When Cortical Bone Matrix Properties Are Indiscernible between Elderly Men with and without Type 2 Diabetes, Fracture Resistance Follows Suit.

Type 2 diabetes mellitus (T2DM) is a metabolic disease affecting bone tissue and leading to increased fracture risk in men and women, independent of bone mineral density (BMD). Thus, bone material quality (i.e., properties that contribute to bone toughness but are not attributed to bone mass or quantity) is suggested to contribute to higher fracture risk in diabetic patients and has been shown to be altered. Fracture toughness properties are assumed to decline with aging and age-related disease, while toughness of human T2DM bone is mostly determined from compression testing of trabecular bone. In this case-control study, we determined fracture resistance in T2DM cortical bone tissue from male individuals in combination with a multiscale approach to assess bone material quality indices. All cortical bone samples stem from male nonosteoporotic individuals and show no significant differences in microstructure in both groups, control and T2DM. Bone material quality analyses reveal that both control and T2DM groups exhibit no significant differences in bone matrix composition assessed with Raman spectroscopy, in BMD distribution determined with quantitative back-scattered electron imaging, and in nanoscale local biomechanical properties assessed via nanoindentation. Finally, notched three-point bending tests revealed that the fracture resistance (measured from the total, elastic, and plastic J-integral) does not significantly differ in T2DM and control group, when both groups exhibit no significant differences in bone microstructure and material quality. This supports recent studies suggesting that not all T2DM patients are affected by a higher fracture risk but that individual risk profiles contribute to fracture susceptibility, which should spur further research on improving bone material quality assessment in vivo and identifying risk factors that increase bone fragility in T2DM. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Challenges and best practices for digital unstructured data enrichment in health research: A systematic narrative review.

Digital data play an increasingly important role in advancing health research and care. However, most digital data in healthcare are in an unstructured and often not readily accessible format for research. Unstructured data are often found in a format that lacks standardization and needs significant preprocessing and feature extraction efforts. This poses challenges when combining such data with other data sources to enhance the existing knowledge base, which we refer to as digital unstructured data enrichment. Overcoming these methodological challenges requires significant resources and may limit the ability to fully leverage their potential for advancing health research and, ultimately, prevention, and patient care delivery. While prevalent challenges associated with unstructured data use in health research are widely reported across literature, a comprehensive interdisciplinary summary of such challenges and possible solutions to facilitate their use in combination with structured data sources is missing. In this study, we report findings from a systematic narrative review on the seven most prevalent challenge areas connected with the digital unstructured data enrichment in the fields of cardiology, neurology and mental health, along with possible solutions to address these challenges. Based on these findings, we developed a checklist that follows the standard data flow in health research studies. This checklist aims to provide initial systematic guidance to inform early planning and feasibility assessments for health research studies aiming combining unstructured data with existing data sources. Overall, the generality of reported unstructured data enrichment methods in the studies included in this review call for more systematic reporting of such methods to achieve greater reproducibility in future studies.

Solvent controlled 2D structures of bottom-up fabricated nanoparticle superlattices.

We demonstrate that oleyl phosphate ligand-stabilized iron oxide nanocubes as building blocks can be assembled into 2D supercrystalline mono- and multilayers on flat YSZ substrates within a few minutes using a simple spin-coating process. As a bottom-up process, the growth takes place in a layer-by-layer mode and therefore by tuning the spin-coating parameters, the exact number of deposited monolayers can be controlled. Furthermore, ex situ scanning electron and atomic force microscopy as well as X-ray reflectivity measurements give evidence that the choice of solvent allows the control of the lattice type of the final supercrystalline monolayers. This observation can be assigned to the different Hansen solubilities of the solvents used for the nanoparticle dispersion because it determines the size and morphology of the ligand shell surrounding the nanoparticle core. Here, by using toluene and chloroform as solvents, it can be controlled whether the resulting monolayers are ordered in a square or hexagonal supercrystalline lattice.

Influence of water and protein content on the creep behavior in dental enamel.

