A sheath (30) closes the opening (18) and embraces an inner portion of the plunger (25), whereby pumping chamber (33) is defined between the pump body (11) and the sheath (30).

一外壳(30)封闭开口(18)并包围柱塞(25)的内部，由此在泵本体(11)和外壳(30)间限定一增压室(33)。

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When these cells die, they tend to die from the inside of the heart's pumping chamber and move outward.

BBC: Dr Robert Judd

When the researchers infused the drug into mice with DMD they found it restored the volume of the hearts major pumping chamber to that of normal mice.

BBC: NEWS | Health | Heart drug for muscular dystrophy

We variously talked about fitting bicycle valves to the caps and pumping them up, building a hyperbaric chamber to fill the bottles under pressure and finally liquid nitrogen.

CNN: From a voyage of discovery to a real ocean odyssey