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Protocol for evaluation of tumor-derived exosome-induced cancer cell metastasis in a mouse model
No full textExosomes mediate intracellular communication between cancer cells and the local/distant microenvironment, which promotes systemic dissemination of cancer. Here, we present a protocol for tumor-derived exosome isolation and in vivo metastasis evaluation in a mouse model. We describe steps for isolating and characterizing exosomes, establishing a metastatic mouse model, and injecting exosomes into mouse. We then detail hematoxylin and eosin staining and analysis. This protocol can be used to investigate exosome function and identify unexplored metastatic regulators related to exosome biogenesis. For complete details on the use and execution of this protocol, please refer to Lee et al. (2023)
A Soft, Self-Sensing Tensile Valve for Perceptive Soft Robots
No full textSoft inflatable robots are a promising paradigm for applications that benefit from their inherent safety and adaptability. However, for perception, complex connections of rigid electronics both in hardware and software remain the mainstay. Although recent efforts have created soft analogs of individual rigid components, the integration of sensing and control systems is challenging to achieve without compromising the complete softness, form factor, or capabilities. Here, we report a soft self-sensing tensile valve that integrates the functional capabilities of sensors and control valves to directly transform applied tensile strain into distinctive steady-state output pressure states using only a single, constant pressure source. By harnessing a unique mechanism, ???helical pinching???, we derive physical sharing of both sensing and control valve structures, achieving all-in-one integration in a compact form factor. We demonstrate programmability and applicability of our platform, illustrating a pathway towards fully soft, electronics-free, untethered, and autonomous robotic systems
Ligand-Tuned Perylene Diimide-Based Versatile Coordination Polymers for Photoluminescent Sensing and Optoelectronics
No full textChiral self-sorting is essential for the establishment of structures in nature and chemistry. Owing to similarities among recognition sites of enantiomers and shared conformational labilities, high-fidelity chiral self-sorting constitutes a substantial challenge. Coordination polymers (CPs) with a high surface area and chemical tunability have potential applications in luminescent probes and optoelectronics. However, it is difficult to synthesize micro-/nano-scale CPs with high conductivity for optoelectronics. Here, a series of perylene diimide (PDI)-based CPs with large & pi;-planes is synthesized by tuning ligands for use in various sensors. A cadmium (Cd)-based coordination polymer with leucine (LeuPDI-Cd) exhibits a unique chiral self-recognition phenomenon when two enantiomeric ligands are mixed with the metal source because homochiral CPs are thermodynamically more stable than their heterochiral analogs. In addition, photoluminescent (PL) LeuPDI-Cd CPs can detect ethylenediamine with high sensitivity and selectivity. Micro-/nano-sized CPs with methionine (MetPDI-Cd) are used in photodetectors and chemiresistive sensors for the detection of toxic phenylhydrazine. Theoretical calculations reveal that the enhanced conductivity is related to the reduced energy gap, which occurs after adsorption of phenylhydrazine onto the CP surface. These results demonstrate the feasibility and versatility of PDI-based CPs for applications in PL sensing and optoelectronics through the tuning of PDI ligands
Confocal Single-Pixel Imaging
No full textObtaining depth-selective images requires gating procedures such as spatial, nonlinear, or coherence gating to differentiate light originating from different depths of the volume of interest. Nonlinear gating requires pulsed excitation sources and excitation probes, limiting easy usage. Coherence gating also requires broadband sources and interferometry requiring specialized stable setups. Spatial gating can be used both for fluorescence and reflection geometry and various light sources and thus has the least requirements on hardware, but still requires the use of a pinhole which makes it difficult to use for photography or widefield imaging schemes. Here, we demonstrate that we can utilize a single digital micromirror device (DMD) to simultaneously function as a dynamic illumination modulator and automatically synchronized dynamic pinhole array to obtain depth-sectioned widefield images. Utilizing the multiplexed measurement advantage of single-pixel imaging, we show that the depth and ballistic light gating of the confocal single pixel imaging scheme can be utilized to obtain images through glare and multiple scattering where conventional widefield imaging fails to recover clear images due to saturation or random scattered noise
High-Fidelity Transient Analysis with STREAM Based on the Predictor-Corrector Quasi-Static Method
