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In this study, nonspherical poly(methyl methacrylate)/poly(styrene-co-divinylbenzene) [PMMA/P(St-co-DVB)] particles having multiple dents on the surface were prepared by seeded soap-free emulsion copolymerization of St and DVB (used as a crosslinker) on spherical linear PMMA seed particles. The effect of various polymerization parameters on particle morphology, as well as polymerization kinetics and morphological evolution, were investigated in detail. It was found that, to prepare this kind of nonspherical particles, it was necessary to conduct the polymerization at a relatively low temperature, using batch monomer addition mode and PMMA seed of relatively high molecular weight. The formation of the nonspherical particles was attributed to the phase separation between the second-stage monomers and the crosslinked P(St-co-DVB) network being formed during polymerization. [ABSTRACT FROM AUTHOR]

Purpose. To study the differential expression of the S100 gene family at the RNA level in human esophageal squamous cell carcinoma (ESCC), and to find the relationship of the S100 gene family with ESCC. Methods. Firstly, the specific primers were designed for the different S100 genes with Software Primer 3, which required that both primer sequences of each S100 gene were from two different exons respectively. Then, the differential expression of 16 S100 genes was examined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) in 62 cases of ESCC versus the corresponding normal esophageal mucosa. All RT-PCR products were analyzed by 1.5% agarose gel. With Fluor-S MultiImager and Multi-Analyst software, the electrophoresis images were evaluated with statistics analysis using SAS 8.1 software. Results. Eleven out of 16 S100 genes were significantly downregulated (p<0.05) in ESCC versus the normal counterparts such as S100A1, S100A2, S100A4, S100A8, S100A9, S100A10, S100A11, S100A12, S100A14, S100B, and S100P genes. Only the S100A7 gene in the S100 family was markedly upregulated (p<0.05). Moreover, the S100B gene was significantly correlated with histological differentiation of ESCC (p=0.0247), and the deregulation of some S100 genes was closely correlated (p<0.05), such as S100A10/S100A11, S100A2/S100A8, S100A2/S100A14, S100A8/S100A14, and S100A2/S100P etc. Conclusions. The S100 gene family is closely associated with ESCC. [ABSTRACT FROM AUTHOR]

It is shown that the state of magnetization of the substrate is one of the main factors affecting the properties of nonreciprocal latching ferrite microstrip phase shifter. Raising the residual magnetization of the substrate, increasing the ratio R(=4π M/4π M ) (4π M-the magnetization of the 'latching state' of the device, 4π M -the saturation magnetization) are effective in reducing the insertion loss of the device, raising the effectiveness of phase shift, extending the band width, and reducing the drive power, etc. Different methods of magnetization are analysed and compared. Photographs indicating the structure and the external form of the device are given and the main performances of single-digit and multi-digit devices are also presented. [ABSTRACT FROM AUTHOR]