The creep behavior of untreated and deproteinized dental enamel in dry and wet state was analyzed by nanoindentation with a spherical tip. Additionally, the influence of the loading rate was investigated. Dry untreated and deproteinized dental enamel only showed minor creep over 100 s and deproteinization did not affect the dry enamel's behavior significantly. With slower loading rates some creep already occurs during the loading period, such that the creep displacement during load hold is less than with faster loading rates. Wet untreated and deproteinized enamel showed significantly more creep compared to the dry samples. The differences between the untreated and deproteinized enamel were only minor but significant, revealing that water affects the creep behavior of biological materials such as enamel significantly. The proposed deformation mechanism of naturally porous enamel under compression is compaction of the HAP crystallites and fluid displacement within material underneath the indented area. STATEMENT OF SIGNIFICANCE: This study investigates the creep behavior of untreated and deproteinized dental enamel in dry and wet conditions. It is shown that while the protein content does not affect enamel's behavior significantly, the wet conditions lead to an increased creep in enamel. The proposed deformation mechanism of naturally porous enamel under compression is compaction of the HAP crystallites and fluid displacement within material underneath the indented area. Based on this observation a simple analytical model has been developed, aiming to deepen our understanding of the deformation behavior of biological materials.

Exploring the role of AI in classifying, analyzing, and generating case reports on assisted suicide cases: feasibility and ethical implications.

This paper presents a study on the use of AI models for the classification of case reports on assisted suicide procedures. The database of the five Dutch regional bioethics committees was scraped to collect the 72 case reports available in English. We trained several AI models for classification according to the categories defined by the Dutch Termination of Life on Request and Assisted Suicide (Review Procedures) Act. We also conducted a related project to fine-tune an OpenAI GPT-3.5-turbo large language model for generating new fictional but plausible cases. As AI is increasingly being used for judgement, it is possible to imagine an application in decision-making regarding assisted suicide. Here we explore two arising questions: feasibility and ethics, with the aim of contributing to a critical assessment of the potential role of AI in decision-making in highly sensitive areas.

Strengthening Engineered Nanocrystal Three-Dimensional Superlattices via Ligand Conformation and Reactivity.

Nanocrystal assembly into ordered structures provides mesostructural functional materials with a precise control that starts at the atomic scale. However, the lack of understanding on the self-assembly itself plus the poor structural integrity of the resulting supercrystalline materials still limits their application into engineered materials and devices. Surface functionalization of the nanobuilding blocks with organic ligands can be used not only as a means to control the interparticle interactions during self-assembly but also as a reactive platform to further strengthen the final material via ligand cross-linking. Here, we explore the influence of the ligands on superlattice formation and during cross-linking via thermal annealing. We elucidate the effect of the surface functionalization on the nanostructure during self-assembly and show how the ligand-promoted superlattice changes subsequently alter the cross-linking behavior. By gaining further insights on the chemical species derived from the thermally activated cross-linking and its effect in the overall mechanical response, we identify an oxidative radical polymerization as the main mechanism responsible for the ligand cross-linking. In the cascade of reactions occurring during the surface-ligands polymerization, the nanocrystal core material plays a catalytic role, being strongly affected by the anchoring group of the surface ligands. Ultimately, we demonstrate how the found mechanistic insights can be used to adjust the mechanical and nanostructural properties of the obtained nanocomposites. These results enable engineering supercrystalline nanocomposites with improved cohesion while preserving their characteristic nanostructure, which is required to achieve the collective properties for broad functional applications.

Direct writing of colloidal suspensions onto inclined surfaces: Optimizing dispense volume for homogeneous structures.

HYPOTHESIS: A process to fabricate structures on inclined substrates has the potential to yield novel applications for colloidal-based structures. However, for conventional techniques, besides the coffee ring effect (CRE), anisotropic particle deposition along the inclination direction (IE) is expected to occur. We hypothesize that both effects can be inhibited by reducing the dispense volume during printing by direct writing. EXPERIMENTS: We combined an additive manufacturing technique, namely direct writing, with colloidal assembly (AMCA) for an automated and localized drop-cast of polystyrene and silica suspensions onto inclined surfaces. Herein, we investigated the influence of the substrate tilting angle and the dispense volume on the printing of colloids and the resulting structures' morphology. FINDINGS: The results demonstrate that a reduction in the dispense volume hinders the CRE and IE for both particles' systems, even though the evaporation mode is different. For polystyrene, the droplets evaporated solely in stick-mode, enabling a "surface capturing effect", while for silica, droplets evaporated in mixed stick-slip mode and a "confinement effect" was observed, which improved uniformity of the deposition. These findings were used to generate a model of the critical droplet radius needed to print homogeneous colloidal-based structures onto inclined substrates.

Tailoring Disorder and Quality of Photonic Glass Templates for Structural Coloration by Particle Charge Interactions.

