163 research outputs found
Comparison of coherence times in three dc SQUID phase qubits
We report measurements of spectroscopic linewidth and Rabi oscillations in
three thin-film dc SQUID phase qubits. One device had a single-turn Al loop,
the second had a 6-turn Nb loop, and the third was a first order gradiometer
formed from 6-turn wound and counter-wound Nb coils to provide isolation from
spatially uniform flux noise. In the 6 - 7.2 GHz range, the spectroscopic
coherence times for the gradiometer varied from 4 ns to 8 ns, about the same as
for the other devices (4 to 10 ns). The time constant for decay of Rabi
oscillations was significantly longer in the single-turn Al device (20 to 30
ns) than either of the Nb devices (10 to 15 ns). These results imply that
spatially uniform flux noise is not the main source of decoherence or
inhomogenous broadening in these devices.Comment: 4 pages, 5 figures, accepted for publication in IEEE Trans. Appl.
Supercon
Seriale telewizyjne a dystanse klasowe w Polsce
Artykuł poświęcony jest jednemu z wymiarów stratyfikacji kultury, jakim jest oglądanie seriali telewizyjnych. Opierając się na danych z badania zrealizowanego w 2019 roku na próbie ogólnopolskiej chcemy ustalić, w jakim stopniu ten sposób spędzania czasu wolnego związany jest z pozycją klasową. Okazuje się, że oglądanie seriali niezbyt silnie zależy od pozycji klasowej, jeżeli kontrolowane są inne czynniki. Ani częstość oglądania, ani rodzaje, ani stopień złożoności seriali nie wchodzą w istotne zależności z usytuowaniem w hierarchii społecznej utożsamianej z pozycją rynkową i stosunkiem do szeroko rozumianej własności. Natomiast ważnymi zmiennymi wyjaśniającymi okazują się inne cechy związane z pozycją klasową. Są to wykształcenie respondentów i pochodzenie społeczne. Zgodnie z oczekiwaniami wyższe wykształcenie respondentów i matek zwiększa szanse oglądania seriali zaliczanych do „wyższej” kultury, podczas gdy oglądanie seriali o niższej złożoności związane jest z niższym kapitałem edukacyjnym. Sugerowałoby to, że oglądanie seriali może sprzyjać odtwarzaniu się podziałów klasowych
Systemic treatment of hormone receptor positive, human epidermal growth factor 2 negative metastatic breast cancer: retrospective analysis from Leeds Cancer Centre
Background
Study aimed to characterise treatment and outcomes for patients with hormone receptor positive (HR+), human epidermal growth factor 2 negative (HER2-) metastatic breast cancer (MBC) within a large regional cancer centre, as a benchmark for evaluating real-world impact of novel therapies.
Methods
Retrospective longitudinal cohort, using electronic patient records of adult females with a first diagnosis of HR+/HER2- MBC January 2012–March 2018.
Results
One hundred ninety-six women were identified with HR+/HER2- MBC. Median age was 67 years, 85.2% were post-menopausal and median time between primary diagnosis and metastasis was 5.4 years. Most (75.1%) patients received endocrine therapy as first line systemic treatment (1st LoT); use of 1st LoT chemotherapy halved between 2012 and 2017. Patients receiving 1st LoT chemotherapy were younger and more likely to have visceral metastasis (p < 0.01). Median OS was 29.5 months and significantly greater for patients with exclusively non-visceral metastasis (p < 0.01). The adjusted hazard ratio for death of patients with visceral (or CNS) metastasis was 1.91 relative to those with exclusively non-visceral metastasis.
