14 research outputs found
Reducing the impact of radioactivity on quantum circuits in a deep-underground facility
As quantum coherence times of superconducting circuits have increased from
nanoseconds to hundreds of microseconds, they are currently one of the leading
platforms for quantum information processing. However, coherence needs to
further improve by orders of magnitude to reduce the prohibitive hardware
overhead of current error correction schemes. Reaching this goal hinges on
reducing the density of broken Cooper pairs, so-called quasiparticles. Here, we
show that environmental radioactivity is a significant source of nonequilibrium
quasiparticles. Moreover, ionizing radiation introduces time-correlated
quasiparticle bursts in resonators on the same chip, further complicating
quantum error correction. Operating in a deep-underground lead-shielded
cryostat decreases the quasiparticle burst rate by a factor fifty and reduces
dissipation up to a factor four, showcasing the importance of radiation
abatement in future solid-state quantum hardware
Lancet
BACKGROUND: In 2015, the second cycle of the CONCORD programme established global surveillance of cancer survival as a metric of the effectiveness of health systems and to inform global policy on cancer control. CONCORD-3 updates the worldwide surveillance of cancer survival to 2014. METHODS: CONCORD-3 includes individual records for 37.5 million patients diagnosed with cancer during the 15-year period 2000-14. Data were provided by 322 population-based cancer registries in 71 countries and territories, 47 of which provided data with 100% population coverage. The study includes 18 cancers or groups of cancers: oesophagus, stomach, colon, rectum, liver, pancreas, lung, breast (women), cervix, ovary, prostate, and melanoma of the skin in adults, and brain tumours, leukaemias, and lymphomas in both adults and children. Standardised quality control procedures were applied; errors were rectified by the registry concerned. We estimated 5-year net survival. Estimates were age-standardised with the International Cancer Survival Standard weights. FINDINGS: For most cancers, 5-year net survival remains among the highest in the world in the USA and Canada, in Australia and New Zealand, and in Finland, Iceland, Norway, and Sweden. For many cancers, Denmark is closing the survival gap with the other Nordic countries. Survival trends are generally increasing, even for some of the more lethal cancers: in some countries, survival has increased by up to 5% for cancers of the liver, pancreas, and lung. For women diagnosed during 2010-14, 5-year survival for breast cancer is now 89.5% in Australia and 90.2% in the USA, but international differences remain very wide, with levels as low as 66.1% in India. For gastrointestinal cancers, the highest levels of 5-year survival are seen in southeast Asia: in South Korea for cancers of the stomach (68.9%), colon (71.8%), and rectum (71.1%); in Japan for oesophageal cancer (36.0%); and in Taiwan for liver cancer (27.9%). By contrast, in the same world region, survival is generally lower than elsewhere for melanoma of the skin (59.9% in South Korea, 52.1% in Taiwan, and 49.6% in China), and for both lymphoid malignancies (52.5%, 50.5%, and 38.3%) and myeloid malignancies (45.9%, 33.4%, and 24.8%). For children diagnosed during 2010-14, 5-year survival for acute lymphoblastic leukaemia ranged from 49.8% in Ecuador to 95.2% in Finland. 5-year survival from brain tumours in children is higher than for adults but the global range is very wide (from 28.9% in Brazil to nearly 80% in Sweden and Denmark). INTERPRETATION: The CONCORD programme enables timely comparisons of the overall effectiveness of health systems in providing care for 18 cancers that collectively represent 75% of all cancers diagnosed worldwide every year. It contributes to the evidence base for global policy on cancer control. Since 2017, the Organisation for Economic Co-operation and Development has used findings from the CONCORD programme as the official benchmark of cancer survival, among their indicators of the quality of health care in 48 countries worldwide. Governments must recognise population-based cancer registries as key policy tools that can be used to evaluate both the impact of cancer prevention strategies and the effectiveness of health systems for all patients diagnosed with cancer. FUNDING: American Cancer Society; Centers for Disease Control and Prevention; Swiss Re; Swiss Cancer Research foundation; Swiss Cancer League; Institut National du Cancer; La Ligue Contre le Cancer; Rossy Family Foundation; US National Cancer Institute; and the Susan G Komen Foundation
Worldwide trends in population-based survival for children, adolescents, and young adults diagnosed with leukaemia, by subtype, during 2000–14 (CONCORD-3) : analysis of individual data from 258 cancer registries in 61 countries
Background Leukaemias comprise a heterogenous group of haematological malignancies. In CONCORD-3, we analysed
data for children (aged 0–14 years) and adults (aged 15–99 years) diagnosed with a haematological malignancy
during 2000–14 in 61 countries. Here, we aimed to examine worldwide trends in survival from leukaemia, by age and
morphology, in young patients (aged 0–24 years).
Methods We analysed data from 258 population-based cancer registries in 61 countries participating in CONCORD-3
that submitted data on patients diagnosed with leukaemia. We grouped patients by age as children (0–14 years),
adolescents (15–19 years), and young adults (20–24 years). We categorised leukaemia subtypes according to the
International Classification of Childhood Cancer (ICCC-3), updated with International Classification of Diseases
for Oncology, third edition (ICD-O-3) codes. We estimated 5-year net survival by age and morphology, with 95% CIs,
using the non-parametric Pohar-Perme estimator. To control for background mortality, we used life tables by
country or region, single year of age, single calendar year and sex, and, where possible, by race or ethnicity. All-age
survival estimates were standardised to the marginal distribution of young people with leukaemia included in the
analysis.
