Frequency-dependent electrical properties of microscale self-enclosed ionic liquid enhanced soft composites.

The incorporation of room temperature ionic liquids (ILs) into dielectric elastomer composites is currently generating great interest due to their potential applications in soft actuators and optical-related devices. Experiments have shown that the electrical properties of IL enhanced soft composites (ILESCs) are dependent on AC (alternating current) frequency of the electrical loading. This current work helps develop a mixed micromechanical model with the incorporation of an electric double layer (EDL) to predict the electrical properties of the ILESCs while revealing the physical mechanisms (including crowding and overscreening structures, percolation thresholds, interfacial tunneling, Maxwell-Wagner-Sillars polarization) that underpin the phenomena. Particularly, Bazant-Storey-Kornyshev (BSK) phenomenological theory is integrated into the EDL surface diffusion model for the first time to evaluate the influence of crowding and overscreening effects. The results show excellent agreement with experimental data of IL enhanced PDMS composites over the frequency range from 1 Hz to 10 GHz. Parametric analysis from the perspective of designing is conducted to explore the methods for optimization of ILESCs with high dielectric constants and frequency-dependent stability. It is found that an IL with a smaller size and aspect ratio increases the dielectric constant of the ILESCs more significantly below the interface relaxation frequency. Increasing the surface charge density of the matrix and using ILs delay the frequency-facilitated dielectric response, which is beneficial to maintain the dielectric stability of the ILESCs.

[Efficacy of Venetoclax Plus Azacitidine in Relapsed/Refractory Acute Myeloid Leukemia Patients with FLT3-ITD Mutation].

OBJECTIVE: To explore the efficacy of venetoclax (VEN) plus azacitidine (AZA) in patients with FLT3-ITD mutated relapsed/refractory acute myeloid leukemia (FLT3-ITDmut R/R AML) and analyze the molecular genetic characteristics of the patients. METHODS: Clinical baseline characteristics and follow-up data of 16 R/R AML patients treatd with VEN plus AZA in the hematology department of Shenzhen Second People's Hospital from November 2018 to April 2021 were collected. Leukemia related genes were detected by next-generation sequencing(NGS) or PCR. The relationship between the efficacy of VEN plus AZA and molecular genetics characteristics of patients with FLT3-ITDmut R/R AML were analyzed. RESULTS: 14.3% (1/7) of the patients in FLT3-ITDmut group and 22.2% (2/9) of the patients in FLT3-ITDwt group achieved complete remission (CR)/CR with incomplete blood count recovery (CRi), respectively, with no significant difference (P=0.69). There was no significant difference in overall response rate (ORR) (CR/CRi+PR) between FLT3-ITDmut group and FLT3-ITDwt group [42.9%(3/7) vs 44.4%(4/9), P=0.95], too. The median overall survival (OS) time of FLT3-ITDmut patients was significantly shorter than that of FLT3-ITDwt patients (130 vs 300 days, respectively) (P =0.02). Co-existing mutations of FLT3-ITD and IDH1 were detected in one patient who achieved CR. Co-existing mutations of FLT3-ITD and SF3B1 were found in one patient who achieved PR. Three FLT3-ITDmut R/R AML patients accompanied with NPM1 mutation had no response to VEN plus AZA. CONCLUSION: VEN plus AZA showed a certain effect on patients with FLT3-ITDmut R/R AML. To improve OS of the patients, bridging transplantation is need. IDH1 and SF3B1 mutations might predict that patients with FLT3-ITDmut R/R AML have treatment response to VEN plus AZA, while the combination of NPM1 mutation may indicate poor response.

[Effect of Myeloma-Derived Exosomes on Surface Activating Receptors of NK Cells].

OBJECTIVE: To investigate the effect of myeloma-derived exosomes on surface activating receptors of NK cells, and to explore the mechanism of the function defect of NK cells. METHODS: The exosomes from the supernatant of multiple myeloma cell lines RPMI8226 and U266 were extracted by ultracentrifugation, and the size of them was identified under electron microscope; the human primary NK cells were extracted, and were co-cultured with the myeloma-derived exosomes (40 µg/ml), then the expression levels of surface activating receptors NKp46, NKp30 and NKG2D of NK cells at 0,1,4 and 24 hours were detected by flow cytometry. RESULTS: The exosomes showed small vesicular, sized 30-100 nm under electron microscope. The expression of surface activating receptors of NK cells declined at different degree after co-cultured with myeloma-derived exosomes. CONCLUSION: Myeloma-derived exosomes can inhibit the expression of surface activating receptors of NK cells.