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OBJECTIVE The authors developed a method to predict the etiology of intracranial large-vessel occlusion stroke (ILVOS) before endovascular treatment. METHODS The authors retrospectively evaluated two etiologies of ILVOS—intracranial atherosclerotic stenosis–related occlusion (ICAS-O) and embolism-related occlusion (EMB-O)—in a cohort of patients from the National Comprehensive Stroke Center database of China. Patients were randomly divided into the derivation and validation cohorts at a ratio of 2:1. The authors derived the score in the derivation cohort and assessed the score in the validation cohort. RESULTS The authors identified 608 of 662 patients with ILVOS who received endovascular treatment during the study period. After adjustment for confounding factors, hypertension (OR 2.90, 95% CI 1.34–6.26), diabetes mellitus (OR 2.80, 95% CI 1.45–5.42), absence of atrial fibrillation (OR 27.29, 95% CI 13.27–56.09), National Institutes of Health Stroke Scale score < 7 (OR 2.92, 95% CI 1.22–6.99), and absence of the computed tomography hyperdense sign (OR 2.86, 95% CI 1.22–6.74) were significantly related to ICAS-O. A score was derived to help predict ICAS-O or EMB-O. The area under the curve values of the receiver operating characteristic curve for ICAS-O identification were 0.886 (95% CI 0.839–0.933) and 0.880 (95% CI 0.846–0.914) in the derivation and validation cohorts, respectively. CONCLUSIONS The atrial fibrillation–blood pressure–clinical neurological deficit–computed tomography hyperdense sign–diabetes mellitus (ABC2D) score can be used to identify atherosclerotic or embolic etiology of patients with ILVOS who require emergency endovascular treatment.

Data from trials investigating the effects and risks of endovascular thrombectomy for the treatment of stroke due to basilar-artery occlusion are limited.We conducted a multicenter, prospective, randomized, controlled trial of endovascular thrombectomy for basilar-artery occlusion at 36 centers in China. Patients were assigned, in a 2:1 ratio, within 12 hours after the estimated time of basilar-artery occlusion to receive endovascular thrombectomy or best medical care (control). The primary outcome was good functional status, defined as a score of 0 to 3 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]), at 90 days. Secondary outcomes included a modified Rankin scale score of 0 to 2, distribution across the modified Rankin scale score categories, and quality of life. Safety outcomes included symptomatic intracranial hemorrhage at 24 to 72 hours, 90-day mortality, and procedural complications.Of the 507 patients who underwent screening, 340 were in the intention-to-treat population, with 226 assigned to the thrombectomy group and 114 to the control group. Intravenous thrombolysis was used in 31% of the patients in the thrombectomy group and in 34% of those in the control group. Good functional status at 90 days occurred in 104 patients (46%) in the thrombectomy group and in 26 (23%) in the control group (adjusted rate ratio, 2.06; 95% confidence interval [CI], 1.46 to 2.91, P0.001). Symptomatic intracranial hemorrhage occurred in 12 patients (5%) in the thrombectomy group and in none in the control group. Results for the secondary clinical and imaging outcomes were generally in the same direction as those for the primary outcome. Mortality at 90 days was 37% in the thrombectomy group and 55% in the control group (adjusted risk ratio, 0.66; 95% CI, 0.52 to 0.82). Procedural complications occurred in 14% of the patients in the thrombectomy group, including one death due to arterial perforation.In a trial involving Chinese patients with basilar-artery occlusion, approximately one third of whom received intravenous thrombolysis, endovascular thrombectomy within 12 hours after stroke onset led to better functional outcomes at 90 days than best medical care but was associated with procedural complications and intracerebral hemorrhage. (Funded by the Program for Innovative Research Team of the First Affiliated Hospital of USTC and others; ATTENTION ClinicalTrials.gov number, NCT04751708.).

