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Near-Quantitative, Catalyst-Free Depolymerization of RAFT Polymethacrylates: Polymer and Colloid Highlights
No full textTailoring Fibre Structure Enabled by X-ray Analytics for Targeted Biomedical Applications
Get PDFThe rising interest in designing fibres via spinning techniques combining the properties of various polymeric materials into advanced functionalised materials is directed towards targeted biomedical applications such as drug delivery, wearable sensors or tissue engineering. Understanding how these functional polymers exhibit multiscale structures ranging from the molecular level to nano-, micro-and millimetre scale is a key prerequisite for their challenging applications that can be addressed by a non-destructive X-ray based analytical approach. X-ray multimodalities combining X-ray imaging, scattering and diffraction allow the study of morphology, molecular structure, and the analysis of nano-domain size and shape, crystallinity and preferential orientation in 3D arrangements. The incorporation of X-ray analytics in the design process of polymeric fibers via their nanostructure under non-ambient conditions (i.e. temperature, mechanical load, humidity…) allows for efficient optimization of the fabrication process as well as quality control along the product lifetime under operating environmental conditions. Here, we demonstrate the successful collaboration between the laboratory of Biomimetic Textiles and Membranes and the Center of X-ray Analytics at Empa for the design, characterisation and optimisation of advanced functionalised polymeric fibrous material systems
Replica-Exchange Enveloping Distribution Sampling: Calculation of Relative Free Energies in GROMOS
Get PDFMolecular dynamics (MD) simulations have become an important tool to investigate biological systems. Free-energy calculations based on MD are playing an increasingly important role for computer-aided drug design and material discovery in recent years. Free-energy differences between pairs of end-states can be estimated using well-established methods such as thermodynamic integration (TI) or Bennett’s acceptance ratio (BAR). An attractive alternative is the recently developed replica-exchange enveloping distribution sampling (RE-EDS) method, which enables estimating relative free-energy differences between multiple molecules from a single simulation. Here, we provide an introduction to the principles underlying RE-EDS and give an overview of the RE-EDS pipeline. In addition, we provide a description of the two complementary tools RestraintMaker and amber2gromos. We briefly discuss the findings of three recent applications of RE-EDS to calculate relative binding or hydration free energies. In all three studies, good agreement was found between the results obtained using RE-EDS and experimental values as well as values obtained using other free-energy methods
Unraveling Atomic and Electronic Surface Structure and Dynamics from Angular Photoelectron Distributions
Get PDFAngle-resolved photoelectron spectroscopy (ARPES) is a powerful tool in solid state sciences. Beside the direct measurement of the energy-momentum dispersion relation, the angular distribution of the photoelectron current reveals the structural environment of the emitting atoms via photoelectron diffraction effects. Moreover, in the case of molecular layers, the angular distribution of emission from molecular orbitals can be directly related to their charge density distribution via so-called orbital tomography. In the present paper we summarize our efforts undertaken over the past 12 years to add the dimension of time to these two methods via pump-probe experiments with femtosecond resolution. We give a comprehensive introduction to standard ARPES and time-resolved two photon photoemission and then focus on our efforts towards time-resolved versions of photoelectron diffraction and orbital tomography. Both, optimization of experimental parameters and data acquisition procedures, as well as new numerical tools are needed in order to realize such challenging full stop missing after experiments
The Discovery of Bicyclopyrone
Get PDFTwo short topics were presented in the lecture titled Some Highlights of an Agro Career presented at the Fall Meeting Swiss Chemical Society, September 10th, 2021. The first of these topics discussed the discovery of the selective corn herbicide Bicyclopyrone. The second topic presented was concerned with host marking pheromones (HMPs), and described the HMP of the Mexican fruit fly anastrepha ludens, and its use in crop protection. The story concerning the host marking pheromones of the Mexican fruit fly has already been published in this journal[1] and thus this review will describe the discovery of Bicyclopyrone
\u27Lessons in Chemistry\u27: The (Un)balanced Chemical Equation of (In)equality : Chemical Education
No full textA literary success in 2022, the novel \u27Lessons in chemistry\u27 describes the struggle for recognition and independence of a female research chemist in the conservative USA of the 1950’s
Swiss Biotech Day, May 2022. Sustainability Across the Pharmaceutical Value Chain - How Switzerland Could Take a Leading Role in Promoting a Greener Approach: Conference Report
No full textThe sustainability of the pharmaceutical industry has aroused interest from various sectors and disciplines, including chemistry, biology and engineering. Given the Swiss drug sector’s innovative engine and enormous economic importance, a Swiss Biotech Day panel discussion was held in May 2022 in Basel to address the question of how “sustainability across the pharmaceutical value chain” can be edged forward in Switzerland. Roche, Lonza, Pheida, ETH, the Swiss Academy of Engineering Sciences (SATW), and a newly established collaborative, Circular Carbon for Chemistry (ccLoop) joined forces and agreed that sustainability must become a key strategic goal for the industry in Switzerland. The panel looked at the sustainability challenge, at how a green transition can be achieved faster, and at how industrial biotechnology applications can improve industry’s performance, energy efficiency and product value while yielding viable sustainable solutions to protect our environment. Switzerland is a leader in drug development and manufacturing. By placing greater energy and resources on the sustainability equation, we ensure continued leadership and a greener world. ‘Swissness’ will increasingly have to denote effective drugs produced sustainably
