a degradation study of a humanoid skin mask made of soft urethane elastomer

Funding Information: The authors would like to thank Dr. Clarimma Sessa, of the Chair of Conservation-Restoration, Art Technology and Conservation Science at the TUM for her support with SEM-EDX investigations; Prof. Takuya Hashimoto of the Tokyo University of Science for sharing information about the robot SAYA; Dr. Frank Dittmann, Nicolas Lange and Susanne Grießbach, curators and conservator of the Deutsches Museum respectively, for the fruitful discussions on the decision-making-process regarding the preservation of SAYA. Publisher Copyright: © 2022, The Author(s).Understanding the degradation of plastic materials is a big challenge for curators, conservators and conservation scientists in museums worldwide aiming to preserve their collections due to the variety of formulations of synthetic polymers and pigments. The conservation of polyurethane (PUR) based objects is challenging because they can suffer from extensive degradation. Particularly PUR elastomers can degrade shortly after their production, as occurred to the mask of the Japanese robot SAYA, which within 8 years suffered from two large tears, discoloration and stickiness. This research aims at studying the degradation phenomena of the androids’ synthetic skin. Better knowledge of the chemical composition of the mask and the chemical and physical decay will contribute to planning a suitable stabilization treatment. Within a multi-analytical approach, colorimetric and microscopic investigations highlighted discolored areas, which showed further color changes within a five months monitoring campaign, confirming the instability of the material likely due to ongoing degradation. Raman microscopy allowed the identification of Pigment White 6 (titanium dioxide TiO2) in the anatase form, known to promote the photosensitivity of PUR substrates towards ultraviolet (UV) light. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy identified the PUR composition of the mask, the presence of phthalates as plasticizers and suggested the formation of quinone chromophores in the polymer structure as a result of photo-oxidation, possibly responsible for the mask yellowing. Evolved gas analysis-mass spectrometry (EGA-MS) and double-shot-gas chromatography/mass spectrometry (TD/Py–GC/MS) analyses support the characterization of the formulation of the mask as being made of methylene diphenyl diisocyanate (MDI) PUR ether elastomer. Plasticizers in high concentration, mainly diisononyl phthalate (DINP) and bis(2-ethylhexyl)phthalate (DEHP), and the UV stabilizer Tinuvin 328 were also detected. In addition, the presence of styrene-acrylonitrile (SAN) could also contribute to the mask’s chemical instability. More amount of UV stabilizer and phthalates were detected at the surface (contributing to its stickiness) than in the inner core. The degradation of the mask results from the light susceptibility of MDI PUR ether and SAN, as well as the higher photochemical activity of anatase. The mask was transferred on to a mannequin and placed in the storage area to prevent light exposure and photo-oxidation. As loose edges had to be stabilized, tests were conducted and adhesive stripes glued with a PUR dispersion were selected for keeping the head’s shape. The novelty of this study is the implementation of conservation science on the study of androids with PUR elastomeric components in robotic collections, which are becoming increasingly popular in technical museums, however still seldomly studied.publishersversionpublishe

Deciphering the Role of Humoral and Cellular Immune Responses in Different COVID-19 Vaccines - A Comparison of Vaccine Candidate Genes in Roborovski Dwarf Hamsters

With the exception of inactivated vaccines, all SARS-CoV-2 vaccines currently used for clinical application focus on the spike envelope glycoprotein as a virus-specific antigen. Compared to other SARS-CoV-2 genes, mutations in the spike protein gene are more rapidly selected and spread within the population, which carries the risk of impairing the efficacy of spike-based vaccines. It is unclear to what extent the loss of neutralizing antibody epitopes can be compensated by cellular immune responses, and whether the use of other SARS-CoV-2 antigens might cause a more diverse immune response and better long-term protection, particularly in light of the continued evolution towards new SARS-CoV-2 variants. To address this question, we explored immunogenicity and protective effects of adenoviral vectors encoding either the full-length spike protein (S), the nucleocapsid protein (N), the receptor binding domain (RBD) or a hybrid construct of RBD and the membrane protein (M) in a highly susceptible COVID-19 hamster model. All adenoviral vaccines provided life-saving protection against SARS-CoV-2-infection. The most efficient protection was achieved after exposure to full-length spike. However, the nucleocapsid protein, which triggered a robust T-cell response but did not facilitate the formation of neutralizing antibodies, controlled early virus replication efficiently and prevented severe pneumonia. Although the full-length spike protein is an excellent target for vaccines, it does not appear to be the only option for future vaccine design

Killer-like receptors and GPR56 progressive expression defines cytokine production of human CD4+ memory T cells

All memory T cells mount an accelerated response on antigen reencounter, but significant functional heterogeneity is present within the respective memory T-cell subsets as defined by CCR7 and CD45RA expression, thereby warranting further stratification. Here we show that several surface markers, including KLRB1, KLRG1, GPR56, and KLRF1, help define low, high, or exhausted cytokine producers within human peripheral and intrahepatic CD4+ memory T-cell populations. Highest simultaneous production of TNF and IFN-γ is observed in KLRB1+KLRG1+GPR56+ CD4 T cells. By contrast, KLRF1 expression is associated with T-cell exhaustion and reduced TNF/IFN-γ production. Lastly, TCRβ repertoire analysis and in vitro differentiation support a regulated, progressive expression for these markers during CD4+ memory T-cell differentiation. Our results thus help refine the classification of human memory T cells to provide insights on inflammatory disease progression and immunotherapy development

