407 research outputs found
Generation of three-qubit entangled states using coupled multi-quantum dots
We discuss a mechanism for generating a maximum entangled state (GHZ) in a
coupled quantum dots system, based on analytical techniques. The reliable
generation of such states is crucial for implementing solid-state based quantum
information schemes. The signature originates from a remarkably weak field
pulse or a far off-resonance effects which could be implemented using
technology that is currently being developed. The results are illustrated with
an application to a specific wide-gap semiconductor quantum dots system, like
Zinc Selenide (ZnSe) based quantum dots.Comment: 8 pages, 2 figure
Perspectives for a mixed two-qubit system with binomial quantum states
The problem of the relationship between entanglement and two-qubit systems in
which it is embedded is central to the quantum information theory. This paper
suggests that the concurrence hierarchy as an entanglement measure provides an
alternative view of how to think about this problem. We consider mixed states
of two qubits and obtain an exact solution of the time-dependent master
equation that describes the evolution of two two-level qubits (or atoms) within
a perfect cavity for the case of multiphoton transition. We consider the
situation for which the field may start from a binomial state. Employing this
solution, the significant features of the entanglement when a second qubit is
weakly coupled to the field and becomes entangled with the first qubit, is
investigated. We also describe the response of the atomic system as it varies
between the Rabi oscillations and the collapse-revival mode and investigate the
atomic inversion and the Q-function. We identify and numerically demonstrate
the region of parameters where significantly large entanglement can be
obtained. Most interestingly, it is shown that features of the entanglement is
influenced significantly when the multi-photon process is involved. Finally, we
obtain illustrative examples of some novel aspects of this system and show how
the off-resonant case can sensitize entanglement to the role of initial state
setting.Comment: 18 pages, 9 figure
Qualitative aspects of the entanglement in the three-level model with photonic crystals
This communication is an enquiry into the circumstances under which
concurrence and phase entropy methods can give an answer to the question of
quantum entanglement in the composite state when the photonic band gap is
exhibited by the presence of photonic crystals in a three-level system. An
analytic approach is proposed for any three-level system in the presence of
photonic band gap. Using this analytic solution, we conclusively calculate the
concurrence and phase entropy, focusing particularly on the entanglement
phenomena. Specifically, we use concurrence as a measure of entanglement for
dipole emitters situated in the thin slab region between two semi-infinite
one-dimensionally periodic photonic crystals, a situation reminiscent of planar
cavity laser structures. One feature of the regime considered here is that
closed-form evaluation of the time evolution may be carried out in the presence
of the detuning and the photonic band gap, which provides insight into the
difference in the nature of the concurrence function for atom-field coupling,
mode frequency and different cavity parameters. We demonstrate how fluctuations
in the phase and number entropies effected by the presence of the
photonic-band-gap. The outcomes are illustrated with numerical simulations
applied to GaAs. Finally, we relate the obtained results to instances of any
three-level system for which the entanglement cost can be calculated. Potential
experimental observations in solid-state systems are discussed and found to be
promising.Comment: 28 pages, 10 figures: Accepted in Applied Physics B: Laser and Optic
Entanglement in squeezed two-level atom
In the previous paper, we adopted the method using quantum mutual entropy to
measure the degree of entanglement in the time development of the
Jaynes-Cummings model. In this paper, we formulate the entanglement in the time
development of the Jaynes-Cummings model with squeezed states, and then show
that the entanglement can be controlled by means of squeezing.Comment: 6 pages, 5 figures, to be published in J.Phys.
