The concept of amplitude-modulated multiplexed flow analysis has been extended to the simultaneous determination of multiple analytes in a sample. A sample solution containing nitrite and nitrate ions is delivered from two channels, but the flow rates are varied at different frequencies. One of the channels has a reduction column for converting nitrate ions to nitrite ions. Downstream, the abso...

Fast Fourier transform (FFT) simulation was used to calculate the power and spatial distribution of resonant fields in optical cavities. This is an important tool when characterizing the effect of imperfect geometry and mirror aberrations. This method is, however, intrinsically slow when the cavities are of relatively high finesse. When this is the case, an accelerated convergence scheme may be...

Two new holostan-type triterpenoid oligoglycosides, named parvimosides A (1) and B (2), were isolated from the warty sea cucumber Stichopus parvimensis (syn. Parastichopus parvimensis). Their structures and total assignments of the proton and carbon signals were established on the basis of spectral evidence, mainly 1H and 13C 1D and 2D NMR spectroscopy including DEPT, COSY, TOCSY, NOESY/ROESY, ...

Energy evaluation using fast Fourier transforms (FFTs) enables sampling billions of putative complex structures and hence revolutionized rigid protein-protein docking. However, in current methods, efficient acceleration is achieved only in either the translational or the rotational subspace. Developing an efficient and accurate docking method that expands FFT-based sampling to five rotational c...

Most state-of-the-art protein-protein docking algorithms use the Fast Fourier Transform (FFT) technique to sample the six-dimensional translational and rotational space. Scoring functions including shape complementarity, electrostatics, and desolvation are usually exploited in ranking the docking conformations. While these rigid-body docking methods provide good performance in bound docking, us...

Two 11(15-->1)abeotaxanes having a tetrahydrofuran ring along the carbon atoms C-2, C-3, C-4, C-20 were identified for the first time from the needles of the Canadian yew, Taxus canadensis. The compounds could be identified as 4alpha,10beta,13alpha-triacetoxy-15-benzoyloxy-2alpha,20beta-epoxy-11(15-->1)abeotax-11-ene-5alpha,7beta,9alpha-triol (1) and 4alpha,7beta,9alpha,10beta,15-pentaacetoxy-2...

The Fast Auroral Snapshot Explorer (FAST), with its 83 inclination orbit and 4000 km apogee, is ideally suited for investigation of the high latitude perturbations to the geomagnetic field. These data can be used to determine fieldaligned currents, but here we emphasize the perturbations themselves, rather than their spatial gradient. This allows us to more readily visualize the forces applied ...

Monte Carlo and molecular dynamics simulations were done with three recent water models TIP4P/2005 (Transferable Intermolecular Potential with 4 Points/2005), TIP4P/Ice (Transferable Intermolecular Potential with 4 Points/ Ice) and TIP4Q (Transferable Intermolecular Potential with 4 charges) combined with two models for methane: an all-atom one OPLS-AA (Optimal Parametrization for the Liquid St...

Fast and accurate solutions of large-scale electromagnetics problems involving homogeneous dielectric objects are considered. Problems are formulated with the electric and magnetic current combined-field integral equation and discretized with the Rao-Wilton-Glisson functions. Solutions are performed iteratively by using the multilevel fast multipole algorithm (MLFMA). For the solution of large-...

Diverse electromagnetic (EM) responses of a programmable metasurface with a relatively large scale have been investigated, where multiple functionalities are obtained on the same surface. The unit cell in the metasurface is integrated with one PIN diode, and thus a binary coded phase is realized for a single polarization. Exploiting this anisotropic characteristic, reconfigurable polarization c...