1,495 research outputs found
Pentacoordinated Ti(IV) Chloride & Sn(IV) Bromide & Iodide Complexes with Acridine & Piperazine
209-21
Complexes of Some Group(IV) Metal Halides with 5-Aminoindazole
The synthesis and characterisation of Sn(IV) halides, Ge(IV),
Ti(IV) and Zr(IV) chloride complexes of the type MX4 : Li_ 2 with
5-aminoindazole has been made. The possible structure of these
complexes has been proposed on the basis of elemental analysis
and infrared spectroscopy. The IR spectra suggest unidentate
behaviour of the ligand involving pyrrole nitrogen in all the cases
except the tin(IV) bromide complex, where the ligand exhibits its
bidentate nature, involving the pyridyl nitrogen. An octahedral
geometry has been proposed for all the complexes. In the case
of MX4 :\u27L type complexes, except for SnBr4 : L, an octahedral
halogen bridged structure has been proposed
Single-shot qubit readout in circuit Quantum Electrodynamics
The future development of quantum information using superconducting circuits
requires Josephson qubits [1] with long coherence times combined to a
high-fidelity readout. Major progress in the control of coherence has recently
been achieved using circuit quantum electrodynamics (cQED) architectures [2,
3], where the qubit is embedded in a coplanar waveguide resonator (CPWR) which
both provides a well controlled electromagnetic environment and serves as qubit
readout. In particular a new qubit design, the transmon, yields reproducibly
long coherence times [4, 5]. However, a high-fidelity single-shot readout of
the transmon, highly desirable for running simple quantum algorithms or measur-
ing quantum correlations in multi-qubit experiments, is still lacking. In this
work, we demonstrate a new transmon circuit where the CPWR is turned into a
sample-and-hold detector, namely a Josephson Bifurcation Amplifer (JBA) [6, 7],
which allows both fast measurement and single-shot discrimination of the qubit
states. We report Rabi oscillations with a high visibility of 94% together with
dephasing and relaxation times longer than 0:5 \mu\s. By performing two
subsequent measurements, we also demonstrate that this new readout does not
induce extra qubit relaxation.Comment: 14 pages including 4 figures, preprint forma
RF bifurcation of a Josephson junction: microwave embedding circuit requirements
A Josephson tunnel junction which is RF-driven near a dynamical bifurcation
point can amplify quantum signals. The bifurcation point will exist robustly
only if the electrodynamic environment of the junction meets certain criteria.
In this article we develop a general formalism for dealing with the non-linear
dynamics of Josephson junction embedded in an arbitrary microwave circuit. We
find sufficient conditions for the existence of the bifurcation regime: a) the
embedding impedance of the junction need to present a resonance at a particular
frequency , with the quality factor of the resonance and the
participation ratio of the junction satisfying , b) the drive
frequency should be low frequency detuned away from by more than
.Comment: Submitted to Phys. Rev. B, 12 pages, 6 figure
Noiseless nonreciprocity in a parametric active device
Nonreciprocal devices such as circulators and isolators belong to an
important class of microwave components employed in applications like the
measurement of mesoscopic circuits at cryogenic temperatures. The measurement
protocols usually involve an amplification chain which relies on circulators to
separate input and output channels and to suppress backaction from different
stages on the sample under test. In these devices the usual reciprocal symmetry
of circuits is broken by the phenomenon of Faraday rotation based on magnetic
materials and fields. However, magnets are averse to on-chip integration, and
magnetic fields are deleterious to delicate superconducting devices. Here we
present a new proposal combining two stages of parametric modulation emulating
the action of a circulator. It is devoid of magnetic components and suitable
for on-chip integration. As the design is free of any dissipative elements and
based on reversible operation, the device operates noiselessly, giving it an
important advantage over other nonreciprocal active devices for quantum
information processing applications.Comment: 17 pages, 4 figures + 12 pages Supplementary Informatio
A multicentre, pragmatic, cluster randomised, controlled feasibility trial of the POD system of care
Objective
to provide a preliminary estimate of the effectiveness of the prevention of delirium (POD) system of care in reducing incident delirium in acute hospital wards and gather data for a future definitive randomised controlled trial.
