1,248 research outputs found
A Polyrotaxane-based pH-labile Drug Delivery System
A novel polyrotaxane (PR)-based triblock copolymer was exploited as polymeric carrier for doxorubicin (DOX). A sample holding a feed molar ratio of Pluronic F127 to β-CD to poly(ethylene glycol) methyl ether methacrylate (PEGMA) equal to 1:30:20 was synthesized via the in situ atom transfer radical polymerization (ATRP) and then conjugated with DOX using pH sensitive hydrazone linker. The resulting PR-DOX conjugates enabled to self-assemble into nano-particles of about 70 nm in diameter in aqueous solution as evidenced by TEM. The release of DOX was varied from 10 % to 37 % over 72 h at physiological and acidic pH, respectively. The PR-based triblock copolymer without DOX conjugation showed almost non toxicity, while these nano-particles with DOX conjugation presented increased toxicity
[μ-1,2-Bis(diphenylphosphino)ethane-κ2 P:P′]bis{[1,2-bis(diphenylphosphino)ethane-κ2 P,P′]cyanidocopper(I)} methanol disolvate
The title centrosymmetric complex, [Cu2(CN)2(C26H24P2)3]·2CH3OH, consists of two five-membered [Cu(dppe)CN] rings [dppe is 1,2-bis(diphenylphosphino)ethane] bridged by one μ2-dppe ligand, and two methanol solvent molecules. The angles around the central metal atom indicate that each CuI atom is located in the center of a distorted tetrahedron. The coordination sphere of each CuI atom is formed by three P atoms from two dppe ligands, and one C atom from the cyanide ligand. The crystal structure is stabilized by O—H⋯N hydrogen bonds, which are formed by the O—H donor group from methanol and the N-atom acceptor from a cyanide ligand
Incorporation of GM-CSF or CD40L Enhances the Immunogenicity of Hantaan Virus-Like Particles
A safe and effective Hantaan virus (HTNV) vaccine is highly desirable because HTNV causes an acute and often fatal disease (hemorrhagic fever with renal syndrome, HFRS). Since the immunity of the inactivated vaccine is weak and the safety is poor, HTNV virus-like particles (VLPs) offer an attractive and safe alternative. These particles lack the viral genome but are perceived by the immune system as virus particles. We hypothesized that adding immunostimulatory signals to VLPs would enhance their efficacy. To accomplish this enhancement, we generated chimeric HTNV VLPs containing glycosylphosphatidylinositol (GPI)-anchored granulocyte macrophage colony-stimulating factor (GM-CSF) or CD40 ligand (CD40L) and investigated their biological activity in vitro. The immunization of mice with chimeric HTNV VLPs containing GM-CSF or CD40L induced stronger humoral immune responses and cellular immune responses compared to the HTNV VLPs and Chinese commercial inactivated hantavirus vaccine. Chimeric HTNV VLPs containing GM-CSF or CD40L also protected mice from an HTNV challenge. Altogether, our results suggest that anchoring immunostimulatory molecules into HTNV VLPs can be a potential approach for the control and prevention of HFRS
Pleiotropic Roles of ChSat4 in Asexual Development, Cell Wall Integrity Maintenance, and Pathogenicity in Colletotrichum higginsianum
Potassium has an important role to play in multiple cellular processes. In Saccharomyces cerevisiae, the serine/threonine (S/T) kinase Sat4/Hal4 is required for potassium accumulation, and thus, regulates the resistance to sodium salts and helps in the stabilization of other plasma membrane transporters. However, the functions of Sat4 in filamentous phytopathogenic fungi are largely unknown. In this study, ChSat4, the yeast Sat4p homolog in Colletotrichum higginsianum, has been identified. Target deletion of ChSAT4 resulted in defects in mycelial growth and sporulation. Intracellular K+ accumulation was significantly decreased in the ChSAT4 deletion mutant. Additionally, the ΔChsat4 mutant showed defects in cell wall integrity, hyperoxide stress response, and pathogenicity. Localization pattern analysis indicated ChSat4 was localized in the cytoplasm. Furthermore, ChSat4 showed high functional conservation with the homolog FgSat4 in Fusarium graminearum. Taken together, our data indicated that ChSat4 was important for intracellular K+ accumulation and infection morphogenesis in C. higginsianum
Spatio-temporal Markov chain model for very-short-term wind power forecasting
Wind power forecasting (WPF) is crucial in helping schedule and trade wind power generation at various spatial and temporal scales. With increasing number of wind farms over a region, research focus of WPF methods has been recently moved onto exploring spatial correlation among wind farms to benefit forecasting. In this study, a spatio-temporal Markov chain model is proposed for very-short-term WPF by extending the traditional discrete-time Markov chain and incorporating off-site reference information to improve forecasting accuracy of regional wind farms. Not only are the transitions between the power output states of the target wind farm itself considered in the forecasting model, but also the transitions from the output states of reference wind farms to that of the target wind farm are introduced. The forecasting results derived from multiple spatio-temporal Markov chains regarding different reference wind farms over the same region are optimally weighted using sparse optimisation to generate forecasts of the target wind farm. The proposed method is validated by comparing with both local and spatio-temporal WPF methods, using a real-world dataset
Phenotypic Differentiation Is Associated with Gender Plasticity and Its Responsive Delay to Environmental Changes in Alternanthera philoxeroides – Phenotypic Differentiation in Alligator Weed
Phenotypic plasticity is common in many taxa, and it may increase an organism's fitness in heterogeneous environments. However, in some cases, the frequency of environmental changes can be faster than the ability of the individual to produce new adaptive phenotypes. The importance of such a time delay in terms of individual fitness and species adaptability has not been well studied. Here, we studied gender plasticity of Alternanthera philoxeroides to address this issue through a reciprocal transplant experiment. We observed that the genders of A. philoxeroides were plastic and reversible between monoclinous and pistillody depending on habitats, the offspring maintained the maternal genders in the first year but changed from year 2 to 5, and there was a cubic relationship between the rate of population gender changes and environmental variations. This relationship indicates that the species must overcome a threshold of environmental variations to switch its developmental path ways between the two genders. This threshold and the maternal gender stability cause a significant delay of gender changes in new environments. At the same time, they result in and maintain the two distinct habitat dependent gender phenotypes. We also observed that there was a significant and adaptive life-history differentiation between monoclinous and pistillody individuals and the gender phenotypes were developmentally linked with the life-history traits. Therefore, the gender phenotypes are adaptive. Low seed production, seed germination failure and matching phenotypes to habitats by gender plasticity indicate that the adaptive phenotypic diversity in A. philoxeroides may not be the result of ecological selection, but of gender plasticity. The delay of the adaptive gender phenotype realization in changing environments can maintain the differentiation between gender systems and their associated life-history traits, which may be an important component in evolution of novel traits and taxonomic diversity
[1,3-Bis(diphenylphosphanyl)propane-κ2 P,P′](1,10-phenanthroline-κ2 N,N′)copper(I) perchlorate
The title compound, [Cu(C12H8N2)(C27H26P2)]ClO4, crystallizes with two CuI complex cations and two perchlorate anions in the asymmetric unit. Each CuI cation is four-coordinated by two P atoms of a 1,3-bis(diphenylphosphanyl)propane molecule and two N atoms of a 1,10-phenanthroline ligand, with a coordination geometry that can be considered as distorted tetrahedral. The crystal studied was twinned with a twin ratio of 0.786 (2):0.214 (2)
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