It's semipermeable, meaning that it lets some thing pass in and out but blocks others.

它是半渗透性的，意味着它某些东西进出，但会阻止某些东西进入。

And separating the two chambers is the semipermeable membrane.

分隔两个腔室的是半透膜。

CSF analysis can also show an elevated protein concentration because the inflammation leads to a more permeable blood brain barrier, or BBB, which is a selective semipermeable barrier between the circulating blood and the central nervous system.

脑脊液检有蛋白含量升高，由于炎症导致介于循环血流和中枢神经系统之间的半透膜屏障，即血脑屏障，通透性升高。