Simple Sol-Gel Protein Stabilization toward Rainbow and White Lighting Devices

Fluorescent proteins (FPs) are heralded as a paradigm of sustainable materials for photonics/optoelectronics. However, their stabilization under non-physiological environments and/or harsh operation conditions is the major challenge. Among the FP-stabilization methods, classical sol-gel is the most effective, but less versatile, as most of the proteins/enzymes are easily degraded due to the need of multi-step processes, surfactants, and mixed water/organic solvents in extreme pH. Herein, sol-gel chemistry with archetypal FPs (mGreenLantern; mCherry) is revisited, simplifying the method by one-pot, surfactant-free, and aqueous media (phosphate buffer saline pH = 7.4). The synthesis mechanism involves the direct reaction of the carboxylic groups at the FP surface with the silica precursor, generating a positively charged FP intermediate that acts as a seed for the formation of size-controlled mesoporous FP@SiO2 nanoparticles. Green-/red-emissive (single-FP component) and dual-emissive (multi-FPs component; kinetic studies not required) FP@SiO2 are prepared without affecting the FP photoluminescence and stabilities (>6 months) under dry storage and organic solvent suspensions. Finally, FP@SiO2 color filters are applied to rainbow and white bio-hybrid light-emitting diodes featuring up to 15-fold enhanced stabilities without reducing luminous efficacy compared to references with native FPs. Overall, an easy, versatile, and effective FP-stabilization method is demonstrated in FP@SiO2 toward sustainable protein lighting.

Influence of microbial biomass content on biodegradation and mechanical properties of poly(3-hydroxybutyrate) composites

Biodegradation rates and mechanical properties of poly(3-hydroxybutyrate) (PHB) composites with green algae and cyanobacteria were investigated for the first time. To the authors knowledge, the addition of microbial biomass led to the biggest observed effect on biodegradation so far. The composites with microbial biomass showed an acceleration of the biodegradation rate and a higher cumulative biodegradation within 132 days compared to PHB or the biomass alone. In order to determine the causes for the faster biodegradation, the molecular weight, the crystallinity, the water uptake, the microbial biomass composition and scanning electron microscope images were assessed. The molecular weight of the PHB in the composites was lower than that of pure PHB while the crystallinity and microbial biomass composition were the same for all samples. A direct correlation of water uptake and crystallinity with biodegradation rate could not be observed. While the degradation of molecular weight of PHB during sample preparation contributed to the improvement of biodegradation, the main reason was attributed to biostimulation by the added biomass. The resulting enhancement of the biodegradation rate appears to be unique in the field of polymer biodegradation. The tensile strength was lowered, elongation at break remained constant and Young's modulus was increased compared to pure PHB.

Photocrosslinkable Cellulose Derivatives for the Manufacturing of All-Cellulose-Based Architectures

Replacing petroleum-based polymers with biopolymers such as polysaccharides is essential for protecting our environment by saving fossil resources. A research field that can benefit from the application of more sustainable and renewable materials is photochemistry. Therefore, cellulose-based photoresists that could be photocrosslinked via UV irradiation (λ = 254 nm and λ = 365 nm) were developed. These biogenic polymers enable the manufacturing of sustainable coatings, even with imprinted microstructures, and cellulose-based bulk materials. Thus, herein, cellulose was functionalized with organic compounds containing carbon double bonds to introduce photocrosslinkable side groups directly onto the cellulose backbone. Therefore, unsaturated anhydrides such as methacrylic acid anhydride and unsaturated and polyunsaturated carboxylic acids such as linoleic acid were utilized. Additionally, these cellulose derivatives were modified with acetate or tosylate groups to generate cellulose-based polymers, which are soluble in organic solvents, making them suitable for multiple processing methods, such as casting, printing and coating. The photocurable resist was basically composed of the UV-crosslinkable biopolymer, an appropriate solvent and, if necessary, a photoinitiator. Moreover, these bio-based photoresists were UV-crosslinkable in the liquid and solid states after the removal of the solvent. Further, the manufactured cellulose-based architectures, even the bulk structures, could be entirely regenerated into pure cellulose devices via a sodium methoxide treatment.

