Charge-transfer (CT) states, bound combinations of an electron and a hole on separate molecules, play a crucial role in organic optoelectronic devices. We report direct nanoscale imaging of the ...transport of long-lived CT states in molecular organic donor-acceptor blends, which demonstrates that the bound electron-hole pairs that form the CT states move geminately over distances of 5-10 nm, driven by energetic disorder and diffusion to lower energy sites. Magnetic field dependence reveals a fluctuating exchange splitting, indicative of a variation in electron-hole spacing during diffusion. The results suggest that the electron-hole pair of the CT state undergoes a stretching transport mechanism analogous to an 'inchworm' motion, in contrast to conventional transport of Frenkel excitons. Given the short exciton lifetimes characteristic of bulk heterojunction organic solar cells, this work confirms the potential importance of CT state transport, suggesting that CT states are likely to diffuse farther than Frenkel excitons in many donor-acceptor blends.
Intense, millisecond-duration bursts of radio waves (named fast radio bursts) have been detected from beyond the Milky Way
. Their dispersion measures-which are greater than would be expected if they ...had propagated only through the interstellar medium of the Milky Way-indicate extragalactic origins and imply contributions from the intergalactic medium and perhaps from other galaxies
. Although several theories exist regarding the sources of these fast radio bursts, their intensities, durations and temporal structures suggest coherent emission from highly magnetized plasma
. Two of these bursts have been observed to repeat
, and one repeater (FRB 121102) has been localized to the largest star-forming region of a dwarf galaxy at a cosmological redshift of 0.19 (refs.
). However, the host galaxies and distances of the hitherto non-repeating fast radio bursts are yet to be identified. Unlike repeating sources, these events must be observed with an interferometer that has sufficient spatial resolution for arcsecond localization at the time of discovery. Here we report the localization of a fast radio burst (FRB 190523) to a few-arcsecond region containing a single massive galaxy at a redshift of 0.66. This galaxy is different from the host of FRB 121102, as it is a thousand times more massive, with a specific star-formation rate (the star-formation rate divided by the mass) a hundred times smaller.
Many patients who require allogeneic hematopoietic stem cell transplantation (allo-HSCT) lack a human leukocyte antigen (HLA)-matched donor. Here, we report a protocol for haploidentical allo-HSCT ...that combines granulocyte-colony stimulating factor primed bone marrow (G-BM) and peripheral blood stem cells (PBSC) without in vitro T-cell depletion (TCD). In this study, 171 patients, including 86 in high-risk group, underwent transplantation from haploidentical family donors. All patients achieved sustained, full donor chimerism. One hundred and eleven patients were alive in remission at a median of 682 (253-1502) days. The cumulative incidence of grade III-IV acute graft-versus-host disease (GVHD) was 23% and that of extensive chronic GVHD, 47%; these were not influenced by HLA disparity. Patients younger than 15 years had less grade III-IV acute GVHD than older patients (P=0.044). The 2-year probability of relapse was 12% for standard-risk disease and 39% for high-risk disease. The 2-year probability of leukemia-free survival (LFS) was 68% for standard-risk patients and 42% for high-risk patients (P=0.0009). Grade III-IV acute GVHD was associated with better LFS (P=0.0017). The results require confirmation and show that G-BM combined with PBSC from haploidentical family donors, without in vitro TCD, may be used as a good source of stem cells for allo-HSCT.
Surfaces and interfaces offer new possibilities for tailoring the many-body interactions that dominate the electrical and thermal properties of transition metal oxides. Here, we use the prototypical ...two-dimensional electron liquid (2DEL) at the SrTiO3(001) surface to reveal a remarkably complex evolution of electron-phonon coupling with the tunable carrier density of this system. At low density, where superconductivity is found in the analogous 2DEL at the LaAlO3/SrTiO3 interface, our angle-resolved photoemission data show replica bands separated by 100 meV from the main bands. This is a hallmark of a coherent polaronic liquid and implies long-range coupling to a single longitudinal optical phonon branch. In the overdoped regime the preferential coupling to this branch decreases and the 2DEL undergoes a crossover to a more conventional metallic state with weaker short-range electron-phonon interaction. These results place constraints on the theoretical description of superconductivity and allow a unified understanding of the transport properties in SrTiO3-based 2DELs.
Particle trapping and binding in optical potential wells provide a versatile platform for various biomedical applications. However, implementation systems to study multi-particle contact interactions ...in an optical lattice remain rare. By configuring an optofluidic lattice, we demonstrate the precise control of particle interactions and functions such as controlling aggregation and multi-hopping. The mean residence time of a single particle is found considerably reduced from 7 s, as predicted by Kramer's theory, to 0.6 s, owing to the mechanical interactions among aggregated particles. The optofluidic lattice also enables single-bacteria-level screening of biological binding agents such as antibodies through particle-enabled bacteria hopping. The binding efficiency of antibodies could be determined directly, selectively, quantitatively and efficiently. This work enriches the fundamental mechanisms of particle kinetics and offers new possibilities for probing and utilising unprecedented biomolecule interactions at single-bacteria level.
We explore the interplay of electron-electron correlations and spin-orbit coupling in the model Fermi liquidSr2RuO4using laser-based angle-resolved photoemission spectroscopy. Our precise measurement ...of the Fermi surface confirms the importance of spin-orbit coupling in this material and reveals that its effective value is enhanced by a factor of about 2, due to electronic correlations. The self-energies for theβandγsheets are found to display significant angular dependence. By taking into account the multi-orbital composition of quasiparticle states, we determine self-energies associated with each orbital component directly from the experimental data. This analysis demonstrates that the perceived angular dependence does not imply momentum-dependent many-body effects but arises from a substantial orbital mixing induced by spin-orbit coupling. A comparison to single-site dynamical mean-field theory further supports the notion of dominantly local orbital self-energies and provides strong evidence for an electronic origin of the observed nonlinear frequency dependence of the self-energies, leading to “kinks” in the quasiparticle dispersion ofSr2RuO4.
