Latest ArticlesDefects at the surface and grain boundaries of the perovskite films are extremely detrimental to both the efficiency and stability of perovskite solar cells (PSCs). Herein, a simple and stable quaternary ammonium halide, named chlormequat chloride (i.e., chlorinated choline chloride, CCC), is introduced to regulate the upper surface chemical environment of perovskite films. The anion (Cl−) and cation [ClCH2CH2N(CH3)3]+ in CCC could effectively self-search and passivate positively and negatively charged ionic defects in perovskites, respectively, which contributes to inhibited nonradiative recombination and reduced energy loss in PSCs. As a result, the champion power conversion efficiency (PCE) of PSCs can be significantly enhanced from 22.82% to 24.07%. Moreover, the unencapsulated device with CCC modification retains 92.0% of its original PCE even subject to thermal aging at 85 ℃ for 2496 h. This work provides guidance for the rational design of functional molecules as defect passivators in PSCs, which is beneficial for the improvements in both device performance and stability.
As a hydrolase, chymotrypsin (CHT) is involved in many physiological activities, and its abnormal activity is closely related to diabetes, pancreatic fibrosis, chronic pancreatitis and pancreatic cancer. In this work, an innovative long-wavelength emission fluorescent probe TCF-CHT was designed and synthesized for the high specificity detection of CHT, which utilized TCF-OH and a mimetic peptide substrate 4-bromobutyryl as chromogenic group and recognition group, respectively. TCF-CHT exhibited excellent selectivity and eye-catching sensitivity (8.91 ng/mL) towards CHT, "off-on" long-wavelength emission at 670 nm and large Stokes shift (140 nm). Furthermore, the successful fulfillment and perfect performance in imaging endogenous CHT in complex organisms (P815 cells, HepG2 cells, zebrafish and tumor-bearing mice) verified its potential as a powerful tool for the recognition of CHT in complicated biological environments.
Molecular-based ferroelastics with dielectric switching properties are highly desirable for their applications on microelectronic dielectric switches, sensors, data storage, and so on. However, the current reports mostly focus on organic-inorganic hybrids containing toxic heavy metal atoms, and the relatively low phase transition temperature limits their application. In this paper, low-toxic organic salt ferroelastic enantiomers (R/S)-4-fluoro-1-azabicyclo[3.2.1]octonium chloride [(R/S)-F-321] were designed and synthesized under the introducing chirality strategy. They undergo a 432F422-type ferroelastic phase transition with a high Curie temperature (Tc) of 470 K, simultaneously exhibiting excellent dielectric switching characteristics. In addition to the ordered-disordered movement of cations, the significant displacement of anions is also responsible for such high Tc and large dielectric switching ratios, which is very rare in molecular-based switching materials. This work enriches the development of molecular ferroelastic switching materials and gives inspiration for the exploration of environmentally friendly high Tc organic salt ferroelastics with prominent switching performances.
An oxidative annulation of 2-arylidene-1,3-indanediones with Meldrum's acid has been developed for the divergent syntheses of spirolactones with a spirocenter located at the γ-position with respect to the carbonyl group. This heteroannulation protocol tolerates various functional groups and delivers moderate-to-good product yields. Interestingly, the reaction outcomes are exclusively controlled by the reaction oxidant/medium. This annulation strategy can also be executed in the flow system with decent product yields. Control experiments revealed that the reaction proceeds via a radical tandem annulation pathway.
A novel biodegradable material, Se@PLA, was designed and prepared via the selenization reaction of polylactic acid using NaHSe as the selenization reagent. This material shows excellent antibacterial activity (EC50 = 13.38 µg/mL) against Xanthomonas oryzae pv. Oryzae, which is a highly destructive pathogen responsible for rice bacterial blight. Se@PLA induces oxidative stress in bacteria, leading to the rupture of bacterial cell membranes and eventual death. Moreover, Se@PLA can significantly inhibit the motility of bacteria and is low toxic to soil and aquatic organisms. This work provides an effective method for preventing and controlling rice bacterial blight, and reveals the great potential of using Se@PLA as an alternative next generation plant bactericide.
