Molecular electronics offers unique scientific and technological possibilities, resulting from both the nanometre scale of the devices and their reproducible chemical complexity. Two fundamental yet ...different effects, with no classical analogue, have been demonstrated experimentally in single-molecule junctions: quantum interference due to competing electron transport pathways, and the Kondo effect due to entanglement from strong electronic interactions. Here we unify these phenomena, showing that transport through a spin-degenerate molecule can be either enhanced or blocked by Kondo correlations, depending on molecular structure, contacting geometry and applied gate voltages. An exact framework is developed, in terms of which the quantum interference properties of interacting molecular junctions can be systematically studied and understood. We prove that an exact Kondo-mediated conductance node results from destructive interference in exchange-cotunneling. Nonstandard temperature dependences and gate-tunable conductance peaks/nodes are demonstrated for prototypical molecular junctions, illustrating the intricate interplay of quantum effects beyond the single-orbital paradigm.
Femtosecond x-ray laser pulses are used to probe the carbon monoxide (CO) oxidation reaction on ruthenium (Ru) initiated by an optical laser pulse. On a time scale of a few hundred femtoseconds, the ...optical laser pulse excites motions of CO and oxygen (O) on the surface, allowing the reactants to collide, and, with a transient close to a picosecond (ps), new electronic states appear in the O K-edge x-ray absorption spectrum. Density functional theory calculations indicate that these result from changes in the adsorption site and bond formation between CO and O with a distribution of OC–O bond lengths close to the transition state (TS). After 1 ps, 10% of the CO populate the TS region, which is consistent with predictions based on a quantum oscillator model.
To explore serum cytokine levels over time in patients with chronic low back pain (cLBP) and Modic changes (MCs), difference in change between treatment groups in the Antibiotics in Modic Changes ...(AIM) study and associations between change in cytokines and low back pain.
Serum concentrations of 39 cytokines were measured at baseline and 1 year from 73 participants in the AIM study; 30 randomized to placebo, 43 to Amoxicillin. Low back pain intensity was measured by numeric rating scale. Change in cytokine levels over time were assessed by paired t-tests. Difference in change in cytokine levels between treatment groups and associations between changes in LBP and cytokine levels were assessed by linear regression models. Networks of cytokine changes in each treatment groups were explored by Pearson's correlations.
Five cytokines changed from baseline to 1 year, (mean change, log transformed values with CI) C-X-C motif chemokine ligand (CXCL) 10 (IP-10) (0.11 (0.01–0.20)), CXCL13 (0.61 (0.00–0.12)), C-C motif chemokine ligand (CCL)26 (0.05 (0.01–0.1)), granulocyte macrophage-colony stimulating factor (GM-CSF) (−0.12 (−0.23 to 0.00)) and CXCL11 (0.12 (0.03–0.22)). Treatment group only influenced change in CCL21 (β 0.07 (0.01–0.12)), and IL-6 (β −0.17 (−0.30 to −0.03)). Change in CXCL13 (β 2.43 (0.49–4.38)), CCL27 (β 3.07 (0.46–5.69)), IL-8 (β 1.83 (0.08–3.58)) and CCL19 (β 3.10 (0.86–5.43)) were associated with change in LBP. The correlation networks of cytokine changes demonstrate small differences between treatment groups.
Cytokine levels are relatively stable over time in our sample, with little difference between treatment groups. Some cytokines may be associated with LBP intensity. The differences between the correlation networks suggest that long-term Amoxicillin-treatment may have longstanding effects to be further explored.
Can different political ideologies explain policy preferences regarding asylum seekers? We focus on attitudes regarding governmental policy towards out-group members and suggest that perceptions of ...threat help to shape these policy attitudes. Study 1 compared public opinion regarding asylum policy in Israel (N = 137) and Australia (N = 138), two countries with restrictive asylum policies and who host a large number of asylum seekers; Study 2, a longitudinal study, was conducted during two different time periods in Israel—before and during the Gaza conflict. Results of both studies showed that threat perceptions of out-group members drive the relationship between conservative political ideologies and support for exclusionary asylum policies among citizens. Perceptions of threat held by members of the host country (the in-group) towards asylum seekers (the out-group) may influence policy formation. The effect of these out-groups threats needs to be critically weighed when considering Israeli and Australian policies towards asylum seekers.
The structure of estrogen sulphotransferase has been solved in the presence of inactive cofactor PAP and substrate 17 beta-estradiol. This structure reveals structural similarities between cytosolic ...sulphotransferases and nucleotide kinases.
PDF
