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• The introduction of quenched-in vacancies in aged Fe81Ga19 polycrystalline alloys leads to a giant magnetostriction of ∼305 ppm, which is significantly improved to the level of single crystal. • Time-resolved small-angle neutron scattering (SANS) was employed to in-situ study the nucleation and growth kinetics of the L60 nanophase at different temperatures, providing a new experimental technique for quantify dynamic nanostructure evolution during aging. • Concentrated vacancies were found to induce nucleation mechanism switching and kinetics acceleration of L60 nanophase during thermal aging. • A strong correlation between the morphology, number density of the nanoprecipitates and the magnetoelastic properties was established, and thus propose a strategy to engineer the magnetostriction. Solid-state precipitation is an effective strategy for tuning the mechanical and functional properties of advanced alloys. Structure design and modification necessitate good knowledge of the kinetic evolution of precipitates during fabrication, which is strongly correlated with defect concentration. For Fe-Ga alloys, giant magnetostriction can be induced by the precipitation of the nanoscale tetragonal L6 0 phase. By introducing quenched-in vacancies, we significantly enhance the magnetostriction of the aged Fe 81 Ga 19 polycrystalline alloys to ∼305 ppm, which is close to the level of single crystals. Although vacancies were found to facilitate the generation of the L6 0 phase, their impact on the precipitation mechanism and kinetics has yet to be revealed. This study combined transmission electron microscopy (TEM) and time-resolved small-angle neutron scattering (SANS) to investigate the precipitation of the L6 0 phase during the isothermal aging at 350 and 400 °C, respectively. The evolution of L6 0 nanophase in morphology and number density in as-cast (AC) and liquid nitrogen quenched (LN) Fe 81 Ga 19 alloys with aging time were quantitatively compared. Interestingly, the nucleation of the L6 0 phase proceeds progressively in AC while suddenly in LN specimens, indicating the homogenous to heterogeneous mechanism switching induced by concentrated vacancies. Moreover, excess vacancies can change the shape of nanoprecipitates and significantly accelerate the growth and coarsening kinetics. The magnetostrictive coefficient is optimized when the size (long-axis) of L6 0 precipitates lies between 100 and 110 Å with a number density between 3.2–4.3 × 10–7 Å–3. Insight from this study validates the feasibility of achieving high magnetoelastic properties through precise manipulation of the nanostructure. [Display omitted] [ABSTRACT FROM AUTHOR]

Considerable efforts have been made to develop nanoparticle-based magnetic resonance contrast agents (CAs) with high relaxivity. The prolonged rotational correlation time (τR) induced relaxivity enhancement is commonly recognized, while the effect of the water coordination numbers (q) on the relaxivity of nanoparticle-based CAs gets less attention. Herein, we first investigated the relationship between T1relaxivity (r1) and qin manganese-based hybrid micellar CAs and proposed a strategy to enhance the relaxivity by increasing q. Hybrid micelles with different ratios of amphiphilic manganese complex (MnL) and DSPE-PEG2000 were prepared, whose qvalues were evaluated by Oxygen-17-NMR spectroscopy. Micelles with lower manganese doping density exhibit increased qand enhanced relaxivity, corroborating the conception. In vivosentinel lymph node (SLN) imaging demonstrates that DSPE-PEG/MnL micelles could differentiate metastatic SLN from inflammatory LN. Our strategy makes it feasible for relaxivity enhancement by modulating q, providing new approaches for the structural design of high-performance hybrid micellar CAs.

