314 research outputs found

    Population-based outcomes after whole brain radiotherapy and re-irradiation in patients with metastatic breast cancer in the trastuzumab era

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    <p>Abstract</p> <p>Purpose</p> <p>This study examined the population-based use and outcomes of brain radiotherapy (BRT) for brain metastases (BM) from breast cancer with a focus on repeat BRT in the trastuzumab era.</p> <p>Methods and materials</p> <p>All women with breast cancer diagnosed from 2000-2007 and treated with BRT were retrospectively identified from a provincial database.</p> <p>Results</p> <p>A total of 441 women with BM from breast cancer were identified. The median age was 55 years and 40% (176/441) had human epidermal growth factor receptor 2 (HER2) positive disease. The median survival (MS) from the initial BRT for all 441 women was 4.5 months. The MS by Radiation Therapy Oncology Group Recursive Partitioning Analysis (RPA) class was: 1 (14.5 months), 2 (6.4 months) and 3 (1.8 months). For the 37 cases receiving repeat BRT, 27% (10/37) had stereotactic radiosurgery (SRS) and 70% (26/37) had HER2 positive disease, of which, 81% (21/26) received trastuzumab in the metastatic setting. For repeat BRT, the median survival by RPA class was: 1 (9.8 months), 2 (7.4 months) and 3 (2.0 months). For RPA class 1 and 2, the one-year overall survival (OS) was 45%.</p> <p>Conclusion</p> <p>The proportion of cases with HER2 positive disease was increased at repeat BRT compared to initial BRT. RPA class 1 and 2 patients should be considered for repeat BRT.</p

    Property trends in simple metals:An empirical potential approach

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    We demonstrate that the melting points and other thermodynamic quantities of the alkali metals can be calculated based on static crystalline properties. To do this we derive analytic interatomic potentials for the alkali metals fitted precisely to cohesive and vacancy energies, elastic moduli, lattice parameter and crystal stability. These potentials are then used to calculate melting points by simulating the equilibration of solid and liquid samples in thermal contact at ambient pressure. With the exception of lithium, remarkably good agreement is found with experimental values. The instability of the bcc structure in Li and Na at low temperatures is also reproduced, and, unusually, is not due to a soft T1N phonon mode. No forces or finite temperature properties are included in the fit, so this demonstrates a surprisingly high level of intrinsic transferrability in the simple potentials. Currently, there are few potentials available for the alkali metals, so in, addition to demonstrating trends in behaviour, we expect that the potentials will be of broad general use

    Markovnikov-Selective, Activator-Free Iron-Catalyzed Vinylarene Hydroboration

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    Two series of structurally related alkoxy-tethered NHC iron­(II) complexes have been developed as catalysts for the regioselective hydroboration of alkenes. Significantly, Markonikov-selective alkene hydroboration with HBpin has been controllably achieved using an iron catalyst (11 examples, 35–90% isolated yield) with up to 37:1 branched:linear selectivity. <i>anti</i>-Markovnikov-selective alkene hydroboration was also achieved using HBcat and modification of the ligand backbone (6 examples, 44–71% yields). In both cases, ligand design has enabled activator-free low-oxidation-state iron catalysis

    Unexpected selective gas adsorption on a 'non-porous' metal organic framework

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    A metal organic framework Cu(tpt)BF 4¡ 3 4 H 2O was synthesized as a potential carbon capture material, with the aim being to exploit the Lewis base interaction of the incorporated ligand functionalities with acidic gas. The material displays high thermal stability but an exceptionally low surface area; however, this contrasts starkly with its ability to capture carbon dioxide, demonstrating significant activated diffusion within the framework. The full characterization of the material shows a robust structure, where the CO 2 sorption is 120% greater than current industrial methods using liquid amine solutions; the thermal energy required for sorbent regeneration is reduced by 65%, indicating the true industrial potential of the synthesized material

    Comprehensive health screening of well elderly adults: an analysis of a community program

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    We examined the yield of a health screening program in a free-standing community senior citizen center and identified factors associated with patient compliance with referral recommendations. Of elderly individuals screened, 94% had some positive finding requiring advice or intervention, and 54% were referred to a physician for further evaluation. The most prevalent findings were skin disorders (52%), genitourinary disorders (44%), and eye-ear-nose-throat disorders (33%). Of individuals referred to a physician, 70% complied with the referral. Of those who complied, 38% reported receiving treatment for the referred condition -15% of the entire group of clients screened. Factors positively associated with compliance with physician referral included the specific type of referred problem, the perceived seriousness of the problem, and absence of financial barriers to medical care. Though controlled trial data are lacking, this and other published studies indicate that many remediable problems can be identified among apparently healthy elderly individuals in community geriatric screening programs

    Aluminium‐Catalyzed C(sp)−H Borylation of Alkynes

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    Historically used in stoichiometric hydroalumination chemistry, recent advances have transformed aluminium hydrides into versatile catalysts for the hydroboration of unsaturated multiple bonds. This catalytic ability is founded on the defining reactivity of aluminium hydrides with alkynes and alkenes: 1,2‐hydroalumination of the unsaturated π‐system. This manuscript reports the aluminium hydride catalyzed dehydroborylation of terminal alkynes. A tethered intramolecular amine ligand controls reactivity at the aluminium hydride centre, switching off hydroalumination and instead enabling selective reactions at the alkyne C−H σ‐bond. Chemoselective C−H borylation was observed across a series of aryl‐ and alkyl‐substituted alkynes (21 examples). On the basis of kinetic and density functional theory studies, a mechanism in which C−H borylation proceeds by σ‐bond metathesis between pinacolborane (HBpin) and alkynyl aluminium intermediates is proposed
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