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

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Lanthanide-based luminescent hybrid materials.

Optical Waveguide Theory

Recent developments in rare-earth doped materials for optoelectronics

Contactless electroreflectance of GaInN/AlInN multi quantum wells: The issue of broadening of optical transitions

In this paper, we present the results of photoreflectance (PR) investigation of an Al 0.45 Ga 0.55 As/ GaAs superlattice (SL). The modulation spectra have revealed a number of features at both room and low temperature (10 K) which could be associated with the optical transitions between the minibands of the superlattice. Based on calculations within the effective mass approximation they have been identified as transitions between the miniband edges, i.e., the so-called Γ and Π points, respectively, including the high index transitions and those related to the light holes. Tuning the structure parameters around the nominal ones treated as semi-free in the theoretical considerations allowed the growth accuracy of such a complex system to be verified.

Photoreflectance study of Al0.45Ga0.55As/GaAs superlattice: optical transitions at the miniband .GAMMA. and .PI. points

Pseudopotential Calculation of the Zn3P2 Energy Band Structure. Antifluoride Approximation

The radiative recombination time (τr) was calculated for inhomogeneous polar InGaN QWs emitting in the green spectral range. These calculations were performed in the framework of a model where the τr is inversely proportional to the electron-hole overlap integral. In order to simulate inhomogeneities in this model, it was assumed that the QW width, barrier widths and indium concentration vary with a Gaussian distribution where the nominal QW width, barrier widths and indium concentration correspond to the mean value in this distribution and their fluctuations correspond to the deviation from the main value. The τr was calculated for five thousands of randomly generated InGaN QWs and next the spectral map of PL decay was generated for the calculated τr which correspond to various QW regions. The obtained maps were compared with the measured maps of PL decay for InGaN QWs emitting in the green spectral range. It has been clearly shown that QW inhomogenities (i.e., QW width fluctuations and indium concentration fluctuations) lead to a spectral dispersion of the τr and the non-exponential behavior of PL decay curves. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Theoretical simulations of radiative recombination time in polar InGaN quantum wells

Recently, there has been increasing interest in III-nitride semiconductors for the fabrication of ultrahigh-speed intersubband (ISB) devices. First of all it is due to the large conduction band discontinuity available in these materials. The very deep quantum wells (QW) which can be fabricated, are used as an active region for ISB devices for telecommunication applications (1.55 and 1.3 μm). Moreover the ISB absorption recovery times in nitride semiconductors are extremely short, typically of the order of 150-400 fs due to enhanced electron-phonon interaction in these highly ionic materials [1]. One can expect that ISB devices could provide ultrafast data transfer in a single channel of optical fiber. The predicted speed should be in the range of 0.1-1 Tbit/s bit-rate regime, which is significantly larger than the speed achieved with current bipolar technology. Our work has focused on the growth of GaInN/AlInN multi QWs on GaN substrates. Properly choosing growth parameters we were able to fabricate high quality ISB structures exhibiting intense ISB absorptions at 1.55 μm [2]. Due to a partially strain compensation even quite thick structures were crack free. However, an application of such structures in highspeed ISB devices requires extremely good optical and electrical parameters, which should be appropriate for μ-size devices. In the present work we show a significant enhancement of ISB absorption for 15.5 A thick GaInN QWs due to increase of the AlInN barrier width. The enhancement of ISB absorption was more then 3 times for enlarged barrier width from 3 to 6 nm. Also, we observe that the barrier width does not influence the energy of interband and intersubband transitions within experimental accuracy. The experimental results have been compared with theoretical calculations which were performed within the electron effective mass approximation solving the Schrodinger and Poisson equations self-consistently. Strain effects as well as the effect of spontaneous and piezoelectric polarization have been included in these calculations. A good agreement between experimental data and theoretical calculations has been observed for the investigated samples. By analyzing the electron wave functions, it has been concluded that the electrons significantly penetrate the quantum well barriers and that the QWs are coupled despite the fact that the energy coupling between QW levels is very weak. The observed enhancement of ISB transitions can be associated with the effect of better localization of the second electron level in QW. This finding seems to be very important and useful to optimize ISB devices. In this paper this issue will be discussed in details. This work was partially supported by the Polish Ministry of Science and Higher Education as scientific projects Nos. N507 011 32/0500 and N202 41090 33.

/pdf/enhancement-of-intersubband-absorption-in-gainn-alinn-1ktrlmtg1z.pdf

Jan Misiewicz

Papers

Contactless electroreflectance of GaInN/AlInN multi quantum wells: The issue of broadening of optical transitions

Photoreflectance study of Al0.45Ga0.55As/GaAs superlattice: optical transitions at the miniband .GAMMA. and .PI. points

Pseudopotential Calculation of the Zn3P2 Energy Band Structure. Antifluoride Approximation

Theoretical simulations of radiative recombination time in polar InGaN quantum wells

Enhancement of Intersubband Absorption in GaInN/AlInN Quantum Wells