Validation of a Leishmania infantum ELISA rapid test for serological diagnosis of Leishmania chagasi in dogs

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Impedance e-tongue instrument for rapid liquid assessment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rapid, quantitative determination of polar compounds in fats and oils by solid-phase extraction and size-exclusion chromatography using monostearin as internal standard

A rapid and simple method was developed for quantitation of polar compounds in fats and oils using monostearin as internal standard. Starting from 50 mg of oil sample, polar compounds were obtained by solid-phase extraction (silica cartridges) and subsequently separated by high-performance size-exclusion chromatography into triglyceride polymers, triglyceride dimers, oxidized triglyceride monomers, diglycerides, internal standard and fatty acids. Quantitation of total polar compounds was achieved through the internal standard method and then amounts of each group of compounds could be calculated. A pool of polar compounds was used to check linearity, precision and accuracy of the method, as well as the solid-phase extraction recovery. The procedure was applied to samples with different content of polar compounds and good quantitative results were obtained, especially for samples of low alteration level.

Structural and electrical properties of strontium barium niobate thin films crystallized by conventional furnace and rapid-thermal annealing process

Strontium barium niobate (SBN) thin films were crystallized by conventional electric furnace annealing and by rapid-thermal annealing (RTA) at different temperatures. The average grain size of films was 70 nm and thickness around 500 nm. Using x-ray diffraction, we identified the presence of polycrystalline SBN phase for films annealed from 500 to 700 °C in both cases. Phases such as SrNb2O6 and BaNb2O6 were predominantly crystallized in films annealed at 500 °C, disappearing at higher temperatures. Dielectric and ferroelectric parameters obtained from films crystallized by conventional furnace and RTA presented essentially the same values.

A simple and rapid extraction for gas chromatographic determination of thiabendazole and imazalil residues in lemons

A rapid and efficient method is described for the determination of thiabendazole and imazalil residues in lemons (peel and pulp). The procedure is based on the extraction with an hexane:ethyl acetate mixture (1:1, v/v) and gas chromatographic analysis using thermionic specific detection (TSD). The possibility of matrix effect was also studied. Mean recoveries from 8 replicates of fortified samples ranged from 79% to 109%, with relative standard deviation values between 2.4% to 12.8%. The detection and quantification limits of the method were 0.2 mg kg-1 and 0.5 mg kg-1, respectively.

Rapid determination of zinc in foods by flow injection analysis with flame AAS using gradient calibration method

A calibration method was developed using flow injection analysis (FI) with a Gradient Calibration Method (GCM). The method allows the rapid determination of zinc In foods (approximately 30 min) after treatment with concentrated sulphuric acid and 30% hydrogen peroxide, and analysis with flame atomic absorption spectrometry (FAAS). The method provides analytical results with a relative standard deviation of about 2% and requires less time than by conventional FI calibration. The electronic selection of different segments along the gradient and monitoring of the technique covers wide concentration ranges while maintaining the inherent high precision of flow injection analysis. Concentrations, flow rates, and flow times of the reagents were optimized in order to obtain best accuracy and precision. Flow rates of 10 mL/min were selected for zinc. In addition, the system enables electronic dilution and calibration where a multipoint curve can be constructed using a single sample injection.

In vitro propagation of Maytenus ilicifolia (Celastraceae) as potential source for antitumoral and antioxidant quinomethide triterpenes production. A rapid quantitative method for their analysis by reverse-phase high-performance liquid chromatography

Cell culture of Maytenus ilicifolia were established in order to produce and to quantify the antitumoral and antioxidant quinonemethide triterpenes. In vitro calli were induced from leaf explants of native plants and cultured in semi-solid medium under controlled conditions of humidity, temperature and photoperiod. The quinonemethide triterpenes showed maximum accumulation in the logarithmic phase growth of the cell culture. A rapid, sensitive and reliable reverse-phase HPLC method was used for quantitative determination of the antitumoral and antioxidant quinonemethide triterpenes, 22β-hydroxymaytenin and maytenin in callus of Maytenus ilicifolia. Well resolved peaks with good detection response and linearity in the range 1.0 - 100 μg/mL were obtained. This quantitative work was performed by an external standard method.

