Latest ArticlesIn the field of organic phototransistor, achieving both broad-spectral and high photosensitivity has always been a big challenge. The innovation of device structure has previously proven to be a possible solution to this problem. Here in this study, a novel organic phototransistor based on a high mobility n-type small molecule as the conducting layer and an isolated bulk heterojunction light-absorbing layer as the floating gate has been demonstrated in this study. With the special designed device structure, the phototransistor shows extremely high sensitivity to broad spectral and weak light irradiation, and the photoresponsivity and photocurrent/dark-current ratio of the device can reach up to 4840 mA/W and 1.8 × 105 respectively. For conclusion, this study suggests a potential way to obtain high-performance phototransistors at room temperature, which will further promote the commercial application of organic phototransistors.
Various structures of G-quadruplex in biosystems play an important role in different diseases and are often regulated by a variety of molecular crowding environments induced by internal and even external factors (e.g., a solvent). Dimethyl sulfoxide (DMSO), a universal solvent, has been widely used in biological studies and for drug therapy, but little is known regarding its effect on G-quadruplex structure and stability. Here, we report the influence of molecular crowding environment induced by DMSO on the conformation and stability of G-quadruplex structure. We show that the G-quadruplex-forming sequences such as human telomeric sequence, which may have diverse conformations in different environments, tend to convert their topologies to parallel structures under the molecular crowding stimulated by DMSO. Moreover, DMSO can increase the stability of the parallel and antiparallel topologies, especially the parallel G-quadruplex sequence c-kit, but not the hybrid topologies. Further analysis of c-kit using the CD and NMR technique, combined with the unique structural characteristics of c-kit, reveals that the crowding, dehydration and interaction of DMSO are conductive to the formation and stability of the parallel G-quadruplex. The present study suggests that, DMSO, a common solvent used in DNA experiments, may have a nonnegligible influence on the structure and stability of G-quadruplex.
Aiming at the construction of novel rotaxanes with desired luminescent properties for practical applications, recently the rapid development of rotaxanes decorated with aggregation-induced emission (AIE) luminogens (i.e., AIEgens) has been witnessed. The combination of AIEgens and rotaxanes leads to the successful construction of a novel type of luminescent rotaxanes with many attractive features. In particular, the unique controllable dynamic feature of rotaxanes endows the resultant AIEgen-based rotaxanes precisely tunable emissions under external stimuli, leading to the construction of a novel type of smart luminescent materials. In this minireview, the recent progress of AIEgen-based rotaxanes has been summarized, with an emphasis on the design strategy and potential applications.
In this work, a liquid-gas heterogeneous microreactor was developed for investigating continuous crystallization of dolutegravir sodium (DTG), as well as revealing reaction kinetics and mixing mechanism with 3-min data acquisition. The reaction kinetics models were established by visually recording the concentration variation of reactants over time in the microchannel via adding pH-sensitive fluorescent dye. The mixing intensification mechanism of liquid-gas flow was quantified through the fluorescent signal to indicate mixing process, demonstrating an outstanding mixing performance with a mixing time less than 0.1 s. Compared with batch crystallization, continuous synthesis of dolutegravir sodium using liquid-gas heterogenous microreactor optimizes crystal distribution size, and successfully modifies the crystal morphology in needle-like habit instead of rod-like habit. The microreactor continuous crystallization can run for 5 h without crystal blockage and achieve D90 of DTG less than 30 µm. This work provides a feasible approach for continuously synthesizing dolutegravir sodium, and can optimize the existing pharmaceutical crystallization.
It is cellular immunotherapy for the tumor that the in vitro modified immunocytes from patients or donors are reinfused into patients to kill tumor cells. Chimeric antigen receptor T cell (CAR-T) therapy, one of the most successful and representative tumor cellular immunotherapies, is now the weapon for cancer after extensive research. Although CAR-T immunotherapy achieves success in treating relapsed/refractory hematological tumors, its drawbacks, including the poor effect in solid tumors, cytokine release syndrome (CRS) or CAR-T-related encephalopathy syndrome (CRES), on-target, off-tumor effect, and high cost, cannot be overlooked. Nanotechnology is advantageous in the construction of CARs, the transfection of T cells, the expansion, delivery, and antitumor effect of CAR-T cells, and the reduction of CAR-T therapy-associated toxicities. Currently, introducing nanotechnology into CAR-T immunotherapy has already been performed in numerous studies with highly promising results. In this review, we summarized the nanotechnologies used in CAR-T immunotherapy and discussed the challenges and directions of CAR-T immunotherapy combined with nanotechnologies in the future.
