Gradient Photonic Materials Based on One‐Dimensional Polymer Photonic Crystals

In nature, animals such as chameleons are well‐known for the complex color patterns of their skin and the ability to adapt and change the color by manipulating sophisticated photonic crystal systems. Artificial gradient photonic materials are inspired by these color patterns. A concept for the preparation of such materials and their function as tunable mechanochromic materials is presented in this work. The system consists of a 1D polymer photonic crystal on a centimeter scale on top of an elastic poly(dimethylsiloxane) substrate with a gradient in stiffness. In the unstrained state, this system reveals a uniform red reflectance over the entire sample. Upon deformation, a gradient in local strain of the substrate is formed and transferred to the photonic crystal. Depending on the magnitude of this local strain, the thickness of the photonic crystal decreases continuously, resulting in a position‐dependent blue shift of the reflectance peak and hence the color in a rainbow‐like fashion. Using more sophisticated hard‐soft‐hard‐soft‐hard gradient elastomers enables the realization of stripe‐like reflectance patterns. Thus, this approach allows for the tunable formation of reflectance gradients and complex reflectance patterns. Envisioned applications are in the field of mechanochromic sensors, telemedicine, smart materials, and metamaterials

Tailoring the excited-state energy landscape in supramolecular nanostructures

Nature's photosynthetic machinery uses precisely arranged pigment-protein complexes, often representing superstructures, for efficient light-harvesting and transport of excitation energy (excitons) during the initial steps of photosynthesis. This function is achieved by defined electronic Coulomb interactions between the conjugated molecules resulting in tailored excited-state energy landscapes. While such complex natural structures are synthetically difficult to achieve, supramolecular chemistry is now on its advent to realize defined artificial supramolecular nanostructures with tailored functionalities via controlled self-assembly processes of small molecules. In this review, we focus on recent work reporting photophysical studies on self-assembled and hierarchical nanostructures as well as complex superstructures. We discuss how the resulting excited-state energy landscapes influence energy transport. Progress in the field of supramolecular chemistry allows for the realization of distinct kinds of H- or J-aggregates with well-defined morphologies on the mesoscale. Advances in the field of optical spectroscopy and microscopy have permitted to resolve the incoherent/coherent dynamics of exciton transport in such systems down to the level of single nanostructures. Although outstanding diffusion lengths of up to several mu m were found in selected nanostructures, a full understanding of the underlying principles is still missing. In particular, the unavoidable structural and electronic disorder in these systems influences the excited-state energy landscapes and thus the transport characteristics, which can be exploited to refine the molecular design criteria of supramolecular nanostructures and complex superstructures. Despite the rapid progress in the field of functional supramolecular nanostructures, we believe that revealing the full potential of such systems is far from complete. In particular, criteria for tailored and optimized (hierarchical) supramolecular nanostructures in view of applications are not yet established. Finally, we outline current challenges and future perspectives for optical and optoelectronic applications of supramolecular nanostructures

In-situ comparison of the NOy instruments flown in MOZAIC and SPURT

Two aircraft instruments for the measurement of total odd nitrogen (NOy) were compared side by side aboard a Learjet A35 in April 2003 during a campaign of the AFO2000 project SPURT (Spurengastransport in der Tropopausenregion). The instruments albeit employing the same measurement principle (gold converter and chemiluminescence) had different inlet configurations. The ECO-Physics instrument operated by ETH-Zürich in SPURT had the gold converter mounted outside the aircraft, whereas the instrument operated by FZ-Jülich in the European project MOZAIC III (Measurements of ozone, water vapour, carbon monoxide and nitrogen oxides aboard Airbus A340 in-service aircraft) employed a Rosemount probe with 80 cm of FEP-tubing connecting the inlet to the gold converter. The NOy concentrations during the flight ranged between 0.3 and 3 ppb. The two data sets were compared in a blind fashion and each team followed its normal operating procedures. On average, the measurements agreed within 7%, i.e. within the combined uncertainty of the two instruments. This puts an upper limit on potential losses of HNO3 in the Rosemount inlet of the MOZAIC instrument. Larger transient deviations were observed during periods after calibrations and when the aircraft entered the stratosphere. The time lag of the MOZAIC instrument observed in these instances is in accordance with the time constant of the MOZAIC inlet line determined in the laboratory for HNO3

