoglobulin G (IgG) against pasteurellosis is detected at concentrations as low as nanograms per milliliter. Furthermore, because of the molecular recognition capability, a distinction can be made between specific and nonspecific IgG. The concepts behind the biosensors reported here may have a large impact for clinical tests, as the procedures to detect the antibody take only a few minutes and the biosensors are relatively low cost.     

1H low- and high-field NMR study of the effects of plasma treatment on the oil and water fractions in crude heavy oil

The chemical and physical properties of a Brazilian heavy oil submitted to plasma treatment were investigated by ¹H low- and high-field nuclear magnetic resonance (NMR) combined to the characterization of rheological properties, thermogravimetry and measurement of basic sediments and water (BSW) content. The crude oil was treated in a dielectric barrier discharge plasma reactor, using natural gas, CO₂ or H₂ as working gas. The results indicated a large drop in the water content of the plasma-treated samples as compared to the crude oil, giving rise to a reduction in the viscosity. No significant chemical change was produced in the oil portion itself, as observed by ¹H NMR. The water contents determined by ¹H low-field NMR analyses agreed well with those obtained by BSW, indicating the low-field NMR methods as a useful tool for following the effects of plasma treatments on heavy oils, allowing the separation of the effects caused on the water and oil fractions.     

Development of cellulose-based bactericidal nanocomposites containing silver nanoparticles and their use as active food packaging

The use of nanomaterials, including metallic as active fillers in polymeric nanocomposites for food packaging has been extensively investigated. Silver nanoparticles (AgNPs), in particular, have been exploited for technological applications as bactericidal agents. In this paper, AgNPs were incorporated into a hydroxypropyl methylcellulose (HPMC) matrix for applications as food packaging materials. The average sizes of the silver nanoparticles were 41 nm and 100 nm, respectively. Mechanical analyses and water vapor barrier properties of the HPMC/AgNPs nanocomposites were analysed. The best results were observed for films containing smaller (41 nm) AgNPs. The antibacterial properties of HPMC/AgNPs thin films were evaluated based on the diameter of inhibition zone in a disk diffusion test against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The disk diffusion studies revealed a greater bactericidal effectiveness for nanocomposites films containing 41 nm Ag nanoparticles.     

Biosensors for efficient diagnosis of leishmaniasis: innovations in bioanalytics for a neglected disease

The need for reliable, fast diagnostics is closely linked to the need for safe, effective treatment of the so-called "neglected" diseases. The list of diseases with no field-adapted diagnostic tools includes leishmaniasis, shigella, typhoid, and bacterial meningitis. Leishmaniasis, in particular, is a parasitic disease caused by Leishmania spp. transmitted by infected phlebotomine sandfly, which remains a public health concern in developing countries with ca. 12 million people infected and 350 million at risk of infection. Despite several attempts, methods for diagnosis are still noneffective, especially with regard to specificity due to false positives with Chagas' disease caused by Trypanosoma cruzi . Accepted golden standards for detecting leishmaniasis involve isolation of parasites either microscopically, or by culture, and in both methods specimens are obtained by invasive means. Here, we show that efficient distinction between cutaneous leishmaniasis and Chagas' disease can be obtained with a low-cost biosensor system made with nanostructured films containing specific Leishmania amazonensis and T. cruzi antigens and employing impedance spectroscopy as the detection method. This unprecedented selectivity was afforded by antigen-antibody molecular recognition processes inherent in the detection with the immobilized antigens, and by statistically correlating the electrical impedance data, which allowed distinction between real samples that tested positive for Chagas' disease and leishmaniasis. Distinction could be made of blood serum samples containing 10(-5) mg/mL of the antibody solution in a few minutes. The methods used here are generic and can be extended to any type of biosensor, which is important for an effective diagnosis of many other diseases.     

Elastomeric composites based on ethylene–propylene–diene monomer rubber and conducting polymer-modified carbon black

Thermally stable elastomeric composites based on ethylene–propylene–diene monomer (EPDM) and conducting polymer-modified carbon black (CPMCB) additives were produced by casting and crosslinked by compression molding. CPMCB represent a novel thermally stable conductive compound made via “in situ” deposition of intrinsically conducting polymers (ICP) such as polyaniline or polypyrrole on carbon black particles. Thermogravimetric analysis showed that the composites are thermally stable with no appreciable degradation at ca. 300°C. Incorporating CPMCB has been found to be advantageous to the processing of composites, as the presence of ICP lead to a better distribution of the filler within the rubber matrix, as confirmed by morphological analysis. These materials have a percolation threshold range of 5–10 phr depending on the formulation and electrical dc conductivity values in the range of 1 × 10⁻³ to 1 × 10⁻² S cm⁻¹ above the percolation threshold. A less pronounced reinforcing effect was observed in composites produced with ICP-modified additives in relation to those produced only with carbon black. The results obtained in this study show the feasibility of this method for producing stable, electrically conducting composites with elastomeric characteristics. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers