Real-time quantum error correction beyond break-even.

The ambition of harnessing the quantum for computation is at odds with the fundamental phenomenon of decoherence. The purpose of quantum error correction (QEC) is to counteract the natural tendency of a complex system to decohere. This cooperative process, which requires participation of multiple quantum and classical components, creates a special type of dissipation that removes the entropy caused by the errors faster than the rate at which these errors corrupt the stored quantum information. Previous experimental attempts to engineer such a process1-7 faced the generation of an excessive number of errors that overwhelmed the error-correcting capability of the process itself. Whether it is practically possible to utilize QEC for extending quantum coherence thus remains an open question. Here we answer it by demonstrating a fully stabilized and error-corrected logical qubit whose quantum coherence is substantially longer than that of all the imperfect quantum components involved in the QEC process, beating the best of them with a coherence gain of G = 2.27 ± 0.07. We achieve this performance by combining innovations in several domains including the fabrication of superconducting quantum circuits and model-free reinforcement learning.

Deterministic quantum state transfer and remote entanglement using microwave photons.

Sharing information coherently between nodes of a quantum network is fundamental to distributed quantum information processing. In this scheme, the computation is divided into subroutines and performed on several smaller quantum registers that are connected by classical and quantum channels 1 . A direct quantum channel, which connects nodes deterministically rather than probabilistically, achieves larger entanglement rates between nodes and is advantageous for distributed fault-tolerant quantum computation 2 . Here we implement deterministic state-transfer and entanglement protocols between two superconducting qubits fabricated on separate chips. Superconducting circuits 3 constitute a universal quantum node 4 that is capable of sending, receiving, storing and processing quantum information5-8. Our implementation is based on an all-microwave cavity-assisted Raman process 9 , which entangles or transfers the qubit state of a transmon-type artificial atom 10 with a time-symmetric itinerant single photon. We transfer qubit states by absorbing these itinerant photons at the receiving node, with a probability of 98.1 ± 0.1 per cent, achieving a transfer-process fidelity of 80.02 ± 0.07 per cent for a protocol duration of only 180 nanoseconds. We also prepare remote entanglement on demand with a fidelity as high as 78.9 ± 0.1 per cent at a rate of 50 kilohertz. Our results are in excellent agreement with numerical simulations based on a master-equation description of the system. This deterministic protocol has the potential to be used for quantum computing distributed across different nodes of a cryogenic network.

Time from first seen in specialist care to surgery does not influence survival outcome in patients with upfront resected pancreatic adenocarcinoma.

BACKGROUND: This study evaluated the impact of time to surgery (TTS) on overall survival (OS), disease free survival (DFS) and postoperative complication rate in patients with upfront resected pancreatic adenocarcinoma (PA). METHODS: We retrospectively included patients who underwent upfront surgery for PA between January 1, 2004 and December 31, 2014 from four French centers. TTS was defined as the number of days between the date of the first consultation in specialist care and the date of surgery. DFS for a 14-day TTS was the primary endpoint. We also analyzed survival depending on different delay cut-offs (7, 14, 28, 60 and 75 days). RESULTS: A total of 168 patients were included. 59 patients (35%) underwent an upfront surgery within 14 days. Patients in the higher delay group (> 14 days) had significantly more vein resections and endoscopic biliary drainage. Adjusted OS (p = 0.44), DFS (p = 0.99), fistulas (p = 0.41), hemorrhage (p = 0.59) and severe post-operative complications (p = 0.82) were not different according to TTS (> 14 days). Other delay cut-offs had no impact on OS or DFS. DISCUSSION: TTS seems to have no impact on OS, DFS and 90-day postoperative morbidity.

Microwave Quantum Link between Superconducting Circuits Housed in Spatially Separated Cryogenic Systems.

Superconducting circuits are a strong contender for realizing quantum computing systems and are also successfully used to study quantum optics and hybrid quantum systems. However, their cryogenic operation temperatures and the current lack of coherence-preserving microwave-to-optical conversion solutions have hindered the realization of superconducting quantum networks spanning different cryogenic systems or larger distances. Here, we report the successful operation of a cryogenic waveguide coherently linking transmon qubits located in two dilution refrigerators separated by a physical distance of five meters. We transfer qubit states and generate entanglement on demand with average transfer and target state fidelities of 85.8% and 79.5%, respectively, between the two nodes of this elementary network. Cryogenic microwave links provide an opportunity to scale up systems for quantum computing and create local area superconducting quantum communication networks over length scales of at least tens of meters.