Periodontal effects of rapid maxillary expansion with tooth-tissue-borne and tooth-borne expanders: A computed tomography evaluation

Introduction: The force delivered during rapid maxillary expansion (RME) produces areas of compression on the periodontal ligament of the supporting teeth. The resulting alveolar bone resorption can lead to unwanted tooth movement in the same direction. The purpose of this study was to evaluate periodontal changes by means of computed tomography after RME with tooth-tissue-borne and tooth-borne expanders. Methods: The sample comprised 8 girls, 11 to 14 years old, with Class I or II malocclusions with unilateral or bilateral posterior crossbites Four girls were treated with tooth-tissue-borne Haas-type expanders, and 4 were treated with tooth-borne Hyrax expanders. The appliances were activated up to the full 7-mm capacity of the expansion screw. Spiral CT scans were taken before expansion and after the 3-month retention period when the expander was removed. One-millimeter thick axial sections were exposed parallel to the palatal plane, comprising the dentoalveolar area and the base of the maxilla up to the inferior third of the nasal cavity. Multiplanar reconstruction was used to measure buccal and lingual bone plate thickness and buccal alveolar bone crest level by means of the computerized method. Results and Conclusions: RME reduced the buccal bone plate thickness of supporting teeth 0.6 to 0.9 mm and increased the lingual bone plate thickness 0.8 to 1.3 mm. The increase in lingual bone plate thickness of the maxillary posterior teeth was greater in the tooth-borne expansion group than in the tooth-tissue-borne group. RME induced bone dehiscences on the anchorage teeth's buccal aspect (7.1 ± 4.6 mm at the first premolars and 3.8 ± 4.4 mm at the mesiobuccal area of the first molars), especially in subjects with thinner buccal bone plates. The tooth-borne expander produced greater reduction of first premolar buccal alveolar bone crest level than did the tooth-tissue-borne expander. © 2006 American Association of Orthodontists.

Bond strength of hard chairside reline resins to a rapid polymerizing denture base resin before and after thermal cycling

Purpose: This study assessed the shear bond strength of 4 hard chairside reline resins (Kooliner, Tokuso Rebase Fast, Duraliner II, Ufi Gel Hard) to a rapid polymerizing denture base resin (QC-20) processed using 2 polymerization cycles (A or B), before and after thermal cycling. Materials and Methods: Cylinders (3.5 mm x 5.0 mm) of the reline resins were bonded to cylinders of QC-20 polymerized using cycle A (boiling water-20 minutes) or B (boiling water; remove heat-20 minutes; boiling water-20 minutes). For each reline resin/polymerization cycle combination, 10 specimens (groups CAt e CBt) were thermally cycled (5 and 55°C; dwell time 30 seconds; 2,000 cycles); the other 10 were tested without thermal cycling (groups CAwt ad CBwt). Shear bond tests (0.5 mm/min) were performed on the specimens and the failure mode was assessed. Data were analyzed by 3-way ANOVA and Newman-Keuls post-hoc test (α=.05). Results: QC-20 resin demonstrated the lowest bond strengths among the reline materials (P<.05) and mainly failed cohesively. Overall, the bond strength of the hard chairside reline resins were similar (10.09±1.40 to 15.17±1.73 MPa) and most of the failures were adhesive/cohesive (mixed mode). However, Ufi Gel Hard bonded to QC-20 polymerized using cycle A and not thermally cycled showed the highest bond strength (P<.001). When Tokuso Rebase Fast and Duraliner II were bonded to QC-20 resin polymerized using cycle A, the bond strength was increased (P=.043) after thermal cycling. Conclusions: QC-20 displayed the lowest bond strength values in all groups. In general, the bond strengths of the hard chairside reline resins were comparable and not affected by polymerization cycle of QC-20 resin and thermal cycling.

Post expansion evaluation of the midpalatal suture in children submitted to rapid palatal expansion: A CT study

The aim of this prospective study was to evalute the midpalatal suture in children submitted to rapid palatal expansion, at the end of the retention stage, with CT scans. The sample was comprised of 17 children aged between 5 years 2 months and 10 years 5 months. The tomographic images showed that the midpalatal suture was completely ossified from the anterior nasal spine area to the posterior nasal spine area at the end of the retention phase, that is, 8 to 9 months post-expansion.

