300 research outputs found

    Stand-alone CuFeSe2 (Eskebornite) nanosheets for photothermal cancer therapy

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    Two-dimensional CuFeSe2 nanosheets have been successfully obtained via solution-phase synthesis using a sacrificial template method. The high purity was confirmed by X-ray diffraction and the two-dimensional morphology was validated by transmission electron microscopy. The in-tense absorption in the 400–1400 nm region has been the basis for the CuFeSe2 nanosheets’ photo-thermal capabilities testing. The colloidal CuFeSe2 (CFS) nanosheets capped with S2− short ligands (CFS-S) exhibit excellent biocompatibility in cell culture studies and strong photothermal effects upon 808 nm laser irradiation. The nanosheets were further loaded with the cancer drug doxorubi-cin and exposed to laser irradiation, which accelerated the release of doxorubicin, achieving synergy in the therapeutic effect

    A ‘quiet revolution’? The impact of Training Schools on initial teacher training partnerships

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    This paper discusses the impact on initial teacher training of a new policy initiative in England: the introduction of Training Schools. First, the Training School project is set in context by exploring the evolution of a partnership approach to initial teacher training in England. Ways in which Training Schools represent a break with established practice are considered together with their implications for the dominant mode of partnership led by higher education institutions (HEIs). The capacity of Training Schools to achieve their own policy objectives is examined, especially their efficacy as a strategy for managing innovation and the dissemination of innovation. The paper ends by focusing on a particular Training School project which has adopted an unusual approach to its work and enquires whether this alternative approach could offer a more profitable way forward. During the course of the paper, five different models of partnership are considered: collaborative, complementary, HEI-led, school-led and partnership within a partnership

    A simple but efficient voice activity detection algorithm through Hilbert transform and dynamic threshold for speech pathologies

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    A simple but efficient voice activity detector based on the Hilbert transform and a dynamic threshold is presented to be used on the pre-processing of audio signals -- The algorithm to define the dynamic threshold is a modification of a convex combination found in literature -- This scheme allows the detection of prosodic and silence segments on a speech in presence of non-ideal conditions like a spectral overlapped noise -- The present work shows preliminary results over a database built with some political speech -- The tests were performed adding artificial noise to natural noises over the audio signals, and some algorithms are compared -- Results will be extrapolated to the field of adaptive filtering on monophonic signals and the analysis of speech pathologies on futures works20th Argentinean Bioengineering Society Congress, SABI 2015 (XX Congreso Argentino de Bioingeniería y IX Jornadas de Ingeniería Clínica)28–30 October 2015, San Nicolás de los Arroyos, Argentin

    Learning through social spaces: migrant women and lifelong learning in post-colonial London

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    This article shows how migrant women engage in learning through social spaces. It argues that such spaces are little recognised, and that there are multiple ways in which migrant women construct and negotiate their informal learning through socialising with other women in different informal modes. Additionally, the article shows how learning is shaped by the socio-political, geographical and multicultural context of living in London, outlining ways in which gendered and racialised identities shape, construct and constrain participation in lifelong learning. The article shows that one way in which migrant women resist (post)colonial constructions of difference is by engaging in informal and non-formal lifelong learning, arguing that the benefits are (at least) two-fold. The women develop skills (including language skills) but also use their informal learning to develop what is referred to in this article as 'relational capital'. The article concludes that informal lifelong learning developed through social spaces can enhance a sense of belonging for migrant women

    Exciton Confinement in Two-Dimensional, In-Plane, Quantum Heterostructures

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    Two-dimensional (2D) semiconductors are promising candidates for optoelectronic application and quantum information processes due to their inherent out-of-plane 2D confinement. In addition, they offer the possibility of achieving low-dimensional in-plane exciton confinement, similar to zero-dimensional quantum dots, with intriguing optical and electronic properties via strain or composition engineering. However, realizing such laterally confined 2D monolayers and systematically controlling size-dependent optical properties remain significant challenges. Here, we report the observation of lateral confinement of excitons in epitaxially grown in-plane MoSe2 quantum dots (~15-60 nm wide) inside a continuous matrix of WSe2 monolayer film via a sequential epitaxial growth process. Various optical spectroscopy techniques reveal the size-dependent exciton confinement in the MoSe2 monolayer quantum dots with exciton blue shift (12-40 meV) at a low temperature as compared to continuous monolayer MoSe2. Finally, single-photon emission was also observed from the smallest dots at 1.6 K. Our study opens the door to compositionally engineered, tunable, in-plane quantum light sources in 2D semiconductors.Comment: Main Manuscript: 29 pages, 4 figures Supplementary Information: 14 pages, 12 figure

    Summary Report on CO{sub 2} Geologic Sequestration & Water Resources Workshop

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    The United States Environmental Protection Agency (EPA) and Lawrence Berkeley National Laboratory (LBNL) jointly hosted a workshop on “CO{sub 2} Geologic Sequestration and Water Resources” in Berkeley, June 1–2, 2011. The focus of the workshop was to evaluate R&D needs related to geological storage of CO{sub 2} and potential impacts on water resources. The objectives were to assess the current status of R&D, to identify key knowledge gaps, and to define specific research areas with relevance to EPA’s mission. About 70 experts from EPA, the DOE National Laboratories, industry, and academia came to Berkeley for two days of intensive discussions. Participants were split into four breakout session groups organized around the following themes: Water Quality and Impact Assessment/Risk Prediction; Modeling and Mapping of Area of Potential Impact; Monitoring and Mitigation; Wells as Leakage Pathways. In each breakout group, participants identified and addressed several key science issues. All groups developed lists of specific research needs; some groups prioritized them, others developed short-term vs. long-term recommendations for research directions. Several crosscutting issues came up. Most participants agreed that the risk of CO{sub 2} leakage from sequestration sites that are properly selected and monitored is expected to be low. However, it also became clear that more work needs to be done to be able to predict and detect potential environmental impacts of CO{sub 2} storage in cases where the storage formation may not provide for perfect containment and leakage of CO{sub 2}–brine might occur

    Restoring Coastal Plants to Improve Global Carbon Storage: Reaping What We Sow

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    Long-term carbon capture and storage (CCS) is currently considered a viable strategy for mitigating rising levels of atmospheric CO2 and associated impacts of global climate change. Until recently, the significant below-ground CCS capacity of coastal vegetation such as seagrasses, salt marshes, and mangroves has largely gone unrecognized in models of global carbon transfer. However, this reservoir of natural, free, and sustainable carbon storage potential is increasingly jeopardized by alarming trends in coastal habitat loss, totalling 30–50% of global abundance over the last century alone. Human intervention to restore lost habitats is a potentially powerful solution to improve natural rates of global CCS, but data suggest this approach is unlikely to substantially improve long-term CCS unless current restoration efforts are increased to an industrial scale. Failure to do so raises the question of whether resources currently used for expensive and time-consuming restoration projects would be more wisely invested in arresting further habitat loss and encouraging natural recovery
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