5,158 research outputs found

    Mesoscopic continuous and discrete channels for quantum information transfer

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    We study the possibility of realizing perfect quantum state transfer in mesoscopic devices. We discuss the case of the Fano-Anderson model extended to two impurities. For a channel with an infinite number of degrees of freedom, we obtain coherent behavior in the case of strong coupling or in weak coupling off-resonance. For a finite number of degrees of freedom, coherent behavior is associated to weak coupling and resonance conditions

    Double dot chain as a macroscopic quantum bit

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    We consider an array of N quantum dot pairs interacting via Coulomb interaction between adjacent dots and hopping inside each pair. We show that at the first order in the ratio of hopping and interaction amplitudes, the array maps in an effective two level system with energy separation becoming exponentially small in the macroscopic (large N) limit. Decoherence at zero temperature is studied in the limit of weak coupling with phonons. In this case the macroscopic limit is robust with respect to decoherence. Some possible applications in quantum information processing are discussed.Comment: Phys. Rev. A (in press

    Therapeutic challenges for cisplatin-resistant ovarian germ cell tumors

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    The majority of patients with advanced ovarian germ cell cancer are treated by cisplatin-based chemotherapy. Despite adequate first-line treatment, nearly one third of patients relapse and almost half develop cisplatin-resistant disease, which is often fatal. The treatment of cisplatin-resistant disease is challenging and prognosis remains poor. There are limited data on the efficacy of specific chemotherapeutic regimens, high-dose chemotherapy with autologous progenitor cell support and targeted therapies. The inclusion of patients in clinical trials is strongly recommended, especially in clinical trials on the most frequent male germ cell tumors, to offer wider therapeutic opportunities. Here, we provide an overview of current and potential new treatment options including combination chemotherapy, high-dose chemotherapy and molecular targeted therapies, for patients with cisplatin-resistant ovarian germ cell tumors

    Second-line high-dose chemotherapy in patients with mediastinal and retroperitoneal primary non-seminomatous germ cell tumors: the EBMT experience

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    Background: Results of second-line chemotherapy in patients with extragonadal non-seminomatous germ cell tumor (NSGCT) appear inferior to results in testicular NSGCT. Patients with retroperitoneal NSGCT achieve a comparable long-term survival rate of 30%, but the salvage rates of patients with mediastinal primary are less than 10%. We conducted a retrospective analysis on patients with mediastinal and retroperitoneal NSGCT treated with second-line high-dose chemotherapy (HDCT) registered with the European Group for Blood and Marrow Transplantation (EBMT). Patients and methods: Between 1987 and 1999, 59 registered patients with retroperitoneal (n=37) and mediastinal (n=22) primary NSGCT, median age 28 years (range 18-60), were treated with second-line HDCT. All had received cisplatin-containing chemotherapy as first-line treatment. Results: Toxic death occurred in three cases (5%). With a median follow-up of 58 months (range 14-114), 18/59 patients (30%) continue to be disease-free. Of three patients who had a disease recurrence after HDCT, one patient achieved a disease-free status with further chemotherapy and surgery. In total, 19 patients (32%) are currently disease-free. Sixteen of 37 patients (43%) with retroperitoneal NSGCT, and three of 22 patients (14%) with mediastinal NSGCT are currently alive and disease-free. Conclusions: Second-line HDCT might represent a possible option for patients with retroperitoneal primary NSGCT. New salvage strategies are needed for patients with mediastinal NSGC

    Real-world efficacy and safety of nivolumab in previously-treated metastatic renal cell carcinoma, and association between immune-related adverse events and survival: the Italian expanded access program

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    Background: The Italian Renal Cell Cancer Early Access Program was an expanded access program that allowed access to nivolumab, for patients (pts) with metastatic renal cell carcinoma (mRCC) prior to regulatory approval. Methods: Pts with previously treated advanced or mRCC were eligible to receive nivolumab 3 mg/kg every 2 weeks. Pts included in the analysis had received ≥1 dose of nivolumab and were monitored for drug-related adverse events (drAEs) using CTCAE v.4.0. Immune-related (ir) AEs were defined as AEs displaying a certain, likely or possible correlation with immunotherapy (cutaneous, endocrine, hepatic, gastro-intestinal and pulmonary). The association between overall survival (OS) and irAEs was assessed, and associations between variables were evaluated with a logistic regression model. Results: A total of 389 pts were enrolled between July 2015 and April 2016. Overall, the objective response rate was 23.1%. At a median follow-up of 12 months, the median progression-free survival was 4.5 months (95% CI 3.7-6.2) and the 12-month overall survival rate was 63%. Any grade and grade 3-4 drAEs were reported in 124 (32%) and 27 (7%) of pts, respectively, and there were no treatment-related deaths. Any grade irAEs occurred in 76 (20%) of patients, 8% cutaneous, 4% endocrine, 2% hepatic, 5% gastro-intestinal and 1% pulmonary. Of the 22 drAEs inducing treatment discontinuation, 10 (45%) were irAEs. Pts with drAEs had a significantly longer survival than those without drAEs (median OS 22.5 versus 16.4 months, p = 0.01). Pts with irAEs versus without irAEs had a more significant survival benefit (median OS not reached versus 16.8 months, p = 0.002), confirmed at the landmark analysis at 6 weeks. The occurrence of irAEs displayed a strong association with OS in univariable (HR 0.48, p = 0.003) and multivariable (HR 0.57, p = 0.02) analysis. Conclusions: The appearance of irAEs strongly correlates with survival benefit in a real-life population of mRCC pts treated with nivolumab
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