179 research outputs found
Generalized Heisenberg algebra coherent states for Power-law potentials
Coherent states for power-law potentials are constructed using generalized
Heisenberg algabras. Klauder's minimal set of conditions required to obtain
coherent states are satisfied. The statistical properties of these states are
investigated through the evaluation of the Mandel's parameter. It is shown that
these coherent states are useful for describing the states of real and ideal
lasers.Comment: 13 pages, 2 figure
Momentum distribution of 1D Bose gases at the quasi-condensation crossover: theoretical and experimental investigation
We investigate the momentum distribution of weakly interacting 1D Bose gases
at thermal equilibrium both experimentally and theoretically. Momentum
distribution of single 1D Bose gases is measured using a focusing technique,
whose resolution we improve via a guiding scheme. The momentum distribution
compares very well with quantum Monte Carlo calculations for the Lieb-Liniger
model at finite temperature, allowing for an accurate thermometry of the gas
that agrees with (and improves upon) the thermometry based on in situ density
fluctuation measurements. The quasi-condensation crossover is investigated via
two different experimental parameter sets, corresponding to the two different
sides of the crossover. Classical field theory is expected to correctly
describe the quasi-condensation crossover of weakly interacting gases. We
derive the condition of validity of the classical field theory, and find that,
in typical experiments, interactions are too strong for this theory to be
accurate. This is confirmed by a comparison between the classical field
predictions and the numerically exact quantum Monte Carlo calculations.Comment: 8 page
Luxation obturatrice de la hanche: un traumatisme rare en pratique sportive
Les luxations antérieures traumatiques de la hanche sans fracture du cotyle ou de la tête fémorale sont rares. Elles sont souvent secondaires à des accidents de haute énergie cinétique. La prise en charge thérapeutique nécessite un chirurgien vigilant et prévenu du risque de complications. Nous rapportons le cas d'une luxation obturatrice (antéro-inférieure) chez un jeune de 18 ans pratiquant le rolle
Dynamics of multipartite quantum correlations under decoherence
Quantum discord is an optimal resource for the quantification of classical
and non-classical correlations as compared to other related measures. Geometric
measure of quantum discord is another measure of quantum correlations.
Recently, the geometric quantum discord for multipartite states has been
introduced by Jianwei Xu [arxiv:quant/ph.1205.0330]. Motivated from the recent
study [Ann. Phys. 327 (2012) 851] for the bipartite systems, I have
investigated global quantum discord (QD) and geometric quantum discord (GQD)
under the influence of external environments for different multipartite states.
Werner-GHZ type three-qubit and six-qubit states are considered in inertial and
non-inertial settings. The dynamics of QD and GQD is investigated under
amplitude damping, phase damping, depolarizing and flipping channels. It is
seen that the quantum discord vanishes for p>0.75 in case of three-qubit GHZ
states and for p>0.5 for six qubit GHZ states. This implies that multipartite
states are more fragile to decoherence for higher values of N. Surprisingly, a
rapid sudden death of discord occurs in case of phase flip channel. However,
for bit flip channel, no sudden death happens for the six-qubit states. On the
other hand, depolarizing channel heavily influences the QD and GQD as compared
to the amplitude damping channel. It means that the depolarizing channel has
the most destructive influence on the discords for multipartite states. From
the perspective of accelerated observers, it is seen that effect of environment
on QD and GQD is much stronger than that of the acceleration of non-inertial
frames. The degradation of QD and GQD happens due to Unruh effect. Furthermore,
QD exhibits more robustness than GQD when the multipartite systems are exposed
to environment.Comment: 15 pages, 4 figures, 4 table
The sudden change phenomenon of quantum discord
Even if the parameters determining a system's state are varied smoothly, the
behavior of quantum correlations alike to quantum discord, and of its classical
counterparts, can be very peculiar, with the appearance of non-analyticities in
its rate of change. Here we review this sudden change phenomenon (SCP)
discussing some important points related to it: Its uncovering,
interpretations, and experimental verifications, its use in the context of the
emergence of the pointer basis in a quantum measurement process, its appearance
and universality under Markovian and non-Markovian dynamics, its theoretical
and experimental investigation in some other physical scenarios, and the
related phenomenon of double sudden change of trace distance discord. Several
open questions are identified, and we envisage that in answering them we will
gain significant further insight about the relation between the SCP and the
symmetry-geometric aspects of the quantum state space.Comment: Lectures on General Quantum Correlations and their Applications, F.
