1,711 research outputs found
Fabrication of a Horizontal and a Vertical Large Surface Area Nanogap Electrochemical Sensor
Nanogap sensors have a wide range of applications as they can provide accurate direct detection of biomolecules through impedimetric or amperometric signals. Signal response from nanogap sensors is dependent on both the electrode spacing and surface area. However, creating large surface area nanogap sensors presents several challenges during fabrication. We show two different approaches to achieve both horizontal and vertical coplanar nanogap geometries. In the first method we use electron-beam lithography (EBL) to pattern an 11 mm long serpentine nanogap (215 nm) between two electrodes. For the second method we use inductively-coupled plasma (ICP) reactive ion etching (RIE) to create a channel in a silicon substrate, optically pattern a buried 1.0 mm × 1.5 mm electrode before anodically bonding a second identical electrode, patterned on glass, directly above. The devices have a wide range of applicability in different sensing techniques with the large area nanogaps presenting advantages over other devices of the same family. As a case study we explore the detection of peptide nucleic acid (PNA)−DNA binding events using dielectric spectroscopy with the horizontal coplanar device
Protein turnover measurement using selected reaction monitoring-mass spectrometry (SRM-MS)
Protein turnover represents an important mechanism in the functioning of cells, with deregulated synthesis and degradation of proteins implicated in many diseased states. Therefore, proteomics strategies to measure turnover rates with high confidence are of vital importance to understanding many biological processes. In this study, the more widely used approach of non-targeted precursor ion signal intensity (MS1) quantification is compared with selected reaction monitoring (SRM), a data acquisition strategy that records data for specific peptides, to determine if improved quantitative data would be obtained using a targeted quantification approach. Using mouse liver as a model system, turnover measurement of four tricarboxylic acid cycle proteins was performed using both MS1 and SRM quantification strategies. SRM outperformed MS1 in terms of sensitivity and selectivity of measurement, allowing more confident determination of protein turnover rates. SRM data are acquired using cheaper and more widely available tandem quadrupole mass spectrometers, making the approach accessible to a larger number of researchers than MS1 quantification, which is best performed on high mass resolution instruments. SRM acquisition is ideally suited to focused studies where the turnover of tens of proteins is measured, making it applicable in determining the dynamics of proteins complexes and complete metabolic pathways
Indian health conditions.
This volume is a compendium of scholarly analyses of the health conditions that together constitute most of the illness borne by American Indians and Alaska Natives. Topics include; health intervention; cancer; cardiovascular diseases; diabetes; digestive system diseases; infant mortality; infectious diseases; maternal health; mental health and mental illness; musculosketetal system disease; oral disease; end-stage renal disease; respiratory diseases; violence; substance abuse; and accidental injuries. This publication was developed in 1986 and although, the data are several years old, much of the analyses and recommendations are still relevant today. It also serves as an important historical or reference document for the Indian Health Service. Each analysis provides an overview of a particular health condition as it affects the IHS service population nationwide and suggests, recommendations regarding the steps that IHS can take to reduce and eventually eliminate the described health problems
Boron-Doped Diamond Dual-Plate Deep-Microtrench Device for Generator-Collector Sulfide Sensing
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.A BDD-BDD dual-plate microtrench electrode with 6μm inter-electrode spacing is investigated using generator-collector electrochemistry and shown to give microtrench depth-dependent sulfide detection down to the μM levels. The effect of the microtrench depth is compared for a "shallow" 44 μm and a "deep" 180μm microtrench and linked to the reduction of oxygen to hydrogen peroxide which interferes with sulfide redox cycling. With a deeper microtrench and a fixed collector potential at -1.4V vs. SCE, two distinct redox cycling potential domains are observed at 0.0V vs. SCE (2-electron) and at 1.1V vs. SCE (6-electron).F. M. and A. J. G. thank EPSRC for financial support (EP/I028706/1)
Family-based Genome-wide Association Study of South Indian Pedigrees Supports WNT7B as a Central Corneal Thickness Locus
