恐惧与焦虑的区别在于（） A.有无惊恐发作 B.有无回避行为 C.有无精神焦

患者。10天前左下肢皮肤划破，1周前突然畏寒、发热，3天来咳嗽、气急，伴右侧胸痛。胸片检查示肺部多发气囊样改变，部分可见液平，右侧可见少量胸腔积液。

其病原体最可能为（）。

A.化脓性链球菌

B.金黄色葡萄球菌

C.厌氧菌

D.铜绿假单胞菌

E.军团杆菌

下列各项中，不符合《中华人民共和国票据法》规定的是( )。

A．商业承兑汇票属于商业汇票

B．商业承兑汇票承兑人是银行以外的付款人

C．银行承兑汇票属于商业汇票

D．银行承兑汇票属于银行汇票

关于CO₂排出综合征的临床特点，下列不正确的是（）

A.其表现为血压下降、心动过速、严重心律失常甚至心脏停搏

B.治疗时不必补充血容量

C.CO突然排出可使冠脉和脑血管收缩

D.PaCO持续升高一段时间后突然降低可诱发此症

E.治疗PaCO升高，通气量要逐步增加

女儿墙

Researchers investigating brain size and mental ability say their work offers evidence that education protects the mind from the brain’s physical deterioration.

(46)It is known that the brain shrinks as the body ages, but the effects on mental ability are different from person to person. Interestingly, in a study of elderly men and women, those who had more education actually had more brain shrinkage.

" That may seem like bad news, " said study author Dr. Edward Coffey, a professor of psychiatry and of neurology at Henry Ford Health System in Detroit. (47)However, he explained, the finding suggests that education allows people to withstand more brain tissue loss before their mental functioning begins to break down.

The study, published in the July issue of Neurology, is the first to provide biological evidence to support a concept called the " reserve" hypothesis, according to the researchers. In recent years, investigators have developed the idea that people who are more educated have greater cognitive reserves to draw upon as the brain ages; in essence, they have more brain tissue to spare.

(48)Examining brain scans of 320 healthy men and women aged 66 to 90, researchers found that for each year of education the subjects had, there was greater shrink age of the outer layer of the brain known as the cortex. Yet on tests of cognition and memory, all participants scored in the range indicating normal.

" Everyone has some degree of brain shrinkage. " Coffey said. " People lose (on average) 2.5 percent per decade starting in adulthood. "

There is, however, a " remarkable range" of shrinkage among people who show no signs of mental decline, Coffey noted. Overall health, he said, accounts for some differences in brain size. Alcohol or drug use, as well as medical conditions such as diabetes and high blood pressure, contribute to brain tissue loss throughout adulthood.

In the absence of such medical conditions, Coffey said, education level helps explain the range of brain shrinkage exhibited among the mentally-fit elderly. The more-educated can withstand greater loss.

(49)Coffey and colleagues gauged shrinkage of the cortex by measuring the cerebrospinal fluid(脑脊液)surrounding the brain. The greater the amount of fluid, the greater the cortical(脑皮层的)shrinkage.

Controlling for the health factors that contribute to brain injury, the researchers found that education was related to the severity of brain shrinkage. For each year of education from first grade on, subjects had an average of 1.77 milliliters 11 more cerebrospinal fluid around the brain. Just how education might affect brain cells is unknown. (50)In their report, the researchers speculated that in people with more education, certain brain structures deeper than the cortex may stay intact to compensate for cortical shrinkage.

(50)In their report, the researchers speculated that in people with more education, certain brain structures deeper than the cortex may stay intact to compensate for cortical shrinkage.