scholarly journals Tunneling Control of Transmission Coefficient and Group Index in a Quantum Dot Nanostructure

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Hamid Reza Hamedi ◽  
A. Khaledi-Nasab ◽  
H. Ghaforyan
Keyword(s):  
Quantum Dot ◽  
Transmission Coefficient ◽  
Group Index ◽  
Index Properties ◽  
Oppositional Behavior ◽  
Probe Field ◽  
Tunnel Coupling ◽  
Probe Transmission ◽  
The Impact ◽  
Incoherent Pump

We theoretically study the transmission and group index properties of the probe field in a four-level quantum dot molecule. It is found that the tunnel coupling plays a very important role in realizing the transmission coefficient of the probe field. Moreover, the impact of an incoherent pump field on imaginary part of susceptibility is investigated. We show that probe transmission exhibits oppositional behavior against weak and strong incoherent pump rates. This approach allows substantial flexibility in the manipulation of group velocity of light.

scholarly journals CdSe/ZnS Core-Shell-Type Quantum Dot Nanoparticles Disrupt the Cellular Homeostasis in Cellular Blood–Brain Barrier Models

2021 ◽  
Vol 22 (3) ◽  
pp. 1068
Author(s):  
Katarzyna Dominika Kania ◽  
Waldemar Wagner ◽  
Łukasz Pułaski
Keyword(s):  
Gene Expression ◽  
Quantum Dot ◽  
Blood Brain Barrier ◽  
Protein Gene ◽  
Brain Barrier ◽  
Core Shell ◽  
Cellular Homeostasis ◽  
Blood Brain ◽  
Shell Type ◽  
The Impact

Two immortalized brain microvascular endothelial cell lines (hCMEC/D3 and RBE4, of human and rat origin, respectively) were applied as an in vitro model of cellular elements of the blood–brain barrier in a nanotoxicological study. We evaluated the impact of CdSe/ZnS core-shell-type quantum dot nanoparticles on cellular homeostasis, using gold nanoparticles as a largely bioorthogonal control. While the investigated nanoparticles had surprisingly negligible acute cytotoxicity in the evaluated models, a multi-faceted study of barrier-related phenotypes and cell condition revealed a complex pattern of homeostasis disruption. Interestingly, some features of the paracellular barrier phenotype (transendothelial electrical resistance, tight junction protein gene expression) were improved by exposure to nanoparticles in a potential hormetic mechanism. However, mitochondrial potential and antioxidant defences largely collapsed under these conditions, paralleled by a strong pro-apoptotic shift in a significant proportion of cells (evidenced by apoptotic protein gene expression, chromosomal DNA fragmentation, and membrane phosphatidylserine exposure). Taken together, our results suggest a reactive oxygen species-mediated cellular mechanism of blood–brain barrier damage by quantum dots, which may be toxicologically significant in the face of increasing human exposure to this type of nanoparticles, both intended (in medical applications) and more often unintended (from consumer goods-derived environmental pollution).

Evaluating the Impact of Interconnections in Quantum-Dot Cellular Automata

2018 ◽  
Author(s):  
Frank Sill Torres ◽  
Robert Wille ◽  
Marcel Walter ◽  
Philipp Niemann ◽  
Daniel GroBe ◽  
...  
Keyword(s):  
Cellular Automata ◽  
Quantum Dot ◽  
Quantum Dot Cellular Automata ◽  
The Impact

Add-on tiotropium versus step-up inhaled corticosteroid plus long-acting beta-2‐agonist in real-world patients with asthma

2020 ◽  
Vol 41 (4) ◽  
pp. 248-255
Author(s):  
Bradley Chipps ◽  
Giselle Mosnaim ◽  
Sameer K. Mathur ◽  
Asif Shaikh ◽  
Samir Khoury ◽  
...  
Keyword(s):  
Real World ◽  
Index Date ◽  
Group Versus ◽  
Group Index ◽  
Inhaled Corticosteroid ◽  
Ed Visits ◽  
Exacerbation Risk ◽  
Beta 2 ◽  
Long Acting ◽  
The Impact