The benefit of combined treatment with intravenous thrombolysis before endovascular thrombectomy in patients with acute ischaemic stroke caused by large vessel occlusion remains unclear. We hypothesised that the clinical outcomes of patients with stroke with large vessel occlusion treated with direct endovascular thrombectomy within 4·5 h would be non-inferior compared with the outcomes of those treated with standard bridging therapy (intravenous thrombolysis before endovascular thrombectomy).DIRECT-SAFE was an international, multicentre, prospective, randomised, open-label, blinded-endpoint trial. Adult patients with stroke and large vessel occlusion in the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or basilar artery, confirmed by non-contrast CT and vascular imaging, and who presented within 4·5 h of stroke onset were recruited from 25 acute-care hospitals in Australia, New Zealand, China, and Vietnam. Eligible patients were randomly assigned (1:1) via a web-based, computer-generated randomisation procedure stratified by site of baseline arterial occlusion and by geographic region to direct endovascular thrombectomy or bridging therapy. Patients assigned to bridging therapy received intravenous thrombolytic (alteplase or tenecteplase) as per standard care at each site; endovascular thrombectomy was also per standard of care, using the Trevo device (Stryker Neurovascular, Fremont, CA, USA) as first-line intervention. Personnel assessing outcomes were masked to group allocation; patients and treating physicians were not. The primary efficacy endpoint was functional independence defined as modified Rankin Scale score 0-2 or return to baseline at 90 days, with a non-inferiority margin of -0·1, analysed by intention to treat (including all randomly assigned and consenting patients) and per protocol. The intention-to-treat population was included in the safety analyses. The trial is registered with ClinicalTrials.gov, NCT03494920, and is closed to new participants.Between June 2, 2018, and July 8, 2021, 295 patients were randomly assigned to direct endovascular thrombectomy (n=148) or bridging therapy (n=147). Functional independence occurred in 80 (55%) of 146 patients in the direct thrombectomy group and 89 (61%) of 147 patients in the bridging therapy group (intention-to-treat risk difference -0·051, two-sided 95% CI -0·160 to 0·059; per-protocol risk difference -0·062, two-sided 95% CI -0·173 to 0·049). Safety outcomes were similar between groups, with symptomatic intracerebral haemorrhage occurring in two (1%) of 146 patients in the direct group and one (1%) of 147 patients in the bridging group (adjusted odds ratio 1·70, 95% CI 0·22-13·04) and death in 22 (15%) of 146 patients in the direct group and 24 (16%) of 147 patients in the bridging group (adjusted odds ratio 0·92, 95% CI 0·46-1·84).We did not show non-inferiority of direct endovascular thrombectomy compared with bridging therapy. The additional information from our study should inform guidelines to recommend bridging therapy as standard treatment.Australian National Health and Medical Research Council and Stryker USA.

The authors compare the effectiveness and safety of endovascular treatment (EVT) versus best medical management (BMM) in strokes attributable to acute basilar artery occlusion (BAO).The present analysis was based on the ongoing, prospective, multicenter ATTENTION (Endovascular Treatment for Acute Basilar Artery Occlusion) trial registry in China. Our analytic sample comprised 2134 patients recruited at 48 sites between 2017 and 2021 and included 462 patients who received BMM and 1672 patients who received EVT. We performed an inversed probability of treatment weighting analysis. Qualifying patients had to present within 24 hours of estimated BAO. The primary clinical outcome was favorable functional outcome (modified Rankin Scale score, 0-3) at 90 days. We also performed a sensitivity analysis with the propensity score matching-based and the instrumental variable-based analysis.In our primary analysis using the inversed probability of treatment weighting-based analysis, there was a significantly higher rate of favorable outcome at 90 days among EVT patients compared with BMM-treated patients (adjusted relative risk, 1.42 [95% CI, 1.19-1.65]; absolute risk difference, 11.8% [95% CI, 6.9-16.7]). The mortality was significantly lower (adjusted relative risk, 0.78 [95% CI, 0.69-0.88]; absolute risk difference, -10.3% [95% CI, -15.8 to -4.9]) in patients undergoing EVT. Results were generally consistent across the secondary end points. Similar associations were seen in the propensity score matching-based and instrumental variable-based analysis.In this real-world study, EVT was associated with significantly better functional outcomes and survival at 90 days. Well-designed randomized studies comparing EVT with BMM in the acute BAO are needed.URL: www.chictr.org.cn; Unique identifier: ChiCTR2000041117.

