Who are the best doctoral candidates at Helmholtz?

Ann-Christin Baranski, Deutsches Krebsforschungszentrum Heidelberg

In a few words: What is your research about?

In treating prostate cancer, the precise removal of the tumor tissue is one of the critical success factors (others being hormone and radiation therapy). During this operation, it is a challenge for the surgeon to distinguish between healthy tissue and tumor tissue and to delimit tumor lesions (injuries) precisely. My doctoral thesis focused on developing low-molecular hybrid connections that bind specifically to PSMA, an antigen that is overexpressed in prostate cancer cells. The connection bears a dual label consisting of a radionuclide and a fluorescent dye. This dual label enables non-invasive pre-operative imaging combined with intra-operative navigation, allowing therapy decisions to be supported by sensitive detection and localization of tumor tissue.

What were the biggest challenges while you were earning your doctorate?

The biggest challenge was the pre-clinical characterization of the connections with near-infrared dye. Many conventional laboratory devices are still unable to detect the near-infrared range. So the challenge was to find alternatives or to design experiments so that clinical equipment such as the Da Vinci surgical system could be used with a near-infrared channel.

What are your plans for the future?

I intend to continue to develop new pharmaceuticals for imaging and endoradiotherapy. I have been heading the biotechnological development group in the Radiopharmaceutical Development department (Deutsches Konsortium für Translationale Krebsforschung, or DKTK, the German Cancer Research Center of Freiburg’s Nuclear Medicine clinic). We are working on identifying new biomarkers for classifying tumors, assessing metastasizing potential, and monitoring therapy. As part of these efforts, we are developing low-molecular peptides that are suitable for such applications as pre-operative and intra-operative imaging and targeted endoradiotherapy.

Oleg Gorobtsov, Deutsches Elektronen-Synchrotron DESY

In a few words: What is your research about?

During my PhD program, I focused on applications and properties of coherent, high-intensity X-ray radiation. X-ray and XUV Free Electron Lasers (FELs) and advanced synchrotron sources developed, built and upgraded in the last decade open new avenues of research: their high coherence allows 3D imaging with nanometer resolution, even for amorphous materials, and ultrashort pulse duration of FELs especially allows studying electronic processes and chemical reactions happening on femtosecond timescales. A big part of my research, therefore, focused on understanding and measuring coherence and temporal properties of these sources. Other projects included modeling implications of radiation damage and some often-overlooked crystal properties for coherent X-ray methods.

What were the biggest challenges while you were earning your doctorate?

The biggest challenge, but also a big benefit, in my opinion, was a wide range of topics that I had to cover during my PhD. I had to familiarize myself with FEL and synchrotron functioning principles, correlation analysis, diffraction imaging methods, ionization processes and electronic processes that follow, dynamical diffraction theory in crystals, and many other connected topics.

What are your plans for the future?

I am now working as a postdoc in Cornell University, Materials Science and Engineering Department. I am applying my expertise with FELs, synchrotrons, and X-ray coherent methods to research in batteries for renewable energy applications and quantum materials.

Alexandra Amherd Hidalgo, Helmholtz-Zentrum Geesthacht (HZG)

In a few words: What is your research about?

Powder metallurgy of titanium is a promising alternative to the conventional manufacturing of wrought titanium for cost-effective production of components. Beside of pressing and sintering, metal injection moulding is the most established Powder Metallurgy technology. However, the manufacture of high-performance titanium components by metal injection moulding is still challenging. The high affinity which titanium has for interstitial elements and the effect of residual porosity are two important aspects that limit the range of applications. Therefore, my research contributes to the fundamental understanding about the influence of interstitials (oxygen and carbon) and sintering aids (iron) on robustness of Ti-6Al-7Nb alloy, suitable for biomedical applications and processed by metal injection moulding.

What were the biggest challenges while you were earning your doctorate?

One of the biggest issues in my doctoral thesis comes from the high affinity which titanium has for interstitial elements (oxygen, carbon and nitrogen). This fact made the production of titanium samples with the desired interstitial content difficult. In addition, the variation of just one interstitial element while keeping the other elements constant was challenging.

What are your plans for the future?

Nowadays I work as a Material Specialist in a Swiss company for watch production. I am very much in contact with materials science, especially with powder technology. I hope this experience gives me new knowledge in materials research and process development from the industrial point of view.

Daniel Leidner, Deutsches Zentrum für Luft- und Raumfahrt (DLR)

In a few words: What is your research about?

Evolution has equipped humans with unique mental abilities that allow us to mentally simulate interactions with the environment, execute actions sensitively, and qualitatively assess the effects of those actions on the environment. In my doctoral thesis, I transferred these abilities to the “Rollin’s Justin” humanoid robot. To this end, I combined planning methods from the artificial intelligence (AI) research field with compliant whole-body manipulation approaches from control technology. This allows the service robot to perform a number of everyday tasks, such as cleaning a window.

What were the biggest challenges while you were earning your doctorate?

At the beginning of my doctoral studies, it became clear very quickly that the planning methods I had developed provided the foundation for Justin’s autonomy concept. This made it even more important that the approaches were designed to be as multifaceted and general as possible and made as robust as possible in regard to application errors. This apparent contradiction was further heightened by the decision that the methods in question would form the basic concept for the planned astronaut-robot collaboration aboard the International Space Station (ISS). These stringent requirements ultimately contributed to the first-ever collaboration between a cognitive assistant robot and astronauts in space.

What are your plans for the future?

I want to transfer my knowledge from space to society![DL1]  Experiments with astronauts, some of whom were untrained, have shown that the technology has advanced to the point where we can now confidently tackle several of the great problems of our time. Servicerobotik für Menschen in Lebenssituationen mit Einschränkungen (SMiLE), or service robotics for people living with limitations, is the next logical step in this process. In the current project, and in its follow-on projects, my approaches are to be used to develop assistant robots for those in need of care. To this end, we are embarking on close collaborative efforts with care experts. I hope that these efforts will also ultimately provide support to care workers in the performance of time-consuming tasks so that they can devote more of their energy to the social components of their duties.

Sinikka Lennartz, Geomar Helmholtz-Zentrum für Ozeanforschung Kiel

In a few words: What is your research about?

My research focuses on the interplay between the ocean and the atmosphere. This interplay determines our climate. Gases form in the ocean, produced by microorganisms or sunlight for example, and reach the atmosphere, where they affect the climate. I paid special attention to sulfuric gases, which become aerosols in the atmosphere and reflect sunlight back into space. My work encompasses both the development of measuring systems and measurements at sea, and the development of models that allow better estimation of the ocean’s emissions and their impacts on the environment.

What were the biggest challenges while you were earning your doctorate?

The technical challenge was refining a measurement system in a laboratory on land that was to be used for measurements at sea, since errors at sea can hardly ever be corrected – there is no second chance out there. A great deal of teamwork went into that effort. Coordinating the three measuring devices, some of which I had refined myself, without any assistance and overcoming the odd setback here and there was certainly challenging. Overall, however, the positives are clearly greater, and I would not have wanted to miss out on this special experience.

What are your plans for the future?

In the near future, I will continue to work in the field of climate and ocean research, but my focus will be on studying natural CO2 storage in the ocean. To that end, I will be transferring to a postdoc position at the Institute for Chemistry and Biology of the Marine Environment (ICBM) at the University of Oldenburg. In the long term, I would like to establish my own working group in the field of marine biogeochemistry.