Biocompatible coatings based on photo-crosslinkable cellulose derivatives

Materials derived from renewable resources have great potential to replace fossil-based plastics in biomedical applications. In this study, the synthesis of cellulose-based photoresists by esterification with methacrylic acid anhydride and sorbic acid was investigated. These resists polymerize under UV irradiation in the range of λ = 254 nm to 365 nm, with or, in the case of the sorbic acid derivative, without using an additional photoinitiator. Usability for biomedical applications was demonstrated by investigating the adhesion and viability of a fibrosarcoma cell line (HT-1080). Compared to polystyrene, the material widely used for cell culture dishes, cell adhesion to the biomaterials tested was even stronger, as assessed by a centrifugation assay. Remarkably, chemical surface modifications of cellulose acetate with methacrylate and sorbic acid allow direct attachment of HT-1080 cells without adding protein modifiers or ligands. Furthermore, cells on both biomaterials show similar cell viability, not significantly different from polystyrene, indicating no significant impairment or enhancement, allowing the use of these cellulose derivatives as support structures for scaffolds or as a self-supporting coating for cell culture solely based on renewable resources.

Analysis of cellulose synthesis in a high-producing acetic acid bacterium Komagataeibacter hansenii

Bacterial cellulose (BC) represents a renewable biomaterial with unique properties promising for biotechnology and biomedicine. Komagataeibacter hansenii ATCC 53,582 is a well-characterized high-yield producer of BC used in the industry. Its genome encodes three distinct cellulose synthases (CS), bcsAB1, bcsAB2, and bcsAB3, which together with genes for accessory proteins are organized in operons of different complexity. The genetic foundation of its high cellulose-producing phenotype was investigated by constructing chromosomal in-frame deletions of the CSs and of two predicted regulatory diguanylate cyclases (DGC), dgcA and dgcB. Proteomic characterization suggested that BcsAB1 was the decisive CS because of its high expression and its exclusive contribution to the formation of microcrystalline cellulose. BcsAB2 showed a lower expression level but contributes significantly to the tensile strength of BC and alters fiber diameter significantly as judged by scanning electron microscopy. Nevertheless, no distinct extracellular polymeric substance (EPS) from this operon was identified after static cultivation. Although transcription of bcsAB3 was observed, expression of the protein was below the detection limit of proteome analysis. Alike BcsAB2, deletion of BcsAB3 resulted in a visible reduction of the cellulose fiber diameter. The high abundance of BcsD and the accessory proteins CmcAx, CcpAx, and BglxA emphasizes their importance for the proper formation of the cellulosic network. Characterization of deletion mutants lacking the DGC genes dgcA and dgcB suggests a new regulatory mechanism of cellulose synthesis and cell motility in K. hansenii ATCC 53,582. Our findings form the basis for rational tailoring of the characteristics of BC. KEY POINTS: • BcsAB1 induces formation of microcrystalline cellulose fibers. • Modifications by BcsAB2 and BcsAB3 alter diameter of cellulose fibers. • Complex regulatory network of DGCs on cellulose pellicle formation and motility.

Synthesis and Characterization of Functional Cellulose-Ether-Based PCL- and PLA-Grafts-Copolymers