The generation and manipulation of highly pure and strongly entangled steady state in a quantum system are vital tasks in the standard continuous-variable teleportation protocol. Especially, the manipulation implemented in integrated devices is even more crucial in practical quantum information applications. Here we propose an effective approach for creating steady-state entanglement between two microwave fields in a four-mode hybrid cavity optomechanical system. The entanglement can be achieved by combining the processes of three beam-splitter interactions and two parametric-amplifier interactions. Due to the dissipation-driven and cavity cooling processes, the entanglement obtained can go far beyond the entanglement limit based on coherent parametric coupling. Moreover, our proposal allows the engineered bath to cool both Bogoliubov modes almost simultaneously. In this way, a highly pure and strongly entangled steady state of two microwave modes is obtained. Our finding may be significant for using the hybrid opto-electro-mechanical system fabricated on chips in various quantum tasks, where the strong and pure entanglement is an important resource.

Background Middle cerebral artery (MCA) fenestration is a rare vascular variant of the MCA. When this occlusion occurs, it presents challenges to identification and recanalization. We describe a patient with a partially occluded MCA fenestration in whom recanalization was successfully achieved via mechanical thrombectomy using a stent retriever with an intermediate catheter. Case Description A 65-year-old man with a history of ischemic stroke and homocysteinemia presented with dysarthria and expressive aphasia 14 hours after symptom onset. National Institutes of Health Stroke Scale score was 12/42. Noncontrast computed tomography scan revealed encephalomalacia in the left cerebral hemisphere. Catheter angiography displayed a left internal carotid artery orifice and M1 segment subocclusion. The primary diagnosis was acute ischemic stroke. Mechanical thrombectomy was performed by passing a stent retriever through the subtotal occlusive segment of the left MCA. After angiography was completed, reperfusion was considered successful, with a modified Thrombolysis in Cerebral Infarction grade 3. The fenestration was discovered in the middle to distal part of the left MCA M1 segment where the thrombus was located. After 3 days, magnetic resonance imaging showed much ischemic damage to the left hemicerebrum area. The day after endovascular treatment, the patient's neurologic deficit recovered to its pre-onset state. At 6-months follow-up, stroke had not recurred, and the patient is living independently with a modified Rankin scale score of 1. Conclusions Mechanical thrombectomy may be feasible and safe in MCA fenestration occlusion.

We propose a scheme to realize robust optical entanglement in cavity optomagnonics, where two optical whispering gallery modes (WGMs) couple to a magnon mode in a yttrium iron garnet (YIG) sphere. The beam-splitter-like and two-mode squeezing magnon-photon interactions can be realized simultaneously when the two optical WGMs are driven by external fields. Entanglement between the two optical modes is then generated via their coupling with magnons. By exploiting the destructive quantum interference between the bright modes of the interface, the effects of initial thermal occupations of magnons can be eliminated. Moreover, the excitation of the Bogoliubov dark mode is capable of protecting the optical entanglement from thermal heating effects. Therefore, the generated optical entanglement is robust against thermal noise and the requirement of cooling the magnon mode is relaxed. Our scheme may find applications in the study of magnon-based quantum information processing.

