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An active droplet system, programmed to repeatedly move autonomously at a specific velocity in a well-defined direction, is demonstrated. Coulombic energy is stored in oversaturated interfacial assemblies of charged nanoparticle-surfactants by an applied DC electric field and can be released on demand. Spontaneous emulsification is suppressed by an increase in the stiffness of the oversaturated assemblies. Rapidly removing the field releases the stored energy in an explosive event that propels the droplet, where thousands of charged microdroplets are ballistically ejected from the surface of the parent droplet. The ejection is made directional by a symmetry breaking of the interfacial assembly, and the combined interaction force of the microdroplet plume on one side of the droplet propels the droplet distances tens of times its size, making the droplet active. The propulsion is autonomous, repeatable, and agnostic to the chemical composition of the nanoparticles. The symmetry-breaking in the nanoparticle assembly controls the microdroplet velocity and direction of propulsion. This mechanism of droplet propulsion will advance soft micro-robotics, establishes a new type of active matter, and introduces new vehicles for compartmentalized delivery.

Adding Fe3O4 nanoparticles to composites of [Fe(Htrz)2(trz)](BF4) spin-crossover polymer and polyaniline (PANI) drives a phase separation of both and restores the molecular structure and cooperative effects of the spin-crossover polymer without compromising the increased conductivity gained through the addition of PANI. We observe an increased on-off ratio for the DC conductivity owing to an enlarged off state resistivity and a 20 times larger AC conductivity of the on state compared with DC values. The Fe3O4 nanoparticles, primarily confined to the [Fe(Htrz)2(trz)](BF4) phase, are ferromagnetically coupled to the local moment of the spin-crossover molecule suggesting the existence of an exchange interaction between both components.

Metal-organic decomposition epitaxy is an economical wet-chemical approach suitable to synthesize high-quality low-spin-damping films for resonator and oscillator applications. This work reports the temperature dependence of ferromagnetic resonances and associated structural and magnetic quantities of yttrium iron garnet nanofilms that coincide with single-crystal values. Despite imperfections originating from wet-chemical deposition and spin coating, the quality factor for out-of-plane and in-plane resonances approaches 600 and 1000, respectively, at room temperature and 40 GHz. These values increase with temperature and are 100 times larger than those offered by commercial devices based on complementary metal-oxide semiconductor voltage-controlled oscillators at comparable production costs.

Abstract Insertion mutations in exon 20 of the epidermal growth factor receptor gene (EGFR exon20ins) are rare, heterogeneous alterations observed in non-small cell lung cancer (NSCLC). With a few exceptions, they are associated with primary resistance to established EGFR tyrosine kinase inhibitors (TKIs). As patients carrying EGFR exon20ins may be eligible for treatment with novel therapeutics—the bispecific antibody amivantamab, the TKI mobocertinib, or potential future innovations—they need to be identified reliably in clinical practice for which quality-based routine genetic testing is crucial. Spearheaded by the German Quality Assurance Initiative Pathology two international proficiency tests were run, assessing the performance of 104 participating institutes detecting EGFR exon20ins in tissue and/or plasma samples. EGFR exon20ins were most reliably identified using next-generation sequencing (NGS). Interestingly, success rates of institutes using commercially available mutation-/allele-specific quantitative (q)PCR were below 30% for tissue samples and 0% for plasma samples. Most of these mutation-/allele-specific (q)PCR assays are not designed to detect the whole spectrum of EGFR exon20ins mutations leading to false negative results. These data suggest that NGS is a suitable method to detect EGFR exon20ins in various types of patient samples and is superior to the detection spectrum of commercially available assays.

Spontaneous emulsification, resulting from the assembly and accumulation of surfactants at liquid–liquid interfaces, is an interfacial instability where microdroplets are generated and diffusively spread from the interface until complete emulsification. Here, it is shown that an external magnetic field can modulate the assembly of paramagnetic nanoparticle surfactants (NPSs) at liquid–liquid interfaces to trigger an oversaturation in the areal density of the NPSs at the interface, as evidenced by a marked reduction in the interfacial tension, γ, and corroborated with a magnetostatic continuum theory. Despite the significant reduction in γ, the presence of the magnetic field does not cause stable interfaces to become unstable. Upon rapid removal of the field, however, an explosive ejection of a plume of microdroplets from the surface occurs, a dynamical interfacial instability which is termed explosive emulsification. This explosive event rapidly reduces the areal density of the NPSs to its pre-field level, stabilizing the interface. The ability to externally suppress or trigger the explosive emulsification and controlled generation of tens of thousands of microdroplets, uncovers an efficient energy storage and release process, that has potential applications for controlled and directed delivery of chemicals and remotely controlled soft microrobots, taking advantage of the ferromagnetic nature of the microdroplets.

