TY - JOUR AB - We derive a weak-strong uniqueness principle for BV solutions to multiphase mean curvature flow of triple line clusters in three dimensions. Our proof is based on the explicit construction of a gradient flow calibration in the sense of the recent work of Fischer et al. (2020) for any such cluster. This extends the two-dimensional construction to the three-dimensional case of surfaces meeting along triple junctions. AU - Hensel, Sebastian AU - Laux, Tim ID - 13043 IS - 1 JF - Interfaces and Free Boundaries SN - 1463-9963 TI - Weak-strong uniqueness for the mean curvature flow of double bubbles VL - 25 ER - TY - JOUR AB - The chemical potential of adsorbed or confined fluids provides insight into their unique thermodynamic properties and determines adsorption isotherms. However, it is often difficult to compute this quantity from atomistic simulations using existing statistical mechanical methods. We introduce a computational framework that utilizes static structure factors, thermodynamic integration, and free energy perturbation for calculating the absolute chemical potential of fluids. For demonstration, we apply the method to compute the adsorption isotherms of carbon dioxide in a metal-organic framework and water in carbon nanotubes. AU - Schmid, Rochus AU - Cheng, Bingqing ID - 12912 IS - 16 JF - The Journal of Chemical Physics TI - Computing chemical potentials of adsorbed or confined fluids VL - 158 ER - TY - JOUR AB - Embroidery is a long-standing and high-quality approach to making logos and images on textiles. Nowadays, it can also be performed via automated machines that weave threads with high spatial accuracy. A characteristic feature of the appearance of the threads is a high degree of anisotropy. The anisotropic behavior is caused by depositing thin but long strings of thread. As a result, the stitched patterns convey both color and direction. Artists leverage this anisotropic behavior to enhance pure color images with textures, illusions of motion, or depth cues. However, designing colorful embroidery patterns with prescribed directionality is a challenging task, one usually requiring an expert designer. In this work, we propose an interactive algorithm that generates machine-fabricable embroidery patterns from multi-chromatic images equipped with user-specified directionality fields.We cast the problem of finding a stitching pattern into vector theory. To find a suitable stitching pattern, we extract sources and sinks from the divergence field of the vector field extracted from the input and use them to trace streamlines. We further optimize the streamlines to guarantee a smooth and connected stitching pattern. The generated patterns approximate the color distribution constrained by the directionality field. To allow for further artistic control, the trade-off between color match and directionality match can be interactively explored via an intuitive slider. We showcase our approach by fabricating several embroidery paths. AU - Liu, Zhenyuan AU - Piovarci, Michael AU - Hafner, Christian AU - Charrondiere, Raphael AU - Bickel, Bernd ID - 12972 IS - 2 JF - Computer Graphics Forum KW - embroidery KW - design KW - directionality KW - density KW - image SN - 1467-8659 TI - Directionality-aware design of embroidery patterns VL - 42 ER - TY - JOUR AB - Current methods for assessing cell proliferation in 3D scaffolds rely on changes in metabolic activity or total DNA, however, direct quantification of cell number in 3D scaffolds remains a challenge. To address this issue, we developed an unbiased stereology approach that uses systematic-random sampling and thin focal-plane optical sectioning of the scaffolds followed by estimation of total cell number (StereoCount). This approach was validated against an indirect method for measuring the total DNA (DNA content); and the Bürker counting chamber, the current reference method for quantifying cell number. We assessed the total cell number for cell seeding density (cells per unit volume) across four values and compared the methods in terms of accuracy, ease-of-use and time demands. The accuracy of StereoCount markedly outperformed the DNA content for cases with ~ 10,000 and ~ 125,000 cells/scaffold. For cases with ~ 250,000 and ~ 375,000 cells/scaffold both StereoCount and DNA content showed lower accuracy than the Bürker but did not differ from each other. In terms of ease-of-use, there was a strong advantage for the StereoCount due to output in terms of absolute cell numbers along with the possibility for an overview of cell distribution and future use of automation for high throughput analysis. Taking together, the StereoCount method is an efficient approach for direct cell quantification in 3D collagen scaffolds. Its major benefit is that automated StereoCount could accelerate research using 3D scaffolds focused on drug discovery for a wide variety of human diseases. AU - Zavadakova, Anna AU - Vistejnova, Lucie AU - Belinova, Tereza AU - Tichanek, Filip AU - Bilikova, Dagmar AU - Mouton, Peter R. ID - 13033 IS - 1 JF - Scientific Reports KW - Multidisciplinary SN - 2045-2322 TI - Novel stereological method for estimation of cell counts in 3D collagen scaffolds VL - 13 ER - TY - JOUR AB - Disulfide bond formation is fundamentally important for protein structure and constitutes a key mechanism by which cells regulate the intracellular oxidation state. Peroxiredoxins (PRDXs) eliminate reactive oxygen species such as hydrogen peroxide through a catalytic cycle of Cys oxidation and reduction. Additionally, upon Cys oxidation PRDXs undergo extensive conformational rearrangements that may underlie their presently structurally poorly defined functions as molecular chaperones. Rearrangements include high molecular-weight oligomerization, the dynamics of which are, however, poorly understood, as is the impact of disulfide bond formation on these properties. Here we show that formation of disulfide bonds along the catalytic cycle induces extensive μs time scale dynamics, as monitored by magic-angle spinning NMR of the 216 kDa-large Tsa1 decameric assembly and solution-NMR of a designed dimeric mutant. We ascribe the conformational dynamics to structural frustration, resulting from