In a general two-mode cavity optomechanical system driven with a mildly amplitude modulated light field, we investigate in detail the properties of entanglement and asymmetric steering between the cavity field and the mechanical oscillator, whose frequency is also applied by a sinusoidal modulation. Twofold modulations of the system inducing interference effects determined by the relative phase between the two modulations. By calculating the logarithmic negativity and quantum steering of the two modes, we show that, different choices of the modulation intensity and the relative phase between the two physical interaction paths can either enhance or cancel the desired quantum effects, two modes can be prepared into an entangled steady state with asymmetric and directional steering. Meanwhile, the effects of interference on entanglement and asymmetric steering are also compared. The results show that the optimal relative phase between the two physical interaction paths are not the same for entanglement and asymmetric steering, opening new perspectives to understand them.

Introduction Thallium poisoning is a rare occurrence. Therefore, thallium poisoning is easily misdiagnosed and is often accompanied by a series of serious sequelae and can even result in death in severe cases. Here, we report long‐term follow‐up of a case of a patient who was poisoned with thallium on two separate occasions. Methods A 43‐year‐old man was initially misdiagnosed as gastroenteritis, diabetic peripheral neuropathy, and Guillain–Barré Syndrome (GBS) within 21 months. The correct diagnosis was confirmed by blood and urine thallium assays. After Prussian blue treatment, thallium was undetectable in the blood by day 60. Following this investigation, a criminal suspect confessed to two instances of adulterating thallium sulfate in the patient's beverage. A 6‐year follow‐up was performed after discharge, and a comprehensive literature was review. Results We found that the original gastrointestinal symptoms, skin lesions, and hair loss were reversed and had recovered, except for residual neurologic damage, even with long‐term rehabilitation. Discussion Thallium intoxication may have been initially identified if neurologic symptoms had occurred concurrently with gastrointestinal and cutaneous symptoms. Neurologic damage represented the main sequelae of thallium poisoning in our present case report., Thallium poisoning; neurologic outcome; neuroelectrophysiology

Background: Data regarding the comparative efficacy and safety of endovascular treatment (EVT) versus best medical management (BMM) in strokes due to acute basilar artery occlusion (BAO) remains controversial. Methods: The present analysis was based on the ongoing prospective multicentre endovascular treatment for acute basilar artery occlusion (ATTENTION) registry in China. We performed a propensity score analysis matching patients treated with BMM with those treated with EVT on a 1:3 ratio. Qualifying patients had to present within 24 hours of estimated BAO. The primary clinical outcome was favourable functional outcome (modified Rankin Score 0-3) at 90 days. We also performed a sensitivity analysis within the inversed propensity of treatment weighting (IPTW) cohort. Findings: Our analytic sample comprised 2,134 patients recruited across 48 sites between 2017 and 2021, including 462 patients received BMM and 1,672 patients who received EVT. Age (median, 65), sex (male, 68%), baseline NIHSS score (median, 21), the proportions of favourable imaging profile (PC-ASPECTS ≥8: ~89%), intravenous alteplase use (~23%) and time from onset to admission (median ~ 333 minutes) were comparable across the PSM groups (n=443 in BMM group; n=1,329 in EVT group). Compared with BMM treated patients, there was a significantly higher rate of favourable outcome at 90 days among EVT patients (adjusted relative risk (1.37 [95% CI: 1.18 to 1.60], absolute risk difference 0.11 [95% CI: 0.06 to 0.15]). The mortality was significantly lower (adjusted relative risk (0.81 [95% CI: 0.72 to 0.91], absolute risk difference -0.09 [95% CI: -0.14 to -0.04]) in patients undergoing EVT. Results were generally consistent across the secondary endpoints. Similar associations were seen in the IPTW cohort. Interpretation: In this large, real-world study, EVT was associated with significantly better functional outcomes and survival at 90 days. Well-designed randomized studies comparing EVT with BMM in the acute BAO are needed. Clinical Trial Registration Details: ATTENTION is registered on the Chinese Clinical Trial Registry (http://www.chictr.org.cn; ChiCTR2000041117). Funding Information: ATTENTION was an independent, investigator-initiated registry, and no external support was received. Declaration of Interests: RGN reports consulting fees for advisory roles with Anaconda, Biogen, Cerenovus, Genentech, Hybernia, Imperative Care, Medtronic, Phenox, Philips, Prolong Pharmaceuticals, Stryker Neurovascular, Shanghai Wallaby, Synchron, and stock options for advisory roles with Astrocyte, Brainomix, Cerebrotech, Ceretrieve, Corindus Vascular Robotics, Vesalio, Viz-AI, RapidPulse and Perfuze. RGN is one of the Principal Investigators of the “Endovascular Therapy for Low NIHSS Ischemic Strokes (ENDOLOW)” trial. Funding for this project is provided by Cerenovus. RGN is an investor in Viz-AI, Perfuze, Cerebrotech, Reist/Q’Apel Medical, Truvic, and Viseon. Other authors have no conflict of interest. Ethics Approval Statement: The study was approved by the ethical committee of the first affiliated hospital of university of science and technology of China. All patients or their legally authorized representatives provided signed informed consent.

