41 research outputs found

    Temperature-Dependence of an Amorphous Organic Thin Film Polariton Laser

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    Since its first observation, the polariton lasing threshold in organic films has been anomalously high, given that Bosonic condensation should occur at vanishingly small pumping powers. Here, we investigate the temperature dependence of a polariton laser employing an amorphous organic thin film, 2,7-bis­[9,9-di­(4-methylphenyl)-fluoren-2-yl]-9,9-di­(4-methylphenyl)­fluorene, in a vertical optical microcavity. An increase in laser threshold is observed at temperatures <45 K, while the threshold remains unchanged as the temperature increases up to room temperature. In contrast, the energy dispersion characteristic of cavity polaritons is independent of temperature. At low temperature, an energy relaxation bottleneck along the polariton dispersion takes place below threshold. The bottleneck is found to be responsible for the anomalous increase in threshold with decreasing temperature. As the pumping power increases, amplified spontaneous emission (ASE) is observed prior to the onset of lasing. We also study the photoluminescence of the neat organic film versus temperature to explain the origin of the bottleneck in the exciton polariton dispersion

    Aerobic Visible-Light Photoredox Radical C–H Functionalization: Catalytic Synthesis of 2-Substituted Benzothiazoles

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    An aerobic visible-light driven photoredox catalytic formation of 2-substituted benzothiazoles through radical cyclization of thioanilides has been accomplished. The reaction features C–H functionalization and C–S bond formation with no direct metal involvement except the sensitizer. The reaction highlights the following: (1) visible-light is the reaction driving force; (2) molecular oxygen is the terminal oxidant, and (3) water is the only byproduct

    Oxacillin Coupled G‑Quadruplexes as a Novel Biofilm-Specific Antibiotic for <i>Staphylococcus aureus</i> Biofilms

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    One of the most important traits of pathogenic microbial biofilms is their high tolerance to conventional antimicrobial agents, which is partially due to the presence of metabolically inactive and transiently resistant persister cells. Here, we use guanine-rich DNA structures known as G-quadruplexes (G4s) coupled with the β-lactam antibiotic, oxacillin (OX), and loaded with an iron-containing protoporphyrin IX (hemin), as OXG4/hemin complex biofilm-specific antibiotic agents. By coupling the OX to the G4, to form an OXG4/hemin complex, the diffusion of the OX was facilitated into the biofilm. Further, by utilizing the known oxidizing behavior (peroxidase-mimicking) of the G4/hemin complex, the entire system was found to be highly effectively against Staphylococcus aureus biofilms. By using G4 structures to penetrate biofilms, this work paves the way for an entirely new DNA-based therapy for biofilm eradication

    Efficient Outcoupling of Organic Light-Emitting Devices Using a Light-Scattering Dielectric Layer

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    It has long been a challenge to develop a highly efficient outcoupling method for organic light-emitting diodes that is independent of wavelength and viewing angle, as well as being nonintrusive into the device structure. Here, we demonstrate a transparent, top emitting structure integrated with a high index of refraction waveguide layer and a rough, dielectric diffuse reflector that eliminates plasmonic, waveguide, and substrate modes without introducing wavelength and viewing-angle dependence. The simple outcoupling structure increases the external quantum efficiency from 15 ± 2% to 37 ± 4% compared to an analogous device with a metal mirror, corresponding to a 2.5-fold enhancement without requiring the use of additional outcoupling structures such as microlens arrays or index matching layers to extract substrate modes. The method is potentially suitable for low-cost, solid-state lighting due to its simplicity and high outcoupling efficiency

    DataSheet_1_bub1 as a potential oncogene and a prognostic biomarker for neuroblastoma.xlsx

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    BackgroundNeuroblastoma is the most common malignant extracranial tumor for children. Molecular mechanisms underpinning the pathogenesis of this disease are yet to be fully clarified. This study aimed to identify a novel oncogene that could be used as a biomarker informing the prognosis of neuroblastoma, and to predict its biological functions, using bioinformatics and molecular biology tools.MethodsThree data sets from the TARGET, GSE62564, and GSE85047 databases were used for analysis. Survivals of patients with high or low expression of bub1 were compared, using the Kaplan-Meier curve and log-rank test. Immune infiltration was evaluated using ESTIMATE and MCP-counter algorithms. Synthetic small interfering RNAs (siRNAs) were employed to silence bub1 expression in neuroblastoma cell lines SH-SY5Y and SK-N-SH, in order to characterize its biological functions. Gene enrichment analyses of bub1 were carried out, using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses.ResultsExpression of bub1 was found to significantly affect overall survival and event-free survival of patients with neuroblastoma, positively correlate with the expressions of tpx2 and the ASPM gene, and negatively correlate with host immune infiltration. Expression of bub1 was elevated in patients with neuroblastoma. Silencing bub1 expression using siRNAs in SH-SY5Y and SK-N-SH resulted in decreased cell growth (p ConclusionWe identified a potential tumor-promoting gene bub1 for neuroblastoma that could also serve as a prognostic biomarker.</p

