Use of ruthenium-(ethylenedinitrito)-tetraacetic acid monohydrate ion immobilized on zirconium(IV) oxide coated silica gel surface as an amperometric sensor for oxygen in water

[Ru(edta)H2O](-) adsorbed on zirconium(IV) oxide coated on the surface of silica gel was used for the construction of an amperometric sensor for O-2 in water, using a carbon paste electrode. The adsorbed complex electrocatalyses the oxygen reduction reaction at -250 mV versus SCE. The cathodic current was linear for an oxygen concentration between 0.55 and 8.0 ppm, with a correlation coefficient of 0.998 and a relative standard deviation of 2.7%. The sensor response is constant within the solution pH values 2.0 and 6.5. The concentration of O-2 in a natural sample was also determined.321250350

Some aspects of immunoassays applied to analytical chemistry.

In the last years, the use of antibody-antigen interactions, has earned attention not only for clinical analysis, but also for food industry and environmental control. Since the scope and diversity of immunoassay technology have shown a wide development. Continuous advances in order to analyse complex matrices, to improve reliability, simplicity (nonseparation) and to get multiple simultaneous assays, and extreme sensitivity (lower than zeptomole detection limits) are increasing. Many strategies have been investigated including chemiluminescent enzyme immunoassays, DNA as label and development of flow injection and immunosensors techniques. This subject became very usefull and important in nowadays that are taught in the undergraduate courses of chemistry in the european universities. However in our country are still ignored in the chemistry course.22687488

Electrochemical study of methylene blue adsorbed on he silica gel modified with niobium oxide.

Methylene blue (AM) was immobilised on surface of the silica gel modified with niobium oxide. This material was incorporated in a carbon paste electrode, which showed a redox couple in a potential of E= -113 mV rs SCE in KCl solution at pH 7.0, The formal potential, in 0.5 mol L-1 KCl at pH 7.0, shifted about 290 mV towards more positive values compared to those observed for AM solubilized in aqueous solution, The dependence on the formal potential with solution pH between 2 and 7 was much lower than those observed for AM solubilized in aqueous solution.23683283

A Nanostructured Piezoelectric Immunosensor for Detection of Human Cardiac Troponin T

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A piezoelectric immunosensor based on gold nanoparticles (AuNPs) co-immobilized on a dithiol-modified surface is proposed for detection of human cardiac troponin T (TnT). Anti-human troponin T (anti-TnT) antibodies were covalently immobilized on the nanostructured electrode surface by thiol-aldehyde linkages. In a homogeneous bulk solution, TnT was captured by anti-TnT immobilized on the QCM electrode. Cyclic voltammetry studies were used to characterize the AuNPs layer on the electrode surface and the anti-TnT immobilization steps. The QCM-flow immunosensor exhibited good reliability, measuring concentrations of TnT from 0.003 to 0.5 ng mL(-1) in human serum with high linearity (r = 0.989; p < 0.01). The immunosensor exhibited a 7% coefficient of variation and 0.0015 ng mL(-1) limit of detection, indicating a high reproducibility and sensitivity. The proposed QCM nanostructured immunosensor is easy to use and has promising potential in the diagnosis of acute myocardial infarction due to its speed and high sensitivity.11111078510797Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [483242/2010-1

A new high-performance chelation ion chromatographic system for the direct determination of trace transition metals in fuel ethanol

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A new chelation ion chromatographic system for the determination of transition metals was developed. The isocratic separation of Fe(2+), Fe(3+) and Cu(2+) simultaneously with Mn(2+), Pb(2+), Cd(2+), Zn(2+) and Ni(2+) was obtained on an iminodiacetic acid (IDA) functionalized silica column 150 x 4.0 mm id. with an optimized eluent composed of 2.5 mmol L(-1) dipicolinic acid, 10 mmol L(-1) HCl and 60% v/v of methanol at flow rate of 0.5 mL min(-1). Post-column reaction with 4-(2-pyridylazo)resorcinol (PAR) was used for sensitive spectrophotometric detection at 510 nm of the separated metals at low ppb level. The applicability of the developed method to the analysis of fuel ethanol was demonstrated.21015651570University of TasmaniaFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2006/03960-1]CNPq [573672/2008-3