Past studies on salt-doped polymer blends indicate that the electrostatic effect is complicated due to the combined effects of translational entropy of dissociated ions, ion solvation, ion–ion correlation, and ion clustering, especially at high salt concentrations. It still remains a challenge to unveil the electrostatic interaction of dissociated ions on phase separation explicitly in experiments. To address this challenge, the key principle of this study is to have the salt at extremely low concentrations, while its effect on phase separation is significant enough to be detected by scattering techniques. This experimental design enables the solvation of dissociated ions as the dominating factor, carefully avoiding complications from other effects. We characterize concentration fluctuations at full length scales by small-angle laser light scattering, X-ray scattering, and neutron scattering. The measured cloud points, spinodal temperatures, correlation lengths, and effective interaction parameters exhibit significant increase with the salt fraction, indicating that the electrostatic interaction promotes phase separation. We further reveal the electrostatic interaction of cations and anions, respectively. The asymmetric deflection of the phase diagram is quantitatively explained by the composition-dependent solvation of dissociated ions. This fundamental research provides experimental support for the progress of recent theoretical work and is helpful to guide the structural control in polymer electrolytes.

Side chains of conjugated polymers (CPs) have played a vital role in the regulation of solution processibility and semiconducting performance. Herein, carbosilane side chains, which manifest the advantages of low-cost and facile synthesis as compared to the common alkyl ones, were employed to regulate the aggregation behaviors and charge transport properties of isoindigo-based polymers. Three polymers, IIDSiC12, IIDSiC8, and IIDC12, with carbosilane side chains of varying bulkiness and alkyls as the control were synthesized via direct arylation polymerization. Anisotropic one-dimensional pre-aggregates of different aspect ratios were developed in solution, as disclosed by solution small-angle neutron scattering, which further determined the order of the microstructure in bar-coated films for organic thin-film transistors (OTFTs). It is noteworthy that the relatively large radius (20.5 Å) and moderate aspect ratio (∼20) of IIDSiC12solution aggregates ensured a solid-state microstructure of the highest order, as evidenced by well-aligned fiber-like morphology and the largest range of packing order. As a result, OTFTs based on IIDSiC12achieved the maximum saturation electron mobility up to 4.10 cm2V–1s–1with a reliability factor of 81%, which is among the highest mobilities of n-type CPs. The results reported here may encourage the easier synthesis of high mobility CPs using the carbosilane side chain engineering.

The environmental condition is a critical regulation factor for protein behavior in solution. Several studies have shown that macromolecular crowders can modulate protein structures, interactions, and functions. Recent publications described the regulation of specific interaction by macromolecular crowders. However, the other category of protein–protein interaction, namely, the transient interaction, is rarely investigated, especially from the perspective of protein structure to study transient interactions between proteins. Here, we used nuclear magnetic resonance and small-angle X-ray/neutron scattering methods to structurally investigate the ensemble of the protein complex in dilute buffer and crowded environments. Histidine phosphocarrier protein (HPr) and the N-terminal domain of enzyme I (EIN) are the important components of the bacterial phosphotransfer system. Our results show that the addition of Ficoll-70 promotes HPr molecules to form the encounter complex with EIN maintained by long-range electrostatic interaction. However, when macromolecular crowder BSA is used, the soft interaction between BSA and HPr perturbs the active site of HPr, driving HPr to form an encounter complex with EIN at the weakly charged interface. Our results indicate that different macromolecular crowders could influence transient EIN-HPr interaction through different mechanisms and provide new insights into protein–protein interaction regulation in native environments.

