职称英语卫生类b级,2017职称英语卫生类B试题及答案解析3

　　Human Heart Can Make New Cells

　　Solving a longstanding mystery, scientists have found that the human heart continues to generate new cardiac cells throughout the life span, although the rate of new cell production slows with age.

　　The finding, published in the April 3 issue of Science, could open a new path for the treatment of heart diseases such as heart failure and heart attack ,experts say.

　　"We find that the beating cells in the heart, cardiomyocytes, are renewed, " said lead researcher Dr. Jonas Frisen, a professor of stem cell research at the Karolinska Institute in Stockholm, Sweden. "It has previously not been known whether we were limited to the cardiomyocytes we are bom with or if they could be renewed." he said.

　　The process of renewing these cells changes over time, Frisen added. In a 20-year-old, about 1 percent of cardiomyocytes are exchanged each year, but the turnover rate decreases with age to only 0. 45 percent by age 75.

　　"If we can understand how the generation of new cardiomyocytes is regulated , it may be potentially possible to develop pharmaceuticals that promote this process to stimulate regeneration after for example, a heart attack, " Frisen said.

　　That could lead to treatment that helps restore damaged hearts.

　　"A lot of people suffer from chronic heart failure," noted co-author Dr. Ratan Bhardwaj.

　　Ratan Bhardwaj, also from the Karolinska Institute. " Chronic heart failure arises from heart cells dying, "he said.

　　With this finding, scientists are "opening the door to potential therapies to having ourselves heal ourselves, " Bhardwaj said. " Maybe one could devise a pharmaceutical agent that would make heart cells make new and more cells to overcome the problem they are facing."

　　But barriers remain. According to Bhardwaj , scientists do not yet know how to increase heart cell production to a rate that would replace cells faster than they are dying off, especially in older patients with heart failure. In addition, the number of new cells the heart produces was estimated using healthy hearts-whether the rate of cell tumover in diseased hearts is the same remains unknown.

　　1. The human heart stops producing cardiac cells

　　A. when a person becomes old

　　B. as soon as a person gets sick

　　C. immediately after a person is born

　　D. once a person dies

　　2. The finding could prove to be useful to

　　A. the analysis of cardiac cells

　　B. the prevention of chronic diseases

　　C. the treatment of heart disease

　　D. the study of longstanding mysteries

　　3. In people in their mid-70s, only 0. 45 percent of cardiomyocytes _ .

　　A. are still functional

　　B. are reduced each year

　　C. are replaced each year

　　D. are damaged each year
　4. Chronic heart failure is attributed to

　　A. the dying heart cells

　　B. the effect of pharmceutical

　　C. the weight of a patient

　　D. the life span of a person

　　5. It is not known yet if the rate of cell turnover in diseased hearts

　　A. is high enough to replace cells faster than they're dying off

　　B. is of any use to researchers

　　C. is the same as that in healthy hearts

　　D. changes over time

　　参考译文及答案：

　

人类心脏可以制造新的细胞

　　科学家发现在人的整个生命进程中，心脏会持续产生新的心肌细胞，尽管新细胞产生的速度会随着年龄的增长而降低，这一发现解决了很长时间以来的一个谜团。

　　这一研究成果发表于《科学》杂志四月三号那一期，专家称，这一研究成果将为心脏病（例如心脏衰竭和心脏病发作）的医治开拓新的途径。

　　研究负责人Jonas Frisen博士是瑞典斯德哥尔摩卡罗琳斯卡研究院研究干细胞的教授。

　　他说："我们发现心脏中的心肌细胞会被更替。在此之前我们不知道我们生来就拥有的心肌细胞是固定的还是可以更新。"

　　Frisen补充说，这些细胞的更替过程会随着时间而变化。一个人20岁时，其每年被更替的心肌细胞大约为1%，随着年龄的增长，该更替率不断下降，等到75岁时，只有0. 45%。

　　Frisen说："如果我们知道新的心肌细胞产生的规律，也许就有可能研发出在心脏病发后能促进细胞生成的药物。"

　　那将有助于受损心脏恢复。

　　该研究论文的合著者Ratan Bhardwaj博士说："很多人都在忍受慢性心衰的折磨。"

　　Ratan Bhardwaj也是来自于卡罗琳斯卡研究院，他说："慢性心衰是由心肌细胞死亡引发的。"

　　有了这一发现，"科学家即将开启一扇通往自愈潜在疗法的大门"，Bhardwaj说："也许我们可以设计出一种药物制剂使心脏细胞生成出更多更新的细胞来克服它们面临的问题。"

　　不过障碍依然存在。根据Bhardwaj的观点，科学家还不知道如何才能使心脏细胞产生的速度超过其死亡的速度，尤其是对于患有心脏病的老年人。此外，心脏产生的新细胞的数量是按照健康心脏计算的，而有心脏病的细胞更替率能否与健康心脏相同还不得而知。

　　1.D [解析]根据是第一段中：…the human heart continues to generate new cardiac cells throughout the life span。在人的整个生命进程中，其心脏不时产生新的心肌细胞。言外之意，这个过程直到人死才会停止。

　　2.C [解析]根据是第二段中：The finding，…，could open a new path for the treatment of heart diseases 这一研究成果将为心脏病的医治开拓新的途径。

　　3.C[解析]第四段说，一个人20岁时，其每年被更替的心肌细胞为1%，随着年龄的增长，该更替率( turnover rate)不断下降，等到75岁时，只有0.45%。

　　4.A [解析]倒数第三段说：Chronic heart failure arises from heart cells dying。慢性心衰是由心肌细胞死亡导致的。

　　5.C[解析]最后一句说：心脏产生的新细胞的数量是按照健康心脏计算的，而有心脏病的细胞更替率是否与健康心脏相同还不得而知。

2017职称英语卫生类B试题及答案解析3.doc

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