What's the difference between hexagonal and tetragonal?

Hexagonal


Definition:

  • (a.) Having six sides and six angles; six-sided.

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.

Tetragonal


Definition:

  • (a.) Of or pertaining to a tetragon; having four angles or sides; thus, the square, the parallelogram, the rhombus, and the trapezium are tetragonal fingers.
  • (a.) Having four prominent longitudinal angles.
  • (a.) Designating, or belonging to, a certain system of crystallization; dimetric. See Tetragonal system, under Crystallization.

Example Sentences:

  • (1) The crystals are tetragonal, with unit cell dimensions a = 48.9 A and c = 82.0 A, space group P 41 21 2 or P 43212.
  • (2) The morphological unit of the regular array appeared to consist of four spherical subunits, each about 2 nm in diameter, which were arranged in a tetragonal pattern about 4.5 by 7.0 nm in dimension.
  • (3) Two different tetragonal crystal forms have been characterized, both diffracting to about 6 A using synchrotron radiation.
  • (4) The outer structured layer was a linear array of particles overlying an inner tetragonal array of larger subunits.
  • (5) An activity assay of redissolved tetragonal form crystals indicates that the uncleaved, functional serpin has been crystallized.
  • (6) The A ring of the steroid in the tetragonal crystal was found to be disordered, and exists in both a normal and inverted conformation.
  • (7) One was in a hexagonal array, and the other was in a tetragonal array.
  • (8) The crystals are tetragonal rods with unit cell dimensions a = 128.6 A, c = 92.5 A.
  • (9) A hydrated cobalt ion is found to coordinate to two N7 atoms of adjacent guanines, forcing these two guanines to destack with a large dihedral angle (32 degrees), in the dimer of the tetragonal form.
  • (10) These tubules are clearly distinguishable by their shape and fine structure from the periodic structure of a P. rhodos cell wall layer, which exhibits a tetragonal pattern, and also from polyheads and polysheaths of defective bacteriophages.
  • (11) The structure crystallizes in the tetragonal space group P41 with a = 8.225 (5) and c = 28.42 (1) A.
  • (12) This truncated S-protein was exported via the periplasm to the cell surface, but could not self-assemble into a tetragonal array or be anchored to the cell surface.
  • (13) Bacillus sphaericus strain P-1 has previously been shown to have a tetragonally arrayed (T layer) protein which forms the outer layer of the cell wall.
  • (14) Its three-dimensional structure from two different crystal forms (tetragonal and trigonal) has been determined by X-ray diffraction analysis at 1 A resolution.
  • (15) Both crystal forms are tetragonal, the space group for form I is P4(1)22 (or P4(3)22), and that for form II is P4(2)22.
  • (16) Density variations suggest an arrangement of subunits, either tetragonal or trigonal, viewed from a variety of angles about the DNA axis.
  • (17) The binuclear copper site is characterized as two tetragonal Cu(II) atoms bridged by both an endogenous protein ligand and the exogenous ligand (i.e., peroxide), with the lack of an electron paramagnetic resonance signal being the result of antiferromagnetic exchange via the endogenous bridge.
  • (18) The crystals are tetragonal, show the symmetry of space group P4(1) or its enantiomer, have lattice constants of a = 58.46 (1) and c = 77.02 (3) A, and scatter to at least 2 A resolution.
  • (19) These elevations were distributed according to a tetragonal pattern with a periodicity of 850 A.
  • (20) Crystals are tetragonal, with space group P42(1)2, a = b = 171 A, c = 150 A in the absence of ATP; and P422, a = b = 101 A, c = 114.4 A in the presence of ATP.