In this study, we report the effects of hydroxypropyl methylcellulose (HPMC) and KH2PO4 on the water resistance of magnesium oxychloride cement (MOC), a novel bone cement composite. Different MOC samples were soaked in simulated body fluid (SBF). After soaking for 7–56 d, the surfaces of the experimental group (1 wt.% HPMC/2 wt.% KH2PO4-MOC) and control group (2 wt.% KH2PO4-MOC) appeared pores, which grew with increasing immersion time. Compared with the control group, the experimental group had smaller pore sizes and a denser surface. Furthermore, the compressive strength in the experimental group increased from 35.1 ± 1.9 MPa to 41.8 ± 2.3 MPa, and the softening coefficient increased from 0.34 to 0.45. Thus, HPMC could improve the water erosion resistance of the MOC. The implantation study of the femoral defects in rats showed that the sample modified by 1 wt.% HPMC/2 wt.% KH2PO4 had good biocompatibility and biodegradability. The results indicate that the modification of MOC with HPMC and KH2PO4 is a promising technique to form biodegradable bone repair materials and has good application prospects in the field of biomedical materials.
Fusarium root and stem rot in sweetpotato are prevalent in the main sweetpotato-growing areas in China, and fungal isolation, morphological characteristics, and molecular phylogenetic analysis of the disease causal agent ( F. solani-melongenae isolate CRI 24-3) were systematically studied. The genome sequence of F. solani-melongenae isolates CRI 24-3 was first reported, which should provide a basis for genome assembly of other closely related Fusarium species.
Realistic image composite requires the appearance of foreground and background layers to be consistent. This is difficult to achieve because the foreground and the background may be taken from very different environments. This paper proposes a novel composite adjustment method that can harmonize appearance of different composite layers. We introduce the Best-Buddy Prior (BBP), which is a novel compact representations of the joint co-occurrence distribution of natural image patches. BBP can be learned from unlabelled images given only the unsupervised regional segmentation. The most-probable adjustment of foreground can be estimated efficiently in the BBP space as the shift vector to the local maximum of density function. Both qualitative and quantitative evaluations show that our method outperforms previous composite adjustment methods.
In a competitive electricity market with substantial involvement of renewable electricity, maximizing profits by optimizing bidding strategies is crucial to different power producers including conventional power plants and renewable ones. This paper proposes a game-theoretic bidding optimization method based on bi-level programming, where power producers are at the upper level and utility companies are at the lower level. The competition among the multiple power producers is formulated as a non-cooperative game in which bidding curves are their strategies, while uniform clearing pricing is considered for utility companies represented by an independent system operator. Consequently, based on the formulated game model, the bidding strategies for power producers are optimized for the day-ahead market and the intraday market with considering the properties of renewable energy; and the clearing pricing for the utility companies, with respect to the power quantity from different power producers, is optimized simultaneously. Furthermore, a distributed algorithm is provided to search the solution of the generalized Nash equilibrium. Finally, simulation results were performed and discussed to verify the feasibility and effectiveness of the proposed non-cooperative game-based bi-level optimization approach.
At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo) and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China's stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress.