QUERCETIN MITIGATES TOXICITY AND OXIDATIVE STRESS MOTIVATED BY BISPHENOL A IN LIVER OF MALE RATS
Objective: Epidemiological reports have indicated a correlation between the increasing of bisphenol A (BPA) levels in the environment and the incidence of hepatotoxicity. The present study aimed to evaluate the protective effect of quercetin on oxidative stress, inflammatory markers, apoptotic and antiapoptotic markers in the liver tissue of the bisphenol A treated rats.Methods: Forty-eight male Wistar rats were divided into six groups; Group(1): Negative control group (Con), Group(2): Corn oil control group orally administered 1 ml of corn oil/rat daily for two months (Corn), Group(3): Olive oil control group orally administered 1 ml olive oil/rat daily for two months (Olive), Group(4): Quercetin (Qu) control group orally received Qu dissolved in olive oil (50 mg/kg b. wt.) daily for two months (Qu). Group(5): Positive control group orally received Bisphenol A (BPA) dissolved in corn oil in a dose of 50 mg/kg b. wt. daily for two months (BPA), Group(6): Quercetin treated group orally administered 50 mg/kg b. wt. of BPA and treated with Qu (50 mg/kg b. wt. Orally) daily for two months (BPA+Qu).Results: BPA exposure resulted in significant elevations of oxidative stress, as evidenced by the increased malondialdehyde level and glutathione-S-transferase activity associated with significant decrease in glutathione peroxidase activity in the liver tissue. Moreover, BPA caused an up regulation in the values of liver function enzymes. Also, BPA produced a significant elevation in the hepatic Interleuckin-6 (IL-6) and caspase-3 levels with a significant decline in antiapoptotic protein B-cell lymphoma 2 (Bcl2) level in liver tissue. Quercetin significantly attenuated the BPA-evoked liver oxidative stress and modulated the activities of liver function enzymes. In addition, treatment of quercetin with BPA resulted in an improvement of IL-6 and caspase-3 levels associated with a significant increase in hepatic protein Bcl2 expression.Conclusion: These data suggest that quercetin protects rat liver from BPA-induced oxidative stress, probably via its antioxidant activity, anti-inflammatory and antiapoptotic effects. So, Quercetin is a promising pharmacological agent for preventing the potential hepatotoxicity of BPA following occupational or environmental exposures.Keywords: Bisphenol A, Quercetin, hepatotoxicity, Antioxidant, Anti-inflammatory effect, Antiapoptotic effec
A Proposed ANN-Based Acceleration Control Scheme for Soft Starting Induction Motor
In this article, a new soft starting control scheme based on an artificial neural network (ANN) is presented for a three-phase induction motor (IM) drive system. The main task of the control scheme is to keep the accelerating torque constant at a level based on the value of reference acceleration. This is accomplished by the proper choice of the firing angles of thyristors in the soft starter. Using the ANN approach, the complexity of the online determination of the thyristors firing angles is resolved. The IM torque-speed characteristic curves are firstly used to train the ANN model. Secondly, the IM- soft starter system is modeled using MATLAB/SIMULINK. To prove the effectiveness of the proposed ANN-based acceleration control scheme, different reference accelerations and loading conditions are applied and investigated. Finally, a laboratory prototype of 3 kW soft starter is implemented. The proposed control scheme is executed in a real-time environment using a digital signal processor (Model: TMS320F28335). The simulation and real-time results significantly confirm that the proposed controller can efficiently reduce the IM starting current and torque pulsations. This in turn ensures a smooth acceleration of the IM during the starting process. Moreover, the proposed control scheme has the superiority over several soft starting control schemes since it has a simple control circuit configuration, less required sensors, and low computational burden of the control algorithm. © 2021 Institute of Electrical and Electronics Engineers Inc.. All rights reserved
Production of Aspergillus quadrilineatus MT083999 Chitinase, ÎČ-1,3-Glucanase and Nano-silver Important for Biocontrol of Fusarium spp. Infecting Crops
416-425In our search for an active biocontrol agent against Fusarium solani and F. oxysporum, the major species causing wilt, root
rot and damping-off in plants affecting crops. The fungal isolate genetically identified as Aspergillus quadrilineatus MT083999
displayed high antagonistic activities against the tested root-rot fungi, and presented valuable chitinase and ÎČ-glucanase
activities of 235.484 and 508.953 U/gds, respectively. Solid state fermentation conditions were optimized by applying 20 trails
of the central composite design (Three-factor-five-level) and two responses of chitinase R1 and ÎČ-glucanase R2 activities,
respectively. The optimum activities of chitinase (386.70 U/gds) and ÎČ-glucanase (1094.70 U/gds) were obtained in trial 4 and 2
respectively, with about 1.64-fold increase in chitinase activity and 2.15-fold increase in ÎČ-glucanase activity when compared
with initial fermentation. Biosynthesis of nano-silver from A. quadrilineatus was evaluated in 10 experiments of another design
of 2-factors-5-levels. The antifungal effects of each biosynthesized nano-silver against F. solani (R1) and F. oxysporum (R2)