Findings 164563 young people were included in this analysis: 121328 (73·7%) children, 22963 (14·0%) adolescents, and
20272 (12·3%) young adults. In 2010–14, the most common subtypes were lymphoid leukaemia (28205 [68·2%] patients)
and acute myeloid leukaemia (7863 [19·0%] patients). Age-standardised 5-year net survival in children, adolescents, and
young adults for all leukaemias combined during 2010–14 varied widely, ranging from 46% in Mexico to more than
85% in Canada, Cyprus, Belgium, Denmark, Finland, and Australia. Individuals with lymphoid leukaemia had better
age-standardised survival (from 43% in Ecuador to ≥80% in parts of Europe, North America, Oceania, and Asia) than
those with acute myeloid leukaemia (from 32% in Peru to ≥70% in most high-income countries in Europe,
North America, and Oceania). Throughout 2000–14, survival from all leukaemias combined remained consistently
higher for children than adolescents and young adults, and minimal improvement was seen for adolescents and young
adults in most countries.
Interpretation This study offers the first worldwide picture of population-based survival from leukaemia in children,
adolescents, and young adults. Adolescents and young adults diagnosed with leukaemia continue to have lower
survival than children. Trends in survival from leukaemia for adolescents and young adults are important indicators
of the quality of cancer management in this age group.peer-reviewe
Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000–2014 (CONCORD-3)
Background:
Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.
Methods:
We analyzed individual data for adults (15–99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000–2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.
Results:
The study included 556,237 adults. In 2010–2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%–38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000–2004 and 2005–2009. These improvements were more noticeable among adults diagnosed aged 40–70 years than among younger adults.
Conclusions:
To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines
Minimizing the Discrimination Time for Quantum States of an Artificial Atom
Fast discrimination between quantum states of superconducting artificial atoms is an important ingredient for quantum information processing. In circuit quantum electrodynamics, increasing the signal-field amplitude in the readout resonator, dispersively coupled to the artificial atom, improves the signal-to-noise ratio and increases the measurement strength. Here, we employ this effect over 2 orders of magnitude in readout power, made possible by the unique combination of a dimer-Josephson-junction-array amplifier with a large dynamic range and the fact that the readout of our granular aluminum fluxonium artificial atom remains quantum nondemolition (QND) at relatively large photon numbers in the readout resonator, up to n = 110. Using Bayesian inference, this allows us to detect quantum jumps faster than the readout-resonator response time 2/κ, where κ is the bandwidth of the readout resonator
Operating in a deep underground facility improves the locking of gradiometric fluxonium qubits at the sweet spots
We demonstrate flux-bias locking and operation of a gradiometric fluxonium artificial atom using two symmetric granular aluminum (grAl) loops to implement the superinductor. The gradiometric fluxonium shows two orders of magnitude suppression of sensitivity to homogeneous magnetic fields, which can be an asset for hybrid quantum systems requiring strong magnetic field biasing. By cooling down the device in an external magnetic field while crossing the metal-to-superconductor transition, the gradiometric fluxonium can be locked either at 0 or 0/2 effective flux bias, corresponding to an even or odd number of trapped fluxons, respectively. At mK temperatures, the fluxon parity prepared during initialization survives to magnetic field bias exceeding 1000. However, even for states biased in the vicinity of 10, we observe unexpectedly short fluxon lifetimes of a few hours, which cannot be explained by thermal or quantum phase slips. When operating in a deep-underground cryostat of the Gran Sasso laboratory, the fluxon lifetimes increase to days, indicating that ionizing events activate phase slips in the grAl superinductor
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DEMETRA: Suppression of the Relaxation Induced by Radioactivity in Superconducting Qubits
Non-equilibrium quasiparticles can deteriorate the performance of superconducting qubits by reducing their coherence. We are investigating a source of quasiparticles that has been too long neglected, namely radioactivity: cosmic rays, environmental radioactivity and contaminants in the materials can all generate phonons of energy sufficient to break Cooper pairs and thus increase the number of quasiparticles. In this contribution, we describe the status of the project and its perspectives
Reducing the impact of radioactivity on quantum circuits in a deep-underground facility
As quantum coherence times of superconducting circuits have increased from nanoseconds to hundreds of microseconds, they are currently one of the leading platforms for quantum information processing. However, coherence needs to further improve by orders of magnitude to reduce the prohibitive hardware overhead of current error correction schemes. Reaching this goal hinges on reducing the density of broken Cooper pairs, so-called quasiparticles. Here, we show that environmental radioactivity is a significant source of nonequilibrium quasiparticles. Moreover, ionizing radiation introduces time-correlated quasiparticle bursts in resonators on the same chip, further complicating quantum error correction. Operating in a deep-underground lead-shielded cryostat decreases the quasiparticle burst rate by a factor thirty and reduces dissipation up to a factor four, showcasing the importance of radiation abatement in future solid-state quantum hardware