问题 单项选择题 A1型题

下列乙肝病毒标记物中反映了乙肝病毒有活动性复制和传染性的是()

A.表面抗原(HBsAg)

B.表面抗体(抗HBs)

C.核心抗体(抗HBC.

D.e抗体(抗HBE.

E.e抗原(HBeAg)

答案

参考答案:E

解析:选项A乙型肝炎表面抗原(HBs):属于HBV的外壳蛋白,不合病毒核酸成分,本身不具传染性,不反映病毒有无复制、复制过程、传染性强弱及预后倾向。其临床意义需结合其他检查项目综合判断。选项B表面抗体(抗-HBs):是保护性抗体,说明机体对乙型肝炎病毒具备了一定的免疫力。选项E为e抗原(HBeAg):是乙肝病毒核心颗粒中的一种可溶性蛋白质,为乙肝病毒复制的标志之一,代表着传染性高低,阳性则说明传染性较强。选项D为e抗体(抗-HBe):出现于HBeAg阴转后,代表传染性下降,但仍具有一定的传染性,且表明病程较长。选项C核心抗体(抗-HBC):是乙型肝炎核心抗原刺激肝细胞所产生的一种免疫球蛋白,是乙肝病毒抗体系统中出现较早的抗体,传染性强。

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.

3()

A.personal

B.unique

C.private

D.single

单项选择题