Search

This study aimed to evaluate the clinical utility of amide proton transfer-weighted imaging (APTw) and arterial spin labeling (ASL) in differentiating solitary brain metastases (SBMs) from glioblastomas (GBMs). All patients underwent conventional MRI, APTw, and ASL scans on a 3.0 T MRI system. The mean APTw value and mean cerebral blood flow (CBF) value were measured. The differences in various parameters between GBMs and SBMs were assessed using the independent-samples t test. The quantitative performance of these MRI parameters in distinguishing between GBMs and SBMs was evaluated using receiver operating characteristic (ROC) curve analysis. Our results showed that GBMs exhibited significantly higher APTw and CBF values in peritumoral regions compared with SBMs (P

In the paper, the application of all kinds of nanometer materials to the food packaging has been reviewed comprehensively. In the meantime, the advantages of these nanomaterials adopted in the food packaging has been generalized. Moreover, the toxicity of nanomaterials that might affect different organelle or cell has been summarized and analyzed.

Lithium dendrites (filaments) propagation in the solid electrolyte (SEs) leading to short circuits is one of the biggest obstacles to the application of all-solid-state lithium metal batteries (ASSLMBs). Due to the lacking of operando techniques that can provide nano-scale spatial resolution, the insufficient knowledge of the lithium dendrite growth inside SEs makes it difficult to suppress dendrite formation. To reveal the mechanism of Li filament growth in SEs, we achieved real-time monitoring of the nanoscale Li filament growth by operando small-angle neutron scattering (SANS) in a Cu|LLZNO|Li cell. On continuous plating, Li filament growth is not simply an accumulation of Li, but there is a dynamic evolution due to the competition between Li filament formation and self-healing. This dynamic evolution of Li filaments has been proved to be prevalent in typical SEs. With the aid of simulations and experiments, this dynamic competition was demonstrated to be highly dependent on the temperature variation. The enhanced self-healing ability of Li at elevated temperatures plays a positive role in suppressing Li filament formation. The cycle life of the cell was improved by heat therapy, which provided a brand-new insight for suppressing Li filament formation. Operando SANS with high Li sensitivity and high spatial resolution provides a new platform for investigating Li filaments in SEs.

Aiming to unveil the correlation among formula, hierarchical structure, and performance of silica filled silicone rubber foams (SRFs), mechanical and structural investigations are performed on three selected samples. Precipitation (P) and fumed (F) silica filled SRFs with diameters of primary particles around 20 nm (PA), 16 nm (FB), and 14 nm (FC) are used, namely SRPA, SRFB, and SRFC. The hierarchical structures are obtained by contrast variation-small-angle neutron scattering (CV-SANS) with an established three-level unified Guinier-exponential/power-law approach. The sizes of both aggregates (agg) and agglomerates (agl) levels have the correlation of SRPA > SRFB > SRFC. Mass-fractals df, agg of SRPA, SRFB, and SRFC are 2.16, 2.16, and 2.54, while df, agl of the set are 2.90, 2.52, and 2.54, respectively. CV-SANS also indicates that the static thickness of bound rubber (TSBR) of SRPA, SRFB, and SRFC decreases from 10.3 nm to 7.5 nm, and then to 6.5 nm. Interestingly, low-field 1H nuclear magnetic resonance (NMR) indicates that the dynamics thickness of bound rubber (TNBR) of the set increases from 3.33 nm to 4.35 nm, and then to 4.41 nm. The discrepancy between TSBR and TNBR is ascribed to the interface interaction. Mechanically, three samples present different behaviors, while SRPA and SRFB have similar extension modules and compressive relaxations. According to a modified constitutive model fitting, and with combining the structural information, the roles of filler-filler and filler-rubber interactions on the reinforcement of SRFs are discussed.

The intrinsic properties of the silicone rubber matrix reinforced by filler silica have been investigated with in situ rheo-small-angle neutron scattering (SANS) and deuterated chain labeling. SANS results reveal that: (i) the average diameter of aggregates and the thickness of bound rubbers (BR) are about 81 nm and 5.6 nm, respectively. (ii) The aggregates size distribution of the filler network is statistically stable during deformation. (iii) Strain mainly causes the agglomerate breakdown/reconstruction and the rubber matrix deformation. Interestingly, the evolution of the aggregates covered with BRs has the similar tendency to the nonlinear strain-stress curve (SSC). However, the tendency of the BR evolution diverges from the SSC. Considering the hydrodynamic amplification effect of filler and the filler-rubber interaction, a modified constitutive model is established and utilized to correlate the macroscopic properties with the micro-structure evolution of silicone rubber. The results suggest that the reinforced rubber matrix might play the dominant role in sustaining the external loading with a hardening effect. While filler presents contradiction effects for reinforcing yet suffering from the agglomerate breakdown and the interface weakening.

The inherent mechanisms of flow-induced crystallization (FIC), especially the amorphous formation, have been revisited inversely, via in situ swelling small angle neutron scattering (SANS). The neutron contrast between crystalline and amorphous phases of crosslinked high-density polyethylene was strengthened by deuterated o-xylene-d10. Thereby, the morphological evolutions and kinetics of various FIC samples (imposed initial strain: 0.6, 0.9, 1.4, and 2.3) during the swelling process were obtained simultaneously. The half time for swelling to reach equilibrium decreases from ca.39100 s–4500 s for S0.0 to S2.3. Moreover, the evolutions of the expanded long period (LP) are similar to the swelling kinetics. Interestingly, the increment LPt-LP1 increases monotonically from 1.55 nm to 4.32 nm. However, the expanding ratio (LPt/LP1) first increases from 1.05 to 1.13 for S0.0 to S1.4, then decreases to 1.11 for S2.3. Combining ex situ small angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC) results, current work demonstrates that both crystalline degree and different morphology contribute to the influences of swelling. It suggests that the generated amorphous networks triggered by different strain were endued with various inherent structure and characters, and the nature of amorphous phase can severely affect the swelling behavior.