The scintillation measured over close-to-ground retro-reflector links can be substantially enhanced due to the correlations experienced by both the direct and reflected echo beams. Experiments were carried out at China Lake, California, over a variety of ranges. The emphasis in this paper is on presenting the data from the 1.1 km retro-reflecting link that was operated for four consecutive days. The dependence of the measured irradiance flux variance on the solar fluence and on the temperature gradient above the ground is presented. The data are consistent with scintillation minima near sunrise and sunset, rising rapidly during the day and saturating at irradiance flux variances of ~10. Measured irradiance probability distributions of the retro-reflected beam are compared with standard probability density functions. The ratio of the irradiance flux variances on the retro-reflected to the direct, single-pass case is investigated with two data sets, one from a monostatic system and the other using an off-axis receiver system.
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http://dx.doi.org/10.1364/AO.51.006147 | DOI Listing |
Photochem Photobiol
January 2025
Instituto COMAV, Edif. 8E, Acceso J, Ciudad Politécnica de la Innovación, Universitat, Politècnica de València, Valencia, Spain.
Spectral Solar Photosynthetically Photon Flux Density (PPFD) (380-780 nm) reaching the surface in different tree shade conditions and heights has been analyzed in order to better understand the different photosynthetic performance of plants depending on their spatial situation, the canopy density and height with respect to the floor. A comparison between the shadow of nine different trees in a sunny day and the case of a cloudy day in an open space has been studied. A poplar, laurel, amber tree, pine, olive tree, fir tree, cypress, elm tree and magnolia tree have been analyzed.
View Article and Find Full Text PDFNucl Med Commun
January 2025
Department of Oncology, University College London Hospitals NHS Foundation Trust and UCL Cancer Institute, University College London, London, UK.
Treatment with radioactive drugs (molecular radiotherapy, MRT) is an option for selected children with neuroblastoma and neuroendocrine cancers. As few hospitals are appropriately equipped and staffed to provide paediatric MRT, many families have to travel long distances from home for prolonged periods. To improve professional understanding of the challenges faced by children receiving these treatments and their parents, and to help them appreciate the difficulties faced by professionals in delivering complex treatments, a meeting bringing together parents, patients and professionals was held.
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March 2025
Experimental Nuclear Physics Department, Nuclear Research Centre, Egyptian Atomic Energy Authority, Egypt; Cyclotron Facility, Egyptian Atomic Energy Authority, Egypt.
Neutron and gamma-ray shielding design for a 30Ci (1.11TBq) Am-Be irradiation facility is studied using MCNP5 Monte Carlo simulation code. The study focuses on the optimization of the shielding layers of the previously planned neutron irradiation facility.
View Article and Find Full Text PDFPlant Cell Environ
January 2025
Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Bonn, Germany.
The cuticle, an extracellular hydrophobic layer impregnated with waxy lipids, serves as the primary interface between plant leaves and their environment and is thus subject to external cues. A previous study on poplar leaves revealed that environmental conditions outdoors promoted the deposition of about 10-fold more cuticular wax compared to the highly artificial climate of a growth chamber. Given that light was the most significant variable distinguishing the two locations, we hypothesized that the quantity of light might serve as a key driver of foliar wax accumulation.
View Article and Find Full Text PDFNat Commun
January 2025
School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-Sen University, Shenzhen, China.
Hypoxic tumors present a significant challenge in cancer therapy due to their ability to adaptation in low-oxygen environments, which supports tumor survival and resistance to treatment. Enhanced mitophagy, the selective degradation of mitochondria by autophagy, is a crucial mechanism that helps sustain cellular homeostasis in hypoxic tumors. In this study, we develop an azocalix[4]arene-modified supramolecular albumin nanoparticle, that co-delivers hydroxychloroquine and a mitochondria-targeting photosensitizer, designed to induce cascaded oxidative stress by regulating mitophagy for the treatment of hypoxic tumors.
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