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Background: Research on the impact of COVID-19 on different patient populations has been of great value for the optimization of patient care since the start of the SARS-CoV-2 pandemic. Earlier, we reported the interim analysis of the immediate outcomes in patients (pts) with hematologic (hem) disease and COVID-19. Long-term results of the CHRONOS19 registry are now available. Methods: CHRONOS19 is an observational prospective cohort study among adult pts ((≥18 years) with hem diseases (malignant or non-malignant) and laboratory-confirmed or suspected (based on clinical symptoms and/or CT) COVID-19 in Russia. Data from 15 centers all over the country were collected on a web-based platform in a de-identified manner at 30, 90, and 180 days after COVID-19 was diagnosed. The primary endpoint was 30-day all-cause mortality. Secondary outcomes included COVID-19 complications, rate of ICU admission and mechanical ventilation, outcomes of hem disease in SARS-CoV-2 infected pts, overall survival, and risk factors for disease severity and mortality. Results: As of July 30, 2021, 666 pts were enrolled (females / males [n (%)]: 317 (48%) / 349 (52%); median [range] age: 56 [18-90] years. Disease types (malignant/non-malignant [n (%)]): 618 (93%) / 48 (7%), including AML 115 (17%), MM 113 (17%), NHL 106 (16%), CML / CMPD 92 (14%), ALL 52 (8%), CLL 50 (8%), MDS 25 (4%), HCL 23 (3%), HL 21 (3%), AA 16 (2%), APL 11 (2%), others 42 (6%); among them induction phase / remission / relapse or refractory / NA in 237 (35%) / 231 (35%) / 152 (23%) / 46 (7%) pts. Concomitant conditions were reported in 385 (58%) pts: cardiovascular 254 (66%), diabetes 76 (20%), obesity 57 (15%), pulmonary 41 (11%), chronic renal 44 (11%) or hepatic 33 (9%) disease, other 90 (23%). At a median follow-up of 7,5(1-19) months, 618 pts were evaluable for the primary outcome. Thirty-day all-cause mortality was 16% (100 pts died). Death due to COVID-19 complications occurred in 82 pts, 14 pts died due to progression of hem disease. Overall, 217 (33%) pts had severe disease, COVID-19 complications were detected in 458 (70%) pts, the most common were pneumonia in 425 (93%) pts, respiratory failure in 252 (55%) pts, multiple organ failure in 56 (12%) pts, cytokine storm in 52 (11%) pts, ARDS in 47 (10%) pts, and sepsis in 44 (10%) pts. The rate of ICU admission was 23% (145 pts) with high mortality in this group of pts (77%), 111 (17%) pts required mechanical ventilation, among them only 5 (4.5%) pts survived. Treatment of hem disease was changed, interrupted, or discontinued in 395 (60%) pts with a median delay of 4 weeks. At 30 days, the rate of relapse / progression of hem disease was 5% / 8% (24 / 40 of 517 evaluable pts). At the longer follow-up (90 and 180 days), relapse / progression occurred in another 9 / 23 pts. At the data cutoff, the median overall survival was not reached. Antibody detection was performed in 253 pts: 211 (84%) pts had IgG to SARS-CoV-2. In a univariate analysis, older age (> 60 years), myelotoxic agranulocytosis, transfusion dependence, diabetes among comorbidities, ARDS and other complications, except CRS, ICU and mechanical ventilation (Fig. 1) were associated with higher risks of mortality (p Conclusions: Patients with hem disease and COVID-19 have higher mortality than a general population with SARS-CoV-2 infection, predominantly due to COVID-19 complications. The longer-term follow-up did not reveal any concerns in terms of hem disease outcomes. Figure 1 Figure 1. Disclosures Vorobyev: Janssen, Roche, Sanofi, Takeda, Biocad, Abbvie: Other: Advisory Boards, Speakers Bureau; Astellas, Novartis, AstraZeneca: Speakers Bureau. Chelysheva: Pharmstandart: Speakers Bureau; Pfizer: Speakers Bureau; Bristol Myers Squibb: Speakers Bureau; Novartis Pharma: Speakers Bureau.