We investigated modifications driven by 7,7,8,8-tetracyanoquinodimethane (TCNQ) to the spin state configuration of [Fe(3-bpp)2](TCNQ)2 co-crystal and both spin state and electric conductivity of [Fe{H2B(pz)2}2(bipy)] and TCNQ mixtures. The Fe2+ site in the [Fe(3-bpp)2](TCNQ)2 co-crystal has a sizable orbital moment. During X-ray absorption measurements, the iron ion is partially excited to the high spin state and strong surface effects are indicated. Mixing TCNQ with the [Fe{H2B(pz)2}2(bipy)] spin crossover complex leads to a molecular combination with increased conductivity and drift carrier lifetimes. [Fe{H2B(pz)2}2(bipy)] thin films with TCNQ, grown using dimethylformamide (DMF), are to great extent locked mainly in the low spin (LS) state across a broad temperature range and exhibit drift carrier lifetimes approaching 0.5 s. When deposited onto a ferroelectric polyvinylidenefluoride-hexafluoropropylene thin film substrate, [Fe{H2B(pz)2}2(bipy)], shows enhanced transistor carrier mobility, likely associated with the increasing cationic character of [Fe{H2B(pz)2}2(bipy)] thin films with TCNQ.

Powder bed fusion of metals using a laser beam (PBF-LB/M) is a widely used additive manufacturing (AM) technique that enables the material-efficient fabrication of complex geometries in metallic parts. However, achieving high-quality parts with desired properties heavily depends on variances in the manufacturing process and powder composition, making quality control an indispensable aspect of almost all applications. Today, mainly grayscale imaging, photodiodes, or pyrometry are employed, whereas in-situ recording of chemical (compositional) information has rarely been done during PBF-LB/M. This pilot study uses Nd-Fe-B as a compositional sensitive model material to explore the feasibility of in-situ optical emission spectroscopy (OES) for elemental analysis of metallic samples during PBF-LB/M, validated by ex-situ analysis. Our results show that the Boltzmann-corrected local emissivity of the Fe and Nd lines in the plume is a reliable indicator for determining the temperature and elemental material concentration voxel-wise, which could enable a digital 3-D reconstruction of the material composition of a printed part in the future.

Understanding magnetic phase transitions from stripe to skyrmion textures provide fundamental scientific insights into the details of the intermediate topologies through which the system evolves. The solitonic nature of spin texture in both stripe and skyrmion phases has been observed in materials with Dzyaloshinskii-Moriya interaction. Here we show that the field evolution in a dipolar interaction mediated Fe/Gd multilayer that exhibits achiral stripe textures behaves similar to a finite-sized chiral soliton lattice. As a function of magnetic field, the stripes exhibit discrete jumps in periodicity indicative of intermediate topologies as the stripes get wound into skyrmions.

Abstract Despite being a major component of Lewy bodies and Lewy neurites, pathogenic variants in the gene encoding alpha-Synuclein (α-Syn) are rare. To date, only four missense variants in the SNCA gene, encoding α-Syn have unequivocally been shown to be disease-causing. We here describe a Parkinson´s disease patient with early cognitive decline carrying an as yet not fully characterized variant in SNCA (NM_001146055: c.44T > C, p.V15A). We used different cellular models, including stably transfected neuroblastoma (SH-SY5Y) cell cultures, induced pluripotent stem cell (iPSC)-derived neuronal cultures, and generated a Drosophila model to elucidate the impact of the p.V15A variant on α-Syn function and aggregation properties compared to other known pathogenic variants. We demonstrate that p.V15A increased the aggregation potential of α-Syn and the levels of apoptotic markers, and impaired the mitochondrial network. Moreover, p.V15A affects the flying ability and survival of mutant flies. Thus, we provide supporting evidence for the pathogenicity of the p.V15A variant, suggesting its inclusion in genetic testing approaches.

