If shoot 30 of hematic mark to be contractive function to be spent again , damage ; of 30 ~ 40 is in degree damage of 40 ~ 50 to be spent gently 如射血分数30为收缩功能重度损害； 30 ~ 40为中度损害40 ~ 50为轻度损害。
However , there is little know about the effect of iron on relaxation and contraction function of blood vessels , and the underlying mechanism was also unclear 然而，目前对于铁的增加引起内皮依赖性血管舒张功能改变的直接效应以及可能的机制并不清楚。此外，铁对血管收缩功能的影响目前仍不明确。
What is the most cost - effective strategy to screen for left ventricular systolic dysfunction : natriuretic peptides , the electrocardiogram , hand - held echocardiography , traditional echocardiography , or their combination 筛选左心室收缩功能障碍最佳费用效益比的策略：钠尿肽、心电图、手持式超声心动图、传统超声心动图或联合应用这些方法？
Potential biological mechanisms underlying the cardiovascular effects include an alteration of cardiac p - receptor responsiveness , an increase in inducible nitric oxide synthase activity in cardiac muscle , associated with release of nitric oxide , no and induction of apoptosis in myocytes 已有研究证实il - 2的心脏作用，但对il - 2心脏作用机制的研究尚不深入。在不同的实验模型上il - 2对心脏收缩功能的影响报道不一。
In order to test the above working hypothesis , the contractile functions in unloaded soleus were observed by using in vitro skeletal muscle strip perfusion , the expression of mhc proteins and mrna was detected by sds - page and rt - pcr , respectively 为验证这一设想，本研究采用大、小鼠尾部悬吊模型模拟失重状态，用离体骨骼肌肌条灌流方法观测收缩功能的变化，并采用sds - page与rt一pcr技术，观测比目鱼肌mhc异构体的表达。