Background Patients (pts) with lymphoproliferative diseases (LPD) are at high risk of COVID-19 severe and lethal course. Objective To evaluate treatment outcomes and risk factors in pts with LPD and COVID-19 in a real-world setting. Methods CHRONOS19 is an ongoing nationwide observational cohort study of adult (≥18 y) pts with hematologic disease and COVID-19. Data from 15 centers were collected on a web-based platform and managed in a de-identified manner. We performed a subgroup analysis of pts with LPD and COVID-19. Primary endpoint was 30-day all-cause mortality. Long-term follow-up was at 90 and 180 days. Results As of data cutoff on April 14, 2021, 626 pts were included, 170 of them with LPD were eligible for primary endpoint assessment n(%): CLL – 64 (38%), Hodgkin lymphoma – 18 (10%), B-cell lymphomas aggressive/indolent – 49(29%) / 19(11%); M/F 96 (56%) / 74(44%), median age 56 [19–90] years, induction phase/R/R/remission 62(36%) / 68(40%) / 40(24%); comorbidities in 86 (51%) pts. Complications occurred in 126 (74%) pts; one-third had severe COVID-19, 25% were admitted to ICU, and 20% required mechanical ventilation. Comparative analysis of basic characteristics between pts with LPD and all other hematologic diseases did not reveal any significant clinical differences. All-cause mortality at 30 days was 14% in pts with LPD vs 15% in pts with other hematologic diseases (p=0.87); 86% of deaths were due to COVID-19 complications. Eight additional deaths due to COVID-19 at 90 days and 5 deaths due to LPD progression at 180 days occurred. In multivariate analysis, ICU + mechanical ventilation (HR, 71.99 [19.5–271.0]), and age ≥60 years (HR, 5.360 [1.08–11.8] were the most significant risk factors of death. COVID-19 affected treatment of LPD in 55% of pts, and 52% experienced treatment delay for a median of 4 [1–10] weeks. Early relapsed/refractory disease occurred in 5 of 170 (2.9%) pts; the association of relapses with impaired treatment is unknown. COVID-19 re-infection occurred in 1 patient. Data on antibodies after SARS-CoV-2 infection are available for 65 patients with LPD: anti-SARS-CoV-2 IgG was detected in 44 (66%) pts and only in 60% of pts with CD20-positive LPD vs 100% of pts with T-cell and Hodgkin lymphomas (p=0.004). Conclusions Thirty-day all-cause mortality in SARS-CoV-2-infected pts with LPD was comparable with other hematological diseases and higher than in the general population. Lower frequency of anti-SARS-CoV-2 IgG in CD20-positive patients is probably due to anti-CD20 therapy.

e18715 Background: Pts with hem diseases are at high risk of COVID-19 severe course and mortality. Emerging data on risk factors and outcomes in this patient population is of great value for developing strategies of medical care. Methods: CHRONOS19 is an ongoing nationwide observational cohort study of adult (≥18 y) pts with hem disease (both malignant and non-malignant) and lab-confirmed or suspected (clinical symptoms and/or CT) COVID-19. Primary objective was to evaluate treatment outcomes. Primary endpoint was 30-day all-cause mortality. Long-term follow-up was performed at 90 and 180 days. Data from 14 centers was collected on a web platform and managed in a deidentified manner. Results: As of data cutoff on January 27, 2021, 575 pts were included in the registry, 486 of them eligible for primary endpoint assessment, n(%): M/F 243(50%)/243(50%), median age 56 [18-90], malignant disease in 452(93%) pts, induction phase/R/R/remission 160(33%)/120(25%)/206(42%). MTA in 93(19%) pts, 158(33%) were transfusion dependent, comorbidities in 278(57%) pts. Complications in 335(69%) pts: pneumonia (67%), CRS (8%), ARDS (7%), sepsis (6%). One-third of pts had severe COVID-19, 25% were admitted to ICU, 20% required mechanical ventilation. All-cause mortality at 30 days – 17%; 80% due to COVID-19 complications. At 90 days, there were 14 new deaths: 6 (43%) due to hem disease progression. Risk factors significantly associated with OS are listed in Tab 1. In multivariate analysis – ICU+mechanical ventilation, HR, 53.3 (29.1-97.8). Acute leukemias were associated with higher risk of death, HR, 2.40 (1.28-4.51), less aggressive diseases (CML, CLL, MM, non-malignant) – with lower risk of death, HR, 0.54 (0.37-0.80). No association between time of COVID-19 diagnosis (Apr-Aug vs. Sep-Jan) and risk of death. COVID-19 affected treatment of hem disease in 65% of pts, 58% experienced treatment delay for a median of 4[1-10] weeks. Relapse rate on Day 30 and 90 – 4%, disease progression on Day 90 detected in 13(7%) pts; 180-day data was not mature at the time of analysis. Several cases of COVID-19 re-infection were described. Conclusions: Thirty-day all-cause mortality in pts with hem disease was higher than in general population with COVID-19. Longer-term follow-up (180 days) for hem disease outcomes and OS will be presented. [Table: see text]

