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High-quality protein crystals of suitable size are an important prerequisite for applying X-ray crystallography to determine the 3-dimensional structure of proteins. However, it is often difficult to obtain protein crystals of appropriate size and quality because nucleation and growth processes can be unsuccessful. Here, we show that by adsorbing proteins onto porous polystyrene-divinylbenzene microspheres (SDB) floating on the surface of the crystallisation solution, a localised high supersaturation region at the surface of the microspheres and a low supersaturation region below the microspheres can coexist in a single solution. The crystals will easily nucleate in the region of high supersaturation, but when they grow to a certain size, they will sediment to the region of low supersaturation and continue to grow. In this way, the probability of crystallisation and crystal quality can be simultaneously increased in a single solution without changing other crystallisation parameters. [ABSTRACT FROM AUTHOR]

Mesoporous silica nanoscale microsphere (MSNM), with a special morphology, high porosity, large pore volume and specific surface area, was successfully prepared and used as the matrix material of lauric acid (LA) to prepare a favorable shape-stabilized phase change material (LA/MSNM). The porous network structure of MSNM is effective to prevent the leakage and enhance the thermal stability of LA/MSNM. For comparison, shape-stabilized phase change material of LA/AC, which contained commercially purchased active carbon (AC) and LA, was prepared by the same method. Characterizations of LA/MSNM and LA/AC, such as chemical properties, structure, thermal properties and crystallization properties were studied. The mechanisms of interaction between LA molecules and MSNM or AC were explicated. The results of TGA test showed that the LA/MSNM and LA/AC had superior thermal stability, and however, the melting and solidification enthalpies of LA/MSNM were much higher than that of LA/AC, which was attributed that the loading capacity of MSNM was better than that of LA/AC. All of the study results demonstrated that the mesoporous silica nanoscale microspheres of MSNM synthesized in this study possessed the potential for practical applications as a suitable supporter of organic phase change materials. [ABSTRACT FROM AUTHOR]

Protein crystallization is affected by many parameters, among which certain parameters have not been well controlled. The temperature at which the protein and precipitant solutions are mixed (i.e., the ambient temperature during mixing) is such a parameter that is typically not well controlled and is often ignored. In this paper, we show that this temperature can influence protein crystallization. The experimental results showed that both higher and lower mixing temperatures can enhance the success of crystallization, which follows a parabolic curve with an increasing ambient temperature. This work illustrates that the crystallization solution preparation temperature is also an important parameter for protein crystallization. Uncontrolled or poorly controlled room temperature may yield poor reproducibility in protein crystallization. [ABSTRACT FROM AUTHOR]