Simulation of Measurement-Based Entanglement in Silicon Spin Qubits

Electron spin qubits in silicon show promise for quantum computing applications due to their long spin-coherence times, small qubit sizes, and the applicability of existing nanofabrication infrastructure and techniques to their construction.One drawback is the relative difficulty of manipulating the electron’s spin state. Measurement-based entanglement (MBE) is a method of generating entangled qubit pairs through the state projection that accompanies a parity or similar measurement.Instead of generating entangled states via direct qubit-qubit interactions, one can use a suitable measurement to project an initial unentangled two-qubit system into an entangled subspace. This entanglement mechanism does not require the creation of any direct qubit-qubit interactions that would need to be turned off before using entangled pairs in a quantum algorithm; only the cessation of measurement is required. Adaptations of these techniques may be an effective addition to the current set of entanglement-generation techniques for silicon spin qubits. This thesis is intended to assess the feasibility of implementing measurement-based entanglement with silicon spin qubits. We will first review the design and operation of electron-spin double-quantum-dot (DQD) qubits in Si/SiGe, outline theoretical models for continuous quantum measurements and open quantum systems, and discuss how parity measurements can be used to establish entanglement between initially unentangled qubits. We will then discuss how such a parity measurement protocol could be implemented in a two-qubit circuit-quantum-electrodynamics experiment.After deriving a stochastic master equation describing the evolution of two flopping-mode DQDs coupled to a resonant cavity, we present and interpret numerical simulation results demonstrating the influence of qubit and cavity parameters on the corresponding final state fidelity. Using simulation results corresponding to current silicon spin-qubit devices, we determine which device parameters must be altered or improved in order to make measurement-based entanglement of silicon spin qubits experimentally viable.Specifically, with cavity loss and qubit decoherence rates κ and γ and charge-photon coupling strength gc corresponding to proposed devices designed to perform coherent cavity-mediated spin-spin coupling, we predict a maximum entangling gate fidelity of ~60%, indicating poor MBE performance. After increasing the cavity output coupling κout by a factor of ten, we predict an overlap between the final state of the MBE protocol and the target Bell state ∣Ψ+⟩ of ~81% for a postselection success probability of 33%, as well as a significant enhancement in the entanglement-of-formation of postselected states. Therefore, we predict that an experimental realization of MBE with silicon quantum dots will be feasible with such a device. Finally, we will discuss the design changes to existing coplanar-waveguide cavity geometries needed to achieve this increase in output coupling, as well as results from the fabrication of prototypes of these designs

Addressing hypertension among Haitian adults with insufficient access to quality healthcare: A discursive review

AimThe purpose of this article is to summarize research targeting hypertension and healthcare access among adults living in rural Haiti. BackgroundHypertension is a significant public health problem that impacts one in five persons globally. It is the leading cause of cardiovascular-related conditions such as stroke and myocardial infarction and accounts for most global non-communicable disease-related deaths. Limited healthcare access and social determinants of health are known contributors to poor health outcomes among persons with hypertension. Among Haitians, there are stark health disparities between those who live in urban versus rural areas. DesignA discursive review. ResultsSeveral issues are identified as barriers to proper hypertension prevention and management. However, after examining the effective interventions, we found that social determinants of health such as transportation costs, lack of field care facilities close to patients, roadway conditions, political disturbance, and ineffective leadership and policies are major barriers to controlling hypertension in Haiti. Although Haiti has received help from international organizations, strengthening its internal infrastructure is paramount in improving healthcare access. DiscussionThe review concludes that Haitians living in rural parts of Haiti are less likely to receive healthcare to manage non-communicable diseases such as hypertension. Similar to other developing countries, a heightened awareness is needed to address the lack of healthcare access for those living in rural communities. Impact to Nursing PracticeNurses and other healthcare professionals working with populations in Haiti should become aware of the barriers and facilitators that promote sufficient healthcare access. To achieve this goal, nurses must understand the social determinants and other factors that serve as barriers for achieving access to quality care for this vulnerable population. No Patient or Public ContributionThere was no patient or public involvement in the design or drafting of this discursive paper

Pharmacokinetic and Pharmacogenetic Study of Etoposide in High-Dose Protocol (TI-CE) for Advanced Germ Cell Tumors

International audienc

Abiraterone acetate in patients with metastatic castration-resistant prostate cancer: Long term outcome of the Temporary Authorization for Use program in France.

International audience264 Background: COU-AA-301 trial has proved that abiraterone acetate (AA), a selective inhibitor of androgen biosynthesis, improved overall survival (OS) of patients with metastatic castration resistant prostate cancer (mCRPC) after a first line of docetaxel. Based on this result, a temporary use authorisation (TUA) was performed between December 2010 and July 2011 to provide patients with mCRPC the opportunity to receive AA before its commercialization. The aim of this study was to evaluate safety and efficacy of AA treatment in this TUA. Methods: Between December 2010 and July 2011, we conducted an ambispective, multicentric cohort study and investigated data from 20 centres participating to the AA TUA for patients presenting mCRPC and already treated by a first line of chemotherapy (CT). Statistical analyses of the data were performed using the Stata software v13 to identify predictive and prognostic factors. Results: Among the 408 patients, 306 were eligible with a follow-up at 3 years. Median OS was 37.1 months from beginning of CT and 14.6 months from AA introduction. 211 patients (69%) received ≥ 3 months of AA and 95 patients (31%) were treated less than 3 months. In the multivariate analyses, duration of AA was significantly correlated with PSA decrease at 3 months. Additionally, shorter time under AA treatment, presence of multiple sites of metastasis and previous hormonal treatment duration were three independent factors associated with poorer OS. At the time of analysis ten patients were still under treatment for more than 3 years. Conclusions: Biochemical response monitored by PSA changes at 3 months is a strong predictive factor for AA treatment duration. Some high responders’ patients could beneficiate from AA for more than 3 years

Abiraterone acetate in patients with metastatic castration-resistant prostate cancer: long term outcome of the Temporary Authorization for Use programme in France

International audienceAbstractBackgroundCOU-AA-301 trial has proved that abiraterone acetate (AA), a selective inhibitor of androgen biosynthesis, improved overall survival (OS) of patients with metastatic castration resistant prostate cancer (mCRPC) after a first line of docetaxel. Based on this result, a Temporary Authorization for Use (TAU) was performed between December 2010 and July 2011 to provide patients with mCRPC the opportunity to receive AA before its commercialization. The aim of this study was to evaluate safety and efficacy of AA treatment in this TAU.MethodsBetween December 2010 and July 2011, we conducted an ambispective, multicentric cohort study and investigated data from 20 centres participating to the AA TAU for patients presenting mCRPC and already treated by a first line of chemotherapy (CT). Statistical analyses of the data were performed using the Stata software v13 to identify predictive and prognostic factors.ResultsAmong the 408 patients, 306 were eligible with a follow-up at 3 years. Median OS was 37.1 months from beginning of CT and 14.6 months from AA introduction. 211 patients (69%) received ≥ 3 months of AA and 95 patients (31%) were treated less than 3 months. In the multivariate analyses, duration of AA was significantly correlated with PSA decrease at 3 months. Additionally, shorter time under AA treatment, presence of multiple sites of metastasis and previous hormonal treatment duration were three independent factors associated with poorer OS. At the time of analysis ten patients were still under treatment for more than 3 years.ConclusionsBiochemical response monitored by PSA changes at 3 months is a strong predictive factor for AA treatment duration. Some high responders’ patients could beneficiate from AA for more than 3 years