Search

Portfolio selection problems are considered in the paper. The securities in the proposed problems are suggested to follow uncertain fractional differential equations which have memory characteristics. By introducing the left semi-deviation of the wealth, two problems are proposed. One is to maximize the expected value and minimize the left semi-variance of the wealth. The other is to maximize the expected value of the wealth with a chance constraint that the left semi-deviation of the wealth is not less than a given number at a confidence level. The problems are equivalent to determinant ones which will be solved by genetic algorithm. Examples are provided to show the effectiveness of the proposed methods.

EGFR signaling promotes ovarian cancer tumorigenesis, and high EGFR expression correlates with poor prognosis. However, EGFR inhibitors alone have demonstrated limited clinical benefit for ovarian cancer patients, owing partly to tumor resistance and the lack of predictive biomarkers. Cotargeting EGFR and the PI3K pathway has been previously shown to yield synergistic antitumor effects in ovarian cancer. Therefore, we reasoned that PI3K may affect cellular response to EGFR inhibition. In this study, we revealed PI3K isoform-specific effects on the sensitivity of ovarian cancer cells to the EGFR inhibitor erlotinib. Gene silencing of PIK3CA (p110α) and PIK3CB (p110β) rendered cells more susceptible to erlotinib. In contrast, low expression of PIK3R2 (p85β) was associated with erlotinib resistance. Depletion of PIK3R2, but not PIK3CA or PIK3CB, led to increased DNA damage and reduced level of the nonhomologous end joining DNA repair protein BRD4. Intriguingly, these defects in DNA repair were reversed upon erlotinib treatment, which caused activation and nuclear import of p38 MAPK to promote DNA repair with increased protein levels of 53BP1 and BRD4 and foci formation of 53BP1. Remarkably, inhibition of p38 MAPK or BRD4 re-sensitized PIK3R2-depleted cells to erlotinib. Collectively, these data suggest that p38 MAPK activation and the subsequent DNA repair serve as a resistance mechanism to EGFR inhibitor. Combined inhibition of EGFR and p38 MAPK or DNA repair may maximize the therapeutic potential of EGFR inhibitor in ovarian cancer.

p85β (PIK3R2), a regulatory subunit of PI3K, has oncogenic properties. Here the authors show that p85β promotes AXL protein stability, which in turn activates p110 to induce PDK1/SGK3 signaling, and therapeutically, p85β-expressing ovarian cancer cells are sensitive to AXL inhibition.

The phosphatidylinositol 3-kinase (PI3K), which is composed of the p85 regulatory and p110 catalytic subunits, is known to be downstream of the receptor tyrosine kinase (RTK). Our recent findings revealed that p85β increases the protein level of AXL (an RTK) to activate p110, suggesting bidirectional regulation between PI3K and RTK.

Highly crystalline body-centered cubic structure Y2O3 with lanthanide (Ln) codopants (Ln = Yb3+/Er3+ and Yb3+/Ho3+) has been synthesized via a moderate hydrothermal method in combination with a subsequent calcination. The structure and morphology of Y(OH)3 precursors and Y2O3 nanoparticles were characterized by X-ray diffraction and transmission electron microscopy. The results reveal that the Y2O3 nanoparticles possess cubic phase and form the quasispherical structure. The upconversion luminescence properties of Y2O3 nanoparticles doped with different Ln3+ (Yb3+/ Er3+ and Yb3+/ Ho3+) ions were well investigated under the 980 nm excitation. The results show that the Yb3+/Er3+ and Yb3+/Ho3+ codoped Y2O3 nanoparticles exhibit strong red and light yellow upconversion emissions, respectively. It is expected that these Y2O3 nanoparticles with tunable multicolor output and intense red upconversion emission may have potential application in color displays and biolabels.

Yb/Er codoped Gd(OH)3 was synthesized firstly via a simple hydrothermal treatment of the corresponding nitrate in the presence of alkali by tuning the pH values. The Gd2O3:Yb/Er nanocrystals were obtained via sintering the corresponding hydroxides precursors. The as-prepared samples were characterized by the typical X-ray diffraction, energy-dispersive X-ray spectroscopy, transmission electron microscopy (TEM), high-resolution TEM, and spectrophotometer. The results revealed that two shapes of the as-prepared Gd2O3:Yb/Er nanocrystals can be readily tuned from lemon-like particle to rod-like structure via tuning pH values from 7 to 14. Moreover, compared with the samples prepared at pH 7, the Gd2O3:Yb/Er nanocrystals prepared at pH 14 exhibit enhanced red upconversion emission and higher upconversion luminescence intensity under the excitation of 980 nm laser.

Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen that causes severe infections in humans and the swine industry. Acquisition and utilization of available carbon sources from challenging host environments is necessary for bacterial pathogens to ensure growth and proliferation. Glycogen is abundant in mammalian body and may support the growth of SS2 during infection in hosts. However, limited information is known about the mechanism between the glycogen utilization and host adaptation of SS2. Here, the pleiotropic effects of exogenous glycogen on SS2were investigated through transcriptome sequencing. Analysis of transcriptome data showed that the main basic metabolic pathways, especially the core carbonmetabolism pathways and virulence-associated factors, of SS2 responded actively to glycogen induction. Glycogen induction led to the perturbation of the glycolysis pathway and citrate cycle, but promoted the pentose phosphate pathway and carbohydrate transport systems. Extracellular glycogen utilization also promoted the mixed-acid fermentation in SS2 rather than homolactic fermentation. Subsequently, apuA, a gene encoding the unique bifunctional amylopullulanase for glycogen degradation, was deleted from the wild type and generated the mutant strain DapuA. The pathogenicity details of the wild type and DapuA cultured in glucose and glycogen were investigated and compared. Results revealed that the capsule synthesis or bacterial morphology were not affected by glycogen incubation or apuA deletion. However, extracellular glycogen utilization significantly enhanced the hemolytic activity, adhesion and invasion ability, and lethality of SS2. The deletion of apuA also impaired the pathogenicity of bacteria cultured in glucose, indicating that ApuA is indeed an important virulence factor. Our results revealed that exogenous glycogen utilization extensively influenced the expression profile of the S. suis genome. Based on the transcriptome response, exogenous glycogen utilization promoted the carbon adaption and pathogenicity of SS2. [ABSTRACT FROM AUTHOR]

A monotone iterations algorithm combined with the finite difference method is constructed for an obstacle problem with semilinear elliptic partial differential equations of second order. By means of Dirac delta function to improve the computation procedure of the discretization, the finite difference method is still practicable even though the obstacle boundary is irregular. The numerical simulations show that our proposed methods are feasible and effective for the nonlinear obstacle problem. [ABSTRACT FROM AUTHOR]

Small-sized BaLaF5:Mn/Yb/Er upconversion nanoparticles (UCNPs) were successfully synthesized for dualmodal X-ray and upconversion (UC) luminescence bioimaging by a simple solvothermal method. The size, shape, and UC luminescence intensity of the as-prepared UCNPs can be readily modified by changing the contents of Mn2+. The size of BaLaF[sub 5] UCNPs doped with Mn2+ decreased largely compared with Mn-free UCNPs. When increasing the content of Mn2+ from 5% to 20%, the size of UCNPs was gradually increased from 6.5 nm to 9.7 nm. The as-prepared BaLaF[sub 5] UCNPs doped with 20% Mn2+ present intense UC luminescence. The in vitro UC luminescence imaging of HeLa cells and localized spectra detected from HeLa cells and the background based on these BaLaF[sub 5]:Mn/Yb/Er (20/20/2%) UCNPs indicate that this sample can serve as an ideal bioprobe with the absence of autofluorescence under the excitation of 980 nm laser. Moreover, an obvious UC signal was observed in in vivo UC bioimaging, demonstrating that these BaLaF5:Mn/Yb/Er (20/20/2%) UCNPs can also be used as bioprobes for whole body optical bioimaging. In addition, owing to the high X-ray mass absorption coefficients of Ba2+, La3+ and the doped Yb3+, the simultaneous X-ray and UC in vivo bioimaging of a nude mouse further demonstrate that the as-prepared UCNPs can be successfully used as dual-modal bioprobes. Ex vivo UC bioimaging revealed that these UCNPs gathered at the lung of a mouse at the initial time, demonstrating that this sample was suitable for the detection of the lung diseases. In addition, the cytotoxicity test showed that the UCNPs possessed little toxicity. Therefore, the small-sized BaLaF5:Yb/Er/Mn UCNPs are ideal nanoprobes for dual-modal UC luminescence/X-ray bioimaging with non-autofluorescence, and enhanced detection of the lung diseases. [ABSTRACT FROM AUTHOR]

Polyethylene glycol (PEG) modified BaLuF5:Gd/Yb/Er upconversion nanoparticles (UCNPs) were synthesized by a facile one-pot hydrothermal method for simultaneous synthesis and surface functionalization. The novel, excellently biocompatible and water-soluble bioprobes were used for simultaneous upconversion (UC) luminescence and X-ray bioimaging for the first time. The as-prepared BaLuF5:Gd/Yb/ Er UCNPs possess a face-centered cubic structure with an average size of 23.7 ± 2.7 nm. Under 980 nm laser excitation, these UCNPs emitted intense UC luminescence via a two-photon process. In vitro bioimaging and localized luminescence spectra detected from HeLa cells and the background reveal that these UCNPs are ideal candidates for optical bioimaging in the absence of autofluorescence. Furthermore, the synergistic in vivo UC luminescence and X-ray bioimaging reveal that these PEG-modified BaLuF5:Gd/Yb/Er UCNPs can be successfully used as ideal dual-modal bioprobes. These results demonstrate that these PEG modified UCNPs are ideal multi-modal nanoprobes for bioimaging. [ABSTRACT FROM AUTHOR]