From bench to bedside

The adaptive immune system has been the main focus of immunological strategies in oncology with only more recent approaches targeting innate immunity. Endosomal toll-like receptors (TLR-7, TLR-9) activate innate immune responses by signaling damage-associated molecular patterns (DAMP) from decaying tumor cells. This has led to the development of DNA-based TLR-9 agonists, which induce antitumor activity through innate and subsequent adaptive immune responses. Early clinical trials with CpG-ODN as TLR-9 agonists were associated with unfavorable tolerability and narrow clinical efficacy, leading to failure in pivotal trials. dSLIM®, the active ingredient of MGN1703, is a DNA-based, radically different molecular alternative to CpG-ODN, which results in genuine antitumor immunomodulation. Preclinical and clinical studies of MGN1703 have confirmed that this TLR-9 agonist has therapeutic potential in a variety of solid tumors, while long-term treatment with high doses was very well tolerated. A pivotal trial of first-line maintenance treatment with MGN1703 in patients with metastatic colorectal cancer is underway

Combinatorial Techniques to Efficiently Investigate and Optimize Organic Thin Film Processing and Properties

In this article we present several developed and improved combinatorial techniques to optimize processing conditions and material properties of organic thin films. The combinatorial approach allows investigations of multi-variable dependencies and is the perfect tool to investigate organic thin films regarding their high performance purposes. In this context we develop and establish the reliable preparation of gradients of material composition, temperature, exposure, and immersion time. Furthermore we demonstrate the smart application of combinations of composition and processing gradients to create combinatorial libraries. First a binary combinatorial library is created by applying two gradients perpendicular to each other. A third gradient is carried out in very small areas and arranged matrix-like over the entire binary combinatorial library resulting in a ternary combinatorial library. Ternary combinatorial libraries allow identifying precise trends for the optimization of multi-variable dependent processes which is demonstrated on the lithographic patterning process. Here we verify conclusively the strong interaction and thus the interdependency of variables in the preparation and properties of complex organic thin film systems. The established gradient preparation techniques are not limited to lithographic patterning. It is possible to utilize and transfer the reported combinatorial techniques to other multi-variable dependent processes and to investigate and optimize thin film layers and devices for optical, electro-optical, and electronic applications

Biogeochemical potential of biomass pyrolysis systems for limiting global warming to 1.5 °C

Negative emission (NE) technologies are recognized to play an increasingly relevant role in strategies limiting mean global warming to 1.5 °C as specified in the Paris Agreement. The potentially significant contribution of pyrogenic carbon capture and storage (PyCCS) is, however, highly underrepresented in the discussion. In this study, we conduct the first quantitative assessment of the global potential of PyCCS as a NE technology based on biomass plantations. Using a process-based biosphere model, we calculate the land use change required to reach specific climate mitigation goals while observing biodiversity protection guardrails. We consider NE targets of 100–300 GtC following socioeconomic pathways consistent with a mean global warming of 1.5 °C as well as the option of additional carbon balancing required in case of failure or delay of decarbonization measures. The technological opportunities of PyCCS are represented by three tracks accounting for the sequestration of different pyrolysis products: biochar (as soil amendment), bio-oil (pumped into geological storages) and permanent-pyrogas (capture and storage of CO2 from gas combustion). In addition, we analyse how the gain in land induced by biochar-mediated yield increases on tropical cropland may reduce the pressure on land. Our results show that meeting the 1.5 °C goal through mitigation strategies including large-scale NE with plantation-based PyCCS may require conversion of natural vegetation to biomass plantations in the order of 133–3280 Mha globally, depending on the applied technology and the NE demand. Advancing towards additional bio-oil sequestration reduces land demand considerably by potentially up to 60%, while the benefits from yield increases account for another 3%–38% reduction (equalling 82–362 Mha). However, when mitigation commitments are increased by high balancing claims, even the most advanced PyCCS technologies and biochar-mediated co-benefits cannot compensate for delayed action towards phasing-out fossil fuels.Bundesministerium für Bildung und Forschung 10.13039/501100002347Peer Reviewe