60 research outputs found
Stabilized tilted-octahedra halide perovskites inhibit local formation of performance-limiting phases.
Efforts to stabilize photoactive formamidinium (FA)–based halide perovskites for perovskite photovoltaics have focused on the growth of cubic formamidinium lead iodide (α-FAPbI3) phases by empirically alloying with cesium, methylammonium (MA) cations, or both. We show that such stabilized FA-rich perovskites are noncubic and exhibit ~2° octahedral tilting at room temperature. This tilting, resolvable only with the use of local nanostructure characterization techniques, imparts phase stability by frustrating transitions from photoactive to hexagonal phases. Although the bulk phase appears stable when examined macroscopically, heterogeneous cation distributions allow microscopically unstable regions to form; we found that these transitioned to hexagonal polytypes, leading to local trap-assisted performance losses and photoinstabilities. Using surface-bound ethylenediaminetetraacetic acid, we engineered an octahedral tilt into pure α-FAPbI3 thin films without any cation alloying. The templated photoactive FAPbI3 film was extremely stable against thermal, environmental, and light stressors
Dual-specific chimeric antigen receptor T cells and an indirect vaccine eradicate a variety of large solid tumors in an immunocompetent, self-antigen setting
Purpose: While adoptive transfer of T cells bearing a chimeric antigen receptor (CAR) can eliminate substantial burdens of some leukemias, the ultimate challenge remains the eradication of large solid tumors for most cancers. We aimed to develop an immunotherapy approach effective against large tumors in an immunocompetent, self-antigen preclinical mouse model. Experimental Design: In this study, we generated dual-specific T cells expressing both a CAR specific for Her2 and a TCR specific for the melanocyte protein (gp100). We used a regimen of adoptive cell transfer incorporating vaccination (ACTIV), with recombinant vaccinia virus expressing gp100, to treat a range of tumors including orthotopic breast tumors and large liver tumors. Results: ACTIV therapy induced durable complete remission of a variety of Her2+ tumors, some in excess of 150 mm2, in immunocompetent mice expressing Her2 in normal tissues, including the breast and brain. Vaccinia virus induced extensive proliferation of T cells, leading to massive infiltration of T cells into tumors. Durable tumor responses required the chemokine receptor CXCR3 and exogenous IL-2, but were independent of IFN-gamma. Mice were resistant to tumor rechallenge, indicating immune memory involving epitope spreading. Evidence of limited neurologic toxicity was observed, associated with infiltration of cerebellum by T cells, but was only transient. Conclusions: This study supports a view that it is possible to design a highly effective combination immunotherapy for solid cancers, with acceptable transient toxicity, even when the target antigen is also expressed in vital tissuesThis work was supported by grants from the Cancer Council of Victoria,
Australia (1066554), The Peter MacCallum Cancer Center Foundation, and the
National Health and Medical Research Council (NHMRC) of Australia
(1103352). C.Y. Slaney and P. Beavis were supported by Postdoctoral Fellowships from the National Breast Cancer Foundation of Australia. A.J. Davenport
and S. Mardiana received Postgraduate Scholarships from the Fight Cancer
Foundation and University of Melbourne respectively. R.W. Johnstone and M.J.
Smyth were supported by Senior Principal Research Fellowships from the
NHMRC. M.H. Kershaw and P.K. Darcy were supported by Senior Research
Fellowships from the NHMRC. S. Ellis was supported by a New Investigator
Grant from the NHMR
Act now against new NHS competition regulations: an open letter to the BMA and the Academy of Medical Royal Colleges calls on them to make a joint public statement of opposition to the amended section 75 regulations.
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
Tourist attractions: evolution, analysis and prospects
The attraction literature in tourism is dominated by the metaphor of magnetism. This image, reoccurring in tourism writing for at least one hundred and fifty years, sees key tourism sites as luring tourists to a specific point. Examples of the 'magnetic' power of key attractions to shape the travel experience are richly featured in travel writing from Mark Twain to John Steinbeck, and from Clive James to Umberto Eco. Visitors, according to this view, are much like iron filings drawn inexorably to a positive magnetic pole. Since such metaphors can overly structure (and limit) our creative thinking, perhaps it is time at the start of a new century to draw some new tourism attraction analogies. In itself this is not a novel suggestion. Leiper (1995) expressed dissatisfaction with the literal interpretation of the term attraction and has explicitly emphasized visitors' needs and the relative qualities of home and visited sites to explain travel flows. Additionally, a diversity of writers in problem-solving, scientific thinking and the creative reformulation of problems has suggested that periodically we need to refresh our metaphors and analogies to stimulate better analysis (Nadler et al., 1999; Gilovich, 1993; Langer, 1989).It is perhaps desirable to suggest that attractions in a region might be thought of as analogous to a dynamic matrix of force fields affecting bodies with varying degrees of susceptibility. Such an analogy directs attention to the competition between attractions in a finite area, addresses management and marketing influences which can shape the power of the fields and highlights audience receptivity and choice. Armed with this new analogy, the present chapter reviews tourist attraction development and classification and, through select examples, profiles empirical studies of attractions varying in their success. Further, the chapter will also consider some key concepts to understand attraction success better and note emerging trends from recent studies of attractions. The work reported here undertakes these reviews in order to establish the nature of the influences which have, are and are likely to work in the force fields of the attraction sector. In conclusion, the chapter will direct attention to emerging technologies and evolving management responses which are likely to produce new attraction products
Tourist attractions: evolution, analysis and prospects
The attraction literature in tourism is dominated by the metaphor of magnetism. This image, reoccurring in tourism writing for at least one hundred and fifty years, sees key tourism sites as luring tourists to a specific point. Examples of the 'magnetic' power of key attractions to shape the travel experience are richly featured in travel writing from Mark Twain to John Steinbeck, and from Clive James to Umberto Eco. Visitors, according to this view, are much like iron filings drawn inexorably to a positive magnetic pole. Since such metaphors can overly structure (and limit) our creative thinking, perhaps it is time at the start of a new century to draw some new tourism attraction analogies. In itself this is not a novel suggestion. Leiper (1995) expressed dissatisfaction with the literal interpretation of the term attraction and has explicitly emphasized visitors' needs and the relative qualities of home and visited sites to explain travel flows. Additionally, a diversity of writers in problem-solving, scientific thinking and the creative reformulation of problems has suggested that periodically we need to refresh our metaphors and analogies to stimulate better analysis (Nadler et al., 1999; Gilovich, 1993; Langer, 1989).It is perhaps desirable to suggest that attractions in a region might be thought of as analogous to a dynamic matrix of force fields affecting bodies with varying degrees of susceptibility. Such an analogy directs attention to the competition between attractions in a finite area, addresses management and marketing influences which can shape the power of the fields and highlights audience receptivity and choice. Armed with this new analogy, the present chapter reviews tourist attraction development and classification and, through select examples, profiles empirical studies of attractions varying in their success. Further, the chapter will also consider some key concepts to understand attraction success better and note emerging trends from recent studies of attractions. The work reported here undertakes these reviews in order to establish the nature of the influences which have, are and are likely to work in the force fields of the attraction sector. In conclusion, the chapter will direct attention to emerging technologies and evolving management responses which are likely to produce new attraction products
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