ABSTRACT
Efficient, electrically tunable, agile, inertialess, near-diffraction-limited one-dimensional optical beam steering is demonstrated at the infrared wavelength of 10.6 microm with a liquid-crystal phased array.
ABSTRACT
Phase imaging is used to compare near-field measurements with the corresponding far-field intensity distribution. A liquid-crystal device serves as a phase object that can be programmed as a variable grating. Real-time phase visualization then provides an avenue for direct optimization of complex phase gratings.
ABSTRACT
Phase retardance of a liquid-crystal-based, electrically tunable wave plate as a function of voltage and incident light intensity at 10.6 microm is measured using the Stokes-MacCullaugh ellipsometry technique. At intensities of up to 900 W/cm(2), device performance is found to be driven by thermal effects and not optically induced reorientation effects.
ABSTRACT
Several leukocyte interferon species have been purified from a continuous human myeloblast cell line. The purification procedure involving selective precipitations, gel chromatography, and several steps of high performance liquid chromatography results in interferons with specific activities of 1 to 4 X 10(8) units/mg on bovine MDBK cells. The total yield of interferon is 23%, with the yield of the individual fractions ranging from 0.2 to 11.4%. Five fractions are homogeneous as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Molecular weights of the interferons were estimated by mobility on the sodium dodecyl sulfate gels and range from 17,600 to 26,200. The species differ in their relative antiviral activities on two cell lines, bovine MDBK and human AG-1732. In addition, the pure species have similar, but distinct, amino acid compositions and tryptic peptide profiles. These result support the conclusion that leukocyte interferon consists of several homologous proteins.
Subject(s)
Interferons/isolation & purification , Leukocytes/immunology , Amino Acids/analysis , Animals , Cattle , Cell Line , Chromatography, High Pressure Liquid , Electrophoresis, Polyacrylamide Gel , Humans , Leukemia, Erythroblastic, Acute/immunology , Molecular WeightABSTRACT
Recombinant human leukocyte interferon produced in bacteria (IFLrA) was purified to homogeneity with the use of monoclonal antibodies against leukocyte interferon. The purified interferon exhibited a single band of Mr = approximately 19,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Amino acid analysis and the NH2-terminal sequence were consistent with the sequence predicted from the DNA. Some of the purified product contained NH2-terminal methionine; the terminal methionine was removed from the rest of the chains.
Subject(s)
Antibodies, Monoclonal , DNA, Recombinant , Interferons/genetics , Amino Acids/analysis , Biological Assay , Humans , Interferons/isolation & purification , Leukocytes , Molecular WeightSubject(s)
Antibodies, Monoclonal , DNA, Recombinant , Interferons/isolation & purification , Leukocytes/immunology , Animals , Chromatography, Affinity , Electrophoresis, Polyacrylamide Gel/methods , Female , Humans , Hybridomas/immunology , Interferons/genetics , Mice , Mice, Inbred BALB C , Molecular WeightABSTRACT
Porcine brain myosin is a cytoplasmic protein similar to, but distinct from, its muscle counterpart. It has a high K+-ATPase activity at high ionic strength in EDTA and a low Mg+2-ATPase activity that is activated fivefold by either porcine brain or rabbit skeletal muscle actin. The molecule consists of three classes of subunits, with molecular weights of approximately 195,000 , 19,000, and 16,000. Brain myosin contains less glutamic acid, less lysine, and more threonine, serine, proline, and tyrosine than skeletal muscle myosin. The brain myosin extinction coefficient at 278 nm is 0.810 cm2/mg. Hydrodynamic studies yield an S020,w of 4.95S, a D020,w of 1.07 x 10(-7) cm2/s for brain myosin, and indicate that the molecules aggregate at high ionic strength. The molecular weight of the molecule, as calculated from extrapolation of D020,w/S20,w to zero concentration, is 444,000. The intrinsic viscosity of brain myosin is 0.191 ml/mg. These data are consistent with a highly asymmetric molecular species. Circular dichroism spectroscopy indicates that brain myosin is 58-60% alpha-helical in the presence of Ca+2 ions, and that removal of Ca+2 causes a small change in the spectrum.
