(n.) A leaf, usually smaller than the true leaves of a plant, from the axil of which a flower stalk arises.
(n.) Any modified leaf, or scale, on a flower stalk or at the base of a flower.
Example Sentences:
(1) Enterobacter agglomerans was the most predominant bacterium on leaf and bract.
(2) Field-dried cotton bract, a contaminant of cotton dust, has been implicated in byssinosis pathogenesis.
(3) Cotton bract tannin is a potent stimulus for platelet aggregation and secretion.
(4) Byssinosis, COPD, cotton fever and cotton pneumoconiosis may be different types of responses due to the different duration of exposure, the different parts of bronchial tree (upper respiratory tract, small airway, and respiratory part) where deposition occurs, and the different components of cotton dust (broken cotton fibers, bracts, pericarps, bacteria, and fungi).
(5) Comparison of the cytotoxicity dose curves for aqueous bracts extracts with those for tannin demonstrated that tannin was the major cytotoxin present in bracts.
(6) Bract is the most abundant component in respirable raw cotton dust.
(7) After clearing and removal of the cuticle, the bracts are bleached, washed, dehydrated, and if studied by light microscopy, stained in 2% chlorazol black E and mounted in Diaphane; or, if studied by scanning electron microscopy, dried by the critical-point method and either left uncoated or coated with a film of various conductive metals.
(8) The human T lymphocyte proliferative response to cotton bract tannin was shown to be dependent upon the presence of monocytes.
(9) Pulmonary function measured by flow changes on partial expiratory flow volume curves was used to assess airway responses to the bract extracts after their inhalation by a panel of volunteers.
(10) The content of bract was unaffected by this harvest-aid practice.
(11) Raw cotton from 4 machine picked varieties and 2 machine stripped varieties is examined by stereomicroscope and bright-field microscopy for presence of plant trash(bract, leaf, stem, seed, boll, and weed fragments-size range 841-2000mum) that gives rise to cotton dust during yarn manufacturing operations.
(12) The effects of a water extract of cotton bracts (CBE) on guinea pig isolated trachealis smooth muscle was studied.
(13) The authors established an in vitro cytotoxicity assay using 51Cr release to assess time- and dose-dependent toxicity of condensed tannin, a component of bracts, on porcine aortic and pulmonary arterial endothelial cells.
(14) Senescence affected the population levels of the various genera on leaf and bract.
(15) The provenance of bristles and bracts suggests that the bristle cells move into their final positions.
(16) Mill workers are exposed to bract which has weathered in the field, but it is not known whether biologic effects of bract are due to intrinsic plant compound(s) or to contamination occurring during field weathering.
(17) To determine if constituents of cotton plants might play a role in byssinosis by injuring pulmonary epithelium, we added extracts of cotton dust, green bract, and field-dried bract to human A549 and rat type II pneumocytes.
(18) Macrophages obtained by bronchoalveolar lavage from volunteers pre-challenged with bract extract release increased amounts of chemotactic factor and superoxide anion.
(19) The role of nonspecific reactivity of the airways in this reaction to cotton bract extract is undefined.
(20) Extracts of cotton dust and field-dried bract produced significant dose- and time-dependent lysis and detachment of both target cells, while green bract extract was less damaging.
Perigone
Definition:
(n.) Any organ inclosing the essential organs of a flower; a perianth.
(n.) In mosses, the involucral bracts of a male flower.
(n.) A sac which surrounds the generative bodies in the gonophore of a hydroid.