Effective Radiative Cooling by Paint-Format Microsphere-Based Photonic Random Media

We demonstrate that photonic media, when properly randomized to minimize the photon transport mean free path, can be used to coat a black substrate and reduce its temperature by radiative cooling. Even under strong solar radiation, the substrate temperature could reach substantially below that of the ambient air. Our random media that consist of silica microspheres considerably outperform commercially available solar-reflective white paint for daytime cooling. We have achieved the outstanding cooling performance through a systematic study on light scattering, which reveals that the structural parameters of the random media for maximum scattering are significantly different from those of the commercial paint. We have created the random media to maximize optical scattering in the solar spectrum and to enhance thermal emission in the atmospheric transparency window. In contrast to previous studies, our random media do not require expensive processing steps or materials, such as silver, and can be applied to almost any surface in a paint format. The facile and scalable processing steps for our random media point to the possibility that low-cost coatings can be used for efficient radiative cooling

Megakaryocytes and platelet-fibrin thrombi characterize multi-organ thrombosis at autopsy in COVID-19: A case series

© 2020 Background: There is increasing recognition of a prothrombotic state in COVID-19. Post-mortem examination can provide important mechanistic insights. Methods: We present a COVID-19 autopsy series including findings in lungs, heart, kidneys, liver, and bone, from a New York academic medical center. Findings: In seven patients (four female), regardless of anticoagulation status, all autopsies demonstrated platelet-rich thrombi in the pulmonary, hepatic, renal, and cardiac microvasculature. Megakaryocytes were seen in higher than usual numbers in the lungs and heart. Two cases had thrombi in the large pulmonary arteries, where casts conformed to the anatomic location. Thrombi in the IVC were not found, but the deep leg veins were not dissected. Two cases had cardiac venous thrombosis with one case exhibiting septal myocardial infarction associated with intramyocardial venous thrombosis, without atherosclerosis. One case had focal acute lymphocyte-predominant inflammation in the myocardium with no virions found in cardiomyocytes. Otherwise, cardiac histopathological changes were limited to minimal epicardial inflammation (n = 1), early ischemic injury (n = 3), and mural fibrin thrombi (n = 2). Platelet-rich peri‑tubular fibrin microthrombi were a prominent renal feature. Acute tubular necrosis, and red blood cell and granular casts were seen in multiple cases. Significant glomerular pathology was notably absent. Numerous platelet-fibrin microthrombi were identified in hepatic sinusoids. All lungs exhibited diffuse alveolar damage (DAD) with a spectrum of exudative and proliferative phases including hyaline membranes, and pneumocyte hyperplasia, with viral inclusions in epithelial cells and macrophages. Three cases had superimposed acute bronchopneumonia, focally necrotizing. Interpretation: In this series of seven COVID-19 autopsies, thrombosis was a prominent feature in multiple organs, in some cases despite full anticoagulation and regardless of timing of the disease course, suggesting that thrombosis plays a role very early in the disease process. The finding of megakaryocytes and platelet-rich thrombi in the lungs, heart and kidneys suggests a role in thrombosis. Funding: None

Chromosomes of Asian Cyprinid Fishes: Genomic Differences in Conserved Karyotypes of ‘Poropuntiinae’ (Teleostei, Cyprinidae)

The representatives of cyprinid lineage ‘Poropuntiinae’ with 16 recognized genera and around 100 species form a significant part of Southeast Asian ichthyofauna. Cytogenetics are valuable when studying fish evolution, especially the dynamics of repetitive DNAs, such as ribosomal DNAs (5S and 18S) and microsatellites, that can vary between species. Here, karyotypes of seven ‘poropuntiin’ species, namely Cosmochilus harmandi, Cyclocheilichthys apogon, Hypsibarbus malcomi, H. wetmorei, Mystacoleucus chilopterus, M. ectypus, and Puntioplties proctozysron occurring in Thailand were examined using conventional and molecular cytogenetic protocols. Variable numbers of uni- and bi-armed chromosomes indicated widespread chromosome rearrangements with a stable diploid chromosome number (2n) of 50. Examination with fluorescence in situ hybridization using major and minor ribosomal probes showed that Cosmochilus harmandi, Cyclocheilichthys apogon, and Puntioplites proctozystron all had one chromosomal pair with 5S rDNA sites. However, more than two sites were found in Hypsibarbus malcolmi, H. wetmorei, Mystacoleucus chilopterus, and M. ectypus. The number of chromosomes with 18S rDNA sites varied amongst their karyotypes from one to three; additionally, comparative genomic hybridization and microsatellite patterns varied among species. Our results reinforce the trend of chromosomal evolution in cyprinifom fishes, with major chromosomal rearrangements, while conserving their 2n