Given a text passage, come up with an appropriate title for it. The title should accurately represent what the main focus of the passage is. The title of a passage may be present in the first few sentences of the passage and/or be referred to multiple times in the passage. The title should be 1-5 words long.

Q: Leukonychia ( or leuconychia ) , also known as white nails or milk spots , is a medical term for white discolouration appearing on nails . It is derived from the Greek words leuko ( `` white '' ) and nychia ( `` nails '' ) . The most common cause is injury to the base of the nail ( the matrix ) where the nail is formed .

A: Leukonychia
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Q: `` Treat You Better '' is a song recorded by Canadian singer and songwriter Shawn Mendes . It was co-written by Mendes with Teddy Geiger , and Scott Harris . It was released on June 3 , 2016 through Island Records as the lead single from his second studio album , Illuminate ( 2016 ) . The music video was released on July 12 , 2016 and features a storyline about an abusive relationship .

A: Treat You Better
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Q: For medical purposes , X-ray filters are used to selectively attenuate , or block out , low - energy rays during x-ray imaging ( radiography ) . Low energy x-rays ( less than 30 keV ) contribute little to the resultant image as they are heavily absorbed by the patient 's soft tissues ( particularly the skin ) . Additionally , this absorption adds to the risk of stochastic ( e.g. cancer ) or non stochastic radiation effects ( e.g. tissue reactions ) in the patient . Thus , it is favorable to remove these low energy X-rays from the incident light beam . X-ray filtration may be inherent due to the X-ray tube and housing material itself or added from additional sheets of filter material . The minimum filtration used is usually 2.5 mm aluminium ( Al ) equivalent , although there is an increasing trend to use greater filtration . Manufacturers of modern fluoroscopy equipment utilize a system of adding a variable thickness of copper ( Cu ) filtration according to patient thickness . This typically ranges from 0.1 to 0.9 mm Cu .

A:
X-ray filter
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