HIV-1 capsid protein (CA) has emerged as a promising target for antiviral treatment considering its structural and regulatory roles in HIV-1 replication. Here, we disclose the design, synthesis, biological assessment, and mechanism investigation of a novel series of phenylalanine derivatives gained by further structural modification of PF74. The newly synthesized compounds demonstrated potent anti-HIV activity, represented by 7n displayed anti-HIV-1 activity 6.25-fold better than PF74, and 7h showed anti-HIV-2 activity with nearly 139 times improved efficacy over PF74. Surface plasmon resonance (SPR) studies of representative compounds proved that HIV-1 CA was the binding target. Competitive SPR studies using CPSF6 and NUP153 peptides identified that 7n binds to a vital CA assembly interface between the N-terminal and C-terminal domain (NTD-CTD interface). Action stage determination assay revealed that the newly synthesized compounds were antiviral with a dual-stage inhibitory profile. Molecular dynamics (MD) simulations offered the crucial foundation for the hopeful antiviral potency of 7n. Besides, 7m and 7n modestly increased metabolic stabilities in human liver microsome (HLM) and human plasma compared to PF74. Overall, these studies offer valuable insights and can regard as the beginning for succedent medicinal chemistry endeavors to discover promising HIV capsid inhibitors with improved efficacy and better drug-like characteristics.
Assembling MnO2 nanowires into macroscopic membrane is a promising engineered technology for catalyst separation and enhancement of Fenton-like reaction activity, yet its development is limited by the deficiencies in preparation and property modulation of the MnO2 nanowires. In this work, we developed a facile method using C2H5OH and CH3COOK as reductive and vital control reagents to react with KMnO4 by hydrothermal reaction at 140 ℃ for 12 h, to prepare the ultralong α-MnO2 nanowires up to tens of micrometers with high purity and aspect ratio. Such strategy not only had the advantages of being mild, easily controlled and environmental pollution-free, but also endowed α-MnO2 nanowires with excellent ability as a Fenton catalyst when assembled into free-standing membrane for degrading phenolic compounds (kobs = 0.0738 ~ 0.1695 min−1) in a continuous flow reaction. The reactive oxygen species (i.e., •OH) from Fenton-like reaction were enriched within this α-MnO2 nanowire membrane via nanoconfinement effect, which further enhanced the mass transportation of •OH available for phenolic contaminants. MnO2 nanowire membrane using our method possessed the high practical potential for water purify due to its easy-preparation and enhanced catalytic performances.
Palladium-catalyzed non-directed CH functionalization provides an efficient approach for direct functionalization of arenes, but it usually suffers from poor site selectivity, limiting its wide application. Herein, it is reported for the first time that the carboxylic acid ligand of 3, 5-dimethyladamantane-1-carboxylic acid (1-DMAdCO2H) can affect the site selectivity during the CH activation step in palladium-catalyzed non-directed CH functionalization, leading to highly para-selective CH olefination of TIPS-protected phenols. This transformation displayed good generality in realizing various other para-selective CH functionalization reactions such as halogenation, and allylation reactions. A wide variety of phenol derivatives including bioactive molecules of triclosan, thymol, and propofol, were compatible substrates, leading to the corresponding para-selective products in moderate to good yields. A preliminary mechanism study revealed that the spatial repulsion factor between carboxylic acid ligand and bulky protecting group resulted in the selective CH activation at the less sterically hindered para-position. This new model non-directed para-selective CH functionalization can provide a straightforward route for remote site-selective CH activations.
A cobalt-catalyzed ring-opening/hydroxylation cascade of highly strained cyclopropanols has been developed for the first time. The reaction was conducted under open-air atmosphere to afford a broad series of structurally diverse β-hydroxy ketones in moderate to good yields with high regioselectivity. The protocol features mild reaction conditions, simple operation, high-functional-group tolerance, facile scalability, and heterocycle compatibility.