To obtain high-quality homogeneous photonic glass-based structural color films over large areas, it is essential to precisely control the degree of disorder of the spherical particles used and reduce the crack density within the films as much as possible. To tailor the disorder and quality of photonic glasses, a heteroaggregation-based process was developed by employing two oppositely charged equal-sized polystyrene (PS) particle types. The influence of the particle size ratio on the extent of heteroaggregation in the suspension mixes is investigated and correlated with both the morphology and the resultant optical properties of the films. The results show that the oppositely charged particle size ratio within the mix greatly influences the assembled structure in the films, affecting their roughness, crack density, and the coffee-ring formation. To better differentiate the morphology of the films, scanning electron microscopy images of the microstructures were classified by a supervised training of a deep convolutional neural network model to find distinctions that are inaccessible by conventional image analysis methods. Selected compositions were then infiltrated with TiO2 via atomic layer deposition, and after removal of the PS spheres, surface-templated inverse photonic glasses were obtained. Different color impressions and optical properties were obtained depending on the heteroaggregation level and thus the quality of the resultant films. The best results regarding the stability of the films and suppression of coffee-ring formation are obtained with a 35 wt % positively charged over negatively charged particle mix, which yielded enhanced structural coloration associated with improved film quality, tailored by the heteroaggregation fabrication process.

Deformation Behavior of Cross-Linked Supercrystalline Nanocomposites: An in Situ SAXS/WAXS Study during Uniaxial Compression.

With the ever-expanding functional applications of supercrystalline nanocomposites (a relatively new category of materials consisting of organically functionalized nanoparticles arranged into periodic structures), it becomes necessary to ensure their structural stability and understand their deformation and failure mechanisms. Inducing the cross-linking of the functionalizing organic ligands, for instance, leads to a remarkable enhancement of the nanocomposites' mechanical properties. It is however still unknown how the cross-linked organic phase redistributes applied loads, how the supercrystalline lattice accommodates the imposed deformations, and thus in general what phenomena govern the overall material's mechanical response. This work elucidates these aspects for cross-linked supercrystalline nanocomposites through an in situ small- and wide-angle X-ray scattering study combined with uniaxial pressing. Because of this loading condition, it emerges that the cross-linked ligands effectively carry and distribute loads homogeneously throughout the nanocomposites, while the superlattice deforms via rotation, slip, and local defects generation.

With a little help from familiar interlocutors: real-world language use in young and older adults.

OBJECTIVES: Functional psychologists are concerned with the performance of cognitive activities in the real world in relation to cognitive changes in older age. Conversational contexts may mitigate the influence of cognitive aging on the cognitive activity of language production. This study examined effects of familiarity with interlocutors, as a context, on language production in the real world. METHOD: We collected speech samples using iPhones, where an audio recording app (i.e. Electronically Activated Recorder [EAR]) was installed. Over 31,300 brief audio files (30-second long) were randomly collected across four days from 61 young and 48 healthy older adults in Switzerland. We transcribed the audio files that included participants' speech and manually coded for familiar interlocutors (i.e. significant other, friends, family members) and strangers. We computed scores of vocabulary richness and grammatical complexity from the transcripts using computational linguistics techniques. RESULTS: Bayesian multilevel analyses showed that participants used richer vocabulary and more complex grammar when talking with familiar interlocutors than with strangers. Young adults used more diverse vocabulary than older adults and the age effects remained stable across contexts. Furthermore, older adults produced equally complex grammar as young adults did with the significant other, but simpler grammar than young adults with friends and family members. CONCLUSION: Familiarity with interlocutors is a promising contextual factor for research on aging and language complexity in the real world. Results were discussed in the context of cognitive aging.

Controlling the Large-Scale Fabrication of Supraparticles.

Controlling the nanoscale interactions of colloidal building blocks is a key step for the transition from single nanoparticles to tailor-made, architected morphologies and their further integration into functional materials. Solvent evaporation-induced self-assembly within emulsion droplets emerges as a fast, versatile, and low-cost approach to obtain spherical, complex structures, such as supraparticles. Nevertheless, some process-structure relationships able to describe the effects of emulsion conditions on the synthesis outcomes still remain to be understood. Here, we explore the effect of different physicochemical parameters of emulsion-templated self-assembly (ETSA) on supraparticles' formation. Supraparticle size, size dispersity, microporosity, and sample homogeneity are rationalized based on the used surfactant formulation, stabilization mechanism, and viscosity of the emulsion. We further demonstrate the significance of the parameters found by optimizing a transferable, large-scale (gram-size) ETSA setup for the controlled synthesis of spherical supraparticles in a range of defined sizes (from 0.1-10 µm). Ultimately, our results provide new key synthetic parameters able to control the process, promoting the development of supraparticle-based, functional nanomaterials for a wide range of applications.

