Fluctuation-Dissipation Relations of a Tunnel Junction Driven by a Quantum Circuit

We derive fluctuation-dissipation relations for a tunnel junction driven by a high impedance microwave resonator, displaying strong quantum fluctuations. We find that the fluctuation-dissipation relations derived for classical forces hold, provided the effect of the circuit's quantum fluctuations is incorporated into a modified non-linear $I(V)$ curve. We also demonstrate that all quantities measured under a coherent time dependent bias can be reconstructed from their dc counterpart with a photo-assisted tunneling relation. We confirm these predictions by implementing the circuit and measuring the dc current through the junction, its high frequency admittance and its current noise at the frequency of the resonator.Comment: Publisehd as Physical Review Letters, 114, 12680

ARTICLE Photon-assisted tunnelling with nonclassical light

International audienceAmong the most exciting recent advances in the field of superconducting quantum circuits is the ability to coherently couple microwave photons in low-loss cavities to quantum electronic conductors. These hybrid quantum systems hold great promise for quantum information-processing applications; even more strikingly, they enable exploration of new physical regimes. Here we study theoretically the new physics emerging when a quantum electronic conductor is exposed to nonclassical microwaves (for example, squeezed states, Fock states). We study this interplay in the experimentally relevant situation where a superconducting microwave cavity is coupled to a conductor in the tunnelling regime. We find that the conductor acts as a nontrivial probe of the microwave state: the emission and absorption of photons by the conductor is characterized by a nonpositive definite quasi-probability distribution, which is related to the Glauber-Sudarshan P-function of quantum optics. These negative quasi-probabilities have a direct influence on the conductance of the conductor

Finite frequency noise in a quantum point contact between helical edge states

We propose and analyze the non-equilibrium finite frequency current-current correlations as a mean to characterize the helical nature of the edge states in a quantum spin hall geometry. We show that the finite frequency noise enables to unambiguously discriminate between the one-particle and the two-particles processes occurring in the helical liquid for both tunneling or weak-backscattering regimes.Comment: 5 pages, 5 figure

Ethanol triggers grape gene expression leading to anthocyanin accumulation during berry ripening

Recent studies have shown that low doses of ethanol stimulate the maturation of some fruits. The present work showed that spraying Cabernet Sauvignon grapes, with 5% ethanol at veraison enhances the anthocyanin accumulation. Veraison is the time when the berries turn from green to purple. HPLC analysis showed a marked increase in the total concentrations of the derivatives of delphinidin, cyanidin, petunidin, peonidin and malvidin from the fourth day after the ethanol treatment until harvest. This was not linked to a difference in berry weight in comparison to controls. Two distinct expression patterns were found for anthocyanin biosynthesis genes in the treated and untreated berries. For one group, consisting of chalcone synthase, flavanone-3-hydroxylase, dihydroxyflavonol-4-reductase and leucoanthocyanidin dioxygenase, the expression was inhibited or unchanged by the ethanol treatment, whereas for UDP glucose-flavonoid 3-O-glucosyltransferase (UFGT) there was a marked increase in expression from 1 to 20 days after ethanol treatment. These results suggest that the UFGT gene is a key factor in the observed anthocyanin accumulation following ethanol treatment

Lessons from the ‘Iressa’ Expanded Access Programme: gefitinib inspecial non-small-cell lung cancer patient populations

Some subgroups of patients with advanced/metastatic non-small-cell lung cancer (NSCLC) are frequently considered ineligible for the aggressive, platinum-based combination chemotherapy that is the recommended treatment. Elderly patients may have a poorer tolerance of chemotherapy due to impaired organ function and frequent comorbidities; patients with poor performance status (PS; greater than or equal to2 due to NSCLC and/or coexisting illnesses) are often considered unfit for chemotherapy; other patients may be unable or unwilling to endure the toxicity or inconvenience of chemotherapy. These patient groups may benefit from novel, relatively nontoxic treatment modalities. Gefitinib (Iressa, ZD1839) 250 mg day(-1) is well tolerated and has proven antitumour and symptom improvement activity in patients with previously treated NSCLC. Phase II trials (IDEAL 1 and 2) of gefitinib in advanced/metastatic NSCLC included 70 out of 425 (16.5%) patients with PS greater than or equal to2, and their response rate, clinical benefit rate and rates of adverse events were similar to those of the overall trial population. In addition, many patients with advanced/metastatic NSCLC with poor PS or advanced age have received gefitinib 250 mg day(-1) in an Expanded Access Programme (EAP). Observations from the EAP support those of IDEAL 1 and 2, and indicate that gefitinib 250 mg day(-1) warrants further investigation in these patient groups

