A role for CT in COVID-19? What data really tell us so farRadiologists have watched the coronavirus disease 2019 (COVID-19) pandemic unfold, wondering if and how imaging could be useful for diagnosis. Perhaps imaging could aid in screening or accelerate the speed of diagnosis, especially with shortages of RT-PCR.Some radiology literature suggests a pivotal role for CT. Ai and colleagues 1 report on 1014 patients who received both RT-PCR and CT in Wuhan, China, during their epidemic. They found that 97% of cases with RT-PCR-confirmed diagnoses had CT findings of pneumonia, and conclude, "CT imaging has high sensitivity for diagnosis of COVID-19". Other investigators are less optimistic. Inui and colleagues 2 reviewed CT scans of 112 cases of understanding and operation of global health.Conversations about how to do so, although just beginning, are long overdue.I declare no competing interests.

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Silicon-rich silicon oxide thin films have been prepared by thermal evaporation of silicon monoxide in vacuum. The SiOx film composition (1.1⩽ x ⩽1.7) has been controlled by varying the deposition rate and residual pressure in the chamber. Long time stability of all films has been ensured by a postdeposition annealing at 523 K for 30 min in Ar atmosphere. Some films were further annealed at 973 K and some others at 1303 K. Raman scattering measurements have implied the formation of amorphous silicon nanoparticles in films annealed at 973 K and Si nanocrystals in films annealed at 1303 K. The latter conclusion is strongly supported by high resolution electron microscopy studies which show a high density of Si nanocrystals in these films. Photoluminescence has been observed from both amorphous and crystalline nanoparticles and interpreted in terms of band-to-band recombination in the nanoparticles having average size greater than 2.5 nm and carrier recombination through defect states in smaller nanoparticles.

SummaryRecently, rapid development in the mobile computing arena has allowed extended reality technologies to achieve performance levels that remove longstanding barriers to medical adoption. Importantly, head-mounted displays have become untethered and are light enough to be worn for extended periods of time, see-through displays allow the user to remain in his or her environment while interacting with digital content, and processing power has allowed displays to keep up with human perception to prevent motion sickness. Across cardiology, many groups are taking advantage of these advances for education, pre-procedural planning, intraprocedural visualization, and patient rehabilitation. Here, we detail these applications and the advances that have made them possible.

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BACKGROUND: E-cigarette and vaping-induced lung injury (EVALI Q8) causes a spectrum of CT lung injury patterns. Relative frequencies and associations with vaping behavior are unknown.RESEARCH QUESTION: What are the frequencies of imaging findings and CT patterns in EVALI and what is the relationship to vaping behavior? STUDY DESIGN AND METHODS: CT scans of 160 subjects with EVALI from 15 institutions were retrospectively reviewed. CT findings and patterns were defined and agreed on via consensus. The parenchymal organizing pneumonia (OP) pattern was defined as regional or diffuse ground-glass opacity (GGO) AE consolidation without centrilobular nodules (CNs). An airway-centered OP pattern was defined as diffuse CNs with little or no GGO, whereas a mixed OP pattern was a combination of the two. Other patterns included diffuse alveolar damage (DAD), acute eosinophilic-like pneumonia, and pulmonary hemorrhage. Cases were classified as atypical if they did not fit into a pattern. Imaging findings, pattern frequencies, and injury severity were correlated with substance vaped (marijuana derives [tetrahydrocannabinol] [THC] only, nicotine derivates only, and both), vaping frequency, regional geography, and state recreational THC legality. One-way analysis of variance, c 2 test, and multivariable analyses were used for statistical analysis.RESULTS: A total of 160 patients (79.4% men) with a mean age of 28.2 years (range, 15-68 years) with EVALI underwent CT scan. Seventy-seven (48.1%), 15 (9.4%), and 68 (42.5%) patients admitted to vaping THC, nicotine, or both, respectively. Common findings included diffuse or lower lobe GGO with subpleural (78.1%), lobular (59.4%), or peribronchovascular (PBV) sparing (40%). Septal thickening (50.6%), lymphadenopathy (63.1%), and CNs (36.3%) were common. PBV sparing was associated with younger age (P ¼ .02). Of 160 subjects, 156 (97.5%) had one of six defined patterns. Parenchymal, airway-centered, and mixed OP patterns were seen in 89 (55.6%), 14 (8.8%), and 32 (20%) patients, respectively. Acute eosinophilic-like pneumonia (six of 160, 3.8%), DAD (nine of 160, 5.6%), pulmonary hemorrhage (six of 160, 3.8%), and atypical (four of 160, 2.5%) patterns were less common.

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The Raman spectra of tetragonal TbPO4 (zircon-type I41/amd structure, D4h19 space group) have been measured at ambient conditions and under variable pressure up to 15.5 GPa inside a diamond anvil cell (DAC). Assignment of the Raman active modes of the tetragonal phase has been carried out based on polarized measurements from a single oriented crystal of TbPO4 at ambient conditions. The abrupt Raman mode discontinuities and the appearance of numerous new Raman peaks at a pressure Pc≈9.5 GPa have provided strong evidence for a first-order phase transition to a lower crystal symmetry, most likely monoclinic. The high-pressure structure appears to be more compact compared to the tetragonal one, and is retained upon bringing the crystal to ambient pressure.