The quantum state control or entanglement preparation for macroscopic matter is an attractive research. Optomechanical system provides an ideal platform to observe the quantum behaviors of macroscopic matter. In this paper, we present a scheme to implement the average excitation fluctuations transfer between two membranes in an optomechanical system via shortcut to adiabatic passage which is based on transitionless quantum driving. In order to quickly attain the transfer, we choose a suitable evolution path and optimize the experimental parameters. Numerical simulation demonstrates that the proposed scheme is robust against membrane damping and cavity decay. Furthermore, this idea can be used to generate entanglement of two membrane modes in a short time. Finally, we also discuss the experimental implementation of this scheme. This work may provide a new method for generating the macroscopic superposition state in the optomechanicalsystem.

We present a proposal to test Bell inequality in the emerging field of cavity optomagnonics, where a sphere of ferromagnetic crystal supports two optical whispering gallery modes and one magnon mode. The two optical modes are driven by two laser pulses, respectively. Entanglement between magnon mode and one of the two optical modes will be generated by the first pulse, and the state of magnon mode is subsequently mapped into another optical mode via the second pulse. Hence correlated photon-photon pairs is created out of the cavity. A Bell test can be implemented using these pairs, which enables us to test local hidden-variable models at macroscopic optomagnonical system. Our results show that a significant violation of Bell inequality can be obtained in the experimentally relevant weak-coupling regime. The violation of Bell inequality not only verifies the entanglement between magnons and photons, but also implies that cavity optomagnonics is a promising platform for quantum information processing tasks.

Background: Identification of occlusion mechanism before endovascular treatment (EVT) is of great significance for intracranial large vessel occlusion stroke (ILVOs). Cardioembolism occlusion and large-artery atherosclerosis are the two common etiologies of ILVOs. However, there is few of valid methods to predict the two etiologies of ILVOs before EVT. Methods: We evaluated retrospectively two etiologies of ILVOs: intracranial atherosclerosis stenosis-related occlusion (ICAS-O) and embolism-related occlusion( EMB-O) in a cohort of patients at a national comprehensive stroke centre database of China over a 77-month period. Patients were divided at a ratio of 2:1 randomly into the training and the validation cohorts. We derived a score for ILVOs in the derivation cohort of patients , and assessed the score in the validation cohort. Results: We identified 608 from 662 patients with ILVOs who received EVT in the study period. Subsequent to adjustment for confounding factors, atrial fibrillation. (AF) (no vs. yes, OR=27·29, 95%CI: 13·27-56·09), hypertension (yes vs. no, OR=2·90, 95%CI: 1·34-6·26), diabetes mellitus (DM) (yes vs. no, OR=2·80, 95%CI: 1·45-5·42), National Institutes of Health Stroke Scale(NIHSS) (

We investigate in detail the properties of the stationary quantum steering of two mechanical modes, where the two mechanical modes interact with two coupling cavity modes, and two four-tone driving lasers are used to pump the two cavity modes. By controlling the pumping lasers, the two cavity modes can act as two engineered reservoirs to cool the two mechanical modes to a squeezed state. When the damping rates of the two mechanical modes are different, numerical simulation results show that there are parameter regions where the state of the two mechanical modes only has one-way quantum steering, which is the most prominent feature of quantum steering from quantum entanglement.

