Washington, D.C.—A team of scientists led by Carnegie’s Jacqueline Faherty has discovered the first evidence of water ice clouds on an object outside of our own Solar System. Water ice clouds exist on our own gas giant planets–Jupiter, Saturn, Uranus, and Neptune–but have not been seen outside of the planets orbiting our Sun until now. […]Read more...
Washington, D.C.—A team of scientists led by Carnegie’s Jacqueline Faherty has discovered the first evidence of water ice clouds on an object outside of our own Solar System. Water ice clouds exist on our own gas giant planets–Jupiter, Saturn, Uranus, and Neptune–but have not been seen outside of the planets orbiting our Sun until now. Their findings are published by The Astrophysical Journal Letters. At the Las Campanas Observatory in Chile, Faherty, along with a team including Carnegie’s Andrew Monson, used the FourStar near infrared camera to detect the coldest brown dwarf ever characterized. Their findings are the result of 151 images taken over three nights and combined. The object, named WISE J085510.83-071442.5, or W0855, was first seen by NASA’s Wide-Field Infrared Explorer mission and published earlier this year. But it was not known if it could be detected by Earth-based facilities.
“This was a battle at the telescope to get the detection,” said Faherty.
Chris Tinney, an Astronomer at the Australian Centre for Astrobiology, UNSW Australia and co-author on the result stated: “This is a great result. This object is so faint and it’s exciting to be the first people to detect it with a telescope on the ground.”
Brown dwarfs aren’t quite very small stars, but they aren’t quite giant planets either. They are too small to sustain the hydrogen fusion process that fuels stars. Their temperatures can range from nearly as hot as a star to as cool as a planet, and their masses also range between star-like and giant planet-like. They are of particular interest to scientists because they offer clues to star-formation processes. They also overlap with the temperatures of planets, but are much easier to study since they are commonly found in isolation.W0855 is the fourth-closest system to our own Sun, practically a next-door neighbor in astronomical distances. A comparison of the team’s near-infrared images of W0855 with models for predicting the atmospheric content of brown dwarfs showed evidence of frozen clouds of sulfide and water. “Ice clouds are predicted to be very important in the atmospheres of planets beyond our Solar System, but they’ve never been observed outside of it before now,” Faherty said. The paper’s other co-author is Andrew Skemer of the University of Arizona.
Boston Children’s Hospital physicians report the first cases of children benefiting from 3D printing of their anatomy before undergoing high-risk brain procedures. The four children had life-threatening cerebrovascular malformations (abnormalities in the brain’s blood vessels) that posed special treatment challenges. Reporting online today in the Journal of Neurosurgery: Pediatrics, the physicians describe the use of […]Read more...
Boston Children’s Hospital physicians report the first cases of children benefiting from 3D printing of their anatomy before undergoing high-risk brain procedures. The four children had life-threatening cerebrovascular malformations (abnormalities in the brain’s blood vessels) that posed special treatment challenges.
Reporting online today in the Journal of Neurosurgery: Pediatrics, the physicians describe the use of 3D printing and synthetic resins to create custom, high-fidelity models of the children’s vessel malformations along with nearby normal blood vessels. In some cases, the surrounding brain anatomy was also printed.
“These children had unique anatomy with deep vessels that were very tricky to operate on,” says Boston Children’s neurosurgeon Edward Smith, MD, senior author of the paper and co-director of the hospital’s Cerebrovascular Surgery and Interventions Center. “The 3D-printed models allowed us to rehearse the cases beforehand and reduce operative risk as much as we could.”
The children ranged in age from 2 months to 16 years old. Three of the four children had arteriovenous malformations (AVMs), in which tangles of arteries and veins connect abnormally, and were treated surgically.
“AVMs are high-risk cases and it’s helpful to know the anatomy so we can cut the vessels in the right sequence, as quickly and efficiently as possible,” says Smith. “You can physically hold the 3D models, view them from different angles, practice the operation with real instruments and get tactile feedback.”
The 2-month-old infant had a rare vein of Galen malformation in which arteries connect directly with veins—bypassing the capillaries—and was treated with an interventional radiology technique to seal off the malformed blood vessels from the inside.
“Even for a radiologist who is comfortable working with and extrapolating from images on the computer to the patient, turning over a 3D model in your hand is transformative,” says Darren Orbach, MD, PhD, chief of Interventional and Neurointerventional Radiology at Boston Children’s and co-director of the Cerebrovascular Surgery and Interventions Center. “Our brains work in three dimensions, and treatment planning with a printed model takes on an intuitive feel that it cannot otherwise have.”
The life-sized and enlarged 3D models were created in collaboration with the Boston Children’s Hospital Simulator Program (SIMPeds) using brain magnetic resonance (MR) and MR arteriography data from each child. Measurements of the models showed 98 percent agreement with the children’s actual anatomy.
All four children’s malformations were successfully removed or eliminated with no complications. When two of the AVM patients were compared with controls who did not have 3D-printed models—matched for age, size and type of AVM, surgeon and operating room—those with 3D models had their surgical time reduced by 12 percent (30 minutes). (Actual surgical time was 254 and 257 minutes for the cases with 3D models and 285 and 288 minutes for the controls.) Even a 30-minute reduction is significant for children who are especially sensitive to anesthesia.
Smith and Orbach are continuing to use 3D models for their trickier cases. “3D printing has become a regular part of our process,” says Smith. “It’s also a tool that allows us to educate our junior colleagues and trainees in a way that’s safe, without putting a child at risk.”
SIMPeds director Peter Weinstock, MD, PhD, was first author on the paper; co-authors were Orbach, Sanjay Prabhu, MBBS, FRCR, and Katie Flynn, BS, ME, all of Boston Children’s Hospital. The study was supported by the Lucas Warner AVM Research Fund and The Kids At Heart Neurosurgery Research Fund.