The nanostructural origin of the ac conductance in dielectric granular metals: the case study of Co_20(ZrO_2)_80

We show which is the nanostructure required in granular Co20(ZrO2)80 thin films to produce an ac response such as the one that is universally observed in a very wide variety of dielectric materials. A bimodal size distribution of Co particles yields randomly competing conductance channels which allow both thermally assisted tunneling through small particles and capacitive conductance among larger particles that are further apart. A model consisting on a simple cubic random resistance-capacitor network describes quantitatively the experimental results as functions of temperature and frequency, and enables the determination of the microscopic parameters controlling the ac response of the samples.Comment: Available online at: http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=APPLAB000091000005052108000001&idtype=cvips&gifs=ye

Models for the magnetic ac susceptibility of granular superferromagnetic CoFe/Al2_2O3_3

The magnetization and magnetic ac susceptibility, $\chi = \chi' - i \chi''$, of superferromagnetic systems are studied by numerical simulations. The Cole-Cole plot, $\chi''$ vs. $\chi'$, is used as a tool for classifying magnetic systems by their dynamical behavior. The simulations of the magnetization hysteresis and the ac susceptibility are performed with two approaches for a driven domain wall in random media. The studies are motivated by recent experimental results on the interacting nanoparticle system Co$_{80}$Fe$_{20}$/Al$_{2}$O$_{3}$ showing superferromagnetic behavior. Its Cole-Cole plot indicates domain wall motion dynamics similarly to a disordered ferromagnet, including pinning and sliding motion. With our models we can successfully reproduce the features found in the experimental Cole-Cole plots.Comment: 8 pages, 6 figure

Particle growing mechanisms in Ag-ZrO2 and Au-ZrO2 granular films obtained by pulsed laser deposition

Thin films consisting of Ag and Au nanoparticles embedded in amorphous ZrO2 matrix were grown by pulsed laser deposition in a wide range of metal volume concentrations in the dielectric regime (0.08<x(Ag)<0.28 and 0.08<x(Au)<0.52). High resolution transmission electron microscopy (TEM) showed regular distribution of spherical Au and Ag nanoparticles having very sharp interfaces with the amorphous matrix. Mean particle size determined from X-ray diffraction agreed with direct TEM observation. The silver mean diameter increases more abruptly with metal volume content than that corresponding to gold particles prepared under the same conditions. Two mechanisms of particle growing are observed: nucleation and particle coalescence, their relative significance being different in both granular systems, which yields very different values of the percolation threshold (xc(Ag)~0.28 and xc(Au)~0.52).Comment: 6 figure

Preserving quality of life as a key treatment goal in advanced soft tissue sarcomas.

Introduction Health-related quality of life (HRQoL) is a patient-reported outcome that addresses patients' perceptions of symptoms across physical, emotional, cognitive and social domains. As HRQoL is currently rarely measured outside clinical trials in oncology, it must be inferred from patients' everyday performance during treatment. To gain insight into the HRQoL of advanced STS patients receiving palliative treatment in clinical practice, three case studies of patients treated with trabectedin are examined. Areas covered: The patient in Case 1 has maintained complete remission for more than 8 years after receiving nine cycles of second-line trabectedin followed by secondary surgery for recurrent myxoid liposarcoma, and was able to resume normal activities during trabectedin treatment. Case 2 describes 10 years' follow-up of a patient with myxoid liposarcoma who remains well after many lines of chemotherapy including extended use of trabectedin in the second line. The third case illustrates the feasibility of extending survival time in an elderly patient with metastatic leiomyosarcoma who was able to maintain a busy and active lifestyle while receiving second-line trabectedin. Expert commentary: Owing to its relatively benign safety profile, trabectedin frequently permits prolonged therapy and is generally well tolerated, often allowing patients to carry on with normal daily activities

SEOM clinical guideline for treatment of kidney cancer (2017)

The goal of this article is to provide recommendations about the management of kidney cancer. Based on pathologic and molecular features, several kidney cancer variants were described. Nephron-sparing techniques are the gold standard of localized disease. After a randomized trial, sunitinib could be considered in adjuvant treatment in high-risk patients. Patients with advanced disease constitute a heterogeneous population. Prognostic classification should be considered. Both sunitinib and pazopanib are the standard options for first-line systemic therapy in advanced renal cell carcinoma. Based on the results of two randomized trials, both nivolumab and cabozantinib should be considered the standard for second and further lines of therapy. Response evaluation for present therapies is a challenge

Finite-Size and surface effects in maghemite nanoparticles: Monte Carlo simulations