Mapping the Mechanical Properties of Hierarchical Supercrystalline Ceramic-Organic Nanocomposites.

Multiscale ceramic-organic supercrystalline nanocomposites with two levels of hierarchy have been developed via self-assembly with tailored content of the organic phase. These nanocomposites consist of organically functionalized ceramic nanoparticles forming supercrystalline micron-sized grains, which are in turn embedded in an organic-rich matrix. By applying an additional heat treatment step at mild temperatures (250-350 °C), the mechanical properties of the hierarchical nanocomposites are here enhanced. The heat treatment leads to partial removal and crosslinking of the organic phase, minimizing the volume occupied by the nanocomposites' soft phase and triggering the formation of covalent bonds through the organic ligands interfacing the ceramic nanoparticles. Elastic modulus and hardness up to 45 and 2.5 GPa are attained, while the hierarchical microstructure is preserved. The presence of an organic phase between the supercrystalline grains provides a toughening effect, by curbing indentation-induced cracks. A mapping of the nanocomposites' mechanical properties reveals the presence of multiple microstructural features and how they evolve with heat treatment temperature. A comparison with non-hierarchical, homogeneous supercrystalline nanocomposites with lower organic content confirms how the hierarchy-inducing organic excess results in toughening, while maintaining the beneficial effects of crosslinking on the materials' stiffness and hardness.

Linear and Nonlinear Age Trajectories of Language Use: A Laboratory Observation Study of Couples' Conflict Conversations.

OBJECTIVES: This study investigated linear and nonlinear age effects on language use with speech samples that were representative of naturally occurring conversations. METHOD: Using a corpus-based approach, we examined couples' conflict conversations in the laboratory. The conversations, from a total of 364 community-dwelling German-speaking heterosexual couples (aged 19-82), were videotaped and transcribed. We examined usage of lower-frequency words, grammatical complexity, and utterance of filled pauses (e.g., äh ["um"]). RESULTS: Multilevel models showed that age effects on the usage of lower-frequency words were nonsignificant. Grammatical complexity increased until middle age (i.e., 54) and then declined. The utterance of filled pauses increased until old age (i.e., 70) and then decreased. DISCUSSION: Results are discussed in relation to cognitive aging research.

The geometrical structure of interfaces in dental enamel: A FIB-STEM investigation.

In this study a high resolution structural analysis revealed that enamel prisms are surrounded by an interface that is discontinuous with frequent mineral to mineral contact separated by gaps. This contact manifests either by crystallites bridging the boundary between prismatic and interprismatic enamel or continuous crystallites curving and bridging the interprismatic enamel to the prisms. The geometrical resolution of this TEM investigation of the interfaces is ≤2 nm as a basis for micromechanical models. Within this resolution, contrary to existing structural descriptions of dental enamel structure in materials science literature, here the crystallites themselves are shown to be either in direct contact with each other, sometimes even fusing together, or are separated by gaps. Image analysis revealed that on average only 57 ± 15% of the interface consists of points of no contact between crystallites. This work reveals structural features of dental enamel that contribute important understanding to both the architecture and mechanical properties of this biological material. A new structural model is proposed and the implications for the mechanical properties of dental enamel are discussed. STATEMENT OF SIGNIFICANCE: In this study a high resolution structural analysis, employing focused ion beam and transmission electron microscopy revealed that enamel prisms are surrounded by interfaces that are discontinuous with frequent mineral to mineral contact separated by gaps. Although the interfaces in enamel have been investigated previously, existing studies are lacking in detail considering the geometry and morphology of the interfaces. We think that this result is of great importance when it comes to the understanding of the mechanical properties. In our opinion the concept of soft sheaths is no longer feasible. The resulting observations are included in a new structural model which provides new qualitative insights into the mechanical behavior. Existing analytical models were applied to simulate the new geometrical structure.

Modulating the Mechanical Properties of Supercrystalline Nanocomposite Materials via Solvent-Ligand Interactions.

Supercrystalline nanocomposite materials with micromechanical properties approaching those of nacre or similar structural biomaterials can be produced by self-assembly of organically modified nanoparticles and further strengthened by cross-linking. The strengthening of these nanocomposites is controlled via thermal treatment, which promotes the formation of covalent bonds between interdigitated ligands on the nanoparticle surface. In this work, it is shown how the extent of the mechanical properties enhancement can be controlled by the solvent used during the self-assembly step. We find that the resulting mechanical properties correlate with the Hansen solubility parameters of the solvents and ligands used for the supercrystal assembly: the hardness and elastic modulus decrease as the Hansen solubility parameter of the solvent approaches the Hansen solubility parameter of the ligands that stabilize the nanoparticles. Moreover, it is shown that self-assembled supercrystals that are subsequently uniaxially pressed can deform up to 6 %. The extent of this deformation is also closely related to the solvent used during the self-assembly step. These results indicate that the conformation and arrangement of the organic ligands on the nanoparticle surface not only control the self-assembly itself but also influence the mechanical properties of the resulting supercrystalline material. The Hansen solubility parameters may therefore serve as a tool to predict what solvents and ligands should be used to obtain supercrystalline materials with good mechanical properties.