were evaluated as Inhibition Zone Diameter (IZD).The high fungicide nano-silver against both tested phytopathogens was
characterized by UV-visible spectrophotometry, Transmission Electron Microscopy (TEM), Zeta Dynamic Light Scatter (DLS)
and Fourier Transform Infrared Spectroscopy (FTIR). The results indicated that A. quadrilineatus MT083999 chitinolytic
enzymes and nano-silver can be applied as a novel candidate in biocontrol of Fusarium wilt infecting crops worldwide
Effectiveness of a mHealth Lifestyle Program With Telephone Support (TXT2BFiT) to Prevent Unhealthy Weight Gain in Young Adults: Randomized Controlled Trial
BACKGROUND: Weight gained in young adulthood often persists throughout later life with associated chronic disease risk. Despite this, current population prevention strategies are not specifically designed for young adults. OBJECTIVE: We designed and assessed the efficacy of an mHealth prevention program, TXT2BFiT, in preventing excess weight gain and improving dietary and physical activity behaviors in young adults at increased risk of obesity and unhealthy lifestyle choices. METHODS: A two-arm, parallel-group randomized controlled trial was conducted. Subjects and analyzing researchers were blinded. A total of 250 18- to 35-year-olds with a high risk of weight gain, a body mass index (BMI) of 23.0 to 24.9 kg/m(2) with at least 2 kg of weight gain in the previous 12 months, or a BMI of 25.0 to 31.9 kg/m(2) were randomized to the intervention or control group. In the 12-week intervention period, the intervention group received 8 text messages weekly based on the transtheoretical model of behavior change, 1 email weekly, 5 personalized coaching calls, a diet booklet, and access to resources and mobile phone apps on a website. Control group participants received only 4 text messages and printed dietary and physical activity guidelines. Measured body weight and height were collected at baseline and at 12 weeks. Outcomes were assessed via online surveys at baseline and at 12 weeks, including self-reported weight and dietary and physical activity measures. RESULTS: A total of 214 participantsâ110 intervention and 104 controlâcompleted the 12-week intervention period. A total of 10 participants out of 250 (4.0%)â10 intervention and 0 controlâdropped out, and 26 participants (10.4%)â5 intervention and 21 controlâdid not complete postintervention online surveys. Adherence to coaching calls and delivery of text messages was over 90%. At 12 weeks, the intervention group were 2.2 kg (95% CI 0.8-3.6) lighter than controls (P=.005). Intervention participants consumed more vegetables (P=.009), fewer sugary soft drinks (P=.002), and fewer energy-dense takeout meals (P=.001) compared to controls. They also increased their total physical activity by 252.5 MET-minutes (95% CI 1.2-503.8, P=.05) and total physical activity by 1.3 days (95% CI 0.5-2.2, P=.003) compared to controls. CONCLUSIONS: The TXT2BFiT low-intensity intervention was successful in preventing weight gain with modest weight loss and improvement in lifestyle behaviors among overweight young adults. The short-term success of the 12-week intervention period shows potential. Maintenance of the behavior change will be monitored at 9 months. TRIAL REGISTRATION: Trial Registration: The Australian New Zealand Clinical Trials Registry ACTRN12612000924853; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12612000924853 (Archived by WebCite at http://www.webcitation.org/6Z6w9LlS9)
Clinical characteristics and role of early cardiac magnetic resonance imaging in patients with suspected ST-elevation myocardial infarction and normal coronary arteries
A variety of conditions other than acute myocardial infarction may cause ST-elevation. Our objective was to evaluate the impact of cardiac magnetic resonance (CMR) on differential diagnosis from a prospective series of patients with suspected ST-elevation myocardial infarction (STEMI) and completely normal coronary arteries. Among 1,145 patients with suspected STEMI, 49 patients had completely normal coronary arteries and entered a prospective registry. CMR was done within 24 h, if possible, and included function analyses, T2-weighted imaging (T2 ratio), T1-weighted imaging before and after gadolineum administration (global relative enhancement; gRE), and late gadolineum enhancement (LGE). All patients were asked for a follow-up CMR after approximately 3 months. The incidence of patients with suspected STEMI and normal coronary arteries was 4.3% and mean age was 45 ± 14 years (STEMI group 64 ± 13 years; P < 0.001). 55% had a recent history of infection. Cardiac biomarkers showed a moderate elevation on admission. There was a significant change from baseline to follow-up for LV end-diastolic volumes (EDV) (P < 0.001), LV mass (P < 0.05), mean T2 ratio (P < 0.05), and LGE volume (P < 0.05). Major diagnostic groups were myocarditis (29%), pericarditis (27%), and takotsubo cardiomyopathy (10%). 18% were regarded as non-diagnostic. The study showed an incidence of 4.3% of patients with suspected STEMI and completely normal coronary arteries. Early CMR was valuable in the evaluation of the differential diagnoses and to exclude myocardial abnormalities in patients with uncertain aetiology. Further studies are needed for the assessment of long-term outcome
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