No abstract

Plants are photosynthetic organisms that depend on sunlight for energy. Plants respond to light through different photoreceptors and show photomorphogenic development. Apart from Photosynthetically Active Radiation (PAR; 400–700 nm), plants are exposed to UV light, which is comprised of UV-C (below 280 nm), UV-B (280–320 nm) and UV-A (320–390 nm). The atmospheric ozone layer protects UV-C radiation from reaching earth while the UVR8 protein acts as a receptor for UV-B radiation. Low levels of UV-B exposure initiate signaling through UVR8 and induce secondary metabolite genes involved in protection against UV while higher dosages are very detrimental to plants. It has also been reported that genes involved in MAPK cascade help the plant in providing tolerance against UV radiation. The important targets of UV radiation in plant cells are DNA, lipids and proteins and also vital processes such as photosynthesis. Recent studies showed that, in response to UV radiation, mitochondria and chloroplasts produce a reactive oxygen species (ROS). Arabidopsis metacaspase-8 (AtMC8) is induced in response to oxidative stress caused by ROS, which acts downstream of the radical induced cell death (AtRCD1) gene making plants vulnerable to cell death. The studies on salicylic and jasmonic acid signaling mutants revealed that SA and JA regulate the ROS level and antagonize ROS mediated cell death. Recently, molecular studies have revealed genes involved in response to UV exposure, with respect to programmed cell death (PCD).

The MTHFR 677TT genotype may be a genetic risk factor for male infertility, especially with severe OAT and non-obstructive azoospermia in unexplained infertile males.

Light-matter interaction gives optical microscopes tremendous versatility compared with other imaging methods such as electron microscopes, scanning probe microscopes, or x-ray scattering where there are various limitations on sample preparation and where the methods are inapplicable to bioimaging with live cells. However, this comes at the expense of a limited resolution due to the diffraction limit. Here, we demonstrate a novel method utilizing elastic scattering from disordered nanoparticles to achieve subdiffraction limited imaging. The measured far-field speckle fields can be used to reconstruct the subwavelength details of the target by time reversal, which allows full-field dynamic super-resolution imaging. The fabrication of the scattering superlens is extremely simple and the method has no restrictions on the wavelength of light that is used. DOI: 10.1103/PhysRevLett.113.113901 PACS numbers: 42.25.Fx, 42.25.Kb, 42.40.-i Since the first experimental demonstration of the nearfield scanning optical microscope (NSOM) [1], various methods to probe the near fields have been proposed. The field of bioimaging has shown the largest number of new techniques due to the direct need to use visible wavelengths and observation in a nonvacuum environment. Although the currently developed methods are comprised of multiple unique ideas, the common goal of all super-resolution techniques is the effective delivery of the high spatial frequency components of the target object's angular spectrum, which are evanescent and are restricted to distances smaller than the wavelength of light from the object of interest.Here, we propose to use multiple scattering in turbid media to deliver the near-field wave vectors to the observable far field, which allows optical subdiffraction limited imaging using conventional optics. Similar to the hyperlens [2] or in structured illumination [3] where a specific nearfield mode corresponds to a corresponding far-field mode, multiple scattering induces the mixture and transfer between the far and near fields. Because elastic scattering is described by Maxwell's equations, which has time-reversal symmetry, multiple scattering of light exhibits time-reversal symmetry no matter how complicated and random each scattering event is. This property has allowed fascinating demonstrations such as the removal of inhomogeneity in the generation of photon echoes [4] or perfect absorption which is the opposite of lasing [5]. In imaging, multiple scattering and the principle of time reversal have been capitalized in reconstructing the incident field prior to multiple scattering [6][7][8]. In the microwave region, it has also been shown that scattering materials placed in the near field of a target object can scatter the near fields into propagating farfield components [9,10]. More recently, similar phenomena have been shown numerically in the optical region utilizing subwavelength coupled resonators [11] and subwavelength imaging has been demonstrated by using the combination of the memory effect and a hig...

We present a study of the fabrication of thin films from a Li 7 La 3 Zr 2 O 12 (LLZO) target using pulsed laser deposition. The effects of substrate temperatures and impurities on electrochemical properties of the films were investigated. The thin films of Li-La-Zr-O were deposited at room temperature and higher temperatures on a variety of substrates.Deposition above 600 °C resulted in a mixture of cubic and tetragonal phases of LLZO, as well as a La 2 Zr 2 O 7 impurity, and resulted in aluminum enrichment at the surface when Al-containing substrates were used. Films deposited at 600 °C exhibited the highest room temperature conductivity, 1.61×10 -6 S/cm. The chemical stability toward metallic lithium was also studied using X-ray photoelectron spectroscopy, which showed that the oxidation state of zirconium remained at +4 following physical contact with heated lithium metal.

We report on an approach to exploit multiple light scattering by shaping the incident wavefront in optical coherence tomography (OCT). Most of the reflected signal from biological tissue consists of multiply scattered light, which is regarded as noise in OCT. A digital mirror device (DMD) is utilized to shape the incident wavefront such that the maximal energy is focused at a specific depth in a highly scattering sample using a coherence-gated reflectance signal as feedback. The proof-of-concept experiment demonstrates that this approach enhances depth-selective focusing in the presence of optical inhomogeneity, and thus extends the penetration depth in spectral domain-OCT (SD-OCT).

Current non-invasive imaging and manipulation of biological systems heavily rely on using light as the probing tool. However, light propagation through highly turbid media such as biological tissue undergo multiple light scattering which results in significant scrambling of light paths and polarization information. Here we demonstrate the full control of polarization dependent light paths through a highly scattering medium by only shaping the incoming wavefront. The resulting polarized state is independent of the incident beam's polarization and has no spatial restrictions. We also show that a turbid medium can be used as a dynamic wave plate by controlling the phase of combined orthogonal polarization states. This approach may find direct applications in efficient energy transfer for photothermal therapy and the transfer of angular momentum in optical manipulation of biological systems.

Current therapeutic strategies are insufficient for suppressing stent-induced restenosis. Here, branched gold nanoparticles (BGNP)-coated self-expandable metallic stents (SEMSs) were developed for a local heat-induced suppression of stent-related tissue hyperplasia. Our polydopamine (PDA) coating on SEMS allowed BGNP crystal growth on the surface of SEMSs. The prepared BGNP-coated SEMS showed effective local heating under near-infrared laser irradiation. The effectiveness of BGNP-coated SEMSs for suppressing stent-related tissue hyperplasia was demonstrated in a rat esophageal model ( n = 52). BGNP-coated SEMS placement under fluoroscopic guidance was technically successful in all rats. The placed BGNP-coated SEMS in rat esophagus achieved three different local heat dose ranges (50, 65, and 80 °C) under fluoroscopic image-guided local irradiation. Follow-up endoscopic examination readily monitored the local heating and observed significantly decreased tissue hyperplasia at 4 weeks of local heat treatments (50 and 65 °C). Finally, Western blot, histology, immunohistochemistry (HSP70, αSMA, and TUNEL), and immunofluorescence (Ki67 and BrdU) analyses along with the statistical analysis confirmed that optimized BGNP-coated SEMS-mediated local heat treatments inducing the expression of anti-inflammatory HSP70 effectively suppresses tissue hyperplasia after stent placement in the esophagus. Our local heating with nanofunctionalized stents represents a promising new approach for suppressing stent-related tissue hyperplasia.