F. Fanchini, D. O. Soares Pinto, and G. Adesso (Eds.), Springer (2017), pp
309-33
Doxorubicin loaded Polymeric Nanoparticulate Delivery System to overcome drug resistance in osteosarcoma
<p>Abstract</p> <p>Background</p> <p>Drug resistance is a primary hindrance for the efficiency of chemotherapy against osteosarcoma. Although chemotherapy has improved the prognosis of osteosarcoma patients dramatically after introduction of neo-adjuvant therapy in the early 1980's, the outcome has since reached plateau at approximately 70% for 5 year survival. The remaining 30% of the patients eventually develop resistance to multiple types of chemotherapy. In order to overcome both the dose-limiting side effects of conventional chemotherapeutic agents and the therapeutic failure incurred from multidrug resistant (MDR) tumor cells, we explored the possibility of loading doxorubicin onto biocompatible, lipid-modified dextran-based polymeric nanoparticles and evaluated the efficacy.</p> <p>Methods</p> <p>Doxorubicin was loaded onto a lipid-modified dextran based polymeric nano-system. The effect of various concentrations of doxorubicin alone or nanoparticle loaded doxorubicin on KHOS, KHOS<sub>R2</sub>, U-2OS, and U-2OS<sub>R2 </sub>cells was analyzed. Effects on drug retention, immunofluorescence, Pgp expression, and induction of apoptosis were also analyzed.</p> <p>Results</p> <p>Dextran nanoparticles loaded with doxorubicin had a curative effect on multidrug resistant osteosarcoma cell lines by increasing the amount of drug accumulation in the nucleus via Pgp independent pathway. Nanoparticles loaded with doxorubicin also showed increased apoptosis in osteosarcoma cells as compared with doxorubicin alone.</p> <p>Conclusion</p> <p>Lipid-modified dextran nanoparticles loaded with doxorubicin showed pronounced anti-proliferative effects against osteosarcoma cell lines. These findings may lead to new treatment options for MDR osteosarcoma.</p
Classic Kaposi's sarcoma in morocco: clinico -epidemiological study at the national institute of oncology
<p>Abstract</p> <p>Background</p> <p>Classic Kaposi's sarcoma (CKS) is a rare disease likely associated with human herpes virus 8 (HHV-8) infection, and occurs predominantly in Jewish, Mediterranean and middle eastern men .There is a dearth of data in Moroccan patients with CKS regarding epidemiology, clinical characteristics and outcomes. This report examines a cohort of patients with CKS evaluated at the national institute of oncology over 11-year period.</p> <p>Methods</p> <p>A retrospective analysis of patients referred to the national institute of oncology with classical Kaposi sarcoma, between January 1998 and February 2008, was performed. Reviewed information included demographics, clinical and pathological staging, death or last follow-up.</p> <p>Results</p> <p>During the study period, 56 patients with a diagnosis of CKS have been referred to our hospital. There were 11(19,7%) females and 45 (80,3%) males (male-to-female ratio: 4:1). Mean age at diagnosis was 61,7 ± 15 (range: 15- 86 years). Nodules and/or plaques were the most frequent type of lesion. The most common location was the lower limbs, particularly the distal lower extremity (90%). In addition to skin involvement, visceral spread was evident in 9 cases. The most common visceral involvement sites were lymph nodes (44%), lung (22%), and gastrointestinal tract (22%). Associated lymphoedema was seen in 24 (42%) of the patients. There were 18 stage I patients (32,14%), 8: stage II (14,28%), 21 stage III(37,5%) and 9 stage IV (16,07%). A second primary malignancy was diagnosed in 6 cases (10,7%), none of the reticuloendothelial system.</p> <p>With a median follow-up of 45 months, 38 (67,8) patients are alive, of whom 25 (65,78%) patients with stable disease, five with progressive disease currently under systemic chemotherapy and 8(21,05%) are alive and free of disease, over a mean interval of 5 years.</p> <p>Conclusion</p> <p>This is the largest reported series in our context. In Morocco, CKS exhibits some special characteristics including a disseminated skin disease at diagnosis especially in men, a more common visceral or lymph node involvement and a less frequent association with second malignancies.</p
A line-balancing strategy for designing flexible assembly systems
We present a rough-cut analysis tool that quickly determines a few potential cost-effective designs at the initial design stage of flexible assembly systems (FASs) prior to a detailed analysis such as simulation. It uses quantitative methods for selecting and configuring the components of an FAS suitable for medium to high volumes of several similar products. The system is organized as a series of assembly stations linked with an automated material-handling system moving parts in a unidirectional flow. Each station consists of a single machine or of identical parallel machines. The methods exploit the ability of flexible hardware to switch almost instantaneously from product to product. Our approach is particularly suitable where the product mix is expected to be stable, since we combine the hardware-configuration phase with the task-allocation phase.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45513/1/10696_2004_Article_BF00167513.pd
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