215 research outputs found

    Ashcroft v. Iqbal: The Question of a Heightened Standard of Pleading in Qualified Immunity Cases

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    Background We have previously shown that Lactobacillus reuteri supplementation from pregnancy week 36 and to the infant through the first year of life decreased the prevalence of IgE-associated eczema at 2 years. The underlying immunological mechanisms are unknown, however. Objective To investigate the immunomodulatory effect of probiotic supplementation on allergen- and mitogen-induced immune responses in children until 2 years of age. Methods Blood mononuclear cells were collected at birth, 6, 12 and 24 months from 61 children (29 probiotic and 32 placebo treated) and cultured with ovalbumin, birch and cat extract and Phytohaemagglutinin (PHA). Cytokine and chemokine secretion was determined using an in-house multiplexed Luminex assay and ELISA. Real-time PCR was performed to investigate the Ebi3, Foxp3, GATA-3 and T-bet mRNA expression. Results Probiotic treatment was associated with low cat-induced Th2-like responses at 6 months (IL-5, P = 0.01, and IL-13, P = 0.009), with a similar trend for IL-5 at 12 months (P = 0.09). Cat-induced IFN-γ responses were also lower after probiotic than after placebo treatment at 24 months (P = 0.007), with similar findings for the anti-inflammatory IL-10 at birth (P = 0.001) and at 12 months (P = 0.009). At 24 months, Th2-associated CCL22 levels were lower in the probiotic than in the placebo group after birch stimulation (P = 0.02), with a similar trend after ovalbumin stimulation (P = 0.07). Lower CCL22 levels were recorded at 12 and 24 months (P = 0.03 and P = 0.01) after PHA stimulation. Conclusion and Clinical Relevance Lactobacillus reuteri supplementation decreases allergen responsiveness and may enhance immunoregulatory capacity during infancy. L. reuteri supplementation from week 36 and during the first year of life significantly decreases IgE-associated eczema and lowers allergen and mitogen responsiveness.Funding Agencies|Swedish Research Council|K2011-56X-21854-01-06|Ekhaga Foundation||Olle Engkvist Foundation||Heart and Lung foundation||Research Council for the South-East Sweden|F2000-106|Swedish Asthma and Allergy Association||Cancer and Allergy Association||BioGaia AB, Stockholm, Sweden||University Hospital of Linkoping, Sweden||</p

    Optically Switchable NIR Photoluminescence of PbS Semiconducting Nanocrystals using Diarylethene Photoswitches

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    Precisely modulated photoluminescence (PL) with external control is highly demanded in material and biological sciences. However, it is challenging to switch the PL on and off in the NIR region with a high modulation contrast. Here, we demonstrate that reversible on and off switching of the PL in the NIR region can be achieved in a bicomponent system comprised of PbS semiconducting nanocrystals (NCs) and diarylethene (DAE) photoswitches. Photoisomerization of DAE to the ring-closed form upon UV light irradiation causes substantial quenching of the NIR PL of PbS NCs due to efficient triplet energy transfer. The NIR PL fully recovers to an on state upon reversing the photoisomerization of DAE to the ring-open form with green light irradiation. Importantly, fully reversible switching occurs without obvious fatigue, and the high PL on/off ratio (&gt;100) outperforms all previously reported assemblies of NCs and photoswitches

    Two-colour photoswitching in photoresponsive inorganic thin films

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    Herein we report the first example of an inorganic photochromic material that allows for spatial addressability. We designed a photoresponsive thin film based on a ruthenium sulfoxide complex, [Ru(deeb)2PySO-iPr]2+, which was immobilized onto a mesoporous ZrO2 surface. The resulting material allows for all-optical detection and shows reversible, selective, photochromic behavior that can be cycled back and forth. The photosiomerization quantum yield is lower on the film than in solution which is attributed to a combination of the immobilization and steric hindrance by molecules in close proximity as evident from a surface coverage dependence of the photoisomerization quantum yield. The results reported here provide an important step towards inorganic photoswitchable materials

    Excited State Dynamics of Bistridentate and Trisbidentate RuII Complexes of Quinoline-Pyrazole Ligands

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    Three homoleptic ruthenium(II) complexes, [Ru(Q3PzH)3]2+, [Ru(Q1Pz)3]2+, and [Ru(DQPz)2]2+, based on the quinoline-pyrazole ligands, Q3PzH (8-(3-pyrazole)-quinoline), Q1Pz (8-(1-pyrazole)-quinoline), and DQPz (bis(quinolinyl)-1,3-pyrazole), have been spectroscopically and theoretically investigated. Spectral component analysis, transient absorption spectroscopy, density functional theory calculations, and ligand exchange reactions with different chlorination agents reveal that the excited state dynamics for Ru(II) complexes with these biheteroaromatic ligands differ significantly from that of traditional polypyridyl complexes. Despite the high energy and low reorganization energy of the excited state, nonradiative decay dominates even at liquid nitrogen temperatures, where triplet metal-to-ligand-charge-transfer emission quantum yields range from 0.7 to 3.8%, and microsecond excited state lifetimes are observed. In contrast to traditional polypyridyl complexes where ligand exchange is facilitated by expansion of the metal-ligand bonds to stabilize a metal-centered state, photoinduced ligand exchange occurs in the bidentate complexes despite no substantial MC state population, while the tridentate complex is extremely photostable despite an activated decay route, highlighting the versatile photochemistry of nonpolypyridine ligands.\ua0\ua9 2019 American Chemical Society

    Covalent incorporation of diphenylanthracene in oxotriphenylhexanoate organogels as a quasi-solid photon upconversion matrix

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    Triplet-triplet annihilation photon upconversion (TTA-UC) in solid state assemblies are desirable since they can be easily incorporated into devices such as solar cells, thus utilizing more of the solar spectrum. Realizing this is, however, a significant challenge that must circumvent the need for molecular diffusion, poor exciton migration, and detrimental back energy transfer among other hurdles. Here, we show that the above-mentioned issues can be overcome using the versatile and easily synthesized oxotriphenylhexanoate (OTHO) gelator that allows covalent incorporation of chromophores (or other functional units) at well-defined positions. To study the self-assembly properties as well as its use as a TTA-UC platform, we combine the benchmark couple platinum octaethylporphyrin as a sensitizer and 9,10-diphenylanthracene (DPA) as an annihilator, where DPA is covalently linked to the OTHO gelator at different positions. We show that TTA-UC can be achieved in the chromophore-decorated gels and that the position of attachment affects the photophysical properties as well as triplet energy transfer and triplet-triplet annihilation. This study not only provides proof-of-principle for the covalent approach but also highlights the need for a detailed mechanistic insight into the photophysical processes underpinning solid state TTA-UC
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