The use of biodegradable materials such as cellulose and polyesters can be extended through the combination, as well as modification, of these biopolymers. By controlling the molecular structure and composition of copolymers of these components, it should also be possible to tailor their material properties. We hereby report on the synthesis and characterization of cellulose-based graft copolymers with a precise molecular composition and copolymer architecture. To prepare such materials, we initially modified cellulose through the regioselective protection of the 6-OH group using trityl chloride. The 6-O protected compound was then alkylated, and deprotection at the 6-OH group provided the desired 2,3-di-O-alkyl cellulose compounds that were used as macroinitiators for ring opening polymerization. Regioselective modification was hereby necessary to obtain compounds with an exact molecular composition. Ring opening polymerization, catalyzed by Sn(Oct)₂, at the primary 6-OH group of the cellulose macroinitiator, using L-lactide or ε-caprolactone, resulted in graft copolymers with the desired functionalization pattern. The materials were characterized using Fourier-transform infrared spectroscopy, ¹H- and ¹³C- nuclear magnetic resonance spectroscopy, size exclusion chromatography as well as X-ray diffraction, and differential scanning calorimetry. PCL-based copolymers exhibited distinct melting point as well as a crystalline phase of up to 47%, while copolymers with PLA segments were highly amorphous, showing a broad amorphous reflex in the XRD spectra, and no melting or crystallization points were discernible using differential scanning calorimetry.

Biorenewable Polyelectrolyte Nanocoating for Flame-Retardant Cotton-Based Paper

Cotton-based raw paper, made of 100% cellulose, is used to make humidity-sensing, cottonid for bio-architecture applications. Despite its renewability and excellent mechanical properties, it is inherently flammable. In an effort to reduce its flammability, thin films of fully renewable and environmentally benign polyelectrolytes, chitosan (CH) and phytic acid (PA), were deposited on raw paper via layer-by-layer (LbL) assembly. Only four bilayers (BL) of the CH/PA coating are required to achieve self-extinguishing behavior, with a 69% reduction in peak heat release rate measured by microscale combustion calorimetry. These results demonstrate that this renewable intumescent LbL-assembled film provides an effective flame-retardant treatment for these environmentally friendly, climate-adaptive construction materials and could potentially be used to protect many cellulosic materials.

Fabrication of Cellulose-Based Biopolymer Optical Fibers and Their Theoretical Attenuation Limit

Currently, almost all polymer optical materials are derived from fossil resources with known consequences for the environment. In this work, a processing route to obtain cellulose-based biopolymer optical fibers is presented. For this purpose, the optical properties such as the transmission and the refractive index dispersion of regenerated cellulose, cellulose diacetate, cellulose acetate propionate, and cellulose acetate butyrate were determined from planar films. Cellulose fibers were produced using a simple wet-spinning setup. They were examined pure and also coated with the cellulose derivatives to obtain core-cladding-structured optical fibers. The cellulose-based optical fibers exhibit minimum attenuations between 56 and 82 dB m^-1 at around 860 nm. The ultimate transmission loss limit of the cellulose-based optical fibers was simulated to characterize the attenuation progression. By reducing extrinsic losses, cellulose-based biopolymer optical fibers could attain theoretical attenuation minima of 84.6 × 10^-3 dB m^-1 (507 nm), 320 × 10^-3 dB m^-1 (674 nm), and 745.2 × 10^-3 dB m^-1 (837 nm) and might substitute fossil-based polymer optical fibers in the future.

Determining paracrystallinity in mixed-tacticity polyhydroxybutyrates

A method to robustly determine paracrystalline contents from Rietveld-refined powder X-ray data is presented and discussed for the example of mixed-tacticity polyhydroxybutyrates.

Recently, the authors reported on the development of crystallinity in mixed-tacticity polyhydroxybutyrates. Comparable values reported in the literature vary depending on the manner of determination, the discrepancies being partially attributable to scattering from paracrystalline portions of the material. These portions can be qualified by peak profile fitting or quantified by allocation of scattered X-ray intensities. However, the latter requires a good quality of the former, which in turn must additionally account for peak broadening inherent in the measurement setup, and due to limited crystallite sizes and the possible presence of microstrain. Since broadening due to microstrain and paracrystalline order both scale with scattering vector, they are easily confounded. In this work, a method to directionally discern these two influences on the peak shape in a Rietveld refinement is presented. Allocating intensities to amorphous, bulk and paracrystalline portions with changing tactic disturbance provided internal validations of the obtained directional numbers. In addition, the correlation between obtained thermal factors and Young’s moduli, determined in earlier work, is discussed.

