问题 多项选择题 案例分析题

病历摘要:患者男性,46岁,原有心脏病史,药物治疗不祥。因呼吸困难1周入院。体检:心脏向左下扩大,心率110次/分,律不齐,心音强弱不等,心尖部可闻及舒张期隆隆样3/6级杂音,胸骨左缘第3、4肋间舒张期哈气性递减型杂音。

此类心电图改变是()提示:患者经用地高辛和呋噻米治疗后,心电图示ST段压低,呈典型鱼钩样改变。

A.洋地黄作用

B.心肌复极异常

C.洋地黄中毒

D.低钾

E.心肌缺血

F.高钾

答案

参考答案:A, B

单项选择题

Despite increased airport security since September 11th, 2001, the technology to scan both passengers and baggage for weapons and bombs remains largely unchanged. Travellers walk through metal detectors and carry-on bags pass through x-ray machines that superimpose colour-coded highlights, but do little else. Checked-in luggage is screened by "computed tomography", which peers inside a suitcase rather like a CAT scan of a brain. These systems can alert an operator to something suspicious, but they cannot tell what it is.

More sophisticated screening technologies are emerging, albeit slowly. There are three main approaches: enhanced x-rays to spot hidden objects, sensor technology to sniff dangerous chemicals, and radio frequencies that can identify liquids and solids.

A number of manufacturers are using "reflective" or "backscatter" x-rays that can be calibrated to see objects through clothing. They can spot things that a metal detector may not, such as a ceramic knife or plastic explosives. But some people think they can reveal too much. In America, civil-liberties groups have stalled the introduction of such equipment, arguing that it is too intrusive. To protect travellers ’modesty, filters have been created to blur genital areas.

Machines that can detect minute traces of explosive are also being tested. Passengers walk through a machine that blows a burst of air, intended to dislodge molecules of substances on a person’s body and clothes. The air is sucked into a filter, which instantaneously analyses it to see whether it includes any suspect substances. The process can work for baggage as well. It is a vast improvement on today’s method, whereby carry-on items are occasionally swabbed and screened for traces of explosives. Because this is a manual operation, only a small share of bags are examined this way.

The most radical of the new approaches uses "quadrupole resonance technology". This involves bombarding an object with radio waves. By reading the returning signals, the machines can identify the molecular structure of the materials it contains. Since every compound—solid, liquid or gas—creates a unique frequency, it can be read like a fingerprint. The system can be used to look for drugs as well as explosives.

For these technologies to make the jump from development labs and small trials to full deployment at airports they must be available at a price that airports are prepared to pay. They must also be easy to use, take up little space and provide quick results, says Chris Yates, a security expert with Jane’s Airport Review. Norman Shanks, an airport security expert, says adding the new technologies costs around $100,000 per machine; he expects the systems to be rolled out commercially over the next 12 months. They might close off one route to destroying an airliner, but a cruel certainty is that terrorists will try to find others.

The delay of employment of x-ray equipment lies in its()

A. unreliable screening

B. full exposure

C. inadequate efficiency

D. travellers’modesty

填空题

[A] The take-up of EVs—which run entirely on electricity stored in rechargeable batteries—is seen as central to the plan to cut the transport sector’s carbon emissions, both here and across the European Union. It is predicted that we will be running a total of 800,000 EVs in Britain by 2020, and as a result the race to install a recharging infrastructure is well under way. Transport for London (TfL) recently announced it will have 1,300 EV charging points in London by 2013—more than the current number of petrol stations in the capital. The London mayor, Boris Johnson, is on the record as saying he wants to make the city the electric car capital of Europe.

[B] However, the power companies, sensing a good business opportunity, are now vying to sign up electric car-owning households with the offer of cheaper and faster off-peak home charging that will cut the time it takes to recharge the vehicle—freeing it to make more journeys, and making them more attractive to buyers. So far, EDF, British Gas, and most recently npower have said they will be targeting EV users with special home services as well as cheaper tariffs for recharging vehicles.

[C] What would make you consider buying an electric car They offer a green way to get around, with the chance to bypass petrol stations. And they are exempt from road tax and London’s congestion charge. Energy company npower (英国电力公司) this week revealed that 33% of UK drivers would think about buying an electric vehicle (EV) in the next five years, rising to 41% when the benefits were explained.

[D] But despite the introduction in January of a generous £ 5,000 government purchase grant to encourage more people to take the plunge, it’s fair to say that sales of electrically powered cars in the UK are yet to really take off. Just over 500 people took the government up on its offer in the first quarter of this year. Their high prices—typically about £ 25,000 after the grant—plus a lack of models by major carmakers and a shortage of charging points, have held back sales. However, the last two points are about to change.

[E] Speaking in Berlin last week, npower’s head of e-mobility, Phil Evans, told Guardian Money that the company sees EVs as a major opportunity, and as a result it is working on building an "upgradable" charging infrastructure that will develop as the cars’ power systems become more sophisticated.

[F] Potential buyers now have a choice of seven models in the UK, with 13 more on the way, while EDF Energy (英国电网), British Gas and npower have recently announced plans to start offering to install faster and cheaper charging points in customers’ homes, in a move they hope will help kick-start sales. The companies are banking on the fact that buyers of the latest, more consumer-friendly electric cars, such as the Nissan Leaf, are going to boost demand for electricity.

[G] Plans are also under way to increase the number of charging points at a variety of locations across the UK—and soon it will be possible for homeowners to upgrade their garages to allow faster, safer home charging. Until recently, most owners of plug-in-to-recharge electric cars have had to rely on the traditional three-point household plug, and wait about eight hours to fully recharge their vehicle at home.

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