Background: A step-up approach (increasing inhaled corticosteroid [ICS] dose and/or add-on treatment) is recommended for asthma that is uncontrolled despite ICS plus long-acting beta-2‐agonist (LABA) combination treatment. Understanding the impact of different treatment options on health outcomes can help guide treatment decision-making. Objective: To compare the effectiveness of add-on tiotropium 1.25 µg (two puffs once daily) versus an increased ICS plus LABA dose in a real-world cohort of patients with asthma initiated on ICS plus LABA. Methods: De-identified data from patients ages ≥12 years and with asthma who were initiated on ICS plus LABA, and then had tiotropium added (Tio group; index date) or an ICS plus LABA dose increased (inc-ICS group; index date) were collected from two medical and pharmacy claims data bases (2014‐2018). To account for population/group differences, propensity score matching was performed. The primary end point was the exacerbation risk after the index date. Secondary end points included exacerbation rates 6 and 12 months postindex, health-care resource utilization, costs, and short-acting beta-2‐agonist (SABA) refills 12 months postindex. Results: Overall, 7857 patients (Tio group, 2619; inc-ICS group, 5238) were included. The exacerbation risk was 35% lower in the Tio group than in the inc-ICS group (hazard ratio 0.65 [95% confidence interval, 0.43‐0.99]; p = 0.044). Exacerbation rates in the Tio group also were significantly lower within 6 and 12 months postindex (64% and 73%, respectively). All-cause and asthma-related emergency department (ED) visits were 47% and 74% lower, respectively (p < 0.0001 for both), and all-cause and asthma-related hospitalizations were 48% (p < 0.01) and 76% (p < 0.001) lower, respectively, in the Tio group. Also, significantly fewer patients in the Tio group versus the inc-ICS group required SABA refills (56% versus 67%, p < 0.0001). Conclusion: Add-on tiotropium significantly decreased the risk and rate of exacerbations, decreased all-cause and asthma-related ED visits and hospitalizations, and reduced SABA refills compared with increasing the ICS plus LABA dose. The findings supported the use of add-on tiotropium for patients with uncontrolled asthma taking ICS plus LABA.

scholarly journals Fluctuation Characteristic Test of Oblique Stress Waves in Infilled Jointed Rock and Study of the Analytic Method

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Jin Yu ◽  
Zehan Liu ◽  
Ze He ◽  
Xianqi Zhou ◽  
Jinbi Ye
Keyword(s):  
Transmission Coefficient ◽  
Impact Velocity ◽  
Joint Angle ◽  
Split Hopkinson Pressure Bar ◽  
Strain Curve ◽  
Stress Waves ◽  
Transmitted Wave ◽  
Impact Rate ◽  
Dip Angle ◽  
The Impact

The propagation of stress waves in filled jointed rocks involves two important influencing factors: transmission-reflection phenomena and energy attenuation. In this paper, the split Hopkinson pressure bar (SHPB) test is used to shock the filled rock with joint angles of 0, 30, and 45° and the thickness of 4 mm and 10 mm, respectively, in three different velocities. The wave curves of the incident wave, reflected wave, and transmission are obtained. The effects of the filling angle and joint thickness on wave propagation are analyzed. Based on the propagation characteristics of stress waves in joints, the stress expression of oblique incident stress waves propagating in filling joints is derived, and the energy coefficient of transmission and reflection is calculated. The results show that the propagation of stress wave in filling joints is related to the impact rate. The larger the impact rate is, the larger the maximum voltage amplitude of the three waves is. And the increasing amplitude of the incident and reflected waves is larger than the transmitted wave; the greater the impact velocity is, the smaller the stress-strain curve gap of the three dip joints is, and the fracture strength of the specimen decreases with the increase of the joint dip angle. The larger the joint dip angle is, the smaller the deformation of the rock-like specimen is. The change of the transmission coefficient is related to the joint angle, and the larger joint angle weakens the influence of the joint width on the transmission of the transmitted wave; under each impact velocity, the theoretical and experimental stress peaks are approximately the same, and the transmission coefficient maintains a good consistency with the oblique incident angle.

scholarly journals Controllable tunnel coupling and molecular states in a graphene double quantum dot

2012 ◽  
Vol 100 (2) ◽  
pp. 022106 ◽  
Author(s):  
Lin-Jun Wang ◽  
Hai-Ou Li ◽  
Tao Tu ◽  
Gang Cao ◽  
Cheng Zhou ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Double Quantum ◽  
Tunnel Coupling ◽  
Double Quantum Dot

A detailed investigation of the impact of varying number of dot layers in strain-coupled multistacked InAs/GaAs quantum dot heterostructures

2016 ◽  
Author(s):  
Debiprasad Panda ◽  
Akshay Balgarkashi ◽  
Saikalash Shetty ◽  
Hemant Ghadi ◽  
Subhananda Chakrabarti
Keyword(s):  
Quantum Dot ◽  
Gaas Quantum Dot ◽  
The Impact

Optical response of a quantum dot–metal nanoparticle hybrid interacting with a weak probe field

2012 ◽  
Vol 25 (4) ◽  
pp. 045304 ◽  
Author(s):  
Spyridon G Kosionis ◽  
Andreas F Terzis ◽  
Seyed M Sadeghi ◽  
Emmanuel Paspalakis
Keyword(s):  
Quantum Dot ◽  
Optical Response ◽  
Metal Nanoparticle ◽  
Probe Field

New Decoupling Scheme for Investigation of Transmission Coefficient Peaks for Asymmetrically Coupled Quantum Dot System

2018 ◽  
Vol 24 (2) ◽  
pp. 918-921
Author(s):  
Sushila Devi ◽  
B. B Brogi ◽  
P. K Ahulwalia ◽  
S Chand
Keyword(s):  
Quantum Dot ◽  
Transmission Coefficient
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