标题: Economist, Apr 4, 2015 (I) [打印本页] 作者: choi 时间: 4-15-2015 18:53 标题: Economist, Apr 4, 2015 (I) (1) Powering space travel | NASA’s Dark Materials; America resumes production of plutonium-238 to keep space within reach. www.economist.com/news/science-a ... in-reach-nasas-dark
("One of the favourites used in space missions is a radioisotope thermoelectric generator (RTG). RTGs were developed by America in the 1950s and work by converting heat produced by the decay of a radioactive material into electricity directly. This is not the same as nuclear fission, a more complex process * * * America’s RTGs use plutonium-238 (238Pu). * * * America has used RTGs in 27 space missions since 1961. * * * NASA has been working on a system called the Advanced Stirling Radioisotope Generator, which offers four times the efficiency of a current RTG. This uses a process known as the Stirling cycle, which uses heat to drive a piston that in turn moves a magnet back and forth through a coil of wire to generate electricity")
My comment: I am not interested in RTGs, though maybe I should. What I am saying is Sterling cycle is used not only in diesel-engine submarines, but most likely in nuclear-powered one also. See Note (c)(v) in my posted titled "Japan Not Interested in Selling Subs to India" and dated Apr 12.作者: choi 时间: 4-15-2015 18:54
(2) Emergency medicine | Someone to Hold Your Hand; Having a companion can get a stroke victim faster treatment. www.economist.com/news/science-a ... t-someone-hold-your
the first two paragraphs:
"EVERYONE arriving at a hospital’s emergency room (ER) wishes to be seen quickly, but for stroke patients it can be a matter of life or death. he most common stroke involves a blood clot blocking vessels in the brain, killing brain cells nearby almost immediately. Luckily, an effective treatment exists. Thrombolytic therapy uses drugs to dissolve the clot and restore the flow of blood. If started within a couple of hours of a stroke occurring, it can limit brain damage and reduce long-term disability. Neurologists even have a catchphrase for this: “time is brain”.
"Understandably, hospitals strive to identify stroke cases and administer such medication without delay. A key step is using a computed tomography (CT) scanner to ensure that there has been no bleeding in the brain, in which case thrombolytic drugs would make things worse. The last couple of decades have seen many innovations in reducing this “time to CT”. Paramedics have been trained to recognise strokes and warn hospitals in advance, CT machines moved into emergency departments, and drugs pre-mixed to inject directly following a successful scan.
My comment:
(a) There is no need to read the rest, which shows, statistically without evidence to explain why, that if a stroke patient arrives at ER alone, his prognosis tends to be worse than if he is accompanied.
(b) "A key step is using a computed tomography (CT) scanner"
(i) NINDS Stroke Information Page. National Institute of Neurological Disorders and Stroke (NINDS), National Institute of Health (NIH), undated www.ninds.nih.gov/disorders/stroke/stroke.htm
("There are two forms of stroke: ischemic - blockage of a blood vessel supplying the brain, and hemorrhagic - bleeding into or around the brain")
Fundamentally "ischemic" (adjective, together with hemorrhagic) occur when a thrombus 血栓 plugs a vessel 血管, whereas "hemorrhagic" happens when a blood vessel (either weakened by a plaque or congenital deformed) bursts. In both situations, the portion of the brain downstream lacks oxygen, However, the treatment for each of the two situations is distinct, as explained by Economist.
(ii) I have wondered how to differentiate the two. Now I know it is by CT scan.
(iii) In CT scan, ischemic stroke shows "hyodensity" (looking "blackish" in CT scan) of the affected area; on the contrary hemorrhagic stroke presents a blood clot which is denser (hence white) than the surrounding, healthy brain tissue (gray).
hyodensity (n; [shortened from] hypo- + density): "(medicine) An area of an X-ray image that is less dense than normal, or than the surrounding areas")
en.wiktionary.org/wiki/hypodensity
作者: choi 时间: 4-15-2015 18:56
(3) An Ancient Mother. www.economist.com/news/science-a ... -cretaceous-insects
("Wang Bo 王博 [副研究员] of the Nanjing Institute of Geology and Palaeontology and his colleagues describe their find, which they have called Wathondara kotejai after a Buddhist earth goddess, in eLife.")
"国际著名刊物 eLife" is a boast. Any startup journal can hardly be "国际著名."
(b) 100-Million-Year-Old Scale Insect Practiced Brood Care. Phys.Org, Apr 1, 2015
phys.org/pdf347100361.pdf
("The international team of scientists gave the 100-million-year-old scale insect the name 'Wathondara kotejai' – after the Buddhist earth goddess Wathondara and the Polish entomologist. Jan Koteja [1932-2004; male]. * * * [The press release is] Provided by University of Bonn")
(i) There is no need to read the rest of this news report.
(ii) For Wathondara, see Phra Mae Thorani
en.wikipedia.org/wiki/Phra_Mae_Thorani
(section 1 Etymology; common in shrines and Buddhist temples of Burma, Cambodia, Thailand and Laos)