Purpose To identify genetic risk factors contributing to central corneal thickness (CCT) in individuals from South India, a population with a high prevalence of ocular disorders. Methods: One hundred ninety-five individuals from 15 large South Indian pedigrees were genotyped using the Omni2.5 bead array. Family-based association for CCT was conducted using the score test in MERLIN. Results: Genome-wide association study (GWAS) identified strongest association for single nucleotide polymorphisms (SNPs) in the first intron of WNT7B and CCT (top SNP rs9330813; β = −0.57, 95% confidence interval [CI]: −0.78 to −0.36; P = 1.7 × 10−7). We further investigated rs9330813 in a Latino cohort and four independent European cohorts. A meta-analysis of these data sets demonstrated statistically significant association between rs9330813 and CCT (β = −3.94, 95% CI: −5.23 to −2.66; P = 1.7 × 10−9). WNT7B SNPs located in the same genomic region that includes rs9330813 have previously been associated with CCT in Latinos but with other ocular quantitative traits related to myopia (corneal curvature and axial length) in a Japanese population (rs10453441 and rs200329677). To evaluate the specificity of the observed WNT7B association with CCT in the South Indian families, we completed an ocular phenome-wide association study (PheWAS) for the top WNT7B SNPs using 45 ocular traits measured in these same families including corneal curvature and axial length. The ocular PheWAS results indicate that in the South Indian families WNT7B SNPs are primarily associated with CCT. Conclusions: The results indicate robust evidence for association between WNT7B SNPs and CCT in South Indian pedigrees, and suggest that WNT7B SNPs can have population-specific effects on ocular quantitative traits
Joint Protection : enabling change in musculoskeletal conditions
Joint protection includes applying ergonomic principles in daily life, altering working methods, using assistive devices, and modifying environments. It is taught to people with musculoskeletal conditions, such as rheumatoid arthritis (RA), osteoarthritis (OA), and soft tissue rheumatisms. Common principles are to: distribute load over several joints; reduce effort using assistive devices; pace activities; use orthoses; and exercise regularly. Cognitive-behavioral, self-efficacy, and motor-learning approaches are employed. Trials demonstrate that using these approaches is significantly more effective than advice and demonstration alone in changing joint-protection behavior, improving self-efficacy, function, and reducing pain in both early and established RA and hand OA. There is still conflicting evidence for its effectiveness in soft-tissue rheumatisms
How are "teaching the teachers" courses in evidence based medicine evaluated? A systematic review
Background
Teaching of evidence-based medicine (EBM) has become widespread in medical education. Teaching the teachers (TTT) courses address the increased teaching demand and the need to improve effectiveness of EBM teaching. We conducted a systematic review of assessment tools for EBM TTT courses. To summarise and appraise existing assessment methods for teaching the teachers courses in EBM by a systematic review.
Methods
We searched PubMed, BioMed, EmBase, Cochrane and Eric databases without language restrictions and included articles that assessed its participants. Study selection and data extraction were conducted independently by two reviewers.
Results
Of 1230 potentially relevant studies, five papers met the selection criteria. There were no specific assessment tools for evaluating effectiveness of EBM TTT courses. Some of the material available might be useful in initiating the development of such an assessment tool.
Conclusion
There is a need for the development of educationally sound assessment tools for teaching the teachers courses in EBM, without which it would be impossible to ascertain if such courses have the desired effect
The Turkey Ig-like receptor family: identification, expression and function.
The chicken leukocyte receptor complex located on microchromosome 31 encodes the chicken Ig-like receptors (CHIR), a vastly expanded gene family which can be further divided into three subgroups: activating CHIR-A, bifunctional CHIR-AB and inhibitory CHIR-B. Here, we investigated the presence of CHIR homologues in other bird species. The available genome databases of turkey, duck and zebra finch were screened with different strategies including BLAST searches employing various CHIR sequences, and keyword searches. We could not identify CHIR homologues in the distantly related zebra finch and duck, however, several partial and complete sequences of CHIR homologues were identified on chromosome 3 of the turkey genome. They were designated as turkey Ig-like receptors (TILR). Using cDNA derived from turkey blood and spleen RNA, six full length TILR could be amplified and further divided according to the typical sequence features into one activating TILR-A, one inhibitory TILR-B and four bifunctional TILR-AB. Since the TILR-AB sequences all displayed the critical residues shown to be involved in binding to IgY, we next confirmed the IgY binding using a soluble TILR-AB1-huIg fusion protein. This fusion protein reacted with IgY derived from various gallinaceous birds, but not with IgY from other bird species. Finally, we tested various mab directed against CHIR for their crossreactivity with either turkey or duck leukocytes. Whereas no staining was detectable with duck cells, the CHIR-AB1 specific mab 8D12 and the CHIR-A2 specific mab 13E2 both reacted with a leukocyte subpopulation that was further identified as thrombocytes by double immunofluorescence employing B-cell, T-cell and thrombocyte specific reagents. In summary, although the turkey harbors similar LRC genes as the chicken, their distribution seems to be distinct with predominance on thrombocytes rather than lymphocytes
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