13 research outputs found
Design and Analysis Method of Piezoelectric Liquid Driving Device with Elastic External Displacement
In piezoelectric drive, resonant drive is an important driving mode in which the external elastic force and electric drive signal are the key factors. In this paper, the effects of the coupling of external elastic force and liquid parameters with the structure on the vibrator resonance frequency and liquid drive are analyzed by numerical simulation. The fluid-structure coupling model for numerical analysis of the elastic force was established, the principle of microdroplet generation and the coupling method of the elastic force were studied, and the changes in the resonant frequency and mode induced by the changes in the liquid parameters in different cavities were analyzed. Through the coupled simulation and calculation of the pressure and deformation of the cavity, the laser vibration measurement test was carried out to test the effect of the vibration mode analysis. The driving model of the fluid jet driven by the elastic force on the piezoelectric drive was further established. The changing shape of the fluid jet under different elastic forces was analyzed, and the influence law of the external elastic force on the change in the droplet separation was determined. It provides reference support for further external microcontrol of droplet motion
Feasibility study of emission policy for photovoltaic integrated building microgrids
The photovoltaics (PV) based microgrids play important role in the development of green buildings. This work investigates the effects of emission policy on the PV integrated commercial and residential building microgrids. The component sizes of microgrid are determined by simulated optimal power dispatch with an optimization algorithm based on minimizing the cost of energy (COE). The COE is computed with consideration of the capital depreciation cost, fuel cost, emissions damage cost and maintenance cost. The simulation results show that the emission policy and photovoltaic subsidy have little effect on sizing the commercial microgrid system. However, the component sizing design for residential microgrid system is sensitive to the emission policy. Increasing emission taxes and photovoltaic subsidy can effectively raise the proportion of PV in the system. The most important factor of restricting PV usage in microgrids is the cost of batteries. Increasing the battery lifetime or selecting the lower cost of battery can significantly increase the installation of PV, thus rise the green building standard
High-Performance Detection of Exosomes Based on Synergistic Amplification of Amino-Functionalized Fe<sub>3</sub>O<sub>4</sub> Nanoparticles and Two-Dimensional MXene Nanosheets
Exosomes derived from cancer cells have been recognized as a promising biomarker for minimally invasive liquid biopsy. Herein, a novel sandwich-type biosensor was fabricated for highly sensitive detection of exosomes. Amino-functionalized Fe3O4 nanoparticles were synthesized as a sensing interface with a large surface area and rapid enrichment capacity, while two-dimensional MXene nanosheets were used as signal amplifiers with excellent electrical properties. Specifically, CD63 aptamer attached Fe3O4 nanoprobes capture the target exosomes. MXene nanosheets modified with epithelial cell adhesion molecule (EpCAM) aptamer were tethered on the electrode surface to enhance the quantification of exosomes captured with the detection of remaining protein sites. With such a design, the proposed biosensor showed a wide linear range from 102 particles μL−1 to 107 particles μL−1 for sensing 4T1 exosomes, with a low detection limit of 43 particles μL−1. In addition, this sensing platform can determine four different tumor cell types (4T1, Hela, HepG2, and A549) using surface proteins corresponding to aptamers 1 and 2 (CD63 and EpCAM) and showcases good specificity in serum samples. These preliminary results demonstrate the feasibility of establishing a sensitive, accurate, and inexpensive electrochemical sensor for detecting exosome concentrations and species. Moreover, they provide a significant reference for exosome applications in clinical settings, such as liquid biopsy and early cancer diagnosis
Green Synthesis of Lutein-Based Carbon Dots Applied for Free-Radical Scavenging within Cells
Reactive oxygen species (ROS) in the body play an important role in various processes. It is well known that harmful high levels of ROS can cause many problems in living organisms in a variety of ways. One effective way to remove intracellular ROS is to use reducing materials that can enter the cell. Herein, we developed a strong reducing carbon nano-dot from a natural product, lutein, as an initial raw material. This is a hydrothermal synthesis method with the advantages of simplicity, high yield, mild reaction conditions, and environmental friendliness. The prepared carbon dots exhibit bright blue fluorescence, and have good water solubility and biocompatibility. In particular, the carbon dots can easily enter the cell and effectively remove ROS. Therefore, the carbon dots are thought to protect cells from oxidative damage by high levels of ROS