We present a proposal to prepare the macroscopic superposition states of a mechanical oscillator in an optomechanical system with quadratic coupling. By coherently driving the optomechanical cavity with an external field, a Kerr-type interaction among phonons is induced. The macroscopic mechanical superposition can be generated by exploiting the Kerr nonlinearity in the mechanical oscillator, just as the generation of a nonclassical state of light in a Kerr medium. One merit of our proposal is that the Kerr nonlinearity can be strongly enhanced by adjusting the amplitude of the driving field. The influence of the system damping on the realization of mechanical non-Gaussian state is discussed by the negativity of the Wigner function. The results show that the macroscopic superposition states are robust against the mechanical thermal noise.

Summary Background Previous randomised trials have shown an overwhelming benefit of mechanical thrombectomy for treating patients with stroke caused by large vessel occlusion of the anterior circulation. Whether endovascular treatment is beneficial for vertebrobasilar artery occlusion remains unknown. In this study, we aimed to investigate the safety and efficacy of endovascular treatment of acute strokes due to vertebrobasilar artery occlusion. Methods We did a multicentre, randomised, open-label trial, with blinded outcome assessment of thrombectomy in patients presenting within 8 h of vertebrobasilar occlusion at 28 centres in China. Patients were randomly assigned (1:1) to endovascular therapy plus standard medical therapy (intervention group) or standard medical therapy alone (control group). The randomisation sequence was computer-generated and stratified by participating centres. Allocation concealment was implemented by use of sealed envelopes. The primary outcome was a modified Rankin scale (mRS) score of 3 or lower (indicating ability to walk unassisted) at 90 days, assessed on an intention-to-treat basis. The primary safety outcome was mortality at 90 days. Secondary safety endpoints included the rates of symptomatic intracranial haemorrhage, device-related complications, and other severe adverse events. The BEST trial is registered with ClinicalTrials.gov , NCT02441556 . Findings Between April 27, 2015, and Sept 27, 2017, we assessed 288 patients for eligibility. The trial was terminated early after 131 patients had been randomly assigned (66 patients to the intervention group and 65 to the control group) because of high crossover rate and poor recruitment. In the intention-to-treat analysis, there was no evidence of a difference in the proportion of participants with mRS 0–3 at 90 days according to treatment (28 [42%] of 66 patients in the intervention group vs 21 [32%] of 65 in the control group; adjusted odds ratio [OR] 1·74, 95% CI 0·81–3·74). Secondary prespecified analyses of the primary outcome, done to assess the effect of crossovers, showed higher rates of mRS 0–3 at 90 days in patients who actually received the intervention compared with those who received standard medical therapy alone in both per-protocol (28 [44%] of 63 patients with intervention vs 13 [25%] of 51 with standard therapy; adjusted OR 2·90, 95% CI 1·20–7·03) and as-treated (36 [47%] of 77 patients with intervention vs 13 [24%] of 54 with standard therapy; 3·02, 1·31–7·00) populations. The 90-day mortality was similar between groups (22 [33%] of 66 patients in the intervention vs 25 [38%] of 65 in the control group; p=0·54) despite a numerically higher prevalence of symptomatic intracranial haemorrhage in the intervention group. Interpretation There was no evidence of a difference in favourable outcomes of patients receiving endovascular therapy compared with those receiving standard medical therapy alone. Results might have been confounded by loss of equipoise over the course of the trial, resulting in poor adherence to the assigned study treatment and a reduced sample size due to the early termination of the study. Funding Jiangsu Provincial Special Program of Medical Science.

