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【单选题】

Los Alamos National Laboratory scientists are using a new technique to see fingerprints on suces that typically make them invisible.
The method uses a technology called mini-X-ray fluorescence (荧光) to detect chemical elements in fmgerprints without altering them, said Christopher Worley, a scientist on the project.
"The conventional methods are meant to bring out fingerprint patterns with regular light and they have to treat those with powder, which alters them," Worley said. "With this you do not have to alter it or treat it at all. We can determine the elements in a fingerprint and get a pattern at the same time."
The technology focuses a tight beam of X-rays on suces with fingerprints and creates a computer picture out of those scans.
The equipment costs about $175,000.
For big labs, the method could be a great way to bring out prints that can’t be seen any other way, said Vahid Majidi, another lab scientist.
"The technique fills a unique gap," Majidi said. "These are prints that would otherwise be useless. If you have prints on a dark suce, for example, they really do not develop well using normal techniques. If you have prints from an adolescent or child, the chemicals in the fingertips are different and do not stick around long enough for traditional methods."
The new method might also be able to tell if the person that left them handled certain types of bomb- materials, said George Havrilla, another lab scientist.
"This is a new approach to f’mgerprint visualization," Havrilla said. "We are lifting prints, but instead of looking at the finger’s natural oils and organic residues (残留物) we’re looking at elemental features left behind"
The technology for scanning the prints is widely available. What’s new is the method the lab has created to see them which includes computer software and Ways of managing the machinery, Worley said.
But the technique isn’t for everyone.
“We have already had some negative comments on it" Havrilla said with a laugh "One reviewer told us it is just not practical. But the goal of our work was to demonstrate that it was feasible to see these things.\
The function of X-ray in the new technique can be properly compared to that of ______

A.
the powder used in the conventional methods
B.
images that can only be seen in computer
C.
a scanner that is connected to a computer
D.
the memory of any digital recorders
题目标签:残留物荧光
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【单选题】真菌检查滤过紫外线灯下见亮绿色荧光的是:

A.
外感风热之毒,阻于肺胃二经,蕴蒸皮肤而发
B.
情志内伤,肝气郁结,久而化火,肝经火毒,外溢皮肤而发
C.
寒湿困脾,脾失健运,肌肤失养而发
D.
肝胆湿热,蕴结肌肤而发
E.
禀赋不耐,风、湿、热毒郁于肌肤而发

【单选题】荧光造影常显示脉络膜低荧光的疾病是

A.
视网膜中央静脉阻塞
B.
年龄相关性黄斑变性
C.
Stargardt病
D.
视网膜中央动脉阻塞
E.
中心性浆液性脉络膜视网膜病变

【多选题】关于间接免疫荧光技术的叙述,下列哪些是正确的

A.
可以检测抗原或抗体
B.
易出现非特异性荧光
C.
敏感性较直接法明显提高
D.
用一种标记的抗球蛋白抗体,能检查多种以球蛋白作为抗体的复合物
E.
需在荧光显微镜下观查

【单选题】荧光量子效率是指()。

A.
荧光强度与吸收光强度之比
B.
发射荧光的量子数与吸收激发光的量子数之比
C.
发射荧光的分子数与物质总分子数之比
D.
激发态的分子数与基态分子数之比

【单选题】寻常型天疱疮直接免疫荧光可见()

A.
棘细胞外IgC4的沉积
B.
棘细胞间IgC3的沉积
C.
棘细胞间IgC2的沉积
D.
棘细胞间IgC1的沉积