问题 单项选择题

Young girls at high risk for depression appear to have a malfunctioning reward system in their brains, a new study suggests. The finding comes from research that (1) a high-risk group of 13 girls, aged 10 to 14, who were not depressed but had mothers who (2) recurrent depression and a low-risk group of 13 girls with no (3) or family history of depression. Both groups were given MRI brain (4) while completing a task that could (5) either reward or punishment.

(6) with girls in the low-risk group, those in the high-risk group had (7) neural responses during both anticipation and receipt of the reward. (8) , the high-risk girls showed no (9) in an area of the brain called the dorsal anterior cingulated cortex (背侧前扣带皮质), believed to play a role in (10) past experiences to assist learning.

The high-risk girls did have greater activation of this brain area (11) receiving punishment, compared with the other girls. The researchers said that this suggests that high-risk girls have easier time (12) information about loss and punishment than information about reward and pleasure.

"Considered together with reduced activation in the striatal (纹状体的) areas commonly observed (13) reward, it seems that the reward-processing system is critically (14) in daughters who are at elevated risk for depression, (15) they have not yet experienced a depressive (16) ," wrote Ian H. Gotlib, of Stanford University, and his colleagues. " (17) , longitudinal studies are needed to determine whether the anomalous activations (18) in this study during the processing of (19) and losses are associated with the (20) onset of depression," they concluded. The study was published in the April of the Archives of General Psychiatry.

18()

A.carried

B.observed

C.effected

D.suffered

答案

参考答案:B

解析:

[解题思路] 本题考查的是对单词意思的辨析,只要清楚每个单词的意思,我们就不难做出选择。此句的句意为:在研究中______的不规则的活化作用是否与抑郁症有关。在实验中,我们经常使用observed表示“观察到的”,而[A]、[C]和[D]意义都不符。

单项选择题
单项选择题

SCID是一种严重缺乏综合免疫力的基因病。在每10万个新生婴儿中,可能就有一个会遭此厄运。SCID病是由于体内缺乏一种称为脱氨基腺苷(简称ADA)的酶所致的。这种酶具有能够破坏体内正常产生的一种化学物质的作用,使它不会在体内过多地积累起来,因为这种化学物质积累太多,就会危害体内的T细胞,从而使人失去免疫力。80年代中期,医学家在临床上曾用从牛体中取得的ADA给病孩注射。一引进研究人员认为,比较理想的是能提供具有ADA基因的细胞复制品,从1990年开始,研究者对两个女婴进行临床试验,他们将复制的基因植入T细胞后给病孩注射。于是这些变异了的T细胞开始制造ADA,使这两个女婴获得免疫力。可是,这些T细胞仅能存活几个月。美国洛杉矶儿童院基因治疗组一位研究人员认为它的更好的办法是将ADA基因植入血液的干细胞中,因为这生存期几乎是永久的,而且又是由它来产生T细胞的,去年5月和6月,研究者先后从三名新生儿的脐带中取了少量的血,并使用一种以干细胞为目标的抗体,将所需的干细胞分离出来,然后,用逆转录病毒作为载体,将ADA基因植进去。可是,脐带血中的干细胞有两种,一种是婴儿干细胞,它只能生存6个月,另一种才是永久干细胞,在婴儿在出生时,它并不活跃,ADA基因已进不去。研究者用生长素来促使这些永久干细胞活跃起来,使它也能获得ADA基因。目前,试验还在进行,还有待于观察那些成熟的永久干细胞是否能有ADA基因。[a]试验获得成功,那些患这种SCID的病孩[b]能真正得救。

下面的表述符合文意的是:()

A.SCID是严重缺乏综合免疫力的基因病的代号

B.脐带血中的干细胞在生长素的促进下会活跃进来,并获得ADA基因

C.基因矫正的过程是先取得干细胞,再将植有ADA基因的逆转录病毒加到干细胞中去,然后注射给婴儿

D.以上说法均不正确