Abstract We describe nonmetal adducts of the phosphorus center of terminal phosphinidene complexes using classical C- and N-ligands from metal coordination chemistry. The nature of the L-P bond has been analyzed by various theoretical methods including a refined method on the variation of the Laplacian of electron density ∇2ρ along the L-P bond path. Studies on thermal stability reveal stark differences between N-ligands such as N-methyl imidazole and C-ligands such as tert-butyl isocyanide, including ligand exchange reactions and a surprising formation of white phosphorus. A milestone is the transformation of a nonmetal-bound isocyanide into phosphaguanidine or an acyclic bisaminocarbene bound to phosphorus; the latter is analogous to the chemistry of transition metal-bound isocyanides, and the former reveals the differences. This example has been studied via cutting-edge DFT calculations leading to two pathways differently favored depending on variations in steric demand. This study reveals the emergence of organometallic from coordination chemistry of a neutral nonmetal center.

Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalized on the resources of the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Consortium to examine age-related trajectories inferred from cross-sectional measures of the ventricles, the basal ganglia (caudate, putamen, pallidum, and nucleus accumbens), the thalamus, hippocampus and amygdala using magnetic resonance imaging data obtained from 18,605 individuals aged 3-90 years. All subcortical structure volumes were at their maximum value early in life. The volume of the basal ganglia showed a monotonic negative association with age thereafter; there was no significant association between age and the volumes of the thalamus, amygdala and the hippocampus (with some degree of decline in thalamus) until the sixth decade of life after which they also showed a steep negative association with age. The lateral ventricles showed continuous enlargement throughout the lifespan. Age was positively associated with inter-individual variability in the hippocampus and amygdala and the lateral ventricles. These results were robust to potential confounders and could be used to examine the functional significance of deviations from typical age-related morphometric patterns.

The problem of poor reproducibility of scientific findings has received much attention over recent years, in a variety of fields including psychology and neuroscience. The problem has been partly attributed to publication bias and unwanted practices such as p-hacking. Low statistical power in individual studies is also understood to be an important factor. In a recent multisite collaborative study, we mapped brain anatomical left-right asymmetries for regional measures of surface area and cortical thickness, in 99 MRI datasets from around the world, for a total of over 17,000 participants. In the present study, we revisited these hemispheric effects from the perspective of reproducibility. Within each dataset, we considered that an effect had been reproduced when it matched the meta-analytic effect from the 98 other datasets, in terms of effect direction and significance threshold. In this sense, the results within each dataset were viewed as coming from separate studies in an "ideal publishing environment," that is, free from selective reporting and p hacking. We found an average reproducibility rate of 63.2% (SD = 22.9%, min = 22.2%, max = 97.0%). As expected, reproducibility was higher for larger effects and in larger datasets. Reproducibility was not obviously related to the age of participants, scanner field strength, FreeSurfer software version, cortical regional measurement reliability, or regional size. These findings constitute an empirical illustration of reproducibility in the absence of publication bias or p hacking, when assessing realistic biological effects in heterogeneous neuroscience data, and given typically-used sample sizes.

Delineating the association of age and cortical thickness in healthy individuals is critical given the association of cortical thickness with cognition and behavior. Previous research has shown that robust estimates of the association between age and brain morphometry require large-scale studies. In response, we used cross-sectional data from 17,075 individuals aged 3-90 years from the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Consortium to infer age-related changes in cortical thickness. We used fractional polynomial (FP) regression to quantify the association between age and cortical thickness, and we computed normalized growth centiles using the parametric Lambda, Mu, and Sigma method. Interindividual variability was estimated using meta-analysis and one-way analysis of variance. For most regions, their highest cortical thickness value was observed in childhood. Age and cortical thickness showed a negative association; the slope was steeper up to the third decade of life and more gradual thereafter; notable exceptions to this general pattern were entorhinal, temporopolar, and anterior cingulate cortices. Interindividual variability was largest in temporal and frontal regions across the lifespan. Age and its FP combinations explained up to 59% variance in cortical thickness. These results may form the basis of further investigation on normative deviation in cortical thickness and its significance for behavioral and cognitive outcomes.

