2,125 research outputs found
Spatio-temporal mapping of variation potentials in leaves of Helianthus annuus L. seedlings in situ using multi-electrode array.
Damaging thermal stimuli trigger long-lasting variation potentials (VPs) in higher plants. Owing to limitations in conventional plant electrophysiological recording techniques, recorded signals are composed of signals originating from all of the cells that are connected to an electrode. This limitation does not enable detailed spatio-temporal distributions of transmission and electrical activities in plants to be visualised. Multi-electrode array (MEA) enables the recording and imaging of dynamic spatio-temporal electrical activities in higher plants. Here, we used an 8 × 8 MEA with a polar distance of 450 μm to measure electrical activities from numerous cells simultaneously. The mapping of the data that were recorded from the MEA revealed the transfer mode of the thermally induced VPs in the leaves of Helianthus annuus L. seedlings in situ. These results suggest that MEA can enable recordings with high spatio-temporal resolution that facilitate the determination of the bioelectrical response mode of higher plants under stress
Manipulating non-Hermitian skin effect via electric fields
In non-Hermitian systems, the phenomenon that the bulk-band eigenstates are
accumulated at the boundaries of the systems under open boundary conditions is
called non-Hermitian skin effect (NHSE), which is one of the most iconic and
important features of a non-Hermitian system. In this work, we investigate the
fate of NHSE in the presence of electric fields by analytically calculating the
dynamical evolution of an initial bulk state and numerically computing the
spectral winding number, the distributions of eigenstates, as well as the
dynamical evolutions. We show abundant manipulation effects of dc and ac fields
on the NHSE, and that the physical mechanism behind these effects is the
interplay between the Stark localization, dynamic localization and the NHSE. In
addition, the finite size analysis of the non-Hermitian system with a pure dc
field shows the phenomenon of size-dependent NHSE. We further propose a scheme
to realize the discussed model based on an electronic circuit. The results will
help to deepen the understanding of NHSE and its manipulation
Systemic Associations with Residual Subretinal Fluid after Ranibizumab in Diabetic Macular Edema
Purpose. To investigate the impact of systemic diseases on the occurrence of subretinal fluid (SRF) in diabetic macular edema (DME) and prognostic factors for residual SRF following three consecutive monthly intravitreal ranibizumab. Methods. Ninety-seven eyes from 68 patients with DME who completed 3 consecutive monthly injections of ranibizumab were enrolled. Systemic parameters mainly included chronic kidney disease (CKD), hypertension, HbA1c, and insulin dependence. Renal parameters for CKD were serum creatinine, estimated glomerular filtration rate (eGFR), and serum albumin. Ocular factors were baseline central macular thickness (CMT), severity of diabetic retinopathy (DR), and status of panretinal photocoagulation (PRP). Results. Chronic kidney disease had significant correlation with baseline SRF (R=0.397, p<0.001 after partial correlation with adjustment for age and DR severity). As for CKD, lower serum albumin, but not eGFR or serum creatinine, was associated with baseline presence of SRF (p=0.026, p=0.08 and p=0.53, resp., after adjustment for age and DR severity). Overall, lower eGFR and lower HbA1c values, contrary to popular belief, predicted the presence of residual SRF following intravitreal injections (p=0.016 and p<0.001, resp.). Conclusions. Tight sugar control and poorer baseline kidney function may slow the resorption of SRF after anti-VEGF injections in patients with DME in the short term
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