Core-Shell Magnetic Gold Nanoparticles for Magnetic Field-Enhanced Radio-Photothermal Therapy in Cervical Cancer
The combination of radiotherapy (RT) and photothermal therapy (PTT) has been considered an attractive strategy in cervical cancer treatment. However, it remains a challenge to simultaneously enhance the radio-sensitivity of tumor tissue, develop tumor tissue-focused radiation therapies and combine dual therapeutic modalities. In this study, core-shell type magnetic gold (Fe3O4@Au) nanoparticles are exploited to achieve the synergistic efficacy of radio-photothermal therapy in cervical cancer. Fe3O4@Au nanoparticles (NPs) with uniform morphology exhibited superior surface plasmon resonance properties, excellent superparamagnetic properties, good biocompatibility and high photothermal conversion efficiency. For the in vitro tests, a low concentration of Fe3O4@Au NPs after a short period of near-infrared irradiation lead to the time-dependent death of cervical cancer cells. Further, the combination of RT and PTT induced synergistic anti-cancer effects in vitro. More importantly, an external magnetic field could significantly enhance the synergistic efficacy of Fe3O4@Au NPs by improving their internalization. Hence, the reported Fe3O4@Au NPs have the potential to be good nanoagents with excellent magnetic targeting ability for cervical cancer radio-photothermal treatment
Effects of borneol on the pharmacokinetics of 9-nitrocamptothecin encapsulated in PLGA nanoparticles with different size via oral administration
Axitinib overcomes multiple imatinib resistant cKIT mutations including the gatekeeper mutation T670I in gastrointestinal stromal tumors
Background: cKIT kinase overexpression and gain-of-function mutations are the critical pathogenesis of gastrointestinal stromal tumors (GISTs). Although the multiple kinase inhibitors such as imatinib, sunitinib, and regorafenib have been approved for GISTs, the acquisition of polyclonal secondary resistance mutations in KIT is still a limitation for GIST treatment. Here we explored the KIT inhibitory activity of axitinib in preclinical models and describe initial characterization of its activity in GIST patient-derived primary cells. Methods: The activities of axitinib against mutant KIT were evaluated using protein-based assay and a panel of engineered and GIST-derived cell lines. The binding modes of axitinib-KIT/KIT mutants were analyzed. Four primary cells derived from GIST patients were also used to assess the drug response of axitinib. Results: Axitinib exhibited potent activities against a variety of cKIT associated primary and secondary mutations. It displayed better activity against cKIT wild-type, cKIT V559D/A/G, and L576P primary gain-of-function mutations than imatinib, sunitinib, and regorafenib. In addition, it could inhibit imatinib resistant cKIT T670I and V654A mutants in vitro and in vivo GIST preclinical models. Conclusion: Our results provide the basis for extending the application of axitinib to GISTs patients who are unresponsive or intolerant to the current therapies
Shape Engineering Boosts Magnetic Mesoporous Silica Nanoparticle-Based Isolation and Detection of Circulating Tumor Cells
Magnetic mesoporous
silica nanoparticles (M-MSNs) are attractive candidates for the immunomagnetic
isolation and detection of circulating tumor cells (CTCs). Understanding
of the interactions between the effects of the shape of M-MSNs and
CTCs is crucial to maximize the binding capacity and capture efficiency
as well as to facilitate the sensitivity and efficiency of detection.
In this work, fluorescent M-MSNs were rationally designed with sphere
and rod morphologies while retaining their robust fluorescence and
uniform surface functionality. After conjugation with the antibody
of epithelial cell adhesion molecule (EpCAM), both of the differently
shaped M-MSNs-EpCAM obtained achieved efficient enrichment of CTCs
and fluorescent-based detection. Importantly, rodlike M-MSNs exhibited
faster immunomagnetic isolation as well as better performance in the
isolation and detection of CTCs in spiked cells and real clinical
blood samples than those of their spherelike counterparts. Our results
showed that shape engineering contributes positively toward immunomagnetic
isolation, which might open new avenues to the rational design of
magnetic-fluorescent nanoprobes for the sensitive and efficient isolation
and detection of CTCs