ObjectiveSome studies have suggested alterations of structural brain asymmetry in attention-deficit/hyperactivity disorder (ADHD), but findings have been contradictory and based on small samples. Here, we performed the largest ever analysis of brain left-right asymmetry in ADHD, using 39 datasets of the ENIGMA consortium.MethodsWe analyzed asymmetry of subcortical and cerebral cortical structures in up to 1,933 people with ADHD and 1,829 unaffected controls. Asymmetry Indexes (AIs) were calculated per participant for each bilaterally paired measure, and linear mixed effects modeling was applied separately in children, adolescents, adults, and the total sample, to test exhaustively for potential associations of ADHD with structural brain asymmetries.ResultsThere was no evidence for altered caudate nucleus asymmetry in ADHD, in contrast to prior literature. In children, there was less rightward asymmetry of the total hemispheric surface area compared to controls (t = 2.1, p = .04). Lower rightward asymmetry of medial orbitofrontal cortex surface area in ADHD (t = 2.7, p = .01) was similar to a recent finding for autism spectrum disorder. There were also some differences in cortical thickness asymmetry across age groups. In adults with ADHD, globus pallidus asymmetry was altered compared to those without ADHD. However, all effects were small (Cohen's d from -0.18 to 0.18) and would not survive study-wide correction for multiple testing.ConclusionPrior studies of altered structural brain asymmetry in ADHD were likely underpowered to detect the small effects reported here. Altered structural asymmetry is unlikely to provide a useful biomarker for ADHD, but may provide neurobiological insights into the trait.

BackgroundAttention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder. Neuroanatomic heterogeneity limits our understanding of ADHD's etiology. This study aimed to parse heterogeneity of ADHD and to determine whether patient subgroups could be discerned based on subcortical brain volumes.MethodsUsing the large ENIGMA-ADHD Working Group dataset, four subsamples of 993 boys with and without ADHD and to subsamples of 653 adult men, 400 girls, and 447 women were included in analyses. We applied exploratory factor analysis (EFA) to seven subcortical volumes in order to constrain the complexity of the input variables and ensure more stable clustering results. Factor scores derived from the EFA were used to build networks. A community detection (CD) algorithm clustered participants into subgroups based on the networks.ResultsExploratory factor analysis revealed three factors (basal ganglia, limbic system, and thalamus) in boys and men with and without ADHD. Factor structures for girls and women differed from those in males. Given sample size considerations, we concentrated subsequent analyses on males. Male participants could be separated into four communities, of which one was absent in healthy men. Significant case-control differences of subcortical volumes were observed within communities in boys, often with stronger effect sizes compared to the entire sample. As in the entire sample, none were observed in men. Affected men in two of the communities presented comorbidities more frequently than those in other communities. There were no significant differences in ADHD symptom severity, IQ, and medication use between communities in either boys or men.ConclusionsOur results indicate that neuroanatomic heterogeneity in subcortical volumes exists, irrespective of ADHD diagnosis. Effect sizes of case-control differences appear more pronounced at least in some of the subgroups.

Abstract Tau deposits in astrocytes are frequently found in Alzheimer’s disease (AD) and other tauopathies. Since astrocytes do not express tau, the inclusions have been suggested to be of neuronal origin. However, the mechanisms behind their appearance and their relevance for disease progression remain unknown. Here we demonstrate, using a battery of experimental techniques that human astrocytes serve as an intermediator, promoting cell-to-cell spreading of pathological tau. Human astrocytes engulf and process, but fail to fully degrade dead neurons with tau pathology, as well as synthetic tau fibrils and tau aggregates isolated from AD brain tissue. Instead, the pathogenic tau is spread to nearby cells via secretion and tunneling nanotube mediated transfer. By performing co-culture experiments we could show that tau-containing astrocytes induce tau pathology in healthy human neurons directly. Furthermore, our results from a FRET based seeding assay, demonstrated that the tau proteoforms secreted by astrocytes have an exceptional seeding capacity, compared to the original tau species engulfed by the cells. Taken together, our study establishes a central role for astrocytes in mediating tau pathology, which could be of relevance for identifying novel treatment targets for AD and other tauopathies.