Systemic high-dose intravenous methotrexate in patients with central nervous system metastatic breast cancer.

BACKGROUND: Infusion of high-dose intravenous methotrexate (MTX) has been demonstrating to penetrate the blood-brain barrier. The aim of this present study was to assess the efficacy and safety of high dose MTX in patients with central nervous system (CNS) metastases of breast cancer. METHODS: Twenty-two patients with CNS metastases treated by MTX (3 g/m2) between April 2004 and October 2009 were enrolled. Clinical response rate, time to progression (TTP), overall survival (OS), and safety were assessed. RESULTS: In terms of brain metastases, 2 patients (9%) achieved a partial response, 10 patients (45%) had disease stabilization, and 10 patients (45%) had disease progression. In others metastatic sites, 7 patients (39%) achieved a disease stabilization, and 11 patients (61%) had disease progression. TTP and OS were 2.1 (95%CI 1.4-2.9) and 6.3 (95%CI 1.8-10) months, respectively. CONCLUSION: High-dose MTX demonstrated a moderate activity at 3 g/m2. Nonetheless, the favorable toxicity profile should suggest the possibility to increase the dosage and further study are planned.

Fast and Unconditional All-Microwave Reset of a Superconducting Qubit.

Active qubit reset is a key operation in many quantum algorithms, and particularly in quantum error correction. Here, we experimentally demonstrate a reset scheme for a three-level transmon artificial atom coupled to a large bandwidth resonator. The reset protocol uses a microwave-induced interaction between the |f,0⟩ and |g,1⟩ states of the coupled transmon-resonator system, with |g⟩ and |f⟩ denoting the ground and second excited states of the transmon, and |0⟩ and |1⟩ the photon Fock states of the resonator. We characterize the reset process and demonstrate reinitialization of the transmon-resonator system to its ground state in less than 500 ns and with 0.2% residual excitation. Our protocol is of practical interest as it has no additional architectural requirements beyond those needed for fast and efficient single-shot readout of transmons, and does not require feedback.

Safe and prolonged survival with long-term exposure to pomalidomide in relapsed/refractory myeloma.

BACKGROUND: The IFM2009-02 trial studied pomalidomide (4 mg daily, 21/28 versus 28/28) and dexamethasone in very advanced relapsed or refractory multiple myeloma (RRMM). We observed that 40% of patients had a prolonged progression-free survival (PFS) and subsequently overall survival (OS). We sought to analyze the characteristics of these patients and study the effect of long exposure to pomalidomide. DESIGN: We separated the studied population into two groups: 3 months to 1 year (<1 year) and more than 1 year (≥1 year) of treatment with pomalidomide and dexamethasone based on clinical judgment and historical control studies. We then analyzed the characteristics of patients according to duration of treatment. RESULTS: The overall response rate (ORR) for the <1-year group was 43%, the median PFS 4.6 months [95% confidence interval (95% CI) 3.8-6.4] with only 6% at 12 months, and the median OS was 15 months (11.7-20.3) and 40% at 18 months. For the ≥1-year group, the response rate and survival were strikingly different, ORR at 83%, median PFS 20.7 months (14.7-35.4), median OS not reached, and 91% at 18 months. CONCLUSION: Pomalidomide and dexamethasone favored prolonged and safe exposure to treatment in 40% of heavily treated and end-stage RRMM, a paradigm shift in the natural history of RRMM characterized with a succession of shorter disease-free intervals and ultimately shorter survival. Although an optimization of pomalidomide-dexamethasone regimen is warranted in advanced RRMM, we claim that pomalidomide has proven once more to change the natural history of myeloma in this series, which should be confirmed in a larger study.

Alterations in bone mineral density and bone turnover markers in newly diagnosed adults with lymphoma receiving chemotherapy: a 1-year prospective pilot study.

