601 research outputs found

    Raman microscopy of lithium-manganese-rich transition metal oxide cathodes

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    Lithium-rich and manganese-rich (LMR) layered transition metal (TM) oxide composites with general formula xLi2MnO3 • (1- x)LiMO2 (M = Ni, Co, Mn) are promising cathode candidates for high energy density lithium ion batteries. Lithium-manganese-rich TM oxides crystallize as a nanocomposite layered phase whose structure further evolves with electrochemical cycling. Raman spectroscopy is a powerful tool to monitor the crystal chemistry and correlate phase changes with electrochemical behavior. While several groups have reported Raman spectra of lithium rich TM oxides, the data show considerable variability in terms of both the vibrational features observed and their interpretation. In this study, Raman microscopy is used to investigate lithium-rich and manganese-rich TM cathodes as a function of voltage and electrochemical cycling at various temperatures. No growth of a spinel phase is observed within the cycling conditions. However, analysis of the Raman spectra does indicate the structure of LMR-NMC deviates significantly from an ideal layered phase. The results also highlight the importance of using low laser power and large sample sizes to obtain consistent data sets

    The determinants of student loan take-up in England

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    Recent changes in higher education financing policies in England have led to more students funding their studies via two types of student loan – for tuition fees and/or for maintenance. Moreover, the average amount borrowed has been increasing. Yet not all students take out loans, and understanding the determinants of take-up is important, not least because those who can manage to study without borrowing enjoy significant advantages both during and after their studies. Using Next Steps, a unique dataset with data on both types of loan and rich information on students’ backgrounds and their attitudes to debt, we analyse loan take-up by type of loan. We estimate the strength of the association of loan take-up with each of students’ family income, indicators of family wealth (home ownership, private education, not living in a deprived area, social class), parental education, gender, ethnicity, and debt aversion. Of these, only social class is found to have no independent effect. We find that these associations can differ according to the type of debt. We also find that, while students from some disadvantaged groups are less likely to take out maintenance loans, this association is accounted for by students living at home while studying, a prime mechanism for debt avoidance

    Optimal spatiotemporal scales to aggregate satellite ocean color data for nearshore reefs and tropical coastal waters: two case studies

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    Remotely sensed ocean color data are useful for monitoring water quality in coastal environments. However, moderate resolution (hundreds of meters to a few kilometers) satellite data are underutilized in these environments because of frequent data gaps from cloud cover and algorithm complexities in shallow waters. Aggregating satellite data over larger space and time scales is a common method to reduce data gaps and generate a more complete time series, but potentially smooths out the small-scale, episodic changes in water quality that can have ecological influences. By comparing aggregated satellite estimates of Kd(490) with related in-water measurements, we can understand the extent to which aggregation methods are viable for filling gaps while being able to characterize ecologically relevant water quality conditions. In this study, we tested a combination of six spatial and seven temporal scales for aggregating data from the VIIRS instrument at several coral reef locations in Maui, Hawai‘i and Puerto Rico and compared these with in situ measurements of Kd(490) and turbidity. In Maui, we found that the median value of a 5-pixels, 7-days spatiotemporal cube of satellite data yielded a robust result capable of differentiating observations across small space and time domains and had the best correlation among spatiotemporal cubes when compared with in situ Kd(490) across 11 nearshore sites (R2 = 0.84). We also found long-term averages (i.e., chronic condition) of VIIRS data using this aggregation method follow a similar spatial pattern to onshore turbidity measurements along the Maui coast over a three-year period. In Puerto Rico, we found that the median of a 13-pixels, 13-days spatiotemporal cube of satellite data yielded the best overall result with an R2 = 0.54 when compared with in situ Kd(490) measurements for one nearshore site with measurement dates spanning 2016–2019. As spatiotemporal cubes of different dimensions yielded optimum results in the two locations, we recommend local analysis of spatial and temporal optima when applying this technique elsewhere. The use of satellite data and in situ water quality measurements provide complementary information, each enhancing understanding of the issues affecting coastal ecosystems, including coral reefs, and the success of management efforts

    Physician-Industry Collaboration: Organizational Considerations for the Future of Innovation and Growth in Dermatology

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    The U.S. medical environment continues to evolve with issues from Privacy to EMR, Insurance regulations, Physician Access and Healthcare Reform, and MACRA (Medicare Access and CHIP Reauthorization Act) on the discussion table. Not since the advent of Medicare and Medicaid in the mid 1960’s, have we seen such widespread changes in the medical healthcare environment (Centers for Medicare and Medicaid Services). Physicians, industry, patients and consumers are affected by the changes. These four groups have historically worked as separate entities, but are now key stakeholders in the future of dermatology. As stakeholders collaborating in building a future together, the dermatologists/physicians will help to ensure and preserve the quality of patient care and best patient outcomes. In the Executive Forum, leaders from the Women’s Dermatologic Society and Industry, explored five important areas: 1) A five-year outlook of Dermatology and Medicine; 2) Access of Industry to Dermatologists and Trainees; 3) The New Practice Environment; 4) Doing Things Differently; and 5) Unmet Specialty Needs. The collaborative group explored solutions for our specialty and the patients we serve

    Expression and subcellular localization of cyclin D1 protein in epithelial ovarian tumour cells

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    The expression of cyclin D1 protein in tumour sections from 81 patients with epithelial ovarian cancer was analysed using immunohistochemistry. The tumours that overexpressed cyclin D1 in more than 10% of neoplastic cells were considered positive. Thus overexpression of cyclin D1 was observed in 72/81 (89%) of the cases examined. Protein was detected in both the nucleus and the cytoplasm in 24/81 (30%) and localized exclusively in the cytoplasm in 48/81 (59%) of the tumours. Cyclin D1 was overexpressed in both borderline and invasive tumours. There was no association between protein overexpression and tumour stage and differentiation. Furthermore, no correlation between cyclin D1 expression and clinical outcome was observed. However, in tumours overexpressing cyclin D1 (n = 72), the proportion displaying exclusively cytoplasmic localization of protein was higher in those with serous compared with non-serous histology (P = 0.004, odds ratio 4.8, 95% confidence interval 1.4–19.1). Western analysis using a monoclonal antibody to cyclin D1 identified a 36 kDa protein in homogenates from seven tumours displaying cytoplasmic only and one tumour demonstrating both nuclear and cytoplasmic immunostaining. Using restriction fragment length polymorphism polymerase chain reaction and PCR-multiplex analysis, amplification of the cyclin D1 gene (CCNDI) was detected in 1/29 of the tumours demonstrating overexpression of cyclin D1 protein. We conclude that deregulation of CCND1 expression leading to both cytoplasmic and nuclear protein localization is a frequent event in ovarian cancer and occurs mainly in the absence of gene amplification. © 1999 Cancer Research Campaig
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