1,067 research outputs found

    A new spin-anisotropic harmonic honeycomb iridate

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    The physics of Mott insulators underlies diverse phenomena ranging from high temperature superconductivity to exotic magnetism. Although both the electron spin and the structure of the local orbitals play a key role in this physics, in most systems these are connected only indirectly --- via the Pauli exclusion principle and the Coulomb interaction. Iridium-based oxides (iridates) open a further dimension to this problem by introducing strong spin-orbit interactions, such that the Mott physics has a strong orbital character. In the layered honeycomb iridates this is thought to generate highly spin-anisotropic interactions, coupling the spin orientation to a given spatial direction of exchange and leading to strongly frustrated magnetism. The potential for new physics emerging from such interactions has driven much scientific excitement, most recently in the search for a new quantum spin liquid, first discussed by Kitaev \cite{kitaev_anyons_2006}. Here we report a new iridate structure that has the same local connectivity as the layered honeycomb, but in a three-dimensional framework. The temperature dependence of the magnetic susceptibility exhibits a striking reordering of the magnetic anisotropy, giving evidence for highly spin-anisotropic exchange interactions. Furthermore, the basic structural units of this material suggest the possibility of a new family of structures, the `harmonic honeycomb' iridates. This compound thus provides a unique and exciting glimpse into the physics of a new class of strongly spin-orbit coupled Mott insulators.Comment: 12 pages including bibliography, 5 figure

    Gemcitabine and Irinotecan for Patients with Untreated Extensive Stage Small Cell Lung Cancer: SWOG 0119

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    IntroductionTo evaluate the activity of a nonplatinum-, nonetoposide-containing regimen for patients with extensive stage small cell lung cancer.MethodsPatients with untreated extensive stage small cell lung cancer were treated with gemcitabine 1000 mg/m2 and irinotecan 100 mg/m2 on days 1 and 8 of a 21-day cycle for a maximum of six cycles. Patients with brain metastases were eligible if asymptomatic or controlled after radiation.ResultsEighty-four eligible patients with untreated extensive stage small cell lung cancer with adequate organ function and a performance status of 0–2 were accrued. The median age was 64 years (range, 42–85) and 45 (54%) were women. Six cycles were completed by 28 (33%) patients. Some degree of diarrhea occurred in 57% (grade 3/4, 18%). Other grade 3/4 toxicities were neutropenia (26%), anemia (10%), thrombocytopenia (8%), febrile neutropenia (5%), fatigue (11%), nausea (10%), and vomiting (8%). The response rate was 32% (95% confidence interval: 22%–43%) among the 81 patients with measurable disease. The median survival was 8.5 months (95% confidence interval: 7.0–9.8) with 1- and 2-year survival rates of 26% and 7%, respectively. Salvage therapy data were captured by prospective collection, and only 50% of patients were treated secondarily.ConclusionThe overall response rate with the combination of gemcitabine and irinotecan was disappointing, and the median survival rate was lower than expected. Further development of this combination in small cell lung cancer is not recommended

    The Influence of In Vitro Gastrointestinal Digestion on the Anticancer Activity of Manuka Honey

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    Manuka honey (MH) is a natural food with many beneficial properties to human health, thanks to its high variety of bioactive compounds; however, little is known about its bioaccessibility. The aim of this study was to evaluate and compare the polyphenol compounds, the antioxidant capacity and the anticancer activity of MH subjected to an in vitro gastrointestinal digestion in human HCT-116 colon cancer cells. Raw MH and digested MH (DMH) were assessed for total polyphenols and flavonoids by spectrophotometric and HPLC-ESI-MS/MS analysis, and total antioxidant capacity (TAC) using different methods. Cell viability, intracellular ROS production, apoptosis, cell cycle and colony formation capacity were tested after treatment with MH or DMH. Results showed that total polyphenols, total flavonoids and TAC were significantly (p < 0.05) reduced after in vitro digestion. In addition, MH and DMH at 8, 16 and 24 mg/mL had similar effects in inducing intracellular ROS production and in inhibiting the colon formation ability; MH induced a more marked apoptosis compared to DMH, while cell cycle was blocked in S phase by MH and in Sub G1 phase by DMH. Our results increase knowledge of the effect of gastrointestinal digestion on the biological effect of honey against colorectal cancer

