Bovine milk ß-casein: Structure, properties, isolation, and targeted application of isolated products.

ß-Casein, an important protein found in bovine milk, has significant potential for application in the food, pharmaceutical, and other related industries. This review first introduces the composition, structure, and functional properties of ß-casein. It then reviews the techniques for isolating ß-casein. Chemical and enzymatic isolation methods result in inactivity of ß-casein and other components in the milk, and it is difficult to control the production conditions, limiting the utilization range of products. Physical technology not only achieves high product purity and activity but also effectively preserves the biological activity of the components. The isolated ß-casein needs to be utilized effectively and efficiently for various purity products in order to achieve optimal targeted application. Bovine ß-casein, which has a purity higher than or close to that of breast ß-casein, can be used in infant formulas. This is achieved by modifying its structure through dephosphorylation, resulting in a formula that closely mimics the composition of breast milk. Bovine ß-casein, which is lower in purity than breast ß-casein, can be maximized for the preparation of functional peptides and for use as natural carriers. The remaining byproducts can be utilized as food ingredients, emulsifiers, and carriers for encapsulating and delivering active substances. Thus, realizing the intensive processing and utilization of bovine ß-casein isolation. This review can promote the industrial production process of ß-casein, which is beneficial for the sustainable development of ß-casein as a food and material. It also provides valuable insights for the development of other active substances in milk.

Mathematical modeling for intracellular transport and binding of HIV-1 Gag proteins.

This paper presents a modeling study for the intracellular trafficking and trimerization of the HIV-1 Gag proteins. A set of differential equations including initial and boundary conditions is used to characterize the transport, diffusion, association and dissociation of Gag monomers and trimers for the time period from the initial production of Gag protein monomers to the initial appearance of immature HIV-1 virions near the cell membrane (the time duration Ta). The existence and stability of the steady-state solution of the initial boundary value problems provide a quantitative characterization of the tendency and equilibrium of Gag protein movement. The numerical simulation results further demonstrate Gag trimerization near the cell membrane. Our calculations of Ta are in good agreement with published experimental data. Sensitivity analysis of Ta to the model parameters indicates that the timing of the initial appearance of HIV-1 virions on the cell membrane is affected by the diffusion and transport processes. These results provide important information and insight into the Gag protein transport and binding and HIV-1 virion formation.

A linear method to derive 3D projective invariants from 4 uncalibrated images.

A well-known method proposed by Quan to compute projective invariants of 3D points uses six points in three 2D images. The method is nonlinear and complicated. It usually produces three possible solutions. It is noted previously that the problem can be solved directly and linearly using six points in five images. This paper presents a method to compute projective invariants of 3D points from four uncalibrated images directly. For a set of six 3D points in general position, we choose four of them as the reference basis and represent the other two points under this basis. It is known that the cross ratios of the coefficients of these representations are projective invariant. After a series of linear transformations, a system of four bilinear equations in the three unknown projective invariants is derived. Systems of nonlinear multivariable equations are usually hard to solve. We show that this form of equations can be solved linearly and uniquely. This finding is remarkable. It means that the natural configuration of the projective reconstruction problem might be six points and four images. The solutions are given in explicit formulas.

Yellow-green 52.3W laser at 556nm based on frequency doubling of a diode side-pumped Q-switched Nd:YAG laser.

We demonstrate a high-power 556nm yellow-green laser generated by intracavity frequency doubling of a diode side-pumped Nd:YAG laser at 1112nm. A symmetrical L-shaped flat-flat cavity was employed to implement efficient operation of the low-gain 1112nm transition and to achieve good power scalability. The coatings of the cavity mirrors were carefully designed to optimize the performance of the laser, and a 92W continuous wave laser output at 1112nm was achieved when the pumping power of the laser diodes reached 960W. By intracavity frequency doubling of the fundamental laser in a lithium triborate crystal, the maximum power of the frequency-doubled output at 556nm was found to be as high as 52.3W with a pulse repetition frequency of 10kHz. This corresponds to an optical-to-optical conversion efficiency of about 5.4%.