Triplet chemotherapy with vinorelbine, gemcitabine, and cisplatin for advanced non-small cell lung cancer: a phase II study

We conducted a phase II trial of triplet chemotherapy consisting of vinorelbine, gemcitabine, and cisplatin in patients with advanced non-small cell lung cancer to assess its efficacy and toxicity. Thirty-three patients with chemotherapy-naïve stage IIIB disease (n=8), stage IV disease (n=23), or recurrence after surgical resection (n=2) were given intravenous infusions of vinorelbine 25 mg m−2, gemcitabine 1000 mg m−2, and cisplatin 40 mg m−2 on days 1 and 8 at 3-week intervals. There were 16 partial responses, and the objective response rate was 48% (95% confidence interval: 31–66%). The median survival time was 13.5 months (95% confidence interval: 10.6–16.4 months), and the one-year survival rate was 61%. Grade 4 haematologic toxicity consisted of neutropenia in 72% of patients, and febrile neutropenia occurred in 42% of the patients. There was one toxic death, and it was attributed to neutropenic fever and haemoptysis. Autopsy revealed diffuse pulmonary haemorrhage secondary to bacterial abscesses and vasculitis in both lungs. The common nonhaematologic toxicities included grade 2–3 nausea (39%) and vomiting (18%). Triplet chemotherapy containing vinorelbine, gemcitabine, and cisplatin is effective in the treatment of chemo-näive patients with advanced non-small cell lung cancer, but produces unacceptable frequent febrile neutropenia

A randomised phase II trial of docetaxel vs docetaxel and irinotecan in patients with stage IIIb–IV non-small-cell lung cancer who failed first-line treatment

Response rate and toxicity of second-line therapy with docetaxel (75 mg m−2) or docetaxel, irinotecan, and lenogastrim (60 mg m−2, 200 mg m−2, and 150 μg m−2 day−1, respectively) were compared in 108 patients with stage IIIb–IV non-small-cell lung cancer. Addition of irinotecan to docetaxel does not improve response rate, and increases gastrointestinal toxicity

Ribonucleotide reductase subunits M1 and M2 mRNA expression levels and clinical outcome of lung adenocarcinoma patients treated with docetaxel/gemcitabine

Ribonucleotide reductase subunits M1 (RRM1) and M2 (RRM2) are involved in the metabolism of gemcitabine (2′,2′-difluorodeoxycytidine), which is used for the treatment of nonsmall cell lung cancer. The mRNA expression of RRM1 and RRM2 in tumours from lung adenocarcinoma patients treated with docetaxel/gemcitabine was assessed and the results correlated with clinical outcome. RMM1 and RMM2 mRNA levels were determined by quantitative real-time PCR in primary tumours of previously untreated patients with advanced lung adenocarcinoma who were subsequently treated with docetaxel/gemcitabine. Amplification was successful in 42 (79%) of 53 enrolled patients. Low levels of RRM2 mRNA were associated with response to treatment (P< 0.001). Patients with the lowest expression levels of RRM1 had a significantly longer time to progression (P=0.044) and overall survival (P=0.02) than patients with the highest levels. Patients with low levels of both RRM1 and RRM2 had a significantly higher response rate (60 vs 14.2%; P=0.049), time to progression (9.9 vs 2.3 months; P=0.003) and overall survival (15.4 vs 3.6; P=0.031) than patients with high levels of both RRM1 and RRM2. Ribonucleotide reductase subunit M1 and RRM2 mRNA expression in lung adenocarcinoma tumours is associated with clinical outcome to docetaxel/gemcitabine. Prospective studies are warranted to evaluate the role of these markers in tailoring chemotherapy