TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: Benign esophageal strictures are frequently encountered pathologies occurring due to various reasons. Repeated dilatations may be needed, particularly in resistant strictures. This study aimed to evaluate patients who underwent repeated dilatations in our clinic due to resistant esophageal strictures.', 'Sixteen patients who underwent multiple dilatations in our clinic with the diagnosis of resistant benign esophageal stricture between 2007 and 2014 were studied for age, sex, etiology, symptoms, complications, number of dilatations, and intervals between dilatations. Under general anesthesia, all patients underwent dilatation with Savary-Gilliard bougie dilators with the help of rigid esophagoscopy.', 'In 10 of the patients, stenosis was cervical, and in others it was in the thoracic esophagus. The mean dilatation performance was 4.4 (range: 3-12). In 9 patients, dilatations were performed when the patients presented with the complaint of dysphagia. Following the initial dilatation performed for dysphagia, 7 patients underwent endoscopy and dilatation 3-5 times with 1-week intervals without waiting for the development of dysphagia symptoms. These patients developed no complications, and no stenting was needed. In 5 patients, restenosis developed despite multiple dilatations, and esophageal stent placement was performed.\Question: Is recurrent dilatation in resistant benign esophageal strictures : timing significant?

SOLUTION: Dilatations performed at frequent intervals without waiting for the symptoms of dysphagia can contribute to safer and more effective results in resistant benign esophageal strictures.

PROBLEM: Context: The etiology of idiopathic scoliosis remains unknown, but growth is a risk factor for progression. Growth pattern differs in children with and without scoliosis. Cartilage oligomeric matrix protein (COMP) may be associated with scoliosis and growth. We, therefore, studied COMP in children with and without idiopathic scoliosis.', 'We included 105 children, with mean age 14.4 years (range 10-16), under observation or treatment for idiopathic scoliosis, and 103 children from an age-matched population-based cohort. COMP was measured in serum at the time of inclusion. Growth velocity was estimated from repeated height measurements. T tests, analysis of covariance or linear regression were used for statistical comparisons.', 'COMP was mean (SD) 11 (5) units/liter (U/L) in children with scoliosis and 13 (5) U/L in the control cohort (p = 0.005, adjusted for sex and sampling time of the day). When patients and controls were analyzed together, high COMP was correlated with high growth velocity (β = 0.19, p = 0.003). When patients and controls were analyzed separately, COMP was correlated with growth velocity in children with scoliosis (β = 0.27, p = 0.007), but not in children without scoliosis (β = 0.02, p = 0.83) (all analyses adjusted for age, sex and sampling time). Low COMP was significantly correlated with large curve size in children with scoliosis (β = -0.29, p = 0.003), but not after adjustment for age, sex and sampling time (β = -0.16; p = 0.14).\Question: Is serum level of cartilage oligomeric matrix protein lower in children with idiopathic scoliosis than in non-scoliotic controls?

SOLUTION: COMP was lower in children with idiopathic scoliosis than in a control cohort. In children with scoliosis, high COMP was modestly correlated with high growth velocity, but not with curve severity.

PROBLEM: Context: Epidermal phenolic compounds (mainly flavonoids) constitute a vital screen that protects the leaf from damage by natural ultraviolet (UV) radiation. The effectiveness of epidermal UV-screening depends on leaf anatomy, the content of UV-screening compounds and their spatial uniformity over the leaf area. To investigate in vivo the spatial pattern of the epidermal UV-screen during leaf development, a fluorescence imaging method was developed to map the epidermal UV-absorbance at a microscopic scale. This study was done on oak (Quercus petraea) leaves that were used as a model of woody dicotyledonous leaves.', 'The leaf development of 2-year-old trees, grown outdoors, was monitored, at a macroscopic scale, by in vivo measurements of chlorophyll content per unit area and epidermal UV-absorbance using two optical leaf-clip meters. The distribution of pigments within leaves was assessed in vivo spectroscopically. The microscopic images of UV-induced fluorescence and UV-absorbance acquired in vivo during leaf development were interpreted from spectral characteristics of leaves.', 'At a macroscopic scale, epidermal UV-absorbance was high on the upper leaf side during leaf development, while it increased on the lower leaf side during leaf expansion and reached the adaxial value at maturity. At a microscopic scale, in immature leaves, for both leaf sides, the spatial distribution of epidermal UV-absorbance was heterogeneous, with a pattern depending on the flavonoid content of vacuoles in developing epidermal cells. At maturity, epidermal UV-absorbance was uniform.\Question: Does developmental changes in spatial distribution of in vivo fluorescence and epidermal UV absorbance over Quercus petraea leave?

SOLUTION:
The spatial pattern of epidermal UV-screen over the area of oak leaves is related to leaf anatomy during development. In vivo spectroscopy and fluorescence imaging of the leaf surface showed the distribution of pigments within the leaf and hence can provide a tool to monitor optically the leaf development in nature.