BACKGROUND: Bone mineral density (BMD) loss is poorly defined in lymphoma patients. The aim of this study was to measure the extent of BMD loss in newly diagnosed lymphoma patients receiving chemotherapy. PATIENTS AND METHODS: This was a prospective, single-center study conducted in patients aged≥18 years with previously confirmed lymphoma treated by chemotherapy. Patients with low baseline BMD defined as Z/T-score less than or equal to -2.5 and/or history of osteoporotic fractures were excluded. BMD was measured at baseline before initiating chemotherapy and 1 year later. Predictive factors of BMD loss were investigated. RESULTS: Forty-one lymphoma patients (31 males and 10 females) receiving chemotherapy were enrolled. The median age at diagnosis was 59 (range: 19-86) years. Histological subtypes were predominantly diffuse large B-cell lymphoma (58%), mostly stage III-IV (54%). All patients received chemotherapy and 22% of patients received second-line treatment due to relapse or progressive disease. Thirty-two patients were evaluable at 1 year. The mean BMD changes were: -2.7%±3.9% for lumbar spine (P<0.001), -2.2%±7.6% for femoral neck (P<0.01) and -2.6%±4.5% for total hip (P<0.0001). In multivariate analysis, predictive factors of BMD loss at baseline were (i) at lumbar spine: female gender (P=0.01), higher lactate dehydrogenase level (P=0.04) and lower creatinine clearance (P=0.01); (ii) at total hip: lower albumin (P=0.01), higher corrected serum calcium (P<0.01), lower alkaline phosphatase (AP) (P<0.01) and autologous stem cell transplant (P=0.03); and (iii) at femoral neck: higher corrected serum calcium (P=0.02) and lower bone AP (P=0.01). CONCLUSION: Adult patients with known lymphoma receiving chemotherapy experienced significant BMD loss at 1 year.

ASSESSMENT OF OVERRANGING AS A FUNCTION OF PITCH, COLLIMATION AND ROTATION TIME FOR THREE OF THE MOST RECENT AND WIDESPREAD CT SCANS IN FRANCE.

PURPOSE: to assess overranging (OR) as a function of pitch, collimation and rotation time for three commonly used CT models in France. METHODS: OR was measured using XR-SP2 Gafchromic films (Ashland, USA) and computed from exposure data for three widely used CT models in France. The impact of collimation, pitch and rotation time on OR was analyzed while comparing the three CT models. RESULTS: for a typical head protocol, measured OR was found to be equal to 1.64 cm for CT scan A, 0.5 cm for CT scan B and 3.44 cm for CT scan C. OR values were respectively of 4.47, 3.24 and 7.81 cm for the typical chest protocol and the 3 CT models. OR was lowest at pitch values <1 for CT scan A, while it linearly increased with pitch for CT scan B and was lowest for high pitch values for CT scan C. Additionally, OR increase with collimation (24 mm to 38.4 mm) was most pronounced for CT scan B (factor of 2.2 for low pitch (0.5) and 2.8 for high pitch (1.2)) while it increased linearly regardless of the pitch for CT scans A and C. Rotation time also proved to slightly affect OR mainly for CT scan B (up to 2.2 mm). CONCLUSION: the present study shows that overranging remains an issue in modern CT scanners with large disparities across the vendors.

Impact of renal impairment on dihydropyrimidine dehydrogenase (DPD) phenotyping.

BACKGROUND: The chemotherapeutic agent 5-fluorouracil (5-FU) is catabolized by dihydropyrimidine dehydrogenase (DPD), the deficiency of which may lead to severe toxicity or death. Since 2019, DPD deficiency testing, based on uracilemia, is mandatory in France and recommended in Europe before initiating fluoropyrimidine-based regimens. However, it has been recently shown that renal impairment may impact uracil concentration and thus DPD phenotyping. PATIENTS AND METHODS: The impact of renal function on uracilemia and DPD phenotype was studied on 3039 samples obtained from three French centers. We also explored the influence of dialysis and measured glomerular filtration rate (mGFR) on both parameters. Finally, using patients as their own controls, we assessed as to what extent modifications in renal function impacted uracilemia and DPD phenotyping. RESULTS: We observed that uracilemia and DPD-deficient phenotypes increased concomitantly to the severity of renal impairment based on the estimated GFR, independently and more critically than hepatic function. This observation was confirmed with the mGFR. The risk of being classified 'DPD deficient' based on uracilemia was statistically higher in patients with renal impairment or dialyzed if uracilemia was measured before dialysis but not after. Indeed, the rate of DPD deficiency decreased from 86.4% before dialysis to 13.7% after. Moreover, for patients with transient renal impairment, the rate of DPD deficiency dropped dramatically from 83.3% to 16.7% when patients restored their renal function, especially in patients with an uracilemia close to 16 ng/ml. CONCLUSIONS: DPD deficiency testing using uracilemia could be misleading in patients with renal impairment. When possible, uracilemia should be reassessed in case of transient renal impairment. For patients under dialysis, testing of DPD deficiency should be carried out on samples taken after dialysis. Hence, 5-FU therapeutic drug monitoring would be particularly helpful to guide dose adjustments in patients with elevated uracil and renal impairment.

