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

We present result of optical studies on InAs/GaIn(As)Sb/InAs type II quantum wells predicted for the active region in interband cascade lasers, and further for laser-based gas sensors operating at room temperature in a broad wavelength range of mid infrared. Using photoreflectance spectroscopy supported by electronic structure calculations we determine the oscillator strength of the fundamental optical transition in structures with GaIn(As)Sb material of various compositions hole confinement layer. We show that incorporation of arsenic into this layer can affect several crucial properties significantly like transition wavelength and its probability, but also the structural material quality affecting the radiative efficiency. Also, by using photoluminescence we investigate one of the crucial parameters for the performance of interband cascade lasers, the spectral emission width of type II quantum wells constituting the laser active region.

Optical characterization of type II quantum wells for long-wavelength mid-infrared interband cascade lasers

Two dimensional hole gas (2DHG) created at modulated doped Al 1- x Ga x As/GaAs heterostructures was studied by optical methods. Samples of different 2DHG concentration p=9.8*10 11 cm $min2 were examined by means of photo luminescence (PL) and photo luminescence excitation (PLE) measurements under magnetic field up to 8T in Faraday configuration. In PL spectra two groups of lines are observed: a broad line at lower energy so called H-band and at higher energy exciton related lines. In magnetic field H-band splits and shifts linearly following Landau level quantization whereas higher energy lines exhibit diamagnetic shift. A strong absorption of H-band in PLE spectra is observed. We propose consistent theoretical model which explains both the nature of H-band and the formation of excitons on 2DHG states.

Excitons at the p-type modulation doped Al0.5Ga0.5As/GaAs interface

Results of modelling and fabrication of photodetectors with composition graded active layers have been presented. Simulated and measured spectral characteristics of the proposed detectors have been shown. Advantages of such structures have been discussed with respect to conventional detectors with non-graded active areas as well as some technological problems of compositionally graded semiconductor layers.

https://www.materialsscience.pwr.wroc.pl/bi/vol26no1/articles/ms_2007_10FES_10.pdf

A(III)B(V) detectors with graded active region

Planarne domieszkowanie krzemem naprężonych studni kwantowych InxGa1-xAs/GaAs w technice MOVPE

The limited speed of direct modulation due to the significant population of hot carriers in quantum dots (QD) is a major drawback of the application of QD based lasers in fibre optics telecommunication. One of the most promising methods of alleviating this problem is the design of tunnel injection (TI) structures, where already cold carries are injected by means of tunnelling through a thin barrier from an adjacent quantum well (QW) directly to the QD ground state. We have investigated the properties of TI structures consisting of an InxGa1−xAs quantum well and a layer of self-assembled In0.6Ga0.4As/GaAs quantum dots versus the properties a reference QD sample. Photoreflectance spectroscopy is applied to determine the energies of optical transitions in this complex system. The obtained energies are then used to verify the reliability of the calculations in the 8 band kp model, which take into account the realistic geometry of the dots, influence of the strain and the coupling between the dot layer and the injector quantum well. Finally, time resolved photoluminescence (PL) experiment is performed at low temperature and its results are related to the acquired structure of confined levels. The influence of the tunnelling process on PL rise and decay times is explained.

Jan Misiewicz

Papers

Optical characterization of type II quantum wells for long-wavelength mid-infrared interband cascade lasers

Excitons at the p-type modulation doped Al0.5Ga0.5As/GaAs interface

A(III)B(V) detectors with graded active region

Planarne domieszkowanie krzemem naprężonych studni kwantowych InxGa1-xAs/GaAs w technice MOVPE

Tunnel injection structures based on InGaAs/GaAs quantum dots: optical properties and energy structure