Quantum state transfer between two nodes is a basic task of long-distance quantum communication. In this paper, we propose a general protocol to transfer quantum state between optical and microwave modes in a three-mode optomechanical system based on transitionless quantum driving. By choosing a well-designed path, the reversible transfer between optical and microwave modes can be achieved in the shorter time than adiabatic passage method. We further apply this idea for implementing the quantum state transfer between optical or microwave and mechanical modes. Numerical simulation results show that the protocol is robust against the cavity decay and mechanical damping. Therefore, this work provides a new method for quantum state transfer between two optical modes with distinct wavelengths in the optomechanical system, which may have great application prospect in quantum communication.

We propose an effective approach for generating highly pure and strong cavity-mechanical entanglement (or optical-microwave entanglement) in a hybrid modulated three-mode optomechanical system. By applying two-tone driving to the cavity and modulating the coupling strength between two mechanical oscillators (or between a mechanical oscillator and a transmission line resonator), we obtain an effective Hamiltonian where an intermediate mechanical mode acting as an engineered reservoir cools the Bogoliubov modes of two target system modes via beam-splitter-like interactions. In this way, the two target modes are driven to two-mode squeezed states in the stationary limit. In particular, we discuss the effects of cavity-driving detuning on the entanglement and the purity. It is found that the cavity-driving detuning plays a critical role in the goal of acquiring highly pure and strongly entangled steady states., Comment: 8 pages, 6 figures

Quantum control of phonons has being become a focus of attention for developing quantum technologies. Here, we propose a proposal to realize phonon blockade in a quadratically coupled optomechanical system, where a strong nonlinear interaction between photons and phonons can be induced by an external field coherently driving the cavity, and the effective coupling strength is tunable by adjusting the amplitude of the driving field. This optically induced nonlinearity is different from standard methods for realization of phonon blockade, where the nonlinearity is achieved by coupling the mechanical system to superconducting qubits. We both analytically and numerically study the phonon statistical properties via the steady-state solution of the second-order correlation function, and find phonon blockade can be efficiently realized for a large cooperativity of the system, which is achievable based on the optically enhanced nonlinear coupling and high quality mechanical system., 6 pages, 6 figures

We systematically study the influence of amplitude modulation on the steady-state bosonic squeezing and entanglement in a dissipative three-mode optomechanical system, where a vibrational mode of the membrane is coupled to the left and right cavity modes via the radiation pressure. Numerical simulation results show that the steady-state bosonic squeezing and entanglement can be significantly enhanced by periodically modulated external laser driving either or both ends of the cavity. Remarkably, the fact that as long as one periodically modulated external laser driving either end of the cavities is sufficient to enhance the squeezing and entanglement is convenient for actual experiment, whose cost is that required modulation period number for achieving system stability is more. In addition, we numerically confirm the analytical prediction for optimal modulation frequency and discuss the corresponding physical mechanism., Comment: 25 pages, 8 figures, accepted for publication in Optics Express

We propose an approach for generating steady-state mechanical entanglement in a coupled optomechanical system. By applying four-tone driving lasers with weighted amplitudes and specific frequencies, we obtain an effective Hamiltonian that couples the delocalized Bogoliubov modes of the two mechanical oscillators to the cavity modes via beam-splitter-like interactions. When the mechanical decay rate is small, the Bogoliubov modes can be effectively cooled by the dissipative dynamics of the cavity modes, generating steady-state entanglement of the mechanical modes. The mechanical entanglement obtained in the stationary regime is strongly dependent on the values of the ratio of the effective optomechanical coupling strengths. Numerical simulation with the full linearized Hamiltonian shows that significant amount of mechanical entanglement can indeed be obtained by balancing the opposing effects of varying the ratio and by carefully avoiding the system parameters that may lead to amplified oscillations of the mechanical mean values detrimental to the entanglement generation.