The detection of aberrant cells by natural killer (NK) cells is controlled by the integration of signals from activating and inhibitory ligands and from cytokines such as IL-15. We identified ...cytokine-inducible SH2-containing protein (CIS, encoded by Cish) as a critical negative regulator of IL-15 signaling in NK cells. Cish was rapidly induced in response to IL-15, and deletion of Cish rendered NK cells hypersensitive to IL-15, as evidenced by enhanced proliferation, survival, IFN-γ production and cytotoxicity toward tumors. This was associated with increased JAK-STAT signaling in NK cells in which Cish was deleted. Correspondingly, CIS interacted with the tyrosine kinase JAK1, inhibiting its enzymatic activity and targeting JAK for proteasomal degradation. Cish(-/-) mice were resistant to melanoma, prostate and breast cancer metastasis in vivo, and this was intrinsic to NK cell activity. Our data uncover a potent intracellular checkpoint in NK cell-mediated tumor immunity and suggest possibilities for new cancer immunotherapies directed at blocking CIS function.
Plumes have been identified as an access region for chorus waves to enter the plasmasphere. Here, for the first time, chorus wave properties are parameterized by distance from the plume boundary. ...Case studies and statistical analysis indicate that the polar wave vector angle, θk, of chorus becomes more oblique near the plume edge. Occurrence rates of θk > 35° on the plume boundary are approximately double that observed further away from the plume. Whilst the increase in θk is apparent on both plume edges, the distribution of θk exhibits different behavior between the Eastward and Westward boundaries. In general, the distribution of azimuthal wave vector angles, ϕk, is symmetric about the anti‐Earthwards direction. However, near the Eastward plume boundary, an Eastwards skew of ϕk is reported. This result provides new insight on chorus propagation in the context of the chorus‐to‐hiss mechanism, and has implications for quantifying wave‐particle interactions in the near‐plume region.
Plain Language Summary
Chorus wave properties are typically parameterized spatially in magnetic coordinates. Here, for the first time, we specifically study chorus wave vector characteristics near density enhancements known as plasmaspheric plumes, which have been identified as an access region for chorus waves to enter the plasmasphere. It is found that chorus waves propagate at larger angles with respect to the background magnetic field directly on the boundary of high‐density plume structures. This behavior is reported on both the Eastward and Westward plume edges, yet the variations in the distribution of wave vector angles is reported to be different between the Eastwards and Westwards edge. In general, it is found that the wave vector, k, is distributed symmetrically about the anti‐Earthwards direction, however, near the Eastwards plume boundary an Eastwards skew is reported. These results shed new light on the propagation of chorus waves near plasmaspheric plumes, which is important for modeling the propagation of waves into the plasmasphere, as well as for modeling interactions between waves and particles in this region.
Key Points
Lower band chorus waves are shown to be more oblique near the boundaries of plasmaspheric plumes, particularly for frequencies below 0.25 fce
Wave vector distribution shows clear differences between Eastward and Westward plume boundaries, despite increase in obliquity on both edges
Azimuthal wave vector angle is generally symmetric about anti‐Earthwards direction, yet Eastwards skew is reported near Eastward plume edge
In this paper, a set of 3D general solutions to static problems of 1D hexagonal piezoelectric quasicrystals is obtained by introducing two displacement functions and utilizing the rigorous operator ...theory. All the physical quantities are expressed by five quasi-harmonic functions. Based on the general solutions and with the help of the superposition principle, fundamental solutions for infinite/half-infinite spaces are presented by trial-and-error technique. The general solutions can be conveniently used to solve the boundary value problems regarding dislocations, cracks and inhomogeneities. The fundamental solutions are of primary significance to development of numerical codes such as boundary element method.
•3D general solutions to 1D hexagonal piezoelectric quasicrystals are expressed.•Infinite/half-infinite spaces subjected to concentrated loads are investigated.•Fundamental solutions are explicitly expressed in terms of elementary functions.
Summary
The two most commonly used airway management techniques during general anaesthesia are supraglottic airway devices and tracheal tubes. In older patients undergoing elective non‐cardiothoracic ...surgery under general anaesthesia with positive pressure ventilation, we hypothesised that a composite measure of in‐hospital postoperative pulmonary complications would be less frequent when a supraglottic airway device was used compared with a tracheal tube. We studied patients aged ≥ 70 years in 17 clinical centres. Patients were allocated randomly to airway management with a supraglottic airway device or a tracheal tube. Between August 2016 and April 2020, 2900 patients were studied, of whom 2751 were included in the primary analysis (1387 with supraglottic airway device and 1364 with a tracheal tube). Pre‐operatively, 2431 (88.4%) patients were estimated to have a postoperative pulmonary complication risk index of 1–2. Postoperative pulmonary complications, mostly coughing, occurred in 270 of 1387 patients (19.5%) allocated to a supraglottic airway device and 342 of 1364 patients (25.1%) assigned to a tracheal tube (absolute difference −5.6% (95%CI −8.7 to −2.5), risk ratio 0.78 (95%CI 0.67–0.89); p < 0.001). Among otherwise healthy older patients undergoing elective surgery under general anaesthesia with intra‐operative positive pressure ventilation of their lungs, there were fewer postoperative pulmonary complications when the airway was managed with a supraglottic airway device compared with a tracheal tube.
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