The chain conformation and solid-state structure of conjugated polymers are important for understanding the structure origin of electronic properties. In this work, a high-performance conjugated polymer, poly(2,5-bis(2-thienyl)-3,6-ditetradecylthieno[3,2-b]thiophene) (PBTTT_C14), is chosen. The chain conformation of PBTTT_C14 in a good solvent (1,2-dichlorobenzene) in the dilute condition is characterized by small-angle neutron scattering (SANS). The persistence length of PBTTT_C14 is estimated as 4.3 ± 0.3 nm, indicating a more rigid backbone compared with poly(3-hexylthiophene-2,5-diyl) (P3HT). In addition, the structural evolution of PBTTT_C14 in bulk was studied in detail. Three transitions are detected during heating, located at 57 °C (Tm1), 133 °C (peak A), and 223 °C (Tm2). Fourier transform infrared spectroscopy (FTIR) results show that a transition from the trans-to gauche-conformation of the side chains occurs at Tm1, corresponding to the melting of the regular packing of the side chains. After that, the system enters liquid crystal states. Oriented films are obtained by shear within the liquid-crystalline phases, in which the backbones align along the shear direction. After assignment of the FTIR bands, it is found that the twist motion of thienothiophene rings in the backbone is activated at peak A. Two liquid-crystalline (LC) phases with different structures at the temperature range of Tm1∼ peak A (LC-1) and peak A ∼ Tm2(LC-2) are determined for PBTTT_C14: the twist motion of backbones leads to an enhanced lamellar order, weaker interchain π–π interaction and vanishes the positional order along the chain axis (disappearance of (003)) for LC-2.

Supplemental Digital Content is Available in the Text.We report a case of pendular seesaw nystagmus caused by bitemporal hemianopia; the nystagmus disappeared while in darkness as previously described, but it also disappeared with monocular occlusion, which indicates the pivotal role of binocular vision in the pathogenesis.

The determination of intrinsic chain stiffness of conjugated polymers is challenging, in particular, for scattering techniques because of their strong light absorption and structural instability due to the complicated intra-/intermolecular interactions. In this work, the chain conformation and aggregation formation of a high charge mobility donor–acceptor polymer (DPPDTT) are systematically investigated by using small-angle neutron scattering (SANS) and static/dynamic light scattering (SLS/DLS). On the one hand, chloroform was chosen as a good solvent, in which SANS reveals a rod-like geometry with a radius of ∼15 Å. Once the absorption effect is properly accounted for, SLS shows a power law of 1 between the radius of gyration (Rg) and molecular weight (Mw) and a negative second virial coefficient (A2). On the other hand, 1,2-dichlorobenzene was chosen as a poor solvent, in which SANS, SLS/DLS, and atomic force microscopy (AFM) reveal a strong temperature-/concentration-dependent assembling behavior. The results provide a general picture of the multiscale assembly process of conjugated polymers.

Pore structures are significant for evaluating shale gas production since they not only control gas capacity but also affect hydraulic fracturing. In this study, we investigated the pore structures of Longmaxi (LMX) shale samples from a shallow drill core in Guizhou Province, China, with large-area electron imaging and neutron scattering. Pores related to the mineral matrix and organic matter (OM) were identified, and the former had greater impacts on the pore shape and porosity, which would enhance fracturing. Large-area electron imaging analysis (with 15 nm resolution) indicated that the majority of LMX shale porosity was contributed by nanopores with diameters smaller than 400 nm. According to the neutron scattering data, micropores and mesopores dominated the pore size distribution (PSD), and pores within cross sections cut perpendicular to the bedding showed preferential orientation accompanied by larger porosity. The porosity (4.6–5.6%) calculated from neutron scattering data was approximately 2 times larger than that calculated from imaging data, suggesting that nanopores smaller than 15 nm contributed more to the porosity than those larger than 100 nm, as they were more resistant to compaction. This study indicated that pore types were controlled by minerals as well as thermal maturity, while PSDs were affected by tectonic movements. The majority of porosity originated from micropores and mesopores, which confirmed the great potential for shale gas reserves in the LMX shale. This conclusion is helpful for building a shale porosity model and eventually improving the reserve assessment.