Quantum error correction (QEC) can overcome the errors experienced by qubits1 and is therefore an essential component of a future quantum computer. To implement QEC, a qubit is redundantly encoded in a higher-dimensional space using quantum states with carefully tailored symmetry properties. Projective measurements of these parity-type observables provide error syndrome information, with which errors can be corrected via simple operations2. The ‘break-even’ point of QEC—at which the lifetime of a qubit exceeds the lifetime of the constituents of the system—has so far remained out of reach3. Although previous works have demonstrated elements of QEC4–16, they primarily illustrate the signatures or scaling properties of QEC codes rather than test the capacity of the system to preserve a qubit over time. Here we demonstrate a QEC system that reaches the break-even point by suppressing the natural errors due to energy loss for a qubit logically encoded in superpositions of Schrodinger-cat states17 of a superconducting resonator18–21. We implement a full QEC protocol by using real-time feedback to encode, monitor naturally occurring errors, decode and correct. As measured by full process tomography, without any post-selection, the corrected qubit lifetime is 320 microseconds, which is longer than the lifetime of any of the parts of the system: 20 times longer than the lifetime of the transmon, about 2.2 times longer than the lifetime of an uncorrected logical encoding and about 1.1 longer than the lifetime of the best physical qubit (the |0〉f and |1〉f Fock states of the resonator). Our results illustrate the benefit of using hardware-efficient qubit encodings rather than traditional QEC schemes. Furthermore, they advance the field of experimental error correction from confirming basic concepts to exploring the metrics that drive system performance and the challenges in realizing a fault-tolerant system.

The Schrodinger's cat thought experiment highlights the counterintuitive concept of entanglement in macroscopically distinguishable systems. The hallmark of entanglement is the detection of strong correlations between systems, most starkly demonstrated by the violation of a Bell inequality. No violation of a Bell inequality has been observed for a system entangled with a superposition of coherent states, known as a cat state. Here we use the Clauser–Horne–Shimony–Holt formulation of a Bell test to characterize entanglement between an artificial atom and a cat state, or a Bell-cat. Using superconducting circuits with high-fidelity measurements and real-time feedback, we detect correlations that surpass the classical maximum of the Bell inequality. We investigate the influence of decoherence with states up to 16 photons in size and characterize the system by introducing joint Wigner tomography. Such techniques demonstrate that information stored in superpositions of coherent states can be extracted efficiently, a crucial requirement for quantum computing with resonators., Qubit-cavity entanglement can be used for quantum information processing and for investigating the quantum-to-classical transition with high control. Here, the authors characterize the entanglement between an artificial atom and a cat state and its susceptibility to decoherence through Bell test witnesses.

