Very High Sensitivity (very + high_sensitivity)

Distribution by Scientific Domains


Selected Abstracts


sgk1, a member of an RNA cluster associated with cell death in a model of Parkinson's disease

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2005
Christine C. Stichel
Abstract In an effort to gain deeper insight into the molecular processes underlying neurodegeneration in Parkinson's disease, we performed gene expression profiling at several early time points after MPTP-injection into old (1-year) mice. We used a PCR-based gene expression profiling method, digital expression pattern display (DEPD), a method of very high sensitivity and reproducibility, which displays almost all transcripts of a tissue. To identify cell death-associated genes, we defined clusters of differentially expressed transcripts with expression behaviour that correlated with the temporal profile of cell death progression and characterized one of these cell death clusters further. We selected one of the strongest regulated genes, the serum and glucocorticoid-regulated kinase 1 (sgk1), and validated its differential expression by Northern blot analysis, semiquantitative PCR and in situ hybridization. Up-regulation of sgk1 (i) coincides with the onset of dopaminergic cell death in both the 8-week acute and 1-year subacute MPTP models, (ii) spans the entire brain, (iii) is attenuated by the l -deprenyl-mediated inhibition of the MPTP conversion to its active metabolite MPP+ and (iv) is not induced by dehydration. This study demonstrated that the combination of the DEPD technology, clustering analysis and a detailed histopathology is a useful tool for elucidating molecular pathways in neurodegenerative diseases. [source]


A Simple and Innovative Route to Prepare a Novel Carbon Nanotube/Prussian Blue Electrode and its Utilization as a Highly Sensitive H2O2 Amperometric Sensor

ADVANCED FUNCTIONAL MATERIALS, Issue 24 2009
Edson Nossol
Abstract The utilization of iron-based species (mainly metallic iron, hematite and magnetite) encapsulated into multi-walled carbon nanotubes (CNTs) as reactants in an electrochemical synthesis is reported for the first time in this work. Prussian blue (PB) is electrosynthesized in a heterogeneous reaction between ferricyanide ions in aqueous solution and the iron-species encapsulated into CNTs, resulting in novel CNT/PB paste electrodes. This innovative preparation route produces an intimate contact between the PB and the CNTs, which improves the stability and redox properties of PB. The PB formation and the chemical interaction between the PB and the CNTs are confirmed by Raman spectroscopy. The electrode is employed as a hydrogen peroxide amperometric sensor, resulting in a very low limit of detection (1.94,×,10,8,mol L,1) and very high sensitivity (15.3,A cm,2M,1). [source]


Talairach-Based Parcellation of Neonatal Brain Magnetic Resonance Imaging Data: Validation of a New Approach

JOURNAL OF NEUROIMAGING, Issue 4 2005
Haissam Haidar PhD
ABSTRACT Background and Purpose. Talairach-based parcellation (TP) of human brain magnetic resonance imaging (MRI) data has been used increasingly in clinical research to make regional measurements of brain structures in vivo. Recently, TP has been applied to pediatric research to elucidate the changes in regional brain volumes related to several neurological disorders. However, all freely available tools have been designed to parcellate adult brain MRI data. Parcellation of neonatal MRI data is very challenging owing to the lack of strong signal contrast, variability in signal intensity within tissues, and the small size and thus difficulty in identifying small structures used as landmarks for TP. Hence the authors designed and validated a new interactive tool to parcellate brain MRI data from newborns and young infants. Methods. The authors' tool was developed as part of a postprocessing pipeline, which includes registration of multichannel MR images, segmentation, and parcellation of the segmented data. The tool employs user-friendly interactive software to visualize and assign the anatomic landmarks required for parcellation, after which the planes and parcels are generated automatically by the algorithm. The authors then performed 3 sets of validation experiments to test the precision and reliability of their tool. Results. Validation experiments of intra-and interrater reliability on data obtained from newborn and 1-year-old children showed a very high sensitivity of >95% and specificity >99.9%. The authors also showed that rotating and reformatting the original MRI data results in a statistically significant difference in parcel volumes, demonstrating the importance of using a tool such as theirs that does not require realignment of the data prior to parcellation. Conclusions. To the authors' knowledge, the presented approach is the first TP method that has been developed and validated specifically for neonatal brain MRI data. Their approach would also be valuable for the analysis of brain MRI data from older children and adults. [source]


An immunochemical technique for the detection of ovalbumin in surimi-derived products

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2002
Ma Angeles Romero-Rodríguez
Abstract Egg white is frequently used in surimi-derived products. However, electrophoretic detection of egg white in such products is not reliable, since the egg white protein ovalbumin and the fish muscle protein actin have very similar molecular weights. We report the development of an immunoblotting (Western blotting) technique for the detection of ovalbumin in products of this type. We initially used a monoclonal antibody, but this did not bind effectively to ovalbumin in surimi-derived products. We therefore switched to the use of a polyclonal antibody, which gave excellent results and showed very high sensitivity (detection limit 0.5,ng,µl,1). © 2002 Society of Chemical Industry [source]


Alkali-Dinitramide Salts Part 2: Oxidizers for Special Pyrotechnic Applications

PROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 4 2006

Abstract Ammonium dinitramide is planned to be a substitute for commonly used oxidizers in rocket motor compositions. Different teams worldwide have already synthesized alkali salts of dinitramide and several times it was used as an oxidizer for pyrotechnic compositions containing boron as a reducing agent. In this paper the results of a systematic investigation to characterize the pyrotechnic redox systems titanium/potassium dinitramide and titanium/cesium dinitramide are presented and the data are compared. The heats of reaction as well as the burning rates of the redox system titanium/potassium dinitramide are higher than those of the redox system titanium/cesium dinitramide. Both systems show a moderate sensitivity to friction and electrostatic discharges. However the sensitivity of mixtures of both redox systems shows a very high sensitivity to impact. These sensitivities are in the range of pure HMX or pentaerythritol tetranitrate. [source]


Testing for high risk human papilloma virus in the initial follow-up of women treated for high-grade squamous intraepithelial lesions

AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 2 2010
Olivia Catherine SMART
Background:, The follow-up schedule of women who have undergone treatment for high grade squamous intraepithelial lesions (HSIL) is a crucial part of the cervical screening programme. The ability to detect residual disease or early recurrence enables the provision of timely secondary intervention. Aims:, The aim of this study was to determine the prevalence of High Risk HPV and cytological abnormalities at first follow-up visit post treatment. The feasibility, safety and cost benefit of omitting routine colposcopy as a first line investigation were evaluated. Methods:, A total of 100 women with histologically confirmed and treated HSIL were recruited prior to first follow-up visit. Colposcopic assessment, cervical cytology using LBC and HR HPV testing was carried out on all women. Results:, In all, 75% of the study group had both a negative HR HPV test and a normal cervical cytology at first follow-up visit. Mean time interval to first follow-up was 9 months. The rate of residual/recurrent high-grade disease within this cohort was 4% followed up to 18 months post treatment. HR HPV had a sensitivity of 100% to detect persistent HSIL. Conclusion:, High-risk human papilloma virus testing in combination with cytology at first follow-up visit in women treated for HSIL has a very high sensitivity and negative predictive value. Colposcopy does not improve specificity in this cohort and could be omitted in patients who have a negative smear and HPV test. [source]