Biomimetics: teaching the tools of the trade

Biomimetics is a known innovation paradigm of the twenty‐first century with significant impact on science, society, economy, and challenges of sustainability. As such, it can be understood as a mindset for creative thinking and as a methodology or technique for effective knowledge transfer between disciplines, mainly biology and technology. As biomimetics is relevant to practitioners in various fields of application, understanding the teaching and training of biomimetics for different audiences is important. With this article, we aim to give a holistic view of teaching and training practices and opportunities. First, we offer a set of learning objectives based on an analysis of various courses worldwide and we give recommendations for the design of future curricula. Second, based on an audience analysis and interviews, we developed a set of personas of the users of biomimetics, and as such, we offer a deeper understanding of their needs for the design of the process, including tools and methods.

Biobased chiral semi-crystalline or amorphous high-performance polyamides and their scalable stereoselective synthesis

The use of renewable feedstock is one of the twelve key principles of sustainable chemistry. Unfortunately, bio-based compounds often suffer from high production cost and low performance. To fully tap the potential of natural compounds it is important to utilize their functionalities that could make them superior compared to fossil-based resources. Here we show the conversion of (+)-3-carene, a by-product of the cellulose industry into ε-lactams from which polyamides. The lactams are selectively prepared in two diastereomeric configurations, leading to semi-crystalline or amorphous, transparent polymers that can compete with the thermal properties of commercial high-performance polyamides. Copolyamides with caprolactam and laurolactam exhibit an increased glass transition and amorphicity compared to the homopolyamides, potentially broadening the scope of standard polyamides. A four-step one-vessel monomer synthesis, applying chemo-enzymatic catalysis for the initial oxidation step, is established. The great potential of the polyamides is outlined.

Light-diffractive patterning of Porphyridium purpureum

Living structures: By projection of a light pattern from a computer-generated hologram, patterns of the algae Porphyridium purpureum were generated. The obtained pixelated pattern was evaluated and discussed in the context of the organism's phototaxis.

A facile route to diatoms decorated with gold nanoparticles and their optical properties

This paper presents a facile route for the decoration of biogenic silica from diatoms with gold nanoparticles (AuNPs) with dimensions from 10 to 40 nm. The AuNP decoration on the diatoms is performed through initial attachment of colloidal AuNPs (2 nm) followed by enhancement of the size of the AuNPs by mild reduction of tetrachloroauric (III) acid from solution. The samples were characterised by transmission electron microscopy (TEM), energy-dispersive X-ray analysis, Fourier transform infrared spectroscopy and light spectroscopy in the ultraviolet and visible (UV/Vis) range. The size of the isolated AuNPs on unmodified acid-cleaned diatoms was 10 nm according to TEM micrograph analysis. The measured UV/Vis spectrum showed an absorption peak at 525 nm, which corresponds well to the optical properties of AuNPs of the same size. The extent of decoration with AuNPs of the diatoms was significantly improved after functionalisation with 3-aminopropyltriethoxysilane of the biogenic silica. The absorption peak in the visible range was redshifted to 590 nm due to enlargement of the AuNPs up to 40 nm and clustering of the AuNPs. The AuNP decoration on the hierarchical and complex structured biogenic silica of diatoms might be interesting for biodiagnostic and surface-enhanced Raman spectroscopic applications.

Electrically-Conductive Sub-Micron Carbon Particles from Lignin: Elucidation of Nanostructure and Use as Filler in Cellulose Nanopapers

Carbon particles were produced from kraft lignin through carbonization of perfectly spherical, sub-micron beads obtained by aerosol flow. The structure of the resulting carbon particles was elucidated and compared to that derived from commercially available technical lignin powder, which is undefined in geometry. In addition to the smaller diameters of the lignin beads (<1 µm) compared to those of the lignin powder (100 µm), the former displayed a slightly higher structural order as revealed by X-ray diffraction and Raman spectroscopy. With regard to potential application in composite structures, the sub-micron carbon beads were clearly advantageous as a filler of cellulose nanopapers, which displayed better mechanical performance but with limited electrical conductivity. Compression sensing was achieved for this nanocomposite system.

