wherein the first cylindrical portion has an outer peripheral surface from which a flange protrudes radially outward, the flange being in contact with the protruding end of the cylindrical portion to define {HEAD ~ a gap} between {TAIL ~ the lid portion} and the semipermeable membrane in the sliding direction 
between
wherein the first cylindrical portion has an outer peripheral surface from which a flange protrudes radially outward , the flange being in contact with the protruding end of the cylindrical portion to define { HEAD ~ a gap } between { TAIL ~ the lid portion } and the semipermeable membrane in the sliding direction
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH