2,753 research outputs found
Effects of an aft facing step on the surface of a laminar flow glider wing
A motor glider was used to perform a flight test study on the effects of aft facing steps in a laminar boundary layer. This study focuses on two dimensional aft facing steps oriented spanwise to the flow. The size and location of the aft facing steps were varied in order to determine the critical size that will force premature transition. Transition over a step was found to be primarily a function of Reynolds number based on step height. Both of the step height Reynolds numbers for premature and full transition were determined. A hot film anemometry system was used to detect transition
Electrochemical Concentration of Aqueous [18F]Fluoride into an Aprotic Solvent in a Disposable Microfluidic Cell
Performance of IPEN-CNEN/SP neutron activation analysis laboratory for microelement determinations in proficiency testing.
The performance of Neutron Activation Laboratory, IPEN ? CNEN/SP, was evaluated for the Ca, Fe, K, Mn, Na and Zn determinations in animal feed samples for ruminants through a proficiency test (PT) program. This PT program is organized by Embrapa Cattle Southeast to evaluate laboratories that analyze animal feed samples. Considering the fractions of satisfactory z-scores (%) of evaluated analytes to determine the laboratories performance, the general performance indicator obtained by IPEN ? CNEN/SP ranged from 90 to 95% of the satisfactory results during the period of participation in the evaluation, four years
Assessment of Technologies for Reducing CO2 Emission
There are a wide variety of technologies for reducing CO2 emissions, of which a greater part are those of energy technologies. The paper aims at assessing these technologies with regional differences of technology characteristics taken into account. The first part examines merits and demerits of individual technology, and thus envisages its possible future. The second part describes a global energy model, which generates comprehensive long term future scenarios of energy and CO2 emission in various regions of the world
The cDNA and deduced amino acid sequence of the γ subunit of the L-type calcium channel from rabbit skeletal muscle
Complementary DNAs for the γ subunit of the calcium channel of rabbit skeletal muscle were isolated on the basis of peptide sequences derived from the purified protein. The deduced primary structure is without homology to other known protein sequences and is consistent with the γ subunit being an integral membrane protein
Pasture establishment in tropical brushlands by aerial herbicide and seeding treatments on Kauai
A gene signature for post-infectious chronic fatigue syndrome
Background: At present, there are no clinically reliable disease markers for chronic fatigue syndrome. DNA chip microarray technology provides a method for examining the differential expression of mRNA from a large number of genes. Our hypothesis was that a gene expression signature, generated by microarray assays, could help identify genes which are dysregulated in patients with post-infectious CFS and so help identify biomarkers for the condition. Methods: Human genome-wide Affymetrix GeneChip arrays (39,000 transcripts derived from 33,000 gene sequences) were used to compare the levels of gene expression in the peripheral blood mononuclear cells of male patients with post-infectious chronic fatigue (n = 8) and male healthy control subjects (n = 7). Results: Patients and healthy subjects differed significantly in the level of expression of 366 genes. Analysis of the differentially expressed genes indicated functional implications in immune modulation, oxidative stress and apoptosis. Prototype biomarkers were identified on the basis of differential levels of gene expression and possible biological significance Conclusion: Differential expression of key genes identified in this study offer an insight into the possible mechanism of chronic fatigue following infection. The representative biomarkers identified in this research appear promising as potential biomarkers for diagnosis and treatment
JC and BK virus sequences are not detectable in leukaemic samples from children with common acute lymphoblastic leukaemia
Epidemiological evidence suggests that childhood leukaemia, and possibly common acute lymphoblastic leukaemia in particular, may have an infectious aetiology. Smith (1997 J Immunother20: 89–100) recently suggested that the critical infectious event occurs during pregnancy, and identified the polyoma virus JC as a candidate agent. In the present study we investigated whether genomes from the JC virus, and closely related BK virus, could be detected in leukaemic cells. No positive results were obtained suggesting that JC virus is unlikely to play a direct role in leukaemogenesis. © 1999 Cancer Research Campaig
Exponential Megapriming PCR (EMP) Cloning-Seamless DNA Insertion into Any Target Plasmid without Sequence Constraints
We present a fast, reliable and inexpensive restriction-free cloning method for seamless DNA insertion into any plasmid without sequence limitation. Exponential megapriming PCR (EMP) cloning requires two consecutive PCR steps and can be carried out in one day. We show that EMP cloning has a higher efficiency than restriction-free (RF) cloning, especially for long inserts above 2.5 kb. EMP further enables simultaneous cloning of multiple inserts.National Institutes of Health (U.S.) (Grant GM077537
Cross Priming Amplification: Mechanism and Optimization for Isothermal DNA Amplification
CPA is a class of isothermal amplification reactions that is carried out by a strand displacement DNA polymerase and does not require an initial denaturation step or the addition of a nicking enzyme. At the assay temperature of 63°C, the formation of a primer-template hybrid at transient, spontaneous denaturation bubbles in the DNA template is favored over re-annealing of the template strands by the high concentration of primer relative to template DNA. Strand displacement is encouraged by the annealing of cross primers with 5′ ends that are not complementary to the template strand and the binding of a displacement primer upstream of the crossing primer. The resulting exponential amplification of target DNA is highly specific and highly sensitive, producing amplicons from as few as four bacterial cells. Here we report on the basic CPA mechanism – single crossing CPA – and provide details on alternative mechanisms
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