Quantum error correction (QEC) is required for a practical quantum computer because of the fragile nature of quantum information. In QEC, information is redundantly stored in a large Hilbert space and one or more observables must be monitored to reveal the occurrence of an error, without disturbing the information encoded in an unknown quantum state. Such observables, typically multi-qubit parities such as , must correspond to a special symmetry property inherent to the encoding scheme. Measurements of these observables, or error syndromes, must also be performed in a quantum non-demolition (QND) way and faster than the rate at which errors occur. Previously, QND measurements of quantum jumps between energy eigenstates have been performed in systems such as trapped ions, electrons, cavity quantum electrodynamics (QED), nitrogen-vacancy (NV) centers, and superconducting qubits. So far, however, no fast and repeated monitoring of an error syndrome has been realized. Here, we track the quantum jumps of a possible error syndrome, the photon number parity of a microwave cavity, by mapping this property onto an ancilla qubit. This quantity is just the error syndrome required in a recently proposed scheme for a hardware-efficient protected quantum memory using Schr\"{o}dinger cat states in a harmonic oscillator. We demonstrate the projective nature of this measurement onto a parity eigenspace by observing the collapse of a coherent state onto even or odd cat states. The measurement is fast compared to the cavity lifetime, has a high single-shot fidelity, and has a 99.8% probability per single measurement of leaving the parity unchanged. In combination with the deterministic encoding of quantum information in cat states realized earlier, our demonstrated QND parity tracking represents a significant step towards implementing an active system that extends the lifetime of a quantum bit., Comment: 6 pages with 4 figures for the main text, 14 pages with 9 figures for supplementary material

Physical systems usually exhibit quantum behavior, such as superpositions and entanglement, only when they are sufficiently decoupled from a lossy environment. Paradoxically, a specially engineered interaction with the environment can become a resource for the generation and protection of quantum states. This notion can be generalized to the confinement of a system into a manifold of quantum states, consisting of all coherent superpositions of multiple stable steady states. We have experimentally confined the state of a harmonic oscillator to the quantum manifold spanned by two coherent states of opposite phases. In particular, we have observed a Schrodinger cat state spontaneously squeeze out of vacuum, before decaying into a classical mixture. This was accomplished by designing a superconducting microwave resonator whose coupling to a cold bath is dominated by photon pair exchange. This experiment opens new avenues in the fields of nonlinear quantum optics and quantum information, where systems with multi-dimensional steady state manifolds can be used as error corrected logical qubits.

We study the photon shot noise dephasing of a superconducting transmon qubit in the strong-dispersive limit, due to the coupling of the qubit to its readout cavity. As each random arrival or departure of a photon is expected to completely dephase the qubit, we can control the rate at which the qubit experiences dephasing events by varying \textit{in situ} the cavity mode population and decay rate. This allows us to verify a pure dephasing mechanism that matches theoretical predictions, and in fact explains the increased dephasing seen in recent transmon experiments as a function of cryostat temperature. We investigate photon dynamics in this limit and observe large increases in coherence times as the cavity is decoupled from the environment. Our experiments suggest that the intrinsic coherence of small Josephson junctions, when corrected with a single Hahn echo, is greater than several hundred microseconds., 5 pages, 4 figures; includes Supporting Online Material of 6 pages with 5 figures

International audience; The circulation of the Gulf of Lion, a large continental shelf north of the western basin of the Mediterranean Sea, is complex and highly variable. During stratified conditions, unexpected barotropic eastward currents can be detected, mostly in the western part of the gulf. Care is given to retrieve inertial oscillations when necessary. The primitive-equation free-surface model Symphonie is used to investigate the processes which can generate and influence these eastward currents. Three main wind forcing create these barotropic eastward currents: northwesterlies channelled in the western part of the gulf, northwesterlies and north winds both homogeneous throughout the gulf. In the first case, the wind stress curl of the channeled northwesterlies generates an elongated cyclonic circulation in the western part of the Gulf of Lion. The southern part of this cyclonic circulation is a barotropic eastward current, detected west of longitude 4.5°E. In the second case, a homogeneous northwesterly wind creates an intrusion of the along-slope geostrophic current on the shelf, generating a strong coastal jet going northward above Cap Creus. In stratified conditions, intrusion at this western end of the continental shelf only occurs during this type of wind forcing. The coastal jet goes north then detaches itself from the coast and goes eastward, north of the 100 m isobath. In the third case, a homogeneous north wind creates an eastward current which occupies the whole shelf north of latitude 43°N. The first two cases are studied in more details since cruise data corroborate the model simulations. The striking characteristic of these eastward currents is that they are barotropic despite the stratified conditions. Otherwise, their amplitude and exact locations are slightly different for the different cases of circulation. These eastward currents probably have an impact on the residence time of water masses in the Gulf of Lion, and hence on the total water budget of the gulf, as well as on primary production and biogeochemical fluxes.