Biosynthesis of poly-3-hydroxybutyrate from grass silage by a two-stage fermentation process based on an integrated biorefinery concept

Grass silage as a renewable feedstock for an integrated biorefinery includes nutrients and carbon sources directly available in the press juice (PJ) and in lignocellulosic saccharides from the plant framework. Here, a novel two-stage fed-batch fermentation process for biosynthesis of poly-3-hydroxybutyrate (PHB) by Cupriavidus necator DSM 531 is presented. For bacterial growth, nutrient-rich PJ was employed as a fermentation medium, without any supplements. Saccharides derived from the mechano-enzymatic hydrolysis of the press cake (PC) were subjected to a lactic acid fermentation process, before the fermentation products were fed into the polymer accumulation phase. By combination of pH-stat feeding and cell recycling, the PHB content in 22 g L^-1 total-dry cells reached 39% after 32 h of cultivation. Using mimicked hydrolyzate of diluted PJ artificially supplemented with glucose and xylose, the resulting cell dry weight of 21 g L^-1 contained 42% PHB.

A Perspective on Bio-Mediated Material Structuring

Bioinspiration, biomorphy, biomimicry, biomimetics, bionics, and biotemplating are terms used to describe the fabrication of materials or, more generally, systems to solve technological problems by abstracting, emulating, using, or transferring structures from biological paradigms. Herein, a brief overview of how the different terminologies are being typically applied is provided. It is proposed that there is a rich field of research that can be expanded by utilizing various novel approaches for the guidance of living organisms for "bio-mediated" material structuring purposes. As examples of contact-based or contact-free guidance, such as substrate patterning, the application of light, magnetic fields, or chemical gradients, potentially interesting methods of creating hierarchically structured monolithic engineering materials, using live patterned biomass, biofilms, or extracellular substances as scaffolds, are presented. The potential advantages of such materials are discussed, and examples of live self-patterning of materials are given.

Toward a New Generation of Smart Biomimetic Actuators for Architecture

Motile plant structures (e.g., leaves, petals, cone scales, and capsules) are functionally highly robust and resilient concept generators for the development of biomimetic actuators for architecture. Here, a concise review of the state-of-the-art of plant movement principles and derived biomimetic devices is provided. Achieving complex and higher-dimensional shape changes and passive-hydraulic actuation at a considerable time scale, as well as mechanical robustness of the motile technical structures, is challenging. For example, almost all currently available bioinspired hydraulic actuators show similar limitations due to the poroelastic time scale. Therefore, a major challenge is increasing the system size to the meter range, with actuation times of minutes or below. This means that response speed and flow rate need significant improvement for the systems, and the long-term performance degradation issue of hygroscopic materials needs to be addressed. A theoretical concept for "escaping" the poroelastic regime is proposed, and the possibilities for enhancing the mechanical properties of passive-hydraulic bilayer actuators are discussed. Furthermore, the promising aspects for further studies to implement tropistic movement behavior are presented, i.e., movement that depends on the direction of the triggering stimulus, which can finally lead to "smart building skins" that autonomously and self-sufficiently react to changing environmental stimuli in a direction-dependent manner.

Dataset on the structural characterization of organosolv lignin obtained from ensiled Poaceae grass and load-dependent molecular weight changes during thermoplastic processing

This article presents experimental data of organosolv lignin from Poacea grass and structural changes after compounding and injection molding as presented in the research article “Effects of high-lignin-loading on thermal, mechanical, and morphological properties of bioplastic composites” [1]. It supplements the article with morphological (SEM), spectroscopic (³¹P NMR, FT-IR) and chromatographic (GPC, EA) data of the starting lignin as well as molar mass characteristics (mass average molar mass (M_w) and Polydispersity (D)) of the extracted lignin. Refer to Schwarz et al. [2] for a detailed description of the production of the organosolv residue and for further information on the raw material used for lignin extraction. The dataset is made publicly available and can be useful for extended lignin research and critical analyzes.