Design
cluster randomised and controlled feasibility trial.
Setting
sixteen acute care of older people and orthopaedic trauma wards in eight hospitals in England and Wales.
Participants
patients 65 years and over admitted to participating wards during the trial period.
Interventions
participating wards were randomly assigned to either the POD programme or usual care, determined by existing local policies and practices. The POD programme is a manualised multicomponent delirium prevention intervention that targets 10 risk factors for delirium. The intervention wards underwent a 6-month implementation period before trial recruitment commenced. Main outcome measure incidence of new-onset delirium measured using the Confusion Assessment Method (CAM) measured daily for up to 10 days post consent.
Results
out of 4449, 3274 patients admitted to the wards were eligible. In total, 714 patients consented (713 registered) to the trial, thirty-three participants (4.6%) withdrew. Adherence to the intervention was classified as at least medium for seven wards. Rates of new-onset delirium were lower than expected and did not differ between groups (24 (7.0%) of participants in the intervention group versus 33 (8.9%) in the control group; odds ratio (95% confidence interval) 0.68 (0.37–1.26); P = 0.2225).
Conclusions
based on these findings, a definitive trial is achievable and would need to recruit 5220 patients in 26 two-ward hospital clusters.
Trial registration: ISRCTN01187372. Registered 13 March 2014
New models of care: a liaison psychiatry service for medically unexplained symptoms and frequent attenders in primary care
Aims and method: This paper describes the process of setting up and the early results from a new liaison psychiatry service in primary care for people identified as frequent general practice attenders with long-term conditions or medically unexplained symptoms. Using a rapid evidence synthesis, we identified existing service models, mechanisms to identify and refer patients, and outcomes for the service. Considering this evidence, with local contingencies we defined options and resources. We agreed a model to set up a service in three diverse general practices. An evaluation explored the feasibility of the service and of collecting data for clinical, service and economic outcomes. Results: High levels of patient and staff satisfaction, and reductions in the utilisation of primary and secondary healthcare, with associated cost savings are reported. Clinical implications: A multidisciplinary liaison psychiatry service integrated in primary care is feasible and may be evaluated using routinely collected data
Intravenous sodium nitrite in acute ST-elevation myocardial infarction: a randomized controlled trial (NIAMI).
AIM: Despite prompt revascularization of acute myocardial infarction (AMI), substantial myocardial injury may occur, in part a consequence of ischaemia reperfusion injury (IRI). There has been considerable interest in therapies that may reduce IRI. In experimental models of AMI, sodium nitrite substantially reduces IRI. In this double-blind randomized placebo controlled parallel-group trial, we investigated the effects of sodium nitrite administered immediately prior to reperfusion in patients with acute ST-elevation myocardial infarction (STEMI).
METHODS AND RESULTS: A total of 229 patients presenting with acute STEMI were randomized to receive either an i.v. infusion of 70 μmol sodium nitrite (n = 118) or matching placebo (n = 111) over 5 min immediately before primary percutaneous intervention (PPCI). Patients underwent cardiac magnetic resonance imaging (CMR) at 6-8 days and at 6 months and serial blood sampling was performed over 72 h for the measurement of plasma creatine kinase (CK) and Troponin I. Myocardial infarct size (extent of late gadolinium enhancement at 6-8 days by CMR-the primary endpoint) did not differ between nitrite and placebo groups after adjustment for area at risk, diabetes status, and centre (effect size -0.7% 95% CI: -2.2%, +0.7%; P = 0.34). There were no significant differences in any of the secondary endpoints, including plasma troponin I and CK area under the curve, left ventricular volumes (LV), and ejection fraction (EF) measured at 6-8 days and at 6 months and final infarct size (FIS) measured at 6 months.
CONCLUSIONS: Sodium nitrite administered intravenously immediately prior to reperfusion in patients with acute STEMI does not reduce infarct size
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