Curvature impacts physical properties across multiple length scales, ranging from the macroscopic scale, where the shape and size vary drastically with the curvature, to the nanoscale at interfaces and inhomogeneities in materials with structural, chemical, electronic, and magnetic short-range order. In quantum materials, where correlations, entanglement, and topology dominate, the curvature opens the path to novel characteristics and phenomena that have recently emerged and could have a dramatic impact on future fundamental and applied studies of materials. Particularly, magnetic systems hosting non-collinear and topological states and 3D magnetic nanostructures strongly benefit from treating curvature as a new design parameter to explore prospective applications in the magnetic field and stress sensing, microrobotics, and information processing and storage. This Perspective gives an overview of recent progress in synthesis, theory, and characterization studies and discusses future directions, challenges, and application potential of the harnessing curvature for 3D nanomagnetism.

Structural and chemical order impact magnetic properties of solids, which are governed by spin-orbit coupling and exchange interaction. The ordered L10 phase of FePt is a key material to heat-assisted magnetic recording; to enable high storage density, a solid understanding is needed of structural and chemical disorder at small length scales, as well as associated modifications of the electronic band structure. Here, we investigate the effect of boron and copper additions (≲6 mol% Cu) on structural and magnetic properties of L10 FePt granular media. Two copper-driven mechanisms, although competing, can lead to improvements in both structural and magnetic properties. In particular, the Cu substitution on the Fe-site leads to a degradation of magnetic properties due to the delocalized electron orbitals originating from a larger Cu d-orbital occupancy. At the same time, Cu substitution leads to an enhanced crystallographic order and consequently magneto-crystalline anisotropy, which offsets the former effect to a large extent. Our study is based on magnetometry, x-ray absorption spectroscopy, ab-initio calculations and a phenomenological theory of disordered FePt granular media. We do not observe a sizable modification to Fe moments and electronic configuration; Cu reveals two different resonances associated with the presence and absence of Cu-B bonds that vary with total Cu concentration.

The assembly and jamming of magnetic nanoparticles (NPs) at liquid-liquid interfaces is a versatile platform to endow structured liquid droplets with a magnetization, i.e., producing ferromagnetic liquid droplets (FMLDs). Here, we use hydrodynamics experiments to probe how the magnetization of FMLDs and their response to external stimuli can be tuned by chemical, structural, and magnetic means. The remanent magnetization stems from magnetic NPs jammed at the liquid-liquid interface and dispersed NPs magneto-statically coupled to the interface. FMLDs form even at low concentrations of magnetic NPs when mixing nonmagnetic and magnetic NPs, since the underlying magnetic dipole-driven clustering of magnetic NP-surfactants at the interface produces local magnetic properties, similar to those found with pure magnetic NP solutions. While the net magnetization is smaller, such a clustering of NPs may enable structured liquids with heterogeneous surfaces.

Topological solitary fields, such as magnetic and polar skyrmions, are envisioned to revolutionize microelectronics. These configurations have been stabilized in solid-state materials with a global inversion symmetry breaking, which translates in magnetic materials into a vector spin exchange known as the Dzyaloshinskii-Moriya interaction (DMI), as well as spin chirality selection and isotropic solitons. This work reports experimental evidence of 3D chiral spin textures, such as helical spins and skyrmions with different chirality and topological charge, stabilized in amorphous Fe-Ge thick films. These results demonstrate that structurally and chemically disordered materials with a random DMI can resemble inversion symmetry broken systems with similar magnetic properties, moments, and states. Disordered systems are distinguished from systems with global inversion symmetry breaking by their degenerate spin chirality that allows for forming isotropic and anisotropic topological spin textures at remanence, while offering greater flexibility in materials synthesis, voltage, and strain manipulation.

ObjectiveAttention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and obsessive-compulsive disorder (OCD) are common neurodevelopmental disorders that frequently co-occur. The authors sought to directly compare these disorders using structural brain imaging data from ENIGMA consortium data.MethodsStructural T1-weighted whole-brain MRI data from healthy control subjects (N=5,827) and from patients with ADHD (N=2,271), ASD (N=1,777), and OCD (N=2,323) from 151 cohorts worldwide were analyzed using standardized processing protocols. The authors examined subcortical volume, cortical thickness, and cortical surface area differences within a mega-analytical framework, pooling measures extracted from each cohort. Analyses were performed separately for children, adolescents, and adults, using linear mixed-effects models adjusting for age, sex, and site (and intracranial volume for subcortical and surface area measures).ResultsNo shared differences were found among all three disorders, and shared differences between any two disorders did not survive correction for multiple comparisons. Children with ADHD compared with those with OCD had smaller hippocampal volumes, possibly influenced by IQ. Children and adolescents with ADHD also had smaller intracranial volume than control subjects and those with OCD or ASD. Adults with ASD showed thicker frontal cortices compared with adult control subjects and other clinical groups. No OCD-specific differences were observed across different age groups and surface area differences among all disorders in childhood and adulthood.ConclusionsThe study findings suggest robust but subtle differences across different age groups among ADHD, ASD, and OCD. ADHD-specific intracranial volume and hippocampal differences in children and adolescents, and ASD-specific cortical thickness differences in the frontal cortex in adults, support previous work emphasizing structural brain differences in these disorders.