Biomimetics and its tools

Biomimetics, as the transfer of strategies from biology to technology, is an emerging research area and has led to significant concepts over the past decades. The development of such concepts is described by the process of biomimetics, encompassing several steps. In Practice, beneficiaries of the process face challenges. Therefore, to overcome challenges and to facilitate the steps, tools have been developed in various areas, such as engineering, computing and design. However, these tools are not widely used yet. This paper presents an overview and a classification study of more than 40 tools with qualitative criteria. The criteria included, for example, the year of development, the accessibility of tools, the facilitated steps of the process or their contribution to sustainability. The classification shows that certain steps of the process and their challenges are well addressed by the tools, while other steps are not. The presented results contribute to the proposal of an improvement of the state of the art, and they build the foundation for future theoretical and practical analyses. These findings could contribute to increasing the implementation of biomimetics in various disciplines in the long term.

Preparation of magnesium oxide and magnesium silicate replicas retaining the hierarchical structure of pine wood

Replicas retaining the structural characteristics of softwood (Pinus sylvestris) were obtained by infiltrating pretreated templates with a methanolic methoxymagnesium methyl carbonate (MeOMgOCO2Me) solution as a precursor which then hydrolyzed into MgCO3 nanoparticles. Subsequent calcination at temperatures ranging from 500 to 1450°C yielded annealed MgO replicas on levels of hierarchy from the macroscopic to the submicron scale. The mechanical stability of the replicas could be improved through calcination at 1450°C. However, this treatment leads to considerable shrinkage (Δax=56%). Even more stable MgO replicas were obtained by infiltrating the pine template first with MeOMgOCO2Me, followed by a second infiltration step with an ethanolic tetraethyl orthosilicate (TEOS) solution and subsequent calcination at 1350°C. The resulting replicas constitute an MgO framework overgrown with Mg2SiO4 (forsterite) and exhibit compression strengths of 31±8 MPa, as well as hierarchical structures combined with an anisotropic porosity.

Biomimetics: process, tools and practice

Biomimetics applies principles and strategies abstracted from biological systems to engineering and technological design. With a huge potential for innovation, biomimetics could evolve into a key process in businesses. Yet challenges remain within the process of biomimetics, especially from the perspective of potential users. We work to clarify the understanding of the process of biomimetics. Therefore, we briefly summarize the terminology of biomimetics and bioinspiration. The implementation of biomimetics requires a stated process. Therefore, we present a model of the problem-driven process of biomimetics that can be used for problem-solving activity. The process of biomimetics can be facilitated by existing tools and creative methods. We mapped a set of tools to the biomimetic process model and set up assessment sheets to evaluate the theoretical and practical value of these tools. We analyzed the tools in interdisciplinary research workshops and present the characteristics of the tools. We also present the attempt of a utility tree which, once finalized, could be used to guide users through the process by choosing appropriate tools respective to their own expertize. The aim of this paper is to foster the dialogue and facilitate a closer collaboration within the field of biomimetics.

Passive and active mechanical properties of biotemplated ceramics revisited

Living nature and human technology apply different principles to create hard, strong and tough materials. In this review, we compare and discuss prominent aspects of these alternative strategies, and demonstrate for selected examples that nanoscale-precision biotemplating is able to produce uncommon mechanical properties as well as actuating behavior, resembling to some extent the properties of the original natural templates. We present and discuss mechanical testing data showing for the first time that nanometer-precision biotemplating can lead to porous ceramic materials with deformation characteristics commonly associated with either biological or highly advanced technical materials. We also review recent findings on the relation between hierarchical structuring and humidity-induced directional motion. Finally, we discuss to which extent the observed behavior is in agreement with previous results and theories on the mechanical properties of multiscale hierarchical materials, as well as studies of highly disperse technical materials, together with an outlook for further lines of investigation.