Finite-size and surface effects in fine particle systems are investigated by Monte Carlo simulation of a model of a $\gamma$-Fe$_2$O$_3$ (maghemite) single particle. Periodic boundary conditions have been used to simulate the bulk properties and the results compared with those for a spherical shaped particle with free boundaries to evidence the role played by the surface on the anomalous magnetic properties displayed by these systems at low temperatures. Several outcomes of the model are in qualitative agreement with the experimental findings. A reduction of the magnetic ordering temperature, spontaneous magnetization, and coercive field is observed as the particle size is decreased. Moreover, the hysteresis loops become elongated with high values of the differential susceptibility, resembling those from frustrated or disordered systems. These facts are consequence of the formation of a surface layer with higher degree of magnetic disorder than the core, which, for small sizes, dominates the magnetization processes of the particle. However, in contradiction with the assumptions of some authors, our model does not predict the freezing of the surface layer into a spin-glass-like state. The results indicate that magnetic disorder at the surface simply facilitates the thermal demagnetization of the particle at zero field, while the magnetization is increased at moderate fields, since surface disorder diminishes ferrimagnetic correlations within the particle. The change in shape of the hysteresis loops with the particle size demonstrates that the reversal mode is strongly influenced by the reduced atomic coordination and disorder at the surface.Comment: Twocolumn RevTex format. 19 pages, 15 Figures included. Submitted to Phys. Rev.

Phase II randomized study of Plitidepsin (Aplidin), alone or in association with L-carnitine, in patients with unresectable advanced renal cell carcinoma

This randomized phase II study evaluated two schedules of the marine compound Plitidepsin with or without co-administration of L-carnitine in patients with renal cell carcinoma. Patients had adequate performance status and organ function. The primary endpoint was the rate of disease control ( no progression) at 12 weeks (RECIST). Other endpoints included the response rate and time dependent efficacy measures. The trial also assessed the efficacy of L-carnitine to prevent Plitidepsin-related toxicity. The two regimes given as 24 hour infusion every two weeks showed hints of antitumoral activity. Disease control at 12 weeks was 15.8% in Arm A (5mg/m2, no L-carnitine) and 11,1% in Arm B (7mg/m2 with L-carnitine). Two partial responses were observed in Arm A ( 19 patients), none in Arm B ( 20 patients). Both schedules had the same progression-free interval (2.1 months). The median overall survival was 7.0 and 7.6 months. The safety profile was similar in both arms of the trial and adverse events were mainly mild to moderate (NCI CTC version 2.0). Increasing the dose to 7mg/m2 did not increase the treatment efficacy but the incidence of transaminase and CPK elevations and serious AEs. Coadministration of L-carnitine did not prevent muscular toxicity or CPK-elevation associated with Plitidepsin

Patient-reported outcomes in a phase III, randomized study of sunitinib versus interferon-{alpha} as first-line systemic therapy for patients with metastatic renal cell carcinoma in a European population

BACKGROUND: The purpose of this study is to evaluate the impact on the health-related quality of life (HRQoL) of sunitinib versus interferon-alpha (IFN-alpha) treatment in patients with metastatic renal cell carcinoma (mRCC). PATIENTS AND METHODS: In all, 304 mRCC patients (European cohort) were randomized 1 : 1 to receive sunitinib (50 mg/day for 4 weeks, followed by 2 weeks off) or IFN-alpha (9 million units s.c. injection three times/week). The following questionnaires were completed (days 1 and 28 per cycle): Functional Assessment of Cancer Therapy-General (FACT-G), the FACT-Kidney Symptom Index and the EuroQol Group's EQ-5D self-report questionnaire (EQ-5D). Results correspond to an ongoing trial with progression-free survival time as primary end point, and patients were still being followed up. Data were analyzed using repeated measures mixed effects models (MEMs) that allow the inclusion of initial differences and uncompleted repeated measures, with the assumption of data missing at random. Six-cycle results were included. RESULTS: Results consistently showed that patients in sunitinib group experienced statistically significantly milder kidney-related symptoms, better cancer-specific HRQoL and general health status (in social utility scores) during the study period as measured by these patient-reported outcome end points. No statistical differences between groups were found on the FACT-G physical well-being subscale or the EQ-5D VAS values. CONCLUSIONS: Results from MEM showed the sunitinib's benefit on HRQoL compared with IFN-alpha

Patient-reported outcomes in a phase III, randomized study of sunitinib versus interferon-α as first-line systemic therapy for patients with metastatic renal cell carcinoma in a European population

Background: The purpose of this study is to evaluate the impact on the health-related quality of life (HRQoL) of sunitinib versus interferon-alpha (IFN-α) treatment in patients with metastatic renal cell carcinoma (mRCC)