在下列哪种条件下,大多数病毒可保持比较稳定的状态()A.pH5.0以下 B.pH9.

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问题:

在下列哪种条件下,大多数病毒可保持比较稳定的状态()

A.pH5.0以下

B.pH9.0以上

C.pH5~9

D.37℃

E.56℃

考点:临床医学检验五、临床病毒学五、临床病毒学题库
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目前已经宣布不用的主动免疫制剂为

A.麻疹减毒活疫苗

B.痘苗

C.脊髓灰质炎活疫苗糖丸

D.结核菌苗

E.百日咳菌苗

题型:单项选择题

可提高婴儿出生后局部免疫屏障的是()

A.IgA

B.IgG

C.IgM

D.IgD

E.IgE

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晚唐有一种叫做词的文学体裁兴起,著名的词人有()()等。

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In meditation (冥想), people sit quietly and focus their attention on their breath. As they breathe in and out, they attend to their feelings. As thoughts go through their minds, they let them go. Breathe. Let go. Breathe. Let go.
According to a recent study at the Insight Meditation Society in Barre, Massachusetts, three months of training in this kind of meditation causes a marked change in how the brain allocates (分配) attention. It appears that the ability to let go thoughts that come into mind frees the brain to attend to more rapidly changing things and events in the outside world. Expert mediators are better than other people at catching such fast-changing stimuli(刺激), like facial-expressions.
The study provides evidence for changes in the workings of the brain with mental training. People can learn and improve abilities of all sorts with practice, everything from driving to playing the piano. The study has shown that meditation is good for the brain. It appears to reduce pressure and promote a sense of well-being.
In an experiment, 17 volunteers with no meditation experience in the experimental group spent three months meditating 10 to 12 hours a day. A control group also with no meditation experience meditated for 20 minutes a day over the same period. Both groups were then given the tests with two numbers in a group of letters. As both groups looked for the numbers, their brain activity was recorded.
Everyone could catch the first number. But the brain recordings showed that the less experienced mediators tended to grasp the first number and hang onto it, so they missed the second number. Those with more experience gave less attention to the first number, as if letting it go, which led to an increased ability to grasp the second number. This shows that attention can change with practice.
Just ask Daniel Levision, who meditated for three months as part of the study. "I am a much better listener," he said, "I do not get lost in my own personal reaction to what people are saying. \

Meditators manage their daily tasks better because they ______.

A.are given less pressure

B.allocate their attention better

C.have more stimuli for life

D.practice them more frequently

题型:单项选择题

患下列哪种疾病时,骨髓巨核细胞明显减少

A.慢性失血性贫血

B.巨幼细胞性贫血

C.原发性血小板减少性紫癜

D.缺铁性贫血

E.再生障碍性贫血

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