Helping Hinz and Kunz? – Analysing and conserving two robotic prototypes from the Deutsches Museum in Munich

In robotic research and the robots’ pre-production phase, the goal is to develop a functional robotic prototype, at least in the short term. As an initial model for subsequent research or production, mainly built in research facilities, laboratories or workshops, the choice of materials is neither always fully thought through nor designed for long-term preservation. Since the materials used are rarely documented, it is very difficult to obtain information about them via the literature or other written sources. Consequently, the preservation of these prototypes and their technology is linked to mostly unknown materials, and is a challenge for collections and museums like the Deutsches Museum in Munich. An example of such a challenge is represented by the two robots ‘Hinz’ and ‘Kunz’ from 1963. Being the first cybernetic models in Europe, they were built to demonstrate learning processes in the human brain. The two prototypes mainly consist of metals and plastics, some of which show severe signs of degradation varying from embrittlement, yellowing and cracks to the migration of crystals. To investigate the material composition, the synthetic polymers were closely examined and analysed using Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR). Based on the information about the material, tailored measures were taken to improve preservation of the robots, using a combination of conservation treatments and custom-made storage and mounting solutions. This case study demonstrates how complex objects like prototypes have special requirements and that they need to be researched to make sure they survive for future generations

(A) IL-17 production (white bars, left Y-axis) and CD44 expression (grey bars, right Y-axis) of naïve-sorted CD4+ T cells before, one, two, three and four days after allogeneic stimulation with BMDCs (n = 4, ± SEM).

<p>(B) IFN-γ production (white bars, left Y-axis) and CD44 expression (grey bars, right Y-axis) of naïve-sorted CD4^<b>+</b> T cells before, one, two, three and four days after allogeneic stimulation with BMDCs (n = 4, ± SEM). (C) Magnetically sorted CD4^<b>+</b> T cells were stimulated four days with allogeneic BMDCs. Co-cultures were left untreated or were treated with 10 μg/ml αCD44 directly before PMA/ionomycin restimulation (n = 5, <i>M</i> ± SEM, Wilcoxon rank sum test, <i>p</i> = 0.06).</p

Differences in the CD44 expression level is strengthened by polarization.

<p>(A) Representative dot plot of IL-17 and IFN-γ production by CD4^<b>+</b> T cells in non-polarized, Th1- and Th17-polarized allogeneic co-cultures for either total CD4^<b>+</b> T cells or for naïve-sorted (CD45RB^<b>high</b>) CD4^<b>+</b> T cells. Percentage of cells is indicated in the plot. Analysis was performed on day four after co-culture. (B) Representative dot plot of the CD44 surface level expression of CD4^<b>+</b> T cells in non-polarized, Th1- and Th17-polarized allogeneic co-cultures for either total CD4^<b>+</b> T cells or for naïve-sorted (CD45RB^<b>high</b>) CD4^<b>+</b> T cells. Percentage of cells within different subpopulations is indicated in the plot. Analysis of total CD4^<b>+</b> T cells was performed on day four and of naïve-sorted on day three after co-culture. (C) Percentage of CD44^<b>+++</b>CD4^<b>+</b> T cells (total CD4^<b>+</b> T cells) under different polarization conditions (n = 6–9, <i>M</i> ± SEM, Kruskal-Wallis test and <i>post-hoc</i> Dunn’s comparison, not significant). (D) Histogram overlay of geometric mean fluorescence intensity (gMFI) for CD44 of IFN-γ producers of Th1-polarized co-cultures (grey) and IL-17 producers of Th17-polarized co-cultures (black line). (E and F) GMFI for IFN-γ and IL-17 producers of different generations is shown as histogram overlay (E) and bar chart (F; n = 6, <i>M</i> ± SEM; 2-way ANOVA and <i>post-hoc</i> Sidak`s multiple comparison, **<i>p</i> ≤ 0.01, ***<i>p</i> ≤ 0.001).</p

CD44 expression level discriminates allo-reactive IL-17⁺ and IFN-γ⁺ CD4⁺ T cells.