Rapid molecular diagnosis of tuberculosis and other mycobacteriosis in smear-negative clinical specimens

Delay in diagnosis of pulmonary and other forms of tuberculosis (TB) can be fatal, particularly in HIV-infected patients. Hence, techniques based on nucleic acid amplification, which are both rapid and of high specificity and sensitivity, are now widely used and recommended for laboratories that diagnose TB. In the present study, diagnostic methods based on mycobacterial DNA amplification were evaluated in comparative trials alongside tradicional bacterial methods, using negative smear samples from patients with clinically-suspected TB (sputum samples from 25 patients with suspected pulmonary TB, urine samples from two patients with suspected renal TB and cerebrospinal fluid samples from one patient with suspected meningeal TB). A specificity of 100% was achieved with DNA amplification methods and tradicional culture/identification methods, in relation to clinical findings and treatment results. For the smear-negative sputa, conventional PCR for M. tuberculosis was positive in 62% of suspected lung TB case, showing the same sensitivity as bacterial identification. Both techniques failed in the detection of extra-pulmonary samples. Nested PCR showed, after species-specific amplification, a sensitivity of 100% for M. avium and 85% for M. tuberculosis. For extra-pulmonary smear-negative samples, only Nested PCR detected M. tuberculosis and all cases were confirmed clinically. Nested PCR, in which two-step amplification reactions are performed, can identify the two most important mycobacteria in human pathology quickly and directly from clinical spicimens.

A simplified reflectometric method for the rapid determination of dipyrone in pharmaceutical formulations

This paper describes a simple, portable and environmentally friendly method for the rapid determination of dipyrone in pharmaceuticals by using diffuse reflectance spectroscopy. The proposed method is based on the reflectance measurements of the orange compound produced from the spot test reaction between dipyrone and p-dimethylaminocinnamaldehyde (p-DAC), in acid medium, using a filter paper as solid support. Experimental design methodologies were used to optimize the measurement conditions. All reflectance measurements were carried out at 510 nm and the linear range was from 1.42 × 10-4-2.85 × 10-3 mol L-1, with a correlation coefficient of 0.999. The limit of detection (LOD) and the limit of quantification (LOQ) were 1.20 × 10-5 mol L-1 and 4.00 × 10-5 mol L-1, respectively. The intraday precision and interday precision were studied for 10 replicate analyses of 7.90 × 10-4 mol L-1 dipyrone solution. The coefficients of variation were 1.1 and 0.9%, respectively. The proposed method was applied successfully to the determination of dipyrone in commercial brands of pharmaceuticals. No interferences were observed from the common excipients in formulations. The results obtained by the proposed method were favorably compared with those given by the Brazilian Pharmacopoeia procedure at 95% confidence level. ©2007 Sociedade Brasileira de Química.

A simple and environmentally friendly reflectometric method for the rapid quantitative analysis of captopril in pharmaceutical formulations

This paper describes a simple, environmentally friendly and rapid quantitative spot test procedure for the determination of captopril (CPT) in bulk drug and in pharmaceutical formulations by using diffuse reflectance spectroscopy. The proposed method is based on the reflectance measurements of the orange compound (λ max 490 nm) produced by the spot test reaction between CPT and p-chloranil (CL). Under optimal conditions, calibration curves were obtained for CPT by plotting the optical density of the reflectance signal (A R) vs. the log of the mol L -1 concentration, from 6.91×10 -3 to 1.17×10 -1, with a good coefficient of determination (R 2 = 0.9992). The common excipients used as additives in pharmaceuticals do not interfere in the proposed method. The method was applied to determine CPT in commercial pharmaceutical formulations. The results obtained by the proposed method are compared favorably with those obtained by an official procedure at 95% confidence level. The method validation results showed that the sensitivity and selectivity of the methods were adequated for drug monitoring in industrial quality control laboratories. © 2011 Moment Publication.