问题 问答题 简答题

生物材料生物相容性分类有哪些?

答案

参考答案:

生物相容性按材料引起的生物学反应不同一般分为三类。

一、血液相容性:若材料用于心血管系统和血液直接接触,主要考虑与血液的相互作用,称为血液相容性,它表示材料与血液之间相互适应的程度,指材料和血液接触后不引起血浆蛋白的变性,不破坏血液的有效成分,不导致血液的凝固和血栓的形成。

二、组织相容性:若与心血管系统外的其他活体组织和器官接触,主要考察与组织的相互作用,称为组织相容性,它表示材料与除血液之外的其他组织的相互适应程度,即不引起细胞突变,畸变,癌变以及排斥反应。

三、免疫相容性:当生物材料植入人体后,材料周围的生物环境必定发生变化,人体自身的生理机能就会对变化着的环境进行防御和适应,若植入的材料在一定时期后适应了生物体的微环境,生物体对植入的材料无明显的免疫应答,则认为植入的材料具有较好的免疫相容性。

阅读理解

     I find some of the ways in which Chinese parents show love for their children rather surprising.

Obviously there are some pretty big differences between our behaviors and theirs in this respect. Most

Chinese children seem to get whatever they want, from ice creams, sweets and toys to endless attention

from the adults around them. Is this a sort of spoiling or love? I wonder.

     Most westerners would think it is a sort of spoiling rather than love. We think love means educating

your children and bringing them up to lead an independent life. That includes learning to accept the fact

that he can't get everything he wants. As an adult, he will not always get the quite expensive car he hunts

for; she will not always manage to acquire the beautiful dress she longs for. So we try to teach our

children early to cope with the disappointment of not getting what they want.

     I find too much such kind of love for the children can actually spoil them. To my surprise, it seems that

the life of a Chinese child is rather hard. Without doubt, the child is the very center of a whole circle of

adults, but on the other hand he or she is also expected to start studying according to adults' wishes.

Many children of my son's age take piano lessons, painting classes and even English lessons. It looks as

if Chinese adults think that just playing without learning anything is a waste of time. So in this respect our

children appear spoiled, just because they are allowed to play. But without this sort of play how can

western children develop such free and rich imaginations? In fact the connection between this imagination

and the creativity is so important in the children's future life.

1. In which way do most Chinese children seem to be spoiled?

A. They can be supported by their parents

B. They can play whenever they want

C. They need not behave themselves

D. Their demand can always be satisfied

2. In the author's opinion, the life of a Chinese child is         .

A. rather hard                    

B. rather easy        

C. independent                    

D. colorful

3. The author thinks western children appear spoiled because         .

A. they can manage time by themselves  

B. they can have the freedom to play

C. they can take piano lessons          

D. they may have expensive toys

4. The best title of the passage could be         .

A. Chinese children's early education  

B. How to develop kids' imagination

C. What is the real love for children    

D. The imagination and creativity

填空题