Conclusions
Diverse endocrine therapies predominate as 1st LoT for patients with HR+/HER2- MBC, chemotherapy being associated with more aggressive disease in younger patients, emphasising the importance of using effective and tolerable therapies early
Entanglement in a quantum annealing processor
Entanglement lies at the core of quantum algorithms designed to solve
problems that are intractable by classical approaches. One such algorithm,
quantum annealing (QA), provides a promising path to a practical quantum
processor. We have built a series of scalable QA processors consisting of
networks of manufactured interacting spins (qubits). Here, we use qubit
tunneling spectroscopy to measure the energy eigenspectrum of two- and
eight-qubit systems within one such processor, demonstrating quantum coherence
in these systems. We present experimental evidence that, during a critical
portion of QA, the qubits become entangled and that entanglement persists even
as these systems reach equilibrium with a thermal environment. Our results
provide an encouraging sign that QA is a viable technology for large-scale
quantum computing.Comment: 13 pages, 8 figures, contact corresponding author for Supplementary
Informatio
SuperPolymyxin™ Medium for the Screening of Colistin-Resistant Gram-Negative Bacteria in Stool Samples
Colistin is one of the last resort antimicrobials for the treatment of infections caused by multidrug-resistant Gram-negative bacteria. After the emergence of transferable colistin resistance genes (mcr-1–5), a reliable culture-based screening method to detect colonization with colistin-resistant Gram-negative bacteria (CRGN) is needed. The objective of this study was to test the performance of SuperPolymyxin™ medium to screen for CRGN in stool samples and to compare different methods for the confirmation of colistin resistance (e.g., Etest®, broth microdilution [BMD], and the Rapid Polymyxin™ NP test). Colonization with CRGN was analyzed in a prospective cohort study among travelers. Stool samples (Fecal TranswabTM) taken before, during and after travel were cultured on SuperPolymyxin™ agar. Every phenotypically different colony was subcultured for species identification using MALDI-TOF mass spectrometry. Susceptibility to colistin was tested using Etest® and confirmed by BMD and the Rapid Polymyxin™ NP test. In total, 128 participants provided 1,495 stool samples. After culture on SuperPolymyxin™ medium (37°C, 24–48 h), 1,851 phenotypically different colonies were isolated. Isolates belonging to intrinsically colistin-resistant genera (e.g., Morganella, Providencia, Proteus) or Stenotrophomonas maltophilia were excluded from further analysis (n = 421). Among the remaining 1,430 isolates, colistin resistance was confirmed in 279 by Etest® (19.5%) and 218 by BMD (15.3%). The Rapid Polymyxin™ NP test was compared with BMD (reference) to detect colistin resistance (specificity: 88.6%, sensitivity 71.1%). SuperPolymyxin™ medium is suitable to screen for fecal colonization with CRGN. The high proportion of colistin-susceptible isolates growing on SuperPolymyxin™ medium caused a high workload. The confirmation of CRGN with the Rapid Polymyxin™ NP Test could be a less labor-intensive alternative to BMD
Multi-level Spectroscopy of Two-Level Systems Coupled to a dc SQUID Phase Qubit
We report spectroscopic measurements of discrete two-level systems (TLSs)
coupled to a dc SQUID phase qubit with a 16 \mu\m2 area Al/AlOx/Al junction.
Applying microwaves in the 10 GHz to 11 GHz range, we found eight avoided level
crossings with splitting sizes from 10 MHz to 200 MHz and spectroscopic
lifetimes from 4 ns to 160 ns. Assuming the transitions are from the ground
state of the composite system to an excited state of the qubit or an excited
state of one of the TLS states, we fit the location and spectral width to get
the energy levels, splitting sizes and spectroscopic coherence times of the
phase qubit and TLSs. The distribution of splittings is consistent with
non-interacting individual charged ions tunneling between random locations in
the tunnel barrier and the distribution of lifetimes is consistent with the
AlOx in the junction barrier having a frequency-independent loss tangent. To
check that the charge of each TLS couples independently to the voltage across
the junction, we also measured the spectrum in the 20-22 GHz range and found
tilted avoided level crossings due to the second excited state of the junction
and states in which both the junction and a TLS were excited
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