Fracture toughness of porous materials - Experimental methods and data.

We provide numerical experimental data and detailed information about the sample preparation and the experimental methods, used by different research groups for measuring the fracture toughness of porous materials. These data are supplemental information to the publication "A Geometric Model for the Fracture Toughness of Porous Materials," [1], which is based on experimental data of ceramic and polymer materials. For the sake of completeness, we provide here also data from fracturing metallic foams. The corresponding theoretical curves, which are based on the model described in the reference, are given additionally in the diagrams. The utilized publications are not a comprehensive compilation of all corresponding measurements concerning porous materials, but should be seen as a typical set of respective experiments with the focus on the fracture toughness of porous materials. The discussion and interpretation are provided in the above-mentioned reference.

Hierarchical supercrystalline nanocomposites through the self-assembly of organically-modified ceramic nanoparticles.

Biomaterials often display outstanding combinations of mechanical properties thanks to their hierarchical structuring, which occurs through a dynamically and biologically controlled growth and self-assembly of their main constituents, typically mineral and protein. However, it is still challenging to obtain this ordered multiscale structural organization in synthetic 3D-nanocomposite materials. Herein, we report a new bottom-up approach for the synthesis of macroscale hierarchical nanocomposite materials in a single step. By controlling the content of organic phase during the self-assembly of monodisperse organically-modified nanoparticles (iron oxide with oleyl phosphate), either purely supercrystalline or hierarchically structured supercrystalline nanocomposite materials are obtained. Beyond a critical concentration of organic phase, a hierarchical material is consistently formed. In such a hierarchical material, individual organically-modified ceramic nanoparticles (Level 0) self-assemble into supercrystals in face-centered cubic superlattices (Level 1), which in turn form granules of up to hundreds of micrometers (Level 2). These micrometric granules are the constituents of the final mm-sized material. This approach demonstrates that the local concentration of organic phase and nano-building blocks during self-assembly controls the final material's microstructure, and thus enables the fine-tuning of inorganic-organic nanocomposites' mechanical behavior, paving the way towards the design of novel high-performance structural materials.

Iron oxide-based nanostructured ceramics with tailored magnetic and mechanical properties: development of mechanically robust, bulk superparamagnetic materials.

Nanostructured iron-oxide based materials with tailored mechanical and magnetic behavior are produced in bulk form. By applying ultra-fast heating routines via spark plasma sintering (SPS) to supercrystalline pellets, materials with an enhanced combination of elastic modulus, hardness and saturation magnetization are achieved. Supercrystallinity - namely the arrangement of the constituent nanoparticles into periodic structures - is achieved through self-assembly of the organically-functionalized iron oxide nanoparticles. The optimization of the following SPS regime allows the control of organics' removal, necking, iron oxide phase transformations and nano-grain size retention, and thus the fine-tuning of both mechanical properties and magnetic response, up until the production of bulk mm-size superparamagnetic materials.

Dataset of ptychographic X-ray computed tomography of inverse opal photonic crystals produced by atomic layer deposition.

This data article describes the detailed parameters for synthesizing mullite inverse opal photonic crystals via Atomic Layer Deposition (ALD), as well as the detailed image analysis routine used to interpret the data obtained by the measurement of such photonic crystals, before and after the heat treatment, via Ptychographic X-ray Computed Tomography (PXCT). The data presented in this article are related to the research article by Furlan and co-authors entitled "Photonic materials for high-temperature applications: Synthesis and characterization by X-ray ptychographic tomography" (Furlan et al., 2018). The data include detailed information about the ALD super-cycle process to generate the ternary oxides inside a photonic crystal template, the raw data from supporting characterization techniques, as well as the full dataset obtained from PXCT. All the data herein described is publicly available in a Mendeley Data archive "Dataset of synthesis and characterization by PXCT of ALD-based mullite inverse opal photonic crystals" located at https://data.mendeley.com/datasets/zn49dsk7x6/1 for any academic, educational, or research purposes.