다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

http://www.maths.qmul.ac.uk/%7Elatora/report_06.pdf

Complex networks: Structure and dynamics

Modern nanotechnology allows one to scale down various important devices (sensors, chips, fibers, etc.) and thus opens up new horizons for their applications. The efficiency of most of them is based on fundamental physical phenomena, such as transport of wave excitations and resonances. Short propagation distances make phase-coherent processes of waves important. Often the scattering of waves involves propagation along different paths and, as a consequence, results in interference phenomena, where constructive interference corresponds to resonant enhancement and destructive interference to resonant suppression of the transmission. Recently, a variety of experimental and theoretical work has revealed such patterns in different physical settings. The purpose of this review is to relate resonant scattering to Fano resonances, known from atomic physics. One of the main features of the Fano resonance is its asymmetric line profile. The asymmetry originates from a close coexistence of resonant transmission and resonant reflection and can be reduced to the interaction of a discrete (localized) state with a continuum of propagation modes. The basic concepts of Fano resonances are introduced, their geometrical and/or dynamical origin are explained, and theoretical and experimental studies of light propagation in photonic devices, charge transport through quantum dots, plasmon scattering in Josephson-junction networks, and matter-wave scattering in ultracold atom systems, among others are reviewed.

/pdf/fano-resonances-in-nanoscale-structures-2c8qeas3bm.pdf

Fano resonances in nanoscale structures

The synchronization of chaotic systems

We demonstrate steady-state, mirrorless superradiance in a cold vapor pumped by weak optical fields. Beyond a critical pump intensity of 1 mW/cm$^2$, the vapor spontaneously transforms into a spatially self-organized state: a density grating forms. Scattering of the pump beams off this grating generates a pair of new, intense optical fields that act back on the vapor to enhance the atomic organization. We map out experimentally the superradiant phase transition boundary and show that it is well-described by our theoretical model. The resulting superradiant emission is nearly coherent, persists for several seconds, displays strong temporal correlations between the various modes, and has a coherence time of several hundred $\mu$s. This system therefore has applications in fundamental studies of many-body physics with long-range interactions as well as all-optical and quantum information processing.

Steady-state, cavity-less, multimode superradiance

The interaction of two strong laser beams
propagating through a nonlinear optical medium is studied
theoretically and experimentally. It is shown that this interaction
is unstable in that new, intense fields can be generated. An
experiment has been performed to investigate the stability
characteristics of near-resonant laser beams counterpropagating in
a sodium vapor. It is found that the states of polarization of the
transmitted waves change abruptly to a value different than the
input polarizations when the intensities of the waves are above a
well-defined threshold. This result demonstrates that
multistability can occur in a cavity-less, nonlinear optical
system. When the intensities of the
counterpropagating waves are far above the threshold for
multistability there are no stable states of the system and the
fields fluctuate chaotically in time. This result shows that an
optical system can be dynamically unstable due solely to the
effects of the nonlinear interaction and the effects of
propagation. The attractors describing the dynamical evolution of
the system are constructed in phase space and the fractal
dimensions and entropies characterizing the attractors are
determined. The boundary of the region of instability is measured
and is found to depend on the detuning of the laser frequency from
the sodium
3S1/2→3P1/2
resonance, on the intensities and polarizations of the input beams,
on the atomic number density, and on the buffer gas pressure.
 The results are in good qualitative agreement
with the predictions of a theory that models the nonlinear optical
response in terms of the optical Kerr effect. Quantitative
agreement is obtained through use of a more detailed model based of
the solutions to the density-matrix equations of motion for the
atomic system.

Instabilities and Chaos of Laser Beams Propagating Through Nonlinear Optical Media.

We describe our progress on achieving quantum key distribution with high photon efficiency and high rate using hyperentanglement. Our goal is encode 10 bits per photon and distribute a secure key at 1 Gbit/s.

Quantum Key Distribution Using Hyperentanglement

We develop a theoretical model of two-photon amplification in laser-driven potassium atoms and use it to analyze the recent experiments reported by Pfister et al. [Phys. Rev. A 60, R4249 (1999)]. The model takes into account most of the essential factors influencing the amplification process, including the atomic hyperfine structure (which makes multiphoton emission possible) and the simultaneous interaction with intense drive and probe beams with arbitrary detunings. We determine the origin and analyze the properties of different multiphoton gain resonances that appear in the light-matter interaction. In particular, the influence of the drive and probe field amplitudes and detunings on the strength and frequency of the two-photon amplification resonance is studied in detail, showing clearly the differences with respect to the behavior of single-photon or other multiphoton amplification processes. In addition, we investigate interferences between different quantum pathways originating from the hyperfine structure and determine the conditions under which they can enhance or suppress multiphoton resonances. The predictions of the model are in good agreement with the observations, indicating that it can be used to understand recent experiments on two-photon lasing reported by Pfister et al. [Phys. Rev. Lett. 86, 4512 (2001)].

https://www.phy.duke.edu/~qelectron/pubs/PRA68043823.pdf

Daniel J. Gauthier

Papers

Steady-state, cavity-less, multimode superradiance

Instabilities and Chaos of Laser Beams Propagating Through Nonlinear Optical Media.

Quantum Key Distribution Using Hyperentanglement

Multiphoton amplification processes and quantum-path interferences in a coherently driven atomic vapor

Predicting heavy metal vaporization dynamics in a circulating fluidized bed riser by a Lagrangian approach