Lycopene/tomato has been discussed as a potential effecter in the prevention and therapy of prostate cancer; however, no systematic review has been reported to illustrate its effect recently. In the present study, a meta-analysis was carried out to determine whether intake of lycopene and tomato/tomato products could reduce the risk of prostate cancer. Eleven cohort studies and six nested case-control studies were identified through searching of international journal databases and reference lists of relevant publications. Two reviewers independently assessed the study quality and extracted data from each identified study; only studies with sufficient quality were included in the review. The main outcome of interest was incidence of prostate cancer. Compared with consumers of lower raw tomato intake, the odds ratio (OR) of incidence of prostate cancer among consumers of higher raw tomato intake was 0.81 [95% confidential interval (CI) 0.59-1.10]; for consumers of higher level of cooked tomato intake versus lower cooked tomato intake, this OR was 0.85 (95% CI 0.69-1.06); the OR of higher lycopene intake versus lower lycopene intake for prostate cancer was 0.93 (95% CI 0.86-1.01) and the OR for higher level of serum lycopene versus lower serum lycopene level was 0.97 (95% CI 0.88-1.08). It's suggested that tomato may play a modest role in the prevention of prostate cancer. Further research would be needed to determine the type and quantity of tomato products regarding their potential in preventing prostate cancer.

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The b-nucleation behavior of isotactic polypropylene (iPP) is a fascinating and important issue in polymer physics; however, little about this phenomenon or its physical nature has been clearly understood. In the present study, by tuning the heating temperature (fusion temperature, T f ), the amount of ordered structures in iPP melt was controlled. In this way, the influence of five types of representative bnucleating agents (b-NA) on the crystallization behavior of iPP with different melt structures (i.e. the amount of ordered structures) was comparatively studied by differential scanning calorimetry (DSC), polarized optical microscopy (PLOM), scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXD) and rheological measurement. A surprising synergetic effect was observed between b-NAs with a-/b-dual polymorphic selectivity (dual-selective b-NA) and the ordered structure of iPP, resulting in significant increases of the b-nucleation efficiency and the b-phase proportion of the sample. PLOM observation of the crystallization process confirmed that with the presence of ordered structures in iPP melt, a mass of dark, small crystal embryos derived from self-nuclei uniformly distributed in the melt and exhibited b-nucleation efficiency. This work provides the first evidence that for iPP nucleated with dualselective b-NA, the ordered structures play a determining role in the b-nucleation of iPP. Under the influence of the dual-selective b-NA, the ordered structures exhibited b-nucleation efficiency and therefore encouraged b-nucleation. A possible mechanism was proposed.

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The physical and chemical effects of ultrasound on polypropylene (PP) melts in extrusion were investigated. By applying ultrasound vibration to the entrance of the die, apparent pressure and viscosity of PP can be obviously decreased under the appropriate ultrasound power. Ultrasound has both physical and chemical effects on the polymer melt. In our study with specific polymer and ultrasound system, we determined that the chemical effect makes up 35-40% of the total effect of ultrasound on the apparent viscosity reduction of PP melts at most of the studied intensities. The physical effect plays a more important role in the ultrasound-applied extrusion than the chemical effect. This chemical effect is an irreversible and permanent change in molecule weight and the molecular-weight distribution due to ultrasound. As the ultrasound intensity increases, the molecular weight of PP reduces and its molecular-weight distribution becomes narrower; the orientation of PP molecules along the flow direction reduces (in melt state) and the crystallinity of PP samples (in solid state) decreases by applying the ultrasound vibration. Ultrasound vibration increases the motion of molecular chains and makes them more disorder; it also affects the relaxation process of polymer melts by shortening the relaxation time of chain segments, leading to weakening the elastic effect and decreasing the extruding swell ratios. All the factors discussed above reduce the non-Newtonian flow characteristics of the polymer melt and result in the viscosity drop of the polymer melt in extrusion.

Polyamide thin film composite (TFC) reverse osmosis (RO) membranes were prepared in this study.

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