In this task, you are given an abstract of article. Your task is to generate label "True" if abstract is structured, otherwise generate "False". A structured abstract is composed of a topic sentence (or key sentence), relevant supporting sentences, and a closing (or transition) sentence. This structure is key to keeping your abstract focused on the main idea and creating a clear and concise image.

[Q]: PURPOSE Anticoagulant prophylaxis in patients with central venous catheters is controversial. We performed a meta-analysis of randomized controlled trials of anticoagulant prophylaxis in patients with central venous catheters.
METHODS MEDLINE and EMBASE were searched up to May 2006, supplemented by manual searches of conference proceedings and bibliographies.
RESULTS Fifteen trials were included. Unfractionated heparin infusion, oral fixed low-dose vitamin K antagonist, and subcutaneous low-molecular-weight heparin were evaluated. For all catheter-associated deep vein thrombosis (symptomatic and asymptomatic combined), the summary relative risks ranged from 0.31 to 0.73 (all achieved statistical significance). For symptomatic deep vein thrombosis, the summary relative risks ranged from 0.28 to 0.72, but did not achieve statistical significance for any individual regimen.
CONCLUSION Anticoagulant prophylaxis is effective for preventing all catheter-associated deep vein thrombosis in patients with central venous catheters. The effectiveness for preventing symptomatic venous thromboembolism, including pulmonary embolism, remains uncertain.
[A]: True

[Q]: Spatial boundaries of homeotic gene expression are initiated and maintained by two sets of transcriptional repressors: the gap gene products and the Polycomb group proteins. Previously, the Hunchback (HB) protein has been implicated in setting the anterior expression limit of the UBX homeotic protein in parasegment 6. Here we investigate DNA elements and trans-acting repressors that control spatial expression of the Abdominal-A (ABD-A) homeotic protein. Analysis of a 1.7-kb enhancer element [iab-2(1.7)] from the iab-2 regulatory region shows that in contrast to Ubx enhancer elements, both HB and Kruppel (KR) are required to set the ABD-A anterior boundary in parasegment 7. DNase I footprinting and site-directed mutagenesis show that HB and KR are direct regulators of this iab-2 enhancer. The single KR site can be moved to a new location 100 bp away and still maintain repressive activity, whereas relocation by 300 bp abolishes activity. These results suggest that KR repression occurs through a local quenching mechanism. We also show that the gap repressor Giant (GT) initially establishes a posterior expression limit at PS9, which shifts posteriorly after the blastoderm stage. Finally, we show that this iab-2 enhancer contains multiple binding sites for the Polycomb group protein Pleiohomeotic (PHO). These iab-2 PHO sites are required in vivo for chromosome pairing-dependent repression of a mini-white reporter. However, the PHO sites are not sufficient to maintain repression of a homeotic reporter gene anterior to PS7. Full maintenance at late embryonic stages requires additional sequences adjacent to the iab-2(1.7) enhancer.
[A]: False

[Q]: BACKGROUND Imiquimod is an immune response modifier that acts through toll-like receptor 7 to induce cytokine production and a subsequent innate and adaptive cell-mediated immune response. Clinical studies have demonstrated clinical and histological clearance of superficial basal cell carcinoma (sBCC) after treatment with imiquimod 5% cream.
OBJECTIVES To evaluate the safety and clinical efficacy of imiquimod (Aldaratrade mark; 3M Pharmaceuticals, St Paul, MN, U.S.A.) 5% cream for the treatment of sBCC in a multicentre, randomized, parallel, vehicle-controlled, double-blind, phase III clinical study conducted at 26 centres in Europe.
METHODS Subjects who had at least one histologically confirmed sBCC tumour were randomized to apply imiquimod or vehicle cream to the target tumour once daily, seven times per week (7 x/week) for 6 weeks. The target tumour location was identified with an indelible ink mark before treatment initiation. The treated tumour site was clinically assessed for treatment response at 12 weeks post-treatment and was then excised for histological evaluation. Efficacy assessments included the composite response rates (proportion of subjects with clinical and histological clearance) and response rates solely based on histology (proportion of subjects with histological clearance). Safety assessments, which included adverse events and scoring of local skin reactions (LSRs), were carried out throughout the study.
RESULTS In total, 166 subjects were enrolled in this study. For the intent-to-treat dataset, there was a statistically significant difference between imiquimod and vehicle groups for both composite clearance rates (clinical and histological assessments) and histological clearance rates. Composite clearance was demonstrated in 77% and 6% of subjects treated with imiquimod and vehicle cream, respectively. Histological clearance was demonstrated in 80% and 6% of subjects treated with imiquimod and vehicle cream, respectively. The most frequently reported safety findings were investigator-assessed LSRs and spontaneous reports by subjects of application site reactions, which occurred more frequently in the imiquimod group than in the vehicle group.
CONCLUSIONS Imiquimod 5% cream administered 7 x/week for 6 weeks is a safe and effective treatment for sBCC when compared with vehicle cream.
[A]:
True