instruction:
Given an abstract, indicate which of the provided candidate titles (Option1 and Option2) best describes it (respond with the text of the title, not option1/2).
question:
Abstract: Mixed sequence DNA can exist in two right-handed and one left-handed double helical conformations--A, B and Z. Under conditions of high water activity the B conformation prevails. If the water activity is reduced on addition of salt or organic solvents, transformation occurs to A-DNA or, in DNAs with alternating purine-pyrimidine sequences, to the left-handed Z-DNA. In crystal structure analyses of oligonucleotides, the free oxygen atoms of adjacent phosphate groups along the polynucleotide chain in B-DNA are found at least 6.6 A apart and individually hydrated whereas they are as close as 5.3 A in A-DNA and 4.4 A in Z-DNA, and bridged by water molecules. We suggest that this more economical hydration in A- and Z-DNA compared with B-DNA is the underlying cause of B----A and B----Z transitions.
Which is the apt title for the abstract? option1: DNA conformation is determined by economics in the hydration of phosphate groups. option2: Albumin labeled with Gd-DTPA as an intravascular, blood pool-enhancing agent for MR imaging: biodistribution and imaging studies.
answer:
DNA conformation is determined by economics in the hydration of phosphate groups.

question:
Abstract: Magnetic resonance imaging (MRI) and computed tomography (CT) were compared in four children who had evidence of intracranial injury caused by shaking. All children had intracranial bleeding, neurologic impairment, and history or physical examination findings suggestive of child abuse. Three had bilateral retinal hemorrhages, and three had visual impairment. MRI revealed bilateral subdural hematomas in all four children, but CT showed this in only one. Skull fractures in one patient were visualized by CT alone. MRI alone demonstrated posterior fossa bleeding in one patient and intraparenchymal bleeding in another; an additional patient in whom CT showed relatively diffuse atrophy also had defined areas of focal atrophy apparent on MRI. Subarachnoid hemorrhages were equally well detected using CT or MRI. Overall, MRI was superior to CT for detection of intracranial injury caused by shaking, and may help to document milder instances of this form of child abuse.
Which is the apt title for the abstract? option1: Magnetic resonance imaging of intracranial injuries from child abuse. option2: Sarcoid cyclitis [letter]
answer:
Magnetic resonance imaging of intracranial injuries from child abuse.

question:
Abstract: Torsional deformity should be localized, quantitated, and usually managed by "observation," an approach that is set forth in detail in this article. Shoe modifications and daytime braces are inappropriate. Night splints or operative procedures are rarely indicated.
Which is the apt title for the abstract? option1: Torsional deformity. option2: Age changes in lumbar zygapophyseal joints. Observations on structure and function.
answer:
Torsional deformity.