Mechanical jamming of nanoparticles at liquid-liquid interfaces has evolved into a versatile approach to structure liquids with solid-state properties. Ferromagnetic liquids obtain their physical and magnetic properties, including a remanent magnetization that distinguishes them from ferrofluids, from the jamming of magnetic nanoparticles assembled at the interface between two distinct liquids to minimize surface tension. This perspective provides an overview of recent progress and discusses future directions, challenges and potential applications of jamming magnetic nanoparticles with regard to 3D nano-magnetism. We address the formation and characterization of curved magnetic geometries, and spin frustration between dipole-coupled nanostructures, and advance our understanding of particle jamming at liquid-liquid interfaces.

Magnetic skyrmions are topologically protected spin textures with promising prospects for applications in data storage. They can form a lattice state due to competing magnetic interactions and are commonly found in a small region of the temperature - magnetic field phase diagram. Recent work has demonstrated that these magnetic quasi-particles fluctuate at the μeV energy scale. Here, we use a coherent x-ray correlation method at an x-ray free-electron laser to investigate these fluctuations in a magnetic phase coexistence region near a first-order transition boundary where fluctuations are not expected to play a major role. Surprisingly, we find that the relaxation of the intermediate scattering function at this transition differs significantly compared to that deep in the skyrmion lattice phase. The observation of a compressed exponential behavior suggests solid-like dynamics, often associated with jamming. We assign this behavior to disorder and the phase coexistence observed in a narrow field-window near the transition, which can cause fluctuations that lead to glassy behavior.

The amorphous iron-germanium system (a-FexGe1-x) lacks long-range structural order and hence lacks a meaningful Brillouin zone. The magnetization of a-FexGe1-x is well explained by the Stoner model for Fe concentrations x above the onset of magnetic order around x=0.4, indicating that the local order of the amorphous structure preserves the spin-split density of states of the Fe-3d states sufficiently to polarize the electronic structure despite k being a bad quantum number. Measurements reveal an enhanced anomalous Hall resistivity ρxyAH relative to crystalline FeGe; this ρxyAH is compared to density-functional theory calculations of the anomalous Hall conductivity to resolve its underlying mechanisms. The intrinsic mechanism, typically understood as the Berry curvature integrated over occupied k states but shown here to be equivalent to the density of curvature integrated over occupied energies in aperiodic materials, dominates the anomalous Hall conductivity of a-FexGe1-x (0.38≤x≤0.61). The density of curvature is the sum of spin-orbit correlations of local orbital states and can hence be calculated with no reference to k space. This result and the accompanying Stoner-like model for the intrinsic anomalous Hall conductivity establish a unified understanding of the underlying physics of the anomalous Hall effect in both crystalline and disordered systems.

The scientific and technological exploration of three-dimensional magnetic nanostructures is an emerging research field that opens the path to exciting novel physical phenomena, originating from the increased complexity in spin textures, topology, and frustration in three dimensions. One can also anticipate a tremendous potential for novel applications with those systems in a magnetic sensor and information processing technologies in terms of improved energy efficiency, processing speed, functionalities, and miniaturization of future spintronic devices. These three-dimensional structures are distinct from traditional bulk systems as they harness the scientific achievements of nanomagnetism, which aimed at lowering the dimensions down to the atomic scale, but expand those now in a tailored and designed way into the third dimension. This research update provides an overview of the scientific challenges and recent progress with regard to advances in synthesis approaches and state-of-the-art nanoscale characterization techniques that are prerequisite to understand, realize, and control the properties, behavior, and functionalities of three-dimensional magnetic nanostructures.