23 research outputs found
Identification of a Sudden Cardiac Death Susceptibility Locus at 2q24.2 through Genome-Wide Association in European Ancestry Individuals
Sudden cardiac death (SCD) continues to be one of the leading causes of mortality worldwide, with an annual incidence estimated at 250,000â300,000 in the United States and with the vast majority occurring in the setting of coronary disease. We performed a genome-wide association meta-analysis in 1,283 SCD cases and >20,000 control individuals of European ancestry from 5 studies, with follow-up genotyping in up to 3,119 SCD cases and 11,146 controls from 11 European ancestry studies, and identify the BAZ2B locus as associated with SCD (Pâ=â1.8Ă10â10). The risk allele, while ancestral, has a frequency of âŒ1.4%, suggesting strong negative selection and increases risk for SCD by 1.92âfold per allele (95% CI 1.57â2.34). We also tested the role of 49 SNPs previously implicated in modulating electrocardiographic traits (QRS, QT, and RR intervals). Consistent with epidemiological studies showing increased risk of SCD with prolonged QRS/QT intervals, the interval-prolonging alleles are in aggregate associated with increased risk for SCD (Pâ=â0.006)
Crowdsourcing hypothesis tests: Making transparent how design choices shape research results
To what extent are research results influenced by subjective decisions that scientists make as they design studies? Fifteen research teams independently designed studies to answer fiveoriginal research questions related to moral judgments, negotiations, and implicit cognition. Participants from two separate large samples (total N > 15,000) were then randomly assigned to complete one version of each study. Effect sizes varied dramatically across different sets of materials designed to test the same hypothesis: materials from different teams renderedstatistically significant effects in opposite directions for four out of five hypotheses, with the narrowest range in estimates being d = -0.37 to +0.26. Meta-analysis and a Bayesian perspective on the results revealed overall support for two hypotheses, and a lack of support for three hypotheses. Overall, practically none of the variability in effect sizes was attributable to the skill of the research team in designing materials, while considerable variability was attributable to the hypothesis being tested. In a forecasting survey, predictions of other scientists were significantly correlated with study results, both across and within hypotheses. Crowdsourced testing of research hypotheses helps reveal the true consistency of empirical support for a scientific claim.</div
An organic field-effect transistor with programmable polarity
Selective ambipolar transport in solution-processed polymer ferroelectric field-effect transistors (FeFETs) is reported. Depending on the polarization state of the ferroelectric, either remanent hole or electron accumulation is achieved in the transistor, as illustrated by a butterfly-shaped current-voltage (I-V) transfer curve (see Figure). For memory purposes, the polarity of the channel can be easily read using the change in drain current in response to a small gate voltage
Through-bond orbital coupling in end-functionalized bicyclohexylidenes - Photoelectron spectroscopy and ab initio SCF-MO calculations
To establish whether through-bond (TB) orbital interactions occur between the functional groups and the hydrocarbon skeleton in a series of end-functionalized oligo(cyclohexylidenes) 1-12, their He(I) photoelectron (PE) spectra were measured and analyzed. Vertical ionization energies, I(vj), of the highest occupied molecular orbitals (MOs) of 1-12 were assigned using ab initio RHF/6-31G* MO energies (-Δ(j)) in combination with Koopmans' theorem. Excellent to good agreement was found between the PES and RHF/6- 31G* results. In addition, the I(vj), assignments were further corroborated by a comparison of the PES data of 1-12 with those previously reported for appropriate reference compounds 13-20. To assess contributions from through- bond (TB) and/or through-space (TS) interactions, RHF/6-31G*/NBO analyses were performed. The results show that in the cases of 1-12, TS interactions do not occur. TB interactions were unequivocally identified for 1-4, 8, 10 and 11-12. These TB interactions were found to be relayed via the H(ax)-C-C- H(ax) precanonical Ï-MOs (Ï-PCMOs) of the cyclohexyl-like moieties
An Organic Field-Effect Transistor with Programmable Polarity
\u3cp\u3eA new type of organic field effect transistor (FET) consisting of an ambipolar semiconductor with a ferroelectric functionalized gate dielectric was presented. The polarity of the channel was remanently switched from p-type to n-type and back, in the ambipolar FET, depending on the polarization state of the ferroelectric. It was found that the gate fields show up as different peaks in the gate current since the ferroelectric switching is a sharp transition at a coercive field. The results show that the FETs may be applied as switches in logic circuits or as a non-volatile memory element.\u3c/p\u3
Doped polyaniline polymer fuses:Electrically programmable read-only-memory elements
\u3cp\u3eWe demonstrate polymeric electrically programmable read-only-memory elements based on camphorsulfonic-acid-doped polyaniline lines. Their working mechanism relies on irreversible reduction of the electrical conductivity by Joule heating like electrical safety fuses. The heating power is supplied electrically. The critical power required to blow up the fuse is strongly reduced by notches. The influence of the notch design can be predicted reasonably well using a simple thermal model. The critical power becomes less than 1 mW for fuses with notches narrower than 2 ÎŒm. This power can be delivered by organic transistors already at modest voltages, opening the way of integration of these memory elements in all-polymer circuits.\u3c/p\u3
High-performance solution-processed polymer ferroelectric field-effect transistors
We demonstrate a rewritable, non-volatile memory device with flexible plastic active layers deposited from solution. The memory device is a ferroelectric field-effect transistor (FeFET) made with a ferroelectric fluoropolymer and a bisalkoxy-substituted poly(p-phenylene vinylene) semiconductor material. The on- and off-state drain currents differ by several orders of magnitude, and have a long retention time, a high programming cycle endurance and short programming time. The remanent semiconductor surface charge density in the on- state has a high value of 18 mC m(-2), which explains the large on/off ratio. Application of a moderate gate field raises the surface charge to 26 mC m(-2), which is of a magnitude that is very difficult to obtain with conventional FETs because they are limited by dielectric breakdown of the gate insulator. In this way, the present ferroelectric-semiconductor interface extends the attainable field-effect band bending in organic semiconductors