    FigS4-Qu+al.gif

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    Animated GIF showing further examples of phenotypes induced by Shot-PE-Life::GFP expression. Primary neurons at 6-8 HIV on glass with scabrous-Gal4-induced expression of Shot-PE-Life::GFP, stained for tubulin (green), actin (red) and GFP (blue); the animation sequence shows single channels as grayscale images, as indicated top left in animation steps. Symbols indicate the following: asterisks, cell bodies; arrowheads, MT bundle split; arrows, 'tennis racket' spools; white curved arrows, unusual MT bundle malformations; open curved arrows, unusually bundled MTs in cell bodies.<br

    DataSheet1_A drilling wellbore pressure calculation model considering the effect of gas dissolution and suspension.xlsx

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    The complex formation pressure system and diverse formation fluid components during deepwater and deep drilling make it easy for gas intrusion accidents to occur. The dissolution and suspension of the intruded gas in the drilling fluid and the difference between the gas–liquid phase distribution characteristics and the gas–water two-phase flow characteristics in the wellbore lead to errors in the calculation of wellbore pressure and overflow assessment after gas intrusion. In this article, a wellbore multiphase flow model, considering gas dissolution and suspension is established, and the influence of gas dissolution and suspension in the drilling fluid on multiphase flow in the wellbore during overflow, well shutdown, and compression is analyzed with the model calculation results. The higher the drilling fluid density and yield stress are, the higher is the gas limit suspension concentration, when free gas is present in the wellbore. After the gas intrusion shutdown, when there are suspended and transported gases in the wellbore, the rate of pressure increase in the wellbore decreases after the shutdown, and the volume fraction of free gas decreases when the shutdown time is longer, and eventually all the gases will be suspended in the drilling fluid. During the pressure process, gas dissolution leads to an increase in the peak pressure in the wellbore and a delay in its occurrence; gas suspension leads to a decrease in the peak pressure in the wellbore and a delay in its occurrence. This article establishes a multiphase flow calculation model for the wellbore, considering both gas dissolution and suspension, which is a guideline for the calculation of wellbore pressure after gas intrusion.</p

    Table_1_RAFT-Derived Polymethacrylates as a Superior Treatment for Recurrent Vulvovaginal Candidiasis by Targeting Biotic Biofilms and Persister Cells.DOCX

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    BackgroundVulvovaginal candidiasis (VVC) is a common infection in need of more effective treatment. Formation of epithelium-associated Candida biofilms and the presence of persister cells are among the major contributing factors to the recurrence of this condition. We have previously developed RAFT-derived polymethacrylates that are effective in killing C. albicans biofilms in vitro. This study aimed to examine the clinical potential of polymethacrylates as antifungals for treatment of recurrent VVC (RVVC).MethodsA mouse model of VVC was used to establish vaginal epithelium-associated biofilms, using C. albicans isolates from VVC/RVVC patients. A comparison was made of the efficacies of polymethacrylates and conventional antifungals, clotrimazole and nystatin, in killing Candida in epithelium-associated biofilms in vivo. Ex vivo biofilms were used for Candida population profiling and to quantify persister cells in vaginal epithelia. The potency of polymethacrylates and conventional antifungals against persister cells, either as sole agents or in combination, was assessed.ResultsPolymethacrylates showed negligible local toxicity, resistance to vaginal acidity, and outstanding in vivo activity against vaginal epithelium-associated C. albicans biofilms. In vivo tests polymethacrylates outperformed the conventional antifungals, nystatin and clotrimazole at concentrations 50 times below the over-the-counter concentrations. Using polymethacrylates was associated with fewer persister cells, and better eradication of persister cells pre-selected by conventional antifungals.ConclusionThis study systematically assessed the clinical potential of RAFT-derived polymethacrylates as an effective treatment for VVC/RVVC in a mouse model. Polymethacrylates effectively killed vaginal epithelium-related C. albicans in vivo by specially targeting biotic biofilms and persister cells. Treatment presented negligible local toxicity.</p

    Injectable enzyme-catalyzed crosslinking hydrogels as BMSCs-laden tunable scaffold for osteogenic differentiation

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    Bone defects caused by trauma or tumor are a significant challenge in clinical practice. Hydrogel-based tissue engineering has been considered an effective strategy. This study successfully formed a series of injectable hydrogels by enzyme-catalyzed crosslinking hyaluronic acid-tyramine (HA-TA) and sodium alginate-tyramine (ALG-TA) under physiological conditions in the presence of both horseradish peroxidase and hydrogen peroxide. The morphology, mechanical properties, swelling properties, and biodegradation properties of hydrogels were investigated. The results showed that the mechanical properties, swelling properties and biodegradation of HA/ALG hydrogels varied with the precursor solution concentration. Furthermore, the proliferation and osteogenic differentiation of BMSCs within the HA/ALG hydrogels were evaluated in vitro. The results illustrated that the hydrogels could offer an excellent microenvironment for BMSCs growth and promote osteogenic differentiation. Therefore, the injectable hydrogels can be used as an effective 3 D scaffold for bone repair and regeneration.</p
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