9,101 research outputs found
Association Signals Unveiled by a Comprehensive Gene Set Enrichment Analysis of Dental Caries Genome-Wide Association Studies
Gene set-based analysis of genome-wide association study (GWAS) data has recently emerged as a useful approach to examine the joint effects of multiple risk loci in complex human diseases or phenotypes. Dental caries is a common, chronic, and complex disease leading to a decrease in quality of life worldwide. In this study, we applied the approaches of gene set enrichment analysis to a major dental caries GWAS dataset, which consists of 537 cases and 605 controls. Using four complementary gene set analysis methods, we analyzed 1331 Gene Ontology (GO) terms collected from the Molecular Signatures Database (MSigDB). Setting false discovery rate (FDR) threshold as 0.05, we identified 13 significantly associated GO terms. Additionally, 17 terms were further included as marginally associated because they were top ranked by each method, although their FDR is higher than 0.05. In total, we identified 30 promising GO terms, including 'Sphingoid metabolic process,' 'Ubiquitin protein ligase activity,' 'Regulation of cytokine secretion,' and 'Ceramide metabolic process.' These GO terms encompass broad functions that potentially interact and contribute to the oral immune response related to caries development, which have not been reported in the standard single marker based analysis. Collectively, our gene set enrichment analysis provided complementary insights into the molecular mechanisms and polygenic interactions in dental caries, revealing promising association signals that could not be detected through single marker analysis of GWAS data. © 2013 Wang et al
High quality beam produced by tightly focused laser driven wakefield accelerators
We propose to use tightly focused lasers to generate high quality electron
beams in laser wakefield accelerators. In this scheme, the expansion of the
laser beam after the focal position enlarges the size of wakefield bubble,
which reduces the effective phase velocity of the wake and triggers injection
of plasma electrons. This scheme injects a relatively long beam with high
charge. The energy spread of the injected beam can be minimized if an optimal
acceleration distance is chosen so that the beam chirp is suppressed.
Particle-in-cell simulations indicate that electron beams with the charge in
the order of nanocoulomb, the energy spread of , and the normalized
emittance of can be generated in uniform plasma
using laser pulses. An empirical formula is also given for
predicting the beam charge. This injection scheme, with a very simple setup,
paves the way towards practical high-quality laser wakefield accelerators for
table-top electron and radiation sources.Comment: 7 pages, 9 figure
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Two NHX-type transporters from Helianthus tuberosus improve the tolerance of rice to salinity and nutrient deficiency stress.
The NHX-type cation/H+ transporters in plants have been shown to mediate Na+ (K+ )/H+ exchange for salinity tolerance and K+ homoeostasis. In this study, we identified and characterized two NHX homologues, HtNHX1 and HtNHX2 from an infertile and salinity tolerant species Helianthus tuberosus (cv. Nanyu No. 1). HtNHX1 and HtNHX2 share identical 5'- and 3'-UTR and coding regions, except for a 342-bp segment encoding 114 amino acids (L272 to Q385 ) which is absent in HtNHX2. Both hydroponics and soil culture experiments showed that the expression of HtNHX1 or HtNHX2 improved the rice tolerance to salinity. Expression of HtNHX2, but not HtNHX1, increased rice grain yield, harvest index, total nutrient uptake under K+ -limited salt-stress or general nutrient deficiency conditions. The results provide a novel insight into NHX function in plant mineral nutrition
Multi-Channel Magnetocardiogardiography System Based on Low-Tc SQUIDs in an Unshielded Environment
AbstractMagnetocardiography (MCG) using superconducting quantum interference devices (SQUIDs) is a new medical diagnostic tool measuring biomagnetic signals that are generated by the electrical activity of the human heart. This technique is completely passive, contactless, and it has an advantage in the early diagnosis of heart diseases. We developed the first unshielded four-channel MCG system based on low-Tc DC SQUIDs in China. Instead of using a costly magnetically shielded room, the environmental noise suppression was realized by using second-order gradiometers and three-axis reference magnetometer. The measured magnetic field resolution of the system is better than 1 pT, and multi-cycle human heart signals can be recorded directly. Also, with the infrared positioning system, 48 points data collection can be realized by moving the non-magnetic bed nine times
Ethyl 2-(3,3-dibutylÂthioÂureido)-4,5,6,7-tetraÂhydroÂbenzo[b]thioÂphene-3-carboxylÂate
In the title compound, C20H32N2O2S2, the cycloÂhexene ring is disordered over two half-boat conformations with occupancy factors of 0.71:0.29. One n-butyl chain is also disordered over two positions with occupancy factors of 0.83:0.17. The molÂecular conformation is stabilized by an intraÂmolecular N—H⋯O hydrogen bond
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