3,448 research outputs found
Quantum Spin Hall Insulators with Interactions and Lattice Anisotropy
We investigate the interplay between spin-orbit coupling and
electron-electron interactions on the honeycomb lattice combining the cellular
dynamical mean-field theory and its real space extension with analytical
approaches. We provide a thorough analysis of the phase diagram and temperature
effects at weak spin-orbit coupling. We systematically discuss the stability of
the quantum spin Hall phase toward interactions and lattice anisotropy
resulting in the plaquette-honeycomb model. We also show the evolution of the
helical edge states characteristic of quantum spin Hall insulators as a
function of Hubbard interaction and anisotropy. At very weak spin-orbit
coupling and intermediate electron-electron interactions, we substantiate the
existence of a quantum spin liquid phase.Comment: 7 pages, 9 figures, final versio
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Silicon Derived from Glass Bottles as Anode Materials for Lithium Ion Full Cell Batteries.
Every year many tons of waste glass end up in landfills without proper recycling, which aggravates the burden of waste disposal in landfill. The conversion from un-recycled glass to favorable materials is of great significance for sustainable strategies. Recently, silicon has been an exceptional anode material towards large-scale energy storage applications, due to its extraordinary lithiation capacity of 3579 mAh g-1 at ambient temperature. Compared with other quartz sources obtained from pre-leaching processes which apply toxic acids and high energy-consuming annealing, an interconnected silicon network is directly derived from glass bottles via magnesiothermic reduction. Carbon-coated glass derived-silicon (gSi@C) electrodes demonstrate excellent electrochemical performance with a capacity of ~1420 mAh g-1 at C/2 after 400 cycles. Full cells consisting of gSi@C anodes and LiCoO2 cathodes are assembled and achieve good initial cycling stability with high energy density
Analysis of Toxic Amyloid Fibril Interactions at Natively Derived Membranes by Ellipsometry
There is an ongoing debate regarding the culprits of cytotoxicity associated with amyloid disorders. Although small pre-fibrillar amyloid oligomers have been implicated as the primary toxic species, the fibrillar amyloid material itself can also induce cytotoxicity. To investigate membrane disruption and cytotoxic effects associated with intact and fragmented fibrils, the novel in situ spectroscopic technique of Total Internal Reflection Ellipsometry (TIRE) was used. Fibril lipid interactions were monitored using natively derived whole cell membranes as a model of the in vivo environment. We show that fragmented fibrils have an increased ability to disrupt these natively derived membranes by causing a loss of material from the deposited surface when compared with unfragmented fibrils. This effect was corroborated by observations of membrane disruption in live cells, and by dye release assay using synthetic liposomes. Through these studies we demonstrate the use of TIRE for the analysis of protein-lipid interactions on natively derived lipid surfaces, and provide an explanation on how amyloid fibrils can cause a toxic gain of function, while entangled amyloid plaques exert minimal biological activity
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The Landscape of Long Non-Coding RNA Dysregulation and Clinical Relevance in Muscle Invasive Bladder Urothelial Carcinoma.
Bladder cancer is one of the most common cancers in the United States, but few advancements in treatment options have occurred in the past few decades. This study aims to identify the most clinically relevant long non-coding RNAs (lncRNAs) to serve as potential biomarkers and treatment targets for muscle invasive bladder cancer (MIBC). Using RNA-sequencing data from 406 patients in The Cancer Genome Atlas (TCGA) database, we identified differentially expressed lncRNAs in MIBC vs. normal tissues. We then associated lncRNA expression with patient survival, clinical variables, oncogenic signatures, cancer- and immune-associated pathways, and genomic alterations. We identified a panel of 20 key lncRNAs that were most implicated in MIBC prognosis after differential expression analysis and prognostic correlations. Almost all lncRNAs we identified are correlated significantly with oncogenic processes. In conclusion, we discovered previously undescribed lncRNAs strongly implicated in the MIBC disease course that may be leveraged for diagnostic and treatment purposes in the future. Functional analysis of these lncRNAs may also reveal distinct mechanisms of bladder cancer carcinogenesis
A qualitative exploration of perceptions and experiences of contraceptive use, abortion and post-abortion family planning services (PAFP) in three provinces in China
Background: The INPAC project aims to evaluate the effectiveness of integrated post-abortion family planning (PAFP) services into existing hospital based abortion services in China. A qualitative study was conducted in three provinces to contribute to developing effective PAFP services through understanding influences on contraceptive use, experiences of abortion and existing PAFP, and their effect on future contraceptive practices from the perspective of users, in the context of social and institutional change.
Methods: Twenty-nine in-depth interviews (IDIs) were undertaken with women who had experienced abortion between 1 and 6 months prior to interview, recruited from three urban and two rural facilities in each province. Thirteen IDIs were also conducted with male partners. Six focus group discussions (FGDs) were carried out with community members from different social groups, including unmarried and married women and men, urban residents and rural-to-urban migrants.
Results: Social networks and norms are important in shaping attitudes and behaviour towards abortion and contraception. Widespread concerns were expressed about side-effects, reliability and effects on future fertility of some modern contraceptives. The combination of limited information and choices and a lack of person-centred counselling in PAFP with anxieties about side effects underlies the widespread use of unreliable methods. Gendered power relations significantly influence contraceptive (non) use, with several examples illustrating women's relative lack of power to decide on a method, particularly in the case of condoms. Although the availability of contraceptive information from respected providers can offer impetus for individual behaviour change, social distance from providers reduces opportunities for clients to discuss their difficulties regarding contraceptive use; particularly, but not exclusively for young, unmarried clients.
Conclusions: Increased access to non-commercial, reliable information on contraceptive methods is needed. PAFP services must go beyond simple information provision to ensure that providers take a more personcentred approach, which considers the most appropriate method for individual clients and probes for the underlying influences on contraceptive (non) use. More sensitive reflection on gender norms and relationships is required during counselling and, where women choose this, efforts should be made to include their male partners. Specific attention to provider positionality and skills for counselling young, unmarried clients is needed
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