Intraperitoneal clearance as a potential biomarker of cisplatin after intraperitoneal perioperative chemotherapy: a population pharmacokinetic study.

BACKGROUND: Intraperitoneal (IP) perioperative chemotherapy with cisplatin is an interesting option in ovarian cancer treatment. A combination of cisplatin with IP epinephrine (already shown to improve IP and decrease systemic platinum (Pt) exposure) was evaluated using a population pharmacokinetic analysis. METHODS: Data from 55 patients treated with cisplatin-based IP perioperative chemotherapy with (n=26) or without (n=29) epinephrine were analysed using NONMEM. RESULTS: Epinephrine halves clearance between peritoneum and serum (IPCL) and increases the Pt central volume of distribution, IP exposure and penetration in tissue. IPCL has a better predictive value than any other parameter with respect to renal toxicity. CONCLUSION: This confirms that IPCL could be useful in assessing renal toxicity. As IPCL is also linked to tissue penetration and IP exposure, it may be proposed as biomarker. In addition to a Bayesian estimation, we propose a single-sample calculation-way to assess it. Prospective studies are needed to validate IPCL as a biomarker in this context.

Outcomes of active surveillance of EU-TIRADS 5 thyroid nodules.

OBJECTIVE: Active surveillance of cytologically proven microcarcinomas has been shown as a safe procedure. However, fine needle aspiration biopsy (FNAB) is not recommended by European Thyroid Association (ETA) and American Thyroid Association (ATA) guidelines for highly suspicious nodules ≤ 10 mm. The aim of the study was to assess the outcomes of active surveillance of EU-TIRADS 5 nodules ≤ 10 mm not initially submitted to FNAB. PATIENTS AND METHODS: 80 patients with at least one EU-TIRADS 5 nodule ≤ 10 mm and no suspicious lymph nodes, accepting active surveillance, were included. RESULTS: Mean baseline diameter and volume were 5.4 mm (±2.0) and 64.4 mm3 (±33.5), respectively. After a median follow-up of 36.1 months, a volumetric increase ≥ 50% occurred in 28 patients (35.0%) and a suspicious lymph node in 3 patients (3.8%). Twenty-four patients underwent an FNAB (30.0%) after at least a 1 year follow-up of which 45.8% were malignant, 8.3% benign, 33.3% undetermined and 8.3% nondiagnostic. Sixteen patients (20.0%) underwent conversion surgery after a median follow-up of 57.2 months, confirming the diagnosis of papillary carcinoma in 15/16 cases (not described in 1 histology report), all in remission at 6-12 months postoperative follow-up. CONCLUSION: Applying ETA and ATA guidelines to avoid FNA of EU-TIRADS 5 sub-centimeter nodules and proceeding to active surveillance of such nodules in selected patients is a safe procedure. Thus, US-FNAB could be postponed until the nodule shows signs of progression or a suspicious lymph node appears, with no added risk for the patient.

Population pharmacokinetics of the humanised monoclonal antibody, HuHMFG1 (AS1402), derived from a phase I study on breast cancer.

BACKGROUND: HuHMFG1 (AS1402) is a humanised monoclonal antibody that has undergone a phase I trial in metastatic breast cancer. The aim of this study was to characterise the pharmacokinetics (PKs) of HuHMFG1 using a population PK model. METHOD: Data were derived from a phase I study of 26 patients receiving HuHMFG1 at doses ranging from 1 to 16 mg kg(-1). Data were analysed using NONMEM software and covariates were included. A limited sampling strategy (LSS) was developed using training and a validation data set. RESULTS: A linear two-compartment model was shown to be adequate to describe data. Covariate analysis indicated that weight was not related to clearance. An LSS was successfully developed on the basis of the model, in which one sample is collected immediately before the start of an infusion and the second is taken at the end of infusion. CONCLUSION: A two-compartment population PK model successfully describes HuHMFG1 behaviour. The model suggests using a fixed dose of HuHMFG1, which would simplify dosing. The model could be used to optimise dose level and dosing schedule if more data on the correlation between exposure and efficacy become available from future studies. The derived LSS could optimise further PK assessment of this antibody.

