1, The aetiological fraction attributable to differences in work environment exposures was calculated to be 40 %.

2, Object To study the epidemiological and aetiological charactristic of infective endocarditis.

3, Objective : To analyze the aetiological characteristics and bacterial susceptibility in paatients with ventilator associated pneumonia.

4, Conclusion The aetiological diagnosis of tuberculous pericarditis and viral pericarditis is difficult.

5, Secondly, familial cases have sometimes shown a lower age at onset than sporadic cases, which is consistent with aetiological heterogeneity.

6, Psychopathological research during the last fifty years has proved beyond all possibility of doubt that the most important aetiological processes in neurosis are essentially unconscious.

7, The nocturnal emission or the spermatorrhea have difference the weight in the card period of five days, but aetiological agent basic consistent.

8, Now, recent investigations devote to gene, and think it one of the major aetiological factors.