Cellulose acetate-based composites with antimicrobial properties from embedded molybdenum trioxide particles

The objective of this research was to develop novel cellulose acetate (biopolymer) composite materials with an excellent antimicrobial activity by embedding molybdenum trioxide particles with unique high specific surface area. High surface area molybdenum trioxide particles were prepared from freshly precipitated molybdenum trioxide dihydrate (MoO₃ ·2H₂ O) and subsequent calcination at 340°C under H₂ /N₂ gas. Microbiological evaluation against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were performed applying a roll-on test and excellent antimicrobial activities were determined for composites with embedded anhydrous molybdenum trioxide with a high specific surface area. Cellulose acetate composites comprising MoO₃ particles can eliminate three harmful bacteria as a result of the release of protons from the material and surface enlargement of the molybdenum trioxide particles. The findings support a proposed antimicrobial mechanism based on local acidity increase due to large specific surface areas.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, development of a novel thermoplastic bio-based composite with excellent antimicrobial surface properties is investigated. To the best of our knowledge, this is the first report to evaluate the antimicrobial properties of molybdenum trioxide embedded into a cellulose acetate as biopolymer matrix. The developed composites might step up to innovative applications used in modern medical and public environments.

Integrated biorefinery concept for grass silage using a combination of adapted pulping methods for advanced saccharification and extraction of lignin

An integrated refining and pulping process for ensiled biomass from permanent grassland was established on laboratory scale. The liquid phase, containing the majority of water-soluble components, including 24% of the initial dry matter (DM), was first separated by mechanical pressing. The fiber fraction was subjected to high solid load saccharification (25% DM) to enhance the lignin content in the feed for subsequent organosolvation. The saccharification enzymes were pre-selected applying experimental design approaches. Cellulose convertibility was improved by a secondary pressing step during liquefaction. Combined saccharification and organosolvation showed high degree of saccharide solubilization with recovery of 98% of the glucan and 73% of the xylan from the fiber fraction in the hydrolysates, and enabled the recovery of 41% of the grass silage lignin. The effects of the treatment were confirmed by XRD and SEM tracking of cellulose crystallinity and fiber morphology throughout the pulping procedure.

Moisture-Driven Ceramic Bilayer Actuators from a Biotemplating Approach

The former ovuliferous scales of biotemplated cones of Pinus nigra show moisture-driven actuation similar to their biological templates, demonstrating a facile route to obtain ceramic moisture-sensitive bilayer actuators. Based on comparative analysis of their hierarchical nanometer-precision replica structures, using, e.g., spatially resolved small-angle X-ray scattering, the origin of the actuation is explained.

Preparation of CaCO3 and CaO Replicas Retaining the Hierarchical Structure of SpruceWood

The principal structural characteristics of softwood (spruce) were replicated in CaCO3 and CaO on various levels of hierarchy from the macroscopic to the submicron scale. Positive replicas were obtained by infiltrating pretreated softwood templates with a Ca(OCOOCH3)2 precursor solution which hydrolyzed into CaCO3 nanoparticles. They reproduce the hierarchical porous structure of the wood template. Calcination at temperatures from 350 to 900 °C yields calcite as the main polymorph. Mechanical stability of the replica is optimized when the specimen is calcined at 900 °C

[Fundus autofluorescence in multiple evanescent white dot syndrome]

Multiple evanescent white dot syndrome (MEWDS), an entity belonging to the group of white dot syndromes, is characterized by pale spots at the posterior pole as a sign of inflammatory changes in the choroid and pigment epithelium. These spots are sometimes difficult to define by fundoscopy. Besides angiography fundus autofluorescence has been shown to be an excellent, noninvasive method to demonstrate these subretinal spots in MEWDS.