The scores of Kidney-yin deficiency symptoms ( sore waist and knees , dry vagina , dysphoria with feverish sensation in the chest , palms and soles , etc. ) were assessed , the number of retrieved oocytes , rates of high quality oocytes and embryos , fertility rate and clinical pregnancy rate were recorded , and the follicular fluid was collected on the day when the ovum was picked up , the differential protein expression was detected using two-dimensional gel electrophoresis , and then , matrix assisted laser desorption ionization time-of flight mass spectrometry ( MALDI-TOF-MS ) was applied to identify the proteins .