The Dimorphos ejecta plume properties revealed by LICIACube.

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.

Using dust shed from asteroids as microsamples to link remote measurements with meteorite classes.

Given the compositional diversity of asteroids, and their distribution in space, it is impossible to consider returning samples from each one to establish their origin. However, the velocity and molecular composition of primary minerals, hydrated silicates, and organic materials can be determined by in situ dust detector instruments. Such instruments could sample the cloud of micrometer-scale particles shed by asteroids to provide direct links to known meteorite groups without returning the samples to terrestrial laboratories. We extend models of the measured lunar dust cloud from LADEE to show that the abundance of detectable impact-generated microsamples around asteroids is a function of the parent body radius, heliocentric distance, flyby distance, and speed. We use Monte Carlo modeling to show that several tens to hundreds of particles, if randomly ejected and detected during a flyby, would be a sufficient number to classify the parent body as an ordinary chondrite, basaltic achondrite, or other class of meteorite. Encountering and measuring microsamples shed from near-Earth and Main Belt asteroids, coupled with complementary imaging and multispectral measurements, could accomplish a thorough characterization of small, airless bodies.

Biophysical and biological characterisation of collagen/resilin-like protein composite fibres.

Collagen type I, in various physical forms, is widely used in tissue engineering and regenerative medicine. To control the mechanical properties and biodegradability of collagen-based devices, exogenous cross-links are introduced into the 3D supramolecular structure. However, potent cross-linking methods are associated with cytotoxicity, whilst mild cross-linking methods are associated with suboptimal mechanical resilience. Herein, we assessed the influence of resilin, a super-elastic and highly stretchable protein found within structures in arthropods where energy storage and long-range elasticity are needed, on the biophysical and biological properties of mildly cross-linked extruded collagen fibres. The addition of resilin-like protein in the 4-arm poly(ethylene glycol) ether tetrasuccinimidyl glutarate cross-linked collagen fibres resulted in a significant increase of stress and strain at break values and a significant decrease of modulus values. The addition of resilin-like protein did not compromise cell metabolic activity and DNA concentration. All groups are supported parallel to the longitudinal fibre axis cell orientation. Herein we provide evidence that the addition of resilin-like protein in mildly cross-linked collagen fibres improves their biomechanical properties, without jeopardising their biological properties.

The shape and surface variation of 2 Pallas from the Hubble Space Telescope.

We obtained Hubble Space Telescope images of 2 Pallas in September 2007 that reveal distinct color and albedo variations across the surface of this large asteroid. Pallas's shape is an ellipsoid with radii of 291 (+/-9), 278 (+/-9), and 250 (+/-9) kilometers, implying a density of 2400 (+/-250) kilograms per cubic meter-a value consistent with a body that formed from water-rich material. Our observations are consistent with the presence of an impact feature, 240 (+/-25) kilometers in diameter, within Pallas's ultraviolet-dark terrain. Our observations imply that Pallas is an intact protoplanet that has undergone impact excavation and probable internal alteration.

Compositional differences between meteorites and near-Earth asteroids.

Understanding the nature and origin of the asteroid population in Earth's vicinity (near-Earth asteroids, and its subset of potentially hazardous asteroids) is a matter of both scientific interest and practical importance. It is generally expected that the compositions of the asteroids that are most likely to hit Earth should reflect those of the most common meteorites. Here we report that most near-Earth asteroids (including the potentially hazardous subset) have spectral properties quantitatively similar to the class of meteorites known as LL chondrites. The prominent Flora family in the inner part of the asteroid belt shares the same spectral properties, suggesting that it is a dominant source of near-Earth asteroids. The observed similarity of near-Earth asteroids to LL chondrites is, however, surprising, as this meteorite class is relatively rare ( approximately 8 per cent of all meteorite falls). One possible explanation is the role of a size-dependent process, such as the Yarkovsky effect, in transporting material from the main belt.

Growth factors influence growth and differentiation of the middle ear mucosa.

OBJECTIVE: Otitis media is a major cause of morbidity in pediatric and adult patients. This inflammatory condition is characterized by mucosal hyperplasia that is thought to be mediated by the complex actions of growth factors and their respective receptors. It was the purpose of this study to determine which growth factors might be responsible for the growth and differentiation of the middle ear epithelium during otitis media. STUDY DESIGN: The effect of several growth factors on the expansion and differentiation of normal middle ear mucosa was evaluated in tissue culture. MATERIALS AND METHODS: Explants of normal rat middle ear mucosa were exposed in vitro to six different growth factors known to influence epithelial cells in other tissues: epidermal growth factor, amphiregulin, betacellulin, heregulin-alpha, keratinocyte growth factor, and hepatocyte growth factor. RESULTS: After 12 days, the growth and level of cytokeratin expression were analyzed for each of the explant outgrowths. Each factor appeared to have a significant, concentration-dependent effect on either the growth or differentiation of the cultured middle ear epithelial cells. CONCLUSION: The results suggest that several of the tested growth factors may play a significant role in controlling hyperplasia of the middle ear mucosa during otitis media.

[Functional furosemide loading test. Practical use in children with kidney diseases]. / Funktsional'naia nagruzochnaia proba s furosemidom. Prakticheskoe ispol'zovanie u detei s zabolevaniiami pochek.

Diuretic and aciduretic reactions were compared in healthy children and children with various renal diseases using furosemide loading test. Diuresis, urinary pH, urinary excretion of titered acids and ammonium, and ammonium coefficient were evaluated in healthy controls, patients with chronic and acute renal insufficiency, convalescents after acute renal insufficiency and acute postinfection glomerulonephritis, patients with chronic pyelonephritis, interstitial nephritis, lipoid nephrosis, hematuric chronic glomerulonephritis, and patients with a solitary kidney. Diuresis, urinary pH, ammonium excretion, and ammonium coefficient are proposed as the main test parameters. Patients with the distal tubular acidosis syndrome formed a special group by the results of urinary pH measurements during the third hour of furosemide action. The test helps evaluate the severity of disease and predict its course.

Recovery from blast lung injury: one-year follow-up.

BACKGROUND: Blast injury to the lung is one of the devastating threats facing victims of an explosion. Although the pathogenesis of blast injury has been studied, little is known about the long-term effects on lung function in survivors. OBJECTIVE: To examine the pulmonary function of survivors 1 year after sustaining a blast injury. DESIGN: Prospective study. SETTING: Pulmonary function test laboratory at Hadassah Medical Center, Jerusalem. PARTICIPANTS: Eleven surviving victims of a blast injury sustained during a bus terrorist explosion. MEASUREMENTS: Twelve months after the injury, physical examinations, lung function tests, and progressive cardiopulmonary exercise examinations were conducted, and chest radiographs were obtained. RESULTS: The average age was 28 +/- 9.8 years. Most of the victims had multiple injuries in addition to the lung injury. Ten patients received mechanical ventilation, and 6 patients required chest drainage. All patients were treated in the ICU, with an average stay of 11.8 +/- 9 days. The patients were discharged to their homes or to a rehabilitation center 32.4 +/- 27. 3 days after the explosion. One year later, none had any pulmonary-related complaints. Physical examination of the lungs was normal. Most of the patients demonstrated normal lung function tests and complete resolution of the chest radiograph findings. CONCLUSION: Most patients who survive lung blast injury will regain good lung function within a year.

Squamous cell metastasis from the tongue to the myocardium presenting as pericardial effusion.

Cardiac metastasis from head and neck cancer is rarely encountered. We present a base-of-tongue squamous cell carcinoma with metastasis to the heart that was diagnosed antemortem. Autopsy series indicate that tongue cancer may metastasize more frequently to the heart than from other head and neck sites. However, none of these studies was controlled. Most importantly, cardiac metastasis should be suspected in any patient with cancer in whom new cardiac symptoms develop. The diagnosis is best confirmed with two-dimensional echocardiography or cardiac MRI. A myocardial or endocardial biopsy specimen can be obtained with angiographic guidance. Despite the improvement in diagnostic capability, available treatments are only palliative. All patients eventually die of their metastatic disease.

The galanin antagonist, M-15, inhibits growth hormone release in rats.

The neuropeptide, galanin, has been implicated in the regulation of rat growth hormone (rGH) release. In the present study, adult male rats were implanted dually with cannulae to the lateral cerebral ventricle and the right atrium. After surgical recovery, rats were infused with M-15, a specific galanin antagonist, into the lateral ventricle. During the course of this brain infusion, rats were subjected to serial blood sampling with red cell and artificial plasma replacement under stress-free conditions. Plasma was saved for rGH assay. Treatment with M-15 reduced rGH pulse amplitude and pulse frequency when compared to vehicle-infused controls. These data suggest that brain galanin participates in the ongoing stimulation of pulsatile rGH release in the adult male rat.