34 research outputs found

    Route to achieving perfect B-site ordering in double perovskite thin films

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    Double perovskites (DP, A2_2BB’O6_6) exhibit a breadth of multifunctional properties with a huge potential range of applications, including magneto-optic and spintronic devices. However, spontaneous cation ordering is limited by the similar size and charge of B and B’ cations. We introduce a route to stimulate B-site rock-salt ordering. By growing thin films on (111)-oriented substrates, ‘in-plane’ strain acts on the intrinsically tilted oxygen octahedra of the DP and produces two different B-site cages (in size and shape), stimulating spontaneous cation ordering. For the ferromagnetic insulator La2_2CoMnO6_6, clear Co/Mn ordering was achieved by growing on (111)-oriented substrates. The difference in B-site cages was further enhanced when grown under minor (111) in-plane compressive strain, resulting in long-range ordering with a saturation magnetization of 5.8 ÎŒB/formula unit (f.u.), close to the theoretical 6 ÎŒB/f.u., without antiferromagnetic behavior. Our approach enables the study of many new ordered DPs which have never been made before.This work was supported by the European Research Council (ERC) (Advanced Investigator grant ERC-2009-AdG-247276-NOVOX), the EPSRC (Equipment Account Grant EP/K035282/1) and the Isaac Newton Trust (Minute 13.38(k)). LJ thank the support of the European Union Seventh Framework Programme under Grant Agreement 312483—ESTEEM2 (Integrated Infrastructure Initiative-I3). SuperSTEM is the UK National Facility for Aberration Corrected STEM funded by EPSRC

    Extra-Intestinal Manifestations of Familial Adenomatous Polyposis

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    Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited disorder, which results from a germ line mutation in the APC (adenomatous polyposis coli) gene. FAP is characterized by the formation of hundreds to thousands of colorectal adenomatous polyps. Although the development of colorectal cancer stands out as the most prevalent complication, FAP is a multisystem disorder of growth. This means, it is comparable to other diseases such as the MEN syndromes, Von Hippel-Lindau disease and neurofibromatosis. However, the incidence of many of its clinical features is much lower. Therefore, a specialized multidisciplinary approach to optimize health care—common for other disorders—is not usually taken for FAP patients. Thus, clinicians that care for and counsel members of high-risk families should have familiarity with all the extra-intestinal manifestations of this syndrome. FAP-related complications, for which medical attention is essential, are not rare and their estimated lifetime risk presumably exceeds 30%. Affected individuals can develop thyroid and pancreatic cancer, hepatoblastomas, CNS tumors (especially medulloblastomas), and various benign tumors such as adrenal adenomas, osteomas, desmoid tumors and dental abnormalities. Due to improved longevity, as a result of better prevention of colorectal cancer, the risk of these clinical problems will further increase

    Consensus guidelines for the use and interpretation of angiogenesis assays

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    The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference

    Insulating-to-conducting behavior and band profile across the La0.9Ba0.1MnO3/Nb:SrTiO3 epitaxial interface

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    La0.9Ba0.1MnO3 is a ferromagnetic insulator in its bulk form, but exhibits metallicity in thin film form. It has a wide potential in a range of spintronic-related applications, and hence it is critical to understand thickness-dependent electronic structure in thin films as well as substrate/film interface effects. Here, using electrical and in-situ photoemission spectroscopy measurements, we report the electronic structure and interface band profile of high-quality layer-by-layer-grown La0.9Ba0.1MnO3 on single crystal Nb:SrTiO3 substrates. A transition from insulating-to-conducting was observed with increasing La0.9Ba0.1MnO3 thickness, which was explained by the determined interface band diagram of La0.9Ba0.1MnO3/Nb: SrTiO3, where a type II heterojunction was formed.This work was supported by EPSRC grant EP/K035282/1, EPSRC grant EP/N004272/1, and the Isaac Newton Trust (Minute 13.38(k))

    Management of extracolonic tumours in patients with Lynch syndrome

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    Hereditary nonpolyposis colorectal cancer, or Lynch syndrome, is responsible for 2-3% of all colorectal cancers. Lynch syndrome is also associated with a high risk of extracolonic cancers, including endometrial, stomach, small bowel, pancreas, biliary tract, ovary, urinary tract, brain, and skin cancer. In this Review, we discuss the risks, surveillance tests, and guidelines for the management of extracolonic tumours associated with Lynch syndrome. For all types of extracolonic cancer, evidence supporting surveillance is scarce. A benefit of surveillance is evident only for endometrial cancer, where transvaginal ultrasound and endometrial sampling detect tumours in early stages. Surveillance is generally recommended for urinary tract and gastric cancer, especially in families with more than one member with these types of cancer. For the other types of cancer, surveillance is typically not recommended. Prophylactic hysterectomy and bilateral salpingo-oophorectomy should be considered for women with Lynch syndrome who are past childbearing age, especially during surgery for colorectal cancer. No data show efficacy of chemopreventive drugs in reducing the risk of extracolonic cancers for patients with Lynch syndrome
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