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141.
Kristian Helmerson Rani Kishore William D. Phillips Howard H. Weetall 《Applied biochemistry and biotechnology》2001,96(1-3):205-213
We used optical tweezers—optical trapping with focused laser beams—to pull microspheres coated with antigens off of an antibody-coated
surface. Using this technique, we could quantify the force required to separate antigen to antibody bonds. At very low surface
density of antigen, we were able to detect the single antigen to antibody binding. The force required to break the antigen-antibody
bonds and pull the microsphere off the surface was shown to increase monotonically with increasing surface density of antigens.
Using the force determination as a transducer, we were able to detect concentrations of free antigens in solution as small
as 10−15 mol/L in a competitive binding assay. 相似文献
142.
143.
Kumar Sundaravel Vivek Rani Gandhi Uma Divyalakshmi Manohar Bhuvanesh Nattamai Muthusubramanian Shanmugam Perumal Subbu 《Molecular diversity》2019,23(3):669-680
Molecular Diversity - Expedient synthesis of benzosuberone-tethered spirooxindoles was accomplished by a three-component 1,3-dipolar cycloaddition reaction between azomethine ylide (generated in... 相似文献
144.
145.
Lingaiah Nagarapu Hanmant K. Gaikwad Rajashaker Bantu Sheeba Rani Manikonda C. Ganesh Kumar Sujitha Pombala 《Tetrahedron letters》2012,53(10):1287-1291
A series of glycosidic-pyrroloquinolinone based novel building blocks of camptothecin (2a–g) were synthesized via Lewis acid-assisted olefin cross-metathesis reaction using Ti(OiPr)4 30 mol % and 10 mol % of Grubb’s second generation catalyst with good to excellent yields. Most of these compounds exhibited significant growth inhibitory effects on all the tested cancer cell lines and three compounds (2c, 2d and 2e) showed potent cytotoxic activity. 相似文献
146.
147.
Pala Rajasekharreddy Pathipati Usha Rani Bojja Sreedhar 《Journal of nanoparticle research》2010,12(5):1711-1721
The development of rapid and ecofriendly processes for the synthesis of silver (Ag) and gold (Au) nanoparticles is of great
importance in the field of nanotechnology. In this study, the extracellular production of Ag and Au nanoparticles was carried
out from the leaves of the plants, Tridax procumbens L. (Coat buttons), Jatropa curcas L. (Barbados nut), Calotropis gigantea L. (Calotropis), Solanum melongena L. (Eggplant), Datura metel L. (Datura), Carica papaya L. (Papaya) and Citrus aurantium L. (Bitter orange) by the sunlight exposure method. Qualitative comparisons of the synthesized nanoparticles between the
plants were measured. Among these T. procumbens, J. curcas and C. gigantea plants synthesized <20 nm sized and spherical-shaped Ag particles, whereas C. papaya, D. metel and S. melongena produced <20 nm sized monodispersed Au particles. The amount of nanoparticles synthesized and its qualitative characterization
was done by UV–vis spectroscopy and transmission electron microscopy (TEM), respectively. X-ray diffraction (XRD) and X-ray
photoelectron spectroscopy (XPS) were used for structural confirmation. Further analysis carried out by fourier transform
infrared spectroscopy (FTIR), provided evidence for the presence of amino groups, which increased the stability of the synthesized
nanoparticles. 相似文献
148.
149.
We study the spherically symmetric collapsing star in terms of dynamical instability. We take the framework of extended teleparallel gravity with a non-diagonal tetrad, a power-law form of the model presenting torsion and a matter distribution as a non-dissipative anisotropic fluid. The vanishing shear scalar condition is adopted to gain insight in a collapsing star. We apply a first order linear perturbation scheme to the metric, the matter, and f(T) functions. The dynamical equations are formulated under this perturbation scheme to develop collapsing equation for finding dynamical instability limits in two regimes, such as the Newtonian and the post-Newtonian regime. We obtain a constraint-free solution of a perturbed time dependent part with the help of a vanishing shear scalar. The adiabatic index exhibits the instability ranges through the second dynamical equation which depend on physical quantities such as the density, the pressure components, the perturbed parts of the symmetry of the star, etc. We also develop some constraints on the positivity of these quantities and obtain instability ranges to satisfy the dynamical instability condition. 相似文献
150.
In this paper, a pair of symmetric dual second-order fractional programming problems is formulated and appropriate duality theorems are established. These results are then used to discuss the minimax mixed integer symmetric dual fractional programs. 相似文献