In the early 1200s century， a nomadic empire meteorically rose in the nowadays eastern steppe based on its undefeated cav......

目的：评估生育力指数（FI）在判断男性生育能力中的作用。方法：对不育组（n=124）和生育组（n=62）进行精液常规检查,并计算FI[FI=精子密度（10^6/m......