No full textThe predictor-corrector quasi-static method (PCQM) is used to solve the transient problem in the STREAM code, a steady-state and transient reactor analysis code with the method of characteristics. In PCQM, the angular neutron flux undergoes a factorized split to form the product of shape and amplitude functions. The time-dependent neutron transport equation is solved to obtain the shape function whereas the amplitude function is obtained by resolving the exact point kinetics equations (EPKEs). A two-level coarse mesh finite difference technique is implemented to reduce the transient running time of the transport solution. Moreover, high-order polynomial interpolation is applied to the kinetics parameters utilized in EPKEs to reduce the error when the reactivity insertion is nonlinear. Several numerical benchmarks are solved to justify the application of the procedure, proving that the method maintains solution accuracy
Coherent consolidation of trillions of nucleations for mono-atom step-level flat surfaces
No full textConstructing a mono-atom step-level ultra-flat material surface is challenging, especially for thin films, because it is prohibitively difficult for trillions of clusters to coherently merge. Even though a rough metal surface, as well as the scattering of carriers at grain boundaries, limits electron transport and obscures their intrinsic properties, the importance of the flat surface has not been emphasised sufficiently. In this study, we describe in detail the initial growth of copper thin films required for mono-atom step-level flat surfaces (MSFSs). Deposition using atomic sputtering epitaxy leads to the coherent merging of trillions of islands into a coplanar layer, eventually forming an MSFS, for which the key factor is suggested to be the individual deposition of single atoms. Theoretical calculations support that single sputtered atoms ensure the formation of highly aligned nanodroplets and help them to merge into a coplanar layer. The realisation of the ultra-flat surfaces is expected to greatly assist efforts to improve quantum behaviour by increasing the coherency of electrons. Constructing atomically flat surface in a single crystal ultrathin film is difficult owing to the coherent merging of trillions of clusters. Here the authors establish the initial growth mechanism of a single crystal Cu thin film with atomically flat surface using atomic sputtering epitaxy
Evaluation of diffusion coefficients as surrogate indicators for electrostatic repulsion in ultrafiltration membrane fouling
No full textImpacted by the electrostatic repulsion between ultrafiltration (UF) membranes and natural organic matter (NOM), organic fouling precipitates significant operational difficulties in water treatment facilities. This study investigated the applicability of diffusion coefficients as surrogate indicators to evaluate the electrostatic repulsive forces between NOMs and UF membrane surfaces. We utilized three distinct types of NOMs and three different UF membranes, each possessing different charge characteristics. Notably, we found that the reduction in diffusion coefficients was markedly pronounced when membranes rich in ionizable functional groups with strong negative charges were involved, indicating heightened electrostatic repulsion. To confirm the reliability of diffusion coefficient reduction as a surrogate indicator of the electrostatic repulsive force, a comprehensive membrane fouling test was conducted. The results revealed a strong correlation between the two parameters, enhancing our understanding of the intricate dynamics of membrane fouling (R2 = 0.9744-0.9907). Thus, this study proposes the concept of utilizing the reduction in the diffusion coefficient as a surrogate indicator to represent the electrostatic repulsive force between NOMs and the UF membrane surface. This innovative approach contributes to enables proactive and predictive assessments of membrane performance, fostering a shift toward proactive maintenance and enhances the operational efficiency of water treatment facilities
Self-heating performance of cement composites devised with carbon black and carbon fiber: Roles of superplasticizer and silica fume
No full textThis study introduces an innovative approach to enhancing the self-heating performance of electrically conductive cement composites (ECCCs) by integrating carbon black and carbon fiber. The main test variables were the contents of silica fume (SF) and superplasticizer (SP). Among the 15 mixtures tested, three mixtures of the 3 % SP series containing 0, 5, and 10 % SF, showing a lower electrical resistivity than the other series, were selected and subjected to 24-h heating performance tests. Subsequently, their hydration characteristics, dispersion of conductive agents, and thermal expansion were examined. The outcomes of these tests unequivocally affirmed that incorporating SF at levels of 0 %???5 % in conjunction with 3 % SP effectively preserved the long-term self-heating performance of ECCCs. This research not only confirms the feasibility of this novel composite formulation but also highlights its potential advantages in maintaining consistent thermal performance, demonstrating its substantial promise for a broad array of applications in construction