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  • Reynolds Melvin posted an update 3 weeks, 2 days ago

    Trivalent praseodymium exhibits a wide range of luminescent phenomena when doped into a variety of different materials. Herein, radioluminescent NaLuF420%Pr3+ nanoparticles are studied. Four different samples of this composition were prepared ranging from 400-70 nm in size. Kinetic studies of radioluminescence as a function of X-ray irradiation time revealed a decrease in the emissions originating from the 1S0 level, due to the formation or optical activation of defects during excitation, and a simultaneous increase in the visible emissions resulting from the lower optical levels. Thermoluminescence measurements elucidated that a local de-trapping mechanism was responsible for the increase in steady state emission and persistent luminescence originating from the lower optical levels. The results and mechanism described through this study serve to provide a novel nanoparticle composition with versatile luminescent properties and provides experimental evidence in favor of a local trapping model.Breast cancer is a metastatic cancer that can spread to other organs, such as the bone, liver, and brain. There are many treatments for breast cancer, such as surgery and chemotherapy, but they lead to resistance and side effects. Therefore, the discovery of new therapies with high efficacy and low toxicity that selectively affect cancer cells is of great importance. Of late, the combination therapy has been suggested as a novel approach compared to existing treatments. In the present study, the effect of the combined treatment of doxorubicin (DOX) and methylene blue activated in the presence of laser irradiation (PDT) on triple-negative breast cancer cells has been investigated. Human breast cancer cell line MDA-MB-231 was exposed to different concentrations of DOX, methylene blue (MB) and DOX-methylene blue (MB-DOX) combination therapy in two different conditions first the treatment with DOX and then with MB-PDT, and another treatment first with MB-PDT and then with DOX. Cell viability was evaluated using the MTT assay. selleck chemicals Morphological and colonization changes were observed by light microscopy. The occurrence of apoptotic cell death was assessed by double-staining ethidium bromide-acridine orange using fluorescence microscopy and flow cytometry. The results showed that the combination of using MB-PDT, followed by DOX (even at low concentrations), has a better effect on inducing cancer cell death in comparison to DOX alone. The result of this study suggests that the combination therapy of MB-PDT-DOX can be used as a potential strategy for the treatment of triple-negative breast cancer cells.This study focused on the processing and photothermal healing of gold nanoparticle (Au NP) and polystyrene (PS) hybrid films. Effects of Au NP contents were investigated using hybrid films with the NP content from 0 to 1 wt% via a solvent-assisted approach. The as-synthesized Au NPs showed an average diameter of 4-5 nm with a face-centered cubic structure. The Au NP agglomeration deteriorated as the content increased and the interparticle distance decreased. The film transparency and flexibility also decreased with the NP content. The Au-PS films demonstrated desirable photothermal healing behaviors, which required more energy with the defect size increase. The simulated temperature distribution on the hybrid films during the photo-induced healing showed good agreement with the experimental results, with particle agglomeration degrading the healing properties. The developed hybrid films can be used in functional devices and coatings with high flexibility and healed using photon energy sources.Isonitriles, being competent σ-donors, show a strong aptitude to form transition-state metal complexes. Nevertheless, until the end of the last century, few metal-isonitrile catalyzed processes were known. Only more recently, scientists recognized the considerable potential of isonitriles as ligands in metal catalysis utilizing both commercially available but also specially designed representatives of this compound class. Isonitrile ligands, which can be both innocent or non-innocent constituents in metal complexes, contributed to the discovery of new catalytic processes and thereby to one of the fastest growing areas of organic chemistry. This review focuses on the special properties and attributes metal-isonitrile complexes offer towards their application in catalysis.A signal amplification strategy based on the horseradish peroxidase catalyzed polymerization of dopamine on a polymeric ion-selective membrane surface is proposed for the sensitive chronopotentiometric detection of an aptamer-target binding event.Macrocyclic hexaoxazoles (6OTDs) are G-quadruplex (G4) ligands, and some derivatives, such as L2H2-6OTD (1a) bearing two aminobutyl side chains, show cytotoxicity towards cancer cells. To identify the cellular target of 1a, we employed a post-target-binding strategy utilizing click reaction (Huisgen cyclization) between the azide-conjugated ligand L2H2-6OTD-Az (1b) and the cell-permeable dye CO-1 bearing a strained alkyne moiety and the BODIPY fluorophore under Cu-free conditions. We confirmed that introduction of the small azide group did not alter the physical or biological properties, including anti-cancer activity, of 1a, and we also demonstrated bias-free localization of CO-1. The post-binding visualization strategy suggested that L2H2-6OTD (1a) colocalized with RNA G4 in living cells.We have developed site-selective bromination on the mesityl substituents of 10,20-dimesityl-5,15-diazaporphyrins. Treatment of 10,20-dimesityl-5,15-diazaporphyrin and its nickel(ii) complex with a combination of AuBr3/AgOTf induced selective bromination on the mesityl groups. These brominated products can be employed for late-stage modification of the aryl substituents.Silanes have enjoyed significant success as synthetic tools in the last few decades. In many of the reactions that use silanes, a pentacoordinate silicate is proposed as the reactive intermediate. Despite this, there is no general method to synthesize pentacoordinate fluorosilicates and use them as reagents instead of organo- or alkoxysilanes. Herein, we report the first practical synthesis of organotetrafluorosilicates. The method is tolerant of a number of different functional groups including electrophiles with preferential attack of the fluoride on the silane rather than the electrophile. This transformaton is generally high yielding, even at the mole scale. Furthermore, we demonstrate that organotetrafluorosilicates are both more reactive than the corresponding trialkoxysilanes and more stable under solvolytic conditions. Organotetrafluorosilicates can be used as substrates for a variety of coupling reactions, oxidations, and radical reactions. Overall, organotetrafluorosilicates represent a new platform on which to develop challenging transformations.

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