Many commercially and industrially important materials aggregate to form nanoscale mass-fractal structures. Unlike hard aggregates such as fumed silica, aqueous pigment-based inks consist of weakly bound nanoparticles stabilized by a surfactant. These soft aggregates can easily break apart and re-form balancing mixing energy and the reduction in surface energy with clustering or aggregation. Rapid thermal motion of small elemental crystallites leads to dense clusters or primary particles. The larger primary particles have slower thermal motion and aggregate into ramified mass fractals to form a dual-level hierarchical structure. It is proposed that the hierarchical structure relies on subtle and competitive equilibria between the different hierarchical structural levels. A new hierarchical thermodynamics model by Vogtt is used. Pigment yellow 14 and pigment blue 15:3 as surfactant-stabilized aqueous dispersions were employed to explore the thermodynamics of nanoparticle hierarchical equilibria. It was demonstrated that reversible nanoparticle aggregation can be described solely by the change in free energy of dissociation and the change in free energy of mixing in the context of a subunit being removed from a cluster. The hierarchical thermodynamics is dominated by the solubility of the dispersing surfactant. At the cloud point for the surfactant, primary particles approach the size of an elemental particle and the degree of aggregation becomes very large. The results indicate that subtle and reproducible control over pigment hierarchical structure and size is possible through thermal equilibration, manipulation of the surfactant properties, and elemental crystallite size.

The free scission energy is the thermodynamic parameter that governs the contour length of wormlike micelles (WLMs). It is the contour length and the propensity to coil and entangle that determine the viscoelastic properties of this commercially important substance class. The free scission energy ΔFscand the associated change in enthalpy ΔHscand entropy ΔSscon scission have been determined for a mixed anionic/zwitterionic surfactant system (sodium laureth sulfate and cocamidopropyl betaine) at various salt concentrations (3–5 wt % NaCl). Both enthalpy ΔHscand entropy ΔSscchanges decrease linearly with increasing NaCl concentration. At NaCl concentrations above 4 wt %, ΔSsceven adopts negative values. The term TΔSscdecreases more rapidly than ΔHscaround room temperature and causes the observed elongation of WLMs upon addition of NaCl. It is suggested that ΔSscis initially positive due to fewer bound counterions per surfactant molecule at end caps compared to the intact, cylindrical parts before scission, leading to a net release of ions upon scission. Negative values of ΔSscare attributed to hydrophobic hydration occurring at the end caps at high salt concentrations. 23Na NMR measurements indicate the presence of immobilized ions, supporting a previously proposed ion-cloud model based on neutron scattering results.

This article presents an approach of simplifying machine tool commissioning processes with web based component data. As commissioning and error compensation processes of machines often require extensive manual labor and repetitive tasks, they present great potential for further digitalization. Therefore, a systematic approach for generating and implementing a digitalization concept is applied. As a result, a commissioning device accessing web based component data is implemented. The device uses geometric errors of individual components in a machine tool and generates compensation values for the control of the machine's axes.

Castleman disease is a rare lymphoproliferative disorder that has many presentations ranging from unifocal or multifocal mass lesions to a monoclonal gammopathy. It has features that may overlap with osteosclerotic myeloma or POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, skin changes) syndrome. We report a patient with papilledema, enlarged lymph nodes, and monoclonal IgG, who subsequently developed a polyneuropathy. Biopsy of enlarged mediastinal lymph nodes confirmed the diagnosis of Castleman disease.

Although the development of artificial light-harvesting systems (LHSs) has attracted increasing attention, the construction of novel artificial LHSs with co-existed various type of precisely-arranged luminogens has been still a major challenge. Herein, starting from [2]rotaxane building blocks AN-Ror TPE-Rfunctionalized with either anthracene or tetraphenylethylene (TPE) moiety, a family of novel rotaxane-branched dendrimers containing two types of energy donors on the branches and one pyrene moiety at the central core as energy acceptor have been successfully constructed through a facile, efficient and controllable divergent approach. Notably, attributed to the solvent-induced switching feature of the rotaxane branches, the integrated rotaxane-branched dendrimers displayed interesting dynamic feature. More importantly, as revealed by fluorescence spectra, the resultant rotaxane-branched dendrimers displayed enhanced antenna effects along with the increase of dendrimer generation. Therefore, these rotaxane-branched dendrimers described herein could serve as not only promising platforms for light harvesting but also excellent candidates for the construction of smart supramolecular materials for practical applications.