Gene expression profiling for molecular distinction and characterization of laser captured primary lung cancers

<p>Abstract</p> <p>Methods</p> <p>We examined gene expression profiles of tumor cells from 29 untreated patients with lung cancer (10 adenocarcinomas (AC), 10 squamous cell carcinomas (SCC), and 9 small cell lung cancer (SCLC)) in comparison to 5 samples of normal lung tissue (NT). The European and American methodological quality guidelines for microarray experiments were followed, including the stipulated use of laser capture microdissection for separation and purification of the lung cancer tumor cells from surrounding tissue.</p> <p>Results</p> <p>Based on differentially expressed genes, different lung cancer samples could be distinguished from each other and from normal lung tissue using hierarchical clustering. Comparing AC, SCC and SCLC with NT, we found 205, 335 and 404 genes, respectively, that were at least 2-fold differentially expressed (estimated false discovery rate: < 2.6%). Different lung cancer subtypes had distinct molecular phenotypes, which also reflected their biological characteristics. Differentially expressed genes in human lung tumors which may be of relevance in the respective lung cancer subtypes were corroborated by quantitative real-time PCR.</p> <p>Genetic programming (GP) was performed to construct a classifier for distinguishing between AC, SCC, SCLC, and NT. Forty genes, that could be used to correctly classify the tumor or NT samples, have been identified. In addition, all samples from an independent test set of 13 further tumors (AC or SCC) were also correctly classified.</p> <p>Conclusion</p> <p>The data from this research identified potential candidate genes which could be used as the basis for the development of diagnostic tools and lung tumor type-specific targeted therapies.</p

Genomic and Epigenomic Responses to Chronic Stress Involve miRNA-Mediated Programming

Stress represents a critical influence on motor system function and has been shown to impair movement performance. We hypothesized that stress-induced motor impairments are due to brain-specific changes in miRNA and protein-encoding gene expression. Here we show a causal link between stress-induced motor impairment and associated genetic and epigenetic responses in relevant central motor areas in a rat model. Exposure to two weeks of mild restraint stress altered the expression of 39 genes and nine miRNAs in the cerebellum. In line with persistent behavioural impairments, some changes in gene and miRNA expression were resistant to recovery from stress. Interestingly, stress up-regulated the expression of Adipoq and prolactin receptor mRNAs in the cerebellum. Stress also altered the expression of Prlr, miR-186, and miR-709 in hippocampus and prefrontal cortex. In addition, our findings demonstrate that miR-186 targets the gene Eps15. Furthermore, we found an age-dependent increase in EphrinB3 and GabaA4 receptors. These data show that even mild stress results in substantial genomic and epigenomic changes involving miRNA expression and associated gene targets in the motor system. These findings suggest a central role of miRNA-regulated gene expression in the stress response and in associated neurological function

Optical imaging in vivo with a focus on paediatric disease: technical progress, current preclinical and clinical applications and future perspectives

To obtain information on the occurrence and location of molecular events as well as to track target-specific probes such as antibodies or peptides, drugs or even cells non-invasively over time, optical imaging (OI) technologies are increasingly applied. Although OI strongly contributes to the advances made in preclinical research, it is so far, with the exception of optical coherence tomography (OCT), only very sparingly applied in clinical settings. Nevertheless, as OI technologies evolve and improve continuously and represent relatively inexpensive and harmful methods, their implementation as clinical tools for the assessment of children disease is increasing. This review focuses on the current preclinical and clinical applications as well as on the future potential of OI in the clinical routine. Herein, we summarize the development of different fluorescence and bioluminescence imaging techniques for microscopic and macroscopic visualization of microstructures and biological processes. In addition, we discuss advantages and limitations of optical probes with distinct mechanisms of target-detection as well as of different bioluminescent reporter systems. Particular attention has been given to the use of near-infrared (NIR) fluorescent probes enabling observation of molecular events in deeper tissue

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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