Phonon blockade is achieved in a quadratically coupled optomechanical system, in which the nonlinear interaction between phonons is induced by a driving field via radiation pressure. It is different from the previous standard methods, where the nonlinear interaction for observing phonon blockade is obtained by coupling the mechanical resonator to a two-level system. The effective coupling strength can be tuned by controlling the amplitudes of the driving field, which allows large nonlinearities for the optomechanical system. The second-order correlation function is discussed both analytically and numerically to characterize the phonon statistical properties and the results show that the phonon blockade is available when the effective coupling strength is larger than the mechanical decay rate. This work provides a possible way to experimentally realize phonon blockade.

We study the quantum nonlocality dynamics of pair coherent states in the double Jaynes-Cummings model. It is shown that the Bell-inequality violation can be fully destroyed in a finite time and then recovered. The inequality violation can obtain better recovery when only one atom couples to either of the cavity fields. Besides, the correlation property of cavity fields is more feasible affected when the atom interacts resonantly with the second cavity field. The difference in the number of photons of the two modes may play an important role in the case of resonant interaciton especially.

We discuss the one-excitation dynamics of two atomic qubits, trapped in separate cavities coupled through a short optical fiber. Our investigation shows that a wide variety of time-evolution behaviors can be realized by modulating the atom–cavity detuning δ , the atom–cavity coupling strength g and the cavity–fiber hopping strength v .

We proposed a scheme for generating arbitrary multiple spatially separated correlated field states. It is based on the resonant interaction of a cascade ( M + 1) level atoms and M separated cavities. Finally, we discuss the experimental feasibility of the scheme.

The configuration of concentricolide was assigned as (S). The configuration of its three analogs, which have anti-HIV-1 activity, were predicted by optical rotation values obtained by the B3LYP/aug-cc-pVDZ//B3LYP/6-31+G(d) and B3LYP/aug-cc-pVDZ//MP2/6-311+G(d) methods. The two methods predict very close optical rotation magnitudes for all three chiral analogs of concentricolide. The two methods were applied in optical rotation predictions for seven other concentricolide analogs. Circular dichroism calculations were performed for four of the seven analogs at the B3LYP/aug-cc-pVDZ level. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

(2S,3R)-2-(2-Hydroxypropan-2-yl)-5-methyltetrahydro-2H-pyran-2,3-diol and its configurational isomer (2R,3R)-2-(2-hydroxypropan-2-yl)-5-methyltetrahydro-2H-pyran-2,3-diol were used in the distribution analyses of configurational and conformational isomers for the identification of 1 alpha,7 alpha-diacetoxyl-17 alpha-20S-21,24-epoxy-apo-tirucall-14-ene-3 alpha,23R,24S,25-tetraol in methanol, chloroform and acetone solvents, respectively. The geometries of configurational and the corresponding conformational isomers were optimized through B3LYP/6-31G(d) and MP2/6-311+G(d) tests in the gas phase and in the three solvents, respectively. PCM and CPCM models were used, respectively. Distributions of different isomers in the three solvents were finally examined by (1)H NMR spectra. Two computational methods were found to give the good predictions of distribution of the configurational and conformational isomers in the three solvents. (C) 2008 Elsevier B.V. All rights reserved.

We investigate the nonlocality dynamics of two initially entangled macroscopic fields each interacting with a resonant two-level atom. The nonlocality of macroscopic field is characterized by the extent to which the Bell Clauser–Horne–Shimony–Holt (CHSH)'s inequality for continuous-variable states is violated. We show that the collapse and revival of the Bell-nonlocality are similar to the collapse and revival of the atomic population inversion of the Jaynes–Cummings model (JCM).

The entanglement characteristics including the so-called sudden death effect between two identical two-level atoms trapped in two separate cavities connected by an optical fiber are studied. The results show that the time evolution of entanglement is sensitive not only to the degree of entanglement of the initial state but also to the ratio between cavity-fiber coupling () and atom-cavity coupling (). This means that the entanglement dynamics can be controlled by choosing specific v and g., 14pages, 3figures, conference