下列关于酶结构与功能的叙述,正确的是
学生出现教师期待的行为后,教师发给学生小红星,学生可用小红星兑换奖励物或参加喜欢的活动。教师采用的方法是( )
行为塑造法
代币奖励法
自我控制法
系统脱敏法
患者,男,70岁。因慢性阻塞性肺气肿入院治疗。今晨护理查房时发现患者躁动不安,有幻觉,对自己所处的位置、目前的时间无法做出正确判断。医嘱给予吸氧,最适合患者的吸氧流量为( )
8L/min
4 L/min
2L/min
10L/min
6L/min
Passage1
Lonely people, it seems, are at greater riskthan the gregarious of developing illnesses associated with chronicinflammation, such as heart disease and certain cancers. A paper published lastyear in the Public Library of Science, Medicine, shows the effect on mortalityof loneliness is comparable with thatof smoking and drinking after examining the results of 148 previous studies andcontrolled for factors such as age and pre-existing illness.
Steven Cole of the University ofCalifornia, Los Angeles, thinks he may know why this is so. He told theAmerican Association for the Advancement of Science meeting in Washington,D.C., about his work studying the expression of genes in lonely people. Dr.Cole harvested samples of white blood cells from both lonely and gregariouspeople. He then analysed the activity of their genes, as measured by theproduction of a substance called messenger RNA. This molecule carries instructions from the genes telling a cellwhich proteins to make. The level of messenger RNA from most genes was the samein both types of people. There were several dozen genes, however, that wereless active m the lonely, and several dozen others that were more active.Moreover, both the less active andthe more active gene types came from a small number of functional groups.
Broadly speaking, the genes less active in thelonely were those involved in staving off viral infections. Those that weremore active were involved in protecting against bacteria. Dr. Cole suspectsthis could help explain not only why the lonely are iller, but how, inevolutionary terms, this odd state of affairs has come about.
The crucial bit ofthe puzzle is that viruses have to be caught from another infected individual andthey are usually species-specific. Bacteria, in contrast, often just lurk inthe environment, and may thrive on manyhosts. The gregarious are therefore at greater risk than the lonely ofcatching viruses, and Dr. Cole thussuggests that past evolution has created a mechanism which causes white cellsto respond appropriately. Conversely, the lonely are better off ramping uptheir protection against bacterialinfection, which is a bigger relative risk to them.
What Dr. Cole seemsto have revealed, then, is a mechanism by which social environment reachesinside a person's body and tweaks its genome so that it responds appropriately.It is not that the lonely and the gregarious are genetically different fromeach other. Rather, their genes are regulated differently, according to howsociable an individual is. Dr. Cole thinks this regulation is part of a widermechanism that tunes individuals to the circumstances they find themselves in.
Dr. Cole made an analysis of the activity of the genes by_____.
患者,男,27 岁。既往体健,体检时肝功能正常,抗 HBs 阳性。HBV 其他血清病毒标记物均为阴性。其很担心自己患上乙型病毒性肝炎,护士应告知患者其此时的状况是( )
乙型病毒性肝炎且有传染性
乙型病毒性肝炎但病情稳定
乙肝病毒携带状态
处于乙型病毒性肝炎恢复期
对乙肝病毒具有免疫力
在中国共产党领导的工人运动史上,多次罢工斗争成为反帝反封建革命的重要力量。其中,以组织严密、规模宏大、坚持时间长而著称,并创下中国工人运动史上持续时间最长纪录的政治大罢工是( )
香港海员大罢工
安源路矿工人大罢工
京汉铁路工人大罢工
省港大罢工