(n.) A plane figure consisting of seven sides and having seven angles.
Example Sentences:
(1) Complementary pairs of pentagons and heptagons are the termination points of edge dislocations.
(2) The change of hexagonal cells was supplemented by the appearance of pentagonal cells and heptagonal cells.
(3) The "equilateral curve heptagon" used for the 50p does have that shape – its height is always the same at whatever point you rest it on its edge.
(4) The percentage of hexagonal endothelial cells decreased by 14% (r = -0.48, P less than 0.001), while the percentage of pentagonal and heptagonal cells increased by 50% (r = 0.44, P less than 0.001) and 40% (r = 0.33, P less than 0.002), respectively, with age.
(5) In Experiment 1, with the number of sides or angles of irregular polygons as cues, programmed training, and a 90% correct criterion (36 of 40), 2 squirrel monkeys' (Saimiri sciureus sciureus and S. boliviensus boliviensus) best performances were to discriminate heptagons from octagons, a 3rd's best was hexagons from heptagons, and a 4th's best was pentagons from heptagons.
(6) In freeze-etched preparations of intact cells numerous positive and negative 60 degree wedge disclinations can be detected which form pentagons and heptagons in the hexagonal array.
Hexagon
Definition:
(n.) A plane figure of six angles.
Example Sentences:
(1) The crystallographic parameters of four different unit cells, all of which are based on hexagonal packing arrangements, indicate that the fundamental unit of the complex is composed of six gene 5 protein dimers.
(2) The molecular structure of the hexagonal crystal form of porcine pepsin (EC 3.4.23.1), an aspartic proteinase from the gastric mucosa, has been determined by molecular replacement using the fungal enzyme, penicillopepsin (EC 3.4.23.6), as the search model.
(3) The "hexagonal ribbon" model proposes that hexagonal profiles are true cross-sections of elongated hexagonal ribbons.
(4) Crystal structure analysis and refinement at 2.0 A resolution of a rhombohedral crystal form of human annexin V at high calcium concentration revealed a domain motion compared to the previously analysed hexagonal crystal form.
(5) Abnormalities included absence of a hexagonal pattern, incomplete portal tracts with dilated veins only, lack of bile ducts and canaliculi, and apparent failure of bile formation and glycogen deposition.
(6) Using a hexagonal electrode array and switching times of 75 min at 45 V for 14 days, nine bands could be resolved.
(7) The PENN-PET scanner consists of six hexagonally arranged position-sensitive Nal(TI) detectors.
(8) This result was quite the same as that of the hexagonal plate crystals.
(9) When negatively stained with uranyl acetate, LPSI was ribbon-like but LPSII exhibited hexagonal lattice structures.
(10) Endothelial specular photography during an attack reveals dramatic changes: large black nonreflecting areas between quite normal-looking hexagonal cells.
(11) It is suggested that distortion in the hexagonal lattice below the pretransition temperature previously reported by X-ray diffraction techniques may be responsible for interchain interactions which give rise to a Raman band observed only in the triclinic lattice of even-numbered n-alkanes.
(12) 31P-NMR and X-ray diffraction techniques are used to study the comparative ability of myelin basic protein (MBP) vs. other basic proteins to convert hexagonal (HII) phases to stable lamellar (L alpha) structures.
(13) The influence of the intercalation of ethidium bromide (EB) on the characteristics of the DNA cholesteric and hexagonal mesophases is studied by optical microscopy, circular dichroism, and X-ray diffraction.
(14) Wide angle X-ray diffraction results indicate no major effect of the protein on the 4.1 A spacing, characteristic of hexagonal packing of the hydrocarbon chains.
(15) After in vitro perfusion of cytochalasin D to the corneal endothelium, the F-actin became randomly distributed throughout the cytoplasm, the hexagonal shape of the endothelial cell was disrupted, and endothelial permeability to carboxyfluorescein increased.
(16) The thermophilic eubacterium Clostridium thermohydrosulfuricum L77-66 is covered by a crystalline surface layer composed of identical glycoprotein subunits which are arranged in a hexagonal lattice with centre-to-centre spacings of approx.
(17) Pyramidal, cubical or hexagonal magnetic grains could be seen in different species of bacteria.
(18) The six subunits form a hexagon which is skewed with respect to the main rows of hexagons in such a way that the subunits lie on rows which make an angle of approximately 37 degrees with the main rows.
(19) In the invaginating synapses of cone pedicles, the plasma membrane of the photoreceptor ending contains an aggregate of A-face particles, a hexagonal array of synaptic vesicle sites, and rows of coated vesicle sites, which are deployed in sequence from apex to base of the synaptic ridge.
(20) The design and construction of a transistor-driven hexagonal contour-clamped homogeneous electric field (CHEF) apparatus is discussed in detail.