Quality Protein Maize (QPM) is a hard-endosperm version of the high-lysine opaque2 (o2) maize (Zea mays) mutant, but the genes involved in modification of the soft o2 endosperm are largely unknown. Pyrophosphate-dependent fructose-6-phosphate 1-phosphotransferase (PFP) catalyzes the ATP-independent conversion of fructose-6-phosphate to fructose-1,6-bisphosphate in glycolysis. We found a large i...

Apodization of linearly chirped QPM gratings in periodically-poled lithium niobate For second harmonic generation (SHG), it has been shown that the transfer function of a quasi-phasematched (QPM) device is directly related to the Fourier transform of its grating function [1]. For a uniform grating of finite length, this results in a sinc2 response of the SH signal as a function of fundamental w...

Soliton propagation direction can be engineered in optical fibers in the presence of high-order effects (HOEs). It is well known that Raman effects can decelerate the soliton. Here we investigate the manipulation of the deceleration or acceleration of soliton emitted from Airy pulse whose spectrum is imposed an initial quadratic phase modulation (QPM) in optical fibers in the absence of HOEs. W...

Wave-front engineering for nonlinear optical interactions was discussed. Using Huygens-Fresnel principle we developed a general theory and technique for domain engineering with conventional quasi-phase-matching (QPM) structures being the special cases. We put forward the concept of local QPM, which suggests that the QPM is fulfilled only locally not globally. Experiments agreed well with the th...

Quality protein maize (QPM) describes a range of maize cultivars with twice the content of limiting amino acids lysine and tryptophan compared with conventional maize, and has been developed to help reduce human malnutrition in areas where protein deficiency is prevalent and where maize is the major protein source in the diet, as in various parts of Sub-Saharan Africa (SSA). The International M...

OBJECTIVES The accurate diagnosis of malignancy from small bile duct biopsy specimens is often challenging. This proof-of-concept study assessed the feasibility of a novel optical technology, spatial-domain low-coherence quantitative phase microscopy (SL-QPM), that assesses nanoscale structural alterations in epithelial nuclei for improving the diagnosis of malignancy in bile duct biopsy specim...

We propose a paradigm for macroscopic control of high-order harmonic generation by modulating the bound-state population of the medium atoms. A unique result of this scheme is that apart from regular spatial quasi-phase-matching (QPM), also purely temporal QPM of the emitted radiation can be established. Our simulations demonstrate temporal QPM by inducing homogenous Rabi oscillations in the me...

We present a brief overview of different methods for simultaneous phase-matching of several parametric optical processes (the so-called multistep cascading) in engineered structures with the modulated second-order nonlinear susceptibility. In particular, we discuss the possibility of double phase-matching in both uniform and non-uniform quasi-phase-matched (QPM) periodic optical superlattices a...

Ewald sphere is a simple vector scheme to depict the X-ray Bragg diffraction in a crystal. A similar method, known as the nonlinear Ewald sphere, was employed to illustrate optical frequency conversion processes. We extend the nonlinear Ewald sphere to the Ewald shell construction. With the Ewald shell, a variety of quasi-phase-matching (QPM) effects, such as the collective envelope effect asso...

High efficiency of the second-harmonic and sum-frequency generation can be obtained in optical superlattice by using the conventional quasi-phase-matched (QPM) method. Although this trick can be played on the acoustic wave, the media with negative nonlinear parameters are not common in acoustics. Furthermore, the QPM method used in acoustic metamaterials has been less studied. In this work, a p...