Due to their efficient recognition and lysis of malignant cells, natural killer (NK) cells are considered as specialized immune cells that can be genetically modified to obtain capable effector cells for adoptive cellular treatment of cancer patients. However, biological and technical hurdles related to gene delivery into NK cells have dramatically restrained progress. Recent technological advancements, including improved cell expansion techniques, chimeric antigen receptors (CAR), CRISPR/Cas9 gene editing and enhanced viral transduction and electroporation, have endowed comprehensive generation and characterization of genetically modified NK cells. These promising developments assist scientists and physicians to design better applications of NK cells in clinical therapy. Notably, redirecting NK cells using CARs holds important promise for cancer immunotherapy. Various preclinical and a limited number of clinical studies using CAR-NK cells show promising results: efficient elimination of target cells without side effects, such as cytokine release syndrome and neurotoxicity which are seen in CAR-T therapies. In this review, we focus on the details of CAR-NK technology, including the design of efficient and safe CAR constructs and associated NK cell engineering techniques: the vehicles to deliver the CAR-containing transgene, detection methods for CARs, as well as NK cell sources and NK cell expansion. We summarize the current CAR-NK cell literature and include valuable lessons learned from the CAR-T cell field. This review also provides an outlook on how these approaches may transform current clinical products and protocols for cancer treatment.

The photophysical properties of two newly synthesized photoactive compounds with asymmetrical D-π-A structure and symmetrical D-π-A-π-D structure are investigated in different aprotic solvents by steady-state and femtosecond fluorescence depletion measurements. It is found that the asymmetrical DA compound has larger dipole moment change than that of the symmetrical DAD compound upon excitation, where the dipole moments of the two compounds have been estimated using the Lippert-Mataga equation. Furthermore, the steady-state spectral results show that increasing solvent polarity results in small solvatochromic shift in the absorption maxima but a large red shift in the fluorescence maxima for them, indicating that the dipole moment changes mainly reflect the changes of dipole moment in excited-state rather than in ground state. The redshifted fluorescence band is attributed to an intramolecular charge transfer (ICT) state upon photoexcitation, which could result in a strong interaction with the surrounding solvents to cause the fast solvent reorganization. The resulting ICT states of symmetrical compounds are less polar than the asymmetrical compounds, indicating the different extents of stabilization of solute-solvent interaction in the excited state. Femtosecond fluorescence depletion measurements are further employed to investigate the fast solvation effects and dynamics of the ICT state of these two novel compounds. The femtosecond fluorescence depletion results show that the DA compound has faster solvation time than that of DAD compound, which corresponds to the formation of relaxed ICT state (i.e., a final ICT state with rearranged solvent molecules after solvation) in polar solvents. It is therefore reasonably understood that the ICT compounds with asymmetrical (D-π-A) structure have better performance for those photovoltaic devices, which strongly rely on the nature of the electron pushpull ability, compared to those symmetrical compounds (D-π-A-π-D).

To suppress the high loss of nickel (Ni)/poly(vinylidene fluoride) (PVDF) while remaining high dielectric constant (k) near the percolation threshold. In this study, core-shell structured Ni (Ni@NiO) particles were prepared by heat treatment of raw Ni powder under air atmosphere and incorporated into PVDF to prepare Ni@NiO/PVDF dielectric composites. The morphological, dielectric properties and thermal conductivity of the composites are characterized. The results indicate that compared with the raw Ni reinforced PVDF composites, the Ni@NiO particles endow PVDF with a high-k and rather low dissipation factor owing to the presence of NiO shell between Ni core and PVDF which serves as an interlayer between the Ni cores preventing them from contacting with each other. Additionally, the Ni@NiO/PVDF composites still possess a high thermal conductivity. Therefore, the as-prepared Ni@NiO/PVDF composites possess high-k but low loss, high thermal conductivity, making them promising for the industrial application as embedded capacitors.

Silver-catalyzed C(sp(2))-H functionalization/C-O cyclization has been developed. The scalable reaction proceeds at room temperature in an open flask. The present method exhibits good functional-group compatibility because of the mild reaction conditions. Using a AgNO3 catalyst and a (NH4)2S2O8 oxidant in CH2Cl2/H2O solvent, various lactones are obtained in good to excellent yields. A kinetic isotope effect (KIE) study indicates that the reaction may occur via a radical process.