The first example of sono-photocatalytic bond formation was reported. With both visible light and ultrasound wave as the energy, various 3-aminoquinoxalin-2(1H)-ones were efficiently obtained with good functional group tolerance in the absence of any additive or external photocatalyst. Compared with the conventional photocatalysis, sono-photocatalysis not only dramatically improved the reaction rates and yields, but also reduced energy consumption.
Activated pancreatic stellate cells (PSCs) are the main source of collagen layer deposition and the key target in pancreatic fibrosis. However, no effective treatment specific to pancreatic fibrosis clinically, owing to the drug accumulation blocked by the collagen barrier and thus it is difficult to inhibit activated PSCs precisely. Herein, a PSCs-targeting nano-system based on “nanodrill” strategy (LA-PC) was designed to enhance the accumulation of all-trans retinoic acid (ATRA) in PSCs, relying on the platelet-derived growth factor receptor beta (PDGFRβ)-targeting peptide (pPB: C*SRNLIDC*) and collagenase (Col). After being injected into fibrotic mice via tail vein, the Col modified on LA-PC can remove the excess collagen layer, and the drug delivery efficiency through pPB targeting peptide was more than 5 times higher than that of free ATRA, as well as the degree of fibrosis significantly reduced. Notably, this nano-system effectively inhibited platelet-derived growth factor subunit B (PDGF-BB)/PDGFRβ axis on PSCs via a down-regulated extracellular signal-regulated protein kinase (ERK) pathway, and accordingly reduced the level of PDGF-BB. Thus, the smart platform provided a promising strategy for the treatment of pancreatic fibrosis to achieve the precise regulation of PSCs.
Sonodynamic therapy (SDT) exhibits promising clinical applications in cancer treatment owing to its advantages, including ultrasonic cavitation effect, mechanical effect, and deep tissue penetration. Titanium dioxide (TiO2) nanomaterials, recognized as excellent sonosensitizers, have been extensively studied in cancer SDT. This review first outlines the mechanism of TiO2-based SDT, then systematically discusses the regulation of TiO2 sonosensitivity, covering aspects such as morphology, particle size, element doping, defect engineering, heterojunction structure, and interactions with the tumor microenvironment. Furthermore, the review generalizes ultrasound-responsive TiO2-based therapeutic modalities for tumor treatment, including SDT, SDT combined with chemotherapy, chemodynamic therapy, photothermal therapy, immunotherapy, and treatment visualization. Finally, the review navigates the ongoing challenges and prospects in TiO2-based cancer SDT.
The occurrence of acquired resistance to cisplatin (DDP) that induces the toxic drug effects has always been a huge challenge and urgently needs to be resolved in the cancer treatment. The combination of anticancer drugs with different mechanisms can remarkably improve the chemotherapeutic efficiency. Given that glutathione (GSH) plays as the driving factors in the resistance of DDP, here we have firstly proposed a “three birds, one stone” based nanoplatform to achieve triple synergetic effects simultaneously addressing DDP resistance in non-small cell lung cancer (NSCLC). Specifically, we initially designed and synthesized a DDP prodrug [Pt(Ⅳ)] bridged silsesquioxane precursor (Pt-Si). Then Pt-Si and bis[3-(triethoxysilyl)propyl]diselenide (BTESePD) were integrated into the framework of mesoporous organosilica nanoparticles (MONs) to obtain a nanocarrier MONPt/Se. After loading with norcantharidin (NCTD) and modifying with the aptamer AS1411 based G-quadruplex (Apt), the Apt@NCTD@MONPt/Se exhibit impressive tumor homing capability. Once being endocytosed, (Ⅰ) the diselenide and -O-Pt(Ⅳ)-O- rich scaffold can be reduced by the excessive GSH, followed by (Ⅱ) breaking the redox homeostasis via GSH depletion and precise release of the DDP. Next, the encapsulated NCTD is also released along with the degradation of the nanocarriers thereby (Ⅲ) achieving the GSH depletion and synergistic anti-tumor effect of NCTD and DDP. Taken together, we believe this “one stone, three birds” strategy may be a promising paradigm to conquer drug resistance for clinical care.