ABSTRACT
The Double Asteroid Redirection Test (DART) had an impact with Dimorphos (a satellite of the asteroid Didymos) on 26 September 20221. Ground-based observations showed that the Didymos system brightened by a factor of 8.3 after the impact because of ejecta, returning to the pre-impact brightness 23.7 days afterwards2. Hubble Space Telescope observations made from 15 minutes after impact to 18.5 days after, with a spatial resolution of 2.1 kilometres per pixel, showed a complex evolution of the ejecta3, consistent with other asteroid impact events. The momentum enhancement factor, determined using the measured binary period change4, ranges between 2.2 and 4.9, depending on the assumptions about the mass and density of Dimorphos5. Here we report observations from the LUKE and LEIA instruments on the LICIACube cube satellite, which was deployed 15 days in advance of the impact of DART. Data were taken from 71 seconds before the impact until 320 seconds afterwards. The ejecta plume was a cone with an aperture angle of 140 ± 4 degrees. The inner region of the plume was blue, becoming redder with increasing distance from Dimorphos. The ejecta plume exhibited a complex and inhomogeneous structure, characterized by filaments, dust grains and single or clustered boulders. The ejecta velocities ranged from a few tens of metres per second to about 500 metres per second.
ABSTRACT
PURPOSE: If could be a potential pathophysiological connection between colonic diverticula and colonic superficial neoplastic lesions, beyond the shared risk factors, has been a subject of debate in the last years. This study tries to evaluate the association between diverticulosis and colonic neoplastic lesions. METHODS: This is a cross-sectional study including asymptomatic patients who underwent a screening colonoscopy (patients with a positive fecal occult blood test under the regional program of colorectal cancer (CRC) screening), surveillance after polypectomy resection, or familiarity (first-degree relatives) between 2020 and 2021 to evaluate the association between diverticula and colonic polyps. A multivariate analysis with multiple logistic regression and odds ratio (OR) to study the independent association between adenomas and adenocarcinomas was performed. RESULTS: One thousand five hundred one patients were included. A statistically significant association between adenomas or CRC alone and colonic diverticula was found (p = 0.045). On a multivariate analysis of demographic (age, gender) and clinical parameters (familiarity for diverticula and adenoma/CRC), only age was significantly associated with the development of colorectal adenomas or cancer (OR 1.05, 95% CI 1.03-1.07, p < 0.0001). CONCLUSIONS: This study showed a statistically significant association between diverticula and colonic adenomas. However, it is impossible to establish a cause-effect relationship due to the intrinsic characteristics of this study design. A study with a prospective design including both patients with diverticulosis and without colonic diverticula aimed at establishing the incidence of adenoma and CRC could help to answer this relevant clinical question, since a potential association could indicate the need for closer endoscopic surveillance.