<p>(A) Cytokine production in CD4^<b>+</b> T cells four days after allogeneic co-culture with bone-marrow derived dendritic cells. Percentage of cells is indicated in the dot plot. (B) CD44 subpopulations of CD4^<b>+</b> T cells and cytokine production within these subpopulations four days after allogeneic co-culture. (C) CD44 expression level of <i>in vitro</i> generated IFN-γ^<b>+</b>CD4^<b>+</b> (grey) and CD4^<b>+</b>IL17^<b>+</b> T cells (black line). Values for the geometric mean fluorescence intensity (gMFI) for CD44 are indicated in the histogram. (D) CD44 expression level (gMFI) of <i>in vitro</i> generated IL-17^<b>+</b>CD4^<b>+</b> and IFN-γ^<b>+</b>CD4^<b>+</b> T cells (n = 13, <i>M</i> ± SEM, Wilcoxon rank sum test). (E) IL-17 and IFN-γ production prior to as well as seven, 14 and 28 days after allogeneic skin transplantation (n = 3–4, <i>M</i> ± SEM, 2-way ANOVA and <i>post-hoc</i> Sidak`s multiple comparison). (F) CD44 expression level of <i>in vivo</i> formed IFN-γ^<b>+</b>CD4^<b>+</b> (grey) and CD4^<b>+</b>IL17^<b>+</b> T cells (black line) from lymph nodes after transplantation (skin-tx) and without transplantation (w/o). GMFI for CD44 is indicated in the histograms. (G) CD44 expression level (gMFI) of <i>in vivo</i> formed IL-17^<b>+</b>CD4^<b>+</b> and IFN-γ^<b>+</b>CD4^<b>+</b> T cells from spleen prior to as well as seven, 14 and 28 days after transplantation (n = 3–4, <i>M</i> ± SEM, 2-way ANOVA and <i>post-hoc</i> Sidak’s multiple comparison. (H) CD44 expression level (gMFI) of <i>in vivo</i> formed IL-17^<b>+</b>CD4^<b>+</b> and IFN-γ^<b>+</b>CD4^<b>+</b> T cells from lymph nodes after transplantation (n = 3–4 <i>M</i> ± SEM, 2-way ANOVA and <i>post-hoc</i> Sidak’s multiple comparison). Statistical significance (<i>p</i>) is within the groups is indicated in the figures (*<i>p</i> ≤ 0.05, **<i>p</i> ≤ 0.01, ***<i>p</i> ≤ 0.001).</p

CD44⁺⁺⁺CD4⁺ T cells have a high cellular activation status.

<p>(A) CD45RB expression level of <i>in vitro</i> generated IFN-γ^<b>+</b>CD4^<b>+</b> (grey) and CD4^<b>+</b>IL-17^<b>+</b> (black line) T cells. GMFI for CD45RB is indicated. (B) CD45RB geometric mean fluorescence intensity (gMFI) of IL-17^<b>+</b>CD4^<b>+</b> and IFN-γ^<b>+</b>CD4^<b>+</b> T cells (n = 5, <i>M</i> ± SEM, Wilcoxon rank sum test, <i>p</i> = 0.06). (C and D) Representative histogram (C) and summary (D) of the ZAP-70 phosphorylation for CD4^<b>+</b>CD44^<b>+</b> (grey solid), CD44^<b>++</b> (grey dotted) and CD44^<b>+++</b> (black line) T cell populations. After four days of allogeneic co-culture cells have been rested for one day. Values for the gMFI of phospho-ZAP-70 are indicated. (E) GMFI of phospho-ZAP-70 of CD4^<b>+</b>CD44^<b>+</b> (grey solid), CD44^<b>++</b> (grey dotted) and CD44^<b>+++</b> T cells (black line) with or without (w/o) αCD44 treatment. A representative histogram overlay out of four independent experiments is shown.</p

Low TCR and CD28 stimulation supports T_H17 development.

<p>(A) IL-17 and IFN-γ production of CD4^<b>+</b> T cells stimulated with different amounts of αCD3. Percentage of positive cells is indicated in the dot plot. (B) Depicted is the IL-17 and IFN-γ production of CD4^<b>+</b> T cells stimulated with 0.01 or 1 μg/ml αCD3 (n = 6, <i>M</i> ± SEM, Wilcoxon rank sum test, between IL-17^<b>+</b>CD4^<b>+</b> cells: not significant, between IFN-γ^<b>+</b>CD4^<b>+</b> cells: <i>p</i> = 0.06). (C) Ratio of αCD44-treated and untreated IL-17^<b>+</b>CD4^<b>+</b> or IFN-γ^<b>+</b>CD4^<b>+</b> T cells stimulated with 0.01 or 1 μg/ml αCD3 (n = 3, <i>M</i> ± SEM, paired t test, between IL-17^<b>+</b>CD4^<b>+</b> cells: *<i>p</i> ≤ 0.05, between IFN-γ^<b>+</b>CD4^<b>+</b> cells: not significant). (D and E) Magnetically sorted CD4^<b>+</b> T cells were stimulated four days with allogeneic BMDCs. Co-cultures were left untreated or 1 μg/ml CTLA-4-Ig was added. Percentage of IL-17^<b>+</b>CD4^<b>+</b> T cells of differently treated co-cultures is shown as a representative dot plot (D) and in a bar chart (E: n = 7, <i>M</i> ± SEM; Wilcoxon rank sum test, *<i>p</i> ≤ 0.05). (F) Magnetically sorted CD4^<b>+</b> T cells were stimulated four days with allogeneic BMDCs. Co-cultures were left untreated or were treated with 1 μg/ml CTLA-4-Ig or 10 μg/ml αCD44 or both. IL-17 and IFN-γ production of CD4^<b>+</b> T cells of the differently treated co-cultures is shown as a representative dot plot out of two independent experiments.</p