Doctoral Researchers

 
Zhang, Xiaoyuan

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Institute/Dep.
Friedrich Schiller University Jena
Institute for Materials Science and Technology (IMT)
PhD Project:

Highly Oriented Nanostructured Surfaces of Block Copolymer for Biomedical Applications

Abstract: During the last decades, one of the major trends in the biomaterial research has been the functionalization of the material surfaces to control the biological response of the host...
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... (human body) to improve the biocompatibility. Prevention of nonspecific protein adsorption and microorganisms adhesion on biomatetial surfaces play key roles for successful integration of implants into the human body. It was reported that fabrication of biomaterial surfaces with different nanostructures, especially with different chemical and physical properties, is an effective method to control the protein adsorption and the microorganisms adhesion. So far, only few work focused on the influence of both topographical and chemical surface properties on the protein and microorganisms behavior. Melt-drawn amphiphilic block copolymer thin films are excellent 2D model surfaces to investigate the interaction between surface properties and proteins as well as microorganisms. These functional biomaterial thin films have potential use for broad biomedical applications, e.g., tissue engineering, antimicrobial mat, drug delivery, and optical device/biosensor application. The aim of this research is to investigate the influence of functional block copolymer surfaces with different nanotopographies and chemical properties on protein and microbial adhesion.
 
 
Institute/Dep.
Friedrich Schiller University Jena
Institute of General Botany and Plant Physiology
Chair for General Botany
PhD Project:

The Role of Photoreceptors in Photoperiodic Control in the Green Alga Chlamydomonas reinhardtii

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Abstract: Plants and animals measure the duration of the day and night in the natural environment for sensing the season of the year, known as photoperiodic control. Thereby, components of the...
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... circadian clock and photoreceptors are involved as shown in the underlying molecular mechanism of the long-day plant Arabidopsis thaliana (Fuijwara et al., 2008, Plant Cell 11:2960-71; Miyata et al., 2011, Plant Signal Behav 8:1162-71). While photoperiodic control is well documented in multicellular organisms, relatively little is known in unicells. One of the few reports of a photoperiodic response includes Chlamydomonas. In the well-known life cycle of this alga, non-optimal conditions provoke the differentiation of haploid vegetative cells into gametes, which form zygotes after fusion. Zygotes resist stressful environmental conditions, thus adapting to seasonal changes such as overwintering. It has been shown that the germination efficiency of Chlamydomoans zygospores is enhanced under long-day conditions (Suzuki and Johnson, 2002, Naturwissenschaften 89:214-20; Mittag et al., 2005, Plant Physiol 137:399-409). Based on the full genome sequence of C. reinhardtii (Merchant et al., 2007, Science 318:245-50) (putative) photoreceptors have been found that may be in functional connection to the circadian clock (Schulze et al., 2010, Protoplasma 244:3-14). Recently, some photoreceptor mutants were generated by an insertional mutagenesis approach and are currently under investigation. The aim of this project is to examine the role of different photoreceptors in Chlamydomonas in the molecular mechanism of photoperiodic control and thereby analyze the potential relationship to the circadian clock. Also, the molecular mechanism of photoperiodic control in a unicell will be compared to that of Arabidopsis in collaboration with the lab of Tsuyoshi Mizoguchi (Japan). It is envisaged that the successful PhD candidate joins the lab in Japan for a few months to also work there on the project.