Robert Beckett, who broke his leg and had to have it
set at the local hospital, was given something to put him to sleep while this
rather painful process was going on. All he remembered afterward was that a
white-coated man made a prick in his arm—the body hardly felt it—and then sat
down beside him and asked him to count slowly to ten.{{U}} (46) {{/U}}
{{U}} (47) {{/U}} While Robert was couting, the
anaesthetist was pressing the plunger of the syringe and injecting into his arm
a small amount of liquid that looked like water. The liquid was not water, but a
solution containing a drug that was powerful enough to put Robert to sleep and
keep him there while his leg was being set. The same drug
would not have been powerful enough to keep Robert unconscious had he required
serious surgery. For operations where the patient must remain unconscious for an
hour or more, the anaesthetist must administer the right amount of anesthetic
continuously. {{U}}(48) {{/U}} It is usually not an injection, but a
kind of gas that the patient breathes in through a mask placed over his face.
{{U}} (49) {{/U}} Like most other early medicines,
they were extracted from plants. Four plants producing such drugs were
particularly well know—the poppy, henbane, hemp and mandrake.
Poppies are still used as a source of morphine, a very widely used drug.
{{U}}(50) {{/U}} Today hemp is most often used as raw material from
which rope is made, but it is still known in parts of Central South America as
"the weed that intoxicates". The other herb, mandrake, is almost unknown today,
but it was widely used among the ancient Egyptians, the Greeks, and peoples of
the Far East. According to one legend, the mandrake plant, when pulled from the
ground, was supposed to give an unearthly shriek, so dreadful that a person who
heard it died or went mad.
A. The type of anesthetic he uses depends on the patient and the type of
surgery to be performed.
B. Robert got as far as seven, then woke up in bed with his leg in plaster.
C. The prick that he felt was caused by the hollow needle of a hypodermic
syringe.
D. That was the state of affairs until the beginning of the last century.
E. Henbane is not so well known, though it is still used in some medicines.
F. Drugs that cause unconsciousness and kill pain are not
new.
Three basic pathophysiologic mechanisms lead to
virtually all the clinical disease states involving endocrine glands:
{{U}}(46) {{/U}} the excessive hormone production and action and
neoplasa. Deficiency of hormone action is most commonly
caused by an abnormally low level of biologically active hormone reaching target
tissues. {{U}}(47) {{/U}} Endocrine gland hypofunciton may be
congenital, caused by a complete failure of gland development, a mutant
gene-encoding the structure of hormone or an enzyme responsible for hormone
biosythesis. {{U}} (48) {{/U}} replacement by tumor,
surgical extirpation, effects of pharmacologic or environmental agents, or
inflammation. Other causes of decreased hormone action in
target tissues are encountered less frequently. Deranged physiologic control of
pituitary gland function causes secondary glandular failure, which can be either
congenital or acquired {{U}}(49) {{/U}} Defective postsecretory hormone
activation or accelerated hormone metabolism may result in abnormally low
hormone activity. Hormonal deficiency states, despite normal
or even elevated concentrations of biologically active hormone in the
circulation, may be due to target-tissue resistance. {{U}}
(50) {{/U}} This failure of target tissue responsiveness may be due to
an abnormality of hormone receptors or in post-binding signaling of the
hormone-receptor interaction.
A. Deficiency of hormone action on target tissues.
B. Improvement of hormone release may result in glandular hypofunction.
C. Functional endocrine tumors secrete a hormonal product.
D. Inadequate hormone production may occur as a result of primary gland
failure.
E. Resistance can be congenital or acquired F. Endocrine gland
failure may also be acquired as a consequence of physiologic
atrophy.
Motoring Technology
1.2 million road deaths worldwide occur each year, plus a further 50 million injuries. To reduce car crash rate, much research now is focused on safety and new fuels—though some electric vehicle and biofuel research aims at going faster.
Travelling at speed has always been risky. One cutting edge area of research in motoring safety is the use of digital in-car assistants. They can ensure you don"t miss crucial road signs or fall asleep. The use of artificial intelligence software allows these assistants to monitor your driving and makes sure your phone or radio doesn"t distract you at a vital moment. Most crashes result from human and not mechanical faults.
Some safety developments aim to improve your vision. Radar can spot obstacles in fog, while other technology "sees through" high-sided vehicles blocking your view.
And improvements to seat belts, pedal controls and tyres are making driving smoother and safer. The colour of a car has been found to be linked with safety, as have, less surprisingly, size and shape.
And alternatives to fossil-fuel based petrol, such as plant oils, are a hot area of research. Fuel cells based on hydrogen burn cleanly, and are the subject of a serious research effort.
But whatever is in the fuel tank, you don"t want a thief in the driving seat and there have been many innovations, some using satellite tracking and remote communications, to fight against car theft. These communication systems can also come into play if you crash, automatically calling for help.
Accidents cause many traffic jams, but there are more subtle interplays between vehicles that can cause jams even on a clear but busy road. Such jams can be analysed using statistical tools. Robotic drivers could be programmed to make traffic flow smoothly and will perhaps one day be everyone"s personal chauffeur, but their latest efforts suggest that won"t be soon.
语法与词汇John has always remained (loyal) to his family and friends.
语法与词汇Einstein''s theory of relativity seemed (incredible) when it was first introduced.
语法与词汇It is taken for granted that a piano without any (defects) would produce very grand music.
语法与词汇During the United States Civil war, many people in the south were forced to (flee) their home.
语法与词汇Experiments enable young scientists to judge accurately what must be accepted and what must be viewed with (suspicion).
语法与词汇The development of the transistor and integrated circuits revolutionized the electronics industry by allowing components to be packaged more (densely).
语法与词汇Everybody {{U}}was glad to{{/U}}see Mary back
语法与词汇He has (thought out) the best way of saving oil for your car.
语法与词汇The price is (somewhat) higher than I expected.
语法与词汇John is {{U}}crazy {{/U}} about pop music
语法与词汇I (spotted) my father in the crowd.
语法与词汇The farmers worried about the (lack) of rain.
语法与词汇He (maintained) that the opinion was wrong.
语法与词汇Putting in a new window will (bring about) cutting away part of the roof.
语法与词汇There was a (number) of children on the playground.
语法与词汇I wonder who first (conceived) the idea of cutting a hole in the door.
语法与词汇At the sports meet, athletes (compete) with each other for the gold medals.