Bistable dynamical systems are widely employed to robustly encode classical bits of information. However, they owe their robustness to inherent losses, making them unsuitable to encode quantum ...information. Surprisingly, there exists a loss mechanism, known as two-photon dissipation, that provides stability without inducing decoherence. An oscillator exchanging pairs of photons with its environment is expected to reach macroscopic bit-flip times between dynamical states containing only a handful of photons. However, previous implementations have observed bit-flip times saturating in the millisecond range. In this experiment, we design a superconducting resonator endowed with two-photon dissipation, and free of all suspected sources of instabilities and inessential ancillary systems. We attain bit-flip times exceeding 100 s in between states containing about 40 photons. Although a full quantum model is necessary to explain our data, the preparation of coherent superposition states remains inaccessible. This experiment demonstrates that macroscopic bit-flip times are attainable with mesoscopic photon numbers in a two-photon dissipative oscillator.
Objectives
To investigate the effects of Au@Fe
2
O
3
core–shell nanoparticle (NP), with and without conjugation to folic acid (FA) as a targeting ligand, on radiosensitization of both cancer and ...healthy cells.
Methods
Au@Fe
2
O
3
NPs were first synthesized, then modified with FA, and finally characterized. Radiation dose enhancement studies were performed on KB cancer cells and L929 healthy cells. NPs at the concentration of 20 µg/ml were first incubated with both cell lines and then different doses of 6 MV X-ray radiation were examined. The end effects were evaluated via MTT assay and flow cytometry using AnnexinV/PI kit.
Results
It was indicated that viability of KB cells has a much lower rate than L929 cells when the cells were treated by {(FA-Au@Fe
2
O
3
) + (X-ray)} regimen. Cell viability was even decreased significantly when X-ray dose increased. Moreover, flow cytometry studies revealed that FA-targeted NPs induced higher level of apoptosis for KB cancer cells than L929 healthy cells.
Conclusion
Our findings provide a new perspective on high ability of the synthesized FA-targeted Au@Fe
2
O
3
NPs which may be considered as an efficient radiosensitizer in the process of targeted radiation therapy of cancer.
It is proven in a previous paper that any modal approximation of the one-dimensional quantum harmonic oscillator is controllable. We prove here that, contrary to such finite-dimensional ...approximations, the original infinite-dimensional system is not controllable: Its controllable part is of dimension 2 and corresponds to the dynamics of the average position. More generally, we prove that, for the quantum harmonic oscillator of any dimension, similar lacks of controllability occur whatever the number of control is: the controllable part still corresponds to the average position dynamics. We show, with the quantum particle in a moving quadratic potential, that some physically interesting motion planning questions can be however solved.
To investigate the effects of Au@Fe
O
core-shell nanoparticle (NP), with and without conjugation to folic acid (FA) as a targeting ligand, on radiosensitization of both cancer and healthy cells.
...Au@Fe
O
NPs were first synthesized, then modified with FA, and finally characterized. Radiation dose enhancement studies were performed on KB cancer cells and L929 healthy cells. NPs at the concentration of 20 µg/ml were first incubated with both cell lines and then different doses of 6 MV X-ray radiation were examined. The end effects were evaluated via MTT assay and flow cytometry using AnnexinV/PI kit.
It was indicated that viability of KB cells has a much lower rate than L929 cells when the cells were treated by {(FA-Au@Fe
O
) + (X-ray)} regimen. Cell viability was even decreased significantly when X-ray dose increased. Moreover, flow cytometry studies revealed that FA-targeted NPs induced higher level of apoptosis for KB cancer cells than L929 healthy cells.
Our findings provide a new perspective on high ability of the synthesized FA-targeted Au@Fe
O
NPs which may be considered as an efficient radiosensitizer in the process of targeted radiation therapy of cancer.
We propose a dissipation engineering scheme that prepares and protects a maximally entangled state of a pair of superconducting qubits. This is done by off-resonantly coupling the two qubits to a ...low-Q cavity mode playing the role of a dissipative reservoir. We engineer this coupling by applying six continuous-wave microwave drives with appropriate frequencies. The two qubits need not be identical. We show that our approach does not require any fine-tuning of the parameters and requires only that certain ratios between them be large. With currently achievable coherence times, simulations indicate that a Bell state can be maintained over arbitrary long times with fidelities above 94%. Such performance leads to a significant violation of Bell's inequality (CHSH correlation larger than 2.6) for arbitrary long times.
Despite the immense benefits of nanoparticle-assisted photothermal therapy (NPTT) in cancer treatment, the limited method and device for detecting temperature during heat operation significantly ...hinder its overall progress. Development of a pre-treatment planning tool for prediction of temperature distribution would greatly improve the accuracy and safety of heat delivery during NPTT. Reliable simulation of NPTT highly relies on accurate geometrical model description of tumor and determining the spatial location of nanoparticles within the tissue. The aim of this study is to develop a computational modeling method for simulation of NPTT by exploiting the theranostic potential of iron oxide‑gold hybrid nanoparticles (IO@Au) that enable NPTT under magnetic resonance imaging (MRI) guidance. To this end, CT26 colon tumor-bearing mice were injected with IO@Au nanohybrid and underwent MR imaging. The geometrical model description of tumor and nanoparticle distribution map were obtained from MR image of the tumor and involved in finite element simulation of heat transfer process. The experimental measurement of tumor temperature confirmed the validity of the model to predict temperature distribution. The constructed model can help to predict temperature distribution during NPTT and then allows to optimize the heating protocol by adjusting the treatment parameters prior to the actual treatment operation.
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•Iron oxide-gold hybrid nanoparticle was used for photothermal therapy under magnetic resonance guidance.•Reliable simulation of photothermal therapy relies on determining the spatial location of nanoparticles in the tissue.•An individualized pre-treatment planning strategy for photothermal therapy has been developed using MR imaging.•The predicted temperature of tumor from numerical modeling was in agreement with measured data from in vivo experiment.
A Lyapunov-based approach for trajectory tracking of the Schrödinger equation is proposed. In the finite dimensional case, convergence is precisely analyzed. Connection between the controllability of ...the linearized system around the reference trajectory and asymptotic tracking is studied. When the linearized system is controllable, such a feedback ensures almost global asymptotic convergence. When the linearized system is not controllable, the stability of the closed-loop system is not asymptotic. To overcome such lack of convergence, we propose, when the reference trajectory is an eigenstate, a modification based on adiabatic invariance. Simulations illustrate the simplicity and also the interest for trajectory generation.
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