[Eosinophilic dermatosis associated with hematological disorders: A clinical, histopathological and immunohistochemical study of six observations]. / Dermatose éosinophilique associée aux hémopathies : étude clinique, histopathologique et immunohistochimique de six cas.

BACKGROUND: Eosinophilic dermatosis of hematologic disease (EDH) or insect bite-like reaction is a pruritic dermatitis described mostly in patients with chronic lymphocytic leukaemia (CLL). We describe six patients with the disorder in association with CLL and other blood dyscrasias. PATIENTS AND METHODS: We reviewed the medical records of patients with EDH seen between 2004 and 2009 in our department and re-examined histological slides. RESULTS: Mean age at dermatosis onset was 75.6 years and the sex ratio was 1. There were three CLL, two mantle-cell lymphomas and one MALT-type lymphoma. The dermatitis was quite polymorphic, with erythematous papules, wheals and plaques. The initial skin lesions appeared at the same time as or after the diagnosis of haematological neoplasm. Their reappearance heralded relapse of the blood disease in three cases. Histologically, all lesions had a dense dermal infiltrate of small, mostly CD4+ T-cells, with numerous eosinophils. In three patients, there was marked folliculotropism, resembling folliculotropic T-cell lymphoma. In most cases, EDH disappeared after appropriate chemotherapy for the blood disorder. DISCUSSION: Our cases show that the clinical expression of EDH is quite polymorphic. Its appearance may precede relapse of or may indicate prompt search screening for blood dyscrasia. The most efficient treatment of this dermatosis appears to be specific chemotherapy for the blood dyscrasia. There is reason to believe that a population of T-helper 2 (Th2) lymphocytes, reactive to malignant B-cells, induces tissue eosinophilia, mainly through production of interleukin (IL)-5, among other cytokines. Eosinophils appear to be the main effector cells.

Tyrosine kinase inhibitors and solid tumours: case report and review of the literature.

Bcr-Abl tyrosine kinase inhibitors (TKIs) such as imatinib or dasatinib produce high cytogenetic response rates in patients with Philadelphia-positive chronic myeloid leukaemia (CML) with a good overall safety profile. Despite a complete molecular response, it is currently recommended to continue these targeted therapies to avoid relapse. The immediate and short-term TKI side effects are well known, but the long-term side effects have not yet been clearly identified. A preclinical study in rats treated with TKI showed a statistically significant increase in benign and malignant renal tumours. The authors report the case of a 61-year-old man with CML treated with imatinib with a good response, and they switched to dasatinib after grade 4 hepatic toxicity. He had received treatment with 400 mg of imatinib per day for 77 days, followed by dasatinib for 133 days. He developed a metastatic carcinoma of unknown origin during TKI therapy. Despite chemotherapy, the patient died 2 months after the diagnosis. Although several cases of solid tumours have been reported during TKI therapy, the link between cancer and TKIs is not yet clear. Imatinib has remarkably improved the prognosis of patients with CML. Monitoring of the long-term safety profile of TKIs is essential due to the prolonged survival of these patients.

[Haematopoietic stem cell transplantation in the treatment of autoimmune diseases]. / Intensification thérapeutique dans les maladies auto-immunes.

PURPOSE: During the past ten years, more than 1000 patients suffering from severe autoimmune disease have received an autologous haematopoietic stem cell transplant. These new therapeutic have been used in systemic sclerosis (scleroderma), multiple sclerosis, rheumatoid arthritis, juvenile idiopathic arthritis and systemic lupus erythematosus. CURRENT KNOWLEDGE AND KEY POINTS: Autologous haematopoietic stem cell transplantation has become a curative option for condition with very poor prognosis as severe systemic sclerosis, lupus erythematosus or other systemic diseases. This review summarizes the current experience in the phase I and II clinical trials in Europe and North America. We describe the main results and the limits of stem cell transplantation in systemic diseases. FUTURE PROSPECTS AND PROJECTS: Autologous haematopoietic stem cell transplant in the treatment of autoimmune disease has evolved from a experimental concept to a clinically feasible and powerful therapy for selected patients with severe disease.