conflicts between the disulfide-constrained reduction of mobility and the desire to fulfill other favorable contacts. AU - Troussicot, Laura AU - Vallet, Alicia AU - Molin, Mikael AU - Burmann, Björn M. AU - Schanda, Paul ID - 13095 IS - 19 JF - Journal of the American Chemical Society SN - 0002-7863 TI - Disulfide-bond-induced structural frustration and dynamic disorder in a peroxiredoxin from MAS NMR VL - 145 ER - TY - JOUR AB - Let Lc,n denote the size of the longest cycle in G(n, c/n),c >1 constant. We show that there exists a continuous function f(c) such that Lc,n/n→f(c) a.s. for c>20, thus extending a result of Frieze and the author to smaller values of c. Thereafter, for c>20, we determine the limit of the probability that G(n, c/n)contains cycles of every length between the length of its shortest and its longest cycles as n→∞. AU - Anastos, Michael ID - 13042 IS - 2 JF - Electronic Journal of Combinatorics TI - A note on long cycles in sparse random graphs VL - 30 ER - TY - DATA AB - Disulfide bond formation is fundamentally important for protein structure, and constitutes a key mechanism by which cells regulate the intracellular oxidation state. Peroxiredoxins (PRDXs) eliminate reactive oxygen species such as hydrogen peroxide through a catalytic cycle of Cys oxidation and reduction. Additionally, upon Cys oxidation PRDXs undergo extensive conformational rearrangements that may underlie their presently structurally poorly defined functions as molecular chaperones. Rearrangements include high molecular-weight oligomerization, the dynamics of which are, however, poorly understood, as is the impact of disulfide bond formation on these properties. Here we show that formation of disulfide bonds along the catalytic cycle induces extensive microsecond time scale dynamics, as monitored by magic-angle spinning NMR of the 216 kDa-large Tsa1 decameric assembly and solution-NMR of a designed dimeric mutant. We ascribe the conformational dynamics to structural frustration, resulting from conflicts between the disulfide-constrained reduction of mobility and the desire to fulfil other favorable contacts. This data repository contains NMR data presented in the associated manuscript AU - Schanda, Paul ID - 12820 TI - Research data of the publication "Disulfide-bond-induced structural frustration and dynamic disorder in a peroxiredoxin from MAS NMR" ER - TY - JOUR AB - We calculate reflectivities of dynamically compressed water, water-ethanol mixtures, and ammonia at infrared and optical wavelengths with density functional theory and molecular dynamics simulations. The influence of the exchange-correlation functional on the results is examined in detail. Our findings indicate that the consistent use of the HSE hybrid functional reproduces experimental results much better than the commonly used PBE functional. The HSE functional offers not only a more accurate description of the electronic band gap but also shifts the onset of molecular dissociation in the molecular dynamics simulations to significantly higher pressures. We also highlight the importance of using accurate reference standards in reflectivity experiments and reanalyze infrared and optical reflectivity data from recent experiments. Thus, our combined theoretical and experimental work explains and resolves lingering discrepancies between calculations and measurements for the investigated molecular substances under shock compression. AU - French, Martin AU - Bethkenhagen, Mandy AU - Ravasio, Alessandra AU - Hernandez, Jean Alexis ID - 13039 IS - 13 JF - Physical Review B SN - 2469-9950 TI - Ab initio calculation of the reflectivity of molecular fluids under shock compression VL - 107 ER - TY - JOUR AB - There is a need for the development of lead-free thermoelectric materials for medium-/high-temperature applications. Here, we report a thiol-free tin telluride (SnTe) precursor that can be thermally decomposed to produce SnTe crystals with sizes ranging from tens to several hundreds of nanometers. We further engineer SnTe–Cu2SnTe3 nanocomposites with a homogeneous phase distribution by decomposing the liquid SnTe precursor containing a dispersion of Cu1.5Te colloidal nanoparticles. The presence of Cu within the SnTe and the segregated semimetallic Cu2SnTe3 phase effectively improves the electrical conductivity of SnTe while simultaneously reducing the lattice thermal conductivity without compromising the Seebeck coefficient. Overall, power factors up to 3.63 mW m–1 K–2 and thermoelectric figures of merit up to 1.04 are obtained at 823 K, which represent a 167% enhancement compared with pristine SnTe. AU - Nan, Bingfei AU - Song, Xuan AU - Chang, Cheng AU - Xiao, Ke AU - Zhang, Yu AU - Yang, Linlin AU - Horta, Sharona AU - Li, Junshan AU - Lim, Khak Ho AU - Ibáñez, Maria AU - Cabot, Andreu ID - 13092 IS - 19 JF - ACS Applied Materials and Interfaces SN - 1944-8244 TI - Bottom-up synthesis of SnTe-based thermoelectric composites VL - 15 ER - TY - JOUR AB - Endocytosis is a key cellular process involved in the uptake of nutrients, pathogens, or the therapy of diseases. Most studies have focused on spherical objects, whereas biologically relevant shapes can be highly anisotropic. In this letter, we use an experimental model system based on Giant Unilamellar Vesicles (GUVs) and dumbbell-shaped colloidal particles to mimic and investigate the first stage of the passive endocytic process: engulfment of an anisotropic object by the membrane. Our model has specific ligand–receptor interactions realized by mobile receptors on the vesicles and immobile ligands on the particles. Through a series of experiments, theory, and molecular dynamics simulations, we quantify the wrapping process of anisotropic dumbbells by GUVs and identify distinct stages of the wrapping pathway. We find that the strong curvature variation in the neck of the dumbbell as well as membrane tension are crucial in determining both the speed of wrapping and the final states. AU - Azadbakht, Ali AU - Meadowcroft, Billie AU - Varkevisser, Thijs AU - Šarić, Anđela AU - Kraft, Daniela J. ID - 13094 IS - 10 JF - Nano Letters SN - 1530-6984 TI - Wrapping pathways of anisotropic dumbbell particles by Giant Unilamellar Vesicles VL - 23 ER -