The effect of chemotherapy drug Mitomycin C (MMC) in combination with recombinant adeno-associated virus II (rAAV2) in cancer therapy was investigated, and the mechanism of MMC affecting rAAV2's bioactivity was also studied. The combination effect was evaluated by the level of GFP and TNF expression in a human glioma cell line, and the mechanism of MMC effects on rAAV mediated gene expression was investigated by AAV transduction related signal molecules. C57 and BALB/c nude mice were injected with rAAV-EGFP or rAAV-TNF alone, or mixed with MMC, to evaluate the effect of MMC on AAV-mediated gene expression and tumor suppression. MMC was shown to improve the infection activity of rAAV2 both in vitro and in vivo. Enhancement was found to be independent of initial rAAV2 receptor binding stage or subsequent second-strand synthesis of target DNA, but was related to cell cycle retardation followed by blocked genome degradation. In vivo injection of MMC combined with rAAV2 into the tumors of the animals resulted in significant suppression of tumor growth. It was thus demonstrated for the first time that MMC could enhance the expression level of the target gene mediated by rAAV2. The combination of rAAV2 and MMC may be a promising strategy in cancer therapy. [ABSTRACT FROM AUTHOR]

Yb/Er codoped Gd(OH)3 was synthesized firstly via a simple hydrothermal treatment of the corresponding nitrate in the presence of alkali by tuning the pH values. The Gd2O3:Yb/Er nanocrystals were obtained via sintering the corresponding hydroxides precursors. The as-prepared samples were characterized by the typical X-ray diffraction, energy-dispersive X-ray spectroscopy, transmission electron microscopy (TEM), high-resolut ion TEM, and spectrophotometer. The results revealed that two shapes of the as-prepared Gd2O3:Yb/Er nanocrystals can be readily tuned from lemon-like particle to rod-like structure via tuning pH values from 7 to 14. Moreover, compared with the samples prepared at pH 7, the Gd3O3:Yb/Er nanocrystals prepared at pH 14 exhibit enhanced red upconversion emission and higher upconversion luminescence intensity under the excitation of 980 nm laser. [ABSTRACT FROM AUTHOR]

Highly crystalline body-centered cubic structure Y2O3 with lanthanide (Ln) codopants (Ln = Yb 3+/Er 3+ and Yb 3+/Ho 3+) has been synthesized via a moderate hydrothermal method in combination with a subsequent calcination. The structure and morphology of Y(OH)3 precursors and Y2O3 nanoparticles were characterized by X-ray diffraction and transmission electron microscopy. The results reveal that the Y2O3 nanoparticles possess cubic phase and form the quasispherical structure. The upconversion luminescence properties of Y2O3 nanoparticles doped with different Ln3+ (Yb 3+/Er 3+ and Yb 3+/Ho 3+) ions were well investigated under the 980 nm excitation. The results show that the Yb Yb 3+/Er 3+ and Yb 3+/Ho 3+ codoped Y2O3 nanoparticles exhibit strong red and light yellow upconversion emissions, respectively. It is expected that these Y2O3 nanoparticles with tunable multicolor output and intense red upconversion emission may have potential application in color displays and biolabels. [ABSTRACT FROM AUTHOR]

A fictitious domain method, in which the Dirichlet boundary conditions are treated using boundary supported Lagrangian multipliers, is considered. The technique of the immersed boundary method is incorporated into the framework of the fictitious domain method. Contrary to conventional methods, it does not make use of the finite element discretization. It has a simpler structure and is easily programmable. The numerical simulation of two-dimensional incompressible inviscid uniform flows over a circular cylinder validates the methodology and the numerical procedure. The numerical simulation of propagation phenomena for time harmonic electromagnetic waves by methods combining controllability and fictitious domain techniques is also presented. Using distributed Lagrangian multipliers, the propagation of the wave can be simulated on an obstacle free computational region with regular finite element meshes essentially independent of the geometry of the obstacle and by a controllability formulation which leads to algorithms with good convergence properties for time-periodic solutions. The numerical results presented are in good agreement with those in the literature using obstacle fitted meshes. [ABSTRACT FROM AUTHOR]