    Impact of an Interactive On-line Tool on Therapeutic Decision-Making for Patients with Advanced Non-Small-Cell Lung Cancer

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    Background:Treatment guidelines provide recommendations but cannot account for the wide variability in patient-tumor characteristics in individual patients. We developed an on-line interactive decision tool to provide expert recommendations for specific patient scenarios in the first-line and maintenance settings for advanced non–small-cell lung cancer. We sought to determine how providing expert feedback would influence clinical decision-making.Method:Five lung cancer experts selected treatment for 96 different patient cases based on patient and/or tumor-specific features. These data were used to develop an on-line decision tool. Participant physicians entered variables for their patient scenario with treatment choices, and then received expert treatment recommendations for that scenario. To determine the impact on decision-making, users were asked whether the expert feedback impacted their original plan.Results:A total of 442 individual physicians, of which 88% were from outside the United States, entered 653 cases, with report on impact in 389 cases. Expert feedback affected treatment choice in 73% of cases (23% changed and 50% confirmed decisions). For cases with epidermal growth factor receptor (EGFR) mutation or anaplastic lymphoma kinase (ALK) fusion, all experts selected targeted therapy whereas 51% and 58% of participants did not. Greater variability was seen between experts and participants for cases involving EGFR or ALK wild-type tumors. Participants were 2.5-fold more likely to change to expert recommended therapy for ALK fusions than for EGFR mutations (p = 0.017).Conclusion:This online tool for treatment decision-making resulted in a positive influence on clinician's decisions. This approach offers opportunities for improving quality of care and meets an educational need in application of new therapeutic paradigms

    Biodiesel Production From Lignocellulosic Biomass Using Oleaginous Microbes: Prospects for Integrated Biofuel Production

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    Biodiesel is an eco-friendly, renewable, and potential liquid biofuel mitigating greenhouse gas emissions. Biodiesel has been produced initially from vegetable oils, non-edible oils, and waste oils. However, these feedstocks have several disadvantages such as requirement of land and labor and remain expensive. Similarly, in reference to waste oils, the feedstock content is succinct in supply and unable to meet the demand. Recent studies demonstrated utilization of lignocellulosic substrates for biodiesel production using oleaginous microorganisms. These microbes accumulate higher lipid content under stress conditions, whose lipid composition is similar to vegetable oils. In this paper, feedstocks used for biodiesel production such as vegetable oils, non-edible oils, oleaginous microalgae, fungi, yeast, and bacteria have been illustrated. Thereafter, steps enumerated in biodiesel production from lignocellulosic substrates through pretreatment, saccharification and oleaginous microbe-mediated fermentation, lipid extraction, transesterification, and purification of biodiesel are discussed. Besides, the importance of metabolic engineering in ensuring biofuels and biorefinery and a brief note on integration of liquid biofuels have been included that have significant importance in terms of circular economy aspects.Fil: Chintagunta, Anjani Devi. Vignan’s Foundation for Science, Technology and Research. Department of Biotechnology; IndiaFil: Zuccaro, Gaetano. Institut National de la Recherche Agronomique; Francia. UniversitĂ  degli Studi di Napoli Federico II; ItaliaFil: Kumar, Mahesh. Central Agricultural University; IndiaFil: Kumar, S. P. Jeevan. Indian Institute of Seed Science; India. Directorate of Floricultural Research; IndiaFil: Garlapati, Vijay Kumar. Jaypee University of Information Technology; IndiaFil: Postemsky, Pablo Daniel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Centro de Recursos Naturales Renovables de la Zona SemiĂĄrida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona SemiĂĄrida; ArgentinaFil: Kumar, N. S. Sampath. Vignan’s Foundation for Science, Technology and Research. Department of Biotechnology; IndiaFil: Chandel, Anuj K.. Universidade de Sao Paulo; BrasilFil: Simal Gandara, Jesus. Universidad de Vigo; Españ
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